fs/ext4/super.c

   1 /*
   2  *  linux/fs/ext4/super.c
   3  *
   4  * Copyright (C) 1992, 1993, 1994, 1995
   5  * Remy Card (card@masi.ibp.fr)
   6  * Laboratoire MASI - Institut Blaise Pascal
   7  * Universite Pierre et Marie Curie (Paris VI)
   8  *
   9  *  from
  10  *
  11  *  linux/fs/minix/inode.c
  12  *
  13  *  Copyright (C) 1991, 1992  Linus Torvalds
  14  *
  15  *  Big-endian to little-endian byte-swapping/bitmaps by
  16  *        David S. Miller (davem@caip.rutgers.edu), 1995
  17  */
  18
  19 #include <linux/module.h>
  20 #include <linux/string.h>
  21 #include <linux/fs.h>
  22 #include <linux/time.h>
  23 #include <linux/vmalloc.h>
  24 #include <linux/slab.h>
  25 #include <linux/init.h>
  26 #include <linux/blkdev.h>
  27 #include <linux/backing-dev.h>
  28 #include <linux/parser.h>
  29 #include <linux/buffer_head.h>
  30 #include <linux/exportfs.h>
  31 #include <linux/vfs.h>
  32 #include <linux/random.h>
  33 #include <linux/mount.h>
  34 #include <linux/namei.h>
  35 #include <linux/quotaops.h>
  36 #include <linux/seq_file.h>
  37 #include <linux/ctype.h>
  38 #include <linux/log2.h>
  39 #include <linux/crc16.h>
  40 #include <linux/cleancache.h>
  41 #include <asm/uaccess.h>
  42
  43 #include <linux/kthread.h>
  44 #include <linux/freezer.h>
  45
  46 #include "ext4.h"
  47 #include "ext4_extents.h"       /* Needed for trace points definition */
  48 #include "ext4_jbd2.h"
  49 #include "xattr.h"
  50 #include "acl.h"
  51 #include "mballoc.h"
  52
  53 #define CREATE_TRACE_POINTS
  54 #include <trace/events/ext4.h>
  55
  56 static struct ext4_lazy_init *ext4_li_info;
  57 static struct mutex ext4_li_mtx;
  58 static struct ratelimit_state ext4_mount_msg_ratelimit;
  59
  60 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
  61                              unsigned long journal_devnum);
  62 static int ext4_show_options(struct seq_file *seq, struct dentry *root);
  63 static int ext4_commit_super(struct super_block *sb, int sync);
  64 static void ext4_mark_recovery_complete(struct super_block *sb,
  65                                         struct ext4_super_block *es);
  66 static void ext4_clear_journal_err(struct super_block *sb,
  67                                    struct ext4_super_block *es);
  68 static int ext4_sync_fs(struct super_block *sb, int wait);
  69 static int ext4_remount(struct super_block *sb, int *flags, char *data);
  70 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
  71 static int ext4_unfreeze(struct super_block *sb);
  72 static int ext4_freeze(struct super_block *sb);
  73 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
  74                        const char *dev_name, void *data);
  75 static inline int ext2_feature_set_ok(struct super_block *sb);
  76 static inline int ext3_feature_set_ok(struct super_block *sb);
  77 static int ext4_feature_set_ok(struct super_block *sb, int readonly);
  78 static void ext4_destroy_lazyinit_thread(void);
  79 static void ext4_unregister_li_request(struct super_block *sb);
  80 static void ext4_clear_request_list(void);
  81 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 (ext4_error_ratelimit(sb)) {
 442                 va_start(args, fmt);
 443                 vaf.fmt = fmt;
 444                 vaf.va = &args;
 445                 printk(KERN_CRIT
 446                        "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
 447                        sb->s_id, function, line, current->comm, &vaf);
 448                 va_end(args);
 449         }
 450         save_error_info(sb, function, line);
 451         ext4_handle_error(sb);
 452 }
 453
 454 void __ext4_error_inode(struct inode *inode, const char *function,
 455                         unsigned int line, ext4_fsblk_t block,
 456                         const char *fmt, ...)
 457 {
 458         va_list args;
 459         struct va_format vaf;
 460         struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
 461
 462         es->s_last_error_ino = cpu_to_le32(inode->i_ino);
 463         es->s_last_error_block = cpu_to_le64(block);
 464         if (ext4_error_ratelimit(inode->i_sb)) {
 465                 va_start(args, fmt);
 466                 vaf.fmt = fmt;
 467                 vaf.va = &args;
 468                 if (block)
 469                         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
 470                                "inode #%lu: block %llu: comm %s: %pV\n",
 471                                inode->i_sb->s_id, function, line, inode->i_ino,
 472                                block, current->comm, &vaf);
 473                 else
 474                         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
 475                                "inode #%lu: comm %s: %pV\n",
 476                                inode->i_sb->s_id, function, line, inode->i_ino,
 477                                current->comm, &vaf);
 478                 va_end(args);
 479         }
 480         save_error_info(inode->i_sb, function, line);
 481         ext4_handle_error(inode->i_sb);
 482 }
 483
 484 void __ext4_error_file(struct file *file, const char *function,
 485                        unsigned int line, ext4_fsblk_t block,
 486                        const char *fmt, ...)
 487 {
 488         va_list args;
 489         struct va_format vaf;
 490         struct ext4_super_block *es;
 491         struct inode *inode = file_inode(file);
 492         char pathname[80], *path;
 493
 494         es = EXT4_SB(inode->i_sb)->s_es;
 495         es->s_last_error_ino = cpu_to_le32(inode->i_ino);
 496         if (ext4_error_ratelimit(inode->i_sb)) {
 497                 path = file_path(file, pathname, sizeof(pathname));
 498                 if (IS_ERR(path))
 499                         path = "(unknown)";
 500                 va_start(args, fmt);
 501                 vaf.fmt = fmt;
 502                 vaf.va = &args;
 503                 if (block)
 504                         printk(KERN_CRIT
 505                                "EXT4-fs error (device %s): %s:%d: inode #%lu: "
 506                                "block %llu: comm %s: path %s: %pV\n",
 507                                inode->i_sb->s_id, function, line, inode->i_ino,
 508                                block, current->comm, path, &vaf);
 509                 else
 510                         printk(KERN_CRIT
 511                                "EXT4-fs error (device %s): %s:%d: inode #%lu: "
 512                                "comm %s: path %s: %pV\n",
 513                                inode->i_sb->s_id, function, line, inode->i_ino,
 514                                current->comm, path, &vaf);
 515                 va_end(args);
 516         }
 517         save_error_info(inode->i_sb, function, line);
 518         ext4_handle_error(inode->i_sb);
 519 }
 520
 521 const char *ext4_decode_error(struct super_block *sb, int errno,
 522                               char nbuf[16])
 523 {
 524         char *errstr = NULL;
 525
 526         switch (errno) {
 527         case -EFSCORRUPTED:
 528                 errstr = "Corrupt filesystem";
 529                 break;
 530         case -EFSBADCRC:
 531                 errstr = "Filesystem failed CRC";
 532                 break;
 533         case -EIO:
 534                 errstr = "IO failure";
 535                 break;
 536         case -ENOMEM:
 537                 errstr = "Out of memory";
 538                 break;
 539         case -EROFS:
 540                 if (!sb || (EXT4_SB(sb)->s_journal &&
 541                             EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
 542                         errstr = "Journal has aborted";
 543                 else
 544                         errstr = "Readonly filesystem";
 545                 break;
 546         default:
 547                 /* If the caller passed in an extra buffer for unknown
 548                  * errors, textualise them now.  Else we just return
 549                  * NULL. */
 550                 if (nbuf) {
 551                         /* Check for truncated error codes... */
 552                         if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
 553                                 errstr = nbuf;
 554                 }
 555                 break;
 556         }
 557
 558         return errstr;
 559 }
 560
 561 /* __ext4_std_error decodes expected errors from journaling functions
 562  * automatically and invokes the appropriate error response.  */
 563
 564 void __ext4_std_error(struct super_block *sb, const char *function,
 565                       unsigned int line, int errno)
 566 {
 567         char nbuf[16];
 568         const char *errstr;
 569
 570         /* Special case: if the error is EROFS, and we're not already
 571          * inside a transaction, then there's really no point in logging
 572          * an error. */
 573         if (errno == -EROFS && journal_current_handle() == NULL &&
 574             (sb->s_flags & MS_RDONLY))
 575                 return;
 576
 577         if (ext4_error_ratelimit(sb)) {
 578                 errstr = ext4_decode_error(sb, errno, nbuf);
 579                 printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
 580                        sb->s_id, function, line, errstr);
 581         }
 582
 583         save_error_info(sb, function, line);
 584         ext4_handle_error(sb);
 585 }
 586
 587 /*
 588  * ext4_abort is a much stronger failure handler than ext4_error.  The
 589  * abort function may be used to deal with unrecoverable failures such
 590  * as journal IO errors or ENOMEM at a critical moment in log management.
 591  *
 592  * We unconditionally force the filesystem into an ABORT|READONLY state,
 593  * unless the error response on the fs has been set to panic in which
 594  * case we take the easy way out and panic immediately.
 595  */
 596
 597 void __ext4_abort(struct super_block *sb, const char *function,
 598                 unsigned int line, const char *fmt, ...)
 599 {
 600         struct va_format vaf;
 601         va_list args;
 602
 603         save_error_info(sb, function, line);
 604         va_start(args, fmt);
 605         vaf.fmt = fmt;
 606         vaf.va = &args;
 607         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: %pV\n",
 608                sb->s_id, function, line, &vaf);
 609         va_end(args);
 610
 611         if ((sb->s_flags & MS_RDONLY) == 0) {
 612                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 613                 EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
 614                 /*
 615                  * Make sure updated value of ->s_mount_flags will be visible
 616                  * before ->s_flags update
 617                  */
 618                 smp_wmb();
 619                 sb->s_flags |= MS_RDONLY;
 620                 if (EXT4_SB(sb)->s_journal)
 621                         jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
 622                 save_error_info(sb, function, line);
 623         }
 624         if (test_opt(sb, ERRORS_PANIC)) {
 625                 if (EXT4_SB(sb)->s_journal &&
 626                   !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
 627                         return;
 628                 panic("EXT4-fs panic from previous error\n");
 629         }
 630 }
 631
 632 void __ext4_msg(struct super_block *sb,
 633                 const char *prefix, const char *fmt, ...)
 634 {
 635         struct va_format vaf;
 636         va_list args;
 637
 638         if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state), "EXT4-fs"))
 639                 return;
 640
 641         va_start(args, fmt);
 642         vaf.fmt = fmt;
 643         vaf.va = &args;
 644         printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
 645         va_end(args);
 646 }
 647
 648 #define ext4_warning_ratelimit(sb)                                      \
 649                 ___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state), \
 650                              "EXT4-fs warning")
 651
 652 void __ext4_warning(struct super_block *sb, const char *function,
 653                     unsigned int line, const char *fmt, ...)
 654 {
 655         struct va_format vaf;
 656         va_list args;
 657
 658         if (!ext4_warning_ratelimit(sb))
 659                 return;
 660
 661         va_start(args, fmt);
 662         vaf.fmt = fmt;
 663         vaf.va = &args;
 664         printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
 665                sb->s_id, function, line, &vaf);
 666         va_end(args);
 667 }
 668
 669 void __ext4_warning_inode(const struct inode *inode, const char *function,
 670                           unsigned int line, const char *fmt, ...)
 671 {
 672         struct va_format vaf;
 673         va_list args;
 674
 675         if (!ext4_warning_ratelimit(inode->i_sb))
 676                 return;
 677
 678         va_start(args, fmt);
 679         vaf.fmt = fmt;
 680         vaf.va = &args;
 681         printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: "
 682                "inode #%lu: comm %s: %pV\n", inode->i_sb->s_id,
 683                function, line, inode->i_ino, current->comm, &vaf);
 684         va_end(args);
 685 }
 686
 687 void __ext4_grp_locked_error(const char *function, unsigned int line,
 688                              struct super_block *sb, ext4_group_t grp,
 689                              unsigned long ino, ext4_fsblk_t block,
 690                              const char *fmt, ...)
 691 __releases(bitlock)
 692 __acquires(bitlock)
 693 {
 694         struct va_format vaf;
 695         va_list args;
 696         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 697
 698         es->s_last_error_ino = cpu_to_le32(ino);
 699         es->s_last_error_block = cpu_to_le64(block);
 700         __save_error_info(sb, function, line);
 701
 702         if (ext4_error_ratelimit(sb)) {
 703                 va_start(args, fmt);
 704                 vaf.fmt = fmt;
 705                 vaf.va = &args;
 706                 printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
 707                        sb->s_id, function, line, grp);
 708                 if (ino)
 709                         printk(KERN_CONT "inode %lu: ", ino);
 710                 if (block)
 711                         printk(KERN_CONT "block %llu:",
 712                                (unsigned long long) block);
 713                 printk(KERN_CONT "%pV\n", &vaf);
 714                 va_end(args);
 715         }
 716
 717         if (test_opt(sb, ERRORS_CONT)) {
 718                 ext4_commit_super(sb, 0);
 719                 return;
 720         }
 721
 722         ext4_unlock_group(sb, grp);
 723         ext4_commit_super(sb, 1);
 724         ext4_handle_error(sb);
 725         /*
 726          * We only get here in the ERRORS_RO case; relocking the group
 727          * may be dangerous, but nothing bad will happen since the
 728          * filesystem will have already been marked read/only and the
 729          * journal has been aborted.  We return 1 as a hint to callers
 730          * who might what to use the return value from
 731          * ext4_grp_locked_error() to distinguish between the
 732          * ERRORS_CONT and ERRORS_RO case, and perhaps return more
 733          * aggressively from the ext4 function in question, with a
 734          * more appropriate error code.
 735          */
 736         ext4_lock_group(sb, grp);
 737         return;
 738 }
 739
 740 void ext4_update_dynamic_rev(struct super_block *sb)
 741 {
 742         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 743
 744         if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
 745                 return;
 746
 747         ext4_warning(sb,
 748                      "updating to rev %d because of new feature flag, "
 749                      "running e2fsck is recommended",
 750                      EXT4_DYNAMIC_REV);
 751
 752         es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
 753         es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
 754         es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
 755         /* leave es->s_feature_*compat flags alone */
 756         /* es->s_uuid will be set by e2fsck if empty */
 757
 758         /*
 759          * The rest of the superblock fields should be zero, and if not it
 760          * means they are likely already in use, so leave them alone.  We
 761          * can leave it up to e2fsck to clean up any inconsistencies there.
 762          */
 763 }
 764
 765 /*
 766  * Open the external journal device
 767  */
 768 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
 769 {
 770         struct block_device *bdev;
 771         char b[BDEVNAME_SIZE];
 772
 773         bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
 774         if (IS_ERR(bdev))
 775                 goto fail;
 776         return bdev;
 777
 778 fail:
 779         ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
 780                         __bdevname(dev, b), PTR_ERR(bdev));
 781         return NULL;
 782 }
 783
 784 /*
 785  * Release the journal device
 786  */
 787 static void ext4_blkdev_put(struct block_device *bdev)
 788 {
 789         blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
 790 }
 791
 792 static void ext4_blkdev_remove(struct ext4_sb_info *sbi)
 793 {
 794         struct block_device *bdev;
 795         bdev = sbi->journal_bdev;
 796         if (bdev) {
 797                 ext4_blkdev_put(bdev);
 798                 sbi->journal_bdev = NULL;
 799         }
 800 }
 801
 802 static inline struct inode *orphan_list_entry(struct list_head *l)
 803 {
 804         return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
 805 }
 806
 807 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
 808 {
 809         struct list_head *l;
 810
 811         ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
 812                  le32_to_cpu(sbi->s_es->s_last_orphan));
 813
 814         printk(KERN_ERR "sb_info orphan list:\n");
 815         list_for_each(l, &sbi->s_orphan) {
 816                 struct inode *inode = orphan_list_entry(l);
 817                 printk(KERN_ERR "  "
 818                        "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
 819                        inode->i_sb->s_id, inode->i_ino, inode,
 820                        inode->i_mode, inode->i_nlink,
 821                        NEXT_ORPHAN(inode));
 822         }
 823 }
 824
 825 static void ext4_put_super(struct super_block *sb)
 826 {
 827         struct ext4_sb_info *sbi = EXT4_SB(sb);
 828         struct ext4_super_block *es = sbi->s_es;
 829         int aborted = 0;
 830         int i, err;
 831
 832         ext4_unregister_li_request(sb);
 833         dquot_disable(sb, -1, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
 834
 835         flush_workqueue(sbi->rsv_conversion_wq);
 836         destroy_workqueue(sbi->rsv_conversion_wq);
 837
 838         if (sbi->s_journal) {
 839                 aborted = is_journal_aborted(sbi->s_journal);
 840                 err = jbd2_journal_destroy(sbi->s_journal);
 841                 sbi->s_journal = NULL;
 842                 if ((err < 0) && !aborted)
 843                         ext4_abort(sb, "Couldn't clean up the journal");
 844         }
 845
 846         ext4_unregister_sysfs(sb);
 847         ext4_es_unregister_shrinker(sbi);
 848         del_timer_sync(&sbi->s_err_report);
 849         ext4_release_system_zone(sb);
 850         ext4_mb_release(sb);
 851         ext4_ext_release(sb);
 852
 853         if (!(sb->s_flags & MS_RDONLY) && !aborted) {
 854                 ext4_clear_feature_journal_needs_recovery(sb);
 855                 es->s_state = cpu_to_le16(sbi->s_mount_state);
 856         }
 857         if (!(sb->s_flags & MS_RDONLY))
 858                 ext4_commit_super(sb, 1);
 859
 860         for (i = 0; i < sbi->s_gdb_count; i++)
 861                 brelse(sbi->s_group_desc[i]);
 862         kvfree(sbi->s_group_desc);
 863         kvfree(sbi->s_flex_groups);
 864         percpu_counter_destroy(&sbi->s_freeclusters_counter);
 865         percpu_counter_destroy(&sbi->s_freeinodes_counter);
 866         percpu_counter_destroy(&sbi->s_dirs_counter);
 867         percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
 868         percpu_free_rwsem(&sbi->s_journal_flag_rwsem);
 869         brelse(sbi->s_sbh);
 870 #ifdef CONFIG_QUOTA
 871         for (i = 0; i < EXT4_MAXQUOTAS; i++)
 872                 kfree(sbi->s_qf_names[i]);
 873 #endif
 874
 875         /* Debugging code just in case the in-memory inode orphan list
 876          * isn't empty.  The on-disk one can be non-empty if we've
 877          * detected an error and taken the fs readonly, but the
 878          * in-memory list had better be clean by this point. */
 879         if (!list_empty(&sbi->s_orphan))
 880                 dump_orphan_list(sb, sbi);
 881         J_ASSERT(list_empty(&sbi->s_orphan));
 882
 883         sync_blockdev(sb->s_bdev);
 884         invalidate_bdev(sb->s_bdev);
 885         if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
 886                 /*
 887                  * Invalidate the journal device's buffers.  We don't want them
 888                  * floating about in memory - the physical journal device may
 889                  * hotswapped, and it breaks the `ro-after' testing code.
 890                  */
 891                 sync_blockdev(sbi->journal_bdev);
 892                 invalidate_bdev(sbi->journal_bdev);
 893                 ext4_blkdev_remove(sbi);
 894         }
 895         if (sbi->s_mb_cache) {
 896                 ext4_xattr_destroy_cache(sbi->s_mb_cache);
 897                 sbi->s_mb_cache = NULL;
 898         }
 899         if (sbi->s_mmp_tsk)
 900                 kthread_stop(sbi->s_mmp_tsk);
 901         sb->s_fs_info = NULL;
 902         /*
 903          * Now that we are completely done shutting down the
 904          * superblock, we need to actually destroy the kobject.
 905          */
 906         kobject_put(&sbi->s_kobj);
 907         wait_for_completion(&sbi->s_kobj_unregister);
 908         if (sbi->s_chksum_driver)
 909                 crypto_free_shash(sbi->s_chksum_driver);
 910         kfree(sbi->s_blockgroup_lock);
 911         kfree(sbi);
 912 }
 913
 914 static struct kmem_cache *ext4_inode_cachep;
 915
 916 /*
 917  * Called inside transaction, so use GFP_NOFS
 918  */
 919 static struct inode *ext4_alloc_inode(struct super_block *sb)
 920 {
 921         struct ext4_inode_info *ei;
 922
 923         ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
 924         if (!ei)
 925                 return NULL;
 926
 927         ei->vfs_inode.i_version = 1;
 928         spin_lock_init(&ei->i_raw_lock);
 929         INIT_LIST_HEAD(&ei->i_prealloc_list);
 930         spin_lock_init(&ei->i_prealloc_lock);
 931         ext4_es_init_tree(&ei->i_es_tree);
 932         rwlock_init(&ei->i_es_lock);
 933         INIT_LIST_HEAD(&ei->i_es_list);
 934         ei->i_es_all_nr = 0;
 935         ei->i_es_shk_nr = 0;
 936         ei->i_es_shrink_lblk = 0;
 937         ei->i_reserved_data_blocks = 0;
 938         ei->i_reserved_meta_blocks = 0;
 939         ei->i_allocated_meta_blocks = 0;
 940         ei->i_da_metadata_calc_len = 0;
 941         ei->i_da_metadata_calc_last_lblock = 0;
 942         spin_lock_init(&(ei->i_block_reservation_lock));
 943 #ifdef CONFIG_QUOTA
 944         ei->i_reserved_quota = 0;
 945         memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
 946 #endif
 947         ei->jinode = NULL;
 948         INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
 949         spin_lock_init(&ei->i_completed_io_lock);
 950         ei->i_sync_tid = 0;
 951         ei->i_datasync_tid = 0;
 952         atomic_set(&ei->i_unwritten, 0);
 953         INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
 954         return &ei->vfs_inode;
 955 }
 956
 957 static int ext4_drop_inode(struct inode *inode)
 958 {
 959         int drop = generic_drop_inode(inode);
 960
 961         trace_ext4_drop_inode(inode, drop);
 962         return drop;
 963 }
 964
 965 static void ext4_i_callback(struct rcu_head *head)
 966 {
 967         struct inode *inode = container_of(head, struct inode, i_rcu);
 968         kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
 969 }
 970
 971 static void ext4_destroy_inode(struct inode *inode)
 972 {
 973         if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
 974                 ext4_msg(inode->i_sb, KERN_ERR,
 975                          "Inode %lu (%p): orphan list check failed!",
 976                          inode->i_ino, EXT4_I(inode));
 977                 print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
 978                                 EXT4_I(inode), sizeof(struct ext4_inode_info),
 979                                 true);
 980                 dump_stack();
 981         }
 982         call_rcu(&inode->i_rcu, ext4_i_callback);
 983 }
 984
 985 static void init_once(void *foo)
 986 {
 987         struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
 988
 989         INIT_LIST_HEAD(&ei->i_orphan);
 990         init_rwsem(&ei->xattr_sem);
 991         init_rwsem(&ei->i_data_sem);
 992         init_rwsem(&ei->i_mmap_sem);
 993         inode_init_once(&ei->vfs_inode);
 994 }
 995
 996 static int __init init_inodecache(void)
 997 {
 998         ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
 999                                              sizeof(struct ext4_inode_info),
1000                                              0, (SLAB_RECLAIM_ACCOUNT|
1001                                                 SLAB_MEM_SPREAD|SLAB_ACCOUNT),
1002                                              init_once);
1003         if (ext4_inode_cachep == NULL)
1004                 return -ENOMEM;
1005         return 0;
1006 }
1007
1008 static void destroy_inodecache(void)
1009 {
1010         /*
1011          * Make sure all delayed rcu free inodes are flushed before we
1012          * destroy cache.
1013          */
1014         rcu_barrier();
1015         kmem_cache_destroy(ext4_inode_cachep);
1016 }
1017
1018 void ext4_clear_inode(struct inode *inode)
1019 {
1020         invalidate_inode_buffers(inode);
1021         clear_inode(inode);
1022         dquot_drop(inode);
1023         ext4_discard_preallocations(inode);
1024         ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
1025         if (EXT4_I(inode)->jinode) {
1026                 jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
1027                                                EXT4_I(inode)->jinode);
1028                 jbd2_free_inode(EXT4_I(inode)->jinode);
1029                 EXT4_I(inode)->jinode = NULL;
1030         }
1031         fscrypt_put_encryption_info(inode);
1032 }
1033
1034 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1035                                         u64 ino, u32 generation)
1036 {
1037         struct inode *inode;
1038
1039         if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
1040                 return ERR_PTR(-ESTALE);
1041         if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
1042                 return ERR_PTR(-ESTALE);
1043
1044         /* iget isn't really right if the inode is currently unallocated!!
1045          *
1046          * ext4_read_inode will return a bad_inode if the inode had been
1047          * deleted, so we should be safe.
1048          *
1049          * Currently we don't know the generation for parent directory, so
1050          * a generation of 0 means "accept any"
1051          */
1052         inode = ext4_iget_normal(sb, ino);
1053         if (IS_ERR(inode))
1054                 return ERR_CAST(inode);
1055         if (generation && inode->i_generation != generation) {
1056                 iput(inode);
1057                 return ERR_PTR(-ESTALE);
1058         }
1059
1060         return inode;
1061 }
1062
1063 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1064                                         int fh_len, int fh_type)
1065 {
1066         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1067                                     ext4_nfs_get_inode);
1068 }
1069
1070 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1071                                         int fh_len, int fh_type)
1072 {
1073         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1074                                     ext4_nfs_get_inode);
1075 }
1076
1077 /*
1078  * Try to release metadata pages (indirect blocks, directories) which are
1079  * mapped via the block device.  Since these pages could have journal heads
1080  * which would prevent try_to_free_buffers() from freeing them, we must use
1081  * jbd2 layer's try_to_free_buffers() function to release them.
1082  */
1083 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1084                                  gfp_t wait)
1085 {
1086         journal_t *journal = EXT4_SB(sb)->s_journal;
1087
1088         WARN_ON(PageChecked(page));
1089         if (!page_has_buffers(page))
1090                 return 0;
1091         if (journal)
1092                 return jbd2_journal_try_to_free_buffers(journal, page,
1093                                                 wait & ~__GFP_DIRECT_RECLAIM);
1094         return try_to_free_buffers(page);
1095 }
1096
1097 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1098 static int ext4_get_context(struct inode *inode, void *ctx, size_t len)
1099 {
1100         return ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION,
1101                                  EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, ctx, len);
1102 }
1103
1104 static int ext4_set_context(struct inode *inode, const void *ctx, size_t len,
1105                                                         void *fs_data)
1106 {
1107         handle_t *handle = fs_data;
1108         int res, res2, retries = 0;
1109
1110         res = ext4_convert_inline_data(inode);
1111         if (res)
1112                 return res;
1113
1114         /*
1115          * If a journal handle was specified, then the encryption context is
1116          * being set on a new inode via inheritance and is part of a larger
1117          * transaction to create the inode.  Otherwise the encryption context is
1118          * being set on an existing inode in its own transaction.  Only in the
1119          * latter case should the "retry on ENOSPC" logic be used.
1120          */
1121
1122         if (handle) {
1123                 res = ext4_xattr_set_handle(handle, inode,
1124                                             EXT4_XATTR_INDEX_ENCRYPTION,
1125                                             EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1126                                             ctx, len, 0);
1127                 if (!res) {
1128                         ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1129                         ext4_clear_inode_state(inode,
1130                                         EXT4_STATE_MAY_INLINE_DATA);
1131                         /*
1132                          * Update inode->i_flags - S_ENCRYPTED will be enabled,
1133                          * S_DAX may be disabled
1134                          */
1135                         ext4_set_inode_flags(inode);
1136                 }
1137                 return res;
1138         }
1139
1140         res = dquot_initialize(inode);
1141         if (res)
1142                 return res;
1143 retry:
1144         handle = ext4_journal_start(inode, EXT4_HT_MISC,
1145                         ext4_jbd2_credits_xattr(inode));
1146         if (IS_ERR(handle))
1147                 return PTR_ERR(handle);
1148
1149         res = ext4_xattr_set_handle(handle, inode, EXT4_XATTR_INDEX_ENCRYPTION,
1150                                     EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1151                                     ctx, len, 0);
1152         if (!res) {
1153                 ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1154                 /*
1155                  * Update inode->i_flags - S_ENCRYPTED will be enabled,
1156                  * S_DAX may be disabled
1157                  */
1158                 ext4_set_inode_flags(inode);
1159                 res = ext4_mark_inode_dirty(handle, inode);
1160                 if (res)
1161                         EXT4_ERROR_INODE(inode, "Failed to mark inode dirty");
1162         }
1163         res2 = ext4_journal_stop(handle);
1164
1165         if (res == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
1166                 goto retry;
1167         if (!res)
1168                 res = res2;
1169         return res;
1170 }
1171
1172 static bool ext4_dummy_context(struct inode *inode)
1173 {
1174         return DUMMY_ENCRYPTION_ENABLED(EXT4_SB(inode->i_sb));
1175 }
1176
1177 static const struct fscrypt_operations ext4_cryptops = {
1178         .key_prefix             = "ext4:",
1179         .get_context            = ext4_get_context,
1180         .set_context            = ext4_set_context,
1181         .dummy_context          = ext4_dummy_context,
1182         .empty_dir              = ext4_empty_dir,
1183         .max_namelen            = EXT4_NAME_LEN,
1184 };
1185 #endif
1186
1187 #ifdef CONFIG_QUOTA
1188 static char *quotatypes[] = INITQFNAMES;
1189 #define QTYPE2NAME(t) (quotatypes[t])
1190
1191 static int ext4_write_dquot(struct dquot *dquot);
1192 static int ext4_acquire_dquot(struct dquot *dquot);
1193 static int ext4_release_dquot(struct dquot *dquot);
1194 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1195 static int ext4_write_info(struct super_block *sb, int type);
1196 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1197                          struct path *path);
1198 static int ext4_quota_off(struct super_block *sb, int type);
1199 static int ext4_quota_on_mount(struct super_block *sb, int type);
1200 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1201                                size_t len, loff_t off);
1202 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1203                                 const char *data, size_t len, loff_t off);
1204 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1205                              unsigned int flags);
1206 static int ext4_enable_quotas(struct super_block *sb);
1207 static int ext4_get_next_id(struct super_block *sb, struct kqid *qid);
1208
1209 static struct dquot **ext4_get_dquots(struct inode *inode)
1210 {
1211         return EXT4_I(inode)->i_dquot;
1212 }
1213
1214 static const struct dquot_operations ext4_quota_operations = {
1215         .get_reserved_space = ext4_get_reserved_space,
1216         .write_dquot    = ext4_write_dquot,
1217         .acquire_dquot  = ext4_acquire_dquot,
1218         .release_dquot  = ext4_release_dquot,
1219         .mark_dirty     = ext4_mark_dquot_dirty,
1220         .write_info     = ext4_write_info,
1221         .alloc_dquot    = dquot_alloc,
1222         .destroy_dquot  = dquot_destroy,
1223         .get_projid     = ext4_get_projid,
1224         .get_next_id    = ext4_get_next_id,
1225 };
1226
1227 static const struct quotactl_ops ext4_qctl_operations = {
1228         .quota_on       = ext4_quota_on,
1229         .quota_off      = ext4_quota_off,
1230         .quota_sync     = dquot_quota_sync,
1231         .get_state      = dquot_get_state,
1232         .set_info       = dquot_set_dqinfo,
1233         .get_dqblk      = dquot_get_dqblk,
1234         .set_dqblk      = dquot_set_dqblk,
1235         .get_nextdqblk  = dquot_get_next_dqblk,
1236 };
1237 #endif
1238
1239 static const struct super_operations ext4_sops = {
1240         .alloc_inode    = ext4_alloc_inode,
1241         .destroy_inode  = ext4_destroy_inode,
1242         .write_inode    = ext4_write_inode,
1243         .dirty_inode    = ext4_dirty_inode,
1244         .drop_inode     = ext4_drop_inode,
1245         .evict_inode    = ext4_evict_inode,
1246         .put_super      = ext4_put_super,
1247         .sync_fs        = ext4_sync_fs,
1248         .freeze_fs      = ext4_freeze,
1249         .unfreeze_fs    = ext4_unfreeze,
1250         .statfs         = ext4_statfs,
1251         .remount_fs     = ext4_remount,
1252         .show_options   = ext4_show_options,
1253 #ifdef CONFIG_QUOTA
1254         .quota_read     = ext4_quota_read,
1255         .quota_write    = ext4_quota_write,
1256         .get_dquots     = ext4_get_dquots,
1257 #endif
1258         .bdev_try_to_free_page = bdev_try_to_free_page,
1259 };
1260
1261 static const struct export_operations ext4_export_ops = {
1262         .fh_to_dentry = ext4_fh_to_dentry,
1263         .fh_to_parent = ext4_fh_to_parent,
1264         .get_parent = ext4_get_parent,
1265 };
1266
1267 enum {
1268         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1269         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1270         Opt_nouid32, Opt_debug, Opt_removed,
1271         Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1272         Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1273         Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1274         Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1275         Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1276         Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
1277         Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1278         Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1279         Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1280         Opt_usrquota, Opt_grpquota, Opt_prjquota, Opt_i_version, Opt_dax,
1281         Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_mblk_io_submit,
1282         Opt_lazytime, Opt_nolazytime,
1283         Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1284         Opt_inode_readahead_blks, Opt_journal_ioprio,
1285         Opt_dioread_nolock, Opt_dioread_lock,
1286         Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1287         Opt_max_dir_size_kb, Opt_nojournal_checksum,
1288 };
1289
1290 static const match_table_t tokens = {
1291         {Opt_bsd_df, "bsddf"},
1292         {Opt_minix_df, "minixdf"},
1293         {Opt_grpid, "grpid"},
1294         {Opt_grpid, "bsdgroups"},
1295         {Opt_nogrpid, "nogrpid"},
1296         {Opt_nogrpid, "sysvgroups"},
1297         {Opt_resgid, "resgid=%u"},
1298         {Opt_resuid, "resuid=%u"},
1299         {Opt_sb, "sb=%u"},
1300         {Opt_err_cont, "errors=continue"},
1301         {Opt_err_panic, "errors=panic"},
1302         {Opt_err_ro, "errors=remount-ro"},
1303         {Opt_nouid32, "nouid32"},
1304         {Opt_debug, "debug"},
1305         {Opt_removed, "oldalloc"},
1306         {Opt_removed, "orlov"},
1307         {Opt_user_xattr, "user_xattr"},
1308         {Opt_nouser_xattr, "nouser_xattr"},
1309         {Opt_acl, "acl"},
1310         {Opt_noacl, "noacl"},
1311         {Opt_noload, "norecovery"},
1312         {Opt_noload, "noload"},
1313         {Opt_removed, "nobh"},
1314         {Opt_removed, "bh"},
1315         {Opt_commit, "commit=%u"},
1316         {Opt_min_batch_time, "min_batch_time=%u"},
1317         {Opt_max_batch_time, "max_batch_time=%u"},
1318         {Opt_journal_dev, "journal_dev=%u"},
1319         {Opt_journal_path, "journal_path=%s"},
1320         {Opt_journal_checksum, "journal_checksum"},
1321         {Opt_nojournal_checksum, "nojournal_checksum"},
1322         {Opt_journal_async_commit, "journal_async_commit"},
1323         {Opt_abort, "abort"},
1324         {Opt_data_journal, "data=journal"},
1325         {Opt_data_ordered, "data=ordered"},
1326         {Opt_data_writeback, "data=writeback"},
1327         {Opt_data_err_abort, "data_err=abort"},
1328         {Opt_data_err_ignore, "data_err=ignore"},
1329         {Opt_offusrjquota, "usrjquota="},
1330         {Opt_usrjquota, "usrjquota=%s"},
1331         {Opt_offgrpjquota, "grpjquota="},
1332         {Opt_grpjquota, "grpjquota=%s"},
1333         {Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1334         {Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1335         {Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1336         {Opt_grpquota, "grpquota"},
1337         {Opt_noquota, "noquota"},
1338         {Opt_quota, "quota"},
1339         {Opt_usrquota, "usrquota"},
1340         {Opt_prjquota, "prjquota"},
1341         {Opt_barrier, "barrier=%u"},
1342         {Opt_barrier, "barrier"},
1343         {Opt_nobarrier, "nobarrier"},
1344         {Opt_i_version, "i_version"},
1345         {Opt_dax, "dax"},
1346         {Opt_stripe, "stripe=%u"},
1347         {Opt_delalloc, "delalloc"},
1348         {Opt_lazytime, "lazytime"},
1349         {Opt_nolazytime, "nolazytime"},
1350         {Opt_nodelalloc, "nodelalloc"},
1351         {Opt_removed, "mblk_io_submit"},
1352         {Opt_removed, "nomblk_io_submit"},
1353         {Opt_block_validity, "block_validity"},
1354         {Opt_noblock_validity, "noblock_validity"},
1355         {Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1356         {Opt_journal_ioprio, "journal_ioprio=%u"},
1357         {Opt_auto_da_alloc, "auto_da_alloc=%u"},
1358         {Opt_auto_da_alloc, "auto_da_alloc"},
1359         {Opt_noauto_da_alloc, "noauto_da_alloc"},
1360         {Opt_dioread_nolock, "dioread_nolock"},
1361         {Opt_dioread_lock, "dioread_lock"},
1362         {Opt_discard, "discard"},
1363         {Opt_nodiscard, "nodiscard"},
1364         {Opt_init_itable, "init_itable=%u"},
1365         {Opt_init_itable, "init_itable"},
1366         {Opt_noinit_itable, "noinit_itable"},
1367         {Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1368         {Opt_test_dummy_encryption, "test_dummy_encryption"},
1369         {Opt_removed, "check=none"},    /* mount option from ext2/3 */
1370         {Opt_removed, "nocheck"},       /* mount option from ext2/3 */
1371         {Opt_removed, "reservation"},   /* mount option from ext2/3 */
1372         {Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1373         {Opt_removed, "journal=%u"},    /* mount option from ext2/3 */
1374         {Opt_err, NULL},
1375 };
1376
1377 static ext4_fsblk_t get_sb_block(void **data)
1378 {
1379         ext4_fsblk_t    sb_block;
1380         char            *options = (char *) *data;
1381
1382         if (!options || strncmp(options, "sb=", 3) != 0)
1383                 return 1;       /* Default location */
1384
1385         options += 3;
1386         /* TODO: use simple_strtoll with >32bit ext4 */
1387         sb_block = simple_strtoul(options, &options, 0);
1388         if (*options && *options != ',') {
1389                 printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1390                        (char *) *data);
1391                 return 1;
1392         }
1393         if (*options == ',')
1394                 options++;
1395         *data = (void *) options;
1396
1397         return sb_block;
1398 }
1399
1400 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1401 static char deprecated_msg[] = "Mount option \"%s\" will be removed by %s\n"
1402         "Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1403
1404 #ifdef CONFIG_QUOTA
1405 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1406 {
1407         struct ext4_sb_info *sbi = EXT4_SB(sb);
1408         char *qname;
1409         int ret = -1;
1410
1411         if (sb_any_quota_loaded(sb) &&
1412                 !sbi->s_qf_names[qtype]) {
1413                 ext4_msg(sb, KERN_ERR,
1414                         "Cannot change journaled "
1415                         "quota options when quota turned on");
1416                 return -1;
1417         }
1418         if (ext4_has_feature_quota(sb)) {
1419                 ext4_msg(sb, KERN_INFO, "Journaled quota options "
1420                          "ignored when QUOTA feature is enabled");
1421                 return 1;
1422         }
1423         qname = match_strdup(args);
1424         if (!qname) {
1425                 ext4_msg(sb, KERN_ERR,
1426                         "Not enough memory for storing quotafile name");
1427                 return -1;
1428         }
1429         if (sbi->s_qf_names[qtype]) {
1430                 if (strcmp(sbi->s_qf_names[qtype], qname) == 0)
1431                         ret = 1;
1432                 else
1433                         ext4_msg(sb, KERN_ERR,
1434                                  "%s quota file already specified",
1435                                  QTYPE2NAME(qtype));
1436                 goto errout;
1437         }
1438         if (strchr(qname, '/')) {
1439                 ext4_msg(sb, KERN_ERR,
1440                         "quotafile must be on filesystem root");
1441                 goto errout;
1442         }
1443         sbi->s_qf_names[qtype] = qname;
1444         set_opt(sb, QUOTA);
1445         return 1;
1446 errout:
1447         kfree(qname);
1448         return ret;
1449 }
1450
1451 static int clear_qf_name(struct super_block *sb, int qtype)
1452 {
1453
1454         struct ext4_sb_info *sbi = EXT4_SB(sb);
1455
1456         if (sb_any_quota_loaded(sb) &&
1457                 sbi->s_qf_names[qtype]) {
1458                 ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1459                         " when quota turned on");
1460                 return -1;
1461         }
1462         kfree(sbi->s_qf_names[qtype]);
1463         sbi->s_qf_names[qtype] = NULL;
1464         return 1;
1465 }
1466 #endif
1467
1468 #define MOPT_SET        0x0001
1469 #define MOPT_CLEAR      0x0002
1470 #define MOPT_NOSUPPORT  0x0004
1471 #define MOPT_EXPLICIT   0x0008
1472 #define MOPT_CLEAR_ERR  0x0010
1473 #define MOPT_GTE0       0x0020
1474 #ifdef CONFIG_QUOTA
1475 #define MOPT_Q          0
1476 #define MOPT_QFMT       0x0040
1477 #else
1478 #define MOPT_Q          MOPT_NOSUPPORT
1479 #define MOPT_QFMT       MOPT_NOSUPPORT
1480 #endif
1481 #define MOPT_DATAJ      0x0080
1482 #define MOPT_NO_EXT2    0x0100
1483 #define MOPT_NO_EXT3    0x0200
1484 #define MOPT_EXT4_ONLY  (MOPT_NO_EXT2 | MOPT_NO_EXT3)
1485 #define MOPT_STRING     0x0400
1486
1487 static const struct mount_opts {
1488         int     token;
1489         int     mount_opt;
1490         int     flags;
1491 } ext4_mount_opts[] = {
1492         {Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1493         {Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1494         {Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1495         {Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1496         {Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1497         {Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1498         {Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1499          MOPT_EXT4_ONLY | MOPT_SET},
1500         {Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1501          MOPT_EXT4_ONLY | MOPT_CLEAR},
1502         {Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1503         {Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1504         {Opt_delalloc, EXT4_MOUNT_DELALLOC,
1505          MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1506         {Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1507          MOPT_EXT4_ONLY | MOPT_CLEAR},
1508         {Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1509          MOPT_EXT4_ONLY | MOPT_CLEAR},
1510         {Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1511          MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1512         {Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1513                                     EXT4_MOUNT_JOURNAL_CHECKSUM),
1514          MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1515         {Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1516         {Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1517         {Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1518         {Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1519         {Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
1520          MOPT_NO_EXT2},
1521         {Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
1522          MOPT_NO_EXT2},
1523         {Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1524         {Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1525         {Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1526         {Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1527         {Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1528         {Opt_commit, 0, MOPT_GTE0},
1529         {Opt_max_batch_time, 0, MOPT_GTE0},
1530         {Opt_min_batch_time, 0, MOPT_GTE0},
1531         {Opt_inode_readahead_blks, 0, MOPT_GTE0},
1532         {Opt_init_itable, 0, MOPT_GTE0},
1533         {Opt_dax, EXT4_MOUNT_DAX, MOPT_SET},
1534         {Opt_stripe, 0, MOPT_GTE0},
1535         {Opt_resuid, 0, MOPT_GTE0},
1536         {Opt_resgid, 0, MOPT_GTE0},
1537         {Opt_journal_dev, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1538         {Opt_journal_path, 0, MOPT_NO_EXT2 | MOPT_STRING},
1539         {Opt_journal_ioprio, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1540         {Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1541         {Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1542         {Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
1543          MOPT_NO_EXT2 | MOPT_DATAJ},
1544         {Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1545         {Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1546 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1547         {Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1548         {Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1549 #else
1550         {Opt_acl, 0, MOPT_NOSUPPORT},
1551         {Opt_noacl, 0, MOPT_NOSUPPORT},
1552 #endif
1553         {Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1554         {Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1555         {Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1556         {Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1557                                                         MOPT_SET | MOPT_Q},
1558         {Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1559                                                         MOPT_SET | MOPT_Q},
1560         {Opt_prjquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_PRJQUOTA,
1561                                                         MOPT_SET | MOPT_Q},
1562         {Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1563                        EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA),
1564                                                         MOPT_CLEAR | MOPT_Q},
1565         {Opt_usrjquota, 0, MOPT_Q},
1566         {Opt_grpjquota, 0, MOPT_Q},
1567         {Opt_offusrjquota, 0, MOPT_Q},
1568         {Opt_offgrpjquota, 0, MOPT_Q},
1569         {Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1570         {Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1571         {Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1572         {Opt_max_dir_size_kb, 0, MOPT_GTE0},
1573         {Opt_test_dummy_encryption, 0, MOPT_GTE0},
1574         {Opt_err, 0, 0}
1575 };
1576
1577 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1578                             substring_t *args, unsigned long *journal_devnum,
1579                             unsigned int *journal_ioprio, int is_remount)
1580 {
1581         struct ext4_sb_info *sbi = EXT4_SB(sb);
1582         const struct mount_opts *m;
1583         kuid_t uid;
1584         kgid_t gid;
1585         int arg = 0;
1586
1587 #ifdef CONFIG_QUOTA
1588         if (token == Opt_usrjquota)
1589                 return set_qf_name(sb, USRQUOTA, &args[0]);
1590         else if (token == Opt_grpjquota)
1591                 return set_qf_name(sb, GRPQUOTA, &args[0]);
1592         else if (token == Opt_offusrjquota)
1593                 return clear_qf_name(sb, USRQUOTA);
1594         else if (token == Opt_offgrpjquota)
1595                 return clear_qf_name(sb, GRPQUOTA);
1596 #endif
1597         switch (token) {
1598         case Opt_noacl:
1599         case Opt_nouser_xattr:
1600                 ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1601                 break;
1602         case Opt_sb:
1603                 return 1;       /* handled by get_sb_block() */
1604         case Opt_removed:
1605                 ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
1606                 return 1;
1607         case Opt_abort:
1608                 sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1609                 return 1;
1610         case Opt_i_version:
1611                 sb->s_flags |= MS_I_VERSION;
1612                 return 1;
1613         case Opt_lazytime:
1614                 sb->s_flags |= MS_LAZYTIME;
1615                 return 1;
1616         case Opt_nolazytime:
1617                 sb->s_flags &= ~MS_LAZYTIME;
1618                 return 1;
1619         }
1620
1621         for (m = ext4_mount_opts; m->token != Opt_err; m++)
1622                 if (token == m->token)
1623                         break;
1624
1625         if (m->token == Opt_err) {
1626                 ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1627                          "or missing value", opt);
1628                 return -1;
1629         }
1630
1631         if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
1632                 ext4_msg(sb, KERN_ERR,
1633                          "Mount option \"%s\" incompatible with ext2", opt);
1634                 return -1;
1635         }
1636         if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
1637                 ext4_msg(sb, KERN_ERR,
1638                          "Mount option \"%s\" incompatible with ext3", opt);
1639                 return -1;
1640         }
1641
1642         if (args->from && !(m->flags & MOPT_STRING) && match_int(args, &arg))
1643                 return -1;
1644         if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1645                 return -1;
1646         if (m->flags & MOPT_EXPLICIT) {
1647                 if (m->mount_opt & EXT4_MOUNT_DELALLOC) {
1648                         set_opt2(sb, EXPLICIT_DELALLOC);
1649                 } else if (m->mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) {
1650                         set_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM);
1651                 } else
1652                         return -1;
1653         }
1654         if (m->flags & MOPT_CLEAR_ERR)
1655                 clear_opt(sb, ERRORS_MASK);
1656         if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1657                 ext4_msg(sb, KERN_ERR, "Cannot change quota "
1658                          "options when quota turned on");
1659                 return -1;
1660         }
1661
1662         if (m->flags & MOPT_NOSUPPORT) {
1663                 ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1664         } else if (token == Opt_commit) {
1665                 if (arg == 0)
1666                         arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1667                 sbi->s_commit_interval = HZ * arg;
1668         } else if (token == Opt_max_batch_time) {
1669                 sbi->s_max_batch_time = arg;
1670         } else if (token == Opt_min_batch_time) {
1671                 sbi->s_min_batch_time = arg;
1672         } else if (token == Opt_inode_readahead_blks) {
1673                 if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
1674                         ext4_msg(sb, KERN_ERR,
1675                                  "EXT4-fs: inode_readahead_blks must be "
1676                                  "0 or a power of 2 smaller than 2^31");
1677                         return -1;
1678                 }
1679                 sbi->s_inode_readahead_blks = arg;
1680         } else if (token == Opt_init_itable) {
1681                 set_opt(sb, INIT_INODE_TABLE);
1682                 if (!args->from)
1683                         arg = EXT4_DEF_LI_WAIT_MULT;
1684                 sbi->s_li_wait_mult = arg;
1685         } else if (token == Opt_max_dir_size_kb) {
1686                 sbi->s_max_dir_size_kb = arg;
1687         } else if (token == Opt_stripe) {
1688                 sbi->s_stripe = arg;
1689         } else if (token == Opt_resuid) {
1690                 uid = make_kuid(current_user_ns(), arg);
1691                 if (!uid_valid(uid)) {
1692                         ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
1693                         return -1;
1694                 }
1695                 sbi->s_resuid = uid;
1696         } else if (token == Opt_resgid) {
1697                 gid = make_kgid(current_user_ns(), arg);
1698                 if (!gid_valid(gid)) {
1699                         ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
1700                         return -1;
1701                 }
1702                 sbi->s_resgid = gid;
1703         } else if (token == Opt_journal_dev) {
1704                 if (is_remount) {
1705                         ext4_msg(sb, KERN_ERR,
1706                                  "Cannot specify journal on remount");
1707                         return -1;
1708                 }
1709                 *journal_devnum = arg;
1710         } else if (token == Opt_journal_path) {
1711                 char *journal_path;
1712                 struct inode *journal_inode;
1713                 struct path path;
1714                 int error;
1715
1716                 if (is_remount) {
1717                         ext4_msg(sb, KERN_ERR,
1718                                  "Cannot specify journal on remount");
1719                         return -1;
1720                 }
1721                 journal_path = match_strdup(&args[0]);
1722                 if (!journal_path) {
1723                         ext4_msg(sb, KERN_ERR, "error: could not dup "
1724                                 "journal device string");
1725                         return -1;
1726                 }
1727
1728                 error = kern_path(journal_path, LOOKUP_FOLLOW, &path);
1729                 if (error) {
1730                         ext4_msg(sb, KERN_ERR, "error: could not find "
1731                                 "journal device path: error %d", error);
1732                         kfree(journal_path);
1733                         return -1;
1734                 }
1735
1736                 journal_inode = d_inode(path.dentry);
1737                 if (!S_ISBLK(journal_inode->i_mode)) {
1738                         ext4_msg(sb, KERN_ERR, "error: journal path %s "
1739                                 "is not a block device", journal_path);
1740                         path_put(&path);
1741                         kfree(journal_path);
1742                         return -1;
1743                 }
1744
1745                 *journal_devnum = new_encode_dev(journal_inode->i_rdev);
1746                 path_put(&path);
1747                 kfree(journal_path);
1748         } else if (token == Opt_journal_ioprio) {
1749                 if (arg > 7) {
1750                         ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
1751                                  " (must be 0-7)");
1752                         return -1;
1753                 }
1754                 *journal_ioprio =
1755                         IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
1756         } else if (token == Opt_test_dummy_encryption) {
1757 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1758                 sbi->s_mount_flags |= EXT4_MF_TEST_DUMMY_ENCRYPTION;
1759                 ext4_msg(sb, KERN_WARNING,
1760                          "Test dummy encryption mode enabled");
1761 #else
1762                 ext4_msg(sb, KERN_WARNING,
1763                          "Test dummy encryption mount option ignored");
1764 #endif
1765         } else if (m->flags & MOPT_DATAJ) {
1766                 if (is_remount) {
1767                         if (!sbi->s_journal)
1768                                 ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
1769                         else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
1770                                 ext4_msg(sb, KERN_ERR,
1771                                          "Cannot change data mode on remount");
1772                                 return -1;
1773                         }
1774                 } else {
1775                         clear_opt(sb, DATA_FLAGS);
1776                         sbi->s_mount_opt |= m->mount_opt;
1777                 }
1778 #ifdef CONFIG_QUOTA
1779         } else if (m->flags & MOPT_QFMT) {
1780                 if (sb_any_quota_loaded(sb) &&
1781                     sbi->s_jquota_fmt != m->mount_opt) {
1782                         ext4_msg(sb, KERN_ERR, "Cannot change journaled "
1783                                  "quota options when quota turned on");
1784                         return -1;
1785                 }
1786                 if (ext4_has_feature_quota(sb)) {
1787                         ext4_msg(sb, KERN_INFO,
1788                                  "Quota format mount options ignored "
1789                                  "when QUOTA feature is enabled");
1790                         return 1;
1791                 }
1792                 sbi->s_jquota_fmt = m->mount_opt;
1793 #endif
1794         } else if (token == Opt_dax) {
1795 #ifdef CONFIG_FS_DAX
1796                 ext4_msg(sb, KERN_WARNING,
1797                 "DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
1798                         sbi->s_mount_opt |= m->mount_opt;
1799 #else
1800                 ext4_msg(sb, KERN_INFO, "dax option not supported");
1801                 return -1;
1802 #endif
1803         } else if (token == Opt_data_err_abort) {
1804                 sbi->s_mount_opt |= m->mount_opt;
1805         } else if (token == Opt_data_err_ignore) {
1806                 sbi->s_mount_opt &= ~m->mount_opt;
1807         } else {
1808                 if (!args->from)
1809                         arg = 1;
1810                 if (m->flags & MOPT_CLEAR)
1811                         arg = !arg;
1812                 else if (unlikely(!(m->flags & MOPT_SET))) {
1813                         ext4_msg(sb, KERN_WARNING,
1814                                  "buggy handling of option %s", opt);
1815                         WARN_ON(1);
1816                         return -1;
1817                 }
1818                 if (arg != 0)
1819                         sbi->s_mount_opt |= m->mount_opt;
1820                 else
1821                         sbi->s_mount_opt &= ~m->mount_opt;
1822         }
1823         return 1;
1824 }
1825
1826 static int parse_options(char *options, struct super_block *sb,
1827                          unsigned long *journal_devnum,
1828                          unsigned int *journal_ioprio,
1829                          int is_remount)
1830 {
1831         struct ext4_sb_info *sbi = EXT4_SB(sb);
1832         char *p;
1833         substring_t args[MAX_OPT_ARGS];
1834         int token;
1835
1836         if (!options)
1837                 return 1;
1838
1839         while ((p = strsep(&options, ",")) != NULL) {
1840                 if (!*p)
1841                         continue;
1842                 /*
1843                  * Initialize args struct so we know whether arg was
1844                  * found; some options take optional arguments.
1845                  */
1846                 args[0].to = args[0].from = NULL;
1847                 token = match_token(p, tokens, args);
1848                 if (handle_mount_opt(sb, p, token, args, journal_devnum,
1849                                      journal_ioprio, is_remount) < 0)
1850                         return 0;
1851         }
1852 #ifdef CONFIG_QUOTA
1853         /*
1854          * We do the test below only for project quotas. 'usrquota' and
1855          * 'grpquota' mount options are allowed even without quota feature
1856          * to support legacy quotas in quota files.
1857          */
1858         if (test_opt(sb, PRJQUOTA) && !ext4_has_feature_project(sb)) {
1859                 ext4_msg(sb, KERN_ERR, "Project quota feature not enabled. "
1860                          "Cannot enable project quota enforcement.");
1861                 return 0;
1862         }
1863         if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1864                 if (test_opt(sb, USRQUOTA) && sbi->s_qf_names[USRQUOTA])
1865                         clear_opt(sb, USRQUOTA);
1866
1867                 if (test_opt(sb, GRPQUOTA) && sbi->s_qf_names[GRPQUOTA])
1868                         clear_opt(sb, GRPQUOTA);
1869
1870                 if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
1871                         ext4_msg(sb, KERN_ERR, "old and new quota "
1872                                         "format mixing");
1873                         return 0;
1874                 }
1875
1876                 if (!sbi->s_jquota_fmt) {
1877                         ext4_msg(sb, KERN_ERR, "journaled quota format "
1878                                         "not specified");
1879                         return 0;
1880                 }
1881         }
1882 #endif
1883         if (test_opt(sb, DIOREAD_NOLOCK)) {
1884                 int blocksize =
1885                         BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
1886
1887                 if (blocksize < PAGE_SIZE) {
1888                         ext4_msg(sb, KERN_ERR, "can't mount with "
1889                                  "dioread_nolock if block size != PAGE_SIZE");
1890                         return 0;
1891                 }
1892         }
1893         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
1894             test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
1895                 ext4_msg(sb, KERN_ERR, "can't mount with journal_async_commit "
1896                          "in data=ordered mode");
1897                 return 0;
1898         }
1899         return 1;
1900 }
1901
1902 static inline void ext4_show_quota_options(struct seq_file *seq,
1903                                            struct super_block *sb)
1904 {
1905 #if defined(CONFIG_QUOTA)
1906         struct ext4_sb_info *sbi = EXT4_SB(sb);
1907
1908         if (sbi->s_jquota_fmt) {
1909                 char *fmtname = "";
1910
1911                 switch (sbi->s_jquota_fmt) {
1912                 case QFMT_VFS_OLD:
1913                         fmtname = "vfsold";
1914                         break;
1915                 case QFMT_VFS_V0:
1916                         fmtname = "vfsv0";
1917                         break;
1918                 case QFMT_VFS_V1:
1919                         fmtname = "vfsv1";
1920                         break;
1921                 }
1922                 seq_printf(seq, ",jqfmt=%s", fmtname);
1923         }
1924
1925         if (sbi->s_qf_names[USRQUOTA])
1926                 seq_show_option(seq, "usrjquota", sbi->s_qf_names[USRQUOTA]);
1927
1928         if (sbi->s_qf_names[GRPQUOTA])
1929                 seq_show_option(seq, "grpjquota", sbi->s_qf_names[GRPQUOTA]);
1930 #endif
1931 }
1932
1933 static const char *token2str(int token)
1934 {
1935         const struct match_token *t;
1936
1937         for (t = tokens; t->token != Opt_err; t++)
1938                 if (t->token == token && !strchr(t->pattern, '='))
1939                         break;
1940         return t->pattern;
1941 }
1942
1943 /*
1944  * Show an option if
1945  *  - it's set to a non-default value OR
1946  *  - if the per-sb default is different from the global default
1947  */
1948 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
1949                               int nodefs)
1950 {
1951         struct ext4_sb_info *sbi = EXT4_SB(sb);
1952         struct ext4_super_block *es = sbi->s_es;
1953         int def_errors, def_mount_opt = nodefs ? 0 : sbi->s_def_mount_opt;
1954         const struct mount_opts *m;
1955         char sep = nodefs ? '\n' : ',';
1956
1957 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
1958 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
1959
1960         if (sbi->s_sb_block != 1)
1961                 SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
1962
1963         for (m = ext4_mount_opts; m->token != Opt_err; m++) {
1964                 int want_set = m->flags & MOPT_SET;
1965                 if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
1966                     (m->flags & MOPT_CLEAR_ERR))
1967                         continue;
1968                 if (!(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
1969                         continue; /* skip if same as the default */
1970                 if ((want_set &&
1971                      (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
1972                     (!want_set && (sbi->s_mount_opt & m->mount_opt)))
1973                         continue; /* select Opt_noFoo vs Opt_Foo */
1974                 SEQ_OPTS_PRINT("%s", token2str(m->token));
1975         }
1976
1977         if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
1978             le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
1979                 SEQ_OPTS_PRINT("resuid=%u",
1980                                 from_kuid_munged(&init_user_ns, sbi->s_resuid));
1981         if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
1982             le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
1983                 SEQ_OPTS_PRINT("resgid=%u",
1984                                 from_kgid_munged(&init_user_ns, sbi->s_resgid));
1985         def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
1986         if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
1987                 SEQ_OPTS_PUTS("errors=remount-ro");
1988         if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
1989                 SEQ_OPTS_PUTS("errors=continue");
1990         if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
1991                 SEQ_OPTS_PUTS("errors=panic");
1992         if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
1993                 SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
1994         if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
1995                 SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
1996         if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
1997                 SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
1998         if (sb->s_flags & MS_I_VERSION)
1999                 SEQ_OPTS_PUTS("i_version");
2000         if (nodefs || sbi->s_stripe)
2001                 SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
2002         if (EXT4_MOUNT_DATA_FLAGS & (sbi->s_mount_opt ^ def_mount_opt)) {
2003                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
2004                         SEQ_OPTS_PUTS("data=journal");
2005                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
2006                         SEQ_OPTS_PUTS("data=ordered");
2007                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
2008                         SEQ_OPTS_PUTS("data=writeback");
2009         }
2010         if (nodefs ||
2011             sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
2012                 SEQ_OPTS_PRINT("inode_readahead_blks=%u",
2013                                sbi->s_inode_readahead_blks);
2014
2015         if (nodefs || (test_opt(sb, INIT_INODE_TABLE) &&
2016                        (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
2017                 SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
2018         if (nodefs || sbi->s_max_dir_size_kb)
2019                 SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
2020         if (test_opt(sb, DATA_ERR_ABORT))
2021                 SEQ_OPTS_PUTS("data_err=abort");
2022
2023         ext4_show_quota_options(seq, sb);
2024         return 0;
2025 }
2026
2027 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
2028 {
2029         return _ext4_show_options(seq, root->d_sb, 0);
2030 }
2031
2032 int ext4_seq_options_show(struct seq_file *seq, void *offset)
2033 {
2034         struct super_block *sb = seq->private;
2035         int rc;
2036
2037         seq_puts(seq, (sb->s_flags & MS_RDONLY) ? "ro" : "rw");
2038         rc = _ext4_show_options(seq, sb, 1);
2039         seq_puts(seq, "\n");
2040         return rc;
2041 }
2042
2043 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
2044                             int read_only)
2045 {
2046         struct ext4_sb_info *sbi = EXT4_SB(sb);
2047         int res = 0;
2048
2049         if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
2050                 ext4_msg(sb, KERN_ERR, "revision level too high, "
2051                          "forcing read-only mode");
2052                 res = MS_RDONLY;
2053         }
2054         if (read_only)
2055                 goto done;
2056         if (!(sbi->s_mount_state & EXT4_VALID_FS))
2057                 ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
2058                          "running e2fsck is recommended");
2059         else if (sbi->s_mount_state & EXT4_ERROR_FS)
2060                 ext4_msg(sb, KERN_WARNING,
2061                          "warning: mounting fs with errors, "
2062                          "running e2fsck is recommended");
2063         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
2064                  le16_to_cpu(es->s_mnt_count) >=
2065                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
2066                 ext4_msg(sb, KERN_WARNING,
2067                          "warning: maximal mount count reached, "
2068                          "running e2fsck is recommended");
2069         else if (le32_to_cpu(es->s_checkinterval) &&
2070                 (le32_to_cpu(es->s_lastcheck) +
2071                         le32_to_cpu(es->s_checkinterval) <= get_seconds()))
2072                 ext4_msg(sb, KERN_WARNING,
2073                          "warning: checktime reached, "
2074                          "running e2fsck is recommended");
2075         if (!sbi->s_journal)
2076                 es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
2077         if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
2078                 es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
2079         le16_add_cpu(&es->s_mnt_count, 1);
2080         es->s_mtime = cpu_to_le32(get_seconds());
2081         ext4_update_dynamic_rev(sb);
2082         if (sbi->s_journal)
2083                 ext4_set_feature_journal_needs_recovery(sb);
2084
2085         ext4_commit_super(sb, 1);
2086 done:
2087         if (test_opt(sb, DEBUG))
2088                 printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
2089                                 "bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
2090                         sb->s_blocksize,
2091                         sbi->s_groups_count,
2092                         EXT4_BLOCKS_PER_GROUP(sb),
2093                         EXT4_INODES_PER_GROUP(sb),
2094                         sbi->s_mount_opt, sbi->s_mount_opt2);
2095
2096         cleancache_init_fs(sb);
2097         return res;
2098 }
2099
2100 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
2101 {
2102         struct ext4_sb_info *sbi = EXT4_SB(sb);
2103         struct flex_groups *new_groups;
2104         int size;
2105
2106         if (!sbi->s_log_groups_per_flex)
2107                 return 0;
2108
2109         size = ext4_flex_group(sbi, ngroup - 1) + 1;
2110         if (size <= sbi->s_flex_groups_allocated)
2111                 return 0;
2112
2113         size = roundup_pow_of_two(size * sizeof(struct flex_groups));
2114         new_groups = ext4_kvzalloc(size, GFP_KERNEL);
2115         if (!new_groups) {
2116                 ext4_msg(sb, KERN_ERR, "not enough memory for %d flex groups",
2117                          size / (int) sizeof(struct flex_groups));
2118                 return -ENOMEM;
2119         }
2120
2121         if (sbi->s_flex_groups) {
2122                 memcpy(new_groups, sbi->s_flex_groups,
2123                        (sbi->s_flex_groups_allocated *
2124                         sizeof(struct flex_groups)));
2125                 kvfree(sbi->s_flex_groups);
2126         }
2127         sbi->s_flex_groups = new_groups;
2128         sbi->s_flex_groups_allocated = size / sizeof(struct flex_groups);
2129         return 0;
2130 }
2131
2132 static int ext4_fill_flex_info(struct super_block *sb)
2133 {
2134         struct ext4_sb_info *sbi = EXT4_SB(sb);
2135         struct ext4_group_desc *gdp = NULL;
2136         ext4_group_t flex_group;
2137         int i, err;
2138
2139         sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
2140         if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
2141                 sbi->s_log_groups_per_flex = 0;
2142                 return 1;
2143         }
2144
2145         err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
2146         if (err)
2147                 goto failed;
2148
2149         for (i = 0; i < sbi->s_groups_count; i++) {
2150                 gdp = ext4_get_group_desc(sb, i, NULL);
2151
2152                 flex_group = ext4_flex_group(sbi, i);
2153                 atomic_add(ext4_free_inodes_count(sb, gdp),
2154                            &sbi->s_flex_groups[flex_group].free_inodes);
2155                 atomic64_add(ext4_free_group_clusters(sb, gdp),
2156                              &sbi->s_flex_groups[flex_group].free_clusters);
2157                 atomic_add(ext4_used_dirs_count(sb, gdp),
2158                            &sbi->s_flex_groups[flex_group].used_dirs);
2159         }
2160
2161         return 1;
2162 failed:
2163         return 0;
2164 }
2165
2166 static __le16 ext4_group_desc_csum(struct super_block *sb, __u32 block_group,
2167                                    struct ext4_group_desc *gdp)
2168 {
2169         int offset = offsetof(struct ext4_group_desc, bg_checksum);
2170         __u16 crc = 0;
2171         __le32 le_group = cpu_to_le32(block_group);
2172         struct ext4_sb_info *sbi = EXT4_SB(sb);
2173
2174         if (ext4_has_metadata_csum(sbi->s_sb)) {
2175                 /* Use new metadata_csum algorithm */
2176                 __u32 csum32;
2177                 __u16 dummy_csum = 0;
2178
2179                 csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
2180                                      sizeof(le_group));
2181                 csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp, offset);
2182                 csum32 = ext4_chksum(sbi, csum32, (__u8 *)&dummy_csum,
2183                                      sizeof(dummy_csum));
2184                 offset += sizeof(dummy_csum);
2185                 if (offset < sbi->s_desc_size)
2186                         csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp + offset,
2187                                              sbi->s_desc_size - offset);
2188
2189                 crc = csum32 & 0xFFFF;
2190                 goto out;
2191         }
2192
2193         /* old crc16 code */
2194         if (!ext4_has_feature_gdt_csum(sb))
2195                 return 0;
2196
2197         crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2198         crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2199         crc = crc16(crc, (__u8 *)gdp, offset);
2200         offset += sizeof(gdp->bg_checksum); /* skip checksum */
2201         /* for checksum of struct ext4_group_desc do the rest...*/
2202         if (ext4_has_feature_64bit(sb) &&
2203             offset < le16_to_cpu(sbi->s_es->s_desc_size))
2204                 crc = crc16(crc, (__u8 *)gdp + offset,
2205                             le16_to_cpu(sbi->s_es->s_desc_size) -
2206                                 offset);
2207
2208 out:
2209         return cpu_to_le16(crc);
2210 }
2211
2212 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2213                                 struct ext4_group_desc *gdp)
2214 {
2215         if (ext4_has_group_desc_csum(sb) &&
2216             (gdp->bg_checksum != ext4_group_desc_csum(sb, block_group, gdp)))
2217                 return 0;
2218
2219         return 1;
2220 }
2221
2222 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2223                               struct ext4_group_desc *gdp)
2224 {
2225         if (!ext4_has_group_desc_csum(sb))
2226                 return;
2227         gdp->bg_checksum = ext4_group_desc_csum(sb, block_group, gdp);
2228 }
2229
2230 /* Called at mount-time, super-block is locked */
2231 static int ext4_check_descriptors(struct super_block *sb,
2232                                   ext4_fsblk_t sb_block,
2233                                   ext4_group_t *first_not_zeroed)
2234 {
2235         struct ext4_sb_info *sbi = EXT4_SB(sb);
2236         ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2237         ext4_fsblk_t last_block;
2238         ext4_fsblk_t last_bg_block = sb_block + ext4_bg_num_gdb(sb, 0);
2239         ext4_fsblk_t block_bitmap;
2240         ext4_fsblk_t inode_bitmap;
2241         ext4_fsblk_t inode_table;
2242         int flexbg_flag = 0;
2243         ext4_group_t i, grp = sbi->s_groups_count;
2244
2245         if (ext4_has_feature_flex_bg(sb))
2246                 flexbg_flag = 1;
2247
2248         ext4_debug("Checking group descriptors");
2249
2250         for (i = 0; i < sbi->s_groups_count; i++) {
2251                 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2252
2253                 if (i == sbi->s_groups_count - 1 || flexbg_flag)
2254                         last_block = ext4_blocks_count(sbi->s_es) - 1;
2255                 else
2256                         last_block = first_block +
2257                                 (EXT4_BLOCKS_PER_GROUP(sb) - 1);
2258
2259                 if ((grp == sbi->s_groups_count) &&
2260                    !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2261                         grp = i;
2262
2263                 block_bitmap = ext4_block_bitmap(sb, gdp);
2264                 if (block_bitmap == sb_block) {
2265                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2266                                  "Block bitmap for group %u overlaps "
2267                                  "superblock", i);
2268                         if (!(sb->s_flags & MS_RDONLY))
2269                                 return 0;
2270                 }
2271                 if (block_bitmap >= sb_block + 1 &&
2272                     block_bitmap <= last_bg_block) {
2273                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2274                                  "Block bitmap for group %u overlaps "
2275                                  "block group descriptors", i);
2276                         if (!(sb->s_flags & MS_RDONLY))
2277                                 return 0;
2278                 }
2279                 if (block_bitmap < first_block || block_bitmap > last_block) {
2280                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2281                                "Block bitmap for group %u not in group "
2282                                "(block %llu)!", i, block_bitmap);
2283                         return 0;
2284                 }
2285                 inode_bitmap = ext4_inode_bitmap(sb, gdp);
2286                 if (inode_bitmap == sb_block) {
2287                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2288                                  "Inode bitmap for group %u overlaps "
2289                                  "superblock", i);
2290                         if (!(sb->s_flags & MS_RDONLY))
2291                                 return 0;
2292                 }
2293                 if (inode_bitmap >= sb_block + 1 &&
2294                     inode_bitmap <= last_bg_block) {
2295                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2296                                  "Inode bitmap for group %u overlaps "
2297                                  "block group descriptors", i);
2298                         if (!(sb->s_flags & MS_RDONLY))
2299                                 return 0;
2300                 }
2301                 if (inode_bitmap < first_block || inode_bitmap > last_block) {
2302                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2303                                "Inode bitmap for group %u not in group "
2304                                "(block %llu)!", i, inode_bitmap);
2305                         return 0;
2306                 }
2307                 inode_table = ext4_inode_table(sb, gdp);
2308                 if (inode_table == sb_block) {
2309                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2310                                  "Inode table for group %u overlaps "
2311                                  "superblock", i);
2312                         if (!(sb->s_flags & MS_RDONLY))
2313                                 return 0;
2314                 }
2315                 if (inode_table >= sb_block + 1 &&
2316                     inode_table <= last_bg_block) {
2317                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2318                                  "Inode table for group %u overlaps "
2319                                  "block group descriptors", i);
2320                         if (!(sb->s_flags & MS_RDONLY))
2321                                 return 0;
2322                 }
2323                 if (inode_table < first_block ||
2324                     inode_table + sbi->s_itb_per_group - 1 > last_block) {
2325                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2326                                "Inode table for group %u not in group "
2327                                "(block %llu)!", i, inode_table);
2328                         return 0;
2329                 }
2330                 ext4_lock_group(sb, i);
2331                 if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2332                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2333                                  "Checksum for group %u failed (%u!=%u)",
2334                                  i, le16_to_cpu(ext4_group_desc_csum(sb, i,
2335                                      gdp)), le16_to_cpu(gdp->bg_checksum));
2336                         if (!(sb->s_flags & MS_RDONLY)) {
2337                                 ext4_unlock_group(sb, i);
2338                                 return 0;
2339                         }
2340                 }
2341                 ext4_unlock_group(sb, i);
2342                 if (!flexbg_flag)
2343                         first_block += EXT4_BLOCKS_PER_GROUP(sb);
2344         }
2345         if (NULL != first_not_zeroed)
2346                 *first_not_zeroed = grp;
2347         return 1;
2348 }
2349
2350 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2351  * the superblock) which were deleted from all directories, but held open by
2352  * a process at the time of a crash.  We walk the list and try to delete these
2353  * inodes at recovery time (only with a read-write filesystem).
2354  *
2355  * In order to keep the orphan inode chain consistent during traversal (in
2356  * case of crash during recovery), we link each inode into the superblock
2357  * orphan list_head and handle it the same way as an inode deletion during
2358  * normal operation (which journals the operations for us).
2359  *
2360  * We only do an iget() and an iput() on each inode, which is very safe if we
2361  * accidentally point at an in-use or already deleted inode.  The worst that
2362  * can happen in this case is that we get a "bit already cleared" message from
2363  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2364  * e2fsck was run on this filesystem, and it must have already done the orphan
2365  * inode cleanup for us, so we can safely abort without any further action.
2366  */
2367 static void ext4_orphan_cleanup(struct super_block *sb,
2368                                 struct ext4_super_block *es)
2369 {
2370         unsigned int s_flags = sb->s_flags;
2371         int nr_orphans = 0, nr_truncates = 0;
2372 #ifdef CONFIG_QUOTA
2373         int quota_update = 0;
2374         int i;
2375 #endif
2376         if (!es->s_last_orphan) {
2377                 jbd_debug(4, "no orphan inodes to clean up\n");
2378                 return;
2379         }
2380
2381         if (bdev_read_only(sb->s_bdev)) {
2382                 ext4_msg(sb, KERN_ERR, "write access "
2383                         "unavailable, skipping orphan cleanup");
2384                 return;
2385         }
2386
2387         /* Check if feature set would not allow a r/w mount */
2388         if (!ext4_feature_set_ok(sb, 0)) {
2389                 ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2390                          "unknown ROCOMPAT features");
2391                 return;
2392         }
2393
2394         if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2395                 /* don't clear list on RO mount w/ errors */
2396                 if (es->s_last_orphan && !(s_flags & MS_RDONLY)) {
2397                         ext4_msg(sb, KERN_INFO, "Errors on filesystem, "
2398                                   "clearing orphan list.\n");
2399                         es->s_last_orphan = 0;
2400                 }
2401                 jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2402                 return;
2403         }
2404
2405         if (s_flags & MS_RDONLY) {
2406                 ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2407                 sb->s_flags &= ~MS_RDONLY;
2408         }
2409 #ifdef CONFIG_QUOTA
2410         /* Needed for iput() to work correctly and not trash data */
2411         sb->s_flags |= MS_ACTIVE;
2412
2413         /*
2414          * Turn on quotas which were not enabled for read-only mounts if
2415          * filesystem has quota feature, so that they are updated correctly.
2416          */
2417         if (ext4_has_feature_quota(sb) && (s_flags & MS_RDONLY)) {
2418                 int ret = ext4_enable_quotas(sb);
2419
2420                 if (!ret)
2421                         quota_update = 1;
2422                 else
2423                         ext4_msg(sb, KERN_ERR,
2424                                 "Cannot turn on quotas: error %d", ret);
2425         }
2426
2427         /* Turn on journaled quotas used for old sytle */
2428         for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2429                 if (EXT4_SB(sb)->s_qf_names[i]) {
2430                         int ret = ext4_quota_on_mount(sb, i);
2431
2432                         if (!ret)
2433                                 quota_update = 1;
2434                         else
2435                                 ext4_msg(sb, KERN_ERR,
2436                                         "Cannot turn on journaled "
2437                                         "quota: type %d: error %d", i, ret);
2438                 }
2439         }
2440 #endif
2441
2442         while (es->s_last_orphan) {
2443                 struct inode *inode;
2444
2445                 /*
2446                  * We may have encountered an error during cleanup; if
2447                  * so, skip the rest.
2448                  */
2449                 if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2450                         jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2451                         es->s_last_orphan = 0;
2452                         break;
2453                 }
2454
2455                 inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2456                 if (IS_ERR(inode)) {
2457                         es->s_last_orphan = 0;
2458                         break;
2459                 }
2460
2461                 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2462                 dquot_initialize(inode);
2463                 if (inode->i_nlink) {
2464                         if (test_opt(sb, DEBUG))
2465                                 ext4_msg(sb, KERN_DEBUG,
2466                                         "%s: truncating inode %lu to %lld bytes",
2467                                         __func__, inode->i_ino, inode->i_size);
2468                         jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2469                                   inode->i_ino, inode->i_size);
2470                         inode_lock(inode);
2471                         truncate_inode_pages(inode->i_mapping, inode->i_size);
2472                         ext4_truncate(inode);
2473                         inode_unlock(inode);
2474                         nr_truncates++;
2475                 } else {
2476                         if (test_opt(sb, DEBUG))
2477                                 ext4_msg(sb, KERN_DEBUG,
2478                                         "%s: deleting unreferenced inode %lu",
2479                                         __func__, inode->i_ino);
2480                         jbd_debug(2, "deleting unreferenced inode %lu\n",
2481                                   inode->i_ino);
2482                         nr_orphans++;
2483                 }
2484                 iput(inode);  /* The delete magic happens here! */
2485         }
2486
2487 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2488
2489         if (nr_orphans)
2490                 ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2491                        PLURAL(nr_orphans));
2492         if (nr_truncates)
2493                 ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2494                        PLURAL(nr_truncates));
2495 #ifdef CONFIG_QUOTA
2496         /* Turn off quotas if they were enabled for orphan cleanup */
2497         if (quota_update) {
2498                 for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2499                         if (sb_dqopt(sb)->files[i])
2500                                 dquot_quota_off(sb, i);
2501                 }
2502         }
2503 #endif
2504         sb->s_flags = s_flags; /* Restore MS_RDONLY status */
2505 }
2506
2507 /*
2508  * Maximal extent format file size.
2509  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2510  * extent format containers, within a sector_t, and within i_blocks
2511  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2512  * so that won't be a limiting factor.
2513  *
2514  * However there is other limiting factor. We do store extents in the form
2515  * of starting block and length, hence the resulting length of the extent
2516  * covering maximum file size must fit into on-disk format containers as
2517  * well. Given that length is always by 1 unit bigger than max unit (because
2518  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2519  *
2520  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2521  */
2522 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2523 {
2524         loff_t res;
2525         loff_t upper_limit = MAX_LFS_FILESIZE;
2526
2527         /* small i_blocks in vfs inode? */
2528         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2529                 /*
2530                  * CONFIG_LBDAF is not enabled implies the inode
2531                  * i_block represent total blocks in 512 bytes
2532                  * 32 == size of vfs inode i_blocks * 8
2533                  */
2534                 upper_limit = (1LL << 32) - 1;
2535
2536                 /* total blocks in file system block size */
2537                 upper_limit >>= (blkbits - 9);
2538                 upper_limit <<= blkbits;
2539         }
2540
2541         /*
2542          * 32-bit extent-start container, ee_block. We lower the maxbytes
2543          * by one fs block, so ee_len can cover the extent of maximum file
2544          * size
2545          */
2546         res = (1LL << 32) - 1;
2547         res <<= blkbits;
2548
2549         /* Sanity check against vm- & vfs- imposed limits */
2550         if (res > upper_limit)
2551                 res = upper_limit;
2552
2553         return res;
2554 }
2555
2556 /*
2557  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2558  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2559  * We need to be 1 filesystem block less than the 2^48 sector limit.
2560  */
2561 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2562 {
2563         loff_t res = EXT4_NDIR_BLOCKS;
2564         int meta_blocks;
2565         loff_t upper_limit;
2566         /* This is calculated to be the largest file size for a dense, block
2567          * mapped file such that the file's total number of 512-byte sectors,
2568          * including data and all indirect blocks, does not exceed (2^48 - 1).
2569          *
2570          * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2571          * number of 512-byte sectors of the file.
2572          */
2573
2574         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2575                 /*
2576                  * !has_huge_files or CONFIG_LBDAF not enabled implies that
2577                  * the inode i_block field represents total file blocks in
2578                  * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2579                  */
2580                 upper_limit = (1LL << 32) - 1;
2581
2582                 /* total blocks in file system block size */
2583                 upper_limit >>= (bits - 9);
2584
2585         } else {
2586                 /*
2587                  * We use 48 bit ext4_inode i_blocks
2588                  * With EXT4_HUGE_FILE_FL set the i_blocks
2589                  * represent total number of blocks in
2590                  * file system block size
2591                  */
2592                 upper_limit = (1LL << 48) - 1;
2593
2594         }
2595
2596         /* indirect blocks */
2597         meta_blocks = 1;
2598         /* double indirect blocks */
2599         meta_blocks += 1 + (1LL << (bits-2));
2600         /* tripple indirect blocks */
2601         meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2602
2603         upper_limit -= meta_blocks;
2604         upper_limit <<= bits;
2605
2606         res += 1LL << (bits-2);
2607         res += 1LL << (2*(bits-2));
2608         res += 1LL << (3*(bits-2));
2609         res <<= bits;
2610         if (res > upper_limit)
2611                 res = upper_limit;
2612
2613         if (res > MAX_LFS_FILESIZE)
2614                 res = MAX_LFS_FILESIZE;
2615
2616         return res;
2617 }
2618
2619 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2620                                    ext4_fsblk_t logical_sb_block, int nr)
2621 {
2622         struct ext4_sb_info *sbi = EXT4_SB(sb);
2623         ext4_group_t bg, first_meta_bg;
2624         int has_super = 0;
2625
2626         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2627
2628         if (!ext4_has_feature_meta_bg(sb) || nr < first_meta_bg)
2629                 return logical_sb_block + nr + 1;
2630         bg = sbi->s_desc_per_block * nr;
2631         if (ext4_bg_has_super(sb, bg))
2632                 has_super = 1;
2633
2634         /*
2635          * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
2636          * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
2637          * on modern mke2fs or blksize > 1k on older mke2fs) then we must
2638          * compensate.
2639          */
2640         if (sb->s_blocksize == 1024 && nr == 0 &&
2641             le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block) == 0)
2642                 has_super++;
2643
2644         return (has_super + ext4_group_first_block_no(sb, bg));
2645 }
2646
2647 /**
2648  * ext4_get_stripe_size: Get the stripe size.
2649  * @sbi: In memory super block info
2650  *
2651  * If we have specified it via mount option, then
2652  * use the mount option value. If the value specified at mount time is
2653  * greater than the blocks per group use the super block value.
2654  * If the super block value is greater than blocks per group return 0.
2655  * Allocator needs it be less than blocks per group.
2656  *
2657  */
2658 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2659 {
2660         unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2661         unsigned long stripe_width =
2662                         le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2663         int ret;
2664
2665         if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2666                 ret = sbi->s_stripe;
2667         else if (stripe_width && stripe_width <= sbi->s_blocks_per_group)
2668                 ret = stripe_width;
2669         else if (stride && stride <= sbi->s_blocks_per_group)
2670                 ret = stride;
2671         else
2672                 ret = 0;
2673
2674         /*
2675          * If the stripe width is 1, this makes no sense and
2676          * we set it to 0 to turn off stripe handling code.
2677          */
2678         if (ret <= 1)
2679                 ret = 0;
2680
2681         return ret;
2682 }
2683
2684 /*
2685  * Check whether this filesystem can be mounted based on
2686  * the features present and the RDONLY/RDWR mount requested.
2687  * Returns 1 if this filesystem can be mounted as requested,
2688  * 0 if it cannot be.
2689  */
2690 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2691 {
2692         if (ext4_has_unknown_ext4_incompat_features(sb)) {
2693                 ext4_msg(sb, KERN_ERR,
2694                         "Couldn't mount because of "
2695                         "unsupported optional features (%x)",
2696                         (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2697                         ~EXT4_FEATURE_INCOMPAT_SUPP));
2698                 return 0;
2699         }
2700
2701         if (readonly)
2702                 return 1;
2703
2704         if (ext4_has_feature_readonly(sb)) {
2705                 ext4_msg(sb, KERN_INFO, "filesystem is read-only");
2706                 sb->s_flags |= MS_RDONLY;
2707                 return 1;
2708         }
2709
2710         /* Check that feature set is OK for a read-write mount */
2711         if (ext4_has_unknown_ext4_ro_compat_features(sb)) {
2712                 ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2713                          "unsupported optional features (%x)",
2714                          (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2715                                 ~EXT4_FEATURE_RO_COMPAT_SUPP));
2716                 return 0;
2717         }
2718         /*
2719          * Large file size enabled file system can only be mounted
2720          * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2721          */
2722         if (ext4_has_feature_huge_file(sb)) {
2723                 if (sizeof(blkcnt_t) < sizeof(u64)) {
2724                         ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2725                                  "cannot be mounted RDWR without "
2726                                  "CONFIG_LBDAF");
2727                         return 0;
2728                 }
2729         }
2730         if (ext4_has_feature_bigalloc(sb) && !ext4_has_feature_extents(sb)) {
2731                 ext4_msg(sb, KERN_ERR,
2732                          "Can't support bigalloc feature without "
2733                          "extents feature\n");
2734                 return 0;
2735         }
2736
2737 #ifndef CONFIG_QUOTA
2738         if (ext4_has_feature_quota(sb) && !readonly) {
2739                 ext4_msg(sb, KERN_ERR,
2740                          "Filesystem with quota feature cannot be mounted RDWR "
2741                          "without CONFIG_QUOTA");
2742                 return 0;
2743         }
2744         if (ext4_has_feature_project(sb) && !readonly) {
2745                 ext4_msg(sb, KERN_ERR,
2746                          "Filesystem with project quota feature cannot be mounted RDWR "
2747                          "without CONFIG_QUOTA");
2748                 return 0;
2749         }
2750 #endif  /* CONFIG_QUOTA */
2751         return 1;
2752 }
2753
2754 /*
2755  * This function is called once a day if we have errors logged
2756  * on the file system
2757  */
2758 static void print_daily_error_info(unsigned long arg)
2759 {
2760         struct super_block *sb = (struct super_block *) arg;
2761         struct ext4_sb_info *sbi;
2762         struct ext4_super_block *es;
2763
2764         sbi = EXT4_SB(sb);
2765         es = sbi->s_es;
2766
2767         if (es->s_error_count)
2768                 /* fsck newer than v1.41.13 is needed to clean this condition. */
2769                 ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
2770                          le32_to_cpu(es->s_error_count));
2771         if (es->s_first_error_time) {
2772                 printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %u: %.*s:%d",
2773                        sb->s_id, le32_to_cpu(es->s_first_error_time),
2774                        (int) sizeof(es->s_first_error_func),
2775                        es->s_first_error_func,
2776                        le32_to_cpu(es->s_first_error_line));
2777                 if (es->s_first_error_ino)
2778                         printk(KERN_CONT ": inode %u",
2779                                le32_to_cpu(es->s_first_error_ino));
2780                 if (es->s_first_error_block)
2781                         printk(KERN_CONT ": block %llu", (unsigned long long)
2782                                le64_to_cpu(es->s_first_error_block));
2783                 printk(KERN_CONT "\n");
2784         }
2785         if (es->s_last_error_time) {
2786                 printk(KERN_NOTICE "EXT4-fs (%s): last error at time %u: %.*s:%d",
2787                        sb->s_id, le32_to_cpu(es->s_last_error_time),
2788                        (int) sizeof(es->s_last_error_func),
2789                        es->s_last_error_func,
2790                        le32_to_cpu(es->s_last_error_line));
2791                 if (es->s_last_error_ino)
2792                         printk(KERN_CONT ": inode %u",
2793                                le32_to_cpu(es->s_last_error_ino));
2794                 if (es->s_last_error_block)
2795                         printk(KERN_CONT ": block %llu", (unsigned long long)
2796                                le64_to_cpu(es->s_last_error_block));
2797                 printk(KERN_CONT "\n");
2798         }
2799         mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2800 }
2801
2802 /* Find next suitable group and run ext4_init_inode_table */
2803 static int ext4_run_li_request(struct ext4_li_request *elr)
2804 {
2805         struct ext4_group_desc *gdp = NULL;
2806         ext4_group_t group, ngroups;
2807         struct super_block *sb;
2808         unsigned long timeout = 0;
2809         int ret = 0;
2810
2811         sb = elr->lr_super;
2812         ngroups = EXT4_SB(sb)->s_groups_count;
2813
2814         for (group = elr->lr_next_group; group < ngroups; group++) {
2815                 gdp = ext4_get_group_desc(sb, group, NULL);
2816                 if (!gdp) {
2817                         ret = 1;
2818                         break;
2819                 }
2820
2821                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2822                         break;
2823         }
2824
2825         if (group >= ngroups)
2826                 ret = 1;
2827
2828         if (!ret) {
2829                 timeout = jiffies;
2830                 ret = ext4_init_inode_table(sb, group,
2831                                             elr->lr_timeout ? 0 : 1);
2832                 if (elr->lr_timeout == 0) {
2833                         timeout = (jiffies - timeout) *
2834                                   elr->lr_sbi->s_li_wait_mult;
2835                         elr->lr_timeout = timeout;
2836                 }
2837                 elr->lr_next_sched = jiffies + elr->lr_timeout;
2838                 elr->lr_next_group = group + 1;
2839         }
2840         return ret;
2841 }
2842
2843 /*
2844  * Remove lr_request from the list_request and free the
2845  * request structure. Should be called with li_list_mtx held
2846  */
2847 static void ext4_remove_li_request(struct ext4_li_request *elr)
2848 {
2849         struct ext4_sb_info *sbi;
2850
2851         if (!elr)
2852                 return;
2853
2854         sbi = elr->lr_sbi;
2855
2856         list_del(&elr->lr_request);
2857         sbi->s_li_request = NULL;
2858         kfree(elr);
2859 }
2860
2861 static void ext4_unregister_li_request(struct super_block *sb)
2862 {
2863         mutex_lock(&ext4_li_mtx);
2864         if (!ext4_li_info) {
2865                 mutex_unlock(&ext4_li_mtx);
2866                 return;
2867         }
2868
2869         mutex_lock(&ext4_li_info->li_list_mtx);
2870         ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
2871         mutex_unlock(&ext4_li_info->li_list_mtx);
2872         mutex_unlock(&ext4_li_mtx);
2873 }
2874
2875 static struct task_struct *ext4_lazyinit_task;
2876
2877 /*
2878  * This is the function where ext4lazyinit thread lives. It walks
2879  * through the request list searching for next scheduled filesystem.
2880  * When such a fs is found, run the lazy initialization request
2881  * (ext4_rn_li_request) and keep track of the time spend in this
2882  * function. Based on that time we compute next schedule time of
2883  * the request. When walking through the list is complete, compute
2884  * next waking time and put itself into sleep.
2885  */
2886 static int ext4_lazyinit_thread(void *arg)
2887 {
2888         struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
2889         struct list_head *pos, *n;
2890         struct ext4_li_request *elr;
2891         unsigned long next_wakeup, cur;
2892
2893         BUG_ON(NULL == eli);
2894
2895 cont_thread:
2896         while (true) {
2897                 next_wakeup = MAX_JIFFY_OFFSET;
2898
2899                 mutex_lock(&eli->li_list_mtx);
2900                 if (list_empty(&eli->li_request_list)) {
2901                         mutex_unlock(&eli->li_list_mtx);
2902                         goto exit_thread;
2903                 }
2904                 list_for_each_safe(pos, n, &eli->li_request_list) {
2905                         int err = 0;
2906                         int progress = 0;
2907                         elr = list_entry(pos, struct ext4_li_request,
2908                                          lr_request);
2909
2910                         if (time_before(jiffies, elr->lr_next_sched)) {
2911                                 if (time_before(elr->lr_next_sched, next_wakeup))
2912                                         next_wakeup = elr->lr_next_sched;
2913                                 continue;
2914                         }
2915                         if (down_read_trylock(&elr->lr_super->s_umount)) {
2916                                 if (sb_start_write_trylock(elr->lr_super)) {
2917                                         progress = 1;
2918                                         /*
2919                                          * We hold sb->s_umount, sb can not
2920                                          * be removed from the list, it is
2921                                          * now safe to drop li_list_mtx
2922                                          */
2923                                         mutex_unlock(&eli->li_list_mtx);
2924                                         err = ext4_run_li_request(elr);
2925                                         sb_end_write(elr->lr_super);
2926                                         mutex_lock(&eli->li_list_mtx);
2927                                         n = pos->next;
2928                                 }
2929                                 up_read((&elr->lr_super->s_umount));
2930                         }
2931                         /* error, remove the lazy_init job */
2932                         if (err) {
2933                                 ext4_remove_li_request(elr);
2934                                 continue;
2935                         }
2936                         if (!progress) {
2937                                 elr->lr_next_sched = jiffies +
2938                                         (prandom_u32()
2939                                          % (EXT4_DEF_LI_MAX_START_DELAY * HZ));
2940                         }
2941                         if (time_before(elr->lr_next_sched, next_wakeup))
2942                                 next_wakeup = elr->lr_next_sched;
2943                 }
2944                 mutex_unlock(&eli->li_list_mtx);
2945
2946                 try_to_freeze();
2947
2948                 cur = jiffies;
2949                 if ((time_after_eq(cur, next_wakeup)) ||
2950                     (MAX_JIFFY_OFFSET == next_wakeup)) {
2951                         cond_resched();
2952                         continue;
2953                 }
2954
2955                 schedule_timeout_interruptible(next_wakeup - cur);
2956
2957                 if (kthread_should_stop()) {
2958                         ext4_clear_request_list();
2959                         goto exit_thread;
2960                 }
2961         }
2962
2963 exit_thread:
2964         /*
2965          * It looks like the request list is empty, but we need
2966          * to check it under the li_list_mtx lock, to prevent any
2967          * additions into it, and of course we should lock ext4_li_mtx
2968          * to atomically free the list and ext4_li_info, because at
2969          * this point another ext4 filesystem could be registering
2970          * new one.
2971          */
2972         mutex_lock(&ext4_li_mtx);
2973         mutex_lock(&eli->li_list_mtx);
2974         if (!list_empty(&eli->li_request_list)) {
2975                 mutex_unlock(&eli->li_list_mtx);
2976                 mutex_unlock(&ext4_li_mtx);
2977                 goto cont_thread;
2978         }
2979         mutex_unlock(&eli->li_list_mtx);
2980         kfree(ext4_li_info);
2981         ext4_li_info = NULL;
2982         mutex_unlock(&ext4_li_mtx);
2983
2984         return 0;
2985 }
2986
2987 static void ext4_clear_request_list(void)
2988 {
2989         struct list_head *pos, *n;
2990         struct ext4_li_request *elr;
2991
2992         mutex_lock(&ext4_li_info->li_list_mtx);
2993         list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
2994                 elr = list_entry(pos, struct ext4_li_request,
2995                                  lr_request);
2996                 ext4_remove_li_request(elr);
2997         }
2998         mutex_unlock(&ext4_li_info->li_list_mtx);
2999 }
3000
3001 static int ext4_run_lazyinit_thread(void)
3002 {
3003         ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
3004                                          ext4_li_info, "ext4lazyinit");
3005         if (IS_ERR(ext4_lazyinit_task)) {
3006                 int err = PTR_ERR(ext4_lazyinit_task);
3007                 ext4_clear_request_list();
3008                 kfree(ext4_li_info);
3009                 ext4_li_info = NULL;
3010                 printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
3011                                  "initialization thread\n",
3012                                  err);
3013                 return err;
3014         }
3015         ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
3016         return 0;
3017 }
3018
3019 /*
3020  * Check whether it make sense to run itable init. thread or not.
3021  * If there is at least one uninitialized inode table, return
3022  * corresponding group number, else the loop goes through all
3023  * groups and return total number of groups.
3024  */
3025 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3026 {
3027         ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3028         struct ext4_group_desc *gdp = NULL;
3029
3030         if (!ext4_has_group_desc_csum(sb))
3031                 return ngroups;
3032
3033         for (group = 0; group < ngroups; group++) {
3034                 gdp = ext4_get_group_desc(sb, group, NULL);
3035                 if (!gdp)
3036                         continue;
3037
3038                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3039                         break;
3040         }
3041
3042         return group;
3043 }
3044
3045 static int ext4_li_info_new(void)
3046 {
3047         struct ext4_lazy_init *eli = NULL;
3048
3049         eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3050         if (!eli)
3051                 return -ENOMEM;
3052
3053         INIT_LIST_HEAD(&eli->li_request_list);
3054         mutex_init(&eli->li_list_mtx);
3055
3056         eli->li_state |= EXT4_LAZYINIT_QUIT;
3057
3058         ext4_li_info = eli;
3059
3060         return 0;
3061 }
3062
3063 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3064                                             ext4_group_t start)
3065 {
3066         struct ext4_sb_info *sbi = EXT4_SB(sb);
3067         struct ext4_li_request *elr;
3068
3069         elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3070         if (!elr)
3071                 return NULL;
3072
3073         elr->lr_super = sb;
3074         elr->lr_sbi = sbi;
3075         elr->lr_next_group = start;
3076
3077         /*
3078          * Randomize first schedule time of the request to
3079          * spread the inode table initialization requests
3080          * better.
3081          */
3082         elr->lr_next_sched = jiffies + (prandom_u32() %
3083                                 (EXT4_DEF_LI_MAX_START_DELAY * HZ));
3084         return elr;
3085 }
3086
3087 int ext4_register_li_request(struct super_block *sb,
3088                              ext4_group_t first_not_zeroed)
3089 {
3090         struct ext4_sb_info *sbi = EXT4_SB(sb);
3091         struct ext4_li_request *elr = NULL;
3092         ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
3093         int ret = 0;
3094
3095         mutex_lock(&ext4_li_mtx);
3096         if (sbi->s_li_request != NULL) {
3097                 /*
3098                  * Reset timeout so it can be computed again, because
3099                  * s_li_wait_mult might have changed.
3100                  */
3101                 sbi->s_li_request->lr_timeout = 0;
3102                 goto out;
3103         }
3104
3105         if (first_not_zeroed == ngroups ||
3106             (sb->s_flags & MS_RDONLY) ||
3107             !test_opt(sb, INIT_INODE_TABLE))
3108                 goto out;
3109
3110         elr = ext4_li_request_new(sb, first_not_zeroed);
3111         if (!elr) {
3112                 ret = -ENOMEM;
3113                 goto out;
3114         }
3115
3116         if (NULL == ext4_li_info) {
3117                 ret = ext4_li_info_new();
3118                 if (ret)
3119                         goto out;
3120         }
3121
3122         mutex_lock(&ext4_li_info->li_list_mtx);
3123         list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3124         mutex_unlock(&ext4_li_info->li_list_mtx);
3125
3126         sbi->s_li_request = elr;
3127         /*
3128          * set elr to NULL here since it has been inserted to
3129          * the request_list and the removal and free of it is
3130          * handled by ext4_clear_request_list from now on.
3131          */
3132         elr = NULL;
3133
3134         if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3135                 ret = ext4_run_lazyinit_thread();
3136                 if (ret)
3137                         goto out;
3138         }
3139 out:
3140         mutex_unlock(&ext4_li_mtx);
3141         if (ret)
3142                 kfree(elr);
3143         return ret;
3144 }
3145
3146 /*
3147  * We do not need to lock anything since this is called on
3148  * module unload.
3149  */
3150 static void ext4_destroy_lazyinit_thread(void)
3151 {
3152         /*
3153          * If thread exited earlier
3154          * there's nothing to be done.
3155          */
3156         if (!ext4_li_info || !ext4_lazyinit_task)
3157                 return;
3158
3159         kthread_stop(ext4_lazyinit_task);
3160 }
3161
3162 static int set_journal_csum_feature_set(struct super_block *sb)
3163 {
3164         int ret = 1;
3165         int compat, incompat;
3166         struct ext4_sb_info *sbi = EXT4_SB(sb);
3167
3168         if (ext4_has_metadata_csum(sb)) {
3169                 /* journal checksum v3 */
3170                 compat = 0;
3171                 incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
3172         } else {
3173                 /* journal checksum v1 */
3174                 compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3175                 incompat = 0;
3176         }
3177
3178         jbd2_journal_clear_features(sbi->s_journal,
3179                         JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3180                         JBD2_FEATURE_INCOMPAT_CSUM_V3 |
3181                         JBD2_FEATURE_INCOMPAT_CSUM_V2);
3182         if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3183                 ret = jbd2_journal_set_features(sbi->s_journal,
3184                                 compat, 0,
3185                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3186                                 incompat);
3187         } else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3188                 ret = jbd2_journal_set_features(sbi->s_journal,
3189                                 compat, 0,
3190                                 incompat);
3191                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3192                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3193         } else {
3194                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3195                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3196         }
3197
3198         return ret;
3199 }
3200
3201 /*
3202  * Note: calculating the overhead so we can be compatible with
3203  * historical BSD practice is quite difficult in the face of
3204  * clusters/bigalloc.  This is because multiple metadata blocks from
3205  * different block group can end up in the same allocation cluster.
3206  * Calculating the exact overhead in the face of clustered allocation
3207  * requires either O(all block bitmaps) in memory or O(number of block
3208  * groups**2) in time.  We will still calculate the superblock for
3209  * older file systems --- and if we come across with a bigalloc file
3210  * system with zero in s_overhead_clusters the estimate will be close to
3211  * correct especially for very large cluster sizes --- but for newer
3212  * file systems, it's better to calculate this figure once at mkfs
3213  * time, and store it in the superblock.  If the superblock value is
3214  * present (even for non-bigalloc file systems), we will use it.
3215  */
3216 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3217                           char *buf)
3218 {
3219         struct ext4_sb_info     *sbi = EXT4_SB(sb);
3220         struct ext4_group_desc  *gdp;
3221         ext4_fsblk_t            first_block, last_block, b;
3222         ext4_group_t            i, ngroups = ext4_get_groups_count(sb);
3223         int                     s, j, count = 0;
3224
3225         if (!ext4_has_feature_bigalloc(sb))
3226                 return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3227                         sbi->s_itb_per_group + 2);
3228
3229         first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3230                 (grp * EXT4_BLOCKS_PER_GROUP(sb));
3231         last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3232         for (i = 0; i < ngroups; i++) {
3233                 gdp = ext4_get_group_desc(sb, i, NULL);
3234                 b = ext4_block_bitmap(sb, gdp);
3235                 if (b >= first_block && b <= last_block) {
3236                         ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3237                         count++;
3238                 }
3239                 b = ext4_inode_bitmap(sb, gdp);
3240                 if (b >= first_block && b <= last_block) {
3241                         ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3242                         count++;
3243                 }
3244                 b = ext4_inode_table(sb, gdp);
3245                 if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3246                         for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3247                                 int c = EXT4_B2C(sbi, b - first_block);
3248                                 ext4_set_bit(c, buf);
3249                                 count++;
3250                         }
3251                 if (i != grp)
3252                         continue;
3253                 s = 0;
3254                 if (ext4_bg_has_super(sb, grp)) {
3255                         ext4_set_bit(s++, buf);
3256                         count++;
3257                 }
3258                 j = ext4_bg_num_gdb(sb, grp);
3259                 if (s + j > EXT4_BLOCKS_PER_GROUP(sb)) {
3260                         ext4_error(sb, "Invalid number of block group "
3261                                    "descriptor blocks: %d", j);
3262                         j = EXT4_BLOCKS_PER_GROUP(sb) - s;
3263                 }
3264                 count += j;
3265                 for (; j > 0; j--)
3266                         ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3267         }
3268         if (!count)
3269                 return 0;
3270         return EXT4_CLUSTERS_PER_GROUP(sb) -
3271                 ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3272 }
3273
3274 /*
3275  * Compute the overhead and stash it in sbi->s_overhead
3276  */
3277 int ext4_calculate_overhead(struct super_block *sb)
3278 {
3279         struct ext4_sb_info *sbi = EXT4_SB(sb);
3280         struct ext4_super_block *es = sbi->s_es;
3281         struct inode *j_inode;
3282         unsigned int j_blocks, j_inum = le32_to_cpu(es->s_journal_inum);
3283         ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3284         ext4_fsblk_t overhead = 0;
3285         char *buf = (char *) get_zeroed_page(GFP_NOFS);
3286
3287         if (!buf)
3288                 return -ENOMEM;
3289
3290         /*
3291          * Compute the overhead (FS structures).  This is constant
3292          * for a given filesystem unless the number of block groups
3293          * changes so we cache the previous value until it does.
3294          */
3295
3296         /*
3297          * All of the blocks before first_data_block are overhead
3298          */
3299         overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3300
3301         /*
3302          * Add the overhead found in each block group
3303          */
3304         for (i = 0; i < ngroups; i++) {
3305                 int blks;
3306
3307                 blks = count_overhead(sb, i, buf);
3308                 overhead += blks;
3309                 if (blks)
3310                         memset(buf, 0, PAGE_SIZE);
3311                 cond_resched();
3312         }
3313
3314         /*
3315          * Add the internal journal blocks whether the journal has been
3316          * loaded or not
3317          */
3318         if (sbi->s_journal && !sbi->journal_bdev)
3319                 overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_maxlen);
3320         else if (ext4_has_feature_journal(sb) && !sbi->s_journal) {
3321                 j_inode = ext4_get_journal_inode(sb, j_inum);
3322                 if (j_inode) {
3323                         j_blocks = j_inode->i_size >> sb->s_blocksize_bits;
3324                         overhead += EXT4_NUM_B2C(sbi, j_blocks);
3325                         iput(j_inode);
3326                 } else {
3327                         ext4_msg(sb, KERN_ERR, "can't get journal size");
3328                 }
3329         }
3330         sbi->s_overhead = overhead;
3331         smp_wmb();
3332         free_page((unsigned long) buf);
3333         return 0;
3334 }
3335
3336 static void ext4_set_resv_clusters(struct super_block *sb)
3337 {
3338         ext4_fsblk_t resv_clusters;
3339         struct ext4_sb_info *sbi = EXT4_SB(sb);
3340
3341         /*
3342          * There's no need to reserve anything when we aren't using extents.
3343          * The space estimates are exact, there are no unwritten extents,
3344          * hole punching doesn't need new metadata... This is needed especially
3345          * to keep ext2/3 backward compatibility.
3346          */
3347         if (!ext4_has_feature_extents(sb))
3348                 return;
3349         /*
3350          * By default we reserve 2% or 4096 clusters, whichever is smaller.
3351          * This should cover the situations where we can not afford to run
3352          * out of space like for example punch hole, or converting
3353          * unwritten extents in delalloc path. In most cases such
3354          * allocation would require 1, or 2 blocks, higher numbers are
3355          * very rare.
3356          */
3357         resv_clusters = (ext4_blocks_count(sbi->s_es) >>
3358                          sbi->s_cluster_bits);
3359
3360         do_div(resv_clusters, 50);
3361         resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
3362
3363         atomic64_set(&sbi->s_resv_clusters, resv_clusters);
3364 }
3365
3366 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3367 {
3368         char *orig_data = kstrdup(data, GFP_KERNEL);
3369         struct buffer_head *bh;
3370         struct ext4_super_block *es = NULL;
3371         struct ext4_sb_info *sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3372         ext4_fsblk_t block;
3373         ext4_fsblk_t sb_block = get_sb_block(&data);
3374         ext4_fsblk_t logical_sb_block;
3375         unsigned long offset = 0;
3376         unsigned long journal_devnum = 0;
3377         unsigned long def_mount_opts;
3378         struct inode *root;
3379         const char *descr;
3380         int ret = -ENOMEM;
3381         int blocksize, clustersize;
3382         unsigned int db_count;
3383         unsigned int i;
3384         int needs_recovery, has_huge_files, has_bigalloc;
3385         __u64 blocks_count;
3386         int err = 0;
3387         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3388         ext4_group_t first_not_zeroed;
3389
3390         if ((data && !orig_data) || !sbi)
3391                 goto out_free_base;
3392
3393         sbi->s_blockgroup_lock =
3394                 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3395         if (!sbi->s_blockgroup_lock)
3396                 goto out_free_base;
3397
3398         sb->s_fs_info = sbi;
3399         sbi->s_sb = sb;
3400         sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3401         sbi->s_sb_block = sb_block;
3402         if (sb->s_bdev->bd_part)
3403                 sbi->s_sectors_written_start =
3404                         part_stat_read(sb->s_bdev->bd_part, sectors[1]);
3405
3406         /* Cleanup superblock name */
3407         strreplace(sb->s_id, '/', '!');
3408
3409         /* -EINVAL is default */
3410         ret = -EINVAL;
3411         blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3412         if (!blocksize) {
3413                 ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3414                 goto out_fail;
3415         }
3416
3417         /*
3418          * The ext4 superblock will not be buffer aligned for other than 1kB
3419          * block sizes.  We need to calculate the offset from buffer start.
3420          */
3421         if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3422                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3423                 offset = do_div(logical_sb_block, blocksize);
3424         } else {
3425                 logical_sb_block = sb_block;
3426         }
3427
3428         if (!(bh = sb_bread_unmovable(sb, logical_sb_block))) {
3429                 ext4_msg(sb, KERN_ERR, "unable to read superblock");
3430                 goto out_fail;
3431         }
3432         /*
3433          * Note: s_es must be initialized as soon as possible because
3434          *       some ext4 macro-instructions depend on its value
3435          */
3436         es = (struct ext4_super_block *) (bh->b_data + offset);
3437         sbi->s_es = es;
3438         sb->s_magic = le16_to_cpu(es->s_magic);
3439         if (sb->s_magic != EXT4_SUPER_MAGIC)
3440                 goto cantfind_ext4;
3441         sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3442
3443         /* Warn if metadata_csum and gdt_csum are both set. */
3444         if (ext4_has_feature_metadata_csum(sb) &&
3445             ext4_has_feature_gdt_csum(sb))
3446                 ext4_warning(sb, "metadata_csum and uninit_bg are "
3447                              "redundant flags; please run fsck.");
3448
3449         /* Check for a known checksum algorithm */
3450         if (!ext4_verify_csum_type(sb, es)) {
3451                 ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3452                          "unknown checksum algorithm.");
3453                 silent = 1;
3454                 goto cantfind_ext4;
3455         }
3456
3457         /* Load the checksum driver */
3458         if (ext4_has_feature_metadata_csum(sb)) {
3459                 sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3460                 if (IS_ERR(sbi->s_chksum_driver)) {
3461                         ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3462                         ret = PTR_ERR(sbi->s_chksum_driver);
3463                         sbi->s_chksum_driver = NULL;
3464                         goto failed_mount;
3465                 }
3466         }
3467
3468         /* Check superblock checksum */
3469         if (!ext4_superblock_csum_verify(sb, es)) {
3470                 ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3471                          "invalid superblock checksum.  Run e2fsck?");
3472                 silent = 1;
3473                 ret = -EFSBADCRC;
3474                 goto cantfind_ext4;
3475         }
3476
3477         /* Precompute checksum seed for all metadata */
3478         if (ext4_has_feature_csum_seed(sb))
3479                 sbi->s_csum_seed = le32_to_cpu(es->s_checksum_seed);
3480         else if (ext4_has_metadata_csum(sb))
3481                 sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3482                                                sizeof(es->s_uuid));
3483
3484         /* Set defaults before we parse the mount options */
3485         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3486         set_opt(sb, INIT_INODE_TABLE);
3487         if (def_mount_opts & EXT4_DEFM_DEBUG)
3488                 set_opt(sb, DEBUG);
3489         if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3490                 set_opt(sb, GRPID);
3491         if (def_mount_opts & EXT4_DEFM_UID16)
3492                 set_opt(sb, NO_UID32);
3493         /* xattr user namespace & acls are now defaulted on */
3494         set_opt(sb, XATTR_USER);
3495 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3496         set_opt(sb, POSIX_ACL);
3497 #endif
3498         /* don't forget to enable journal_csum when metadata_csum is enabled. */
3499         if (ext4_has_metadata_csum(sb))
3500                 set_opt(sb, JOURNAL_CHECKSUM);
3501
3502         if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3503                 set_opt(sb, JOURNAL_DATA);
3504         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3505                 set_opt(sb, ORDERED_DATA);
3506         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3507                 set_opt(sb, WRITEBACK_DATA);
3508
3509         if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3510                 set_opt(sb, ERRORS_PANIC);
3511         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3512                 set_opt(sb, ERRORS_CONT);
3513         else
3514                 set_opt(sb, ERRORS_RO);
3515         /* block_validity enabled by default; disable with noblock_validity */
3516         set_opt(sb, BLOCK_VALIDITY);
3517         if (def_mount_opts & EXT4_DEFM_DISCARD)
3518                 set_opt(sb, DISCARD);
3519
3520         sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3521         sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3522         sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3523         sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3524         sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3525
3526         if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3527                 set_opt(sb, BARRIER);
3528
3529         /*
3530          * enable delayed allocation by default
3531          * Use -o nodelalloc to turn it off
3532          */
3533         if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
3534             ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3535                 set_opt(sb, DELALLOC);
3536
3537         /*
3538          * set default s_li_wait_mult for lazyinit, for the case there is
3539          * no mount option specified.
3540          */
3541         sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3542
3543         if (sbi->s_es->s_mount_opts[0]) {
3544                 char *s_mount_opts = kstrndup(sbi->s_es->s_mount_opts,
3545                                               sizeof(sbi->s_es->s_mount_opts),
3546                                               GFP_KERNEL);
3547                 if (!s_mount_opts)
3548                         goto failed_mount;
3549                 if (!parse_options(s_mount_opts, sb, &journal_devnum,
3550                                    &journal_ioprio, 0)) {
3551                         ext4_msg(sb, KERN_WARNING,
3552                                  "failed to parse options in superblock: %s",
3553                                  s_mount_opts);
3554                 }
3555                 kfree(s_mount_opts);
3556         }
3557         sbi->s_def_mount_opt = sbi->s_mount_opt;
3558         if (!parse_options((char *) data, sb, &journal_devnum,
3559                            &journal_ioprio, 0))
3560                 goto failed_mount;
3561
3562         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3563                 printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3564                             "with data=journal disables delayed "
3565                             "allocation and O_DIRECT support!\n");
3566                 if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3567                         ext4_msg(sb, KERN_ERR, "can't mount with "
3568                                  "both data=journal and delalloc");
3569                         goto failed_mount;
3570                 }
3571                 if (test_opt(sb, DIOREAD_NOLOCK)) {
3572                         ext4_msg(sb, KERN_ERR, "can't mount with "
3573                                  "both data=journal and dioread_nolock");
3574                         goto failed_mount;
3575                 }
3576                 if (test_opt(sb, DAX)) {
3577                         ext4_msg(sb, KERN_ERR, "can't mount with "
3578                                  "both data=journal and dax");
3579                         goto failed_mount;
3580                 }
3581                 if (ext4_has_feature_encrypt(sb)) {
3582                         ext4_msg(sb, KERN_WARNING,
3583                                  "encrypted files will use data=ordered "
3584                                  "instead of data journaling mode");
3585                 }
3586                 if (test_opt(sb, DELALLOC))
3587                         clear_opt(sb, DELALLOC);
3588         } else {
3589                 sb->s_iflags |= SB_I_CGROUPWB;
3590         }
3591
3592         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
3593                 (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
3594
3595         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3596             (ext4_has_compat_features(sb) ||
3597              ext4_has_ro_compat_features(sb) ||
3598              ext4_has_incompat_features(sb)))
3599                 ext4_msg(sb, KERN_WARNING,
3600                        "feature flags set on rev 0 fs, "
3601                        "running e2fsck is recommended");
3602
3603         if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
3604                 set_opt2(sb, HURD_COMPAT);
3605                 if (ext4_has_feature_64bit(sb)) {
3606                         ext4_msg(sb, KERN_ERR,
3607                                  "The Hurd can't support 64-bit file systems");
3608                         goto failed_mount;
3609                 }
3610         }
3611
3612         if (IS_EXT2_SB(sb)) {
3613                 if (ext2_feature_set_ok(sb))
3614                         ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3615                                  "using the ext4 subsystem");
3616                 else {
3617                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3618                                  "to feature incompatibilities");
3619                         goto failed_mount;
3620                 }
3621         }
3622
3623         if (IS_EXT3_SB(sb)) {
3624                 if (ext3_feature_set_ok(sb))
3625                         ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3626                                  "using the ext4 subsystem");
3627                 else {
3628                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3629                                  "to feature incompatibilities");
3630                         goto failed_mount;
3631                 }
3632         }
3633
3634         /*
3635          * Check feature flags regardless of the revision level, since we
3636          * previously didn't change the revision level when setting the flags,
3637          * so there is a chance incompat flags are set on a rev 0 filesystem.
3638          */
3639         if (!ext4_feature_set_ok(sb, (sb->s_flags & MS_RDONLY)))
3640                 goto failed_mount;
3641
3642         blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3643         if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3644             blocksize > EXT4_MAX_BLOCK_SIZE) {
3645                 ext4_msg(sb, KERN_ERR,
3646                        "Unsupported filesystem blocksize %d (%d log_block_size)",
3647                          blocksize, le32_to_cpu(es->s_log_block_size));
3648                 goto failed_mount;
3649         }
3650         if (le32_to_cpu(es->s_log_block_size) >
3651             (EXT4_MAX_BLOCK_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
3652                 ext4_msg(sb, KERN_ERR,
3653                          "Invalid log block size: %u",
3654                          le32_to_cpu(es->s_log_block_size));
3655                 goto failed_mount;
3656         }
3657         if (le32_to_cpu(es->s_log_cluster_size) >
3658             (EXT4_MAX_CLUSTER_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
3659                 ext4_msg(sb, KERN_ERR,
3660                          "Invalid log cluster size: %u",
3661                          le32_to_cpu(es->s_log_cluster_size));
3662                 goto failed_mount;
3663         }
3664
3665         if (le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) > (blocksize / 4)) {
3666                 ext4_msg(sb, KERN_ERR,
3667                          "Number of reserved GDT blocks insanely large: %d",
3668                          le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks));
3669                 goto failed_mount;
3670         }
3671
3672         if (sbi->s_mount_opt & EXT4_MOUNT_DAX) {
3673                 err = bdev_dax_supported(sb, blocksize);
3674                 if (err)
3675                         goto failed_mount;
3676         }
3677
3678         if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) {
3679                 ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
3680                          es->s_encryption_level);
3681                 goto failed_mount;
3682         }
3683
3684         if (sb->s_blocksize != blocksize) {
3685                 /* Validate the filesystem blocksize */
3686                 if (!sb_set_blocksize(sb, blocksize)) {
3687                         ext4_msg(sb, KERN_ERR, "bad block size %d",
3688                                         blocksize);
3689                         goto failed_mount;
3690                 }
3691
3692                 brelse(bh);
3693                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3694                 offset = do_div(logical_sb_block, blocksize);
3695                 bh = sb_bread_unmovable(sb, logical_sb_block);
3696                 if (!bh) {
3697                         ext4_msg(sb, KERN_ERR,
3698                                "Can't read superblock on 2nd try");
3699                         goto failed_mount;
3700                 }
3701                 es = (struct ext4_super_block *)(bh->b_data + offset);
3702                 sbi->s_es = es;
3703                 if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
3704                         ext4_msg(sb, KERN_ERR,
3705                                "Magic mismatch, very weird!");
3706                         goto failed_mount;
3707                 }
3708         }
3709
3710         has_huge_files = ext4_has_feature_huge_file(sb);
3711         sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
3712                                                       has_huge_files);
3713         sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
3714
3715         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3716                 sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3717                 sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3718         } else {
3719                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3720                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3721                 if (sbi->s_first_ino < EXT4_GOOD_OLD_FIRST_INO) {
3722                         ext4_msg(sb, KERN_ERR, "invalid first ino: %u",
3723                                  sbi->s_first_ino);
3724                         goto failed_mount;
3725                 }
3726                 if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3727                     (!is_power_of_2(sbi->s_inode_size)) ||
3728                     (sbi->s_inode_size > blocksize)) {
3729                         ext4_msg(sb, KERN_ERR,
3730                                "unsupported inode size: %d",
3731                                sbi->s_inode_size);
3732                         goto failed_mount;
3733                 }
3734                 if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
3735                         sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
3736         }
3737
3738         sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
3739         if (ext4_has_feature_64bit(sb)) {
3740                 if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
3741                     sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
3742                     !is_power_of_2(sbi->s_desc_size)) {
3743                         ext4_msg(sb, KERN_ERR,
3744                                "unsupported descriptor size %lu",
3745                                sbi->s_desc_size);
3746                         goto failed_mount;
3747                 }
3748         } else
3749                 sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
3750
3751         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
3752         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
3753
3754         sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
3755         if (sbi->s_inodes_per_block == 0)
3756                 goto cantfind_ext4;
3757         if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
3758             sbi->s_inodes_per_group > blocksize * 8) {
3759                 ext4_msg(sb, KERN_ERR, "invalid inodes per group: %lu\n",
3760                          sbi->s_blocks_per_group);
3761                 goto failed_mount;
3762         }
3763         sbi->s_itb_per_group = sbi->s_inodes_per_group /
3764                                         sbi->s_inodes_per_block;
3765         sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
3766         sbi->s_sbh = bh;
3767         sbi->s_mount_state = le16_to_cpu(es->s_state);
3768         sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
3769         sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
3770
3771         for (i = 0; i < 4; i++)
3772                 sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
3773         sbi->s_def_hash_version = es->s_def_hash_version;
3774         if (ext4_has_feature_dir_index(sb)) {
3775                 i = le32_to_cpu(es->s_flags);
3776                 if (i & EXT2_FLAGS_UNSIGNED_HASH)
3777                         sbi->s_hash_unsigned = 3;
3778                 else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
3779 #ifdef __CHAR_UNSIGNED__
3780                         if (!(sb->s_flags & MS_RDONLY))
3781                                 es->s_flags |=
3782                                         cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
3783                         sbi->s_hash_unsigned = 3;
3784 #else
3785                         if (!(sb->s_flags & MS_RDONLY))
3786                                 es->s_flags |=
3787                                         cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
3788 #endif
3789                 }
3790         }
3791
3792         /* Handle clustersize */
3793         clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
3794         has_bigalloc = ext4_has_feature_bigalloc(sb);
3795         if (has_bigalloc) {
3796                 if (clustersize < blocksize) {
3797                         ext4_msg(sb, KERN_ERR,
3798                                  "cluster size (%d) smaller than "
3799                                  "block size (%d)", clustersize, blocksize);
3800                         goto failed_mount;
3801                 }
3802                 sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
3803                         le32_to_cpu(es->s_log_block_size);
3804                 sbi->s_clusters_per_group =
3805                         le32_to_cpu(es->s_clusters_per_group);
3806                 if (sbi->s_clusters_per_group > blocksize * 8) {
3807                         ext4_msg(sb, KERN_ERR,
3808                                  "#clusters per group too big: %lu",
3809                                  sbi->s_clusters_per_group);
3810                         goto failed_mount;
3811                 }
3812                 if (sbi->s_blocks_per_group !=
3813                     (sbi->s_clusters_per_group * (clustersize / blocksize))) {
3814                         ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
3815                                  "clusters per group (%lu) inconsistent",
3816                                  sbi->s_blocks_per_group,
3817                                  sbi->s_clusters_per_group);
3818                         goto failed_mount;
3819                 }
3820         } else {
3821                 if (clustersize != blocksize) {
3822                         ext4_msg(sb, KERN_ERR,
3823                                  "fragment/cluster size (%d) != "
3824                                  "block size (%d)", clustersize, blocksize);
3825                         goto failed_mount;
3826                 }
3827                 if (sbi->s_blocks_per_group > blocksize * 8) {
3828                         ext4_msg(sb, KERN_ERR,
3829                                  "#blocks per group too big: %lu",
3830                                  sbi->s_blocks_per_group);
3831                         goto failed_mount;
3832                 }
3833                 sbi->s_clusters_per_group = sbi->s_blocks_per_group;
3834                 sbi->s_cluster_bits = 0;
3835         }
3836         sbi->s_cluster_ratio = clustersize / blocksize;
3837
3838         /* Do we have standard group size of clustersize * 8 blocks ? */
3839         if (sbi->s_blocks_per_group == clustersize << 3)
3840                 set_opt2(sb, STD_GROUP_SIZE);
3841
3842         /*
3843          * Test whether we have more sectors than will fit in sector_t,
3844          * and whether the max offset is addressable by the page cache.
3845          */
3846         err = generic_check_addressable(sb->s_blocksize_bits,
3847                                         ext4_blocks_count(es));
3848         if (err) {
3849                 ext4_msg(sb, KERN_ERR, "filesystem"
3850                          " too large to mount safely on this system");
3851                 if (sizeof(sector_t) < 8)
3852                         ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
3853                 goto failed_mount;
3854         }
3855
3856         if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
3857                 goto cantfind_ext4;
3858
3859         /* check blocks count against device size */
3860         blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
3861         if (blocks_count && ext4_blocks_count(es) > blocks_count) {
3862                 ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
3863                        "exceeds size of device (%llu blocks)",
3864                        ext4_blocks_count(es), blocks_count);
3865                 goto failed_mount;
3866         }
3867
3868         /*
3869          * It makes no sense for the first data block to be beyond the end
3870          * of the filesystem.
3871          */
3872         if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
3873                 ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
3874                          "block %u is beyond end of filesystem (%llu)",
3875                          le32_to_cpu(es->s_first_data_block),
3876                          ext4_blocks_count(es));
3877                 goto failed_mount;
3878         }
3879         if ((es->s_first_data_block == 0) && (es->s_log_block_size == 0) &&
3880             (sbi->s_cluster_ratio == 1)) {
3881                 ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
3882                          "block is 0 with a 1k block and cluster size");
3883                 goto failed_mount;
3884         }
3885
3886         blocks_count = (ext4_blocks_count(es) -
3887                         le32_to_cpu(es->s_first_data_block) +
3888                         EXT4_BLOCKS_PER_GROUP(sb) - 1);
3889         do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
3890         if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
3891                 ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
3892                        "(block count %llu, first data block %u, "
3893                        "blocks per group %lu)", sbi->s_groups_count,
3894                        ext4_blocks_count(es),
3895                        le32_to_cpu(es->s_first_data_block),
3896                        EXT4_BLOCKS_PER_GROUP(sb));
3897                 goto failed_mount;
3898         }
3899         sbi->s_groups_count = blocks_count;
3900         sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
3901                         (EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
3902         db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
3903                    EXT4_DESC_PER_BLOCK(sb);
3904         if (ext4_has_feature_meta_bg(sb)) {
3905                 if (le32_to_cpu(es->s_first_meta_bg) > db_count) {
3906                         ext4_msg(sb, KERN_WARNING,
3907                                  "first meta block group too large: %u "
3908                                  "(group descriptor block count %u)",
3909                                  le32_to_cpu(es->s_first_meta_bg), db_count);
3910                         goto failed_mount;
3911                 }
3912         }
3913         sbi->s_group_desc = ext4_kvmalloc(db_count *
3914                                           sizeof(struct buffer_head *),
3915                                           GFP_KERNEL);
3916         if (sbi->s_group_desc == NULL) {
3917                 ext4_msg(sb, KERN_ERR, "not enough memory");
3918                 ret = -ENOMEM;
3919                 goto failed_mount;
3920         }
3921         if (((u64)sbi->s_groups_count * sbi->s_inodes_per_group) !=
3922             le32_to_cpu(es->s_inodes_count)) {
3923                 ext4_msg(sb, KERN_ERR, "inodes count not valid: %u vs %llu",
3924                          le32_to_cpu(es->s_inodes_count),
3925                          ((u64)sbi->s_groups_count * sbi->s_inodes_per_group));
3926                 ret = -EINVAL;
3927                 goto failed_mount;
3928         }
3929
3930         bgl_lock_init(sbi->s_blockgroup_lock);
3931
3932         for (i = 0; i < db_count; i++) {
3933                 block = descriptor_loc(sb, logical_sb_block, i);
3934                 sbi->s_group_desc[i] = sb_bread_unmovable(sb, block);
3935                 if (!sbi->s_group_desc[i]) {
3936                         ext4_msg(sb, KERN_ERR,
3937                                "can't read group descriptor %d", i);
3938                         db_count = i;
3939                         goto failed_mount2;
3940                 }
3941         }
3942         sbi->s_gdb_count = db_count;
3943         if (!ext4_check_descriptors(sb, logical_sb_block, &first_not_zeroed)) {
3944                 ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
3945                 ret = -EFSCORRUPTED;
3946                 goto failed_mount2;
3947         }
3948
3949         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
3950         spin_lock_init(&sbi->s_next_gen_lock);
3951
3952         setup_timer(&sbi->s_err_report, print_daily_error_info,
3953                 (unsigned long) sb);
3954
3955         /* Register extent status tree shrinker */
3956         if (ext4_es_register_shrinker(sbi))
3957                 goto failed_mount3;
3958
3959         sbi->s_stripe = ext4_get_stripe_size(sbi);
3960         sbi->s_extent_max_zeroout_kb = 32;
3961
3962         /*
3963          * set up enough so that it can read an inode
3964          */
3965         sb->s_op = &ext4_sops;
3966         sb->s_export_op = &ext4_export_ops;
3967         sb->s_xattr = ext4_xattr_handlers;
3968 #ifdef CONFIG_EXT4_FS_ENCRYPTION
3969         sb->s_cop = &ext4_cryptops;
3970 #endif
3971 #ifdef CONFIG_QUOTA
3972         sb->dq_op = &ext4_quota_operations;
3973         if (ext4_has_feature_quota(sb))
3974                 sb->s_qcop = &dquot_quotactl_sysfile_ops;
3975         else
3976                 sb->s_qcop = &ext4_qctl_operations;
3977         sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
3978 #endif
3979         memcpy(sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
3980
3981         INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
3982         mutex_init(&sbi->s_orphan_lock);
3983
3984         sb->s_root = NULL;
3985
3986         needs_recovery = (es->s_last_orphan != 0 ||
3987                           ext4_has_feature_journal_needs_recovery(sb));
3988
3989         if (ext4_has_feature_mmp(sb) && !(sb->s_flags & MS_RDONLY))
3990                 if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
3991                         goto failed_mount3a;
3992
3993         /*
3994          * The first inode we look at is the journal inode.  Don't try
3995          * root first: it may be modified in the journal!
3996          */
3997         if (!test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) {
3998                 err = ext4_load_journal(sb, es, journal_devnum);
3999                 if (err)
4000                         goto failed_mount3a;
4001         } else if (test_opt(sb, NOLOAD) && !(sb->s_flags & MS_RDONLY) &&
4002                    ext4_has_feature_journal_needs_recovery(sb)) {
4003                 ext4_msg(sb, KERN_ERR, "required journal recovery "
4004                        "suppressed and not mounted read-only");
4005                 goto failed_mount_wq;
4006         } else {
4007                 /* Nojournal mode, all journal mount options are illegal */
4008                 if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM)) {
4009                         ext4_msg(sb, KERN_ERR, "can't mount with "
4010                                  "journal_checksum, fs mounted w/o journal");
4011                         goto failed_mount_wq;
4012                 }
4013                 if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4014                         ext4_msg(sb, KERN_ERR, "can't mount with "
4015                                  "journal_async_commit, fs mounted w/o journal");
4016                         goto failed_mount_wq;
4017                 }
4018                 if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
4019                         ext4_msg(sb, KERN_ERR, "can't mount with "
4020                                  "commit=%lu, fs mounted w/o journal",
4021                                  sbi->s_commit_interval / HZ);
4022                         goto failed_mount_wq;
4023                 }
4024                 if (EXT4_MOUNT_DATA_FLAGS &
4025                     (sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
4026                         ext4_msg(sb, KERN_ERR, "can't mount with "
4027                                  "data=, fs mounted w/o journal");
4028                         goto failed_mount_wq;
4029                 }
4030                 sbi->s_def_mount_opt &= EXT4_MOUNT_JOURNAL_CHECKSUM;
4031                 clear_opt(sb, JOURNAL_CHECKSUM);
4032                 clear_opt(sb, DATA_FLAGS);
4033                 sbi->s_journal = NULL;
4034                 needs_recovery = 0;
4035                 goto no_journal;
4036         }
4037
4038         if (ext4_has_feature_64bit(sb) &&
4039             !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4040                                        JBD2_FEATURE_INCOMPAT_64BIT)) {
4041                 ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
4042                 goto failed_mount_wq;
4043         }
4044
4045         if (!set_journal_csum_feature_set(sb)) {
4046                 ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
4047                          "feature set");
4048                 goto failed_mount_wq;
4049         }
4050
4051         /* We have now updated the journal if required, so we can
4052          * validate the data journaling mode. */
4053         switch (test_opt(sb, DATA_FLAGS)) {
4054         case 0:
4055                 /* No mode set, assume a default based on the journal
4056                  * capabilities: ORDERED_DATA if the journal can
4057                  * cope, else JOURNAL_DATA
4058                  */
4059                 if (jbd2_journal_check_available_features
4060                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
4061                         set_opt(sb, ORDERED_DATA);
4062                 else
4063                         set_opt(sb, JOURNAL_DATA);
4064                 break;
4065
4066         case EXT4_MOUNT_ORDERED_DATA:
4067         case EXT4_MOUNT_WRITEBACK_DATA:
4068                 if (!jbd2_journal_check_available_features
4069                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4070                         ext4_msg(sb, KERN_ERR, "Journal does not support "
4071                                "requested data journaling mode");
4072                         goto failed_mount_wq;
4073                 }
4074         default:
4075                 break;
4076         }
4077         set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4078
4079         sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
4080
4081 no_journal:
4082         sbi->s_mb_cache = ext4_xattr_create_cache();
4083         if (!sbi->s_mb_cache) {
4084                 ext4_msg(sb, KERN_ERR, "Failed to create an mb_cache");
4085                 goto failed_mount_wq;
4086         }
4087
4088         if ((DUMMY_ENCRYPTION_ENABLED(sbi) || ext4_has_feature_encrypt(sb)) &&
4089             (blocksize != PAGE_SIZE)) {
4090                 ext4_msg(sb, KERN_ERR,
4091                          "Unsupported blocksize for fs encryption");
4092                 goto failed_mount_wq;
4093         }
4094
4095         if (DUMMY_ENCRYPTION_ENABLED(sbi) && !(sb->s_flags & MS_RDONLY) &&
4096             !ext4_has_feature_encrypt(sb)) {
4097                 ext4_set_feature_encrypt(sb);
4098                 ext4_commit_super(sb, 1);
4099         }
4100
4101         /*
4102          * Get the # of file system overhead blocks from the
4103          * superblock if present.
4104          */
4105         if (es->s_overhead_clusters)
4106                 sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
4107         else {
4108                 err = ext4_calculate_overhead(sb);
4109                 if (err)
4110                         goto failed_mount_wq;
4111         }
4112
4113         /*
4114          * The maximum number of concurrent works can be high and
4115          * concurrency isn't really necessary.  Limit it to 1.
4116          */
4117         EXT4_SB(sb)->rsv_conversion_wq =
4118                 alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
4119         if (!EXT4_SB(sb)->rsv_conversion_wq) {
4120                 printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
4121                 ret = -ENOMEM;
4122                 goto failed_mount4;
4123         }
4124
4125         /*
4126          * The jbd2_journal_load will have done any necessary log recovery,
4127          * so we can safely mount the rest of the filesystem now.
4128          */
4129
4130         root = ext4_iget(sb, EXT4_ROOT_INO);
4131         if (IS_ERR(root)) {
4132                 ext4_msg(sb, KERN_ERR, "get root inode failed");
4133                 ret = PTR_ERR(root);
4134                 root = NULL;
4135                 goto failed_mount4;
4136         }
4137         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
4138                 ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
4139                 iput(root);
4140                 goto failed_mount4;
4141         }
4142         sb->s_root = d_make_root(root);
4143         if (!sb->s_root) {
4144                 ext4_msg(sb, KERN_ERR, "get root dentry failed");
4145                 ret = -ENOMEM;
4146                 goto failed_mount4;
4147         }
4148
4149         if (ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY))
4150                 sb->s_flags |= MS_RDONLY;
4151
4152         /* determine the minimum size of new large inodes, if present */
4153         if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
4154                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4155                                                      EXT4_GOOD_OLD_INODE_SIZE;
4156                 if (ext4_has_feature_extra_isize(sb)) {
4157                         if (sbi->s_want_extra_isize <
4158                             le16_to_cpu(es->s_want_extra_isize))
4159                                 sbi->s_want_extra_isize =
4160                                         le16_to_cpu(es->s_want_extra_isize);
4161                         if (sbi->s_want_extra_isize <
4162                             le16_to_cpu(es->s_min_extra_isize))
4163                                 sbi->s_want_extra_isize =
4164                                         le16_to_cpu(es->s_min_extra_isize);
4165                 }
4166         }
4167         /* Check if enough inode space is available */
4168         if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
4169                                                         sbi->s_inode_size) {
4170                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4171                                                        EXT4_GOOD_OLD_INODE_SIZE;
4172                 ext4_msg(sb, KERN_INFO, "required extra inode space not"
4173                          "available");
4174         }
4175
4176         ext4_set_resv_clusters(sb);
4177
4178         err = ext4_setup_system_zone(sb);
4179         if (err) {
4180                 ext4_msg(sb, KERN_ERR, "failed to initialize system "
4181                          "zone (%d)", err);
4182                 goto failed_mount4a;
4183         }
4184
4185         ext4_ext_init(sb);
4186         err = ext4_mb_init(sb);
4187         if (err) {
4188                 ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
4189                          err);
4190                 goto failed_mount5;
4191         }
4192
4193         block = ext4_count_free_clusters(sb);
4194         ext4_free_blocks_count_set(sbi->s_es,
4195                                    EXT4_C2B(sbi, block));
4196         err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
4197                                   GFP_KERNEL);
4198         if (!err) {
4199                 unsigned long freei = ext4_count_free_inodes(sb);
4200                 sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
4201                 err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
4202                                           GFP_KERNEL);
4203         }
4204         if (!err)
4205                 err = percpu_counter_init(&sbi->s_dirs_counter,
4206                                           ext4_count_dirs(sb), GFP_KERNEL);
4207         if (!err)
4208                 err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
4209                                           GFP_KERNEL);
4210         if (!err)
4211                 err = percpu_init_rwsem(&sbi->s_journal_flag_rwsem);
4212
4213         if (err) {
4214                 ext4_msg(sb, KERN_ERR, "insufficient memory");
4215                 goto failed_mount6;
4216         }
4217
4218         if (ext4_has_feature_flex_bg(sb))
4219                 if (!ext4_fill_flex_info(sb)) {
4220                         ext4_msg(sb, KERN_ERR,
4221                                "unable to initialize "
4222                                "flex_bg meta info!");
4223                         goto failed_mount6;
4224                 }
4225
4226         err = ext4_register_li_request(sb, first_not_zeroed);
4227         if (err)
4228                 goto failed_mount6;
4229
4230         err = ext4_register_sysfs(sb);
4231         if (err)
4232                 goto failed_mount7;
4233
4234 #ifdef CONFIG_QUOTA
4235         /* Enable quota usage during mount. */
4236         if (ext4_has_feature_quota(sb) && !(sb->s_flags & MS_RDONLY)) {
4237                 err = ext4_enable_quotas(sb);
4238                 if (err)
4239                         goto failed_mount8;
4240         }
4241 #endif  /* CONFIG_QUOTA */
4242
4243         EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
4244         ext4_orphan_cleanup(sb, es);
4245         EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
4246         if (needs_recovery) {
4247                 ext4_msg(sb, KERN_INFO, "recovery complete");
4248                 ext4_mark_recovery_complete(sb, es);
4249         }
4250         if (EXT4_SB(sb)->s_journal) {
4251                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
4252                         descr = " journalled data mode";
4253                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
4254                         descr = " ordered data mode";
4255                 else
4256                         descr = " writeback data mode";
4257         } else
4258                 descr = "out journal";
4259
4260         if (test_opt(sb, DISCARD)) {
4261                 struct request_queue *q = bdev_get_queue(sb->s_bdev);
4262                 if (!blk_queue_discard(q))
4263                         ext4_msg(sb, KERN_WARNING,
4264                                  "mounting with \"discard\" option, but "
4265                                  "the device does not support discard");
4266         }
4267
4268         if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
4269                 ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
4270                          "Opts: %.*s%s%s", descr,
4271                          (int) sizeof(sbi->s_es->s_mount_opts),
4272                          sbi->s_es->s_mount_opts,
4273                          *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
4274
4275         if (es->s_error_count)
4276                 mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
4277
4278         /* Enable message ratelimiting. Default is 10 messages per 5 secs. */
4279         ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
4280         ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
4281         ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
4282
4283         kfree(orig_data);
4284         return 0;
4285
4286 cantfind_ext4:
4287         if (!silent)
4288                 ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
4289         goto failed_mount;
4290
4291 #ifdef CONFIG_QUOTA
4292 failed_mount8:
4293         ext4_unregister_sysfs(sb);
4294 #endif
4295 failed_mount7:
4296         ext4_unregister_li_request(sb);
4297 failed_mount6:
4298         ext4_mb_release(sb);
4299         if (sbi->s_flex_groups)
4300                 kvfree(sbi->s_flex_groups);
4301         percpu_counter_destroy(&sbi->s_freeclusters_counter);
4302         percpu_counter_destroy(&sbi->s_freeinodes_counter);
4303         percpu_counter_destroy(&sbi->s_dirs_counter);
4304         percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4305 failed_mount5:
4306         ext4_ext_release(sb);
4307         ext4_release_system_zone(sb);
4308 failed_mount4a:
4309         dput(sb->s_root);
4310         sb->s_root = NULL;
4311 failed_mount4:
4312         ext4_msg(sb, KERN_ERR, "mount failed");
4313         if (EXT4_SB(sb)->rsv_conversion_wq)
4314                 destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4315 failed_mount_wq:
4316         if (sbi->s_mb_cache) {
4317                 ext4_xattr_destroy_cache(sbi->s_mb_cache);
4318                 sbi->s_mb_cache = NULL;
4319         }
4320         if (sbi->s_journal) {
4321                 jbd2_journal_destroy(sbi->s_journal);
4322                 sbi->s_journal = NULL;
4323         }
4324 failed_mount3a:
4325         ext4_es_unregister_shrinker(sbi);
4326 failed_mount3:
4327         del_timer_sync(&sbi->s_err_report);
4328         if (sbi->s_mmp_tsk)
4329                 kthread_stop(sbi->s_mmp_tsk);
4330 failed_mount2:
4331         for (i = 0; i < db_count; i++)
4332                 brelse(sbi->s_group_desc[i]);
4333         kvfree(sbi->s_group_desc);
4334 failed_mount:
4335         if (sbi->s_chksum_driver)
4336                 crypto_free_shash(sbi->s_chksum_driver);
4337 #ifdef CONFIG_QUOTA
4338         for (i = 0; i < EXT4_MAXQUOTAS; i++)
4339                 kfree(sbi->s_qf_names[i]);
4340 #endif
4341         ext4_blkdev_remove(sbi);
4342         brelse(bh);
4343 out_fail:
4344         sb->s_fs_info = NULL;
4345         kfree(sbi->s_blockgroup_lock);
4346 out_free_base:
4347         kfree(sbi);
4348         kfree(orig_data);
4349         return err ? err : ret;
4350 }
4351
4352 /*
4353  * Setup any per-fs journal parameters now.  We'll do this both on
4354  * initial mount, once the journal has been initialised but before we've
4355  * done any recovery; and again on any subsequent remount.
4356  */
4357 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4358 {
4359         struct ext4_sb_info *sbi = EXT4_SB(sb);
4360
4361         journal->j_commit_interval = sbi->s_commit_interval;
4362         journal->j_min_batch_time = sbi->s_min_batch_time;
4363         journal->j_max_batch_time = sbi->s_max_batch_time;
4364
4365         write_lock(&journal->j_state_lock);
4366         if (test_opt(sb, BARRIER))
4367                 journal->j_flags |= JBD2_BARRIER;
4368         else
4369                 journal->j_flags &= ~JBD2_BARRIER;
4370         if (test_opt(sb, DATA_ERR_ABORT))
4371                 journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4372         else
4373                 journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4374         write_unlock(&journal->j_state_lock);
4375 }
4376
4377 static struct inode *ext4_get_journal_inode(struct super_block *sb,
4378                                              unsigned int journal_inum)
4379 {
4380         struct inode *journal_inode;
4381
4382         /*
4383          * Test for the existence of a valid inode on disk.  Bad things
4384          * happen if we iget() an unused inode, as the subsequent iput()
4385          * will try to delete it.
4386          */
4387         journal_inode = ext4_iget(sb, journal_inum);
4388         if (IS_ERR(journal_inode)) {
4389                 ext4_msg(sb, KERN_ERR, "no journal found");
4390                 return NULL;
4391         }
4392         if (!journal_inode->i_nlink) {
4393                 make_bad_inode(journal_inode);
4394                 iput(journal_inode);
4395                 ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4396                 return NULL;
4397         }
4398
4399         jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4400                   journal_inode, journal_inode->i_size);
4401         if (!S_ISREG(journal_inode->i_mode)) {
4402                 ext4_msg(sb, KERN_ERR, "invalid journal inode");
4403                 iput(journal_inode);
4404                 return NULL;
4405         }
4406         return journal_inode;
4407 }
4408
4409 static journal_t *ext4_get_journal(struct super_block *sb,
4410                                    unsigned int journal_inum)
4411 {
4412         struct inode *journal_inode;
4413         journal_t *journal;
4414
4415         BUG_ON(!ext4_has_feature_journal(sb));
4416
4417         journal_inode = ext4_get_journal_inode(sb, journal_inum);
4418         if (!journal_inode)
4419                 return NULL;
4420
4421         journal = jbd2_journal_init_inode(journal_inode);
4422         if (!journal) {
4423                 ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4424                 iput(journal_inode);
4425                 return NULL;
4426         }
4427         journal->j_private = sb;
4428         ext4_init_journal_params(sb, journal);
4429         return journal;
4430 }
4431
4432 static journal_t *ext4_get_dev_journal(struct super_block *sb,
4433                                        dev_t j_dev)
4434 {
4435         struct buffer_head *bh;
4436         journal_t *journal;
4437         ext4_fsblk_t start;
4438         ext4_fsblk_t len;
4439         int hblock, blocksize;
4440         ext4_fsblk_t sb_block;
4441         unsigned long offset;
4442         struct ext4_super_block *es;
4443         struct block_device *bdev;
4444
4445         BUG_ON(!ext4_has_feature_journal(sb));
4446
4447         bdev = ext4_blkdev_get(j_dev, sb);
4448         if (bdev == NULL)
4449                 return NULL;
4450
4451         blocksize = sb->s_blocksize;
4452         hblock = bdev_logical_block_size(bdev);
4453         if (blocksize < hblock) {
4454                 ext4_msg(sb, KERN_ERR,
4455                         "blocksize too small for journal device");
4456                 goto out_bdev;
4457         }
4458
4459         sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4460         offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4461         set_blocksize(bdev, blocksize);
4462         if (!(bh = __bread(bdev, sb_block, blocksize))) {
4463                 ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4464                        "external journal");
4465                 goto out_bdev;
4466         }
4467
4468         es = (struct ext4_super_block *) (bh->b_data + offset);
4469         if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4470             !(le32_to_cpu(es->s_feature_incompat) &
4471               EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4472                 ext4_msg(sb, KERN_ERR, "external journal has "
4473                                         "bad superblock");
4474                 brelse(bh);
4475                 goto out_bdev;
4476         }
4477
4478         if ((le32_to_cpu(es->s_feature_ro_compat) &
4479              EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
4480             es->s_checksum != ext4_superblock_csum(sb, es)) {
4481                 ext4_msg(sb, KERN_ERR, "external journal has "
4482                                        "corrupt superblock");
4483                 brelse(bh);
4484                 goto out_bdev;
4485         }
4486
4487         if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4488                 ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4489                 brelse(bh);
4490                 goto out_bdev;
4491         }
4492
4493         len = ext4_blocks_count(es);
4494         start = sb_block + 1;
4495         brelse(bh);     /* we're done with the superblock */
4496
4497         journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4498                                         start, len, blocksize);
4499         if (!journal) {
4500                 ext4_msg(sb, KERN_ERR, "failed to create device journal");
4501                 goto out_bdev;
4502         }
4503         journal->j_private = sb;
4504         ll_rw_block(REQ_OP_READ, REQ_META | REQ_PRIO, 1, &journal->j_sb_buffer);
4505         wait_on_buffer(journal->j_sb_buffer);
4506         if (!buffer_uptodate(journal->j_sb_buffer)) {
4507                 ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4508                 goto out_journal;
4509         }
4510         if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4511                 ext4_msg(sb, KERN_ERR, "External journal has more than one "
4512                                         "user (unsupported) - %d",
4513                         be32_to_cpu(journal->j_superblock->s_nr_users));
4514                 goto out_journal;
4515         }
4516         EXT4_SB(sb)->journal_bdev = bdev;
4517         ext4_init_journal_params(sb, journal);
4518         return journal;
4519
4520 out_journal:
4521         jbd2_journal_destroy(journal);
4522 out_bdev:
4523         ext4_blkdev_put(bdev);
4524         return NULL;
4525 }
4526
4527 static int ext4_load_journal(struct super_block *sb,
4528                              struct ext4_super_block *es,
4529                              unsigned long journal_devnum)
4530 {
4531         journal_t *journal;
4532         unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4533         dev_t journal_dev;
4534         int err = 0;
4535         int really_read_only;
4536
4537         BUG_ON(!ext4_has_feature_journal(sb));
4538
4539         if (journal_devnum &&
4540             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4541                 ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4542                         "numbers have changed");
4543                 journal_dev = new_decode_dev(journal_devnum);
4544         } else
4545                 journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4546
4547         really_read_only = bdev_read_only(sb->s_bdev);
4548
4549         /*
4550          * Are we loading a blank journal or performing recovery after a
4551          * crash?  For recovery, we need to check in advance whether we
4552          * can get read-write access to the device.
4553          */
4554         if (ext4_has_feature_journal_needs_recovery(sb)) {
4555                 if (sb->s_flags & MS_RDONLY) {
4556                         ext4_msg(sb, KERN_INFO, "INFO: recovery "
4557                                         "required on readonly filesystem");
4558                         if (really_read_only) {
4559                                 ext4_msg(sb, KERN_ERR, "write access "
4560                                         "unavailable, cannot proceed");
4561                                 return -EROFS;
4562                         }
4563                         ext4_msg(sb, KERN_INFO, "write access will "
4564                                "be enabled during recovery");
4565                 }
4566         }
4567
4568         if (journal_inum && journal_dev) {
4569                 ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4570                        "and inode journals!");
4571                 return -EINVAL;
4572         }
4573
4574         if (journal_inum) {
4575                 if (!(journal = ext4_get_journal(sb, journal_inum)))
4576                         return -EINVAL;
4577         } else {
4578                 if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4579                         return -EINVAL;
4580         }
4581
4582         if (!(journal->j_flags & JBD2_BARRIER))
4583                 ext4_msg(sb, KERN_INFO, "barriers disabled");
4584
4585         if (!ext4_has_feature_journal_needs_recovery(sb))
4586                 err = jbd2_journal_wipe(journal, !really_read_only);
4587         if (!err) {
4588                 char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4589                 if (save)
4590                         memcpy(save, ((char *) es) +
4591                                EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4592                 err = jbd2_journal_load(journal);
4593                 if (save)
4594                         memcpy(((char *) es) + EXT4_S_ERR_START,
4595                                save, EXT4_S_ERR_LEN);
4596                 kfree(save);
4597         }
4598
4599         if (err) {
4600                 ext4_msg(sb, KERN_ERR, "error loading journal");
4601                 jbd2_journal_destroy(journal);
4602                 return err;
4603         }
4604
4605         EXT4_SB(sb)->s_journal = journal;
4606         ext4_clear_journal_err(sb, es);
4607
4608         if (!really_read_only && journal_devnum &&
4609             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4610                 es->s_journal_dev = cpu_to_le32(journal_devnum);
4611
4612                 /* Make sure we flush the recovery flag to disk. */
4613                 ext4_commit_super(sb, 1);
4614         }
4615
4616         return 0;
4617 }
4618
4619 static int ext4_commit_super(struct super_block *sb, int sync)
4620 {
4621         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4622         struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4623         int error = 0;
4624
4625         if (!sbh || block_device_ejected(sb))
4626                 return error;
4627
4628         /*
4629          * The superblock bh should be mapped, but it might not be if the
4630          * device was hot-removed. Not much we can do but fail the I/O.
4631          */
4632         if (!buffer_mapped(sbh))
4633                 return error;
4634
4635         /*
4636          * If the file system is mounted read-only, don't update the
4637          * superblock write time.  This avoids updating the superblock
4638          * write time when we are mounting the root file system
4639          * read/only but we need to replay the journal; at that point,
4640          * for people who are east of GMT and who make their clock
4641          * tick in localtime for Windows bug-for-bug compatibility,
4642          * the clock is set in the future, and this will cause e2fsck
4643          * to complain and force a full file system check.
4644          */
4645         if (!(sb->s_flags & MS_RDONLY))
4646                 es->s_wtime = cpu_to_le32(get_seconds());
4647         if (sb->s_bdev->bd_part)
4648                 es->s_kbytes_written =
4649                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
4650                             ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
4651                               EXT4_SB(sb)->s_sectors_written_start) >> 1));
4652         else
4653                 es->s_kbytes_written =
4654                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
4655         if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeclusters_counter))
4656                 ext4_free_blocks_count_set(es,
4657                         EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
4658                                 &EXT4_SB(sb)->s_freeclusters_counter)));
4659         if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeinodes_counter))
4660                 es->s_free_inodes_count =
4661                         cpu_to_le32(percpu_counter_sum_positive(
4662                                 &EXT4_SB(sb)->s_freeinodes_counter));
4663         BUFFER_TRACE(sbh, "marking dirty");
4664         ext4_superblock_csum_set(sb);
4665         if (sync)
4666                 lock_buffer(sbh);
4667         if (buffer_write_io_error(sbh)) {
4668                 /*
4669                  * Oh, dear.  A previous attempt to write the
4670                  * superblock failed.  This could happen because the
4671                  * USB device was yanked out.  Or it could happen to
4672                  * be a transient write error and maybe the block will
4673                  * be remapped.  Nothing we can do but to retry the
4674                  * write and hope for the best.
4675                  */
4676                 ext4_msg(sb, KERN_ERR, "previous I/O error to "
4677                        "superblock detected");
4678                 clear_buffer_write_io_error(sbh);
4679                 set_buffer_uptodate(sbh);
4680         }
4681         mark_buffer_dirty(sbh);
4682         if (sync) {
4683                 unlock_buffer(sbh);
4684                 error = __sync_dirty_buffer(sbh,
4685                         test_opt(sb, BARRIER) ? WRITE_FUA : WRITE_SYNC);
4686                 if (error)
4687                         return error;
4688
4689                 error = buffer_write_io_error(sbh);
4690                 if (error) {
4691                         ext4_msg(sb, KERN_ERR, "I/O error while writing "
4692                                "superblock");
4693                         clear_buffer_write_io_error(sbh);
4694                         set_buffer_uptodate(sbh);
4695                 }
4696         }
4697         return error;
4698 }
4699
4700 /*
4701  * Have we just finished recovery?  If so, and if we are mounting (or
4702  * remounting) the filesystem readonly, then we will end up with a
4703  * consistent fs on disk.  Record that fact.
4704  */
4705 static void ext4_mark_recovery_complete(struct super_block *sb,
4706                                         struct ext4_super_block *es)
4707 {
4708         journal_t *journal = EXT4_SB(sb)->s_journal;
4709
4710         if (!ext4_has_feature_journal(sb)) {
4711                 BUG_ON(journal != NULL);
4712                 return;
4713         }
4714         jbd2_journal_lock_updates(journal);
4715         if (jbd2_journal_flush(journal) < 0)
4716                 goto out;
4717
4718         if (ext4_has_feature_journal_needs_recovery(sb) &&
4719             sb->s_flags & MS_RDONLY) {
4720                 ext4_clear_feature_journal_needs_recovery(sb);
4721                 ext4_commit_super(sb, 1);
4722         }
4723
4724 out:
4725         jbd2_journal_unlock_updates(journal);
4726 }
4727
4728 /*
4729  * If we are mounting (or read-write remounting) a filesystem whose journal
4730  * has recorded an error from a previous lifetime, move that error to the
4731  * main filesystem now.
4732  */
4733 static void ext4_clear_journal_err(struct super_block *sb,
4734                                    struct ext4_super_block *es)
4735 {
4736         journal_t *journal;
4737         int j_errno;
4738         const char *errstr;
4739
4740         BUG_ON(!ext4_has_feature_journal(sb));
4741
4742         journal = EXT4_SB(sb)->s_journal;
4743
4744         /*
4745          * Now check for any error status which may have been recorded in the
4746          * journal by a prior ext4_error() or ext4_abort()
4747          */
4748
4749         j_errno = jbd2_journal_errno(journal);
4750         if (j_errno) {
4751                 char nbuf[16];
4752
4753                 errstr = ext4_decode_error(sb, j_errno, nbuf);
4754                 ext4_warning(sb, "Filesystem error recorded "
4755                              "from previous mount: %s", errstr);
4756                 ext4_warning(sb, "Marking fs in need of filesystem check.");
4757
4758                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
4759                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
4760                 ext4_commit_super(sb, 1);
4761
4762                 jbd2_journal_clear_err(journal);
4763                 jbd2_journal_update_sb_errno(journal);
4764         }
4765 }
4766
4767 /*
4768  * Force the running and committing transactions to commit,
4769  * and wait on the commit.
4770  */
4771 int ext4_force_commit(struct super_block *sb)
4772 {
4773         journal_t *journal;
4774
4775         if (sb->s_flags & MS_RDONLY)
4776                 return 0;
4777
4778         journal = EXT4_SB(sb)->s_journal;
4779         return ext4_journal_force_commit(journal);
4780 }
4781
4782 static int ext4_sync_fs(struct super_block *sb, int wait)
4783 {
4784         int ret = 0;
4785         tid_t target;
4786         bool needs_barrier = false;
4787         struct ext4_sb_info *sbi = EXT4_SB(sb);
4788
4789         trace_ext4_sync_fs(sb, wait);
4790         flush_workqueue(sbi->rsv_conversion_wq);
4791         /*
4792          * Writeback quota in non-journalled quota case - journalled quota has
4793          * no dirty dquots
4794          */
4795         dquot_writeback_dquots(sb, -1);
4796         /*
4797          * Data writeback is possible w/o journal transaction, so barrier must
4798          * being sent at the end of the function. But we can skip it if
4799          * transaction_commit will do it for us.
4800          */
4801         if (sbi->s_journal) {
4802                 target = jbd2_get_latest_transaction(sbi->s_journal);
4803                 if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
4804                     !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
4805                         needs_barrier = true;
4806
4807                 if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
4808                         if (wait)
4809                                 ret = jbd2_log_wait_commit(sbi->s_journal,
4810                                                            target);
4811                 }
4812         } else if (wait && test_opt(sb, BARRIER))
4813                 needs_barrier = true;
4814         if (needs_barrier) {
4815                 int err;
4816                 err = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
4817                 if (!ret)
4818                         ret = err;
4819         }
4820
4821         return ret;
4822 }
4823
4824 /*
4825  * LVM calls this function before a (read-only) snapshot is created.  This
4826  * gives us a chance to flush the journal completely and mark the fs clean.
4827  *
4828  * Note that only this function cannot bring a filesystem to be in a clean
4829  * state independently. It relies on upper layer to stop all data & metadata
4830  * modifications.
4831  */
4832 static int ext4_freeze(struct super_block *sb)
4833 {
4834         int error = 0;
4835         journal_t *journal;
4836
4837         if (sb->s_flags & MS_RDONLY)
4838                 return 0;
4839
4840         journal = EXT4_SB(sb)->s_journal;
4841
4842         if (journal) {
4843                 /* Now we set up the journal barrier. */
4844                 jbd2_journal_lock_updates(journal);
4845
4846                 /*
4847                  * Don't clear the needs_recovery flag if we failed to
4848                  * flush the journal.
4849                  */
4850                 error = jbd2_journal_flush(journal);
4851                 if (error < 0)
4852                         goto out;
4853
4854                 /* Journal blocked and flushed, clear needs_recovery flag. */
4855                 ext4_clear_feature_journal_needs_recovery(sb);
4856         }
4857
4858         error = ext4_commit_super(sb, 1);
4859 out:
4860         if (journal)
4861                 /* we rely on upper layer to stop further updates */
4862                 jbd2_journal_unlock_updates(journal);
4863         return error;
4864 }
4865
4866 /*
4867  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
4868  * flag here, even though the filesystem is not technically dirty yet.
4869  */
4870 static int ext4_unfreeze(struct super_block *sb)
4871 {
4872         if (sb->s_flags & MS_RDONLY)
4873                 return 0;
4874
4875         if (EXT4_SB(sb)->s_journal) {
4876                 /* Reset the needs_recovery flag before the fs is unlocked. */
4877                 ext4_set_feature_journal_needs_recovery(sb);
4878         }
4879
4880         ext4_commit_super(sb, 1);
4881         return 0;
4882 }
4883
4884 /*
4885  * Structure to save mount options for ext4_remount's benefit
4886  */
4887 struct ext4_mount_options {
4888         unsigned long s_mount_opt;
4889         unsigned long s_mount_opt2;
4890         kuid_t s_resuid;
4891         kgid_t s_resgid;
4892         unsigned long s_commit_interval;
4893         u32 s_min_batch_time, s_max_batch_time;
4894 #ifdef CONFIG_QUOTA
4895         int s_jquota_fmt;
4896         char *s_qf_names[EXT4_MAXQUOTAS];
4897 #endif
4898 };
4899
4900 static int ext4_remount(struct super_block *sb, int *flags, char *data)
4901 {
4902         struct ext4_super_block *es;
4903         struct ext4_sb_info *sbi = EXT4_SB(sb);
4904         unsigned long old_sb_flags;
4905         struct ext4_mount_options old_opts;
4906         int enable_quota = 0;
4907         ext4_group_t g;
4908         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4909         int err = 0;
4910 #ifdef CONFIG_QUOTA
4911         int i, j;
4912 #endif
4913         char *orig_data = kstrdup(data, GFP_KERNEL);
4914
4915         /* Store the original options */
4916         old_sb_flags = sb->s_flags;
4917         old_opts.s_mount_opt = sbi->s_mount_opt;
4918         old_opts.s_mount_opt2 = sbi->s_mount_opt2;
4919         old_opts.s_resuid = sbi->s_resuid;
4920         old_opts.s_resgid = sbi->s_resgid;
4921         old_opts.s_commit_interval = sbi->s_commit_interval;
4922         old_opts.s_min_batch_time = sbi->s_min_batch_time;
4923         old_opts.s_max_batch_time = sbi->s_max_batch_time;
4924 #ifdef CONFIG_QUOTA
4925         old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
4926         for (i = 0; i < EXT4_MAXQUOTAS; i++)
4927                 if (sbi->s_qf_names[i]) {
4928                         old_opts.s_qf_names[i] = kstrdup(sbi->s_qf_names[i],
4929                                                          GFP_KERNEL);
4930                         if (!old_opts.s_qf_names[i]) {
4931                                 for (j = 0; j < i; j++)
4932                                         kfree(old_opts.s_qf_names[j]);
4933                                 kfree(orig_data);
4934                                 return -ENOMEM;
4935                         }
4936                 } else
4937                         old_opts.s_qf_names[i] = NULL;
4938 #endif
4939         if (sbi->s_journal && sbi->s_journal->j_task->io_context)
4940                 journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
4941
4942         if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
4943                 err = -EINVAL;
4944                 goto restore_opts;
4945         }
4946
4947         if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
4948             test_opt(sb, JOURNAL_CHECKSUM)) {
4949                 ext4_msg(sb, KERN_ERR, "changing journal_checksum "
4950                          "during remount not supported; ignoring");
4951                 sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
4952         }
4953
4954         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
4955                 if (test_opt2(sb, EXPLICIT_DELALLOC)) {
4956                         ext4_msg(sb, KERN_ERR, "can't mount with "
4957                                  "both data=journal and delalloc");
4958                         err = -EINVAL;
4959                         goto restore_opts;
4960                 }
4961                 if (test_opt(sb, DIOREAD_NOLOCK)) {
4962                         ext4_msg(sb, KERN_ERR, "can't mount with "
4963                                  "both data=journal and dioread_nolock");
4964                         err = -EINVAL;
4965                         goto restore_opts;
4966                 }
4967                 if (test_opt(sb, DAX)) {
4968                         ext4_msg(sb, KERN_ERR, "can't mount with "
4969                                  "both data=journal and dax");
4970                         err = -EINVAL;
4971                         goto restore_opts;
4972                 }
4973         }
4974
4975         if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_DAX) {
4976                 ext4_msg(sb, KERN_WARNING, "warning: refusing change of "
4977                         "dax flag with busy inodes while remounting");
4978                 sbi->s_mount_opt ^= EXT4_MOUNT_DAX;
4979         }
4980
4981         if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
4982                 ext4_abort(sb, "Abort forced by user");
4983
4984         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
4985                 (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
4986
4987         es = sbi->s_es;
4988
4989         if (sbi->s_journal) {
4990                 ext4_init_journal_params(sb, sbi->s_journal);
4991                 set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4992         }
4993
4994         if (*flags & MS_LAZYTIME)
4995                 sb->s_flags |= MS_LAZYTIME;
4996
4997         if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY)) {
4998                 if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
4999                         err = -EROFS;
5000                         goto restore_opts;
5001                 }
5002
5003                 if (*flags & MS_RDONLY) {
5004                         err = sync_filesystem(sb);
5005                         if (err < 0)
5006                                 goto restore_opts;
5007                         err = dquot_suspend(sb, -1);
5008                         if (err < 0)
5009                                 goto restore_opts;
5010
5011                         /*
5012                          * First of all, the unconditional stuff we have to do
5013                          * to disable replay of the journal when we next remount
5014                          */
5015                         sb->s_flags |= MS_RDONLY;
5016
5017                         /*
5018                          * OK, test if we are remounting a valid rw partition
5019                          * readonly, and if so set the rdonly flag and then
5020                          * mark the partition as valid again.
5021                          */
5022                         if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
5023                             (sbi->s_mount_state & EXT4_VALID_FS))
5024                                 es->s_state = cpu_to_le16(sbi->s_mount_state);
5025
5026                         if (sbi->s_journal)
5027                                 ext4_mark_recovery_complete(sb, es);
5028                 } else {
5029                         /* Make sure we can mount this feature set readwrite */
5030                         if (ext4_has_feature_readonly(sb) ||
5031                             !ext4_feature_set_ok(sb, 0)) {
5032                                 err = -EROFS;
5033                                 goto restore_opts;
5034                         }
5035                         /*
5036                          * Make sure the group descriptor checksums
5037                          * are sane.  If they aren't, refuse to remount r/w.
5038                          */
5039                         for (g = 0; g < sbi->s_groups_count; g++) {
5040                                 struct ext4_group_desc *gdp =
5041                                         ext4_get_group_desc(sb, g, NULL);
5042
5043                                 if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
5044                                         ext4_msg(sb, KERN_ERR,
5045                "ext4_remount: Checksum for group %u failed (%u!=%u)",
5046                 g, le16_to_cpu(ext4_group_desc_csum(sb, g, gdp)),
5047                                                le16_to_cpu(gdp->bg_checksum));
5048                                         err = -EFSBADCRC;
5049                                         goto restore_opts;
5050                                 }
5051                         }
5052
5053                         /*
5054                          * If we have an unprocessed orphan list hanging
5055                          * around from a previously readonly bdev mount,
5056                          * require a full umount/remount for now.
5057                          */
5058                         if (es->s_last_orphan) {
5059                                 ext4_msg(sb, KERN_WARNING, "Couldn't "
5060                                        "remount RDWR because of unprocessed "
5061                                        "orphan inode list.  Please "
5062                                        "umount/remount instead");
5063                                 err = -EINVAL;
5064                                 goto restore_opts;
5065                         }
5066
5067                         /*
5068                          * Mounting a RDONLY partition read-write, so reread
5069                          * and store the current valid flag.  (It may have
5070                          * been changed by e2fsck since we originally mounted
5071                          * the partition.)
5072                          */
5073                         if (sbi->s_journal)
5074                                 ext4_clear_journal_err(sb, es);
5075                         sbi->s_mount_state = le16_to_cpu(es->s_state);
5076                         if (!ext4_setup_super(sb, es, 0))
5077                                 sb->s_flags &= ~MS_RDONLY;
5078                         if (ext4_has_feature_mmp(sb))
5079                                 if (ext4_multi_mount_protect(sb,
5080                                                 le64_to_cpu(es->s_mmp_block))) {
5081                                         err = -EROFS;
5082                                         goto restore_opts;
5083                                 }
5084                         enable_quota = 1;
5085                 }
5086         }
5087
5088         /*
5089          * Reinitialize lazy itable initialization thread based on
5090          * current settings
5091          */
5092         if ((sb->s_flags & MS_RDONLY) || !test_opt(sb, INIT_INODE_TABLE))
5093                 ext4_unregister_li_request(sb);
5094         else {
5095                 ext4_group_t first_not_zeroed;
5096                 first_not_zeroed = ext4_has_uninit_itable(sb);
5097                 ext4_register_li_request(sb, first_not_zeroed);
5098         }
5099
5100         ext4_setup_system_zone(sb);
5101         if (sbi->s_journal == NULL && !(old_sb_flags & MS_RDONLY))
5102                 ext4_commit_super(sb, 1);
5103
5104 #ifdef CONFIG_QUOTA
5105         /* Release old quota file names */
5106         for (i = 0; i < EXT4_MAXQUOTAS; i++)
5107                 kfree(old_opts.s_qf_names[i]);
5108         if (enable_quota) {
5109                 if (sb_any_quota_suspended(sb))
5110                         dquot_resume(sb, -1);
5111                 else if (ext4_has_feature_quota(sb)) {
5112                         err = ext4_enable_quotas(sb);
5113                         if (err)
5114                                 goto restore_opts;
5115                 }
5116         }
5117 #endif
5118
5119         *flags = (*flags & ~MS_LAZYTIME) | (sb->s_flags & MS_LAZYTIME);
5120         ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
5121         kfree(orig_data);
5122         return 0;
5123
5124 restore_opts:
5125         sb->s_flags = old_sb_flags;
5126         sbi->s_mount_opt = old_opts.s_mount_opt;
5127         sbi->s_mount_opt2 = old_opts.s_mount_opt2;
5128         sbi->s_resuid = old_opts.s_resuid;
5129         sbi->s_resgid = old_opts.s_resgid;
5130         sbi->s_commit_interval = old_opts.s_commit_interval;
5131         sbi->s_min_batch_time = old_opts.s_min_batch_time;
5132         sbi->s_max_batch_time = old_opts.s_max_batch_time;
5133 #ifdef CONFIG_QUOTA
5134         sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
5135         for (i = 0; i < EXT4_MAXQUOTAS; i++) {
5136                 kfree(sbi->s_qf_names[i]);
5137                 sbi->s_qf_names[i] = old_opts.s_qf_names[i];
5138         }
5139 #endif
5140         kfree(orig_data);
5141         return err;
5142 }
5143
5144 #ifdef CONFIG_QUOTA
5145 static int ext4_statfs_project(struct super_block *sb,
5146                                kprojid_t projid, struct kstatfs *buf)
5147 {
5148         struct kqid qid;
5149         struct dquot *dquot;
5150         u64 limit;
5151         u64 curblock;
5152
5153         qid = make_kqid_projid(projid);
5154         dquot = dqget(sb, qid);
5155         if (IS_ERR(dquot))
5156                 return PTR_ERR(dquot);
5157         spin_lock(&dq_data_lock);
5158
5159         limit = (dquot->dq_dqb.dqb_bsoftlimit ?
5160                  dquot->dq_dqb.dqb_bsoftlimit :
5161                  dquot->dq_dqb.dqb_bhardlimit) >> sb->s_blocksize_bits;
5162         if (limit && buf->f_blocks > limit) {
5163                 curblock = dquot->dq_dqb.dqb_curspace >> sb->s_blocksize_bits;
5164                 buf->f_blocks = limit;
5165                 buf->f_bfree = buf->f_bavail =
5166                         (buf->f_blocks > curblock) ?
5167                          (buf->f_blocks - curblock) : 0;
5168         }
5169
5170         limit = dquot->dq_dqb.dqb_isoftlimit ?
5171                 dquot->dq_dqb.dqb_isoftlimit :
5172                 dquot->dq_dqb.dqb_ihardlimit;
5173         if (limit && buf->f_files > limit) {
5174                 buf->f_files = limit;
5175                 buf->f_ffree =
5176                         (buf->f_files > dquot->dq_dqb.dqb_curinodes) ?
5177                          (buf->f_files - dquot->dq_dqb.dqb_curinodes) : 0;
5178         }
5179
5180         spin_unlock(&dq_data_lock);
5181         dqput(dquot);
5182         return 0;
5183 }
5184 #endif
5185
5186 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
5187 {
5188         struct super_block *sb = dentry->d_sb;
5189         struct ext4_sb_info *sbi = EXT4_SB(sb);
5190         struct ext4_super_block *es = sbi->s_es;
5191         ext4_fsblk_t overhead = 0, resv_blocks;
5192         u64 fsid;
5193         s64 bfree;
5194         resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
5195
5196         if (!test_opt(sb, MINIX_DF))
5197                 overhead = sbi->s_overhead;
5198
5199         buf->f_type = EXT4_SUPER_MAGIC;
5200         buf->f_bsize = sb->s_blocksize;
5201         buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
5202         bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
5203                 percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
5204         /* prevent underflow in case that few free space is available */
5205         buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
5206         buf->f_bavail = buf->f_bfree -
5207                         (ext4_r_blocks_count(es) + resv_blocks);
5208         if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
5209                 buf->f_bavail = 0;
5210         buf->f_files = le32_to_cpu(es->s_inodes_count);
5211         buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
5212         buf->f_namelen = EXT4_NAME_LEN;
5213         fsid = le64_to_cpup((void *)es->s_uuid) ^
5214                le64_to_cpup((void *)es->s_uuid + sizeof(u64));
5215         buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
5216         buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
5217
5218 #ifdef CONFIG_QUOTA
5219         if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&
5220             sb_has_quota_limits_enabled(sb, PRJQUOTA))
5221                 ext4_statfs_project(sb, EXT4_I(dentry->d_inode)->i_projid, buf);
5222 #endif
5223         return 0;
5224 }
5225
5226 /* Helper function for writing quotas on sync - we need to start transaction
5227  * before quota file is locked for write. Otherwise the are possible deadlocks:
5228  * Process 1                         Process 2
5229  * ext4_create()                     quota_sync()
5230  *   jbd2_journal_start()                  write_dquot()
5231  *   dquot_initialize()                         down(dqio_mutex)
5232  *     down(dqio_mutex)                    jbd2_journal_start()
5233  *
5234  */
5235
5236 #ifdef CONFIG_QUOTA
5237
5238 static inline struct inode *dquot_to_inode(struct dquot *dquot)
5239 {
5240         return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
5241 }
5242
5243 static int ext4_write_dquot(struct dquot *dquot)
5244 {
5245         int ret, err;
5246         handle_t *handle;
5247         struct inode *inode;
5248
5249         inode = dquot_to_inode(dquot);
5250         handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
5251                                     EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
5252         if (IS_ERR(handle))
5253                 return PTR_ERR(handle);
5254         ret = dquot_commit(dquot);
5255         err = ext4_journal_stop(handle);
5256         if (!ret)
5257                 ret = err;
5258         return ret;
5259 }
5260
5261 static int ext4_acquire_dquot(struct dquot *dquot)
5262 {
5263         int ret, err;
5264         handle_t *handle;
5265
5266         handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5267                                     EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
5268         if (IS_ERR(handle))
5269                 return PTR_ERR(handle);
5270         ret = dquot_acquire(dquot);
5271         err = ext4_journal_stop(handle);
5272         if (!ret)
5273                 ret = err;
5274         return ret;
5275 }
5276
5277 static int ext4_release_dquot(struct dquot *dquot)
5278 {
5279         int ret, err;
5280         handle_t *handle;
5281
5282         handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5283                                     EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
5284         if (IS_ERR(handle)) {
5285                 /* Release dquot anyway to avoid endless cycle in dqput() */
5286                 dquot_release(dquot);
5287                 return PTR_ERR(handle);
5288         }
5289         ret = dquot_release(dquot);
5290         err = ext4_journal_stop(handle);
5291         if (!ret)
5292                 ret = err;
5293         return ret;
5294 }
5295
5296 static int ext4_mark_dquot_dirty(struct dquot *dquot)
5297 {
5298         struct super_block *sb = dquot->dq_sb;
5299         struct ext4_sb_info *sbi = EXT4_SB(sb);
5300
5301         /* Are we journaling quotas? */
5302         if (ext4_has_feature_quota(sb) ||
5303             sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
5304                 dquot_mark_dquot_dirty(dquot);
5305                 return ext4_write_dquot(dquot);
5306         } else {
5307                 return dquot_mark_dquot_dirty(dquot);
5308         }
5309 }
5310
5311 static int ext4_write_info(struct super_block *sb, int type)
5312 {
5313         int ret, err;
5314         handle_t *handle;
5315
5316         /* Data block + inode block */
5317         handle = ext4_journal_start(d_inode(sb->s_root), EXT4_HT_QUOTA, 2);
5318         if (IS_ERR(handle))
5319                 return PTR_ERR(handle);
5320         ret = dquot_commit_info(sb, type);
5321         err = ext4_journal_stop(handle);
5322         if (!ret)
5323                 ret = err;
5324         return ret;
5325 }
5326
5327 /*
5328  * Turn on quotas during mount time - we need to find
5329  * the quota file and such...
5330  */
5331 static int ext4_quota_on_mount(struct super_block *sb, int type)
5332 {
5333         return dquot_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
5334                                         EXT4_SB(sb)->s_jquota_fmt, type);
5335 }
5336
5337 static void lockdep_set_quota_inode(struct inode *inode, int subclass)
5338 {
5339         struct ext4_inode_info *ei = EXT4_I(inode);
5340
5341         /* The first argument of lockdep_set_subclass has to be
5342          * *exactly* the same as the argument to init_rwsem() --- in
5343          * this case, in init_once() --- or lockdep gets unhappy
5344          * because the name of the lock is set using the
5345          * stringification of the argument to init_rwsem().
5346          */
5347         (void) ei;      /* shut up clang warning if !CONFIG_LOCKDEP */
5348         lockdep_set_subclass(&ei->i_data_sem, subclass);
5349 }
5350
5351 /*
5352  * Standard function to be called on quota_on
5353  */
5354 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
5355                          struct path *path)
5356 {
5357         int err;
5358
5359         if (!test_opt(sb, QUOTA))
5360                 return -EINVAL;
5361
5362         /* Quotafile not on the same filesystem? */
5363         if (path->dentry->d_sb != sb)
5364                 return -EXDEV;
5365         /* Journaling quota? */
5366         if (EXT4_SB(sb)->s_qf_names[type]) {
5367                 /* Quotafile not in fs root? */
5368                 if (path->dentry->d_parent != sb->s_root)
5369                         ext4_msg(sb, KERN_WARNING,
5370                                 "Quota file not on filesystem root. "
5371                                 "Journaled quota will not work");
5372         }
5373
5374         /*
5375          * When we journal data on quota file, we have to flush journal to see
5376          * all updates to the file when we bypass pagecache...
5377          */
5378         if (EXT4_SB(sb)->s_journal &&
5379             ext4_should_journal_data(d_inode(path->dentry))) {
5380                 /*
5381                  * We don't need to lock updates but journal_flush() could
5382                  * otherwise be livelocked...
5383                  */
5384                 jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
5385                 err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
5386                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
5387                 if (err)
5388                         return err;
5389         }
5390         lockdep_set_quota_inode(path->dentry->d_inode, I_DATA_SEM_QUOTA);
5391         err = dquot_quota_on(sb, type, format_id, path);
5392         if (err)
5393                 lockdep_set_quota_inode(path->dentry->d_inode,
5394                                              I_DATA_SEM_NORMAL);
5395         return err;
5396 }
5397
5398 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
5399                              unsigned int flags)
5400 {
5401         int err;
5402         struct inode *qf_inode;
5403         unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5404                 le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5405                 le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5406                 le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5407         };
5408
5409         BUG_ON(!ext4_has_feature_quota(sb));
5410
5411         if (!qf_inums[type])
5412                 return -EPERM;
5413
5414         qf_inode = ext4_iget(sb, qf_inums[type]);
5415         if (IS_ERR(qf_inode)) {
5416                 ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
5417                 return PTR_ERR(qf_inode);
5418         }
5419
5420         /* Don't account quota for quota files to avoid recursion */
5421         qf_inode->i_flags |= S_NOQUOTA;
5422         lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);
5423         err = dquot_enable(qf_inode, type, format_id, flags);
5424         iput(qf_inode);
5425         if (err)
5426                 lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);
5427
5428         return err;
5429 }
5430
5431 /* Enable usage tracking for all quota types. */
5432 static int ext4_enable_quotas(struct super_block *sb)
5433 {
5434         int type, err = 0;
5435         unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5436                 le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5437                 le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5438                 le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5439         };
5440         bool quota_mopt[EXT4_MAXQUOTAS] = {
5441                 test_opt(sb, USRQUOTA),
5442                 test_opt(sb, GRPQUOTA),
5443                 test_opt(sb, PRJQUOTA),
5444         };
5445
5446         sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE;
5447         for (type = 0; type < EXT4_MAXQUOTAS; type++) {
5448                 if (qf_inums[type]) {
5449                         err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
5450                                 DQUOT_USAGE_ENABLED |
5451                                 (quota_mopt[type] ? DQUOT_LIMITS_ENABLED : 0));
5452                         if (err) {
5453                                 for (type--; type >= 0; type--)
5454                                         dquot_quota_off(sb, type);
5455
5456                                 ext4_warning(sb,
5457                                         "Failed to enable quota tracking "
5458                                         "(type=%d, err=%d). Please run "
5459                                         "e2fsck to fix.", type, err);
5460                                 return err;
5461                         }
5462                 }
5463         }
5464         return 0;
5465 }
5466
5467 static int ext4_quota_off(struct super_block *sb, int type)
5468 {
5469         struct inode *inode = sb_dqopt(sb)->files[type];
5470         handle_t *handle;
5471
5472         /* Force all delayed allocation blocks to be allocated.
5473          * Caller already holds s_umount sem */
5474         if (test_opt(sb, DELALLOC))
5475                 sync_filesystem(sb);
5476
5477         if (!inode)
5478                 goto out;
5479
5480         /* Update modification times of quota files when userspace can
5481          * start looking at them */
5482         handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5483         if (IS_ERR(handle))
5484                 goto out;
5485         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
5486         ext4_mark_inode_dirty(handle, inode);
5487         ext4_journal_stop(handle);
5488
5489 out:
5490         return dquot_quota_off(sb, type);
5491 }
5492
5493 /* Read data from quotafile - avoid pagecache and such because we cannot afford
5494  * acquiring the locks... As quota files are never truncated and quota code
5495  * itself serializes the operations (and no one else should touch the files)
5496  * we don't have to be afraid of races */
5497 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
5498                                size_t len, loff_t off)
5499 {
5500         struct inode *inode = sb_dqopt(sb)->files[type];
5501         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5502         int offset = off & (sb->s_blocksize - 1);
5503         int tocopy;
5504         size_t toread;
5505         struct buffer_head *bh;
5506         loff_t i_size = i_size_read(inode);
5507
5508         if (off > i_size)
5509                 return 0;
5510         if (off+len > i_size)
5511                 len = i_size-off;
5512         toread = len;
5513         while (toread > 0) {
5514                 tocopy = sb->s_blocksize - offset < toread ?
5515                                 sb->s_blocksize - offset : toread;
5516                 bh = ext4_bread(NULL, inode, blk, 0);
5517                 if (IS_ERR(bh))
5518                         return PTR_ERR(bh);
5519                 if (!bh)        /* A hole? */
5520                         memset(data, 0, tocopy);
5521                 else
5522                         memcpy(data, bh->b_data+offset, tocopy);
5523                 brelse(bh);
5524                 offset = 0;
5525                 toread -= tocopy;
5526                 data += tocopy;
5527                 blk++;
5528         }
5529         return len;
5530 }
5531
5532 /* Write to quotafile (we know the transaction is already started and has
5533  * enough credits) */
5534 static ssize_t ext4_quota_write(struct super_block *sb, int type,
5535                                 const char *data, size_t len, loff_t off)
5536 {
5537         struct inode *inode = sb_dqopt(sb)->files[type];
5538         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5539         int err, offset = off & (sb->s_blocksize - 1);
5540         int retries = 0;
5541         struct buffer_head *bh;
5542         handle_t *handle = journal_current_handle();
5543
5544         if (EXT4_SB(sb)->s_journal && !handle) {
5545                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5546                         " cancelled because transaction is not started",
5547                         (unsigned long long)off, (unsigned long long)len);
5548                 return -EIO;
5549         }
5550         /*
5551          * Since we account only one data block in transaction credits,
5552          * then it is impossible to cross a block boundary.
5553          */
5554         if (sb->s_blocksize - offset < len) {
5555                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5556                         " cancelled because not block aligned",
5557                         (unsigned long long)off, (unsigned long long)len);
5558                 return -EIO;
5559         }
5560
5561         do {
5562                 bh = ext4_bread(handle, inode, blk,
5563                                 EXT4_GET_BLOCKS_CREATE |
5564                                 EXT4_GET_BLOCKS_METADATA_NOFAIL);
5565         } while (IS_ERR(bh) && (PTR_ERR(bh) == -ENOSPC) &&
5566                  ext4_should_retry_alloc(inode->i_sb, &retries));
5567         if (IS_ERR(bh))
5568                 return PTR_ERR(bh);
5569         if (!bh)
5570                 goto out;
5571         BUFFER_TRACE(bh, "get write access");
5572         err = ext4_journal_get_write_access(handle, bh);
5573         if (err) {
5574                 brelse(bh);
5575                 return err;
5576         }
5577         lock_buffer(bh);
5578         memcpy(bh->b_data+offset, data, len);
5579         flush_dcache_page(bh->b_page);
5580         unlock_buffer(bh);
5581         err = ext4_handle_dirty_metadata(handle, NULL, bh);
5582         brelse(bh);
5583 out:
5584         if (inode->i_size < off + len) {
5585                 i_size_write(inode, off + len);
5586                 EXT4_I(inode)->i_disksize = inode->i_size;
5587                 ext4_mark_inode_dirty(handle, inode);
5588         }
5589         return len;
5590 }
5591
5592 static int ext4_get_next_id(struct super_block *sb, struct kqid *qid)
5593 {
5594         const struct quota_format_ops   *ops;
5595
5596         if (!sb_has_quota_loaded(sb, qid->type))
5597                 return -ESRCH;
5598         ops = sb_dqopt(sb)->ops[qid->type];
5599         if (!ops || !ops->get_next_id)
5600                 return -ENOSYS;
5601         return dquot_get_next_id(sb, qid);
5602 }
5603 #endif
5604
5605 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
5606                        const char *dev_name, void *data)
5607 {
5608         return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
5609 }
5610
5611 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
5612 static inline void register_as_ext2(void)
5613 {
5614         int err = register_filesystem(&ext2_fs_type);
5615         if (err)
5616                 printk(KERN_WARNING
5617                        "EXT4-fs: Unable to register as ext2 (%d)\n", err);
5618 }
5619
5620 static inline void unregister_as_ext2(void)
5621 {
5622         unregister_filesystem(&ext2_fs_type);
5623 }
5624
5625 static inline int ext2_feature_set_ok(struct super_block *sb)
5626 {
5627         if (ext4_has_unknown_ext2_incompat_features(sb))
5628                 return 0;
5629         if (sb->s_flags & MS_RDONLY)
5630                 return 1;
5631         if (ext4_has_unknown_ext2_ro_compat_features(sb))
5632                 return 0;
5633         return 1;
5634 }
5635 #else
5636 static inline void register_as_ext2(void) { }
5637 static inline void unregister_as_ext2(void) { }
5638 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
5639 #endif
5640
5641 static inline void register_as_ext3(void)
5642 {
5643         int err = register_filesystem(&ext3_fs_type);
5644         if (err)
5645                 printk(KERN_WARNING
5646                        "EXT4-fs: Unable to register as ext3 (%d)\n", err);
5647 }
5648
5649 static inline void unregister_as_ext3(void)
5650 {
5651         unregister_filesystem(&ext3_fs_type);
5652 }
5653
5654 static inline int ext3_feature_set_ok(struct super_block *sb)
5655 {
5656         if (ext4_has_unknown_ext3_incompat_features(sb))
5657                 return 0;
5658         if (!ext4_has_feature_journal(sb))
5659                 return 0;
5660         if (sb->s_flags & MS_RDONLY)
5661                 return 1;
5662         if (ext4_has_unknown_ext3_ro_compat_features(sb))
5663                 return 0;
5664         return 1;
5665 }
5666
5667 static struct file_system_type ext4_fs_type = {
5668         .owner          = THIS_MODULE,
5669         .name           = "ext4",
5670         .mount          = ext4_mount,
5671         .kill_sb        = kill_block_super,
5672         .fs_flags       = FS_REQUIRES_DEV,
5673 };
5674 MODULE_ALIAS_FS("ext4");
5675
5676 /* Shared across all ext4 file systems */
5677 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
5678
5679 static int __init ext4_init_fs(void)
5680 {
5681         int i, err;
5682
5683         ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
5684         ext4_li_info = NULL;
5685         mutex_init(&ext4_li_mtx);
5686
5687         /* Build-time check for flags consistency */
5688         ext4_check_flag_values();
5689
5690         for (i = 0; i < EXT4_WQ_HASH_SZ; i++)
5691                 init_waitqueue_head(&ext4__ioend_wq[i]);
5692
5693         err = ext4_init_es();
5694         if (err)
5695                 return err;
5696
5697         err = ext4_init_pageio();
5698         if (err)
5699                 goto out5;
5700
5701         err = ext4_init_system_zone();
5702         if (err)
5703                 goto out4;
5704
5705         err = ext4_init_sysfs();
5706         if (err)
5707                 goto out3;
5708
5709         err = ext4_init_mballoc();
5710         if (err)
5711                 goto out2;
5712         err = init_inodecache();
5713         if (err)
5714                 goto out1;
5715         register_as_ext3();
5716         register_as_ext2();
5717         err = register_filesystem(&ext4_fs_type);
5718         if (err)
5719                 goto out;
5720
5721         return 0;
5722 out:
5723         unregister_as_ext2();
5724         unregister_as_ext3();
5725         destroy_inodecache();
5726 out1:
5727         ext4_exit_mballoc();
5728 out2:
5729         ext4_exit_sysfs();
5730 out3:
5731         ext4_exit_system_zone();
5732 out4:
5733         ext4_exit_pageio();
5734 out5:
5735         ext4_exit_es();
5736
5737         return err;
5738 }
5739
5740 static void __exit ext4_exit_fs(void)
5741 {
5742         ext4_destroy_lazyinit_thread();
5743         unregister_as_ext2();
5744         unregister_as_ext3();
5745         unregister_filesystem(&ext4_fs_type);
5746         destroy_inodecache();
5747         ext4_exit_mballoc();
5748         ext4_exit_sysfs();
5749         ext4_exit_system_zone();
5750         ext4_exit_pageio();
5751         ext4_exit_es();
5752 }
5753
5754 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
5755 MODULE_DESCRIPTION("Fourth Extended Filesystem");
5756 MODULE_LICENSE("GPL");
5757 module_init(ext4_init_fs)
5758 module_exit(ext4_exit_fs)