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 <linux/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 static struct inode *ext4_get_journal_inode(struct super_block *sb,
  82                                             unsigned int journal_inum);
  83
  84 /*
  85  * Lock ordering
  86  *
  87  * Note the difference between i_mmap_sem (EXT4_I(inode)->i_mmap_sem) and
  88  * i_mmap_rwsem (inode->i_mmap_rwsem)!
  89  *
  90  * page fault path:
  91  * mmap_sem -> sb_start_pagefault -> i_mmap_sem (r) -> transaction start ->
  92  *   page lock -> i_data_sem (rw)
  93  *
  94  * buffered write path:
  95  * sb_start_write -> i_mutex -> mmap_sem
  96  * sb_start_write -> i_mutex -> transaction start -> page lock ->
  97  *   i_data_sem (rw)
  98  *
  99  * truncate:
 100  * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (w) -> i_mmap_sem (w) ->
 101  *   i_mmap_rwsem (w) -> page lock
 102  * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (w) -> i_mmap_sem (w) ->
 103  *   transaction start -> i_data_sem (rw)
 104  *
 105  * direct IO:
 106  * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (r) -> mmap_sem
 107  * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (r) ->
 108  *   transaction start -> i_data_sem (rw)
 109  *
 110  * writepages:
 111  * transaction start -> page lock(s) -> i_data_sem (rw)
 112  */
 113
 114 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
 115 static struct file_system_type ext2_fs_type = {
 116         .owner          = THIS_MODULE,
 117         .name           = "ext2",
 118         .mount          = ext4_mount,
 119         .kill_sb        = kill_block_super,
 120         .fs_flags       = FS_REQUIRES_DEV,
 121 };
 122 MODULE_ALIAS_FS("ext2");
 123 MODULE_ALIAS("ext2");
 124 #define IS_EXT2_SB(sb) ((sb)->s_bdev->bd_holder == &ext2_fs_type)
 125 #else
 126 #define IS_EXT2_SB(sb) (0)
 127 #endif
 128
 129
 130 static struct file_system_type ext3_fs_type = {
 131         .owner          = THIS_MODULE,
 132         .name           = "ext3",
 133         .mount          = ext4_mount,
 134         .kill_sb        = kill_block_super,
 135         .fs_flags       = FS_REQUIRES_DEV,
 136 };
 137 MODULE_ALIAS_FS("ext3");
 138 MODULE_ALIAS("ext3");
 139 #define IS_EXT3_SB(sb) ((sb)->s_bdev->bd_holder == &ext3_fs_type)
 140
 141 static int ext4_verify_csum_type(struct super_block *sb,
 142                                  struct ext4_super_block *es)
 143 {
 144         if (!ext4_has_feature_metadata_csum(sb))
 145                 return 1;
 146
 147         return es->s_checksum_type == EXT4_CRC32C_CHKSUM;
 148 }
 149
 150 static __le32 ext4_superblock_csum(struct super_block *sb,
 151                                    struct ext4_super_block *es)
 152 {
 153         struct ext4_sb_info *sbi = EXT4_SB(sb);
 154         int offset = offsetof(struct ext4_super_block, s_checksum);
 155         __u32 csum;
 156
 157         csum = ext4_chksum(sbi, ~0, (char *)es, offset);
 158
 159         return cpu_to_le32(csum);
 160 }
 161
 162 static int ext4_superblock_csum_verify(struct super_block *sb,
 163                                        struct ext4_super_block *es)
 164 {
 165         if (!ext4_has_metadata_csum(sb))
 166                 return 1;
 167
 168         return es->s_checksum == ext4_superblock_csum(sb, es);
 169 }
 170
 171 void ext4_superblock_csum_set(struct super_block *sb)
 172 {
 173         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 174
 175         if (!ext4_has_metadata_csum(sb))
 176                 return;
 177
 178         es->s_checksum = ext4_superblock_csum(sb, es);
 179 }
 180
 181 void *ext4_kvmalloc(size_t size, gfp_t flags)
 182 {
 183         void *ret;
 184
 185         ret = kmalloc(size, flags | __GFP_NOWARN);
 186         if (!ret)
 187                 ret = __vmalloc(size, flags, PAGE_KERNEL);
 188         return ret;
 189 }
 190
 191 void *ext4_kvzalloc(size_t size, gfp_t flags)
 192 {
 193         void *ret;
 194
 195         ret = kzalloc(size, flags | __GFP_NOWARN);
 196         if (!ret)
 197                 ret = __vmalloc(size, flags | __GFP_ZERO, PAGE_KERNEL);
 198         return ret;
 199 }
 200
 201 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
 202                                struct ext4_group_desc *bg)
 203 {
 204         return le32_to_cpu(bg->bg_block_bitmap_lo) |
 205                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 206                  (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
 207 }
 208
 209 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
 210                                struct ext4_group_desc *bg)
 211 {
 212         return le32_to_cpu(bg->bg_inode_bitmap_lo) |
 213                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 214                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
 215 }
 216
 217 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
 218                               struct ext4_group_desc *bg)
 219 {
 220         return le32_to_cpu(bg->bg_inode_table_lo) |
 221                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 222                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
 223 }
 224
 225 __u32 ext4_free_group_clusters(struct super_block *sb,
 226                                struct ext4_group_desc *bg)
 227 {
 228         return le16_to_cpu(bg->bg_free_blocks_count_lo) |
 229                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 230                  (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
 231 }
 232
 233 __u32 ext4_free_inodes_count(struct super_block *sb,
 234                               struct ext4_group_desc *bg)
 235 {
 236         return le16_to_cpu(bg->bg_free_inodes_count_lo) |
 237                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 238                  (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
 239 }
 240
 241 __u32 ext4_used_dirs_count(struct super_block *sb,
 242                               struct ext4_group_desc *bg)
 243 {
 244         return le16_to_cpu(bg->bg_used_dirs_count_lo) |
 245                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 246                  (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
 247 }
 248
 249 __u32 ext4_itable_unused_count(struct super_block *sb,
 250                               struct ext4_group_desc *bg)
 251 {
 252         return le16_to_cpu(bg->bg_itable_unused_lo) |
 253                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 254                  (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
 255 }
 256
 257 void ext4_block_bitmap_set(struct super_block *sb,
 258                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 259 {
 260         bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
 261         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 262                 bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
 263 }
 264
 265 void ext4_inode_bitmap_set(struct super_block *sb,
 266                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 267 {
 268         bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
 269         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 270                 bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
 271 }
 272
 273 void ext4_inode_table_set(struct super_block *sb,
 274                           struct ext4_group_desc *bg, ext4_fsblk_t blk)
 275 {
 276         bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
 277         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 278                 bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
 279 }
 280
 281 void ext4_free_group_clusters_set(struct super_block *sb,
 282                                   struct ext4_group_desc *bg, __u32 count)
 283 {
 284         bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
 285         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 286                 bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
 287 }
 288
 289 void ext4_free_inodes_set(struct super_block *sb,
 290                           struct ext4_group_desc *bg, __u32 count)
 291 {
 292         bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
 293         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 294                 bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
 295 }
 296
 297 void ext4_used_dirs_set(struct super_block *sb,
 298                           struct ext4_group_desc *bg, __u32 count)
 299 {
 300         bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
 301         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 302                 bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
 303 }
 304
 305 void ext4_itable_unused_set(struct super_block *sb,
 306                           struct ext4_group_desc *bg, __u32 count)
 307 {
 308         bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
 309         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 310                 bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
 311 }
 312
 313
 314 static void __save_error_info(struct super_block *sb, const char *func,
 315                             unsigned int line)
 316 {
 317         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 318
 319         EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
 320         if (bdev_read_only(sb->s_bdev))
 321                 return;
 322         es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
 323         es->s_last_error_time = cpu_to_le32(get_seconds());
 324         strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
 325         es->s_last_error_line = cpu_to_le32(line);
 326         if (!es->s_first_error_time) {
 327                 es->s_first_error_time = es->s_last_error_time;
 328                 strncpy(es->s_first_error_func, func,
 329                         sizeof(es->s_first_error_func));
 330                 es->s_first_error_line = cpu_to_le32(line);
 331                 es->s_first_error_ino = es->s_last_error_ino;
 332                 es->s_first_error_block = es->s_last_error_block;
 333         }
 334         /*
 335          * Start the daily error reporting function if it hasn't been
 336          * started already
 337          */
 338         if (!es->s_error_count)
 339                 mod_timer(&EXT4_SB(sb)->s_err_report, jiffies + 24*60*60*HZ);
 340         le32_add_cpu(&es->s_error_count, 1);
 341 }
 342
 343 static void save_error_info(struct super_block *sb, const char *func,
 344                             unsigned int line)
 345 {
 346         __save_error_info(sb, func, line);
 347         ext4_commit_super(sb, 1);
 348 }
 349
 350 /*
 351  * The del_gendisk() function uninitializes the disk-specific data
 352  * structures, including the bdi structure, without telling anyone
 353  * else.  Once this happens, any attempt to call mark_buffer_dirty()
 354  * (for example, by ext4_commit_super), will cause a kernel OOPS.
 355  * This is a kludge to prevent these oops until we can put in a proper
 356  * hook in del_gendisk() to inform the VFS and file system layers.
 357  */
 358 static int block_device_ejected(struct super_block *sb)
 359 {
 360         struct inode *bd_inode = sb->s_bdev->bd_inode;
 361         struct backing_dev_info *bdi = inode_to_bdi(bd_inode);
 362
 363         return bdi->dev == NULL;
 364 }
 365
 366 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
 367 {
 368         struct super_block              *sb = journal->j_private;
 369         struct ext4_sb_info             *sbi = EXT4_SB(sb);
 370         int                             error = is_journal_aborted(journal);
 371         struct ext4_journal_cb_entry    *jce;
 372
 373         BUG_ON(txn->t_state == T_FINISHED);
 374         spin_lock(&sbi->s_md_lock);
 375         while (!list_empty(&txn->t_private_list)) {
 376                 jce = list_entry(txn->t_private_list.next,
 377                                  struct ext4_journal_cb_entry, jce_list);
 378                 list_del_init(&jce->jce_list);
 379                 spin_unlock(&sbi->s_md_lock);
 380                 jce->jce_func(sb, jce, error);
 381                 spin_lock(&sbi->s_md_lock);
 382         }
 383         spin_unlock(&sbi->s_md_lock);
 384 }
 385
 386 /* Deal with the reporting of failure conditions on a filesystem such as
 387  * inconsistencies detected or read IO failures.
 388  *
 389  * On ext2, we can store the error state of the filesystem in the
 390  * superblock.  That is not possible on ext4, because we may have other
 391  * write ordering constraints on the superblock which prevent us from
 392  * writing it out straight away; and given that the journal is about to
 393  * be aborted, we can't rely on the current, or future, transactions to
 394  * write out the superblock safely.
 395  *
 396  * We'll just use the jbd2_journal_abort() error code to record an error in
 397  * the journal instead.  On recovery, the journal will complain about
 398  * that error until we've noted it down and cleared it.
 399  */
 400
 401 static void ext4_handle_error(struct super_block *sb)
 402 {
 403         if (sb->s_flags & MS_RDONLY)
 404                 return;
 405
 406         if (!test_opt(sb, ERRORS_CONT)) {
 407                 journal_t *journal = EXT4_SB(sb)->s_journal;
 408
 409                 EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
 410                 if (journal)
 411                         jbd2_journal_abort(journal, -EIO);
 412         }
 413         if (test_opt(sb, ERRORS_RO)) {
 414                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 415                 /*
 416                  * Make sure updated value of ->s_mount_flags will be visible
 417                  * before ->s_flags update
 418                  */
 419                 smp_wmb();
 420                 sb->s_flags |= MS_RDONLY;
 421         }
 422         if (test_opt(sb, ERRORS_PANIC)) {
 423                 if (EXT4_SB(sb)->s_journal &&
 424                   !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
 425                         return;
 426                 panic("EXT4-fs (device %s): panic forced after error\n",
 427                         sb->s_id);
 428         }
 429 }
 430
 431 #define ext4_error_ratelimit(sb)                                        \
 432                 ___ratelimit(&(EXT4_SB(sb)->s_err_ratelimit_state),     \
 433                              "EXT4-fs error")
 434
 435 void __ext4_error(struct super_block *sb, const char *function,
 436                   unsigned int line, const char *fmt, ...)
 437 {
 438         struct va_format vaf;
 439         va_list args;
 440
 441         if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
 442                 return;
 443
 444         if (ext4_error_ratelimit(sb)) {
 445                 va_start(args, fmt);
 446                 vaf.fmt = fmt;
 447                 vaf.va = &args;
 448                 printk(KERN_CRIT
 449                        "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
 450                        sb->s_id, function, line, current->comm, &vaf);
 451                 va_end(args);
 452         }
 453         save_error_info(sb, function, line);
 454         ext4_handle_error(sb);
 455 }
 456
 457 void __ext4_error_inode(struct inode *inode, const char *function,
 458                         unsigned int line, ext4_fsblk_t block,
 459                         const char *fmt, ...)
 460 {
 461         va_list args;
 462         struct va_format vaf;
 463         struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
 464
 465         if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
 466                 return;
 467
 468         es->s_last_error_ino = cpu_to_le32(inode->i_ino);
 469         es->s_last_error_block = cpu_to_le64(block);
 470         if (ext4_error_ratelimit(inode->i_sb)) {
 471                 va_start(args, fmt);
 472                 vaf.fmt = fmt;
 473                 vaf.va = &args;
 474                 if (block)
 475                         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
 476                                "inode #%lu: block %llu: comm %s: %pV\n",
 477                                inode->i_sb->s_id, function, line, inode->i_ino,
 478                                block, current->comm, &vaf);
 479                 else
 480                         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
 481                                "inode #%lu: comm %s: %pV\n",
 482                                inode->i_sb->s_id, function, line, inode->i_ino,
 483                                current->comm, &vaf);
 484                 va_end(args);
 485         }
 486         save_error_info(inode->i_sb, function, line);
 487         ext4_handle_error(inode->i_sb);
 488 }
 489
 490 void __ext4_error_file(struct file *file, const char *function,
 491                        unsigned int line, ext4_fsblk_t block,
 492                        const char *fmt, ...)
 493 {
 494         va_list args;
 495         struct va_format vaf;
 496         struct ext4_super_block *es;
 497         struct inode *inode = file_inode(file);
 498         char pathname[80], *path;
 499
 500         if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
 501                 return;
 502
 503         es = EXT4_SB(inode->i_sb)->s_es;
 504         es->s_last_error_ino = cpu_to_le32(inode->i_ino);
 505         if (ext4_error_ratelimit(inode->i_sb)) {
 506                 path = file_path(file, pathname, sizeof(pathname));
 507                 if (IS_ERR(path))
 508                         path = "(unknown)";
 509                 va_start(args, fmt);
 510                 vaf.fmt = fmt;
 511                 vaf.va = &args;
 512                 if (block)
 513                         printk(KERN_CRIT
 514                                "EXT4-fs error (device %s): %s:%d: inode #%lu: "
 515                                "block %llu: comm %s: path %s: %pV\n",
 516                                inode->i_sb->s_id, function, line, inode->i_ino,
 517                                block, current->comm, path, &vaf);
 518                 else
 519                         printk(KERN_CRIT
 520                                "EXT4-fs error (device %s): %s:%d: inode #%lu: "
 521                                "comm %s: path %s: %pV\n",
 522                                inode->i_sb->s_id, function, line, inode->i_ino,
 523                                current->comm, path, &vaf);
 524                 va_end(args);
 525         }
 526         save_error_info(inode->i_sb, function, line);
 527         ext4_handle_error(inode->i_sb);
 528 }
 529
 530 const char *ext4_decode_error(struct super_block *sb, int errno,
 531                               char nbuf[16])
 532 {
 533         char *errstr = NULL;
 534
 535         switch (errno) {
 536         case -EFSCORRUPTED:
 537                 errstr = "Corrupt filesystem";
 538                 break;
 539         case -EFSBADCRC:
 540                 errstr = "Filesystem failed CRC";
 541                 break;
 542         case -EIO:
 543                 errstr = "IO failure";
 544                 break;
 545         case -ENOMEM:
 546                 errstr = "Out of memory";
 547                 break;
 548         case -EROFS:
 549                 if (!sb || (EXT4_SB(sb)->s_journal &&
 550                             EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
 551                         errstr = "Journal has aborted";
 552                 else
 553                         errstr = "Readonly filesystem";
 554                 break;
 555         default:
 556                 /* If the caller passed in an extra buffer for unknown
 557                  * errors, textualise them now.  Else we just return
 558                  * NULL. */
 559                 if (nbuf) {
 560                         /* Check for truncated error codes... */
 561                         if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
 562                                 errstr = nbuf;
 563                 }
 564                 break;
 565         }
 566
 567         return errstr;
 568 }
 569
 570 /* __ext4_std_error decodes expected errors from journaling functions
 571  * automatically and invokes the appropriate error response.  */
 572
 573 void __ext4_std_error(struct super_block *sb, const char *function,
 574                       unsigned int line, int errno)
 575 {
 576         char nbuf[16];
 577         const char *errstr;
 578
 579         if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
 580                 return;
 581
 582         /* Special case: if the error is EROFS, and we're not already
 583          * inside a transaction, then there's really no point in logging
 584          * an error. */
 585         if (errno == -EROFS && journal_current_handle() == NULL &&
 586             (sb->s_flags & MS_RDONLY))
 587                 return;
 588
 589         if (ext4_error_ratelimit(sb)) {
 590                 errstr = ext4_decode_error(sb, errno, nbuf);
 591                 printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
 592                        sb->s_id, function, line, errstr);
 593         }
 594
 595         save_error_info(sb, function, line);
 596         ext4_handle_error(sb);
 597 }
 598
 599 /*
 600  * ext4_abort is a much stronger failure handler than ext4_error.  The
 601  * abort function may be used to deal with unrecoverable failures such
 602  * as journal IO errors or ENOMEM at a critical moment in log management.
 603  *
 604  * We unconditionally force the filesystem into an ABORT|READONLY state,
 605  * unless the error response on the fs has been set to panic in which
 606  * case we take the easy way out and panic immediately.
 607  */
 608
 609 void __ext4_abort(struct super_block *sb, const char *function,
 610                 unsigned int line, const char *fmt, ...)
 611 {
 612         struct va_format vaf;
 613         va_list args;
 614
 615         if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
 616                 return;
 617
 618         save_error_info(sb, function, line);
 619         va_start(args, fmt);
 620         vaf.fmt = fmt;
 621         vaf.va = &args;
 622         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: %pV\n",
 623                sb->s_id, function, line, &vaf);
 624         va_end(args);
 625
 626         if ((sb->s_flags & MS_RDONLY) == 0) {
 627                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 628                 EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
 629                 /*
 630                  * Make sure updated value of ->s_mount_flags will be visible
 631                  * before ->s_flags update
 632                  */
 633                 smp_wmb();
 634                 sb->s_flags |= MS_RDONLY;
 635                 if (EXT4_SB(sb)->s_journal)
 636                         jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
 637                 save_error_info(sb, function, line);
 638         }
 639         if (test_opt(sb, ERRORS_PANIC)) {
 640                 if (EXT4_SB(sb)->s_journal &&
 641                   !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
 642                         return;
 643                 panic("EXT4-fs panic from previous error\n");
 644         }
 645 }
 646
 647 void __ext4_msg(struct super_block *sb,
 648                 const char *prefix, const char *fmt, ...)
 649 {
 650         struct va_format vaf;
 651         va_list args;
 652
 653         if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state), "EXT4-fs"))
 654                 return;
 655
 656         va_start(args, fmt);
 657         vaf.fmt = fmt;
 658         vaf.va = &args;
 659         printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
 660         va_end(args);
 661 }
 662
 663 #define ext4_warning_ratelimit(sb)                                      \
 664                 ___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state), \
 665                              "EXT4-fs warning")
 666
 667 void __ext4_warning(struct super_block *sb, const char *function,
 668                     unsigned int line, const char *fmt, ...)
 669 {
 670         struct va_format vaf;
 671         va_list args;
 672
 673         if (!ext4_warning_ratelimit(sb))
 674                 return;
 675
 676         va_start(args, fmt);
 677         vaf.fmt = fmt;
 678         vaf.va = &args;
 679         printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
 680                sb->s_id, function, line, &vaf);
 681         va_end(args);
 682 }
 683
 684 void __ext4_warning_inode(const struct inode *inode, const char *function,
 685                           unsigned int line, const char *fmt, ...)
 686 {
 687         struct va_format vaf;
 688         va_list args;
 689
 690         if (!ext4_warning_ratelimit(inode->i_sb))
 691                 return;
 692
 693         va_start(args, fmt);
 694         vaf.fmt = fmt;
 695         vaf.va = &args;
 696         printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: "
 697                "inode #%lu: comm %s: %pV\n", inode->i_sb->s_id,
 698                function, line, inode->i_ino, current->comm, &vaf);
 699         va_end(args);
 700 }
 701
 702 void __ext4_grp_locked_error(const char *function, unsigned int line,
 703                              struct super_block *sb, ext4_group_t grp,
 704                              unsigned long ino, ext4_fsblk_t block,
 705                              const char *fmt, ...)
 706 __releases(bitlock)
 707 __acquires(bitlock)
 708 {
 709         struct va_format vaf;
 710         va_list args;
 711         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 712
 713         if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
 714                 return;
 715
 716         es->s_last_error_ino = cpu_to_le32(ino);
 717         es->s_last_error_block = cpu_to_le64(block);
 718         __save_error_info(sb, function, line);
 719
 720         if (ext4_error_ratelimit(sb)) {
 721                 va_start(args, fmt);
 722                 vaf.fmt = fmt;
 723                 vaf.va = &args;
 724                 printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
 725                        sb->s_id, function, line, grp);
 726                 if (ino)
 727                         printk(KERN_CONT "inode %lu: ", ino);
 728                 if (block)
 729                         printk(KERN_CONT "block %llu:",
 730                                (unsigned long long) block);
 731                 printk(KERN_CONT "%pV\n", &vaf);
 732                 va_end(args);
 733         }
 734
 735         if (test_opt(sb, ERRORS_CONT)) {
 736                 ext4_commit_super(sb, 0);
 737                 return;
 738         }
 739
 740         ext4_unlock_group(sb, grp);
 741         ext4_handle_error(sb);
 742         /*
 743          * We only get here in the ERRORS_RO case; relocking the group
 744          * may be dangerous, but nothing bad will happen since the
 745          * filesystem will have already been marked read/only and the
 746          * journal has been aborted.  We return 1 as a hint to callers
 747          * who might what to use the return value from
 748          * ext4_grp_locked_error() to distinguish between the
 749          * ERRORS_CONT and ERRORS_RO case, and perhaps return more
 750          * aggressively from the ext4 function in question, with a
 751          * more appropriate error code.
 752          */
 753         ext4_lock_group(sb, grp);
 754         return;
 755 }
 756
 757 void ext4_update_dynamic_rev(struct super_block *sb)
 758 {
 759         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 760
 761         if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
 762                 return;
 763
 764         ext4_warning(sb,
 765                      "updating to rev %d because of new feature flag, "
 766                      "running e2fsck is recommended",
 767                      EXT4_DYNAMIC_REV);
 768
 769         es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
 770         es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
 771         es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
 772         /* leave es->s_feature_*compat flags alone */
 773         /* es->s_uuid will be set by e2fsck if empty */
 774
 775         /*
 776          * The rest of the superblock fields should be zero, and if not it
 777          * means they are likely already in use, so leave them alone.  We
 778          * can leave it up to e2fsck to clean up any inconsistencies there.
 779          */
 780 }
 781
 782 /*
 783  * Open the external journal device
 784  */
 785 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
 786 {
 787         struct block_device *bdev;
 788         char b[BDEVNAME_SIZE];
 789
 790         bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
 791         if (IS_ERR(bdev))
 792                 goto fail;
 793         return bdev;
 794
 795 fail:
 796         ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
 797                         __bdevname(dev, b), PTR_ERR(bdev));
 798         return NULL;
 799 }
 800
 801 /*
 802  * Release the journal device
 803  */
 804 static void ext4_blkdev_put(struct block_device *bdev)
 805 {
 806         blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
 807 }
 808
 809 static void ext4_blkdev_remove(struct ext4_sb_info *sbi)
 810 {
 811         struct block_device *bdev;
 812         bdev = sbi->journal_bdev;
 813         if (bdev) {
 814                 ext4_blkdev_put(bdev);
 815                 sbi->journal_bdev = NULL;
 816         }
 817 }
 818
 819 static inline struct inode *orphan_list_entry(struct list_head *l)
 820 {
 821         return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
 822 }
 823
 824 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
 825 {
 826         struct list_head *l;
 827
 828         ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
 829                  le32_to_cpu(sbi->s_es->s_last_orphan));
 830
 831         printk(KERN_ERR "sb_info orphan list:\n");
 832         list_for_each(l, &sbi->s_orphan) {
 833                 struct inode *inode = orphan_list_entry(l);
 834                 printk(KERN_ERR "  "
 835                        "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
 836                        inode->i_sb->s_id, inode->i_ino, inode,
 837                        inode->i_mode, inode->i_nlink,
 838                        NEXT_ORPHAN(inode));
 839         }
 840 }
 841
 842 static void ext4_put_super(struct super_block *sb)
 843 {
 844         struct ext4_sb_info *sbi = EXT4_SB(sb);
 845         struct ext4_super_block *es = sbi->s_es;
 846         int aborted = 0;
 847         int i, err;
 848
 849         ext4_unregister_li_request(sb);
 850         dquot_disable(sb, -1, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
 851
 852         flush_workqueue(sbi->rsv_conversion_wq);
 853         destroy_workqueue(sbi->rsv_conversion_wq);
 854
 855         if (sbi->s_journal) {
 856                 aborted = is_journal_aborted(sbi->s_journal);
 857                 err = jbd2_journal_destroy(sbi->s_journal);
 858                 sbi->s_journal = NULL;
 859                 if ((err < 0) && !aborted)
 860                         ext4_abort(sb, "Couldn't clean up the journal");
 861         }
 862
 863         ext4_unregister_sysfs(sb);
 864         ext4_es_unregister_shrinker(sbi);
 865         del_timer_sync(&sbi->s_err_report);
 866         ext4_release_system_zone(sb);
 867         ext4_mb_release(sb);
 868         ext4_ext_release(sb);
 869
 870         if (!(sb->s_flags & MS_RDONLY) && !aborted) {
 871                 ext4_clear_feature_journal_needs_recovery(sb);
 872                 es->s_state = cpu_to_le16(sbi->s_mount_state);
 873         }
 874         if (!(sb->s_flags & MS_RDONLY))
 875                 ext4_commit_super(sb, 1);
 876
 877         for (i = 0; i < sbi->s_gdb_count; i++)
 878                 brelse(sbi->s_group_desc[i]);
 879         kvfree(sbi->s_group_desc);
 880         kvfree(sbi->s_flex_groups);
 881         percpu_counter_destroy(&sbi->s_freeclusters_counter);
 882         percpu_counter_destroy(&sbi->s_freeinodes_counter);
 883         percpu_counter_destroy(&sbi->s_dirs_counter);
 884         percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
 885         percpu_free_rwsem(&sbi->s_journal_flag_rwsem);
 886 #ifdef CONFIG_QUOTA
 887         for (i = 0; i < EXT4_MAXQUOTAS; i++)
 888                 kfree(sbi->s_qf_names[i]);
 889 #endif
 890
 891         /* Debugging code just in case the in-memory inode orphan list
 892          * isn't empty.  The on-disk one can be non-empty if we've
 893          * detected an error and taken the fs readonly, but the
 894          * in-memory list had better be clean by this point. */
 895         if (!list_empty(&sbi->s_orphan))
 896                 dump_orphan_list(sb, sbi);
 897         J_ASSERT(list_empty(&sbi->s_orphan));
 898
 899         sync_blockdev(sb->s_bdev);
 900         invalidate_bdev(sb->s_bdev);
 901         if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
 902                 /*
 903                  * Invalidate the journal device's buffers.  We don't want them
 904                  * floating about in memory - the physical journal device may
 905                  * hotswapped, and it breaks the `ro-after' testing code.
 906                  */
 907                 sync_blockdev(sbi->journal_bdev);
 908                 invalidate_bdev(sbi->journal_bdev);
 909                 ext4_blkdev_remove(sbi);
 910         }
 911         if (sbi->s_mb_cache) {
 912                 ext4_xattr_destroy_cache(sbi->s_mb_cache);
 913                 sbi->s_mb_cache = NULL;
 914         }
 915         if (sbi->s_mmp_tsk)
 916                 kthread_stop(sbi->s_mmp_tsk);
 917         brelse(sbi->s_sbh);
 918         sb->s_fs_info = NULL;
 919         /*
 920          * Now that we are completely done shutting down the
 921          * superblock, we need to actually destroy the kobject.
 922          */
 923         kobject_put(&sbi->s_kobj);
 924         wait_for_completion(&sbi->s_kobj_unregister);
 925         if (sbi->s_chksum_driver)
 926                 crypto_free_shash(sbi->s_chksum_driver);
 927         kfree(sbi->s_blockgroup_lock);
 928         kfree(sbi);
 929 }
 930
 931 static struct kmem_cache *ext4_inode_cachep;
 932
 933 /*
 934  * Called inside transaction, so use GFP_NOFS
 935  */
 936 static struct inode *ext4_alloc_inode(struct super_block *sb)
 937 {
 938         struct ext4_inode_info *ei;
 939
 940         ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
 941         if (!ei)
 942                 return NULL;
 943
 944         ei->vfs_inode.i_version = 1;
 945         spin_lock_init(&ei->i_raw_lock);
 946         INIT_LIST_HEAD(&ei->i_prealloc_list);
 947         spin_lock_init(&ei->i_prealloc_lock);
 948         ext4_es_init_tree(&ei->i_es_tree);
 949         rwlock_init(&ei->i_es_lock);
 950         INIT_LIST_HEAD(&ei->i_es_list);
 951         ei->i_es_all_nr = 0;
 952         ei->i_es_shk_nr = 0;
 953         ei->i_es_shrink_lblk = 0;
 954         ei->i_reserved_data_blocks = 0;
 955         ei->i_reserved_meta_blocks = 0;
 956         ei->i_allocated_meta_blocks = 0;
 957         ei->i_da_metadata_calc_len = 0;
 958         ei->i_da_metadata_calc_last_lblock = 0;
 959         spin_lock_init(&(ei->i_block_reservation_lock));
 960 #ifdef CONFIG_QUOTA
 961         ei->i_reserved_quota = 0;
 962         memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
 963 #endif
 964         ei->jinode = NULL;
 965         INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
 966         spin_lock_init(&ei->i_completed_io_lock);
 967         ei->i_sync_tid = 0;
 968         ei->i_datasync_tid = 0;
 969         atomic_set(&ei->i_unwritten, 0);
 970         INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
 971         return &ei->vfs_inode;
 972 }
 973
 974 static int ext4_drop_inode(struct inode *inode)
 975 {
 976         int drop = generic_drop_inode(inode);
 977
 978         trace_ext4_drop_inode(inode, drop);
 979         return drop;
 980 }
 981
 982 static void ext4_i_callback(struct rcu_head *head)
 983 {
 984         struct inode *inode = container_of(head, struct inode, i_rcu);
 985         kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
 986 }
 987
 988 static void ext4_destroy_inode(struct inode *inode)
 989 {
 990         if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
 991                 ext4_msg(inode->i_sb, KERN_ERR,
 992                          "Inode %lu (%p): orphan list check failed!",
 993                          inode->i_ino, EXT4_I(inode));
 994                 print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
 995                                 EXT4_I(inode), sizeof(struct ext4_inode_info),
 996                                 true);
 997                 dump_stack();
 998         }
 999         call_rcu(&inode->i_rcu, ext4_i_callback);
1000 }
1001
1002 static void init_once(void *foo)
1003 {
1004         struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
1005
1006         INIT_LIST_HEAD(&ei->i_orphan);
1007         init_rwsem(&ei->xattr_sem);
1008         init_rwsem(&ei->i_data_sem);
1009         init_rwsem(&ei->i_mmap_sem);
1010         inode_init_once(&ei->vfs_inode);
1011 }
1012
1013 static int __init init_inodecache(void)
1014 {
1015         ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
1016                                              sizeof(struct ext4_inode_info),
1017                                              0, (SLAB_RECLAIM_ACCOUNT|
1018                                                 SLAB_MEM_SPREAD|SLAB_ACCOUNT),
1019                                              init_once);
1020         if (ext4_inode_cachep == NULL)
1021                 return -ENOMEM;
1022         return 0;
1023 }
1024
1025 static void destroy_inodecache(void)
1026 {
1027         /*
1028          * Make sure all delayed rcu free inodes are flushed before we
1029          * destroy cache.
1030          */
1031         rcu_barrier();
1032         kmem_cache_destroy(ext4_inode_cachep);
1033 }
1034
1035 void ext4_clear_inode(struct inode *inode)
1036 {
1037         invalidate_inode_buffers(inode);
1038         clear_inode(inode);
1039         dquot_drop(inode);
1040         ext4_discard_preallocations(inode);
1041         ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
1042         if (EXT4_I(inode)->jinode) {
1043                 jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
1044                                                EXT4_I(inode)->jinode);
1045                 jbd2_free_inode(EXT4_I(inode)->jinode);
1046                 EXT4_I(inode)->jinode = NULL;
1047         }
1048 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1049         fscrypt_put_encryption_info(inode, NULL);
1050 #endif
1051 }
1052
1053 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1054                                         u64 ino, u32 generation)
1055 {
1056         struct inode *inode;
1057
1058         if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
1059                 return ERR_PTR(-ESTALE);
1060         if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
1061                 return ERR_PTR(-ESTALE);
1062
1063         /* iget isn't really right if the inode is currently unallocated!!
1064          *
1065          * ext4_read_inode will return a bad_inode if the inode had been
1066          * deleted, so we should be safe.
1067          *
1068          * Currently we don't know the generation for parent directory, so
1069          * a generation of 0 means "accept any"
1070          */
1071         inode = ext4_iget_normal(sb, ino);
1072         if (IS_ERR(inode))
1073                 return ERR_CAST(inode);
1074         if (generation && inode->i_generation != generation) {
1075                 iput(inode);
1076                 return ERR_PTR(-ESTALE);
1077         }
1078
1079         return inode;
1080 }
1081
1082 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1083                                         int fh_len, int fh_type)
1084 {
1085         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1086                                     ext4_nfs_get_inode);
1087 }
1088
1089 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1090                                         int fh_len, int fh_type)
1091 {
1092         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1093                                     ext4_nfs_get_inode);
1094 }
1095
1096 /*
1097  * Try to release metadata pages (indirect blocks, directories) which are
1098  * mapped via the block device.  Since these pages could have journal heads
1099  * which would prevent try_to_free_buffers() from freeing them, we must use
1100  * jbd2 layer's try_to_free_buffers() function to release them.
1101  */
1102 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1103                                  gfp_t wait)
1104 {
1105         journal_t *journal = EXT4_SB(sb)->s_journal;
1106
1107         WARN_ON(PageChecked(page));
1108         if (!page_has_buffers(page))
1109                 return 0;
1110         if (journal)
1111                 return jbd2_journal_try_to_free_buffers(journal, page,
1112                                                 wait & ~__GFP_DIRECT_RECLAIM);
1113         return try_to_free_buffers(page);
1114 }
1115
1116 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1117 static int ext4_get_context(struct inode *inode, void *ctx, size_t len)
1118 {
1119         return ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION,
1120                                  EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, ctx, len);
1121 }
1122
1123 static int ext4_prepare_context(struct inode *inode)
1124 {
1125         return ext4_convert_inline_data(inode);
1126 }
1127
1128 static int ext4_set_context(struct inode *inode, const void *ctx, size_t len,
1129                                                         void *fs_data)
1130 {
1131         handle_t *handle = fs_data;
1132         int res, res2, retries = 0;
1133
1134         /*
1135          * If a journal handle was specified, then the encryption context is
1136          * being set on a new inode via inheritance and is part of a larger
1137          * transaction to create the inode.  Otherwise the encryption context is
1138          * being set on an existing inode in its own transaction.  Only in the
1139          * latter case should the "retry on ENOSPC" logic be used.
1140          */
1141
1142         if (handle) {
1143                 res = ext4_xattr_set_handle(handle, inode,
1144                                             EXT4_XATTR_INDEX_ENCRYPTION,
1145                                             EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1146                                             ctx, len, 0);
1147                 if (!res) {
1148                         ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1149                         ext4_clear_inode_state(inode,
1150                                         EXT4_STATE_MAY_INLINE_DATA);
1151                         /*
1152                          * Update inode->i_flags - e.g. S_DAX may get disabled
1153                          */
1154                         ext4_set_inode_flags(inode);
1155                 }
1156                 return res;
1157         }
1158
1159 retry:
1160         handle = ext4_journal_start(inode, EXT4_HT_MISC,
1161                         ext4_jbd2_credits_xattr(inode));
1162         if (IS_ERR(handle))
1163                 return PTR_ERR(handle);
1164
1165         res = ext4_xattr_set_handle(handle, inode, EXT4_XATTR_INDEX_ENCRYPTION,
1166                                     EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1167                                     ctx, len, 0);
1168         if (!res) {
1169                 ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1170                 /* Update inode->i_flags - e.g. S_DAX may get disabled */
1171                 ext4_set_inode_flags(inode);
1172                 res = ext4_mark_inode_dirty(handle, inode);
1173                 if (res)
1174                         EXT4_ERROR_INODE(inode, "Failed to mark inode dirty");
1175         }
1176         res2 = ext4_journal_stop(handle);
1177
1178         if (res == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
1179                 goto retry;
1180         if (!res)
1181                 res = res2;
1182         return res;
1183 }
1184
1185 static int ext4_dummy_context(struct inode *inode)
1186 {
1187         return DUMMY_ENCRYPTION_ENABLED(EXT4_SB(inode->i_sb));
1188 }
1189
1190 static unsigned ext4_max_namelen(struct inode *inode)
1191 {
1192         return S_ISLNK(inode->i_mode) ? inode->i_sb->s_blocksize :
1193                 EXT4_NAME_LEN;
1194 }
1195
1196 static const struct fscrypt_operations ext4_cryptops = {
1197         .key_prefix             = "ext4:",
1198         .get_context            = ext4_get_context,
1199         .prepare_context        = ext4_prepare_context,
1200         .set_context            = ext4_set_context,
1201         .dummy_context          = ext4_dummy_context,
1202         .is_encrypted           = ext4_encrypted_inode,
1203         .empty_dir              = ext4_empty_dir,
1204         .max_namelen            = ext4_max_namelen,
1205 };
1206 #else
1207 static const struct fscrypt_operations ext4_cryptops = {
1208         .is_encrypted           = ext4_encrypted_inode,
1209 };
1210 #endif
1211
1212 #ifdef CONFIG_QUOTA
1213 static char *quotatypes[] = INITQFNAMES;
1214 #define QTYPE2NAME(t) (quotatypes[t])
1215
1216 static int ext4_write_dquot(struct dquot *dquot);
1217 static int ext4_acquire_dquot(struct dquot *dquot);
1218 static int ext4_release_dquot(struct dquot *dquot);
1219 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1220 static int ext4_write_info(struct super_block *sb, int type);
1221 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1222                          const struct path *path);
1223 static int ext4_quota_off(struct super_block *sb, int type);
1224 static int ext4_quota_on_mount(struct super_block *sb, int type);
1225 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1226                                size_t len, loff_t off);
1227 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1228                                 const char *data, size_t len, loff_t off);
1229 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1230                              unsigned int flags);
1231 static int ext4_enable_quotas(struct super_block *sb);
1232 static int ext4_get_next_id(struct super_block *sb, struct kqid *qid);
1233
1234 static struct dquot **ext4_get_dquots(struct inode *inode)
1235 {
1236         return EXT4_I(inode)->i_dquot;
1237 }
1238
1239 static const struct dquot_operations ext4_quota_operations = {
1240         .get_reserved_space = ext4_get_reserved_space,
1241         .write_dquot    = ext4_write_dquot,
1242         .acquire_dquot  = ext4_acquire_dquot,
1243         .release_dquot  = ext4_release_dquot,
1244         .mark_dirty     = ext4_mark_dquot_dirty,
1245         .write_info     = ext4_write_info,
1246         .alloc_dquot    = dquot_alloc,
1247         .destroy_dquot  = dquot_destroy,
1248         .get_projid     = ext4_get_projid,
1249         .get_next_id    = ext4_get_next_id,
1250 };
1251
1252 static const struct quotactl_ops ext4_qctl_operations = {
1253         .quota_on       = ext4_quota_on,
1254         .quota_off      = ext4_quota_off,
1255         .quota_sync     = dquot_quota_sync,
1256         .get_state      = dquot_get_state,
1257         .set_info       = dquot_set_dqinfo,
1258         .get_dqblk      = dquot_get_dqblk,
1259         .set_dqblk      = dquot_set_dqblk,
1260         .get_nextdqblk  = dquot_get_next_dqblk,
1261 };
1262 #endif
1263
1264 static const struct super_operations ext4_sops = {
1265         .alloc_inode    = ext4_alloc_inode,
1266         .destroy_inode  = ext4_destroy_inode,
1267         .write_inode    = ext4_write_inode,
1268         .dirty_inode    = ext4_dirty_inode,
1269         .drop_inode     = ext4_drop_inode,
1270         .evict_inode    = ext4_evict_inode,
1271         .put_super      = ext4_put_super,
1272         .sync_fs        = ext4_sync_fs,
1273         .freeze_fs      = ext4_freeze,
1274         .unfreeze_fs    = ext4_unfreeze,
1275         .statfs         = ext4_statfs,
1276         .remount_fs     = ext4_remount,
1277         .show_options   = ext4_show_options,
1278 #ifdef CONFIG_QUOTA
1279         .quota_read     = ext4_quota_read,
1280         .quota_write    = ext4_quota_write,
1281         .get_dquots     = ext4_get_dquots,
1282 #endif
1283         .bdev_try_to_free_page = bdev_try_to_free_page,
1284 };
1285
1286 static const struct export_operations ext4_export_ops = {
1287         .fh_to_dentry = ext4_fh_to_dentry,
1288         .fh_to_parent = ext4_fh_to_parent,
1289         .get_parent = ext4_get_parent,
1290 };
1291
1292 enum {
1293         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1294         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1295         Opt_nouid32, Opt_debug, Opt_removed,
1296         Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1297         Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1298         Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1299         Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1300         Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1301         Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
1302         Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1303         Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1304         Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1305         Opt_usrquota, Opt_grpquota, Opt_prjquota, Opt_i_version, Opt_dax,
1306         Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_mblk_io_submit,
1307         Opt_lazytime, Opt_nolazytime, Opt_debug_want_extra_isize,
1308         Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1309         Opt_inode_readahead_blks, Opt_journal_ioprio,
1310         Opt_dioread_nolock, Opt_dioread_lock,
1311         Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1312         Opt_max_dir_size_kb, Opt_nojournal_checksum,
1313 };
1314
1315 static const match_table_t tokens = {
1316         {Opt_bsd_df, "bsddf"},
1317         {Opt_minix_df, "minixdf"},
1318         {Opt_grpid, "grpid"},
1319         {Opt_grpid, "bsdgroups"},
1320         {Opt_nogrpid, "nogrpid"},
1321         {Opt_nogrpid, "sysvgroups"},
1322         {Opt_resgid, "resgid=%u"},
1323         {Opt_resuid, "resuid=%u"},
1324         {Opt_sb, "sb=%u"},
1325         {Opt_err_cont, "errors=continue"},
1326         {Opt_err_panic, "errors=panic"},
1327         {Opt_err_ro, "errors=remount-ro"},
1328         {Opt_nouid32, "nouid32"},
1329         {Opt_debug, "debug"},
1330         {Opt_removed, "oldalloc"},
1331         {Opt_removed, "orlov"},
1332         {Opt_user_xattr, "user_xattr"},
1333         {Opt_nouser_xattr, "nouser_xattr"},
1334         {Opt_acl, "acl"},
1335         {Opt_noacl, "noacl"},
1336         {Opt_noload, "norecovery"},
1337         {Opt_noload, "noload"},
1338         {Opt_removed, "nobh"},
1339         {Opt_removed, "bh"},
1340         {Opt_commit, "commit=%u"},
1341         {Opt_min_batch_time, "min_batch_time=%u"},
1342         {Opt_max_batch_time, "max_batch_time=%u"},
1343         {Opt_journal_dev, "journal_dev=%u"},
1344         {Opt_journal_path, "journal_path=%s"},
1345         {Opt_journal_checksum, "journal_checksum"},
1346         {Opt_nojournal_checksum, "nojournal_checksum"},
1347         {Opt_journal_async_commit, "journal_async_commit"},
1348         {Opt_abort, "abort"},
1349         {Opt_data_journal, "data=journal"},
1350         {Opt_data_ordered, "data=ordered"},
1351         {Opt_data_writeback, "data=writeback"},
1352         {Opt_data_err_abort, "data_err=abort"},
1353         {Opt_data_err_ignore, "data_err=ignore"},
1354         {Opt_offusrjquota, "usrjquota="},
1355         {Opt_usrjquota, "usrjquota=%s"},
1356         {Opt_offgrpjquota, "grpjquota="},
1357         {Opt_grpjquota, "grpjquota=%s"},
1358         {Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1359         {Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1360         {Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1361         {Opt_grpquota, "grpquota"},
1362         {Opt_noquota, "noquota"},
1363         {Opt_quota, "quota"},
1364         {Opt_usrquota, "usrquota"},
1365         {Opt_prjquota, "prjquota"},
1366         {Opt_barrier, "barrier=%u"},
1367         {Opt_barrier, "barrier"},
1368         {Opt_nobarrier, "nobarrier"},
1369         {Opt_i_version, "i_version"},
1370         {Opt_dax, "dax"},
1371         {Opt_stripe, "stripe=%u"},
1372         {Opt_delalloc, "delalloc"},
1373         {Opt_lazytime, "lazytime"},
1374         {Opt_nolazytime, "nolazytime"},
1375         {Opt_debug_want_extra_isize, "debug_want_extra_isize=%u"},
1376         {Opt_nodelalloc, "nodelalloc"},
1377         {Opt_removed, "mblk_io_submit"},
1378         {Opt_removed, "nomblk_io_submit"},
1379         {Opt_block_validity, "block_validity"},
1380         {Opt_noblock_validity, "noblock_validity"},
1381         {Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1382         {Opt_journal_ioprio, "journal_ioprio=%u"},
1383         {Opt_auto_da_alloc, "auto_da_alloc=%u"},
1384         {Opt_auto_da_alloc, "auto_da_alloc"},
1385         {Opt_noauto_da_alloc, "noauto_da_alloc"},
1386         {Opt_dioread_nolock, "dioread_nolock"},
1387         {Opt_dioread_lock, "dioread_lock"},
1388         {Opt_discard, "discard"},
1389         {Opt_nodiscard, "nodiscard"},
1390         {Opt_init_itable, "init_itable=%u"},
1391         {Opt_init_itable, "init_itable"},
1392         {Opt_noinit_itable, "noinit_itable"},
1393         {Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1394         {Opt_test_dummy_encryption, "test_dummy_encryption"},
1395         {Opt_removed, "check=none"},    /* mount option from ext2/3 */
1396         {Opt_removed, "nocheck"},       /* mount option from ext2/3 */
1397         {Opt_removed, "reservation"},   /* mount option from ext2/3 */
1398         {Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1399         {Opt_removed, "journal=%u"},    /* mount option from ext2/3 */
1400         {Opt_err, NULL},
1401 };
1402
1403 static ext4_fsblk_t get_sb_block(void **data)
1404 {
1405         ext4_fsblk_t    sb_block;
1406         char            *options = (char *) *data;
1407
1408         if (!options || strncmp(options, "sb=", 3) != 0)
1409                 return 1;       /* Default location */
1410
1411         options += 3;
1412         /* TODO: use simple_strtoll with >32bit ext4 */
1413         sb_block = simple_strtoul(options, &options, 0);
1414         if (*options && *options != ',') {
1415                 printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1416                        (char *) *data);
1417                 return 1;
1418         }
1419         if (*options == ',')
1420                 options++;
1421         *data = (void *) options;
1422
1423         return sb_block;
1424 }
1425
1426 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1427 static char deprecated_msg[] = "Mount option \"%s\" will be removed by %s\n"
1428         "Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1429
1430 #ifdef CONFIG_QUOTA
1431 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1432 {
1433         struct ext4_sb_info *sbi = EXT4_SB(sb);
1434         char *qname;
1435         int ret = -1;
1436
1437         if (sb_any_quota_loaded(sb) &&
1438                 !sbi->s_qf_names[qtype]) {
1439                 ext4_msg(sb, KERN_ERR,
1440                         "Cannot change journaled "
1441                         "quota options when quota turned on");
1442                 return -1;
1443         }
1444         if (ext4_has_feature_quota(sb)) {
1445                 ext4_msg(sb, KERN_INFO, "Journaled quota options "
1446                          "ignored when QUOTA feature is enabled");
1447                 return 1;
1448         }
1449         qname = match_strdup(args);
1450         if (!qname) {
1451                 ext4_msg(sb, KERN_ERR,
1452                         "Not enough memory for storing quotafile name");
1453                 return -1;
1454         }
1455         if (sbi->s_qf_names[qtype]) {
1456                 if (strcmp(sbi->s_qf_names[qtype], qname) == 0)
1457                         ret = 1;
1458                 else
1459                         ext4_msg(sb, KERN_ERR,
1460                                  "%s quota file already specified",
1461                                  QTYPE2NAME(qtype));
1462                 goto errout;
1463         }
1464         if (strchr(qname, '/')) {
1465                 ext4_msg(sb, KERN_ERR,
1466                         "quotafile must be on filesystem root");
1467                 goto errout;
1468         }
1469         sbi->s_qf_names[qtype] = qname;
1470         set_opt(sb, QUOTA);
1471         return 1;
1472 errout:
1473         kfree(qname);
1474         return ret;
1475 }
1476
1477 static int clear_qf_name(struct super_block *sb, int qtype)
1478 {
1479
1480         struct ext4_sb_info *sbi = EXT4_SB(sb);
1481
1482         if (sb_any_quota_loaded(sb) &&
1483                 sbi->s_qf_names[qtype]) {
1484                 ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1485                         " when quota turned on");
1486                 return -1;
1487         }
1488         kfree(sbi->s_qf_names[qtype]);
1489         sbi->s_qf_names[qtype] = NULL;
1490         return 1;
1491 }
1492 #endif
1493
1494 #define MOPT_SET        0x0001
1495 #define MOPT_CLEAR      0x0002
1496 #define MOPT_NOSUPPORT  0x0004
1497 #define MOPT_EXPLICIT   0x0008
1498 #define MOPT_CLEAR_ERR  0x0010
1499 #define MOPT_GTE0       0x0020
1500 #ifdef CONFIG_QUOTA
1501 #define MOPT_Q          0
1502 #define MOPT_QFMT       0x0040
1503 #else
1504 #define MOPT_Q          MOPT_NOSUPPORT
1505 #define MOPT_QFMT       MOPT_NOSUPPORT
1506 #endif
1507 #define MOPT_DATAJ      0x0080
1508 #define MOPT_NO_EXT2    0x0100
1509 #define MOPT_NO_EXT3    0x0200
1510 #define MOPT_EXT4_ONLY  (MOPT_NO_EXT2 | MOPT_NO_EXT3)
1511 #define MOPT_STRING     0x0400
1512
1513 static const struct mount_opts {
1514         int     token;
1515         int     mount_opt;
1516         int     flags;
1517 } ext4_mount_opts[] = {
1518         {Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1519         {Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1520         {Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1521         {Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1522         {Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1523         {Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1524         {Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1525          MOPT_EXT4_ONLY | MOPT_SET},
1526         {Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1527          MOPT_EXT4_ONLY | MOPT_CLEAR},
1528         {Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1529         {Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1530         {Opt_delalloc, EXT4_MOUNT_DELALLOC,
1531          MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1532         {Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1533          MOPT_EXT4_ONLY | MOPT_CLEAR},
1534         {Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1535          MOPT_EXT4_ONLY | MOPT_CLEAR},
1536         {Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1537          MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1538         {Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1539                                     EXT4_MOUNT_JOURNAL_CHECKSUM),
1540          MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1541         {Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1542         {Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1543         {Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1544         {Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1545         {Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
1546          MOPT_NO_EXT2},
1547         {Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
1548          MOPT_NO_EXT2},
1549         {Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1550         {Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1551         {Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1552         {Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1553         {Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1554         {Opt_commit, 0, MOPT_GTE0},
1555         {Opt_max_batch_time, 0, MOPT_GTE0},
1556         {Opt_min_batch_time, 0, MOPT_GTE0},
1557         {Opt_inode_readahead_blks, 0, MOPT_GTE0},
1558         {Opt_init_itable, 0, MOPT_GTE0},
1559         {Opt_dax, EXT4_MOUNT_DAX, MOPT_SET},
1560         {Opt_stripe, 0, MOPT_GTE0},
1561         {Opt_resuid, 0, MOPT_GTE0},
1562         {Opt_resgid, 0, MOPT_GTE0},
1563         {Opt_journal_dev, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1564         {Opt_journal_path, 0, MOPT_NO_EXT2 | MOPT_STRING},
1565         {Opt_journal_ioprio, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1566         {Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1567         {Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1568         {Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
1569          MOPT_NO_EXT2 | MOPT_DATAJ},
1570         {Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1571         {Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1572 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1573         {Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1574         {Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1575 #else
1576         {Opt_acl, 0, MOPT_NOSUPPORT},
1577         {Opt_noacl, 0, MOPT_NOSUPPORT},
1578 #endif
1579         {Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1580         {Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1581         {Opt_debug_want_extra_isize, 0, MOPT_GTE0},
1582         {Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1583         {Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1584                                                         MOPT_SET | MOPT_Q},
1585         {Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1586                                                         MOPT_SET | MOPT_Q},
1587         {Opt_prjquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_PRJQUOTA,
1588                                                         MOPT_SET | MOPT_Q},
1589         {Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1590                        EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA),
1591                                                         MOPT_CLEAR | MOPT_Q},
1592         {Opt_usrjquota, 0, MOPT_Q},
1593         {Opt_grpjquota, 0, MOPT_Q},
1594         {Opt_offusrjquota, 0, MOPT_Q},
1595         {Opt_offgrpjquota, 0, MOPT_Q},
1596         {Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1597         {Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1598         {Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1599         {Opt_max_dir_size_kb, 0, MOPT_GTE0},
1600         {Opt_test_dummy_encryption, 0, MOPT_GTE0},
1601         {Opt_err, 0, 0}
1602 };
1603
1604 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1605                             substring_t *args, unsigned long *journal_devnum,
1606                             unsigned int *journal_ioprio, int is_remount)
1607 {
1608         struct ext4_sb_info *sbi = EXT4_SB(sb);
1609         const struct mount_opts *m;
1610         kuid_t uid;
1611         kgid_t gid;
1612         int arg = 0;
1613
1614 #ifdef CONFIG_QUOTA
1615         if (token == Opt_usrjquota)
1616                 return set_qf_name(sb, USRQUOTA, &args[0]);
1617         else if (token == Opt_grpjquota)
1618                 return set_qf_name(sb, GRPQUOTA, &args[0]);
1619         else if (token == Opt_offusrjquota)
1620                 return clear_qf_name(sb, USRQUOTA);
1621         else if (token == Opt_offgrpjquota)
1622                 return clear_qf_name(sb, GRPQUOTA);
1623 #endif
1624         switch (token) {
1625         case Opt_noacl:
1626         case Opt_nouser_xattr:
1627                 ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1628                 break;
1629         case Opt_sb:
1630                 return 1;       /* handled by get_sb_block() */
1631         case Opt_removed:
1632                 ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
1633                 return 1;
1634         case Opt_abort:
1635                 sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1636                 return 1;
1637         case Opt_i_version:
1638                 sb->s_flags |= MS_I_VERSION;
1639                 return 1;
1640         case Opt_lazytime:
1641                 sb->s_flags |= MS_LAZYTIME;
1642                 return 1;
1643         case Opt_nolazytime:
1644                 sb->s_flags &= ~MS_LAZYTIME;
1645                 return 1;
1646         }
1647
1648         for (m = ext4_mount_opts; m->token != Opt_err; m++)
1649                 if (token == m->token)
1650                         break;
1651
1652         if (m->token == Opt_err) {
1653                 ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1654                          "or missing value", opt);
1655                 return -1;
1656         }
1657
1658         if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
1659                 ext4_msg(sb, KERN_ERR,
1660                          "Mount option \"%s\" incompatible with ext2", opt);
1661                 return -1;
1662         }
1663         if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
1664                 ext4_msg(sb, KERN_ERR,
1665                          "Mount option \"%s\" incompatible with ext3", opt);
1666                 return -1;
1667         }
1668
1669         if (args->from && !(m->flags & MOPT_STRING) && match_int(args, &arg))
1670                 return -1;
1671         if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1672                 return -1;
1673         if (m->flags & MOPT_EXPLICIT) {
1674                 if (m->mount_opt & EXT4_MOUNT_DELALLOC) {
1675                         set_opt2(sb, EXPLICIT_DELALLOC);
1676                 } else if (m->mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) {
1677                         set_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM);
1678                 } else
1679                         return -1;
1680         }
1681         if (m->flags & MOPT_CLEAR_ERR)
1682                 clear_opt(sb, ERRORS_MASK);
1683         if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1684                 ext4_msg(sb, KERN_ERR, "Cannot change quota "
1685                          "options when quota turned on");
1686                 return -1;
1687         }
1688
1689         if (m->flags & MOPT_NOSUPPORT) {
1690                 ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1691         } else if (token == Opt_commit) {
1692                 if (arg == 0)
1693                         arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1694                 sbi->s_commit_interval = HZ * arg;
1695         } else if (token == Opt_debug_want_extra_isize) {
1696                 sbi->s_want_extra_isize = arg;
1697         } else if (token == Opt_max_batch_time) {
1698                 sbi->s_max_batch_time = arg;
1699         } else if (token == Opt_min_batch_time) {
1700                 sbi->s_min_batch_time = arg;
1701         } else if (token == Opt_inode_readahead_blks) {
1702                 if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
1703                         ext4_msg(sb, KERN_ERR,
1704                                  "EXT4-fs: inode_readahead_blks must be "
1705                                  "0 or a power of 2 smaller than 2^31");
1706                         return -1;
1707                 }
1708                 sbi->s_inode_readahead_blks = arg;
1709         } else if (token == Opt_init_itable) {
1710                 set_opt(sb, INIT_INODE_TABLE);
1711                 if (!args->from)
1712                         arg = EXT4_DEF_LI_WAIT_MULT;
1713                 sbi->s_li_wait_mult = arg;
1714         } else if (token == Opt_max_dir_size_kb) {
1715                 sbi->s_max_dir_size_kb = arg;
1716         } else if (token == Opt_stripe) {
1717                 sbi->s_stripe = arg;
1718         } else if (token == Opt_resuid) {
1719                 uid = make_kuid(current_user_ns(), arg);
1720                 if (!uid_valid(uid)) {
1721                         ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
1722                         return -1;
1723                 }
1724                 sbi->s_resuid = uid;
1725         } else if (token == Opt_resgid) {
1726                 gid = make_kgid(current_user_ns(), arg);
1727                 if (!gid_valid(gid)) {
1728                         ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
1729                         return -1;
1730                 }
1731                 sbi->s_resgid = gid;
1732         } else if (token == Opt_journal_dev) {
1733                 if (is_remount) {
1734                         ext4_msg(sb, KERN_ERR,
1735                                  "Cannot specify journal on remount");
1736                         return -1;
1737                 }
1738                 *journal_devnum = arg;
1739         } else if (token == Opt_journal_path) {
1740                 char *journal_path;
1741                 struct inode *journal_inode;
1742                 struct path path;
1743                 int error;
1744
1745                 if (is_remount) {
1746                         ext4_msg(sb, KERN_ERR,
1747                                  "Cannot specify journal on remount");
1748                         return -1;
1749                 }
1750                 journal_path = match_strdup(&args[0]);
1751                 if (!journal_path) {
1752                         ext4_msg(sb, KERN_ERR, "error: could not dup "
1753                                 "journal device string");
1754                         return -1;
1755                 }
1756
1757                 error = kern_path(journal_path, LOOKUP_FOLLOW, &path);
1758                 if (error) {
1759                         ext4_msg(sb, KERN_ERR, "error: could not find "
1760                                 "journal device path: error %d", error);
1761                         kfree(journal_path);
1762                         return -1;
1763                 }
1764
1765                 journal_inode = d_inode(path.dentry);
1766                 if (!S_ISBLK(journal_inode->i_mode)) {
1767                         ext4_msg(sb, KERN_ERR, "error: journal path %s "
1768                                 "is not a block device", journal_path);
1769                         path_put(&path);
1770                         kfree(journal_path);
1771                         return -1;
1772                 }
1773
1774                 *journal_devnum = new_encode_dev(journal_inode->i_rdev);
1775                 path_put(&path);
1776                 kfree(journal_path);
1777         } else if (token == Opt_journal_ioprio) {
1778                 if (arg > 7) {
1779                         ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
1780                                  " (must be 0-7)");
1781                         return -1;
1782                 }
1783                 *journal_ioprio =
1784                         IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
1785         } else if (token == Opt_test_dummy_encryption) {
1786 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1787                 sbi->s_mount_flags |= EXT4_MF_TEST_DUMMY_ENCRYPTION;
1788                 ext4_msg(sb, KERN_WARNING,
1789                          "Test dummy encryption mode enabled");
1790 #else
1791                 ext4_msg(sb, KERN_WARNING,
1792                          "Test dummy encryption mount option ignored");
1793 #endif
1794         } else if (m->flags & MOPT_DATAJ) {
1795                 if (is_remount) {
1796                         if (!sbi->s_journal)
1797                                 ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
1798                         else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
1799                                 ext4_msg(sb, KERN_ERR,
1800                                          "Cannot change data mode on remount");
1801                                 return -1;
1802                         }
1803                 } else {
1804                         clear_opt(sb, DATA_FLAGS);
1805                         sbi->s_mount_opt |= m->mount_opt;
1806                 }
1807 #ifdef CONFIG_QUOTA
1808         } else if (m->flags & MOPT_QFMT) {
1809                 if (sb_any_quota_loaded(sb) &&
1810                     sbi->s_jquota_fmt != m->mount_opt) {
1811                         ext4_msg(sb, KERN_ERR, "Cannot change journaled "
1812                                  "quota options when quota turned on");
1813                         return -1;
1814                 }
1815                 if (ext4_has_feature_quota(sb)) {
1816                         ext4_msg(sb, KERN_INFO,
1817                                  "Quota format mount options ignored "
1818                                  "when QUOTA feature is enabled");
1819                         return 1;
1820                 }
1821                 sbi->s_jquota_fmt = m->mount_opt;
1822 #endif
1823         } else if (token == Opt_dax) {
1824 #ifdef CONFIG_FS_DAX
1825                 ext4_msg(sb, KERN_WARNING,
1826                 "DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
1827                         sbi->s_mount_opt |= m->mount_opt;
1828 #else
1829                 ext4_msg(sb, KERN_INFO, "dax option not supported");
1830                 return -1;
1831 #endif
1832         } else if (token == Opt_data_err_abort) {
1833                 sbi->s_mount_opt |= m->mount_opt;
1834         } else if (token == Opt_data_err_ignore) {
1835                 sbi->s_mount_opt &= ~m->mount_opt;
1836         } else {
1837                 if (!args->from)
1838                         arg = 1;
1839                 if (m->flags & MOPT_CLEAR)
1840                         arg = !arg;
1841                 else if (unlikely(!(m->flags & MOPT_SET))) {
1842                         ext4_msg(sb, KERN_WARNING,
1843                                  "buggy handling of option %s", opt);
1844                         WARN_ON(1);
1845                         return -1;
1846                 }
1847                 if (arg != 0)
1848                         sbi->s_mount_opt |= m->mount_opt;
1849                 else
1850                         sbi->s_mount_opt &= ~m->mount_opt;
1851         }
1852         return 1;
1853 }
1854
1855 static int parse_options(char *options, struct super_block *sb,
1856                          unsigned long *journal_devnum,
1857                          unsigned int *journal_ioprio,
1858                          int is_remount)
1859 {
1860         struct ext4_sb_info *sbi = EXT4_SB(sb);
1861         char *p;
1862         substring_t args[MAX_OPT_ARGS];
1863         int token;
1864
1865         if (!options)
1866                 return 1;
1867
1868         while ((p = strsep(&options, ",")) != NULL) {
1869                 if (!*p)
1870                         continue;
1871                 /*
1872                  * Initialize args struct so we know whether arg was
1873                  * found; some options take optional arguments.
1874                  */
1875                 args[0].to = args[0].from = NULL;
1876                 token = match_token(p, tokens, args);
1877                 if (handle_mount_opt(sb, p, token, args, journal_devnum,
1878                                      journal_ioprio, is_remount) < 0)
1879                         return 0;
1880         }
1881 #ifdef CONFIG_QUOTA
1882         /*
1883          * We do the test below only for project quotas. 'usrquota' and
1884          * 'grpquota' mount options are allowed even without quota feature
1885          * to support legacy quotas in quota files.
1886          */
1887         if (test_opt(sb, PRJQUOTA) && !ext4_has_feature_project(sb)) {
1888                 ext4_msg(sb, KERN_ERR, "Project quota feature not enabled. "
1889                          "Cannot enable project quota enforcement.");
1890                 return 0;
1891         }
1892         if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1893                 if (test_opt(sb, USRQUOTA) && sbi->s_qf_names[USRQUOTA])
1894                         clear_opt(sb, USRQUOTA);
1895
1896                 if (test_opt(sb, GRPQUOTA) && sbi->s_qf_names[GRPQUOTA])
1897                         clear_opt(sb, GRPQUOTA);
1898
1899                 if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
1900                         ext4_msg(sb, KERN_ERR, "old and new quota "
1901                                         "format mixing");
1902                         return 0;
1903                 }
1904
1905                 if (!sbi->s_jquota_fmt) {
1906                         ext4_msg(sb, KERN_ERR, "journaled quota format "
1907                                         "not specified");
1908                         return 0;
1909                 }
1910         }
1911 #endif
1912         if (test_opt(sb, DIOREAD_NOLOCK)) {
1913                 int blocksize =
1914                         BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
1915
1916                 if (blocksize < PAGE_SIZE) {
1917                         ext4_msg(sb, KERN_ERR, "can't mount with "
1918                                  "dioread_nolock if block size != PAGE_SIZE");
1919                         return 0;
1920                 }
1921         }
1922         return 1;
1923 }
1924
1925 static inline void ext4_show_quota_options(struct seq_file *seq,
1926                                            struct super_block *sb)
1927 {
1928 #if defined(CONFIG_QUOTA)
1929         struct ext4_sb_info *sbi = EXT4_SB(sb);
1930
1931         if (sbi->s_jquota_fmt) {
1932                 char *fmtname = "";
1933
1934                 switch (sbi->s_jquota_fmt) {
1935                 case QFMT_VFS_OLD:
1936                         fmtname = "vfsold";
1937                         break;
1938                 case QFMT_VFS_V0:
1939                         fmtname = "vfsv0";
1940                         break;
1941                 case QFMT_VFS_V1:
1942                         fmtname = "vfsv1";
1943                         break;
1944                 }
1945                 seq_printf(seq, ",jqfmt=%s", fmtname);
1946         }
1947
1948         if (sbi->s_qf_names[USRQUOTA])
1949                 seq_show_option(seq, "usrjquota", sbi->s_qf_names[USRQUOTA]);
1950
1951         if (sbi->s_qf_names[GRPQUOTA])
1952                 seq_show_option(seq, "grpjquota", sbi->s_qf_names[GRPQUOTA]);
1953 #endif
1954 }
1955
1956 static const char *token2str(int token)
1957 {
1958         const struct match_token *t;
1959
1960         for (t = tokens; t->token != Opt_err; t++)
1961                 if (t->token == token && !strchr(t->pattern, '='))
1962                         break;
1963         return t->pattern;
1964 }
1965
1966 /*
1967  * Show an option if
1968  *  - it's set to a non-default value OR
1969  *  - if the per-sb default is different from the global default
1970  */
1971 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
1972                               int nodefs)
1973 {
1974         struct ext4_sb_info *sbi = EXT4_SB(sb);
1975         struct ext4_super_block *es = sbi->s_es;
1976         int def_errors, def_mount_opt = nodefs ? 0 : sbi->s_def_mount_opt;
1977         const struct mount_opts *m;
1978         char sep = nodefs ? '\n' : ',';
1979
1980 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
1981 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
1982
1983         if (sbi->s_sb_block != 1)
1984                 SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
1985
1986         for (m = ext4_mount_opts; m->token != Opt_err; m++) {
1987                 int want_set = m->flags & MOPT_SET;
1988                 if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
1989                     (m->flags & MOPT_CLEAR_ERR))
1990                         continue;
1991                 if (!(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
1992                         continue; /* skip if same as the default */
1993                 if ((want_set &&
1994                      (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
1995                     (!want_set && (sbi->s_mount_opt & m->mount_opt)))
1996                         continue; /* select Opt_noFoo vs Opt_Foo */
1997                 SEQ_OPTS_PRINT("%s", token2str(m->token));
1998         }
1999
2000         if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
2001             le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
2002                 SEQ_OPTS_PRINT("resuid=%u",
2003                                 from_kuid_munged(&init_user_ns, sbi->s_resuid));
2004         if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
2005             le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
2006                 SEQ_OPTS_PRINT("resgid=%u",
2007                                 from_kgid_munged(&init_user_ns, sbi->s_resgid));
2008         def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
2009         if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
2010                 SEQ_OPTS_PUTS("errors=remount-ro");
2011         if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
2012                 SEQ_OPTS_PUTS("errors=continue");
2013         if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
2014                 SEQ_OPTS_PUTS("errors=panic");
2015         if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
2016                 SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
2017         if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
2018                 SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
2019         if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
2020                 SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
2021         if (sb->s_flags & MS_I_VERSION)
2022                 SEQ_OPTS_PUTS("i_version");
2023         if (nodefs || sbi->s_stripe)
2024                 SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
2025         if (EXT4_MOUNT_DATA_FLAGS & (sbi->s_mount_opt ^ def_mount_opt)) {
2026                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
2027                         SEQ_OPTS_PUTS("data=journal");
2028                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
2029                         SEQ_OPTS_PUTS("data=ordered");
2030                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
2031                         SEQ_OPTS_PUTS("data=writeback");
2032         }
2033         if (nodefs ||
2034             sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
2035                 SEQ_OPTS_PRINT("inode_readahead_blks=%u",
2036                                sbi->s_inode_readahead_blks);
2037
2038         if (nodefs || (test_opt(sb, INIT_INODE_TABLE) &&
2039                        (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
2040                 SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
2041         if (nodefs || sbi->s_max_dir_size_kb)
2042                 SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
2043         if (test_opt(sb, DATA_ERR_ABORT))
2044                 SEQ_OPTS_PUTS("data_err=abort");
2045
2046         ext4_show_quota_options(seq, sb);
2047         return 0;
2048 }
2049
2050 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
2051 {
2052         return _ext4_show_options(seq, root->d_sb, 0);
2053 }
2054
2055 int ext4_seq_options_show(struct seq_file *seq, void *offset)
2056 {
2057         struct super_block *sb = seq->private;
2058         int rc;
2059
2060         seq_puts(seq, (sb->s_flags & MS_RDONLY) ? "ro" : "rw");
2061         rc = _ext4_show_options(seq, sb, 1);
2062         seq_puts(seq, "\n");
2063         return rc;
2064 }
2065
2066 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
2067                             int read_only)
2068 {
2069         struct ext4_sb_info *sbi = EXT4_SB(sb);
2070         int res = 0;
2071
2072         if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
2073                 ext4_msg(sb, KERN_ERR, "revision level too high, "
2074                          "forcing read-only mode");
2075                 res = MS_RDONLY;
2076         }
2077         if (read_only)
2078                 goto done;
2079         if (!(sbi->s_mount_state & EXT4_VALID_FS))
2080                 ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
2081                          "running e2fsck is recommended");
2082         else if (sbi->s_mount_state & EXT4_ERROR_FS)
2083                 ext4_msg(sb, KERN_WARNING,
2084                          "warning: mounting fs with errors, "
2085                          "running e2fsck is recommended");
2086         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
2087                  le16_to_cpu(es->s_mnt_count) >=
2088                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
2089                 ext4_msg(sb, KERN_WARNING,
2090                          "warning: maximal mount count reached, "
2091                          "running e2fsck is recommended");
2092         else if (le32_to_cpu(es->s_checkinterval) &&
2093                 (le32_to_cpu(es->s_lastcheck) +
2094                         le32_to_cpu(es->s_checkinterval) <= get_seconds()))
2095                 ext4_msg(sb, KERN_WARNING,
2096                          "warning: checktime reached, "
2097                          "running e2fsck is recommended");
2098         if (!sbi->s_journal)
2099                 es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
2100         if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
2101                 es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
2102         le16_add_cpu(&es->s_mnt_count, 1);
2103         es->s_mtime = cpu_to_le32(get_seconds());
2104         ext4_update_dynamic_rev(sb);
2105         if (sbi->s_journal)
2106                 ext4_set_feature_journal_needs_recovery(sb);
2107
2108         ext4_commit_super(sb, 1);
2109 done:
2110         if (test_opt(sb, DEBUG))
2111                 printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
2112                                 "bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
2113                         sb->s_blocksize,
2114                         sbi->s_groups_count,
2115                         EXT4_BLOCKS_PER_GROUP(sb),
2116                         EXT4_INODES_PER_GROUP(sb),
2117                         sbi->s_mount_opt, sbi->s_mount_opt2);
2118
2119         cleancache_init_fs(sb);
2120         return res;
2121 }
2122
2123 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
2124 {
2125         struct ext4_sb_info *sbi = EXT4_SB(sb);
2126         struct flex_groups *new_groups;
2127         int size;
2128
2129         if (!sbi->s_log_groups_per_flex)
2130                 return 0;
2131
2132         size = ext4_flex_group(sbi, ngroup - 1) + 1;
2133         if (size <= sbi->s_flex_groups_allocated)
2134                 return 0;
2135
2136         size = roundup_pow_of_two(size * sizeof(struct flex_groups));
2137         new_groups = ext4_kvzalloc(size, GFP_KERNEL);
2138         if (!new_groups) {
2139                 ext4_msg(sb, KERN_ERR, "not enough memory for %d flex groups",
2140                          size / (int) sizeof(struct flex_groups));
2141                 return -ENOMEM;
2142         }
2143
2144         if (sbi->s_flex_groups) {
2145                 memcpy(new_groups, sbi->s_flex_groups,
2146                        (sbi->s_flex_groups_allocated *
2147                         sizeof(struct flex_groups)));
2148                 kvfree(sbi->s_flex_groups);
2149         }
2150         sbi->s_flex_groups = new_groups;
2151         sbi->s_flex_groups_allocated = size / sizeof(struct flex_groups);
2152         return 0;
2153 }
2154
2155 static int ext4_fill_flex_info(struct super_block *sb)
2156 {
2157         struct ext4_sb_info *sbi = EXT4_SB(sb);
2158         struct ext4_group_desc *gdp = NULL;
2159         ext4_group_t flex_group;
2160         int i, err;
2161
2162         sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
2163         if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
2164                 sbi->s_log_groups_per_flex = 0;
2165                 return 1;
2166         }
2167
2168         err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
2169         if (err)
2170                 goto failed;
2171
2172         for (i = 0; i < sbi->s_groups_count; i++) {
2173                 gdp = ext4_get_group_desc(sb, i, NULL);
2174
2175                 flex_group = ext4_flex_group(sbi, i);
2176                 atomic_add(ext4_free_inodes_count(sb, gdp),
2177                            &sbi->s_flex_groups[flex_group].free_inodes);
2178                 atomic64_add(ext4_free_group_clusters(sb, gdp),
2179                              &sbi->s_flex_groups[flex_group].free_clusters);
2180                 atomic_add(ext4_used_dirs_count(sb, gdp),
2181                            &sbi->s_flex_groups[flex_group].used_dirs);
2182         }
2183
2184         return 1;
2185 failed:
2186         return 0;
2187 }
2188
2189 static __le16 ext4_group_desc_csum(struct super_block *sb, __u32 block_group,
2190                                    struct ext4_group_desc *gdp)
2191 {
2192         int offset = offsetof(struct ext4_group_desc, bg_checksum);
2193         __u16 crc = 0;
2194         __le32 le_group = cpu_to_le32(block_group);
2195         struct ext4_sb_info *sbi = EXT4_SB(sb);
2196
2197         if (ext4_has_metadata_csum(sbi->s_sb)) {
2198                 /* Use new metadata_csum algorithm */
2199                 __u32 csum32;
2200                 __u16 dummy_csum = 0;
2201
2202                 csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
2203                                      sizeof(le_group));
2204                 csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp, offset);
2205                 csum32 = ext4_chksum(sbi, csum32, (__u8 *)&dummy_csum,
2206                                      sizeof(dummy_csum));
2207                 offset += sizeof(dummy_csum);
2208                 if (offset < sbi->s_desc_size)
2209                         csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp + offset,
2210                                              sbi->s_desc_size - offset);
2211
2212                 crc = csum32 & 0xFFFF;
2213                 goto out;
2214         }
2215
2216         /* old crc16 code */
2217         if (!ext4_has_feature_gdt_csum(sb))
2218                 return 0;
2219
2220         crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2221         crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2222         crc = crc16(crc, (__u8 *)gdp, offset);
2223         offset += sizeof(gdp->bg_checksum); /* skip checksum */
2224         /* for checksum of struct ext4_group_desc do the rest...*/
2225         if (ext4_has_feature_64bit(sb) &&
2226             offset < le16_to_cpu(sbi->s_es->s_desc_size))
2227                 crc = crc16(crc, (__u8 *)gdp + offset,
2228                             le16_to_cpu(sbi->s_es->s_desc_size) -
2229                                 offset);
2230
2231 out:
2232         return cpu_to_le16(crc);
2233 }
2234
2235 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2236                                 struct ext4_group_desc *gdp)
2237 {
2238         if (ext4_has_group_desc_csum(sb) &&
2239             (gdp->bg_checksum != ext4_group_desc_csum(sb, block_group, gdp)))
2240                 return 0;
2241
2242         return 1;
2243 }
2244
2245 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2246                               struct ext4_group_desc *gdp)
2247 {
2248         if (!ext4_has_group_desc_csum(sb))
2249                 return;
2250         gdp->bg_checksum = ext4_group_desc_csum(sb, block_group, gdp);
2251 }
2252
2253 /* Called at mount-time, super-block is locked */
2254 static int ext4_check_descriptors(struct super_block *sb,
2255                                   ext4_fsblk_t sb_block,
2256                                   ext4_group_t *first_not_zeroed)
2257 {
2258         struct ext4_sb_info *sbi = EXT4_SB(sb);
2259         ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2260         ext4_fsblk_t last_block;
2261         ext4_fsblk_t block_bitmap;
2262         ext4_fsblk_t inode_bitmap;
2263         ext4_fsblk_t inode_table;
2264         int flexbg_flag = 0;
2265         ext4_group_t i, grp = sbi->s_groups_count;
2266
2267         if (ext4_has_feature_flex_bg(sb))
2268                 flexbg_flag = 1;
2269
2270         ext4_debug("Checking group descriptors");
2271
2272         for (i = 0; i < sbi->s_groups_count; i++) {
2273                 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2274
2275                 if (i == sbi->s_groups_count - 1 || flexbg_flag)
2276                         last_block = ext4_blocks_count(sbi->s_es) - 1;
2277                 else
2278                         last_block = first_block +
2279                                 (EXT4_BLOCKS_PER_GROUP(sb) - 1);
2280
2281                 if ((grp == sbi->s_groups_count) &&
2282                    !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2283                         grp = i;
2284
2285                 block_bitmap = ext4_block_bitmap(sb, gdp);
2286                 if (block_bitmap == sb_block) {
2287                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2288                                  "Block bitmap for group %u overlaps "
2289                                  "superblock", i);
2290                 }
2291                 if (block_bitmap < first_block || block_bitmap > last_block) {
2292                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2293                                "Block bitmap for group %u not in group "
2294                                "(block %llu)!", i, block_bitmap);
2295                         return 0;
2296                 }
2297                 inode_bitmap = ext4_inode_bitmap(sb, gdp);
2298                 if (inode_bitmap == sb_block) {
2299                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2300                                  "Inode bitmap for group %u overlaps "
2301                                  "superblock", i);
2302                 }
2303                 if (inode_bitmap < first_block || inode_bitmap > last_block) {
2304                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2305                                "Inode bitmap for group %u not in group "
2306                                "(block %llu)!", i, inode_bitmap);
2307                         return 0;
2308                 }
2309                 inode_table = ext4_inode_table(sb, gdp);
2310                 if (inode_table == sb_block) {
2311                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2312                                  "Inode table for group %u overlaps "
2313                                  "superblock", i);
2314                 }
2315                 if (inode_table < first_block ||
2316                     inode_table + sbi->s_itb_per_group - 1 > last_block) {
2317                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2318                                "Inode table for group %u not in group "
2319                                "(block %llu)!", i, inode_table);
2320                         return 0;
2321                 }
2322                 ext4_lock_group(sb, i);
2323                 if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2324                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2325                                  "Checksum for group %u failed (%u!=%u)",
2326                                  i, le16_to_cpu(ext4_group_desc_csum(sb, i,
2327                                      gdp)), le16_to_cpu(gdp->bg_checksum));
2328                         if (!(sb->s_flags & MS_RDONLY)) {
2329                                 ext4_unlock_group(sb, i);
2330                                 return 0;
2331                         }
2332                 }
2333                 ext4_unlock_group(sb, i);
2334                 if (!flexbg_flag)
2335                         first_block += EXT4_BLOCKS_PER_GROUP(sb);
2336         }
2337         if (NULL != first_not_zeroed)
2338                 *first_not_zeroed = grp;
2339         return 1;
2340 }
2341
2342 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2343  * the superblock) which were deleted from all directories, but held open by
2344  * a process at the time of a crash.  We walk the list and try to delete these
2345  * inodes at recovery time (only with a read-write filesystem).
2346  *
2347  * In order to keep the orphan inode chain consistent during traversal (in
2348  * case of crash during recovery), we link each inode into the superblock
2349  * orphan list_head and handle it the same way as an inode deletion during
2350  * normal operation (which journals the operations for us).
2351  *
2352  * We only do an iget() and an iput() on each inode, which is very safe if we
2353  * accidentally point at an in-use or already deleted inode.  The worst that
2354  * can happen in this case is that we get a "bit already cleared" message from
2355  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2356  * e2fsck was run on this filesystem, and it must have already done the orphan
2357  * inode cleanup for us, so we can safely abort without any further action.
2358  */
2359 static void ext4_orphan_cleanup(struct super_block *sb,
2360                                 struct ext4_super_block *es)
2361 {
2362         unsigned int s_flags = sb->s_flags;
2363         int ret, nr_orphans = 0, nr_truncates = 0;
2364 #ifdef CONFIG_QUOTA
2365         int i;
2366 #endif
2367         if (!es->s_last_orphan) {
2368                 jbd_debug(4, "no orphan inodes to clean up\n");
2369                 return;
2370         }
2371
2372         if (bdev_read_only(sb->s_bdev)) {
2373                 ext4_msg(sb, KERN_ERR, "write access "
2374                         "unavailable, skipping orphan cleanup");
2375                 return;
2376         }
2377
2378         /* Check if feature set would not allow a r/w mount */
2379         if (!ext4_feature_set_ok(sb, 0)) {
2380                 ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2381                          "unknown ROCOMPAT features");
2382                 return;
2383         }
2384
2385         if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2386                 /* don't clear list on RO mount w/ errors */
2387                 if (es->s_last_orphan && !(s_flags & MS_RDONLY)) {
2388                         ext4_msg(sb, KERN_INFO, "Errors on filesystem, "
2389                                   "clearing orphan list.\n");
2390                         es->s_last_orphan = 0;
2391                 }
2392                 jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2393                 return;
2394         }
2395
2396         if (s_flags & MS_RDONLY) {
2397                 ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2398                 sb->s_flags &= ~MS_RDONLY;
2399         }
2400 #ifdef CONFIG_QUOTA
2401         /* Needed for iput() to work correctly and not trash data */
2402         sb->s_flags |= MS_ACTIVE;
2403         /* Turn on quotas so that they are updated correctly */
2404         for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2405                 if (EXT4_SB(sb)->s_qf_names[i]) {
2406                         int ret = ext4_quota_on_mount(sb, i);
2407                         if (ret < 0)
2408                                 ext4_msg(sb, KERN_ERR,
2409                                         "Cannot turn on journaled "
2410                                         "quota: error %d", ret);
2411                 }
2412         }
2413 #endif
2414
2415         while (es->s_last_orphan) {
2416                 struct inode *inode;
2417
2418                 /*
2419                  * We may have encountered an error during cleanup; if
2420                  * so, skip the rest.
2421                  */
2422                 if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2423                         jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2424                         es->s_last_orphan = 0;
2425                         break;
2426                 }
2427
2428                 inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2429                 if (IS_ERR(inode)) {
2430                         es->s_last_orphan = 0;
2431                         break;
2432                 }
2433
2434                 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2435                 dquot_initialize(inode);
2436                 if (inode->i_nlink) {
2437                         if (test_opt(sb, DEBUG))
2438                                 ext4_msg(sb, KERN_DEBUG,
2439                                         "%s: truncating inode %lu to %lld bytes",
2440                                         __func__, inode->i_ino, inode->i_size);
2441                         jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2442                                   inode->i_ino, inode->i_size);
2443                         inode_lock(inode);
2444                         truncate_inode_pages(inode->i_mapping, inode->i_size);
2445                         ret = ext4_truncate(inode);
2446                         if (ret)
2447                                 ext4_std_error(inode->i_sb, ret);
2448                         inode_unlock(inode);
2449                         nr_truncates++;
2450                 } else {
2451                         if (test_opt(sb, DEBUG))
2452                                 ext4_msg(sb, KERN_DEBUG,
2453                                         "%s: deleting unreferenced inode %lu",
2454                                         __func__, inode->i_ino);
2455                         jbd_debug(2, "deleting unreferenced inode %lu\n",
2456                                   inode->i_ino);
2457                         nr_orphans++;
2458                 }
2459                 iput(inode);  /* The delete magic happens here! */
2460         }
2461
2462 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2463
2464         if (nr_orphans)
2465                 ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2466                        PLURAL(nr_orphans));
2467         if (nr_truncates)
2468                 ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2469                        PLURAL(nr_truncates));
2470 #ifdef CONFIG_QUOTA
2471         /* Turn quotas off */
2472         for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2473                 if (sb_dqopt(sb)->files[i])
2474                         dquot_quota_off(sb, i);
2475         }
2476 #endif
2477         sb->s_flags = s_flags; /* Restore MS_RDONLY status */
2478 }
2479
2480 /*
2481  * Maximal extent format file size.
2482  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2483  * extent format containers, within a sector_t, and within i_blocks
2484  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2485  * so that won't be a limiting factor.
2486  *
2487  * However there is other limiting factor. We do store extents in the form
2488  * of starting block and length, hence the resulting length of the extent
2489  * covering maximum file size must fit into on-disk format containers as
2490  * well. Given that length is always by 1 unit bigger than max unit (because
2491  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2492  *
2493  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2494  */
2495 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2496 {
2497         loff_t res;
2498         loff_t upper_limit = MAX_LFS_FILESIZE;
2499
2500         /* small i_blocks in vfs inode? */
2501         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2502                 /*
2503                  * CONFIG_LBDAF is not enabled implies the inode
2504                  * i_block represent total blocks in 512 bytes
2505                  * 32 == size of vfs inode i_blocks * 8
2506                  */
2507                 upper_limit = (1LL << 32) - 1;
2508
2509                 /* total blocks in file system block size */
2510                 upper_limit >>= (blkbits - 9);
2511                 upper_limit <<= blkbits;
2512         }
2513
2514         /*
2515          * 32-bit extent-start container, ee_block. We lower the maxbytes
2516          * by one fs block, so ee_len can cover the extent of maximum file
2517          * size
2518          */
2519         res = (1LL << 32) - 1;
2520         res <<= blkbits;
2521
2522         /* Sanity check against vm- & vfs- imposed limits */
2523         if (res > upper_limit)
2524                 res = upper_limit;
2525
2526         return res;
2527 }
2528
2529 /*
2530  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2531  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2532  * We need to be 1 filesystem block less than the 2^48 sector limit.
2533  */
2534 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2535 {
2536         loff_t res = EXT4_NDIR_BLOCKS;
2537         int meta_blocks;
2538         loff_t upper_limit;
2539         /* This is calculated to be the largest file size for a dense, block
2540          * mapped file such that the file's total number of 512-byte sectors,
2541          * including data and all indirect blocks, does not exceed (2^48 - 1).
2542          *
2543          * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2544          * number of 512-byte sectors of the file.
2545          */
2546
2547         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2548                 /*
2549                  * !has_huge_files or CONFIG_LBDAF not enabled implies that
2550                  * the inode i_block field represents total file blocks in
2551                  * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2552                  */
2553                 upper_limit = (1LL << 32) - 1;
2554
2555                 /* total blocks in file system block size */
2556                 upper_limit >>= (bits - 9);
2557
2558         } else {
2559                 /*
2560                  * We use 48 bit ext4_inode i_blocks
2561                  * With EXT4_HUGE_FILE_FL set the i_blocks
2562                  * represent total number of blocks in
2563                  * file system block size
2564                  */
2565                 upper_limit = (1LL << 48) - 1;
2566
2567         }
2568
2569         /* indirect blocks */
2570         meta_blocks = 1;
2571         /* double indirect blocks */
2572         meta_blocks += 1 + (1LL << (bits-2));
2573         /* tripple indirect blocks */
2574         meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2575
2576         upper_limit -= meta_blocks;
2577         upper_limit <<= bits;
2578
2579         res += 1LL << (bits-2);
2580         res += 1LL << (2*(bits-2));
2581         res += 1LL << (3*(bits-2));
2582         res <<= bits;
2583         if (res > upper_limit)
2584                 res = upper_limit;
2585
2586         if (res > MAX_LFS_FILESIZE)
2587                 res = MAX_LFS_FILESIZE;
2588
2589         return res;
2590 }
2591
2592 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2593                                    ext4_fsblk_t logical_sb_block, int nr)
2594 {
2595         struct ext4_sb_info *sbi = EXT4_SB(sb);
2596         ext4_group_t bg, first_meta_bg;
2597         int has_super = 0;
2598
2599         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2600
2601         if (!ext4_has_feature_meta_bg(sb) || nr < first_meta_bg)
2602                 return logical_sb_block + nr + 1;
2603         bg = sbi->s_desc_per_block * nr;
2604         if (ext4_bg_has_super(sb, bg))
2605                 has_super = 1;
2606
2607         /*
2608          * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
2609          * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
2610          * on modern mke2fs or blksize > 1k on older mke2fs) then we must
2611          * compensate.
2612          */
2613         if (sb->s_blocksize == 1024 && nr == 0 &&
2614             le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block) == 0)
2615                 has_super++;
2616
2617         return (has_super + ext4_group_first_block_no(sb, bg));
2618 }
2619
2620 /**
2621  * ext4_get_stripe_size: Get the stripe size.
2622  * @sbi: In memory super block info
2623  *
2624  * If we have specified it via mount option, then
2625  * use the mount option value. If the value specified at mount time is
2626  * greater than the blocks per group use the super block value.
2627  * If the super block value is greater than blocks per group return 0.
2628  * Allocator needs it be less than blocks per group.
2629  *
2630  */
2631 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2632 {
2633         unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2634         unsigned long stripe_width =
2635                         le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2636         int ret;
2637
2638         if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2639                 ret = sbi->s_stripe;
2640         else if (stripe_width && stripe_width <= sbi->s_blocks_per_group)
2641                 ret = stripe_width;
2642         else if (stride && stride <= sbi->s_blocks_per_group)
2643                 ret = stride;
2644         else
2645                 ret = 0;
2646
2647         /*
2648          * If the stripe width is 1, this makes no sense and
2649          * we set it to 0 to turn off stripe handling code.
2650          */
2651         if (ret <= 1)
2652                 ret = 0;
2653
2654         return ret;
2655 }
2656
2657 /*
2658  * Check whether this filesystem can be mounted based on
2659  * the features present and the RDONLY/RDWR mount requested.
2660  * Returns 1 if this filesystem can be mounted as requested,
2661  * 0 if it cannot be.
2662  */
2663 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2664 {
2665         if (ext4_has_unknown_ext4_incompat_features(sb)) {
2666                 ext4_msg(sb, KERN_ERR,
2667                         "Couldn't mount because of "
2668                         "unsupported optional features (%x)",
2669                         (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2670                         ~EXT4_FEATURE_INCOMPAT_SUPP));
2671                 return 0;
2672         }
2673
2674         if (readonly)
2675                 return 1;
2676
2677         if (ext4_has_feature_readonly(sb)) {
2678                 ext4_msg(sb, KERN_INFO, "filesystem is read-only");
2679                 sb->s_flags |= MS_RDONLY;
2680                 return 1;
2681         }
2682
2683         /* Check that feature set is OK for a read-write mount */
2684         if (ext4_has_unknown_ext4_ro_compat_features(sb)) {
2685                 ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2686                          "unsupported optional features (%x)",
2687                          (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2688                                 ~EXT4_FEATURE_RO_COMPAT_SUPP));
2689                 return 0;
2690         }
2691         /*
2692          * Large file size enabled file system can only be mounted
2693          * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2694          */
2695         if (ext4_has_feature_huge_file(sb)) {
2696                 if (sizeof(blkcnt_t) < sizeof(u64)) {
2697                         ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2698                                  "cannot be mounted RDWR without "
2699                                  "CONFIG_LBDAF");
2700                         return 0;
2701                 }
2702         }
2703         if (ext4_has_feature_bigalloc(sb) && !ext4_has_feature_extents(sb)) {
2704                 ext4_msg(sb, KERN_ERR,
2705                          "Can't support bigalloc feature without "
2706                          "extents feature\n");
2707                 return 0;
2708         }
2709
2710 #ifndef CONFIG_QUOTA
2711         if (ext4_has_feature_quota(sb) && !readonly) {
2712                 ext4_msg(sb, KERN_ERR,
2713                          "Filesystem with quota feature cannot be mounted RDWR "
2714                          "without CONFIG_QUOTA");
2715                 return 0;
2716         }
2717         if (ext4_has_feature_project(sb) && !readonly) {
2718                 ext4_msg(sb, KERN_ERR,
2719                          "Filesystem with project quota feature cannot be mounted RDWR "
2720                          "without CONFIG_QUOTA");
2721                 return 0;
2722         }
2723 #endif  /* CONFIG_QUOTA */
2724         return 1;
2725 }
2726
2727 /*
2728  * This function is called once a day if we have errors logged
2729  * on the file system
2730  */
2731 static void print_daily_error_info(unsigned long arg)
2732 {
2733         struct super_block *sb = (struct super_block *) arg;
2734         struct ext4_sb_info *sbi;
2735         struct ext4_super_block *es;
2736
2737         sbi = EXT4_SB(sb);
2738         es = sbi->s_es;
2739
2740         if (es->s_error_count)
2741                 /* fsck newer than v1.41.13 is needed to clean this condition. */
2742                 ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
2743                          le32_to_cpu(es->s_error_count));
2744         if (es->s_first_error_time) {
2745                 printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %u: %.*s:%d",
2746                        sb->s_id, le32_to_cpu(es->s_first_error_time),
2747                        (int) sizeof(es->s_first_error_func),
2748                        es->s_first_error_func,
2749                        le32_to_cpu(es->s_first_error_line));
2750                 if (es->s_first_error_ino)
2751                         printk(KERN_CONT ": inode %u",
2752                                le32_to_cpu(es->s_first_error_ino));
2753                 if (es->s_first_error_block)
2754                         printk(KERN_CONT ": block %llu", (unsigned long long)
2755                                le64_to_cpu(es->s_first_error_block));
2756                 printk(KERN_CONT "\n");
2757         }
2758         if (es->s_last_error_time) {
2759                 printk(KERN_NOTICE "EXT4-fs (%s): last error at time %u: %.*s:%d",
2760                        sb->s_id, le32_to_cpu(es->s_last_error_time),
2761                        (int) sizeof(es->s_last_error_func),
2762                        es->s_last_error_func,
2763                        le32_to_cpu(es->s_last_error_line));
2764                 if (es->s_last_error_ino)
2765                         printk(KERN_CONT ": inode %u",
2766                                le32_to_cpu(es->s_last_error_ino));
2767                 if (es->s_last_error_block)
2768                         printk(KERN_CONT ": block %llu", (unsigned long long)
2769                                le64_to_cpu(es->s_last_error_block));
2770                 printk(KERN_CONT "\n");
2771         }
2772         mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2773 }
2774
2775 /* Find next suitable group and run ext4_init_inode_table */
2776 static int ext4_run_li_request(struct ext4_li_request *elr)
2777 {
2778         struct ext4_group_desc *gdp = NULL;
2779         ext4_group_t group, ngroups;
2780         struct super_block *sb;
2781         unsigned long timeout = 0;
2782         int ret = 0;
2783
2784         sb = elr->lr_super;
2785         ngroups = EXT4_SB(sb)->s_groups_count;
2786
2787         for (group = elr->lr_next_group; group < ngroups; group++) {
2788                 gdp = ext4_get_group_desc(sb, group, NULL);
2789                 if (!gdp) {
2790                         ret = 1;
2791                         break;
2792                 }
2793
2794                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2795                         break;
2796         }
2797
2798         if (group >= ngroups)
2799                 ret = 1;
2800
2801         if (!ret) {
2802                 timeout = jiffies;
2803                 ret = ext4_init_inode_table(sb, group,
2804                                             elr->lr_timeout ? 0 : 1);
2805                 if (elr->lr_timeout == 0) {
2806                         timeout = (jiffies - timeout) *
2807                                   elr->lr_sbi->s_li_wait_mult;
2808                         elr->lr_timeout = timeout;
2809                 }
2810                 elr->lr_next_sched = jiffies + elr->lr_timeout;
2811                 elr->lr_next_group = group + 1;
2812         }
2813         return ret;
2814 }
2815
2816 /*
2817  * Remove lr_request from the list_request and free the
2818  * request structure. Should be called with li_list_mtx held
2819  */
2820 static void ext4_remove_li_request(struct ext4_li_request *elr)
2821 {
2822         struct ext4_sb_info *sbi;
2823
2824         if (!elr)
2825                 return;
2826
2827         sbi = elr->lr_sbi;
2828
2829         list_del(&elr->lr_request);
2830         sbi->s_li_request = NULL;
2831         kfree(elr);
2832 }
2833
2834 static void ext4_unregister_li_request(struct super_block *sb)
2835 {
2836         mutex_lock(&ext4_li_mtx);
2837         if (!ext4_li_info) {
2838                 mutex_unlock(&ext4_li_mtx);
2839                 return;
2840         }
2841
2842         mutex_lock(&ext4_li_info->li_list_mtx);
2843         ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
2844         mutex_unlock(&ext4_li_info->li_list_mtx);
2845         mutex_unlock(&ext4_li_mtx);
2846 }
2847
2848 static struct task_struct *ext4_lazyinit_task;
2849
2850 /*
2851  * This is the function where ext4lazyinit thread lives. It walks
2852  * through the request list searching for next scheduled filesystem.
2853  * When such a fs is found, run the lazy initialization request
2854  * (ext4_rn_li_request) and keep track of the time spend in this
2855  * function. Based on that time we compute next schedule time of
2856  * the request. When walking through the list is complete, compute
2857  * next waking time and put itself into sleep.
2858  */
2859 static int ext4_lazyinit_thread(void *arg)
2860 {
2861         struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
2862         struct list_head *pos, *n;
2863         struct ext4_li_request *elr;
2864         unsigned long next_wakeup, cur;
2865
2866         BUG_ON(NULL == eli);
2867
2868 cont_thread:
2869         while (true) {
2870                 next_wakeup = MAX_JIFFY_OFFSET;
2871
2872                 mutex_lock(&eli->li_list_mtx);
2873                 if (list_empty(&eli->li_request_list)) {
2874                         mutex_unlock(&eli->li_list_mtx);
2875                         goto exit_thread;
2876                 }
2877                 list_for_each_safe(pos, n, &eli->li_request_list) {
2878                         int err = 0;
2879                         int progress = 0;
2880                         elr = list_entry(pos, struct ext4_li_request,
2881                                          lr_request);
2882
2883                         if (time_before(jiffies, elr->lr_next_sched)) {
2884                                 if (time_before(elr->lr_next_sched, next_wakeup))
2885                                         next_wakeup = elr->lr_next_sched;
2886                                 continue;
2887                         }
2888                         if (down_read_trylock(&elr->lr_super->s_umount)) {
2889                                 if (sb_start_write_trylock(elr->lr_super)) {
2890                                         progress = 1;
2891                                         /*
2892                                          * We hold sb->s_umount, sb can not
2893                                          * be removed from the list, it is
2894                                          * now safe to drop li_list_mtx
2895                                          */
2896                                         mutex_unlock(&eli->li_list_mtx);
2897                                         err = ext4_run_li_request(elr);
2898                                         sb_end_write(elr->lr_super);
2899                                         mutex_lock(&eli->li_list_mtx);
2900                                         n = pos->next;
2901                                 }
2902                                 up_read((&elr->lr_super->s_umount));
2903                         }
2904                         /* error, remove the lazy_init job */
2905                         if (err) {
2906                                 ext4_remove_li_request(elr);
2907                                 continue;
2908                         }
2909                         if (!progress) {
2910                                 elr->lr_next_sched = jiffies +
2911                                         (prandom_u32()
2912                                          % (EXT4_DEF_LI_MAX_START_DELAY * HZ));
2913                         }
2914                         if (time_before(elr->lr_next_sched, next_wakeup))
2915                                 next_wakeup = elr->lr_next_sched;
2916                 }
2917                 mutex_unlock(&eli->li_list_mtx);
2918
2919                 try_to_freeze();
2920
2921                 cur = jiffies;
2922                 if ((time_after_eq(cur, next_wakeup)) ||
2923                     (MAX_JIFFY_OFFSET == next_wakeup)) {
2924                         cond_resched();
2925                         continue;
2926                 }
2927
2928                 schedule_timeout_interruptible(next_wakeup - cur);
2929
2930                 if (kthread_should_stop()) {
2931                         ext4_clear_request_list();
2932                         goto exit_thread;
2933                 }
2934         }
2935
2936 exit_thread:
2937         /*
2938          * It looks like the request list is empty, but we need
2939          * to check it under the li_list_mtx lock, to prevent any
2940          * additions into it, and of course we should lock ext4_li_mtx
2941          * to atomically free the list and ext4_li_info, because at
2942          * this point another ext4 filesystem could be registering
2943          * new one.
2944          */
2945         mutex_lock(&ext4_li_mtx);
2946         mutex_lock(&eli->li_list_mtx);
2947         if (!list_empty(&eli->li_request_list)) {
2948                 mutex_unlock(&eli->li_list_mtx);
2949                 mutex_unlock(&ext4_li_mtx);
2950                 goto cont_thread;
2951         }
2952         mutex_unlock(&eli->li_list_mtx);
2953         kfree(ext4_li_info);
2954         ext4_li_info = NULL;
2955         mutex_unlock(&ext4_li_mtx);
2956
2957         return 0;
2958 }
2959
2960 static void ext4_clear_request_list(void)
2961 {
2962         struct list_head *pos, *n;
2963         struct ext4_li_request *elr;
2964
2965         mutex_lock(&ext4_li_info->li_list_mtx);
2966         list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
2967                 elr = list_entry(pos, struct ext4_li_request,
2968                                  lr_request);
2969                 ext4_remove_li_request(elr);
2970         }
2971         mutex_unlock(&ext4_li_info->li_list_mtx);
2972 }
2973
2974 static int ext4_run_lazyinit_thread(void)
2975 {
2976         ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
2977                                          ext4_li_info, "ext4lazyinit");
2978         if (IS_ERR(ext4_lazyinit_task)) {
2979                 int err = PTR_ERR(ext4_lazyinit_task);
2980                 ext4_clear_request_list();
2981                 kfree(ext4_li_info);
2982                 ext4_li_info = NULL;
2983                 printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
2984                                  "initialization thread\n",
2985                                  err);
2986                 return err;
2987         }
2988         ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
2989         return 0;
2990 }
2991
2992 /*
2993  * Check whether it make sense to run itable init. thread or not.
2994  * If there is at least one uninitialized inode table, return
2995  * corresponding group number, else the loop goes through all
2996  * groups and return total number of groups.
2997  */
2998 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
2999 {
3000         ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3001         struct ext4_group_desc *gdp = NULL;
3002
3003         for (group = 0; group < ngroups; group++) {
3004                 gdp = ext4_get_group_desc(sb, group, NULL);
3005                 if (!gdp)
3006                         continue;
3007
3008                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3009                         break;
3010         }
3011
3012         return group;
3013 }
3014
3015 static int ext4_li_info_new(void)
3016 {
3017         struct ext4_lazy_init *eli = NULL;
3018
3019         eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3020         if (!eli)
3021                 return -ENOMEM;
3022
3023         INIT_LIST_HEAD(&eli->li_request_list);
3024         mutex_init(&eli->li_list_mtx);
3025
3026         eli->li_state |= EXT4_LAZYINIT_QUIT;
3027
3028         ext4_li_info = eli;
3029
3030         return 0;
3031 }
3032
3033 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3034                                             ext4_group_t start)
3035 {
3036         struct ext4_sb_info *sbi = EXT4_SB(sb);
3037         struct ext4_li_request *elr;
3038
3039         elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3040         if (!elr)
3041                 return NULL;
3042
3043         elr->lr_super = sb;
3044         elr->lr_sbi = sbi;
3045         elr->lr_next_group = start;
3046
3047         /*
3048          * Randomize first schedule time of the request to
3049          * spread the inode table initialization requests
3050          * better.
3051          */
3052         elr->lr_next_sched = jiffies + (prandom_u32() %
3053                                 (EXT4_DEF_LI_MAX_START_DELAY * HZ));
3054         return elr;
3055 }
3056
3057 int ext4_register_li_request(struct super_block *sb,
3058                              ext4_group_t first_not_zeroed)
3059 {
3060         struct ext4_sb_info *sbi = EXT4_SB(sb);
3061         struct ext4_li_request *elr = NULL;
3062         ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
3063         int ret = 0;
3064
3065         mutex_lock(&ext4_li_mtx);
3066         if (sbi->s_li_request != NULL) {
3067                 /*
3068                  * Reset timeout so it can be computed again, because
3069                  * s_li_wait_mult might have changed.
3070                  */
3071                 sbi->s_li_request->lr_timeout = 0;
3072                 goto out;
3073         }
3074
3075         if (first_not_zeroed == ngroups ||
3076             (sb->s_flags & MS_RDONLY) ||
3077             !test_opt(sb, INIT_INODE_TABLE))
3078                 goto out;
3079
3080         elr = ext4_li_request_new(sb, first_not_zeroed);
3081         if (!elr) {
3082                 ret = -ENOMEM;
3083                 goto out;
3084         }
3085
3086         if (NULL == ext4_li_info) {
3087                 ret = ext4_li_info_new();
3088                 if (ret)
3089                         goto out;
3090         }
3091
3092         mutex_lock(&ext4_li_info->li_list_mtx);
3093         list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3094         mutex_unlock(&ext4_li_info->li_list_mtx);
3095
3096         sbi->s_li_request = elr;
3097         /*
3098          * set elr to NULL here since it has been inserted to
3099          * the request_list and the removal and free of it is
3100          * handled by ext4_clear_request_list from now on.
3101          */
3102         elr = NULL;
3103
3104         if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3105                 ret = ext4_run_lazyinit_thread();
3106                 if (ret)
3107                         goto out;
3108         }
3109 out:
3110         mutex_unlock(&ext4_li_mtx);
3111         if (ret)
3112                 kfree(elr);
3113         return ret;
3114 }
3115
3116 /*
3117  * We do not need to lock anything since this is called on
3118  * module unload.
3119  */
3120 static void ext4_destroy_lazyinit_thread(void)
3121 {
3122         /*
3123          * If thread exited earlier
3124          * there's nothing to be done.
3125          */
3126         if (!ext4_li_info || !ext4_lazyinit_task)
3127                 return;
3128
3129         kthread_stop(ext4_lazyinit_task);
3130 }
3131
3132 static int set_journal_csum_feature_set(struct super_block *sb)
3133 {
3134         int ret = 1;
3135         int compat, incompat;
3136         struct ext4_sb_info *sbi = EXT4_SB(sb);
3137
3138         if (ext4_has_metadata_csum(sb)) {
3139                 /* journal checksum v3 */
3140                 compat = 0;
3141                 incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
3142         } else {
3143                 /* journal checksum v1 */
3144                 compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3145                 incompat = 0;
3146         }
3147
3148         jbd2_journal_clear_features(sbi->s_journal,
3149                         JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3150                         JBD2_FEATURE_INCOMPAT_CSUM_V3 |
3151                         JBD2_FEATURE_INCOMPAT_CSUM_V2);
3152         if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3153                 ret = jbd2_journal_set_features(sbi->s_journal,
3154                                 compat, 0,
3155                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3156                                 incompat);
3157         } else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3158                 ret = jbd2_journal_set_features(sbi->s_journal,
3159                                 compat, 0,
3160                                 incompat);
3161                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3162                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3163         } else {
3164                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3165                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3166         }
3167
3168         return ret;
3169 }
3170
3171 /*
3172  * Note: calculating the overhead so we can be compatible with
3173  * historical BSD practice is quite difficult in the face of
3174  * clusters/bigalloc.  This is because multiple metadata blocks from
3175  * different block group can end up in the same allocation cluster.
3176  * Calculating the exact overhead in the face of clustered allocation
3177  * requires either O(all block bitmaps) in memory or O(number of block
3178  * groups**2) in time.  We will still calculate the superblock for
3179  * older file systems --- and if we come across with a bigalloc file
3180  * system with zero in s_overhead_clusters the estimate will be close to
3181  * correct especially for very large cluster sizes --- but for newer
3182  * file systems, it's better to calculate this figure once at mkfs
3183  * time, and store it in the superblock.  If the superblock value is
3184  * present (even for non-bigalloc file systems), we will use it.
3185  */
3186 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3187                           char *buf)
3188 {
3189         struct ext4_sb_info     *sbi = EXT4_SB(sb);
3190         struct ext4_group_desc  *gdp;
3191         ext4_fsblk_t            first_block, last_block, b;
3192         ext4_group_t            i, ngroups = ext4_get_groups_count(sb);
3193         int                     s, j, count = 0;
3194
3195         if (!ext4_has_feature_bigalloc(sb))
3196                 return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3197                         sbi->s_itb_per_group + 2);
3198
3199         first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3200                 (grp * EXT4_BLOCKS_PER_GROUP(sb));
3201         last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3202         for (i = 0; i < ngroups; i++) {
3203                 gdp = ext4_get_group_desc(sb, i, NULL);
3204                 b = ext4_block_bitmap(sb, gdp);
3205                 if (b >= first_block && b <= last_block) {
3206                         ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3207                         count++;
3208                 }
3209                 b = ext4_inode_bitmap(sb, gdp);
3210                 if (b >= first_block && b <= last_block) {
3211                         ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3212                         count++;
3213                 }
3214                 b = ext4_inode_table(sb, gdp);
3215                 if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3216                         for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3217                                 int c = EXT4_B2C(sbi, b - first_block);
3218                                 ext4_set_bit(c, buf);
3219                                 count++;
3220                         }
3221                 if (i != grp)
3222                         continue;
3223                 s = 0;
3224                 if (ext4_bg_has_super(sb, grp)) {
3225                         ext4_set_bit(s++, buf);
3226                         count++;
3227                 }
3228                 j = ext4_bg_num_gdb(sb, grp);
3229                 if (s + j > EXT4_BLOCKS_PER_GROUP(sb)) {
3230                         ext4_error(sb, "Invalid number of block group "
3231                                    "descriptor blocks: %d", j);
3232                         j = EXT4_BLOCKS_PER_GROUP(sb) - s;
3233                 }
3234                 count += j;
3235                 for (; j > 0; j--)
3236                         ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3237         }
3238         if (!count)
3239                 return 0;
3240         return EXT4_CLUSTERS_PER_GROUP(sb) -
3241                 ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3242 }
3243
3244 /*
3245  * Compute the overhead and stash it in sbi->s_overhead
3246  */
3247 int ext4_calculate_overhead(struct super_block *sb)
3248 {
3249         struct ext4_sb_info *sbi = EXT4_SB(sb);
3250         struct ext4_super_block *es = sbi->s_es;
3251         struct inode *j_inode;
3252         unsigned int j_blocks, j_inum = le32_to_cpu(es->s_journal_inum);
3253         ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3254         ext4_fsblk_t overhead = 0;
3255         char *buf = (char *) get_zeroed_page(GFP_NOFS);
3256
3257         if (!buf)
3258                 return -ENOMEM;
3259
3260         /*
3261          * Compute the overhead (FS structures).  This is constant
3262          * for a given filesystem unless the number of block groups
3263          * changes so we cache the previous value until it does.
3264          */
3265
3266         /*
3267          * All of the blocks before first_data_block are overhead
3268          */
3269         overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3270
3271         /*
3272          * Add the overhead found in each block group
3273          */
3274         for (i = 0; i < ngroups; i++) {
3275                 int blks;
3276
3277                 blks = count_overhead(sb, i, buf);
3278                 overhead += blks;
3279                 if (blks)
3280                         memset(buf, 0, PAGE_SIZE);
3281                 cond_resched();
3282         }
3283
3284         /*
3285          * Add the internal journal blocks whether the journal has been
3286          * loaded or not
3287          */
3288         if (sbi->s_journal && !sbi->journal_bdev)
3289                 overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_maxlen);
3290         else if (ext4_has_feature_journal(sb) && !sbi->s_journal) {
3291                 j_inode = ext4_get_journal_inode(sb, j_inum);
3292                 if (j_inode) {
3293                         j_blocks = j_inode->i_size >> sb->s_blocksize_bits;
3294                         overhead += EXT4_NUM_B2C(sbi, j_blocks);
3295                         iput(j_inode);
3296                 } else {
3297                         ext4_msg(sb, KERN_ERR, "can't get journal size");
3298                 }
3299         }
3300         sbi->s_overhead = overhead;
3301         smp_wmb();
3302         free_page((unsigned long) buf);
3303         return 0;
3304 }
3305
3306 static void ext4_set_resv_clusters(struct super_block *sb)
3307 {
3308         ext4_fsblk_t resv_clusters;
3309         struct ext4_sb_info *sbi = EXT4_SB(sb);
3310
3311         /*
3312          * There's no need to reserve anything when we aren't using extents.
3313          * The space estimates are exact, there are no unwritten extents,
3314          * hole punching doesn't need new metadata... This is needed especially
3315          * to keep ext2/3 backward compatibility.
3316          */
3317         if (!ext4_has_feature_extents(sb))
3318                 return;
3319         /*
3320          * By default we reserve 2% or 4096 clusters, whichever is smaller.
3321          * This should cover the situations where we can not afford to run
3322          * out of space like for example punch hole, or converting
3323          * unwritten extents in delalloc path. In most cases such
3324          * allocation would require 1, or 2 blocks, higher numbers are
3325          * very rare.
3326          */
3327         resv_clusters = (ext4_blocks_count(sbi->s_es) >>
3328                          sbi->s_cluster_bits);
3329
3330         do_div(resv_clusters, 50);
3331         resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
3332
3333         atomic64_set(&sbi->s_resv_clusters, resv_clusters);
3334 }
3335
3336 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3337 {
3338         char *orig_data = kstrdup(data, GFP_KERNEL);
3339         struct buffer_head *bh;
3340         struct ext4_super_block *es = NULL;
3341         struct ext4_sb_info *sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3342         ext4_fsblk_t block;
3343         ext4_fsblk_t sb_block = get_sb_block(&data);
3344         ext4_fsblk_t logical_sb_block;
3345         unsigned long offset = 0;
3346         unsigned long journal_devnum = 0;
3347         unsigned long def_mount_opts;
3348         struct inode *root;
3349         const char *descr;
3350         int ret = -ENOMEM;
3351         int blocksize, clustersize;
3352         unsigned int db_count;
3353         unsigned int i;
3354         int needs_recovery, has_huge_files, has_bigalloc;
3355         __u64 blocks_count;
3356         int err = 0;
3357         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3358         ext4_group_t first_not_zeroed;
3359
3360         if ((data && !orig_data) || !sbi)
3361                 goto out_free_base;
3362
3363         sbi->s_blockgroup_lock =
3364                 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3365         if (!sbi->s_blockgroup_lock)
3366                 goto out_free_base;
3367
3368         sb->s_fs_info = sbi;
3369         sbi->s_sb = sb;
3370         sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3371         sbi->s_sb_block = sb_block;
3372         if (sb->s_bdev->bd_part)
3373                 sbi->s_sectors_written_start =
3374                         part_stat_read(sb->s_bdev->bd_part, sectors[1]);
3375
3376         /* Cleanup superblock name */
3377         strreplace(sb->s_id, '/', '!');
3378
3379         /* -EINVAL is default */
3380         ret = -EINVAL;
3381         blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3382         if (!blocksize) {
3383                 ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3384                 goto out_fail;
3385         }
3386
3387         /*
3388          * The ext4 superblock will not be buffer aligned for other than 1kB
3389          * block sizes.  We need to calculate the offset from buffer start.
3390          */
3391         if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3392                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3393                 offset = do_div(logical_sb_block, blocksize);
3394         } else {
3395                 logical_sb_block = sb_block;
3396         }
3397
3398         if (!(bh = sb_bread_unmovable(sb, logical_sb_block))) {
3399                 ext4_msg(sb, KERN_ERR, "unable to read superblock");
3400                 goto out_fail;
3401         }
3402         /*
3403          * Note: s_es must be initialized as soon as possible because
3404          *       some ext4 macro-instructions depend on its value
3405          */
3406         es = (struct ext4_super_block *) (bh->b_data + offset);
3407         sbi->s_es = es;
3408         sb->s_magic = le16_to_cpu(es->s_magic);
3409         if (sb->s_magic != EXT4_SUPER_MAGIC)
3410                 goto cantfind_ext4;
3411         sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3412
3413         /* Warn if metadata_csum and gdt_csum are both set. */
3414         if (ext4_has_feature_metadata_csum(sb) &&
3415             ext4_has_feature_gdt_csum(sb))
3416                 ext4_warning(sb, "metadata_csum and uninit_bg are "
3417                              "redundant flags; please run fsck.");
3418
3419         /* Check for a known checksum algorithm */
3420         if (!ext4_verify_csum_type(sb, es)) {
3421                 ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3422                          "unknown checksum algorithm.");
3423                 silent = 1;
3424                 goto cantfind_ext4;
3425         }
3426
3427         /* Load the checksum driver */
3428         if (ext4_has_feature_metadata_csum(sb)) {
3429                 sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3430                 if (IS_ERR(sbi->s_chksum_driver)) {
3431                         ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3432                         ret = PTR_ERR(sbi->s_chksum_driver);
3433                         sbi->s_chksum_driver = NULL;
3434                         goto failed_mount;
3435                 }
3436         }
3437
3438         /* Check superblock checksum */
3439         if (!ext4_superblock_csum_verify(sb, es)) {
3440                 ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3441                          "invalid superblock checksum.  Run e2fsck?");
3442                 silent = 1;
3443                 ret = -EFSBADCRC;
3444                 goto cantfind_ext4;
3445         }
3446
3447         /* Precompute checksum seed for all metadata */
3448         if (ext4_has_feature_csum_seed(sb))
3449                 sbi->s_csum_seed = le32_to_cpu(es->s_checksum_seed);
3450         else if (ext4_has_metadata_csum(sb))
3451                 sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3452                                                sizeof(es->s_uuid));
3453
3454         /* Set defaults before we parse the mount options */
3455         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3456         set_opt(sb, INIT_INODE_TABLE);
3457         if (def_mount_opts & EXT4_DEFM_DEBUG)
3458                 set_opt(sb, DEBUG);
3459         if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3460                 set_opt(sb, GRPID);
3461         if (def_mount_opts & EXT4_DEFM_UID16)
3462                 set_opt(sb, NO_UID32);
3463         /* xattr user namespace & acls are now defaulted on */
3464         set_opt(sb, XATTR_USER);
3465 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3466         set_opt(sb, POSIX_ACL);
3467 #endif
3468         /* don't forget to enable journal_csum when metadata_csum is enabled. */
3469         if (ext4_has_metadata_csum(sb))
3470                 set_opt(sb, JOURNAL_CHECKSUM);
3471
3472         if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3473                 set_opt(sb, JOURNAL_DATA);
3474         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3475                 set_opt(sb, ORDERED_DATA);
3476         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3477                 set_opt(sb, WRITEBACK_DATA);
3478
3479         if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3480                 set_opt(sb, ERRORS_PANIC);
3481         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3482                 set_opt(sb, ERRORS_CONT);
3483         else
3484                 set_opt(sb, ERRORS_RO);
3485         /* block_validity enabled by default; disable with noblock_validity */
3486         set_opt(sb, BLOCK_VALIDITY);
3487         if (def_mount_opts & EXT4_DEFM_DISCARD)
3488                 set_opt(sb, DISCARD);
3489
3490         sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3491         sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3492         sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3493         sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3494         sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3495
3496         if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3497                 set_opt(sb, BARRIER);
3498
3499         /*
3500          * enable delayed allocation by default
3501          * Use -o nodelalloc to turn it off
3502          */
3503         if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
3504             ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3505                 set_opt(sb, DELALLOC);
3506
3507         /*
3508          * set default s_li_wait_mult for lazyinit, for the case there is
3509          * no mount option specified.
3510          */
3511         sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3512
3513         if (sbi->s_es->s_mount_opts[0]) {
3514                 char *s_mount_opts = kstrndup(sbi->s_es->s_mount_opts,
3515                                               sizeof(sbi->s_es->s_mount_opts),
3516                                               GFP_KERNEL);
3517                 if (!s_mount_opts)
3518                         goto failed_mount;
3519                 if (!parse_options(s_mount_opts, sb, &journal_devnum,
3520                                    &journal_ioprio, 0)) {
3521                         ext4_msg(sb, KERN_WARNING,
3522                                  "failed to parse options in superblock: %s",
3523                                  s_mount_opts);
3524                 }
3525                 kfree(s_mount_opts);
3526         }
3527         sbi->s_def_mount_opt = sbi->s_mount_opt;
3528         if (!parse_options((char *) data, sb, &journal_devnum,
3529                            &journal_ioprio, 0))
3530                 goto failed_mount;
3531
3532         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3533                 printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3534                             "with data=journal disables delayed "
3535                             "allocation and O_DIRECT support!\n");
3536                 if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3537                         ext4_msg(sb, KERN_ERR, "can't mount with "
3538                                  "both data=journal and delalloc");
3539                         goto failed_mount;
3540                 }
3541                 if (test_opt(sb, DIOREAD_NOLOCK)) {
3542                         ext4_msg(sb, KERN_ERR, "can't mount with "
3543                                  "both data=journal and dioread_nolock");
3544                         goto failed_mount;
3545                 }
3546                 if (test_opt(sb, DAX)) {
3547                         ext4_msg(sb, KERN_ERR, "can't mount with "
3548                                  "both data=journal and dax");
3549                         goto failed_mount;
3550                 }
3551                 if (ext4_has_feature_encrypt(sb)) {
3552                         ext4_msg(sb, KERN_WARNING,
3553                                  "encrypted files will use data=ordered "
3554                                  "instead of data journaling mode");
3555                 }
3556                 if (test_opt(sb, DELALLOC))
3557                         clear_opt(sb, DELALLOC);
3558         } else {
3559                 sb->s_iflags |= SB_I_CGROUPWB;
3560         }
3561
3562         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
3563                 (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
3564
3565         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3566             (ext4_has_compat_features(sb) ||
3567              ext4_has_ro_compat_features(sb) ||
3568              ext4_has_incompat_features(sb)))
3569                 ext4_msg(sb, KERN_WARNING,
3570                        "feature flags set on rev 0 fs, "
3571                        "running e2fsck is recommended");
3572
3573         if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
3574                 set_opt2(sb, HURD_COMPAT);
3575                 if (ext4_has_feature_64bit(sb)) {
3576                         ext4_msg(sb, KERN_ERR,
3577                                  "The Hurd can't support 64-bit file systems");
3578                         goto failed_mount;
3579                 }
3580         }
3581
3582         if (IS_EXT2_SB(sb)) {
3583                 if (ext2_feature_set_ok(sb))
3584                         ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3585                                  "using the ext4 subsystem");
3586                 else {
3587                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3588                                  "to feature incompatibilities");
3589                         goto failed_mount;
3590                 }
3591         }
3592
3593         if (IS_EXT3_SB(sb)) {
3594                 if (ext3_feature_set_ok(sb))
3595                         ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3596                                  "using the ext4 subsystem");
3597                 else {
3598                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3599                                  "to feature incompatibilities");
3600                         goto failed_mount;
3601                 }
3602         }
3603
3604         /*
3605          * Check feature flags regardless of the revision level, since we
3606          * previously didn't change the revision level when setting the flags,
3607          * so there is a chance incompat flags are set on a rev 0 filesystem.
3608          */
3609         if (!ext4_feature_set_ok(sb, (sb->s_flags & MS_RDONLY)))
3610                 goto failed_mount;
3611
3612         blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3613         if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3614             blocksize > EXT4_MAX_BLOCK_SIZE) {
3615                 ext4_msg(sb, KERN_ERR,
3616                        "Unsupported filesystem blocksize %d (%d log_block_size)",
3617                          blocksize, le32_to_cpu(es->s_log_block_size));
3618                 goto failed_mount;
3619         }
3620         if (le32_to_cpu(es->s_log_block_size) >
3621             (EXT4_MAX_BLOCK_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
3622                 ext4_msg(sb, KERN_ERR,
3623                          "Invalid log block size: %u",
3624                          le32_to_cpu(es->s_log_block_size));
3625                 goto failed_mount;
3626         }
3627
3628         if (le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) > (blocksize / 4)) {
3629                 ext4_msg(sb, KERN_ERR,
3630                          "Number of reserved GDT blocks insanely large: %d",
3631                          le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks));
3632                 goto failed_mount;
3633         }
3634
3635         if (sbi->s_mount_opt & EXT4_MOUNT_DAX) {
3636                 err = bdev_dax_supported(sb, blocksize);
3637                 if (err)
3638                         goto failed_mount;
3639         }
3640
3641         if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) {
3642                 ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
3643                          es->s_encryption_level);
3644                 goto failed_mount;
3645         }
3646
3647         if (sb->s_blocksize != blocksize) {
3648                 /* Validate the filesystem blocksize */
3649                 if (!sb_set_blocksize(sb, blocksize)) {
3650                         ext4_msg(sb, KERN_ERR, "bad block size %d",
3651                                         blocksize);
3652                         goto failed_mount;
3653                 }
3654
3655                 brelse(bh);
3656                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3657                 offset = do_div(logical_sb_block, blocksize);
3658                 bh = sb_bread_unmovable(sb, logical_sb_block);
3659                 if (!bh) {
3660                         ext4_msg(sb, KERN_ERR,
3661                                "Can't read superblock on 2nd try");
3662                         goto failed_mount;
3663                 }
3664                 es = (struct ext4_super_block *)(bh->b_data + offset);
3665                 sbi->s_es = es;
3666                 if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
3667                         ext4_msg(sb, KERN_ERR,
3668                                "Magic mismatch, very weird!");
3669                         goto failed_mount;
3670                 }
3671         }
3672
3673         has_huge_files = ext4_has_feature_huge_file(sb);
3674         sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
3675                                                       has_huge_files);
3676         sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
3677
3678         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3679                 sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3680                 sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3681         } else {
3682                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3683                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3684                 if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3685                     (!is_power_of_2(sbi->s_inode_size)) ||
3686                     (sbi->s_inode_size > blocksize)) {
3687                         ext4_msg(sb, KERN_ERR,
3688                                "unsupported inode size: %d",
3689                                sbi->s_inode_size);
3690                         goto failed_mount;
3691                 }
3692                 if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
3693                         sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
3694         }
3695
3696         sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
3697         if (ext4_has_feature_64bit(sb)) {
3698                 if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
3699                     sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
3700                     !is_power_of_2(sbi->s_desc_size)) {
3701                         ext4_msg(sb, KERN_ERR,
3702                                "unsupported descriptor size %lu",
3703                                sbi->s_desc_size);
3704                         goto failed_mount;
3705                 }
3706         } else
3707                 sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
3708
3709         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
3710         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
3711
3712         sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
3713         if (sbi->s_inodes_per_block == 0)
3714                 goto cantfind_ext4;
3715         if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
3716             sbi->s_inodes_per_group > blocksize * 8) {
3717                 ext4_msg(sb, KERN_ERR, "invalid inodes per group: %lu\n",
3718                          sbi->s_blocks_per_group);
3719                 goto failed_mount;
3720         }
3721         sbi->s_itb_per_group = sbi->s_inodes_per_group /
3722                                         sbi->s_inodes_per_block;
3723         sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
3724         sbi->s_sbh = bh;
3725         sbi->s_mount_state = le16_to_cpu(es->s_state);
3726         sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
3727         sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
3728
3729         for (i = 0; i < 4; i++)
3730                 sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
3731         sbi->s_def_hash_version = es->s_def_hash_version;
3732         if (ext4_has_feature_dir_index(sb)) {
3733                 i = le32_to_cpu(es->s_flags);
3734                 if (i & EXT2_FLAGS_UNSIGNED_HASH)
3735                         sbi->s_hash_unsigned = 3;
3736                 else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
3737 #ifdef __CHAR_UNSIGNED__
3738                         if (!(sb->s_flags & MS_RDONLY))
3739                                 es->s_flags |=
3740                                         cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
3741                         sbi->s_hash_unsigned = 3;
3742 #else
3743                         if (!(sb->s_flags & MS_RDONLY))
3744                                 es->s_flags |=
3745                                         cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
3746 #endif
3747                 }
3748         }
3749
3750         /* Handle clustersize */
3751         clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
3752         has_bigalloc = ext4_has_feature_bigalloc(sb);
3753         if (has_bigalloc) {
3754                 if (clustersize < blocksize) {
3755                         ext4_msg(sb, KERN_ERR,
3756                                  "cluster size (%d) smaller than "
3757                                  "block size (%d)", clustersize, blocksize);
3758                         goto failed_mount;
3759                 }
3760                 if (le32_to_cpu(es->s_log_cluster_size) >
3761                     (EXT4_MAX_CLUSTER_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
3762                         ext4_msg(sb, KERN_ERR,
3763                                  "Invalid log cluster size: %u",
3764                                  le32_to_cpu(es->s_log_cluster_size));
3765                         goto failed_mount;
3766                 }
3767                 sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
3768                         le32_to_cpu(es->s_log_block_size);
3769                 sbi->s_clusters_per_group =
3770                         le32_to_cpu(es->s_clusters_per_group);
3771                 if (sbi->s_clusters_per_group > blocksize * 8) {
3772                         ext4_msg(sb, KERN_ERR,
3773                                  "#clusters per group too big: %lu",
3774                                  sbi->s_clusters_per_group);
3775                         goto failed_mount;
3776                 }
3777                 if (sbi->s_blocks_per_group !=
3778                     (sbi->s_clusters_per_group * (clustersize / blocksize))) {
3779                         ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
3780                                  "clusters per group (%lu) inconsistent",
3781                                  sbi->s_blocks_per_group,
3782                                  sbi->s_clusters_per_group);
3783                         goto failed_mount;
3784                 }
3785         } else {
3786                 if (clustersize != blocksize) {
3787                         ext4_warning(sb, "fragment/cluster size (%d) != "
3788                                      "block size (%d)", clustersize,
3789                                      blocksize);
3790                         clustersize = blocksize;
3791                 }
3792                 if (sbi->s_blocks_per_group > blocksize * 8) {
3793                         ext4_msg(sb, KERN_ERR,
3794                                  "#blocks per group too big: %lu",
3795                                  sbi->s_blocks_per_group);
3796                         goto failed_mount;
3797                 }
3798                 sbi->s_clusters_per_group = sbi->s_blocks_per_group;
3799                 sbi->s_cluster_bits = 0;
3800         }
3801         sbi->s_cluster_ratio = clustersize / blocksize;
3802
3803         /* Do we have standard group size of clustersize * 8 blocks ? */
3804         if (sbi->s_blocks_per_group == clustersize << 3)
3805                 set_opt2(sb, STD_GROUP_SIZE);
3806
3807         /*
3808          * Test whether we have more sectors than will fit in sector_t,
3809          * and whether the max offset is addressable by the page cache.
3810          */
3811         err = generic_check_addressable(sb->s_blocksize_bits,
3812                                         ext4_blocks_count(es));
3813         if (err) {
3814                 ext4_msg(sb, KERN_ERR, "filesystem"
3815                          " too large to mount safely on this system");
3816                 if (sizeof(sector_t) < 8)
3817                         ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
3818                 goto failed_mount;
3819         }
3820
3821         if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
3822                 goto cantfind_ext4;
3823
3824         /* check blocks count against device size */
3825         blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
3826         if (blocks_count && ext4_blocks_count(es) > blocks_count) {
3827                 ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
3828                        "exceeds size of device (%llu blocks)",
3829                        ext4_blocks_count(es), blocks_count);
3830                 goto failed_mount;
3831         }
3832
3833         /*
3834          * It makes no sense for the first data block to be beyond the end
3835          * of the filesystem.
3836          */
3837         if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
3838                 ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
3839                          "block %u is beyond end of filesystem (%llu)",
3840                          le32_to_cpu(es->s_first_data_block),
3841                          ext4_blocks_count(es));
3842                 goto failed_mount;
3843         }
3844         blocks_count = (ext4_blocks_count(es) -
3845                         le32_to_cpu(es->s_first_data_block) +
3846                         EXT4_BLOCKS_PER_GROUP(sb) - 1);
3847         do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
3848         if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
3849                 ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
3850                        "(block count %llu, first data block %u, "
3851                        "blocks per group %lu)", sbi->s_groups_count,
3852                        ext4_blocks_count(es),
3853                        le32_to_cpu(es->s_first_data_block),
3854                        EXT4_BLOCKS_PER_GROUP(sb));
3855                 goto failed_mount;
3856         }
3857         sbi->s_groups_count = blocks_count;
3858         sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
3859                         (EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
3860         db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
3861                    EXT4_DESC_PER_BLOCK(sb);
3862         if (ext4_has_feature_meta_bg(sb)) {
3863                 if (le32_to_cpu(es->s_first_meta_bg) > db_count) {
3864                         ext4_msg(sb, KERN_WARNING,
3865                                  "first meta block group too large: %u "
3866                                  "(group descriptor block count %u)",
3867                                  le32_to_cpu(es->s_first_meta_bg), db_count);
3868                         goto failed_mount;
3869                 }
3870         }
3871         sbi->s_group_desc = ext4_kvmalloc(db_count *
3872                                           sizeof(struct buffer_head *),
3873                                           GFP_KERNEL);
3874         if (sbi->s_group_desc == NULL) {
3875                 ext4_msg(sb, KERN_ERR, "not enough memory");
3876                 ret = -ENOMEM;
3877                 goto failed_mount;
3878         }
3879
3880         bgl_lock_init(sbi->s_blockgroup_lock);
3881
3882         for (i = 0; i < db_count; i++) {
3883                 block = descriptor_loc(sb, logical_sb_block, i);
3884                 sbi->s_group_desc[i] = sb_bread_unmovable(sb, block);
3885                 if (!sbi->s_group_desc[i]) {
3886                         ext4_msg(sb, KERN_ERR,
3887                                "can't read group descriptor %d", i);
3888                         db_count = i;
3889                         goto failed_mount2;
3890                 }
3891         }
3892         if (!ext4_check_descriptors(sb, logical_sb_block, &first_not_zeroed)) {
3893                 ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
3894                 ret = -EFSCORRUPTED;
3895                 goto failed_mount2;
3896         }
3897
3898         sbi->s_gdb_count = db_count;
3899         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
3900         spin_lock_init(&sbi->s_next_gen_lock);
3901
3902         setup_timer(&sbi->s_err_report, print_daily_error_info,
3903                 (unsigned long) sb);
3904
3905         /* Register extent status tree shrinker */
3906         if (ext4_es_register_shrinker(sbi))
3907                 goto failed_mount3;
3908
3909         sbi->s_stripe = ext4_get_stripe_size(sbi);
3910         sbi->s_extent_max_zeroout_kb = 32;
3911
3912         /*
3913          * set up enough so that it can read an inode
3914          */
3915         sb->s_op = &ext4_sops;
3916         sb->s_export_op = &ext4_export_ops;
3917         sb->s_xattr = ext4_xattr_handlers;
3918         sb->s_cop = &ext4_cryptops;
3919 #ifdef CONFIG_QUOTA
3920         sb->dq_op = &ext4_quota_operations;
3921         if (ext4_has_feature_quota(sb))
3922                 sb->s_qcop = &dquot_quotactl_sysfile_ops;
3923         else
3924                 sb->s_qcop = &ext4_qctl_operations;
3925         sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
3926 #endif
3927         memcpy(sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
3928
3929         INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
3930         mutex_init(&sbi->s_orphan_lock);
3931
3932         sb->s_root = NULL;
3933
3934         needs_recovery = (es->s_last_orphan != 0 ||
3935                           ext4_has_feature_journal_needs_recovery(sb));
3936
3937         if (ext4_has_feature_mmp(sb) && !(sb->s_flags & MS_RDONLY))
3938                 if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
3939                         goto failed_mount3a;
3940
3941         /*
3942          * The first inode we look at is the journal inode.  Don't try
3943          * root first: it may be modified in the journal!
3944          */
3945         if (!test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) {
3946                 err = ext4_load_journal(sb, es, journal_devnum);
3947                 if (err)
3948                         goto failed_mount3a;
3949         } else if (test_opt(sb, NOLOAD) && !(sb->s_flags & MS_RDONLY) &&
3950                    ext4_has_feature_journal_needs_recovery(sb)) {
3951                 ext4_msg(sb, KERN_ERR, "required journal recovery "
3952                        "suppressed and not mounted read-only");
3953                 goto failed_mount_wq;
3954         } else {
3955                 /* Nojournal mode, all journal mount options are illegal */
3956                 if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM)) {
3957                         ext4_msg(sb, KERN_ERR, "can't mount with "
3958                                  "journal_checksum, fs mounted w/o journal");
3959                         goto failed_mount_wq;
3960                 }
3961                 if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3962                         ext4_msg(sb, KERN_ERR, "can't mount with "
3963                                  "journal_async_commit, fs mounted w/o journal");
3964                         goto failed_mount_wq;
3965                 }
3966                 if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
3967                         ext4_msg(sb, KERN_ERR, "can't mount with "
3968                                  "commit=%lu, fs mounted w/o journal",
3969                                  sbi->s_commit_interval / HZ);
3970                         goto failed_mount_wq;
3971                 }
3972                 if (EXT4_MOUNT_DATA_FLAGS &
3973                     (sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
3974                         ext4_msg(sb, KERN_ERR, "can't mount with "
3975                                  "data=, fs mounted w/o journal");
3976                         goto failed_mount_wq;
3977                 }
3978                 sbi->s_def_mount_opt &= EXT4_MOUNT_JOURNAL_CHECKSUM;
3979                 clear_opt(sb, JOURNAL_CHECKSUM);
3980                 clear_opt(sb, DATA_FLAGS);
3981                 sbi->s_journal = NULL;
3982                 needs_recovery = 0;
3983                 goto no_journal;
3984         }
3985
3986         if (ext4_has_feature_64bit(sb) &&
3987             !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
3988                                        JBD2_FEATURE_INCOMPAT_64BIT)) {
3989                 ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
3990                 goto failed_mount_wq;
3991         }
3992
3993         if (!set_journal_csum_feature_set(sb)) {
3994                 ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
3995                          "feature set");
3996                 goto failed_mount_wq;
3997         }
3998
3999         /* We have now updated the journal if required, so we can
4000          * validate the data journaling mode. */
4001         switch (test_opt(sb, DATA_FLAGS)) {
4002         case 0:
4003                 /* No mode set, assume a default based on the journal
4004                  * capabilities: ORDERED_DATA if the journal can
4005                  * cope, else JOURNAL_DATA
4006                  */
4007                 if (jbd2_journal_check_available_features
4008                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
4009                         set_opt(sb, ORDERED_DATA);
4010                 else
4011                         set_opt(sb, JOURNAL_DATA);
4012                 break;
4013
4014         case EXT4_MOUNT_ORDERED_DATA:
4015         case EXT4_MOUNT_WRITEBACK_DATA:
4016                 if (!jbd2_journal_check_available_features
4017                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4018                         ext4_msg(sb, KERN_ERR, "Journal does not support "
4019                                "requested data journaling mode");
4020                         goto failed_mount_wq;
4021                 }
4022         default:
4023                 break;
4024         }
4025
4026         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
4027             test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4028                 ext4_msg(sb, KERN_ERR, "can't mount with "
4029                         "journal_async_commit in data=ordered mode");
4030                 goto failed_mount_wq;
4031         }
4032
4033         set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4034
4035         sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
4036
4037 no_journal:
4038         sbi->s_mb_cache = ext4_xattr_create_cache();
4039         if (!sbi->s_mb_cache) {
4040                 ext4_msg(sb, KERN_ERR, "Failed to create an mb_cache");
4041                 goto failed_mount_wq;
4042         }
4043
4044         if ((DUMMY_ENCRYPTION_ENABLED(sbi) || ext4_has_feature_encrypt(sb)) &&
4045             (blocksize != PAGE_SIZE)) {
4046                 ext4_msg(sb, KERN_ERR,
4047                          "Unsupported blocksize for fs encryption");
4048                 goto failed_mount_wq;
4049         }
4050
4051         if (DUMMY_ENCRYPTION_ENABLED(sbi) && !(sb->s_flags & MS_RDONLY) &&
4052             !ext4_has_feature_encrypt(sb)) {
4053                 ext4_set_feature_encrypt(sb);
4054                 ext4_commit_super(sb, 1);
4055         }
4056
4057         /*
4058          * Get the # of file system overhead blocks from the
4059          * superblock if present.
4060          */
4061         if (es->s_overhead_clusters)
4062                 sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
4063         else {
4064                 err = ext4_calculate_overhead(sb);
4065                 if (err)
4066                         goto failed_mount_wq;
4067         }
4068
4069         /*
4070          * The maximum number of concurrent works can be high and
4071          * concurrency isn't really necessary.  Limit it to 1.
4072          */
4073         EXT4_SB(sb)->rsv_conversion_wq =
4074                 alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
4075         if (!EXT4_SB(sb)->rsv_conversion_wq) {
4076                 printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
4077                 ret = -ENOMEM;
4078                 goto failed_mount4;
4079         }
4080
4081         /*
4082          * The jbd2_journal_load will have done any necessary log recovery,
4083          * so we can safely mount the rest of the filesystem now.
4084          */
4085
4086         root = ext4_iget(sb, EXT4_ROOT_INO);
4087         if (IS_ERR(root)) {
4088                 ext4_msg(sb, KERN_ERR, "get root inode failed");
4089                 ret = PTR_ERR(root);
4090                 root = NULL;
4091                 goto failed_mount4;
4092         }
4093         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
4094                 ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
4095                 iput(root);
4096                 goto failed_mount4;
4097         }
4098         sb->s_root = d_make_root(root);
4099         if (!sb->s_root) {
4100                 ext4_msg(sb, KERN_ERR, "get root dentry failed");
4101                 ret = -ENOMEM;
4102                 goto failed_mount4;
4103         }
4104
4105         if (ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY))
4106                 sb->s_flags |= MS_RDONLY;
4107
4108         /* determine the minimum size of new large inodes, if present */
4109         if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE &&
4110             sbi->s_want_extra_isize == 0) {
4111                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4112                                                      EXT4_GOOD_OLD_INODE_SIZE;
4113                 if (ext4_has_feature_extra_isize(sb)) {
4114                         if (sbi->s_want_extra_isize <
4115                             le16_to_cpu(es->s_want_extra_isize))
4116                                 sbi->s_want_extra_isize =
4117                                         le16_to_cpu(es->s_want_extra_isize);
4118                         if (sbi->s_want_extra_isize <
4119                             le16_to_cpu(es->s_min_extra_isize))
4120                                 sbi->s_want_extra_isize =
4121                                         le16_to_cpu(es->s_min_extra_isize);
4122                 }
4123         }
4124         /* Check if enough inode space is available */
4125         if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
4126                                                         sbi->s_inode_size) {
4127                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4128                                                        EXT4_GOOD_OLD_INODE_SIZE;
4129                 ext4_msg(sb, KERN_INFO, "required extra inode space not"
4130                          "available");
4131         }
4132
4133         ext4_set_resv_clusters(sb);
4134
4135         err = ext4_setup_system_zone(sb);
4136         if (err) {
4137                 ext4_msg(sb, KERN_ERR, "failed to initialize system "
4138                          "zone (%d)", err);
4139                 goto failed_mount4a;
4140         }
4141
4142         ext4_ext_init(sb);
4143         err = ext4_mb_init(sb);
4144         if (err) {
4145                 ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
4146                          err);
4147                 goto failed_mount5;
4148         }
4149
4150         block = ext4_count_free_clusters(sb);
4151         ext4_free_blocks_count_set(sbi->s_es,
4152                                    EXT4_C2B(sbi, block));
4153         err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
4154                                   GFP_KERNEL);
4155         if (!err) {
4156                 unsigned long freei = ext4_count_free_inodes(sb);
4157                 sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
4158                 err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
4159                                           GFP_KERNEL);
4160         }
4161         if (!err)
4162                 err = percpu_counter_init(&sbi->s_dirs_counter,
4163                                           ext4_count_dirs(sb), GFP_KERNEL);
4164         if (!err)
4165                 err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
4166                                           GFP_KERNEL);
4167         if (!err)
4168                 err = percpu_init_rwsem(&sbi->s_journal_flag_rwsem);
4169
4170         if (err) {
4171                 ext4_msg(sb, KERN_ERR, "insufficient memory");
4172                 goto failed_mount6;
4173         }
4174
4175         if (ext4_has_feature_flex_bg(sb))
4176                 if (!ext4_fill_flex_info(sb)) {
4177                         ext4_msg(sb, KERN_ERR,
4178                                "unable to initialize "
4179                                "flex_bg meta info!");
4180                         goto failed_mount6;
4181                 }
4182
4183         err = ext4_register_li_request(sb, first_not_zeroed);
4184         if (err)
4185                 goto failed_mount6;
4186
4187         err = ext4_register_sysfs(sb);
4188         if (err)
4189                 goto failed_mount7;
4190
4191 #ifdef CONFIG_QUOTA
4192         /* Enable quota usage during mount. */
4193         if (ext4_has_feature_quota(sb) && !(sb->s_flags & MS_RDONLY)) {
4194                 err = ext4_enable_quotas(sb);
4195                 if (err)
4196                         goto failed_mount8;
4197         }
4198 #endif  /* CONFIG_QUOTA */
4199
4200         EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
4201         ext4_orphan_cleanup(sb, es);
4202         EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
4203         if (needs_recovery) {
4204                 ext4_msg(sb, KERN_INFO, "recovery complete");
4205                 ext4_mark_recovery_complete(sb, es);
4206         }
4207         if (EXT4_SB(sb)->s_journal) {
4208                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
4209                         descr = " journalled data mode";
4210                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
4211                         descr = " ordered data mode";
4212                 else
4213                         descr = " writeback data mode";
4214         } else
4215                 descr = "out journal";
4216
4217         if (test_opt(sb, DISCARD)) {
4218                 struct request_queue *q = bdev_get_queue(sb->s_bdev);
4219                 if (!blk_queue_discard(q))
4220                         ext4_msg(sb, KERN_WARNING,
4221                                  "mounting with \"discard\" option, but "
4222                                  "the device does not support discard");
4223         }
4224
4225         if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
4226                 ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
4227                          "Opts: %.*s%s%s", descr,
4228                          (int) sizeof(sbi->s_es->s_mount_opts),
4229                          sbi->s_es->s_mount_opts,
4230                          *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
4231
4232         if (es->s_error_count)
4233                 mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
4234
4235         /* Enable message ratelimiting. Default is 10 messages per 5 secs. */
4236         ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
4237         ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
4238         ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
4239
4240         kfree(orig_data);
4241         return 0;
4242
4243 cantfind_ext4:
4244         if (!silent)
4245                 ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
4246         goto failed_mount;
4247
4248 #ifdef CONFIG_QUOTA
4249 failed_mount8:
4250         ext4_unregister_sysfs(sb);
4251 #endif
4252 failed_mount7:
4253         ext4_unregister_li_request(sb);
4254 failed_mount6:
4255         ext4_mb_release(sb);
4256         if (sbi->s_flex_groups)
4257                 kvfree(sbi->s_flex_groups);
4258         percpu_counter_destroy(&sbi->s_freeclusters_counter);
4259         percpu_counter_destroy(&sbi->s_freeinodes_counter);
4260         percpu_counter_destroy(&sbi->s_dirs_counter);
4261         percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4262 failed_mount5:
4263         ext4_ext_release(sb);
4264         ext4_release_system_zone(sb);
4265 failed_mount4a:
4266         dput(sb->s_root);
4267         sb->s_root = NULL;
4268 failed_mount4:
4269         ext4_msg(sb, KERN_ERR, "mount failed");
4270         if (EXT4_SB(sb)->rsv_conversion_wq)
4271                 destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4272 failed_mount_wq:
4273         if (sbi->s_mb_cache) {
4274                 ext4_xattr_destroy_cache(sbi->s_mb_cache);
4275                 sbi->s_mb_cache = NULL;
4276         }
4277         if (sbi->s_journal) {
4278                 jbd2_journal_destroy(sbi->s_journal);
4279                 sbi->s_journal = NULL;
4280         }
4281 failed_mount3a:
4282         ext4_es_unregister_shrinker(sbi);
4283 failed_mount3:
4284         del_timer_sync(&sbi->s_err_report);
4285         if (sbi->s_mmp_tsk)
4286                 kthread_stop(sbi->s_mmp_tsk);
4287 failed_mount2:
4288         for (i = 0; i < db_count; i++)
4289                 brelse(sbi->s_group_desc[i]);
4290         kvfree(sbi->s_group_desc);
4291 failed_mount:
4292         if (sbi->s_chksum_driver)
4293                 crypto_free_shash(sbi->s_chksum_driver);
4294 #ifdef CONFIG_QUOTA
4295         for (i = 0; i < EXT4_MAXQUOTAS; i++)
4296                 kfree(sbi->s_qf_names[i]);
4297 #endif
4298         ext4_blkdev_remove(sbi);
4299         brelse(bh);
4300 out_fail:
4301         sb->s_fs_info = NULL;
4302         kfree(sbi->s_blockgroup_lock);
4303 out_free_base:
4304         kfree(sbi);
4305         kfree(orig_data);
4306         return err ? err : ret;
4307 }
4308
4309 /*
4310  * Setup any per-fs journal parameters now.  We'll do this both on
4311  * initial mount, once the journal has been initialised but before we've
4312  * done any recovery; and again on any subsequent remount.
4313  */
4314 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4315 {
4316         struct ext4_sb_info *sbi = EXT4_SB(sb);
4317
4318         journal->j_commit_interval = sbi->s_commit_interval;
4319         journal->j_min_batch_time = sbi->s_min_batch_time;
4320         journal->j_max_batch_time = sbi->s_max_batch_time;
4321
4322         write_lock(&journal->j_state_lock);
4323         if (test_opt(sb, BARRIER))
4324                 journal->j_flags |= JBD2_BARRIER;
4325         else
4326                 journal->j_flags &= ~JBD2_BARRIER;
4327         if (test_opt(sb, DATA_ERR_ABORT))
4328                 journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4329         else
4330                 journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4331         write_unlock(&journal->j_state_lock);
4332 }
4333
4334 static struct inode *ext4_get_journal_inode(struct super_block *sb,
4335                                              unsigned int journal_inum)
4336 {
4337         struct inode *journal_inode;
4338
4339         /*
4340          * Test for the existence of a valid inode on disk.  Bad things
4341          * happen if we iget() an unused inode, as the subsequent iput()
4342          * will try to delete it.
4343          */
4344         journal_inode = ext4_iget(sb, journal_inum);
4345         if (IS_ERR(journal_inode)) {
4346                 ext4_msg(sb, KERN_ERR, "no journal found");
4347                 return NULL;
4348         }
4349         if (!journal_inode->i_nlink) {
4350                 make_bad_inode(journal_inode);
4351                 iput(journal_inode);
4352                 ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4353                 return NULL;
4354         }
4355
4356         jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4357                   journal_inode, journal_inode->i_size);
4358         if (!S_ISREG(journal_inode->i_mode)) {
4359                 ext4_msg(sb, KERN_ERR, "invalid journal inode");
4360                 iput(journal_inode);
4361                 return NULL;
4362         }
4363         return journal_inode;
4364 }
4365
4366 static journal_t *ext4_get_journal(struct super_block *sb,
4367                                    unsigned int journal_inum)
4368 {
4369         struct inode *journal_inode;
4370         journal_t *journal;
4371
4372         BUG_ON(!ext4_has_feature_journal(sb));
4373
4374         journal_inode = ext4_get_journal_inode(sb, journal_inum);
4375         if (!journal_inode)
4376                 return NULL;
4377
4378         journal = jbd2_journal_init_inode(journal_inode);
4379         if (!journal) {
4380                 ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4381                 iput(journal_inode);
4382                 return NULL;
4383         }
4384         journal->j_private = sb;
4385         ext4_init_journal_params(sb, journal);
4386         return journal;
4387 }
4388
4389 static journal_t *ext4_get_dev_journal(struct super_block *sb,
4390                                        dev_t j_dev)
4391 {
4392         struct buffer_head *bh;
4393         journal_t *journal;
4394         ext4_fsblk_t start;
4395         ext4_fsblk_t len;
4396         int hblock, blocksize;
4397         ext4_fsblk_t sb_block;
4398         unsigned long offset;
4399         struct ext4_super_block *es;
4400         struct block_device *bdev;
4401
4402         BUG_ON(!ext4_has_feature_journal(sb));
4403
4404         bdev = ext4_blkdev_get(j_dev, sb);
4405         if (bdev == NULL)
4406                 return NULL;
4407
4408         blocksize = sb->s_blocksize;
4409         hblock = bdev_logical_block_size(bdev);
4410         if (blocksize < hblock) {
4411                 ext4_msg(sb, KERN_ERR,
4412                         "blocksize too small for journal device");
4413                 goto out_bdev;
4414         }
4415
4416         sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4417         offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4418         set_blocksize(bdev, blocksize);
4419         if (!(bh = __bread(bdev, sb_block, blocksize))) {
4420                 ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4421                        "external journal");
4422                 goto out_bdev;
4423         }
4424
4425         es = (struct ext4_super_block *) (bh->b_data + offset);
4426         if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4427             !(le32_to_cpu(es->s_feature_incompat) &
4428               EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4429                 ext4_msg(sb, KERN_ERR, "external journal has "
4430                                         "bad superblock");
4431                 brelse(bh);
4432                 goto out_bdev;
4433         }
4434
4435         if ((le32_to_cpu(es->s_feature_ro_compat) &
4436              EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
4437             es->s_checksum != ext4_superblock_csum(sb, es)) {
4438                 ext4_msg(sb, KERN_ERR, "external journal has "
4439                                        "corrupt superblock");
4440                 brelse(bh);
4441                 goto out_bdev;
4442         }
4443
4444         if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4445                 ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4446                 brelse(bh);
4447                 goto out_bdev;
4448         }
4449
4450         len = ext4_blocks_count(es);
4451         start = sb_block + 1;
4452         brelse(bh);     /* we're done with the superblock */
4453
4454         journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4455                                         start, len, blocksize);
4456         if (!journal) {
4457                 ext4_msg(sb, KERN_ERR, "failed to create device journal");
4458                 goto out_bdev;
4459         }
4460         journal->j_private = sb;
4461         ll_rw_block(REQ_OP_READ, REQ_META | REQ_PRIO, 1, &journal->j_sb_buffer);
4462         wait_on_buffer(journal->j_sb_buffer);
4463         if (!buffer_uptodate(journal->j_sb_buffer)) {
4464                 ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4465                 goto out_journal;
4466         }
4467         if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4468                 ext4_msg(sb, KERN_ERR, "External journal has more than one "
4469                                         "user (unsupported) - %d",
4470                         be32_to_cpu(journal->j_superblock->s_nr_users));
4471                 goto out_journal;
4472         }
4473         EXT4_SB(sb)->journal_bdev = bdev;
4474         ext4_init_journal_params(sb, journal);
4475         return journal;
4476
4477 out_journal:
4478         jbd2_journal_destroy(journal);
4479 out_bdev:
4480         ext4_blkdev_put(bdev);
4481         return NULL;
4482 }
4483
4484 static int ext4_load_journal(struct super_block *sb,
4485                              struct ext4_super_block *es,
4486                              unsigned long journal_devnum)
4487 {
4488         journal_t *journal;
4489         unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4490         dev_t journal_dev;
4491         int err = 0;
4492         int really_read_only;
4493
4494         BUG_ON(!ext4_has_feature_journal(sb));
4495
4496         if (journal_devnum &&
4497             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4498                 ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4499                         "numbers have changed");
4500                 journal_dev = new_decode_dev(journal_devnum);
4501         } else
4502                 journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4503
4504         really_read_only = bdev_read_only(sb->s_bdev);
4505
4506         /*
4507          * Are we loading a blank journal or performing recovery after a
4508          * crash?  For recovery, we need to check in advance whether we
4509          * can get read-write access to the device.
4510          */
4511         if (ext4_has_feature_journal_needs_recovery(sb)) {
4512                 if (sb->s_flags & MS_RDONLY) {
4513                         ext4_msg(sb, KERN_INFO, "INFO: recovery "
4514                                         "required on readonly filesystem");
4515                         if (really_read_only) {
4516                                 ext4_msg(sb, KERN_ERR, "write access "
4517                                         "unavailable, cannot proceed");
4518                                 return -EROFS;
4519                         }
4520                         ext4_msg(sb, KERN_INFO, "write access will "
4521                                "be enabled during recovery");
4522                 }
4523         }
4524
4525         if (journal_inum && journal_dev) {
4526                 ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4527                        "and inode journals!");
4528                 return -EINVAL;
4529         }
4530
4531         if (journal_inum) {
4532                 if (!(journal = ext4_get_journal(sb, journal_inum)))
4533                         return -EINVAL;
4534         } else {
4535                 if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4536                         return -EINVAL;
4537         }
4538
4539         if (!(journal->j_flags & JBD2_BARRIER))
4540                 ext4_msg(sb, KERN_INFO, "barriers disabled");
4541
4542         if (!ext4_has_feature_journal_needs_recovery(sb))
4543                 err = jbd2_journal_wipe(journal, !really_read_only);
4544         if (!err) {
4545                 char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4546                 if (save)
4547                         memcpy(save, ((char *) es) +
4548                                EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4549                 err = jbd2_journal_load(journal);
4550                 if (save)
4551                         memcpy(((char *) es) + EXT4_S_ERR_START,
4552                                save, EXT4_S_ERR_LEN);
4553                 kfree(save);
4554         }
4555
4556         if (err) {
4557                 ext4_msg(sb, KERN_ERR, "error loading journal");
4558                 jbd2_journal_destroy(journal);
4559                 return err;
4560         }
4561
4562         EXT4_SB(sb)->s_journal = journal;
4563         ext4_clear_journal_err(sb, es);
4564
4565         if (!really_read_only && journal_devnum &&
4566             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4567                 es->s_journal_dev = cpu_to_le32(journal_devnum);
4568
4569                 /* Make sure we flush the recovery flag to disk. */
4570                 ext4_commit_super(sb, 1);
4571         }
4572
4573         return 0;
4574 }
4575
4576 static int ext4_commit_super(struct super_block *sb, int sync)
4577 {
4578         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4579         struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4580         int error = 0;
4581
4582         if (!sbh || block_device_ejected(sb))
4583                 return error;
4584         /*
4585          * If the file system is mounted read-only, don't update the
4586          * superblock write time.  This avoids updating the superblock
4587          * write time when we are mounting the root file system
4588          * read/only but we need to replay the journal; at that point,
4589          * for people who are east of GMT and who make their clock
4590          * tick in localtime for Windows bug-for-bug compatibility,
4591          * the clock is set in the future, and this will cause e2fsck
4592          * to complain and force a full file system check.
4593          */
4594         if (!(sb->s_flags & MS_RDONLY))
4595                 es->s_wtime = cpu_to_le32(get_seconds());
4596         if (sb->s_bdev->bd_part)
4597                 es->s_kbytes_written =
4598                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
4599                             ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
4600                               EXT4_SB(sb)->s_sectors_written_start) >> 1));
4601         else
4602                 es->s_kbytes_written =
4603                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
4604         if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeclusters_counter))
4605                 ext4_free_blocks_count_set(es,
4606                         EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
4607                                 &EXT4_SB(sb)->s_freeclusters_counter)));
4608         if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeinodes_counter))
4609                 es->s_free_inodes_count =
4610                         cpu_to_le32(percpu_counter_sum_positive(
4611                                 &EXT4_SB(sb)->s_freeinodes_counter));
4612         BUFFER_TRACE(sbh, "marking dirty");
4613         ext4_superblock_csum_set(sb);
4614         if (sync)
4615                 lock_buffer(sbh);
4616         if (buffer_write_io_error(sbh)) {
4617                 /*
4618                  * Oh, dear.  A previous attempt to write the
4619                  * superblock failed.  This could happen because the
4620                  * USB device was yanked out.  Or it could happen to
4621                  * be a transient write error and maybe the block will
4622                  * be remapped.  Nothing we can do but to retry the
4623                  * write and hope for the best.
4624                  */
4625                 ext4_msg(sb, KERN_ERR, "previous I/O error to "
4626                        "superblock detected");
4627                 clear_buffer_write_io_error(sbh);
4628                 set_buffer_uptodate(sbh);
4629         }
4630         mark_buffer_dirty(sbh);
4631         if (sync) {
4632                 unlock_buffer(sbh);
4633                 error = __sync_dirty_buffer(sbh,
4634                         test_opt(sb, BARRIER) ? REQ_FUA : REQ_SYNC);
4635                 if (error)
4636                         return error;
4637
4638                 error = buffer_write_io_error(sbh);
4639                 if (error) {
4640                         ext4_msg(sb, KERN_ERR, "I/O error while writing "
4641                                "superblock");
4642                         clear_buffer_write_io_error(sbh);
4643                         set_buffer_uptodate(sbh);
4644                 }
4645         }
4646         return error;
4647 }
4648
4649 /*
4650  * Have we just finished recovery?  If so, and if we are mounting (or
4651  * remounting) the filesystem readonly, then we will end up with a
4652  * consistent fs on disk.  Record that fact.
4653  */
4654 static void ext4_mark_recovery_complete(struct super_block *sb,
4655                                         struct ext4_super_block *es)
4656 {
4657         journal_t *journal = EXT4_SB(sb)->s_journal;
4658
4659         if (!ext4_has_feature_journal(sb)) {
4660                 BUG_ON(journal != NULL);
4661                 return;
4662         }
4663         jbd2_journal_lock_updates(journal);
4664         if (jbd2_journal_flush(journal) < 0)
4665                 goto out;
4666
4667         if (ext4_has_feature_journal_needs_recovery(sb) &&
4668             sb->s_flags & MS_RDONLY) {
4669                 ext4_clear_feature_journal_needs_recovery(sb);
4670                 ext4_commit_super(sb, 1);
4671         }
4672
4673 out:
4674         jbd2_journal_unlock_updates(journal);
4675 }
4676
4677 /*
4678  * If we are mounting (or read-write remounting) a filesystem whose journal
4679  * has recorded an error from a previous lifetime, move that error to the
4680  * main filesystem now.
4681  */
4682 static void ext4_clear_journal_err(struct super_block *sb,
4683                                    struct ext4_super_block *es)
4684 {
4685         journal_t *journal;
4686         int j_errno;
4687         const char *errstr;
4688
4689         BUG_ON(!ext4_has_feature_journal(sb));
4690
4691         journal = EXT4_SB(sb)->s_journal;
4692
4693         /*
4694          * Now check for any error status which may have been recorded in the
4695          * journal by a prior ext4_error() or ext4_abort()
4696          */
4697
4698         j_errno = jbd2_journal_errno(journal);
4699         if (j_errno) {
4700                 char nbuf[16];
4701
4702                 errstr = ext4_decode_error(sb, j_errno, nbuf);
4703                 ext4_warning(sb, "Filesystem error recorded "
4704                              "from previous mount: %s", errstr);
4705                 ext4_warning(sb, "Marking fs in need of filesystem check.");
4706
4707                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
4708                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
4709                 ext4_commit_super(sb, 1);
4710
4711                 jbd2_journal_clear_err(journal);
4712                 jbd2_journal_update_sb_errno(journal);
4713         }
4714 }
4715
4716 /*
4717  * Force the running and committing transactions to commit,
4718  * and wait on the commit.
4719  */
4720 int ext4_force_commit(struct super_block *sb)
4721 {
4722         journal_t *journal;
4723
4724         if (sb->s_flags & MS_RDONLY)
4725                 return 0;
4726
4727         journal = EXT4_SB(sb)->s_journal;
4728         return ext4_journal_force_commit(journal);
4729 }
4730
4731 static int ext4_sync_fs(struct super_block *sb, int wait)
4732 {
4733         int ret = 0;
4734         tid_t target;
4735         bool needs_barrier = false;
4736         struct ext4_sb_info *sbi = EXT4_SB(sb);
4737
4738         if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
4739                 return 0;
4740
4741         trace_ext4_sync_fs(sb, wait);
4742         flush_workqueue(sbi->rsv_conversion_wq);
4743         /*
4744          * Writeback quota in non-journalled quota case - journalled quota has
4745          * no dirty dquots
4746          */
4747         dquot_writeback_dquots(sb, -1);
4748         /*
4749          * Data writeback is possible w/o journal transaction, so barrier must
4750          * being sent at the end of the function. But we can skip it if
4751          * transaction_commit will do it for us.
4752          */
4753         if (sbi->s_journal) {
4754                 target = jbd2_get_latest_transaction(sbi->s_journal);
4755                 if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
4756                     !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
4757                         needs_barrier = true;
4758
4759                 if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
4760                         if (wait)
4761                                 ret = jbd2_log_wait_commit(sbi->s_journal,
4762                                                            target);
4763                 }
4764         } else if (wait && test_opt(sb, BARRIER))
4765                 needs_barrier = true;
4766         if (needs_barrier) {
4767                 int err;
4768                 err = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
4769                 if (!ret)
4770                         ret = err;
4771         }
4772
4773         return ret;
4774 }
4775
4776 /*
4777  * LVM calls this function before a (read-only) snapshot is created.  This
4778  * gives us a chance to flush the journal completely and mark the fs clean.
4779  *
4780  * Note that only this function cannot bring a filesystem to be in a clean
4781  * state independently. It relies on upper layer to stop all data & metadata
4782  * modifications.
4783  */
4784 static int ext4_freeze(struct super_block *sb)
4785 {
4786         int error = 0;
4787         journal_t *journal;
4788
4789         if (sb->s_flags & MS_RDONLY)
4790                 return 0;
4791
4792         journal = EXT4_SB(sb)->s_journal;
4793
4794         if (journal) {
4795                 /* Now we set up the journal barrier. */
4796                 jbd2_journal_lock_updates(journal);
4797
4798                 /*
4799                  * Don't clear the needs_recovery flag if we failed to
4800                  * flush the journal.
4801                  */
4802                 error = jbd2_journal_flush(journal);
4803                 if (error < 0)
4804                         goto out;
4805
4806                 /* Journal blocked and flushed, clear needs_recovery flag. */
4807                 ext4_clear_feature_journal_needs_recovery(sb);
4808         }
4809
4810         error = ext4_commit_super(sb, 1);
4811 out:
4812         if (journal)
4813                 /* we rely on upper layer to stop further updates */
4814                 jbd2_journal_unlock_updates(journal);
4815         return error;
4816 }
4817
4818 /*
4819  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
4820  * flag here, even though the filesystem is not technically dirty yet.
4821  */
4822 static int ext4_unfreeze(struct super_block *sb)
4823 {
4824         if ((sb->s_flags & MS_RDONLY) || ext4_forced_shutdown(EXT4_SB(sb)))
4825                 return 0;
4826
4827         if (EXT4_SB(sb)->s_journal) {
4828                 /* Reset the needs_recovery flag before the fs is unlocked. */
4829                 ext4_set_feature_journal_needs_recovery(sb);
4830         }
4831
4832         ext4_commit_super(sb, 1);
4833         return 0;
4834 }
4835
4836 /*
4837  * Structure to save mount options for ext4_remount's benefit
4838  */
4839 struct ext4_mount_options {
4840         unsigned long s_mount_opt;
4841         unsigned long s_mount_opt2;
4842         kuid_t s_resuid;
4843         kgid_t s_resgid;
4844         unsigned long s_commit_interval;
4845         u32 s_min_batch_time, s_max_batch_time;
4846 #ifdef CONFIG_QUOTA
4847         int s_jquota_fmt;
4848         char *s_qf_names[EXT4_MAXQUOTAS];
4849 #endif
4850 };
4851
4852 static int ext4_remount(struct super_block *sb, int *flags, char *data)
4853 {
4854         struct ext4_super_block *es;
4855         struct ext4_sb_info *sbi = EXT4_SB(sb);
4856         unsigned long old_sb_flags;
4857         struct ext4_mount_options old_opts;
4858         int enable_quota = 0;
4859         ext4_group_t g;
4860         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4861         int err = 0;
4862 #ifdef CONFIG_QUOTA
4863         int i, j;
4864 #endif
4865         char *orig_data = kstrdup(data, GFP_KERNEL);
4866
4867         /* Store the original options */
4868         old_sb_flags = sb->s_flags;
4869         old_opts.s_mount_opt = sbi->s_mount_opt;
4870         old_opts.s_mount_opt2 = sbi->s_mount_opt2;
4871         old_opts.s_resuid = sbi->s_resuid;
4872         old_opts.s_resgid = sbi->s_resgid;
4873         old_opts.s_commit_interval = sbi->s_commit_interval;
4874         old_opts.s_min_batch_time = sbi->s_min_batch_time;
4875         old_opts.s_max_batch_time = sbi->s_max_batch_time;
4876 #ifdef CONFIG_QUOTA
4877         old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
4878         for (i = 0; i < EXT4_MAXQUOTAS; i++)
4879                 if (sbi->s_qf_names[i]) {
4880                         old_opts.s_qf_names[i] = kstrdup(sbi->s_qf_names[i],
4881                                                          GFP_KERNEL);
4882                         if (!old_opts.s_qf_names[i]) {
4883                                 for (j = 0; j < i; j++)
4884                                         kfree(old_opts.s_qf_names[j]);
4885                                 kfree(orig_data);
4886                                 return -ENOMEM;
4887                         }
4888                 } else
4889                         old_opts.s_qf_names[i] = NULL;
4890 #endif
4891         if (sbi->s_journal && sbi->s_journal->j_task->io_context)
4892                 journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
4893
4894         if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
4895                 err = -EINVAL;
4896                 goto restore_opts;
4897         }
4898
4899         if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
4900             test_opt(sb, JOURNAL_CHECKSUM)) {
4901                 ext4_msg(sb, KERN_ERR, "changing journal_checksum "
4902                          "during remount not supported; ignoring");
4903                 sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
4904         }
4905
4906         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
4907                 if (test_opt2(sb, EXPLICIT_DELALLOC)) {
4908                         ext4_msg(sb, KERN_ERR, "can't mount with "
4909                                  "both data=journal and delalloc");
4910                         err = -EINVAL;
4911                         goto restore_opts;
4912                 }
4913                 if (test_opt(sb, DIOREAD_NOLOCK)) {
4914                         ext4_msg(sb, KERN_ERR, "can't mount with "
4915                                  "both data=journal and dioread_nolock");
4916                         err = -EINVAL;
4917                         goto restore_opts;
4918                 }
4919                 if (test_opt(sb, DAX)) {
4920                         ext4_msg(sb, KERN_ERR, "can't mount with "
4921                                  "both data=journal and dax");
4922                         err = -EINVAL;
4923                         goto restore_opts;
4924                 }
4925         } else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA) {
4926                 if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4927                         ext4_msg(sb, KERN_ERR, "can't mount with "
4928                                 "journal_async_commit in data=ordered mode");
4929                         err = -EINVAL;
4930                         goto restore_opts;
4931                 }
4932         }
4933
4934         if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_DAX) {
4935                 ext4_msg(sb, KERN_WARNING, "warning: refusing change of "
4936                         "dax flag with busy inodes while remounting");
4937                 sbi->s_mount_opt ^= EXT4_MOUNT_DAX;
4938         }
4939
4940         if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
4941                 ext4_abort(sb, "Abort forced by user");
4942
4943         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
4944                 (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
4945
4946         es = sbi->s_es;
4947
4948         if (sbi->s_journal) {
4949                 ext4_init_journal_params(sb, sbi->s_journal);
4950                 set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4951         }
4952
4953         if (*flags & MS_LAZYTIME)
4954                 sb->s_flags |= MS_LAZYTIME;
4955
4956         if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY)) {
4957                 if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
4958                         err = -EROFS;
4959                         goto restore_opts;
4960                 }
4961
4962                 if (*flags & MS_RDONLY) {
4963                         err = sync_filesystem(sb);
4964                         if (err < 0)
4965                                 goto restore_opts;
4966                         err = dquot_suspend(sb, -1);
4967                         if (err < 0)
4968                                 goto restore_opts;
4969
4970                         /*
4971                          * First of all, the unconditional stuff we have to do
4972                          * to disable replay of the journal when we next remount
4973                          */
4974                         sb->s_flags |= MS_RDONLY;
4975
4976                         /*
4977                          * OK, test if we are remounting a valid rw partition
4978                          * readonly, and if so set the rdonly flag and then
4979                          * mark the partition as valid again.
4980                          */
4981                         if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
4982                             (sbi->s_mount_state & EXT4_VALID_FS))
4983                                 es->s_state = cpu_to_le16(sbi->s_mount_state);
4984
4985                         if (sbi->s_journal)
4986                                 ext4_mark_recovery_complete(sb, es);
4987                 } else {
4988                         /* Make sure we can mount this feature set readwrite */
4989                         if (ext4_has_feature_readonly(sb) ||
4990                             !ext4_feature_set_ok(sb, 0)) {
4991                                 err = -EROFS;
4992                                 goto restore_opts;
4993                         }
4994                         /*
4995                          * Make sure the group descriptor checksums
4996                          * are sane.  If they aren't, refuse to remount r/w.
4997                          */
4998                         for (g = 0; g < sbi->s_groups_count; g++) {
4999                                 struct ext4_group_desc *gdp =
5000                                         ext4_get_group_desc(sb, g, NULL);
5001
5002                                 if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
5003                                         ext4_msg(sb, KERN_ERR,
5004                "ext4_remount: Checksum for group %u failed (%u!=%u)",
5005                 g, le16_to_cpu(ext4_group_desc_csum(sb, g, gdp)),
5006                                                le16_to_cpu(gdp->bg_checksum));
5007                                         err = -EFSBADCRC;
5008                                         goto restore_opts;
5009                                 }
5010                         }
5011
5012                         /*
5013                          * If we have an unprocessed orphan list hanging
5014                          * around from a previously readonly bdev mount,
5015                          * require a full umount/remount for now.
5016                          */
5017                         if (es->s_last_orphan) {
5018                                 ext4_msg(sb, KERN_WARNING, "Couldn't "
5019                                        "remount RDWR because of unprocessed "
5020                                        "orphan inode list.  Please "
5021                                        "umount/remount instead");
5022                                 err = -EINVAL;
5023                                 goto restore_opts;
5024                         }
5025
5026                         /*
5027                          * Mounting a RDONLY partition read-write, so reread
5028                          * and store the current valid flag.  (It may have
5029                          * been changed by e2fsck since we originally mounted
5030                          * the partition.)
5031                          */
5032                         if (sbi->s_journal)
5033                                 ext4_clear_journal_err(sb, es);
5034                         sbi->s_mount_state = le16_to_cpu(es->s_state);
5035                         if (!ext4_setup_super(sb, es, 0))
5036                                 sb->s_flags &= ~MS_RDONLY;
5037                         if (ext4_has_feature_mmp(sb))
5038                                 if (ext4_multi_mount_protect(sb,
5039                                                 le64_to_cpu(es->s_mmp_block))) {
5040                                         err = -EROFS;
5041                                         goto restore_opts;
5042                                 }
5043                         enable_quota = 1;
5044                 }
5045         }
5046
5047         /*
5048          * Reinitialize lazy itable initialization thread based on
5049          * current settings
5050          */
5051         if ((sb->s_flags & MS_RDONLY) || !test_opt(sb, INIT_INODE_TABLE))
5052                 ext4_unregister_li_request(sb);
5053         else {
5054                 ext4_group_t first_not_zeroed;
5055                 first_not_zeroed = ext4_has_uninit_itable(sb);
5056                 ext4_register_li_request(sb, first_not_zeroed);
5057         }
5058
5059         ext4_setup_system_zone(sb);
5060         if (sbi->s_journal == NULL && !(old_sb_flags & MS_RDONLY))
5061                 ext4_commit_super(sb, 1);
5062
5063 #ifdef CONFIG_QUOTA
5064         /* Release old quota file names */
5065         for (i = 0; i < EXT4_MAXQUOTAS; i++)
5066                 kfree(old_opts.s_qf_names[i]);
5067         if (enable_quota) {
5068                 if (sb_any_quota_suspended(sb))
5069                         dquot_resume(sb, -1);
5070                 else if (ext4_has_feature_quota(sb)) {
5071                         err = ext4_enable_quotas(sb);
5072                         if (err)
5073                                 goto restore_opts;
5074                 }
5075         }
5076 #endif
5077
5078         *flags = (*flags & ~MS_LAZYTIME) | (sb->s_flags & MS_LAZYTIME);
5079         ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
5080         kfree(orig_data);
5081         return 0;
5082
5083 restore_opts:
5084         sb->s_flags = old_sb_flags;
5085         sbi->s_mount_opt = old_opts.s_mount_opt;
5086         sbi->s_mount_opt2 = old_opts.s_mount_opt2;
5087         sbi->s_resuid = old_opts.s_resuid;
5088         sbi->s_resgid = old_opts.s_resgid;
5089         sbi->s_commit_interval = old_opts.s_commit_interval;
5090         sbi->s_min_batch_time = old_opts.s_min_batch_time;
5091         sbi->s_max_batch_time = old_opts.s_max_batch_time;
5092 #ifdef CONFIG_QUOTA
5093         sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
5094         for (i = 0; i < EXT4_MAXQUOTAS; i++) {
5095                 kfree(sbi->s_qf_names[i]);
5096                 sbi->s_qf_names[i] = old_opts.s_qf_names[i];
5097         }
5098 #endif
5099         kfree(orig_data);
5100         return err;
5101 }
5102
5103 #ifdef CONFIG_QUOTA
5104 static int ext4_statfs_project(struct super_block *sb,
5105                                kprojid_t projid, struct kstatfs *buf)
5106 {
5107         struct kqid qid;
5108         struct dquot *dquot;
5109         u64 limit;
5110         u64 curblock;
5111
5112         qid = make_kqid_projid(projid);
5113         dquot = dqget(sb, qid);
5114         if (IS_ERR(dquot))
5115                 return PTR_ERR(dquot);
5116         spin_lock(&dq_data_lock);
5117
5118         limit = (dquot->dq_dqb.dqb_bsoftlimit ?
5119                  dquot->dq_dqb.dqb_bsoftlimit :
5120                  dquot->dq_dqb.dqb_bhardlimit) >> sb->s_blocksize_bits;
5121         if (limit && buf->f_blocks > limit) {
5122                 curblock = dquot->dq_dqb.dqb_curspace >> sb->s_blocksize_bits;
5123                 buf->f_blocks = limit;
5124                 buf->f_bfree = buf->f_bavail =
5125                         (buf->f_blocks > curblock) ?
5126                          (buf->f_blocks - curblock) : 0;
5127         }
5128
5129         limit = dquot->dq_dqb.dqb_isoftlimit ?
5130                 dquot->dq_dqb.dqb_isoftlimit :
5131                 dquot->dq_dqb.dqb_ihardlimit;
5132         if (limit && buf->f_files > limit) {
5133                 buf->f_files = limit;
5134                 buf->f_ffree =
5135                         (buf->f_files > dquot->dq_dqb.dqb_curinodes) ?
5136                          (buf->f_files - dquot->dq_dqb.dqb_curinodes) : 0;
5137         }
5138
5139         spin_unlock(&dq_data_lock);
5140         dqput(dquot);
5141         return 0;
5142 }
5143 #endif
5144
5145 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
5146 {
5147         struct super_block *sb = dentry->d_sb;
5148         struct ext4_sb_info *sbi = EXT4_SB(sb);
5149         struct ext4_super_block *es = sbi->s_es;
5150         ext4_fsblk_t overhead = 0, resv_blocks;
5151         u64 fsid;
5152         s64 bfree;
5153         resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
5154
5155         if (!test_opt(sb, MINIX_DF))
5156                 overhead = sbi->s_overhead;
5157
5158         buf->f_type = EXT4_SUPER_MAGIC;
5159         buf->f_bsize = sb->s_blocksize;
5160         buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
5161         bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
5162                 percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
5163         /* prevent underflow in case that few free space is available */
5164         buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
5165         buf->f_bavail = buf->f_bfree -
5166                         (ext4_r_blocks_count(es) + resv_blocks);
5167         if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
5168                 buf->f_bavail = 0;
5169         buf->f_files = le32_to_cpu(es->s_inodes_count);
5170         buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
5171         buf->f_namelen = EXT4_NAME_LEN;
5172         fsid = le64_to_cpup((void *)es->s_uuid) ^
5173                le64_to_cpup((void *)es->s_uuid + sizeof(u64));
5174         buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
5175         buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
5176
5177 #ifdef CONFIG_QUOTA
5178         if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&
5179             sb_has_quota_limits_enabled(sb, PRJQUOTA))
5180                 ext4_statfs_project(sb, EXT4_I(dentry->d_inode)->i_projid, buf);
5181 #endif
5182         return 0;
5183 }
5184
5185 /* Helper function for writing quotas on sync - we need to start transaction
5186  * before quota file is locked for write. Otherwise the are possible deadlocks:
5187  * Process 1                         Process 2
5188  * ext4_create()                     quota_sync()
5189  *   jbd2_journal_start()                  write_dquot()
5190  *   dquot_initialize()                         down(dqio_mutex)
5191  *     down(dqio_mutex)                    jbd2_journal_start()
5192  *
5193  */
5194
5195 #ifdef CONFIG_QUOTA
5196
5197 static inline struct inode *dquot_to_inode(struct dquot *dquot)
5198 {
5199         return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
5200 }
5201
5202 static int ext4_write_dquot(struct dquot *dquot)
5203 {
5204         int ret, err;
5205         handle_t *handle;
5206         struct inode *inode;
5207
5208         inode = dquot_to_inode(dquot);
5209         handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
5210                                     EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
5211         if (IS_ERR(handle))
5212                 return PTR_ERR(handle);
5213         ret = dquot_commit(dquot);
5214         err = ext4_journal_stop(handle);
5215         if (!ret)
5216                 ret = err;
5217         return ret;
5218 }
5219
5220 static int ext4_acquire_dquot(struct dquot *dquot)
5221 {
5222         int ret, err;
5223         handle_t *handle;
5224
5225         handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5226                                     EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
5227         if (IS_ERR(handle))
5228                 return PTR_ERR(handle);
5229         ret = dquot_acquire(dquot);
5230         err = ext4_journal_stop(handle);
5231         if (!ret)
5232                 ret = err;
5233         return ret;
5234 }
5235
5236 static int ext4_release_dquot(struct dquot *dquot)
5237 {
5238         int ret, err;
5239         handle_t *handle;
5240
5241         handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5242                                     EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
5243         if (IS_ERR(handle)) {
5244                 /* Release dquot anyway to avoid endless cycle in dqput() */
5245                 dquot_release(dquot);
5246                 return PTR_ERR(handle);
5247         }
5248         ret = dquot_release(dquot);
5249         err = ext4_journal_stop(handle);
5250         if (!ret)
5251                 ret = err;
5252         return ret;
5253 }
5254
5255 static int ext4_mark_dquot_dirty(struct dquot *dquot)
5256 {
5257         struct super_block *sb = dquot->dq_sb;
5258         struct ext4_sb_info *sbi = EXT4_SB(sb);
5259
5260         /* Are we journaling quotas? */
5261         if (ext4_has_feature_quota(sb) ||
5262             sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
5263                 dquot_mark_dquot_dirty(dquot);
5264                 return ext4_write_dquot(dquot);
5265         } else {
5266                 return dquot_mark_dquot_dirty(dquot);
5267         }
5268 }
5269
5270 static int ext4_write_info(struct super_block *sb, int type)
5271 {
5272         int ret, err;
5273         handle_t *handle;
5274
5275         /* Data block + inode block */
5276         handle = ext4_journal_start(d_inode(sb->s_root), EXT4_HT_QUOTA, 2);
5277         if (IS_ERR(handle))
5278                 return PTR_ERR(handle);
5279         ret = dquot_commit_info(sb, type);
5280         err = ext4_journal_stop(handle);
5281         if (!ret)
5282                 ret = err;
5283         return ret;
5284 }
5285
5286 /*
5287  * Turn on quotas during mount time - we need to find
5288  * the quota file and such...
5289  */
5290 static int ext4_quota_on_mount(struct super_block *sb, int type)
5291 {
5292         return dquot_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
5293                                         EXT4_SB(sb)->s_jquota_fmt, type);
5294 }
5295
5296 static void lockdep_set_quota_inode(struct inode *inode, int subclass)
5297 {
5298         struct ext4_inode_info *ei = EXT4_I(inode);
5299
5300         /* The first argument of lockdep_set_subclass has to be
5301          * *exactly* the same as the argument to init_rwsem() --- in
5302          * this case, in init_once() --- or lockdep gets unhappy
5303          * because the name of the lock is set using the
5304          * stringification of the argument to init_rwsem().
5305          */
5306         (void) ei;      /* shut up clang warning if !CONFIG_LOCKDEP */
5307         lockdep_set_subclass(&ei->i_data_sem, subclass);
5308 }
5309
5310 /*
5311  * Standard function to be called on quota_on
5312  */
5313 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
5314                          const struct path *path)
5315 {
5316         int err;
5317
5318         if (!test_opt(sb, QUOTA))
5319                 return -EINVAL;
5320
5321         /* Quotafile not on the same filesystem? */
5322         if (path->dentry->d_sb != sb)
5323                 return -EXDEV;
5324         /* Journaling quota? */
5325         if (EXT4_SB(sb)->s_qf_names[type]) {
5326                 /* Quotafile not in fs root? */
5327                 if (path->dentry->d_parent != sb->s_root)
5328                         ext4_msg(sb, KERN_WARNING,
5329                                 "Quota file not on filesystem root. "
5330                                 "Journaled quota will not work");
5331         }
5332
5333         /*
5334          * When we journal data on quota file, we have to flush journal to see
5335          * all updates to the file when we bypass pagecache...
5336          */
5337         if (EXT4_SB(sb)->s_journal &&
5338             ext4_should_journal_data(d_inode(path->dentry))) {
5339                 /*
5340                  * We don't need to lock updates but journal_flush() could
5341                  * otherwise be livelocked...
5342                  */
5343                 jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
5344                 err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
5345                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
5346                 if (err)
5347                         return err;
5348         }
5349         lockdep_set_quota_inode(path->dentry->d_inode, I_DATA_SEM_QUOTA);
5350         err = dquot_quota_on(sb, type, format_id, path);
5351         if (err)
5352                 lockdep_set_quota_inode(path->dentry->d_inode,
5353                                              I_DATA_SEM_NORMAL);
5354         return err;
5355 }
5356
5357 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
5358                              unsigned int flags)
5359 {
5360         int err;
5361         struct inode *qf_inode;
5362         unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5363                 le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5364                 le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5365                 le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5366         };
5367
5368         BUG_ON(!ext4_has_feature_quota(sb));
5369
5370         if (!qf_inums[type])
5371                 return -EPERM;
5372
5373         qf_inode = ext4_iget(sb, qf_inums[type]);
5374         if (IS_ERR(qf_inode)) {
5375                 ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
5376                 return PTR_ERR(qf_inode);
5377         }
5378
5379         /* Don't account quota for quota files to avoid recursion */
5380         qf_inode->i_flags |= S_NOQUOTA;
5381         lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);
5382         err = dquot_enable(qf_inode, type, format_id, flags);
5383         iput(qf_inode);
5384         if (err)
5385                 lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);
5386
5387         return err;
5388 }
5389
5390 /* Enable usage tracking for all quota types. */
5391 static int ext4_enable_quotas(struct super_block *sb)
5392 {
5393         int type, err = 0;
5394         unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5395                 le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5396                 le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5397                 le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5398         };
5399         bool quota_mopt[EXT4_MAXQUOTAS] = {
5400                 test_opt(sb, USRQUOTA),
5401                 test_opt(sb, GRPQUOTA),
5402                 test_opt(sb, PRJQUOTA),
5403         };
5404
5405         sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE;
5406         for (type = 0; type < EXT4_MAXQUOTAS; type++) {
5407                 if (qf_inums[type]) {
5408                         err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
5409                                 DQUOT_USAGE_ENABLED |
5410                                 (quota_mopt[type] ? DQUOT_LIMITS_ENABLED : 0));
5411                         if (err) {
5412                                 ext4_warning(sb,
5413                                         "Failed to enable quota tracking "
5414                                         "(type=%d, err=%d). Please run "
5415                                         "e2fsck to fix.", type, err);
5416                                 return err;
5417                         }
5418                 }
5419         }
5420         return 0;
5421 }
5422
5423 static int ext4_quota_off(struct super_block *sb, int type)
5424 {
5425         struct inode *inode = sb_dqopt(sb)->files[type];
5426         handle_t *handle;
5427
5428         /* Force all delayed allocation blocks to be allocated.
5429          * Caller already holds s_umount sem */
5430         if (test_opt(sb, DELALLOC))
5431                 sync_filesystem(sb);
5432
5433         if (!inode)
5434                 goto out;
5435
5436         /* Update modification times of quota files when userspace can
5437          * start looking at them */
5438         handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5439         if (IS_ERR(handle))
5440                 goto out;
5441         inode->i_mtime = inode->i_ctime = current_time(inode);
5442         ext4_mark_inode_dirty(handle, inode);
5443         ext4_journal_stop(handle);
5444
5445 out:
5446         return dquot_quota_off(sb, type);
5447 }
5448
5449 /* Read data from quotafile - avoid pagecache and such because we cannot afford
5450  * acquiring the locks... As quota files are never truncated and quota code
5451  * itself serializes the operations (and no one else should touch the files)
5452  * we don't have to be afraid of races */
5453 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
5454                                size_t len, loff_t off)
5455 {
5456         struct inode *inode = sb_dqopt(sb)->files[type];
5457         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5458         int offset = off & (sb->s_blocksize - 1);
5459         int tocopy;
5460         size_t toread;
5461         struct buffer_head *bh;
5462         loff_t i_size = i_size_read(inode);
5463
5464         if (off > i_size)
5465                 return 0;
5466         if (off+len > i_size)
5467                 len = i_size-off;
5468         toread = len;
5469         while (toread > 0) {
5470                 tocopy = sb->s_blocksize - offset < toread ?
5471                                 sb->s_blocksize - offset : toread;
5472                 bh = ext4_bread(NULL, inode, blk, 0);
5473                 if (IS_ERR(bh))
5474                         return PTR_ERR(bh);
5475                 if (!bh)        /* A hole? */
5476                         memset(data, 0, tocopy);
5477                 else
5478                         memcpy(data, bh->b_data+offset, tocopy);
5479                 brelse(bh);
5480                 offset = 0;
5481                 toread -= tocopy;
5482                 data += tocopy;
5483                 blk++;
5484         }
5485         return len;
5486 }
5487
5488 /* Write to quotafile (we know the transaction is already started and has
5489  * enough credits) */
5490 static ssize_t ext4_quota_write(struct super_block *sb, int type,
5491                                 const char *data, size_t len, loff_t off)
5492 {
5493         struct inode *inode = sb_dqopt(sb)->files[type];
5494         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5495         int err, offset = off & (sb->s_blocksize - 1);
5496         int retries = 0;
5497         struct buffer_head *bh;
5498         handle_t *handle = journal_current_handle();
5499
5500         if (EXT4_SB(sb)->s_journal && !handle) {
5501                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5502                         " cancelled because transaction is not started",
5503                         (unsigned long long)off, (unsigned long long)len);
5504                 return -EIO;
5505         }
5506         /*
5507          * Since we account only one data block in transaction credits,
5508          * then it is impossible to cross a block boundary.
5509          */
5510         if (sb->s_blocksize - offset < len) {
5511                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5512                         " cancelled because not block aligned",
5513                         (unsigned long long)off, (unsigned long long)len);
5514                 return -EIO;
5515         }
5516
5517         do {
5518                 bh = ext4_bread(handle, inode, blk,
5519                                 EXT4_GET_BLOCKS_CREATE |
5520                                 EXT4_GET_BLOCKS_METADATA_NOFAIL);
5521         } while (IS_ERR(bh) && (PTR_ERR(bh) == -ENOSPC) &&
5522                  ext4_should_retry_alloc(inode->i_sb, &retries));
5523         if (IS_ERR(bh))
5524                 return PTR_ERR(bh);
5525         if (!bh)
5526                 goto out;
5527         BUFFER_TRACE(bh, "get write access");
5528         err = ext4_journal_get_write_access(handle, bh);
5529         if (err) {
5530                 brelse(bh);
5531                 return err;
5532         }
5533         lock_buffer(bh);
5534         memcpy(bh->b_data+offset, data, len);
5535         flush_dcache_page(bh->b_page);
5536         unlock_buffer(bh);
5537         err = ext4_handle_dirty_metadata(handle, NULL, bh);
5538         brelse(bh);
5539 out:
5540         if (inode->i_size < off + len) {
5541                 i_size_write(inode, off + len);
5542                 EXT4_I(inode)->i_disksize = inode->i_size;
5543                 ext4_mark_inode_dirty(handle, inode);
5544         }
5545         return len;
5546 }
5547
5548 static int ext4_get_next_id(struct super_block *sb, struct kqid *qid)
5549 {
5550         const struct quota_format_ops   *ops;
5551
5552         if (!sb_has_quota_loaded(sb, qid->type))
5553                 return -ESRCH;
5554         ops = sb_dqopt(sb)->ops[qid->type];
5555         if (!ops || !ops->get_next_id)
5556                 return -ENOSYS;
5557         return dquot_get_next_id(sb, qid);
5558 }
5559 #endif
5560
5561 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
5562                        const char *dev_name, void *data)
5563 {
5564         return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
5565 }
5566
5567 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
5568 static inline void register_as_ext2(void)
5569 {
5570         int err = register_filesystem(&ext2_fs_type);
5571         if (err)
5572                 printk(KERN_WARNING
5573                        "EXT4-fs: Unable to register as ext2 (%d)\n", err);
5574 }
5575
5576 static inline void unregister_as_ext2(void)
5577 {
5578         unregister_filesystem(&ext2_fs_type);
5579 }
5580
5581 static inline int ext2_feature_set_ok(struct super_block *sb)
5582 {
5583         if (ext4_has_unknown_ext2_incompat_features(sb))
5584                 return 0;
5585         if (sb->s_flags & MS_RDONLY)
5586                 return 1;
5587         if (ext4_has_unknown_ext2_ro_compat_features(sb))
5588                 return 0;
5589         return 1;
5590 }
5591 #else
5592 static inline void register_as_ext2(void) { }
5593 static inline void unregister_as_ext2(void) { }
5594 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
5595 #endif
5596
5597 static inline void register_as_ext3(void)
5598 {
5599         int err = register_filesystem(&ext3_fs_type);
5600         if (err)
5601                 printk(KERN_WARNING
5602                        "EXT4-fs: Unable to register as ext3 (%d)\n", err);
5603 }
5604
5605 static inline void unregister_as_ext3(void)
5606 {
5607         unregister_filesystem(&ext3_fs_type);
5608 }
5609
5610 static inline int ext3_feature_set_ok(struct super_block *sb)
5611 {
5612         if (ext4_has_unknown_ext3_incompat_features(sb))
5613                 return 0;
5614         if (!ext4_has_feature_journal(sb))
5615                 return 0;
5616         if (sb->s_flags & MS_RDONLY)
5617                 return 1;
5618         if (ext4_has_unknown_ext3_ro_compat_features(sb))
5619                 return 0;
5620         return 1;
5621 }
5622
5623 static struct file_system_type ext4_fs_type = {
5624         .owner          = THIS_MODULE,
5625         .name           = "ext4",
5626         .mount          = ext4_mount,
5627         .kill_sb        = kill_block_super,
5628         .fs_flags       = FS_REQUIRES_DEV,
5629 };
5630 MODULE_ALIAS_FS("ext4");
5631
5632 /* Shared across all ext4 file systems */
5633 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
5634
5635 static int __init ext4_init_fs(void)
5636 {
5637         int i, err;
5638
5639         ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
5640         ext4_li_info = NULL;
5641         mutex_init(&ext4_li_mtx);
5642
5643         /* Build-time check for flags consistency */
5644         ext4_check_flag_values();
5645
5646         for (i = 0; i < EXT4_WQ_HASH_SZ; i++)
5647                 init_waitqueue_head(&ext4__ioend_wq[i]);
5648
5649         err = ext4_init_es();
5650         if (err)
5651                 return err;
5652
5653         err = ext4_init_pageio();
5654         if (err)
5655                 goto out5;
5656
5657         err = ext4_init_system_zone();
5658         if (err)
5659                 goto out4;
5660
5661         err = ext4_init_sysfs();
5662         if (err)
5663                 goto out3;
5664
5665         err = ext4_init_mballoc();
5666         if (err)
5667                 goto out2;
5668         err = init_inodecache();
5669         if (err)
5670                 goto out1;
5671         register_as_ext3();
5672         register_as_ext2();
5673         err = register_filesystem(&ext4_fs_type);
5674         if (err)
5675                 goto out;
5676
5677         return 0;
5678 out:
5679         unregister_as_ext2();
5680         unregister_as_ext3();
5681         destroy_inodecache();
5682 out1:
5683         ext4_exit_mballoc();
5684 out2:
5685         ext4_exit_sysfs();
5686 out3:
5687         ext4_exit_system_zone();
5688 out4:
5689         ext4_exit_pageio();
5690 out5:
5691         ext4_exit_es();
5692
5693         return err;
5694 }
5695
5696 static void __exit ext4_exit_fs(void)
5697 {
5698         ext4_destroy_lazyinit_thread();
5699         unregister_as_ext2();
5700         unregister_as_ext3();
5701         unregister_filesystem(&ext4_fs_type);
5702         destroy_inodecache();
5703         ext4_exit_mballoc();
5704         ext4_exit_sysfs();
5705         ext4_exit_system_zone();
5706         ext4_exit_pageio();
5707         ext4_exit_es();
5708 }
5709
5710 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
5711 MODULE_DESCRIPTION("Fourth Extended Filesystem");
5712 MODULE_LICENSE("GPL");
5713 module_init(ext4_init_fs)
5714 module_exit(ext4_exit_fs)