fs/ext4/super.c

   1 /*
   2  *  linux/fs/ext4/super.c
   3  *
   4  * Copyright (C) 1992, 1993, 1994, 1995
   5  * Remy Card (card@masi.ibp.fr)
   6  * Laboratoire MASI - Institut Blaise Pascal
   7  * Universite Pierre et Marie Curie (Paris VI)
   8  *
   9  *  from
  10  *
  11  *  linux/fs/minix/inode.c
  12  *
  13  *  Copyright (C) 1991, 1992  Linus Torvalds
  14  *
  15  *  Big-endian to little-endian byte-swapping/bitmaps by
  16  *        David S. Miller (davem@caip.rutgers.edu), 1995
  17  */
  18
  19 #include <linux/module.h>
  20 #include <linux/string.h>
  21 #include <linux/fs.h>
  22 #include <linux/time.h>
  23 #include <linux/vmalloc.h>
  24 #include <linux/slab.h>
  25 #include <linux/init.h>
  26 #include <linux/blkdev.h>
  27 #include <linux/backing-dev.h>
  28 #include <linux/parser.h>
  29 #include <linux/buffer_head.h>
  30 #include <linux/exportfs.h>
  31 #include <linux/vfs.h>
  32 #include <linux/random.h>
  33 #include <linux/mount.h>
  34 #include <linux/namei.h>
  35 #include <linux/quotaops.h>
  36 #include <linux/seq_file.h>
  37 #include <linux/ctype.h>
  38 #include <linux/log2.h>
  39 #include <linux/crc16.h>
  40 #include <linux/cleancache.h>
  41 #include <asm/uaccess.h>
  42
  43 #include <linux/kthread.h>
  44 #include <linux/freezer.h>
  45
  46 #include "ext4.h"
  47 #include "ext4_extents.h"       /* Needed for trace points definition */
  48 #include "ext4_jbd2.h"
  49 #include "xattr.h"
  50 #include "acl.h"
  51 #include "mballoc.h"
  52
  53 #define CREATE_TRACE_POINTS
  54 #include <trace/events/ext4.h>
  55
  56 static struct ext4_lazy_init *ext4_li_info;
  57 static struct mutex ext4_li_mtx;
  58 static struct ratelimit_state ext4_mount_msg_ratelimit;
  59
  60 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
  61                              unsigned long journal_devnum);
  62 static int ext4_show_options(struct seq_file *seq, struct dentry *root);
  63 static int ext4_commit_super(struct super_block *sb, int sync);
  64 static void ext4_mark_recovery_complete(struct super_block *sb,
  65                                         struct ext4_super_block *es);
  66 static void ext4_clear_journal_err(struct super_block *sb,
  67                                    struct ext4_super_block *es);
  68 static int ext4_sync_fs(struct super_block *sb, int wait);
  69 static int ext4_remount(struct super_block *sb, int *flags, char *data);
  70 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
  71 static int ext4_unfreeze(struct super_block *sb);
  72 static int ext4_freeze(struct super_block *sb);
  73 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
  74                        const char *dev_name, void *data);
  75 static inline int ext2_feature_set_ok(struct super_block *sb);
  76 static inline int ext3_feature_set_ok(struct super_block *sb);
  77 static int ext4_feature_set_ok(struct super_block *sb, int readonly);
  78 static void ext4_destroy_lazyinit_thread(void);
  79 static void ext4_unregister_li_request(struct super_block *sb);
  80 static void ext4_clear_request_list(void);
  81
  82 /*
  83  * Lock ordering
  84  *
  85  * Note the difference between i_mmap_sem (EXT4_I(inode)->i_mmap_sem) and
  86  * i_mmap_rwsem (inode->i_mmap_rwsem)!
  87  *
  88  * page fault path:
  89  * mmap_sem -> sb_start_pagefault -> i_mmap_sem (r) -> transaction start ->
  90  *   page lock -> i_data_sem (rw)
  91  *
  92  * buffered write path:
  93  * sb_start_write -> i_mutex -> mmap_sem
  94  * sb_start_write -> i_mutex -> transaction start -> page lock ->
  95  *   i_data_sem (rw)
  96  *
  97  * truncate:
  98  * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (w) -> i_mmap_sem (w) ->
  99  *   i_mmap_rwsem (w) -> page lock
 100  * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (w) -> i_mmap_sem (w) ->
 101  *   transaction start -> i_data_sem (rw)
 102  *
 103  * direct IO:
 104  * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (r) -> mmap_sem
 105  * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (r) ->
 106  *   transaction start -> i_data_sem (rw)
 107  *
 108  * writepages:
 109  * transaction start -> page lock(s) -> i_data_sem (rw)
 110  */
 111
 112 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
 113 static struct file_system_type ext2_fs_type = {
 114         .owner          = THIS_MODULE,
 115         .name           = "ext2",
 116         .mount          = ext4_mount,
 117         .kill_sb        = kill_block_super,
 118         .fs_flags       = FS_REQUIRES_DEV,
 119 };
 120 MODULE_ALIAS_FS("ext2");
 121 MODULE_ALIAS("ext2");
 122 #define IS_EXT2_SB(sb) ((sb)->s_bdev->bd_holder == &ext2_fs_type)
 123 #else
 124 #define IS_EXT2_SB(sb) (0)
 125 #endif
 126
 127
 128 static struct file_system_type ext3_fs_type = {
 129         .owner          = THIS_MODULE,
 130         .name           = "ext3",
 131         .mount          = ext4_mount,
 132         .kill_sb        = kill_block_super,
 133         .fs_flags       = FS_REQUIRES_DEV,
 134 };
 135 MODULE_ALIAS_FS("ext3");
 136 MODULE_ALIAS("ext3");
 137 #define IS_EXT3_SB(sb) ((sb)->s_bdev->bd_holder == &ext3_fs_type)
 138
 139 static int ext4_verify_csum_type(struct super_block *sb,
 140                                  struct ext4_super_block *es)
 141 {
 142         if (!ext4_has_feature_metadata_csum(sb))
 143                 return 1;
 144
 145         return es->s_checksum_type == EXT4_CRC32C_CHKSUM;
 146 }
 147
 148 static __le32 ext4_superblock_csum(struct super_block *sb,
 149                                    struct ext4_super_block *es)
 150 {
 151         struct ext4_sb_info *sbi = EXT4_SB(sb);
 152         int offset = offsetof(struct ext4_super_block, s_checksum);
 153         __u32 csum;
 154
 155         csum = ext4_chksum(sbi, ~0, (char *)es, offset);
 156
 157         return cpu_to_le32(csum);
 158 }
 159
 160 static int ext4_superblock_csum_verify(struct super_block *sb,
 161                                        struct ext4_super_block *es)
 162 {
 163         if (!ext4_has_metadata_csum(sb))
 164                 return 1;
 165
 166         return es->s_checksum == ext4_superblock_csum(sb, es);
 167 }
 168
 169 void ext4_superblock_csum_set(struct super_block *sb)
 170 {
 171         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 172
 173         if (!ext4_has_metadata_csum(sb))
 174                 return;
 175
 176         es->s_checksum = ext4_superblock_csum(sb, es);
 177 }
 178
 179 void *ext4_kvmalloc(size_t size, gfp_t flags)
 180 {
 181         void *ret;
 182
 183         ret = kmalloc(size, flags | __GFP_NOWARN);
 184         if (!ret)
 185                 ret = __vmalloc(size, flags, PAGE_KERNEL);
 186         return ret;
 187 }
 188
 189 void *ext4_kvzalloc(size_t size, gfp_t flags)
 190 {
 191         void *ret;
 192
 193         ret = kzalloc(size, flags | __GFP_NOWARN);
 194         if (!ret)
 195                 ret = __vmalloc(size, flags | __GFP_ZERO, PAGE_KERNEL);
 196         return ret;
 197 }
 198
 199 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
 200                                struct ext4_group_desc *bg)
 201 {
 202         return le32_to_cpu(bg->bg_block_bitmap_lo) |
 203                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 204                  (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
 205 }
 206
 207 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
 208                                struct ext4_group_desc *bg)
 209 {
 210         return le32_to_cpu(bg->bg_inode_bitmap_lo) |
 211                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 212                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
 213 }
 214
 215 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
 216                               struct ext4_group_desc *bg)
 217 {
 218         return le32_to_cpu(bg->bg_inode_table_lo) |
 219                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 220                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
 221 }
 222
 223 __u32 ext4_free_group_clusters(struct super_block *sb,
 224                                struct ext4_group_desc *bg)
 225 {
 226         return le16_to_cpu(bg->bg_free_blocks_count_lo) |
 227                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 228                  (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
 229 }
 230
 231 __u32 ext4_free_inodes_count(struct super_block *sb,
 232                               struct ext4_group_desc *bg)
 233 {
 234         return le16_to_cpu(bg->bg_free_inodes_count_lo) |
 235                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 236                  (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
 237 }
 238
 239 __u32 ext4_used_dirs_count(struct super_block *sb,
 240                               struct ext4_group_desc *bg)
 241 {
 242         return le16_to_cpu(bg->bg_used_dirs_count_lo) |
 243                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 244                  (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
 245 }
 246
 247 __u32 ext4_itable_unused_count(struct super_block *sb,
 248                               struct ext4_group_desc *bg)
 249 {
 250         return le16_to_cpu(bg->bg_itable_unused_lo) |
 251                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 252                  (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
 253 }
 254
 255 void ext4_block_bitmap_set(struct super_block *sb,
 256                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 257 {
 258         bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
 259         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 260                 bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
 261 }
 262
 263 void ext4_inode_bitmap_set(struct super_block *sb,
 264                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 265 {
 266         bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
 267         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 268                 bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
 269 }
 270
 271 void ext4_inode_table_set(struct super_block *sb,
 272                           struct ext4_group_desc *bg, ext4_fsblk_t blk)
 273 {
 274         bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
 275         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 276                 bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
 277 }
 278
 279 void ext4_free_group_clusters_set(struct super_block *sb,
 280                                   struct ext4_group_desc *bg, __u32 count)
 281 {
 282         bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
 283         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 284                 bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
 285 }
 286
 287 void ext4_free_inodes_set(struct super_block *sb,
 288                           struct ext4_group_desc *bg, __u32 count)
 289 {
 290         bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
 291         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 292                 bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
 293 }
 294
 295 void ext4_used_dirs_set(struct super_block *sb,
 296                           struct ext4_group_desc *bg, __u32 count)
 297 {
 298         bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
 299         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 300                 bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
 301 }
 302
 303 void ext4_itable_unused_set(struct super_block *sb,
 304                           struct ext4_group_desc *bg, __u32 count)
 305 {
 306         bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
 307         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 308                 bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
 309 }
 310
 311
 312 static void __save_error_info(struct super_block *sb, const char *func,
 313                             unsigned int line)
 314 {
 315         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 316
 317         EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
 318         if (bdev_read_only(sb->s_bdev))
 319                 return;
 320         es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
 321         es->s_last_error_time = cpu_to_le32(get_seconds());
 322         strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
 323         es->s_last_error_line = cpu_to_le32(line);
 324         if (!es->s_first_error_time) {
 325                 es->s_first_error_time = es->s_last_error_time;
 326                 strncpy(es->s_first_error_func, func,
 327                         sizeof(es->s_first_error_func));
 328                 es->s_first_error_line = cpu_to_le32(line);
 329                 es->s_first_error_ino = es->s_last_error_ino;
 330                 es->s_first_error_block = es->s_last_error_block;
 331         }
 332         /*
 333          * Start the daily error reporting function if it hasn't been
 334          * started already
 335          */
 336         if (!es->s_error_count)
 337                 mod_timer(&EXT4_SB(sb)->s_err_report, jiffies + 24*60*60*HZ);
 338         le32_add_cpu(&es->s_error_count, 1);
 339 }
 340
 341 static void save_error_info(struct super_block *sb, const char *func,
 342                             unsigned int line)
 343 {
 344         __save_error_info(sb, func, line);
 345         ext4_commit_super(sb, 1);
 346 }
 347
 348 /*
 349  * The del_gendisk() function uninitializes the disk-specific data
 350  * structures, including the bdi structure, without telling anyone
 351  * else.  Once this happens, any attempt to call mark_buffer_dirty()
 352  * (for example, by ext4_commit_super), will cause a kernel OOPS.
 353  * This is a kludge to prevent these oops until we can put in a proper
 354  * hook in del_gendisk() to inform the VFS and file system layers.
 355  */
 356 static int block_device_ejected(struct super_block *sb)
 357 {
 358         struct inode *bd_inode = sb->s_bdev->bd_inode;
 359         struct backing_dev_info *bdi = inode_to_bdi(bd_inode);
 360
 361         return bdi->dev == NULL;
 362 }
 363
 364 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
 365 {
 366         struct super_block              *sb = journal->j_private;
 367         struct ext4_sb_info             *sbi = EXT4_SB(sb);
 368         int                             error = is_journal_aborted(journal);
 369         struct ext4_journal_cb_entry    *jce;
 370
 371         BUG_ON(txn->t_state == T_FINISHED);
 372         spin_lock(&sbi->s_md_lock);
 373         while (!list_empty(&txn->t_private_list)) {
 374                 jce = list_entry(txn->t_private_list.next,
 375                                  struct ext4_journal_cb_entry, jce_list);
 376                 list_del_init(&jce->jce_list);
 377                 spin_unlock(&sbi->s_md_lock);
 378                 jce->jce_func(sb, jce, error);
 379                 spin_lock(&sbi->s_md_lock);
 380         }
 381         spin_unlock(&sbi->s_md_lock);
 382 }
 383
 384 /* Deal with the reporting of failure conditions on a filesystem such as
 385  * inconsistencies detected or read IO failures.
 386  *
 387  * On ext2, we can store the error state of the filesystem in the
 388  * superblock.  That is not possible on ext4, because we may have other
 389  * write ordering constraints on the superblock which prevent us from
 390  * writing it out straight away; and given that the journal is about to
 391  * be aborted, we can't rely on the current, or future, transactions to
 392  * write out the superblock safely.
 393  *
 394  * We'll just use the jbd2_journal_abort() error code to record an error in
 395  * the journal instead.  On recovery, the journal will complain about
 396  * that error until we've noted it down and cleared it.
 397  */
 398
 399 static void ext4_handle_error(struct super_block *sb)
 400 {
 401         if (sb->s_flags & MS_RDONLY)
 402                 return;
 403
 404         if (!test_opt(sb, ERRORS_CONT)) {
 405                 journal_t *journal = EXT4_SB(sb)->s_journal;
 406
 407                 EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
 408                 if (journal)
 409                         jbd2_journal_abort(journal, -EIO);
 410         }
 411         if (test_opt(sb, ERRORS_RO)) {
 412                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 413                 /*
 414                  * Make sure updated value of ->s_mount_flags will be visible
 415                  * before ->s_flags update
 416                  */
 417                 smp_wmb();
 418                 sb->s_flags |= MS_RDONLY;
 419         }
 420         if (test_opt(sb, ERRORS_PANIC)) {
 421                 if (EXT4_SB(sb)->s_journal &&
 422                   !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
 423                         return;
 424                 panic("EXT4-fs (device %s): panic forced after error\n",
 425                         sb->s_id);
 426         }
 427 }
 428
 429 #define ext4_error_ratelimit(sb)                                        \
 430                 ___ratelimit(&(EXT4_SB(sb)->s_err_ratelimit_state),     \
 431                              "EXT4-fs error")
 432
 433 void __ext4_error(struct super_block *sb, const char *function,
 434                   unsigned int line, const char *fmt, ...)
 435 {
 436         struct va_format vaf;
 437         va_list args;
 438
 439         if (ext4_error_ratelimit(sb)) {
 440                 va_start(args, fmt);
 441                 vaf.fmt = fmt;
 442                 vaf.va = &args;
 443                 printk(KERN_CRIT
 444                        "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
 445                        sb->s_id, function, line, current->comm, &vaf);
 446                 va_end(args);
 447         }
 448         save_error_info(sb, function, line);
 449         ext4_handle_error(sb);
 450 }
 451
 452 void __ext4_error_inode(struct inode *inode, const char *function,
 453                         unsigned int line, ext4_fsblk_t block,
 454                         const char *fmt, ...)
 455 {
 456         va_list args;
 457         struct va_format vaf;
 458         struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
 459
 460         es->s_last_error_ino = cpu_to_le32(inode->i_ino);
 461         es->s_last_error_block = cpu_to_le64(block);
 462         if (ext4_error_ratelimit(inode->i_sb)) {
 463                 va_start(args, fmt);
 464                 vaf.fmt = fmt;
 465                 vaf.va = &args;
 466                 if (block)
 467                         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
 468                                "inode #%lu: block %llu: comm %s: %pV\n",
 469                                inode->i_sb->s_id, function, line, inode->i_ino,
 470                                block, current->comm, &vaf);
 471                 else
 472                         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
 473                                "inode #%lu: comm %s: %pV\n",
 474                                inode->i_sb->s_id, function, line, inode->i_ino,
 475                                current->comm, &vaf);
 476                 va_end(args);
 477         }
 478         save_error_info(inode->i_sb, function, line);
 479         ext4_handle_error(inode->i_sb);
 480 }
 481
 482 void __ext4_error_file(struct file *file, const char *function,
 483                        unsigned int line, ext4_fsblk_t block,
 484                        const char *fmt, ...)
 485 {
 486         va_list args;
 487         struct va_format vaf;
 488         struct ext4_super_block *es;
 489         struct inode *inode = file_inode(file);
 490         char pathname[80], *path;
 491
 492         es = EXT4_SB(inode->i_sb)->s_es;
 493         es->s_last_error_ino = cpu_to_le32(inode->i_ino);
 494         if (ext4_error_ratelimit(inode->i_sb)) {
 495                 path = file_path(file, pathname, sizeof(pathname));
 496                 if (IS_ERR(path))
 497                         path = "(unknown)";
 498                 va_start(args, fmt);
 499                 vaf.fmt = fmt;
 500                 vaf.va = &args;
 501                 if (block)
 502                         printk(KERN_CRIT
 503                                "EXT4-fs error (device %s): %s:%d: inode #%lu: "
 504                                "block %llu: comm %s: path %s: %pV\n",
 505                                inode->i_sb->s_id, function, line, inode->i_ino,
 506                                block, current->comm, path, &vaf);
 507                 else
 508                         printk(KERN_CRIT
 509                                "EXT4-fs error (device %s): %s:%d: inode #%lu: "
 510                                "comm %s: path %s: %pV\n",
 511                                inode->i_sb->s_id, function, line, inode->i_ino,
 512                                current->comm, path, &vaf);
 513                 va_end(args);
 514         }
 515         save_error_info(inode->i_sb, function, line);
 516         ext4_handle_error(inode->i_sb);
 517 }
 518
 519 const char *ext4_decode_error(struct super_block *sb, int errno,
 520                               char nbuf[16])
 521 {
 522         char *errstr = NULL;
 523
 524         switch (errno) {
 525         case -EFSCORRUPTED:
 526                 errstr = "Corrupt filesystem";
 527                 break;
 528         case -EFSBADCRC:
 529                 errstr = "Filesystem failed CRC";
 530                 break;
 531         case -EIO:
 532                 errstr = "IO failure";
 533                 break;
 534         case -ENOMEM:
 535                 errstr = "Out of memory";
 536                 break;
 537         case -EROFS:
 538                 if (!sb || (EXT4_SB(sb)->s_journal &&
 539                             EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
 540                         errstr = "Journal has aborted";
 541                 else
 542                         errstr = "Readonly filesystem";
 543                 break;
 544         default:
 545                 /* If the caller passed in an extra buffer for unknown
 546                  * errors, textualise them now.  Else we just return
 547                  * NULL. */
 548                 if (nbuf) {
 549                         /* Check for truncated error codes... */
 550                         if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
 551                                 errstr = nbuf;
 552                 }
 553                 break;
 554         }
 555
 556         return errstr;
 557 }
 558
 559 /* __ext4_std_error decodes expected errors from journaling functions
 560  * automatically and invokes the appropriate error response.  */
 561
 562 void __ext4_std_error(struct super_block *sb, const char *function,
 563                       unsigned int line, int errno)
 564 {
 565         char nbuf[16];
 566         const char *errstr;
 567
 568         /* Special case: if the error is EROFS, and we're not already
 569          * inside a transaction, then there's really no point in logging
 570          * an error. */
 571         if (errno == -EROFS && journal_current_handle() == NULL &&
 572             (sb->s_flags & MS_RDONLY))
 573                 return;
 574
 575         if (ext4_error_ratelimit(sb)) {
 576                 errstr = ext4_decode_error(sb, errno, nbuf);
 577                 printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
 578                        sb->s_id, function, line, errstr);
 579         }
 580
 581         save_error_info(sb, function, line);
 582         ext4_handle_error(sb);
 583 }
 584
 585 /*
 586  * ext4_abort is a much stronger failure handler than ext4_error.  The
 587  * abort function may be used to deal with unrecoverable failures such
 588  * as journal IO errors or ENOMEM at a critical moment in log management.
 589  *
 590  * We unconditionally force the filesystem into an ABORT|READONLY state,
 591  * unless the error response on the fs has been set to panic in which
 592  * case we take the easy way out and panic immediately.
 593  */
 594
 595 void __ext4_abort(struct super_block *sb, const char *function,
 596                 unsigned int line, const char *fmt, ...)
 597 {
 598         va_list args;
 599
 600         save_error_info(sb, function, line);
 601         va_start(args, fmt);
 602         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: ", sb->s_id,
 603                function, line);
 604         vprintk(fmt, args);
 605         printk("\n");
 606         va_end(args);
 607
 608         if ((sb->s_flags & MS_RDONLY) == 0) {
 609                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 610                 EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
 611                 /*
 612                  * Make sure updated value of ->s_mount_flags will be visible
 613                  * before ->s_flags update
 614                  */
 615                 smp_wmb();
 616                 sb->s_flags |= MS_RDONLY;
 617                 if (EXT4_SB(sb)->s_journal)
 618                         jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
 619                 save_error_info(sb, function, line);
 620         }
 621         if (test_opt(sb, ERRORS_PANIC)) {
 622                 if (EXT4_SB(sb)->s_journal &&
 623                   !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
 624                         return;
 625                 panic("EXT4-fs panic from previous error\n");
 626         }
 627 }
 628
 629 void __ext4_msg(struct super_block *sb,
 630                 const char *prefix, const char *fmt, ...)
 631 {
 632         struct va_format vaf;
 633         va_list args;
 634
 635         if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state), "EXT4-fs"))
 636                 return;
 637
 638         va_start(args, fmt);
 639         vaf.fmt = fmt;
 640         vaf.va = &args;
 641         printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
 642         va_end(args);
 643 }
 644
 645 #define ext4_warning_ratelimit(sb)                                      \
 646                 ___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state), \
 647                              "EXT4-fs warning")
 648
 649 void __ext4_warning(struct super_block *sb, const char *function,
 650                     unsigned int line, const char *fmt, ...)
 651 {
 652         struct va_format vaf;
 653         va_list args;
 654
 655         if (!ext4_warning_ratelimit(sb))
 656                 return;
 657
 658         va_start(args, fmt);
 659         vaf.fmt = fmt;
 660         vaf.va = &args;
 661         printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
 662                sb->s_id, function, line, &vaf);
 663         va_end(args);
 664 }
 665
 666 void __ext4_warning_inode(const struct inode *inode, const char *function,
 667                           unsigned int line, const char *fmt, ...)
 668 {
 669         struct va_format vaf;
 670         va_list args;
 671
 672         if (!ext4_warning_ratelimit(inode->i_sb))
 673                 return;
 674
 675         va_start(args, fmt);
 676         vaf.fmt = fmt;
 677         vaf.va = &args;
 678         printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: "
 679                "inode #%lu: comm %s: %pV\n", inode->i_sb->s_id,
 680                function, line, inode->i_ino, current->comm, &vaf);
 681         va_end(args);
 682 }
 683
 684 void __ext4_grp_locked_error(const char *function, unsigned int line,
 685                              struct super_block *sb, ext4_group_t grp,
 686                              unsigned long ino, ext4_fsblk_t block,
 687                              const char *fmt, ...)
 688 __releases(bitlock)
 689 __acquires(bitlock)
 690 {
 691         struct va_format vaf;
 692         va_list args;
 693         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 694
 695         es->s_last_error_ino = cpu_to_le32(ino);
 696         es->s_last_error_block = cpu_to_le64(block);
 697         __save_error_info(sb, function, line);
 698
 699         if (ext4_error_ratelimit(sb)) {
 700                 va_start(args, fmt);
 701                 vaf.fmt = fmt;
 702                 vaf.va = &args;
 703                 printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
 704                        sb->s_id, function, line, grp);
 705                 if (ino)
 706                         printk(KERN_CONT "inode %lu: ", ino);
 707                 if (block)
 708                         printk(KERN_CONT "block %llu:",
 709                                (unsigned long long) block);
 710                 printk(KERN_CONT "%pV\n", &vaf);
 711                 va_end(args);
 712         }
 713
 714         if (test_opt(sb, ERRORS_CONT)) {
 715                 ext4_commit_super(sb, 0);
 716                 return;
 717         }
 718
 719         ext4_unlock_group(sb, grp);
 720         ext4_handle_error(sb);
 721         /*
 722          * We only get here in the ERRORS_RO case; relocking the group
 723          * may be dangerous, but nothing bad will happen since the
 724          * filesystem will have already been marked read/only and the
 725          * journal has been aborted.  We return 1 as a hint to callers
 726          * who might what to use the return value from
 727          * ext4_grp_locked_error() to distinguish between the
 728          * ERRORS_CONT and ERRORS_RO case, and perhaps return more
 729          * aggressively from the ext4 function in question, with a
 730          * more appropriate error code.
 731          */
 732         ext4_lock_group(sb, grp);
 733         return;
 734 }
 735
 736 void ext4_update_dynamic_rev(struct super_block *sb)
 737 {
 738         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 739
 740         if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
 741                 return;
 742
 743         ext4_warning(sb,
 744                      "updating to rev %d because of new feature flag, "
 745                      "running e2fsck is recommended",
 746                      EXT4_DYNAMIC_REV);
 747
 748         es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
 749         es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
 750         es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
 751         /* leave es->s_feature_*compat flags alone */
 752         /* es->s_uuid will be set by e2fsck if empty */
 753
 754         /*
 755          * The rest of the superblock fields should be zero, and if not it
 756          * means they are likely already in use, so leave them alone.  We
 757          * can leave it up to e2fsck to clean up any inconsistencies there.
 758          */
 759 }
 760
 761 /*
 762  * Open the external journal device
 763  */
 764 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
 765 {
 766         struct block_device *bdev;
 767         char b[BDEVNAME_SIZE];
 768
 769         bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
 770         if (IS_ERR(bdev))
 771                 goto fail;
 772         return bdev;
 773
 774 fail:
 775         ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
 776                         __bdevname(dev, b), PTR_ERR(bdev));
 777         return NULL;
 778 }
 779
 780 /*
 781  * Release the journal device
 782  */
 783 static void ext4_blkdev_put(struct block_device *bdev)
 784 {
 785         blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
 786 }
 787
 788 static void ext4_blkdev_remove(struct ext4_sb_info *sbi)
 789 {
 790         struct block_device *bdev;
 791         bdev = sbi->journal_bdev;
 792         if (bdev) {
 793                 ext4_blkdev_put(bdev);
 794                 sbi->journal_bdev = NULL;
 795         }
 796 }
 797
 798 static inline struct inode *orphan_list_entry(struct list_head *l)
 799 {
 800         return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
 801 }
 802
 803 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
 804 {
 805         struct list_head *l;
 806
 807         ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
 808                  le32_to_cpu(sbi->s_es->s_last_orphan));
 809
 810         printk(KERN_ERR "sb_info orphan list:\n");
 811         list_for_each(l, &sbi->s_orphan) {
 812                 struct inode *inode = orphan_list_entry(l);
 813                 printk(KERN_ERR "  "
 814                        "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
 815                        inode->i_sb->s_id, inode->i_ino, inode,
 816                        inode->i_mode, inode->i_nlink,
 817                        NEXT_ORPHAN(inode));
 818         }
 819 }
 820
 821 static void ext4_put_super(struct super_block *sb)
 822 {
 823         struct ext4_sb_info *sbi = EXT4_SB(sb);
 824         struct ext4_super_block *es = sbi->s_es;
 825         int i, err;
 826
 827         ext4_unregister_li_request(sb);
 828         dquot_disable(sb, -1, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
 829
 830         flush_workqueue(sbi->rsv_conversion_wq);
 831         destroy_workqueue(sbi->rsv_conversion_wq);
 832
 833         if (sbi->s_journal) {
 834                 err = jbd2_journal_destroy(sbi->s_journal);
 835                 sbi->s_journal = NULL;
 836                 if (err < 0)
 837                         ext4_abort(sb, "Couldn't clean up the journal");
 838         }
 839
 840         ext4_unregister_sysfs(sb);
 841         ext4_es_unregister_shrinker(sbi);
 842         del_timer_sync(&sbi->s_err_report);
 843         ext4_release_system_zone(sb);
 844         ext4_mb_release(sb);
 845         ext4_ext_release(sb);
 846
 847         if (!(sb->s_flags & MS_RDONLY)) {
 848                 ext4_clear_feature_journal_needs_recovery(sb);
 849                 es->s_state = cpu_to_le16(sbi->s_mount_state);
 850         }
 851         if (!(sb->s_flags & MS_RDONLY))
 852                 ext4_commit_super(sb, 1);
 853
 854         for (i = 0; i < sbi->s_gdb_count; i++)
 855                 brelse(sbi->s_group_desc[i]);
 856         kvfree(sbi->s_group_desc);
 857         kvfree(sbi->s_flex_groups);
 858         percpu_counter_destroy(&sbi->s_freeclusters_counter);
 859         percpu_counter_destroy(&sbi->s_freeinodes_counter);
 860         percpu_counter_destroy(&sbi->s_dirs_counter);
 861         percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
 862         brelse(sbi->s_sbh);
 863 #ifdef CONFIG_QUOTA
 864         for (i = 0; i < EXT4_MAXQUOTAS; i++)
 865                 kfree(sbi->s_qf_names[i]);
 866 #endif
 867
 868         /* Debugging code just in case the in-memory inode orphan list
 869          * isn't empty.  The on-disk one can be non-empty if we've
 870          * detected an error and taken the fs readonly, but the
 871          * in-memory list had better be clean by this point. */
 872         if (!list_empty(&sbi->s_orphan))
 873                 dump_orphan_list(sb, sbi);
 874         J_ASSERT(list_empty(&sbi->s_orphan));
 875
 876         sync_blockdev(sb->s_bdev);
 877         invalidate_bdev(sb->s_bdev);
 878         if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
 879                 /*
 880                  * Invalidate the journal device's buffers.  We don't want them
 881                  * floating about in memory - the physical journal device may
 882                  * hotswapped, and it breaks the `ro-after' testing code.
 883                  */
 884                 sync_blockdev(sbi->journal_bdev);
 885                 invalidate_bdev(sbi->journal_bdev);
 886                 ext4_blkdev_remove(sbi);
 887         }
 888         if (sbi->s_mb_cache) {
 889                 ext4_xattr_destroy_cache(sbi->s_mb_cache);
 890                 sbi->s_mb_cache = NULL;
 891         }
 892         if (sbi->s_mmp_tsk)
 893                 kthread_stop(sbi->s_mmp_tsk);
 894         sb->s_fs_info = NULL;
 895         /*
 896          * Now that we are completely done shutting down the
 897          * superblock, we need to actually destroy the kobject.
 898          */
 899         kobject_put(&sbi->s_kobj);
 900         wait_for_completion(&sbi->s_kobj_unregister);
 901         if (sbi->s_chksum_driver)
 902                 crypto_free_shash(sbi->s_chksum_driver);
 903         kfree(sbi->s_blockgroup_lock);
 904         kfree(sbi);
 905 }
 906
 907 static struct kmem_cache *ext4_inode_cachep;
 908
 909 /*
 910  * Called inside transaction, so use GFP_NOFS
 911  */
 912 static struct inode *ext4_alloc_inode(struct super_block *sb)
 913 {
 914         struct ext4_inode_info *ei;
 915
 916         ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
 917         if (!ei)
 918                 return NULL;
 919
 920         ei->vfs_inode.i_version = 1;
 921         spin_lock_init(&ei->i_raw_lock);
 922         INIT_LIST_HEAD(&ei->i_prealloc_list);
 923         spin_lock_init(&ei->i_prealloc_lock);
 924         ext4_es_init_tree(&ei->i_es_tree);
 925         rwlock_init(&ei->i_es_lock);
 926         INIT_LIST_HEAD(&ei->i_es_list);
 927         ei->i_es_all_nr = 0;
 928         ei->i_es_shk_nr = 0;
 929         ei->i_es_shrink_lblk = 0;
 930         ei->i_reserved_data_blocks = 0;
 931         ei->i_reserved_meta_blocks = 0;
 932         ei->i_allocated_meta_blocks = 0;
 933         ei->i_da_metadata_calc_len = 0;
 934         ei->i_da_metadata_calc_last_lblock = 0;
 935         spin_lock_init(&(ei->i_block_reservation_lock));
 936 #ifdef CONFIG_QUOTA
 937         ei->i_reserved_quota = 0;
 938         memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
 939 #endif
 940         ei->jinode = NULL;
 941         INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
 942         spin_lock_init(&ei->i_completed_io_lock);
 943         ei->i_sync_tid = 0;
 944         ei->i_datasync_tid = 0;
 945         atomic_set(&ei->i_unwritten, 0);
 946         INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
 947 #ifdef CONFIG_EXT4_FS_ENCRYPTION
 948         ei->i_crypt_info = NULL;
 949 #endif
 950         return &ei->vfs_inode;
 951 }
 952
 953 static int ext4_drop_inode(struct inode *inode)
 954 {
 955         int drop = generic_drop_inode(inode);
 956
 957         trace_ext4_drop_inode(inode, drop);
 958         return drop;
 959 }
 960
 961 static void ext4_i_callback(struct rcu_head *head)
 962 {
 963         struct inode *inode = container_of(head, struct inode, i_rcu);
 964         kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
 965 }
 966
 967 static void ext4_destroy_inode(struct inode *inode)
 968 {
 969         if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
 970                 ext4_msg(inode->i_sb, KERN_ERR,
 971                          "Inode %lu (%p): orphan list check failed!",
 972                          inode->i_ino, EXT4_I(inode));
 973                 print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
 974                                 EXT4_I(inode), sizeof(struct ext4_inode_info),
 975                                 true);
 976                 dump_stack();
 977         }
 978         call_rcu(&inode->i_rcu, ext4_i_callback);
 979 }
 980
 981 static void init_once(void *foo)
 982 {
 983         struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
 984
 985         INIT_LIST_HEAD(&ei->i_orphan);
 986         init_rwsem(&ei->xattr_sem);
 987         init_rwsem(&ei->i_data_sem);
 988         init_rwsem(&ei->i_mmap_sem);
 989         inode_init_once(&ei->vfs_inode);
 990 }
 991
 992 static int __init init_inodecache(void)
 993 {
 994         ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
 995                                              sizeof(struct ext4_inode_info),
 996                                              0, (SLAB_RECLAIM_ACCOUNT|
 997                                                 SLAB_MEM_SPREAD|SLAB_ACCOUNT),
 998                                              init_once);
 999         if (ext4_inode_cachep == NULL)
1000                 return -ENOMEM;
1001         return 0;
1002 }
1003
1004 static void destroy_inodecache(void)
1005 {
1006         /*
1007          * Make sure all delayed rcu free inodes are flushed before we
1008          * destroy cache.
1009          */
1010         rcu_barrier();
1011         kmem_cache_destroy(ext4_inode_cachep);
1012 }
1013
1014 void ext4_clear_inode(struct inode *inode)
1015 {
1016         invalidate_inode_buffers(inode);
1017         clear_inode(inode);
1018         dquot_drop(inode);
1019         ext4_discard_preallocations(inode);
1020         ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
1021         if (EXT4_I(inode)->jinode) {
1022                 jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
1023                                                EXT4_I(inode)->jinode);
1024                 jbd2_free_inode(EXT4_I(inode)->jinode);
1025                 EXT4_I(inode)->jinode = NULL;
1026         }
1027 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1028         if (EXT4_I(inode)->i_crypt_info)
1029                 ext4_free_encryption_info(inode, EXT4_I(inode)->i_crypt_info);
1030 #endif
1031 }
1032
1033 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1034                                         u64 ino, u32 generation)
1035 {
1036         struct inode *inode;
1037
1038         if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
1039                 return ERR_PTR(-ESTALE);
1040         if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
1041                 return ERR_PTR(-ESTALE);
1042
1043         /* iget isn't really right if the inode is currently unallocated!!
1044          *
1045          * ext4_read_inode will return a bad_inode if the inode had been
1046          * deleted, so we should be safe.
1047          *
1048          * Currently we don't know the generation for parent directory, so
1049          * a generation of 0 means "accept any"
1050          */
1051         inode = ext4_iget_normal(sb, ino);
1052         if (IS_ERR(inode))
1053                 return ERR_CAST(inode);
1054         if (generation && inode->i_generation != generation) {
1055                 iput(inode);
1056                 return ERR_PTR(-ESTALE);
1057         }
1058
1059         return inode;
1060 }
1061
1062 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1063                                         int fh_len, int fh_type)
1064 {
1065         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1066                                     ext4_nfs_get_inode);
1067 }
1068
1069 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1070                                         int fh_len, int fh_type)
1071 {
1072         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1073                                     ext4_nfs_get_inode);
1074 }
1075
1076 /*
1077  * Try to release metadata pages (indirect blocks, directories) which are
1078  * mapped via the block device.  Since these pages could have journal heads
1079  * which would prevent try_to_free_buffers() from freeing them, we must use
1080  * jbd2 layer's try_to_free_buffers() function to release them.
1081  */
1082 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1083                                  gfp_t wait)
1084 {
1085         journal_t *journal = EXT4_SB(sb)->s_journal;
1086
1087         WARN_ON(PageChecked(page));
1088         if (!page_has_buffers(page))
1089                 return 0;
1090         if (journal)
1091                 return jbd2_journal_try_to_free_buffers(journal, page,
1092                                                 wait & ~__GFP_DIRECT_RECLAIM);
1093         return try_to_free_buffers(page);
1094 }
1095
1096 #ifdef CONFIG_QUOTA
1097 static char *quotatypes[] = INITQFNAMES;
1098 #define QTYPE2NAME(t) (quotatypes[t])
1099
1100 static int ext4_write_dquot(struct dquot *dquot);
1101 static int ext4_acquire_dquot(struct dquot *dquot);
1102 static int ext4_release_dquot(struct dquot *dquot);
1103 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1104 static int ext4_write_info(struct super_block *sb, int type);
1105 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1106                          struct path *path);
1107 static int ext4_quota_off(struct super_block *sb, int type);
1108 static int ext4_quota_on_mount(struct super_block *sb, int type);
1109 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1110                                size_t len, loff_t off);
1111 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1112                                 const char *data, size_t len, loff_t off);
1113 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1114                              unsigned int flags);
1115 static int ext4_enable_quotas(struct super_block *sb);
1116 static int ext4_get_next_id(struct super_block *sb, struct kqid *qid);
1117
1118 static struct dquot **ext4_get_dquots(struct inode *inode)
1119 {
1120         return EXT4_I(inode)->i_dquot;
1121 }
1122
1123 static const struct dquot_operations ext4_quota_operations = {
1124         .get_reserved_space = ext4_get_reserved_space,
1125         .write_dquot    = ext4_write_dquot,
1126         .acquire_dquot  = ext4_acquire_dquot,
1127         .release_dquot  = ext4_release_dquot,
1128         .mark_dirty     = ext4_mark_dquot_dirty,
1129         .write_info     = ext4_write_info,
1130         .alloc_dquot    = dquot_alloc,
1131         .destroy_dquot  = dquot_destroy,
1132         .get_projid     = ext4_get_projid,
1133         .get_next_id    = ext4_get_next_id,
1134 };
1135
1136 static const struct quotactl_ops ext4_qctl_operations = {
1137         .quota_on       = ext4_quota_on,
1138         .quota_off      = ext4_quota_off,
1139         .quota_sync     = dquot_quota_sync,
1140         .get_state      = dquot_get_state,
1141         .set_info       = dquot_set_dqinfo,
1142         .get_dqblk      = dquot_get_dqblk,
1143         .set_dqblk      = dquot_set_dqblk,
1144         .get_nextdqblk  = dquot_get_next_dqblk,
1145 };
1146 #endif
1147
1148 static const struct super_operations ext4_sops = {
1149         .alloc_inode    = ext4_alloc_inode,
1150         .destroy_inode  = ext4_destroy_inode,
1151         .write_inode    = ext4_write_inode,
1152         .dirty_inode    = ext4_dirty_inode,
1153         .drop_inode     = ext4_drop_inode,
1154         .evict_inode    = ext4_evict_inode,
1155         .put_super      = ext4_put_super,
1156         .sync_fs        = ext4_sync_fs,
1157         .freeze_fs      = ext4_freeze,
1158         .unfreeze_fs    = ext4_unfreeze,
1159         .statfs         = ext4_statfs,
1160         .remount_fs     = ext4_remount,
1161         .show_options   = ext4_show_options,
1162 #ifdef CONFIG_QUOTA
1163         .quota_read     = ext4_quota_read,
1164         .quota_write    = ext4_quota_write,
1165         .get_dquots     = ext4_get_dquots,
1166 #endif
1167         .bdev_try_to_free_page = bdev_try_to_free_page,
1168 };
1169
1170 static const struct export_operations ext4_export_ops = {
1171         .fh_to_dentry = ext4_fh_to_dentry,
1172         .fh_to_parent = ext4_fh_to_parent,
1173         .get_parent = ext4_get_parent,
1174 };
1175
1176 enum {
1177         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1178         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1179         Opt_nouid32, Opt_debug, Opt_removed,
1180         Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1181         Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1182         Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1183         Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1184         Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1185         Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
1186         Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1187         Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1188         Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1189         Opt_usrquota, Opt_grpquota, Opt_i_version, Opt_dax,
1190         Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_mblk_io_submit,
1191         Opt_lazytime, Opt_nolazytime,
1192         Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1193         Opt_inode_readahead_blks, Opt_journal_ioprio,
1194         Opt_dioread_nolock, Opt_dioread_lock,
1195         Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1196         Opt_max_dir_size_kb, Opt_nojournal_checksum,
1197 };
1198
1199 static const match_table_t tokens = {
1200         {Opt_bsd_df, "bsddf"},
1201         {Opt_minix_df, "minixdf"},
1202         {Opt_grpid, "grpid"},
1203         {Opt_grpid, "bsdgroups"},
1204         {Opt_nogrpid, "nogrpid"},
1205         {Opt_nogrpid, "sysvgroups"},
1206         {Opt_resgid, "resgid=%u"},
1207         {Opt_resuid, "resuid=%u"},
1208         {Opt_sb, "sb=%u"},
1209         {Opt_err_cont, "errors=continue"},
1210         {Opt_err_panic, "errors=panic"},
1211         {Opt_err_ro, "errors=remount-ro"},
1212         {Opt_nouid32, "nouid32"},
1213         {Opt_debug, "debug"},
1214         {Opt_removed, "oldalloc"},
1215         {Opt_removed, "orlov"},
1216         {Opt_user_xattr, "user_xattr"},
1217         {Opt_nouser_xattr, "nouser_xattr"},
1218         {Opt_acl, "acl"},
1219         {Opt_noacl, "noacl"},
1220         {Opt_noload, "norecovery"},
1221         {Opt_noload, "noload"},
1222         {Opt_removed, "nobh"},
1223         {Opt_removed, "bh"},
1224         {Opt_commit, "commit=%u"},
1225         {Opt_min_batch_time, "min_batch_time=%u"},
1226         {Opt_max_batch_time, "max_batch_time=%u"},
1227         {Opt_journal_dev, "journal_dev=%u"},
1228         {Opt_journal_path, "journal_path=%s"},
1229         {Opt_journal_checksum, "journal_checksum"},
1230         {Opt_nojournal_checksum, "nojournal_checksum"},
1231         {Opt_journal_async_commit, "journal_async_commit"},
1232         {Opt_abort, "abort"},
1233         {Opt_data_journal, "data=journal"},
1234         {Opt_data_ordered, "data=ordered"},
1235         {Opt_data_writeback, "data=writeback"},
1236         {Opt_data_err_abort, "data_err=abort"},
1237         {Opt_data_err_ignore, "data_err=ignore"},
1238         {Opt_offusrjquota, "usrjquota="},
1239         {Opt_usrjquota, "usrjquota=%s"},
1240         {Opt_offgrpjquota, "grpjquota="},
1241         {Opt_grpjquota, "grpjquota=%s"},
1242         {Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1243         {Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1244         {Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1245         {Opt_grpquota, "grpquota"},
1246         {Opt_noquota, "noquota"},
1247         {Opt_quota, "quota"},
1248         {Opt_usrquota, "usrquota"},
1249         {Opt_barrier, "barrier=%u"},
1250         {Opt_barrier, "barrier"},
1251         {Opt_nobarrier, "nobarrier"},
1252         {Opt_i_version, "i_version"},
1253         {Opt_dax, "dax"},
1254         {Opt_stripe, "stripe=%u"},
1255         {Opt_delalloc, "delalloc"},
1256         {Opt_lazytime, "lazytime"},
1257         {Opt_nolazytime, "nolazytime"},
1258         {Opt_nodelalloc, "nodelalloc"},
1259         {Opt_removed, "mblk_io_submit"},
1260         {Opt_removed, "nomblk_io_submit"},
1261         {Opt_block_validity, "block_validity"},
1262         {Opt_noblock_validity, "noblock_validity"},
1263         {Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1264         {Opt_journal_ioprio, "journal_ioprio=%u"},
1265         {Opt_auto_da_alloc, "auto_da_alloc=%u"},
1266         {Opt_auto_da_alloc, "auto_da_alloc"},
1267         {Opt_noauto_da_alloc, "noauto_da_alloc"},
1268         {Opt_dioread_nolock, "dioread_nolock"},
1269         {Opt_dioread_lock, "dioread_lock"},
1270         {Opt_discard, "discard"},
1271         {Opt_nodiscard, "nodiscard"},
1272         {Opt_init_itable, "init_itable=%u"},
1273         {Opt_init_itable, "init_itable"},
1274         {Opt_noinit_itable, "noinit_itable"},
1275         {Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1276         {Opt_test_dummy_encryption, "test_dummy_encryption"},
1277         {Opt_removed, "check=none"},    /* mount option from ext2/3 */
1278         {Opt_removed, "nocheck"},       /* mount option from ext2/3 */
1279         {Opt_removed, "reservation"},   /* mount option from ext2/3 */
1280         {Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1281         {Opt_removed, "journal=%u"},    /* mount option from ext2/3 */
1282         {Opt_err, NULL},
1283 };
1284
1285 static ext4_fsblk_t get_sb_block(void **data)
1286 {
1287         ext4_fsblk_t    sb_block;
1288         char            *options = (char *) *data;
1289
1290         if (!options || strncmp(options, "sb=", 3) != 0)
1291                 return 1;       /* Default location */
1292
1293         options += 3;
1294         /* TODO: use simple_strtoll with >32bit ext4 */
1295         sb_block = simple_strtoul(options, &options, 0);
1296         if (*options && *options != ',') {
1297                 printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1298                        (char *) *data);
1299                 return 1;
1300         }
1301         if (*options == ',')
1302                 options++;
1303         *data = (void *) options;
1304
1305         return sb_block;
1306 }
1307
1308 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1309 static char deprecated_msg[] = "Mount option \"%s\" will be removed by %s\n"
1310         "Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1311
1312 #ifdef CONFIG_QUOTA
1313 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1314 {
1315         struct ext4_sb_info *sbi = EXT4_SB(sb);
1316         char *qname;
1317         int ret = -1;
1318
1319         if (sb_any_quota_loaded(sb) &&
1320                 !sbi->s_qf_names[qtype]) {
1321                 ext4_msg(sb, KERN_ERR,
1322                         "Cannot change journaled "
1323                         "quota options when quota turned on");
1324                 return -1;
1325         }
1326         if (ext4_has_feature_quota(sb)) {
1327                 ext4_msg(sb, KERN_INFO, "Journaled quota options "
1328                          "ignored when QUOTA feature is enabled");
1329                 return 1;
1330         }
1331         qname = match_strdup(args);
1332         if (!qname) {
1333                 ext4_msg(sb, KERN_ERR,
1334                         "Not enough memory for storing quotafile name");
1335                 return -1;
1336         }
1337         if (sbi->s_qf_names[qtype]) {
1338                 if (strcmp(sbi->s_qf_names[qtype], qname) == 0)
1339                         ret = 1;
1340                 else
1341                         ext4_msg(sb, KERN_ERR,
1342                                  "%s quota file already specified",
1343                                  QTYPE2NAME(qtype));
1344                 goto errout;
1345         }
1346         if (strchr(qname, '/')) {
1347                 ext4_msg(sb, KERN_ERR,
1348                         "quotafile must be on filesystem root");
1349                 goto errout;
1350         }
1351         sbi->s_qf_names[qtype] = qname;
1352         set_opt(sb, QUOTA);
1353         return 1;
1354 errout:
1355         kfree(qname);
1356         return ret;
1357 }
1358
1359 static int clear_qf_name(struct super_block *sb, int qtype)
1360 {
1361
1362         struct ext4_sb_info *sbi = EXT4_SB(sb);
1363
1364         if (sb_any_quota_loaded(sb) &&
1365                 sbi->s_qf_names[qtype]) {
1366                 ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1367                         " when quota turned on");
1368                 return -1;
1369         }
1370         kfree(sbi->s_qf_names[qtype]);
1371         sbi->s_qf_names[qtype] = NULL;
1372         return 1;
1373 }
1374 #endif
1375
1376 #define MOPT_SET        0x0001
1377 #define MOPT_CLEAR      0x0002
1378 #define MOPT_NOSUPPORT  0x0004
1379 #define MOPT_EXPLICIT   0x0008
1380 #define MOPT_CLEAR_ERR  0x0010
1381 #define MOPT_GTE0       0x0020
1382 #ifdef CONFIG_QUOTA
1383 #define MOPT_Q          0
1384 #define MOPT_QFMT       0x0040
1385 #else
1386 #define MOPT_Q          MOPT_NOSUPPORT
1387 #define MOPT_QFMT       MOPT_NOSUPPORT
1388 #endif
1389 #define MOPT_DATAJ      0x0080
1390 #define MOPT_NO_EXT2    0x0100
1391 #define MOPT_NO_EXT3    0x0200
1392 #define MOPT_EXT4_ONLY  (MOPT_NO_EXT2 | MOPT_NO_EXT3)
1393 #define MOPT_STRING     0x0400
1394
1395 static const struct mount_opts {
1396         int     token;
1397         int     mount_opt;
1398         int     flags;
1399 } ext4_mount_opts[] = {
1400         {Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1401         {Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1402         {Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1403         {Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1404         {Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1405         {Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1406         {Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1407          MOPT_EXT4_ONLY | MOPT_SET},
1408         {Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1409          MOPT_EXT4_ONLY | MOPT_CLEAR},
1410         {Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1411         {Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1412         {Opt_delalloc, EXT4_MOUNT_DELALLOC,
1413          MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1414         {Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1415          MOPT_EXT4_ONLY | MOPT_CLEAR},
1416         {Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1417          MOPT_EXT4_ONLY | MOPT_CLEAR},
1418         {Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1419          MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1420         {Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1421                                     EXT4_MOUNT_JOURNAL_CHECKSUM),
1422          MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1423         {Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1424         {Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1425         {Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1426         {Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1427         {Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
1428          MOPT_NO_EXT2},
1429         {Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
1430          MOPT_NO_EXT2},
1431         {Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1432         {Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1433         {Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1434         {Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1435         {Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1436         {Opt_commit, 0, MOPT_GTE0},
1437         {Opt_max_batch_time, 0, MOPT_GTE0},
1438         {Opt_min_batch_time, 0, MOPT_GTE0},
1439         {Opt_inode_readahead_blks, 0, MOPT_GTE0},
1440         {Opt_init_itable, 0, MOPT_GTE0},
1441         {Opt_dax, EXT4_MOUNT_DAX, MOPT_SET},
1442         {Opt_stripe, 0, MOPT_GTE0},
1443         {Opt_resuid, 0, MOPT_GTE0},
1444         {Opt_resgid, 0, MOPT_GTE0},
1445         {Opt_journal_dev, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1446         {Opt_journal_path, 0, MOPT_NO_EXT2 | MOPT_STRING},
1447         {Opt_journal_ioprio, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1448         {Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1449         {Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1450         {Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
1451          MOPT_NO_EXT2 | MOPT_DATAJ},
1452         {Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1453         {Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1454 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1455         {Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1456         {Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1457 #else
1458         {Opt_acl, 0, MOPT_NOSUPPORT},
1459         {Opt_noacl, 0, MOPT_NOSUPPORT},
1460 #endif
1461         {Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1462         {Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1463         {Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1464         {Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1465                                                         MOPT_SET | MOPT_Q},
1466         {Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1467                                                         MOPT_SET | MOPT_Q},
1468         {Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1469                        EXT4_MOUNT_GRPQUOTA), MOPT_CLEAR | MOPT_Q},
1470         {Opt_usrjquota, 0, MOPT_Q},
1471         {Opt_grpjquota, 0, MOPT_Q},
1472         {Opt_offusrjquota, 0, MOPT_Q},
1473         {Opt_offgrpjquota, 0, MOPT_Q},
1474         {Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1475         {Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1476         {Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1477         {Opt_max_dir_size_kb, 0, MOPT_GTE0},
1478         {Opt_test_dummy_encryption, 0, MOPT_GTE0},
1479         {Opt_err, 0, 0}
1480 };
1481
1482 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1483                             substring_t *args, unsigned long *journal_devnum,
1484                             unsigned int *journal_ioprio, int is_remount)
1485 {
1486         struct ext4_sb_info *sbi = EXT4_SB(sb);
1487         const struct mount_opts *m;
1488         kuid_t uid;
1489         kgid_t gid;
1490         int arg = 0;
1491
1492 #ifdef CONFIG_QUOTA
1493         if (token == Opt_usrjquota)
1494                 return set_qf_name(sb, USRQUOTA, &args[0]);
1495         else if (token == Opt_grpjquota)
1496                 return set_qf_name(sb, GRPQUOTA, &args[0]);
1497         else if (token == Opt_offusrjquota)
1498                 return clear_qf_name(sb, USRQUOTA);
1499         else if (token == Opt_offgrpjquota)
1500                 return clear_qf_name(sb, GRPQUOTA);
1501 #endif
1502         switch (token) {
1503         case Opt_noacl:
1504         case Opt_nouser_xattr:
1505                 ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1506                 break;
1507         case Opt_sb:
1508                 return 1;       /* handled by get_sb_block() */
1509         case Opt_removed:
1510                 ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
1511                 return 1;
1512         case Opt_abort:
1513                 sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1514                 return 1;
1515         case Opt_i_version:
1516                 sb->s_flags |= MS_I_VERSION;
1517                 return 1;
1518         case Opt_lazytime:
1519                 sb->s_flags |= MS_LAZYTIME;
1520                 return 1;
1521         case Opt_nolazytime:
1522                 sb->s_flags &= ~MS_LAZYTIME;
1523                 return 1;
1524         }
1525
1526         for (m = ext4_mount_opts; m->token != Opt_err; m++)
1527                 if (token == m->token)
1528                         break;
1529
1530         if (m->token == Opt_err) {
1531                 ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1532                          "or missing value", opt);
1533                 return -1;
1534         }
1535
1536         if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
1537                 ext4_msg(sb, KERN_ERR,
1538                          "Mount option \"%s\" incompatible with ext2", opt);
1539                 return -1;
1540         }
1541         if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
1542                 ext4_msg(sb, KERN_ERR,
1543                          "Mount option \"%s\" incompatible with ext3", opt);
1544                 return -1;
1545         }
1546
1547         if (args->from && !(m->flags & MOPT_STRING) && match_int(args, &arg))
1548                 return -1;
1549         if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1550                 return -1;
1551         if (m->flags & MOPT_EXPLICIT) {
1552                 if (m->mount_opt & EXT4_MOUNT_DELALLOC) {
1553                         set_opt2(sb, EXPLICIT_DELALLOC);
1554                 } else if (m->mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) {
1555                         set_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM);
1556                 } else
1557                         return -1;
1558         }
1559         if (m->flags & MOPT_CLEAR_ERR)
1560                 clear_opt(sb, ERRORS_MASK);
1561         if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1562                 ext4_msg(sb, KERN_ERR, "Cannot change quota "
1563                          "options when quota turned on");
1564                 return -1;
1565         }
1566
1567         if (m->flags & MOPT_NOSUPPORT) {
1568                 ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1569         } else if (token == Opt_commit) {
1570                 if (arg == 0)
1571                         arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1572                 sbi->s_commit_interval = HZ * arg;
1573         } else if (token == Opt_max_batch_time) {
1574                 sbi->s_max_batch_time = arg;
1575         } else if (token == Opt_min_batch_time) {
1576                 sbi->s_min_batch_time = arg;
1577         } else if (token == Opt_inode_readahead_blks) {
1578                 if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
1579                         ext4_msg(sb, KERN_ERR,
1580                                  "EXT4-fs: inode_readahead_blks must be "
1581                                  "0 or a power of 2 smaller than 2^31");
1582                         return -1;
1583                 }
1584                 sbi->s_inode_readahead_blks = arg;
1585         } else if (token == Opt_init_itable) {
1586                 set_opt(sb, INIT_INODE_TABLE);
1587                 if (!args->from)
1588                         arg = EXT4_DEF_LI_WAIT_MULT;
1589                 sbi->s_li_wait_mult = arg;
1590         } else if (token == Opt_max_dir_size_kb) {
1591                 sbi->s_max_dir_size_kb = arg;
1592         } else if (token == Opt_stripe) {
1593                 sbi->s_stripe = arg;
1594         } else if (token == Opt_resuid) {
1595                 uid = make_kuid(current_user_ns(), arg);
1596                 if (!uid_valid(uid)) {
1597                         ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
1598                         return -1;
1599                 }
1600                 sbi->s_resuid = uid;
1601         } else if (token == Opt_resgid) {
1602                 gid = make_kgid(current_user_ns(), arg);
1603                 if (!gid_valid(gid)) {
1604                         ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
1605                         return -1;
1606                 }
1607                 sbi->s_resgid = gid;
1608         } else if (token == Opt_journal_dev) {
1609                 if (is_remount) {
1610                         ext4_msg(sb, KERN_ERR,
1611                                  "Cannot specify journal on remount");
1612                         return -1;
1613                 }
1614                 *journal_devnum = arg;
1615         } else if (token == Opt_journal_path) {
1616                 char *journal_path;
1617                 struct inode *journal_inode;
1618                 struct path path;
1619                 int error;
1620
1621                 if (is_remount) {
1622                         ext4_msg(sb, KERN_ERR,
1623                                  "Cannot specify journal on remount");
1624                         return -1;
1625                 }
1626                 journal_path = match_strdup(&args[0]);
1627                 if (!journal_path) {
1628                         ext4_msg(sb, KERN_ERR, "error: could not dup "
1629                                 "journal device string");
1630                         return -1;
1631                 }
1632
1633                 error = kern_path(journal_path, LOOKUP_FOLLOW, &path);
1634                 if (error) {
1635                         ext4_msg(sb, KERN_ERR, "error: could not find "
1636                                 "journal device path: error %d", error);
1637                         kfree(journal_path);
1638                         return -1;
1639                 }
1640
1641                 journal_inode = d_inode(path.dentry);
1642                 if (!S_ISBLK(journal_inode->i_mode)) {
1643                         ext4_msg(sb, KERN_ERR, "error: journal path %s "
1644                                 "is not a block device", journal_path);
1645                         path_put(&path);
1646                         kfree(journal_path);
1647                         return -1;
1648                 }
1649
1650                 *journal_devnum = new_encode_dev(journal_inode->i_rdev);
1651                 path_put(&path);
1652                 kfree(journal_path);
1653         } else if (token == Opt_journal_ioprio) {
1654                 if (arg > 7) {
1655                         ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
1656                                  " (must be 0-7)");
1657                         return -1;
1658                 }
1659                 *journal_ioprio =
1660                         IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
1661         } else if (token == Opt_test_dummy_encryption) {
1662 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1663                 sbi->s_mount_flags |= EXT4_MF_TEST_DUMMY_ENCRYPTION;
1664                 ext4_msg(sb, KERN_WARNING,
1665                          "Test dummy encryption mode enabled");
1666 #else
1667                 ext4_msg(sb, KERN_WARNING,
1668                          "Test dummy encryption mount option ignored");
1669 #endif
1670         } else if (m->flags & MOPT_DATAJ) {
1671                 if (is_remount) {
1672                         if (!sbi->s_journal)
1673                                 ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
1674                         else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
1675                                 ext4_msg(sb, KERN_ERR,
1676                                          "Cannot change data mode on remount");
1677                                 return -1;
1678                         }
1679                 } else {
1680                         clear_opt(sb, DATA_FLAGS);
1681                         sbi->s_mount_opt |= m->mount_opt;
1682                 }
1683 #ifdef CONFIG_QUOTA
1684         } else if (m->flags & MOPT_QFMT) {
1685                 if (sb_any_quota_loaded(sb) &&
1686                     sbi->s_jquota_fmt != m->mount_opt) {
1687                         ext4_msg(sb, KERN_ERR, "Cannot change journaled "
1688                                  "quota options when quota turned on");
1689                         return -1;
1690                 }
1691                 if (ext4_has_feature_quota(sb)) {
1692                         ext4_msg(sb, KERN_INFO,
1693                                  "Quota format mount options ignored "
1694                                  "when QUOTA feature is enabled");
1695                         return 1;
1696                 }
1697                 sbi->s_jquota_fmt = m->mount_opt;
1698 #endif
1699         } else if (token == Opt_dax) {
1700 #ifdef CONFIG_FS_DAX
1701                 ext4_msg(sb, KERN_WARNING,
1702                 "DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
1703                         sbi->s_mount_opt |= m->mount_opt;
1704 #else
1705                 ext4_msg(sb, KERN_INFO, "dax option not supported");
1706                 return -1;
1707 #endif
1708         } else if (token == Opt_data_err_abort) {
1709                 sbi->s_mount_opt |= m->mount_opt;
1710         } else if (token == Opt_data_err_ignore) {
1711                 sbi->s_mount_opt &= ~m->mount_opt;
1712         } else {
1713                 if (!args->from)
1714                         arg = 1;
1715                 if (m->flags & MOPT_CLEAR)
1716                         arg = !arg;
1717                 else if (unlikely(!(m->flags & MOPT_SET))) {
1718                         ext4_msg(sb, KERN_WARNING,
1719                                  "buggy handling of option %s", opt);
1720                         WARN_ON(1);
1721                         return -1;
1722                 }
1723                 if (arg != 0)
1724                         sbi->s_mount_opt |= m->mount_opt;
1725                 else
1726                         sbi->s_mount_opt &= ~m->mount_opt;
1727         }
1728         return 1;
1729 }
1730
1731 static int parse_options(char *options, struct super_block *sb,
1732                          unsigned long *journal_devnum,
1733                          unsigned int *journal_ioprio,
1734                          int is_remount)
1735 {
1736         struct ext4_sb_info *sbi = EXT4_SB(sb);
1737         char *p;
1738         substring_t args[MAX_OPT_ARGS];
1739         int token;
1740
1741         if (!options)
1742                 return 1;
1743
1744         while ((p = strsep(&options, ",")) != NULL) {
1745                 if (!*p)
1746                         continue;
1747                 /*
1748                  * Initialize args struct so we know whether arg was
1749                  * found; some options take optional arguments.
1750                  */
1751                 args[0].to = args[0].from = NULL;
1752                 token = match_token(p, tokens, args);
1753                 if (handle_mount_opt(sb, p, token, args, journal_devnum,
1754                                      journal_ioprio, is_remount) < 0)
1755                         return 0;
1756         }
1757 #ifdef CONFIG_QUOTA
1758         if (ext4_has_feature_quota(sb) &&
1759             (test_opt(sb, USRQUOTA) || test_opt(sb, GRPQUOTA))) {
1760                 ext4_msg(sb, KERN_INFO, "Quota feature enabled, usrquota and grpquota "
1761                          "mount options ignored.");
1762                 clear_opt(sb, USRQUOTA);
1763                 clear_opt(sb, GRPQUOTA);
1764         } else if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1765                 if (test_opt(sb, USRQUOTA) && sbi->s_qf_names[USRQUOTA])
1766                         clear_opt(sb, USRQUOTA);
1767
1768                 if (test_opt(sb, GRPQUOTA) && sbi->s_qf_names[GRPQUOTA])
1769                         clear_opt(sb, GRPQUOTA);
1770
1771                 if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
1772                         ext4_msg(sb, KERN_ERR, "old and new quota "
1773                                         "format mixing");
1774                         return 0;
1775                 }
1776
1777                 if (!sbi->s_jquota_fmt) {
1778                         ext4_msg(sb, KERN_ERR, "journaled quota format "
1779                                         "not specified");
1780                         return 0;
1781                 }
1782         }
1783 #endif
1784         if (test_opt(sb, DIOREAD_NOLOCK)) {
1785                 int blocksize =
1786                         BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
1787
1788                 if (blocksize < PAGE_SIZE) {
1789                         ext4_msg(sb, KERN_ERR, "can't mount with "
1790                                  "dioread_nolock if block size != PAGE_SIZE");
1791                         return 0;
1792                 }
1793         }
1794         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
1795             test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
1796                 ext4_msg(sb, KERN_ERR, "can't mount with journal_async_commit "
1797                          "in data=ordered mode");
1798                 return 0;
1799         }
1800         return 1;
1801 }
1802
1803 static inline void ext4_show_quota_options(struct seq_file *seq,
1804                                            struct super_block *sb)
1805 {
1806 #if defined(CONFIG_QUOTA)
1807         struct ext4_sb_info *sbi = EXT4_SB(sb);
1808
1809         if (sbi->s_jquota_fmt) {
1810                 char *fmtname = "";
1811
1812                 switch (sbi->s_jquota_fmt) {
1813                 case QFMT_VFS_OLD:
1814                         fmtname = "vfsold";
1815                         break;
1816                 case QFMT_VFS_V0:
1817                         fmtname = "vfsv0";
1818                         break;
1819                 case QFMT_VFS_V1:
1820                         fmtname = "vfsv1";
1821                         break;
1822                 }
1823                 seq_printf(seq, ",jqfmt=%s", fmtname);
1824         }
1825
1826         if (sbi->s_qf_names[USRQUOTA])
1827                 seq_show_option(seq, "usrjquota", sbi->s_qf_names[USRQUOTA]);
1828
1829         if (sbi->s_qf_names[GRPQUOTA])
1830                 seq_show_option(seq, "grpjquota", sbi->s_qf_names[GRPQUOTA]);
1831 #endif
1832 }
1833
1834 static const char *token2str(int token)
1835 {
1836         const struct match_token *t;
1837
1838         for (t = tokens; t->token != Opt_err; t++)
1839                 if (t->token == token && !strchr(t->pattern, '='))
1840                         break;
1841         return t->pattern;
1842 }
1843
1844 /*
1845  * Show an option if
1846  *  - it's set to a non-default value OR
1847  *  - if the per-sb default is different from the global default
1848  */
1849 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
1850                               int nodefs)
1851 {
1852         struct ext4_sb_info *sbi = EXT4_SB(sb);
1853         struct ext4_super_block *es = sbi->s_es;
1854         int def_errors, def_mount_opt = nodefs ? 0 : sbi->s_def_mount_opt;
1855         const struct mount_opts *m;
1856         char sep = nodefs ? '\n' : ',';
1857
1858 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
1859 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
1860
1861         if (sbi->s_sb_block != 1)
1862                 SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
1863
1864         for (m = ext4_mount_opts; m->token != Opt_err; m++) {
1865                 int want_set = m->flags & MOPT_SET;
1866                 if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
1867                     (m->flags & MOPT_CLEAR_ERR))
1868                         continue;
1869                 if (!(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
1870                         continue; /* skip if same as the default */
1871                 if ((want_set &&
1872                      (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
1873                     (!want_set && (sbi->s_mount_opt & m->mount_opt)))
1874                         continue; /* select Opt_noFoo vs Opt_Foo */
1875                 SEQ_OPTS_PRINT("%s", token2str(m->token));
1876         }
1877
1878         if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
1879             le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
1880                 SEQ_OPTS_PRINT("resuid=%u",
1881                                 from_kuid_munged(&init_user_ns, sbi->s_resuid));
1882         if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
1883             le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
1884                 SEQ_OPTS_PRINT("resgid=%u",
1885                                 from_kgid_munged(&init_user_ns, sbi->s_resgid));
1886         def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
1887         if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
1888                 SEQ_OPTS_PUTS("errors=remount-ro");
1889         if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
1890                 SEQ_OPTS_PUTS("errors=continue");
1891         if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
1892                 SEQ_OPTS_PUTS("errors=panic");
1893         if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
1894                 SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
1895         if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
1896                 SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
1897         if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
1898                 SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
1899         if (sb->s_flags & MS_I_VERSION)
1900                 SEQ_OPTS_PUTS("i_version");
1901         if (nodefs || sbi->s_stripe)
1902                 SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
1903         if (EXT4_MOUNT_DATA_FLAGS & (sbi->s_mount_opt ^ def_mount_opt)) {
1904                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
1905                         SEQ_OPTS_PUTS("data=journal");
1906                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
1907                         SEQ_OPTS_PUTS("data=ordered");
1908                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
1909                         SEQ_OPTS_PUTS("data=writeback");
1910         }
1911         if (nodefs ||
1912             sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
1913                 SEQ_OPTS_PRINT("inode_readahead_blks=%u",
1914                                sbi->s_inode_readahead_blks);
1915
1916         if (nodefs || (test_opt(sb, INIT_INODE_TABLE) &&
1917                        (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
1918                 SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
1919         if (nodefs || sbi->s_max_dir_size_kb)
1920                 SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
1921         if (test_opt(sb, DATA_ERR_ABORT))
1922                 SEQ_OPTS_PUTS("data_err=abort");
1923
1924         ext4_show_quota_options(seq, sb);
1925         return 0;
1926 }
1927
1928 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
1929 {
1930         return _ext4_show_options(seq, root->d_sb, 0);
1931 }
1932
1933 int ext4_seq_options_show(struct seq_file *seq, void *offset)
1934 {
1935         struct super_block *sb = seq->private;
1936         int rc;
1937
1938         seq_puts(seq, (sb->s_flags & MS_RDONLY) ? "ro" : "rw");
1939         rc = _ext4_show_options(seq, sb, 1);
1940         seq_puts(seq, "\n");
1941         return rc;
1942 }
1943
1944 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
1945                             int read_only)
1946 {
1947         struct ext4_sb_info *sbi = EXT4_SB(sb);
1948         int res = 0;
1949
1950         if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
1951                 ext4_msg(sb, KERN_ERR, "revision level too high, "
1952                          "forcing read-only mode");
1953                 res = MS_RDONLY;
1954         }
1955         if (read_only)
1956                 goto done;
1957         if (!(sbi->s_mount_state & EXT4_VALID_FS))
1958                 ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
1959                          "running e2fsck is recommended");
1960         else if (sbi->s_mount_state & EXT4_ERROR_FS)
1961                 ext4_msg(sb, KERN_WARNING,
1962                          "warning: mounting fs with errors, "
1963                          "running e2fsck is recommended");
1964         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
1965                  le16_to_cpu(es->s_mnt_count) >=
1966                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
1967                 ext4_msg(sb, KERN_WARNING,
1968                          "warning: maximal mount count reached, "
1969                          "running e2fsck is recommended");
1970         else if (le32_to_cpu(es->s_checkinterval) &&
1971                 (le32_to_cpu(es->s_lastcheck) +
1972                         le32_to_cpu(es->s_checkinterval) <= get_seconds()))
1973                 ext4_msg(sb, KERN_WARNING,
1974                          "warning: checktime reached, "
1975                          "running e2fsck is recommended");
1976         if (!sbi->s_journal)
1977                 es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
1978         if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
1979                 es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
1980         le16_add_cpu(&es->s_mnt_count, 1);
1981         es->s_mtime = cpu_to_le32(get_seconds());
1982         ext4_update_dynamic_rev(sb);
1983         if (sbi->s_journal)
1984                 ext4_set_feature_journal_needs_recovery(sb);
1985
1986         ext4_commit_super(sb, 1);
1987 done:
1988         if (test_opt(sb, DEBUG))
1989                 printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
1990                                 "bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
1991                         sb->s_blocksize,
1992                         sbi->s_groups_count,
1993                         EXT4_BLOCKS_PER_GROUP(sb),
1994                         EXT4_INODES_PER_GROUP(sb),
1995                         sbi->s_mount_opt, sbi->s_mount_opt2);
1996
1997         cleancache_init_fs(sb);
1998         return res;
1999 }
2000
2001 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
2002 {
2003         struct ext4_sb_info *sbi = EXT4_SB(sb);
2004         struct flex_groups *new_groups;
2005         int size;
2006
2007         if (!sbi->s_log_groups_per_flex)
2008                 return 0;
2009
2010         size = ext4_flex_group(sbi, ngroup - 1) + 1;
2011         if (size <= sbi->s_flex_groups_allocated)
2012                 return 0;
2013
2014         size = roundup_pow_of_two(size * sizeof(struct flex_groups));
2015         new_groups = ext4_kvzalloc(size, GFP_KERNEL);
2016         if (!new_groups) {
2017                 ext4_msg(sb, KERN_ERR, "not enough memory for %d flex groups",
2018                          size / (int) sizeof(struct flex_groups));
2019                 return -ENOMEM;
2020         }
2021
2022         if (sbi->s_flex_groups) {
2023                 memcpy(new_groups, sbi->s_flex_groups,
2024                        (sbi->s_flex_groups_allocated *
2025                         sizeof(struct flex_groups)));
2026                 kvfree(sbi->s_flex_groups);
2027         }
2028         sbi->s_flex_groups = new_groups;
2029         sbi->s_flex_groups_allocated = size / sizeof(struct flex_groups);
2030         return 0;
2031 }
2032
2033 static int ext4_fill_flex_info(struct super_block *sb)
2034 {
2035         struct ext4_sb_info *sbi = EXT4_SB(sb);
2036         struct ext4_group_desc *gdp = NULL;
2037         ext4_group_t flex_group;
2038         int i, err;
2039
2040         sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
2041         if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
2042                 sbi->s_log_groups_per_flex = 0;
2043                 return 1;
2044         }
2045
2046         err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
2047         if (err)
2048                 goto failed;
2049
2050         for (i = 0; i < sbi->s_groups_count; i++) {
2051                 gdp = ext4_get_group_desc(sb, i, NULL);
2052
2053                 flex_group = ext4_flex_group(sbi, i);
2054                 atomic_add(ext4_free_inodes_count(sb, gdp),
2055                            &sbi->s_flex_groups[flex_group].free_inodes);
2056                 atomic64_add(ext4_free_group_clusters(sb, gdp),
2057                              &sbi->s_flex_groups[flex_group].free_clusters);
2058                 atomic_add(ext4_used_dirs_count(sb, gdp),
2059                            &sbi->s_flex_groups[flex_group].used_dirs);
2060         }
2061
2062         return 1;
2063 failed:
2064         return 0;
2065 }
2066
2067 static __le16 ext4_group_desc_csum(struct super_block *sb, __u32 block_group,
2068                                    struct ext4_group_desc *gdp)
2069 {
2070         int offset;
2071         __u16 crc = 0;
2072         __le32 le_group = cpu_to_le32(block_group);
2073         struct ext4_sb_info *sbi = EXT4_SB(sb);
2074
2075         if (ext4_has_metadata_csum(sbi->s_sb)) {
2076                 /* Use new metadata_csum algorithm */
2077                 __le16 save_csum;
2078                 __u32 csum32;
2079
2080                 save_csum = gdp->bg_checksum;
2081                 gdp->bg_checksum = 0;
2082                 csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
2083                                      sizeof(le_group));
2084                 csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp,
2085                                      sbi->s_desc_size);
2086                 gdp->bg_checksum = save_csum;
2087
2088                 crc = csum32 & 0xFFFF;
2089                 goto out;
2090         }
2091
2092         /* old crc16 code */
2093         if (!ext4_has_feature_gdt_csum(sb))
2094                 return 0;
2095
2096         offset = offsetof(struct ext4_group_desc, bg_checksum);
2097
2098         crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2099         crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2100         crc = crc16(crc, (__u8 *)gdp, offset);
2101         offset += sizeof(gdp->bg_checksum); /* skip checksum */
2102         /* for checksum of struct ext4_group_desc do the rest...*/
2103         if (ext4_has_feature_64bit(sb) &&
2104             offset < le16_to_cpu(sbi->s_es->s_desc_size))
2105                 crc = crc16(crc, (__u8 *)gdp + offset,
2106                             le16_to_cpu(sbi->s_es->s_desc_size) -
2107                                 offset);
2108
2109 out:
2110         return cpu_to_le16(crc);
2111 }
2112
2113 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2114                                 struct ext4_group_desc *gdp)
2115 {
2116         if (ext4_has_group_desc_csum(sb) &&
2117             (gdp->bg_checksum != ext4_group_desc_csum(sb, block_group, gdp)))
2118                 return 0;
2119
2120         return 1;
2121 }
2122
2123 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2124                               struct ext4_group_desc *gdp)
2125 {
2126         if (!ext4_has_group_desc_csum(sb))
2127                 return;
2128         gdp->bg_checksum = ext4_group_desc_csum(sb, block_group, gdp);
2129 }
2130
2131 /* Called at mount-time, super-block is locked */
2132 static int ext4_check_descriptors(struct super_block *sb,
2133                                   ext4_group_t *first_not_zeroed)
2134 {
2135         struct ext4_sb_info *sbi = EXT4_SB(sb);
2136         ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2137         ext4_fsblk_t last_block;
2138         ext4_fsblk_t block_bitmap;
2139         ext4_fsblk_t inode_bitmap;
2140         ext4_fsblk_t inode_table;
2141         int flexbg_flag = 0;
2142         ext4_group_t i, grp = sbi->s_groups_count;
2143
2144         if (ext4_has_feature_flex_bg(sb))
2145                 flexbg_flag = 1;
2146
2147         ext4_debug("Checking group descriptors");
2148
2149         for (i = 0; i < sbi->s_groups_count; i++) {
2150                 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2151
2152                 if (i == sbi->s_groups_count - 1 || flexbg_flag)
2153                         last_block = ext4_blocks_count(sbi->s_es) - 1;
2154                 else
2155                         last_block = first_block +
2156                                 (EXT4_BLOCKS_PER_GROUP(sb) - 1);
2157
2158                 if ((grp == sbi->s_groups_count) &&
2159                    !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2160                         grp = i;
2161
2162                 block_bitmap = ext4_block_bitmap(sb, gdp);
2163                 if (block_bitmap < first_block || block_bitmap > last_block) {
2164                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2165                                "Block bitmap for group %u not in group "
2166                                "(block %llu)!", i, block_bitmap);
2167                         return 0;
2168                 }
2169                 inode_bitmap = ext4_inode_bitmap(sb, gdp);
2170                 if (inode_bitmap < first_block || inode_bitmap > last_block) {
2171                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2172                                "Inode bitmap for group %u not in group "
2173                                "(block %llu)!", i, inode_bitmap);
2174                         return 0;
2175                 }
2176                 inode_table = ext4_inode_table(sb, gdp);
2177                 if (inode_table < first_block ||
2178                     inode_table + sbi->s_itb_per_group - 1 > last_block) {
2179                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2180                                "Inode table for group %u not in group "
2181                                "(block %llu)!", i, inode_table);
2182                         return 0;
2183                 }
2184                 ext4_lock_group(sb, i);
2185                 if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2186                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2187                                  "Checksum for group %u failed (%u!=%u)",
2188                                  i, le16_to_cpu(ext4_group_desc_csum(sb, i,
2189                                      gdp)), le16_to_cpu(gdp->bg_checksum));
2190                         if (!(sb->s_flags & MS_RDONLY)) {
2191                                 ext4_unlock_group(sb, i);
2192                                 return 0;
2193                         }
2194                 }
2195                 ext4_unlock_group(sb, i);
2196                 if (!flexbg_flag)
2197                         first_block += EXT4_BLOCKS_PER_GROUP(sb);
2198         }
2199         if (NULL != first_not_zeroed)
2200                 *first_not_zeroed = grp;
2201         return 1;
2202 }
2203
2204 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2205  * the superblock) which were deleted from all directories, but held open by
2206  * a process at the time of a crash.  We walk the list and try to delete these
2207  * inodes at recovery time (only with a read-write filesystem).
2208  *
2209  * In order to keep the orphan inode chain consistent during traversal (in
2210  * case of crash during recovery), we link each inode into the superblock
2211  * orphan list_head and handle it the same way as an inode deletion during
2212  * normal operation (which journals the operations for us).
2213  *
2214  * We only do an iget() and an iput() on each inode, which is very safe if we
2215  * accidentally point at an in-use or already deleted inode.  The worst that
2216  * can happen in this case is that we get a "bit already cleared" message from
2217  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2218  * e2fsck was run on this filesystem, and it must have already done the orphan
2219  * inode cleanup for us, so we can safely abort without any further action.
2220  */
2221 static void ext4_orphan_cleanup(struct super_block *sb,
2222                                 struct ext4_super_block *es)
2223 {
2224         unsigned int s_flags = sb->s_flags;
2225         int nr_orphans = 0, nr_truncates = 0;
2226 #ifdef CONFIG_QUOTA
2227         int i;
2228 #endif
2229         if (!es->s_last_orphan) {
2230                 jbd_debug(4, "no orphan inodes to clean up\n");
2231                 return;
2232         }
2233
2234         if (bdev_read_only(sb->s_bdev)) {
2235                 ext4_msg(sb, KERN_ERR, "write access "
2236                         "unavailable, skipping orphan cleanup");
2237                 return;
2238         }
2239
2240         /* Check if feature set would not allow a r/w mount */
2241         if (!ext4_feature_set_ok(sb, 0)) {
2242                 ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2243                          "unknown ROCOMPAT features");
2244                 return;
2245         }
2246
2247         if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2248                 /* don't clear list on RO mount w/ errors */
2249                 if (es->s_last_orphan && !(s_flags & MS_RDONLY)) {
2250                         ext4_msg(sb, KERN_INFO, "Errors on filesystem, "
2251                                   "clearing orphan list.\n");
2252                         es->s_last_orphan = 0;
2253                 }
2254                 jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2255                 return;
2256         }
2257
2258         if (s_flags & MS_RDONLY) {
2259                 ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2260                 sb->s_flags &= ~MS_RDONLY;
2261         }
2262 #ifdef CONFIG_QUOTA
2263         /* Needed for iput() to work correctly and not trash data */
2264         sb->s_flags |= MS_ACTIVE;
2265         /* Turn on quotas so that they are updated correctly */
2266         for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2267                 if (EXT4_SB(sb)->s_qf_names[i]) {
2268                         int ret = ext4_quota_on_mount(sb, i);
2269                         if (ret < 0)
2270                                 ext4_msg(sb, KERN_ERR,
2271                                         "Cannot turn on journaled "
2272                                         "quota: error %d", ret);
2273                 }
2274         }
2275 #endif
2276
2277         while (es->s_last_orphan) {
2278                 struct inode *inode;
2279
2280                 inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2281                 if (IS_ERR(inode)) {
2282                         es->s_last_orphan = 0;
2283                         break;
2284                 }
2285
2286                 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2287                 dquot_initialize(inode);
2288                 if (inode->i_nlink) {
2289                         if (test_opt(sb, DEBUG))
2290                                 ext4_msg(sb, KERN_DEBUG,
2291                                         "%s: truncating inode %lu to %lld bytes",
2292                                         __func__, inode->i_ino, inode->i_size);
2293                         jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2294                                   inode->i_ino, inode->i_size);
2295                         inode_lock(inode);
2296                         truncate_inode_pages(inode->i_mapping, inode->i_size);
2297                         ext4_truncate(inode);
2298                         inode_unlock(inode);
2299                         nr_truncates++;
2300                 } else {
2301                         if (test_opt(sb, DEBUG))
2302                                 ext4_msg(sb, KERN_DEBUG,
2303                                         "%s: deleting unreferenced inode %lu",
2304                                         __func__, inode->i_ino);
2305                         jbd_debug(2, "deleting unreferenced inode %lu\n",
2306                                   inode->i_ino);
2307                         nr_orphans++;
2308                 }
2309                 iput(inode);  /* The delete magic happens here! */
2310         }
2311
2312 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2313
2314         if (nr_orphans)
2315                 ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2316                        PLURAL(nr_orphans));
2317         if (nr_truncates)
2318                 ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2319                        PLURAL(nr_truncates));
2320 #ifdef CONFIG_QUOTA
2321         /* Turn quotas off */
2322         for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2323                 if (sb_dqopt(sb)->files[i])
2324                         dquot_quota_off(sb, i);
2325         }
2326 #endif
2327         sb->s_flags = s_flags; /* Restore MS_RDONLY status */
2328 }
2329
2330 /*
2331  * Maximal extent format file size.
2332  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2333  * extent format containers, within a sector_t, and within i_blocks
2334  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2335  * so that won't be a limiting factor.
2336  *
2337  * However there is other limiting factor. We do store extents in the form
2338  * of starting block and length, hence the resulting length of the extent
2339  * covering maximum file size must fit into on-disk format containers as
2340  * well. Given that length is always by 1 unit bigger than max unit (because
2341  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2342  *
2343  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2344  */
2345 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2346 {
2347         loff_t res;
2348         loff_t upper_limit = MAX_LFS_FILESIZE;
2349
2350         /* small i_blocks in vfs inode? */
2351         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2352                 /*
2353                  * CONFIG_LBDAF is not enabled implies the inode
2354                  * i_block represent total blocks in 512 bytes
2355                  * 32 == size of vfs inode i_blocks * 8
2356                  */
2357                 upper_limit = (1LL << 32) - 1;
2358
2359                 /* total blocks in file system block size */
2360                 upper_limit >>= (blkbits - 9);
2361                 upper_limit <<= blkbits;
2362         }
2363
2364         /*
2365          * 32-bit extent-start container, ee_block. We lower the maxbytes
2366          * by one fs block, so ee_len can cover the extent of maximum file
2367          * size
2368          */
2369         res = (1LL << 32) - 1;
2370         res <<= blkbits;
2371
2372         /* Sanity check against vm- & vfs- imposed limits */
2373         if (res > upper_limit)
2374                 res = upper_limit;
2375
2376         return res;
2377 }
2378
2379 /*
2380  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2381  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2382  * We need to be 1 filesystem block less than the 2^48 sector limit.
2383  */
2384 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2385 {
2386         loff_t res = EXT4_NDIR_BLOCKS;
2387         int meta_blocks;
2388         loff_t upper_limit;
2389         /* This is calculated to be the largest file size for a dense, block
2390          * mapped file such that the file's total number of 512-byte sectors,
2391          * including data and all indirect blocks, does not exceed (2^48 - 1).
2392          *
2393          * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2394          * number of 512-byte sectors of the file.
2395          */
2396
2397         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2398                 /*
2399                  * !has_huge_files or CONFIG_LBDAF not enabled implies that
2400                  * the inode i_block field represents total file blocks in
2401                  * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2402                  */
2403                 upper_limit = (1LL << 32) - 1;
2404
2405                 /* total blocks in file system block size */
2406                 upper_limit >>= (bits - 9);
2407
2408         } else {
2409                 /*
2410                  * We use 48 bit ext4_inode i_blocks
2411                  * With EXT4_HUGE_FILE_FL set the i_blocks
2412                  * represent total number of blocks in
2413                  * file system block size
2414                  */
2415                 upper_limit = (1LL << 48) - 1;
2416
2417         }
2418
2419         /* indirect blocks */
2420         meta_blocks = 1;
2421         /* double indirect blocks */
2422         meta_blocks += 1 + (1LL << (bits-2));
2423         /* tripple indirect blocks */
2424         meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2425
2426         upper_limit -= meta_blocks;
2427         upper_limit <<= bits;
2428
2429         res += 1LL << (bits-2);
2430         res += 1LL << (2*(bits-2));
2431         res += 1LL << (3*(bits-2));
2432         res <<= bits;
2433         if (res > upper_limit)
2434                 res = upper_limit;
2435
2436         if (res > MAX_LFS_FILESIZE)
2437                 res = MAX_LFS_FILESIZE;
2438
2439         return res;
2440 }
2441
2442 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2443                                    ext4_fsblk_t logical_sb_block, int nr)
2444 {
2445         struct ext4_sb_info *sbi = EXT4_SB(sb);
2446         ext4_group_t bg, first_meta_bg;
2447         int has_super = 0;
2448
2449         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2450
2451         if (!ext4_has_feature_meta_bg(sb) || nr < first_meta_bg)
2452                 return logical_sb_block + nr + 1;
2453         bg = sbi->s_desc_per_block * nr;
2454         if (ext4_bg_has_super(sb, bg))
2455                 has_super = 1;
2456
2457         /*
2458          * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
2459          * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
2460          * on modern mke2fs or blksize > 1k on older mke2fs) then we must
2461          * compensate.
2462          */
2463         if (sb->s_blocksize == 1024 && nr == 0 &&
2464             le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block) == 0)
2465                 has_super++;
2466
2467         return (has_super + ext4_group_first_block_no(sb, bg));
2468 }
2469
2470 /**
2471  * ext4_get_stripe_size: Get the stripe size.
2472  * @sbi: In memory super block info
2473  *
2474  * If we have specified it via mount option, then
2475  * use the mount option value. If the value specified at mount time is
2476  * greater than the blocks per group use the super block value.
2477  * If the super block value is greater than blocks per group return 0.
2478  * Allocator needs it be less than blocks per group.
2479  *
2480  */
2481 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2482 {
2483         unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2484         unsigned long stripe_width =
2485                         le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2486         int ret;
2487
2488         if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2489                 ret = sbi->s_stripe;
2490         else if (stripe_width <= sbi->s_blocks_per_group)
2491                 ret = stripe_width;
2492         else if (stride <= sbi->s_blocks_per_group)
2493                 ret = stride;
2494         else
2495                 ret = 0;
2496
2497         /*
2498          * If the stripe width is 1, this makes no sense and
2499          * we set it to 0 to turn off stripe handling code.
2500          */
2501         if (ret <= 1)
2502                 ret = 0;
2503
2504         return ret;
2505 }
2506
2507 /*
2508  * Check whether this filesystem can be mounted based on
2509  * the features present and the RDONLY/RDWR mount requested.
2510  * Returns 1 if this filesystem can be mounted as requested,
2511  * 0 if it cannot be.
2512  */
2513 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2514 {
2515         if (ext4_has_unknown_ext4_incompat_features(sb)) {
2516                 ext4_msg(sb, KERN_ERR,
2517                         "Couldn't mount because of "
2518                         "unsupported optional features (%x)",
2519                         (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2520                         ~EXT4_FEATURE_INCOMPAT_SUPP));
2521                 return 0;
2522         }
2523
2524         if (readonly)
2525                 return 1;
2526
2527         if (ext4_has_feature_readonly(sb)) {
2528                 ext4_msg(sb, KERN_INFO, "filesystem is read-only");
2529                 sb->s_flags |= MS_RDONLY;
2530                 return 1;
2531         }
2532
2533         /* Check that feature set is OK for a read-write mount */
2534         if (ext4_has_unknown_ext4_ro_compat_features(sb)) {
2535                 ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2536                          "unsupported optional features (%x)",
2537                          (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2538                                 ~EXT4_FEATURE_RO_COMPAT_SUPP));
2539                 return 0;
2540         }
2541         /*
2542          * Large file size enabled file system can only be mounted
2543          * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2544          */
2545         if (ext4_has_feature_huge_file(sb)) {
2546                 if (sizeof(blkcnt_t) < sizeof(u64)) {
2547                         ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2548                                  "cannot be mounted RDWR without "
2549                                  "CONFIG_LBDAF");
2550                         return 0;
2551                 }
2552         }
2553         if (ext4_has_feature_bigalloc(sb) && !ext4_has_feature_extents(sb)) {
2554                 ext4_msg(sb, KERN_ERR,
2555                          "Can't support bigalloc feature without "
2556                          "extents feature\n");
2557                 return 0;
2558         }
2559
2560 #ifndef CONFIG_QUOTA
2561         if (ext4_has_feature_quota(sb) && !readonly) {
2562                 ext4_msg(sb, KERN_ERR,
2563                          "Filesystem with quota feature cannot be mounted RDWR "
2564                          "without CONFIG_QUOTA");
2565                 return 0;
2566         }
2567         if (ext4_has_feature_project(sb) && !readonly) {
2568                 ext4_msg(sb, KERN_ERR,
2569                          "Filesystem with project quota feature cannot be mounted RDWR "
2570                          "without CONFIG_QUOTA");
2571                 return 0;
2572         }
2573 #endif  /* CONFIG_QUOTA */
2574         return 1;
2575 }
2576
2577 /*
2578  * This function is called once a day if we have errors logged
2579  * on the file system
2580  */
2581 static void print_daily_error_info(unsigned long arg)
2582 {
2583         struct super_block *sb = (struct super_block *) arg;
2584         struct ext4_sb_info *sbi;
2585         struct ext4_super_block *es;
2586
2587         sbi = EXT4_SB(sb);
2588         es = sbi->s_es;
2589
2590         if (es->s_error_count)
2591                 /* fsck newer than v1.41.13 is needed to clean this condition. */
2592                 ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
2593                          le32_to_cpu(es->s_error_count));
2594         if (es->s_first_error_time) {
2595                 printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %u: %.*s:%d",
2596                        sb->s_id, le32_to_cpu(es->s_first_error_time),
2597                        (int) sizeof(es->s_first_error_func),
2598                        es->s_first_error_func,
2599                        le32_to_cpu(es->s_first_error_line));
2600                 if (es->s_first_error_ino)
2601                         printk(": inode %u",
2602                                le32_to_cpu(es->s_first_error_ino));
2603                 if (es->s_first_error_block)
2604                         printk(": block %llu", (unsigned long long)
2605                                le64_to_cpu(es->s_first_error_block));
2606                 printk("\n");
2607         }
2608         if (es->s_last_error_time) {
2609                 printk(KERN_NOTICE "EXT4-fs (%s): last error at time %u: %.*s:%d",
2610                        sb->s_id, le32_to_cpu(es->s_last_error_time),
2611                        (int) sizeof(es->s_last_error_func),
2612                        es->s_last_error_func,
2613                        le32_to_cpu(es->s_last_error_line));
2614                 if (es->s_last_error_ino)
2615                         printk(": inode %u",
2616                                le32_to_cpu(es->s_last_error_ino));
2617                 if (es->s_last_error_block)
2618                         printk(": block %llu", (unsigned long long)
2619                                le64_to_cpu(es->s_last_error_block));
2620                 printk("\n");
2621         }
2622         mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2623 }
2624
2625 /* Find next suitable group and run ext4_init_inode_table */
2626 static int ext4_run_li_request(struct ext4_li_request *elr)
2627 {
2628         struct ext4_group_desc *gdp = NULL;
2629         ext4_group_t group, ngroups;
2630         struct super_block *sb;
2631         unsigned long timeout = 0;
2632         int ret = 0;
2633
2634         sb = elr->lr_super;
2635         ngroups = EXT4_SB(sb)->s_groups_count;
2636
2637         sb_start_write(sb);
2638         for (group = elr->lr_next_group; group < ngroups; group++) {
2639                 gdp = ext4_get_group_desc(sb, group, NULL);
2640                 if (!gdp) {
2641                         ret = 1;
2642                         break;
2643                 }
2644
2645                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2646                         break;
2647         }
2648
2649         if (group >= ngroups)
2650                 ret = 1;
2651
2652         if (!ret) {
2653                 timeout = jiffies;
2654                 ret = ext4_init_inode_table(sb, group,
2655                                             elr->lr_timeout ? 0 : 1);
2656                 if (elr->lr_timeout == 0) {
2657                         timeout = (jiffies - timeout) *
2658                                   elr->lr_sbi->s_li_wait_mult;
2659                         elr->lr_timeout = timeout;
2660                 }
2661                 elr->lr_next_sched = jiffies + elr->lr_timeout;
2662                 elr->lr_next_group = group + 1;
2663         }
2664         sb_end_write(sb);
2665
2666         return ret;
2667 }
2668
2669 /*
2670  * Remove lr_request from the list_request and free the
2671  * request structure. Should be called with li_list_mtx held
2672  */
2673 static void ext4_remove_li_request(struct ext4_li_request *elr)
2674 {
2675         struct ext4_sb_info *sbi;
2676
2677         if (!elr)
2678                 return;
2679
2680         sbi = elr->lr_sbi;
2681
2682         list_del(&elr->lr_request);
2683         sbi->s_li_request = NULL;
2684         kfree(elr);
2685 }
2686
2687 static void ext4_unregister_li_request(struct super_block *sb)
2688 {
2689         mutex_lock(&ext4_li_mtx);
2690         if (!ext4_li_info) {
2691                 mutex_unlock(&ext4_li_mtx);
2692                 return;
2693         }
2694
2695         mutex_lock(&ext4_li_info->li_list_mtx);
2696         ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
2697         mutex_unlock(&ext4_li_info->li_list_mtx);
2698         mutex_unlock(&ext4_li_mtx);
2699 }
2700
2701 static struct task_struct *ext4_lazyinit_task;
2702
2703 /*
2704  * This is the function where ext4lazyinit thread lives. It walks
2705  * through the request list searching for next scheduled filesystem.
2706  * When such a fs is found, run the lazy initialization request
2707  * (ext4_rn_li_request) and keep track of the time spend in this
2708  * function. Based on that time we compute next schedule time of
2709  * the request. When walking through the list is complete, compute
2710  * next waking time and put itself into sleep.
2711  */
2712 static int ext4_lazyinit_thread(void *arg)
2713 {
2714         struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
2715         struct list_head *pos, *n;
2716         struct ext4_li_request *elr;
2717         unsigned long next_wakeup, cur;
2718
2719         BUG_ON(NULL == eli);
2720
2721 cont_thread:
2722         while (true) {
2723                 next_wakeup = MAX_JIFFY_OFFSET;
2724
2725                 mutex_lock(&eli->li_list_mtx);
2726                 if (list_empty(&eli->li_request_list)) {
2727                         mutex_unlock(&eli->li_list_mtx);
2728                         goto exit_thread;
2729                 }
2730
2731                 list_for_each_safe(pos, n, &eli->li_request_list) {
2732                         elr = list_entry(pos, struct ext4_li_request,
2733                                          lr_request);
2734
2735                         if (time_after_eq(jiffies, elr->lr_next_sched)) {
2736                                 if (ext4_run_li_request(elr) != 0) {
2737                                         /* error, remove the lazy_init job */
2738                                         ext4_remove_li_request(elr);
2739                                         continue;
2740                                 }
2741                         }
2742
2743                         if (time_before(elr->lr_next_sched, next_wakeup))
2744                                 next_wakeup = elr->lr_next_sched;
2745                 }
2746                 mutex_unlock(&eli->li_list_mtx);
2747
2748                 try_to_freeze();
2749
2750                 cur = jiffies;
2751                 if ((time_after_eq(cur, next_wakeup)) ||
2752                     (MAX_JIFFY_OFFSET == next_wakeup)) {
2753                         cond_resched();
2754                         continue;
2755                 }
2756
2757                 schedule_timeout_interruptible(next_wakeup - cur);
2758
2759                 if (kthread_should_stop()) {
2760                         ext4_clear_request_list();
2761                         goto exit_thread;
2762                 }
2763         }
2764
2765 exit_thread:
2766         /*
2767          * It looks like the request list is empty, but we need
2768          * to check it under the li_list_mtx lock, to prevent any
2769          * additions into it, and of course we should lock ext4_li_mtx
2770          * to atomically free the list and ext4_li_info, because at
2771          * this point another ext4 filesystem could be registering
2772          * new one.
2773          */
2774         mutex_lock(&ext4_li_mtx);
2775         mutex_lock(&eli->li_list_mtx);
2776         if (!list_empty(&eli->li_request_list)) {
2777                 mutex_unlock(&eli->li_list_mtx);
2778                 mutex_unlock(&ext4_li_mtx);
2779                 goto cont_thread;
2780         }
2781         mutex_unlock(&eli->li_list_mtx);
2782         kfree(ext4_li_info);
2783         ext4_li_info = NULL;
2784         mutex_unlock(&ext4_li_mtx);
2785
2786         return 0;
2787 }
2788
2789 static void ext4_clear_request_list(void)
2790 {
2791         struct list_head *pos, *n;
2792         struct ext4_li_request *elr;
2793
2794         mutex_lock(&ext4_li_info->li_list_mtx);
2795         list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
2796                 elr = list_entry(pos, struct ext4_li_request,
2797                                  lr_request);
2798                 ext4_remove_li_request(elr);
2799         }
2800         mutex_unlock(&ext4_li_info->li_list_mtx);
2801 }
2802
2803 static int ext4_run_lazyinit_thread(void)
2804 {
2805         ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
2806                                          ext4_li_info, "ext4lazyinit");
2807         if (IS_ERR(ext4_lazyinit_task)) {
2808                 int err = PTR_ERR(ext4_lazyinit_task);
2809                 ext4_clear_request_list();
2810                 kfree(ext4_li_info);
2811                 ext4_li_info = NULL;
2812                 printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
2813                                  "initialization thread\n",
2814                                  err);
2815                 return err;
2816         }
2817         ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
2818         return 0;
2819 }
2820
2821 /*
2822  * Check whether it make sense to run itable init. thread or not.
2823  * If there is at least one uninitialized inode table, return
2824  * corresponding group number, else the loop goes through all
2825  * groups and return total number of groups.
2826  */
2827 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
2828 {
2829         ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
2830         struct ext4_group_desc *gdp = NULL;
2831
2832         for (group = 0; group < ngroups; group++) {
2833                 gdp = ext4_get_group_desc(sb, group, NULL);
2834                 if (!gdp)
2835                         continue;
2836
2837                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2838                         break;
2839         }
2840
2841         return group;
2842 }
2843
2844 static int ext4_li_info_new(void)
2845 {
2846         struct ext4_lazy_init *eli = NULL;
2847
2848         eli = kzalloc(sizeof(*eli), GFP_KERNEL);
2849         if (!eli)
2850                 return -ENOMEM;
2851
2852         INIT_LIST_HEAD(&eli->li_request_list);
2853         mutex_init(&eli->li_list_mtx);
2854
2855         eli->li_state |= EXT4_LAZYINIT_QUIT;
2856
2857         ext4_li_info = eli;
2858
2859         return 0;
2860 }
2861
2862 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
2863                                             ext4_group_t start)
2864 {
2865         struct ext4_sb_info *sbi = EXT4_SB(sb);
2866         struct ext4_li_request *elr;
2867
2868         elr = kzalloc(sizeof(*elr), GFP_KERNEL);
2869         if (!elr)
2870                 return NULL;
2871
2872         elr->lr_super = sb;
2873         elr->lr_sbi = sbi;
2874         elr->lr_next_group = start;
2875
2876         /*
2877          * Randomize first schedule time of the request to
2878          * spread the inode table initialization requests
2879          * better.
2880          */
2881         elr->lr_next_sched = jiffies + (prandom_u32() %
2882                                 (EXT4_DEF_LI_MAX_START_DELAY * HZ));
2883         return elr;
2884 }
2885
2886 int ext4_register_li_request(struct super_block *sb,
2887                              ext4_group_t first_not_zeroed)
2888 {
2889         struct ext4_sb_info *sbi = EXT4_SB(sb);
2890         struct ext4_li_request *elr = NULL;
2891         ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
2892         int ret = 0;
2893
2894         mutex_lock(&ext4_li_mtx);
2895         if (sbi->s_li_request != NULL) {
2896                 /*
2897                  * Reset timeout so it can be computed again, because
2898                  * s_li_wait_mult might have changed.
2899                  */
2900                 sbi->s_li_request->lr_timeout = 0;
2901                 goto out;
2902         }
2903
2904         if (first_not_zeroed == ngroups ||
2905             (sb->s_flags & MS_RDONLY) ||
2906             !test_opt(sb, INIT_INODE_TABLE))
2907                 goto out;
2908
2909         elr = ext4_li_request_new(sb, first_not_zeroed);
2910         if (!elr) {
2911                 ret = -ENOMEM;
2912                 goto out;
2913         }
2914
2915         if (NULL == ext4_li_info) {
2916                 ret = ext4_li_info_new();
2917                 if (ret)
2918                         goto out;
2919         }
2920
2921         mutex_lock(&ext4_li_info->li_list_mtx);
2922         list_add(&elr->lr_request, &ext4_li_info->li_request_list);
2923         mutex_unlock(&ext4_li_info->li_list_mtx);
2924
2925         sbi->s_li_request = elr;
2926         /*
2927          * set elr to NULL here since it has been inserted to
2928          * the request_list and the removal and free of it is
2929          * handled by ext4_clear_request_list from now on.
2930          */
2931         elr = NULL;
2932
2933         if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
2934                 ret = ext4_run_lazyinit_thread();
2935                 if (ret)
2936                         goto out;
2937         }
2938 out:
2939         mutex_unlock(&ext4_li_mtx);
2940         if (ret)
2941                 kfree(elr);
2942         return ret;
2943 }
2944
2945 /*
2946  * We do not need to lock anything since this is called on
2947  * module unload.
2948  */
2949 static void ext4_destroy_lazyinit_thread(void)
2950 {
2951         /*
2952          * If thread exited earlier
2953          * there's nothing to be done.
2954          */
2955         if (!ext4_li_info || !ext4_lazyinit_task)
2956                 return;
2957
2958         kthread_stop(ext4_lazyinit_task);
2959 }
2960
2961 static int set_journal_csum_feature_set(struct super_block *sb)
2962 {
2963         int ret = 1;
2964         int compat, incompat;
2965         struct ext4_sb_info *sbi = EXT4_SB(sb);
2966
2967         if (ext4_has_metadata_csum(sb)) {
2968                 /* journal checksum v3 */
2969                 compat = 0;
2970                 incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
2971         } else {
2972                 /* journal checksum v1 */
2973                 compat = JBD2_FEATURE_COMPAT_CHECKSUM;
2974                 incompat = 0;
2975         }
2976
2977         jbd2_journal_clear_features(sbi->s_journal,
2978                         JBD2_FEATURE_COMPAT_CHECKSUM, 0,
2979                         JBD2_FEATURE_INCOMPAT_CSUM_V3 |
2980                         JBD2_FEATURE_INCOMPAT_CSUM_V2);
2981         if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
2982                 ret = jbd2_journal_set_features(sbi->s_journal,
2983                                 compat, 0,
2984                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
2985                                 incompat);
2986         } else if (test_opt(sb, JOURNAL_CHECKSUM)) {
2987                 ret = jbd2_journal_set_features(sbi->s_journal,
2988                                 compat, 0,
2989                                 incompat);
2990                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
2991                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
2992         } else {
2993                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
2994                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
2995         }
2996
2997         return ret;
2998 }
2999
3000 /*
3001  * Note: calculating the overhead so we can be compatible with
3002  * historical BSD practice is quite difficult in the face of
3003  * clusters/bigalloc.  This is because multiple metadata blocks from
3004  * different block group can end up in the same allocation cluster.
3005  * Calculating the exact overhead in the face of clustered allocation
3006  * requires either O(all block bitmaps) in memory or O(number of block
3007  * groups**2) in time.  We will still calculate the superblock for
3008  * older file systems --- and if we come across with a bigalloc file
3009  * system with zero in s_overhead_clusters the estimate will be close to
3010  * correct especially for very large cluster sizes --- but for newer
3011  * file systems, it's better to calculate this figure once at mkfs
3012  * time, and store it in the superblock.  If the superblock value is
3013  * present (even for non-bigalloc file systems), we will use it.
3014  */
3015 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3016                           char *buf)
3017 {
3018         struct ext4_sb_info     *sbi = EXT4_SB(sb);
3019         struct ext4_group_desc  *gdp;
3020         ext4_fsblk_t            first_block, last_block, b;
3021         ext4_group_t            i, ngroups = ext4_get_groups_count(sb);
3022         int                     s, j, count = 0;
3023
3024         if (!ext4_has_feature_bigalloc(sb))
3025                 return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3026                         sbi->s_itb_per_group + 2);
3027
3028         first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3029                 (grp * EXT4_BLOCKS_PER_GROUP(sb));
3030         last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3031         for (i = 0; i < ngroups; i++) {
3032                 gdp = ext4_get_group_desc(sb, i, NULL);
3033                 b = ext4_block_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_bitmap(sb, gdp);
3039                 if (b >= first_block && b <= last_block) {
3040                         ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3041                         count++;
3042                 }
3043                 b = ext4_inode_table(sb, gdp);
3044                 if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3045                         for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3046                                 int c = EXT4_B2C(sbi, b - first_block);
3047                                 ext4_set_bit(c, buf);
3048                                 count++;
3049                         }
3050                 if (i != grp)
3051                         continue;
3052                 s = 0;
3053                 if (ext4_bg_has_super(sb, grp)) {
3054                         ext4_set_bit(s++, buf);
3055                         count++;
3056                 }
3057                 for (j = ext4_bg_num_gdb(sb, grp); j > 0; j--) {
3058                         ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3059                         count++;
3060                 }
3061         }
3062         if (!count)
3063                 return 0;
3064         return EXT4_CLUSTERS_PER_GROUP(sb) -
3065                 ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3066 }
3067
3068 /*
3069  * Compute the overhead and stash it in sbi->s_overhead
3070  */
3071 int ext4_calculate_overhead(struct super_block *sb)
3072 {
3073         struct ext4_sb_info *sbi = EXT4_SB(sb);
3074         struct ext4_super_block *es = sbi->s_es;
3075         ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3076         ext4_fsblk_t overhead = 0;
3077         char *buf = (char *) get_zeroed_page(GFP_NOFS);
3078
3079         if (!buf)
3080                 return -ENOMEM;
3081
3082         /*
3083          * Compute the overhead (FS structures).  This is constant
3084          * for a given filesystem unless the number of block groups
3085          * changes so we cache the previous value until it does.
3086          */
3087
3088         /*
3089          * All of the blocks before first_data_block are overhead
3090          */
3091         overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3092
3093         /*
3094          * Add the overhead found in each block group
3095          */
3096         for (i = 0; i < ngroups; i++) {
3097                 int blks;
3098
3099                 blks = count_overhead(sb, i, buf);
3100                 overhead += blks;
3101                 if (blks)
3102                         memset(buf, 0, PAGE_SIZE);
3103                 cond_resched();
3104         }
3105         /* Add the internal journal blocks as well */
3106         if (sbi->s_journal && !sbi->journal_bdev)
3107                 overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_maxlen);
3108
3109         sbi->s_overhead = overhead;
3110         smp_wmb();
3111         free_page((unsigned long) buf);
3112         return 0;
3113 }
3114
3115 static void ext4_set_resv_clusters(struct super_block *sb)
3116 {
3117         ext4_fsblk_t resv_clusters;
3118         struct ext4_sb_info *sbi = EXT4_SB(sb);
3119
3120         /*
3121          * There's no need to reserve anything when we aren't using extents.
3122          * The space estimates are exact, there are no unwritten extents,
3123          * hole punching doesn't need new metadata... This is needed especially
3124          * to keep ext2/3 backward compatibility.
3125          */
3126         if (!ext4_has_feature_extents(sb))
3127                 return;
3128         /*
3129          * By default we reserve 2% or 4096 clusters, whichever is smaller.
3130          * This should cover the situations where we can not afford to run
3131          * out of space like for example punch hole, or converting
3132          * unwritten extents in delalloc path. In most cases such
3133          * allocation would require 1, or 2 blocks, higher numbers are
3134          * very rare.
3135          */
3136         resv_clusters = (ext4_blocks_count(sbi->s_es) >>
3137                          sbi->s_cluster_bits);
3138
3139         do_div(resv_clusters, 50);
3140         resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
3141
3142         atomic64_set(&sbi->s_resv_clusters, resv_clusters);
3143 }
3144
3145 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3146 {
3147         char *orig_data = kstrdup(data, GFP_KERNEL);
3148         struct buffer_head *bh;
3149         struct ext4_super_block *es = NULL;
3150         struct ext4_sb_info *sbi;
3151         ext4_fsblk_t block;
3152         ext4_fsblk_t sb_block = get_sb_block(&data);
3153         ext4_fsblk_t logical_sb_block;
3154         unsigned long offset = 0;
3155         unsigned long journal_devnum = 0;
3156         unsigned long def_mount_opts;
3157         struct inode *root;
3158         const char *descr;
3159         int ret = -ENOMEM;
3160         int blocksize, clustersize;
3161         unsigned int db_count;
3162         unsigned int i;
3163         int needs_recovery, has_huge_files, has_bigalloc;
3164         __u64 blocks_count;
3165         int err = 0;
3166         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3167         ext4_group_t first_not_zeroed;
3168
3169         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3170         if (!sbi)
3171                 goto out_free_orig;
3172
3173         sbi->s_blockgroup_lock =
3174                 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3175         if (!sbi->s_blockgroup_lock) {
3176                 kfree(sbi);
3177                 goto out_free_orig;
3178         }
3179         sb->s_fs_info = sbi;
3180         sbi->s_sb = sb;
3181         sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3182         sbi->s_sb_block = sb_block;
3183         if (sb->s_bdev->bd_part)
3184                 sbi->s_sectors_written_start =
3185                         part_stat_read(sb->s_bdev->bd_part, sectors[1]);
3186
3187         /* Cleanup superblock name */
3188         strreplace(sb->s_id, '/', '!');
3189
3190         /* -EINVAL is default */
3191         ret = -EINVAL;
3192         blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3193         if (!blocksize) {
3194                 ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3195                 goto out_fail;
3196         }
3197
3198         /*
3199          * The ext4 superblock will not be buffer aligned for other than 1kB
3200          * block sizes.  We need to calculate the offset from buffer start.
3201          */
3202         if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3203                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3204                 offset = do_div(logical_sb_block, blocksize);
3205         } else {
3206                 logical_sb_block = sb_block;
3207         }
3208
3209         if (!(bh = sb_bread_unmovable(sb, logical_sb_block))) {
3210                 ext4_msg(sb, KERN_ERR, "unable to read superblock");
3211                 goto out_fail;
3212         }
3213         /*
3214          * Note: s_es must be initialized as soon as possible because
3215          *       some ext4 macro-instructions depend on its value
3216          */
3217         es = (struct ext4_super_block *) (bh->b_data + offset);
3218         sbi->s_es = es;
3219         sb->s_magic = le16_to_cpu(es->s_magic);
3220         if (sb->s_magic != EXT4_SUPER_MAGIC)
3221                 goto cantfind_ext4;
3222         sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3223
3224         /* Warn if metadata_csum and gdt_csum are both set. */
3225         if (ext4_has_feature_metadata_csum(sb) &&
3226             ext4_has_feature_gdt_csum(sb))
3227                 ext4_warning(sb, "metadata_csum and uninit_bg are "
3228                              "redundant flags; please run fsck.");
3229
3230         /* Check for a known checksum algorithm */
3231         if (!ext4_verify_csum_type(sb, es)) {
3232                 ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3233                          "unknown checksum algorithm.");
3234                 silent = 1;
3235                 goto cantfind_ext4;
3236         }
3237
3238         /* Load the checksum driver */
3239         if (ext4_has_feature_metadata_csum(sb)) {
3240                 sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3241                 if (IS_ERR(sbi->s_chksum_driver)) {
3242                         ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3243                         ret = PTR_ERR(sbi->s_chksum_driver);
3244                         sbi->s_chksum_driver = NULL;
3245                         goto failed_mount;
3246                 }
3247         }
3248
3249         /* Check superblock checksum */
3250         if (!ext4_superblock_csum_verify(sb, es)) {
3251                 ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3252                          "invalid superblock checksum.  Run e2fsck?");
3253                 silent = 1;
3254                 ret = -EFSBADCRC;
3255                 goto cantfind_ext4;
3256         }
3257
3258         /* Precompute checksum seed for all metadata */
3259         if (ext4_has_feature_csum_seed(sb))
3260                 sbi->s_csum_seed = le32_to_cpu(es->s_checksum_seed);
3261         else if (ext4_has_metadata_csum(sb))
3262                 sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3263                                                sizeof(es->s_uuid));
3264
3265         /* Set defaults before we parse the mount options */
3266         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3267         set_opt(sb, INIT_INODE_TABLE);
3268         if (def_mount_opts & EXT4_DEFM_DEBUG)
3269                 set_opt(sb, DEBUG);
3270         if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3271                 set_opt(sb, GRPID);
3272         if (def_mount_opts & EXT4_DEFM_UID16)
3273                 set_opt(sb, NO_UID32);
3274         /* xattr user namespace & acls are now defaulted on */
3275         set_opt(sb, XATTR_USER);
3276 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3277         set_opt(sb, POSIX_ACL);
3278 #endif
3279         /* don't forget to enable journal_csum when metadata_csum is enabled. */
3280         if (ext4_has_metadata_csum(sb))
3281                 set_opt(sb, JOURNAL_CHECKSUM);
3282
3283         if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3284                 set_opt(sb, JOURNAL_DATA);
3285         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3286                 set_opt(sb, ORDERED_DATA);
3287         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3288                 set_opt(sb, WRITEBACK_DATA);
3289
3290         if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3291                 set_opt(sb, ERRORS_PANIC);
3292         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3293                 set_opt(sb, ERRORS_CONT);
3294         else
3295                 set_opt(sb, ERRORS_RO);
3296         /* block_validity enabled by default; disable with noblock_validity */
3297         set_opt(sb, BLOCK_VALIDITY);
3298         if (def_mount_opts & EXT4_DEFM_DISCARD)
3299                 set_opt(sb, DISCARD);
3300
3301         sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3302         sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3303         sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3304         sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3305         sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3306
3307         if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3308                 set_opt(sb, BARRIER);
3309
3310         /*
3311          * enable delayed allocation by default
3312          * Use -o nodelalloc to turn it off
3313          */
3314         if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
3315             ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3316                 set_opt(sb, DELALLOC);
3317
3318         /*
3319          * set default s_li_wait_mult for lazyinit, for the case there is
3320          * no mount option specified.
3321          */
3322         sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3323
3324         if (!parse_options((char *) sbi->s_es->s_mount_opts, sb,
3325                            &journal_devnum, &journal_ioprio, 0)) {
3326                 ext4_msg(sb, KERN_WARNING,
3327                          "failed to parse options in superblock: %s",
3328                          sbi->s_es->s_mount_opts);
3329         }
3330         sbi->s_def_mount_opt = sbi->s_mount_opt;
3331         if (!parse_options((char *) data, sb, &journal_devnum,
3332                            &journal_ioprio, 0))
3333                 goto failed_mount;
3334
3335         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3336                 printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3337                             "with data=journal disables delayed "
3338                             "allocation and O_DIRECT support!\n");
3339                 if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3340                         ext4_msg(sb, KERN_ERR, "can't mount with "
3341                                  "both data=journal and delalloc");
3342                         goto failed_mount;
3343                 }
3344                 if (test_opt(sb, DIOREAD_NOLOCK)) {
3345                         ext4_msg(sb, KERN_ERR, "can't mount with "
3346                                  "both data=journal and dioread_nolock");
3347                         goto failed_mount;
3348                 }
3349                 if (test_opt(sb, DAX)) {
3350                         ext4_msg(sb, KERN_ERR, "can't mount with "
3351                                  "both data=journal and dax");
3352                         goto failed_mount;
3353                 }
3354                 if (test_opt(sb, DELALLOC))
3355                         clear_opt(sb, DELALLOC);
3356         } else {
3357                 sb->s_iflags |= SB_I_CGROUPWB;
3358         }
3359
3360         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
3361                 (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
3362
3363         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3364             (ext4_has_compat_features(sb) ||
3365              ext4_has_ro_compat_features(sb) ||
3366              ext4_has_incompat_features(sb)))
3367                 ext4_msg(sb, KERN_WARNING,
3368                        "feature flags set on rev 0 fs, "
3369                        "running e2fsck is recommended");
3370
3371         if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
3372                 set_opt2(sb, HURD_COMPAT);
3373                 if (ext4_has_feature_64bit(sb)) {
3374                         ext4_msg(sb, KERN_ERR,
3375                                  "The Hurd can't support 64-bit file systems");
3376                         goto failed_mount;
3377                 }
3378         }
3379
3380         if (IS_EXT2_SB(sb)) {
3381                 if (ext2_feature_set_ok(sb))
3382                         ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3383                                  "using the ext4 subsystem");
3384                 else {
3385                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3386                                  "to feature incompatibilities");
3387                         goto failed_mount;
3388                 }
3389         }
3390
3391         if (IS_EXT3_SB(sb)) {
3392                 if (ext3_feature_set_ok(sb))
3393                         ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3394                                  "using the ext4 subsystem");
3395                 else {
3396                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3397                                  "to feature incompatibilities");
3398                         goto failed_mount;
3399                 }
3400         }
3401
3402         /*
3403          * Check feature flags regardless of the revision level, since we
3404          * previously didn't change the revision level when setting the flags,
3405          * so there is a chance incompat flags are set on a rev 0 filesystem.
3406          */
3407         if (!ext4_feature_set_ok(sb, (sb->s_flags & MS_RDONLY)))
3408                 goto failed_mount;
3409
3410         blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3411         if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3412             blocksize > EXT4_MAX_BLOCK_SIZE) {
3413                 ext4_msg(sb, KERN_ERR,
3414                        "Unsupported filesystem blocksize %d", blocksize);
3415                 goto failed_mount;
3416         }
3417
3418         if (sbi->s_mount_opt & EXT4_MOUNT_DAX) {
3419                 if (blocksize != PAGE_SIZE) {
3420                         ext4_msg(sb, KERN_ERR,
3421                                         "error: unsupported blocksize for dax");
3422                         goto failed_mount;
3423                 }
3424                 if (!sb->s_bdev->bd_disk->fops->direct_access) {
3425                         ext4_msg(sb, KERN_ERR,
3426                                         "error: device does not support dax");
3427                         goto failed_mount;
3428                 }
3429         }
3430
3431         if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) {
3432                 ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
3433                          es->s_encryption_level);
3434                 goto failed_mount;
3435         }
3436
3437         if (sb->s_blocksize != blocksize) {
3438                 /* Validate the filesystem blocksize */
3439                 if (!sb_set_blocksize(sb, blocksize)) {
3440                         ext4_msg(sb, KERN_ERR, "bad block size %d",
3441                                         blocksize);
3442                         goto failed_mount;
3443                 }
3444
3445                 brelse(bh);
3446                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3447                 offset = do_div(logical_sb_block, blocksize);
3448                 bh = sb_bread_unmovable(sb, logical_sb_block);
3449                 if (!bh) {
3450                         ext4_msg(sb, KERN_ERR,
3451                                "Can't read superblock on 2nd try");
3452                         goto failed_mount;
3453                 }
3454                 es = (struct ext4_super_block *)(bh->b_data + offset);
3455                 sbi->s_es = es;
3456                 if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
3457                         ext4_msg(sb, KERN_ERR,
3458                                "Magic mismatch, very weird!");
3459                         goto failed_mount;
3460                 }
3461         }
3462
3463         has_huge_files = ext4_has_feature_huge_file(sb);
3464         sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
3465                                                       has_huge_files);
3466         sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
3467
3468         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3469                 sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3470                 sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3471         } else {
3472                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3473                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3474                 if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3475                     (!is_power_of_2(sbi->s_inode_size)) ||
3476                     (sbi->s_inode_size > blocksize)) {
3477                         ext4_msg(sb, KERN_ERR,
3478                                "unsupported inode size: %d",
3479                                sbi->s_inode_size);
3480                         goto failed_mount;
3481                 }
3482                 if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
3483                         sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
3484         }
3485
3486         sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
3487         if (ext4_has_feature_64bit(sb)) {
3488                 if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
3489                     sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
3490                     !is_power_of_2(sbi->s_desc_size)) {
3491                         ext4_msg(sb, KERN_ERR,
3492                                "unsupported descriptor size %lu",
3493                                sbi->s_desc_size);
3494                         goto failed_mount;
3495                 }
3496         } else
3497                 sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
3498
3499         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
3500         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
3501         if (EXT4_INODE_SIZE(sb) == 0 || EXT4_INODES_PER_GROUP(sb) == 0)
3502                 goto cantfind_ext4;
3503
3504         sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
3505         if (sbi->s_inodes_per_block == 0)
3506                 goto cantfind_ext4;
3507         sbi->s_itb_per_group = sbi->s_inodes_per_group /
3508                                         sbi->s_inodes_per_block;
3509         sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
3510         sbi->s_sbh = bh;
3511         sbi->s_mount_state = le16_to_cpu(es->s_state);
3512         sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
3513         sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
3514
3515         for (i = 0; i < 4; i++)
3516                 sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
3517         sbi->s_def_hash_version = es->s_def_hash_version;
3518         if (ext4_has_feature_dir_index(sb)) {
3519                 i = le32_to_cpu(es->s_flags);
3520                 if (i & EXT2_FLAGS_UNSIGNED_HASH)
3521                         sbi->s_hash_unsigned = 3;
3522                 else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
3523 #ifdef __CHAR_UNSIGNED__
3524                         if (!(sb->s_flags & MS_RDONLY))
3525                                 es->s_flags |=
3526                                         cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
3527                         sbi->s_hash_unsigned = 3;
3528 #else
3529                         if (!(sb->s_flags & MS_RDONLY))
3530                                 es->s_flags |=
3531                                         cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
3532 #endif
3533                 }
3534         }
3535
3536         /* Handle clustersize */
3537         clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
3538         has_bigalloc = ext4_has_feature_bigalloc(sb);
3539         if (has_bigalloc) {
3540                 if (clustersize < blocksize) {
3541                         ext4_msg(sb, KERN_ERR,
3542                                  "cluster size (%d) smaller than "
3543                                  "block size (%d)", clustersize, blocksize);
3544                         goto failed_mount;
3545                 }
3546                 sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
3547                         le32_to_cpu(es->s_log_block_size);
3548                 sbi->s_clusters_per_group =
3549                         le32_to_cpu(es->s_clusters_per_group);
3550                 if (sbi->s_clusters_per_group > blocksize * 8) {
3551                         ext4_msg(sb, KERN_ERR,
3552                                  "#clusters per group too big: %lu",
3553                                  sbi->s_clusters_per_group);
3554                         goto failed_mount;
3555                 }
3556                 if (sbi->s_blocks_per_group !=
3557                     (sbi->s_clusters_per_group * (clustersize / blocksize))) {
3558                         ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
3559                                  "clusters per group (%lu) inconsistent",
3560                                  sbi->s_blocks_per_group,
3561                                  sbi->s_clusters_per_group);
3562                         goto failed_mount;
3563                 }
3564         } else {
3565                 if (clustersize != blocksize) {
3566                         ext4_warning(sb, "fragment/cluster size (%d) != "
3567                                      "block size (%d)", clustersize,
3568                                      blocksize);
3569                         clustersize = blocksize;
3570                 }
3571                 if (sbi->s_blocks_per_group > blocksize * 8) {
3572                         ext4_msg(sb, KERN_ERR,
3573                                  "#blocks per group too big: %lu",
3574                                  sbi->s_blocks_per_group);
3575                         goto failed_mount;
3576                 }
3577                 sbi->s_clusters_per_group = sbi->s_blocks_per_group;
3578                 sbi->s_cluster_bits = 0;
3579         }
3580         sbi->s_cluster_ratio = clustersize / blocksize;
3581
3582         if (sbi->s_inodes_per_group > blocksize * 8) {
3583                 ext4_msg(sb, KERN_ERR,
3584                        "#inodes per group too big: %lu",
3585                        sbi->s_inodes_per_group);
3586                 goto failed_mount;
3587         }
3588
3589         /* Do we have standard group size of clustersize * 8 blocks ? */
3590         if (sbi->s_blocks_per_group == clustersize << 3)
3591                 set_opt2(sb, STD_GROUP_SIZE);
3592
3593         /*
3594          * Test whether we have more sectors than will fit in sector_t,
3595          * and whether the max offset is addressable by the page cache.
3596          */
3597         err = generic_check_addressable(sb->s_blocksize_bits,
3598                                         ext4_blocks_count(es));
3599         if (err) {
3600                 ext4_msg(sb, KERN_ERR, "filesystem"
3601                          " too large to mount safely on this system");
3602                 if (sizeof(sector_t) < 8)
3603                         ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
3604                 goto failed_mount;
3605         }
3606
3607         if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
3608                 goto cantfind_ext4;
3609
3610         /* check blocks count against device size */
3611         blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
3612         if (blocks_count && ext4_blocks_count(es) > blocks_count) {
3613                 ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
3614                        "exceeds size of device (%llu blocks)",
3615                        ext4_blocks_count(es), blocks_count);
3616                 goto failed_mount;
3617         }
3618
3619         /*
3620          * It makes no sense for the first data block to be beyond the end
3621          * of the filesystem.
3622          */
3623         if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
3624                 ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
3625                          "block %u is beyond end of filesystem (%llu)",
3626                          le32_to_cpu(es->s_first_data_block),
3627                          ext4_blocks_count(es));
3628                 goto failed_mount;
3629         }
3630         blocks_count = (ext4_blocks_count(es) -
3631                         le32_to_cpu(es->s_first_data_block) +
3632                         EXT4_BLOCKS_PER_GROUP(sb) - 1);
3633         do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
3634         if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
3635                 ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
3636                        "(block count %llu, first data block %u, "
3637                        "blocks per group %lu)", sbi->s_groups_count,
3638                        ext4_blocks_count(es),
3639                        le32_to_cpu(es->s_first_data_block),
3640                        EXT4_BLOCKS_PER_GROUP(sb));
3641                 goto failed_mount;
3642         }
3643         sbi->s_groups_count = blocks_count;
3644         sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
3645                         (EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
3646         db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
3647                    EXT4_DESC_PER_BLOCK(sb);
3648         sbi->s_group_desc = ext4_kvmalloc(db_count *
3649                                           sizeof(struct buffer_head *),
3650                                           GFP_KERNEL);
3651         if (sbi->s_group_desc == NULL) {
3652                 ext4_msg(sb, KERN_ERR, "not enough memory");
3653                 ret = -ENOMEM;
3654                 goto failed_mount;
3655         }
3656
3657         bgl_lock_init(sbi->s_blockgroup_lock);
3658
3659         for (i = 0; i < db_count; i++) {
3660                 block = descriptor_loc(sb, logical_sb_block, i);
3661                 sbi->s_group_desc[i] = sb_bread_unmovable(sb, block);
3662                 if (!sbi->s_group_desc[i]) {
3663                         ext4_msg(sb, KERN_ERR,
3664                                "can't read group descriptor %d", i);
3665                         db_count = i;
3666                         goto failed_mount2;
3667                 }
3668         }
3669         if (!ext4_check_descriptors(sb, &first_not_zeroed)) {
3670                 ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
3671                 ret = -EFSCORRUPTED;
3672                 goto failed_mount2;
3673         }
3674
3675         sbi->s_gdb_count = db_count;
3676         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
3677         spin_lock_init(&sbi->s_next_gen_lock);
3678
3679         setup_timer(&sbi->s_err_report, print_daily_error_info,
3680                 (unsigned long) sb);
3681
3682         /* Register extent status tree shrinker */
3683         if (ext4_es_register_shrinker(sbi))
3684                 goto failed_mount3;
3685
3686         sbi->s_stripe = ext4_get_stripe_size(sbi);
3687         sbi->s_extent_max_zeroout_kb = 32;
3688
3689         /*
3690          * set up enough so that it can read an inode
3691          */
3692         sb->s_op = &ext4_sops;
3693         sb->s_export_op = &ext4_export_ops;
3694         sb->s_xattr = ext4_xattr_handlers;
3695 #ifdef CONFIG_QUOTA
3696         sb->dq_op = &ext4_quota_operations;
3697         if (ext4_has_feature_quota(sb))
3698                 sb->s_qcop = &dquot_quotactl_sysfile_ops;
3699         else
3700                 sb->s_qcop = &ext4_qctl_operations;
3701         sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
3702 #endif
3703         memcpy(sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
3704
3705         INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
3706         mutex_init(&sbi->s_orphan_lock);
3707
3708         sb->s_root = NULL;
3709
3710         needs_recovery = (es->s_last_orphan != 0 ||
3711                           ext4_has_feature_journal_needs_recovery(sb));
3712
3713         if (ext4_has_feature_mmp(sb) && !(sb->s_flags & MS_RDONLY))
3714                 if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
3715                         goto failed_mount3a;
3716
3717         /*
3718          * The first inode we look at is the journal inode.  Don't try
3719          * root first: it may be modified in the journal!
3720          */
3721         if (!test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) {
3722                 if (ext4_load_journal(sb, es, journal_devnum))
3723                         goto failed_mount3a;
3724         } else if (test_opt(sb, NOLOAD) && !(sb->s_flags & MS_RDONLY) &&
3725                    ext4_has_feature_journal_needs_recovery(sb)) {
3726                 ext4_msg(sb, KERN_ERR, "required journal recovery "
3727                        "suppressed and not mounted read-only");
3728                 goto failed_mount_wq;
3729         } else {
3730                 /* Nojournal mode, all journal mount options are illegal */
3731                 if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM)) {
3732                         ext4_msg(sb, KERN_ERR, "can't mount with "
3733                                  "journal_checksum, fs mounted w/o journal");
3734                         goto failed_mount_wq;
3735                 }
3736                 if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3737                         ext4_msg(sb, KERN_ERR, "can't mount with "
3738                                  "journal_async_commit, fs mounted w/o journal");
3739                         goto failed_mount_wq;
3740                 }
3741                 if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
3742                         ext4_msg(sb, KERN_ERR, "can't mount with "
3743                                  "commit=%lu, fs mounted w/o journal",
3744                                  sbi->s_commit_interval / HZ);
3745                         goto failed_mount_wq;
3746                 }
3747                 if (EXT4_MOUNT_DATA_FLAGS &
3748                     (sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
3749                         ext4_msg(sb, KERN_ERR, "can't mount with "
3750                                  "data=, fs mounted w/o journal");
3751                         goto failed_mount_wq;
3752                 }
3753                 sbi->s_def_mount_opt &= EXT4_MOUNT_JOURNAL_CHECKSUM;
3754                 clear_opt(sb, JOURNAL_CHECKSUM);
3755                 clear_opt(sb, DATA_FLAGS);
3756                 sbi->s_journal = NULL;
3757                 needs_recovery = 0;
3758                 goto no_journal;
3759         }
3760
3761         if (ext4_has_feature_64bit(sb) &&
3762             !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
3763                                        JBD2_FEATURE_INCOMPAT_64BIT)) {
3764                 ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
3765                 goto failed_mount_wq;
3766         }
3767
3768         if (!set_journal_csum_feature_set(sb)) {
3769                 ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
3770                          "feature set");
3771                 goto failed_mount_wq;
3772         }
3773
3774         /* We have now updated the journal if required, so we can
3775          * validate the data journaling mode. */
3776         switch (test_opt(sb, DATA_FLAGS)) {
3777         case 0:
3778                 /* No mode set, assume a default based on the journal
3779                  * capabilities: ORDERED_DATA if the journal can
3780                  * cope, else JOURNAL_DATA
3781                  */
3782                 if (jbd2_journal_check_available_features
3783                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
3784                         set_opt(sb, ORDERED_DATA);
3785                 else
3786                         set_opt(sb, JOURNAL_DATA);
3787                 break;
3788
3789         case EXT4_MOUNT_ORDERED_DATA:
3790         case EXT4_MOUNT_WRITEBACK_DATA:
3791                 if (!jbd2_journal_check_available_features
3792                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
3793                         ext4_msg(sb, KERN_ERR, "Journal does not support "
3794                                "requested data journaling mode");
3795                         goto failed_mount_wq;
3796                 }
3797         default:
3798                 break;
3799         }
3800         set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
3801
3802         sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
3803
3804 no_journal:
3805         sbi->s_mb_cache = ext4_xattr_create_cache();
3806         if (!sbi->s_mb_cache) {
3807                 ext4_msg(sb, KERN_ERR, "Failed to create an mb_cache");
3808                 goto failed_mount_wq;
3809         }
3810
3811         if ((DUMMY_ENCRYPTION_ENABLED(sbi) || ext4_has_feature_encrypt(sb)) &&
3812             (blocksize != PAGE_SIZE)) {
3813                 ext4_msg(sb, KERN_ERR,
3814                          "Unsupported blocksize for fs encryption");
3815                 goto failed_mount_wq;
3816         }
3817
3818         if (DUMMY_ENCRYPTION_ENABLED(sbi) && !(sb->s_flags & MS_RDONLY) &&
3819             !ext4_has_feature_encrypt(sb)) {
3820                 ext4_set_feature_encrypt(sb);
3821                 ext4_commit_super(sb, 1);
3822         }
3823
3824         /*
3825          * Get the # of file system overhead blocks from the
3826          * superblock if present.
3827          */
3828         if (es->s_overhead_clusters)
3829                 sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
3830         else {
3831                 err = ext4_calculate_overhead(sb);
3832                 if (err)
3833                         goto failed_mount_wq;
3834         }
3835
3836         /*
3837          * The maximum number of concurrent works can be high and
3838          * concurrency isn't really necessary.  Limit it to 1.
3839          */
3840         EXT4_SB(sb)->rsv_conversion_wq =
3841                 alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
3842         if (!EXT4_SB(sb)->rsv_conversion_wq) {
3843                 printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
3844                 ret = -ENOMEM;
3845                 goto failed_mount4;
3846         }
3847
3848         /*
3849          * The jbd2_journal_load will have done any necessary log recovery,
3850          * so we can safely mount the rest of the filesystem now.
3851          */
3852
3853         root = ext4_iget(sb, EXT4_ROOT_INO);
3854         if (IS_ERR(root)) {
3855                 ext4_msg(sb, KERN_ERR, "get root inode failed");
3856                 ret = PTR_ERR(root);
3857                 root = NULL;
3858                 goto failed_mount4;
3859         }
3860         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
3861                 ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
3862                 iput(root);
3863                 goto failed_mount4;
3864         }
3865         sb->s_root = d_make_root(root);
3866         if (!sb->s_root) {
3867                 ext4_msg(sb, KERN_ERR, "get root dentry failed");
3868                 ret = -ENOMEM;
3869                 goto failed_mount4;
3870         }
3871
3872         if (ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY))
3873                 sb->s_flags |= MS_RDONLY;
3874
3875         /* determine the minimum size of new large inodes, if present */
3876         if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
3877                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
3878                                                      EXT4_GOOD_OLD_INODE_SIZE;
3879                 if (ext4_has_feature_extra_isize(sb)) {
3880                         if (sbi->s_want_extra_isize <
3881                             le16_to_cpu(es->s_want_extra_isize))
3882                                 sbi->s_want_extra_isize =
3883                                         le16_to_cpu(es->s_want_extra_isize);
3884                         if (sbi->s_want_extra_isize <
3885                             le16_to_cpu(es->s_min_extra_isize))
3886                                 sbi->s_want_extra_isize =
3887                                         le16_to_cpu(es->s_min_extra_isize);
3888                 }
3889         }
3890         /* Check if enough inode space is available */
3891         if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
3892                                                         sbi->s_inode_size) {
3893                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
3894                                                        EXT4_GOOD_OLD_INODE_SIZE;
3895                 ext4_msg(sb, KERN_INFO, "required extra inode space not"
3896                          "available");
3897         }
3898
3899         ext4_set_resv_clusters(sb);
3900
3901         err = ext4_setup_system_zone(sb);
3902         if (err) {
3903                 ext4_msg(sb, KERN_ERR, "failed to initialize system "
3904                          "zone (%d)", err);
3905                 goto failed_mount4a;
3906         }
3907
3908         ext4_ext_init(sb);
3909         err = ext4_mb_init(sb);
3910         if (err) {
3911                 ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
3912                          err);
3913                 goto failed_mount5;
3914         }
3915
3916         block = ext4_count_free_clusters(sb);
3917         ext4_free_blocks_count_set(sbi->s_es,
3918                                    EXT4_C2B(sbi, block));
3919         err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
3920                                   GFP_KERNEL);
3921         if (!err) {
3922                 unsigned long freei = ext4_count_free_inodes(sb);
3923                 sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
3924                 err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
3925                                           GFP_KERNEL);
3926         }
3927         if (!err)
3928                 err = percpu_counter_init(&sbi->s_dirs_counter,
3929                                           ext4_count_dirs(sb), GFP_KERNEL);
3930         if (!err)
3931                 err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
3932                                           GFP_KERNEL);
3933         if (err) {
3934                 ext4_msg(sb, KERN_ERR, "insufficient memory");
3935                 goto failed_mount6;
3936         }
3937
3938         if (ext4_has_feature_flex_bg(sb))
3939                 if (!ext4_fill_flex_info(sb)) {
3940                         ext4_msg(sb, KERN_ERR,
3941                                "unable to initialize "
3942                                "flex_bg meta info!");
3943                         goto failed_mount6;
3944                 }
3945
3946         err = ext4_register_li_request(sb, first_not_zeroed);
3947         if (err)
3948                 goto failed_mount6;
3949
3950         err = ext4_register_sysfs(sb);
3951         if (err)
3952                 goto failed_mount7;
3953
3954 #ifdef CONFIG_QUOTA
3955         /* Enable quota usage during mount. */
3956         if (ext4_has_feature_quota(sb) && !(sb->s_flags & MS_RDONLY)) {
3957                 err = ext4_enable_quotas(sb);
3958                 if (err)
3959                         goto failed_mount8;
3960         }
3961 #endif  /* CONFIG_QUOTA */
3962
3963         EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
3964         ext4_orphan_cleanup(sb, es);
3965         EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
3966         if (needs_recovery) {
3967                 ext4_msg(sb, KERN_INFO, "recovery complete");
3968                 ext4_mark_recovery_complete(sb, es);
3969         }
3970         if (EXT4_SB(sb)->s_journal) {
3971                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
3972                         descr = " journalled data mode";
3973                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
3974                         descr = " ordered data mode";
3975                 else
3976                         descr = " writeback data mode";
3977         } else
3978                 descr = "out journal";
3979
3980         if (test_opt(sb, DISCARD)) {
3981                 struct request_queue *q = bdev_get_queue(sb->s_bdev);
3982                 if (!blk_queue_discard(q))
3983                         ext4_msg(sb, KERN_WARNING,
3984                                  "mounting with \"discard\" option, but "
3985                                  "the device does not support discard");
3986         }
3987
3988         if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
3989                 ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
3990                          "Opts: %s%s%s", descr, sbi->s_es->s_mount_opts,
3991                          *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
3992
3993         if (es->s_error_count)
3994                 mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
3995
3996         /* Enable message ratelimiting. Default is 10 messages per 5 secs. */
3997         ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
3998         ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
3999         ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
4000
4001         kfree(orig_data);
4002         return 0;
4003
4004 cantfind_ext4:
4005         if (!silent)
4006                 ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
4007         goto failed_mount;
4008
4009 #ifdef CONFIG_QUOTA
4010 failed_mount8:
4011         ext4_unregister_sysfs(sb);
4012 #endif
4013 failed_mount7:
4014         ext4_unregister_li_request(sb);
4015 failed_mount6:
4016         ext4_mb_release(sb);
4017         if (sbi->s_flex_groups)
4018                 kvfree(sbi->s_flex_groups);
4019         percpu_counter_destroy(&sbi->s_freeclusters_counter);
4020         percpu_counter_destroy(&sbi->s_freeinodes_counter);
4021         percpu_counter_destroy(&sbi->s_dirs_counter);
4022         percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4023 failed_mount5:
4024         ext4_ext_release(sb);
4025         ext4_release_system_zone(sb);
4026 failed_mount4a:
4027         dput(sb->s_root);
4028         sb->s_root = NULL;
4029 failed_mount4:
4030         ext4_msg(sb, KERN_ERR, "mount failed");
4031         if (EXT4_SB(sb)->rsv_conversion_wq)
4032                 destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4033 failed_mount_wq:
4034         if (sbi->s_mb_cache) {
4035                 ext4_xattr_destroy_cache(sbi->s_mb_cache);
4036                 sbi->s_mb_cache = NULL;
4037         }
4038         if (sbi->s_journal) {
4039                 jbd2_journal_destroy(sbi->s_journal);
4040                 sbi->s_journal = NULL;
4041         }
4042 failed_mount3a:
4043         ext4_es_unregister_shrinker(sbi);
4044 failed_mount3:
4045         del_timer_sync(&sbi->s_err_report);
4046         if (sbi->s_mmp_tsk)
4047                 kthread_stop(sbi->s_mmp_tsk);
4048 failed_mount2:
4049         for (i = 0; i < db_count; i++)
4050                 brelse(sbi->s_group_desc[i]);
4051         kvfree(sbi->s_group_desc);
4052 failed_mount:
4053         if (sbi->s_chksum_driver)
4054                 crypto_free_shash(sbi->s_chksum_driver);
4055 #ifdef CONFIG_QUOTA
4056         for (i = 0; i < EXT4_MAXQUOTAS; i++)
4057                 kfree(sbi->s_qf_names[i]);
4058 #endif
4059         ext4_blkdev_remove(sbi);
4060         brelse(bh);
4061 out_fail:
4062         sb->s_fs_info = NULL;
4063         kfree(sbi->s_blockgroup_lock);
4064         kfree(sbi);
4065 out_free_orig:
4066         kfree(orig_data);
4067         return err ? err : ret;
4068 }
4069
4070 /*
4071  * Setup any per-fs journal parameters now.  We'll do this both on
4072  * initial mount, once the journal has been initialised but before we've
4073  * done any recovery; and again on any subsequent remount.
4074  */
4075 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4076 {
4077         struct ext4_sb_info *sbi = EXT4_SB(sb);
4078
4079         journal->j_commit_interval = sbi->s_commit_interval;
4080         journal->j_min_batch_time = sbi->s_min_batch_time;
4081         journal->j_max_batch_time = sbi->s_max_batch_time;
4082
4083         write_lock(&journal->j_state_lock);
4084         if (test_opt(sb, BARRIER))
4085                 journal->j_flags |= JBD2_BARRIER;
4086         else
4087                 journal->j_flags &= ~JBD2_BARRIER;
4088         if (test_opt(sb, DATA_ERR_ABORT))
4089                 journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4090         else
4091                 journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4092         write_unlock(&journal->j_state_lock);
4093 }
4094
4095 static journal_t *ext4_get_journal(struct super_block *sb,
4096                                    unsigned int journal_inum)
4097 {
4098         struct inode *journal_inode;
4099         journal_t *journal;
4100
4101         BUG_ON(!ext4_has_feature_journal(sb));
4102
4103         /* First, test for the existence of a valid inode on disk.  Bad
4104          * things happen if we iget() an unused inode, as the subsequent
4105          * iput() will try to delete it. */
4106
4107         journal_inode = ext4_iget(sb, journal_inum);
4108         if (IS_ERR(journal_inode)) {
4109                 ext4_msg(sb, KERN_ERR, "no journal found");
4110                 return NULL;
4111         }
4112         if (!journal_inode->i_nlink) {
4113                 make_bad_inode(journal_inode);
4114                 iput(journal_inode);
4115                 ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4116                 return NULL;
4117         }
4118
4119         jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4120                   journal_inode, journal_inode->i_size);
4121         if (!S_ISREG(journal_inode->i_mode)) {
4122                 ext4_msg(sb, KERN_ERR, "invalid journal inode");
4123                 iput(journal_inode);
4124                 return NULL;
4125         }
4126
4127         journal = jbd2_journal_init_inode(journal_inode);
4128         if (!journal) {
4129                 ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4130                 iput(journal_inode);
4131                 return NULL;
4132         }
4133         journal->j_private = sb;
4134         ext4_init_journal_params(sb, journal);
4135         return journal;
4136 }
4137
4138 static journal_t *ext4_get_dev_journal(struct super_block *sb,
4139                                        dev_t j_dev)
4140 {
4141         struct buffer_head *bh;
4142         journal_t *journal;
4143         ext4_fsblk_t start;
4144         ext4_fsblk_t len;
4145         int hblock, blocksize;
4146         ext4_fsblk_t sb_block;
4147         unsigned long offset;
4148         struct ext4_super_block *es;
4149         struct block_device *bdev;
4150
4151         BUG_ON(!ext4_has_feature_journal(sb));
4152
4153         bdev = ext4_blkdev_get(j_dev, sb);
4154         if (bdev == NULL)
4155                 return NULL;
4156
4157         blocksize = sb->s_blocksize;
4158         hblock = bdev_logical_block_size(bdev);
4159         if (blocksize < hblock) {
4160                 ext4_msg(sb, KERN_ERR,
4161                         "blocksize too small for journal device");
4162                 goto out_bdev;
4163         }
4164
4165         sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4166         offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4167         set_blocksize(bdev, blocksize);
4168         if (!(bh = __bread(bdev, sb_block, blocksize))) {
4169                 ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4170                        "external journal");
4171                 goto out_bdev;
4172         }
4173
4174         es = (struct ext4_super_block *) (bh->b_data + offset);
4175         if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4176             !(le32_to_cpu(es->s_feature_incompat) &
4177               EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4178                 ext4_msg(sb, KERN_ERR, "external journal has "
4179                                         "bad superblock");
4180                 brelse(bh);
4181                 goto out_bdev;
4182         }
4183
4184         if ((le32_to_cpu(es->s_feature_ro_compat) &
4185              EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
4186             es->s_checksum != ext4_superblock_csum(sb, es)) {
4187                 ext4_msg(sb, KERN_ERR, "external journal has "
4188                                        "corrupt superblock");
4189                 brelse(bh);
4190                 goto out_bdev;
4191         }
4192
4193         if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4194                 ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4195                 brelse(bh);
4196                 goto out_bdev;
4197         }
4198
4199         len = ext4_blocks_count(es);
4200         start = sb_block + 1;
4201         brelse(bh);     /* we're done with the superblock */
4202
4203         journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4204                                         start, len, blocksize);
4205         if (!journal) {
4206                 ext4_msg(sb, KERN_ERR, "failed to create device journal");
4207                 goto out_bdev;
4208         }
4209         journal->j_private = sb;
4210         ll_rw_block(READ | REQ_META | REQ_PRIO, 1, &journal->j_sb_buffer);
4211         wait_on_buffer(journal->j_sb_buffer);
4212         if (!buffer_uptodate(journal->j_sb_buffer)) {
4213                 ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4214                 goto out_journal;
4215         }
4216         if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4217                 ext4_msg(sb, KERN_ERR, "External journal has more than one "
4218                                         "user (unsupported) - %d",
4219                         be32_to_cpu(journal->j_superblock->s_nr_users));
4220                 goto out_journal;
4221         }
4222         EXT4_SB(sb)->journal_bdev = bdev;
4223         ext4_init_journal_params(sb, journal);
4224         return journal;
4225
4226 out_journal:
4227         jbd2_journal_destroy(journal);
4228 out_bdev:
4229         ext4_blkdev_put(bdev);
4230         return NULL;
4231 }
4232
4233 static int ext4_load_journal(struct super_block *sb,
4234                              struct ext4_super_block *es,
4235                              unsigned long journal_devnum)
4236 {
4237         journal_t *journal;
4238         unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4239         dev_t journal_dev;
4240         int err = 0;
4241         int really_read_only;
4242
4243         BUG_ON(!ext4_has_feature_journal(sb));
4244
4245         if (journal_devnum &&
4246             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4247                 ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4248                         "numbers have changed");
4249                 journal_dev = new_decode_dev(journal_devnum);
4250         } else
4251                 journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4252
4253         really_read_only = bdev_read_only(sb->s_bdev);
4254
4255         /*
4256          * Are we loading a blank journal or performing recovery after a
4257          * crash?  For recovery, we need to check in advance whether we
4258          * can get read-write access to the device.
4259          */
4260         if (ext4_has_feature_journal_needs_recovery(sb)) {
4261                 if (sb->s_flags & MS_RDONLY) {
4262                         ext4_msg(sb, KERN_INFO, "INFO: recovery "
4263                                         "required on readonly filesystem");
4264                         if (really_read_only) {
4265                                 ext4_msg(sb, KERN_ERR, "write access "
4266                                         "unavailable, cannot proceed");
4267                                 return -EROFS;
4268                         }
4269                         ext4_msg(sb, KERN_INFO, "write access will "
4270                                "be enabled during recovery");
4271                 }
4272         }
4273
4274         if (journal_inum && journal_dev) {
4275                 ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4276                        "and inode journals!");
4277                 return -EINVAL;
4278         }
4279
4280         if (journal_inum) {
4281                 if (!(journal = ext4_get_journal(sb, journal_inum)))
4282                         return -EINVAL;
4283         } else {
4284                 if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4285                         return -EINVAL;
4286         }
4287
4288         if (!(journal->j_flags & JBD2_BARRIER))
4289                 ext4_msg(sb, KERN_INFO, "barriers disabled");
4290
4291         if (!ext4_has_feature_journal_needs_recovery(sb))
4292                 err = jbd2_journal_wipe(journal, !really_read_only);
4293         if (!err) {
4294                 char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4295                 if (save)
4296                         memcpy(save, ((char *) es) +
4297                                EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4298                 err = jbd2_journal_load(journal);
4299                 if (save)
4300                         memcpy(((char *) es) + EXT4_S_ERR_START,
4301                                save, EXT4_S_ERR_LEN);
4302                 kfree(save);
4303         }
4304
4305         if (err) {
4306                 ext4_msg(sb, KERN_ERR, "error loading journal");
4307                 jbd2_journal_destroy(journal);
4308                 return err;
4309         }
4310
4311         EXT4_SB(sb)->s_journal = journal;
4312         ext4_clear_journal_err(sb, es);
4313
4314         if (!really_read_only && journal_devnum &&
4315             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4316                 es->s_journal_dev = cpu_to_le32(journal_devnum);
4317
4318                 /* Make sure we flush the recovery flag to disk. */
4319                 ext4_commit_super(sb, 1);
4320         }
4321
4322         return 0;
4323 }
4324
4325 static int ext4_commit_super(struct super_block *sb, int sync)
4326 {
4327         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4328         struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4329         int error = 0;
4330
4331         if (!sbh || block_device_ejected(sb))
4332                 return error;
4333         if (buffer_write_io_error(sbh)) {
4334                 /*
4335                  * Oh, dear.  A previous attempt to write the
4336                  * superblock failed.  This could happen because the
4337                  * USB device was yanked out.  Or it could happen to
4338                  * be a transient write error and maybe the block will
4339                  * be remapped.  Nothing we can do but to retry the
4340                  * write and hope for the best.
4341                  */
4342                 ext4_msg(sb, KERN_ERR, "previous I/O error to "
4343                        "superblock detected");
4344                 clear_buffer_write_io_error(sbh);
4345                 set_buffer_uptodate(sbh);
4346         }
4347         /*
4348          * If the file system is mounted read-only, don't update the
4349          * superblock write time.  This avoids updating the superblock
4350          * write time when we are mounting the root file system
4351          * read/only but we need to replay the journal; at that point,
4352          * for people who are east of GMT and who make their clock
4353          * tick in localtime for Windows bug-for-bug compatibility,
4354          * the clock is set in the future, and this will cause e2fsck
4355          * to complain and force a full file system check.
4356          */
4357         if (!(sb->s_flags & MS_RDONLY))
4358                 es->s_wtime = cpu_to_le32(get_seconds());
4359         if (sb->s_bdev->bd_part)
4360                 es->s_kbytes_written =
4361                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
4362                             ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
4363                               EXT4_SB(sb)->s_sectors_written_start) >> 1));
4364         else
4365                 es->s_kbytes_written =
4366                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
4367         if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeclusters_counter))
4368                 ext4_free_blocks_count_set(es,
4369                         EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
4370                                 &EXT4_SB(sb)->s_freeclusters_counter)));
4371         if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeinodes_counter))
4372                 es->s_free_inodes_count =
4373                         cpu_to_le32(percpu_counter_sum_positive(
4374                                 &EXT4_SB(sb)->s_freeinodes_counter));
4375         BUFFER_TRACE(sbh, "marking dirty");
4376         ext4_superblock_csum_set(sb);
4377         mark_buffer_dirty(sbh);
4378         if (sync) {
4379                 error = __sync_dirty_buffer(sbh,
4380                         test_opt(sb, BARRIER) ? WRITE_FUA : WRITE_SYNC);
4381                 if (error)
4382                         return error;
4383
4384                 error = buffer_write_io_error(sbh);
4385                 if (error) {
4386                         ext4_msg(sb, KERN_ERR, "I/O error while writing "
4387                                "superblock");
4388                         clear_buffer_write_io_error(sbh);
4389                         set_buffer_uptodate(sbh);
4390                 }
4391         }
4392         return error;
4393 }
4394
4395 /*
4396  * Have we just finished recovery?  If so, and if we are mounting (or
4397  * remounting) the filesystem readonly, then we will end up with a
4398  * consistent fs on disk.  Record that fact.
4399  */
4400 static void ext4_mark_recovery_complete(struct super_block *sb,
4401                                         struct ext4_super_block *es)
4402 {
4403         journal_t *journal = EXT4_SB(sb)->s_journal;
4404
4405         if (!ext4_has_feature_journal(sb)) {
4406                 BUG_ON(journal != NULL);
4407                 return;
4408         }
4409         jbd2_journal_lock_updates(journal);
4410         if (jbd2_journal_flush(journal) < 0)
4411                 goto out;
4412
4413         if (ext4_has_feature_journal_needs_recovery(sb) &&
4414             sb->s_flags & MS_RDONLY) {
4415                 ext4_clear_feature_journal_needs_recovery(sb);
4416                 ext4_commit_super(sb, 1);
4417         }
4418
4419 out:
4420         jbd2_journal_unlock_updates(journal);
4421 }
4422
4423 /*
4424  * If we are mounting (or read-write remounting) a filesystem whose journal
4425  * has recorded an error from a previous lifetime, move that error to the
4426  * main filesystem now.
4427  */
4428 static void ext4_clear_journal_err(struct super_block *sb,
4429                                    struct ext4_super_block *es)
4430 {
4431         journal_t *journal;
4432         int j_errno;
4433         const char *errstr;
4434
4435         BUG_ON(!ext4_has_feature_journal(sb));
4436
4437         journal = EXT4_SB(sb)->s_journal;
4438
4439         /*
4440          * Now check for any error status which may have been recorded in the
4441          * journal by a prior ext4_error() or ext4_abort()
4442          */
4443
4444         j_errno = jbd2_journal_errno(journal);
4445         if (j_errno) {
4446                 char nbuf[16];
4447
4448                 errstr = ext4_decode_error(sb, j_errno, nbuf);
4449                 ext4_warning(sb, "Filesystem error recorded "
4450                              "from previous mount: %s", errstr);
4451                 ext4_warning(sb, "Marking fs in need of filesystem check.");
4452
4453                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
4454                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
4455                 ext4_commit_super(sb, 1);
4456
4457                 jbd2_journal_clear_err(journal);
4458                 jbd2_journal_update_sb_errno(journal);
4459         }
4460 }
4461
4462 /*
4463  * Force the running and committing transactions to commit,
4464  * and wait on the commit.
4465  */
4466 int ext4_force_commit(struct super_block *sb)
4467 {
4468         journal_t *journal;
4469
4470         if (sb->s_flags & MS_RDONLY)
4471                 return 0;
4472
4473         journal = EXT4_SB(sb)->s_journal;
4474         return ext4_journal_force_commit(journal);
4475 }
4476
4477 static int ext4_sync_fs(struct super_block *sb, int wait)
4478 {
4479         int ret = 0;
4480         tid_t target;
4481         bool needs_barrier = false;
4482         struct ext4_sb_info *sbi = EXT4_SB(sb);
4483
4484         trace_ext4_sync_fs(sb, wait);
4485         flush_workqueue(sbi->rsv_conversion_wq);
4486         /*
4487          * Writeback quota in non-journalled quota case - journalled quota has
4488          * no dirty dquots
4489          */
4490         dquot_writeback_dquots(sb, -1);
4491         /*
4492          * Data writeback is possible w/o journal transaction, so barrier must
4493          * being sent at the end of the function. But we can skip it if
4494          * transaction_commit will do it for us.
4495          */
4496         if (sbi->s_journal) {
4497                 target = jbd2_get_latest_transaction(sbi->s_journal);
4498                 if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
4499                     !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
4500                         needs_barrier = true;
4501
4502                 if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
4503                         if (wait)
4504                                 ret = jbd2_log_wait_commit(sbi->s_journal,
4505                                                            target);
4506                 }
4507         } else if (wait && test_opt(sb, BARRIER))
4508                 needs_barrier = true;
4509         if (needs_barrier) {
4510                 int err;
4511                 err = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
4512                 if (!ret)
4513                         ret = err;
4514         }
4515
4516         return ret;
4517 }
4518
4519 /*
4520  * LVM calls this function before a (read-only) snapshot is created.  This
4521  * gives us a chance to flush the journal completely and mark the fs clean.
4522  *
4523  * Note that only this function cannot bring a filesystem to be in a clean
4524  * state independently. It relies on upper layer to stop all data & metadata
4525  * modifications.
4526  */
4527 static int ext4_freeze(struct super_block *sb)
4528 {
4529         int error = 0;
4530         journal_t *journal;
4531
4532         if (sb->s_flags & MS_RDONLY)
4533                 return 0;
4534
4535         journal = EXT4_SB(sb)->s_journal;
4536
4537         if (journal) {
4538                 /* Now we set up the journal barrier. */
4539                 jbd2_journal_lock_updates(journal);
4540
4541                 /*
4542                  * Don't clear the needs_recovery flag if we failed to
4543                  * flush the journal.
4544                  */
4545                 error = jbd2_journal_flush(journal);
4546                 if (error < 0)
4547                         goto out;
4548
4549                 /* Journal blocked and flushed, clear needs_recovery flag. */
4550                 ext4_clear_feature_journal_needs_recovery(sb);
4551         }
4552
4553         error = ext4_commit_super(sb, 1);
4554 out:
4555         if (journal)
4556                 /* we rely on upper layer to stop further updates */
4557                 jbd2_journal_unlock_updates(journal);
4558         return error;
4559 }
4560
4561 /*
4562  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
4563  * flag here, even though the filesystem is not technically dirty yet.
4564  */
4565 static int ext4_unfreeze(struct super_block *sb)
4566 {
4567         if (sb->s_flags & MS_RDONLY)
4568                 return 0;
4569
4570         if (EXT4_SB(sb)->s_journal) {
4571                 /* Reset the needs_recovery flag before the fs is unlocked. */
4572                 ext4_set_feature_journal_needs_recovery(sb);
4573         }
4574
4575         ext4_commit_super(sb, 1);
4576         return 0;
4577 }
4578
4579 /*
4580  * Structure to save mount options for ext4_remount's benefit
4581  */
4582 struct ext4_mount_options {
4583         unsigned long s_mount_opt;
4584         unsigned long s_mount_opt2;
4585         kuid_t s_resuid;
4586         kgid_t s_resgid;
4587         unsigned long s_commit_interval;
4588         u32 s_min_batch_time, s_max_batch_time;
4589 #ifdef CONFIG_QUOTA
4590         int s_jquota_fmt;
4591         char *s_qf_names[EXT4_MAXQUOTAS];
4592 #endif
4593 };
4594
4595 static int ext4_remount(struct super_block *sb, int *flags, char *data)
4596 {
4597         struct ext4_super_block *es;
4598         struct ext4_sb_info *sbi = EXT4_SB(sb);
4599         unsigned long old_sb_flags;
4600         struct ext4_mount_options old_opts;
4601         int enable_quota = 0;
4602         ext4_group_t g;
4603         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4604         int err = 0;
4605 #ifdef CONFIG_QUOTA
4606         int i, j;
4607 #endif
4608         char *orig_data = kstrdup(data, GFP_KERNEL);
4609
4610         /* Store the original options */
4611         old_sb_flags = sb->s_flags;
4612         old_opts.s_mount_opt = sbi->s_mount_opt;
4613         old_opts.s_mount_opt2 = sbi->s_mount_opt2;
4614         old_opts.s_resuid = sbi->s_resuid;
4615         old_opts.s_resgid = sbi->s_resgid;
4616         old_opts.s_commit_interval = sbi->s_commit_interval;
4617         old_opts.s_min_batch_time = sbi->s_min_batch_time;
4618         old_opts.s_max_batch_time = sbi->s_max_batch_time;
4619 #ifdef CONFIG_QUOTA
4620         old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
4621         for (i = 0; i < EXT4_MAXQUOTAS; i++)
4622                 if (sbi->s_qf_names[i]) {
4623                         old_opts.s_qf_names[i] = kstrdup(sbi->s_qf_names[i],
4624                                                          GFP_KERNEL);
4625                         if (!old_opts.s_qf_names[i]) {
4626                                 for (j = 0; j < i; j++)
4627                                         kfree(old_opts.s_qf_names[j]);
4628                                 kfree(orig_data);
4629                                 return -ENOMEM;
4630                         }
4631                 } else
4632                         old_opts.s_qf_names[i] = NULL;
4633 #endif
4634         if (sbi->s_journal && sbi->s_journal->j_task->io_context)
4635                 journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
4636
4637         if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
4638                 err = -EINVAL;
4639                 goto restore_opts;
4640         }
4641
4642         if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
4643             test_opt(sb, JOURNAL_CHECKSUM)) {
4644                 ext4_msg(sb, KERN_ERR, "changing journal_checksum "
4645                          "during remount not supported; ignoring");
4646                 sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
4647         }
4648
4649         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
4650                 if (test_opt2(sb, EXPLICIT_DELALLOC)) {
4651                         ext4_msg(sb, KERN_ERR, "can't mount with "
4652                                  "both data=journal and delalloc");
4653                         err = -EINVAL;
4654                         goto restore_opts;
4655                 }
4656                 if (test_opt(sb, DIOREAD_NOLOCK)) {
4657                         ext4_msg(sb, KERN_ERR, "can't mount with "
4658                                  "both data=journal and dioread_nolock");
4659                         err = -EINVAL;
4660                         goto restore_opts;
4661                 }
4662                 if (test_opt(sb, DAX)) {
4663                         ext4_msg(sb, KERN_ERR, "can't mount with "
4664                                  "both data=journal and dax");
4665                         err = -EINVAL;
4666                         goto restore_opts;
4667                 }
4668         }
4669
4670         if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_DAX) {
4671                 ext4_msg(sb, KERN_WARNING, "warning: refusing change of "
4672                         "dax flag with busy inodes while remounting");
4673                 sbi->s_mount_opt ^= EXT4_MOUNT_DAX;
4674         }
4675
4676         if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
4677                 ext4_abort(sb, "Abort forced by user");
4678
4679         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
4680                 (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
4681
4682         es = sbi->s_es;
4683
4684         if (sbi->s_journal) {
4685                 ext4_init_journal_params(sb, sbi->s_journal);
4686                 set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4687         }
4688
4689         if (*flags & MS_LAZYTIME)
4690                 sb->s_flags |= MS_LAZYTIME;
4691
4692         if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY)) {
4693                 if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
4694                         err = -EROFS;
4695                         goto restore_opts;
4696                 }
4697
4698                 if (*flags & MS_RDONLY) {
4699                         err = sync_filesystem(sb);
4700                         if (err < 0)
4701                                 goto restore_opts;
4702                         err = dquot_suspend(sb, -1);
4703                         if (err < 0)
4704                                 goto restore_opts;
4705
4706                         /*
4707                          * First of all, the unconditional stuff we have to do
4708                          * to disable replay of the journal when we next remount
4709                          */
4710                         sb->s_flags |= MS_RDONLY;
4711
4712                         /*
4713                          * OK, test if we are remounting a valid rw partition
4714                          * readonly, and if so set the rdonly flag and then
4715                          * mark the partition as valid again.
4716                          */
4717                         if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
4718                             (sbi->s_mount_state & EXT4_VALID_FS))
4719                                 es->s_state = cpu_to_le16(sbi->s_mount_state);
4720
4721                         if (sbi->s_journal)
4722                                 ext4_mark_recovery_complete(sb, es);
4723                 } else {
4724                         /* Make sure we can mount this feature set readwrite */
4725                         if (ext4_has_feature_readonly(sb) ||
4726                             !ext4_feature_set_ok(sb, 0)) {
4727                                 err = -EROFS;
4728                                 goto restore_opts;
4729                         }
4730                         /*
4731                          * Make sure the group descriptor checksums
4732                          * are sane.  If they aren't, refuse to remount r/w.
4733                          */
4734                         for (g = 0; g < sbi->s_groups_count; g++) {
4735                                 struct ext4_group_desc *gdp =
4736                                         ext4_get_group_desc(sb, g, NULL);
4737
4738                                 if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
4739                                         ext4_msg(sb, KERN_ERR,
4740                "ext4_remount: Checksum for group %u failed (%u!=%u)",
4741                 g, le16_to_cpu(ext4_group_desc_csum(sb, g, gdp)),
4742                                                le16_to_cpu(gdp->bg_checksum));
4743                                         err = -EFSBADCRC;
4744                                         goto restore_opts;
4745                                 }
4746                         }
4747
4748                         /*
4749                          * If we have an unprocessed orphan list hanging
4750                          * around from a previously readonly bdev mount,
4751                          * require a full umount/remount for now.
4752                          */
4753                         if (es->s_last_orphan) {
4754                                 ext4_msg(sb, KERN_WARNING, "Couldn't "
4755                                        "remount RDWR because of unprocessed "
4756                                        "orphan inode list.  Please "
4757                                        "umount/remount instead");
4758                                 err = -EINVAL;
4759                                 goto restore_opts;
4760                         }
4761
4762                         /*
4763                          * Mounting a RDONLY partition read-write, so reread
4764                          * and store the current valid flag.  (It may have
4765                          * been changed by e2fsck since we originally mounted
4766                          * the partition.)
4767                          */
4768                         if (sbi->s_journal)
4769                                 ext4_clear_journal_err(sb, es);
4770                         sbi->s_mount_state = le16_to_cpu(es->s_state);
4771                         if (!ext4_setup_super(sb, es, 0))
4772                                 sb->s_flags &= ~MS_RDONLY;
4773                         if (ext4_has_feature_mmp(sb))
4774                                 if (ext4_multi_mount_protect(sb,
4775                                                 le64_to_cpu(es->s_mmp_block))) {
4776                                         err = -EROFS;
4777                                         goto restore_opts;
4778                                 }
4779                         enable_quota = 1;
4780                 }
4781         }
4782
4783         /*
4784          * Reinitialize lazy itable initialization thread based on
4785          * current settings
4786          */
4787         if ((sb->s_flags & MS_RDONLY) || !test_opt(sb, INIT_INODE_TABLE))
4788                 ext4_unregister_li_request(sb);
4789         else {
4790                 ext4_group_t first_not_zeroed;
4791                 first_not_zeroed = ext4_has_uninit_itable(sb);
4792                 ext4_register_li_request(sb, first_not_zeroed);
4793         }
4794
4795         ext4_setup_system_zone(sb);
4796         if (sbi->s_journal == NULL && !(old_sb_flags & MS_RDONLY))
4797                 ext4_commit_super(sb, 1);
4798
4799 #ifdef CONFIG_QUOTA
4800         /* Release old quota file names */
4801         for (i = 0; i < EXT4_MAXQUOTAS; i++)
4802                 kfree(old_opts.s_qf_names[i]);
4803         if (enable_quota) {
4804                 if (sb_any_quota_suspended(sb))
4805                         dquot_resume(sb, -1);
4806                 else if (ext4_has_feature_quota(sb)) {
4807                         err = ext4_enable_quotas(sb);
4808                         if (err)
4809                                 goto restore_opts;
4810                 }
4811         }
4812 #endif
4813
4814         *flags = (*flags & ~MS_LAZYTIME) | (sb->s_flags & MS_LAZYTIME);
4815         ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
4816         kfree(orig_data);
4817         return 0;
4818
4819 restore_opts:
4820         sb->s_flags = old_sb_flags;
4821         sbi->s_mount_opt = old_opts.s_mount_opt;
4822         sbi->s_mount_opt2 = old_opts.s_mount_opt2;
4823         sbi->s_resuid = old_opts.s_resuid;
4824         sbi->s_resgid = old_opts.s_resgid;
4825         sbi->s_commit_interval = old_opts.s_commit_interval;
4826         sbi->s_min_batch_time = old_opts.s_min_batch_time;
4827         sbi->s_max_batch_time = old_opts.s_max_batch_time;
4828 #ifdef CONFIG_QUOTA
4829         sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
4830         for (i = 0; i < EXT4_MAXQUOTAS; i++) {
4831                 kfree(sbi->s_qf_names[i]);
4832                 sbi->s_qf_names[i] = old_opts.s_qf_names[i];
4833         }
4834 #endif
4835         kfree(orig_data);
4836         return err;
4837 }
4838
4839 #ifdef CONFIG_QUOTA
4840 static int ext4_statfs_project(struct super_block *sb,
4841                                kprojid_t projid, struct kstatfs *buf)
4842 {
4843         struct kqid qid;
4844         struct dquot *dquot;
4845         u64 limit;
4846         u64 curblock;
4847
4848         qid = make_kqid_projid(projid);
4849         dquot = dqget(sb, qid);
4850         if (IS_ERR(dquot))
4851                 return PTR_ERR(dquot);
4852         spin_lock(&dq_data_lock);
4853
4854         limit = (dquot->dq_dqb.dqb_bsoftlimit ?
4855                  dquot->dq_dqb.dqb_bsoftlimit :
4856                  dquot->dq_dqb.dqb_bhardlimit) >> sb->s_blocksize_bits;
4857         if (limit && buf->f_blocks > limit) {
4858                 curblock = dquot->dq_dqb.dqb_curspace >> sb->s_blocksize_bits;
4859                 buf->f_blocks = limit;
4860                 buf->f_bfree = buf->f_bavail =
4861                         (buf->f_blocks > curblock) ?
4862                          (buf->f_blocks - curblock) : 0;
4863         }
4864
4865         limit = dquot->dq_dqb.dqb_isoftlimit ?
4866                 dquot->dq_dqb.dqb_isoftlimit :
4867                 dquot->dq_dqb.dqb_ihardlimit;
4868         if (limit && buf->f_files > limit) {
4869                 buf->f_files = limit;
4870                 buf->f_ffree =
4871                         (buf->f_files > dquot->dq_dqb.dqb_curinodes) ?
4872                          (buf->f_files - dquot->dq_dqb.dqb_curinodes) : 0;
4873         }
4874
4875         spin_unlock(&dq_data_lock);
4876         dqput(dquot);
4877         return 0;
4878 }
4879 #endif
4880
4881 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
4882 {
4883         struct super_block *sb = dentry->d_sb;
4884         struct ext4_sb_info *sbi = EXT4_SB(sb);
4885         struct ext4_super_block *es = sbi->s_es;
4886         ext4_fsblk_t overhead = 0, resv_blocks;
4887         u64 fsid;
4888         s64 bfree;
4889         resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
4890
4891         if (!test_opt(sb, MINIX_DF))
4892                 overhead = sbi->s_overhead;
4893
4894         buf->f_type = EXT4_SUPER_MAGIC;
4895         buf->f_bsize = sb->s_blocksize;
4896         buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
4897         bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
4898                 percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
4899         /* prevent underflow in case that few free space is available */
4900         buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
4901         buf->f_bavail = buf->f_bfree -
4902                         (ext4_r_blocks_count(es) + resv_blocks);
4903         if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
4904                 buf->f_bavail = 0;
4905         buf->f_files = le32_to_cpu(es->s_inodes_count);
4906         buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
4907         buf->f_namelen = EXT4_NAME_LEN;
4908         fsid = le64_to_cpup((void *)es->s_uuid) ^
4909                le64_to_cpup((void *)es->s_uuid + sizeof(u64));
4910         buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
4911         buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
4912
4913 #ifdef CONFIG_QUOTA
4914         if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&
4915             sb_has_quota_limits_enabled(sb, PRJQUOTA))
4916                 ext4_statfs_project(sb, EXT4_I(dentry->d_inode)->i_projid, buf);
4917 #endif
4918         return 0;
4919 }
4920
4921 /* Helper function for writing quotas on sync - we need to start transaction
4922  * before quota file is locked for write. Otherwise the are possible deadlocks:
4923  * Process 1                         Process 2
4924  * ext4_create()                     quota_sync()
4925  *   jbd2_journal_start()                  write_dquot()
4926  *   dquot_initialize()                         down(dqio_mutex)
4927  *     down(dqio_mutex)                    jbd2_journal_start()
4928  *
4929  */
4930
4931 #ifdef CONFIG_QUOTA
4932
4933 static inline struct inode *dquot_to_inode(struct dquot *dquot)
4934 {
4935         return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
4936 }
4937
4938 static int ext4_write_dquot(struct dquot *dquot)
4939 {
4940         int ret, err;
4941         handle_t *handle;
4942         struct inode *inode;
4943
4944         inode = dquot_to_inode(dquot);
4945         handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
4946                                     EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
4947         if (IS_ERR(handle))
4948                 return PTR_ERR(handle);
4949         ret = dquot_commit(dquot);
4950         err = ext4_journal_stop(handle);
4951         if (!ret)
4952                 ret = err;
4953         return ret;
4954 }
4955
4956 static int ext4_acquire_dquot(struct dquot *dquot)
4957 {
4958         int ret, err;
4959         handle_t *handle;
4960
4961         handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
4962                                     EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
4963         if (IS_ERR(handle))
4964                 return PTR_ERR(handle);
4965         ret = dquot_acquire(dquot);
4966         err = ext4_journal_stop(handle);
4967         if (!ret)
4968                 ret = err;
4969         return ret;
4970 }
4971
4972 static int ext4_release_dquot(struct dquot *dquot)
4973 {
4974         int ret, err;
4975         handle_t *handle;
4976
4977         handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
4978                                     EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
4979         if (IS_ERR(handle)) {
4980                 /* Release dquot anyway to avoid endless cycle in dqput() */
4981                 dquot_release(dquot);
4982                 return PTR_ERR(handle);
4983         }
4984         ret = dquot_release(dquot);
4985         err = ext4_journal_stop(handle);
4986         if (!ret)
4987                 ret = err;
4988         return ret;
4989 }
4990
4991 static int ext4_mark_dquot_dirty(struct dquot *dquot)
4992 {
4993         struct super_block *sb = dquot->dq_sb;
4994         struct ext4_sb_info *sbi = EXT4_SB(sb);
4995
4996         /* Are we journaling quotas? */
4997         if (ext4_has_feature_quota(sb) ||
4998             sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
4999                 dquot_mark_dquot_dirty(dquot);
5000                 return ext4_write_dquot(dquot);
5001         } else {
5002                 return dquot_mark_dquot_dirty(dquot);
5003         }
5004 }
5005
5006 static int ext4_write_info(struct super_block *sb, int type)
5007 {
5008         int ret, err;
5009         handle_t *handle;
5010
5011         /* Data block + inode block */
5012         handle = ext4_journal_start(d_inode(sb->s_root), EXT4_HT_QUOTA, 2);
5013         if (IS_ERR(handle))
5014                 return PTR_ERR(handle);
5015         ret = dquot_commit_info(sb, type);
5016         err = ext4_journal_stop(handle);
5017         if (!ret)
5018                 ret = err;
5019         return ret;
5020 }
5021
5022 /*
5023  * Turn on quotas during mount time - we need to find
5024  * the quota file and such...
5025  */
5026 static int ext4_quota_on_mount(struct super_block *sb, int type)
5027 {
5028         return dquot_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
5029                                         EXT4_SB(sb)->s_jquota_fmt, type);
5030 }
5031
5032 static void lockdep_set_quota_inode(struct inode *inode, int subclass)
5033 {
5034         struct ext4_inode_info *ei = EXT4_I(inode);
5035
5036         /* The first argument of lockdep_set_subclass has to be
5037          * *exactly* the same as the argument to init_rwsem() --- in
5038          * this case, in init_once() --- or lockdep gets unhappy
5039          * because the name of the lock is set using the
5040          * stringification of the argument to init_rwsem().
5041          */
5042         (void) ei;      /* shut up clang warning if !CONFIG_LOCKDEP */
5043         lockdep_set_subclass(&ei->i_data_sem, subclass);
5044 }
5045
5046 /*
5047  * Standard function to be called on quota_on
5048  */
5049 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
5050                          struct path *path)
5051 {
5052         int err;
5053
5054         if (!test_opt(sb, QUOTA))
5055                 return -EINVAL;
5056
5057         /* Quotafile not on the same filesystem? */
5058         if (path->dentry->d_sb != sb)
5059                 return -EXDEV;
5060         /* Journaling quota? */
5061         if (EXT4_SB(sb)->s_qf_names[type]) {
5062                 /* Quotafile not in fs root? */
5063                 if (path->dentry->d_parent != sb->s_root)
5064                         ext4_msg(sb, KERN_WARNING,
5065                                 "Quota file not on filesystem root. "
5066                                 "Journaled quota will not work");
5067         }
5068
5069         /*
5070          * When we journal data on quota file, we have to flush journal to see
5071          * all updates to the file when we bypass pagecache...
5072          */
5073         if (EXT4_SB(sb)->s_journal &&
5074             ext4_should_journal_data(d_inode(path->dentry))) {
5075                 /*
5076                  * We don't need to lock updates but journal_flush() could
5077                  * otherwise be livelocked...
5078                  */
5079                 jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
5080                 err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
5081                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
5082                 if (err)
5083                         return err;
5084         }
5085         lockdep_set_quota_inode(path->dentry->d_inode, I_DATA_SEM_QUOTA);
5086         err = dquot_quota_on(sb, type, format_id, path);
5087         if (err)
5088                 lockdep_set_quota_inode(path->dentry->d_inode,
5089                                              I_DATA_SEM_NORMAL);
5090         return err;
5091 }
5092
5093 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
5094                              unsigned int flags)
5095 {
5096         int err;
5097         struct inode *qf_inode;
5098         unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5099                 le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5100                 le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5101                 le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5102         };
5103
5104         BUG_ON(!ext4_has_feature_quota(sb));
5105
5106         if (!qf_inums[type])
5107                 return -EPERM;
5108
5109         qf_inode = ext4_iget(sb, qf_inums[type]);
5110         if (IS_ERR(qf_inode)) {
5111                 ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
5112                 return PTR_ERR(qf_inode);
5113         }
5114
5115         /* Don't account quota for quota files to avoid recursion */
5116         qf_inode->i_flags |= S_NOQUOTA;
5117         lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);
5118         err = dquot_enable(qf_inode, type, format_id, flags);
5119         iput(qf_inode);
5120         if (err)
5121                 lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);
5122
5123         return err;
5124 }
5125
5126 /* Enable usage tracking for all quota types. */
5127 static int ext4_enable_quotas(struct super_block *sb)
5128 {
5129         int type, err = 0;
5130         unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5131                 le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5132                 le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5133                 le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5134         };
5135
5136         sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE;
5137         for (type = 0; type < EXT4_MAXQUOTAS; type++) {
5138                 if (qf_inums[type]) {
5139                         err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
5140                                                 DQUOT_USAGE_ENABLED);
5141                         if (err) {
5142                                 ext4_warning(sb,
5143                                         "Failed to enable quota tracking "
5144                                         "(type=%d, err=%d). Please run "
5145                                         "e2fsck to fix.", type, err);
5146                                 return err;
5147                         }
5148                 }
5149         }
5150         return 0;
5151 }
5152
5153 static int ext4_quota_off(struct super_block *sb, int type)
5154 {
5155         struct inode *inode = sb_dqopt(sb)->files[type];
5156         handle_t *handle;
5157
5158         /* Force all delayed allocation blocks to be allocated.
5159          * Caller already holds s_umount sem */
5160         if (test_opt(sb, DELALLOC))
5161                 sync_filesystem(sb);
5162
5163         if (!inode)
5164                 goto out;
5165
5166         /* Update modification times of quota files when userspace can
5167          * start looking at them */
5168         handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5169         if (IS_ERR(handle))
5170                 goto out;
5171         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
5172         ext4_mark_inode_dirty(handle, inode);
5173         ext4_journal_stop(handle);
5174
5175 out:
5176         return dquot_quota_off(sb, type);
5177 }
5178
5179 /* Read data from quotafile - avoid pagecache and such because we cannot afford
5180  * acquiring the locks... As quota files are never truncated and quota code
5181  * itself serializes the operations (and no one else should touch the files)
5182  * we don't have to be afraid of races */
5183 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
5184                                size_t len, loff_t off)
5185 {
5186         struct inode *inode = sb_dqopt(sb)->files[type];
5187         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5188         int offset = off & (sb->s_blocksize - 1);
5189         int tocopy;
5190         size_t toread;
5191         struct buffer_head *bh;
5192         loff_t i_size = i_size_read(inode);
5193
5194         if (off > i_size)
5195                 return 0;
5196         if (off+len > i_size)
5197                 len = i_size-off;
5198         toread = len;
5199         while (toread > 0) {
5200                 tocopy = sb->s_blocksize - offset < toread ?
5201                                 sb->s_blocksize - offset : toread;
5202                 bh = ext4_bread(NULL, inode, blk, 0);
5203                 if (IS_ERR(bh))
5204                         return PTR_ERR(bh);
5205                 if (!bh)        /* A hole? */
5206                         memset(data, 0, tocopy);
5207                 else
5208                         memcpy(data, bh->b_data+offset, tocopy);
5209                 brelse(bh);
5210                 offset = 0;
5211                 toread -= tocopy;
5212                 data += tocopy;
5213                 blk++;
5214         }
5215         return len;
5216 }
5217
5218 /* Write to quotafile (we know the transaction is already started and has
5219  * enough credits) */
5220 static ssize_t ext4_quota_write(struct super_block *sb, int type,
5221                                 const char *data, size_t len, loff_t off)
5222 {
5223         struct inode *inode = sb_dqopt(sb)->files[type];
5224         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5225         int err, offset = off & (sb->s_blocksize - 1);
5226         int retries = 0;
5227         struct buffer_head *bh;
5228         handle_t *handle = journal_current_handle();
5229
5230         if (EXT4_SB(sb)->s_journal && !handle) {
5231                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5232                         " cancelled because transaction is not started",
5233                         (unsigned long long)off, (unsigned long long)len);
5234                 return -EIO;
5235         }
5236         /*
5237          * Since we account only one data block in transaction credits,
5238          * then it is impossible to cross a block boundary.
5239          */
5240         if (sb->s_blocksize - offset < len) {
5241                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5242                         " cancelled because not block aligned",
5243                         (unsigned long long)off, (unsigned long long)len);
5244                 return -EIO;
5245         }
5246
5247         do {
5248                 bh = ext4_bread(handle, inode, blk,
5249                                 EXT4_GET_BLOCKS_CREATE |
5250                                 EXT4_GET_BLOCKS_METADATA_NOFAIL);
5251         } while (IS_ERR(bh) && (PTR_ERR(bh) == -ENOSPC) &&
5252                  ext4_should_retry_alloc(inode->i_sb, &retries));
5253         if (IS_ERR(bh))
5254                 return PTR_ERR(bh);
5255         if (!bh)
5256                 goto out;
5257         BUFFER_TRACE(bh, "get write access");
5258         err = ext4_journal_get_write_access(handle, bh);
5259         if (err) {
5260                 brelse(bh);
5261                 return err;
5262         }
5263         lock_buffer(bh);
5264         memcpy(bh->b_data+offset, data, len);
5265         flush_dcache_page(bh->b_page);
5266         unlock_buffer(bh);
5267         err = ext4_handle_dirty_metadata(handle, NULL, bh);
5268         brelse(bh);
5269 out:
5270         if (inode->i_size < off + len) {
5271                 i_size_write(inode, off + len);
5272                 EXT4_I(inode)->i_disksize = inode->i_size;
5273                 ext4_mark_inode_dirty(handle, inode);
5274         }
5275         return len;
5276 }
5277
5278 static int ext4_get_next_id(struct super_block *sb, struct kqid *qid)
5279 {
5280         const struct quota_format_ops   *ops;
5281
5282         if (!sb_has_quota_loaded(sb, qid->type))
5283                 return -ESRCH;
5284         ops = sb_dqopt(sb)->ops[qid->type];
5285         if (!ops || !ops->get_next_id)
5286                 return -ENOSYS;
5287         return dquot_get_next_id(sb, qid);
5288 }
5289 #endif
5290
5291 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
5292                        const char *dev_name, void *data)
5293 {
5294         return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
5295 }
5296
5297 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
5298 static inline void register_as_ext2(void)
5299 {
5300         int err = register_filesystem(&ext2_fs_type);
5301         if (err)
5302                 printk(KERN_WARNING
5303                        "EXT4-fs: Unable to register as ext2 (%d)\n", err);
5304 }
5305
5306 static inline void unregister_as_ext2(void)
5307 {
5308         unregister_filesystem(&ext2_fs_type);
5309 }
5310
5311 static inline int ext2_feature_set_ok(struct super_block *sb)
5312 {
5313         if (ext4_has_unknown_ext2_incompat_features(sb))
5314                 return 0;
5315         if (sb->s_flags & MS_RDONLY)
5316                 return 1;
5317         if (ext4_has_unknown_ext2_ro_compat_features(sb))
5318                 return 0;
5319         return 1;
5320 }
5321 #else
5322 static inline void register_as_ext2(void) { }
5323 static inline void unregister_as_ext2(void) { }
5324 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
5325 #endif
5326
5327 static inline void register_as_ext3(void)
5328 {
5329         int err = register_filesystem(&ext3_fs_type);
5330         if (err)
5331                 printk(KERN_WARNING
5332                        "EXT4-fs: Unable to register as ext3 (%d)\n", err);
5333 }
5334
5335 static inline void unregister_as_ext3(void)
5336 {
5337         unregister_filesystem(&ext3_fs_type);
5338 }
5339
5340 static inline int ext3_feature_set_ok(struct super_block *sb)
5341 {
5342         if (ext4_has_unknown_ext3_incompat_features(sb))
5343                 return 0;
5344         if (!ext4_has_feature_journal(sb))
5345                 return 0;
5346         if (sb->s_flags & MS_RDONLY)
5347                 return 1;
5348         if (ext4_has_unknown_ext3_ro_compat_features(sb))
5349                 return 0;
5350         return 1;
5351 }
5352
5353 static struct file_system_type ext4_fs_type = {
5354         .owner          = THIS_MODULE,
5355         .name           = "ext4",
5356         .mount          = ext4_mount,
5357         .kill_sb        = kill_block_super,
5358         .fs_flags       = FS_REQUIRES_DEV,
5359 };
5360 MODULE_ALIAS_FS("ext4");
5361
5362 /* Shared across all ext4 file systems */
5363 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
5364
5365 static int __init ext4_init_fs(void)
5366 {
5367         int i, err;
5368
5369         ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
5370         ext4_li_info = NULL;
5371         mutex_init(&ext4_li_mtx);
5372
5373         /* Build-time check for flags consistency */
5374         ext4_check_flag_values();
5375
5376         for (i = 0; i < EXT4_WQ_HASH_SZ; i++)
5377                 init_waitqueue_head(&ext4__ioend_wq[i]);
5378
5379         err = ext4_init_es();
5380         if (err)
5381                 return err;
5382
5383         err = ext4_init_pageio();
5384         if (err)
5385                 goto out5;
5386
5387         err = ext4_init_system_zone();
5388         if (err)
5389                 goto out4;
5390
5391         err = ext4_init_sysfs();
5392         if (err)
5393                 goto out3;
5394
5395         err = ext4_init_mballoc();
5396         if (err)
5397                 goto out2;
5398         err = init_inodecache();
5399         if (err)
5400                 goto out1;
5401         register_as_ext3();
5402         register_as_ext2();
5403         err = register_filesystem(&ext4_fs_type);
5404         if (err)
5405                 goto out;
5406
5407         return 0;
5408 out:
5409         unregister_as_ext2();
5410         unregister_as_ext3();
5411         destroy_inodecache();
5412 out1:
5413         ext4_exit_mballoc();
5414 out2:
5415         ext4_exit_sysfs();
5416 out3:
5417         ext4_exit_system_zone();
5418 out4:
5419         ext4_exit_pageio();
5420 out5:
5421         ext4_exit_es();
5422
5423         return err;
5424 }
5425
5426 static void __exit ext4_exit_fs(void)
5427 {
5428         ext4_exit_crypto();
5429         ext4_destroy_lazyinit_thread();
5430         unregister_as_ext2();
5431         unregister_as_ext3();
5432         unregister_filesystem(&ext4_fs_type);
5433         destroy_inodecache();
5434         ext4_exit_mballoc();
5435         ext4_exit_sysfs();
5436         ext4_exit_system_zone();
5437         ext4_exit_pageio();
5438         ext4_exit_es();
5439 }
5440
5441 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
5442 MODULE_DESCRIPTION("Fourth Extended Filesystem");
5443 MODULE_LICENSE("GPL");
5444 module_init(ext4_init_fs)
5445 module_exit(ext4_exit_fs)