fs/ext4/super.c

   1 /*
   2  *  linux/fs/ext4/super.c
   3  *
   4  * Copyright (C) 1992, 1993, 1994, 1995
   5  * Remy Card (card@masi.ibp.fr)
   6  * Laboratoire MASI - Institut Blaise Pascal
   7  * Universite Pierre et Marie Curie (Paris VI)
   8  *
   9  *  from
  10  *
  11  *  linux/fs/minix/inode.c
  12  *
  13  *  Copyright (C) 1991, 1992  Linus Torvalds
  14  *
  15  *  Big-endian to little-endian byte-swapping/bitmaps by
  16  *        David S. Miller (davem@caip.rutgers.edu), 1995
  17  */
  18
  19 #include <linux/module.h>
  20 #include <linux/string.h>
  21 #include <linux/fs.h>
  22 #include <linux/time.h>
  23 #include <linux/vmalloc.h>
  24 #include <linux/slab.h>
  25 #include <linux/init.h>
  26 #include <linux/blkdev.h>
  27 #include <linux/backing-dev.h>
  28 #include <linux/parser.h>
  29 #include <linux/buffer_head.h>
  30 #include <linux/exportfs.h>
  31 #include <linux/vfs.h>
  32 #include <linux/random.h>
  33 #include <linux/mount.h>
  34 #include <linux/namei.h>
  35 #include <linux/quotaops.h>
  36 #include <linux/seq_file.h>
  37 #include <linux/ctype.h>
  38 #include <linux/log2.h>
  39 #include <linux/crc16.h>
  40 #include <linux/cleancache.h>
  41 #include <asm/uaccess.h>
  42
  43 #include <linux/kthread.h>
  44 #include <linux/freezer.h>
  45
  46 #include "ext4.h"
  47 #include "ext4_extents.h"       /* Needed for trace points definition */
  48 #include "ext4_jbd2.h"
  49 #include "xattr.h"
  50 #include "acl.h"
  51 #include "mballoc.h"
  52
  53 #define CREATE_TRACE_POINTS
  54 #include <trace/events/ext4.h>
  55
  56 static struct ext4_lazy_init *ext4_li_info;
  57 static struct mutex ext4_li_mtx;
  58 static struct ratelimit_state ext4_mount_msg_ratelimit;
  59
  60 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
  61                              unsigned long journal_devnum);
  62 static int ext4_show_options(struct seq_file *seq, struct dentry *root);
  63 static int ext4_commit_super(struct super_block *sb, int sync);
  64 static void ext4_mark_recovery_complete(struct super_block *sb,
  65                                         struct ext4_super_block *es);
  66 static void ext4_clear_journal_err(struct super_block *sb,
  67                                    struct ext4_super_block *es);
  68 static int ext4_sync_fs(struct super_block *sb, int wait);
  69 static int ext4_remount(struct super_block *sb, int *flags, char *data);
  70 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
  71 static int ext4_unfreeze(struct super_block *sb);
  72 static int ext4_freeze(struct super_block *sb);
  73 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
  74                        const char *dev_name, void *data);
  75 static inline int ext2_feature_set_ok(struct super_block *sb);
  76 static inline int ext3_feature_set_ok(struct super_block *sb);
  77 static int ext4_feature_set_ok(struct super_block *sb, int readonly);
  78 static void ext4_destroy_lazyinit_thread(void);
  79 static void ext4_unregister_li_request(struct super_block *sb);
  80 static void ext4_clear_request_list(void);
  81
  82 /*
  83  * Lock ordering
  84  *
  85  * Note the difference between i_mmap_sem (EXT4_I(inode)->i_mmap_sem) and
  86  * i_mmap_rwsem (inode->i_mmap_rwsem)!
  87  *
  88  * page fault path:
  89  * mmap_sem -> sb_start_pagefault -> i_mmap_sem (r) -> transaction start ->
  90  *   page lock -> i_data_sem (rw)
  91  *
  92  * buffered write path:
  93  * sb_start_write -> i_mutex -> mmap_sem
  94  * sb_start_write -> i_mutex -> transaction start -> page lock ->
  95  *   i_data_sem (rw)
  96  *
  97  * truncate:
  98  * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (w) -> i_mmap_sem (w) ->
  99  *   i_mmap_rwsem (w) -> page lock
 100  * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (w) -> i_mmap_sem (w) ->
 101  *   transaction start -> i_data_sem (rw)
 102  *
 103  * direct IO:
 104  * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (r) -> mmap_sem
 105  * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (r) ->
 106  *   transaction start -> i_data_sem (rw)
 107  *
 108  * writepages:
 109  * transaction start -> page lock(s) -> i_data_sem (rw)
 110  */
 111
 112 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
 113 static struct file_system_type ext2_fs_type = {
 114         .owner          = THIS_MODULE,
 115         .name           = "ext2",
 116         .mount          = ext4_mount,
 117         .kill_sb        = kill_block_super,
 118         .fs_flags       = FS_REQUIRES_DEV,
 119 };
 120 MODULE_ALIAS_FS("ext2");
 121 MODULE_ALIAS("ext2");
 122 #define IS_EXT2_SB(sb) ((sb)->s_bdev->bd_holder == &ext2_fs_type)
 123 #else
 124 #define IS_EXT2_SB(sb) (0)
 125 #endif
 126
 127
 128 static struct file_system_type ext3_fs_type = {
 129         .owner          = THIS_MODULE,
 130         .name           = "ext3",
 131         .mount          = ext4_mount,
 132         .kill_sb        = kill_block_super,
 133         .fs_flags       = FS_REQUIRES_DEV,
 134 };
 135 MODULE_ALIAS_FS("ext3");
 136 MODULE_ALIAS("ext3");
 137 #define IS_EXT3_SB(sb) ((sb)->s_bdev->bd_holder == &ext3_fs_type)
 138
 139 static int ext4_verify_csum_type(struct super_block *sb,
 140                                  struct ext4_super_block *es)
 141 {
 142         if (!ext4_has_feature_metadata_csum(sb))
 143                 return 1;
 144
 145         return es->s_checksum_type == EXT4_CRC32C_CHKSUM;
 146 }
 147
 148 static __le32 ext4_superblock_csum(struct super_block *sb,
 149                                    struct ext4_super_block *es)
 150 {
 151         struct ext4_sb_info *sbi = EXT4_SB(sb);
 152         int offset = offsetof(struct ext4_super_block, s_checksum);
 153         __u32 csum;
 154
 155         csum = ext4_chksum(sbi, ~0, (char *)es, offset);
 156
 157         return cpu_to_le32(csum);
 158 }
 159
 160 static int ext4_superblock_csum_verify(struct super_block *sb,
 161                                        struct ext4_super_block *es)
 162 {
 163         if (!ext4_has_metadata_csum(sb))
 164                 return 1;
 165
 166         return es->s_checksum == ext4_superblock_csum(sb, es);
 167 }
 168
 169 void ext4_superblock_csum_set(struct super_block *sb)
 170 {
 171         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 172
 173         if (!ext4_has_metadata_csum(sb))
 174                 return;
 175
 176         es->s_checksum = ext4_superblock_csum(sb, es);
 177 }
 178
 179 void *ext4_kvmalloc(size_t size, gfp_t flags)
 180 {
 181         void *ret;
 182
 183         ret = kmalloc(size, flags | __GFP_NOWARN);
 184         if (!ret)
 185                 ret = __vmalloc(size, flags, PAGE_KERNEL);
 186         return ret;
 187 }
 188
 189 void *ext4_kvzalloc(size_t size, gfp_t flags)
 190 {
 191         void *ret;
 192
 193         ret = kzalloc(size, flags | __GFP_NOWARN);
 194         if (!ret)
 195                 ret = __vmalloc(size, flags | __GFP_ZERO, PAGE_KERNEL);
 196         return ret;
 197 }
 198
 199 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
 200                                struct ext4_group_desc *bg)
 201 {
 202         return le32_to_cpu(bg->bg_block_bitmap_lo) |
 203                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 204                  (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
 205 }
 206
 207 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
 208                                struct ext4_group_desc *bg)
 209 {
 210         return le32_to_cpu(bg->bg_inode_bitmap_lo) |
 211                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 212                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
 213 }
 214
 215 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
 216                               struct ext4_group_desc *bg)
 217 {
 218         return le32_to_cpu(bg->bg_inode_table_lo) |
 219                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 220                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
 221 }
 222
 223 __u32 ext4_free_group_clusters(struct super_block *sb,
 224                                struct ext4_group_desc *bg)
 225 {
 226         return le16_to_cpu(bg->bg_free_blocks_count_lo) |
 227                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 228                  (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
 229 }
 230
 231 __u32 ext4_free_inodes_count(struct super_block *sb,
 232                               struct ext4_group_desc *bg)
 233 {
 234         return le16_to_cpu(bg->bg_free_inodes_count_lo) |
 235                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 236                  (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
 237 }
 238
 239 __u32 ext4_used_dirs_count(struct super_block *sb,
 240                               struct ext4_group_desc *bg)
 241 {
 242         return le16_to_cpu(bg->bg_used_dirs_count_lo) |
 243                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 244                  (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
 245 }
 246
 247 __u32 ext4_itable_unused_count(struct super_block *sb,
 248                               struct ext4_group_desc *bg)
 249 {
 250         return le16_to_cpu(bg->bg_itable_unused_lo) |
 251                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 252                  (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
 253 }
 254
 255 void ext4_block_bitmap_set(struct super_block *sb,
 256                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 257 {
 258         bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
 259         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 260                 bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
 261 }
 262
 263 void ext4_inode_bitmap_set(struct super_block *sb,
 264                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 265 {
 266         bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
 267         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 268                 bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
 269 }
 270
 271 void ext4_inode_table_set(struct super_block *sb,
 272                           struct ext4_group_desc *bg, ext4_fsblk_t blk)
 273 {
 274         bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
 275         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 276                 bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
 277 }
 278
 279 void ext4_free_group_clusters_set(struct super_block *sb,
 280                                   struct ext4_group_desc *bg, __u32 count)
 281 {
 282         bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
 283         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 284                 bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
 285 }
 286
 287 void ext4_free_inodes_set(struct super_block *sb,
 288                           struct ext4_group_desc *bg, __u32 count)
 289 {
 290         bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
 291         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 292                 bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
 293 }
 294
 295 void ext4_used_dirs_set(struct super_block *sb,
 296                           struct ext4_group_desc *bg, __u32 count)
 297 {
 298         bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
 299         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 300                 bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
 301 }
 302
 303 void ext4_itable_unused_set(struct super_block *sb,
 304                           struct ext4_group_desc *bg, __u32 count)
 305 {
 306         bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
 307         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 308                 bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
 309 }
 310
 311
 312 static void __save_error_info(struct super_block *sb, const char *func,
 313                             unsigned int line)
 314 {
 315         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 316
 317         EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
 318         if (bdev_read_only(sb->s_bdev))
 319                 return;
 320         es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
 321         es->s_last_error_time = cpu_to_le32(get_seconds());
 322         strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
 323         es->s_last_error_line = cpu_to_le32(line);
 324         if (!es->s_first_error_time) {
 325                 es->s_first_error_time = es->s_last_error_time;
 326                 strncpy(es->s_first_error_func, func,
 327                         sizeof(es->s_first_error_func));
 328                 es->s_first_error_line = cpu_to_le32(line);
 329                 es->s_first_error_ino = es->s_last_error_ino;
 330                 es->s_first_error_block = es->s_last_error_block;
 331         }
 332         /*
 333          * Start the daily error reporting function if it hasn't been
 334          * started already
 335          */
 336         if (!es->s_error_count)
 337                 mod_timer(&EXT4_SB(sb)->s_err_report, jiffies + 24*60*60*HZ);
 338         le32_add_cpu(&es->s_error_count, 1);
 339 }
 340
 341 static void save_error_info(struct super_block *sb, const char *func,
 342                             unsigned int line)
 343 {
 344         __save_error_info(sb, func, line);
 345         ext4_commit_super(sb, 1);
 346 }
 347
 348 /*
 349  * The del_gendisk() function uninitializes the disk-specific data
 350  * structures, including the bdi structure, without telling anyone
 351  * else.  Once this happens, any attempt to call mark_buffer_dirty()
 352  * (for example, by ext4_commit_super), will cause a kernel OOPS.
 353  * This is a kludge to prevent these oops until we can put in a proper
 354  * hook in del_gendisk() to inform the VFS and file system layers.
 355  */
 356 static int block_device_ejected(struct super_block *sb)
 357 {
 358         struct inode *bd_inode = sb->s_bdev->bd_inode;
 359         struct backing_dev_info *bdi = inode_to_bdi(bd_inode);
 360
 361         return bdi->dev == NULL;
 362 }
 363
 364 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
 365 {
 366         struct super_block              *sb = journal->j_private;
 367         struct ext4_sb_info             *sbi = EXT4_SB(sb);
 368         int                             error = is_journal_aborted(journal);
 369         struct ext4_journal_cb_entry    *jce;
 370
 371         BUG_ON(txn->t_state == T_FINISHED);
 372         spin_lock(&sbi->s_md_lock);
 373         while (!list_empty(&txn->t_private_list)) {
 374                 jce = list_entry(txn->t_private_list.next,
 375                                  struct ext4_journal_cb_entry, jce_list);
 376                 list_del_init(&jce->jce_list);
 377                 spin_unlock(&sbi->s_md_lock);
 378                 jce->jce_func(sb, jce, error);
 379                 spin_lock(&sbi->s_md_lock);
 380         }
 381         spin_unlock(&sbi->s_md_lock);
 382 }
 383
 384 /* Deal with the reporting of failure conditions on a filesystem such as
 385  * inconsistencies detected or read IO failures.
 386  *
 387  * On ext2, we can store the error state of the filesystem in the
 388  * superblock.  That is not possible on ext4, because we may have other
 389  * write ordering constraints on the superblock which prevent us from
 390  * writing it out straight away; and given that the journal is about to
 391  * be aborted, we can't rely on the current, or future, transactions to
 392  * write out the superblock safely.
 393  *
 394  * We'll just use the jbd2_journal_abort() error code to record an error in
 395  * the journal instead.  On recovery, the journal will complain about
 396  * that error until we've noted it down and cleared it.
 397  */
 398
 399 static void ext4_handle_error(struct super_block *sb)
 400 {
 401         if (sb->s_flags & MS_RDONLY)
 402                 return;
 403
 404         if (!test_opt(sb, ERRORS_CONT)) {
 405                 journal_t *journal = EXT4_SB(sb)->s_journal;
 406
 407                 EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
 408                 if (journal)
 409                         jbd2_journal_abort(journal, -EIO);
 410         }
 411         if (test_opt(sb, ERRORS_RO)) {
 412                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 413                 /*
 414                  * Make sure updated value of ->s_mount_flags will be visible
 415                  * before ->s_flags update
 416                  */
 417                 smp_wmb();
 418                 sb->s_flags |= MS_RDONLY;
 419         }
 420         if (test_opt(sb, ERRORS_PANIC)) {
 421                 if (EXT4_SB(sb)->s_journal &&
 422                   !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
 423                         return;
 424                 panic("EXT4-fs (device %s): panic forced after error\n",
 425                         sb->s_id);
 426         }
 427 }
 428
 429 #define ext4_error_ratelimit(sb)                                        \
 430                 ___ratelimit(&(EXT4_SB(sb)->s_err_ratelimit_state),     \
 431                              "EXT4-fs error")
 432
 433 void __ext4_error(struct super_block *sb, const char *function,
 434                   unsigned int line, const char *fmt, ...)
 435 {
 436         struct va_format vaf;
 437         va_list args;
 438
 439         if (ext4_error_ratelimit(sb)) {
 440                 va_start(args, fmt);
 441                 vaf.fmt = fmt;
 442                 vaf.va = &args;
 443                 printk(KERN_CRIT
 444                        "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
 445                        sb->s_id, function, line, current->comm, &vaf);
 446                 va_end(args);
 447         }
 448         save_error_info(sb, function, line);
 449         ext4_handle_error(sb);
 450 }
 451
 452 void __ext4_error_inode(struct inode *inode, const char *function,
 453                         unsigned int line, ext4_fsblk_t block,
 454                         const char *fmt, ...)
 455 {
 456         va_list args;
 457         struct va_format vaf;
 458         struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
 459
 460         es->s_last_error_ino = cpu_to_le32(inode->i_ino);
 461         es->s_last_error_block = cpu_to_le64(block);
 462         if (ext4_error_ratelimit(inode->i_sb)) {
 463                 va_start(args, fmt);
 464                 vaf.fmt = fmt;
 465                 vaf.va = &args;
 466                 if (block)
 467                         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
 468                                "inode #%lu: block %llu: comm %s: %pV\n",
 469                                inode->i_sb->s_id, function, line, inode->i_ino,
 470                                block, current->comm, &vaf);
 471                 else
 472                         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
 473                                "inode #%lu: comm %s: %pV\n",
 474                                inode->i_sb->s_id, function, line, inode->i_ino,
 475                                current->comm, &vaf);
 476                 va_end(args);
 477         }
 478         save_error_info(inode->i_sb, function, line);
 479         ext4_handle_error(inode->i_sb);
 480 }
 481
 482 void __ext4_error_file(struct file *file, const char *function,
 483                        unsigned int line, ext4_fsblk_t block,
 484                        const char *fmt, ...)
 485 {
 486         va_list args;
 487         struct va_format vaf;
 488         struct ext4_super_block *es;
 489         struct inode *inode = file_inode(file);
 490         char pathname[80], *path;
 491
 492         es = EXT4_SB(inode->i_sb)->s_es;
 493         es->s_last_error_ino = cpu_to_le32(inode->i_ino);
 494         if (ext4_error_ratelimit(inode->i_sb)) {
 495                 path = file_path(file, pathname, sizeof(pathname));
 496                 if (IS_ERR(path))
 497                         path = "(unknown)";
 498                 va_start(args, fmt);
 499                 vaf.fmt = fmt;
 500                 vaf.va = &args;
 501                 if (block)
 502                         printk(KERN_CRIT
 503                                "EXT4-fs error (device %s): %s:%d: inode #%lu: "
 504                                "block %llu: comm %s: path %s: %pV\n",
 505                                inode->i_sb->s_id, function, line, inode->i_ino,
 506                                block, current->comm, path, &vaf);
 507                 else
 508                         printk(KERN_CRIT
 509                                "EXT4-fs error (device %s): %s:%d: inode #%lu: "
 510                                "comm %s: path %s: %pV\n",
 511                                inode->i_sb->s_id, function, line, inode->i_ino,
 512                                current->comm, path, &vaf);
 513                 va_end(args);
 514         }
 515         save_error_info(inode->i_sb, function, line);
 516         ext4_handle_error(inode->i_sb);
 517 }
 518
 519 const char *ext4_decode_error(struct super_block *sb, int errno,
 520                               char nbuf[16])
 521 {
 522         char *errstr = NULL;
 523
 524         switch (errno) {
 525         case -EFSCORRUPTED:
 526                 errstr = "Corrupt filesystem";
 527                 break;
 528         case -EFSBADCRC:
 529                 errstr = "Filesystem failed CRC";
 530                 break;
 531         case -EIO:
 532                 errstr = "IO failure";
 533                 break;
 534         case -ENOMEM:
 535                 errstr = "Out of memory";
 536                 break;
 537         case -EROFS:
 538                 if (!sb || (EXT4_SB(sb)->s_journal &&
 539                             EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
 540                         errstr = "Journal has aborted";
 541                 else
 542                         errstr = "Readonly filesystem";
 543                 break;
 544         default:
 545                 /* If the caller passed in an extra buffer for unknown
 546                  * errors, textualise them now.  Else we just return
 547                  * NULL. */
 548                 if (nbuf) {
 549                         /* Check for truncated error codes... */
 550                         if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
 551                                 errstr = nbuf;
 552                 }
 553                 break;
 554         }
 555
 556         return errstr;
 557 }
 558
 559 /* __ext4_std_error decodes expected errors from journaling functions
 560  * automatically and invokes the appropriate error response.  */
 561
 562 void __ext4_std_error(struct super_block *sb, const char *function,
 563                       unsigned int line, int errno)
 564 {
 565         char nbuf[16];
 566         const char *errstr;
 567
 568         /* Special case: if the error is EROFS, and we're not already
 569          * inside a transaction, then there's really no point in logging
 570          * an error. */
 571         if (errno == -EROFS && journal_current_handle() == NULL &&
 572             (sb->s_flags & MS_RDONLY))
 573                 return;
 574
 575         if (ext4_error_ratelimit(sb)) {
 576                 errstr = ext4_decode_error(sb, errno, nbuf);
 577                 printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
 578                        sb->s_id, function, line, errstr);
 579         }
 580
 581         save_error_info(sb, function, line);
 582         ext4_handle_error(sb);
 583 }
 584
 585 /*
 586  * ext4_abort is a much stronger failure handler than ext4_error.  The
 587  * abort function may be used to deal with unrecoverable failures such
 588  * as journal IO errors or ENOMEM at a critical moment in log management.
 589  *
 590  * We unconditionally force the filesystem into an ABORT|READONLY state,
 591  * unless the error response on the fs has been set to panic in which
 592  * case we take the easy way out and panic immediately.
 593  */
 594
 595 void __ext4_abort(struct super_block *sb, const char *function,
 596                 unsigned int line, const char *fmt, ...)
 597 {
 598         va_list args;
 599
 600         save_error_info(sb, function, line);
 601         va_start(args, fmt);
 602         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: ", sb->s_id,
 603                function, line);
 604         vprintk(fmt, args);
 605         printk("\n");
 606         va_end(args);
 607
 608         if ((sb->s_flags & MS_RDONLY) == 0) {
 609                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 610                 EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
 611                 /*
 612                  * Make sure updated value of ->s_mount_flags will be visible
 613                  * before ->s_flags update
 614                  */
 615                 smp_wmb();
 616                 sb->s_flags |= MS_RDONLY;
 617                 if (EXT4_SB(sb)->s_journal)
 618                         jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
 619                 save_error_info(sb, function, line);
 620         }
 621         if (test_opt(sb, ERRORS_PANIC)) {
 622                 if (EXT4_SB(sb)->s_journal &&
 623                   !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
 624                         return;
 625                 panic("EXT4-fs panic from previous error\n");
 626         }
 627 }
 628
 629 void __ext4_msg(struct super_block *sb,
 630                 const char *prefix, const char *fmt, ...)
 631 {
 632         struct va_format vaf;
 633         va_list args;
 634
 635         if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state), "EXT4-fs"))
 636                 return;
 637
 638         va_start(args, fmt);
 639         vaf.fmt = fmt;
 640         vaf.va = &args;
 641         printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
 642         va_end(args);
 643 }
 644
 645 #define ext4_warning_ratelimit(sb)                                      \
 646                 ___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state), \
 647                              "EXT4-fs warning")
 648
 649 void __ext4_warning(struct super_block *sb, const char *function,
 650                     unsigned int line, const char *fmt, ...)
 651 {
 652         struct va_format vaf;
 653         va_list args;
 654
 655         if (!ext4_warning_ratelimit(sb))
 656                 return;
 657
 658         va_start(args, fmt);
 659         vaf.fmt = fmt;
 660         vaf.va = &args;
 661         printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
 662                sb->s_id, function, line, &vaf);
 663         va_end(args);
 664 }
 665
 666 void __ext4_warning_inode(const struct inode *inode, const char *function,
 667                           unsigned int line, const char *fmt, ...)
 668 {
 669         struct va_format vaf;
 670         va_list args;
 671
 672         if (!ext4_warning_ratelimit(inode->i_sb))
 673                 return;
 674
 675         va_start(args, fmt);
 676         vaf.fmt = fmt;
 677         vaf.va = &args;
 678         printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: "
 679                "inode #%lu: comm %s: %pV\n", inode->i_sb->s_id,
 680                function, line, inode->i_ino, current->comm, &vaf);
 681         va_end(args);
 682 }
 683
 684 void __ext4_grp_locked_error(const char *function, unsigned int line,
 685                              struct super_block *sb, ext4_group_t grp,
 686                              unsigned long ino, ext4_fsblk_t block,
 687                              const char *fmt, ...)
 688 __releases(bitlock)
 689 __acquires(bitlock)
 690 {
 691         struct va_format vaf;
 692         va_list args;
 693         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 694
 695         es->s_last_error_ino = cpu_to_le32(ino);
 696         es->s_last_error_block = cpu_to_le64(block);
 697         __save_error_info(sb, function, line);
 698
 699         if (ext4_error_ratelimit(sb)) {
 700                 va_start(args, fmt);
 701                 vaf.fmt = fmt;
 702                 vaf.va = &args;
 703                 printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
 704                        sb->s_id, function, line, grp);
 705                 if (ino)
 706                         printk(KERN_CONT "inode %lu: ", ino);
 707                 if (block)
 708                         printk(KERN_CONT "block %llu:",
 709                                (unsigned long long) block);
 710                 printk(KERN_CONT "%pV\n", &vaf);
 711                 va_end(args);
 712         }
 713
 714         if (test_opt(sb, ERRORS_CONT)) {
 715                 ext4_commit_super(sb, 0);
 716                 return;
 717         }
 718
 719         ext4_unlock_group(sb, grp);
 720         ext4_handle_error(sb);
 721         /*
 722          * We only get here in the ERRORS_RO case; relocking the group
 723          * may be dangerous, but nothing bad will happen since the
 724          * filesystem will have already been marked read/only and the
 725          * journal has been aborted.  We return 1 as a hint to callers
 726          * who might what to use the return value from
 727          * ext4_grp_locked_error() to distinguish between the
 728          * ERRORS_CONT and ERRORS_RO case, and perhaps return more
 729          * aggressively from the ext4 function in question, with a
 730          * more appropriate error code.
 731          */
 732         ext4_lock_group(sb, grp);
 733         return;
 734 }
 735
 736 void ext4_update_dynamic_rev(struct super_block *sb)
 737 {
 738         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 739
 740         if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
 741                 return;
 742
 743         ext4_warning(sb,
 744                      "updating to rev %d because of new feature flag, "
 745                      "running e2fsck is recommended",
 746                      EXT4_DYNAMIC_REV);
 747
 748         es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
 749         es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
 750         es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
 751         /* leave es->s_feature_*compat flags alone */
 752         /* es->s_uuid will be set by e2fsck if empty */
 753
 754         /*
 755          * The rest of the superblock fields should be zero, and if not it
 756          * means they are likely already in use, so leave them alone.  We
 757          * can leave it up to e2fsck to clean up any inconsistencies there.
 758          */
 759 }
 760
 761 /*
 762  * Open the external journal device
 763  */
 764 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
 765 {
 766         struct block_device *bdev;
 767         char b[BDEVNAME_SIZE];
 768
 769         bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
 770         if (IS_ERR(bdev))
 771                 goto fail;
 772         return bdev;
 773
 774 fail:
 775         ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
 776                         __bdevname(dev, b), PTR_ERR(bdev));
 777         return NULL;
 778 }
 779
 780 /*
 781  * Release the journal device
 782  */
 783 static void ext4_blkdev_put(struct block_device *bdev)
 784 {
 785         blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
 786 }
 787
 788 static void ext4_blkdev_remove(struct ext4_sb_info *sbi)
 789 {
 790         struct block_device *bdev;
 791         bdev = sbi->journal_bdev;
 792         if (bdev) {
 793                 ext4_blkdev_put(bdev);
 794                 sbi->journal_bdev = NULL;
 795         }
 796 }
 797
 798 static inline struct inode *orphan_list_entry(struct list_head *l)
 799 {
 800         return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
 801 }
 802
 803 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
 804 {
 805         struct list_head *l;
 806
 807         ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
 808                  le32_to_cpu(sbi->s_es->s_last_orphan));
 809
 810         printk(KERN_ERR "sb_info orphan list:\n");
 811         list_for_each(l, &sbi->s_orphan) {
 812                 struct inode *inode = orphan_list_entry(l);
 813                 printk(KERN_ERR "  "
 814                        "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
 815                        inode->i_sb->s_id, inode->i_ino, inode,
 816                        inode->i_mode, inode->i_nlink,
 817                        NEXT_ORPHAN(inode));
 818         }
 819 }
 820
 821 static void ext4_put_super(struct super_block *sb)
 822 {
 823         struct ext4_sb_info *sbi = EXT4_SB(sb);
 824         struct ext4_super_block *es = sbi->s_es;
 825         int i, err;
 826
 827         ext4_unregister_li_request(sb);
 828         dquot_disable(sb, -1, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
 829
 830         flush_workqueue(sbi->rsv_conversion_wq);
 831         destroy_workqueue(sbi->rsv_conversion_wq);
 832
 833         if (sbi->s_journal) {
 834                 err = jbd2_journal_destroy(sbi->s_journal);
 835                 sbi->s_journal = NULL;
 836                 if (err < 0)
 837                         ext4_abort(sb, "Couldn't clean up the journal");
 838         }
 839
 840         ext4_unregister_sysfs(sb);
 841         ext4_es_unregister_shrinker(sbi);
 842         del_timer_sync(&sbi->s_err_report);
 843         ext4_release_system_zone(sb);
 844         ext4_mb_release(sb);
 845         ext4_ext_release(sb);
 846
 847         if (!(sb->s_flags & MS_RDONLY)) {
 848                 ext4_clear_feature_journal_needs_recovery(sb);
 849                 es->s_state = cpu_to_le16(sbi->s_mount_state);
 850         }
 851         if (!(sb->s_flags & MS_RDONLY))
 852                 ext4_commit_super(sb, 1);
 853
 854         for (i = 0; i < sbi->s_gdb_count; i++)
 855                 brelse(sbi->s_group_desc[i]);
 856         kvfree(sbi->s_group_desc);
 857         kvfree(sbi->s_flex_groups);
 858         percpu_counter_destroy(&sbi->s_freeclusters_counter);
 859         percpu_counter_destroy(&sbi->s_freeinodes_counter);
 860         percpu_counter_destroy(&sbi->s_dirs_counter);
 861         percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
 862         percpu_free_rwsem(&sbi->s_journal_flag_rwsem);
 863         brelse(sbi->s_sbh);
 864 #ifdef CONFIG_QUOTA
 865         for (i = 0; i < EXT4_MAXQUOTAS; i++)
 866                 kfree(sbi->s_qf_names[i]);
 867 #endif
 868
 869         /* Debugging code just in case the in-memory inode orphan list
 870          * isn't empty.  The on-disk one can be non-empty if we've
 871          * detected an error and taken the fs readonly, but the
 872          * in-memory list had better be clean by this point. */
 873         if (!list_empty(&sbi->s_orphan))
 874                 dump_orphan_list(sb, sbi);
 875         J_ASSERT(list_empty(&sbi->s_orphan));
 876
 877         sync_blockdev(sb->s_bdev);
 878         invalidate_bdev(sb->s_bdev);
 879         if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
 880                 /*
 881                  * Invalidate the journal device's buffers.  We don't want them
 882                  * floating about in memory - the physical journal device may
 883                  * hotswapped, and it breaks the `ro-after' testing code.
 884                  */
 885                 sync_blockdev(sbi->journal_bdev);
 886                 invalidate_bdev(sbi->journal_bdev);
 887                 ext4_blkdev_remove(sbi);
 888         }
 889         if (sbi->s_mb_cache) {
 890                 ext4_xattr_destroy_cache(sbi->s_mb_cache);
 891                 sbi->s_mb_cache = NULL;
 892         }
 893         if (sbi->s_mmp_tsk)
 894                 kthread_stop(sbi->s_mmp_tsk);
 895         sb->s_fs_info = NULL;
 896         /*
 897          * Now that we are completely done shutting down the
 898          * superblock, we need to actually destroy the kobject.
 899          */
 900         kobject_put(&sbi->s_kobj);
 901         wait_for_completion(&sbi->s_kobj_unregister);
 902         if (sbi->s_chksum_driver)
 903                 crypto_free_shash(sbi->s_chksum_driver);
 904         kfree(sbi->s_blockgroup_lock);
 905         kfree(sbi);
 906 }
 907
 908 static struct kmem_cache *ext4_inode_cachep;
 909
 910 /*
 911  * Called inside transaction, so use GFP_NOFS
 912  */
 913 static struct inode *ext4_alloc_inode(struct super_block *sb)
 914 {
 915         struct ext4_inode_info *ei;
 916
 917         ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
 918         if (!ei)
 919                 return NULL;
 920
 921         ei->vfs_inode.i_version = 1;
 922         spin_lock_init(&ei->i_raw_lock);
 923         INIT_LIST_HEAD(&ei->i_prealloc_list);
 924         spin_lock_init(&ei->i_prealloc_lock);
 925         ext4_es_init_tree(&ei->i_es_tree);
 926         rwlock_init(&ei->i_es_lock);
 927         INIT_LIST_HEAD(&ei->i_es_list);
 928         ei->i_es_all_nr = 0;
 929         ei->i_es_shk_nr = 0;
 930         ei->i_es_shrink_lblk = 0;
 931         ei->i_reserved_data_blocks = 0;
 932         ei->i_reserved_meta_blocks = 0;
 933         ei->i_allocated_meta_blocks = 0;
 934         ei->i_da_metadata_calc_len = 0;
 935         ei->i_da_metadata_calc_last_lblock = 0;
 936         spin_lock_init(&(ei->i_block_reservation_lock));
 937 #ifdef CONFIG_QUOTA
 938         ei->i_reserved_quota = 0;
 939         memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
 940 #endif
 941         ei->jinode = NULL;
 942         INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
 943         spin_lock_init(&ei->i_completed_io_lock);
 944         ei->i_sync_tid = 0;
 945         ei->i_datasync_tid = 0;
 946         atomic_set(&ei->i_unwritten, 0);
 947         INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
 948 #ifdef CONFIG_EXT4_FS_ENCRYPTION
 949         ei->i_crypt_info = NULL;
 950 #endif
 951         return &ei->vfs_inode;
 952 }
 953
 954 static int ext4_drop_inode(struct inode *inode)
 955 {
 956         int drop = generic_drop_inode(inode);
 957
 958         trace_ext4_drop_inode(inode, drop);
 959         return drop;
 960 }
 961
 962 static void ext4_i_callback(struct rcu_head *head)
 963 {
 964         struct inode *inode = container_of(head, struct inode, i_rcu);
 965         kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
 966 }
 967
 968 static void ext4_destroy_inode(struct inode *inode)
 969 {
 970         if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
 971                 ext4_msg(inode->i_sb, KERN_ERR,
 972                          "Inode %lu (%p): orphan list check failed!",
 973                          inode->i_ino, EXT4_I(inode));
 974                 print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
 975                                 EXT4_I(inode), sizeof(struct ext4_inode_info),
 976                                 true);
 977                 dump_stack();
 978         }
 979         call_rcu(&inode->i_rcu, ext4_i_callback);
 980 }
 981
 982 static void init_once(void *foo)
 983 {
 984         struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
 985
 986         INIT_LIST_HEAD(&ei->i_orphan);
 987         init_rwsem(&ei->xattr_sem);
 988         init_rwsem(&ei->i_data_sem);
 989         init_rwsem(&ei->i_mmap_sem);
 990         inode_init_once(&ei->vfs_inode);
 991 }
 992
 993 static int __init init_inodecache(void)
 994 {
 995         ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
 996                                              sizeof(struct ext4_inode_info),
 997                                              0, (SLAB_RECLAIM_ACCOUNT|
 998                                                 SLAB_MEM_SPREAD|SLAB_ACCOUNT),
 999                                              init_once);
1000         if (ext4_inode_cachep == NULL)
1001                 return -ENOMEM;
1002         return 0;
1003 }
1004
1005 static void destroy_inodecache(void)
1006 {
1007         /*
1008          * Make sure all delayed rcu free inodes are flushed before we
1009          * destroy cache.
1010          */
1011         rcu_barrier();
1012         kmem_cache_destroy(ext4_inode_cachep);
1013 }
1014
1015 void ext4_clear_inode(struct inode *inode)
1016 {
1017         invalidate_inode_buffers(inode);
1018         clear_inode(inode);
1019         dquot_drop(inode);
1020         ext4_discard_preallocations(inode);
1021         ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
1022         if (EXT4_I(inode)->jinode) {
1023                 jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
1024                                                EXT4_I(inode)->jinode);
1025                 jbd2_free_inode(EXT4_I(inode)->jinode);
1026                 EXT4_I(inode)->jinode = NULL;
1027         }
1028 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1029         if (EXT4_I(inode)->i_crypt_info)
1030                 ext4_free_encryption_info(inode, EXT4_I(inode)->i_crypt_info);
1031 #endif
1032 }
1033
1034 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1035                                         u64 ino, u32 generation)
1036 {
1037         struct inode *inode;
1038
1039         if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
1040                 return ERR_PTR(-ESTALE);
1041         if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
1042                 return ERR_PTR(-ESTALE);
1043
1044         /* iget isn't really right if the inode is currently unallocated!!
1045          *
1046          * ext4_read_inode will return a bad_inode if the inode had been
1047          * deleted, so we should be safe.
1048          *
1049          * Currently we don't know the generation for parent directory, so
1050          * a generation of 0 means "accept any"
1051          */
1052         inode = ext4_iget_normal(sb, ino);
1053         if (IS_ERR(inode))
1054                 return ERR_CAST(inode);
1055         if (generation && inode->i_generation != generation) {
1056                 iput(inode);
1057                 return ERR_PTR(-ESTALE);
1058         }
1059
1060         return inode;
1061 }
1062
1063 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1064                                         int fh_len, int fh_type)
1065 {
1066         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1067                                     ext4_nfs_get_inode);
1068 }
1069
1070 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1071                                         int fh_len, int fh_type)
1072 {
1073         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1074                                     ext4_nfs_get_inode);
1075 }
1076
1077 /*
1078  * Try to release metadata pages (indirect blocks, directories) which are
1079  * mapped via the block device.  Since these pages could have journal heads
1080  * which would prevent try_to_free_buffers() from freeing them, we must use
1081  * jbd2 layer's try_to_free_buffers() function to release them.
1082  */
1083 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1084                                  gfp_t wait)
1085 {
1086         journal_t *journal = EXT4_SB(sb)->s_journal;
1087
1088         WARN_ON(PageChecked(page));
1089         if (!page_has_buffers(page))
1090                 return 0;
1091         if (journal)
1092                 return jbd2_journal_try_to_free_buffers(journal, page,
1093                                                 wait & ~__GFP_DIRECT_RECLAIM);
1094         return try_to_free_buffers(page);
1095 }
1096
1097 #ifdef CONFIG_QUOTA
1098 static char *quotatypes[] = INITQFNAMES;
1099 #define QTYPE2NAME(t) (quotatypes[t])
1100
1101 static int ext4_write_dquot(struct dquot *dquot);
1102 static int ext4_acquire_dquot(struct dquot *dquot);
1103 static int ext4_release_dquot(struct dquot *dquot);
1104 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1105 static int ext4_write_info(struct super_block *sb, int type);
1106 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1107                          struct path *path);
1108 static int ext4_quota_off(struct super_block *sb, int type);
1109 static int ext4_quota_on_mount(struct super_block *sb, int type);
1110 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1111                                size_t len, loff_t off);
1112 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1113                                 const char *data, size_t len, loff_t off);
1114 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1115                              unsigned int flags);
1116 static int ext4_enable_quotas(struct super_block *sb);
1117 static int ext4_get_next_id(struct super_block *sb, struct kqid *qid);
1118
1119 static struct dquot **ext4_get_dquots(struct inode *inode)
1120 {
1121         return EXT4_I(inode)->i_dquot;
1122 }
1123
1124 static const struct dquot_operations ext4_quota_operations = {
1125         .get_reserved_space = ext4_get_reserved_space,
1126         .write_dquot    = ext4_write_dquot,
1127         .acquire_dquot  = ext4_acquire_dquot,
1128         .release_dquot  = ext4_release_dquot,
1129         .mark_dirty     = ext4_mark_dquot_dirty,
1130         .write_info     = ext4_write_info,
1131         .alloc_dquot    = dquot_alloc,
1132         .destroy_dquot  = dquot_destroy,
1133         .get_projid     = ext4_get_projid,
1134         .get_next_id    = ext4_get_next_id,
1135 };
1136
1137 static const struct quotactl_ops ext4_qctl_operations = {
1138         .quota_on       = ext4_quota_on,
1139         .quota_off      = ext4_quota_off,
1140         .quota_sync     = dquot_quota_sync,
1141         .get_state      = dquot_get_state,
1142         .set_info       = dquot_set_dqinfo,
1143         .get_dqblk      = dquot_get_dqblk,
1144         .set_dqblk      = dquot_set_dqblk,
1145         .get_nextdqblk  = dquot_get_next_dqblk,
1146 };
1147 #endif
1148
1149 static const struct super_operations ext4_sops = {
1150         .alloc_inode    = ext4_alloc_inode,
1151         .destroy_inode  = ext4_destroy_inode,
1152         .write_inode    = ext4_write_inode,
1153         .dirty_inode    = ext4_dirty_inode,
1154         .drop_inode     = ext4_drop_inode,
1155         .evict_inode    = ext4_evict_inode,
1156         .put_super      = ext4_put_super,
1157         .sync_fs        = ext4_sync_fs,
1158         .freeze_fs      = ext4_freeze,
1159         .unfreeze_fs    = ext4_unfreeze,
1160         .statfs         = ext4_statfs,
1161         .remount_fs     = ext4_remount,
1162         .show_options   = ext4_show_options,
1163 #ifdef CONFIG_QUOTA
1164         .quota_read     = ext4_quota_read,
1165         .quota_write    = ext4_quota_write,
1166         .get_dquots     = ext4_get_dquots,
1167 #endif
1168         .bdev_try_to_free_page = bdev_try_to_free_page,
1169 };
1170
1171 static const struct export_operations ext4_export_ops = {
1172         .fh_to_dentry = ext4_fh_to_dentry,
1173         .fh_to_parent = ext4_fh_to_parent,
1174         .get_parent = ext4_get_parent,
1175 };
1176
1177 enum {
1178         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1179         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1180         Opt_nouid32, Opt_debug, Opt_removed,
1181         Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1182         Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1183         Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1184         Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1185         Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1186         Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
1187         Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1188         Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1189         Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1190         Opt_usrquota, Opt_grpquota, Opt_i_version, Opt_dax,
1191         Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_mblk_io_submit,
1192         Opt_lazytime, Opt_nolazytime,
1193         Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1194         Opt_inode_readahead_blks, Opt_journal_ioprio,
1195         Opt_dioread_nolock, Opt_dioread_lock,
1196         Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1197         Opt_max_dir_size_kb, Opt_nojournal_checksum,
1198 };
1199
1200 static const match_table_t tokens = {
1201         {Opt_bsd_df, "bsddf"},
1202         {Opt_minix_df, "minixdf"},
1203         {Opt_grpid, "grpid"},
1204         {Opt_grpid, "bsdgroups"},
1205         {Opt_nogrpid, "nogrpid"},
1206         {Opt_nogrpid, "sysvgroups"},
1207         {Opt_resgid, "resgid=%u"},
1208         {Opt_resuid, "resuid=%u"},
1209         {Opt_sb, "sb=%u"},
1210         {Opt_err_cont, "errors=continue"},
1211         {Opt_err_panic, "errors=panic"},
1212         {Opt_err_ro, "errors=remount-ro"},
1213         {Opt_nouid32, "nouid32"},
1214         {Opt_debug, "debug"},
1215         {Opt_removed, "oldalloc"},
1216         {Opt_removed, "orlov"},
1217         {Opt_user_xattr, "user_xattr"},
1218         {Opt_nouser_xattr, "nouser_xattr"},
1219         {Opt_acl, "acl"},
1220         {Opt_noacl, "noacl"},
1221         {Opt_noload, "norecovery"},
1222         {Opt_noload, "noload"},
1223         {Opt_removed, "nobh"},
1224         {Opt_removed, "bh"},
1225         {Opt_commit, "commit=%u"},
1226         {Opt_min_batch_time, "min_batch_time=%u"},
1227         {Opt_max_batch_time, "max_batch_time=%u"},
1228         {Opt_journal_dev, "journal_dev=%u"},
1229         {Opt_journal_path, "journal_path=%s"},
1230         {Opt_journal_checksum, "journal_checksum"},
1231         {Opt_nojournal_checksum, "nojournal_checksum"},
1232         {Opt_journal_async_commit, "journal_async_commit"},
1233         {Opt_abort, "abort"},
1234         {Opt_data_journal, "data=journal"},
1235         {Opt_data_ordered, "data=ordered"},
1236         {Opt_data_writeback, "data=writeback"},
1237         {Opt_data_err_abort, "data_err=abort"},
1238         {Opt_data_err_ignore, "data_err=ignore"},
1239         {Opt_offusrjquota, "usrjquota="},
1240         {Opt_usrjquota, "usrjquota=%s"},
1241         {Opt_offgrpjquota, "grpjquota="},
1242         {Opt_grpjquota, "grpjquota=%s"},
1243         {Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1244         {Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1245         {Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1246         {Opt_grpquota, "grpquota"},
1247         {Opt_noquota, "noquota"},
1248         {Opt_quota, "quota"},
1249         {Opt_usrquota, "usrquota"},
1250         {Opt_barrier, "barrier=%u"},
1251         {Opt_barrier, "barrier"},
1252         {Opt_nobarrier, "nobarrier"},
1253         {Opt_i_version, "i_version"},
1254         {Opt_dax, "dax"},
1255         {Opt_stripe, "stripe=%u"},
1256         {Opt_delalloc, "delalloc"},
1257         {Opt_lazytime, "lazytime"},
1258         {Opt_nolazytime, "nolazytime"},
1259         {Opt_nodelalloc, "nodelalloc"},
1260         {Opt_removed, "mblk_io_submit"},
1261         {Opt_removed, "nomblk_io_submit"},
1262         {Opt_block_validity, "block_validity"},
1263         {Opt_noblock_validity, "noblock_validity"},
1264         {Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1265         {Opt_journal_ioprio, "journal_ioprio=%u"},
1266         {Opt_auto_da_alloc, "auto_da_alloc=%u"},
1267         {Opt_auto_da_alloc, "auto_da_alloc"},
1268         {Opt_noauto_da_alloc, "noauto_da_alloc"},
1269         {Opt_dioread_nolock, "dioread_nolock"},
1270         {Opt_dioread_lock, "dioread_lock"},
1271         {Opt_discard, "discard"},
1272         {Opt_nodiscard, "nodiscard"},
1273         {Opt_init_itable, "init_itable=%u"},
1274         {Opt_init_itable, "init_itable"},
1275         {Opt_noinit_itable, "noinit_itable"},
1276         {Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1277         {Opt_test_dummy_encryption, "test_dummy_encryption"},
1278         {Opt_removed, "check=none"},    /* mount option from ext2/3 */
1279         {Opt_removed, "nocheck"},       /* mount option from ext2/3 */
1280         {Opt_removed, "reservation"},   /* mount option from ext2/3 */
1281         {Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1282         {Opt_removed, "journal=%u"},    /* mount option from ext2/3 */
1283         {Opt_err, NULL},
1284 };
1285
1286 static ext4_fsblk_t get_sb_block(void **data)
1287 {
1288         ext4_fsblk_t    sb_block;
1289         char            *options = (char *) *data;
1290
1291         if (!options || strncmp(options, "sb=", 3) != 0)
1292                 return 1;       /* Default location */
1293
1294         options += 3;
1295         /* TODO: use simple_strtoll with >32bit ext4 */
1296         sb_block = simple_strtoul(options, &options, 0);
1297         if (*options && *options != ',') {
1298                 printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1299                        (char *) *data);
1300                 return 1;
1301         }
1302         if (*options == ',')
1303                 options++;
1304         *data = (void *) options;
1305
1306         return sb_block;
1307 }
1308
1309 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1310 static char deprecated_msg[] = "Mount option \"%s\" will be removed by %s\n"
1311         "Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1312
1313 #ifdef CONFIG_QUOTA
1314 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1315 {
1316         struct ext4_sb_info *sbi = EXT4_SB(sb);
1317         char *qname;
1318         int ret = -1;
1319
1320         if (sb_any_quota_loaded(sb) &&
1321                 !sbi->s_qf_names[qtype]) {
1322                 ext4_msg(sb, KERN_ERR,
1323                         "Cannot change journaled "
1324                         "quota options when quota turned on");
1325                 return -1;
1326         }
1327         if (ext4_has_feature_quota(sb)) {
1328                 ext4_msg(sb, KERN_INFO, "Journaled quota options "
1329                          "ignored when QUOTA feature is enabled");
1330                 return 1;
1331         }
1332         qname = match_strdup(args);
1333         if (!qname) {
1334                 ext4_msg(sb, KERN_ERR,
1335                         "Not enough memory for storing quotafile name");
1336                 return -1;
1337         }
1338         if (sbi->s_qf_names[qtype]) {
1339                 if (strcmp(sbi->s_qf_names[qtype], qname) == 0)
1340                         ret = 1;
1341                 else
1342                         ext4_msg(sb, KERN_ERR,
1343                                  "%s quota file already specified",
1344                                  QTYPE2NAME(qtype));
1345                 goto errout;
1346         }
1347         if (strchr(qname, '/')) {
1348                 ext4_msg(sb, KERN_ERR,
1349                         "quotafile must be on filesystem root");
1350                 goto errout;
1351         }
1352         sbi->s_qf_names[qtype] = qname;
1353         set_opt(sb, QUOTA);
1354         return 1;
1355 errout:
1356         kfree(qname);
1357         return ret;
1358 }
1359
1360 static int clear_qf_name(struct super_block *sb, int qtype)
1361 {
1362
1363         struct ext4_sb_info *sbi = EXT4_SB(sb);
1364
1365         if (sb_any_quota_loaded(sb) &&
1366                 sbi->s_qf_names[qtype]) {
1367                 ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1368                         " when quota turned on");
1369                 return -1;
1370         }
1371         kfree(sbi->s_qf_names[qtype]);
1372         sbi->s_qf_names[qtype] = NULL;
1373         return 1;
1374 }
1375 #endif
1376
1377 #define MOPT_SET        0x0001
1378 #define MOPT_CLEAR      0x0002
1379 #define MOPT_NOSUPPORT  0x0004
1380 #define MOPT_EXPLICIT   0x0008
1381 #define MOPT_CLEAR_ERR  0x0010
1382 #define MOPT_GTE0       0x0020
1383 #ifdef CONFIG_QUOTA
1384 #define MOPT_Q          0
1385 #define MOPT_QFMT       0x0040
1386 #else
1387 #define MOPT_Q          MOPT_NOSUPPORT
1388 #define MOPT_QFMT       MOPT_NOSUPPORT
1389 #endif
1390 #define MOPT_DATAJ      0x0080
1391 #define MOPT_NO_EXT2    0x0100
1392 #define MOPT_NO_EXT3    0x0200
1393 #define MOPT_EXT4_ONLY  (MOPT_NO_EXT2 | MOPT_NO_EXT3)
1394 #define MOPT_STRING     0x0400
1395
1396 static const struct mount_opts {
1397         int     token;
1398         int     mount_opt;
1399         int     flags;
1400 } ext4_mount_opts[] = {
1401         {Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1402         {Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1403         {Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1404         {Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1405         {Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1406         {Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1407         {Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1408          MOPT_EXT4_ONLY | MOPT_SET},
1409         {Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1410          MOPT_EXT4_ONLY | MOPT_CLEAR},
1411         {Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1412         {Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1413         {Opt_delalloc, EXT4_MOUNT_DELALLOC,
1414          MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1415         {Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1416          MOPT_EXT4_ONLY | MOPT_CLEAR},
1417         {Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1418          MOPT_EXT4_ONLY | MOPT_CLEAR},
1419         {Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1420          MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1421         {Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1422                                     EXT4_MOUNT_JOURNAL_CHECKSUM),
1423          MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1424         {Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1425         {Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1426         {Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1427         {Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1428         {Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
1429          MOPT_NO_EXT2},
1430         {Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
1431          MOPT_NO_EXT2},
1432         {Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1433         {Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1434         {Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1435         {Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1436         {Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1437         {Opt_commit, 0, MOPT_GTE0},
1438         {Opt_max_batch_time, 0, MOPT_GTE0},
1439         {Opt_min_batch_time, 0, MOPT_GTE0},
1440         {Opt_inode_readahead_blks, 0, MOPT_GTE0},
1441         {Opt_init_itable, 0, MOPT_GTE0},
1442         {Opt_dax, EXT4_MOUNT_DAX, MOPT_SET},
1443         {Opt_stripe, 0, MOPT_GTE0},
1444         {Opt_resuid, 0, MOPT_GTE0},
1445         {Opt_resgid, 0, MOPT_GTE0},
1446         {Opt_journal_dev, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1447         {Opt_journal_path, 0, MOPT_NO_EXT2 | MOPT_STRING},
1448         {Opt_journal_ioprio, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1449         {Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1450         {Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1451         {Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
1452          MOPT_NO_EXT2 | MOPT_DATAJ},
1453         {Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1454         {Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1455 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1456         {Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1457         {Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1458 #else
1459         {Opt_acl, 0, MOPT_NOSUPPORT},
1460         {Opt_noacl, 0, MOPT_NOSUPPORT},
1461 #endif
1462         {Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1463         {Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1464         {Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1465         {Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1466                                                         MOPT_SET | MOPT_Q},
1467         {Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1468                                                         MOPT_SET | MOPT_Q},
1469         {Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1470                        EXT4_MOUNT_GRPQUOTA), MOPT_CLEAR | MOPT_Q},
1471         {Opt_usrjquota, 0, MOPT_Q},
1472         {Opt_grpjquota, 0, MOPT_Q},
1473         {Opt_offusrjquota, 0, MOPT_Q},
1474         {Opt_offgrpjquota, 0, MOPT_Q},
1475         {Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1476         {Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1477         {Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1478         {Opt_max_dir_size_kb, 0, MOPT_GTE0},
1479         {Opt_test_dummy_encryption, 0, MOPT_GTE0},
1480         {Opt_err, 0, 0}
1481 };
1482
1483 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1484                             substring_t *args, unsigned long *journal_devnum,
1485                             unsigned int *journal_ioprio, int is_remount)
1486 {
1487         struct ext4_sb_info *sbi = EXT4_SB(sb);
1488         const struct mount_opts *m;
1489         kuid_t uid;
1490         kgid_t gid;
1491         int arg = 0;
1492
1493 #ifdef CONFIG_QUOTA
1494         if (token == Opt_usrjquota)
1495                 return set_qf_name(sb, USRQUOTA, &args[0]);
1496         else if (token == Opt_grpjquota)
1497                 return set_qf_name(sb, GRPQUOTA, &args[0]);
1498         else if (token == Opt_offusrjquota)
1499                 return clear_qf_name(sb, USRQUOTA);
1500         else if (token == Opt_offgrpjquota)
1501                 return clear_qf_name(sb, GRPQUOTA);
1502 #endif
1503         switch (token) {
1504         case Opt_noacl:
1505         case Opt_nouser_xattr:
1506                 ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1507                 break;
1508         case Opt_sb:
1509                 return 1;       /* handled by get_sb_block() */
1510         case Opt_removed:
1511                 ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
1512                 return 1;
1513         case Opt_abort:
1514                 sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1515                 return 1;
1516         case Opt_i_version:
1517                 sb->s_flags |= MS_I_VERSION;
1518                 return 1;
1519         case Opt_lazytime:
1520                 sb->s_flags |= MS_LAZYTIME;
1521                 return 1;
1522         case Opt_nolazytime:
1523                 sb->s_flags &= ~MS_LAZYTIME;
1524                 return 1;
1525         }
1526
1527         for (m = ext4_mount_opts; m->token != Opt_err; m++)
1528                 if (token == m->token)
1529                         break;
1530
1531         if (m->token == Opt_err) {
1532                 ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1533                          "or missing value", opt);
1534                 return -1;
1535         }
1536
1537         if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
1538                 ext4_msg(sb, KERN_ERR,
1539                          "Mount option \"%s\" incompatible with ext2", opt);
1540                 return -1;
1541         }
1542         if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
1543                 ext4_msg(sb, KERN_ERR,
1544                          "Mount option \"%s\" incompatible with ext3", opt);
1545                 return -1;
1546         }
1547
1548         if (args->from && !(m->flags & MOPT_STRING) && match_int(args, &arg))
1549                 return -1;
1550         if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1551                 return -1;
1552         if (m->flags & MOPT_EXPLICIT) {
1553                 if (m->mount_opt & EXT4_MOUNT_DELALLOC) {
1554                         set_opt2(sb, EXPLICIT_DELALLOC);
1555                 } else if (m->mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) {
1556                         set_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM);
1557                 } else
1558                         return -1;
1559         }
1560         if (m->flags & MOPT_CLEAR_ERR)
1561                 clear_opt(sb, ERRORS_MASK);
1562         if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1563                 ext4_msg(sb, KERN_ERR, "Cannot change quota "
1564                          "options when quota turned on");
1565                 return -1;
1566         }
1567
1568         if (m->flags & MOPT_NOSUPPORT) {
1569                 ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1570         } else if (token == Opt_commit) {
1571                 if (arg == 0)
1572                         arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1573                 sbi->s_commit_interval = HZ * arg;
1574         } else if (token == Opt_max_batch_time) {
1575                 sbi->s_max_batch_time = arg;
1576         } else if (token == Opt_min_batch_time) {
1577                 sbi->s_min_batch_time = arg;
1578         } else if (token == Opt_inode_readahead_blks) {
1579                 if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
1580                         ext4_msg(sb, KERN_ERR,
1581                                  "EXT4-fs: inode_readahead_blks must be "
1582                                  "0 or a power of 2 smaller than 2^31");
1583                         return -1;
1584                 }
1585                 sbi->s_inode_readahead_blks = arg;
1586         } else if (token == Opt_init_itable) {
1587                 set_opt(sb, INIT_INODE_TABLE);
1588                 if (!args->from)
1589                         arg = EXT4_DEF_LI_WAIT_MULT;
1590                 sbi->s_li_wait_mult = arg;
1591         } else if (token == Opt_max_dir_size_kb) {
1592                 sbi->s_max_dir_size_kb = arg;
1593         } else if (token == Opt_stripe) {
1594                 sbi->s_stripe = arg;
1595         } else if (token == Opt_resuid) {
1596                 uid = make_kuid(current_user_ns(), arg);
1597                 if (!uid_valid(uid)) {
1598                         ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
1599                         return -1;
1600                 }
1601                 sbi->s_resuid = uid;
1602         } else if (token == Opt_resgid) {
1603                 gid = make_kgid(current_user_ns(), arg);
1604                 if (!gid_valid(gid)) {
1605                         ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
1606                         return -1;
1607                 }
1608                 sbi->s_resgid = gid;
1609         } else if (token == Opt_journal_dev) {
1610                 if (is_remount) {
1611                         ext4_msg(sb, KERN_ERR,
1612                                  "Cannot specify journal on remount");
1613                         return -1;
1614                 }
1615                 *journal_devnum = arg;
1616         } else if (token == Opt_journal_path) {
1617                 char *journal_path;
1618                 struct inode *journal_inode;
1619                 struct path path;
1620                 int error;
1621
1622                 if (is_remount) {
1623                         ext4_msg(sb, KERN_ERR,
1624                                  "Cannot specify journal on remount");
1625                         return -1;
1626                 }
1627                 journal_path = match_strdup(&args[0]);
1628                 if (!journal_path) {
1629                         ext4_msg(sb, KERN_ERR, "error: could not dup "
1630                                 "journal device string");
1631                         return -1;
1632                 }
1633
1634                 error = kern_path(journal_path, LOOKUP_FOLLOW, &path);
1635                 if (error) {
1636                         ext4_msg(sb, KERN_ERR, "error: could not find "
1637                                 "journal device path: error %d", error);
1638                         kfree(journal_path);
1639                         return -1;
1640                 }
1641
1642                 journal_inode = d_inode(path.dentry);
1643                 if (!S_ISBLK(journal_inode->i_mode)) {
1644                         ext4_msg(sb, KERN_ERR, "error: journal path %s "
1645                                 "is not a block device", journal_path);
1646                         path_put(&path);
1647                         kfree(journal_path);
1648                         return -1;
1649                 }
1650
1651                 *journal_devnum = new_encode_dev(journal_inode->i_rdev);
1652                 path_put(&path);
1653                 kfree(journal_path);
1654         } else if (token == Opt_journal_ioprio) {
1655                 if (arg > 7) {
1656                         ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
1657                                  " (must be 0-7)");
1658                         return -1;
1659                 }
1660                 *journal_ioprio =
1661                         IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
1662         } else if (token == Opt_test_dummy_encryption) {
1663 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1664                 sbi->s_mount_flags |= EXT4_MF_TEST_DUMMY_ENCRYPTION;
1665                 ext4_msg(sb, KERN_WARNING,
1666                          "Test dummy encryption mode enabled");
1667 #else
1668                 ext4_msg(sb, KERN_WARNING,
1669                          "Test dummy encryption mount option ignored");
1670 #endif
1671         } else if (m->flags & MOPT_DATAJ) {
1672                 if (is_remount) {
1673                         if (!sbi->s_journal)
1674                                 ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
1675                         else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
1676                                 ext4_msg(sb, KERN_ERR,
1677                                          "Cannot change data mode on remount");
1678                                 return -1;
1679                         }
1680                 } else {
1681                         clear_opt(sb, DATA_FLAGS);
1682                         sbi->s_mount_opt |= m->mount_opt;
1683                 }
1684 #ifdef CONFIG_QUOTA
1685         } else if (m->flags & MOPT_QFMT) {
1686                 if (sb_any_quota_loaded(sb) &&
1687                     sbi->s_jquota_fmt != m->mount_opt) {
1688                         ext4_msg(sb, KERN_ERR, "Cannot change journaled "
1689                                  "quota options when quota turned on");
1690                         return -1;
1691                 }
1692                 if (ext4_has_feature_quota(sb)) {
1693                         ext4_msg(sb, KERN_INFO,
1694                                  "Quota format mount options ignored "
1695                                  "when QUOTA feature is enabled");
1696                         return 1;
1697                 }
1698                 sbi->s_jquota_fmt = m->mount_opt;
1699 #endif
1700         } else if (token == Opt_dax) {
1701 #ifdef CONFIG_FS_DAX
1702                 ext4_msg(sb, KERN_WARNING,
1703                 "DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
1704                         sbi->s_mount_opt |= m->mount_opt;
1705 #else
1706                 ext4_msg(sb, KERN_INFO, "dax option not supported");
1707                 return -1;
1708 #endif
1709         } else if (token == Opt_data_err_abort) {
1710                 sbi->s_mount_opt |= m->mount_opt;
1711         } else if (token == Opt_data_err_ignore) {
1712                 sbi->s_mount_opt &= ~m->mount_opt;
1713         } else {
1714                 if (!args->from)
1715                         arg = 1;
1716                 if (m->flags & MOPT_CLEAR)
1717                         arg = !arg;
1718                 else if (unlikely(!(m->flags & MOPT_SET))) {
1719                         ext4_msg(sb, KERN_WARNING,
1720                                  "buggy handling of option %s", opt);
1721                         WARN_ON(1);
1722                         return -1;
1723                 }
1724                 if (arg != 0)
1725                         sbi->s_mount_opt |= m->mount_opt;
1726                 else
1727                         sbi->s_mount_opt &= ~m->mount_opt;
1728         }
1729         return 1;
1730 }
1731
1732 static int parse_options(char *options, struct super_block *sb,
1733                          unsigned long *journal_devnum,
1734                          unsigned int *journal_ioprio,
1735                          int is_remount)
1736 {
1737         struct ext4_sb_info *sbi = EXT4_SB(sb);
1738         char *p;
1739         substring_t args[MAX_OPT_ARGS];
1740         int token;
1741
1742         if (!options)
1743                 return 1;
1744
1745         while ((p = strsep(&options, ",")) != NULL) {
1746                 if (!*p)
1747                         continue;
1748                 /*
1749                  * Initialize args struct so we know whether arg was
1750                  * found; some options take optional arguments.
1751                  */
1752                 args[0].to = args[0].from = NULL;
1753                 token = match_token(p, tokens, args);
1754                 if (handle_mount_opt(sb, p, token, args, journal_devnum,
1755                                      journal_ioprio, is_remount) < 0)
1756                         return 0;
1757         }
1758 #ifdef CONFIG_QUOTA
1759         if (ext4_has_feature_quota(sb) &&
1760             (test_opt(sb, USRQUOTA) || test_opt(sb, GRPQUOTA))) {
1761                 ext4_msg(sb, KERN_INFO, "Quota feature enabled, usrquota and grpquota "
1762                          "mount options ignored.");
1763                 clear_opt(sb, USRQUOTA);
1764                 clear_opt(sb, GRPQUOTA);
1765         } else if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1766                 if (test_opt(sb, USRQUOTA) && sbi->s_qf_names[USRQUOTA])
1767                         clear_opt(sb, USRQUOTA);
1768
1769                 if (test_opt(sb, GRPQUOTA) && sbi->s_qf_names[GRPQUOTA])
1770                         clear_opt(sb, GRPQUOTA);
1771
1772                 if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
1773                         ext4_msg(sb, KERN_ERR, "old and new quota "
1774                                         "format mixing");
1775                         return 0;
1776                 }
1777
1778                 if (!sbi->s_jquota_fmt) {
1779                         ext4_msg(sb, KERN_ERR, "journaled quota format "
1780                                         "not specified");
1781                         return 0;
1782                 }
1783         }
1784 #endif
1785         if (test_opt(sb, DIOREAD_NOLOCK)) {
1786                 int blocksize =
1787                         BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
1788
1789                 if (blocksize < PAGE_SIZE) {
1790                         ext4_msg(sb, KERN_ERR, "can't mount with "
1791                                  "dioread_nolock if block size != PAGE_SIZE");
1792                         return 0;
1793                 }
1794         }
1795         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
1796             test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
1797                 ext4_msg(sb, KERN_ERR, "can't mount with journal_async_commit "
1798                          "in data=ordered mode");
1799                 return 0;
1800         }
1801         return 1;
1802 }
1803
1804 static inline void ext4_show_quota_options(struct seq_file *seq,
1805                                            struct super_block *sb)
1806 {
1807 #if defined(CONFIG_QUOTA)
1808         struct ext4_sb_info *sbi = EXT4_SB(sb);
1809
1810         if (sbi->s_jquota_fmt) {
1811                 char *fmtname = "";
1812
1813                 switch (sbi->s_jquota_fmt) {
1814                 case QFMT_VFS_OLD:
1815                         fmtname = "vfsold";
1816                         break;
1817                 case QFMT_VFS_V0:
1818                         fmtname = "vfsv0";
1819                         break;
1820                 case QFMT_VFS_V1:
1821                         fmtname = "vfsv1";
1822                         break;
1823                 }
1824                 seq_printf(seq, ",jqfmt=%s", fmtname);
1825         }
1826
1827         if (sbi->s_qf_names[USRQUOTA])
1828                 seq_show_option(seq, "usrjquota", sbi->s_qf_names[USRQUOTA]);
1829
1830         if (sbi->s_qf_names[GRPQUOTA])
1831                 seq_show_option(seq, "grpjquota", sbi->s_qf_names[GRPQUOTA]);
1832 #endif
1833 }
1834
1835 static const char *token2str(int token)
1836 {
1837         const struct match_token *t;
1838
1839         for (t = tokens; t->token != Opt_err; t++)
1840                 if (t->token == token && !strchr(t->pattern, '='))
1841                         break;
1842         return t->pattern;
1843 }
1844
1845 /*
1846  * Show an option if
1847  *  - it's set to a non-default value OR
1848  *  - if the per-sb default is different from the global default
1849  */
1850 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
1851                               int nodefs)
1852 {
1853         struct ext4_sb_info *sbi = EXT4_SB(sb);
1854         struct ext4_super_block *es = sbi->s_es;
1855         int def_errors, def_mount_opt = nodefs ? 0 : sbi->s_def_mount_opt;
1856         const struct mount_opts *m;
1857         char sep = nodefs ? '\n' : ',';
1858
1859 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
1860 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
1861
1862         if (sbi->s_sb_block != 1)
1863                 SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
1864
1865         for (m = ext4_mount_opts; m->token != Opt_err; m++) {
1866                 int want_set = m->flags & MOPT_SET;
1867                 if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
1868                     (m->flags & MOPT_CLEAR_ERR))
1869                         continue;
1870                 if (!(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
1871                         continue; /* skip if same as the default */
1872                 if ((want_set &&
1873                      (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
1874                     (!want_set && (sbi->s_mount_opt & m->mount_opt)))
1875                         continue; /* select Opt_noFoo vs Opt_Foo */
1876                 SEQ_OPTS_PRINT("%s", token2str(m->token));
1877         }
1878
1879         if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
1880             le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
1881                 SEQ_OPTS_PRINT("resuid=%u",
1882                                 from_kuid_munged(&init_user_ns, sbi->s_resuid));
1883         if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
1884             le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
1885                 SEQ_OPTS_PRINT("resgid=%u",
1886                                 from_kgid_munged(&init_user_ns, sbi->s_resgid));
1887         def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
1888         if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
1889                 SEQ_OPTS_PUTS("errors=remount-ro");
1890         if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
1891                 SEQ_OPTS_PUTS("errors=continue");
1892         if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
1893                 SEQ_OPTS_PUTS("errors=panic");
1894         if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
1895                 SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
1896         if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
1897                 SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
1898         if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
1899                 SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
1900         if (sb->s_flags & MS_I_VERSION)
1901                 SEQ_OPTS_PUTS("i_version");
1902         if (nodefs || sbi->s_stripe)
1903                 SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
1904         if (EXT4_MOUNT_DATA_FLAGS & (sbi->s_mount_opt ^ def_mount_opt)) {
1905                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
1906                         SEQ_OPTS_PUTS("data=journal");
1907                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
1908                         SEQ_OPTS_PUTS("data=ordered");
1909                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
1910                         SEQ_OPTS_PUTS("data=writeback");
1911         }
1912         if (nodefs ||
1913             sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
1914                 SEQ_OPTS_PRINT("inode_readahead_blks=%u",
1915                                sbi->s_inode_readahead_blks);
1916
1917         if (nodefs || (test_opt(sb, INIT_INODE_TABLE) &&
1918                        (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
1919                 SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
1920         if (nodefs || sbi->s_max_dir_size_kb)
1921                 SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
1922         if (test_opt(sb, DATA_ERR_ABORT))
1923                 SEQ_OPTS_PUTS("data_err=abort");
1924
1925         ext4_show_quota_options(seq, sb);
1926         return 0;
1927 }
1928
1929 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
1930 {
1931         return _ext4_show_options(seq, root->d_sb, 0);
1932 }
1933
1934 int ext4_seq_options_show(struct seq_file *seq, void *offset)
1935 {
1936         struct super_block *sb = seq->private;
1937         int rc;
1938
1939         seq_puts(seq, (sb->s_flags & MS_RDONLY) ? "ro" : "rw");
1940         rc = _ext4_show_options(seq, sb, 1);
1941         seq_puts(seq, "\n");
1942         return rc;
1943 }
1944
1945 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
1946                             int read_only)
1947 {
1948         struct ext4_sb_info *sbi = EXT4_SB(sb);
1949         int res = 0;
1950
1951         if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
1952                 ext4_msg(sb, KERN_ERR, "revision level too high, "
1953                          "forcing read-only mode");
1954                 res = MS_RDONLY;
1955         }
1956         if (read_only)
1957                 goto done;
1958         if (!(sbi->s_mount_state & EXT4_VALID_FS))
1959                 ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
1960                          "running e2fsck is recommended");
1961         else if (sbi->s_mount_state & EXT4_ERROR_FS)
1962                 ext4_msg(sb, KERN_WARNING,
1963                          "warning: mounting fs with errors, "
1964                          "running e2fsck is recommended");
1965         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
1966                  le16_to_cpu(es->s_mnt_count) >=
1967                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
1968                 ext4_msg(sb, KERN_WARNING,
1969                          "warning: maximal mount count reached, "
1970                          "running e2fsck is recommended");
1971         else if (le32_to_cpu(es->s_checkinterval) &&
1972                 (le32_to_cpu(es->s_lastcheck) +
1973                         le32_to_cpu(es->s_checkinterval) <= get_seconds()))
1974                 ext4_msg(sb, KERN_WARNING,
1975                          "warning: checktime reached, "
1976                          "running e2fsck is recommended");
1977         if (!sbi->s_journal)
1978                 es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
1979         if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
1980                 es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
1981         le16_add_cpu(&es->s_mnt_count, 1);
1982         es->s_mtime = cpu_to_le32(get_seconds());
1983         ext4_update_dynamic_rev(sb);
1984         if (sbi->s_journal)
1985                 ext4_set_feature_journal_needs_recovery(sb);
1986
1987         ext4_commit_super(sb, 1);
1988 done:
1989         if (test_opt(sb, DEBUG))
1990                 printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
1991                                 "bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
1992                         sb->s_blocksize,
1993                         sbi->s_groups_count,
1994                         EXT4_BLOCKS_PER_GROUP(sb),
1995                         EXT4_INODES_PER_GROUP(sb),
1996                         sbi->s_mount_opt, sbi->s_mount_opt2);
1997
1998         cleancache_init_fs(sb);
1999         return res;
2000 }
2001
2002 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
2003 {
2004         struct ext4_sb_info *sbi = EXT4_SB(sb);
2005         struct flex_groups *new_groups;
2006         int size;
2007
2008         if (!sbi->s_log_groups_per_flex)
2009                 return 0;
2010
2011         size = ext4_flex_group(sbi, ngroup - 1) + 1;
2012         if (size <= sbi->s_flex_groups_allocated)
2013                 return 0;
2014
2015         size = roundup_pow_of_two(size * sizeof(struct flex_groups));
2016         new_groups = ext4_kvzalloc(size, GFP_KERNEL);
2017         if (!new_groups) {
2018                 ext4_msg(sb, KERN_ERR, "not enough memory for %d flex groups",
2019                          size / (int) sizeof(struct flex_groups));
2020                 return -ENOMEM;
2021         }
2022
2023         if (sbi->s_flex_groups) {
2024                 memcpy(new_groups, sbi->s_flex_groups,
2025                        (sbi->s_flex_groups_allocated *
2026                         sizeof(struct flex_groups)));
2027                 kvfree(sbi->s_flex_groups);
2028         }
2029         sbi->s_flex_groups = new_groups;
2030         sbi->s_flex_groups_allocated = size / sizeof(struct flex_groups);
2031         return 0;
2032 }
2033
2034 static int ext4_fill_flex_info(struct super_block *sb)
2035 {
2036         struct ext4_sb_info *sbi = EXT4_SB(sb);
2037         struct ext4_group_desc *gdp = NULL;
2038         ext4_group_t flex_group;
2039         int i, err;
2040
2041         sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
2042         if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
2043                 sbi->s_log_groups_per_flex = 0;
2044                 return 1;
2045         }
2046
2047         err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
2048         if (err)
2049                 goto failed;
2050
2051         for (i = 0; i < sbi->s_groups_count; i++) {
2052                 gdp = ext4_get_group_desc(sb, i, NULL);
2053
2054                 flex_group = ext4_flex_group(sbi, i);
2055                 atomic_add(ext4_free_inodes_count(sb, gdp),
2056                            &sbi->s_flex_groups[flex_group].free_inodes);
2057                 atomic64_add(ext4_free_group_clusters(sb, gdp),
2058                              &sbi->s_flex_groups[flex_group].free_clusters);
2059                 atomic_add(ext4_used_dirs_count(sb, gdp),
2060                            &sbi->s_flex_groups[flex_group].used_dirs);
2061         }
2062
2063         return 1;
2064 failed:
2065         return 0;
2066 }
2067
2068 static __le16 ext4_group_desc_csum(struct super_block *sb, __u32 block_group,
2069                                    struct ext4_group_desc *gdp)
2070 {
2071         int offset;
2072         __u16 crc = 0;
2073         __le32 le_group = cpu_to_le32(block_group);
2074         struct ext4_sb_info *sbi = EXT4_SB(sb);
2075
2076         if (ext4_has_metadata_csum(sbi->s_sb)) {
2077                 /* Use new metadata_csum algorithm */
2078                 __le16 save_csum;
2079                 __u32 csum32;
2080
2081                 save_csum = gdp->bg_checksum;
2082                 gdp->bg_checksum = 0;
2083                 csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
2084                                      sizeof(le_group));
2085                 csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp,
2086                                      sbi->s_desc_size);
2087                 gdp->bg_checksum = save_csum;
2088
2089                 crc = csum32 & 0xFFFF;
2090                 goto out;
2091         }
2092
2093         /* old crc16 code */
2094         if (!ext4_has_feature_gdt_csum(sb))
2095                 return 0;
2096
2097         offset = offsetof(struct ext4_group_desc, bg_checksum);
2098
2099         crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2100         crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2101         crc = crc16(crc, (__u8 *)gdp, offset);
2102         offset += sizeof(gdp->bg_checksum); /* skip checksum */
2103         /* for checksum of struct ext4_group_desc do the rest...*/
2104         if (ext4_has_feature_64bit(sb) &&
2105             offset < le16_to_cpu(sbi->s_es->s_desc_size))
2106                 crc = crc16(crc, (__u8 *)gdp + offset,
2107                             le16_to_cpu(sbi->s_es->s_desc_size) -
2108                                 offset);
2109
2110 out:
2111         return cpu_to_le16(crc);
2112 }
2113
2114 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2115                                 struct ext4_group_desc *gdp)
2116 {
2117         if (ext4_has_group_desc_csum(sb) &&
2118             (gdp->bg_checksum != ext4_group_desc_csum(sb, block_group, gdp)))
2119                 return 0;
2120
2121         return 1;
2122 }
2123
2124 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2125                               struct ext4_group_desc *gdp)
2126 {
2127         if (!ext4_has_group_desc_csum(sb))
2128                 return;
2129         gdp->bg_checksum = ext4_group_desc_csum(sb, block_group, gdp);
2130 }
2131
2132 /* Called at mount-time, super-block is locked */
2133 static int ext4_check_descriptors(struct super_block *sb,
2134                                   ext4_group_t *first_not_zeroed)
2135 {
2136         struct ext4_sb_info *sbi = EXT4_SB(sb);
2137         ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2138         ext4_fsblk_t last_block;
2139         ext4_fsblk_t block_bitmap;
2140         ext4_fsblk_t inode_bitmap;
2141         ext4_fsblk_t inode_table;
2142         int flexbg_flag = 0;
2143         ext4_group_t i, grp = sbi->s_groups_count;
2144
2145         if (ext4_has_feature_flex_bg(sb))
2146                 flexbg_flag = 1;
2147
2148         ext4_debug("Checking group descriptors");
2149
2150         for (i = 0; i < sbi->s_groups_count; i++) {
2151                 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2152
2153                 if (i == sbi->s_groups_count - 1 || flexbg_flag)
2154                         last_block = ext4_blocks_count(sbi->s_es) - 1;
2155                 else
2156                         last_block = first_block +
2157                                 (EXT4_BLOCKS_PER_GROUP(sb) - 1);
2158
2159                 if ((grp == sbi->s_groups_count) &&
2160                    !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2161                         grp = i;
2162
2163                 block_bitmap = ext4_block_bitmap(sb, gdp);
2164                 if (block_bitmap < first_block || block_bitmap > last_block) {
2165                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2166                                "Block bitmap for group %u not in group "
2167                                "(block %llu)!", i, block_bitmap);
2168                         return 0;
2169                 }
2170                 inode_bitmap = ext4_inode_bitmap(sb, gdp);
2171                 if (inode_bitmap < first_block || inode_bitmap > last_block) {
2172                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2173                                "Inode bitmap for group %u not in group "
2174                                "(block %llu)!", i, inode_bitmap);
2175                         return 0;
2176                 }
2177                 inode_table = ext4_inode_table(sb, gdp);
2178                 if (inode_table < first_block ||
2179                     inode_table + sbi->s_itb_per_group - 1 > last_block) {
2180                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2181                                "Inode table for group %u not in group "
2182                                "(block %llu)!", i, inode_table);
2183                         return 0;
2184                 }
2185                 ext4_lock_group(sb, i);
2186                 if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2187                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2188                                  "Checksum for group %u failed (%u!=%u)",
2189                                  i, le16_to_cpu(ext4_group_desc_csum(sb, i,
2190                                      gdp)), le16_to_cpu(gdp->bg_checksum));
2191                         if (!(sb->s_flags & MS_RDONLY)) {
2192                                 ext4_unlock_group(sb, i);
2193                                 return 0;
2194                         }
2195                 }
2196                 ext4_unlock_group(sb, i);
2197                 if (!flexbg_flag)
2198                         first_block += EXT4_BLOCKS_PER_GROUP(sb);
2199         }
2200         if (NULL != first_not_zeroed)
2201                 *first_not_zeroed = grp;
2202         return 1;
2203 }
2204
2205 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2206  * the superblock) which were deleted from all directories, but held open by
2207  * a process at the time of a crash.  We walk the list and try to delete these
2208  * inodes at recovery time (only with a read-write filesystem).
2209  *
2210  * In order to keep the orphan inode chain consistent during traversal (in
2211  * case of crash during recovery), we link each inode into the superblock
2212  * orphan list_head and handle it the same way as an inode deletion during
2213  * normal operation (which journals the operations for us).
2214  *
2215  * We only do an iget() and an iput() on each inode, which is very safe if we
2216  * accidentally point at an in-use or already deleted inode.  The worst that
2217  * can happen in this case is that we get a "bit already cleared" message from
2218  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2219  * e2fsck was run on this filesystem, and it must have already done the orphan
2220  * inode cleanup for us, so we can safely abort without any further action.
2221  */
2222 static void ext4_orphan_cleanup(struct super_block *sb,
2223                                 struct ext4_super_block *es)
2224 {
2225         unsigned int s_flags = sb->s_flags;
2226         int nr_orphans = 0, nr_truncates = 0;
2227 #ifdef CONFIG_QUOTA
2228         int i;
2229 #endif
2230         if (!es->s_last_orphan) {
2231                 jbd_debug(4, "no orphan inodes to clean up\n");
2232                 return;
2233         }
2234
2235         if (bdev_read_only(sb->s_bdev)) {
2236                 ext4_msg(sb, KERN_ERR, "write access "
2237                         "unavailable, skipping orphan cleanup");
2238                 return;
2239         }
2240
2241         /* Check if feature set would not allow a r/w mount */
2242         if (!ext4_feature_set_ok(sb, 0)) {
2243                 ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2244                          "unknown ROCOMPAT features");
2245                 return;
2246         }
2247
2248         if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2249                 /* don't clear list on RO mount w/ errors */
2250                 if (es->s_last_orphan && !(s_flags & MS_RDONLY)) {
2251                         ext4_msg(sb, KERN_INFO, "Errors on filesystem, "
2252                                   "clearing orphan list.\n");
2253                         es->s_last_orphan = 0;
2254                 }
2255                 jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2256                 return;
2257         }
2258
2259         if (s_flags & MS_RDONLY) {
2260                 ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2261                 sb->s_flags &= ~MS_RDONLY;
2262         }
2263 #ifdef CONFIG_QUOTA
2264         /* Needed for iput() to work correctly and not trash data */
2265         sb->s_flags |= MS_ACTIVE;
2266         /* Turn on quotas so that they are updated correctly */
2267         for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2268                 if (EXT4_SB(sb)->s_qf_names[i]) {
2269                         int ret = ext4_quota_on_mount(sb, i);
2270                         if (ret < 0)
2271                                 ext4_msg(sb, KERN_ERR,
2272                                         "Cannot turn on journaled "
2273                                         "quota: error %d", ret);
2274                 }
2275         }
2276 #endif
2277
2278         while (es->s_last_orphan) {
2279                 struct inode *inode;
2280
2281                 inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2282                 if (IS_ERR(inode)) {
2283                         es->s_last_orphan = 0;
2284                         break;
2285                 }
2286
2287                 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2288                 dquot_initialize(inode);
2289                 if (inode->i_nlink) {
2290                         if (test_opt(sb, DEBUG))
2291                                 ext4_msg(sb, KERN_DEBUG,
2292                                         "%s: truncating inode %lu to %lld bytes",
2293                                         __func__, inode->i_ino, inode->i_size);
2294                         jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2295                                   inode->i_ino, inode->i_size);
2296                         inode_lock(inode);
2297                         truncate_inode_pages(inode->i_mapping, inode->i_size);
2298                         ext4_truncate(inode);
2299                         inode_unlock(inode);
2300                         nr_truncates++;
2301                 } else {
2302                         if (test_opt(sb, DEBUG))
2303                                 ext4_msg(sb, KERN_DEBUG,
2304                                         "%s: deleting unreferenced inode %lu",
2305                                         __func__, inode->i_ino);
2306                         jbd_debug(2, "deleting unreferenced inode %lu\n",
2307                                   inode->i_ino);
2308                         nr_orphans++;
2309                 }
2310                 iput(inode);  /* The delete magic happens here! */
2311         }
2312
2313 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2314
2315         if (nr_orphans)
2316                 ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2317                        PLURAL(nr_orphans));
2318         if (nr_truncates)
2319                 ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2320                        PLURAL(nr_truncates));
2321 #ifdef CONFIG_QUOTA
2322         /* Turn quotas off */
2323         for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2324                 if (sb_dqopt(sb)->files[i])
2325                         dquot_quota_off(sb, i);
2326         }
2327 #endif
2328         sb->s_flags = s_flags; /* Restore MS_RDONLY status */
2329 }
2330
2331 /*
2332  * Maximal extent format file size.
2333  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2334  * extent format containers, within a sector_t, and within i_blocks
2335  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2336  * so that won't be a limiting factor.
2337  *
2338  * However there is other limiting factor. We do store extents in the form
2339  * of starting block and length, hence the resulting length of the extent
2340  * covering maximum file size must fit into on-disk format containers as
2341  * well. Given that length is always by 1 unit bigger than max unit (because
2342  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2343  *
2344  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2345  */
2346 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2347 {
2348         loff_t res;
2349         loff_t upper_limit = MAX_LFS_FILESIZE;
2350
2351         /* small i_blocks in vfs inode? */
2352         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2353                 /*
2354                  * CONFIG_LBDAF is not enabled implies the inode
2355                  * i_block represent total blocks in 512 bytes
2356                  * 32 == size of vfs inode i_blocks * 8
2357                  */
2358                 upper_limit = (1LL << 32) - 1;
2359
2360                 /* total blocks in file system block size */
2361                 upper_limit >>= (blkbits - 9);
2362                 upper_limit <<= blkbits;
2363         }
2364
2365         /*
2366          * 32-bit extent-start container, ee_block. We lower the maxbytes
2367          * by one fs block, so ee_len can cover the extent of maximum file
2368          * size
2369          */
2370         res = (1LL << 32) - 1;
2371         res <<= blkbits;
2372
2373         /* Sanity check against vm- & vfs- imposed limits */
2374         if (res > upper_limit)
2375                 res = upper_limit;
2376
2377         return res;
2378 }
2379
2380 /*
2381  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2382  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2383  * We need to be 1 filesystem block less than the 2^48 sector limit.
2384  */
2385 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2386 {
2387         loff_t res = EXT4_NDIR_BLOCKS;
2388         int meta_blocks;
2389         loff_t upper_limit;
2390         /* This is calculated to be the largest file size for a dense, block
2391          * mapped file such that the file's total number of 512-byte sectors,
2392          * including data and all indirect blocks, does not exceed (2^48 - 1).
2393          *
2394          * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2395          * number of 512-byte sectors of the file.
2396          */
2397
2398         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2399                 /*
2400                  * !has_huge_files or CONFIG_LBDAF not enabled implies that
2401                  * the inode i_block field represents total file blocks in
2402                  * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2403                  */
2404                 upper_limit = (1LL << 32) - 1;
2405
2406                 /* total blocks in file system block size */
2407                 upper_limit >>= (bits - 9);
2408
2409         } else {
2410                 /*
2411                  * We use 48 bit ext4_inode i_blocks
2412                  * With EXT4_HUGE_FILE_FL set the i_blocks
2413                  * represent total number of blocks in
2414                  * file system block size
2415                  */
2416                 upper_limit = (1LL << 48) - 1;
2417
2418         }
2419
2420         /* indirect blocks */
2421         meta_blocks = 1;
2422         /* double indirect blocks */
2423         meta_blocks += 1 + (1LL << (bits-2));
2424         /* tripple indirect blocks */
2425         meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2426
2427         upper_limit -= meta_blocks;
2428         upper_limit <<= bits;
2429
2430         res += 1LL << (bits-2);
2431         res += 1LL << (2*(bits-2));
2432         res += 1LL << (3*(bits-2));
2433         res <<= bits;
2434         if (res > upper_limit)
2435                 res = upper_limit;
2436
2437         if (res > MAX_LFS_FILESIZE)
2438                 res = MAX_LFS_FILESIZE;
2439
2440         return res;
2441 }
2442
2443 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2444                                    ext4_fsblk_t logical_sb_block, int nr)
2445 {
2446         struct ext4_sb_info *sbi = EXT4_SB(sb);
2447         ext4_group_t bg, first_meta_bg;
2448         int has_super = 0;
2449
2450         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2451
2452         if (!ext4_has_feature_meta_bg(sb) || nr < first_meta_bg)
2453                 return logical_sb_block + nr + 1;
2454         bg = sbi->s_desc_per_block * nr;
2455         if (ext4_bg_has_super(sb, bg))
2456                 has_super = 1;
2457
2458         /*
2459          * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
2460          * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
2461          * on modern mke2fs or blksize > 1k on older mke2fs) then we must
2462          * compensate.
2463          */
2464         if (sb->s_blocksize == 1024 && nr == 0 &&
2465             le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block) == 0)
2466                 has_super++;
2467
2468         return (has_super + ext4_group_first_block_no(sb, bg));
2469 }
2470
2471 /**
2472  * ext4_get_stripe_size: Get the stripe size.
2473  * @sbi: In memory super block info
2474  *
2475  * If we have specified it via mount option, then
2476  * use the mount option value. If the value specified at mount time is
2477  * greater than the blocks per group use the super block value.
2478  * If the super block value is greater than blocks per group return 0.
2479  * Allocator needs it be less than blocks per group.
2480  *
2481  */
2482 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2483 {
2484         unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2485         unsigned long stripe_width =
2486                         le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2487         int ret;
2488
2489         if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2490                 ret = sbi->s_stripe;
2491         else if (stripe_width <= sbi->s_blocks_per_group)
2492                 ret = stripe_width;
2493         else if (stride <= sbi->s_blocks_per_group)
2494                 ret = stride;
2495         else
2496                 ret = 0;
2497
2498         /*
2499          * If the stripe width is 1, this makes no sense and
2500          * we set it to 0 to turn off stripe handling code.
2501          */
2502         if (ret <= 1)
2503                 ret = 0;
2504
2505         return ret;
2506 }
2507
2508 /*
2509  * Check whether this filesystem can be mounted based on
2510  * the features present and the RDONLY/RDWR mount requested.
2511  * Returns 1 if this filesystem can be mounted as requested,
2512  * 0 if it cannot be.
2513  */
2514 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2515 {
2516         if (ext4_has_unknown_ext4_incompat_features(sb)) {
2517                 ext4_msg(sb, KERN_ERR,
2518                         "Couldn't mount because of "
2519                         "unsupported optional features (%x)",
2520                         (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2521                         ~EXT4_FEATURE_INCOMPAT_SUPP));
2522                 return 0;
2523         }
2524
2525         if (readonly)
2526                 return 1;
2527
2528         if (ext4_has_feature_readonly(sb)) {
2529                 ext4_msg(sb, KERN_INFO, "filesystem is read-only");
2530                 sb->s_flags |= MS_RDONLY;
2531                 return 1;
2532         }
2533
2534         /* Check that feature set is OK for a read-write mount */
2535         if (ext4_has_unknown_ext4_ro_compat_features(sb)) {
2536                 ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2537                          "unsupported optional features (%x)",
2538                          (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2539                                 ~EXT4_FEATURE_RO_COMPAT_SUPP));
2540                 return 0;
2541         }
2542         /*
2543          * Large file size enabled file system can only be mounted
2544          * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2545          */
2546         if (ext4_has_feature_huge_file(sb)) {
2547                 if (sizeof(blkcnt_t) < sizeof(u64)) {
2548                         ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2549                                  "cannot be mounted RDWR without "
2550                                  "CONFIG_LBDAF");
2551                         return 0;
2552                 }
2553         }
2554         if (ext4_has_feature_bigalloc(sb) && !ext4_has_feature_extents(sb)) {
2555                 ext4_msg(sb, KERN_ERR,
2556                          "Can't support bigalloc feature without "
2557                          "extents feature\n");
2558                 return 0;
2559         }
2560
2561 #ifndef CONFIG_QUOTA
2562         if (ext4_has_feature_quota(sb) && !readonly) {
2563                 ext4_msg(sb, KERN_ERR,
2564                          "Filesystem with quota feature cannot be mounted RDWR "
2565                          "without CONFIG_QUOTA");
2566                 return 0;
2567         }
2568         if (ext4_has_feature_project(sb) && !readonly) {
2569                 ext4_msg(sb, KERN_ERR,
2570                          "Filesystem with project quota feature cannot be mounted RDWR "
2571                          "without CONFIG_QUOTA");
2572                 return 0;
2573         }
2574 #endif  /* CONFIG_QUOTA */
2575         return 1;
2576 }
2577
2578 /*
2579  * This function is called once a day if we have errors logged
2580  * on the file system
2581  */
2582 static void print_daily_error_info(unsigned long arg)
2583 {
2584         struct super_block *sb = (struct super_block *) arg;
2585         struct ext4_sb_info *sbi;
2586         struct ext4_super_block *es;
2587
2588         sbi = EXT4_SB(sb);
2589         es = sbi->s_es;
2590
2591         if (es->s_error_count)
2592                 /* fsck newer than v1.41.13 is needed to clean this condition. */
2593                 ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
2594                          le32_to_cpu(es->s_error_count));
2595         if (es->s_first_error_time) {
2596                 printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %u: %.*s:%d",
2597                        sb->s_id, le32_to_cpu(es->s_first_error_time),
2598                        (int) sizeof(es->s_first_error_func),
2599                        es->s_first_error_func,
2600                        le32_to_cpu(es->s_first_error_line));
2601                 if (es->s_first_error_ino)
2602                         printk(": inode %u",
2603                                le32_to_cpu(es->s_first_error_ino));
2604                 if (es->s_first_error_block)
2605                         printk(": block %llu", (unsigned long long)
2606                                le64_to_cpu(es->s_first_error_block));
2607                 printk("\n");
2608         }
2609         if (es->s_last_error_time) {
2610                 printk(KERN_NOTICE "EXT4-fs (%s): last error at time %u: %.*s:%d",
2611                        sb->s_id, le32_to_cpu(es->s_last_error_time),
2612                        (int) sizeof(es->s_last_error_func),
2613                        es->s_last_error_func,
2614                        le32_to_cpu(es->s_last_error_line));
2615                 if (es->s_last_error_ino)
2616                         printk(": inode %u",
2617                                le32_to_cpu(es->s_last_error_ino));
2618                 if (es->s_last_error_block)
2619                         printk(": block %llu", (unsigned long long)
2620                                le64_to_cpu(es->s_last_error_block));
2621                 printk("\n");
2622         }
2623         mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2624 }
2625
2626 /* Find next suitable group and run ext4_init_inode_table */
2627 static int ext4_run_li_request(struct ext4_li_request *elr)
2628 {
2629         struct ext4_group_desc *gdp = NULL;
2630         ext4_group_t group, ngroups;
2631         struct super_block *sb;
2632         unsigned long timeout = 0;
2633         int ret = 0;
2634
2635         sb = elr->lr_super;
2636         ngroups = EXT4_SB(sb)->s_groups_count;
2637
2638         sb_start_write(sb);
2639         for (group = elr->lr_next_group; group < ngroups; group++) {
2640                 gdp = ext4_get_group_desc(sb, group, NULL);
2641                 if (!gdp) {
2642                         ret = 1;
2643                         break;
2644                 }
2645
2646                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2647                         break;
2648         }
2649
2650         if (group >= ngroups)
2651                 ret = 1;
2652
2653         if (!ret) {
2654                 timeout = jiffies;
2655                 ret = ext4_init_inode_table(sb, group,
2656                                             elr->lr_timeout ? 0 : 1);
2657                 if (elr->lr_timeout == 0) {
2658                         timeout = (jiffies - timeout) *
2659                                   elr->lr_sbi->s_li_wait_mult;
2660                         elr->lr_timeout = timeout;
2661                 }
2662                 elr->lr_next_sched = jiffies + elr->lr_timeout;
2663                 elr->lr_next_group = group + 1;
2664         }
2665         sb_end_write(sb);
2666
2667         return ret;
2668 }
2669
2670 /*
2671  * Remove lr_request from the list_request and free the
2672  * request structure. Should be called with li_list_mtx held
2673  */
2674 static void ext4_remove_li_request(struct ext4_li_request *elr)
2675 {
2676         struct ext4_sb_info *sbi;
2677
2678         if (!elr)
2679                 return;
2680
2681         sbi = elr->lr_sbi;
2682
2683         list_del(&elr->lr_request);
2684         sbi->s_li_request = NULL;
2685         kfree(elr);
2686 }
2687
2688 static void ext4_unregister_li_request(struct super_block *sb)
2689 {
2690         mutex_lock(&ext4_li_mtx);
2691         if (!ext4_li_info) {
2692                 mutex_unlock(&ext4_li_mtx);
2693                 return;
2694         }
2695
2696         mutex_lock(&ext4_li_info->li_list_mtx);
2697         ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
2698         mutex_unlock(&ext4_li_info->li_list_mtx);
2699         mutex_unlock(&ext4_li_mtx);
2700 }
2701
2702 static struct task_struct *ext4_lazyinit_task;
2703
2704 /*
2705  * This is the function where ext4lazyinit thread lives. It walks
2706  * through the request list searching for next scheduled filesystem.
2707  * When such a fs is found, run the lazy initialization request
2708  * (ext4_rn_li_request) and keep track of the time spend in this
2709  * function. Based on that time we compute next schedule time of
2710  * the request. When walking through the list is complete, compute
2711  * next waking time and put itself into sleep.
2712  */
2713 static int ext4_lazyinit_thread(void *arg)
2714 {
2715         struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
2716         struct list_head *pos, *n;
2717         struct ext4_li_request *elr;
2718         unsigned long next_wakeup, cur;
2719
2720         BUG_ON(NULL == eli);
2721
2722 cont_thread:
2723         while (true) {
2724                 next_wakeup = MAX_JIFFY_OFFSET;
2725
2726                 mutex_lock(&eli->li_list_mtx);
2727                 if (list_empty(&eli->li_request_list)) {
2728                         mutex_unlock(&eli->li_list_mtx);
2729                         goto exit_thread;
2730                 }
2731
2732                 list_for_each_safe(pos, n, &eli->li_request_list) {
2733                         elr = list_entry(pos, struct ext4_li_request,
2734                                          lr_request);
2735
2736                         if (time_after_eq(jiffies, elr->lr_next_sched)) {
2737                                 if (ext4_run_li_request(elr) != 0) {
2738                                         /* error, remove the lazy_init job */
2739                                         ext4_remove_li_request(elr);
2740                                         continue;
2741                                 }
2742                         }
2743
2744                         if (time_before(elr->lr_next_sched, next_wakeup))
2745                                 next_wakeup = elr->lr_next_sched;
2746                 }
2747                 mutex_unlock(&eli->li_list_mtx);
2748
2749                 try_to_freeze();
2750
2751                 cur = jiffies;
2752                 if ((time_after_eq(cur, next_wakeup)) ||
2753                     (MAX_JIFFY_OFFSET == next_wakeup)) {
2754                         cond_resched();
2755                         continue;
2756                 }
2757
2758                 schedule_timeout_interruptible(next_wakeup - cur);
2759
2760                 if (kthread_should_stop()) {
2761                         ext4_clear_request_list();
2762                         goto exit_thread;
2763                 }
2764         }
2765
2766 exit_thread:
2767         /*
2768          * It looks like the request list is empty, but we need
2769          * to check it under the li_list_mtx lock, to prevent any
2770          * additions into it, and of course we should lock ext4_li_mtx
2771          * to atomically free the list and ext4_li_info, because at
2772          * this point another ext4 filesystem could be registering
2773          * new one.
2774          */
2775         mutex_lock(&ext4_li_mtx);
2776         mutex_lock(&eli->li_list_mtx);
2777         if (!list_empty(&eli->li_request_list)) {
2778                 mutex_unlock(&eli->li_list_mtx);
2779                 mutex_unlock(&ext4_li_mtx);
2780                 goto cont_thread;
2781         }
2782         mutex_unlock(&eli->li_list_mtx);
2783         kfree(ext4_li_info);
2784         ext4_li_info = NULL;
2785         mutex_unlock(&ext4_li_mtx);
2786
2787         return 0;
2788 }
2789
2790 static void ext4_clear_request_list(void)
2791 {
2792         struct list_head *pos, *n;
2793         struct ext4_li_request *elr;
2794
2795         mutex_lock(&ext4_li_info->li_list_mtx);
2796         list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
2797                 elr = list_entry(pos, struct ext4_li_request,
2798                                  lr_request);
2799                 ext4_remove_li_request(elr);
2800         }
2801         mutex_unlock(&ext4_li_info->li_list_mtx);
2802 }
2803
2804 static int ext4_run_lazyinit_thread(void)
2805 {
2806         ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
2807                                          ext4_li_info, "ext4lazyinit");
2808         if (IS_ERR(ext4_lazyinit_task)) {
2809                 int err = PTR_ERR(ext4_lazyinit_task);
2810                 ext4_clear_request_list();
2811                 kfree(ext4_li_info);
2812                 ext4_li_info = NULL;
2813                 printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
2814                                  "initialization thread\n",
2815                                  err);
2816                 return err;
2817         }
2818         ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
2819         return 0;
2820 }
2821
2822 /*
2823  * Check whether it make sense to run itable init. thread or not.
2824  * If there is at least one uninitialized inode table, return
2825  * corresponding group number, else the loop goes through all
2826  * groups and return total number of groups.
2827  */
2828 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
2829 {
2830         ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
2831         struct ext4_group_desc *gdp = NULL;
2832
2833         for (group = 0; group < ngroups; group++) {
2834                 gdp = ext4_get_group_desc(sb, group, NULL);
2835                 if (!gdp)
2836                         continue;
2837
2838                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2839                         break;
2840         }
2841
2842         return group;
2843 }
2844
2845 static int ext4_li_info_new(void)
2846 {
2847         struct ext4_lazy_init *eli = NULL;
2848
2849         eli = kzalloc(sizeof(*eli), GFP_KERNEL);
2850         if (!eli)
2851                 return -ENOMEM;
2852
2853         INIT_LIST_HEAD(&eli->li_request_list);
2854         mutex_init(&eli->li_list_mtx);
2855
2856         eli->li_state |= EXT4_LAZYINIT_QUIT;
2857
2858         ext4_li_info = eli;
2859
2860         return 0;
2861 }
2862
2863 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
2864                                             ext4_group_t start)
2865 {
2866         struct ext4_sb_info *sbi = EXT4_SB(sb);
2867         struct ext4_li_request *elr;
2868
2869         elr = kzalloc(sizeof(*elr), GFP_KERNEL);
2870         if (!elr)
2871                 return NULL;
2872
2873         elr->lr_super = sb;
2874         elr->lr_sbi = sbi;
2875         elr->lr_next_group = start;
2876
2877         /*
2878          * Randomize first schedule time of the request to
2879          * spread the inode table initialization requests
2880          * better.
2881          */
2882         elr->lr_next_sched = jiffies + (prandom_u32() %
2883                                 (EXT4_DEF_LI_MAX_START_DELAY * HZ));
2884         return elr;
2885 }
2886
2887 int ext4_register_li_request(struct super_block *sb,
2888                              ext4_group_t first_not_zeroed)
2889 {
2890         struct ext4_sb_info *sbi = EXT4_SB(sb);
2891         struct ext4_li_request *elr = NULL;
2892         ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
2893         int ret = 0;
2894
2895         mutex_lock(&ext4_li_mtx);
2896         if (sbi->s_li_request != NULL) {
2897                 /*
2898                  * Reset timeout so it can be computed again, because
2899                  * s_li_wait_mult might have changed.
2900                  */
2901                 sbi->s_li_request->lr_timeout = 0;
2902                 goto out;
2903         }
2904
2905         if (first_not_zeroed == ngroups ||
2906             (sb->s_flags & MS_RDONLY) ||
2907             !test_opt(sb, INIT_INODE_TABLE))
2908                 goto out;
2909
2910         elr = ext4_li_request_new(sb, first_not_zeroed);
2911         if (!elr) {
2912                 ret = -ENOMEM;
2913                 goto out;
2914         }
2915
2916         if (NULL == ext4_li_info) {
2917                 ret = ext4_li_info_new();
2918                 if (ret)
2919                         goto out;
2920         }
2921
2922         mutex_lock(&ext4_li_info->li_list_mtx);
2923         list_add(&elr->lr_request, &ext4_li_info->li_request_list);
2924         mutex_unlock(&ext4_li_info->li_list_mtx);
2925
2926         sbi->s_li_request = elr;
2927         /*
2928          * set elr to NULL here since it has been inserted to
2929          * the request_list and the removal and free of it is
2930          * handled by ext4_clear_request_list from now on.
2931          */
2932         elr = NULL;
2933
2934         if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
2935                 ret = ext4_run_lazyinit_thread();
2936                 if (ret)
2937                         goto out;
2938         }
2939 out:
2940         mutex_unlock(&ext4_li_mtx);
2941         if (ret)
2942                 kfree(elr);
2943         return ret;
2944 }
2945
2946 /*
2947  * We do not need to lock anything since this is called on
2948  * module unload.
2949  */
2950 static void ext4_destroy_lazyinit_thread(void)
2951 {
2952         /*
2953          * If thread exited earlier
2954          * there's nothing to be done.
2955          */
2956         if (!ext4_li_info || !ext4_lazyinit_task)
2957                 return;
2958
2959         kthread_stop(ext4_lazyinit_task);
2960 }
2961
2962 static int set_journal_csum_feature_set(struct super_block *sb)
2963 {
2964         int ret = 1;
2965         int compat, incompat;
2966         struct ext4_sb_info *sbi = EXT4_SB(sb);
2967
2968         if (ext4_has_metadata_csum(sb)) {
2969                 /* journal checksum v3 */
2970                 compat = 0;
2971                 incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
2972         } else {
2973                 /* journal checksum v1 */
2974                 compat = JBD2_FEATURE_COMPAT_CHECKSUM;
2975                 incompat = 0;
2976         }
2977
2978         jbd2_journal_clear_features(sbi->s_journal,
2979                         JBD2_FEATURE_COMPAT_CHECKSUM, 0,
2980                         JBD2_FEATURE_INCOMPAT_CSUM_V3 |
2981                         JBD2_FEATURE_INCOMPAT_CSUM_V2);
2982         if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
2983                 ret = jbd2_journal_set_features(sbi->s_journal,
2984                                 compat, 0,
2985                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
2986                                 incompat);
2987         } else if (test_opt(sb, JOURNAL_CHECKSUM)) {
2988                 ret = jbd2_journal_set_features(sbi->s_journal,
2989                                 compat, 0,
2990                                 incompat);
2991                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
2992                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
2993         } else {
2994                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
2995                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
2996         }
2997
2998         return ret;
2999 }
3000
3001 /*
3002  * Note: calculating the overhead so we can be compatible with
3003  * historical BSD practice is quite difficult in the face of
3004  * clusters/bigalloc.  This is because multiple metadata blocks from
3005  * different block group can end up in the same allocation cluster.
3006  * Calculating the exact overhead in the face of clustered allocation
3007  * requires either O(all block bitmaps) in memory or O(number of block
3008  * groups**2) in time.  We will still calculate the superblock for
3009  * older file systems --- and if we come across with a bigalloc file
3010  * system with zero in s_overhead_clusters the estimate will be close to
3011  * correct especially for very large cluster sizes --- but for newer
3012  * file systems, it's better to calculate this figure once at mkfs
3013  * time, and store it in the superblock.  If the superblock value is
3014  * present (even for non-bigalloc file systems), we will use it.
3015  */
3016 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3017                           char *buf)
3018 {
3019         struct ext4_sb_info     *sbi = EXT4_SB(sb);
3020         struct ext4_group_desc  *gdp;
3021         ext4_fsblk_t            first_block, last_block, b;
3022         ext4_group_t            i, ngroups = ext4_get_groups_count(sb);
3023         int                     s, j, count = 0;
3024
3025         if (!ext4_has_feature_bigalloc(sb))
3026                 return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3027                         sbi->s_itb_per_group + 2);
3028
3029         first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3030                 (grp * EXT4_BLOCKS_PER_GROUP(sb));
3031         last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3032         for (i = 0; i < ngroups; i++) {
3033                 gdp = ext4_get_group_desc(sb, i, NULL);
3034                 b = ext4_block_bitmap(sb, gdp);
3035                 if (b >= first_block && b <= last_block) {
3036                         ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3037                         count++;
3038                 }
3039                 b = ext4_inode_bitmap(sb, gdp);
3040                 if (b >= first_block && b <= last_block) {
3041                         ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3042                         count++;
3043                 }
3044                 b = ext4_inode_table(sb, gdp);
3045                 if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3046                         for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3047                                 int c = EXT4_B2C(sbi, b - first_block);
3048                                 ext4_set_bit(c, buf);
3049                                 count++;
3050                         }
3051                 if (i != grp)
3052                         continue;
3053                 s = 0;
3054                 if (ext4_bg_has_super(sb, grp)) {
3055                         ext4_set_bit(s++, buf);
3056                         count++;
3057                 }
3058                 for (j = ext4_bg_num_gdb(sb, grp); j > 0; j--) {
3059                         ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3060                         count++;
3061                 }
3062         }
3063         if (!count)
3064                 return 0;
3065         return EXT4_CLUSTERS_PER_GROUP(sb) -
3066                 ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3067 }
3068
3069 /*
3070  * Compute the overhead and stash it in sbi->s_overhead
3071  */
3072 int ext4_calculate_overhead(struct super_block *sb)
3073 {
3074         struct ext4_sb_info *sbi = EXT4_SB(sb);
3075         struct ext4_super_block *es = sbi->s_es;
3076         ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3077         ext4_fsblk_t overhead = 0;
3078         char *buf = (char *) get_zeroed_page(GFP_NOFS);
3079
3080         if (!buf)
3081                 return -ENOMEM;
3082
3083         /*
3084          * Compute the overhead (FS structures).  This is constant
3085          * for a given filesystem unless the number of block groups
3086          * changes so we cache the previous value until it does.
3087          */
3088
3089         /*
3090          * All of the blocks before first_data_block are overhead
3091          */
3092         overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3093
3094         /*
3095          * Add the overhead found in each block group
3096          */
3097         for (i = 0; i < ngroups; i++) {
3098                 int blks;
3099
3100                 blks = count_overhead(sb, i, buf);
3101                 overhead += blks;
3102                 if (blks)
3103                         memset(buf, 0, PAGE_SIZE);
3104                 cond_resched();
3105         }
3106         /* Add the internal journal blocks as well */
3107         if (sbi->s_journal && !sbi->journal_bdev)
3108                 overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_maxlen);
3109
3110         sbi->s_overhead = overhead;
3111         smp_wmb();
3112         free_page((unsigned long) buf);
3113         return 0;
3114 }
3115
3116 static void ext4_set_resv_clusters(struct super_block *sb)
3117 {
3118         ext4_fsblk_t resv_clusters;
3119         struct ext4_sb_info *sbi = EXT4_SB(sb);
3120
3121         /*
3122          * There's no need to reserve anything when we aren't using extents.
3123          * The space estimates are exact, there are no unwritten extents,
3124          * hole punching doesn't need new metadata... This is needed especially
3125          * to keep ext2/3 backward compatibility.
3126          */
3127         if (!ext4_has_feature_extents(sb))
3128                 return;
3129         /*
3130          * By default we reserve 2% or 4096 clusters, whichever is smaller.
3131          * This should cover the situations where we can not afford to run
3132          * out of space like for example punch hole, or converting
3133          * unwritten extents in delalloc path. In most cases such
3134          * allocation would require 1, or 2 blocks, higher numbers are
3135          * very rare.
3136          */
3137         resv_clusters = (ext4_blocks_count(sbi->s_es) >>
3138                          sbi->s_cluster_bits);
3139
3140         do_div(resv_clusters, 50);
3141         resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
3142
3143         atomic64_set(&sbi->s_resv_clusters, resv_clusters);
3144 }
3145
3146 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3147 {
3148         char *orig_data = kstrdup(data, GFP_KERNEL);
3149         struct buffer_head *bh;
3150         struct ext4_super_block *es = NULL;
3151         struct ext4_sb_info *sbi;
3152         ext4_fsblk_t block;
3153         ext4_fsblk_t sb_block = get_sb_block(&data);
3154         ext4_fsblk_t logical_sb_block;
3155         unsigned long offset = 0;
3156         unsigned long journal_devnum = 0;
3157         unsigned long def_mount_opts;
3158         struct inode *root;
3159         const char *descr;
3160         int ret = -ENOMEM;
3161         int blocksize, clustersize;
3162         unsigned int db_count;
3163         unsigned int i;
3164         int needs_recovery, has_huge_files, has_bigalloc;
3165         __u64 blocks_count;
3166         int err = 0;
3167         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3168         ext4_group_t first_not_zeroed;
3169
3170         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3171         if (!sbi)
3172                 goto out_free_orig;
3173
3174         sbi->s_blockgroup_lock =
3175                 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3176         if (!sbi->s_blockgroup_lock) {
3177                 kfree(sbi);
3178                 goto out_free_orig;
3179         }
3180         sb->s_fs_info = sbi;
3181         sbi->s_sb = sb;
3182         sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3183         sbi->s_sb_block = sb_block;
3184         if (sb->s_bdev->bd_part)
3185                 sbi->s_sectors_written_start =
3186                         part_stat_read(sb->s_bdev->bd_part, sectors[1]);
3187
3188         /* Cleanup superblock name */
3189         strreplace(sb->s_id, '/', '!');
3190
3191         /* -EINVAL is default */
3192         ret = -EINVAL;
3193         blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3194         if (!blocksize) {
3195                 ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3196                 goto out_fail;
3197         }
3198
3199         /*
3200          * The ext4 superblock will not be buffer aligned for other than 1kB
3201          * block sizes.  We need to calculate the offset from buffer start.
3202          */
3203         if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3204                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3205                 offset = do_div(logical_sb_block, blocksize);
3206         } else {
3207                 logical_sb_block = sb_block;
3208         }
3209
3210         if (!(bh = sb_bread_unmovable(sb, logical_sb_block))) {
3211                 ext4_msg(sb, KERN_ERR, "unable to read superblock");
3212                 goto out_fail;
3213         }
3214         /*
3215          * Note: s_es must be initialized as soon as possible because
3216          *       some ext4 macro-instructions depend on its value
3217          */
3218         es = (struct ext4_super_block *) (bh->b_data + offset);
3219         sbi->s_es = es;
3220         sb->s_magic = le16_to_cpu(es->s_magic);
3221         if (sb->s_magic != EXT4_SUPER_MAGIC)
3222                 goto cantfind_ext4;
3223         sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3224
3225         /* Warn if metadata_csum and gdt_csum are both set. */
3226         if (ext4_has_feature_metadata_csum(sb) &&
3227             ext4_has_feature_gdt_csum(sb))
3228                 ext4_warning(sb, "metadata_csum and uninit_bg are "
3229                              "redundant flags; please run fsck.");
3230
3231         /* Check for a known checksum algorithm */
3232         if (!ext4_verify_csum_type(sb, es)) {
3233                 ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3234                          "unknown checksum algorithm.");
3235                 silent = 1;
3236                 goto cantfind_ext4;
3237         }
3238
3239         /* Load the checksum driver */
3240         if (ext4_has_feature_metadata_csum(sb)) {
3241                 sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3242                 if (IS_ERR(sbi->s_chksum_driver)) {
3243                         ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3244                         ret = PTR_ERR(sbi->s_chksum_driver);
3245                         sbi->s_chksum_driver = NULL;
3246                         goto failed_mount;
3247                 }
3248         }
3249
3250         /* Check superblock checksum */
3251         if (!ext4_superblock_csum_verify(sb, es)) {
3252                 ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3253                          "invalid superblock checksum.  Run e2fsck?");
3254                 silent = 1;
3255                 ret = -EFSBADCRC;
3256                 goto cantfind_ext4;
3257         }
3258
3259         /* Precompute checksum seed for all metadata */
3260         if (ext4_has_feature_csum_seed(sb))
3261                 sbi->s_csum_seed = le32_to_cpu(es->s_checksum_seed);
3262         else if (ext4_has_metadata_csum(sb))
3263                 sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3264                                                sizeof(es->s_uuid));
3265
3266         /* Set defaults before we parse the mount options */
3267         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3268         set_opt(sb, INIT_INODE_TABLE);
3269         if (def_mount_opts & EXT4_DEFM_DEBUG)
3270                 set_opt(sb, DEBUG);
3271         if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3272                 set_opt(sb, GRPID);
3273         if (def_mount_opts & EXT4_DEFM_UID16)
3274                 set_opt(sb, NO_UID32);
3275         /* xattr user namespace & acls are now defaulted on */
3276         set_opt(sb, XATTR_USER);
3277 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3278         set_opt(sb, POSIX_ACL);
3279 #endif
3280         /* don't forget to enable journal_csum when metadata_csum is enabled. */
3281         if (ext4_has_metadata_csum(sb))
3282                 set_opt(sb, JOURNAL_CHECKSUM);
3283
3284         if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3285                 set_opt(sb, JOURNAL_DATA);
3286         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3287                 set_opt(sb, ORDERED_DATA);
3288         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3289                 set_opt(sb, WRITEBACK_DATA);
3290
3291         if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3292                 set_opt(sb, ERRORS_PANIC);
3293         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3294                 set_opt(sb, ERRORS_CONT);
3295         else
3296                 set_opt(sb, ERRORS_RO);
3297         /* block_validity enabled by default; disable with noblock_validity */
3298         set_opt(sb, BLOCK_VALIDITY);
3299         if (def_mount_opts & EXT4_DEFM_DISCARD)
3300                 set_opt(sb, DISCARD);
3301
3302         sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3303         sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3304         sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3305         sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3306         sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3307
3308         if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3309                 set_opt(sb, BARRIER);
3310
3311         /*
3312          * enable delayed allocation by default
3313          * Use -o nodelalloc to turn it off
3314          */
3315         if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
3316             ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3317                 set_opt(sb, DELALLOC);
3318
3319         /*
3320          * set default s_li_wait_mult for lazyinit, for the case there is
3321          * no mount option specified.
3322          */
3323         sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3324
3325         if (!parse_options((char *) sbi->s_es->s_mount_opts, sb,
3326                            &journal_devnum, &journal_ioprio, 0)) {
3327                 ext4_msg(sb, KERN_WARNING,
3328                          "failed to parse options in superblock: %s",
3329                          sbi->s_es->s_mount_opts);
3330         }
3331         sbi->s_def_mount_opt = sbi->s_mount_opt;
3332         if (!parse_options((char *) data, sb, &journal_devnum,
3333                            &journal_ioprio, 0))
3334                 goto failed_mount;
3335
3336         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3337                 printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3338                             "with data=journal disables delayed "
3339                             "allocation and O_DIRECT support!\n");
3340                 if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3341                         ext4_msg(sb, KERN_ERR, "can't mount with "
3342                                  "both data=journal and delalloc");
3343                         goto failed_mount;
3344                 }
3345                 if (test_opt(sb, DIOREAD_NOLOCK)) {
3346                         ext4_msg(sb, KERN_ERR, "can't mount with "
3347                                  "both data=journal and dioread_nolock");
3348                         goto failed_mount;
3349                 }
3350                 if (test_opt(sb, DAX)) {
3351                         ext4_msg(sb, KERN_ERR, "can't mount with "
3352                                  "both data=journal and dax");
3353                         goto failed_mount;
3354                 }
3355                 if (test_opt(sb, DELALLOC))
3356                         clear_opt(sb, DELALLOC);
3357         } else {
3358                 sb->s_iflags |= SB_I_CGROUPWB;
3359         }
3360
3361         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
3362                 (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
3363
3364         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3365             (ext4_has_compat_features(sb) ||
3366              ext4_has_ro_compat_features(sb) ||
3367              ext4_has_incompat_features(sb)))
3368                 ext4_msg(sb, KERN_WARNING,
3369                        "feature flags set on rev 0 fs, "
3370                        "running e2fsck is recommended");
3371
3372         if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
3373                 set_opt2(sb, HURD_COMPAT);
3374                 if (ext4_has_feature_64bit(sb)) {
3375                         ext4_msg(sb, KERN_ERR,
3376                                  "The Hurd can't support 64-bit file systems");
3377                         goto failed_mount;
3378                 }
3379         }
3380
3381         if (IS_EXT2_SB(sb)) {
3382                 if (ext2_feature_set_ok(sb))
3383                         ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3384                                  "using the ext4 subsystem");
3385                 else {
3386                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3387                                  "to feature incompatibilities");
3388                         goto failed_mount;
3389                 }
3390         }
3391
3392         if (IS_EXT3_SB(sb)) {
3393                 if (ext3_feature_set_ok(sb))
3394                         ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3395                                  "using the ext4 subsystem");
3396                 else {
3397                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3398                                  "to feature incompatibilities");
3399                         goto failed_mount;
3400                 }
3401         }
3402
3403         /*
3404          * Check feature flags regardless of the revision level, since we
3405          * previously didn't change the revision level when setting the flags,
3406          * so there is a chance incompat flags are set on a rev 0 filesystem.
3407          */
3408         if (!ext4_feature_set_ok(sb, (sb->s_flags & MS_RDONLY)))
3409                 goto failed_mount;
3410
3411         blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3412         if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3413             blocksize > EXT4_MAX_BLOCK_SIZE) {
3414                 ext4_msg(sb, KERN_ERR,
3415                        "Unsupported filesystem blocksize %d", blocksize);
3416                 goto failed_mount;
3417         }
3418
3419         if (sbi->s_mount_opt & EXT4_MOUNT_DAX) {
3420                 if (blocksize != PAGE_SIZE) {
3421                         ext4_msg(sb, KERN_ERR,
3422                                         "error: unsupported blocksize for dax");
3423                         goto failed_mount;
3424                 }
3425                 if (!sb->s_bdev->bd_disk->fops->direct_access) {
3426                         ext4_msg(sb, KERN_ERR,
3427                                         "error: device does not support dax");
3428                         goto failed_mount;
3429                 }
3430         }
3431
3432         if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) {
3433                 ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
3434                          es->s_encryption_level);
3435                 goto failed_mount;
3436         }
3437
3438         if (sb->s_blocksize != blocksize) {
3439                 /* Validate the filesystem blocksize */
3440                 if (!sb_set_blocksize(sb, blocksize)) {
3441                         ext4_msg(sb, KERN_ERR, "bad block size %d",
3442                                         blocksize);
3443                         goto failed_mount;
3444                 }
3445
3446                 brelse(bh);
3447                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3448                 offset = do_div(logical_sb_block, blocksize);
3449                 bh = sb_bread_unmovable(sb, logical_sb_block);
3450                 if (!bh) {
3451                         ext4_msg(sb, KERN_ERR,
3452                                "Can't read superblock on 2nd try");
3453                         goto failed_mount;
3454                 }
3455                 es = (struct ext4_super_block *)(bh->b_data + offset);
3456                 sbi->s_es = es;
3457                 if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
3458                         ext4_msg(sb, KERN_ERR,
3459                                "Magic mismatch, very weird!");
3460                         goto failed_mount;
3461                 }
3462         }
3463
3464         has_huge_files = ext4_has_feature_huge_file(sb);
3465         sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
3466                                                       has_huge_files);
3467         sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
3468
3469         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3470                 sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3471                 sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3472         } else {
3473                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3474                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3475                 if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3476                     (!is_power_of_2(sbi->s_inode_size)) ||
3477                     (sbi->s_inode_size > blocksize)) {
3478                         ext4_msg(sb, KERN_ERR,
3479                                "unsupported inode size: %d",
3480                                sbi->s_inode_size);
3481                         goto failed_mount;
3482                 }
3483                 if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
3484                         sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
3485         }
3486
3487         sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
3488         if (ext4_has_feature_64bit(sb)) {
3489                 if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
3490                     sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
3491                     !is_power_of_2(sbi->s_desc_size)) {
3492                         ext4_msg(sb, KERN_ERR,
3493                                "unsupported descriptor size %lu",
3494                                sbi->s_desc_size);
3495                         goto failed_mount;
3496                 }
3497         } else
3498                 sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
3499
3500         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
3501         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
3502         if (EXT4_INODE_SIZE(sb) == 0 || EXT4_INODES_PER_GROUP(sb) == 0)
3503                 goto cantfind_ext4;
3504
3505         sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
3506         if (sbi->s_inodes_per_block == 0)
3507                 goto cantfind_ext4;
3508         sbi->s_itb_per_group = sbi->s_inodes_per_group /
3509                                         sbi->s_inodes_per_block;
3510         sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
3511         sbi->s_sbh = bh;
3512         sbi->s_mount_state = le16_to_cpu(es->s_state);
3513         sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
3514         sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
3515
3516         for (i = 0; i < 4; i++)
3517                 sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
3518         sbi->s_def_hash_version = es->s_def_hash_version;
3519         if (ext4_has_feature_dir_index(sb)) {
3520                 i = le32_to_cpu(es->s_flags);
3521                 if (i & EXT2_FLAGS_UNSIGNED_HASH)
3522                         sbi->s_hash_unsigned = 3;
3523                 else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
3524 #ifdef __CHAR_UNSIGNED__
3525                         if (!(sb->s_flags & MS_RDONLY))
3526                                 es->s_flags |=
3527                                         cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
3528                         sbi->s_hash_unsigned = 3;
3529 #else
3530                         if (!(sb->s_flags & MS_RDONLY))
3531                                 es->s_flags |=
3532                                         cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
3533 #endif
3534                 }
3535         }
3536
3537         /* Handle clustersize */
3538         clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
3539         has_bigalloc = ext4_has_feature_bigalloc(sb);
3540         if (has_bigalloc) {
3541                 if (clustersize < blocksize) {
3542                         ext4_msg(sb, KERN_ERR,
3543                                  "cluster size (%d) smaller than "
3544                                  "block size (%d)", clustersize, blocksize);
3545                         goto failed_mount;
3546                 }
3547                 sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
3548                         le32_to_cpu(es->s_log_block_size);
3549                 sbi->s_clusters_per_group =
3550                         le32_to_cpu(es->s_clusters_per_group);
3551                 if (sbi->s_clusters_per_group > blocksize * 8) {
3552                         ext4_msg(sb, KERN_ERR,
3553                                  "#clusters per group too big: %lu",
3554                                  sbi->s_clusters_per_group);
3555                         goto failed_mount;
3556                 }
3557                 if (sbi->s_blocks_per_group !=
3558                     (sbi->s_clusters_per_group * (clustersize / blocksize))) {
3559                         ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
3560                                  "clusters per group (%lu) inconsistent",
3561                                  sbi->s_blocks_per_group,
3562                                  sbi->s_clusters_per_group);
3563                         goto failed_mount;
3564                 }
3565         } else {
3566                 if (clustersize != blocksize) {
3567                         ext4_warning(sb, "fragment/cluster size (%d) != "
3568                                      "block size (%d)", clustersize,
3569                                      blocksize);
3570                         clustersize = blocksize;
3571                 }
3572                 if (sbi->s_blocks_per_group > blocksize * 8) {
3573                         ext4_msg(sb, KERN_ERR,
3574                                  "#blocks per group too big: %lu",
3575                                  sbi->s_blocks_per_group);
3576                         goto failed_mount;
3577                 }
3578                 sbi->s_clusters_per_group = sbi->s_blocks_per_group;
3579                 sbi->s_cluster_bits = 0;
3580         }
3581         sbi->s_cluster_ratio = clustersize / blocksize;
3582
3583         if (sbi->s_inodes_per_group > blocksize * 8) {
3584                 ext4_msg(sb, KERN_ERR,
3585                        "#inodes per group too big: %lu",
3586                        sbi->s_inodes_per_group);
3587                 goto failed_mount;
3588         }
3589
3590         /* Do we have standard group size of clustersize * 8 blocks ? */
3591         if (sbi->s_blocks_per_group == clustersize << 3)
3592                 set_opt2(sb, STD_GROUP_SIZE);
3593
3594         /*
3595          * Test whether we have more sectors than will fit in sector_t,
3596          * and whether the max offset is addressable by the page cache.
3597          */
3598         err = generic_check_addressable(sb->s_blocksize_bits,
3599                                         ext4_blocks_count(es));
3600         if (err) {
3601                 ext4_msg(sb, KERN_ERR, "filesystem"
3602                          " too large to mount safely on this system");
3603                 if (sizeof(sector_t) < 8)
3604                         ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
3605                 goto failed_mount;
3606         }
3607
3608         if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
3609                 goto cantfind_ext4;
3610
3611         /* check blocks count against device size */
3612         blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
3613         if (blocks_count && ext4_blocks_count(es) > blocks_count) {
3614                 ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
3615                        "exceeds size of device (%llu blocks)",
3616                        ext4_blocks_count(es), blocks_count);
3617                 goto failed_mount;
3618         }
3619
3620         /*
3621          * It makes no sense for the first data block to be beyond the end
3622          * of the filesystem.
3623          */
3624         if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
3625                 ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
3626                          "block %u is beyond end of filesystem (%llu)",
3627                          le32_to_cpu(es->s_first_data_block),
3628                          ext4_blocks_count(es));
3629                 goto failed_mount;
3630         }
3631         blocks_count = (ext4_blocks_count(es) -
3632                         le32_to_cpu(es->s_first_data_block) +
3633                         EXT4_BLOCKS_PER_GROUP(sb) - 1);
3634         do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
3635         if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
3636                 ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
3637                        "(block count %llu, first data block %u, "
3638                        "blocks per group %lu)", sbi->s_groups_count,
3639                        ext4_blocks_count(es),
3640                        le32_to_cpu(es->s_first_data_block),
3641                        EXT4_BLOCKS_PER_GROUP(sb));
3642                 goto failed_mount;
3643         }
3644         sbi->s_groups_count = blocks_count;
3645         sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
3646                         (EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
3647         db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
3648                    EXT4_DESC_PER_BLOCK(sb);
3649         sbi->s_group_desc = ext4_kvmalloc(db_count *
3650                                           sizeof(struct buffer_head *),
3651                                           GFP_KERNEL);
3652         if (sbi->s_group_desc == NULL) {
3653                 ext4_msg(sb, KERN_ERR, "not enough memory");
3654                 ret = -ENOMEM;
3655                 goto failed_mount;
3656         }
3657
3658         bgl_lock_init(sbi->s_blockgroup_lock);
3659
3660         for (i = 0; i < db_count; i++) {
3661                 block = descriptor_loc(sb, logical_sb_block, i);
3662                 sbi->s_group_desc[i] = sb_bread_unmovable(sb, block);
3663                 if (!sbi->s_group_desc[i]) {
3664                         ext4_msg(sb, KERN_ERR,
3665                                "can't read group descriptor %d", i);
3666                         db_count = i;
3667                         goto failed_mount2;
3668                 }
3669         }
3670         if (!ext4_check_descriptors(sb, &first_not_zeroed)) {
3671                 ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
3672                 ret = -EFSCORRUPTED;
3673                 goto failed_mount2;
3674         }
3675
3676         sbi->s_gdb_count = db_count;
3677         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
3678         spin_lock_init(&sbi->s_next_gen_lock);
3679
3680         setup_timer(&sbi->s_err_report, print_daily_error_info,
3681                 (unsigned long) sb);
3682
3683         /* Register extent status tree shrinker */
3684         if (ext4_es_register_shrinker(sbi))
3685                 goto failed_mount3;
3686
3687         sbi->s_stripe = ext4_get_stripe_size(sbi);
3688         sbi->s_extent_max_zeroout_kb = 32;
3689
3690         /*
3691          * set up enough so that it can read an inode
3692          */
3693         sb->s_op = &ext4_sops;
3694         sb->s_export_op = &ext4_export_ops;
3695         sb->s_xattr = ext4_xattr_handlers;
3696 #ifdef CONFIG_QUOTA
3697         sb->dq_op = &ext4_quota_operations;
3698         if (ext4_has_feature_quota(sb))
3699                 sb->s_qcop = &dquot_quotactl_sysfile_ops;
3700         else
3701                 sb->s_qcop = &ext4_qctl_operations;
3702         sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
3703 #endif
3704         memcpy(sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
3705
3706         INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
3707         mutex_init(&sbi->s_orphan_lock);
3708
3709         sb->s_root = NULL;
3710
3711         needs_recovery = (es->s_last_orphan != 0 ||
3712                           ext4_has_feature_journal_needs_recovery(sb));
3713
3714         if (ext4_has_feature_mmp(sb) && !(sb->s_flags & MS_RDONLY))
3715                 if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
3716                         goto failed_mount3a;
3717
3718         /*
3719          * The first inode we look at is the journal inode.  Don't try
3720          * root first: it may be modified in the journal!
3721          */
3722         if (!test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) {
3723                 if (ext4_load_journal(sb, es, journal_devnum))
3724                         goto failed_mount3a;
3725         } else if (test_opt(sb, NOLOAD) && !(sb->s_flags & MS_RDONLY) &&
3726                    ext4_has_feature_journal_needs_recovery(sb)) {
3727                 ext4_msg(sb, KERN_ERR, "required journal recovery "
3728                        "suppressed and not mounted read-only");
3729                 goto failed_mount_wq;
3730         } else {
3731                 /* Nojournal mode, all journal mount options are illegal */
3732                 if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM)) {
3733                         ext4_msg(sb, KERN_ERR, "can't mount with "
3734                                  "journal_checksum, fs mounted w/o journal");
3735                         goto failed_mount_wq;
3736                 }
3737                 if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3738                         ext4_msg(sb, KERN_ERR, "can't mount with "
3739                                  "journal_async_commit, fs mounted w/o journal");
3740                         goto failed_mount_wq;
3741                 }
3742                 if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
3743                         ext4_msg(sb, KERN_ERR, "can't mount with "
3744                                  "commit=%lu, fs mounted w/o journal",
3745                                  sbi->s_commit_interval / HZ);
3746                         goto failed_mount_wq;
3747                 }
3748                 if (EXT4_MOUNT_DATA_FLAGS &
3749                     (sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
3750                         ext4_msg(sb, KERN_ERR, "can't mount with "
3751                                  "data=, fs mounted w/o journal");
3752                         goto failed_mount_wq;
3753                 }
3754                 sbi->s_def_mount_opt &= EXT4_MOUNT_JOURNAL_CHECKSUM;
3755                 clear_opt(sb, JOURNAL_CHECKSUM);
3756                 clear_opt(sb, DATA_FLAGS);
3757                 sbi->s_journal = NULL;
3758                 needs_recovery = 0;
3759                 goto no_journal;
3760         }
3761
3762         if (ext4_has_feature_64bit(sb) &&
3763             !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
3764                                        JBD2_FEATURE_INCOMPAT_64BIT)) {
3765                 ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
3766                 goto failed_mount_wq;
3767         }
3768
3769         if (!set_journal_csum_feature_set(sb)) {
3770                 ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
3771                          "feature set");
3772                 goto failed_mount_wq;
3773         }
3774
3775         /* We have now updated the journal if required, so we can
3776          * validate the data journaling mode. */
3777         switch (test_opt(sb, DATA_FLAGS)) {
3778         case 0:
3779                 /* No mode set, assume a default based on the journal
3780                  * capabilities: ORDERED_DATA if the journal can
3781                  * cope, else JOURNAL_DATA
3782                  */
3783                 if (jbd2_journal_check_available_features
3784                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
3785                         set_opt(sb, ORDERED_DATA);
3786                 else
3787                         set_opt(sb, JOURNAL_DATA);
3788                 break;
3789
3790         case EXT4_MOUNT_ORDERED_DATA:
3791         case EXT4_MOUNT_WRITEBACK_DATA:
3792                 if (!jbd2_journal_check_available_features
3793                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
3794                         ext4_msg(sb, KERN_ERR, "Journal does not support "
3795                                "requested data journaling mode");
3796                         goto failed_mount_wq;
3797                 }
3798         default:
3799                 break;
3800         }
3801         set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
3802
3803         sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
3804
3805 no_journal:
3806         sbi->s_mb_cache = ext4_xattr_create_cache();
3807         if (!sbi->s_mb_cache) {
3808                 ext4_msg(sb, KERN_ERR, "Failed to create an mb_cache");
3809                 goto failed_mount_wq;
3810         }
3811
3812         if ((DUMMY_ENCRYPTION_ENABLED(sbi) || ext4_has_feature_encrypt(sb)) &&
3813             (blocksize != PAGE_SIZE)) {
3814                 ext4_msg(sb, KERN_ERR,
3815                          "Unsupported blocksize for fs encryption");
3816                 goto failed_mount_wq;
3817         }
3818
3819         if (DUMMY_ENCRYPTION_ENABLED(sbi) && !(sb->s_flags & MS_RDONLY) &&
3820             !ext4_has_feature_encrypt(sb)) {
3821                 ext4_set_feature_encrypt(sb);
3822                 ext4_commit_super(sb, 1);
3823         }
3824
3825         /*
3826          * Get the # of file system overhead blocks from the
3827          * superblock if present.
3828          */
3829         if (es->s_overhead_clusters)
3830                 sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
3831         else {
3832                 err = ext4_calculate_overhead(sb);
3833                 if (err)
3834                         goto failed_mount_wq;
3835         }
3836
3837         /*
3838          * The maximum number of concurrent works can be high and
3839          * concurrency isn't really necessary.  Limit it to 1.
3840          */
3841         EXT4_SB(sb)->rsv_conversion_wq =
3842                 alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
3843         if (!EXT4_SB(sb)->rsv_conversion_wq) {
3844                 printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
3845                 ret = -ENOMEM;
3846                 goto failed_mount4;
3847         }
3848
3849         /*
3850          * The jbd2_journal_load will have done any necessary log recovery,
3851          * so we can safely mount the rest of the filesystem now.
3852          */
3853
3854         root = ext4_iget(sb, EXT4_ROOT_INO);
3855         if (IS_ERR(root)) {
3856                 ext4_msg(sb, KERN_ERR, "get root inode failed");
3857                 ret = PTR_ERR(root);
3858                 root = NULL;
3859                 goto failed_mount4;
3860         }
3861         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
3862                 ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
3863                 iput(root);
3864                 goto failed_mount4;
3865         }
3866         sb->s_root = d_make_root(root);
3867         if (!sb->s_root) {
3868                 ext4_msg(sb, KERN_ERR, "get root dentry failed");
3869                 ret = -ENOMEM;
3870                 goto failed_mount4;
3871         }
3872
3873         if (ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY))
3874                 sb->s_flags |= MS_RDONLY;
3875
3876         /* determine the minimum size of new large inodes, if present */
3877         if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
3878                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
3879                                                      EXT4_GOOD_OLD_INODE_SIZE;
3880                 if (ext4_has_feature_extra_isize(sb)) {
3881                         if (sbi->s_want_extra_isize <
3882                             le16_to_cpu(es->s_want_extra_isize))
3883                                 sbi->s_want_extra_isize =
3884                                         le16_to_cpu(es->s_want_extra_isize);
3885                         if (sbi->s_want_extra_isize <
3886                             le16_to_cpu(es->s_min_extra_isize))
3887                                 sbi->s_want_extra_isize =
3888                                         le16_to_cpu(es->s_min_extra_isize);
3889                 }
3890         }
3891         /* Check if enough inode space is available */
3892         if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
3893                                                         sbi->s_inode_size) {
3894                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
3895                                                        EXT4_GOOD_OLD_INODE_SIZE;
3896                 ext4_msg(sb, KERN_INFO, "required extra inode space not"
3897                          "available");
3898         }
3899
3900         ext4_set_resv_clusters(sb);
3901
3902         err = ext4_setup_system_zone(sb);
3903         if (err) {
3904                 ext4_msg(sb, KERN_ERR, "failed to initialize system "
3905                          "zone (%d)", err);
3906                 goto failed_mount4a;
3907         }
3908
3909         ext4_ext_init(sb);
3910         err = ext4_mb_init(sb);
3911         if (err) {
3912                 ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
3913                          err);
3914                 goto failed_mount5;
3915         }
3916
3917         block = ext4_count_free_clusters(sb);
3918         ext4_free_blocks_count_set(sbi->s_es,
3919                                    EXT4_C2B(sbi, block));
3920         err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
3921                                   GFP_KERNEL);
3922         if (!err) {
3923                 unsigned long freei = ext4_count_free_inodes(sb);
3924                 sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
3925                 err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
3926                                           GFP_KERNEL);
3927         }
3928         if (!err)
3929                 err = percpu_counter_init(&sbi->s_dirs_counter,
3930                                           ext4_count_dirs(sb), GFP_KERNEL);
3931         if (!err)
3932                 err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
3933                                           GFP_KERNEL);
3934         if (!err)
3935                 err = percpu_init_rwsem(&sbi->s_journal_flag_rwsem);
3936
3937         if (err) {
3938                 ext4_msg(sb, KERN_ERR, "insufficient memory");
3939                 goto failed_mount6;
3940         }
3941
3942         if (ext4_has_feature_flex_bg(sb))
3943                 if (!ext4_fill_flex_info(sb)) {
3944                         ext4_msg(sb, KERN_ERR,
3945                                "unable to initialize "
3946                                "flex_bg meta info!");
3947                         goto failed_mount6;
3948                 }
3949
3950         err = ext4_register_li_request(sb, first_not_zeroed);
3951         if (err)
3952                 goto failed_mount6;
3953
3954         err = ext4_register_sysfs(sb);
3955         if (err)
3956                 goto failed_mount7;
3957
3958 #ifdef CONFIG_QUOTA
3959         /* Enable quota usage during mount. */
3960         if (ext4_has_feature_quota(sb) && !(sb->s_flags & MS_RDONLY)) {
3961                 err = ext4_enable_quotas(sb);
3962                 if (err)
3963                         goto failed_mount8;
3964         }
3965 #endif  /* CONFIG_QUOTA */
3966
3967         EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
3968         ext4_orphan_cleanup(sb, es);
3969         EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
3970         if (needs_recovery) {
3971                 ext4_msg(sb, KERN_INFO, "recovery complete");
3972                 ext4_mark_recovery_complete(sb, es);
3973         }
3974         if (EXT4_SB(sb)->s_journal) {
3975                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
3976                         descr = " journalled data mode";
3977                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
3978                         descr = " ordered data mode";
3979                 else
3980                         descr = " writeback data mode";
3981         } else
3982                 descr = "out journal";
3983
3984         if (test_opt(sb, DISCARD)) {
3985                 struct request_queue *q = bdev_get_queue(sb->s_bdev);
3986                 if (!blk_queue_discard(q))
3987                         ext4_msg(sb, KERN_WARNING,
3988                                  "mounting with \"discard\" option, but "
3989                                  "the device does not support discard");
3990         }
3991
3992         if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
3993                 ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
3994                          "Opts: %s%s%s", descr, sbi->s_es->s_mount_opts,
3995                          *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
3996
3997         if (es->s_error_count)
3998                 mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
3999
4000         /* Enable message ratelimiting. Default is 10 messages per 5 secs. */
4001         ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
4002         ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
4003         ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
4004
4005         kfree(orig_data);
4006         return 0;
4007
4008 cantfind_ext4:
4009         if (!silent)
4010                 ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
4011         goto failed_mount;
4012
4013 #ifdef CONFIG_QUOTA
4014 failed_mount8:
4015         ext4_unregister_sysfs(sb);
4016 #endif
4017 failed_mount7:
4018         ext4_unregister_li_request(sb);
4019 failed_mount6:
4020         ext4_mb_release(sb);
4021         if (sbi->s_flex_groups)
4022                 kvfree(sbi->s_flex_groups);
4023         percpu_counter_destroy(&sbi->s_freeclusters_counter);
4024         percpu_counter_destroy(&sbi->s_freeinodes_counter);
4025         percpu_counter_destroy(&sbi->s_dirs_counter);
4026         percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4027 failed_mount5:
4028         ext4_ext_release(sb);
4029         ext4_release_system_zone(sb);
4030 failed_mount4a:
4031         dput(sb->s_root);
4032         sb->s_root = NULL;
4033 failed_mount4:
4034         ext4_msg(sb, KERN_ERR, "mount failed");
4035         if (EXT4_SB(sb)->rsv_conversion_wq)
4036                 destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4037 failed_mount_wq:
4038         if (sbi->s_mb_cache) {
4039                 ext4_xattr_destroy_cache(sbi->s_mb_cache);
4040                 sbi->s_mb_cache = NULL;
4041         }
4042         if (sbi->s_journal) {
4043                 jbd2_journal_destroy(sbi->s_journal);
4044                 sbi->s_journal = NULL;
4045         }
4046 failed_mount3a:
4047         ext4_es_unregister_shrinker(sbi);
4048 failed_mount3:
4049         del_timer_sync(&sbi->s_err_report);
4050         if (sbi->s_mmp_tsk)
4051                 kthread_stop(sbi->s_mmp_tsk);
4052 failed_mount2:
4053         for (i = 0; i < db_count; i++)
4054                 brelse(sbi->s_group_desc[i]);
4055         kvfree(sbi->s_group_desc);
4056 failed_mount:
4057         if (sbi->s_chksum_driver)
4058                 crypto_free_shash(sbi->s_chksum_driver);
4059 #ifdef CONFIG_QUOTA
4060         for (i = 0; i < EXT4_MAXQUOTAS; i++)
4061                 kfree(sbi->s_qf_names[i]);
4062 #endif
4063         ext4_blkdev_remove(sbi);
4064         brelse(bh);
4065 out_fail:
4066         sb->s_fs_info = NULL;
4067         kfree(sbi->s_blockgroup_lock);
4068         kfree(sbi);
4069 out_free_orig:
4070         kfree(orig_data);
4071         return err ? err : ret;
4072 }
4073
4074 /*
4075  * Setup any per-fs journal parameters now.  We'll do this both on
4076  * initial mount, once the journal has been initialised but before we've
4077  * done any recovery; and again on any subsequent remount.
4078  */
4079 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4080 {
4081         struct ext4_sb_info *sbi = EXT4_SB(sb);
4082
4083         journal->j_commit_interval = sbi->s_commit_interval;
4084         journal->j_min_batch_time = sbi->s_min_batch_time;
4085         journal->j_max_batch_time = sbi->s_max_batch_time;
4086
4087         write_lock(&journal->j_state_lock);
4088         if (test_opt(sb, BARRIER))
4089                 journal->j_flags |= JBD2_BARRIER;
4090         else
4091                 journal->j_flags &= ~JBD2_BARRIER;
4092         if (test_opt(sb, DATA_ERR_ABORT))
4093                 journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4094         else
4095                 journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4096         write_unlock(&journal->j_state_lock);
4097 }
4098
4099 static journal_t *ext4_get_journal(struct super_block *sb,
4100                                    unsigned int journal_inum)
4101 {
4102         struct inode *journal_inode;
4103         journal_t *journal;
4104
4105         BUG_ON(!ext4_has_feature_journal(sb));
4106
4107         /* First, test for the existence of a valid inode on disk.  Bad
4108          * things happen if we iget() an unused inode, as the subsequent
4109          * iput() will try to delete it. */
4110
4111         journal_inode = ext4_iget(sb, journal_inum);
4112         if (IS_ERR(journal_inode)) {
4113                 ext4_msg(sb, KERN_ERR, "no journal found");
4114                 return NULL;
4115         }
4116         if (!journal_inode->i_nlink) {
4117                 make_bad_inode(journal_inode);
4118                 iput(journal_inode);
4119                 ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4120                 return NULL;
4121         }
4122
4123         jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4124                   journal_inode, journal_inode->i_size);
4125         if (!S_ISREG(journal_inode->i_mode)) {
4126                 ext4_msg(sb, KERN_ERR, "invalid journal inode");
4127                 iput(journal_inode);
4128                 return NULL;
4129         }
4130
4131         journal = jbd2_journal_init_inode(journal_inode);
4132         if (!journal) {
4133                 ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4134                 iput(journal_inode);
4135                 return NULL;
4136         }
4137         journal->j_private = sb;
4138         ext4_init_journal_params(sb, journal);
4139         return journal;
4140 }
4141
4142 static journal_t *ext4_get_dev_journal(struct super_block *sb,
4143                                        dev_t j_dev)
4144 {
4145         struct buffer_head *bh;
4146         journal_t *journal;
4147         ext4_fsblk_t start;
4148         ext4_fsblk_t len;
4149         int hblock, blocksize;
4150         ext4_fsblk_t sb_block;
4151         unsigned long offset;
4152         struct ext4_super_block *es;
4153         struct block_device *bdev;
4154
4155         BUG_ON(!ext4_has_feature_journal(sb));
4156
4157         bdev = ext4_blkdev_get(j_dev, sb);
4158         if (bdev == NULL)
4159                 return NULL;
4160
4161         blocksize = sb->s_blocksize;
4162         hblock = bdev_logical_block_size(bdev);
4163         if (blocksize < hblock) {
4164                 ext4_msg(sb, KERN_ERR,
4165                         "blocksize too small for journal device");
4166                 goto out_bdev;
4167         }
4168
4169         sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4170         offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4171         set_blocksize(bdev, blocksize);
4172         if (!(bh = __bread(bdev, sb_block, blocksize))) {
4173                 ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4174                        "external journal");
4175                 goto out_bdev;
4176         }
4177
4178         es = (struct ext4_super_block *) (bh->b_data + offset);
4179         if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4180             !(le32_to_cpu(es->s_feature_incompat) &
4181               EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4182                 ext4_msg(sb, KERN_ERR, "external journal has "
4183                                         "bad superblock");
4184                 brelse(bh);
4185                 goto out_bdev;
4186         }
4187
4188         if ((le32_to_cpu(es->s_feature_ro_compat) &
4189              EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
4190             es->s_checksum != ext4_superblock_csum(sb, es)) {
4191                 ext4_msg(sb, KERN_ERR, "external journal has "
4192                                        "corrupt superblock");
4193                 brelse(bh);
4194                 goto out_bdev;
4195         }
4196
4197         if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4198                 ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4199                 brelse(bh);
4200                 goto out_bdev;
4201         }
4202
4203         len = ext4_blocks_count(es);
4204         start = sb_block + 1;
4205         brelse(bh);     /* we're done with the superblock */
4206
4207         journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4208                                         start, len, blocksize);
4209         if (!journal) {
4210                 ext4_msg(sb, KERN_ERR, "failed to create device journal");
4211                 goto out_bdev;
4212         }
4213         journal->j_private = sb;
4214         ll_rw_block(READ | REQ_META | REQ_PRIO, 1, &journal->j_sb_buffer);
4215         wait_on_buffer(journal->j_sb_buffer);
4216         if (!buffer_uptodate(journal->j_sb_buffer)) {
4217                 ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4218                 goto out_journal;
4219         }
4220         if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4221                 ext4_msg(sb, KERN_ERR, "External journal has more than one "
4222                                         "user (unsupported) - %d",
4223                         be32_to_cpu(journal->j_superblock->s_nr_users));
4224                 goto out_journal;
4225         }
4226         EXT4_SB(sb)->journal_bdev = bdev;
4227         ext4_init_journal_params(sb, journal);
4228         return journal;
4229
4230 out_journal:
4231         jbd2_journal_destroy(journal);
4232 out_bdev:
4233         ext4_blkdev_put(bdev);
4234         return NULL;
4235 }
4236
4237 static int ext4_load_journal(struct super_block *sb,
4238                              struct ext4_super_block *es,
4239                              unsigned long journal_devnum)
4240 {
4241         journal_t *journal;
4242         unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4243         dev_t journal_dev;
4244         int err = 0;
4245         int really_read_only;
4246
4247         BUG_ON(!ext4_has_feature_journal(sb));
4248
4249         if (journal_devnum &&
4250             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4251                 ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4252                         "numbers have changed");
4253                 journal_dev = new_decode_dev(journal_devnum);
4254         } else
4255                 journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4256
4257         really_read_only = bdev_read_only(sb->s_bdev);
4258
4259         /*
4260          * Are we loading a blank journal or performing recovery after a
4261          * crash?  For recovery, we need to check in advance whether we
4262          * can get read-write access to the device.
4263          */
4264         if (ext4_has_feature_journal_needs_recovery(sb)) {
4265                 if (sb->s_flags & MS_RDONLY) {
4266                         ext4_msg(sb, KERN_INFO, "INFO: recovery "
4267                                         "required on readonly filesystem");
4268                         if (really_read_only) {
4269                                 ext4_msg(sb, KERN_ERR, "write access "
4270                                         "unavailable, cannot proceed");
4271                                 return -EROFS;
4272                         }
4273                         ext4_msg(sb, KERN_INFO, "write access will "
4274                                "be enabled during recovery");
4275                 }
4276         }
4277
4278         if (journal_inum && journal_dev) {
4279                 ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4280                        "and inode journals!");
4281                 return -EINVAL;
4282         }
4283
4284         if (journal_inum) {
4285                 if (!(journal = ext4_get_journal(sb, journal_inum)))
4286                         return -EINVAL;
4287         } else {
4288                 if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4289                         return -EINVAL;
4290         }
4291
4292         if (!(journal->j_flags & JBD2_BARRIER))
4293                 ext4_msg(sb, KERN_INFO, "barriers disabled");
4294
4295         if (!ext4_has_feature_journal_needs_recovery(sb))
4296                 err = jbd2_journal_wipe(journal, !really_read_only);
4297         if (!err) {
4298                 char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4299                 if (save)
4300                         memcpy(save, ((char *) es) +
4301                                EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4302                 err = jbd2_journal_load(journal);
4303                 if (save)
4304                         memcpy(((char *) es) + EXT4_S_ERR_START,
4305                                save, EXT4_S_ERR_LEN);
4306                 kfree(save);
4307         }
4308
4309         if (err) {
4310                 ext4_msg(sb, KERN_ERR, "error loading journal");
4311                 jbd2_journal_destroy(journal);
4312                 return err;
4313         }
4314
4315         EXT4_SB(sb)->s_journal = journal;
4316         ext4_clear_journal_err(sb, es);
4317
4318         if (!really_read_only && journal_devnum &&
4319             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4320                 es->s_journal_dev = cpu_to_le32(journal_devnum);
4321
4322                 /* Make sure we flush the recovery flag to disk. */
4323                 ext4_commit_super(sb, 1);
4324         }
4325
4326         return 0;
4327 }
4328
4329 static int ext4_commit_super(struct super_block *sb, int sync)
4330 {
4331         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4332         struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4333         int error = 0;
4334
4335         if (!sbh || block_device_ejected(sb))
4336                 return error;
4337         if (buffer_write_io_error(sbh)) {
4338                 /*
4339                  * Oh, dear.  A previous attempt to write the
4340                  * superblock failed.  This could happen because the
4341                  * USB device was yanked out.  Or it could happen to
4342                  * be a transient write error and maybe the block will
4343                  * be remapped.  Nothing we can do but to retry the
4344                  * write and hope for the best.
4345                  */
4346                 ext4_msg(sb, KERN_ERR, "previous I/O error to "
4347                        "superblock detected");
4348                 clear_buffer_write_io_error(sbh);
4349                 set_buffer_uptodate(sbh);
4350         }
4351         /*
4352          * If the file system is mounted read-only, don't update the
4353          * superblock write time.  This avoids updating the superblock
4354          * write time when we are mounting the root file system
4355          * read/only but we need to replay the journal; at that point,
4356          * for people who are east of GMT and who make their clock
4357          * tick in localtime for Windows bug-for-bug compatibility,
4358          * the clock is set in the future, and this will cause e2fsck
4359          * to complain and force a full file system check.
4360          */
4361         if (!(sb->s_flags & MS_RDONLY))
4362                 es->s_wtime = cpu_to_le32(get_seconds());
4363         if (sb->s_bdev->bd_part)
4364                 es->s_kbytes_written =
4365                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
4366                             ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
4367                               EXT4_SB(sb)->s_sectors_written_start) >> 1));
4368         else
4369                 es->s_kbytes_written =
4370                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
4371         if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeclusters_counter))
4372                 ext4_free_blocks_count_set(es,
4373                         EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
4374                                 &EXT4_SB(sb)->s_freeclusters_counter)));
4375         if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeinodes_counter))
4376                 es->s_free_inodes_count =
4377                         cpu_to_le32(percpu_counter_sum_positive(
4378                                 &EXT4_SB(sb)->s_freeinodes_counter));
4379         BUFFER_TRACE(sbh, "marking dirty");
4380         ext4_superblock_csum_set(sb);
4381         mark_buffer_dirty(sbh);
4382         if (sync) {
4383                 error = __sync_dirty_buffer(sbh,
4384                         test_opt(sb, BARRIER) ? WRITE_FUA : WRITE_SYNC);
4385                 if (error)
4386                         return error;
4387
4388                 error = buffer_write_io_error(sbh);
4389                 if (error) {
4390                         ext4_msg(sb, KERN_ERR, "I/O error while writing "
4391                                "superblock");
4392                         clear_buffer_write_io_error(sbh);
4393                         set_buffer_uptodate(sbh);
4394                 }
4395         }
4396         return error;
4397 }
4398
4399 /*
4400  * Have we just finished recovery?  If so, and if we are mounting (or
4401  * remounting) the filesystem readonly, then we will end up with a
4402  * consistent fs on disk.  Record that fact.
4403  */
4404 static void ext4_mark_recovery_complete(struct super_block *sb,
4405                                         struct ext4_super_block *es)
4406 {
4407         journal_t *journal = EXT4_SB(sb)->s_journal;
4408
4409         if (!ext4_has_feature_journal(sb)) {
4410                 BUG_ON(journal != NULL);
4411                 return;
4412         }
4413         jbd2_journal_lock_updates(journal);
4414         if (jbd2_journal_flush(journal) < 0)
4415                 goto out;
4416
4417         if (ext4_has_feature_journal_needs_recovery(sb) &&
4418             sb->s_flags & MS_RDONLY) {
4419                 ext4_clear_feature_journal_needs_recovery(sb);
4420                 ext4_commit_super(sb, 1);
4421         }
4422
4423 out:
4424         jbd2_journal_unlock_updates(journal);
4425 }
4426
4427 /*
4428  * If we are mounting (or read-write remounting) a filesystem whose journal
4429  * has recorded an error from a previous lifetime, move that error to the
4430  * main filesystem now.
4431  */
4432 static void ext4_clear_journal_err(struct super_block *sb,
4433                                    struct ext4_super_block *es)
4434 {
4435         journal_t *journal;
4436         int j_errno;
4437         const char *errstr;
4438
4439         BUG_ON(!ext4_has_feature_journal(sb));
4440
4441         journal = EXT4_SB(sb)->s_journal;
4442
4443         /*
4444          * Now check for any error status which may have been recorded in the
4445          * journal by a prior ext4_error() or ext4_abort()
4446          */
4447
4448         j_errno = jbd2_journal_errno(journal);
4449         if (j_errno) {
4450                 char nbuf[16];
4451
4452                 errstr = ext4_decode_error(sb, j_errno, nbuf);
4453                 ext4_warning(sb, "Filesystem error recorded "
4454                              "from previous mount: %s", errstr);
4455                 ext4_warning(sb, "Marking fs in need of filesystem check.");
4456
4457                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
4458                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
4459                 ext4_commit_super(sb, 1);
4460
4461                 jbd2_journal_clear_err(journal);
4462                 jbd2_journal_update_sb_errno(journal);
4463         }
4464 }
4465
4466 /*
4467  * Force the running and committing transactions to commit,
4468  * and wait on the commit.
4469  */
4470 int ext4_force_commit(struct super_block *sb)
4471 {
4472         journal_t *journal;
4473
4474         if (sb->s_flags & MS_RDONLY)
4475                 return 0;
4476
4477         journal = EXT4_SB(sb)->s_journal;
4478         return ext4_journal_force_commit(journal);
4479 }
4480
4481 static int ext4_sync_fs(struct super_block *sb, int wait)
4482 {
4483         int ret = 0;
4484         tid_t target;
4485         bool needs_barrier = false;
4486         struct ext4_sb_info *sbi = EXT4_SB(sb);
4487
4488         trace_ext4_sync_fs(sb, wait);
4489         flush_workqueue(sbi->rsv_conversion_wq);
4490         /*
4491          * Writeback quota in non-journalled quota case - journalled quota has
4492          * no dirty dquots
4493          */
4494         dquot_writeback_dquots(sb, -1);
4495         /*
4496          * Data writeback is possible w/o journal transaction, so barrier must
4497          * being sent at the end of the function. But we can skip it if
4498          * transaction_commit will do it for us.
4499          */
4500         if (sbi->s_journal) {
4501                 target = jbd2_get_latest_transaction(sbi->s_journal);
4502                 if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
4503                     !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
4504                         needs_barrier = true;
4505
4506                 if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
4507                         if (wait)
4508                                 ret = jbd2_log_wait_commit(sbi->s_journal,
4509                                                            target);
4510                 }
4511         } else if (wait && test_opt(sb, BARRIER))
4512                 needs_barrier = true;
4513         if (needs_barrier) {
4514                 int err;
4515                 err = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
4516                 if (!ret)
4517                         ret = err;
4518         }
4519
4520         return ret;
4521 }
4522
4523 /*
4524  * LVM calls this function before a (read-only) snapshot is created.  This
4525  * gives us a chance to flush the journal completely and mark the fs clean.
4526  *
4527  * Note that only this function cannot bring a filesystem to be in a clean
4528  * state independently. It relies on upper layer to stop all data & metadata
4529  * modifications.
4530  */
4531 static int ext4_freeze(struct super_block *sb)
4532 {
4533         int error = 0;
4534         journal_t *journal;
4535
4536         if (sb->s_flags & MS_RDONLY)
4537                 return 0;
4538
4539         journal = EXT4_SB(sb)->s_journal;
4540
4541         if (journal) {
4542                 /* Now we set up the journal barrier. */
4543                 jbd2_journal_lock_updates(journal);
4544
4545                 /*
4546                  * Don't clear the needs_recovery flag if we failed to
4547                  * flush the journal.
4548                  */
4549                 error = jbd2_journal_flush(journal);
4550                 if (error < 0)
4551                         goto out;
4552
4553                 /* Journal blocked and flushed, clear needs_recovery flag. */
4554                 ext4_clear_feature_journal_needs_recovery(sb);
4555         }
4556
4557         error = ext4_commit_super(sb, 1);
4558 out:
4559         if (journal)
4560                 /* we rely on upper layer to stop further updates */
4561                 jbd2_journal_unlock_updates(journal);
4562         return error;
4563 }
4564
4565 /*
4566  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
4567  * flag here, even though the filesystem is not technically dirty yet.
4568  */
4569 static int ext4_unfreeze(struct super_block *sb)
4570 {
4571         if (sb->s_flags & MS_RDONLY)
4572                 return 0;
4573
4574         if (EXT4_SB(sb)->s_journal) {
4575                 /* Reset the needs_recovery flag before the fs is unlocked. */
4576                 ext4_set_feature_journal_needs_recovery(sb);
4577         }
4578
4579         ext4_commit_super(sb, 1);
4580         return 0;
4581 }
4582
4583 /*
4584  * Structure to save mount options for ext4_remount's benefit
4585  */
4586 struct ext4_mount_options {
4587         unsigned long s_mount_opt;
4588         unsigned long s_mount_opt2;
4589         kuid_t s_resuid;
4590         kgid_t s_resgid;
4591         unsigned long s_commit_interval;
4592         u32 s_min_batch_time, s_max_batch_time;
4593 #ifdef CONFIG_QUOTA
4594         int s_jquota_fmt;
4595         char *s_qf_names[EXT4_MAXQUOTAS];
4596 #endif
4597 };
4598
4599 static int ext4_remount(struct super_block *sb, int *flags, char *data)
4600 {
4601         struct ext4_super_block *es;
4602         struct ext4_sb_info *sbi = EXT4_SB(sb);
4603         unsigned long old_sb_flags;
4604         struct ext4_mount_options old_opts;
4605         int enable_quota = 0;
4606         ext4_group_t g;
4607         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4608         int err = 0;
4609 #ifdef CONFIG_QUOTA
4610         int i, j;
4611 #endif
4612         char *orig_data = kstrdup(data, GFP_KERNEL);
4613
4614         /* Store the original options */
4615         old_sb_flags = sb->s_flags;
4616         old_opts.s_mount_opt = sbi->s_mount_opt;
4617         old_opts.s_mount_opt2 = sbi->s_mount_opt2;
4618         old_opts.s_resuid = sbi->s_resuid;
4619         old_opts.s_resgid = sbi->s_resgid;
4620         old_opts.s_commit_interval = sbi->s_commit_interval;
4621         old_opts.s_min_batch_time = sbi->s_min_batch_time;
4622         old_opts.s_max_batch_time = sbi->s_max_batch_time;
4623 #ifdef CONFIG_QUOTA
4624         old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
4625         for (i = 0; i < EXT4_MAXQUOTAS; i++)
4626                 if (sbi->s_qf_names[i]) {
4627                         old_opts.s_qf_names[i] = kstrdup(sbi->s_qf_names[i],
4628                                                          GFP_KERNEL);
4629                         if (!old_opts.s_qf_names[i]) {
4630                                 for (j = 0; j < i; j++)
4631                                         kfree(old_opts.s_qf_names[j]);
4632                                 kfree(orig_data);
4633                                 return -ENOMEM;
4634                         }
4635                 } else
4636                         old_opts.s_qf_names[i] = NULL;
4637 #endif
4638         if (sbi->s_journal && sbi->s_journal->j_task->io_context)
4639                 journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
4640
4641         if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
4642                 err = -EINVAL;
4643                 goto restore_opts;
4644         }
4645
4646         if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
4647             test_opt(sb, JOURNAL_CHECKSUM)) {
4648                 ext4_msg(sb, KERN_ERR, "changing journal_checksum "
4649                          "during remount not supported; ignoring");
4650                 sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
4651         }
4652
4653         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
4654                 if (test_opt2(sb, EXPLICIT_DELALLOC)) {
4655                         ext4_msg(sb, KERN_ERR, "can't mount with "
4656                                  "both data=journal and delalloc");
4657                         err = -EINVAL;
4658                         goto restore_opts;
4659                 }
4660                 if (test_opt(sb, DIOREAD_NOLOCK)) {
4661                         ext4_msg(sb, KERN_ERR, "can't mount with "
4662                                  "both data=journal and dioread_nolock");
4663                         err = -EINVAL;
4664                         goto restore_opts;
4665                 }
4666                 if (test_opt(sb, DAX)) {
4667                         ext4_msg(sb, KERN_ERR, "can't mount with "
4668                                  "both data=journal and dax");
4669                         err = -EINVAL;
4670                         goto restore_opts;
4671                 }
4672         }
4673
4674         if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_DAX) {
4675                 ext4_msg(sb, KERN_WARNING, "warning: refusing change of "
4676                         "dax flag with busy inodes while remounting");
4677                 sbi->s_mount_opt ^= EXT4_MOUNT_DAX;
4678         }
4679
4680         if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
4681                 ext4_abort(sb, "Abort forced by user");
4682
4683         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
4684                 (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
4685
4686         es = sbi->s_es;
4687
4688         if (sbi->s_journal) {
4689                 ext4_init_journal_params(sb, sbi->s_journal);
4690                 set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4691         }
4692
4693         if (*flags & MS_LAZYTIME)
4694                 sb->s_flags |= MS_LAZYTIME;
4695
4696         if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY)) {
4697                 if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
4698                         err = -EROFS;
4699                         goto restore_opts;
4700                 }
4701
4702                 if (*flags & MS_RDONLY) {
4703                         err = sync_filesystem(sb);
4704                         if (err < 0)
4705                                 goto restore_opts;
4706                         err = dquot_suspend(sb, -1);
4707                         if (err < 0)
4708                                 goto restore_opts;
4709
4710                         /*
4711                          * First of all, the unconditional stuff we have to do
4712                          * to disable replay of the journal when we next remount
4713                          */
4714                         sb->s_flags |= MS_RDONLY;
4715
4716                         /*
4717                          * OK, test if we are remounting a valid rw partition
4718                          * readonly, and if so set the rdonly flag and then
4719                          * mark the partition as valid again.
4720                          */
4721                         if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
4722                             (sbi->s_mount_state & EXT4_VALID_FS))
4723                                 es->s_state = cpu_to_le16(sbi->s_mount_state);
4724
4725                         if (sbi->s_journal)
4726                                 ext4_mark_recovery_complete(sb, es);
4727                 } else {
4728                         /* Make sure we can mount this feature set readwrite */
4729                         if (ext4_has_feature_readonly(sb) ||
4730                             !ext4_feature_set_ok(sb, 0)) {
4731                                 err = -EROFS;
4732                                 goto restore_opts;
4733                         }
4734                         /*
4735                          * Make sure the group descriptor checksums
4736                          * are sane.  If they aren't, refuse to remount r/w.
4737                          */
4738                         for (g = 0; g < sbi->s_groups_count; g++) {
4739                                 struct ext4_group_desc *gdp =
4740                                         ext4_get_group_desc(sb, g, NULL);
4741
4742                                 if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
4743                                         ext4_msg(sb, KERN_ERR,
4744                "ext4_remount: Checksum for group %u failed (%u!=%u)",
4745                 g, le16_to_cpu(ext4_group_desc_csum(sb, g, gdp)),
4746                                                le16_to_cpu(gdp->bg_checksum));
4747                                         err = -EFSBADCRC;
4748                                         goto restore_opts;
4749                                 }
4750                         }
4751
4752                         /*
4753                          * If we have an unprocessed orphan list hanging
4754                          * around from a previously readonly bdev mount,
4755                          * require a full umount/remount for now.
4756                          */
4757                         if (es->s_last_orphan) {
4758                                 ext4_msg(sb, KERN_WARNING, "Couldn't "
4759                                        "remount RDWR because of unprocessed "
4760                                        "orphan inode list.  Please "
4761                                        "umount/remount instead");
4762                                 err = -EINVAL;
4763                                 goto restore_opts;
4764                         }
4765
4766                         /*
4767                          * Mounting a RDONLY partition read-write, so reread
4768                          * and store the current valid flag.  (It may have
4769                          * been changed by e2fsck since we originally mounted
4770                          * the partition.)
4771                          */
4772                         if (sbi->s_journal)
4773                                 ext4_clear_journal_err(sb, es);
4774                         sbi->s_mount_state = le16_to_cpu(es->s_state);
4775                         if (!ext4_setup_super(sb, es, 0))
4776                                 sb->s_flags &= ~MS_RDONLY;
4777                         if (ext4_has_feature_mmp(sb))
4778                                 if (ext4_multi_mount_protect(sb,
4779                                                 le64_to_cpu(es->s_mmp_block))) {
4780                                         err = -EROFS;
4781                                         goto restore_opts;
4782                                 }
4783                         enable_quota = 1;
4784                 }
4785         }
4786
4787         /*
4788          * Reinitialize lazy itable initialization thread based on
4789          * current settings
4790          */
4791         if ((sb->s_flags & MS_RDONLY) || !test_opt(sb, INIT_INODE_TABLE))
4792                 ext4_unregister_li_request(sb);
4793         else {
4794                 ext4_group_t first_not_zeroed;
4795                 first_not_zeroed = ext4_has_uninit_itable(sb);
4796                 ext4_register_li_request(sb, first_not_zeroed);
4797         }
4798
4799         ext4_setup_system_zone(sb);
4800         if (sbi->s_journal == NULL && !(old_sb_flags & MS_RDONLY))
4801                 ext4_commit_super(sb, 1);
4802
4803 #ifdef CONFIG_QUOTA
4804         /* Release old quota file names */
4805         for (i = 0; i < EXT4_MAXQUOTAS; i++)
4806                 kfree(old_opts.s_qf_names[i]);
4807         if (enable_quota) {
4808                 if (sb_any_quota_suspended(sb))
4809                         dquot_resume(sb, -1);
4810                 else if (ext4_has_feature_quota(sb)) {
4811                         err = ext4_enable_quotas(sb);
4812                         if (err)
4813                                 goto restore_opts;
4814                 }
4815         }
4816 #endif
4817
4818         *flags = (*flags & ~MS_LAZYTIME) | (sb->s_flags & MS_LAZYTIME);
4819         ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
4820         kfree(orig_data);
4821         return 0;
4822
4823 restore_opts:
4824         sb->s_flags = old_sb_flags;
4825         sbi->s_mount_opt = old_opts.s_mount_opt;
4826         sbi->s_mount_opt2 = old_opts.s_mount_opt2;
4827         sbi->s_resuid = old_opts.s_resuid;
4828         sbi->s_resgid = old_opts.s_resgid;
4829         sbi->s_commit_interval = old_opts.s_commit_interval;
4830         sbi->s_min_batch_time = old_opts.s_min_batch_time;
4831         sbi->s_max_batch_time = old_opts.s_max_batch_time;
4832 #ifdef CONFIG_QUOTA
4833         sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
4834         for (i = 0; i < EXT4_MAXQUOTAS; i++) {
4835                 kfree(sbi->s_qf_names[i]);
4836                 sbi->s_qf_names[i] = old_opts.s_qf_names[i];
4837         }
4838 #endif
4839         kfree(orig_data);
4840         return err;
4841 }
4842
4843 #ifdef CONFIG_QUOTA
4844 static int ext4_statfs_project(struct super_block *sb,
4845                                kprojid_t projid, struct kstatfs *buf)
4846 {
4847         struct kqid qid;
4848         struct dquot *dquot;
4849         u64 limit;
4850         u64 curblock;
4851
4852         qid = make_kqid_projid(projid);
4853         dquot = dqget(sb, qid);
4854         if (IS_ERR(dquot))
4855                 return PTR_ERR(dquot);
4856         spin_lock(&dq_data_lock);
4857
4858         limit = (dquot->dq_dqb.dqb_bsoftlimit ?
4859                  dquot->dq_dqb.dqb_bsoftlimit :
4860                  dquot->dq_dqb.dqb_bhardlimit) >> sb->s_blocksize_bits;
4861         if (limit && buf->f_blocks > limit) {
4862                 curblock = dquot->dq_dqb.dqb_curspace >> sb->s_blocksize_bits;
4863                 buf->f_blocks = limit;
4864                 buf->f_bfree = buf->f_bavail =
4865                         (buf->f_blocks > curblock) ?
4866                          (buf->f_blocks - curblock) : 0;
4867         }
4868
4869         limit = dquot->dq_dqb.dqb_isoftlimit ?
4870                 dquot->dq_dqb.dqb_isoftlimit :
4871                 dquot->dq_dqb.dqb_ihardlimit;
4872         if (limit && buf->f_files > limit) {
4873                 buf->f_files = limit;
4874                 buf->f_ffree =
4875                         (buf->f_files > dquot->dq_dqb.dqb_curinodes) ?
4876                          (buf->f_files - dquot->dq_dqb.dqb_curinodes) : 0;
4877         }
4878
4879         spin_unlock(&dq_data_lock);
4880         dqput(dquot);
4881         return 0;
4882 }
4883 #endif
4884
4885 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
4886 {
4887         struct super_block *sb = dentry->d_sb;
4888         struct ext4_sb_info *sbi = EXT4_SB(sb);
4889         struct ext4_super_block *es = sbi->s_es;
4890         ext4_fsblk_t overhead = 0, resv_blocks;
4891         u64 fsid;
4892         s64 bfree;
4893         resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
4894
4895         if (!test_opt(sb, MINIX_DF))
4896                 overhead = sbi->s_overhead;
4897
4898         buf->f_type = EXT4_SUPER_MAGIC;
4899         buf->f_bsize = sb->s_blocksize;
4900         buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
4901         bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
4902                 percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
4903         /* prevent underflow in case that few free space is available */
4904         buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
4905         buf->f_bavail = buf->f_bfree -
4906                         (ext4_r_blocks_count(es) + resv_blocks);
4907         if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
4908                 buf->f_bavail = 0;
4909         buf->f_files = le32_to_cpu(es->s_inodes_count);
4910         buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
4911         buf->f_namelen = EXT4_NAME_LEN;
4912         fsid = le64_to_cpup((void *)es->s_uuid) ^
4913                le64_to_cpup((void *)es->s_uuid + sizeof(u64));
4914         buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
4915         buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
4916
4917 #ifdef CONFIG_QUOTA
4918         if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&
4919             sb_has_quota_limits_enabled(sb, PRJQUOTA))
4920                 ext4_statfs_project(sb, EXT4_I(dentry->d_inode)->i_projid, buf);
4921 #endif
4922         return 0;
4923 }
4924
4925 /* Helper function for writing quotas on sync - we need to start transaction
4926  * before quota file is locked for write. Otherwise the are possible deadlocks:
4927  * Process 1                         Process 2
4928  * ext4_create()                     quota_sync()
4929  *   jbd2_journal_start()                  write_dquot()
4930  *   dquot_initialize()                         down(dqio_mutex)
4931  *     down(dqio_mutex)                    jbd2_journal_start()
4932  *
4933  */
4934
4935 #ifdef CONFIG_QUOTA
4936
4937 static inline struct inode *dquot_to_inode(struct dquot *dquot)
4938 {
4939         return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
4940 }
4941
4942 static int ext4_write_dquot(struct dquot *dquot)
4943 {
4944         int ret, err;
4945         handle_t *handle;
4946         struct inode *inode;
4947
4948         inode = dquot_to_inode(dquot);
4949         handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
4950                                     EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
4951         if (IS_ERR(handle))
4952                 return PTR_ERR(handle);
4953         ret = dquot_commit(dquot);
4954         err = ext4_journal_stop(handle);
4955         if (!ret)
4956                 ret = err;
4957         return ret;
4958 }
4959
4960 static int ext4_acquire_dquot(struct dquot *dquot)
4961 {
4962         int ret, err;
4963         handle_t *handle;
4964
4965         handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
4966                                     EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
4967         if (IS_ERR(handle))
4968                 return PTR_ERR(handle);
4969         ret = dquot_acquire(dquot);
4970         err = ext4_journal_stop(handle);
4971         if (!ret)
4972                 ret = err;
4973         return ret;
4974 }
4975
4976 static int ext4_release_dquot(struct dquot *dquot)
4977 {
4978         int ret, err;
4979         handle_t *handle;
4980
4981         handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
4982                                     EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
4983         if (IS_ERR(handle)) {
4984                 /* Release dquot anyway to avoid endless cycle in dqput() */
4985                 dquot_release(dquot);
4986                 return PTR_ERR(handle);
4987         }
4988         ret = dquot_release(dquot);
4989         err = ext4_journal_stop(handle);
4990         if (!ret)
4991                 ret = err;
4992         return ret;
4993 }
4994
4995 static int ext4_mark_dquot_dirty(struct dquot *dquot)
4996 {
4997         struct super_block *sb = dquot->dq_sb;
4998         struct ext4_sb_info *sbi = EXT4_SB(sb);
4999
5000         /* Are we journaling quotas? */
5001         if (ext4_has_feature_quota(sb) ||
5002             sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
5003                 dquot_mark_dquot_dirty(dquot);
5004                 return ext4_write_dquot(dquot);
5005         } else {
5006                 return dquot_mark_dquot_dirty(dquot);
5007         }
5008 }
5009
5010 static int ext4_write_info(struct super_block *sb, int type)
5011 {
5012         int ret, err;
5013         handle_t *handle;
5014
5015         /* Data block + inode block */
5016         handle = ext4_journal_start(d_inode(sb->s_root), EXT4_HT_QUOTA, 2);
5017         if (IS_ERR(handle))
5018                 return PTR_ERR(handle);
5019         ret = dquot_commit_info(sb, type);
5020         err = ext4_journal_stop(handle);
5021         if (!ret)
5022                 ret = err;
5023         return ret;
5024 }
5025
5026 /*
5027  * Turn on quotas during mount time - we need to find
5028  * the quota file and such...
5029  */
5030 static int ext4_quota_on_mount(struct super_block *sb, int type)
5031 {
5032         return dquot_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
5033                                         EXT4_SB(sb)->s_jquota_fmt, type);
5034 }
5035
5036 static void lockdep_set_quota_inode(struct inode *inode, int subclass)
5037 {
5038         struct ext4_inode_info *ei = EXT4_I(inode);
5039
5040         /* The first argument of lockdep_set_subclass has to be
5041          * *exactly* the same as the argument to init_rwsem() --- in
5042          * this case, in init_once() --- or lockdep gets unhappy
5043          * because the name of the lock is set using the
5044          * stringification of the argument to init_rwsem().
5045          */
5046         (void) ei;      /* shut up clang warning if !CONFIG_LOCKDEP */
5047         lockdep_set_subclass(&ei->i_data_sem, subclass);
5048 }
5049
5050 /*
5051  * Standard function to be called on quota_on
5052  */
5053 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
5054                          struct path *path)
5055 {
5056         int err;
5057
5058         if (!test_opt(sb, QUOTA))
5059                 return -EINVAL;
5060
5061         /* Quotafile not on the same filesystem? */
5062         if (path->dentry->d_sb != sb)
5063                 return -EXDEV;
5064         /* Journaling quota? */
5065         if (EXT4_SB(sb)->s_qf_names[type]) {
5066                 /* Quotafile not in fs root? */
5067                 if (path->dentry->d_parent != sb->s_root)
5068                         ext4_msg(sb, KERN_WARNING,
5069                                 "Quota file not on filesystem root. "
5070                                 "Journaled quota will not work");
5071         }
5072
5073         /*
5074          * When we journal data on quota file, we have to flush journal to see
5075          * all updates to the file when we bypass pagecache...
5076          */
5077         if (EXT4_SB(sb)->s_journal &&
5078             ext4_should_journal_data(d_inode(path->dentry))) {
5079                 /*
5080                  * We don't need to lock updates but journal_flush() could
5081                  * otherwise be livelocked...
5082                  */
5083                 jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
5084                 err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
5085                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
5086                 if (err)
5087                         return err;
5088         }
5089         lockdep_set_quota_inode(path->dentry->d_inode, I_DATA_SEM_QUOTA);
5090         err = dquot_quota_on(sb, type, format_id, path);
5091         if (err)
5092                 lockdep_set_quota_inode(path->dentry->d_inode,
5093                                              I_DATA_SEM_NORMAL);
5094         return err;
5095 }
5096
5097 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
5098                              unsigned int flags)
5099 {
5100         int err;
5101         struct inode *qf_inode;
5102         unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5103                 le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5104                 le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5105                 le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5106         };
5107
5108         BUG_ON(!ext4_has_feature_quota(sb));
5109
5110         if (!qf_inums[type])
5111                 return -EPERM;
5112
5113         qf_inode = ext4_iget(sb, qf_inums[type]);
5114         if (IS_ERR(qf_inode)) {
5115                 ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
5116                 return PTR_ERR(qf_inode);
5117         }
5118
5119         /* Don't account quota for quota files to avoid recursion */
5120         qf_inode->i_flags |= S_NOQUOTA;
5121         lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);
5122         err = dquot_enable(qf_inode, type, format_id, flags);
5123         iput(qf_inode);
5124         if (err)
5125                 lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);
5126
5127         return err;
5128 }
5129
5130 /* Enable usage tracking for all quota types. */
5131 static int ext4_enable_quotas(struct super_block *sb)
5132 {
5133         int type, err = 0;
5134         unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5135                 le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5136                 le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5137                 le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5138         };
5139
5140         sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE;
5141         for (type = 0; type < EXT4_MAXQUOTAS; type++) {
5142                 if (qf_inums[type]) {
5143                         err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
5144                                                 DQUOT_USAGE_ENABLED);
5145                         if (err) {
5146                                 ext4_warning(sb,
5147                                         "Failed to enable quota tracking "
5148                                         "(type=%d, err=%d). Please run "
5149                                         "e2fsck to fix.", type, err);
5150                                 return err;
5151                         }
5152                 }
5153         }
5154         return 0;
5155 }
5156
5157 static int ext4_quota_off(struct super_block *sb, int type)
5158 {
5159         struct inode *inode = sb_dqopt(sb)->files[type];
5160         handle_t *handle;
5161
5162         /* Force all delayed allocation blocks to be allocated.
5163          * Caller already holds s_umount sem */
5164         if (test_opt(sb, DELALLOC))
5165                 sync_filesystem(sb);
5166
5167         if (!inode)
5168                 goto out;
5169
5170         /* Update modification times of quota files when userspace can
5171          * start looking at them */
5172         handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5173         if (IS_ERR(handle))
5174                 goto out;
5175         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
5176         ext4_mark_inode_dirty(handle, inode);
5177         ext4_journal_stop(handle);
5178
5179 out:
5180         return dquot_quota_off(sb, type);
5181 }
5182
5183 /* Read data from quotafile - avoid pagecache and such because we cannot afford
5184  * acquiring the locks... As quota files are never truncated and quota code
5185  * itself serializes the operations (and no one else should touch the files)
5186  * we don't have to be afraid of races */
5187 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
5188                                size_t len, loff_t off)
5189 {
5190         struct inode *inode = sb_dqopt(sb)->files[type];
5191         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5192         int offset = off & (sb->s_blocksize - 1);
5193         int tocopy;
5194         size_t toread;
5195         struct buffer_head *bh;
5196         loff_t i_size = i_size_read(inode);
5197
5198         if (off > i_size)
5199                 return 0;
5200         if (off+len > i_size)
5201                 len = i_size-off;
5202         toread = len;
5203         while (toread > 0) {
5204                 tocopy = sb->s_blocksize - offset < toread ?
5205                                 sb->s_blocksize - offset : toread;
5206                 bh = ext4_bread(NULL, inode, blk, 0);
5207                 if (IS_ERR(bh))
5208                         return PTR_ERR(bh);
5209                 if (!bh)        /* A hole? */
5210                         memset(data, 0, tocopy);
5211                 else
5212                         memcpy(data, bh->b_data+offset, tocopy);
5213                 brelse(bh);
5214                 offset = 0;
5215                 toread -= tocopy;
5216                 data += tocopy;
5217                 blk++;
5218         }
5219         return len;
5220 }
5221
5222 /* Write to quotafile (we know the transaction is already started and has
5223  * enough credits) */
5224 static ssize_t ext4_quota_write(struct super_block *sb, int type,
5225                                 const char *data, size_t len, loff_t off)
5226 {
5227         struct inode *inode = sb_dqopt(sb)->files[type];
5228         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5229         int err, offset = off & (sb->s_blocksize - 1);
5230         int retries = 0;
5231         struct buffer_head *bh;
5232         handle_t *handle = journal_current_handle();
5233
5234         if (EXT4_SB(sb)->s_journal && !handle) {
5235                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5236                         " cancelled because transaction is not started",
5237                         (unsigned long long)off, (unsigned long long)len);
5238                 return -EIO;
5239         }
5240         /*
5241          * Since we account only one data block in transaction credits,
5242          * then it is impossible to cross a block boundary.
5243          */
5244         if (sb->s_blocksize - offset < len) {
5245                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5246                         " cancelled because not block aligned",
5247                         (unsigned long long)off, (unsigned long long)len);
5248                 return -EIO;
5249         }
5250
5251         do {
5252                 bh = ext4_bread(handle, inode, blk,
5253                                 EXT4_GET_BLOCKS_CREATE |
5254                                 EXT4_GET_BLOCKS_METADATA_NOFAIL);
5255         } while (IS_ERR(bh) && (PTR_ERR(bh) == -ENOSPC) &&
5256                  ext4_should_retry_alloc(inode->i_sb, &retries));
5257         if (IS_ERR(bh))
5258                 return PTR_ERR(bh);
5259         if (!bh)
5260                 goto out;
5261         BUFFER_TRACE(bh, "get write access");
5262         err = ext4_journal_get_write_access(handle, bh);
5263         if (err) {
5264                 brelse(bh);
5265                 return err;
5266         }
5267         lock_buffer(bh);
5268         memcpy(bh->b_data+offset, data, len);
5269         flush_dcache_page(bh->b_page);
5270         unlock_buffer(bh);
5271         err = ext4_handle_dirty_metadata(handle, NULL, bh);
5272         brelse(bh);
5273 out:
5274         if (inode->i_size < off + len) {
5275                 i_size_write(inode, off + len);
5276                 EXT4_I(inode)->i_disksize = inode->i_size;
5277                 ext4_mark_inode_dirty(handle, inode);
5278         }
5279         return len;
5280 }
5281
5282 static int ext4_get_next_id(struct super_block *sb, struct kqid *qid)
5283 {
5284         const struct quota_format_ops   *ops;
5285
5286         if (!sb_has_quota_loaded(sb, qid->type))
5287                 return -ESRCH;
5288         ops = sb_dqopt(sb)->ops[qid->type];
5289         if (!ops || !ops->get_next_id)
5290                 return -ENOSYS;
5291         return dquot_get_next_id(sb, qid);
5292 }
5293 #endif
5294
5295 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
5296                        const char *dev_name, void *data)
5297 {
5298         return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
5299 }
5300
5301 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
5302 static inline void register_as_ext2(void)
5303 {
5304         int err = register_filesystem(&ext2_fs_type);
5305         if (err)
5306                 printk(KERN_WARNING
5307                        "EXT4-fs: Unable to register as ext2 (%d)\n", err);
5308 }
5309
5310 static inline void unregister_as_ext2(void)
5311 {
5312         unregister_filesystem(&ext2_fs_type);
5313 }
5314
5315 static inline int ext2_feature_set_ok(struct super_block *sb)
5316 {
5317         if (ext4_has_unknown_ext2_incompat_features(sb))
5318                 return 0;
5319         if (sb->s_flags & MS_RDONLY)
5320                 return 1;
5321         if (ext4_has_unknown_ext2_ro_compat_features(sb))
5322                 return 0;
5323         return 1;
5324 }
5325 #else
5326 static inline void register_as_ext2(void) { }
5327 static inline void unregister_as_ext2(void) { }
5328 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
5329 #endif
5330
5331 static inline void register_as_ext3(void)
5332 {
5333         int err = register_filesystem(&ext3_fs_type);
5334         if (err)
5335                 printk(KERN_WARNING
5336                        "EXT4-fs: Unable to register as ext3 (%d)\n", err);
5337 }
5338
5339 static inline void unregister_as_ext3(void)
5340 {
5341         unregister_filesystem(&ext3_fs_type);
5342 }
5343
5344 static inline int ext3_feature_set_ok(struct super_block *sb)
5345 {
5346         if (ext4_has_unknown_ext3_incompat_features(sb))
5347                 return 0;
5348         if (!ext4_has_feature_journal(sb))
5349                 return 0;
5350         if (sb->s_flags & MS_RDONLY)
5351                 return 1;
5352         if (ext4_has_unknown_ext3_ro_compat_features(sb))
5353                 return 0;
5354         return 1;
5355 }
5356
5357 static struct file_system_type ext4_fs_type = {
5358         .owner          = THIS_MODULE,
5359         .name           = "ext4",
5360         .mount          = ext4_mount,
5361         .kill_sb        = kill_block_super,
5362         .fs_flags       = FS_REQUIRES_DEV,
5363 };
5364 MODULE_ALIAS_FS("ext4");
5365
5366 /* Shared across all ext4 file systems */
5367 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
5368
5369 static int __init ext4_init_fs(void)
5370 {
5371         int i, err;
5372
5373         ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
5374         ext4_li_info = NULL;
5375         mutex_init(&ext4_li_mtx);
5376
5377         /* Build-time check for flags consistency */
5378         ext4_check_flag_values();
5379
5380         for (i = 0; i < EXT4_WQ_HASH_SZ; i++)
5381                 init_waitqueue_head(&ext4__ioend_wq[i]);
5382
5383         err = ext4_init_es();
5384         if (err)
5385                 return err;
5386
5387         err = ext4_init_pageio();
5388         if (err)
5389                 goto out5;
5390
5391         err = ext4_init_system_zone();
5392         if (err)
5393                 goto out4;
5394
5395         err = ext4_init_sysfs();
5396         if (err)
5397                 goto out3;
5398
5399         err = ext4_init_mballoc();
5400         if (err)
5401                 goto out2;
5402         err = init_inodecache();
5403         if (err)
5404                 goto out1;
5405         register_as_ext3();
5406         register_as_ext2();
5407         err = register_filesystem(&ext4_fs_type);
5408         if (err)
5409                 goto out;
5410
5411         return 0;
5412 out:
5413         unregister_as_ext2();
5414         unregister_as_ext3();
5415         destroy_inodecache();
5416 out1:
5417         ext4_exit_mballoc();
5418 out2:
5419         ext4_exit_sysfs();
5420 out3:
5421         ext4_exit_system_zone();
5422 out4:
5423         ext4_exit_pageio();
5424 out5:
5425         ext4_exit_es();
5426
5427         return err;
5428 }
5429
5430 static void __exit ext4_exit_fs(void)
5431 {
5432         ext4_exit_crypto();
5433         ext4_destroy_lazyinit_thread();
5434         unregister_as_ext2();
5435         unregister_as_ext3();
5436         unregister_filesystem(&ext4_fs_type);
5437         destroy_inodecache();
5438         ext4_exit_mballoc();
5439         ext4_exit_sysfs();
5440         ext4_exit_system_zone();
5441         ext4_exit_pageio();
5442         ext4_exit_es();
5443 }
5444
5445 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
5446 MODULE_DESCRIPTION("Fourth Extended Filesystem");
5447 MODULE_LICENSE("GPL");
5448 module_init(ext4_init_fs)
5449 module_exit(ext4_exit_fs)