fs/ext4/super.c

   1 /*
   2  *  linux/fs/ext4/super.c
   3  *
   4  * Copyright (C) 1992, 1993, 1994, 1995
   5  * Remy Card (card@masi.ibp.fr)
   6  * Laboratoire MASI - Institut Blaise Pascal
   7  * Universite Pierre et Marie Curie (Paris VI)
   8  *
   9  *  from
  10  *
  11  *  linux/fs/minix/inode.c
  12  *
  13  *  Copyright (C) 1991, 1992  Linus Torvalds
  14  *
  15  *  Big-endian to little-endian byte-swapping/bitmaps by
  16  *        David S. Miller (davem@caip.rutgers.edu), 1995
  17  */
  18
  19 #include <linux/module.h>
  20 #include <linux/string.h>
  21 #include <linux/fs.h>
  22 #include <linux/time.h>
  23 #include <linux/vmalloc.h>
  24 #include <linux/slab.h>
  25 #include <linux/init.h>
  26 #include <linux/blkdev.h>
  27 #include <linux/backing-dev.h>
  28 #include <linux/parser.h>
  29 #include <linux/buffer_head.h>
  30 #include <linux/exportfs.h>
  31 #include <linux/vfs.h>
  32 #include <linux/random.h>
  33 #include <linux/mount.h>
  34 #include <linux/namei.h>
  35 #include <linux/quotaops.h>
  36 #include <linux/seq_file.h>
  37 #include <linux/ctype.h>
  38 #include <linux/log2.h>
  39 #include <linux/crc16.h>
  40 #include <linux/cleancache.h>
  41 #include <linux/uaccess.h>
  42
  43 #include <linux/kthread.h>
  44 #include <linux/freezer.h>
  45
  46 #include "ext4.h"
  47 #include "ext4_extents.h"       /* Needed for trace points definition */
  48 #include "ext4_jbd2.h"
  49 #include "xattr.h"
  50 #include "acl.h"
  51 #include "mballoc.h"
  52
  53 #define CREATE_TRACE_POINTS
  54 #include <trace/events/ext4.h>
  55
  56 static struct ext4_lazy_init *ext4_li_info;
  57 static struct mutex ext4_li_mtx;
  58 static struct ratelimit_state ext4_mount_msg_ratelimit;
  59
  60 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
  61                              unsigned long journal_devnum);
  62 static int ext4_show_options(struct seq_file *seq, struct dentry *root);
  63 static int ext4_commit_super(struct super_block *sb, int sync);
  64 static void ext4_mark_recovery_complete(struct super_block *sb,
  65                                         struct ext4_super_block *es);
  66 static void ext4_clear_journal_err(struct super_block *sb,
  67                                    struct ext4_super_block *es);
  68 static int ext4_sync_fs(struct super_block *sb, int wait);
  69 static int ext4_remount(struct super_block *sb, int *flags, char *data);
  70 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
  71 static int ext4_unfreeze(struct super_block *sb);
  72 static int ext4_freeze(struct super_block *sb);
  73 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
  74                        const char *dev_name, void *data);
  75 static inline int ext2_feature_set_ok(struct super_block *sb);
  76 static inline int ext3_feature_set_ok(struct super_block *sb);
  77 static int ext4_feature_set_ok(struct super_block *sb, int readonly);
  78 static void ext4_destroy_lazyinit_thread(void);
  79 static void ext4_unregister_li_request(struct super_block *sb);
  80 static void ext4_clear_request_list(void);
  81 static struct inode *ext4_get_journal_inode(struct super_block *sb,
  82                                             unsigned int journal_inum);
  83
  84 /*
  85  * Lock ordering
  86  *
  87  * Note the difference between i_mmap_sem (EXT4_I(inode)->i_mmap_sem) and
  88  * i_mmap_rwsem (inode->i_mmap_rwsem)!
  89  *
  90  * page fault path:
  91  * mmap_sem -> sb_start_pagefault -> i_mmap_sem (r) -> transaction start ->
  92  *   page lock -> i_data_sem (rw)
  93  *
  94  * buffered write path:
  95  * sb_start_write -> i_mutex -> mmap_sem
  96  * sb_start_write -> i_mutex -> transaction start -> page lock ->
  97  *   i_data_sem (rw)
  98  *
  99  * truncate:
 100  * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (w) -> i_mmap_sem (w) ->
 101  *   i_mmap_rwsem (w) -> page lock
 102  * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (w) -> i_mmap_sem (w) ->
 103  *   transaction start -> i_data_sem (rw)
 104  *
 105  * direct IO:
 106  * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (r) -> mmap_sem
 107  * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (r) ->
 108  *   transaction start -> i_data_sem (rw)
 109  *
 110  * writepages:
 111  * transaction start -> page lock(s) -> i_data_sem (rw)
 112  */
 113
 114 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
 115 static struct file_system_type ext2_fs_type = {
 116         .owner          = THIS_MODULE,
 117         .name           = "ext2",
 118         .mount          = ext4_mount,
 119         .kill_sb        = kill_block_super,
 120         .fs_flags       = FS_REQUIRES_DEV,
 121 };
 122 MODULE_ALIAS_FS("ext2");
 123 MODULE_ALIAS("ext2");
 124 #define IS_EXT2_SB(sb) ((sb)->s_bdev->bd_holder == &ext2_fs_type)
 125 #else
 126 #define IS_EXT2_SB(sb) (0)
 127 #endif
 128
 129
 130 static struct file_system_type ext3_fs_type = {
 131         .owner          = THIS_MODULE,
 132         .name           = "ext3",
 133         .mount          = ext4_mount,
 134         .kill_sb        = kill_block_super,
 135         .fs_flags       = FS_REQUIRES_DEV,
 136 };
 137 MODULE_ALIAS_FS("ext3");
 138 MODULE_ALIAS("ext3");
 139 #define IS_EXT3_SB(sb) ((sb)->s_bdev->bd_holder == &ext3_fs_type)
 140
 141 static int ext4_verify_csum_type(struct super_block *sb,
 142                                  struct ext4_super_block *es)
 143 {
 144         if (!ext4_has_feature_metadata_csum(sb))
 145                 return 1;
 146
 147         return es->s_checksum_type == EXT4_CRC32C_CHKSUM;
 148 }
 149
 150 static __le32 ext4_superblock_csum(struct super_block *sb,
 151                                    struct ext4_super_block *es)
 152 {
 153         struct ext4_sb_info *sbi = EXT4_SB(sb);
 154         int offset = offsetof(struct ext4_super_block, s_checksum);
 155         __u32 csum;
 156
 157         csum = ext4_chksum(sbi, ~0, (char *)es, offset);
 158
 159         return cpu_to_le32(csum);
 160 }
 161
 162 static int ext4_superblock_csum_verify(struct super_block *sb,
 163                                        struct ext4_super_block *es)
 164 {
 165         if (!ext4_has_metadata_csum(sb))
 166                 return 1;
 167
 168         return es->s_checksum == ext4_superblock_csum(sb, es);
 169 }
 170
 171 void ext4_superblock_csum_set(struct super_block *sb)
 172 {
 173         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 174
 175         if (!ext4_has_metadata_csum(sb))
 176                 return;
 177
 178         es->s_checksum = ext4_superblock_csum(sb, es);
 179 }
 180
 181 void *ext4_kvmalloc(size_t size, gfp_t flags)
 182 {
 183         void *ret;
 184
 185         ret = kmalloc(size, flags | __GFP_NOWARN);
 186         if (!ret)
 187                 ret = __vmalloc(size, flags, PAGE_KERNEL);
 188         return ret;
 189 }
 190
 191 void *ext4_kvzalloc(size_t size, gfp_t flags)
 192 {
 193         void *ret;
 194
 195         ret = kzalloc(size, flags | __GFP_NOWARN);
 196         if (!ret)
 197                 ret = __vmalloc(size, flags | __GFP_ZERO, PAGE_KERNEL);
 198         return ret;
 199 }
 200
 201 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
 202                                struct ext4_group_desc *bg)
 203 {
 204         return le32_to_cpu(bg->bg_block_bitmap_lo) |
 205                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 206                  (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
 207 }
 208
 209 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
 210                                struct ext4_group_desc *bg)
 211 {
 212         return le32_to_cpu(bg->bg_inode_bitmap_lo) |
 213                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 214                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
 215 }
 216
 217 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
 218                               struct ext4_group_desc *bg)
 219 {
 220         return le32_to_cpu(bg->bg_inode_table_lo) |
 221                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 222                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
 223 }
 224
 225 __u32 ext4_free_group_clusters(struct super_block *sb,
 226                                struct ext4_group_desc *bg)
 227 {
 228         return le16_to_cpu(bg->bg_free_blocks_count_lo) |
 229                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 230                  (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
 231 }
 232
 233 __u32 ext4_free_inodes_count(struct super_block *sb,
 234                               struct ext4_group_desc *bg)
 235 {
 236         return le16_to_cpu(bg->bg_free_inodes_count_lo) |
 237                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 238                  (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
 239 }
 240
 241 __u32 ext4_used_dirs_count(struct super_block *sb,
 242                               struct ext4_group_desc *bg)
 243 {
 244         return le16_to_cpu(bg->bg_used_dirs_count_lo) |
 245                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 246                  (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
 247 }
 248
 249 __u32 ext4_itable_unused_count(struct super_block *sb,
 250                               struct ext4_group_desc *bg)
 251 {
 252         return le16_to_cpu(bg->bg_itable_unused_lo) |
 253                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 254                  (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
 255 }
 256
 257 void ext4_block_bitmap_set(struct super_block *sb,
 258                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 259 {
 260         bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
 261         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 262                 bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
 263 }
 264
 265 void ext4_inode_bitmap_set(struct super_block *sb,
 266                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 267 {
 268         bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
 269         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 270                 bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
 271 }
 272
 273 void ext4_inode_table_set(struct super_block *sb,
 274                           struct ext4_group_desc *bg, ext4_fsblk_t blk)
 275 {
 276         bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
 277         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 278                 bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
 279 }
 280
 281 void ext4_free_group_clusters_set(struct super_block *sb,
 282                                   struct ext4_group_desc *bg, __u32 count)
 283 {
 284         bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
 285         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 286                 bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
 287 }
 288
 289 void ext4_free_inodes_set(struct super_block *sb,
 290                           struct ext4_group_desc *bg, __u32 count)
 291 {
 292         bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
 293         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 294                 bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
 295 }
 296
 297 void ext4_used_dirs_set(struct super_block *sb,
 298                           struct ext4_group_desc *bg, __u32 count)
 299 {
 300         bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
 301         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 302                 bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
 303 }
 304
 305 void ext4_itable_unused_set(struct super_block *sb,
 306                           struct ext4_group_desc *bg, __u32 count)
 307 {
 308         bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
 309         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 310                 bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
 311 }
 312
 313
 314 static void __save_error_info(struct super_block *sb, const char *func,
 315                             unsigned int line)
 316 {
 317         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 318
 319         EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
 320         if (bdev_read_only(sb->s_bdev))
 321                 return;
 322         es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
 323         es->s_last_error_time = cpu_to_le32(get_seconds());
 324         strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
 325         es->s_last_error_line = cpu_to_le32(line);
 326         if (!es->s_first_error_time) {
 327                 es->s_first_error_time = es->s_last_error_time;
 328                 strncpy(es->s_first_error_func, func,
 329                         sizeof(es->s_first_error_func));
 330                 es->s_first_error_line = cpu_to_le32(line);
 331                 es->s_first_error_ino = es->s_last_error_ino;
 332                 es->s_first_error_block = es->s_last_error_block;
 333         }
 334         /*
 335          * Start the daily error reporting function if it hasn't been
 336          * started already
 337          */
 338         if (!es->s_error_count)
 339                 mod_timer(&EXT4_SB(sb)->s_err_report, jiffies + 24*60*60*HZ);
 340         le32_add_cpu(&es->s_error_count, 1);
 341 }
 342
 343 static void save_error_info(struct super_block *sb, const char *func,
 344                             unsigned int line)
 345 {
 346         __save_error_info(sb, func, line);
 347         ext4_commit_super(sb, 1);
 348 }
 349
 350 /*
 351  * The del_gendisk() function uninitializes the disk-specific data
 352  * structures, including the bdi structure, without telling anyone
 353  * else.  Once this happens, any attempt to call mark_buffer_dirty()
 354  * (for example, by ext4_commit_super), will cause a kernel OOPS.
 355  * This is a kludge to prevent these oops until we can put in a proper
 356  * hook in del_gendisk() to inform the VFS and file system layers.
 357  */
 358 static int block_device_ejected(struct super_block *sb)
 359 {
 360         struct inode *bd_inode = sb->s_bdev->bd_inode;
 361         struct backing_dev_info *bdi = inode_to_bdi(bd_inode);
 362
 363         return bdi->dev == NULL;
 364 }
 365
 366 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
 367 {
 368         struct super_block              *sb = journal->j_private;
 369         struct ext4_sb_info             *sbi = EXT4_SB(sb);
 370         int                             error = is_journal_aborted(journal);
 371         struct ext4_journal_cb_entry    *jce;
 372
 373         BUG_ON(txn->t_state == T_FINISHED);
 374         spin_lock(&sbi->s_md_lock);
 375         while (!list_empty(&txn->t_private_list)) {
 376                 jce = list_entry(txn->t_private_list.next,
 377                                  struct ext4_journal_cb_entry, jce_list);
 378                 list_del_init(&jce->jce_list);
 379                 spin_unlock(&sbi->s_md_lock);
 380                 jce->jce_func(sb, jce, error);
 381                 spin_lock(&sbi->s_md_lock);
 382         }
 383         spin_unlock(&sbi->s_md_lock);
 384 }
 385
 386 /* Deal with the reporting of failure conditions on a filesystem such as
 387  * inconsistencies detected or read IO failures.
 388  *
 389  * On ext2, we can store the error state of the filesystem in the
 390  * superblock.  That is not possible on ext4, because we may have other
 391  * write ordering constraints on the superblock which prevent us from
 392  * writing it out straight away; and given that the journal is about to
 393  * be aborted, we can't rely on the current, or future, transactions to
 394  * write out the superblock safely.
 395  *
 396  * We'll just use the jbd2_journal_abort() error code to record an error in
 397  * the journal instead.  On recovery, the journal will complain about
 398  * that error until we've noted it down and cleared it.
 399  */
 400
 401 static void ext4_handle_error(struct super_block *sb)
 402 {
 403         if (sb->s_flags & MS_RDONLY)
 404                 return;
 405
 406         if (!test_opt(sb, ERRORS_CONT)) {
 407                 journal_t *journal = EXT4_SB(sb)->s_journal;
 408
 409                 EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
 410                 if (journal)
 411                         jbd2_journal_abort(journal, -EIO);
 412         }
 413         if (test_opt(sb, ERRORS_RO)) {
 414                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 415                 /*
 416                  * Make sure updated value of ->s_mount_flags will be visible
 417                  * before ->s_flags update
 418                  */
 419                 smp_wmb();
 420                 sb->s_flags |= MS_RDONLY;
 421         }
 422         if (test_opt(sb, ERRORS_PANIC)) {
 423                 if (EXT4_SB(sb)->s_journal &&
 424                   !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
 425                         return;
 426                 panic("EXT4-fs (device %s): panic forced after error\n",
 427                         sb->s_id);
 428         }
 429 }
 430
 431 #define ext4_error_ratelimit(sb)                                        \
 432                 ___ratelimit(&(EXT4_SB(sb)->s_err_ratelimit_state),     \
 433                              "EXT4-fs error")
 434
 435 void __ext4_error(struct super_block *sb, const char *function,
 436                   unsigned int line, const char *fmt, ...)
 437 {
 438         struct va_format vaf;
 439         va_list args;
 440
 441         if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
 442                 return;
 443
 444         if (ext4_error_ratelimit(sb)) {
 445                 va_start(args, fmt);
 446                 vaf.fmt = fmt;
 447                 vaf.va = &args;
 448                 printk(KERN_CRIT
 449                        "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
 450                        sb->s_id, function, line, current->comm, &vaf);
 451                 va_end(args);
 452         }
 453         save_error_info(sb, function, line);
 454         ext4_handle_error(sb);
 455 }
 456
 457 void __ext4_error_inode(struct inode *inode, const char *function,
 458                         unsigned int line, ext4_fsblk_t block,
 459                         const char *fmt, ...)
 460 {
 461         va_list args;
 462         struct va_format vaf;
 463         struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
 464
 465         if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
 466                 return;
 467
 468         es->s_last_error_ino = cpu_to_le32(inode->i_ino);
 469         es->s_last_error_block = cpu_to_le64(block);
 470         if (ext4_error_ratelimit(inode->i_sb)) {
 471                 va_start(args, fmt);
 472                 vaf.fmt = fmt;
 473                 vaf.va = &args;
 474                 if (block)
 475                         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
 476                                "inode #%lu: block %llu: comm %s: %pV\n",
 477                                inode->i_sb->s_id, function, line, inode->i_ino,
 478                                block, current->comm, &vaf);
 479                 else
 480                         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
 481                                "inode #%lu: comm %s: %pV\n",
 482                                inode->i_sb->s_id, function, line, inode->i_ino,
 483                                current->comm, &vaf);
 484                 va_end(args);
 485         }
 486         save_error_info(inode->i_sb, function, line);
 487         ext4_handle_error(inode->i_sb);
 488 }
 489
 490 void __ext4_error_file(struct file *file, const char *function,
 491                        unsigned int line, ext4_fsblk_t block,
 492                        const char *fmt, ...)
 493 {
 494         va_list args;
 495         struct va_format vaf;
 496         struct ext4_super_block *es;
 497         struct inode *inode = file_inode(file);
 498         char pathname[80], *path;
 499
 500         if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
 501                 return;
 502
 503         es = EXT4_SB(inode->i_sb)->s_es;
 504         es->s_last_error_ino = cpu_to_le32(inode->i_ino);
 505         if (ext4_error_ratelimit(inode->i_sb)) {
 506                 path = file_path(file, pathname, sizeof(pathname));
 507                 if (IS_ERR(path))
 508                         path = "(unknown)";
 509                 va_start(args, fmt);
 510                 vaf.fmt = fmt;
 511                 vaf.va = &args;
 512                 if (block)
 513                         printk(KERN_CRIT
 514                                "EXT4-fs error (device %s): %s:%d: inode #%lu: "
 515                                "block %llu: comm %s: path %s: %pV\n",
 516                                inode->i_sb->s_id, function, line, inode->i_ino,
 517                                block, current->comm, path, &vaf);
 518                 else
 519                         printk(KERN_CRIT
 520                                "EXT4-fs error (device %s): %s:%d: inode #%lu: "
 521                                "comm %s: path %s: %pV\n",
 522                                inode->i_sb->s_id, function, line, inode->i_ino,
 523                                current->comm, path, &vaf);
 524                 va_end(args);
 525         }
 526         save_error_info(inode->i_sb, function, line);
 527         ext4_handle_error(inode->i_sb);
 528 }
 529
 530 const char *ext4_decode_error(struct super_block *sb, int errno,
 531                               char nbuf[16])
 532 {
 533         char *errstr = NULL;
 534
 535         switch (errno) {
 536         case -EFSCORRUPTED:
 537                 errstr = "Corrupt filesystem";
 538                 break;
 539         case -EFSBADCRC:
 540                 errstr = "Filesystem failed CRC";
 541                 break;
 542         case -EIO:
 543                 errstr = "IO failure";
 544                 break;
 545         case -ENOMEM:
 546                 errstr = "Out of memory";
 547                 break;
 548         case -EROFS:
 549                 if (!sb || (EXT4_SB(sb)->s_journal &&
 550                             EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
 551                         errstr = "Journal has aborted";
 552                 else
 553                         errstr = "Readonly filesystem";
 554                 break;
 555         default:
 556                 /* If the caller passed in an extra buffer for unknown
 557                  * errors, textualise them now.  Else we just return
 558                  * NULL. */
 559                 if (nbuf) {
 560                         /* Check for truncated error codes... */
 561                         if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
 562                                 errstr = nbuf;
 563                 }
 564                 break;
 565         }
 566
 567         return errstr;
 568 }
 569
 570 /* __ext4_std_error decodes expected errors from journaling functions
 571  * automatically and invokes the appropriate error response.  */
 572
 573 void __ext4_std_error(struct super_block *sb, const char *function,
 574                       unsigned int line, int errno)
 575 {
 576         char nbuf[16];
 577         const char *errstr;
 578
 579         if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
 580                 return;
 581
 582         /* Special case: if the error is EROFS, and we're not already
 583          * inside a transaction, then there's really no point in logging
 584          * an error. */
 585         if (errno == -EROFS && journal_current_handle() == NULL &&
 586             (sb->s_flags & MS_RDONLY))
 587                 return;
 588
 589         if (ext4_error_ratelimit(sb)) {
 590                 errstr = ext4_decode_error(sb, errno, nbuf);
 591                 printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
 592                        sb->s_id, function, line, errstr);
 593         }
 594
 595         save_error_info(sb, function, line);
 596         ext4_handle_error(sb);
 597 }
 598
 599 /*
 600  * ext4_abort is a much stronger failure handler than ext4_error.  The
 601  * abort function may be used to deal with unrecoverable failures such
 602  * as journal IO errors or ENOMEM at a critical moment in log management.
 603  *
 604  * We unconditionally force the filesystem into an ABORT|READONLY state,
 605  * unless the error response on the fs has been set to panic in which
 606  * case we take the easy way out and panic immediately.
 607  */
 608
 609 void __ext4_abort(struct super_block *sb, const char *function,
 610                 unsigned int line, const char *fmt, ...)
 611 {
 612         struct va_format vaf;
 613         va_list args;
 614
 615         if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
 616                 return;
 617
 618         save_error_info(sb, function, line);
 619         va_start(args, fmt);
 620         vaf.fmt = fmt;
 621         vaf.va = &args;
 622         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: %pV\n",
 623                sb->s_id, function, line, &vaf);
 624         va_end(args);
 625
 626         if ((sb->s_flags & MS_RDONLY) == 0) {
 627                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 628                 EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
 629                 /*
 630                  * Make sure updated value of ->s_mount_flags will be visible
 631                  * before ->s_flags update
 632                  */
 633                 smp_wmb();
 634                 sb->s_flags |= MS_RDONLY;
 635                 if (EXT4_SB(sb)->s_journal)
 636                         jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
 637                 save_error_info(sb, function, line);
 638         }
 639         if (test_opt(sb, ERRORS_PANIC)) {
 640                 if (EXT4_SB(sb)->s_journal &&
 641                   !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
 642                         return;
 643                 panic("EXT4-fs panic from previous error\n");
 644         }
 645 }
 646
 647 void __ext4_msg(struct super_block *sb,
 648                 const char *prefix, const char *fmt, ...)
 649 {
 650         struct va_format vaf;
 651         va_list args;
 652
 653         if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state), "EXT4-fs"))
 654                 return;
 655
 656         va_start(args, fmt);
 657         vaf.fmt = fmt;
 658         vaf.va = &args;
 659         printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
 660         va_end(args);
 661 }
 662
 663 #define ext4_warning_ratelimit(sb)                                      \
 664                 ___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state), \
 665                              "EXT4-fs warning")
 666
 667 void __ext4_warning(struct super_block *sb, const char *function,
 668                     unsigned int line, const char *fmt, ...)
 669 {
 670         struct va_format vaf;
 671         va_list args;
 672
 673         if (!ext4_warning_ratelimit(sb))
 674                 return;
 675
 676         va_start(args, fmt);
 677         vaf.fmt = fmt;
 678         vaf.va = &args;
 679         printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
 680                sb->s_id, function, line, &vaf);
 681         va_end(args);
 682 }
 683
 684 void __ext4_warning_inode(const struct inode *inode, const char *function,
 685                           unsigned int line, const char *fmt, ...)
 686 {
 687         struct va_format vaf;
 688         va_list args;
 689
 690         if (!ext4_warning_ratelimit(inode->i_sb))
 691                 return;
 692
 693         va_start(args, fmt);
 694         vaf.fmt = fmt;
 695         vaf.va = &args;
 696         printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: "
 697                "inode #%lu: comm %s: %pV\n", inode->i_sb->s_id,
 698                function, line, inode->i_ino, current->comm, &vaf);
 699         va_end(args);
 700 }
 701
 702 void __ext4_grp_locked_error(const char *function, unsigned int line,
 703                              struct super_block *sb, ext4_group_t grp,
 704                              unsigned long ino, ext4_fsblk_t block,
 705                              const char *fmt, ...)
 706 __releases(bitlock)
 707 __acquires(bitlock)
 708 {
 709         struct va_format vaf;
 710         va_list args;
 711         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 712
 713         if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
 714                 return;
 715
 716         es->s_last_error_ino = cpu_to_le32(ino);
 717         es->s_last_error_block = cpu_to_le64(block);
 718         __save_error_info(sb, function, line);
 719
 720         if (ext4_error_ratelimit(sb)) {
 721                 va_start(args, fmt);
 722                 vaf.fmt = fmt;
 723                 vaf.va = &args;
 724                 printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
 725                        sb->s_id, function, line, grp);
 726                 if (ino)
 727                         printk(KERN_CONT "inode %lu: ", ino);
 728                 if (block)
 729                         printk(KERN_CONT "block %llu:",
 730                                (unsigned long long) block);
 731                 printk(KERN_CONT "%pV\n", &vaf);
 732                 va_end(args);
 733         }
 734
 735         if (test_opt(sb, ERRORS_CONT)) {
 736                 ext4_commit_super(sb, 0);
 737                 return;
 738         }
 739
 740         ext4_unlock_group(sb, grp);
 741         ext4_handle_error(sb);
 742         /*
 743          * We only get here in the ERRORS_RO case; relocking the group
 744          * may be dangerous, but nothing bad will happen since the
 745          * filesystem will have already been marked read/only and the
 746          * journal has been aborted.  We return 1 as a hint to callers
 747          * who might what to use the return value from
 748          * ext4_grp_locked_error() to distinguish between the
 749          * ERRORS_CONT and ERRORS_RO case, and perhaps return more
 750          * aggressively from the ext4 function in question, with a
 751          * more appropriate error code.
 752          */
 753         ext4_lock_group(sb, grp);
 754         return;
 755 }
 756
 757 void ext4_update_dynamic_rev(struct super_block *sb)
 758 {
 759         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 760
 761         if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
 762                 return;
 763
 764         ext4_warning(sb,
 765                      "updating to rev %d because of new feature flag, "
 766                      "running e2fsck is recommended",
 767                      EXT4_DYNAMIC_REV);
 768
 769         es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
 770         es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
 771         es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
 772         /* leave es->s_feature_*compat flags alone */
 773         /* es->s_uuid will be set by e2fsck if empty */
 774
 775         /*
 776          * The rest of the superblock fields should be zero, and if not it
 777          * means they are likely already in use, so leave them alone.  We
 778          * can leave it up to e2fsck to clean up any inconsistencies there.
 779          */
 780 }
 781
 782 /*
 783  * Open the external journal device
 784  */
 785 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
 786 {
 787         struct block_device *bdev;
 788         char b[BDEVNAME_SIZE];
 789
 790         bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
 791         if (IS_ERR(bdev))
 792                 goto fail;
 793         return bdev;
 794
 795 fail:
 796         ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
 797                         __bdevname(dev, b), PTR_ERR(bdev));
 798         return NULL;
 799 }
 800
 801 /*
 802  * Release the journal device
 803  */
 804 static void ext4_blkdev_put(struct block_device *bdev)
 805 {
 806         blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
 807 }
 808
 809 static void ext4_blkdev_remove(struct ext4_sb_info *sbi)
 810 {
 811         struct block_device *bdev;
 812         bdev = sbi->journal_bdev;
 813         if (bdev) {
 814                 ext4_blkdev_put(bdev);
 815                 sbi->journal_bdev = NULL;
 816         }
 817 }
 818
 819 static inline struct inode *orphan_list_entry(struct list_head *l)
 820 {
 821         return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
 822 }
 823
 824 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
 825 {
 826         struct list_head *l;
 827
 828         ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
 829                  le32_to_cpu(sbi->s_es->s_last_orphan));
 830
 831         printk(KERN_ERR "sb_info orphan list:\n");
 832         list_for_each(l, &sbi->s_orphan) {
 833                 struct inode *inode = orphan_list_entry(l);
 834                 printk(KERN_ERR "  "
 835                        "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
 836                        inode->i_sb->s_id, inode->i_ino, inode,
 837                        inode->i_mode, inode->i_nlink,
 838                        NEXT_ORPHAN(inode));
 839         }
 840 }
 841
 842 #ifdef CONFIG_QUOTA
 843 static int ext4_quota_off(struct super_block *sb, int type);
 844
 845 static inline void ext4_quota_off_umount(struct super_block *sb)
 846 {
 847         int type;
 848
 849         if (ext4_has_feature_quota(sb)) {
 850                 dquot_disable(sb, -1,
 851                               DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
 852         } else {
 853                 /* Use our quota_off function to clear inode flags etc. */
 854                 for (type = 0; type < EXT4_MAXQUOTAS; type++)
 855                         ext4_quota_off(sb, type);
 856         }
 857 }
 858 #else
 859 static inline void ext4_quota_off_umount(struct super_block *sb)
 860 {
 861 }
 862 #endif
 863
 864 static void ext4_put_super(struct super_block *sb)
 865 {
 866         struct ext4_sb_info *sbi = EXT4_SB(sb);
 867         struct ext4_super_block *es = sbi->s_es;
 868         int aborted = 0;
 869         int i, err;
 870
 871         ext4_unregister_li_request(sb);
 872         ext4_quota_off_umount(sb);
 873
 874         flush_workqueue(sbi->rsv_conversion_wq);
 875         destroy_workqueue(sbi->rsv_conversion_wq);
 876
 877         if (sbi->s_journal) {
 878                 aborted = is_journal_aborted(sbi->s_journal);
 879                 err = jbd2_journal_destroy(sbi->s_journal);
 880                 sbi->s_journal = NULL;
 881                 if ((err < 0) && !aborted)
 882                         ext4_abort(sb, "Couldn't clean up the journal");
 883         }
 884
 885         ext4_unregister_sysfs(sb);
 886         ext4_es_unregister_shrinker(sbi);
 887         del_timer_sync(&sbi->s_err_report);
 888         ext4_release_system_zone(sb);
 889         ext4_mb_release(sb);
 890         ext4_ext_release(sb);
 891
 892         if (!(sb->s_flags & MS_RDONLY) && !aborted) {
 893                 ext4_clear_feature_journal_needs_recovery(sb);
 894                 es->s_state = cpu_to_le16(sbi->s_mount_state);
 895         }
 896         if (!(sb->s_flags & MS_RDONLY))
 897                 ext4_commit_super(sb, 1);
 898
 899         for (i = 0; i < sbi->s_gdb_count; i++)
 900                 brelse(sbi->s_group_desc[i]);
 901         kvfree(sbi->s_group_desc);
 902         kvfree(sbi->s_flex_groups);
 903         percpu_counter_destroy(&sbi->s_freeclusters_counter);
 904         percpu_counter_destroy(&sbi->s_freeinodes_counter);
 905         percpu_counter_destroy(&sbi->s_dirs_counter);
 906         percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
 907         percpu_free_rwsem(&sbi->s_journal_flag_rwsem);
 908 #ifdef CONFIG_QUOTA
 909         for (i = 0; i < EXT4_MAXQUOTAS; i++)
 910                 kfree(sbi->s_qf_names[i]);
 911 #endif
 912
 913         /* Debugging code just in case the in-memory inode orphan list
 914          * isn't empty.  The on-disk one can be non-empty if we've
 915          * detected an error and taken the fs readonly, but the
 916          * in-memory list had better be clean by this point. */
 917         if (!list_empty(&sbi->s_orphan))
 918                 dump_orphan_list(sb, sbi);
 919         J_ASSERT(list_empty(&sbi->s_orphan));
 920
 921         sync_blockdev(sb->s_bdev);
 922         invalidate_bdev(sb->s_bdev);
 923         if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
 924                 /*
 925                  * Invalidate the journal device's buffers.  We don't want them
 926                  * floating about in memory - the physical journal device may
 927                  * hotswapped, and it breaks the `ro-after' testing code.
 928                  */
 929                 sync_blockdev(sbi->journal_bdev);
 930                 invalidate_bdev(sbi->journal_bdev);
 931                 ext4_blkdev_remove(sbi);
 932         }
 933         if (sbi->s_mb_cache) {
 934                 ext4_xattr_destroy_cache(sbi->s_mb_cache);
 935                 sbi->s_mb_cache = NULL;
 936         }
 937         if (sbi->s_mmp_tsk)
 938                 kthread_stop(sbi->s_mmp_tsk);
 939         brelse(sbi->s_sbh);
 940         sb->s_fs_info = NULL;
 941         /*
 942          * Now that we are completely done shutting down the
 943          * superblock, we need to actually destroy the kobject.
 944          */
 945         kobject_put(&sbi->s_kobj);
 946         wait_for_completion(&sbi->s_kobj_unregister);
 947         if (sbi->s_chksum_driver)
 948                 crypto_free_shash(sbi->s_chksum_driver);
 949         kfree(sbi->s_blockgroup_lock);
 950         kfree(sbi);
 951 }
 952
 953 static struct kmem_cache *ext4_inode_cachep;
 954
 955 /*
 956  * Called inside transaction, so use GFP_NOFS
 957  */
 958 static struct inode *ext4_alloc_inode(struct super_block *sb)
 959 {
 960         struct ext4_inode_info *ei;
 961
 962         ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
 963         if (!ei)
 964                 return NULL;
 965
 966         ei->vfs_inode.i_version = 1;
 967         spin_lock_init(&ei->i_raw_lock);
 968         INIT_LIST_HEAD(&ei->i_prealloc_list);
 969         spin_lock_init(&ei->i_prealloc_lock);
 970         ext4_es_init_tree(&ei->i_es_tree);
 971         rwlock_init(&ei->i_es_lock);
 972         INIT_LIST_HEAD(&ei->i_es_list);
 973         ei->i_es_all_nr = 0;
 974         ei->i_es_shk_nr = 0;
 975         ei->i_es_shrink_lblk = 0;
 976         ei->i_reserved_data_blocks = 0;
 977         ei->i_reserved_meta_blocks = 0;
 978         ei->i_allocated_meta_blocks = 0;
 979         ei->i_da_metadata_calc_len = 0;
 980         ei->i_da_metadata_calc_last_lblock = 0;
 981         spin_lock_init(&(ei->i_block_reservation_lock));
 982 #ifdef CONFIG_QUOTA
 983         ei->i_reserved_quota = 0;
 984         memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
 985 #endif
 986         ei->jinode = NULL;
 987         INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
 988         spin_lock_init(&ei->i_completed_io_lock);
 989         ei->i_sync_tid = 0;
 990         ei->i_datasync_tid = 0;
 991         atomic_set(&ei->i_unwritten, 0);
 992         INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
 993         return &ei->vfs_inode;
 994 }
 995
 996 static int ext4_drop_inode(struct inode *inode)
 997 {
 998         int drop = generic_drop_inode(inode);
 999
1000         trace_ext4_drop_inode(inode, drop);
1001         return drop;
1002 }
1003
1004 static void ext4_i_callback(struct rcu_head *head)
1005 {
1006         struct inode *inode = container_of(head, struct inode, i_rcu);
1007         kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
1008 }
1009
1010 static void ext4_destroy_inode(struct inode *inode)
1011 {
1012         if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
1013                 ext4_msg(inode->i_sb, KERN_ERR,
1014                          "Inode %lu (%p): orphan list check failed!",
1015                          inode->i_ino, EXT4_I(inode));
1016                 print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
1017                                 EXT4_I(inode), sizeof(struct ext4_inode_info),
1018                                 true);
1019                 dump_stack();
1020         }
1021         call_rcu(&inode->i_rcu, ext4_i_callback);
1022 }
1023
1024 static void init_once(void *foo)
1025 {
1026         struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
1027
1028         INIT_LIST_HEAD(&ei->i_orphan);
1029         init_rwsem(&ei->xattr_sem);
1030         init_rwsem(&ei->i_data_sem);
1031         init_rwsem(&ei->i_mmap_sem);
1032         inode_init_once(&ei->vfs_inode);
1033 }
1034
1035 static int __init init_inodecache(void)
1036 {
1037         ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
1038                                              sizeof(struct ext4_inode_info),
1039                                              0, (SLAB_RECLAIM_ACCOUNT|
1040                                                 SLAB_MEM_SPREAD|SLAB_ACCOUNT),
1041                                              init_once);
1042         if (ext4_inode_cachep == NULL)
1043                 return -ENOMEM;
1044         return 0;
1045 }
1046
1047 static void destroy_inodecache(void)
1048 {
1049         /*
1050          * Make sure all delayed rcu free inodes are flushed before we
1051          * destroy cache.
1052          */
1053         rcu_barrier();
1054         kmem_cache_destroy(ext4_inode_cachep);
1055 }
1056
1057 void ext4_clear_inode(struct inode *inode)
1058 {
1059         invalidate_inode_buffers(inode);
1060         clear_inode(inode);
1061         dquot_drop(inode);
1062         ext4_discard_preallocations(inode);
1063         ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
1064         if (EXT4_I(inode)->jinode) {
1065                 jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
1066                                                EXT4_I(inode)->jinode);
1067                 jbd2_free_inode(EXT4_I(inode)->jinode);
1068                 EXT4_I(inode)->jinode = NULL;
1069         }
1070 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1071         fscrypt_put_encryption_info(inode, NULL);
1072 #endif
1073 }
1074
1075 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1076                                         u64 ino, u32 generation)
1077 {
1078         struct inode *inode;
1079
1080         if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
1081                 return ERR_PTR(-ESTALE);
1082         if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
1083                 return ERR_PTR(-ESTALE);
1084
1085         /* iget isn't really right if the inode is currently unallocated!!
1086          *
1087          * ext4_read_inode will return a bad_inode if the inode had been
1088          * deleted, so we should be safe.
1089          *
1090          * Currently we don't know the generation for parent directory, so
1091          * a generation of 0 means "accept any"
1092          */
1093         inode = ext4_iget_normal(sb, ino);
1094         if (IS_ERR(inode))
1095                 return ERR_CAST(inode);
1096         if (generation && inode->i_generation != generation) {
1097                 iput(inode);
1098                 return ERR_PTR(-ESTALE);
1099         }
1100
1101         return inode;
1102 }
1103
1104 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1105                                         int fh_len, int fh_type)
1106 {
1107         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1108                                     ext4_nfs_get_inode);
1109 }
1110
1111 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1112                                         int fh_len, int fh_type)
1113 {
1114         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1115                                     ext4_nfs_get_inode);
1116 }
1117
1118 /*
1119  * Try to release metadata pages (indirect blocks, directories) which are
1120  * mapped via the block device.  Since these pages could have journal heads
1121  * which would prevent try_to_free_buffers() from freeing them, we must use
1122  * jbd2 layer's try_to_free_buffers() function to release them.
1123  */
1124 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1125                                  gfp_t wait)
1126 {
1127         journal_t *journal = EXT4_SB(sb)->s_journal;
1128
1129         WARN_ON(PageChecked(page));
1130         if (!page_has_buffers(page))
1131                 return 0;
1132         if (journal)
1133                 return jbd2_journal_try_to_free_buffers(journal, page,
1134                                                 wait & ~__GFP_DIRECT_RECLAIM);
1135         return try_to_free_buffers(page);
1136 }
1137
1138 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1139 static int ext4_get_context(struct inode *inode, void *ctx, size_t len)
1140 {
1141         return ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION,
1142                                  EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, ctx, len);
1143 }
1144
1145 static int ext4_set_context(struct inode *inode, const void *ctx, size_t len,
1146                                                         void *fs_data)
1147 {
1148         handle_t *handle = fs_data;
1149         int res, res2, retries = 0;
1150
1151         res = ext4_convert_inline_data(inode);
1152         if (res)
1153                 return res;
1154
1155         /*
1156          * If a journal handle was specified, then the encryption context is
1157          * being set on a new inode via inheritance and is part of a larger
1158          * transaction to create the inode.  Otherwise the encryption context is
1159          * being set on an existing inode in its own transaction.  Only in the
1160          * latter case should the "retry on ENOSPC" logic be used.
1161          */
1162
1163         if (handle) {
1164                 res = ext4_xattr_set_handle(handle, inode,
1165                                             EXT4_XATTR_INDEX_ENCRYPTION,
1166                                             EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1167                                             ctx, len, 0);
1168                 if (!res) {
1169                         ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1170                         ext4_clear_inode_state(inode,
1171                                         EXT4_STATE_MAY_INLINE_DATA);
1172                         /*
1173                          * Update inode->i_flags - e.g. S_DAX may get disabled
1174                          */
1175                         ext4_set_inode_flags(inode);
1176                 }
1177                 return res;
1178         }
1179
1180 retry:
1181         handle = ext4_journal_start(inode, EXT4_HT_MISC,
1182                         ext4_jbd2_credits_xattr(inode));
1183         if (IS_ERR(handle))
1184                 return PTR_ERR(handle);
1185
1186         res = ext4_xattr_set_handle(handle, inode, EXT4_XATTR_INDEX_ENCRYPTION,
1187                                     EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1188                                     ctx, len, 0);
1189         if (!res) {
1190                 ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1191                 /* Update inode->i_flags - e.g. S_DAX may get disabled */
1192                 ext4_set_inode_flags(inode);
1193                 res = ext4_mark_inode_dirty(handle, inode);
1194                 if (res)
1195                         EXT4_ERROR_INODE(inode, "Failed to mark inode dirty");
1196         }
1197         res2 = ext4_journal_stop(handle);
1198
1199         if (res == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
1200                 goto retry;
1201         if (!res)
1202                 res = res2;
1203         return res;
1204 }
1205
1206 static int ext4_dummy_context(struct inode *inode)
1207 {
1208         return DUMMY_ENCRYPTION_ENABLED(EXT4_SB(inode->i_sb));
1209 }
1210
1211 static unsigned ext4_max_namelen(struct inode *inode)
1212 {
1213         return S_ISLNK(inode->i_mode) ? inode->i_sb->s_blocksize :
1214                 EXT4_NAME_LEN;
1215 }
1216
1217 static const struct fscrypt_operations ext4_cryptops = {
1218         .key_prefix             = "ext4:",
1219         .get_context            = ext4_get_context,
1220         .set_context            = ext4_set_context,
1221         .dummy_context          = ext4_dummy_context,
1222         .is_encrypted           = ext4_encrypted_inode,
1223         .empty_dir              = ext4_empty_dir,
1224         .max_namelen            = ext4_max_namelen,
1225 };
1226 #else
1227 static const struct fscrypt_operations ext4_cryptops = {
1228         .is_encrypted           = ext4_encrypted_inode,
1229 };
1230 #endif
1231
1232 #ifdef CONFIG_QUOTA
1233 static char *quotatypes[] = INITQFNAMES;
1234 #define QTYPE2NAME(t) (quotatypes[t])
1235
1236 static int ext4_write_dquot(struct dquot *dquot);
1237 static int ext4_acquire_dquot(struct dquot *dquot);
1238 static int ext4_release_dquot(struct dquot *dquot);
1239 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1240 static int ext4_write_info(struct super_block *sb, int type);
1241 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1242                          const struct path *path);
1243 static int ext4_quota_on_mount(struct super_block *sb, int type);
1244 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1245                                size_t len, loff_t off);
1246 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1247                                 const char *data, size_t len, loff_t off);
1248 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1249                              unsigned int flags);
1250 static int ext4_enable_quotas(struct super_block *sb);
1251 static int ext4_get_next_id(struct super_block *sb, struct kqid *qid);
1252
1253 static struct dquot **ext4_get_dquots(struct inode *inode)
1254 {
1255         return EXT4_I(inode)->i_dquot;
1256 }
1257
1258 static const struct dquot_operations ext4_quota_operations = {
1259         .get_reserved_space = ext4_get_reserved_space,
1260         .write_dquot    = ext4_write_dquot,
1261         .acquire_dquot  = ext4_acquire_dquot,
1262         .release_dquot  = ext4_release_dquot,
1263         .mark_dirty     = ext4_mark_dquot_dirty,
1264         .write_info     = ext4_write_info,
1265         .alloc_dquot    = dquot_alloc,
1266         .destroy_dquot  = dquot_destroy,
1267         .get_projid     = ext4_get_projid,
1268         .get_next_id    = ext4_get_next_id,
1269 };
1270
1271 static const struct quotactl_ops ext4_qctl_operations = {
1272         .quota_on       = ext4_quota_on,
1273         .quota_off      = ext4_quota_off,
1274         .quota_sync     = dquot_quota_sync,
1275         .get_state      = dquot_get_state,
1276         .set_info       = dquot_set_dqinfo,
1277         .get_dqblk      = dquot_get_dqblk,
1278         .set_dqblk      = dquot_set_dqblk,
1279         .get_nextdqblk  = dquot_get_next_dqblk,
1280 };
1281 #endif
1282
1283 static const struct super_operations ext4_sops = {
1284         .alloc_inode    = ext4_alloc_inode,
1285         .destroy_inode  = ext4_destroy_inode,
1286         .write_inode    = ext4_write_inode,
1287         .dirty_inode    = ext4_dirty_inode,
1288         .drop_inode     = ext4_drop_inode,
1289         .evict_inode    = ext4_evict_inode,
1290         .put_super      = ext4_put_super,
1291         .sync_fs        = ext4_sync_fs,
1292         .freeze_fs      = ext4_freeze,
1293         .unfreeze_fs    = ext4_unfreeze,
1294         .statfs         = ext4_statfs,
1295         .remount_fs     = ext4_remount,
1296         .show_options   = ext4_show_options,
1297 #ifdef CONFIG_QUOTA
1298         .quota_read     = ext4_quota_read,
1299         .quota_write    = ext4_quota_write,
1300         .get_dquots     = ext4_get_dquots,
1301 #endif
1302         .bdev_try_to_free_page = bdev_try_to_free_page,
1303 };
1304
1305 static const struct export_operations ext4_export_ops = {
1306         .fh_to_dentry = ext4_fh_to_dentry,
1307         .fh_to_parent = ext4_fh_to_parent,
1308         .get_parent = ext4_get_parent,
1309 };
1310
1311 enum {
1312         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1313         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1314         Opt_nouid32, Opt_debug, Opt_removed,
1315         Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1316         Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1317         Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1318         Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1319         Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1320         Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
1321         Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1322         Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1323         Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1324         Opt_usrquota, Opt_grpquota, Opt_prjquota, Opt_i_version, Opt_dax,
1325         Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_mblk_io_submit,
1326         Opt_lazytime, Opt_nolazytime, Opt_debug_want_extra_isize,
1327         Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1328         Opt_inode_readahead_blks, Opt_journal_ioprio,
1329         Opt_dioread_nolock, Opt_dioread_lock,
1330         Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1331         Opt_max_dir_size_kb, Opt_nojournal_checksum,
1332 };
1333
1334 static const match_table_t tokens = {
1335         {Opt_bsd_df, "bsddf"},
1336         {Opt_minix_df, "minixdf"},
1337         {Opt_grpid, "grpid"},
1338         {Opt_grpid, "bsdgroups"},
1339         {Opt_nogrpid, "nogrpid"},
1340         {Opt_nogrpid, "sysvgroups"},
1341         {Opt_resgid, "resgid=%u"},
1342         {Opt_resuid, "resuid=%u"},
1343         {Opt_sb, "sb=%u"},
1344         {Opt_err_cont, "errors=continue"},
1345         {Opt_err_panic, "errors=panic"},
1346         {Opt_err_ro, "errors=remount-ro"},
1347         {Opt_nouid32, "nouid32"},
1348         {Opt_debug, "debug"},
1349         {Opt_removed, "oldalloc"},
1350         {Opt_removed, "orlov"},
1351         {Opt_user_xattr, "user_xattr"},
1352         {Opt_nouser_xattr, "nouser_xattr"},
1353         {Opt_acl, "acl"},
1354         {Opt_noacl, "noacl"},
1355         {Opt_noload, "norecovery"},
1356         {Opt_noload, "noload"},
1357         {Opt_removed, "nobh"},
1358         {Opt_removed, "bh"},
1359         {Opt_commit, "commit=%u"},
1360         {Opt_min_batch_time, "min_batch_time=%u"},
1361         {Opt_max_batch_time, "max_batch_time=%u"},
1362         {Opt_journal_dev, "journal_dev=%u"},
1363         {Opt_journal_path, "journal_path=%s"},
1364         {Opt_journal_checksum, "journal_checksum"},
1365         {Opt_nojournal_checksum, "nojournal_checksum"},
1366         {Opt_journal_async_commit, "journal_async_commit"},
1367         {Opt_abort, "abort"},
1368         {Opt_data_journal, "data=journal"},
1369         {Opt_data_ordered, "data=ordered"},
1370         {Opt_data_writeback, "data=writeback"},
1371         {Opt_data_err_abort, "data_err=abort"},
1372         {Opt_data_err_ignore, "data_err=ignore"},
1373         {Opt_offusrjquota, "usrjquota="},
1374         {Opt_usrjquota, "usrjquota=%s"},
1375         {Opt_offgrpjquota, "grpjquota="},
1376         {Opt_grpjquota, "grpjquota=%s"},
1377         {Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1378         {Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1379         {Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1380         {Opt_grpquota, "grpquota"},
1381         {Opt_noquota, "noquota"},
1382         {Opt_quota, "quota"},
1383         {Opt_usrquota, "usrquota"},
1384         {Opt_prjquota, "prjquota"},
1385         {Opt_barrier, "barrier=%u"},
1386         {Opt_barrier, "barrier"},
1387         {Opt_nobarrier, "nobarrier"},
1388         {Opt_i_version, "i_version"},
1389         {Opt_dax, "dax"},
1390         {Opt_stripe, "stripe=%u"},
1391         {Opt_delalloc, "delalloc"},
1392         {Opt_lazytime, "lazytime"},
1393         {Opt_nolazytime, "nolazytime"},
1394         {Opt_debug_want_extra_isize, "debug_want_extra_isize=%u"},
1395         {Opt_nodelalloc, "nodelalloc"},
1396         {Opt_removed, "mblk_io_submit"},
1397         {Opt_removed, "nomblk_io_submit"},
1398         {Opt_block_validity, "block_validity"},
1399         {Opt_noblock_validity, "noblock_validity"},
1400         {Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1401         {Opt_journal_ioprio, "journal_ioprio=%u"},
1402         {Opt_auto_da_alloc, "auto_da_alloc=%u"},
1403         {Opt_auto_da_alloc, "auto_da_alloc"},
1404         {Opt_noauto_da_alloc, "noauto_da_alloc"},
1405         {Opt_dioread_nolock, "dioread_nolock"},
1406         {Opt_dioread_lock, "dioread_lock"},
1407         {Opt_discard, "discard"},
1408         {Opt_nodiscard, "nodiscard"},
1409         {Opt_init_itable, "init_itable=%u"},
1410         {Opt_init_itable, "init_itable"},
1411         {Opt_noinit_itable, "noinit_itable"},
1412         {Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1413         {Opt_test_dummy_encryption, "test_dummy_encryption"},
1414         {Opt_removed, "check=none"},    /* mount option from ext2/3 */
1415         {Opt_removed, "nocheck"},       /* mount option from ext2/3 */
1416         {Opt_removed, "reservation"},   /* mount option from ext2/3 */
1417         {Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1418         {Opt_removed, "journal=%u"},    /* mount option from ext2/3 */
1419         {Opt_err, NULL},
1420 };
1421
1422 static ext4_fsblk_t get_sb_block(void **data)
1423 {
1424         ext4_fsblk_t    sb_block;
1425         char            *options = (char *) *data;
1426
1427         if (!options || strncmp(options, "sb=", 3) != 0)
1428                 return 1;       /* Default location */
1429
1430         options += 3;
1431         /* TODO: use simple_strtoll with >32bit ext4 */
1432         sb_block = simple_strtoul(options, &options, 0);
1433         if (*options && *options != ',') {
1434                 printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1435                        (char *) *data);
1436                 return 1;
1437         }
1438         if (*options == ',')
1439                 options++;
1440         *data = (void *) options;
1441
1442         return sb_block;
1443 }
1444
1445 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1446 static char deprecated_msg[] = "Mount option \"%s\" will be removed by %s\n"
1447         "Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1448
1449 #ifdef CONFIG_QUOTA
1450 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1451 {
1452         struct ext4_sb_info *sbi = EXT4_SB(sb);
1453         char *qname;
1454         int ret = -1;
1455
1456         if (sb_any_quota_loaded(sb) &&
1457                 !sbi->s_qf_names[qtype]) {
1458                 ext4_msg(sb, KERN_ERR,
1459                         "Cannot change journaled "
1460                         "quota options when quota turned on");
1461                 return -1;
1462         }
1463         if (ext4_has_feature_quota(sb)) {
1464                 ext4_msg(sb, KERN_INFO, "Journaled quota options "
1465                          "ignored when QUOTA feature is enabled");
1466                 return 1;
1467         }
1468         qname = match_strdup(args);
1469         if (!qname) {
1470                 ext4_msg(sb, KERN_ERR,
1471                         "Not enough memory for storing quotafile name");
1472                 return -1;
1473         }
1474         if (sbi->s_qf_names[qtype]) {
1475                 if (strcmp(sbi->s_qf_names[qtype], qname) == 0)
1476                         ret = 1;
1477                 else
1478                         ext4_msg(sb, KERN_ERR,
1479                                  "%s quota file already specified",
1480                                  QTYPE2NAME(qtype));
1481                 goto errout;
1482         }
1483         if (strchr(qname, '/')) {
1484                 ext4_msg(sb, KERN_ERR,
1485                         "quotafile must be on filesystem root");
1486                 goto errout;
1487         }
1488         sbi->s_qf_names[qtype] = qname;
1489         set_opt(sb, QUOTA);
1490         return 1;
1491 errout:
1492         kfree(qname);
1493         return ret;
1494 }
1495
1496 static int clear_qf_name(struct super_block *sb, int qtype)
1497 {
1498
1499         struct ext4_sb_info *sbi = EXT4_SB(sb);
1500
1501         if (sb_any_quota_loaded(sb) &&
1502                 sbi->s_qf_names[qtype]) {
1503                 ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1504                         " when quota turned on");
1505                 return -1;
1506         }
1507         kfree(sbi->s_qf_names[qtype]);
1508         sbi->s_qf_names[qtype] = NULL;
1509         return 1;
1510 }
1511 #endif
1512
1513 #define MOPT_SET        0x0001
1514 #define MOPT_CLEAR      0x0002
1515 #define MOPT_NOSUPPORT  0x0004
1516 #define MOPT_EXPLICIT   0x0008
1517 #define MOPT_CLEAR_ERR  0x0010
1518 #define MOPT_GTE0       0x0020
1519 #ifdef CONFIG_QUOTA
1520 #define MOPT_Q          0
1521 #define MOPT_QFMT       0x0040
1522 #else
1523 #define MOPT_Q          MOPT_NOSUPPORT
1524 #define MOPT_QFMT       MOPT_NOSUPPORT
1525 #endif
1526 #define MOPT_DATAJ      0x0080
1527 #define MOPT_NO_EXT2    0x0100
1528 #define MOPT_NO_EXT3    0x0200
1529 #define MOPT_EXT4_ONLY  (MOPT_NO_EXT2 | MOPT_NO_EXT3)
1530 #define MOPT_STRING     0x0400
1531
1532 static const struct mount_opts {
1533         int     token;
1534         int     mount_opt;
1535         int     flags;
1536 } ext4_mount_opts[] = {
1537         {Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1538         {Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1539         {Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1540         {Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1541         {Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1542         {Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1543         {Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1544          MOPT_EXT4_ONLY | MOPT_SET},
1545         {Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1546          MOPT_EXT4_ONLY | MOPT_CLEAR},
1547         {Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1548         {Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1549         {Opt_delalloc, EXT4_MOUNT_DELALLOC,
1550          MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1551         {Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1552          MOPT_EXT4_ONLY | MOPT_CLEAR},
1553         {Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1554          MOPT_EXT4_ONLY | MOPT_CLEAR},
1555         {Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1556          MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1557         {Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1558                                     EXT4_MOUNT_JOURNAL_CHECKSUM),
1559          MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1560         {Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1561         {Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1562         {Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1563         {Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1564         {Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
1565          MOPT_NO_EXT2},
1566         {Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
1567          MOPT_NO_EXT2},
1568         {Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1569         {Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1570         {Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1571         {Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1572         {Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1573         {Opt_commit, 0, MOPT_GTE0},
1574         {Opt_max_batch_time, 0, MOPT_GTE0},
1575         {Opt_min_batch_time, 0, MOPT_GTE0},
1576         {Opt_inode_readahead_blks, 0, MOPT_GTE0},
1577         {Opt_init_itable, 0, MOPT_GTE0},
1578         {Opt_dax, EXT4_MOUNT_DAX, MOPT_SET},
1579         {Opt_stripe, 0, MOPT_GTE0},
1580         {Opt_resuid, 0, MOPT_GTE0},
1581         {Opt_resgid, 0, MOPT_GTE0},
1582         {Opt_journal_dev, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1583         {Opt_journal_path, 0, MOPT_NO_EXT2 | MOPT_STRING},
1584         {Opt_journal_ioprio, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1585         {Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1586         {Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1587         {Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
1588          MOPT_NO_EXT2 | MOPT_DATAJ},
1589         {Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1590         {Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1591 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1592         {Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1593         {Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1594 #else
1595         {Opt_acl, 0, MOPT_NOSUPPORT},
1596         {Opt_noacl, 0, MOPT_NOSUPPORT},
1597 #endif
1598         {Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1599         {Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1600         {Opt_debug_want_extra_isize, 0, MOPT_GTE0},
1601         {Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1602         {Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1603                                                         MOPT_SET | MOPT_Q},
1604         {Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1605                                                         MOPT_SET | MOPT_Q},
1606         {Opt_prjquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_PRJQUOTA,
1607                                                         MOPT_SET | MOPT_Q},
1608         {Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1609                        EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA),
1610                                                         MOPT_CLEAR | MOPT_Q},
1611         {Opt_usrjquota, 0, MOPT_Q},
1612         {Opt_grpjquota, 0, MOPT_Q},
1613         {Opt_offusrjquota, 0, MOPT_Q},
1614         {Opt_offgrpjquota, 0, MOPT_Q},
1615         {Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1616         {Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1617         {Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1618         {Opt_max_dir_size_kb, 0, MOPT_GTE0},
1619         {Opt_test_dummy_encryption, 0, MOPT_GTE0},
1620         {Opt_err, 0, 0}
1621 };
1622
1623 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1624                             substring_t *args, unsigned long *journal_devnum,
1625                             unsigned int *journal_ioprio, int is_remount)
1626 {
1627         struct ext4_sb_info *sbi = EXT4_SB(sb);
1628         const struct mount_opts *m;
1629         kuid_t uid;
1630         kgid_t gid;
1631         int arg = 0;
1632
1633 #ifdef CONFIG_QUOTA
1634         if (token == Opt_usrjquota)
1635                 return set_qf_name(sb, USRQUOTA, &args[0]);
1636         else if (token == Opt_grpjquota)
1637                 return set_qf_name(sb, GRPQUOTA, &args[0]);
1638         else if (token == Opt_offusrjquota)
1639                 return clear_qf_name(sb, USRQUOTA);
1640         else if (token == Opt_offgrpjquota)
1641                 return clear_qf_name(sb, GRPQUOTA);
1642 #endif
1643         switch (token) {
1644         case Opt_noacl:
1645         case Opt_nouser_xattr:
1646                 ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1647                 break;
1648         case Opt_sb:
1649                 return 1;       /* handled by get_sb_block() */
1650         case Opt_removed:
1651                 ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
1652                 return 1;
1653         case Opt_abort:
1654                 sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1655                 return 1;
1656         case Opt_i_version:
1657                 sb->s_flags |= MS_I_VERSION;
1658                 return 1;
1659         case Opt_lazytime:
1660                 sb->s_flags |= MS_LAZYTIME;
1661                 return 1;
1662         case Opt_nolazytime:
1663                 sb->s_flags &= ~MS_LAZYTIME;
1664                 return 1;
1665         }
1666
1667         for (m = ext4_mount_opts; m->token != Opt_err; m++)
1668                 if (token == m->token)
1669                         break;
1670
1671         if (m->token == Opt_err) {
1672                 ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1673                          "or missing value", opt);
1674                 return -1;
1675         }
1676
1677         if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
1678                 ext4_msg(sb, KERN_ERR,
1679                          "Mount option \"%s\" incompatible with ext2", opt);
1680                 return -1;
1681         }
1682         if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
1683                 ext4_msg(sb, KERN_ERR,
1684                          "Mount option \"%s\" incompatible with ext3", opt);
1685                 return -1;
1686         }
1687
1688         if (args->from && !(m->flags & MOPT_STRING) && match_int(args, &arg))
1689                 return -1;
1690         if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1691                 return -1;
1692         if (m->flags & MOPT_EXPLICIT) {
1693                 if (m->mount_opt & EXT4_MOUNT_DELALLOC) {
1694                         set_opt2(sb, EXPLICIT_DELALLOC);
1695                 } else if (m->mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) {
1696                         set_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM);
1697                 } else
1698                         return -1;
1699         }
1700         if (m->flags & MOPT_CLEAR_ERR)
1701                 clear_opt(sb, ERRORS_MASK);
1702         if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1703                 ext4_msg(sb, KERN_ERR, "Cannot change quota "
1704                          "options when quota turned on");
1705                 return -1;
1706         }
1707
1708         if (m->flags & MOPT_NOSUPPORT) {
1709                 ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1710         } else if (token == Opt_commit) {
1711                 if (arg == 0)
1712                         arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1713                 sbi->s_commit_interval = HZ * arg;
1714         } else if (token == Opt_debug_want_extra_isize) {
1715                 sbi->s_want_extra_isize = arg;
1716         } else if (token == Opt_max_batch_time) {
1717                 sbi->s_max_batch_time = arg;
1718         } else if (token == Opt_min_batch_time) {
1719                 sbi->s_min_batch_time = arg;
1720         } else if (token == Opt_inode_readahead_blks) {
1721                 if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
1722                         ext4_msg(sb, KERN_ERR,
1723                                  "EXT4-fs: inode_readahead_blks must be "
1724                                  "0 or a power of 2 smaller than 2^31");
1725                         return -1;
1726                 }
1727                 sbi->s_inode_readahead_blks = arg;
1728         } else if (token == Opt_init_itable) {
1729                 set_opt(sb, INIT_INODE_TABLE);
1730                 if (!args->from)
1731                         arg = EXT4_DEF_LI_WAIT_MULT;
1732                 sbi->s_li_wait_mult = arg;
1733         } else if (token == Opt_max_dir_size_kb) {
1734                 sbi->s_max_dir_size_kb = arg;
1735         } else if (token == Opt_stripe) {
1736                 sbi->s_stripe = arg;
1737         } else if (token == Opt_resuid) {
1738                 uid = make_kuid(current_user_ns(), arg);
1739                 if (!uid_valid(uid)) {
1740                         ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
1741                         return -1;
1742                 }
1743                 sbi->s_resuid = uid;
1744         } else if (token == Opt_resgid) {
1745                 gid = make_kgid(current_user_ns(), arg);
1746                 if (!gid_valid(gid)) {
1747                         ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
1748                         return -1;
1749                 }
1750                 sbi->s_resgid = gid;
1751         } else if (token == Opt_journal_dev) {
1752                 if (is_remount) {
1753                         ext4_msg(sb, KERN_ERR,
1754                                  "Cannot specify journal on remount");
1755                         return -1;
1756                 }
1757                 *journal_devnum = arg;
1758         } else if (token == Opt_journal_path) {
1759                 char *journal_path;
1760                 struct inode *journal_inode;
1761                 struct path path;
1762                 int error;
1763
1764                 if (is_remount) {
1765                         ext4_msg(sb, KERN_ERR,
1766                                  "Cannot specify journal on remount");
1767                         return -1;
1768                 }
1769                 journal_path = match_strdup(&args[0]);
1770                 if (!journal_path) {
1771                         ext4_msg(sb, KERN_ERR, "error: could not dup "
1772                                 "journal device string");
1773                         return -1;
1774                 }
1775
1776                 error = kern_path(journal_path, LOOKUP_FOLLOW, &path);
1777                 if (error) {
1778                         ext4_msg(sb, KERN_ERR, "error: could not find "
1779                                 "journal device path: error %d", error);
1780                         kfree(journal_path);
1781                         return -1;
1782                 }
1783
1784                 journal_inode = d_inode(path.dentry);
1785                 if (!S_ISBLK(journal_inode->i_mode)) {
1786                         ext4_msg(sb, KERN_ERR, "error: journal path %s "
1787                                 "is not a block device", journal_path);
1788                         path_put(&path);
1789                         kfree(journal_path);
1790                         return -1;
1791                 }
1792
1793                 *journal_devnum = new_encode_dev(journal_inode->i_rdev);
1794                 path_put(&path);
1795                 kfree(journal_path);
1796         } else if (token == Opt_journal_ioprio) {
1797                 if (arg > 7) {
1798                         ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
1799                                  " (must be 0-7)");
1800                         return -1;
1801                 }
1802                 *journal_ioprio =
1803                         IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
1804         } else if (token == Opt_test_dummy_encryption) {
1805 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1806                 sbi->s_mount_flags |= EXT4_MF_TEST_DUMMY_ENCRYPTION;
1807                 ext4_msg(sb, KERN_WARNING,
1808                          "Test dummy encryption mode enabled");
1809 #else
1810                 ext4_msg(sb, KERN_WARNING,
1811                          "Test dummy encryption mount option ignored");
1812 #endif
1813         } else if (m->flags & MOPT_DATAJ) {
1814                 if (is_remount) {
1815                         if (!sbi->s_journal)
1816                                 ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
1817                         else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
1818                                 ext4_msg(sb, KERN_ERR,
1819                                          "Cannot change data mode on remount");
1820                                 return -1;
1821                         }
1822                 } else {
1823                         clear_opt(sb, DATA_FLAGS);
1824                         sbi->s_mount_opt |= m->mount_opt;
1825                 }
1826 #ifdef CONFIG_QUOTA
1827         } else if (m->flags & MOPT_QFMT) {
1828                 if (sb_any_quota_loaded(sb) &&
1829                     sbi->s_jquota_fmt != m->mount_opt) {
1830                         ext4_msg(sb, KERN_ERR, "Cannot change journaled "
1831                                  "quota options when quota turned on");
1832                         return -1;
1833                 }
1834                 if (ext4_has_feature_quota(sb)) {
1835                         ext4_msg(sb, KERN_INFO,
1836                                  "Quota format mount options ignored "
1837                                  "when QUOTA feature is enabled");
1838                         return 1;
1839                 }
1840                 sbi->s_jquota_fmt = m->mount_opt;
1841 #endif
1842         } else if (token == Opt_dax) {
1843 #ifdef CONFIG_FS_DAX
1844                 ext4_msg(sb, KERN_WARNING,
1845                 "DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
1846                         sbi->s_mount_opt |= m->mount_opt;
1847 #else
1848                 ext4_msg(sb, KERN_INFO, "dax option not supported");
1849                 return -1;
1850 #endif
1851         } else if (token == Opt_data_err_abort) {
1852                 sbi->s_mount_opt |= m->mount_opt;
1853         } else if (token == Opt_data_err_ignore) {
1854                 sbi->s_mount_opt &= ~m->mount_opt;
1855         } else {
1856                 if (!args->from)
1857                         arg = 1;
1858                 if (m->flags & MOPT_CLEAR)
1859                         arg = !arg;
1860                 else if (unlikely(!(m->flags & MOPT_SET))) {
1861                         ext4_msg(sb, KERN_WARNING,
1862                                  "buggy handling of option %s", opt);
1863                         WARN_ON(1);
1864                         return -1;
1865                 }
1866                 if (arg != 0)
1867                         sbi->s_mount_opt |= m->mount_opt;
1868                 else
1869                         sbi->s_mount_opt &= ~m->mount_opt;
1870         }
1871         return 1;
1872 }
1873
1874 static int parse_options(char *options, struct super_block *sb,
1875                          unsigned long *journal_devnum,
1876                          unsigned int *journal_ioprio,
1877                          int is_remount)
1878 {
1879         struct ext4_sb_info *sbi = EXT4_SB(sb);
1880         char *p;
1881         substring_t args[MAX_OPT_ARGS];
1882         int token;
1883
1884         if (!options)
1885                 return 1;
1886
1887         while ((p = strsep(&options, ",")) != NULL) {
1888                 if (!*p)
1889                         continue;
1890                 /*
1891                  * Initialize args struct so we know whether arg was
1892                  * found; some options take optional arguments.
1893                  */
1894                 args[0].to = args[0].from = NULL;
1895                 token = match_token(p, tokens, args);
1896                 if (handle_mount_opt(sb, p, token, args, journal_devnum,
1897                                      journal_ioprio, is_remount) < 0)
1898                         return 0;
1899         }
1900 #ifdef CONFIG_QUOTA
1901         /*
1902          * We do the test below only for project quotas. 'usrquota' and
1903          * 'grpquota' mount options are allowed even without quota feature
1904          * to support legacy quotas in quota files.
1905          */
1906         if (test_opt(sb, PRJQUOTA) && !ext4_has_feature_project(sb)) {
1907                 ext4_msg(sb, KERN_ERR, "Project quota feature not enabled. "
1908                          "Cannot enable project quota enforcement.");
1909                 return 0;
1910         }
1911         if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1912                 if (test_opt(sb, USRQUOTA) && sbi->s_qf_names[USRQUOTA])
1913                         clear_opt(sb, USRQUOTA);
1914
1915                 if (test_opt(sb, GRPQUOTA) && sbi->s_qf_names[GRPQUOTA])
1916                         clear_opt(sb, GRPQUOTA);
1917
1918                 if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
1919                         ext4_msg(sb, KERN_ERR, "old and new quota "
1920                                         "format mixing");
1921                         return 0;
1922                 }
1923
1924                 if (!sbi->s_jquota_fmt) {
1925                         ext4_msg(sb, KERN_ERR, "journaled quota format "
1926                                         "not specified");
1927                         return 0;
1928                 }
1929         }
1930 #endif
1931         if (test_opt(sb, DIOREAD_NOLOCK)) {
1932                 int blocksize =
1933                         BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
1934
1935                 if (blocksize < PAGE_SIZE) {
1936                         ext4_msg(sb, KERN_ERR, "can't mount with "
1937                                  "dioread_nolock if block size != PAGE_SIZE");
1938                         return 0;
1939                 }
1940         }
1941         return 1;
1942 }
1943
1944 static inline void ext4_show_quota_options(struct seq_file *seq,
1945                                            struct super_block *sb)
1946 {
1947 #if defined(CONFIG_QUOTA)
1948         struct ext4_sb_info *sbi = EXT4_SB(sb);
1949
1950         if (sbi->s_jquota_fmt) {
1951                 char *fmtname = "";
1952
1953                 switch (sbi->s_jquota_fmt) {
1954                 case QFMT_VFS_OLD:
1955                         fmtname = "vfsold";
1956                         break;
1957                 case QFMT_VFS_V0:
1958                         fmtname = "vfsv0";
1959                         break;
1960                 case QFMT_VFS_V1:
1961                         fmtname = "vfsv1";
1962                         break;
1963                 }
1964                 seq_printf(seq, ",jqfmt=%s", fmtname);
1965         }
1966
1967         if (sbi->s_qf_names[USRQUOTA])
1968                 seq_show_option(seq, "usrjquota", sbi->s_qf_names[USRQUOTA]);
1969
1970         if (sbi->s_qf_names[GRPQUOTA])
1971                 seq_show_option(seq, "grpjquota", sbi->s_qf_names[GRPQUOTA]);
1972 #endif
1973 }
1974
1975 static const char *token2str(int token)
1976 {
1977         const struct match_token *t;
1978
1979         for (t = tokens; t->token != Opt_err; t++)
1980                 if (t->token == token && !strchr(t->pattern, '='))
1981                         break;
1982         return t->pattern;
1983 }
1984
1985 /*
1986  * Show an option if
1987  *  - it's set to a non-default value OR
1988  *  - if the per-sb default is different from the global default
1989  */
1990 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
1991                               int nodefs)
1992 {
1993         struct ext4_sb_info *sbi = EXT4_SB(sb);
1994         struct ext4_super_block *es = sbi->s_es;
1995         int def_errors, def_mount_opt = nodefs ? 0 : sbi->s_def_mount_opt;
1996         const struct mount_opts *m;
1997         char sep = nodefs ? '\n' : ',';
1998
1999 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
2000 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
2001
2002         if (sbi->s_sb_block != 1)
2003                 SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
2004
2005         for (m = ext4_mount_opts; m->token != Opt_err; m++) {
2006                 int want_set = m->flags & MOPT_SET;
2007                 if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
2008                     (m->flags & MOPT_CLEAR_ERR))
2009                         continue;
2010                 if (!(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
2011                         continue; /* skip if same as the default */
2012                 if ((want_set &&
2013                      (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
2014                     (!want_set && (sbi->s_mount_opt & m->mount_opt)))
2015                         continue; /* select Opt_noFoo vs Opt_Foo */
2016                 SEQ_OPTS_PRINT("%s", token2str(m->token));
2017         }
2018
2019         if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
2020             le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
2021                 SEQ_OPTS_PRINT("resuid=%u",
2022                                 from_kuid_munged(&init_user_ns, sbi->s_resuid));
2023         if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
2024             le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
2025                 SEQ_OPTS_PRINT("resgid=%u",
2026                                 from_kgid_munged(&init_user_ns, sbi->s_resgid));
2027         def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
2028         if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
2029                 SEQ_OPTS_PUTS("errors=remount-ro");
2030         if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
2031                 SEQ_OPTS_PUTS("errors=continue");
2032         if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
2033                 SEQ_OPTS_PUTS("errors=panic");
2034         if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
2035                 SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
2036         if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
2037                 SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
2038         if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
2039                 SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
2040         if (sb->s_flags & MS_I_VERSION)
2041                 SEQ_OPTS_PUTS("i_version");
2042         if (nodefs || sbi->s_stripe)
2043                 SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
2044         if (EXT4_MOUNT_DATA_FLAGS & (sbi->s_mount_opt ^ def_mount_opt)) {
2045                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
2046                         SEQ_OPTS_PUTS("data=journal");
2047                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
2048                         SEQ_OPTS_PUTS("data=ordered");
2049                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
2050                         SEQ_OPTS_PUTS("data=writeback");
2051         }
2052         if (nodefs ||
2053             sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
2054                 SEQ_OPTS_PRINT("inode_readahead_blks=%u",
2055                                sbi->s_inode_readahead_blks);
2056
2057         if (nodefs || (test_opt(sb, INIT_INODE_TABLE) &&
2058                        (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
2059                 SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
2060         if (nodefs || sbi->s_max_dir_size_kb)
2061                 SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
2062         if (test_opt(sb, DATA_ERR_ABORT))
2063                 SEQ_OPTS_PUTS("data_err=abort");
2064
2065         ext4_show_quota_options(seq, sb);
2066         return 0;
2067 }
2068
2069 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
2070 {
2071         return _ext4_show_options(seq, root->d_sb, 0);
2072 }
2073
2074 int ext4_seq_options_show(struct seq_file *seq, void *offset)
2075 {
2076         struct super_block *sb = seq->private;
2077         int rc;
2078
2079         seq_puts(seq, (sb->s_flags & MS_RDONLY) ? "ro" : "rw");
2080         rc = _ext4_show_options(seq, sb, 1);
2081         seq_puts(seq, "\n");
2082         return rc;
2083 }
2084
2085 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
2086                             int read_only)
2087 {
2088         struct ext4_sb_info *sbi = EXT4_SB(sb);
2089         int res = 0;
2090
2091         if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
2092                 ext4_msg(sb, KERN_ERR, "revision level too high, "
2093                          "forcing read-only mode");
2094                 res = MS_RDONLY;
2095         }
2096         if (read_only)
2097                 goto done;
2098         if (!(sbi->s_mount_state & EXT4_VALID_FS))
2099                 ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
2100                          "running e2fsck is recommended");
2101         else if (sbi->s_mount_state & EXT4_ERROR_FS)
2102                 ext4_msg(sb, KERN_WARNING,
2103                          "warning: mounting fs with errors, "
2104                          "running e2fsck is recommended");
2105         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
2106                  le16_to_cpu(es->s_mnt_count) >=
2107                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
2108                 ext4_msg(sb, KERN_WARNING,
2109                          "warning: maximal mount count reached, "
2110                          "running e2fsck is recommended");
2111         else if (le32_to_cpu(es->s_checkinterval) &&
2112                 (le32_to_cpu(es->s_lastcheck) +
2113                         le32_to_cpu(es->s_checkinterval) <= get_seconds()))
2114                 ext4_msg(sb, KERN_WARNING,
2115                          "warning: checktime reached, "
2116                          "running e2fsck is recommended");
2117         if (!sbi->s_journal)
2118                 es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
2119         if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
2120                 es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
2121         le16_add_cpu(&es->s_mnt_count, 1);
2122         es->s_mtime = cpu_to_le32(get_seconds());
2123         ext4_update_dynamic_rev(sb);
2124         if (sbi->s_journal)
2125                 ext4_set_feature_journal_needs_recovery(sb);
2126
2127         ext4_commit_super(sb, 1);
2128 done:
2129         if (test_opt(sb, DEBUG))
2130                 printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
2131                                 "bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
2132                         sb->s_blocksize,
2133                         sbi->s_groups_count,
2134                         EXT4_BLOCKS_PER_GROUP(sb),
2135                         EXT4_INODES_PER_GROUP(sb),
2136                         sbi->s_mount_opt, sbi->s_mount_opt2);
2137
2138         cleancache_init_fs(sb);
2139         return res;
2140 }
2141
2142 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
2143 {
2144         struct ext4_sb_info *sbi = EXT4_SB(sb);
2145         struct flex_groups *new_groups;
2146         int size;
2147
2148         if (!sbi->s_log_groups_per_flex)
2149                 return 0;
2150
2151         size = ext4_flex_group(sbi, ngroup - 1) + 1;
2152         if (size <= sbi->s_flex_groups_allocated)
2153                 return 0;
2154
2155         size = roundup_pow_of_two(size * sizeof(struct flex_groups));
2156         new_groups = ext4_kvzalloc(size, GFP_KERNEL);
2157         if (!new_groups) {
2158                 ext4_msg(sb, KERN_ERR, "not enough memory for %d flex groups",
2159                          size / (int) sizeof(struct flex_groups));
2160                 return -ENOMEM;
2161         }
2162
2163         if (sbi->s_flex_groups) {
2164                 memcpy(new_groups, sbi->s_flex_groups,
2165                        (sbi->s_flex_groups_allocated *
2166                         sizeof(struct flex_groups)));
2167                 kvfree(sbi->s_flex_groups);
2168         }
2169         sbi->s_flex_groups = new_groups;
2170         sbi->s_flex_groups_allocated = size / sizeof(struct flex_groups);
2171         return 0;
2172 }
2173
2174 static int ext4_fill_flex_info(struct super_block *sb)
2175 {
2176         struct ext4_sb_info *sbi = EXT4_SB(sb);
2177         struct ext4_group_desc *gdp = NULL;
2178         ext4_group_t flex_group;
2179         int i, err;
2180
2181         sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
2182         if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
2183                 sbi->s_log_groups_per_flex = 0;
2184                 return 1;
2185         }
2186
2187         err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
2188         if (err)
2189                 goto failed;
2190
2191         for (i = 0; i < sbi->s_groups_count; i++) {
2192                 gdp = ext4_get_group_desc(sb, i, NULL);
2193
2194                 flex_group = ext4_flex_group(sbi, i);
2195                 atomic_add(ext4_free_inodes_count(sb, gdp),
2196                            &sbi->s_flex_groups[flex_group].free_inodes);
2197                 atomic64_add(ext4_free_group_clusters(sb, gdp),
2198                              &sbi->s_flex_groups[flex_group].free_clusters);
2199                 atomic_add(ext4_used_dirs_count(sb, gdp),
2200                            &sbi->s_flex_groups[flex_group].used_dirs);
2201         }
2202
2203         return 1;
2204 failed:
2205         return 0;
2206 }
2207
2208 static __le16 ext4_group_desc_csum(struct super_block *sb, __u32 block_group,
2209                                    struct ext4_group_desc *gdp)
2210 {
2211         int offset = offsetof(struct ext4_group_desc, bg_checksum);
2212         __u16 crc = 0;
2213         __le32 le_group = cpu_to_le32(block_group);
2214         struct ext4_sb_info *sbi = EXT4_SB(sb);
2215
2216         if (ext4_has_metadata_csum(sbi->s_sb)) {
2217                 /* Use new metadata_csum algorithm */
2218                 __u32 csum32;
2219                 __u16 dummy_csum = 0;
2220
2221                 csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
2222                                      sizeof(le_group));
2223                 csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp, offset);
2224                 csum32 = ext4_chksum(sbi, csum32, (__u8 *)&dummy_csum,
2225                                      sizeof(dummy_csum));
2226                 offset += sizeof(dummy_csum);
2227                 if (offset < sbi->s_desc_size)
2228                         csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp + offset,
2229                                              sbi->s_desc_size - offset);
2230
2231                 crc = csum32 & 0xFFFF;
2232                 goto out;
2233         }
2234
2235         /* old crc16 code */
2236         if (!ext4_has_feature_gdt_csum(sb))
2237                 return 0;
2238
2239         crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2240         crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2241         crc = crc16(crc, (__u8 *)gdp, offset);
2242         offset += sizeof(gdp->bg_checksum); /* skip checksum */
2243         /* for checksum of struct ext4_group_desc do the rest...*/
2244         if (ext4_has_feature_64bit(sb) &&
2245             offset < le16_to_cpu(sbi->s_es->s_desc_size))
2246                 crc = crc16(crc, (__u8 *)gdp + offset,
2247                             le16_to_cpu(sbi->s_es->s_desc_size) -
2248                                 offset);
2249
2250 out:
2251         return cpu_to_le16(crc);
2252 }
2253
2254 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2255                                 struct ext4_group_desc *gdp)
2256 {
2257         if (ext4_has_group_desc_csum(sb) &&
2258             (gdp->bg_checksum != ext4_group_desc_csum(sb, block_group, gdp)))
2259                 return 0;
2260
2261         return 1;
2262 }
2263
2264 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2265                               struct ext4_group_desc *gdp)
2266 {
2267         if (!ext4_has_group_desc_csum(sb))
2268                 return;
2269         gdp->bg_checksum = ext4_group_desc_csum(sb, block_group, gdp);
2270 }
2271
2272 /* Called at mount-time, super-block is locked */
2273 static int ext4_check_descriptors(struct super_block *sb,
2274                                   ext4_fsblk_t sb_block,
2275                                   ext4_group_t *first_not_zeroed)
2276 {
2277         struct ext4_sb_info *sbi = EXT4_SB(sb);
2278         ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2279         ext4_fsblk_t last_block;
2280         ext4_fsblk_t block_bitmap;
2281         ext4_fsblk_t inode_bitmap;
2282         ext4_fsblk_t inode_table;
2283         int flexbg_flag = 0;
2284         ext4_group_t i, grp = sbi->s_groups_count;
2285
2286         if (ext4_has_feature_flex_bg(sb))
2287                 flexbg_flag = 1;
2288
2289         ext4_debug("Checking group descriptors");
2290
2291         for (i = 0; i < sbi->s_groups_count; i++) {
2292                 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2293
2294                 if (i == sbi->s_groups_count - 1 || flexbg_flag)
2295                         last_block = ext4_blocks_count(sbi->s_es) - 1;
2296                 else
2297                         last_block = first_block +
2298                                 (EXT4_BLOCKS_PER_GROUP(sb) - 1);
2299
2300                 if ((grp == sbi->s_groups_count) &&
2301                    !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2302                         grp = i;
2303
2304                 block_bitmap = ext4_block_bitmap(sb, gdp);
2305                 if (block_bitmap == sb_block) {
2306                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2307                                  "Block bitmap for group %u overlaps "
2308                                  "superblock", i);
2309                 }
2310                 if (block_bitmap < first_block || block_bitmap > last_block) {
2311                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2312                                "Block bitmap for group %u not in group "
2313                                "(block %llu)!", i, block_bitmap);
2314                         return 0;
2315                 }
2316                 inode_bitmap = ext4_inode_bitmap(sb, gdp);
2317                 if (inode_bitmap == sb_block) {
2318                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2319                                  "Inode bitmap for group %u overlaps "
2320                                  "superblock", i);
2321                 }
2322                 if (inode_bitmap < first_block || inode_bitmap > last_block) {
2323                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2324                                "Inode bitmap for group %u not in group "
2325                                "(block %llu)!", i, inode_bitmap);
2326                         return 0;
2327                 }
2328                 inode_table = ext4_inode_table(sb, gdp);
2329                 if (inode_table == sb_block) {
2330                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2331                                  "Inode table for group %u overlaps "
2332                                  "superblock", i);
2333                 }
2334                 if (inode_table < first_block ||
2335                     inode_table + sbi->s_itb_per_group - 1 > last_block) {
2336                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2337                                "Inode table for group %u not in group "
2338                                "(block %llu)!", i, inode_table);
2339                         return 0;
2340                 }
2341                 ext4_lock_group(sb, i);
2342                 if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2343                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2344                                  "Checksum for group %u failed (%u!=%u)",
2345                                  i, le16_to_cpu(ext4_group_desc_csum(sb, i,
2346                                      gdp)), le16_to_cpu(gdp->bg_checksum));
2347                         if (!(sb->s_flags & MS_RDONLY)) {
2348                                 ext4_unlock_group(sb, i);
2349                                 return 0;
2350                         }
2351                 }
2352                 ext4_unlock_group(sb, i);
2353                 if (!flexbg_flag)
2354                         first_block += EXT4_BLOCKS_PER_GROUP(sb);
2355         }
2356         if (NULL != first_not_zeroed)
2357                 *first_not_zeroed = grp;
2358         return 1;
2359 }
2360
2361 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2362  * the superblock) which were deleted from all directories, but held open by
2363  * a process at the time of a crash.  We walk the list and try to delete these
2364  * inodes at recovery time (only with a read-write filesystem).
2365  *
2366  * In order to keep the orphan inode chain consistent during traversal (in
2367  * case of crash during recovery), we link each inode into the superblock
2368  * orphan list_head and handle it the same way as an inode deletion during
2369  * normal operation (which journals the operations for us).
2370  *
2371  * We only do an iget() and an iput() on each inode, which is very safe if we
2372  * accidentally point at an in-use or already deleted inode.  The worst that
2373  * can happen in this case is that we get a "bit already cleared" message from
2374  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2375  * e2fsck was run on this filesystem, and it must have already done the orphan
2376  * inode cleanup for us, so we can safely abort without any further action.
2377  */
2378 static void ext4_orphan_cleanup(struct super_block *sb,
2379                                 struct ext4_super_block *es)
2380 {
2381         unsigned int s_flags = sb->s_flags;
2382         int ret, nr_orphans = 0, nr_truncates = 0;
2383 #ifdef CONFIG_QUOTA
2384         int i;
2385 #endif
2386         if (!es->s_last_orphan) {
2387                 jbd_debug(4, "no orphan inodes to clean up\n");
2388                 return;
2389         }
2390
2391         if (bdev_read_only(sb->s_bdev)) {
2392                 ext4_msg(sb, KERN_ERR, "write access "
2393                         "unavailable, skipping orphan cleanup");
2394                 return;
2395         }
2396
2397         /* Check if feature set would not allow a r/w mount */
2398         if (!ext4_feature_set_ok(sb, 0)) {
2399                 ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2400                          "unknown ROCOMPAT features");
2401                 return;
2402         }
2403
2404         if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2405                 /* don't clear list on RO mount w/ errors */
2406                 if (es->s_last_orphan && !(s_flags & MS_RDONLY)) {
2407                         ext4_msg(sb, KERN_INFO, "Errors on filesystem, "
2408                                   "clearing orphan list.\n");
2409                         es->s_last_orphan = 0;
2410                 }
2411                 jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2412                 return;
2413         }
2414
2415         if (s_flags & MS_RDONLY) {
2416                 ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2417                 sb->s_flags &= ~MS_RDONLY;
2418         }
2419 #ifdef CONFIG_QUOTA
2420         /* Needed for iput() to work correctly and not trash data */
2421         sb->s_flags |= MS_ACTIVE;
2422         /* Turn on quotas so that they are updated correctly */
2423         for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2424                 if (EXT4_SB(sb)->s_qf_names[i]) {
2425                         int ret = ext4_quota_on_mount(sb, i);
2426                         if (ret < 0)
2427                                 ext4_msg(sb, KERN_ERR,
2428                                         "Cannot turn on journaled "
2429                                         "quota: error %d", ret);
2430                 }
2431         }
2432 #endif
2433
2434         while (es->s_last_orphan) {
2435                 struct inode *inode;
2436
2437                 /*
2438                  * We may have encountered an error during cleanup; if
2439                  * so, skip the rest.
2440                  */
2441                 if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2442                         jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2443                         es->s_last_orphan = 0;
2444                         break;
2445                 }
2446
2447                 inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2448                 if (IS_ERR(inode)) {
2449                         es->s_last_orphan = 0;
2450                         break;
2451                 }
2452
2453                 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2454                 dquot_initialize(inode);
2455                 if (inode->i_nlink) {
2456                         if (test_opt(sb, DEBUG))
2457                                 ext4_msg(sb, KERN_DEBUG,
2458                                         "%s: truncating inode %lu to %lld bytes",
2459                                         __func__, inode->i_ino, inode->i_size);
2460                         jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2461                                   inode->i_ino, inode->i_size);
2462                         inode_lock(inode);
2463                         truncate_inode_pages(inode->i_mapping, inode->i_size);
2464                         ret = ext4_truncate(inode);
2465                         if (ret)
2466                                 ext4_std_error(inode->i_sb, ret);
2467                         inode_unlock(inode);
2468                         nr_truncates++;
2469                 } else {
2470                         if (test_opt(sb, DEBUG))
2471                                 ext4_msg(sb, KERN_DEBUG,
2472                                         "%s: deleting unreferenced inode %lu",
2473                                         __func__, inode->i_ino);
2474                         jbd_debug(2, "deleting unreferenced inode %lu\n",
2475                                   inode->i_ino);
2476                         nr_orphans++;
2477                 }
2478                 iput(inode);  /* The delete magic happens here! */
2479         }
2480
2481 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2482
2483         if (nr_orphans)
2484                 ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2485                        PLURAL(nr_orphans));
2486         if (nr_truncates)
2487                 ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2488                        PLURAL(nr_truncates));
2489 #ifdef CONFIG_QUOTA
2490         /* Turn quotas off */
2491         for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2492                 if (sb_dqopt(sb)->files[i])
2493                         dquot_quota_off(sb, i);
2494         }
2495 #endif
2496         sb->s_flags = s_flags; /* Restore MS_RDONLY status */
2497 }
2498
2499 /*
2500  * Maximal extent format file size.
2501  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2502  * extent format containers, within a sector_t, and within i_blocks
2503  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2504  * so that won't be a limiting factor.
2505  *
2506  * However there is other limiting factor. We do store extents in the form
2507  * of starting block and length, hence the resulting length of the extent
2508  * covering maximum file size must fit into on-disk format containers as
2509  * well. Given that length is always by 1 unit bigger than max unit (because
2510  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2511  *
2512  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2513  */
2514 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2515 {
2516         loff_t res;
2517         loff_t upper_limit = MAX_LFS_FILESIZE;
2518
2519         /* small i_blocks in vfs inode? */
2520         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2521                 /*
2522                  * CONFIG_LBDAF is not enabled implies the inode
2523                  * i_block represent total blocks in 512 bytes
2524                  * 32 == size of vfs inode i_blocks * 8
2525                  */
2526                 upper_limit = (1LL << 32) - 1;
2527
2528                 /* total blocks in file system block size */
2529                 upper_limit >>= (blkbits - 9);
2530                 upper_limit <<= blkbits;
2531         }
2532
2533         /*
2534          * 32-bit extent-start container, ee_block. We lower the maxbytes
2535          * by one fs block, so ee_len can cover the extent of maximum file
2536          * size
2537          */
2538         res = (1LL << 32) - 1;
2539         res <<= blkbits;
2540
2541         /* Sanity check against vm- & vfs- imposed limits */
2542         if (res > upper_limit)
2543                 res = upper_limit;
2544
2545         return res;
2546 }
2547
2548 /*
2549  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2550  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2551  * We need to be 1 filesystem block less than the 2^48 sector limit.
2552  */
2553 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2554 {
2555         loff_t res = EXT4_NDIR_BLOCKS;
2556         int meta_blocks;
2557         loff_t upper_limit;
2558         /* This is calculated to be the largest file size for a dense, block
2559          * mapped file such that the file's total number of 512-byte sectors,
2560          * including data and all indirect blocks, does not exceed (2^48 - 1).
2561          *
2562          * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2563          * number of 512-byte sectors of the file.
2564          */
2565
2566         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2567                 /*
2568                  * !has_huge_files or CONFIG_LBDAF not enabled implies that
2569                  * the inode i_block field represents total file blocks in
2570                  * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2571                  */
2572                 upper_limit = (1LL << 32) - 1;
2573
2574                 /* total blocks in file system block size */
2575                 upper_limit >>= (bits - 9);
2576
2577         } else {
2578                 /*
2579                  * We use 48 bit ext4_inode i_blocks
2580                  * With EXT4_HUGE_FILE_FL set the i_blocks
2581                  * represent total number of blocks in
2582                  * file system block size
2583                  */
2584                 upper_limit = (1LL << 48) - 1;
2585
2586         }
2587
2588         /* indirect blocks */
2589         meta_blocks = 1;
2590         /* double indirect blocks */
2591         meta_blocks += 1 + (1LL << (bits-2));
2592         /* tripple indirect blocks */
2593         meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2594
2595         upper_limit -= meta_blocks;
2596         upper_limit <<= bits;
2597
2598         res += 1LL << (bits-2);
2599         res += 1LL << (2*(bits-2));
2600         res += 1LL << (3*(bits-2));
2601         res <<= bits;
2602         if (res > upper_limit)
2603                 res = upper_limit;
2604
2605         if (res > MAX_LFS_FILESIZE)
2606                 res = MAX_LFS_FILESIZE;
2607
2608         return res;
2609 }
2610
2611 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2612                                    ext4_fsblk_t logical_sb_block, int nr)
2613 {
2614         struct ext4_sb_info *sbi = EXT4_SB(sb);
2615         ext4_group_t bg, first_meta_bg;
2616         int has_super = 0;
2617
2618         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2619
2620         if (!ext4_has_feature_meta_bg(sb) || nr < first_meta_bg)
2621                 return logical_sb_block + nr + 1;
2622         bg = sbi->s_desc_per_block * nr;
2623         if (ext4_bg_has_super(sb, bg))
2624                 has_super = 1;
2625
2626         /*
2627          * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
2628          * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
2629          * on modern mke2fs or blksize > 1k on older mke2fs) then we must
2630          * compensate.
2631          */
2632         if (sb->s_blocksize == 1024 && nr == 0 &&
2633             le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block) == 0)
2634                 has_super++;
2635
2636         return (has_super + ext4_group_first_block_no(sb, bg));
2637 }
2638
2639 /**
2640  * ext4_get_stripe_size: Get the stripe size.
2641  * @sbi: In memory super block info
2642  *
2643  * If we have specified it via mount option, then
2644  * use the mount option value. If the value specified at mount time is
2645  * greater than the blocks per group use the super block value.
2646  * If the super block value is greater than blocks per group return 0.
2647  * Allocator needs it be less than blocks per group.
2648  *
2649  */
2650 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2651 {
2652         unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2653         unsigned long stripe_width =
2654                         le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2655         int ret;
2656
2657         if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2658                 ret = sbi->s_stripe;
2659         else if (stripe_width && stripe_width <= sbi->s_blocks_per_group)
2660                 ret = stripe_width;
2661         else if (stride && stride <= sbi->s_blocks_per_group)
2662                 ret = stride;
2663         else
2664                 ret = 0;
2665
2666         /*
2667          * If the stripe width is 1, this makes no sense and
2668          * we set it to 0 to turn off stripe handling code.
2669          */
2670         if (ret <= 1)
2671                 ret = 0;
2672
2673         return ret;
2674 }
2675
2676 /*
2677  * Check whether this filesystem can be mounted based on
2678  * the features present and the RDONLY/RDWR mount requested.
2679  * Returns 1 if this filesystem can be mounted as requested,
2680  * 0 if it cannot be.
2681  */
2682 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2683 {
2684         if (ext4_has_unknown_ext4_incompat_features(sb)) {
2685                 ext4_msg(sb, KERN_ERR,
2686                         "Couldn't mount because of "
2687                         "unsupported optional features (%x)",
2688                         (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2689                         ~EXT4_FEATURE_INCOMPAT_SUPP));
2690                 return 0;
2691         }
2692
2693         if (readonly)
2694                 return 1;
2695
2696         if (ext4_has_feature_readonly(sb)) {
2697                 ext4_msg(sb, KERN_INFO, "filesystem is read-only");
2698                 sb->s_flags |= MS_RDONLY;
2699                 return 1;
2700         }
2701
2702         /* Check that feature set is OK for a read-write mount */
2703         if (ext4_has_unknown_ext4_ro_compat_features(sb)) {
2704                 ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2705                          "unsupported optional features (%x)",
2706                          (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2707                                 ~EXT4_FEATURE_RO_COMPAT_SUPP));
2708                 return 0;
2709         }
2710         /*
2711          * Large file size enabled file system can only be mounted
2712          * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2713          */
2714         if (ext4_has_feature_huge_file(sb)) {
2715                 if (sizeof(blkcnt_t) < sizeof(u64)) {
2716                         ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2717                                  "cannot be mounted RDWR without "
2718                                  "CONFIG_LBDAF");
2719                         return 0;
2720                 }
2721         }
2722         if (ext4_has_feature_bigalloc(sb) && !ext4_has_feature_extents(sb)) {
2723                 ext4_msg(sb, KERN_ERR,
2724                          "Can't support bigalloc feature without "
2725                          "extents feature\n");
2726                 return 0;
2727         }
2728
2729 #ifndef CONFIG_QUOTA
2730         if (ext4_has_feature_quota(sb) && !readonly) {
2731                 ext4_msg(sb, KERN_ERR,
2732                          "Filesystem with quota feature cannot be mounted RDWR "
2733                          "without CONFIG_QUOTA");
2734                 return 0;
2735         }
2736         if (ext4_has_feature_project(sb) && !readonly) {
2737                 ext4_msg(sb, KERN_ERR,
2738                          "Filesystem with project quota feature cannot be mounted RDWR "
2739                          "without CONFIG_QUOTA");
2740                 return 0;
2741         }
2742 #endif  /* CONFIG_QUOTA */
2743         return 1;
2744 }
2745
2746 /*
2747  * This function is called once a day if we have errors logged
2748  * on the file system
2749  */
2750 static void print_daily_error_info(unsigned long arg)
2751 {
2752         struct super_block *sb = (struct super_block *) arg;
2753         struct ext4_sb_info *sbi;
2754         struct ext4_super_block *es;
2755
2756         sbi = EXT4_SB(sb);
2757         es = sbi->s_es;
2758
2759         if (es->s_error_count)
2760                 /* fsck newer than v1.41.13 is needed to clean this condition. */
2761                 ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
2762                          le32_to_cpu(es->s_error_count));
2763         if (es->s_first_error_time) {
2764                 printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %u: %.*s:%d",
2765                        sb->s_id, le32_to_cpu(es->s_first_error_time),
2766                        (int) sizeof(es->s_first_error_func),
2767                        es->s_first_error_func,
2768                        le32_to_cpu(es->s_first_error_line));
2769                 if (es->s_first_error_ino)
2770                         printk(KERN_CONT ": inode %u",
2771                                le32_to_cpu(es->s_first_error_ino));
2772                 if (es->s_first_error_block)
2773                         printk(KERN_CONT ": block %llu", (unsigned long long)
2774                                le64_to_cpu(es->s_first_error_block));
2775                 printk(KERN_CONT "\n");
2776         }
2777         if (es->s_last_error_time) {
2778                 printk(KERN_NOTICE "EXT4-fs (%s): last error at time %u: %.*s:%d",
2779                        sb->s_id, le32_to_cpu(es->s_last_error_time),
2780                        (int) sizeof(es->s_last_error_func),
2781                        es->s_last_error_func,
2782                        le32_to_cpu(es->s_last_error_line));
2783                 if (es->s_last_error_ino)
2784                         printk(KERN_CONT ": inode %u",
2785                                le32_to_cpu(es->s_last_error_ino));
2786                 if (es->s_last_error_block)
2787                         printk(KERN_CONT ": block %llu", (unsigned long long)
2788                                le64_to_cpu(es->s_last_error_block));
2789                 printk(KERN_CONT "\n");
2790         }
2791         mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2792 }
2793
2794 /* Find next suitable group and run ext4_init_inode_table */
2795 static int ext4_run_li_request(struct ext4_li_request *elr)
2796 {
2797         struct ext4_group_desc *gdp = NULL;
2798         ext4_group_t group, ngroups;
2799         struct super_block *sb;
2800         unsigned long timeout = 0;
2801         int ret = 0;
2802
2803         sb = elr->lr_super;
2804         ngroups = EXT4_SB(sb)->s_groups_count;
2805
2806         for (group = elr->lr_next_group; group < ngroups; group++) {
2807                 gdp = ext4_get_group_desc(sb, group, NULL);
2808                 if (!gdp) {
2809                         ret = 1;
2810                         break;
2811                 }
2812
2813                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2814                         break;
2815         }
2816
2817         if (group >= ngroups)
2818                 ret = 1;
2819
2820         if (!ret) {
2821                 timeout = jiffies;
2822                 ret = ext4_init_inode_table(sb, group,
2823                                             elr->lr_timeout ? 0 : 1);
2824                 if (elr->lr_timeout == 0) {
2825                         timeout = (jiffies - timeout) *
2826                                   elr->lr_sbi->s_li_wait_mult;
2827                         elr->lr_timeout = timeout;
2828                 }
2829                 elr->lr_next_sched = jiffies + elr->lr_timeout;
2830                 elr->lr_next_group = group + 1;
2831         }
2832         return ret;
2833 }
2834
2835 /*
2836  * Remove lr_request from the list_request and free the
2837  * request structure. Should be called with li_list_mtx held
2838  */
2839 static void ext4_remove_li_request(struct ext4_li_request *elr)
2840 {
2841         struct ext4_sb_info *sbi;
2842
2843         if (!elr)
2844                 return;
2845
2846         sbi = elr->lr_sbi;
2847
2848         list_del(&elr->lr_request);
2849         sbi->s_li_request = NULL;
2850         kfree(elr);
2851 }
2852
2853 static void ext4_unregister_li_request(struct super_block *sb)
2854 {
2855         mutex_lock(&ext4_li_mtx);
2856         if (!ext4_li_info) {
2857                 mutex_unlock(&ext4_li_mtx);
2858                 return;
2859         }
2860
2861         mutex_lock(&ext4_li_info->li_list_mtx);
2862         ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
2863         mutex_unlock(&ext4_li_info->li_list_mtx);
2864         mutex_unlock(&ext4_li_mtx);
2865 }
2866
2867 static struct task_struct *ext4_lazyinit_task;
2868
2869 /*
2870  * This is the function where ext4lazyinit thread lives. It walks
2871  * through the request list searching for next scheduled filesystem.
2872  * When such a fs is found, run the lazy initialization request
2873  * (ext4_rn_li_request) and keep track of the time spend in this
2874  * function. Based on that time we compute next schedule time of
2875  * the request. When walking through the list is complete, compute
2876  * next waking time and put itself into sleep.
2877  */
2878 static int ext4_lazyinit_thread(void *arg)
2879 {
2880         struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
2881         struct list_head *pos, *n;
2882         struct ext4_li_request *elr;
2883         unsigned long next_wakeup, cur;
2884
2885         BUG_ON(NULL == eli);
2886
2887 cont_thread:
2888         while (true) {
2889                 next_wakeup = MAX_JIFFY_OFFSET;
2890
2891                 mutex_lock(&eli->li_list_mtx);
2892                 if (list_empty(&eli->li_request_list)) {
2893                         mutex_unlock(&eli->li_list_mtx);
2894                         goto exit_thread;
2895                 }
2896                 list_for_each_safe(pos, n, &eli->li_request_list) {
2897                         int err = 0;
2898                         int progress = 0;
2899                         elr = list_entry(pos, struct ext4_li_request,
2900                                          lr_request);
2901
2902                         if (time_before(jiffies, elr->lr_next_sched)) {
2903                                 if (time_before(elr->lr_next_sched, next_wakeup))
2904                                         next_wakeup = elr->lr_next_sched;
2905                                 continue;
2906                         }
2907                         if (down_read_trylock(&elr->lr_super->s_umount)) {
2908                                 if (sb_start_write_trylock(elr->lr_super)) {
2909                                         progress = 1;
2910                                         /*
2911                                          * We hold sb->s_umount, sb can not
2912                                          * be removed from the list, it is
2913                                          * now safe to drop li_list_mtx
2914                                          */
2915                                         mutex_unlock(&eli->li_list_mtx);
2916                                         err = ext4_run_li_request(elr);
2917                                         sb_end_write(elr->lr_super);
2918                                         mutex_lock(&eli->li_list_mtx);
2919                                         n = pos->next;
2920                                 }
2921                                 up_read((&elr->lr_super->s_umount));
2922                         }
2923                         /* error, remove the lazy_init job */
2924                         if (err) {
2925                                 ext4_remove_li_request(elr);
2926                                 continue;
2927                         }
2928                         if (!progress) {
2929                                 elr->lr_next_sched = jiffies +
2930                                         (prandom_u32()
2931                                          % (EXT4_DEF_LI_MAX_START_DELAY * HZ));
2932                         }
2933                         if (time_before(elr->lr_next_sched, next_wakeup))
2934                                 next_wakeup = elr->lr_next_sched;
2935                 }
2936                 mutex_unlock(&eli->li_list_mtx);
2937
2938                 try_to_freeze();
2939
2940                 cur = jiffies;
2941                 if ((time_after_eq(cur, next_wakeup)) ||
2942                     (MAX_JIFFY_OFFSET == next_wakeup)) {
2943                         cond_resched();
2944                         continue;
2945                 }
2946
2947                 schedule_timeout_interruptible(next_wakeup - cur);
2948
2949                 if (kthread_should_stop()) {
2950                         ext4_clear_request_list();
2951                         goto exit_thread;
2952                 }
2953         }
2954
2955 exit_thread:
2956         /*
2957          * It looks like the request list is empty, but we need
2958          * to check it under the li_list_mtx lock, to prevent any
2959          * additions into it, and of course we should lock ext4_li_mtx
2960          * to atomically free the list and ext4_li_info, because at
2961          * this point another ext4 filesystem could be registering
2962          * new one.
2963          */
2964         mutex_lock(&ext4_li_mtx);
2965         mutex_lock(&eli->li_list_mtx);
2966         if (!list_empty(&eli->li_request_list)) {
2967                 mutex_unlock(&eli->li_list_mtx);
2968                 mutex_unlock(&ext4_li_mtx);
2969                 goto cont_thread;
2970         }
2971         mutex_unlock(&eli->li_list_mtx);
2972         kfree(ext4_li_info);
2973         ext4_li_info = NULL;
2974         mutex_unlock(&ext4_li_mtx);
2975
2976         return 0;
2977 }
2978
2979 static void ext4_clear_request_list(void)
2980 {
2981         struct list_head *pos, *n;
2982         struct ext4_li_request *elr;
2983
2984         mutex_lock(&ext4_li_info->li_list_mtx);
2985         list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
2986                 elr = list_entry(pos, struct ext4_li_request,
2987                                  lr_request);
2988                 ext4_remove_li_request(elr);
2989         }
2990         mutex_unlock(&ext4_li_info->li_list_mtx);
2991 }
2992
2993 static int ext4_run_lazyinit_thread(void)
2994 {
2995         ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
2996                                          ext4_li_info, "ext4lazyinit");
2997         if (IS_ERR(ext4_lazyinit_task)) {
2998                 int err = PTR_ERR(ext4_lazyinit_task);
2999                 ext4_clear_request_list();
3000                 kfree(ext4_li_info);
3001                 ext4_li_info = NULL;
3002                 printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
3003                                  "initialization thread\n",
3004                                  err);
3005                 return err;
3006         }
3007         ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
3008         return 0;
3009 }
3010
3011 /*
3012  * Check whether it make sense to run itable init. thread or not.
3013  * If there is at least one uninitialized inode table, return
3014  * corresponding group number, else the loop goes through all
3015  * groups and return total number of groups.
3016  */
3017 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3018 {
3019         ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3020         struct ext4_group_desc *gdp = NULL;
3021
3022         for (group = 0; group < ngroups; group++) {
3023                 gdp = ext4_get_group_desc(sb, group, NULL);
3024                 if (!gdp)
3025                         continue;
3026
3027                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3028                         break;
3029         }
3030
3031         return group;
3032 }
3033
3034 static int ext4_li_info_new(void)
3035 {
3036         struct ext4_lazy_init *eli = NULL;
3037
3038         eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3039         if (!eli)
3040                 return -ENOMEM;
3041
3042         INIT_LIST_HEAD(&eli->li_request_list);
3043         mutex_init(&eli->li_list_mtx);
3044
3045         eli->li_state |= EXT4_LAZYINIT_QUIT;
3046
3047         ext4_li_info = eli;
3048
3049         return 0;
3050 }
3051
3052 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3053                                             ext4_group_t start)
3054 {
3055         struct ext4_sb_info *sbi = EXT4_SB(sb);
3056         struct ext4_li_request *elr;
3057
3058         elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3059         if (!elr)
3060                 return NULL;
3061
3062         elr->lr_super = sb;
3063         elr->lr_sbi = sbi;
3064         elr->lr_next_group = start;
3065
3066         /*
3067          * Randomize first schedule time of the request to
3068          * spread the inode table initialization requests
3069          * better.
3070          */
3071         elr->lr_next_sched = jiffies + (prandom_u32() %
3072                                 (EXT4_DEF_LI_MAX_START_DELAY * HZ));
3073         return elr;
3074 }
3075
3076 int ext4_register_li_request(struct super_block *sb,
3077                              ext4_group_t first_not_zeroed)
3078 {
3079         struct ext4_sb_info *sbi = EXT4_SB(sb);
3080         struct ext4_li_request *elr = NULL;
3081         ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
3082         int ret = 0;
3083
3084         mutex_lock(&ext4_li_mtx);
3085         if (sbi->s_li_request != NULL) {
3086                 /*
3087                  * Reset timeout so it can be computed again, because
3088                  * s_li_wait_mult might have changed.
3089                  */
3090                 sbi->s_li_request->lr_timeout = 0;
3091                 goto out;
3092         }
3093
3094         if (first_not_zeroed == ngroups ||
3095             (sb->s_flags & MS_RDONLY) ||
3096             !test_opt(sb, INIT_INODE_TABLE))
3097                 goto out;
3098
3099         elr = ext4_li_request_new(sb, first_not_zeroed);
3100         if (!elr) {
3101                 ret = -ENOMEM;
3102                 goto out;
3103         }
3104
3105         if (NULL == ext4_li_info) {
3106                 ret = ext4_li_info_new();
3107                 if (ret)
3108                         goto out;
3109         }
3110
3111         mutex_lock(&ext4_li_info->li_list_mtx);
3112         list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3113         mutex_unlock(&ext4_li_info->li_list_mtx);
3114
3115         sbi->s_li_request = elr;
3116         /*
3117          * set elr to NULL here since it has been inserted to
3118          * the request_list and the removal and free of it is
3119          * handled by ext4_clear_request_list from now on.
3120          */
3121         elr = NULL;
3122
3123         if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3124                 ret = ext4_run_lazyinit_thread();
3125                 if (ret)
3126                         goto out;
3127         }
3128 out:
3129         mutex_unlock(&ext4_li_mtx);
3130         if (ret)
3131                 kfree(elr);
3132         return ret;
3133 }
3134
3135 /*
3136  * We do not need to lock anything since this is called on
3137  * module unload.
3138  */
3139 static void ext4_destroy_lazyinit_thread(void)
3140 {
3141         /*
3142          * If thread exited earlier
3143          * there's nothing to be done.
3144          */
3145         if (!ext4_li_info || !ext4_lazyinit_task)
3146                 return;
3147
3148         kthread_stop(ext4_lazyinit_task);
3149 }
3150
3151 static int set_journal_csum_feature_set(struct super_block *sb)
3152 {
3153         int ret = 1;
3154         int compat, incompat;
3155         struct ext4_sb_info *sbi = EXT4_SB(sb);
3156
3157         if (ext4_has_metadata_csum(sb)) {
3158                 /* journal checksum v3 */
3159                 compat = 0;
3160                 incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
3161         } else {
3162                 /* journal checksum v1 */
3163                 compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3164                 incompat = 0;
3165         }
3166
3167         jbd2_journal_clear_features(sbi->s_journal,
3168                         JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3169                         JBD2_FEATURE_INCOMPAT_CSUM_V3 |
3170                         JBD2_FEATURE_INCOMPAT_CSUM_V2);
3171         if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3172                 ret = jbd2_journal_set_features(sbi->s_journal,
3173                                 compat, 0,
3174                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3175                                 incompat);
3176         } else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3177                 ret = jbd2_journal_set_features(sbi->s_journal,
3178                                 compat, 0,
3179                                 incompat);
3180                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3181                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3182         } else {
3183                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3184                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3185         }
3186
3187         return ret;
3188 }
3189
3190 /*
3191  * Note: calculating the overhead so we can be compatible with
3192  * historical BSD practice is quite difficult in the face of
3193  * clusters/bigalloc.  This is because multiple metadata blocks from
3194  * different block group can end up in the same allocation cluster.
3195  * Calculating the exact overhead in the face of clustered allocation
3196  * requires either O(all block bitmaps) in memory or O(number of block
3197  * groups**2) in time.  We will still calculate the superblock for
3198  * older file systems --- and if we come across with a bigalloc file
3199  * system with zero in s_overhead_clusters the estimate will be close to
3200  * correct especially for very large cluster sizes --- but for newer
3201  * file systems, it's better to calculate this figure once at mkfs
3202  * time, and store it in the superblock.  If the superblock value is
3203  * present (even for non-bigalloc file systems), we will use it.
3204  */
3205 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3206                           char *buf)
3207 {
3208         struct ext4_sb_info     *sbi = EXT4_SB(sb);
3209         struct ext4_group_desc  *gdp;
3210         ext4_fsblk_t            first_block, last_block, b;
3211         ext4_group_t            i, ngroups = ext4_get_groups_count(sb);
3212         int                     s, j, count = 0;
3213
3214         if (!ext4_has_feature_bigalloc(sb))
3215                 return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3216                         sbi->s_itb_per_group + 2);
3217
3218         first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3219                 (grp * EXT4_BLOCKS_PER_GROUP(sb));
3220         last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3221         for (i = 0; i < ngroups; i++) {
3222                 gdp = ext4_get_group_desc(sb, i, NULL);
3223                 b = ext4_block_bitmap(sb, gdp);
3224                 if (b >= first_block && b <= last_block) {
3225                         ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3226                         count++;
3227                 }
3228                 b = ext4_inode_bitmap(sb, gdp);
3229                 if (b >= first_block && b <= last_block) {
3230                         ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3231                         count++;
3232                 }
3233                 b = ext4_inode_table(sb, gdp);
3234                 if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3235                         for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3236                                 int c = EXT4_B2C(sbi, b - first_block);
3237                                 ext4_set_bit(c, buf);
3238                                 count++;
3239                         }
3240                 if (i != grp)
3241                         continue;
3242                 s = 0;
3243                 if (ext4_bg_has_super(sb, grp)) {
3244                         ext4_set_bit(s++, buf);
3245                         count++;
3246                 }
3247                 j = ext4_bg_num_gdb(sb, grp);
3248                 if (s + j > EXT4_BLOCKS_PER_GROUP(sb)) {
3249                         ext4_error(sb, "Invalid number of block group "
3250                                    "descriptor blocks: %d", j);
3251                         j = EXT4_BLOCKS_PER_GROUP(sb) - s;
3252                 }
3253                 count += j;
3254                 for (; j > 0; j--)
3255                         ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3256         }
3257         if (!count)
3258                 return 0;
3259         return EXT4_CLUSTERS_PER_GROUP(sb) -
3260                 ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3261 }
3262
3263 /*
3264  * Compute the overhead and stash it in sbi->s_overhead
3265  */
3266 int ext4_calculate_overhead(struct super_block *sb)
3267 {
3268         struct ext4_sb_info *sbi = EXT4_SB(sb);
3269         struct ext4_super_block *es = sbi->s_es;
3270         struct inode *j_inode;
3271         unsigned int j_blocks, j_inum = le32_to_cpu(es->s_journal_inum);
3272         ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3273         ext4_fsblk_t overhead = 0;
3274         char *buf = (char *) get_zeroed_page(GFP_NOFS);
3275
3276         if (!buf)
3277                 return -ENOMEM;
3278
3279         /*
3280          * Compute the overhead (FS structures).  This is constant
3281          * for a given filesystem unless the number of block groups
3282          * changes so we cache the previous value until it does.
3283          */
3284
3285         /*
3286          * All of the blocks before first_data_block are overhead
3287          */
3288         overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3289
3290         /*
3291          * Add the overhead found in each block group
3292          */
3293         for (i = 0; i < ngroups; i++) {
3294                 int blks;
3295
3296                 blks = count_overhead(sb, i, buf);
3297                 overhead += blks;
3298                 if (blks)
3299                         memset(buf, 0, PAGE_SIZE);
3300                 cond_resched();
3301         }
3302
3303         /*
3304          * Add the internal journal blocks whether the journal has been
3305          * loaded or not
3306          */
3307         if (sbi->s_journal && !sbi->journal_bdev)
3308                 overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_maxlen);
3309         else if (ext4_has_feature_journal(sb) && !sbi->s_journal) {
3310                 j_inode = ext4_get_journal_inode(sb, j_inum);
3311                 if (j_inode) {
3312                         j_blocks = j_inode->i_size >> sb->s_blocksize_bits;
3313                         overhead += EXT4_NUM_B2C(sbi, j_blocks);
3314                         iput(j_inode);
3315                 } else {
3316                         ext4_msg(sb, KERN_ERR, "can't get journal size");
3317                 }
3318         }
3319         sbi->s_overhead = overhead;
3320         smp_wmb();
3321         free_page((unsigned long) buf);
3322         return 0;
3323 }
3324
3325 static void ext4_set_resv_clusters(struct super_block *sb)
3326 {
3327         ext4_fsblk_t resv_clusters;
3328         struct ext4_sb_info *sbi = EXT4_SB(sb);
3329
3330         /*
3331          * There's no need to reserve anything when we aren't using extents.
3332          * The space estimates are exact, there are no unwritten extents,
3333          * hole punching doesn't need new metadata... This is needed especially
3334          * to keep ext2/3 backward compatibility.
3335          */
3336         if (!ext4_has_feature_extents(sb))
3337                 return;
3338         /*
3339          * By default we reserve 2% or 4096 clusters, whichever is smaller.
3340          * This should cover the situations where we can not afford to run
3341          * out of space like for example punch hole, or converting
3342          * unwritten extents in delalloc path. In most cases such
3343          * allocation would require 1, or 2 blocks, higher numbers are
3344          * very rare.
3345          */
3346         resv_clusters = (ext4_blocks_count(sbi->s_es) >>
3347                          sbi->s_cluster_bits);
3348
3349         do_div(resv_clusters, 50);
3350         resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
3351
3352         atomic64_set(&sbi->s_resv_clusters, resv_clusters);
3353 }
3354
3355 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3356 {
3357         char *orig_data = kstrdup(data, GFP_KERNEL);
3358         struct buffer_head *bh;
3359         struct ext4_super_block *es = NULL;
3360         struct ext4_sb_info *sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3361         ext4_fsblk_t block;
3362         ext4_fsblk_t sb_block = get_sb_block(&data);
3363         ext4_fsblk_t logical_sb_block;
3364         unsigned long offset = 0;
3365         unsigned long journal_devnum = 0;
3366         unsigned long def_mount_opts;
3367         struct inode *root;
3368         const char *descr;
3369         int ret = -ENOMEM;
3370         int blocksize, clustersize;
3371         unsigned int db_count;
3372         unsigned int i;
3373         int needs_recovery, has_huge_files, has_bigalloc;
3374         __u64 blocks_count;
3375         int err = 0;
3376         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3377         ext4_group_t first_not_zeroed;
3378
3379         if ((data && !orig_data) || !sbi)
3380                 goto out_free_base;
3381
3382         sbi->s_blockgroup_lock =
3383                 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3384         if (!sbi->s_blockgroup_lock)
3385                 goto out_free_base;
3386
3387         sb->s_fs_info = sbi;
3388         sbi->s_sb = sb;
3389         sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3390         sbi->s_sb_block = sb_block;
3391         if (sb->s_bdev->bd_part)
3392                 sbi->s_sectors_written_start =
3393                         part_stat_read(sb->s_bdev->bd_part, sectors[1]);
3394
3395         /* Cleanup superblock name */
3396         strreplace(sb->s_id, '/', '!');
3397
3398         /* -EINVAL is default */
3399         ret = -EINVAL;
3400         blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3401         if (!blocksize) {
3402                 ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3403                 goto out_fail;
3404         }
3405
3406         /*
3407          * The ext4 superblock will not be buffer aligned for other than 1kB
3408          * block sizes.  We need to calculate the offset from buffer start.
3409          */
3410         if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3411                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3412                 offset = do_div(logical_sb_block, blocksize);
3413         } else {
3414                 logical_sb_block = sb_block;
3415         }
3416
3417         if (!(bh = sb_bread_unmovable(sb, logical_sb_block))) {
3418                 ext4_msg(sb, KERN_ERR, "unable to read superblock");
3419                 goto out_fail;
3420         }
3421         /*
3422          * Note: s_es must be initialized as soon as possible because
3423          *       some ext4 macro-instructions depend on its value
3424          */
3425         es = (struct ext4_super_block *) (bh->b_data + offset);
3426         sbi->s_es = es;
3427         sb->s_magic = le16_to_cpu(es->s_magic);
3428         if (sb->s_magic != EXT4_SUPER_MAGIC)
3429                 goto cantfind_ext4;
3430         sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3431
3432         /* Warn if metadata_csum and gdt_csum are both set. */
3433         if (ext4_has_feature_metadata_csum(sb) &&
3434             ext4_has_feature_gdt_csum(sb))
3435                 ext4_warning(sb, "metadata_csum and uninit_bg are "
3436                              "redundant flags; please run fsck.");
3437
3438         /* Check for a known checksum algorithm */
3439         if (!ext4_verify_csum_type(sb, es)) {
3440                 ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3441                          "unknown checksum algorithm.");
3442                 silent = 1;
3443                 goto cantfind_ext4;
3444         }
3445
3446         /* Load the checksum driver */
3447         if (ext4_has_feature_metadata_csum(sb)) {
3448                 sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3449                 if (IS_ERR(sbi->s_chksum_driver)) {
3450                         ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3451                         ret = PTR_ERR(sbi->s_chksum_driver);
3452                         sbi->s_chksum_driver = NULL;
3453                         goto failed_mount;
3454                 }
3455         }
3456
3457         /* Check superblock checksum */
3458         if (!ext4_superblock_csum_verify(sb, es)) {
3459                 ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3460                          "invalid superblock checksum.  Run e2fsck?");
3461                 silent = 1;
3462                 ret = -EFSBADCRC;
3463                 goto cantfind_ext4;
3464         }
3465
3466         /* Precompute checksum seed for all metadata */
3467         if (ext4_has_feature_csum_seed(sb))
3468                 sbi->s_csum_seed = le32_to_cpu(es->s_checksum_seed);
3469         else if (ext4_has_metadata_csum(sb))
3470                 sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3471                                                sizeof(es->s_uuid));
3472
3473         /* Set defaults before we parse the mount options */
3474         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3475         set_opt(sb, INIT_INODE_TABLE);
3476         if (def_mount_opts & EXT4_DEFM_DEBUG)
3477                 set_opt(sb, DEBUG);
3478         if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3479                 set_opt(sb, GRPID);
3480         if (def_mount_opts & EXT4_DEFM_UID16)
3481                 set_opt(sb, NO_UID32);
3482         /* xattr user namespace & acls are now defaulted on */
3483         set_opt(sb, XATTR_USER);
3484 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3485         set_opt(sb, POSIX_ACL);
3486 #endif
3487         /* don't forget to enable journal_csum when metadata_csum is enabled. */
3488         if (ext4_has_metadata_csum(sb))
3489                 set_opt(sb, JOURNAL_CHECKSUM);
3490
3491         if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3492                 set_opt(sb, JOURNAL_DATA);
3493         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3494                 set_opt(sb, ORDERED_DATA);
3495         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3496                 set_opt(sb, WRITEBACK_DATA);
3497
3498         if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3499                 set_opt(sb, ERRORS_PANIC);
3500         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3501                 set_opt(sb, ERRORS_CONT);
3502         else
3503                 set_opt(sb, ERRORS_RO);
3504         /* block_validity enabled by default; disable with noblock_validity */
3505         set_opt(sb, BLOCK_VALIDITY);
3506         if (def_mount_opts & EXT4_DEFM_DISCARD)
3507                 set_opt(sb, DISCARD);
3508
3509         sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3510         sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3511         sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3512         sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3513         sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3514
3515         if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3516                 set_opt(sb, BARRIER);
3517
3518         /*
3519          * enable delayed allocation by default
3520          * Use -o nodelalloc to turn it off
3521          */
3522         if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
3523             ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3524                 set_opt(sb, DELALLOC);
3525
3526         /*
3527          * set default s_li_wait_mult for lazyinit, for the case there is
3528          * no mount option specified.
3529          */
3530         sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3531
3532         if (sbi->s_es->s_mount_opts[0]) {
3533                 char *s_mount_opts = kstrndup(sbi->s_es->s_mount_opts,
3534                                               sizeof(sbi->s_es->s_mount_opts),
3535                                               GFP_KERNEL);
3536                 if (!s_mount_opts)
3537                         goto failed_mount;
3538                 if (!parse_options(s_mount_opts, sb, &journal_devnum,
3539                                    &journal_ioprio, 0)) {
3540                         ext4_msg(sb, KERN_WARNING,
3541                                  "failed to parse options in superblock: %s",
3542                                  s_mount_opts);
3543                 }
3544                 kfree(s_mount_opts);
3545         }
3546         sbi->s_def_mount_opt = sbi->s_mount_opt;
3547         if (!parse_options((char *) data, sb, &journal_devnum,
3548                            &journal_ioprio, 0))
3549                 goto failed_mount;
3550
3551         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3552                 printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3553                             "with data=journal disables delayed "
3554                             "allocation and O_DIRECT support!\n");
3555                 if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3556                         ext4_msg(sb, KERN_ERR, "can't mount with "
3557                                  "both data=journal and delalloc");
3558                         goto failed_mount;
3559                 }
3560                 if (test_opt(sb, DIOREAD_NOLOCK)) {
3561                         ext4_msg(sb, KERN_ERR, "can't mount with "
3562                                  "both data=journal and dioread_nolock");
3563                         goto failed_mount;
3564                 }
3565                 if (test_opt(sb, DAX)) {
3566                         ext4_msg(sb, KERN_ERR, "can't mount with "
3567                                  "both data=journal and dax");
3568                         goto failed_mount;
3569                 }
3570                 if (ext4_has_feature_encrypt(sb)) {
3571                         ext4_msg(sb, KERN_WARNING,
3572                                  "encrypted files will use data=ordered "
3573                                  "instead of data journaling mode");
3574                 }
3575                 if (test_opt(sb, DELALLOC))
3576                         clear_opt(sb, DELALLOC);
3577         } else {
3578                 sb->s_iflags |= SB_I_CGROUPWB;
3579         }
3580
3581         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
3582                 (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
3583
3584         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3585             (ext4_has_compat_features(sb) ||
3586              ext4_has_ro_compat_features(sb) ||
3587              ext4_has_incompat_features(sb)))
3588                 ext4_msg(sb, KERN_WARNING,
3589                        "feature flags set on rev 0 fs, "
3590                        "running e2fsck is recommended");
3591
3592         if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
3593                 set_opt2(sb, HURD_COMPAT);
3594                 if (ext4_has_feature_64bit(sb)) {
3595                         ext4_msg(sb, KERN_ERR,
3596                                  "The Hurd can't support 64-bit file systems");
3597                         goto failed_mount;
3598                 }
3599         }
3600
3601         if (IS_EXT2_SB(sb)) {
3602                 if (ext2_feature_set_ok(sb))
3603                         ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3604                                  "using the ext4 subsystem");
3605                 else {
3606                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3607                                  "to feature incompatibilities");
3608                         goto failed_mount;
3609                 }
3610         }
3611
3612         if (IS_EXT3_SB(sb)) {
3613                 if (ext3_feature_set_ok(sb))
3614                         ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3615                                  "using the ext4 subsystem");
3616                 else {
3617                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3618                                  "to feature incompatibilities");
3619                         goto failed_mount;
3620                 }
3621         }
3622
3623         /*
3624          * Check feature flags regardless of the revision level, since we
3625          * previously didn't change the revision level when setting the flags,
3626          * so there is a chance incompat flags are set on a rev 0 filesystem.
3627          */
3628         if (!ext4_feature_set_ok(sb, (sb->s_flags & MS_RDONLY)))
3629                 goto failed_mount;
3630
3631         blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3632         if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3633             blocksize > EXT4_MAX_BLOCK_SIZE) {
3634                 ext4_msg(sb, KERN_ERR,
3635                        "Unsupported filesystem blocksize %d (%d log_block_size)",
3636                          blocksize, le32_to_cpu(es->s_log_block_size));
3637                 goto failed_mount;
3638         }
3639         if (le32_to_cpu(es->s_log_block_size) >
3640             (EXT4_MAX_BLOCK_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
3641                 ext4_msg(sb, KERN_ERR,
3642                          "Invalid log block size: %u",
3643                          le32_to_cpu(es->s_log_block_size));
3644                 goto failed_mount;
3645         }
3646
3647         if (le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) > (blocksize / 4)) {
3648                 ext4_msg(sb, KERN_ERR,
3649                          "Number of reserved GDT blocks insanely large: %d",
3650                          le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks));
3651                 goto failed_mount;
3652         }
3653
3654         if (sbi->s_mount_opt & EXT4_MOUNT_DAX) {
3655                 err = bdev_dax_supported(sb, blocksize);
3656                 if (err)
3657                         goto failed_mount;
3658         }
3659
3660         if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) {
3661                 ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
3662                          es->s_encryption_level);
3663                 goto failed_mount;
3664         }
3665
3666         if (sb->s_blocksize != blocksize) {
3667                 /* Validate the filesystem blocksize */
3668                 if (!sb_set_blocksize(sb, blocksize)) {
3669                         ext4_msg(sb, KERN_ERR, "bad block size %d",
3670                                         blocksize);
3671                         goto failed_mount;
3672                 }
3673
3674                 brelse(bh);
3675                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3676                 offset = do_div(logical_sb_block, blocksize);
3677                 bh = sb_bread_unmovable(sb, logical_sb_block);
3678                 if (!bh) {
3679                         ext4_msg(sb, KERN_ERR,
3680                                "Can't read superblock on 2nd try");
3681                         goto failed_mount;
3682                 }
3683                 es = (struct ext4_super_block *)(bh->b_data + offset);
3684                 sbi->s_es = es;
3685                 if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
3686                         ext4_msg(sb, KERN_ERR,
3687                                "Magic mismatch, very weird!");
3688                         goto failed_mount;
3689                 }
3690         }
3691
3692         has_huge_files = ext4_has_feature_huge_file(sb);
3693         sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
3694                                                       has_huge_files);
3695         sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
3696
3697         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3698                 sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3699                 sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3700         } else {
3701                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3702                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3703                 if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3704                     (!is_power_of_2(sbi->s_inode_size)) ||
3705                     (sbi->s_inode_size > blocksize)) {
3706                         ext4_msg(sb, KERN_ERR,
3707                                "unsupported inode size: %d",
3708                                sbi->s_inode_size);
3709                         goto failed_mount;
3710                 }
3711                 if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
3712                         sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
3713         }
3714
3715         sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
3716         if (ext4_has_feature_64bit(sb)) {
3717                 if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
3718                     sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
3719                     !is_power_of_2(sbi->s_desc_size)) {
3720                         ext4_msg(sb, KERN_ERR,
3721                                "unsupported descriptor size %lu",
3722                                sbi->s_desc_size);
3723                         goto failed_mount;
3724                 }
3725         } else
3726                 sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
3727
3728         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
3729         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
3730
3731         sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
3732         if (sbi->s_inodes_per_block == 0)
3733                 goto cantfind_ext4;
3734         if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
3735             sbi->s_inodes_per_group > blocksize * 8) {
3736                 ext4_msg(sb, KERN_ERR, "invalid inodes per group: %lu\n",
3737                          sbi->s_blocks_per_group);
3738                 goto failed_mount;
3739         }
3740         sbi->s_itb_per_group = sbi->s_inodes_per_group /
3741                                         sbi->s_inodes_per_block;
3742         sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
3743         sbi->s_sbh = bh;
3744         sbi->s_mount_state = le16_to_cpu(es->s_state);
3745         sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
3746         sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
3747
3748         for (i = 0; i < 4; i++)
3749                 sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
3750         sbi->s_def_hash_version = es->s_def_hash_version;
3751         if (ext4_has_feature_dir_index(sb)) {
3752                 i = le32_to_cpu(es->s_flags);
3753                 if (i & EXT2_FLAGS_UNSIGNED_HASH)
3754                         sbi->s_hash_unsigned = 3;
3755                 else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
3756 #ifdef __CHAR_UNSIGNED__
3757                         if (!(sb->s_flags & MS_RDONLY))
3758                                 es->s_flags |=
3759                                         cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
3760                         sbi->s_hash_unsigned = 3;
3761 #else
3762                         if (!(sb->s_flags & MS_RDONLY))
3763                                 es->s_flags |=
3764                                         cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
3765 #endif
3766                 }
3767         }
3768
3769         /* Handle clustersize */
3770         clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
3771         has_bigalloc = ext4_has_feature_bigalloc(sb);
3772         if (has_bigalloc) {
3773                 if (clustersize < blocksize) {
3774                         ext4_msg(sb, KERN_ERR,
3775                                  "cluster size (%d) smaller than "
3776                                  "block size (%d)", clustersize, blocksize);
3777                         goto failed_mount;
3778                 }
3779                 if (le32_to_cpu(es->s_log_cluster_size) >
3780                     (EXT4_MAX_CLUSTER_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
3781                         ext4_msg(sb, KERN_ERR,
3782                                  "Invalid log cluster size: %u",
3783                                  le32_to_cpu(es->s_log_cluster_size));
3784                         goto failed_mount;
3785                 }
3786                 sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
3787                         le32_to_cpu(es->s_log_block_size);
3788                 sbi->s_clusters_per_group =
3789                         le32_to_cpu(es->s_clusters_per_group);
3790                 if (sbi->s_clusters_per_group > blocksize * 8) {
3791                         ext4_msg(sb, KERN_ERR,
3792                                  "#clusters per group too big: %lu",
3793                                  sbi->s_clusters_per_group);
3794                         goto failed_mount;
3795                 }
3796                 if (sbi->s_blocks_per_group !=
3797                     (sbi->s_clusters_per_group * (clustersize / blocksize))) {
3798                         ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
3799                                  "clusters per group (%lu) inconsistent",
3800                                  sbi->s_blocks_per_group,
3801                                  sbi->s_clusters_per_group);
3802                         goto failed_mount;
3803                 }
3804         } else {
3805                 if (clustersize != blocksize) {
3806                         ext4_warning(sb, "fragment/cluster size (%d) != "
3807                                      "block size (%d)", clustersize,
3808                                      blocksize);
3809                         clustersize = blocksize;
3810                 }
3811                 if (sbi->s_blocks_per_group > blocksize * 8) {
3812                         ext4_msg(sb, KERN_ERR,
3813                                  "#blocks per group too big: %lu",
3814                                  sbi->s_blocks_per_group);
3815                         goto failed_mount;
3816                 }
3817                 sbi->s_clusters_per_group = sbi->s_blocks_per_group;
3818                 sbi->s_cluster_bits = 0;
3819         }
3820         sbi->s_cluster_ratio = clustersize / blocksize;
3821
3822         /* Do we have standard group size of clustersize * 8 blocks ? */
3823         if (sbi->s_blocks_per_group == clustersize << 3)
3824                 set_opt2(sb, STD_GROUP_SIZE);
3825
3826         /*
3827          * Test whether we have more sectors than will fit in sector_t,
3828          * and whether the max offset is addressable by the page cache.
3829          */
3830         err = generic_check_addressable(sb->s_blocksize_bits,
3831                                         ext4_blocks_count(es));
3832         if (err) {
3833                 ext4_msg(sb, KERN_ERR, "filesystem"
3834                          " too large to mount safely on this system");
3835                 if (sizeof(sector_t) < 8)
3836                         ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
3837                 goto failed_mount;
3838         }
3839
3840         if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
3841                 goto cantfind_ext4;
3842
3843         /* check blocks count against device size */
3844         blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
3845         if (blocks_count && ext4_blocks_count(es) > blocks_count) {
3846                 ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
3847                        "exceeds size of device (%llu blocks)",
3848                        ext4_blocks_count(es), blocks_count);
3849                 goto failed_mount;
3850         }
3851
3852         /*
3853          * It makes no sense for the first data block to be beyond the end
3854          * of the filesystem.
3855          */
3856         if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
3857                 ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
3858                          "block %u is beyond end of filesystem (%llu)",
3859                          le32_to_cpu(es->s_first_data_block),
3860                          ext4_blocks_count(es));
3861                 goto failed_mount;
3862         }
3863         blocks_count = (ext4_blocks_count(es) -
3864                         le32_to_cpu(es->s_first_data_block) +
3865                         EXT4_BLOCKS_PER_GROUP(sb) - 1);
3866         do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
3867         if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
3868                 ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
3869                        "(block count %llu, first data block %u, "
3870                        "blocks per group %lu)", sbi->s_groups_count,
3871                        ext4_blocks_count(es),
3872                        le32_to_cpu(es->s_first_data_block),
3873                        EXT4_BLOCKS_PER_GROUP(sb));
3874                 goto failed_mount;
3875         }
3876         sbi->s_groups_count = blocks_count;
3877         sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
3878                         (EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
3879         db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
3880                    EXT4_DESC_PER_BLOCK(sb);
3881         if (ext4_has_feature_meta_bg(sb)) {
3882                 if (le32_to_cpu(es->s_first_meta_bg) > db_count) {
3883                         ext4_msg(sb, KERN_WARNING,
3884                                  "first meta block group too large: %u "
3885                                  "(group descriptor block count %u)",
3886                                  le32_to_cpu(es->s_first_meta_bg), db_count);
3887                         goto failed_mount;
3888                 }
3889         }
3890         sbi->s_group_desc = ext4_kvmalloc(db_count *
3891                                           sizeof(struct buffer_head *),
3892                                           GFP_KERNEL);
3893         if (sbi->s_group_desc == NULL) {
3894                 ext4_msg(sb, KERN_ERR, "not enough memory");
3895                 ret = -ENOMEM;
3896                 goto failed_mount;
3897         }
3898
3899         bgl_lock_init(sbi->s_blockgroup_lock);
3900
3901         for (i = 0; i < db_count; i++) {
3902                 block = descriptor_loc(sb, logical_sb_block, i);
3903                 sbi->s_group_desc[i] = sb_bread_unmovable(sb, block);
3904                 if (!sbi->s_group_desc[i]) {
3905                         ext4_msg(sb, KERN_ERR,
3906                                "can't read group descriptor %d", i);
3907                         db_count = i;
3908                         goto failed_mount2;
3909                 }
3910         }
3911         if (!ext4_check_descriptors(sb, logical_sb_block, &first_not_zeroed)) {
3912                 ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
3913                 ret = -EFSCORRUPTED;
3914                 goto failed_mount2;
3915         }
3916
3917         sbi->s_gdb_count = db_count;
3918         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
3919         spin_lock_init(&sbi->s_next_gen_lock);
3920
3921         setup_timer(&sbi->s_err_report, print_daily_error_info,
3922                 (unsigned long) sb);
3923
3924         /* Register extent status tree shrinker */
3925         if (ext4_es_register_shrinker(sbi))
3926                 goto failed_mount3;
3927
3928         sbi->s_stripe = ext4_get_stripe_size(sbi);
3929         sbi->s_extent_max_zeroout_kb = 32;
3930
3931         /*
3932          * set up enough so that it can read an inode
3933          */
3934         sb->s_op = &ext4_sops;
3935         sb->s_export_op = &ext4_export_ops;
3936         sb->s_xattr = ext4_xattr_handlers;
3937         sb->s_cop = &ext4_cryptops;
3938 #ifdef CONFIG_QUOTA
3939         sb->dq_op = &ext4_quota_operations;
3940         if (ext4_has_feature_quota(sb))
3941                 sb->s_qcop = &dquot_quotactl_sysfile_ops;
3942         else
3943                 sb->s_qcop = &ext4_qctl_operations;
3944         sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
3945 #endif
3946         memcpy(sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
3947
3948         INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
3949         mutex_init(&sbi->s_orphan_lock);
3950
3951         sb->s_root = NULL;
3952
3953         needs_recovery = (es->s_last_orphan != 0 ||
3954                           ext4_has_feature_journal_needs_recovery(sb));
3955
3956         if (ext4_has_feature_mmp(sb) && !(sb->s_flags & MS_RDONLY))
3957                 if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
3958                         goto failed_mount3a;
3959
3960         /*
3961          * The first inode we look at is the journal inode.  Don't try
3962          * root first: it may be modified in the journal!
3963          */
3964         if (!test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) {
3965                 err = ext4_load_journal(sb, es, journal_devnum);
3966                 if (err)
3967                         goto failed_mount3a;
3968         } else if (test_opt(sb, NOLOAD) && !(sb->s_flags & MS_RDONLY) &&
3969                    ext4_has_feature_journal_needs_recovery(sb)) {
3970                 ext4_msg(sb, KERN_ERR, "required journal recovery "
3971                        "suppressed and not mounted read-only");
3972                 goto failed_mount_wq;
3973         } else {
3974                 /* Nojournal mode, all journal mount options are illegal */
3975                 if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM)) {
3976                         ext4_msg(sb, KERN_ERR, "can't mount with "
3977                                  "journal_checksum, fs mounted w/o journal");
3978                         goto failed_mount_wq;
3979                 }
3980                 if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3981                         ext4_msg(sb, KERN_ERR, "can't mount with "
3982                                  "journal_async_commit, fs mounted w/o journal");
3983                         goto failed_mount_wq;
3984                 }
3985                 if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
3986                         ext4_msg(sb, KERN_ERR, "can't mount with "
3987                                  "commit=%lu, fs mounted w/o journal",
3988                                  sbi->s_commit_interval / HZ);
3989                         goto failed_mount_wq;
3990                 }
3991                 if (EXT4_MOUNT_DATA_FLAGS &
3992                     (sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
3993                         ext4_msg(sb, KERN_ERR, "can't mount with "
3994                                  "data=, fs mounted w/o journal");
3995                         goto failed_mount_wq;
3996                 }
3997                 sbi->s_def_mount_opt &= EXT4_MOUNT_JOURNAL_CHECKSUM;
3998                 clear_opt(sb, JOURNAL_CHECKSUM);
3999                 clear_opt(sb, DATA_FLAGS);
4000                 sbi->s_journal = NULL;
4001                 needs_recovery = 0;
4002                 goto no_journal;
4003         }
4004
4005         if (ext4_has_feature_64bit(sb) &&
4006             !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4007                                        JBD2_FEATURE_INCOMPAT_64BIT)) {
4008                 ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
4009                 goto failed_mount_wq;
4010         }
4011
4012         if (!set_journal_csum_feature_set(sb)) {
4013                 ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
4014                          "feature set");
4015                 goto failed_mount_wq;
4016         }
4017
4018         /* We have now updated the journal if required, so we can
4019          * validate the data journaling mode. */
4020         switch (test_opt(sb, DATA_FLAGS)) {
4021         case 0:
4022                 /* No mode set, assume a default based on the journal
4023                  * capabilities: ORDERED_DATA if the journal can
4024                  * cope, else JOURNAL_DATA
4025                  */
4026                 if (jbd2_journal_check_available_features
4027                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
4028                         set_opt(sb, ORDERED_DATA);
4029                 else
4030                         set_opt(sb, JOURNAL_DATA);
4031                 break;
4032
4033         case EXT4_MOUNT_ORDERED_DATA:
4034         case EXT4_MOUNT_WRITEBACK_DATA:
4035                 if (!jbd2_journal_check_available_features
4036                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4037                         ext4_msg(sb, KERN_ERR, "Journal does not support "
4038                                "requested data journaling mode");
4039                         goto failed_mount_wq;
4040                 }
4041         default:
4042                 break;
4043         }
4044
4045         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
4046             test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4047                 ext4_msg(sb, KERN_ERR, "can't mount with "
4048                         "journal_async_commit in data=ordered mode");
4049                 goto failed_mount_wq;
4050         }
4051
4052         set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4053
4054         sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
4055
4056 no_journal:
4057         sbi->s_mb_cache = ext4_xattr_create_cache();
4058         if (!sbi->s_mb_cache) {
4059                 ext4_msg(sb, KERN_ERR, "Failed to create an mb_cache");
4060                 goto failed_mount_wq;
4061         }
4062
4063         if ((DUMMY_ENCRYPTION_ENABLED(sbi) || ext4_has_feature_encrypt(sb)) &&
4064             (blocksize != PAGE_SIZE)) {
4065                 ext4_msg(sb, KERN_ERR,
4066                          "Unsupported blocksize for fs encryption");
4067                 goto failed_mount_wq;
4068         }
4069
4070         if (DUMMY_ENCRYPTION_ENABLED(sbi) && !(sb->s_flags & MS_RDONLY) &&
4071             !ext4_has_feature_encrypt(sb)) {
4072                 ext4_set_feature_encrypt(sb);
4073                 ext4_commit_super(sb, 1);
4074         }
4075
4076         /*
4077          * Get the # of file system overhead blocks from the
4078          * superblock if present.
4079          */
4080         if (es->s_overhead_clusters)
4081                 sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
4082         else {
4083                 err = ext4_calculate_overhead(sb);
4084                 if (err)
4085                         goto failed_mount_wq;
4086         }
4087
4088         /*
4089          * The maximum number of concurrent works can be high and
4090          * concurrency isn't really necessary.  Limit it to 1.
4091          */
4092         EXT4_SB(sb)->rsv_conversion_wq =
4093                 alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
4094         if (!EXT4_SB(sb)->rsv_conversion_wq) {
4095                 printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
4096                 ret = -ENOMEM;
4097                 goto failed_mount4;
4098         }
4099
4100         /*
4101          * The jbd2_journal_load will have done any necessary log recovery,
4102          * so we can safely mount the rest of the filesystem now.
4103          */
4104
4105         root = ext4_iget(sb, EXT4_ROOT_INO);
4106         if (IS_ERR(root)) {
4107                 ext4_msg(sb, KERN_ERR, "get root inode failed");
4108                 ret = PTR_ERR(root);
4109                 root = NULL;
4110                 goto failed_mount4;
4111         }
4112         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
4113                 ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
4114                 iput(root);
4115                 goto failed_mount4;
4116         }
4117         sb->s_root = d_make_root(root);
4118         if (!sb->s_root) {
4119                 ext4_msg(sb, KERN_ERR, "get root dentry failed");
4120                 ret = -ENOMEM;
4121                 goto failed_mount4;
4122         }
4123
4124         if (ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY))
4125                 sb->s_flags |= MS_RDONLY;
4126
4127         /* determine the minimum size of new large inodes, if present */
4128         if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE &&
4129             sbi->s_want_extra_isize == 0) {
4130                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4131                                                      EXT4_GOOD_OLD_INODE_SIZE;
4132                 if (ext4_has_feature_extra_isize(sb)) {
4133                         if (sbi->s_want_extra_isize <
4134                             le16_to_cpu(es->s_want_extra_isize))
4135                                 sbi->s_want_extra_isize =
4136                                         le16_to_cpu(es->s_want_extra_isize);
4137                         if (sbi->s_want_extra_isize <
4138                             le16_to_cpu(es->s_min_extra_isize))
4139                                 sbi->s_want_extra_isize =
4140                                         le16_to_cpu(es->s_min_extra_isize);
4141                 }
4142         }
4143         /* Check if enough inode space is available */
4144         if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
4145                                                         sbi->s_inode_size) {
4146                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4147                                                        EXT4_GOOD_OLD_INODE_SIZE;
4148                 ext4_msg(sb, KERN_INFO, "required extra inode space not"
4149                          "available");
4150         }
4151
4152         ext4_set_resv_clusters(sb);
4153
4154         err = ext4_setup_system_zone(sb);
4155         if (err) {
4156                 ext4_msg(sb, KERN_ERR, "failed to initialize system "
4157                          "zone (%d)", err);
4158                 goto failed_mount4a;
4159         }
4160
4161         ext4_ext_init(sb);
4162         err = ext4_mb_init(sb);
4163         if (err) {
4164                 ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
4165                          err);
4166                 goto failed_mount5;
4167         }
4168
4169         block = ext4_count_free_clusters(sb);
4170         ext4_free_blocks_count_set(sbi->s_es,
4171                                    EXT4_C2B(sbi, block));
4172         err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
4173                                   GFP_KERNEL);
4174         if (!err) {
4175                 unsigned long freei = ext4_count_free_inodes(sb);
4176                 sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
4177                 err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
4178                                           GFP_KERNEL);
4179         }
4180         if (!err)
4181                 err = percpu_counter_init(&sbi->s_dirs_counter,
4182                                           ext4_count_dirs(sb), GFP_KERNEL);
4183         if (!err)
4184                 err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
4185                                           GFP_KERNEL);
4186         if (!err)
4187                 err = percpu_init_rwsem(&sbi->s_journal_flag_rwsem);
4188
4189         if (err) {
4190                 ext4_msg(sb, KERN_ERR, "insufficient memory");
4191                 goto failed_mount6;
4192         }
4193
4194         if (ext4_has_feature_flex_bg(sb))
4195                 if (!ext4_fill_flex_info(sb)) {
4196                         ext4_msg(sb, KERN_ERR,
4197                                "unable to initialize "
4198                                "flex_bg meta info!");
4199                         goto failed_mount6;
4200                 }
4201
4202         err = ext4_register_li_request(sb, first_not_zeroed);
4203         if (err)
4204                 goto failed_mount6;
4205
4206         err = ext4_register_sysfs(sb);
4207         if (err)
4208                 goto failed_mount7;
4209
4210 #ifdef CONFIG_QUOTA
4211         /* Enable quota usage during mount. */
4212         if (ext4_has_feature_quota(sb) && !(sb->s_flags & MS_RDONLY)) {
4213                 err = ext4_enable_quotas(sb);
4214                 if (err)
4215                         goto failed_mount8;
4216         }
4217 #endif  /* CONFIG_QUOTA */
4218
4219         EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
4220         ext4_orphan_cleanup(sb, es);
4221         EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
4222         if (needs_recovery) {
4223                 ext4_msg(sb, KERN_INFO, "recovery complete");
4224                 ext4_mark_recovery_complete(sb, es);
4225         }
4226         if (EXT4_SB(sb)->s_journal) {
4227                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
4228                         descr = " journalled data mode";
4229                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
4230                         descr = " ordered data mode";
4231                 else
4232                         descr = " writeback data mode";
4233         } else
4234                 descr = "out journal";
4235
4236         if (test_opt(sb, DISCARD)) {
4237                 struct request_queue *q = bdev_get_queue(sb->s_bdev);
4238                 if (!blk_queue_discard(q))
4239                         ext4_msg(sb, KERN_WARNING,
4240                                  "mounting with \"discard\" option, but "
4241                                  "the device does not support discard");
4242         }
4243
4244         if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
4245                 ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
4246                          "Opts: %.*s%s%s", descr,
4247                          (int) sizeof(sbi->s_es->s_mount_opts),
4248                          sbi->s_es->s_mount_opts,
4249                          *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
4250
4251         if (es->s_error_count)
4252                 mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
4253
4254         /* Enable message ratelimiting. Default is 10 messages per 5 secs. */
4255         ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
4256         ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
4257         ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
4258
4259         kfree(orig_data);
4260         return 0;
4261
4262 cantfind_ext4:
4263         if (!silent)
4264                 ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
4265         goto failed_mount;
4266
4267 #ifdef CONFIG_QUOTA
4268 failed_mount8:
4269         ext4_unregister_sysfs(sb);
4270 #endif
4271 failed_mount7:
4272         ext4_unregister_li_request(sb);
4273 failed_mount6:
4274         ext4_mb_release(sb);
4275         if (sbi->s_flex_groups)
4276                 kvfree(sbi->s_flex_groups);
4277         percpu_counter_destroy(&sbi->s_freeclusters_counter);
4278         percpu_counter_destroy(&sbi->s_freeinodes_counter);
4279         percpu_counter_destroy(&sbi->s_dirs_counter);
4280         percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4281 failed_mount5:
4282         ext4_ext_release(sb);
4283         ext4_release_system_zone(sb);
4284 failed_mount4a:
4285         dput(sb->s_root);
4286         sb->s_root = NULL;
4287 failed_mount4:
4288         ext4_msg(sb, KERN_ERR, "mount failed");
4289         if (EXT4_SB(sb)->rsv_conversion_wq)
4290                 destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4291 failed_mount_wq:
4292         if (sbi->s_mb_cache) {
4293                 ext4_xattr_destroy_cache(sbi->s_mb_cache);
4294                 sbi->s_mb_cache = NULL;
4295         }
4296         if (sbi->s_journal) {
4297                 jbd2_journal_destroy(sbi->s_journal);
4298                 sbi->s_journal = NULL;
4299         }
4300 failed_mount3a:
4301         ext4_es_unregister_shrinker(sbi);
4302 failed_mount3:
4303         del_timer_sync(&sbi->s_err_report);
4304         if (sbi->s_mmp_tsk)
4305                 kthread_stop(sbi->s_mmp_tsk);
4306 failed_mount2:
4307         for (i = 0; i < db_count; i++)
4308                 brelse(sbi->s_group_desc[i]);
4309         kvfree(sbi->s_group_desc);
4310 failed_mount:
4311         if (sbi->s_chksum_driver)
4312                 crypto_free_shash(sbi->s_chksum_driver);
4313 #ifdef CONFIG_QUOTA
4314         for (i = 0; i < EXT4_MAXQUOTAS; i++)
4315                 kfree(sbi->s_qf_names[i]);
4316 #endif
4317         ext4_blkdev_remove(sbi);
4318         brelse(bh);
4319 out_fail:
4320         sb->s_fs_info = NULL;
4321         kfree(sbi->s_blockgroup_lock);
4322 out_free_base:
4323         kfree(sbi);
4324         kfree(orig_data);
4325         return err ? err : ret;
4326 }
4327
4328 /*
4329  * Setup any per-fs journal parameters now.  We'll do this both on
4330  * initial mount, once the journal has been initialised but before we've
4331  * done any recovery; and again on any subsequent remount.
4332  */
4333 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4334 {
4335         struct ext4_sb_info *sbi = EXT4_SB(sb);
4336
4337         journal->j_commit_interval = sbi->s_commit_interval;
4338         journal->j_min_batch_time = sbi->s_min_batch_time;
4339         journal->j_max_batch_time = sbi->s_max_batch_time;
4340
4341         write_lock(&journal->j_state_lock);
4342         if (test_opt(sb, BARRIER))
4343                 journal->j_flags |= JBD2_BARRIER;
4344         else
4345                 journal->j_flags &= ~JBD2_BARRIER;
4346         if (test_opt(sb, DATA_ERR_ABORT))
4347                 journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4348         else
4349                 journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4350         write_unlock(&journal->j_state_lock);
4351 }
4352
4353 static struct inode *ext4_get_journal_inode(struct super_block *sb,
4354                                              unsigned int journal_inum)
4355 {
4356         struct inode *journal_inode;
4357
4358         /*
4359          * Test for the existence of a valid inode on disk.  Bad things
4360          * happen if we iget() an unused inode, as the subsequent iput()
4361          * will try to delete it.
4362          */
4363         journal_inode = ext4_iget(sb, journal_inum);
4364         if (IS_ERR(journal_inode)) {
4365                 ext4_msg(sb, KERN_ERR, "no journal found");
4366                 return NULL;
4367         }
4368         if (!journal_inode->i_nlink) {
4369                 make_bad_inode(journal_inode);
4370                 iput(journal_inode);
4371                 ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4372                 return NULL;
4373         }
4374
4375         jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4376                   journal_inode, journal_inode->i_size);
4377         if (!S_ISREG(journal_inode->i_mode)) {
4378                 ext4_msg(sb, KERN_ERR, "invalid journal inode");
4379                 iput(journal_inode);
4380                 return NULL;
4381         }
4382         return journal_inode;
4383 }
4384
4385 static journal_t *ext4_get_journal(struct super_block *sb,
4386                                    unsigned int journal_inum)
4387 {
4388         struct inode *journal_inode;
4389         journal_t *journal;
4390
4391         BUG_ON(!ext4_has_feature_journal(sb));
4392
4393         journal_inode = ext4_get_journal_inode(sb, journal_inum);
4394         if (!journal_inode)
4395                 return NULL;
4396
4397         journal = jbd2_journal_init_inode(journal_inode);
4398         if (!journal) {
4399                 ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4400                 iput(journal_inode);
4401                 return NULL;
4402         }
4403         journal->j_private = sb;
4404         ext4_init_journal_params(sb, journal);
4405         return journal;
4406 }
4407
4408 static journal_t *ext4_get_dev_journal(struct super_block *sb,
4409                                        dev_t j_dev)
4410 {
4411         struct buffer_head *bh;
4412         journal_t *journal;
4413         ext4_fsblk_t start;
4414         ext4_fsblk_t len;
4415         int hblock, blocksize;
4416         ext4_fsblk_t sb_block;
4417         unsigned long offset;
4418         struct ext4_super_block *es;
4419         struct block_device *bdev;
4420
4421         BUG_ON(!ext4_has_feature_journal(sb));
4422
4423         bdev = ext4_blkdev_get(j_dev, sb);
4424         if (bdev == NULL)
4425                 return NULL;
4426
4427         blocksize = sb->s_blocksize;
4428         hblock = bdev_logical_block_size(bdev);
4429         if (blocksize < hblock) {
4430                 ext4_msg(sb, KERN_ERR,
4431                         "blocksize too small for journal device");
4432                 goto out_bdev;
4433         }
4434
4435         sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4436         offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4437         set_blocksize(bdev, blocksize);
4438         if (!(bh = __bread(bdev, sb_block, blocksize))) {
4439                 ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4440                        "external journal");
4441                 goto out_bdev;
4442         }
4443
4444         es = (struct ext4_super_block *) (bh->b_data + offset);
4445         if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4446             !(le32_to_cpu(es->s_feature_incompat) &
4447               EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4448                 ext4_msg(sb, KERN_ERR, "external journal has "
4449                                         "bad superblock");
4450                 brelse(bh);
4451                 goto out_bdev;
4452         }
4453
4454         if ((le32_to_cpu(es->s_feature_ro_compat) &
4455              EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
4456             es->s_checksum != ext4_superblock_csum(sb, es)) {
4457                 ext4_msg(sb, KERN_ERR, "external journal has "
4458                                        "corrupt superblock");
4459                 brelse(bh);
4460                 goto out_bdev;
4461         }
4462
4463         if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4464                 ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4465                 brelse(bh);
4466                 goto out_bdev;
4467         }
4468
4469         len = ext4_blocks_count(es);
4470         start = sb_block + 1;
4471         brelse(bh);     /* we're done with the superblock */
4472
4473         journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4474                                         start, len, blocksize);
4475         if (!journal) {
4476                 ext4_msg(sb, KERN_ERR, "failed to create device journal");
4477                 goto out_bdev;
4478         }
4479         journal->j_private = sb;
4480         ll_rw_block(REQ_OP_READ, REQ_META | REQ_PRIO, 1, &journal->j_sb_buffer);
4481         wait_on_buffer(journal->j_sb_buffer);
4482         if (!buffer_uptodate(journal->j_sb_buffer)) {
4483                 ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4484                 goto out_journal;
4485         }
4486         if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4487                 ext4_msg(sb, KERN_ERR, "External journal has more than one "
4488                                         "user (unsupported) - %d",
4489                         be32_to_cpu(journal->j_superblock->s_nr_users));
4490                 goto out_journal;
4491         }
4492         EXT4_SB(sb)->journal_bdev = bdev;
4493         ext4_init_journal_params(sb, journal);
4494         return journal;
4495
4496 out_journal:
4497         jbd2_journal_destroy(journal);
4498 out_bdev:
4499         ext4_blkdev_put(bdev);
4500         return NULL;
4501 }
4502
4503 static int ext4_load_journal(struct super_block *sb,
4504                              struct ext4_super_block *es,
4505                              unsigned long journal_devnum)
4506 {
4507         journal_t *journal;
4508         unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4509         dev_t journal_dev;
4510         int err = 0;
4511         int really_read_only;
4512
4513         BUG_ON(!ext4_has_feature_journal(sb));
4514
4515         if (journal_devnum &&
4516             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4517                 ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4518                         "numbers have changed");
4519                 journal_dev = new_decode_dev(journal_devnum);
4520         } else
4521                 journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4522
4523         really_read_only = bdev_read_only(sb->s_bdev);
4524
4525         /*
4526          * Are we loading a blank journal or performing recovery after a
4527          * crash?  For recovery, we need to check in advance whether we
4528          * can get read-write access to the device.
4529          */
4530         if (ext4_has_feature_journal_needs_recovery(sb)) {
4531                 if (sb->s_flags & MS_RDONLY) {
4532                         ext4_msg(sb, KERN_INFO, "INFO: recovery "
4533                                         "required on readonly filesystem");
4534                         if (really_read_only) {
4535                                 ext4_msg(sb, KERN_ERR, "write access "
4536                                         "unavailable, cannot proceed");
4537                                 return -EROFS;
4538                         }
4539                         ext4_msg(sb, KERN_INFO, "write access will "
4540                                "be enabled during recovery");
4541                 }
4542         }
4543
4544         if (journal_inum && journal_dev) {
4545                 ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4546                        "and inode journals!");
4547                 return -EINVAL;
4548         }
4549
4550         if (journal_inum) {
4551                 if (!(journal = ext4_get_journal(sb, journal_inum)))
4552                         return -EINVAL;
4553         } else {
4554                 if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4555                         return -EINVAL;
4556         }
4557
4558         if (!(journal->j_flags & JBD2_BARRIER))
4559                 ext4_msg(sb, KERN_INFO, "barriers disabled");
4560
4561         if (!ext4_has_feature_journal_needs_recovery(sb))
4562                 err = jbd2_journal_wipe(journal, !really_read_only);
4563         if (!err) {
4564                 char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4565                 if (save)
4566                         memcpy(save, ((char *) es) +
4567                                EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4568                 err = jbd2_journal_load(journal);
4569                 if (save)
4570                         memcpy(((char *) es) + EXT4_S_ERR_START,
4571                                save, EXT4_S_ERR_LEN);
4572                 kfree(save);
4573         }
4574
4575         if (err) {
4576                 ext4_msg(sb, KERN_ERR, "error loading journal");
4577                 jbd2_journal_destroy(journal);
4578                 return err;
4579         }
4580
4581         EXT4_SB(sb)->s_journal = journal;
4582         ext4_clear_journal_err(sb, es);
4583
4584         if (!really_read_only && journal_devnum &&
4585             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4586                 es->s_journal_dev = cpu_to_le32(journal_devnum);
4587
4588                 /* Make sure we flush the recovery flag to disk. */
4589                 ext4_commit_super(sb, 1);
4590         }
4591
4592         return 0;
4593 }
4594
4595 static int ext4_commit_super(struct super_block *sb, int sync)
4596 {
4597         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4598         struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4599         int error = 0;
4600
4601         if (!sbh || block_device_ejected(sb))
4602                 return error;
4603         /*
4604          * If the file system is mounted read-only, don't update the
4605          * superblock write time.  This avoids updating the superblock
4606          * write time when we are mounting the root file system
4607          * read/only but we need to replay the journal; at that point,
4608          * for people who are east of GMT and who make their clock
4609          * tick in localtime for Windows bug-for-bug compatibility,
4610          * the clock is set in the future, and this will cause e2fsck
4611          * to complain and force a full file system check.
4612          */
4613         if (!(sb->s_flags & MS_RDONLY))
4614                 es->s_wtime = cpu_to_le32(get_seconds());
4615         if (sb->s_bdev->bd_part)
4616                 es->s_kbytes_written =
4617                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
4618                             ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
4619                               EXT4_SB(sb)->s_sectors_written_start) >> 1));
4620         else
4621                 es->s_kbytes_written =
4622                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
4623         if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeclusters_counter))
4624                 ext4_free_blocks_count_set(es,
4625                         EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
4626                                 &EXT4_SB(sb)->s_freeclusters_counter)));
4627         if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeinodes_counter))
4628                 es->s_free_inodes_count =
4629                         cpu_to_le32(percpu_counter_sum_positive(
4630                                 &EXT4_SB(sb)->s_freeinodes_counter));
4631         BUFFER_TRACE(sbh, "marking dirty");
4632         ext4_superblock_csum_set(sb);
4633         if (sync)
4634                 lock_buffer(sbh);
4635         if (buffer_write_io_error(sbh)) {
4636                 /*
4637                  * Oh, dear.  A previous attempt to write the
4638                  * superblock failed.  This could happen because the
4639                  * USB device was yanked out.  Or it could happen to
4640                  * be a transient write error and maybe the block will
4641                  * be remapped.  Nothing we can do but to retry the
4642                  * write and hope for the best.
4643                  */
4644                 ext4_msg(sb, KERN_ERR, "previous I/O error to "
4645                        "superblock detected");
4646                 clear_buffer_write_io_error(sbh);
4647                 set_buffer_uptodate(sbh);
4648         }
4649         mark_buffer_dirty(sbh);
4650         if (sync) {
4651                 unlock_buffer(sbh);
4652                 error = __sync_dirty_buffer(sbh,
4653                         test_opt(sb, BARRIER) ? REQ_FUA : REQ_SYNC);
4654                 if (error)
4655                         return error;
4656
4657                 error = buffer_write_io_error(sbh);
4658                 if (error) {
4659                         ext4_msg(sb, KERN_ERR, "I/O error while writing "
4660                                "superblock");
4661                         clear_buffer_write_io_error(sbh);
4662                         set_buffer_uptodate(sbh);
4663                 }
4664         }
4665         return error;
4666 }
4667
4668 /*
4669  * Have we just finished recovery?  If so, and if we are mounting (or
4670  * remounting) the filesystem readonly, then we will end up with a
4671  * consistent fs on disk.  Record that fact.
4672  */
4673 static void ext4_mark_recovery_complete(struct super_block *sb,
4674                                         struct ext4_super_block *es)
4675 {
4676         journal_t *journal = EXT4_SB(sb)->s_journal;
4677
4678         if (!ext4_has_feature_journal(sb)) {
4679                 BUG_ON(journal != NULL);
4680                 return;
4681         }
4682         jbd2_journal_lock_updates(journal);
4683         if (jbd2_journal_flush(journal) < 0)
4684                 goto out;
4685
4686         if (ext4_has_feature_journal_needs_recovery(sb) &&
4687             sb->s_flags & MS_RDONLY) {
4688                 ext4_clear_feature_journal_needs_recovery(sb);
4689                 ext4_commit_super(sb, 1);
4690         }
4691
4692 out:
4693         jbd2_journal_unlock_updates(journal);
4694 }
4695
4696 /*
4697  * If we are mounting (or read-write remounting) a filesystem whose journal
4698  * has recorded an error from a previous lifetime, move that error to the
4699  * main filesystem now.
4700  */
4701 static void ext4_clear_journal_err(struct super_block *sb,
4702                                    struct ext4_super_block *es)
4703 {
4704         journal_t *journal;
4705         int j_errno;
4706         const char *errstr;
4707
4708         BUG_ON(!ext4_has_feature_journal(sb));
4709
4710         journal = EXT4_SB(sb)->s_journal;
4711
4712         /*
4713          * Now check for any error status which may have been recorded in the
4714          * journal by a prior ext4_error() or ext4_abort()
4715          */
4716
4717         j_errno = jbd2_journal_errno(journal);
4718         if (j_errno) {
4719                 char nbuf[16];
4720
4721                 errstr = ext4_decode_error(sb, j_errno, nbuf);
4722                 ext4_warning(sb, "Filesystem error recorded "
4723                              "from previous mount: %s", errstr);
4724                 ext4_warning(sb, "Marking fs in need of filesystem check.");
4725
4726                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
4727                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
4728                 ext4_commit_super(sb, 1);
4729
4730                 jbd2_journal_clear_err(journal);
4731                 jbd2_journal_update_sb_errno(journal);
4732         }
4733 }
4734
4735 /*
4736  * Force the running and committing transactions to commit,
4737  * and wait on the commit.
4738  */
4739 int ext4_force_commit(struct super_block *sb)
4740 {
4741         journal_t *journal;
4742
4743         if (sb->s_flags & MS_RDONLY)
4744                 return 0;
4745
4746         journal = EXT4_SB(sb)->s_journal;
4747         return ext4_journal_force_commit(journal);
4748 }
4749
4750 static int ext4_sync_fs(struct super_block *sb, int wait)
4751 {
4752         int ret = 0;
4753         tid_t target;
4754         bool needs_barrier = false;
4755         struct ext4_sb_info *sbi = EXT4_SB(sb);
4756
4757         if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
4758                 return 0;
4759
4760         trace_ext4_sync_fs(sb, wait);
4761         flush_workqueue(sbi->rsv_conversion_wq);
4762         /*
4763          * Writeback quota in non-journalled quota case - journalled quota has
4764          * no dirty dquots
4765          */
4766         dquot_writeback_dquots(sb, -1);
4767         /*
4768          * Data writeback is possible w/o journal transaction, so barrier must
4769          * being sent at the end of the function. But we can skip it if
4770          * transaction_commit will do it for us.
4771          */
4772         if (sbi->s_journal) {
4773                 target = jbd2_get_latest_transaction(sbi->s_journal);
4774                 if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
4775                     !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
4776                         needs_barrier = true;
4777
4778                 if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
4779                         if (wait)
4780                                 ret = jbd2_log_wait_commit(sbi->s_journal,
4781                                                            target);
4782                 }
4783         } else if (wait && test_opt(sb, BARRIER))
4784                 needs_barrier = true;
4785         if (needs_barrier) {
4786                 int err;
4787                 err = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
4788                 if (!ret)
4789                         ret = err;
4790         }
4791
4792         return ret;
4793 }
4794
4795 /*
4796  * LVM calls this function before a (read-only) snapshot is created.  This
4797  * gives us a chance to flush the journal completely and mark the fs clean.
4798  *
4799  * Note that only this function cannot bring a filesystem to be in a clean
4800  * state independently. It relies on upper layer to stop all data & metadata
4801  * modifications.
4802  */
4803 static int ext4_freeze(struct super_block *sb)
4804 {
4805         int error = 0;
4806         journal_t *journal;
4807
4808         if (sb->s_flags & MS_RDONLY)
4809                 return 0;
4810
4811         journal = EXT4_SB(sb)->s_journal;
4812
4813         if (journal) {
4814                 /* Now we set up the journal barrier. */
4815                 jbd2_journal_lock_updates(journal);
4816
4817                 /*
4818                  * Don't clear the needs_recovery flag if we failed to
4819                  * flush the journal.
4820                  */
4821                 error = jbd2_journal_flush(journal);
4822                 if (error < 0)
4823                         goto out;
4824
4825                 /* Journal blocked and flushed, clear needs_recovery flag. */
4826                 ext4_clear_feature_journal_needs_recovery(sb);
4827         }
4828
4829         error = ext4_commit_super(sb, 1);
4830 out:
4831         if (journal)
4832                 /* we rely on upper layer to stop further updates */
4833                 jbd2_journal_unlock_updates(journal);
4834         return error;
4835 }
4836
4837 /*
4838  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
4839  * flag here, even though the filesystem is not technically dirty yet.
4840  */
4841 static int ext4_unfreeze(struct super_block *sb)
4842 {
4843         if ((sb->s_flags & MS_RDONLY) || ext4_forced_shutdown(EXT4_SB(sb)))
4844                 return 0;
4845
4846         if (EXT4_SB(sb)->s_journal) {
4847                 /* Reset the needs_recovery flag before the fs is unlocked. */
4848                 ext4_set_feature_journal_needs_recovery(sb);
4849         }
4850
4851         ext4_commit_super(sb, 1);
4852         return 0;
4853 }
4854
4855 /*
4856  * Structure to save mount options for ext4_remount's benefit
4857  */
4858 struct ext4_mount_options {
4859         unsigned long s_mount_opt;
4860         unsigned long s_mount_opt2;
4861         kuid_t s_resuid;
4862         kgid_t s_resgid;
4863         unsigned long s_commit_interval;
4864         u32 s_min_batch_time, s_max_batch_time;
4865 #ifdef CONFIG_QUOTA
4866         int s_jquota_fmt;
4867         char *s_qf_names[EXT4_MAXQUOTAS];
4868 #endif
4869 };
4870
4871 static int ext4_remount(struct super_block *sb, int *flags, char *data)
4872 {
4873         struct ext4_super_block *es;
4874         struct ext4_sb_info *sbi = EXT4_SB(sb);
4875         unsigned long old_sb_flags;
4876         struct ext4_mount_options old_opts;
4877         int enable_quota = 0;
4878         ext4_group_t g;
4879         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4880         int err = 0;
4881 #ifdef CONFIG_QUOTA
4882         int i, j;
4883 #endif
4884         char *orig_data = kstrdup(data, GFP_KERNEL);
4885
4886         /* Store the original options */
4887         old_sb_flags = sb->s_flags;
4888         old_opts.s_mount_opt = sbi->s_mount_opt;
4889         old_opts.s_mount_opt2 = sbi->s_mount_opt2;
4890         old_opts.s_resuid = sbi->s_resuid;
4891         old_opts.s_resgid = sbi->s_resgid;
4892         old_opts.s_commit_interval = sbi->s_commit_interval;
4893         old_opts.s_min_batch_time = sbi->s_min_batch_time;
4894         old_opts.s_max_batch_time = sbi->s_max_batch_time;
4895 #ifdef CONFIG_QUOTA
4896         old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
4897         for (i = 0; i < EXT4_MAXQUOTAS; i++)
4898                 if (sbi->s_qf_names[i]) {
4899                         old_opts.s_qf_names[i] = kstrdup(sbi->s_qf_names[i],
4900                                                          GFP_KERNEL);
4901                         if (!old_opts.s_qf_names[i]) {
4902                                 for (j = 0; j < i; j++)
4903                                         kfree(old_opts.s_qf_names[j]);
4904                                 kfree(orig_data);
4905                                 return -ENOMEM;
4906                         }
4907                 } else
4908                         old_opts.s_qf_names[i] = NULL;
4909 #endif
4910         if (sbi->s_journal && sbi->s_journal->j_task->io_context)
4911                 journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
4912
4913         if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
4914                 err = -EINVAL;
4915                 goto restore_opts;
4916         }
4917
4918         if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
4919             test_opt(sb, JOURNAL_CHECKSUM)) {
4920                 ext4_msg(sb, KERN_ERR, "changing journal_checksum "
4921                          "during remount not supported; ignoring");
4922                 sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
4923         }
4924
4925         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
4926                 if (test_opt2(sb, EXPLICIT_DELALLOC)) {
4927                         ext4_msg(sb, KERN_ERR, "can't mount with "
4928                                  "both data=journal and delalloc");
4929                         err = -EINVAL;
4930                         goto restore_opts;
4931                 }
4932                 if (test_opt(sb, DIOREAD_NOLOCK)) {
4933                         ext4_msg(sb, KERN_ERR, "can't mount with "
4934                                  "both data=journal and dioread_nolock");
4935                         err = -EINVAL;
4936                         goto restore_opts;
4937                 }
4938                 if (test_opt(sb, DAX)) {
4939                         ext4_msg(sb, KERN_ERR, "can't mount with "
4940                                  "both data=journal and dax");
4941                         err = -EINVAL;
4942                         goto restore_opts;
4943                 }
4944         } else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA) {
4945                 if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4946                         ext4_msg(sb, KERN_ERR, "can't mount with "
4947                                 "journal_async_commit in data=ordered mode");
4948                         err = -EINVAL;
4949                         goto restore_opts;
4950                 }
4951         }
4952
4953         if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_DAX) {
4954                 ext4_msg(sb, KERN_WARNING, "warning: refusing change of "
4955                         "dax flag with busy inodes while remounting");
4956                 sbi->s_mount_opt ^= EXT4_MOUNT_DAX;
4957         }
4958
4959         if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
4960                 ext4_abort(sb, "Abort forced by user");
4961
4962         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
4963                 (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
4964
4965         es = sbi->s_es;
4966
4967         if (sbi->s_journal) {
4968                 ext4_init_journal_params(sb, sbi->s_journal);
4969                 set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4970         }
4971
4972         if (*flags & MS_LAZYTIME)
4973                 sb->s_flags |= MS_LAZYTIME;
4974
4975         if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY)) {
4976                 if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
4977                         err = -EROFS;
4978                         goto restore_opts;
4979                 }
4980
4981                 if (*flags & MS_RDONLY) {
4982                         err = sync_filesystem(sb);
4983                         if (err < 0)
4984                                 goto restore_opts;
4985                         err = dquot_suspend(sb, -1);
4986                         if (err < 0)
4987                                 goto restore_opts;
4988
4989                         /*
4990                          * First of all, the unconditional stuff we have to do
4991                          * to disable replay of the journal when we next remount
4992                          */
4993                         sb->s_flags |= MS_RDONLY;
4994
4995                         /*
4996                          * OK, test if we are remounting a valid rw partition
4997                          * readonly, and if so set the rdonly flag and then
4998                          * mark the partition as valid again.
4999                          */
5000                         if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
5001                             (sbi->s_mount_state & EXT4_VALID_FS))
5002                                 es->s_state = cpu_to_le16(sbi->s_mount_state);
5003
5004                         if (sbi->s_journal)
5005                                 ext4_mark_recovery_complete(sb, es);
5006                 } else {
5007                         /* Make sure we can mount this feature set readwrite */
5008                         if (ext4_has_feature_readonly(sb) ||
5009                             !ext4_feature_set_ok(sb, 0)) {
5010                                 err = -EROFS;
5011                                 goto restore_opts;
5012                         }
5013                         /*
5014                          * Make sure the group descriptor checksums
5015                          * are sane.  If they aren't, refuse to remount r/w.
5016                          */
5017                         for (g = 0; g < sbi->s_groups_count; g++) {
5018                                 struct ext4_group_desc *gdp =
5019                                         ext4_get_group_desc(sb, g, NULL);
5020
5021                                 if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
5022                                         ext4_msg(sb, KERN_ERR,
5023                "ext4_remount: Checksum for group %u failed (%u!=%u)",
5024                 g, le16_to_cpu(ext4_group_desc_csum(sb, g, gdp)),
5025                                                le16_to_cpu(gdp->bg_checksum));
5026                                         err = -EFSBADCRC;
5027                                         goto restore_opts;
5028                                 }
5029                         }
5030
5031                         /*
5032                          * If we have an unprocessed orphan list hanging
5033                          * around from a previously readonly bdev mount,
5034                          * require a full umount/remount for now.
5035                          */
5036                         if (es->s_last_orphan) {
5037                                 ext4_msg(sb, KERN_WARNING, "Couldn't "
5038                                        "remount RDWR because of unprocessed "
5039                                        "orphan inode list.  Please "
5040                                        "umount/remount instead");
5041                                 err = -EINVAL;
5042                                 goto restore_opts;
5043                         }
5044
5045                         /*
5046                          * Mounting a RDONLY partition read-write, so reread
5047                          * and store the current valid flag.  (It may have
5048                          * been changed by e2fsck since we originally mounted
5049                          * the partition.)
5050                          */
5051                         if (sbi->s_journal)
5052                                 ext4_clear_journal_err(sb, es);
5053                         sbi->s_mount_state = le16_to_cpu(es->s_state);
5054                         if (!ext4_setup_super(sb, es, 0))
5055                                 sb->s_flags &= ~MS_RDONLY;
5056                         if (ext4_has_feature_mmp(sb))
5057                                 if (ext4_multi_mount_protect(sb,
5058                                                 le64_to_cpu(es->s_mmp_block))) {
5059                                         err = -EROFS;
5060                                         goto restore_opts;
5061                                 }
5062                         enable_quota = 1;
5063                 }
5064         }
5065
5066         /*
5067          * Reinitialize lazy itable initialization thread based on
5068          * current settings
5069          */
5070         if ((sb->s_flags & MS_RDONLY) || !test_opt(sb, INIT_INODE_TABLE))
5071                 ext4_unregister_li_request(sb);
5072         else {
5073                 ext4_group_t first_not_zeroed;
5074                 first_not_zeroed = ext4_has_uninit_itable(sb);
5075                 ext4_register_li_request(sb, first_not_zeroed);
5076         }
5077
5078         ext4_setup_system_zone(sb);
5079         if (sbi->s_journal == NULL && !(old_sb_flags & MS_RDONLY))
5080                 ext4_commit_super(sb, 1);
5081
5082 #ifdef CONFIG_QUOTA
5083         /* Release old quota file names */
5084         for (i = 0; i < EXT4_MAXQUOTAS; i++)
5085                 kfree(old_opts.s_qf_names[i]);
5086         if (enable_quota) {
5087                 if (sb_any_quota_suspended(sb))
5088                         dquot_resume(sb, -1);
5089                 else if (ext4_has_feature_quota(sb)) {
5090                         err = ext4_enable_quotas(sb);
5091                         if (err)
5092                                 goto restore_opts;
5093                 }
5094         }
5095 #endif
5096
5097         *flags = (*flags & ~MS_LAZYTIME) | (sb->s_flags & MS_LAZYTIME);
5098         ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
5099         kfree(orig_data);
5100         return 0;
5101
5102 restore_opts:
5103         sb->s_flags = old_sb_flags;
5104         sbi->s_mount_opt = old_opts.s_mount_opt;
5105         sbi->s_mount_opt2 = old_opts.s_mount_opt2;
5106         sbi->s_resuid = old_opts.s_resuid;
5107         sbi->s_resgid = old_opts.s_resgid;
5108         sbi->s_commit_interval = old_opts.s_commit_interval;
5109         sbi->s_min_batch_time = old_opts.s_min_batch_time;
5110         sbi->s_max_batch_time = old_opts.s_max_batch_time;
5111 #ifdef CONFIG_QUOTA
5112         sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
5113         for (i = 0; i < EXT4_MAXQUOTAS; i++) {
5114                 kfree(sbi->s_qf_names[i]);
5115                 sbi->s_qf_names[i] = old_opts.s_qf_names[i];
5116         }
5117 #endif
5118         kfree(orig_data);
5119         return err;
5120 }
5121
5122 #ifdef CONFIG_QUOTA
5123 static int ext4_statfs_project(struct super_block *sb,
5124                                kprojid_t projid, struct kstatfs *buf)
5125 {
5126         struct kqid qid;
5127         struct dquot *dquot;
5128         u64 limit;
5129         u64 curblock;
5130
5131         qid = make_kqid_projid(projid);
5132         dquot = dqget(sb, qid);
5133         if (IS_ERR(dquot))
5134                 return PTR_ERR(dquot);
5135         spin_lock(&dq_data_lock);
5136
5137         limit = (dquot->dq_dqb.dqb_bsoftlimit ?
5138                  dquot->dq_dqb.dqb_bsoftlimit :
5139                  dquot->dq_dqb.dqb_bhardlimit) >> sb->s_blocksize_bits;
5140         if (limit && buf->f_blocks > limit) {
5141                 curblock = dquot->dq_dqb.dqb_curspace >> sb->s_blocksize_bits;
5142                 buf->f_blocks = limit;
5143                 buf->f_bfree = buf->f_bavail =
5144                         (buf->f_blocks > curblock) ?
5145                          (buf->f_blocks - curblock) : 0;
5146         }
5147
5148         limit = dquot->dq_dqb.dqb_isoftlimit ?
5149                 dquot->dq_dqb.dqb_isoftlimit :
5150                 dquot->dq_dqb.dqb_ihardlimit;
5151         if (limit && buf->f_files > limit) {
5152                 buf->f_files = limit;
5153                 buf->f_ffree =
5154                         (buf->f_files > dquot->dq_dqb.dqb_curinodes) ?
5155                          (buf->f_files - dquot->dq_dqb.dqb_curinodes) : 0;
5156         }
5157
5158         spin_unlock(&dq_data_lock);
5159         dqput(dquot);
5160         return 0;
5161 }
5162 #endif
5163
5164 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
5165 {
5166         struct super_block *sb = dentry->d_sb;
5167         struct ext4_sb_info *sbi = EXT4_SB(sb);
5168         struct ext4_super_block *es = sbi->s_es;
5169         ext4_fsblk_t overhead = 0, resv_blocks;
5170         u64 fsid;
5171         s64 bfree;
5172         resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
5173
5174         if (!test_opt(sb, MINIX_DF))
5175                 overhead = sbi->s_overhead;
5176
5177         buf->f_type = EXT4_SUPER_MAGIC;
5178         buf->f_bsize = sb->s_blocksize;
5179         buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
5180         bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
5181                 percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
5182         /* prevent underflow in case that few free space is available */
5183         buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
5184         buf->f_bavail = buf->f_bfree -
5185                         (ext4_r_blocks_count(es) + resv_blocks);
5186         if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
5187                 buf->f_bavail = 0;
5188         buf->f_files = le32_to_cpu(es->s_inodes_count);
5189         buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
5190         buf->f_namelen = EXT4_NAME_LEN;
5191         fsid = le64_to_cpup((void *)es->s_uuid) ^
5192                le64_to_cpup((void *)es->s_uuid + sizeof(u64));
5193         buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
5194         buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
5195
5196 #ifdef CONFIG_QUOTA
5197         if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&
5198             sb_has_quota_limits_enabled(sb, PRJQUOTA))
5199                 ext4_statfs_project(sb, EXT4_I(dentry->d_inode)->i_projid, buf);
5200 #endif
5201         return 0;
5202 }
5203
5204 /* Helper function for writing quotas on sync - we need to start transaction
5205  * before quota file is locked for write. Otherwise the are possible deadlocks:
5206  * Process 1                         Process 2
5207  * ext4_create()                     quota_sync()
5208  *   jbd2_journal_start()                  write_dquot()
5209  *   dquot_initialize()                         down(dqio_mutex)
5210  *     down(dqio_mutex)                    jbd2_journal_start()
5211  *
5212  */
5213
5214 #ifdef CONFIG_QUOTA
5215
5216 static inline struct inode *dquot_to_inode(struct dquot *dquot)
5217 {
5218         return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
5219 }
5220
5221 static int ext4_write_dquot(struct dquot *dquot)
5222 {
5223         int ret, err;
5224         handle_t *handle;
5225         struct inode *inode;
5226
5227         inode = dquot_to_inode(dquot);
5228         handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
5229                                     EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
5230         if (IS_ERR(handle))
5231                 return PTR_ERR(handle);
5232         ret = dquot_commit(dquot);
5233         err = ext4_journal_stop(handle);
5234         if (!ret)
5235                 ret = err;
5236         return ret;
5237 }
5238
5239 static int ext4_acquire_dquot(struct dquot *dquot)
5240 {
5241         int ret, err;
5242         handle_t *handle;
5243
5244         handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5245                                     EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
5246         if (IS_ERR(handle))
5247                 return PTR_ERR(handle);
5248         ret = dquot_acquire(dquot);
5249         err = ext4_journal_stop(handle);
5250         if (!ret)
5251                 ret = err;
5252         return ret;
5253 }
5254
5255 static int ext4_release_dquot(struct dquot *dquot)
5256 {
5257         int ret, err;
5258         handle_t *handle;
5259
5260         handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5261                                     EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
5262         if (IS_ERR(handle)) {
5263                 /* Release dquot anyway to avoid endless cycle in dqput() */
5264                 dquot_release(dquot);
5265                 return PTR_ERR(handle);
5266         }
5267         ret = dquot_release(dquot);
5268         err = ext4_journal_stop(handle);
5269         if (!ret)
5270                 ret = err;
5271         return ret;
5272 }
5273
5274 static int ext4_mark_dquot_dirty(struct dquot *dquot)
5275 {
5276         struct super_block *sb = dquot->dq_sb;
5277         struct ext4_sb_info *sbi = EXT4_SB(sb);
5278
5279         /* Are we journaling quotas? */
5280         if (ext4_has_feature_quota(sb) ||
5281             sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
5282                 dquot_mark_dquot_dirty(dquot);
5283                 return ext4_write_dquot(dquot);
5284         } else {
5285                 return dquot_mark_dquot_dirty(dquot);
5286         }
5287 }
5288
5289 static int ext4_write_info(struct super_block *sb, int type)
5290 {
5291         int ret, err;
5292         handle_t *handle;
5293
5294         /* Data block + inode block */
5295         handle = ext4_journal_start(d_inode(sb->s_root), EXT4_HT_QUOTA, 2);
5296         if (IS_ERR(handle))
5297                 return PTR_ERR(handle);
5298         ret = dquot_commit_info(sb, type);
5299         err = ext4_journal_stop(handle);
5300         if (!ret)
5301                 ret = err;
5302         return ret;
5303 }
5304
5305 /*
5306  * Turn on quotas during mount time - we need to find
5307  * the quota file and such...
5308  */
5309 static int ext4_quota_on_mount(struct super_block *sb, int type)
5310 {
5311         return dquot_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
5312                                         EXT4_SB(sb)->s_jquota_fmt, type);
5313 }
5314
5315 static void lockdep_set_quota_inode(struct inode *inode, int subclass)
5316 {
5317         struct ext4_inode_info *ei = EXT4_I(inode);
5318
5319         /* The first argument of lockdep_set_subclass has to be
5320          * *exactly* the same as the argument to init_rwsem() --- in
5321          * this case, in init_once() --- or lockdep gets unhappy
5322          * because the name of the lock is set using the
5323          * stringification of the argument to init_rwsem().
5324          */
5325         (void) ei;      /* shut up clang warning if !CONFIG_LOCKDEP */
5326         lockdep_set_subclass(&ei->i_data_sem, subclass);
5327 }
5328
5329 /*
5330  * Standard function to be called on quota_on
5331  */
5332 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
5333                          const struct path *path)
5334 {
5335         int err;
5336
5337         if (!test_opt(sb, QUOTA))
5338                 return -EINVAL;
5339
5340         /* Quotafile not on the same filesystem? */
5341         if (path->dentry->d_sb != sb)
5342                 return -EXDEV;
5343         /* Journaling quota? */
5344         if (EXT4_SB(sb)->s_qf_names[type]) {
5345                 /* Quotafile not in fs root? */
5346                 if (path->dentry->d_parent != sb->s_root)
5347                         ext4_msg(sb, KERN_WARNING,
5348                                 "Quota file not on filesystem root. "
5349                                 "Journaled quota will not work");
5350         }
5351
5352         /*
5353          * When we journal data on quota file, we have to flush journal to see
5354          * all updates to the file when we bypass pagecache...
5355          */
5356         if (EXT4_SB(sb)->s_journal &&
5357             ext4_should_journal_data(d_inode(path->dentry))) {
5358                 /*
5359                  * We don't need to lock updates but journal_flush() could
5360                  * otherwise be livelocked...
5361                  */
5362                 jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
5363                 err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
5364                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
5365                 if (err)
5366                         return err;
5367         }
5368
5369         lockdep_set_quota_inode(path->dentry->d_inode, I_DATA_SEM_QUOTA);
5370         err = dquot_quota_on(sb, type, format_id, path);
5371         if (err) {
5372                 lockdep_set_quota_inode(path->dentry->d_inode,
5373                                              I_DATA_SEM_NORMAL);
5374         } else {
5375                 struct inode *inode = d_inode(path->dentry);
5376                 handle_t *handle;
5377
5378                 /*
5379                  * Set inode flags to prevent userspace from messing with quota
5380                  * files. If this fails, we return success anyway since quotas
5381                  * are already enabled and this is not a hard failure.
5382                  */
5383                 inode_lock(inode);
5384                 handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5385                 if (IS_ERR(handle))
5386                         goto unlock_inode;
5387                 EXT4_I(inode)->i_flags |= EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL;
5388                 inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
5389                                 S_NOATIME | S_IMMUTABLE);
5390                 ext4_mark_inode_dirty(handle, inode);
5391                 ext4_journal_stop(handle);
5392         unlock_inode:
5393                 inode_unlock(inode);
5394         }
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                                 ext4_warning(sb,
5454                                         "Failed to enable quota tracking "
5455                                         "(type=%d, err=%d). Please run "
5456                                         "e2fsck to fix.", type, err);
5457                                 return err;
5458                         }
5459                 }
5460         }
5461         return 0;
5462 }
5463
5464 static int ext4_quota_off(struct super_block *sb, int type)
5465 {
5466         struct inode *inode = sb_dqopt(sb)->files[type];
5467         handle_t *handle;
5468         int err;
5469
5470         /* Force all delayed allocation blocks to be allocated.
5471          * Caller already holds s_umount sem */
5472         if (test_opt(sb, DELALLOC))
5473                 sync_filesystem(sb);
5474
5475         if (!inode || !igrab(inode))
5476                 goto out;
5477
5478         err = dquot_quota_off(sb, type);
5479         if (err)
5480                 goto out_put;
5481
5482         inode_lock(inode);
5483         /*
5484          * Update modification times of quota files when userspace can
5485          * start looking at them. If we fail, we return success anyway since
5486          * this is not a hard failure and quotas are already disabled.
5487          */
5488         handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5489         if (IS_ERR(handle))
5490                 goto out_unlock;
5491         EXT4_I(inode)->i_flags &= ~(EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL);
5492         inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
5493         inode->i_mtime = inode->i_ctime = current_time(inode);
5494         ext4_mark_inode_dirty(handle, inode);
5495         ext4_journal_stop(handle);
5496 out_unlock:
5497         inode_unlock(inode);
5498 out_put:
5499         iput(inode);
5500         return err;
5501 out:
5502         return dquot_quota_off(sb, type);
5503 }
5504
5505 /* Read data from quotafile - avoid pagecache and such because we cannot afford
5506  * acquiring the locks... As quota files are never truncated and quota code
5507  * itself serializes the operations (and no one else should touch the files)
5508  * we don't have to be afraid of races */
5509 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
5510                                size_t len, loff_t off)
5511 {
5512         struct inode *inode = sb_dqopt(sb)->files[type];
5513         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5514         int offset = off & (sb->s_blocksize - 1);
5515         int tocopy;
5516         size_t toread;
5517         struct buffer_head *bh;
5518         loff_t i_size = i_size_read(inode);
5519
5520         if (off > i_size)
5521                 return 0;
5522         if (off+len > i_size)
5523                 len = i_size-off;
5524         toread = len;
5525         while (toread > 0) {
5526                 tocopy = sb->s_blocksize - offset < toread ?
5527                                 sb->s_blocksize - offset : toread;
5528                 bh = ext4_bread(NULL, inode, blk, 0);
5529                 if (IS_ERR(bh))
5530                         return PTR_ERR(bh);
5531                 if (!bh)        /* A hole? */
5532                         memset(data, 0, tocopy);
5533                 else
5534                         memcpy(data, bh->b_data+offset, tocopy);
5535                 brelse(bh);
5536                 offset = 0;
5537                 toread -= tocopy;
5538                 data += tocopy;
5539                 blk++;
5540         }
5541         return len;
5542 }
5543
5544 /* Write to quotafile (we know the transaction is already started and has
5545  * enough credits) */
5546 static ssize_t ext4_quota_write(struct super_block *sb, int type,
5547                                 const char *data, size_t len, loff_t off)
5548 {
5549         struct inode *inode = sb_dqopt(sb)->files[type];
5550         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5551         int err, offset = off & (sb->s_blocksize - 1);
5552         int retries = 0;
5553         struct buffer_head *bh;
5554         handle_t *handle = journal_current_handle();
5555
5556         if (EXT4_SB(sb)->s_journal && !handle) {
5557                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5558                         " cancelled because transaction is not started",
5559                         (unsigned long long)off, (unsigned long long)len);
5560                 return -EIO;
5561         }
5562         /*
5563          * Since we account only one data block in transaction credits,
5564          * then it is impossible to cross a block boundary.
5565          */
5566         if (sb->s_blocksize - offset < len) {
5567                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5568                         " cancelled because not block aligned",
5569                         (unsigned long long)off, (unsigned long long)len);
5570                 return -EIO;
5571         }
5572
5573         do {
5574                 bh = ext4_bread(handle, inode, blk,
5575                                 EXT4_GET_BLOCKS_CREATE |
5576                                 EXT4_GET_BLOCKS_METADATA_NOFAIL);
5577         } while (IS_ERR(bh) && (PTR_ERR(bh) == -ENOSPC) &&
5578                  ext4_should_retry_alloc(inode->i_sb, &retries));
5579         if (IS_ERR(bh))
5580                 return PTR_ERR(bh);
5581         if (!bh)
5582                 goto out;
5583         BUFFER_TRACE(bh, "get write access");
5584         err = ext4_journal_get_write_access(handle, bh);
5585         if (err) {
5586                 brelse(bh);
5587                 return err;
5588         }
5589         lock_buffer(bh);
5590         memcpy(bh->b_data+offset, data, len);
5591         flush_dcache_page(bh->b_page);
5592         unlock_buffer(bh);
5593         err = ext4_handle_dirty_metadata(handle, NULL, bh);
5594         brelse(bh);
5595 out:
5596         if (inode->i_size < off + len) {
5597                 i_size_write(inode, off + len);
5598                 EXT4_I(inode)->i_disksize = inode->i_size;
5599                 ext4_mark_inode_dirty(handle, inode);
5600         }
5601         return len;
5602 }
5603
5604 static int ext4_get_next_id(struct super_block *sb, struct kqid *qid)
5605 {
5606         const struct quota_format_ops   *ops;
5607
5608         if (!sb_has_quota_loaded(sb, qid->type))
5609                 return -ESRCH;
5610         ops = sb_dqopt(sb)->ops[qid->type];
5611         if (!ops || !ops->get_next_id)
5612                 return -ENOSYS;
5613         return dquot_get_next_id(sb, qid);
5614 }
5615 #endif
5616
5617 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
5618                        const char *dev_name, void *data)
5619 {
5620         return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
5621 }
5622
5623 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
5624 static inline void register_as_ext2(void)
5625 {
5626         int err = register_filesystem(&ext2_fs_type);
5627         if (err)
5628                 printk(KERN_WARNING
5629                        "EXT4-fs: Unable to register as ext2 (%d)\n", err);
5630 }
5631
5632 static inline void unregister_as_ext2(void)
5633 {
5634         unregister_filesystem(&ext2_fs_type);
5635 }
5636
5637 static inline int ext2_feature_set_ok(struct super_block *sb)
5638 {
5639         if (ext4_has_unknown_ext2_incompat_features(sb))
5640                 return 0;
5641         if (sb->s_flags & MS_RDONLY)
5642                 return 1;
5643         if (ext4_has_unknown_ext2_ro_compat_features(sb))
5644                 return 0;
5645         return 1;
5646 }
5647 #else
5648 static inline void register_as_ext2(void) { }
5649 static inline void unregister_as_ext2(void) { }
5650 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
5651 #endif
5652
5653 static inline void register_as_ext3(void)
5654 {
5655         int err = register_filesystem(&ext3_fs_type);
5656         if (err)
5657                 printk(KERN_WARNING
5658                        "EXT4-fs: Unable to register as ext3 (%d)\n", err);
5659 }
5660
5661 static inline void unregister_as_ext3(void)
5662 {
5663         unregister_filesystem(&ext3_fs_type);
5664 }
5665
5666 static inline int ext3_feature_set_ok(struct super_block *sb)
5667 {
5668         if (ext4_has_unknown_ext3_incompat_features(sb))
5669                 return 0;
5670         if (!ext4_has_feature_journal(sb))
5671                 return 0;
5672         if (sb->s_flags & MS_RDONLY)
5673                 return 1;
5674         if (ext4_has_unknown_ext3_ro_compat_features(sb))
5675                 return 0;
5676         return 1;
5677 }
5678
5679 static struct file_system_type ext4_fs_type = {
5680         .owner          = THIS_MODULE,
5681         .name           = "ext4",
5682         .mount          = ext4_mount,
5683         .kill_sb        = kill_block_super,
5684         .fs_flags       = FS_REQUIRES_DEV,
5685 };
5686 MODULE_ALIAS_FS("ext4");
5687
5688 /* Shared across all ext4 file systems */
5689 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
5690
5691 static int __init ext4_init_fs(void)
5692 {
5693         int i, err;
5694
5695         ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
5696         ext4_li_info = NULL;
5697         mutex_init(&ext4_li_mtx);
5698
5699         /* Build-time check for flags consistency */
5700         ext4_check_flag_values();
5701
5702         for (i = 0; i < EXT4_WQ_HASH_SZ; i++)
5703                 init_waitqueue_head(&ext4__ioend_wq[i]);
5704
5705         err = ext4_init_es();
5706         if (err)
5707                 return err;
5708
5709         err = ext4_init_pageio();
5710         if (err)
5711                 goto out5;
5712
5713         err = ext4_init_system_zone();
5714         if (err)
5715                 goto out4;
5716
5717         err = ext4_init_sysfs();
5718         if (err)
5719                 goto out3;
5720
5721         err = ext4_init_mballoc();
5722         if (err)
5723                 goto out2;
5724         err = init_inodecache();
5725         if (err)
5726                 goto out1;
5727         register_as_ext3();
5728         register_as_ext2();
5729         err = register_filesystem(&ext4_fs_type);
5730         if (err)
5731                 goto out;
5732
5733         return 0;
5734 out:
5735         unregister_as_ext2();
5736         unregister_as_ext3();
5737         destroy_inodecache();
5738 out1:
5739         ext4_exit_mballoc();
5740 out2:
5741         ext4_exit_sysfs();
5742 out3:
5743         ext4_exit_system_zone();
5744 out4:
5745         ext4_exit_pageio();
5746 out5:
5747         ext4_exit_es();
5748
5749         return err;
5750 }
5751
5752 static void __exit ext4_exit_fs(void)
5753 {
5754         ext4_destroy_lazyinit_thread();
5755         unregister_as_ext2();
5756         unregister_as_ext3();
5757         unregister_filesystem(&ext4_fs_type);
5758         destroy_inodecache();
5759         ext4_exit_mballoc();
5760         ext4_exit_sysfs();
5761         ext4_exit_system_zone();
5762         ext4_exit_pageio();
5763         ext4_exit_es();
5764 }
5765
5766 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
5767 MODULE_DESCRIPTION("Fourth Extended Filesystem");
5768 MODULE_LICENSE("GPL");
5769 module_init(ext4_init_fs)
5770 module_exit(ext4_exit_fs)