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 int ext4_mballoc_ready;
  59 static struct ratelimit_state ext4_mount_msg_ratelimit;
  60
  61 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
  62                              unsigned long journal_devnum);
  63 static int ext4_show_options(struct seq_file *seq, struct dentry *root);
  64 static int ext4_commit_super(struct super_block *sb, int sync);
  65 static void ext4_mark_recovery_complete(struct super_block *sb,
  66                                         struct ext4_super_block *es);
  67 static void ext4_clear_journal_err(struct super_block *sb,
  68                                    struct ext4_super_block *es);
  69 static int ext4_sync_fs(struct super_block *sb, int wait);
  70 static int ext4_remount(struct super_block *sb, int *flags, char *data);
  71 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
  72 static int ext4_unfreeze(struct super_block *sb);
  73 static int ext4_freeze(struct super_block *sb);
  74 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
  75                        const char *dev_name, void *data);
  76 static inline int ext2_feature_set_ok(struct super_block *sb);
  77 static inline int ext3_feature_set_ok(struct super_block *sb);
  78 static int ext4_feature_set_ok(struct super_block *sb, int readonly);
  79 static void ext4_destroy_lazyinit_thread(void);
  80 static void ext4_unregister_li_request(struct super_block *sb);
  81 static void ext4_clear_request_list(void);
  82
  83 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
  84 static struct file_system_type ext2_fs_type = {
  85         .owner          = THIS_MODULE,
  86         .name           = "ext2",
  87         .mount          = ext4_mount,
  88         .kill_sb        = kill_block_super,
  89         .fs_flags       = FS_REQUIRES_DEV,
  90 };
  91 MODULE_ALIAS_FS("ext2");
  92 MODULE_ALIAS("ext2");
  93 #define IS_EXT2_SB(sb) ((sb)->s_bdev->bd_holder == &ext2_fs_type)
  94 #else
  95 #define IS_EXT2_SB(sb) (0)
  96 #endif
  97
  98
  99 static struct file_system_type ext3_fs_type = {
 100         .owner          = THIS_MODULE,
 101         .name           = "ext3",
 102         .mount          = ext4_mount,
 103         .kill_sb        = kill_block_super,
 104         .fs_flags       = FS_REQUIRES_DEV,
 105 };
 106 MODULE_ALIAS_FS("ext3");
 107 MODULE_ALIAS("ext3");
 108 #define IS_EXT3_SB(sb) ((sb)->s_bdev->bd_holder == &ext3_fs_type)
 109
 110 static int ext4_verify_csum_type(struct super_block *sb,
 111                                  struct ext4_super_block *es)
 112 {
 113         if (!ext4_has_feature_metadata_csum(sb))
 114                 return 1;
 115
 116         return es->s_checksum_type == EXT4_CRC32C_CHKSUM;
 117 }
 118
 119 static __le32 ext4_superblock_csum(struct super_block *sb,
 120                                    struct ext4_super_block *es)
 121 {
 122         struct ext4_sb_info *sbi = EXT4_SB(sb);
 123         int offset = offsetof(struct ext4_super_block, s_checksum);
 124         __u32 csum;
 125
 126         csum = ext4_chksum(sbi, ~0, (char *)es, offset);
 127
 128         return cpu_to_le32(csum);
 129 }
 130
 131 static int ext4_superblock_csum_verify(struct super_block *sb,
 132                                        struct ext4_super_block *es)
 133 {
 134         if (!ext4_has_metadata_csum(sb))
 135                 return 1;
 136
 137         return es->s_checksum == ext4_superblock_csum(sb, es);
 138 }
 139
 140 void ext4_superblock_csum_set(struct super_block *sb)
 141 {
 142         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 143
 144         if (!ext4_has_metadata_csum(sb))
 145                 return;
 146
 147         es->s_checksum = ext4_superblock_csum(sb, es);
 148 }
 149
 150 void *ext4_kvmalloc(size_t size, gfp_t flags)
 151 {
 152         void *ret;
 153
 154         ret = kmalloc(size, flags | __GFP_NOWARN);
 155         if (!ret)
 156                 ret = __vmalloc(size, flags, PAGE_KERNEL);
 157         return ret;
 158 }
 159
 160 void *ext4_kvzalloc(size_t size, gfp_t flags)
 161 {
 162         void *ret;
 163
 164         ret = kzalloc(size, flags | __GFP_NOWARN);
 165         if (!ret)
 166                 ret = __vmalloc(size, flags | __GFP_ZERO, PAGE_KERNEL);
 167         return ret;
 168 }
 169
 170 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
 171                                struct ext4_group_desc *bg)
 172 {
 173         return le32_to_cpu(bg->bg_block_bitmap_lo) |
 174                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 175                  (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
 176 }
 177
 178 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
 179                                struct ext4_group_desc *bg)
 180 {
 181         return le32_to_cpu(bg->bg_inode_bitmap_lo) |
 182                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 183                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
 184 }
 185
 186 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
 187                               struct ext4_group_desc *bg)
 188 {
 189         return le32_to_cpu(bg->bg_inode_table_lo) |
 190                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 191                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
 192 }
 193
 194 __u32 ext4_free_group_clusters(struct super_block *sb,
 195                                struct ext4_group_desc *bg)
 196 {
 197         return le16_to_cpu(bg->bg_free_blocks_count_lo) |
 198                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 199                  (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
 200 }
 201
 202 __u32 ext4_free_inodes_count(struct super_block *sb,
 203                               struct ext4_group_desc *bg)
 204 {
 205         return le16_to_cpu(bg->bg_free_inodes_count_lo) |
 206                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 207                  (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
 208 }
 209
 210 __u32 ext4_used_dirs_count(struct super_block *sb,
 211                               struct ext4_group_desc *bg)
 212 {
 213         return le16_to_cpu(bg->bg_used_dirs_count_lo) |
 214                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 215                  (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
 216 }
 217
 218 __u32 ext4_itable_unused_count(struct super_block *sb,
 219                               struct ext4_group_desc *bg)
 220 {
 221         return le16_to_cpu(bg->bg_itable_unused_lo) |
 222                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 223                  (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
 224 }
 225
 226 void ext4_block_bitmap_set(struct super_block *sb,
 227                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 228 {
 229         bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
 230         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 231                 bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
 232 }
 233
 234 void ext4_inode_bitmap_set(struct super_block *sb,
 235                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 236 {
 237         bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
 238         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 239                 bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
 240 }
 241
 242 void ext4_inode_table_set(struct super_block *sb,
 243                           struct ext4_group_desc *bg, ext4_fsblk_t blk)
 244 {
 245         bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
 246         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 247                 bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
 248 }
 249
 250 void ext4_free_group_clusters_set(struct super_block *sb,
 251                                   struct ext4_group_desc *bg, __u32 count)
 252 {
 253         bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
 254         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 255                 bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
 256 }
 257
 258 void ext4_free_inodes_set(struct super_block *sb,
 259                           struct ext4_group_desc *bg, __u32 count)
 260 {
 261         bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
 262         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 263                 bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
 264 }
 265
 266 void ext4_used_dirs_set(struct super_block *sb,
 267                           struct ext4_group_desc *bg, __u32 count)
 268 {
 269         bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
 270         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 271                 bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
 272 }
 273
 274 void ext4_itable_unused_set(struct super_block *sb,
 275                           struct ext4_group_desc *bg, __u32 count)
 276 {
 277         bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
 278         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 279                 bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
 280 }
 281
 282
 283 static void __save_error_info(struct super_block *sb, const char *func,
 284                             unsigned int line)
 285 {
 286         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 287
 288         EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
 289         if (bdev_read_only(sb->s_bdev))
 290                 return;
 291         es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
 292         es->s_last_error_time = cpu_to_le32(get_seconds());
 293         strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
 294         es->s_last_error_line = cpu_to_le32(line);
 295         if (!es->s_first_error_time) {
 296                 es->s_first_error_time = es->s_last_error_time;
 297                 strncpy(es->s_first_error_func, func,
 298                         sizeof(es->s_first_error_func));
 299                 es->s_first_error_line = cpu_to_le32(line);
 300                 es->s_first_error_ino = es->s_last_error_ino;
 301                 es->s_first_error_block = es->s_last_error_block;
 302         }
 303         /*
 304          * Start the daily error reporting function if it hasn't been
 305          * started already
 306          */
 307         if (!es->s_error_count)
 308                 mod_timer(&EXT4_SB(sb)->s_err_report, jiffies + 24*60*60*HZ);
 309         le32_add_cpu(&es->s_error_count, 1);
 310 }
 311
 312 static void save_error_info(struct super_block *sb, const char *func,
 313                             unsigned int line)
 314 {
 315         __save_error_info(sb, func, line);
 316         ext4_commit_super(sb, 1);
 317 }
 318
 319 /*
 320  * The del_gendisk() function uninitializes the disk-specific data
 321  * structures, including the bdi structure, without telling anyone
 322  * else.  Once this happens, any attempt to call mark_buffer_dirty()
 323  * (for example, by ext4_commit_super), will cause a kernel OOPS.
 324  * This is a kludge to prevent these oops until we can put in a proper
 325  * hook in del_gendisk() to inform the VFS and file system layers.
 326  */
 327 static int block_device_ejected(struct super_block *sb)
 328 {
 329         struct inode *bd_inode = sb->s_bdev->bd_inode;
 330         struct backing_dev_info *bdi = inode_to_bdi(bd_inode);
 331
 332         return bdi->dev == NULL;
 333 }
 334
 335 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
 336 {
 337         struct super_block              *sb = journal->j_private;
 338         struct ext4_sb_info             *sbi = EXT4_SB(sb);
 339         int                             error = is_journal_aborted(journal);
 340         struct ext4_journal_cb_entry    *jce;
 341
 342         BUG_ON(txn->t_state == T_FINISHED);
 343         spin_lock(&sbi->s_md_lock);
 344         while (!list_empty(&txn->t_private_list)) {
 345                 jce = list_entry(txn->t_private_list.next,
 346                                  struct ext4_journal_cb_entry, jce_list);
 347                 list_del_init(&jce->jce_list);
 348                 spin_unlock(&sbi->s_md_lock);
 349                 jce->jce_func(sb, jce, error);
 350                 spin_lock(&sbi->s_md_lock);
 351         }
 352         spin_unlock(&sbi->s_md_lock);
 353 }
 354
 355 /* Deal with the reporting of failure conditions on a filesystem such as
 356  * inconsistencies detected or read IO failures.
 357  *
 358  * On ext2, we can store the error state of the filesystem in the
 359  * superblock.  That is not possible on ext4, because we may have other
 360  * write ordering constraints on the superblock which prevent us from
 361  * writing it out straight away; and given that the journal is about to
 362  * be aborted, we can't rely on the current, or future, transactions to
 363  * write out the superblock safely.
 364  *
 365  * We'll just use the jbd2_journal_abort() error code to record an error in
 366  * the journal instead.  On recovery, the journal will complain about
 367  * that error until we've noted it down and cleared it.
 368  */
 369
 370 static void ext4_handle_error(struct super_block *sb)
 371 {
 372         if (sb->s_flags & MS_RDONLY)
 373                 return;
 374
 375         if (!test_opt(sb, ERRORS_CONT)) {
 376                 journal_t *journal = EXT4_SB(sb)->s_journal;
 377
 378                 EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
 379                 if (journal)
 380                         jbd2_journal_abort(journal, -EIO);
 381         }
 382         if (test_opt(sb, ERRORS_RO)) {
 383                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 384                 /*
 385                  * Make sure updated value of ->s_mount_flags will be visible
 386                  * before ->s_flags update
 387                  */
 388                 smp_wmb();
 389                 sb->s_flags |= MS_RDONLY;
 390         }
 391         if (test_opt(sb, ERRORS_PANIC)) {
 392                 if (EXT4_SB(sb)->s_journal &&
 393                   !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
 394                         return;
 395                 panic("EXT4-fs (device %s): panic forced after error\n",
 396                         sb->s_id);
 397         }
 398 }
 399
 400 #define ext4_error_ratelimit(sb)                                        \
 401                 ___ratelimit(&(EXT4_SB(sb)->s_err_ratelimit_state),     \
 402                              "EXT4-fs error")
 403
 404 void __ext4_error(struct super_block *sb, const char *function,
 405                   unsigned int line, const char *fmt, ...)
 406 {
 407         struct va_format vaf;
 408         va_list args;
 409
 410         if (ext4_error_ratelimit(sb)) {
 411                 va_start(args, fmt);
 412                 vaf.fmt = fmt;
 413                 vaf.va = &args;
 414                 printk(KERN_CRIT
 415                        "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
 416                        sb->s_id, function, line, current->comm, &vaf);
 417                 va_end(args);
 418         }
 419         save_error_info(sb, function, line);
 420         ext4_handle_error(sb);
 421 }
 422
 423 void __ext4_error_inode(struct inode *inode, const char *function,
 424                         unsigned int line, ext4_fsblk_t block,
 425                         const char *fmt, ...)
 426 {
 427         va_list args;
 428         struct va_format vaf;
 429         struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
 430
 431         es->s_last_error_ino = cpu_to_le32(inode->i_ino);
 432         es->s_last_error_block = cpu_to_le64(block);
 433         if (ext4_error_ratelimit(inode->i_sb)) {
 434                 va_start(args, fmt);
 435                 vaf.fmt = fmt;
 436                 vaf.va = &args;
 437                 if (block)
 438                         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
 439                                "inode #%lu: block %llu: comm %s: %pV\n",
 440                                inode->i_sb->s_id, function, line, inode->i_ino,
 441                                block, current->comm, &vaf);
 442                 else
 443                         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
 444                                "inode #%lu: comm %s: %pV\n",
 445                                inode->i_sb->s_id, function, line, inode->i_ino,
 446                                current->comm, &vaf);
 447                 va_end(args);
 448         }
 449         save_error_info(inode->i_sb, function, line);
 450         ext4_handle_error(inode->i_sb);
 451 }
 452
 453 void __ext4_error_file(struct file *file, const char *function,
 454                        unsigned int line, ext4_fsblk_t block,
 455                        const char *fmt, ...)
 456 {
 457         va_list args;
 458         struct va_format vaf;
 459         struct ext4_super_block *es;
 460         struct inode *inode = file_inode(file);
 461         char pathname[80], *path;
 462
 463         es = EXT4_SB(inode->i_sb)->s_es;
 464         es->s_last_error_ino = cpu_to_le32(inode->i_ino);
 465         if (ext4_error_ratelimit(inode->i_sb)) {
 466                 path = file_path(file, pathname, sizeof(pathname));
 467                 if (IS_ERR(path))
 468                         path = "(unknown)";
 469                 va_start(args, fmt);
 470                 vaf.fmt = fmt;
 471                 vaf.va = &args;
 472                 if (block)
 473                         printk(KERN_CRIT
 474                                "EXT4-fs error (device %s): %s:%d: inode #%lu: "
 475                                "block %llu: comm %s: path %s: %pV\n",
 476                                inode->i_sb->s_id, function, line, inode->i_ino,
 477                                block, current->comm, path, &vaf);
 478                 else
 479                         printk(KERN_CRIT
 480                                "EXT4-fs error (device %s): %s:%d: inode #%lu: "
 481                                "comm %s: path %s: %pV\n",
 482                                inode->i_sb->s_id, function, line, inode->i_ino,
 483                                current->comm, path, &vaf);
 484                 va_end(args);
 485         }
 486         save_error_info(inode->i_sb, function, line);
 487         ext4_handle_error(inode->i_sb);
 488 }
 489
 490 const char *ext4_decode_error(struct super_block *sb, int errno,
 491                               char nbuf[16])
 492 {
 493         char *errstr = NULL;
 494
 495         switch (errno) {
 496         case -EFSCORRUPTED:
 497                 errstr = "Corrupt filesystem";
 498                 break;
 499         case -EFSBADCRC:
 500                 errstr = "Filesystem failed CRC";
 501                 break;
 502         case -EIO:
 503                 errstr = "IO failure";
 504                 break;
 505         case -ENOMEM:
 506                 errstr = "Out of memory";
 507                 break;
 508         case -EROFS:
 509                 if (!sb || (EXT4_SB(sb)->s_journal &&
 510                             EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
 511                         errstr = "Journal has aborted";
 512                 else
 513                         errstr = "Readonly filesystem";
 514                 break;
 515         default:
 516                 /* If the caller passed in an extra buffer for unknown
 517                  * errors, textualise them now.  Else we just return
 518                  * NULL. */
 519                 if (nbuf) {
 520                         /* Check for truncated error codes... */
 521                         if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
 522                                 errstr = nbuf;
 523                 }
 524                 break;
 525         }
 526
 527         return errstr;
 528 }
 529
 530 /* __ext4_std_error decodes expected errors from journaling functions
 531  * automatically and invokes the appropriate error response.  */
 532
 533 void __ext4_std_error(struct super_block *sb, const char *function,
 534                       unsigned int line, int errno)
 535 {
 536         char nbuf[16];
 537         const char *errstr;
 538
 539         /* Special case: if the error is EROFS, and we're not already
 540          * inside a transaction, then there's really no point in logging
 541          * an error. */
 542         if (errno == -EROFS && journal_current_handle() == NULL &&
 543             (sb->s_flags & MS_RDONLY))
 544                 return;
 545
 546         if (ext4_error_ratelimit(sb)) {
 547                 errstr = ext4_decode_error(sb, errno, nbuf);
 548                 printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
 549                        sb->s_id, function, line, errstr);
 550         }
 551
 552         save_error_info(sb, function, line);
 553         ext4_handle_error(sb);
 554 }
 555
 556 /*
 557  * ext4_abort is a much stronger failure handler than ext4_error.  The
 558  * abort function may be used to deal with unrecoverable failures such
 559  * as journal IO errors or ENOMEM at a critical moment in log management.
 560  *
 561  * We unconditionally force the filesystem into an ABORT|READONLY state,
 562  * unless the error response on the fs has been set to panic in which
 563  * case we take the easy way out and panic immediately.
 564  */
 565
 566 void __ext4_abort(struct super_block *sb, const char *function,
 567                 unsigned int line, const char *fmt, ...)
 568 {
 569         va_list args;
 570
 571         save_error_info(sb, function, line);
 572         va_start(args, fmt);
 573         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: ", sb->s_id,
 574                function, line);
 575         vprintk(fmt, args);
 576         printk("\n");
 577         va_end(args);
 578
 579         if ((sb->s_flags & MS_RDONLY) == 0) {
 580                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 581                 EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
 582                 /*
 583                  * Make sure updated value of ->s_mount_flags will be visible
 584                  * before ->s_flags update
 585                  */
 586                 smp_wmb();
 587                 sb->s_flags |= MS_RDONLY;
 588                 if (EXT4_SB(sb)->s_journal)
 589                         jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
 590                 save_error_info(sb, function, line);
 591         }
 592         if (test_opt(sb, ERRORS_PANIC)) {
 593                 if (EXT4_SB(sb)->s_journal &&
 594                   !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
 595                         return;
 596                 panic("EXT4-fs panic from previous error\n");
 597         }
 598 }
 599
 600 void __ext4_msg(struct super_block *sb,
 601                 const char *prefix, const char *fmt, ...)
 602 {
 603         struct va_format vaf;
 604         va_list args;
 605
 606         if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state), "EXT4-fs"))
 607                 return;
 608
 609         va_start(args, fmt);
 610         vaf.fmt = fmt;
 611         vaf.va = &args;
 612         printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
 613         va_end(args);
 614 }
 615
 616 #define ext4_warning_ratelimit(sb)                                      \
 617                 ___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state), \
 618                              "EXT4-fs warning")
 619
 620 void __ext4_warning(struct super_block *sb, const char *function,
 621                     unsigned int line, const char *fmt, ...)
 622 {
 623         struct va_format vaf;
 624         va_list args;
 625
 626         if (!ext4_warning_ratelimit(sb))
 627                 return;
 628
 629         va_start(args, fmt);
 630         vaf.fmt = fmt;
 631         vaf.va = &args;
 632         printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
 633                sb->s_id, function, line, &vaf);
 634         va_end(args);
 635 }
 636
 637 void __ext4_warning_inode(const struct inode *inode, const char *function,
 638                           unsigned int line, const char *fmt, ...)
 639 {
 640         struct va_format vaf;
 641         va_list args;
 642
 643         if (!ext4_warning_ratelimit(inode->i_sb))
 644                 return;
 645
 646         va_start(args, fmt);
 647         vaf.fmt = fmt;
 648         vaf.va = &args;
 649         printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: "
 650                "inode #%lu: comm %s: %pV\n", inode->i_sb->s_id,
 651                function, line, inode->i_ino, current->comm, &vaf);
 652         va_end(args);
 653 }
 654
 655 void __ext4_grp_locked_error(const char *function, unsigned int line,
 656                              struct super_block *sb, ext4_group_t grp,
 657                              unsigned long ino, ext4_fsblk_t block,
 658                              const char *fmt, ...)
 659 __releases(bitlock)
 660 __acquires(bitlock)
 661 {
 662         struct va_format vaf;
 663         va_list args;
 664         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 665
 666         es->s_last_error_ino = cpu_to_le32(ino);
 667         es->s_last_error_block = cpu_to_le64(block);
 668         __save_error_info(sb, function, line);
 669
 670         if (ext4_error_ratelimit(sb)) {
 671                 va_start(args, fmt);
 672                 vaf.fmt = fmt;
 673                 vaf.va = &args;
 674                 printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
 675                        sb->s_id, function, line, grp);
 676                 if (ino)
 677                         printk(KERN_CONT "inode %lu: ", ino);
 678                 if (block)
 679                         printk(KERN_CONT "block %llu:",
 680                                (unsigned long long) block);
 681                 printk(KERN_CONT "%pV\n", &vaf);
 682                 va_end(args);
 683         }
 684
 685         if (test_opt(sb, ERRORS_CONT)) {
 686                 ext4_commit_super(sb, 0);
 687                 return;
 688         }
 689
 690         ext4_unlock_group(sb, grp);
 691         ext4_handle_error(sb);
 692         /*
 693          * We only get here in the ERRORS_RO case; relocking the group
 694          * may be dangerous, but nothing bad will happen since the
 695          * filesystem will have already been marked read/only and the
 696          * journal has been aborted.  We return 1 as a hint to callers
 697          * who might what to use the return value from
 698          * ext4_grp_locked_error() to distinguish between the
 699          * ERRORS_CONT and ERRORS_RO case, and perhaps return more
 700          * aggressively from the ext4 function in question, with a
 701          * more appropriate error code.
 702          */
 703         ext4_lock_group(sb, grp);
 704         return;
 705 }
 706
 707 void ext4_update_dynamic_rev(struct super_block *sb)
 708 {
 709         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 710
 711         if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
 712                 return;
 713
 714         ext4_warning(sb,
 715                      "updating to rev %d because of new feature flag, "
 716                      "running e2fsck is recommended",
 717                      EXT4_DYNAMIC_REV);
 718
 719         es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
 720         es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
 721         es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
 722         /* leave es->s_feature_*compat flags alone */
 723         /* es->s_uuid will be set by e2fsck if empty */
 724
 725         /*
 726          * The rest of the superblock fields should be zero, and if not it
 727          * means they are likely already in use, so leave them alone.  We
 728          * can leave it up to e2fsck to clean up any inconsistencies there.
 729          */
 730 }
 731
 732 /*
 733  * Open the external journal device
 734  */
 735 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
 736 {
 737         struct block_device *bdev;
 738         char b[BDEVNAME_SIZE];
 739
 740         bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
 741         if (IS_ERR(bdev))
 742                 goto fail;
 743         return bdev;
 744
 745 fail:
 746         ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
 747                         __bdevname(dev, b), PTR_ERR(bdev));
 748         return NULL;
 749 }
 750
 751 /*
 752  * Release the journal device
 753  */
 754 static void ext4_blkdev_put(struct block_device *bdev)
 755 {
 756         blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
 757 }
 758
 759 static void ext4_blkdev_remove(struct ext4_sb_info *sbi)
 760 {
 761         struct block_device *bdev;
 762         bdev = sbi->journal_bdev;
 763         if (bdev) {
 764                 ext4_blkdev_put(bdev);
 765                 sbi->journal_bdev = NULL;
 766         }
 767 }
 768
 769 static inline struct inode *orphan_list_entry(struct list_head *l)
 770 {
 771         return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
 772 }
 773
 774 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
 775 {
 776         struct list_head *l;
 777
 778         ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
 779                  le32_to_cpu(sbi->s_es->s_last_orphan));
 780
 781         printk(KERN_ERR "sb_info orphan list:\n");
 782         list_for_each(l, &sbi->s_orphan) {
 783                 struct inode *inode = orphan_list_entry(l);
 784                 printk(KERN_ERR "  "
 785                        "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
 786                        inode->i_sb->s_id, inode->i_ino, inode,
 787                        inode->i_mode, inode->i_nlink,
 788                        NEXT_ORPHAN(inode));
 789         }
 790 }
 791
 792 static void ext4_put_super(struct super_block *sb)
 793 {
 794         struct ext4_sb_info *sbi = EXT4_SB(sb);
 795         struct ext4_super_block *es = sbi->s_es;
 796         int i, err;
 797
 798         ext4_unregister_li_request(sb);
 799         dquot_disable(sb, -1, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
 800
 801         flush_workqueue(sbi->rsv_conversion_wq);
 802         destroy_workqueue(sbi->rsv_conversion_wq);
 803
 804         if (sbi->s_journal) {
 805                 err = jbd2_journal_destroy(sbi->s_journal);
 806                 sbi->s_journal = NULL;
 807                 if (err < 0)
 808                         ext4_abort(sb, "Couldn't clean up the journal");
 809         }
 810
 811         ext4_unregister_sysfs(sb);
 812         ext4_es_unregister_shrinker(sbi);
 813         del_timer_sync(&sbi->s_err_report);
 814         ext4_release_system_zone(sb);
 815         ext4_mb_release(sb);
 816         ext4_ext_release(sb);
 817         ext4_xattr_put_super(sb);
 818
 819         if (!(sb->s_flags & MS_RDONLY)) {
 820                 ext4_clear_feature_journal_needs_recovery(sb);
 821                 es->s_state = cpu_to_le16(sbi->s_mount_state);
 822         }
 823         if (!(sb->s_flags & MS_RDONLY))
 824                 ext4_commit_super(sb, 1);
 825
 826         for (i = 0; i < sbi->s_gdb_count; i++)
 827                 brelse(sbi->s_group_desc[i]);
 828         kvfree(sbi->s_group_desc);
 829         kvfree(sbi->s_flex_groups);
 830         percpu_counter_destroy(&sbi->s_freeclusters_counter);
 831         percpu_counter_destroy(&sbi->s_freeinodes_counter);
 832         percpu_counter_destroy(&sbi->s_dirs_counter);
 833         percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
 834         brelse(sbi->s_sbh);
 835 #ifdef CONFIG_QUOTA
 836         for (i = 0; i < EXT4_MAXQUOTAS; i++)
 837                 kfree(sbi->s_qf_names[i]);
 838 #endif
 839
 840         /* Debugging code just in case the in-memory inode orphan list
 841          * isn't empty.  The on-disk one can be non-empty if we've
 842          * detected an error and taken the fs readonly, but the
 843          * in-memory list had better be clean by this point. */
 844         if (!list_empty(&sbi->s_orphan))
 845                 dump_orphan_list(sb, sbi);
 846         J_ASSERT(list_empty(&sbi->s_orphan));
 847
 848         sync_blockdev(sb->s_bdev);
 849         invalidate_bdev(sb->s_bdev);
 850         if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
 851                 /*
 852                  * Invalidate the journal device's buffers.  We don't want them
 853                  * floating about in memory - the physical journal device may
 854                  * hotswapped, and it breaks the `ro-after' testing code.
 855                  */
 856                 sync_blockdev(sbi->journal_bdev);
 857                 invalidate_bdev(sbi->journal_bdev);
 858                 ext4_blkdev_remove(sbi);
 859         }
 860         if (sbi->s_mb_cache) {
 861                 ext4_xattr_destroy_cache(sbi->s_mb_cache);
 862                 sbi->s_mb_cache = NULL;
 863         }
 864         if (sbi->s_mmp_tsk)
 865                 kthread_stop(sbi->s_mmp_tsk);
 866         sb->s_fs_info = NULL;
 867         /*
 868          * Now that we are completely done shutting down the
 869          * superblock, we need to actually destroy the kobject.
 870          */
 871         kobject_put(&sbi->s_kobj);
 872         wait_for_completion(&sbi->s_kobj_unregister);
 873         if (sbi->s_chksum_driver)
 874                 crypto_free_shash(sbi->s_chksum_driver);
 875         kfree(sbi->s_blockgroup_lock);
 876         kfree(sbi);
 877 }
 878
 879 static struct kmem_cache *ext4_inode_cachep;
 880
 881 /*
 882  * Called inside transaction, so use GFP_NOFS
 883  */
 884 static struct inode *ext4_alloc_inode(struct super_block *sb)
 885 {
 886         struct ext4_inode_info *ei;
 887
 888         ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
 889         if (!ei)
 890                 return NULL;
 891
 892         ei->vfs_inode.i_version = 1;
 893         spin_lock_init(&ei->i_raw_lock);
 894         INIT_LIST_HEAD(&ei->i_prealloc_list);
 895         spin_lock_init(&ei->i_prealloc_lock);
 896         ext4_es_init_tree(&ei->i_es_tree);
 897         rwlock_init(&ei->i_es_lock);
 898         INIT_LIST_HEAD(&ei->i_es_list);
 899         ei->i_es_all_nr = 0;
 900         ei->i_es_shk_nr = 0;
 901         ei->i_es_shrink_lblk = 0;
 902         ei->i_reserved_data_blocks = 0;
 903         ei->i_reserved_meta_blocks = 0;
 904         ei->i_allocated_meta_blocks = 0;
 905         ei->i_da_metadata_calc_len = 0;
 906         ei->i_da_metadata_calc_last_lblock = 0;
 907         spin_lock_init(&(ei->i_block_reservation_lock));
 908 #ifdef CONFIG_QUOTA
 909         ei->i_reserved_quota = 0;
 910         memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
 911 #endif
 912         ei->jinode = NULL;
 913         INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
 914         spin_lock_init(&ei->i_completed_io_lock);
 915         ei->i_sync_tid = 0;
 916         ei->i_datasync_tid = 0;
 917         atomic_set(&ei->i_ioend_count, 0);
 918         atomic_set(&ei->i_unwritten, 0);
 919         INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
 920 #ifdef CONFIG_EXT4_FS_ENCRYPTION
 921         ei->i_crypt_info = NULL;
 922 #endif
 923         return &ei->vfs_inode;
 924 }
 925
 926 static int ext4_drop_inode(struct inode *inode)
 927 {
 928         int drop = generic_drop_inode(inode);
 929
 930         trace_ext4_drop_inode(inode, drop);
 931         return drop;
 932 }
 933
 934 static void ext4_i_callback(struct rcu_head *head)
 935 {
 936         struct inode *inode = container_of(head, struct inode, i_rcu);
 937         kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
 938 }
 939
 940 static void ext4_destroy_inode(struct inode *inode)
 941 {
 942         if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
 943                 ext4_msg(inode->i_sb, KERN_ERR,
 944                          "Inode %lu (%p): orphan list check failed!",
 945                          inode->i_ino, EXT4_I(inode));
 946                 print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
 947                                 EXT4_I(inode), sizeof(struct ext4_inode_info),
 948                                 true);
 949                 dump_stack();
 950         }
 951         call_rcu(&inode->i_rcu, ext4_i_callback);
 952 }
 953
 954 static void init_once(void *foo)
 955 {
 956         struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
 957
 958         INIT_LIST_HEAD(&ei->i_orphan);
 959         init_rwsem(&ei->xattr_sem);
 960         init_rwsem(&ei->i_data_sem);
 961         init_rwsem(&ei->i_mmap_sem);
 962         inode_init_once(&ei->vfs_inode);
 963 }
 964
 965 static int __init init_inodecache(void)
 966 {
 967         ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
 968                                              sizeof(struct ext4_inode_info),
 969                                              0, (SLAB_RECLAIM_ACCOUNT|
 970                                                 SLAB_MEM_SPREAD),
 971                                              init_once);
 972         if (ext4_inode_cachep == NULL)
 973                 return -ENOMEM;
 974         return 0;
 975 }
 976
 977 static void destroy_inodecache(void)
 978 {
 979         /*
 980          * Make sure all delayed rcu free inodes are flushed before we
 981          * destroy cache.
 982          */
 983         rcu_barrier();
 984         kmem_cache_destroy(ext4_inode_cachep);
 985 }
 986
 987 void ext4_clear_inode(struct inode *inode)
 988 {
 989         invalidate_inode_buffers(inode);
 990         clear_inode(inode);
 991         dquot_drop(inode);
 992         ext4_discard_preallocations(inode);
 993         ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
 994         if (EXT4_I(inode)->jinode) {
 995                 jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
 996                                                EXT4_I(inode)->jinode);
 997                 jbd2_free_inode(EXT4_I(inode)->jinode);
 998                 EXT4_I(inode)->jinode = NULL;
 999         }
1000 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1001         if (EXT4_I(inode)->i_crypt_info)
1002                 ext4_free_encryption_info(inode, EXT4_I(inode)->i_crypt_info);
1003 #endif
1004 }
1005
1006 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1007                                         u64 ino, u32 generation)
1008 {
1009         struct inode *inode;
1010
1011         if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
1012                 return ERR_PTR(-ESTALE);
1013         if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
1014                 return ERR_PTR(-ESTALE);
1015
1016         /* iget isn't really right if the inode is currently unallocated!!
1017          *
1018          * ext4_read_inode will return a bad_inode if the inode had been
1019          * deleted, so we should be safe.
1020          *
1021          * Currently we don't know the generation for parent directory, so
1022          * a generation of 0 means "accept any"
1023          */
1024         inode = ext4_iget_normal(sb, ino);
1025         if (IS_ERR(inode))
1026                 return ERR_CAST(inode);
1027         if (generation && inode->i_generation != generation) {
1028                 iput(inode);
1029                 return ERR_PTR(-ESTALE);
1030         }
1031
1032         return inode;
1033 }
1034
1035 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1036                                         int fh_len, int fh_type)
1037 {
1038         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1039                                     ext4_nfs_get_inode);
1040 }
1041
1042 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1043                                         int fh_len, int fh_type)
1044 {
1045         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1046                                     ext4_nfs_get_inode);
1047 }
1048
1049 /*
1050  * Try to release metadata pages (indirect blocks, directories) which are
1051  * mapped via the block device.  Since these pages could have journal heads
1052  * which would prevent try_to_free_buffers() from freeing them, we must use
1053  * jbd2 layer's try_to_free_buffers() function to release them.
1054  */
1055 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1056                                  gfp_t wait)
1057 {
1058         journal_t *journal = EXT4_SB(sb)->s_journal;
1059
1060         WARN_ON(PageChecked(page));
1061         if (!page_has_buffers(page))
1062                 return 0;
1063         if (journal)
1064                 return jbd2_journal_try_to_free_buffers(journal, page,
1065                                                 wait & ~__GFP_DIRECT_RECLAIM);
1066         return try_to_free_buffers(page);
1067 }
1068
1069 #ifdef CONFIG_QUOTA
1070 #define QTYPE2NAME(t) ((t) == USRQUOTA ? "user" : "group")
1071 #define QTYPE2MOPT(on, t) ((t) == USRQUOTA?((on)##USRJQUOTA):((on)##GRPJQUOTA))
1072
1073 static int ext4_write_dquot(struct dquot *dquot);
1074 static int ext4_acquire_dquot(struct dquot *dquot);
1075 static int ext4_release_dquot(struct dquot *dquot);
1076 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1077 static int ext4_write_info(struct super_block *sb, int type);
1078 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1079                          struct path *path);
1080 static int ext4_quota_off(struct super_block *sb, int type);
1081 static int ext4_quota_on_mount(struct super_block *sb, int type);
1082 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1083                                size_t len, loff_t off);
1084 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1085                                 const char *data, size_t len, loff_t off);
1086 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1087                              unsigned int flags);
1088 static int ext4_enable_quotas(struct super_block *sb);
1089
1090 static struct dquot **ext4_get_dquots(struct inode *inode)
1091 {
1092         return EXT4_I(inode)->i_dquot;
1093 }
1094
1095 static const struct dquot_operations ext4_quota_operations = {
1096         .get_reserved_space = ext4_get_reserved_space,
1097         .write_dquot    = ext4_write_dquot,
1098         .acquire_dquot  = ext4_acquire_dquot,
1099         .release_dquot  = ext4_release_dquot,
1100         .mark_dirty     = ext4_mark_dquot_dirty,
1101         .write_info     = ext4_write_info,
1102         .alloc_dquot    = dquot_alloc,
1103         .destroy_dquot  = dquot_destroy,
1104 };
1105
1106 static const struct quotactl_ops ext4_qctl_operations = {
1107         .quota_on       = ext4_quota_on,
1108         .quota_off      = ext4_quota_off,
1109         .quota_sync     = dquot_quota_sync,
1110         .get_state      = dquot_get_state,
1111         .set_info       = dquot_set_dqinfo,
1112         .get_dqblk      = dquot_get_dqblk,
1113         .set_dqblk      = dquot_set_dqblk
1114 };
1115 #endif
1116
1117 static const struct super_operations ext4_sops = {
1118         .alloc_inode    = ext4_alloc_inode,
1119         .destroy_inode  = ext4_destroy_inode,
1120         .write_inode    = ext4_write_inode,
1121         .dirty_inode    = ext4_dirty_inode,
1122         .drop_inode     = ext4_drop_inode,
1123         .evict_inode    = ext4_evict_inode,
1124         .put_super      = ext4_put_super,
1125         .sync_fs        = ext4_sync_fs,
1126         .freeze_fs      = ext4_freeze,
1127         .unfreeze_fs    = ext4_unfreeze,
1128         .statfs         = ext4_statfs,
1129         .remount_fs     = ext4_remount,
1130         .show_options   = ext4_show_options,
1131 #ifdef CONFIG_QUOTA
1132         .quota_read     = ext4_quota_read,
1133         .quota_write    = ext4_quota_write,
1134         .get_dquots     = ext4_get_dquots,
1135 #endif
1136         .bdev_try_to_free_page = bdev_try_to_free_page,
1137 };
1138
1139 static const struct export_operations ext4_export_ops = {
1140         .fh_to_dentry = ext4_fh_to_dentry,
1141         .fh_to_parent = ext4_fh_to_parent,
1142         .get_parent = ext4_get_parent,
1143 };
1144
1145 enum {
1146         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1147         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1148         Opt_nouid32, Opt_debug, Opt_removed,
1149         Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1150         Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1151         Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1152         Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1153         Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1154         Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
1155         Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1156         Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1157         Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1158         Opt_usrquota, Opt_grpquota, Opt_i_version, Opt_dax,
1159         Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_mblk_io_submit,
1160         Opt_lazytime, Opt_nolazytime,
1161         Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1162         Opt_inode_readahead_blks, Opt_journal_ioprio,
1163         Opt_dioread_nolock, Opt_dioread_lock,
1164         Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1165         Opt_max_dir_size_kb, Opt_nojournal_checksum,
1166 };
1167
1168 static const match_table_t tokens = {
1169         {Opt_bsd_df, "bsddf"},
1170         {Opt_minix_df, "minixdf"},
1171         {Opt_grpid, "grpid"},
1172         {Opt_grpid, "bsdgroups"},
1173         {Opt_nogrpid, "nogrpid"},
1174         {Opt_nogrpid, "sysvgroups"},
1175         {Opt_resgid, "resgid=%u"},
1176         {Opt_resuid, "resuid=%u"},
1177         {Opt_sb, "sb=%u"},
1178         {Opt_err_cont, "errors=continue"},
1179         {Opt_err_panic, "errors=panic"},
1180         {Opt_err_ro, "errors=remount-ro"},
1181         {Opt_nouid32, "nouid32"},
1182         {Opt_debug, "debug"},
1183         {Opt_removed, "oldalloc"},
1184         {Opt_removed, "orlov"},
1185         {Opt_user_xattr, "user_xattr"},
1186         {Opt_nouser_xattr, "nouser_xattr"},
1187         {Opt_acl, "acl"},
1188         {Opt_noacl, "noacl"},
1189         {Opt_noload, "norecovery"},
1190         {Opt_noload, "noload"},
1191         {Opt_removed, "nobh"},
1192         {Opt_removed, "bh"},
1193         {Opt_commit, "commit=%u"},
1194         {Opt_min_batch_time, "min_batch_time=%u"},
1195         {Opt_max_batch_time, "max_batch_time=%u"},
1196         {Opt_journal_dev, "journal_dev=%u"},
1197         {Opt_journal_path, "journal_path=%s"},
1198         {Opt_journal_checksum, "journal_checksum"},
1199         {Opt_nojournal_checksum, "nojournal_checksum"},
1200         {Opt_journal_async_commit, "journal_async_commit"},
1201         {Opt_abort, "abort"},
1202         {Opt_data_journal, "data=journal"},
1203         {Opt_data_ordered, "data=ordered"},
1204         {Opt_data_writeback, "data=writeback"},
1205         {Opt_data_err_abort, "data_err=abort"},
1206         {Opt_data_err_ignore, "data_err=ignore"},
1207         {Opt_offusrjquota, "usrjquota="},
1208         {Opt_usrjquota, "usrjquota=%s"},
1209         {Opt_offgrpjquota, "grpjquota="},
1210         {Opt_grpjquota, "grpjquota=%s"},
1211         {Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1212         {Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1213         {Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1214         {Opt_grpquota, "grpquota"},
1215         {Opt_noquota, "noquota"},
1216         {Opt_quota, "quota"},
1217         {Opt_usrquota, "usrquota"},
1218         {Opt_barrier, "barrier=%u"},
1219         {Opt_barrier, "barrier"},
1220         {Opt_nobarrier, "nobarrier"},
1221         {Opt_i_version, "i_version"},
1222         {Opt_dax, "dax"},
1223         {Opt_stripe, "stripe=%u"},
1224         {Opt_delalloc, "delalloc"},
1225         {Opt_lazytime, "lazytime"},
1226         {Opt_nolazytime, "nolazytime"},
1227         {Opt_nodelalloc, "nodelalloc"},
1228         {Opt_removed, "mblk_io_submit"},
1229         {Opt_removed, "nomblk_io_submit"},
1230         {Opt_block_validity, "block_validity"},
1231         {Opt_noblock_validity, "noblock_validity"},
1232         {Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1233         {Opt_journal_ioprio, "journal_ioprio=%u"},
1234         {Opt_auto_da_alloc, "auto_da_alloc=%u"},
1235         {Opt_auto_da_alloc, "auto_da_alloc"},
1236         {Opt_noauto_da_alloc, "noauto_da_alloc"},
1237         {Opt_dioread_nolock, "dioread_nolock"},
1238         {Opt_dioread_lock, "dioread_lock"},
1239         {Opt_discard, "discard"},
1240         {Opt_nodiscard, "nodiscard"},
1241         {Opt_init_itable, "init_itable=%u"},
1242         {Opt_init_itable, "init_itable"},
1243         {Opt_noinit_itable, "noinit_itable"},
1244         {Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1245         {Opt_test_dummy_encryption, "test_dummy_encryption"},
1246         {Opt_removed, "check=none"},    /* mount option from ext2/3 */
1247         {Opt_removed, "nocheck"},       /* mount option from ext2/3 */
1248         {Opt_removed, "reservation"},   /* mount option from ext2/3 */
1249         {Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1250         {Opt_removed, "journal=%u"},    /* mount option from ext2/3 */
1251         {Opt_err, NULL},
1252 };
1253
1254 static ext4_fsblk_t get_sb_block(void **data)
1255 {
1256         ext4_fsblk_t    sb_block;
1257         char            *options = (char *) *data;
1258
1259         if (!options || strncmp(options, "sb=", 3) != 0)
1260                 return 1;       /* Default location */
1261
1262         options += 3;
1263         /* TODO: use simple_strtoll with >32bit ext4 */
1264         sb_block = simple_strtoul(options, &options, 0);
1265         if (*options && *options != ',') {
1266                 printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1267                        (char *) *data);
1268                 return 1;
1269         }
1270         if (*options == ',')
1271                 options++;
1272         *data = (void *) options;
1273
1274         return sb_block;
1275 }
1276
1277 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1278 static char deprecated_msg[] = "Mount option \"%s\" will be removed by %s\n"
1279         "Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1280
1281 #ifdef CONFIG_QUOTA
1282 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1283 {
1284         struct ext4_sb_info *sbi = EXT4_SB(sb);
1285         char *qname;
1286         int ret = -1;
1287
1288         if (sb_any_quota_loaded(sb) &&
1289                 !sbi->s_qf_names[qtype]) {
1290                 ext4_msg(sb, KERN_ERR,
1291                         "Cannot change journaled "
1292                         "quota options when quota turned on");
1293                 return -1;
1294         }
1295         if (ext4_has_feature_quota(sb)) {
1296                 ext4_msg(sb, KERN_INFO, "Journaled quota options "
1297                          "ignored when QUOTA feature is enabled");
1298                 return 1;
1299         }
1300         qname = match_strdup(args);
1301         if (!qname) {
1302                 ext4_msg(sb, KERN_ERR,
1303                         "Not enough memory for storing quotafile name");
1304                 return -1;
1305         }
1306         if (sbi->s_qf_names[qtype]) {
1307                 if (strcmp(sbi->s_qf_names[qtype], qname) == 0)
1308                         ret = 1;
1309                 else
1310                         ext4_msg(sb, KERN_ERR,
1311                                  "%s quota file already specified",
1312                                  QTYPE2NAME(qtype));
1313                 goto errout;
1314         }
1315         if (strchr(qname, '/')) {
1316                 ext4_msg(sb, KERN_ERR,
1317                         "quotafile must be on filesystem root");
1318                 goto errout;
1319         }
1320         sbi->s_qf_names[qtype] = qname;
1321         set_opt(sb, QUOTA);
1322         return 1;
1323 errout:
1324         kfree(qname);
1325         return ret;
1326 }
1327
1328 static int clear_qf_name(struct super_block *sb, int qtype)
1329 {
1330
1331         struct ext4_sb_info *sbi = EXT4_SB(sb);
1332
1333         if (sb_any_quota_loaded(sb) &&
1334                 sbi->s_qf_names[qtype]) {
1335                 ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1336                         " when quota turned on");
1337                 return -1;
1338         }
1339         kfree(sbi->s_qf_names[qtype]);
1340         sbi->s_qf_names[qtype] = NULL;
1341         return 1;
1342 }
1343 #endif
1344
1345 #define MOPT_SET        0x0001
1346 #define MOPT_CLEAR      0x0002
1347 #define MOPT_NOSUPPORT  0x0004
1348 #define MOPT_EXPLICIT   0x0008
1349 #define MOPT_CLEAR_ERR  0x0010
1350 #define MOPT_GTE0       0x0020
1351 #ifdef CONFIG_QUOTA
1352 #define MOPT_Q          0
1353 #define MOPT_QFMT       0x0040
1354 #else
1355 #define MOPT_Q          MOPT_NOSUPPORT
1356 #define MOPT_QFMT       MOPT_NOSUPPORT
1357 #endif
1358 #define MOPT_DATAJ      0x0080
1359 #define MOPT_NO_EXT2    0x0100
1360 #define MOPT_NO_EXT3    0x0200
1361 #define MOPT_EXT4_ONLY  (MOPT_NO_EXT2 | MOPT_NO_EXT3)
1362 #define MOPT_STRING     0x0400
1363
1364 static const struct mount_opts {
1365         int     token;
1366         int     mount_opt;
1367         int     flags;
1368 } ext4_mount_opts[] = {
1369         {Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1370         {Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1371         {Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1372         {Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1373         {Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1374         {Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1375         {Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1376          MOPT_EXT4_ONLY | MOPT_SET},
1377         {Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1378          MOPT_EXT4_ONLY | MOPT_CLEAR},
1379         {Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1380         {Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1381         {Opt_delalloc, EXT4_MOUNT_DELALLOC,
1382          MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1383         {Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1384          MOPT_EXT4_ONLY | MOPT_CLEAR},
1385         {Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1386          MOPT_EXT4_ONLY | MOPT_CLEAR},
1387         {Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1388          MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1389         {Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1390                                     EXT4_MOUNT_JOURNAL_CHECKSUM),
1391          MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1392         {Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1393         {Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1394         {Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1395         {Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1396         {Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
1397          MOPT_NO_EXT2 | MOPT_SET},
1398         {Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
1399          MOPT_NO_EXT2 | MOPT_CLEAR},
1400         {Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1401         {Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1402         {Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1403         {Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1404         {Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1405         {Opt_commit, 0, MOPT_GTE0},
1406         {Opt_max_batch_time, 0, MOPT_GTE0},
1407         {Opt_min_batch_time, 0, MOPT_GTE0},
1408         {Opt_inode_readahead_blks, 0, MOPT_GTE0},
1409         {Opt_init_itable, 0, MOPT_GTE0},
1410         {Opt_dax, EXT4_MOUNT_DAX, MOPT_SET},
1411         {Opt_stripe, 0, MOPT_GTE0},
1412         {Opt_resuid, 0, MOPT_GTE0},
1413         {Opt_resgid, 0, MOPT_GTE0},
1414         {Opt_journal_dev, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1415         {Opt_journal_path, 0, MOPT_NO_EXT2 | MOPT_STRING},
1416         {Opt_journal_ioprio, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1417         {Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1418         {Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1419         {Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
1420          MOPT_NO_EXT2 | MOPT_DATAJ},
1421         {Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1422         {Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1423 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1424         {Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1425         {Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1426 #else
1427         {Opt_acl, 0, MOPT_NOSUPPORT},
1428         {Opt_noacl, 0, MOPT_NOSUPPORT},
1429 #endif
1430         {Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1431         {Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1432         {Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1433         {Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1434                                                         MOPT_SET | MOPT_Q},
1435         {Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1436                                                         MOPT_SET | MOPT_Q},
1437         {Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1438                        EXT4_MOUNT_GRPQUOTA), MOPT_CLEAR | MOPT_Q},
1439         {Opt_usrjquota, 0, MOPT_Q},
1440         {Opt_grpjquota, 0, MOPT_Q},
1441         {Opt_offusrjquota, 0, MOPT_Q},
1442         {Opt_offgrpjquota, 0, MOPT_Q},
1443         {Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1444         {Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1445         {Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1446         {Opt_max_dir_size_kb, 0, MOPT_GTE0},
1447         {Opt_test_dummy_encryption, 0, MOPT_GTE0},
1448         {Opt_err, 0, 0}
1449 };
1450
1451 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1452                             substring_t *args, unsigned long *journal_devnum,
1453                             unsigned int *journal_ioprio, int is_remount)
1454 {
1455         struct ext4_sb_info *sbi = EXT4_SB(sb);
1456         const struct mount_opts *m;
1457         kuid_t uid;
1458         kgid_t gid;
1459         int arg = 0;
1460
1461 #ifdef CONFIG_QUOTA
1462         if (token == Opt_usrjquota)
1463                 return set_qf_name(sb, USRQUOTA, &args[0]);
1464         else if (token == Opt_grpjquota)
1465                 return set_qf_name(sb, GRPQUOTA, &args[0]);
1466         else if (token == Opt_offusrjquota)
1467                 return clear_qf_name(sb, USRQUOTA);
1468         else if (token == Opt_offgrpjquota)
1469                 return clear_qf_name(sb, GRPQUOTA);
1470 #endif
1471         switch (token) {
1472         case Opt_noacl:
1473         case Opt_nouser_xattr:
1474                 ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1475                 break;
1476         case Opt_sb:
1477                 return 1;       /* handled by get_sb_block() */
1478         case Opt_removed:
1479                 ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
1480                 return 1;
1481         case Opt_abort:
1482                 sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1483                 return 1;
1484         case Opt_i_version:
1485                 sb->s_flags |= MS_I_VERSION;
1486                 return 1;
1487         case Opt_lazytime:
1488                 sb->s_flags |= MS_LAZYTIME;
1489                 return 1;
1490         case Opt_nolazytime:
1491                 sb->s_flags &= ~MS_LAZYTIME;
1492                 return 1;
1493         }
1494
1495         for (m = ext4_mount_opts; m->token != Opt_err; m++)
1496                 if (token == m->token)
1497                         break;
1498
1499         if (m->token == Opt_err) {
1500                 ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1501                          "or missing value", opt);
1502                 return -1;
1503         }
1504
1505         if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
1506                 ext4_msg(sb, KERN_ERR,
1507                          "Mount option \"%s\" incompatible with ext2", opt);
1508                 return -1;
1509         }
1510         if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
1511                 ext4_msg(sb, KERN_ERR,
1512                          "Mount option \"%s\" incompatible with ext3", opt);
1513                 return -1;
1514         }
1515
1516         if (args->from && !(m->flags & MOPT_STRING) && match_int(args, &arg))
1517                 return -1;
1518         if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1519                 return -1;
1520         if (m->flags & MOPT_EXPLICIT) {
1521                 if (m->mount_opt & EXT4_MOUNT_DELALLOC) {
1522                         set_opt2(sb, EXPLICIT_DELALLOC);
1523                 } else if (m->mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) {
1524                         set_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM);
1525                 } else
1526                         return -1;
1527         }
1528         if (m->flags & MOPT_CLEAR_ERR)
1529                 clear_opt(sb, ERRORS_MASK);
1530         if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1531                 ext4_msg(sb, KERN_ERR, "Cannot change quota "
1532                          "options when quota turned on");
1533                 return -1;
1534         }
1535
1536         if (m->flags & MOPT_NOSUPPORT) {
1537                 ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1538         } else if (token == Opt_commit) {
1539                 if (arg == 0)
1540                         arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1541                 sbi->s_commit_interval = HZ * arg;
1542         } else if (token == Opt_max_batch_time) {
1543                 sbi->s_max_batch_time = arg;
1544         } else if (token == Opt_min_batch_time) {
1545                 sbi->s_min_batch_time = arg;
1546         } else if (token == Opt_inode_readahead_blks) {
1547                 if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
1548                         ext4_msg(sb, KERN_ERR,
1549                                  "EXT4-fs: inode_readahead_blks must be "
1550                                  "0 or a power of 2 smaller than 2^31");
1551                         return -1;
1552                 }
1553                 sbi->s_inode_readahead_blks = arg;
1554         } else if (token == Opt_init_itable) {
1555                 set_opt(sb, INIT_INODE_TABLE);
1556                 if (!args->from)
1557                         arg = EXT4_DEF_LI_WAIT_MULT;
1558                 sbi->s_li_wait_mult = arg;
1559         } else if (token == Opt_max_dir_size_kb) {
1560                 sbi->s_max_dir_size_kb = arg;
1561         } else if (token == Opt_stripe) {
1562                 sbi->s_stripe = arg;
1563         } else if (token == Opt_resuid) {
1564                 uid = make_kuid(current_user_ns(), arg);
1565                 if (!uid_valid(uid)) {
1566                         ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
1567                         return -1;
1568                 }
1569                 sbi->s_resuid = uid;
1570         } else if (token == Opt_resgid) {
1571                 gid = make_kgid(current_user_ns(), arg);
1572                 if (!gid_valid(gid)) {
1573                         ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
1574                         return -1;
1575                 }
1576                 sbi->s_resgid = gid;
1577         } else if (token == Opt_journal_dev) {
1578                 if (is_remount) {
1579                         ext4_msg(sb, KERN_ERR,
1580                                  "Cannot specify journal on remount");
1581                         return -1;
1582                 }
1583                 *journal_devnum = arg;
1584         } else if (token == Opt_journal_path) {
1585                 char *journal_path;
1586                 struct inode *journal_inode;
1587                 struct path path;
1588                 int error;
1589
1590                 if (is_remount) {
1591                         ext4_msg(sb, KERN_ERR,
1592                                  "Cannot specify journal on remount");
1593                         return -1;
1594                 }
1595                 journal_path = match_strdup(&args[0]);
1596                 if (!journal_path) {
1597                         ext4_msg(sb, KERN_ERR, "error: could not dup "
1598                                 "journal device string");
1599                         return -1;
1600                 }
1601
1602                 error = kern_path(journal_path, LOOKUP_FOLLOW, &path);
1603                 if (error) {
1604                         ext4_msg(sb, KERN_ERR, "error: could not find "
1605                                 "journal device path: error %d", error);
1606                         kfree(journal_path);
1607                         return -1;
1608                 }
1609
1610                 journal_inode = d_inode(path.dentry);
1611                 if (!S_ISBLK(journal_inode->i_mode)) {
1612                         ext4_msg(sb, KERN_ERR, "error: journal path %s "
1613                                 "is not a block device", journal_path);
1614                         path_put(&path);
1615                         kfree(journal_path);
1616                         return -1;
1617                 }
1618
1619                 *journal_devnum = new_encode_dev(journal_inode->i_rdev);
1620                 path_put(&path);
1621                 kfree(journal_path);
1622         } else if (token == Opt_journal_ioprio) {
1623                 if (arg > 7) {
1624                         ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
1625                                  " (must be 0-7)");
1626                         return -1;
1627                 }
1628                 *journal_ioprio =
1629                         IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
1630         } else if (token == Opt_test_dummy_encryption) {
1631 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1632                 sbi->s_mount_flags |= EXT4_MF_TEST_DUMMY_ENCRYPTION;
1633                 ext4_msg(sb, KERN_WARNING,
1634                          "Test dummy encryption mode enabled");
1635 #else
1636                 ext4_msg(sb, KERN_WARNING,
1637                          "Test dummy encryption mount option ignored");
1638 #endif
1639         } else if (m->flags & MOPT_DATAJ) {
1640                 if (is_remount) {
1641                         if (!sbi->s_journal)
1642                                 ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
1643                         else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
1644                                 ext4_msg(sb, KERN_ERR,
1645                                          "Cannot change data mode on remount");
1646                                 return -1;
1647                         }
1648                 } else {
1649                         clear_opt(sb, DATA_FLAGS);
1650                         sbi->s_mount_opt |= m->mount_opt;
1651                 }
1652 #ifdef CONFIG_QUOTA
1653         } else if (m->flags & MOPT_QFMT) {
1654                 if (sb_any_quota_loaded(sb) &&
1655                     sbi->s_jquota_fmt != m->mount_opt) {
1656                         ext4_msg(sb, KERN_ERR, "Cannot change journaled "
1657                                  "quota options when quota turned on");
1658                         return -1;
1659                 }
1660                 if (ext4_has_feature_quota(sb)) {
1661                         ext4_msg(sb, KERN_INFO,
1662                                  "Quota format mount options ignored "
1663                                  "when QUOTA feature is enabled");
1664                         return 1;
1665                 }
1666                 sbi->s_jquota_fmt = m->mount_opt;
1667 #endif
1668         } else if (token == Opt_dax) {
1669 #ifdef CONFIG_FS_DAX
1670                 ext4_msg(sb, KERN_WARNING,
1671                 "DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
1672                         sbi->s_mount_opt |= m->mount_opt;
1673 #else
1674                 ext4_msg(sb, KERN_INFO, "dax option not supported");
1675                 return -1;
1676 #endif
1677         } else {
1678                 if (!args->from)
1679                         arg = 1;
1680                 if (m->flags & MOPT_CLEAR)
1681                         arg = !arg;
1682                 else if (unlikely(!(m->flags & MOPT_SET))) {
1683                         ext4_msg(sb, KERN_WARNING,
1684                                  "buggy handling of option %s", opt);
1685                         WARN_ON(1);
1686                         return -1;
1687                 }
1688                 if (arg != 0)
1689                         sbi->s_mount_opt |= m->mount_opt;
1690                 else
1691                         sbi->s_mount_opt &= ~m->mount_opt;
1692         }
1693         return 1;
1694 }
1695
1696 static int parse_options(char *options, struct super_block *sb,
1697                          unsigned long *journal_devnum,
1698                          unsigned int *journal_ioprio,
1699                          int is_remount)
1700 {
1701         struct ext4_sb_info *sbi = EXT4_SB(sb);
1702         char *p;
1703         substring_t args[MAX_OPT_ARGS];
1704         int token;
1705
1706         if (!options)
1707                 return 1;
1708
1709         while ((p = strsep(&options, ",")) != NULL) {
1710                 if (!*p)
1711                         continue;
1712                 /*
1713                  * Initialize args struct so we know whether arg was
1714                  * found; some options take optional arguments.
1715                  */
1716                 args[0].to = args[0].from = NULL;
1717                 token = match_token(p, tokens, args);
1718                 if (handle_mount_opt(sb, p, token, args, journal_devnum,
1719                                      journal_ioprio, is_remount) < 0)
1720                         return 0;
1721         }
1722 #ifdef CONFIG_QUOTA
1723         if (ext4_has_feature_quota(sb) &&
1724             (test_opt(sb, USRQUOTA) || test_opt(sb, GRPQUOTA))) {
1725                 ext4_msg(sb, KERN_INFO, "Quota feature enabled, usrquota and grpquota "
1726                          "mount options ignored.");
1727                 clear_opt(sb, USRQUOTA);
1728                 clear_opt(sb, GRPQUOTA);
1729         } else if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1730                 if (test_opt(sb, USRQUOTA) && sbi->s_qf_names[USRQUOTA])
1731                         clear_opt(sb, USRQUOTA);
1732
1733                 if (test_opt(sb, GRPQUOTA) && sbi->s_qf_names[GRPQUOTA])
1734                         clear_opt(sb, GRPQUOTA);
1735
1736                 if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
1737                         ext4_msg(sb, KERN_ERR, "old and new quota "
1738                                         "format mixing");
1739                         return 0;
1740                 }
1741
1742                 if (!sbi->s_jquota_fmt) {
1743                         ext4_msg(sb, KERN_ERR, "journaled quota format "
1744                                         "not specified");
1745                         return 0;
1746                 }
1747         }
1748 #endif
1749         if (test_opt(sb, DIOREAD_NOLOCK)) {
1750                 int blocksize =
1751                         BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
1752
1753                 if (blocksize < PAGE_CACHE_SIZE) {
1754                         ext4_msg(sb, KERN_ERR, "can't mount with "
1755                                  "dioread_nolock if block size != PAGE_SIZE");
1756                         return 0;
1757                 }
1758         }
1759         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
1760             test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
1761                 ext4_msg(sb, KERN_ERR, "can't mount with journal_async_commit "
1762                          "in data=ordered mode");
1763                 return 0;
1764         }
1765         return 1;
1766 }
1767
1768 static inline void ext4_show_quota_options(struct seq_file *seq,
1769                                            struct super_block *sb)
1770 {
1771 #if defined(CONFIG_QUOTA)
1772         struct ext4_sb_info *sbi = EXT4_SB(sb);
1773
1774         if (sbi->s_jquota_fmt) {
1775                 char *fmtname = "";
1776
1777                 switch (sbi->s_jquota_fmt) {
1778                 case QFMT_VFS_OLD:
1779                         fmtname = "vfsold";
1780                         break;
1781                 case QFMT_VFS_V0:
1782                         fmtname = "vfsv0";
1783                         break;
1784                 case QFMT_VFS_V1:
1785                         fmtname = "vfsv1";
1786                         break;
1787                 }
1788                 seq_printf(seq, ",jqfmt=%s", fmtname);
1789         }
1790
1791         if (sbi->s_qf_names[USRQUOTA])
1792                 seq_show_option(seq, "usrjquota", sbi->s_qf_names[USRQUOTA]);
1793
1794         if (sbi->s_qf_names[GRPQUOTA])
1795                 seq_show_option(seq, "grpjquota", sbi->s_qf_names[GRPQUOTA]);
1796 #endif
1797 }
1798
1799 static const char *token2str(int token)
1800 {
1801         const struct match_token *t;
1802
1803         for (t = tokens; t->token != Opt_err; t++)
1804                 if (t->token == token && !strchr(t->pattern, '='))
1805                         break;
1806         return t->pattern;
1807 }
1808
1809 /*
1810  * Show an option if
1811  *  - it's set to a non-default value OR
1812  *  - if the per-sb default is different from the global default
1813  */
1814 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
1815                               int nodefs)
1816 {
1817         struct ext4_sb_info *sbi = EXT4_SB(sb);
1818         struct ext4_super_block *es = sbi->s_es;
1819         int def_errors, def_mount_opt = nodefs ? 0 : sbi->s_def_mount_opt;
1820         const struct mount_opts *m;
1821         char sep = nodefs ? '\n' : ',';
1822
1823 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
1824 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
1825
1826         if (sbi->s_sb_block != 1)
1827                 SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
1828
1829         for (m = ext4_mount_opts; m->token != Opt_err; m++) {
1830                 int want_set = m->flags & MOPT_SET;
1831                 if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
1832                     (m->flags & MOPT_CLEAR_ERR))
1833                         continue;
1834                 if (!(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
1835                         continue; /* skip if same as the default */
1836                 if ((want_set &&
1837                      (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
1838                     (!want_set && (sbi->s_mount_opt & m->mount_opt)))
1839                         continue; /* select Opt_noFoo vs Opt_Foo */
1840                 SEQ_OPTS_PRINT("%s", token2str(m->token));
1841         }
1842
1843         if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
1844             le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
1845                 SEQ_OPTS_PRINT("resuid=%u",
1846                                 from_kuid_munged(&init_user_ns, sbi->s_resuid));
1847         if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
1848             le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
1849                 SEQ_OPTS_PRINT("resgid=%u",
1850                                 from_kgid_munged(&init_user_ns, sbi->s_resgid));
1851         def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
1852         if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
1853                 SEQ_OPTS_PUTS("errors=remount-ro");
1854         if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
1855                 SEQ_OPTS_PUTS("errors=continue");
1856         if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
1857                 SEQ_OPTS_PUTS("errors=panic");
1858         if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
1859                 SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
1860         if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
1861                 SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
1862         if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
1863                 SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
1864         if (sb->s_flags & MS_I_VERSION)
1865                 SEQ_OPTS_PUTS("i_version");
1866         if (nodefs || sbi->s_stripe)
1867                 SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
1868         if (EXT4_MOUNT_DATA_FLAGS & (sbi->s_mount_opt ^ def_mount_opt)) {
1869                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
1870                         SEQ_OPTS_PUTS("data=journal");
1871                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
1872                         SEQ_OPTS_PUTS("data=ordered");
1873                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
1874                         SEQ_OPTS_PUTS("data=writeback");
1875         }
1876         if (nodefs ||
1877             sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
1878                 SEQ_OPTS_PRINT("inode_readahead_blks=%u",
1879                                sbi->s_inode_readahead_blks);
1880
1881         if (nodefs || (test_opt(sb, INIT_INODE_TABLE) &&
1882                        (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
1883                 SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
1884         if (nodefs || sbi->s_max_dir_size_kb)
1885                 SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
1886
1887         ext4_show_quota_options(seq, sb);
1888         return 0;
1889 }
1890
1891 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
1892 {
1893         return _ext4_show_options(seq, root->d_sb, 0);
1894 }
1895
1896 int ext4_seq_options_show(struct seq_file *seq, void *offset)
1897 {
1898         struct super_block *sb = seq->private;
1899         int rc;
1900
1901         seq_puts(seq, (sb->s_flags & MS_RDONLY) ? "ro" : "rw");
1902         rc = _ext4_show_options(seq, sb, 1);
1903         seq_puts(seq, "\n");
1904         return rc;
1905 }
1906
1907 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
1908                             int read_only)
1909 {
1910         struct ext4_sb_info *sbi = EXT4_SB(sb);
1911         int res = 0;
1912
1913         if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
1914                 ext4_msg(sb, KERN_ERR, "revision level too high, "
1915                          "forcing read-only mode");
1916                 res = MS_RDONLY;
1917         }
1918         if (read_only)
1919                 goto done;
1920         if (!(sbi->s_mount_state & EXT4_VALID_FS))
1921                 ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
1922                          "running e2fsck is recommended");
1923         else if (sbi->s_mount_state & EXT4_ERROR_FS)
1924                 ext4_msg(sb, KERN_WARNING,
1925                          "warning: mounting fs with errors, "
1926                          "running e2fsck is recommended");
1927         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
1928                  le16_to_cpu(es->s_mnt_count) >=
1929                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
1930                 ext4_msg(sb, KERN_WARNING,
1931                          "warning: maximal mount count reached, "
1932                          "running e2fsck is recommended");
1933         else if (le32_to_cpu(es->s_checkinterval) &&
1934                 (le32_to_cpu(es->s_lastcheck) +
1935                         le32_to_cpu(es->s_checkinterval) <= get_seconds()))
1936                 ext4_msg(sb, KERN_WARNING,
1937                          "warning: checktime reached, "
1938                          "running e2fsck is recommended");
1939         if (!sbi->s_journal)
1940                 es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
1941         if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
1942                 es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
1943         le16_add_cpu(&es->s_mnt_count, 1);
1944         es->s_mtime = cpu_to_le32(get_seconds());
1945         ext4_update_dynamic_rev(sb);
1946         if (sbi->s_journal)
1947                 ext4_set_feature_journal_needs_recovery(sb);
1948
1949         ext4_commit_super(sb, 1);
1950 done:
1951         if (test_opt(sb, DEBUG))
1952                 printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
1953                                 "bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
1954                         sb->s_blocksize,
1955                         sbi->s_groups_count,
1956                         EXT4_BLOCKS_PER_GROUP(sb),
1957                         EXT4_INODES_PER_GROUP(sb),
1958                         sbi->s_mount_opt, sbi->s_mount_opt2);
1959
1960         cleancache_init_fs(sb);
1961         return res;
1962 }
1963
1964 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
1965 {
1966         struct ext4_sb_info *sbi = EXT4_SB(sb);
1967         struct flex_groups *new_groups;
1968         int size;
1969
1970         if (!sbi->s_log_groups_per_flex)
1971                 return 0;
1972
1973         size = ext4_flex_group(sbi, ngroup - 1) + 1;
1974         if (size <= sbi->s_flex_groups_allocated)
1975                 return 0;
1976
1977         size = roundup_pow_of_two(size * sizeof(struct flex_groups));
1978         new_groups = ext4_kvzalloc(size, GFP_KERNEL);
1979         if (!new_groups) {
1980                 ext4_msg(sb, KERN_ERR, "not enough memory for %d flex groups",
1981                          size / (int) sizeof(struct flex_groups));
1982                 return -ENOMEM;
1983         }
1984
1985         if (sbi->s_flex_groups) {
1986                 memcpy(new_groups, sbi->s_flex_groups,
1987                        (sbi->s_flex_groups_allocated *
1988                         sizeof(struct flex_groups)));
1989                 kvfree(sbi->s_flex_groups);
1990         }
1991         sbi->s_flex_groups = new_groups;
1992         sbi->s_flex_groups_allocated = size / sizeof(struct flex_groups);
1993         return 0;
1994 }
1995
1996 static int ext4_fill_flex_info(struct super_block *sb)
1997 {
1998         struct ext4_sb_info *sbi = EXT4_SB(sb);
1999         struct ext4_group_desc *gdp = NULL;
2000         ext4_group_t flex_group;
2001         int i, err;
2002
2003         sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
2004         if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
2005                 sbi->s_log_groups_per_flex = 0;
2006                 return 1;
2007         }
2008
2009         err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
2010         if (err)
2011                 goto failed;
2012
2013         for (i = 0; i < sbi->s_groups_count; i++) {
2014                 gdp = ext4_get_group_desc(sb, i, NULL);
2015
2016                 flex_group = ext4_flex_group(sbi, i);
2017                 atomic_add(ext4_free_inodes_count(sb, gdp),
2018                            &sbi->s_flex_groups[flex_group].free_inodes);
2019                 atomic64_add(ext4_free_group_clusters(sb, gdp),
2020                              &sbi->s_flex_groups[flex_group].free_clusters);
2021                 atomic_add(ext4_used_dirs_count(sb, gdp),
2022                            &sbi->s_flex_groups[flex_group].used_dirs);
2023         }
2024
2025         return 1;
2026 failed:
2027         return 0;
2028 }
2029
2030 static __le16 ext4_group_desc_csum(struct super_block *sb, __u32 block_group,
2031                                    struct ext4_group_desc *gdp)
2032 {
2033         int offset = offsetof(struct ext4_group_desc, bg_checksum);
2034         __u16 crc = 0;
2035         __le32 le_group = cpu_to_le32(block_group);
2036         struct ext4_sb_info *sbi = EXT4_SB(sb);
2037
2038         if (ext4_has_metadata_csum(sbi->s_sb)) {
2039                 /* Use new metadata_csum algorithm */
2040                 __u32 csum32;
2041                 __u16 dummy_csum = 0;
2042
2043                 csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
2044                                      sizeof(le_group));
2045                 csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp, offset);
2046                 csum32 = ext4_chksum(sbi, csum32, (__u8 *)&dummy_csum,
2047                                      sizeof(dummy_csum));
2048                 offset += sizeof(dummy_csum);
2049                 if (offset < sbi->s_desc_size)
2050                         csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp + offset,
2051                                              sbi->s_desc_size - offset);
2052
2053                 crc = csum32 & 0xFFFF;
2054                 goto out;
2055         }
2056
2057         /* old crc16 code */
2058         if (!ext4_has_feature_gdt_csum(sb))
2059                 return 0;
2060
2061         crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2062         crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2063         crc = crc16(crc, (__u8 *)gdp, offset);
2064         offset += sizeof(gdp->bg_checksum); /* skip checksum */
2065         /* for checksum of struct ext4_group_desc do the rest...*/
2066         if (ext4_has_feature_64bit(sb) &&
2067             offset < le16_to_cpu(sbi->s_es->s_desc_size))
2068                 crc = crc16(crc, (__u8 *)gdp + offset,
2069                             le16_to_cpu(sbi->s_es->s_desc_size) -
2070                                 offset);
2071
2072 out:
2073         return cpu_to_le16(crc);
2074 }
2075
2076 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2077                                 struct ext4_group_desc *gdp)
2078 {
2079         if (ext4_has_group_desc_csum(sb) &&
2080             (gdp->bg_checksum != ext4_group_desc_csum(sb, block_group, gdp)))
2081                 return 0;
2082
2083         return 1;
2084 }
2085
2086 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2087                               struct ext4_group_desc *gdp)
2088 {
2089         if (!ext4_has_group_desc_csum(sb))
2090                 return;
2091         gdp->bg_checksum = ext4_group_desc_csum(sb, block_group, gdp);
2092 }
2093
2094 /* Called at mount-time, super-block is locked */
2095 static int ext4_check_descriptors(struct super_block *sb,
2096                                   ext4_fsblk_t sb_block,
2097                                   ext4_group_t *first_not_zeroed)
2098 {
2099         struct ext4_sb_info *sbi = EXT4_SB(sb);
2100         ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2101         ext4_fsblk_t last_block;
2102         ext4_fsblk_t block_bitmap;
2103         ext4_fsblk_t inode_bitmap;
2104         ext4_fsblk_t inode_table;
2105         int flexbg_flag = 0;
2106         ext4_group_t i, grp = sbi->s_groups_count;
2107
2108         if (ext4_has_feature_flex_bg(sb))
2109                 flexbg_flag = 1;
2110
2111         ext4_debug("Checking group descriptors");
2112
2113         for (i = 0; i < sbi->s_groups_count; i++) {
2114                 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2115
2116                 if (i == sbi->s_groups_count - 1 || flexbg_flag)
2117                         last_block = ext4_blocks_count(sbi->s_es) - 1;
2118                 else
2119                         last_block = first_block +
2120                                 (EXT4_BLOCKS_PER_GROUP(sb) - 1);
2121
2122                 if ((grp == sbi->s_groups_count) &&
2123                    !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2124                         grp = i;
2125
2126                 block_bitmap = ext4_block_bitmap(sb, gdp);
2127                 if (block_bitmap == sb_block) {
2128                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2129                                  "Block bitmap for group %u overlaps "
2130                                  "superblock", i);
2131                 }
2132                 if (block_bitmap < first_block || block_bitmap > last_block) {
2133                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2134                                "Block bitmap for group %u not in group "
2135                                "(block %llu)!", i, block_bitmap);
2136                         return 0;
2137                 }
2138                 inode_bitmap = ext4_inode_bitmap(sb, gdp);
2139                 if (inode_bitmap == sb_block) {
2140                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2141                                  "Inode bitmap for group %u overlaps "
2142                                  "superblock", i);
2143                 }
2144                 if (inode_bitmap < first_block || inode_bitmap > last_block) {
2145                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2146                                "Inode bitmap for group %u not in group "
2147                                "(block %llu)!", i, inode_bitmap);
2148                         return 0;
2149                 }
2150                 inode_table = ext4_inode_table(sb, gdp);
2151                 if (inode_table == sb_block) {
2152                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2153                                  "Inode table for group %u overlaps "
2154                                  "superblock", i);
2155                 }
2156                 if (inode_table < first_block ||
2157                     inode_table + sbi->s_itb_per_group - 1 > last_block) {
2158                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2159                                "Inode table for group %u not in group "
2160                                "(block %llu)!", i, inode_table);
2161                         return 0;
2162                 }
2163                 ext4_lock_group(sb, i);
2164                 if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2165                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2166                                  "Checksum for group %u failed (%u!=%u)",
2167                                  i, le16_to_cpu(ext4_group_desc_csum(sb, i,
2168                                      gdp)), le16_to_cpu(gdp->bg_checksum));
2169                         if (!(sb->s_flags & MS_RDONLY)) {
2170                                 ext4_unlock_group(sb, i);
2171                                 return 0;
2172                         }
2173                 }
2174                 ext4_unlock_group(sb, i);
2175                 if (!flexbg_flag)
2176                         first_block += EXT4_BLOCKS_PER_GROUP(sb);
2177         }
2178         if (NULL != first_not_zeroed)
2179                 *first_not_zeroed = grp;
2180         return 1;
2181 }
2182
2183 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2184  * the superblock) which were deleted from all directories, but held open by
2185  * a process at the time of a crash.  We walk the list and try to delete these
2186  * inodes at recovery time (only with a read-write filesystem).
2187  *
2188  * In order to keep the orphan inode chain consistent during traversal (in
2189  * case of crash during recovery), we link each inode into the superblock
2190  * orphan list_head and handle it the same way as an inode deletion during
2191  * normal operation (which journals the operations for us).
2192  *
2193  * We only do an iget() and an iput() on each inode, which is very safe if we
2194  * accidentally point at an in-use or already deleted inode.  The worst that
2195  * can happen in this case is that we get a "bit already cleared" message from
2196  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2197  * e2fsck was run on this filesystem, and it must have already done the orphan
2198  * inode cleanup for us, so we can safely abort without any further action.
2199  */
2200 static void ext4_orphan_cleanup(struct super_block *sb,
2201                                 struct ext4_super_block *es)
2202 {
2203         unsigned int s_flags = sb->s_flags;
2204         int nr_orphans = 0, nr_truncates = 0;
2205 #ifdef CONFIG_QUOTA
2206         int i;
2207 #endif
2208         if (!es->s_last_orphan) {
2209                 jbd_debug(4, "no orphan inodes to clean up\n");
2210                 return;
2211         }
2212
2213         if (bdev_read_only(sb->s_bdev)) {
2214                 ext4_msg(sb, KERN_ERR, "write access "
2215                         "unavailable, skipping orphan cleanup");
2216                 return;
2217         }
2218
2219         /* Check if feature set would not allow a r/w mount */
2220         if (!ext4_feature_set_ok(sb, 0)) {
2221                 ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2222                          "unknown ROCOMPAT features");
2223                 return;
2224         }
2225
2226         if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2227                 /* don't clear list on RO mount w/ errors */
2228                 if (es->s_last_orphan && !(s_flags & MS_RDONLY)) {
2229                         ext4_msg(sb, KERN_INFO, "Errors on filesystem, "
2230                                   "clearing orphan list.\n");
2231                         es->s_last_orphan = 0;
2232                 }
2233                 jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2234                 return;
2235         }
2236
2237         if (s_flags & MS_RDONLY) {
2238                 ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2239                 sb->s_flags &= ~MS_RDONLY;
2240         }
2241 #ifdef CONFIG_QUOTA
2242         /* Needed for iput() to work correctly and not trash data */
2243         sb->s_flags |= MS_ACTIVE;
2244         /* Turn on quotas so that they are updated correctly */
2245         for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2246                 if (EXT4_SB(sb)->s_qf_names[i]) {
2247                         int ret = ext4_quota_on_mount(sb, i);
2248                         if (ret < 0)
2249                                 ext4_msg(sb, KERN_ERR,
2250                                         "Cannot turn on journaled "
2251                                         "quota: error %d", ret);
2252                 }
2253         }
2254 #endif
2255
2256         while (es->s_last_orphan) {
2257                 struct inode *inode;
2258
2259                 /*
2260                  * We may have encountered an error during cleanup; if
2261                  * so, skip the rest.
2262                  */
2263                 if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2264                         jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2265                         es->s_last_orphan = 0;
2266                         break;
2267                 }
2268
2269                 inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2270                 if (IS_ERR(inode)) {
2271                         es->s_last_orphan = 0;
2272                         break;
2273                 }
2274
2275                 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2276                 dquot_initialize(inode);
2277                 if (inode->i_nlink) {
2278                         if (test_opt(sb, DEBUG))
2279                                 ext4_msg(sb, KERN_DEBUG,
2280                                         "%s: truncating inode %lu to %lld bytes",
2281                                         __func__, inode->i_ino, inode->i_size);
2282                         jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2283                                   inode->i_ino, inode->i_size);
2284                         mutex_lock(&inode->i_mutex);
2285                         truncate_inode_pages(inode->i_mapping, inode->i_size);
2286                         ext4_truncate(inode);
2287                         mutex_unlock(&inode->i_mutex);
2288                         nr_truncates++;
2289                 } else {
2290                         if (test_opt(sb, DEBUG))
2291                                 ext4_msg(sb, KERN_DEBUG,
2292                                         "%s: deleting unreferenced inode %lu",
2293                                         __func__, inode->i_ino);
2294                         jbd_debug(2, "deleting unreferenced inode %lu\n",
2295                                   inode->i_ino);
2296                         nr_orphans++;
2297                 }
2298                 iput(inode);  /* The delete magic happens here! */
2299         }
2300
2301 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2302
2303         if (nr_orphans)
2304                 ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2305                        PLURAL(nr_orphans));
2306         if (nr_truncates)
2307                 ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2308                        PLURAL(nr_truncates));
2309 #ifdef CONFIG_QUOTA
2310         /* Turn quotas off */
2311         for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2312                 if (sb_dqopt(sb)->files[i])
2313                         dquot_quota_off(sb, i);
2314         }
2315 #endif
2316         sb->s_flags = s_flags; /* Restore MS_RDONLY status */
2317 }
2318
2319 /*
2320  * Maximal extent format file size.
2321  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2322  * extent format containers, within a sector_t, and within i_blocks
2323  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2324  * so that won't be a limiting factor.
2325  *
2326  * However there is other limiting factor. We do store extents in the form
2327  * of starting block and length, hence the resulting length of the extent
2328  * covering maximum file size must fit into on-disk format containers as
2329  * well. Given that length is always by 1 unit bigger than max unit (because
2330  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2331  *
2332  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2333  */
2334 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2335 {
2336         loff_t res;
2337         loff_t upper_limit = MAX_LFS_FILESIZE;
2338
2339         /* small i_blocks in vfs inode? */
2340         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2341                 /*
2342                  * CONFIG_LBDAF is not enabled implies the inode
2343                  * i_block represent total blocks in 512 bytes
2344                  * 32 == size of vfs inode i_blocks * 8
2345                  */
2346                 upper_limit = (1LL << 32) - 1;
2347
2348                 /* total blocks in file system block size */
2349                 upper_limit >>= (blkbits - 9);
2350                 upper_limit <<= blkbits;
2351         }
2352
2353         /*
2354          * 32-bit extent-start container, ee_block. We lower the maxbytes
2355          * by one fs block, so ee_len can cover the extent of maximum file
2356          * size
2357          */
2358         res = (1LL << 32) - 1;
2359         res <<= blkbits;
2360
2361         /* Sanity check against vm- & vfs- imposed limits */
2362         if (res > upper_limit)
2363                 res = upper_limit;
2364
2365         return res;
2366 }
2367
2368 /*
2369  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2370  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2371  * We need to be 1 filesystem block less than the 2^48 sector limit.
2372  */
2373 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2374 {
2375         loff_t res = EXT4_NDIR_BLOCKS;
2376         int meta_blocks;
2377         loff_t upper_limit;
2378         /* This is calculated to be the largest file size for a dense, block
2379          * mapped file such that the file's total number of 512-byte sectors,
2380          * including data and all indirect blocks, does not exceed (2^48 - 1).
2381          *
2382          * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2383          * number of 512-byte sectors of the file.
2384          */
2385
2386         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2387                 /*
2388                  * !has_huge_files or CONFIG_LBDAF not enabled implies that
2389                  * the inode i_block field represents total file blocks in
2390                  * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2391                  */
2392                 upper_limit = (1LL << 32) - 1;
2393
2394                 /* total blocks in file system block size */
2395                 upper_limit >>= (bits - 9);
2396
2397         } else {
2398                 /*
2399                  * We use 48 bit ext4_inode i_blocks
2400                  * With EXT4_HUGE_FILE_FL set the i_blocks
2401                  * represent total number of blocks in
2402                  * file system block size
2403                  */
2404                 upper_limit = (1LL << 48) - 1;
2405
2406         }
2407
2408         /* indirect blocks */
2409         meta_blocks = 1;
2410         /* double indirect blocks */
2411         meta_blocks += 1 + (1LL << (bits-2));
2412         /* tripple indirect blocks */
2413         meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2414
2415         upper_limit -= meta_blocks;
2416         upper_limit <<= bits;
2417
2418         res += 1LL << (bits-2);
2419         res += 1LL << (2*(bits-2));
2420         res += 1LL << (3*(bits-2));
2421         res <<= bits;
2422         if (res > upper_limit)
2423                 res = upper_limit;
2424
2425         if (res > MAX_LFS_FILESIZE)
2426                 res = MAX_LFS_FILESIZE;
2427
2428         return res;
2429 }
2430
2431 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2432                                    ext4_fsblk_t logical_sb_block, int nr)
2433 {
2434         struct ext4_sb_info *sbi = EXT4_SB(sb);
2435         ext4_group_t bg, first_meta_bg;
2436         int has_super = 0;
2437
2438         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2439
2440         if (!ext4_has_feature_meta_bg(sb) || nr < first_meta_bg)
2441                 return logical_sb_block + nr + 1;
2442         bg = sbi->s_desc_per_block * nr;
2443         if (ext4_bg_has_super(sb, bg))
2444                 has_super = 1;
2445
2446         /*
2447          * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
2448          * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
2449          * on modern mke2fs or blksize > 1k on older mke2fs) then we must
2450          * compensate.
2451          */
2452         if (sb->s_blocksize == 1024 && nr == 0 &&
2453             le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block) == 0)
2454                 has_super++;
2455
2456         return (has_super + ext4_group_first_block_no(sb, bg));
2457 }
2458
2459 /**
2460  * ext4_get_stripe_size: Get the stripe size.
2461  * @sbi: In memory super block info
2462  *
2463  * If we have specified it via mount option, then
2464  * use the mount option value. If the value specified at mount time is
2465  * greater than the blocks per group use the super block value.
2466  * If the super block value is greater than blocks per group return 0.
2467  * Allocator needs it be less than blocks per group.
2468  *
2469  */
2470 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2471 {
2472         unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2473         unsigned long stripe_width =
2474                         le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2475         int ret;
2476
2477         if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2478                 ret = sbi->s_stripe;
2479         else if (stripe_width <= sbi->s_blocks_per_group)
2480                 ret = stripe_width;
2481         else if (stride <= sbi->s_blocks_per_group)
2482                 ret = stride;
2483         else
2484                 ret = 0;
2485
2486         /*
2487          * If the stripe width is 1, this makes no sense and
2488          * we set it to 0 to turn off stripe handling code.
2489          */
2490         if (ret <= 1)
2491                 ret = 0;
2492
2493         return ret;
2494 }
2495
2496 /*
2497  * Check whether this filesystem can be mounted based on
2498  * the features present and the RDONLY/RDWR mount requested.
2499  * Returns 1 if this filesystem can be mounted as requested,
2500  * 0 if it cannot be.
2501  */
2502 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2503 {
2504         if (ext4_has_unknown_ext4_incompat_features(sb)) {
2505                 ext4_msg(sb, KERN_ERR,
2506                         "Couldn't mount because of "
2507                         "unsupported optional features (%x)",
2508                         (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2509                         ~EXT4_FEATURE_INCOMPAT_SUPP));
2510                 return 0;
2511         }
2512
2513         if (readonly)
2514                 return 1;
2515
2516         if (ext4_has_feature_readonly(sb)) {
2517                 ext4_msg(sb, KERN_INFO, "filesystem is read-only");
2518                 sb->s_flags |= MS_RDONLY;
2519                 return 1;
2520         }
2521
2522         /* Check that feature set is OK for a read-write mount */
2523         if (ext4_has_unknown_ext4_ro_compat_features(sb)) {
2524                 ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2525                          "unsupported optional features (%x)",
2526                          (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2527                                 ~EXT4_FEATURE_RO_COMPAT_SUPP));
2528                 return 0;
2529         }
2530         /*
2531          * Large file size enabled file system can only be mounted
2532          * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2533          */
2534         if (ext4_has_feature_huge_file(sb)) {
2535                 if (sizeof(blkcnt_t) < sizeof(u64)) {
2536                         ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2537                                  "cannot be mounted RDWR without "
2538                                  "CONFIG_LBDAF");
2539                         return 0;
2540                 }
2541         }
2542         if (ext4_has_feature_bigalloc(sb) && !ext4_has_feature_extents(sb)) {
2543                 ext4_msg(sb, KERN_ERR,
2544                          "Can't support bigalloc feature without "
2545                          "extents feature\n");
2546                 return 0;
2547         }
2548
2549 #ifndef CONFIG_QUOTA
2550         if (ext4_has_feature_quota(sb) && !readonly) {
2551                 ext4_msg(sb, KERN_ERR,
2552                          "Filesystem with quota feature cannot be mounted RDWR "
2553                          "without CONFIG_QUOTA");
2554                 return 0;
2555         }
2556 #endif  /* CONFIG_QUOTA */
2557         return 1;
2558 }
2559
2560 /*
2561  * This function is called once a day if we have errors logged
2562  * on the file system
2563  */
2564 static void print_daily_error_info(unsigned long arg)
2565 {
2566         struct super_block *sb = (struct super_block *) arg;
2567         struct ext4_sb_info *sbi;
2568         struct ext4_super_block *es;
2569
2570         sbi = EXT4_SB(sb);
2571         es = sbi->s_es;
2572
2573         if (es->s_error_count)
2574                 /* fsck newer than v1.41.13 is needed to clean this condition. */
2575                 ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
2576                          le32_to_cpu(es->s_error_count));
2577         if (es->s_first_error_time) {
2578                 printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %u: %.*s:%d",
2579                        sb->s_id, le32_to_cpu(es->s_first_error_time),
2580                        (int) sizeof(es->s_first_error_func),
2581                        es->s_first_error_func,
2582                        le32_to_cpu(es->s_first_error_line));
2583                 if (es->s_first_error_ino)
2584                         printk(": inode %u",
2585                                le32_to_cpu(es->s_first_error_ino));
2586                 if (es->s_first_error_block)
2587                         printk(": block %llu", (unsigned long long)
2588                                le64_to_cpu(es->s_first_error_block));
2589                 printk("\n");
2590         }
2591         if (es->s_last_error_time) {
2592                 printk(KERN_NOTICE "EXT4-fs (%s): last error at time %u: %.*s:%d",
2593                        sb->s_id, le32_to_cpu(es->s_last_error_time),
2594                        (int) sizeof(es->s_last_error_func),
2595                        es->s_last_error_func,
2596                        le32_to_cpu(es->s_last_error_line));
2597                 if (es->s_last_error_ino)
2598                         printk(": inode %u",
2599                                le32_to_cpu(es->s_last_error_ino));
2600                 if (es->s_last_error_block)
2601                         printk(": block %llu", (unsigned long long)
2602                                le64_to_cpu(es->s_last_error_block));
2603                 printk("\n");
2604         }
2605         mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2606 }
2607
2608 /* Find next suitable group and run ext4_init_inode_table */
2609 static int ext4_run_li_request(struct ext4_li_request *elr)
2610 {
2611         struct ext4_group_desc *gdp = NULL;
2612         ext4_group_t group, ngroups;
2613         struct super_block *sb;
2614         unsigned long timeout = 0;
2615         int ret = 0;
2616
2617         sb = elr->lr_super;
2618         ngroups = EXT4_SB(sb)->s_groups_count;
2619
2620         sb_start_write(sb);
2621         for (group = elr->lr_next_group; group < ngroups; group++) {
2622                 gdp = ext4_get_group_desc(sb, group, NULL);
2623                 if (!gdp) {
2624                         ret = 1;
2625                         break;
2626                 }
2627
2628                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2629                         break;
2630         }
2631
2632         if (group >= ngroups)
2633                 ret = 1;
2634
2635         if (!ret) {
2636                 timeout = jiffies;
2637                 ret = ext4_init_inode_table(sb, group,
2638                                             elr->lr_timeout ? 0 : 1);
2639                 if (elr->lr_timeout == 0) {
2640                         timeout = (jiffies - timeout) *
2641                                   elr->lr_sbi->s_li_wait_mult;
2642                         elr->lr_timeout = timeout;
2643                 }
2644                 elr->lr_next_sched = jiffies + elr->lr_timeout;
2645                 elr->lr_next_group = group + 1;
2646         }
2647         sb_end_write(sb);
2648
2649         return ret;
2650 }
2651
2652 /*
2653  * Remove lr_request from the list_request and free the
2654  * request structure. Should be called with li_list_mtx held
2655  */
2656 static void ext4_remove_li_request(struct ext4_li_request *elr)
2657 {
2658         struct ext4_sb_info *sbi;
2659
2660         if (!elr)
2661                 return;
2662
2663         sbi = elr->lr_sbi;
2664
2665         list_del(&elr->lr_request);
2666         sbi->s_li_request = NULL;
2667         kfree(elr);
2668 }
2669
2670 static void ext4_unregister_li_request(struct super_block *sb)
2671 {
2672         mutex_lock(&ext4_li_mtx);
2673         if (!ext4_li_info) {
2674                 mutex_unlock(&ext4_li_mtx);
2675                 return;
2676         }
2677
2678         mutex_lock(&ext4_li_info->li_list_mtx);
2679         ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
2680         mutex_unlock(&ext4_li_info->li_list_mtx);
2681         mutex_unlock(&ext4_li_mtx);
2682 }
2683
2684 static struct task_struct *ext4_lazyinit_task;
2685
2686 /*
2687  * This is the function where ext4lazyinit thread lives. It walks
2688  * through the request list searching for next scheduled filesystem.
2689  * When such a fs is found, run the lazy initialization request
2690  * (ext4_rn_li_request) and keep track of the time spend in this
2691  * function. Based on that time we compute next schedule time of
2692  * the request. When walking through the list is complete, compute
2693  * next waking time and put itself into sleep.
2694  */
2695 static int ext4_lazyinit_thread(void *arg)
2696 {
2697         struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
2698         struct list_head *pos, *n;
2699         struct ext4_li_request *elr;
2700         unsigned long next_wakeup, cur;
2701
2702         BUG_ON(NULL == eli);
2703
2704 cont_thread:
2705         while (true) {
2706                 next_wakeup = MAX_JIFFY_OFFSET;
2707
2708                 mutex_lock(&eli->li_list_mtx);
2709                 if (list_empty(&eli->li_request_list)) {
2710                         mutex_unlock(&eli->li_list_mtx);
2711                         goto exit_thread;
2712                 }
2713
2714                 list_for_each_safe(pos, n, &eli->li_request_list) {
2715                         elr = list_entry(pos, struct ext4_li_request,
2716                                          lr_request);
2717
2718                         if (time_after_eq(jiffies, elr->lr_next_sched)) {
2719                                 if (ext4_run_li_request(elr) != 0) {
2720                                         /* error, remove the lazy_init job */
2721                                         ext4_remove_li_request(elr);
2722                                         continue;
2723                                 }
2724                         }
2725
2726                         if (time_before(elr->lr_next_sched, next_wakeup))
2727                                 next_wakeup = elr->lr_next_sched;
2728                 }
2729                 mutex_unlock(&eli->li_list_mtx);
2730
2731                 try_to_freeze();
2732
2733                 cur = jiffies;
2734                 if ((time_after_eq(cur, next_wakeup)) ||
2735                     (MAX_JIFFY_OFFSET == next_wakeup)) {
2736                         cond_resched();
2737                         continue;
2738                 }
2739
2740                 schedule_timeout_interruptible(next_wakeup - cur);
2741
2742                 if (kthread_should_stop()) {
2743                         ext4_clear_request_list();
2744                         goto exit_thread;
2745                 }
2746         }
2747
2748 exit_thread:
2749         /*
2750          * It looks like the request list is empty, but we need
2751          * to check it under the li_list_mtx lock, to prevent any
2752          * additions into it, and of course we should lock ext4_li_mtx
2753          * to atomically free the list and ext4_li_info, because at
2754          * this point another ext4 filesystem could be registering
2755          * new one.
2756          */
2757         mutex_lock(&ext4_li_mtx);
2758         mutex_lock(&eli->li_list_mtx);
2759         if (!list_empty(&eli->li_request_list)) {
2760                 mutex_unlock(&eli->li_list_mtx);
2761                 mutex_unlock(&ext4_li_mtx);
2762                 goto cont_thread;
2763         }
2764         mutex_unlock(&eli->li_list_mtx);
2765         kfree(ext4_li_info);
2766         ext4_li_info = NULL;
2767         mutex_unlock(&ext4_li_mtx);
2768
2769         return 0;
2770 }
2771
2772 static void ext4_clear_request_list(void)
2773 {
2774         struct list_head *pos, *n;
2775         struct ext4_li_request *elr;
2776
2777         mutex_lock(&ext4_li_info->li_list_mtx);
2778         list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
2779                 elr = list_entry(pos, struct ext4_li_request,
2780                                  lr_request);
2781                 ext4_remove_li_request(elr);
2782         }
2783         mutex_unlock(&ext4_li_info->li_list_mtx);
2784 }
2785
2786 static int ext4_run_lazyinit_thread(void)
2787 {
2788         ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
2789                                          ext4_li_info, "ext4lazyinit");
2790         if (IS_ERR(ext4_lazyinit_task)) {
2791                 int err = PTR_ERR(ext4_lazyinit_task);
2792                 ext4_clear_request_list();
2793                 kfree(ext4_li_info);
2794                 ext4_li_info = NULL;
2795                 printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
2796                                  "initialization thread\n",
2797                                  err);
2798                 return err;
2799         }
2800         ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
2801         return 0;
2802 }
2803
2804 /*
2805  * Check whether it make sense to run itable init. thread or not.
2806  * If there is at least one uninitialized inode table, return
2807  * corresponding group number, else the loop goes through all
2808  * groups and return total number of groups.
2809  */
2810 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
2811 {
2812         ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
2813         struct ext4_group_desc *gdp = NULL;
2814
2815         for (group = 0; group < ngroups; group++) {
2816                 gdp = ext4_get_group_desc(sb, group, NULL);
2817                 if (!gdp)
2818                         continue;
2819
2820                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2821                         break;
2822         }
2823
2824         return group;
2825 }
2826
2827 static int ext4_li_info_new(void)
2828 {
2829         struct ext4_lazy_init *eli = NULL;
2830
2831         eli = kzalloc(sizeof(*eli), GFP_KERNEL);
2832         if (!eli)
2833                 return -ENOMEM;
2834
2835         INIT_LIST_HEAD(&eli->li_request_list);
2836         mutex_init(&eli->li_list_mtx);
2837
2838         eli->li_state |= EXT4_LAZYINIT_QUIT;
2839
2840         ext4_li_info = eli;
2841
2842         return 0;
2843 }
2844
2845 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
2846                                             ext4_group_t start)
2847 {
2848         struct ext4_sb_info *sbi = EXT4_SB(sb);
2849         struct ext4_li_request *elr;
2850
2851         elr = kzalloc(sizeof(*elr), GFP_KERNEL);
2852         if (!elr)
2853                 return NULL;
2854
2855         elr->lr_super = sb;
2856         elr->lr_sbi = sbi;
2857         elr->lr_next_group = start;
2858
2859         /*
2860          * Randomize first schedule time of the request to
2861          * spread the inode table initialization requests
2862          * better.
2863          */
2864         elr->lr_next_sched = jiffies + (prandom_u32() %
2865                                 (EXT4_DEF_LI_MAX_START_DELAY * HZ));
2866         return elr;
2867 }
2868
2869 int ext4_register_li_request(struct super_block *sb,
2870                              ext4_group_t first_not_zeroed)
2871 {
2872         struct ext4_sb_info *sbi = EXT4_SB(sb);
2873         struct ext4_li_request *elr = NULL;
2874         ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
2875         int ret = 0;
2876
2877         mutex_lock(&ext4_li_mtx);
2878         if (sbi->s_li_request != NULL) {
2879                 /*
2880                  * Reset timeout so it can be computed again, because
2881                  * s_li_wait_mult might have changed.
2882                  */
2883                 sbi->s_li_request->lr_timeout = 0;
2884                 goto out;
2885         }
2886
2887         if (first_not_zeroed == ngroups ||
2888             (sb->s_flags & MS_RDONLY) ||
2889             !test_opt(sb, INIT_INODE_TABLE))
2890                 goto out;
2891
2892         elr = ext4_li_request_new(sb, first_not_zeroed);
2893         if (!elr) {
2894                 ret = -ENOMEM;
2895                 goto out;
2896         }
2897
2898         if (NULL == ext4_li_info) {
2899                 ret = ext4_li_info_new();
2900                 if (ret)
2901                         goto out;
2902         }
2903
2904         mutex_lock(&ext4_li_info->li_list_mtx);
2905         list_add(&elr->lr_request, &ext4_li_info->li_request_list);
2906         mutex_unlock(&ext4_li_info->li_list_mtx);
2907
2908         sbi->s_li_request = elr;
2909         /*
2910          * set elr to NULL here since it has been inserted to
2911          * the request_list and the removal and free of it is
2912          * handled by ext4_clear_request_list from now on.
2913          */
2914         elr = NULL;
2915
2916         if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
2917                 ret = ext4_run_lazyinit_thread();
2918                 if (ret)
2919                         goto out;
2920         }
2921 out:
2922         mutex_unlock(&ext4_li_mtx);
2923         if (ret)
2924                 kfree(elr);
2925         return ret;
2926 }
2927
2928 /*
2929  * We do not need to lock anything since this is called on
2930  * module unload.
2931  */
2932 static void ext4_destroy_lazyinit_thread(void)
2933 {
2934         /*
2935          * If thread exited earlier
2936          * there's nothing to be done.
2937          */
2938         if (!ext4_li_info || !ext4_lazyinit_task)
2939                 return;
2940
2941         kthread_stop(ext4_lazyinit_task);
2942 }
2943
2944 static int set_journal_csum_feature_set(struct super_block *sb)
2945 {
2946         int ret = 1;
2947         int compat, incompat;
2948         struct ext4_sb_info *sbi = EXT4_SB(sb);
2949
2950         if (ext4_has_metadata_csum(sb)) {
2951                 /* journal checksum v3 */
2952                 compat = 0;
2953                 incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
2954         } else {
2955                 /* journal checksum v1 */
2956                 compat = JBD2_FEATURE_COMPAT_CHECKSUM;
2957                 incompat = 0;
2958         }
2959
2960         jbd2_journal_clear_features(sbi->s_journal,
2961                         JBD2_FEATURE_COMPAT_CHECKSUM, 0,
2962                         JBD2_FEATURE_INCOMPAT_CSUM_V3 |
2963                         JBD2_FEATURE_INCOMPAT_CSUM_V2);
2964         if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
2965                 ret = jbd2_journal_set_features(sbi->s_journal,
2966                                 compat, 0,
2967                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
2968                                 incompat);
2969         } else if (test_opt(sb, JOURNAL_CHECKSUM)) {
2970                 ret = jbd2_journal_set_features(sbi->s_journal,
2971                                 compat, 0,
2972                                 incompat);
2973                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
2974                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
2975         } else {
2976                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
2977                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
2978         }
2979
2980         return ret;
2981 }
2982
2983 /*
2984  * Note: calculating the overhead so we can be compatible with
2985  * historical BSD practice is quite difficult in the face of
2986  * clusters/bigalloc.  This is because multiple metadata blocks from
2987  * different block group can end up in the same allocation cluster.
2988  * Calculating the exact overhead in the face of clustered allocation
2989  * requires either O(all block bitmaps) in memory or O(number of block
2990  * groups**2) in time.  We will still calculate the superblock for
2991  * older file systems --- and if we come across with a bigalloc file
2992  * system with zero in s_overhead_clusters the estimate will be close to
2993  * correct especially for very large cluster sizes --- but for newer
2994  * file systems, it's better to calculate this figure once at mkfs
2995  * time, and store it in the superblock.  If the superblock value is
2996  * present (even for non-bigalloc file systems), we will use it.
2997  */
2998 static int count_overhead(struct super_block *sb, ext4_group_t grp,
2999                           char *buf)
3000 {
3001         struct ext4_sb_info     *sbi = EXT4_SB(sb);
3002         struct ext4_group_desc  *gdp;
3003         ext4_fsblk_t            first_block, last_block, b;
3004         ext4_group_t            i, ngroups = ext4_get_groups_count(sb);
3005         int                     s, j, count = 0;
3006
3007         if (!ext4_has_feature_bigalloc(sb))
3008                 return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3009                         sbi->s_itb_per_group + 2);
3010
3011         first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3012                 (grp * EXT4_BLOCKS_PER_GROUP(sb));
3013         last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3014         for (i = 0; i < ngroups; i++) {
3015                 gdp = ext4_get_group_desc(sb, i, NULL);
3016                 b = ext4_block_bitmap(sb, gdp);
3017                 if (b >= first_block && b <= last_block) {
3018                         ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3019                         count++;
3020                 }
3021                 b = ext4_inode_bitmap(sb, gdp);
3022                 if (b >= first_block && b <= last_block) {
3023                         ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3024                         count++;
3025                 }
3026                 b = ext4_inode_table(sb, gdp);
3027                 if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3028                         for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3029                                 int c = EXT4_B2C(sbi, b - first_block);
3030                                 ext4_set_bit(c, buf);
3031                                 count++;
3032                         }
3033                 if (i != grp)
3034                         continue;
3035                 s = 0;
3036                 if (ext4_bg_has_super(sb, grp)) {
3037                         ext4_set_bit(s++, buf);
3038                         count++;
3039                 }
3040                 j = ext4_bg_num_gdb(sb, grp);
3041                 if (s + j > EXT4_BLOCKS_PER_GROUP(sb)) {
3042                         ext4_error(sb, "Invalid number of block group "
3043                                    "descriptor blocks: %d", j);
3044                         j = EXT4_BLOCKS_PER_GROUP(sb) - s;
3045                 }
3046                 count += j;
3047                 for (; j > 0; j--)
3048                         ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3049         }
3050         if (!count)
3051                 return 0;
3052         return EXT4_CLUSTERS_PER_GROUP(sb) -
3053                 ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3054 }
3055
3056 /*
3057  * Compute the overhead and stash it in sbi->s_overhead
3058  */
3059 int ext4_calculate_overhead(struct super_block *sb)
3060 {
3061         struct ext4_sb_info *sbi = EXT4_SB(sb);
3062         struct ext4_super_block *es = sbi->s_es;
3063         ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3064         ext4_fsblk_t overhead = 0;
3065         char *buf = (char *) get_zeroed_page(GFP_NOFS);
3066
3067         if (!buf)
3068                 return -ENOMEM;
3069
3070         /*
3071          * Compute the overhead (FS structures).  This is constant
3072          * for a given filesystem unless the number of block groups
3073          * changes so we cache the previous value until it does.
3074          */
3075
3076         /*
3077          * All of the blocks before first_data_block are overhead
3078          */
3079         overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3080
3081         /*
3082          * Add the overhead found in each block group
3083          */
3084         for (i = 0; i < ngroups; i++) {
3085                 int blks;
3086
3087                 blks = count_overhead(sb, i, buf);
3088                 overhead += blks;
3089                 if (blks)
3090                         memset(buf, 0, PAGE_SIZE);
3091                 cond_resched();
3092         }
3093         /* Add the internal journal blocks as well */
3094         if (sbi->s_journal && !sbi->journal_bdev)
3095                 overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_maxlen);
3096
3097         sbi->s_overhead = overhead;
3098         smp_wmb();
3099         free_page((unsigned long) buf);
3100         return 0;
3101 }
3102
3103 static void ext4_set_resv_clusters(struct super_block *sb)
3104 {
3105         ext4_fsblk_t resv_clusters;
3106         struct ext4_sb_info *sbi = EXT4_SB(sb);
3107
3108         /*
3109          * There's no need to reserve anything when we aren't using extents.
3110          * The space estimates are exact, there are no unwritten extents,
3111          * hole punching doesn't need new metadata... This is needed especially
3112          * to keep ext2/3 backward compatibility.
3113          */
3114         if (!ext4_has_feature_extents(sb))
3115                 return;
3116         /*
3117          * By default we reserve 2% or 4096 clusters, whichever is smaller.
3118          * This should cover the situations where we can not afford to run
3119          * out of space like for example punch hole, or converting
3120          * unwritten extents in delalloc path. In most cases such
3121          * allocation would require 1, or 2 blocks, higher numbers are
3122          * very rare.
3123          */
3124         resv_clusters = (ext4_blocks_count(sbi->s_es) >>
3125                          sbi->s_cluster_bits);
3126
3127         do_div(resv_clusters, 50);
3128         resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
3129
3130         atomic64_set(&sbi->s_resv_clusters, resv_clusters);
3131 }
3132
3133 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3134 {
3135         char *orig_data = kstrdup(data, GFP_KERNEL);
3136         struct buffer_head *bh;
3137         struct ext4_super_block *es = NULL;
3138         struct ext4_sb_info *sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3139         ext4_fsblk_t block;
3140         ext4_fsblk_t sb_block = get_sb_block(&data);
3141         ext4_fsblk_t logical_sb_block;
3142         unsigned long offset = 0;
3143         unsigned long journal_devnum = 0;
3144         unsigned long def_mount_opts;
3145         struct inode *root;
3146         const char *descr;
3147         int ret = -ENOMEM;
3148         int blocksize, clustersize;
3149         unsigned int db_count;
3150         unsigned int i;
3151         int needs_recovery, has_huge_files, has_bigalloc;
3152         __u64 blocks_count;
3153         int err = 0;
3154         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3155         ext4_group_t first_not_zeroed;
3156
3157         if ((data && !orig_data) || !sbi)
3158                 goto out_free_base;
3159
3160         sbi->s_blockgroup_lock =
3161                 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3162         if (!sbi->s_blockgroup_lock)
3163                 goto out_free_base;
3164
3165         sb->s_fs_info = sbi;
3166         sbi->s_sb = sb;
3167         sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3168         sbi->s_sb_block = sb_block;
3169         if (sb->s_bdev->bd_part)
3170                 sbi->s_sectors_written_start =
3171                         part_stat_read(sb->s_bdev->bd_part, sectors[1]);
3172
3173         /* Cleanup superblock name */
3174         strreplace(sb->s_id, '/', '!');
3175
3176         /* -EINVAL is default */
3177         ret = -EINVAL;
3178         blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3179         if (!blocksize) {
3180                 ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3181                 goto out_fail;
3182         }
3183
3184         /*
3185          * The ext4 superblock will not be buffer aligned for other than 1kB
3186          * block sizes.  We need to calculate the offset from buffer start.
3187          */
3188         if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3189                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3190                 offset = do_div(logical_sb_block, blocksize);
3191         } else {
3192                 logical_sb_block = sb_block;
3193         }
3194
3195         if (!(bh = sb_bread_unmovable(sb, logical_sb_block))) {
3196                 ext4_msg(sb, KERN_ERR, "unable to read superblock");
3197                 goto out_fail;
3198         }
3199         /*
3200          * Note: s_es must be initialized as soon as possible because
3201          *       some ext4 macro-instructions depend on its value
3202          */
3203         es = (struct ext4_super_block *) (bh->b_data + offset);
3204         sbi->s_es = es;
3205         sb->s_magic = le16_to_cpu(es->s_magic);
3206         if (sb->s_magic != EXT4_SUPER_MAGIC)
3207                 goto cantfind_ext4;
3208         sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3209
3210         /* Warn if metadata_csum and gdt_csum are both set. */
3211         if (ext4_has_feature_metadata_csum(sb) &&
3212             ext4_has_feature_gdt_csum(sb))
3213                 ext4_warning(sb, "metadata_csum and uninit_bg are "
3214                              "redundant flags; please run fsck.");
3215
3216         /* Check for a known checksum algorithm */
3217         if (!ext4_verify_csum_type(sb, es)) {
3218                 ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3219                          "unknown checksum algorithm.");
3220                 silent = 1;
3221                 goto cantfind_ext4;
3222         }
3223
3224         /* Load the checksum driver */
3225         if (ext4_has_feature_metadata_csum(sb)) {
3226                 sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3227                 if (IS_ERR(sbi->s_chksum_driver)) {
3228                         ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3229                         ret = PTR_ERR(sbi->s_chksum_driver);
3230                         sbi->s_chksum_driver = NULL;
3231                         goto failed_mount;
3232                 }
3233         }
3234
3235         /* Check superblock checksum */
3236         if (!ext4_superblock_csum_verify(sb, es)) {
3237                 ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3238                          "invalid superblock checksum.  Run e2fsck?");
3239                 silent = 1;
3240                 ret = -EFSBADCRC;
3241                 goto cantfind_ext4;
3242         }
3243
3244         /* Precompute checksum seed for all metadata */
3245         if (ext4_has_feature_csum_seed(sb))
3246                 sbi->s_csum_seed = le32_to_cpu(es->s_checksum_seed);
3247         else if (ext4_has_metadata_csum(sb))
3248                 sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3249                                                sizeof(es->s_uuid));
3250
3251         /* Set defaults before we parse the mount options */
3252         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3253         set_opt(sb, INIT_INODE_TABLE);
3254         if (def_mount_opts & EXT4_DEFM_DEBUG)
3255                 set_opt(sb, DEBUG);
3256         if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3257                 set_opt(sb, GRPID);
3258         if (def_mount_opts & EXT4_DEFM_UID16)
3259                 set_opt(sb, NO_UID32);
3260         /* xattr user namespace & acls are now defaulted on */
3261         set_opt(sb, XATTR_USER);
3262 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3263         set_opt(sb, POSIX_ACL);
3264 #endif
3265         /* don't forget to enable journal_csum when metadata_csum is enabled. */
3266         if (ext4_has_metadata_csum(sb))
3267                 set_opt(sb, JOURNAL_CHECKSUM);
3268
3269         if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3270                 set_opt(sb, JOURNAL_DATA);
3271         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3272                 set_opt(sb, ORDERED_DATA);
3273         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3274                 set_opt(sb, WRITEBACK_DATA);
3275
3276         if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3277                 set_opt(sb, ERRORS_PANIC);
3278         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3279                 set_opt(sb, ERRORS_CONT);
3280         else
3281                 set_opt(sb, ERRORS_RO);
3282         /* block_validity enabled by default; disable with noblock_validity */
3283         set_opt(sb, BLOCK_VALIDITY);
3284         if (def_mount_opts & EXT4_DEFM_DISCARD)
3285                 set_opt(sb, DISCARD);
3286
3287         sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3288         sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3289         sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3290         sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3291         sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3292
3293         if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3294                 set_opt(sb, BARRIER);
3295
3296         /*
3297          * enable delayed allocation by default
3298          * Use -o nodelalloc to turn it off
3299          */
3300         if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
3301             ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3302                 set_opt(sb, DELALLOC);
3303
3304         /*
3305          * set default s_li_wait_mult for lazyinit, for the case there is
3306          * no mount option specified.
3307          */
3308         sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3309
3310         if (sbi->s_es->s_mount_opts[0]) {
3311                 char *s_mount_opts = kstrndup(sbi->s_es->s_mount_opts,
3312                                               sizeof(sbi->s_es->s_mount_opts),
3313                                               GFP_KERNEL);
3314                 if (!s_mount_opts)
3315                         goto failed_mount;
3316                 if (!parse_options(s_mount_opts, sb, &journal_devnum,
3317                                    &journal_ioprio, 0)) {
3318                         ext4_msg(sb, KERN_WARNING,
3319                                  "failed to parse options in superblock: %s",
3320                                  s_mount_opts);
3321                 }
3322                 kfree(s_mount_opts);
3323         }
3324         sbi->s_def_mount_opt = sbi->s_mount_opt;
3325         if (!parse_options((char *) data, sb, &journal_devnum,
3326                            &journal_ioprio, 0))
3327                 goto failed_mount;
3328
3329         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3330                 printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3331                             "with data=journal disables delayed "
3332                             "allocation and O_DIRECT support!\n");
3333                 if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3334                         ext4_msg(sb, KERN_ERR, "can't mount with "
3335                                  "both data=journal and delalloc");
3336                         goto failed_mount;
3337                 }
3338                 if (test_opt(sb, DIOREAD_NOLOCK)) {
3339                         ext4_msg(sb, KERN_ERR, "can't mount with "
3340                                  "both data=journal and dioread_nolock");
3341                         goto failed_mount;
3342                 }
3343                 if (test_opt(sb, DAX)) {
3344                         ext4_msg(sb, KERN_ERR, "can't mount with "
3345                                  "both data=journal and dax");
3346                         goto failed_mount;
3347                 }
3348                 if (ext4_has_feature_encrypt(sb)) {
3349                         ext4_msg(sb, KERN_WARNING,
3350                                  "encrypted files will use data=ordered "
3351                                  "instead of data journaling mode");
3352                 }
3353                 if (test_opt(sb, DELALLOC))
3354                         clear_opt(sb, DELALLOC);
3355         } else {
3356                 sb->s_iflags |= SB_I_CGROUPWB;
3357         }
3358
3359         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
3360                 (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
3361
3362         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3363             (ext4_has_compat_features(sb) ||
3364              ext4_has_ro_compat_features(sb) ||
3365              ext4_has_incompat_features(sb)))
3366                 ext4_msg(sb, KERN_WARNING,
3367                        "feature flags set on rev 0 fs, "
3368                        "running e2fsck is recommended");
3369
3370         if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
3371                 set_opt2(sb, HURD_COMPAT);
3372                 if (ext4_has_feature_64bit(sb)) {
3373                         ext4_msg(sb, KERN_ERR,
3374                                  "The Hurd can't support 64-bit file systems");
3375                         goto failed_mount;
3376                 }
3377         }
3378
3379         if (IS_EXT2_SB(sb)) {
3380                 if (ext2_feature_set_ok(sb))
3381                         ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3382                                  "using the ext4 subsystem");
3383                 else {
3384                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3385                                  "to feature incompatibilities");
3386                         goto failed_mount;
3387                 }
3388         }
3389
3390         if (IS_EXT3_SB(sb)) {
3391                 if (ext3_feature_set_ok(sb))
3392                         ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3393                                  "using the ext4 subsystem");
3394                 else {
3395                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3396                                  "to feature incompatibilities");
3397                         goto failed_mount;
3398                 }
3399         }
3400
3401         /*
3402          * Check feature flags regardless of the revision level, since we
3403          * previously didn't change the revision level when setting the flags,
3404          * so there is a chance incompat flags are set on a rev 0 filesystem.
3405          */
3406         if (!ext4_feature_set_ok(sb, (sb->s_flags & MS_RDONLY)))
3407                 goto failed_mount;
3408
3409         blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3410         if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3411             blocksize > EXT4_MAX_BLOCK_SIZE) {
3412                 ext4_msg(sb, KERN_ERR,
3413                        "Unsupported filesystem blocksize %d (%d log_block_size)",
3414                          blocksize, le32_to_cpu(es->s_log_block_size));
3415                 goto failed_mount;
3416         }
3417         if (le32_to_cpu(es->s_log_block_size) >
3418             (EXT4_MAX_BLOCK_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
3419                 ext4_msg(sb, KERN_ERR,
3420                          "Invalid log block size: %u",
3421                          le32_to_cpu(es->s_log_block_size));
3422                 goto failed_mount;
3423         }
3424
3425         if (le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) > (blocksize / 4)) {
3426                 ext4_msg(sb, KERN_ERR,
3427                          "Number of reserved GDT blocks insanely large: %d",
3428                          le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks));
3429                 goto failed_mount;
3430         }
3431
3432         if (sbi->s_mount_opt & EXT4_MOUNT_DAX) {
3433                 if (blocksize != PAGE_SIZE) {
3434                         ext4_msg(sb, KERN_ERR,
3435                                         "error: unsupported blocksize for dax");
3436                         goto failed_mount;
3437                 }
3438                 if (!sb->s_bdev->bd_disk->fops->direct_access) {
3439                         ext4_msg(sb, KERN_ERR,
3440                                         "error: device does not support dax");
3441                         goto failed_mount;
3442                 }
3443         }
3444
3445         if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) {
3446                 ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
3447                          es->s_encryption_level);
3448                 goto failed_mount;
3449         }
3450
3451         if (sb->s_blocksize != blocksize) {
3452                 /* Validate the filesystem blocksize */
3453                 if (!sb_set_blocksize(sb, blocksize)) {
3454                         ext4_msg(sb, KERN_ERR, "bad block size %d",
3455                                         blocksize);
3456                         goto failed_mount;
3457                 }
3458
3459                 brelse(bh);
3460                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3461                 offset = do_div(logical_sb_block, blocksize);
3462                 bh = sb_bread_unmovable(sb, logical_sb_block);
3463                 if (!bh) {
3464                         ext4_msg(sb, KERN_ERR,
3465                                "Can't read superblock on 2nd try");
3466                         goto failed_mount;
3467                 }
3468                 es = (struct ext4_super_block *)(bh->b_data + offset);
3469                 sbi->s_es = es;
3470                 if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
3471                         ext4_msg(sb, KERN_ERR,
3472                                "Magic mismatch, very weird!");
3473                         goto failed_mount;
3474                 }
3475         }
3476
3477         has_huge_files = ext4_has_feature_huge_file(sb);
3478         sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
3479                                                       has_huge_files);
3480         sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
3481
3482         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3483                 sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3484                 sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3485         } else {
3486                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3487                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3488                 if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3489                     (!is_power_of_2(sbi->s_inode_size)) ||
3490                     (sbi->s_inode_size > blocksize)) {
3491                         ext4_msg(sb, KERN_ERR,
3492                                "unsupported inode size: %d",
3493                                sbi->s_inode_size);
3494                         goto failed_mount;
3495                 }
3496                 if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
3497                         sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
3498         }
3499
3500         sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
3501         if (ext4_has_feature_64bit(sb)) {
3502                 if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
3503                     sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
3504                     !is_power_of_2(sbi->s_desc_size)) {
3505                         ext4_msg(sb, KERN_ERR,
3506                                "unsupported descriptor size %lu",
3507                                sbi->s_desc_size);
3508                         goto failed_mount;
3509                 }
3510         } else
3511                 sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
3512
3513         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
3514         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
3515
3516         sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
3517         if (sbi->s_inodes_per_block == 0)
3518                 goto cantfind_ext4;
3519         if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
3520             sbi->s_inodes_per_group > blocksize * 8) {
3521                 ext4_msg(sb, KERN_ERR, "invalid inodes per group: %lu\n",
3522                          sbi->s_blocks_per_group);
3523                 goto failed_mount;
3524         }
3525         sbi->s_itb_per_group = sbi->s_inodes_per_group /
3526                                         sbi->s_inodes_per_block;
3527         sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
3528         sbi->s_sbh = bh;
3529         sbi->s_mount_state = le16_to_cpu(es->s_state);
3530         sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
3531         sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
3532
3533         for (i = 0; i < 4; i++)
3534                 sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
3535         sbi->s_def_hash_version = es->s_def_hash_version;
3536         if (ext4_has_feature_dir_index(sb)) {
3537                 i = le32_to_cpu(es->s_flags);
3538                 if (i & EXT2_FLAGS_UNSIGNED_HASH)
3539                         sbi->s_hash_unsigned = 3;
3540                 else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
3541 #ifdef __CHAR_UNSIGNED__
3542                         if (!(sb->s_flags & MS_RDONLY))
3543                                 es->s_flags |=
3544                                         cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
3545                         sbi->s_hash_unsigned = 3;
3546 #else
3547                         if (!(sb->s_flags & MS_RDONLY))
3548                                 es->s_flags |=
3549                                         cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
3550 #endif
3551                 }
3552         }
3553
3554         /* Handle clustersize */
3555         clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
3556         has_bigalloc = ext4_has_feature_bigalloc(sb);
3557         if (has_bigalloc) {
3558                 if (clustersize < blocksize) {
3559                         ext4_msg(sb, KERN_ERR,
3560                                  "cluster size (%d) smaller than "
3561                                  "block size (%d)", clustersize, blocksize);
3562                         goto failed_mount;
3563                 }
3564                 if (le32_to_cpu(es->s_log_cluster_size) >
3565                     (EXT4_MAX_CLUSTER_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
3566                         ext4_msg(sb, KERN_ERR,
3567                                  "Invalid log cluster size: %u",
3568                                  le32_to_cpu(es->s_log_cluster_size));
3569                         goto failed_mount;
3570                 }
3571                 sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
3572                         le32_to_cpu(es->s_log_block_size);
3573                 sbi->s_clusters_per_group =
3574                         le32_to_cpu(es->s_clusters_per_group);
3575                 if (sbi->s_clusters_per_group > blocksize * 8) {
3576                         ext4_msg(sb, KERN_ERR,
3577                                  "#clusters per group too big: %lu",
3578                                  sbi->s_clusters_per_group);
3579                         goto failed_mount;
3580                 }
3581                 if (sbi->s_blocks_per_group !=
3582                     (sbi->s_clusters_per_group * (clustersize / blocksize))) {
3583                         ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
3584                                  "clusters per group (%lu) inconsistent",
3585                                  sbi->s_blocks_per_group,
3586                                  sbi->s_clusters_per_group);
3587                         goto failed_mount;
3588                 }
3589         } else {
3590                 if (clustersize != blocksize) {
3591                         ext4_warning(sb, "fragment/cluster size (%d) != "
3592                                      "block size (%d)", clustersize,
3593                                      blocksize);
3594                         clustersize = blocksize;
3595                 }
3596                 if (sbi->s_blocks_per_group > blocksize * 8) {
3597                         ext4_msg(sb, KERN_ERR,
3598                                  "#blocks per group too big: %lu",
3599                                  sbi->s_blocks_per_group);
3600                         goto failed_mount;
3601                 }
3602                 sbi->s_clusters_per_group = sbi->s_blocks_per_group;
3603                 sbi->s_cluster_bits = 0;
3604         }
3605         sbi->s_cluster_ratio = clustersize / blocksize;
3606
3607         /* Do we have standard group size of clustersize * 8 blocks ? */
3608         if (sbi->s_blocks_per_group == clustersize << 3)
3609                 set_opt2(sb, STD_GROUP_SIZE);
3610
3611         /*
3612          * Test whether we have more sectors than will fit in sector_t,
3613          * and whether the max offset is addressable by the page cache.
3614          */
3615         err = generic_check_addressable(sb->s_blocksize_bits,
3616                                         ext4_blocks_count(es));
3617         if (err) {
3618                 ext4_msg(sb, KERN_ERR, "filesystem"
3619                          " too large to mount safely on this system");
3620                 if (sizeof(sector_t) < 8)
3621                         ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
3622                 goto failed_mount;
3623         }
3624
3625         if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
3626                 goto cantfind_ext4;
3627
3628         /* check blocks count against device size */
3629         blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
3630         if (blocks_count && ext4_blocks_count(es) > blocks_count) {
3631                 ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
3632                        "exceeds size of device (%llu blocks)",
3633                        ext4_blocks_count(es), blocks_count);
3634                 goto failed_mount;
3635         }
3636
3637         /*
3638          * It makes no sense for the first data block to be beyond the end
3639          * of the filesystem.
3640          */
3641         if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
3642                 ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
3643                          "block %u is beyond end of filesystem (%llu)",
3644                          le32_to_cpu(es->s_first_data_block),
3645                          ext4_blocks_count(es));
3646                 goto failed_mount;
3647         }
3648         blocks_count = (ext4_blocks_count(es) -
3649                         le32_to_cpu(es->s_first_data_block) +
3650                         EXT4_BLOCKS_PER_GROUP(sb) - 1);
3651         do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
3652         if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
3653                 ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
3654                        "(block count %llu, first data block %u, "
3655                        "blocks per group %lu)", sbi->s_groups_count,
3656                        ext4_blocks_count(es),
3657                        le32_to_cpu(es->s_first_data_block),
3658                        EXT4_BLOCKS_PER_GROUP(sb));
3659                 goto failed_mount;
3660         }
3661         sbi->s_groups_count = blocks_count;
3662         sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
3663                         (EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
3664         db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
3665                    EXT4_DESC_PER_BLOCK(sb);
3666         if (ext4_has_feature_meta_bg(sb)) {
3667                 if (le32_to_cpu(es->s_first_meta_bg) >= db_count) {
3668                         ext4_msg(sb, KERN_WARNING,
3669                                  "first meta block group too large: %u "
3670                                  "(group descriptor block count %u)",
3671                                  le32_to_cpu(es->s_first_meta_bg), db_count);
3672                         goto failed_mount;
3673                 }
3674         }
3675         sbi->s_group_desc = ext4_kvmalloc(db_count *
3676                                           sizeof(struct buffer_head *),
3677                                           GFP_KERNEL);
3678         if (sbi->s_group_desc == NULL) {
3679                 ext4_msg(sb, KERN_ERR, "not enough memory");
3680                 ret = -ENOMEM;
3681                 goto failed_mount;
3682         }
3683
3684         bgl_lock_init(sbi->s_blockgroup_lock);
3685
3686         for (i = 0; i < db_count; i++) {
3687                 block = descriptor_loc(sb, logical_sb_block, i);
3688                 sbi->s_group_desc[i] = sb_bread_unmovable(sb, block);
3689                 if (!sbi->s_group_desc[i]) {
3690                         ext4_msg(sb, KERN_ERR,
3691                                "can't read group descriptor %d", i);
3692                         db_count = i;
3693                         goto failed_mount2;
3694                 }
3695         }
3696         if (!ext4_check_descriptors(sb, logical_sb_block, &first_not_zeroed)) {
3697                 ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
3698                 ret = -EFSCORRUPTED;
3699                 goto failed_mount2;
3700         }
3701
3702         sbi->s_gdb_count = db_count;
3703         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
3704         spin_lock_init(&sbi->s_next_gen_lock);
3705
3706         setup_timer(&sbi->s_err_report, print_daily_error_info,
3707                 (unsigned long) sb);
3708
3709         /* Register extent status tree shrinker */
3710         if (ext4_es_register_shrinker(sbi))
3711                 goto failed_mount3;
3712
3713         sbi->s_stripe = ext4_get_stripe_size(sbi);
3714         sbi->s_extent_max_zeroout_kb = 32;
3715
3716         /*
3717          * set up enough so that it can read an inode
3718          */
3719         sb->s_op = &ext4_sops;
3720         sb->s_export_op = &ext4_export_ops;
3721         sb->s_xattr = ext4_xattr_handlers;
3722 #ifdef CONFIG_QUOTA
3723         sb->dq_op = &ext4_quota_operations;
3724         if (ext4_has_feature_quota(sb))
3725                 sb->s_qcop = &dquot_quotactl_sysfile_ops;
3726         else
3727                 sb->s_qcop = &ext4_qctl_operations;
3728         sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP;
3729 #endif
3730         memcpy(sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
3731
3732         INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
3733         mutex_init(&sbi->s_orphan_lock);
3734
3735         sb->s_root = NULL;
3736
3737         needs_recovery = (es->s_last_orphan != 0 ||
3738                           ext4_has_feature_journal_needs_recovery(sb));
3739
3740         if (ext4_has_feature_mmp(sb) && !(sb->s_flags & MS_RDONLY))
3741                 if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
3742                         goto failed_mount3a;
3743
3744         /*
3745          * The first inode we look at is the journal inode.  Don't try
3746          * root first: it may be modified in the journal!
3747          */
3748         if (!test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) {
3749                 if (ext4_load_journal(sb, es, journal_devnum))
3750                         goto failed_mount3a;
3751         } else if (test_opt(sb, NOLOAD) && !(sb->s_flags & MS_RDONLY) &&
3752                    ext4_has_feature_journal_needs_recovery(sb)) {
3753                 ext4_msg(sb, KERN_ERR, "required journal recovery "
3754                        "suppressed and not mounted read-only");
3755                 goto failed_mount_wq;
3756         } else {
3757                 /* Nojournal mode, all journal mount options are illegal */
3758                 if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM)) {
3759                         ext4_msg(sb, KERN_ERR, "can't mount with "
3760                                  "journal_checksum, fs mounted w/o journal");
3761                         goto failed_mount_wq;
3762                 }
3763                 if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3764                         ext4_msg(sb, KERN_ERR, "can't mount with "
3765                                  "journal_async_commit, fs mounted w/o journal");
3766                         goto failed_mount_wq;
3767                 }
3768                 if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
3769                         ext4_msg(sb, KERN_ERR, "can't mount with "
3770                                  "commit=%lu, fs mounted w/o journal",
3771                                  sbi->s_commit_interval / HZ);
3772                         goto failed_mount_wq;
3773                 }
3774                 if (EXT4_MOUNT_DATA_FLAGS &
3775                     (sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
3776                         ext4_msg(sb, KERN_ERR, "can't mount with "
3777                                  "data=, fs mounted w/o journal");
3778                         goto failed_mount_wq;
3779                 }
3780                 sbi->s_def_mount_opt &= EXT4_MOUNT_JOURNAL_CHECKSUM;
3781                 clear_opt(sb, JOURNAL_CHECKSUM);
3782                 clear_opt(sb, DATA_FLAGS);
3783                 sbi->s_journal = NULL;
3784                 needs_recovery = 0;
3785                 goto no_journal;
3786         }
3787
3788         if (ext4_has_feature_64bit(sb) &&
3789             !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
3790                                        JBD2_FEATURE_INCOMPAT_64BIT)) {
3791                 ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
3792                 goto failed_mount_wq;
3793         }
3794
3795         if (!set_journal_csum_feature_set(sb)) {
3796                 ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
3797                          "feature set");
3798                 goto failed_mount_wq;
3799         }
3800
3801         /* We have now updated the journal if required, so we can
3802          * validate the data journaling mode. */
3803         switch (test_opt(sb, DATA_FLAGS)) {
3804         case 0:
3805                 /* No mode set, assume a default based on the journal
3806                  * capabilities: ORDERED_DATA if the journal can
3807                  * cope, else JOURNAL_DATA
3808                  */
3809                 if (jbd2_journal_check_available_features
3810                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
3811                         set_opt(sb, ORDERED_DATA);
3812                 else
3813                         set_opt(sb, JOURNAL_DATA);
3814                 break;
3815
3816         case EXT4_MOUNT_ORDERED_DATA:
3817         case EXT4_MOUNT_WRITEBACK_DATA:
3818                 if (!jbd2_journal_check_available_features
3819                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
3820                         ext4_msg(sb, KERN_ERR, "Journal does not support "
3821                                "requested data journaling mode");
3822                         goto failed_mount_wq;
3823                 }
3824         default:
3825                 break;
3826         }
3827         set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
3828
3829         sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
3830
3831 no_journal:
3832         if (ext4_mballoc_ready) {
3833                 sbi->s_mb_cache = ext4_xattr_create_cache(sb->s_id);
3834                 if (!sbi->s_mb_cache) {
3835                         ext4_msg(sb, KERN_ERR, "Failed to create an mb_cache");
3836                         goto failed_mount_wq;
3837                 }
3838         }
3839
3840         if ((DUMMY_ENCRYPTION_ENABLED(sbi) || ext4_has_feature_encrypt(sb)) &&
3841             (blocksize != PAGE_CACHE_SIZE)) {
3842                 ext4_msg(sb, KERN_ERR,
3843                          "Unsupported blocksize for fs encryption");
3844                 goto failed_mount_wq;
3845         }
3846
3847         if (DUMMY_ENCRYPTION_ENABLED(sbi) && !(sb->s_flags & MS_RDONLY) &&
3848             !ext4_has_feature_encrypt(sb)) {
3849                 ext4_set_feature_encrypt(sb);
3850                 ext4_commit_super(sb, 1);
3851         }
3852
3853         /*
3854          * Get the # of file system overhead blocks from the
3855          * superblock if present.
3856          */
3857         if (es->s_overhead_clusters)
3858                 sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
3859         else {
3860                 err = ext4_calculate_overhead(sb);
3861                 if (err)
3862                         goto failed_mount_wq;
3863         }
3864
3865         /*
3866          * The maximum number of concurrent works can be high and
3867          * concurrency isn't really necessary.  Limit it to 1.
3868          */
3869         EXT4_SB(sb)->rsv_conversion_wq =
3870                 alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
3871         if (!EXT4_SB(sb)->rsv_conversion_wq) {
3872                 printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
3873                 ret = -ENOMEM;
3874                 goto failed_mount4;
3875         }
3876
3877         /*
3878          * The jbd2_journal_load will have done any necessary log recovery,
3879          * so we can safely mount the rest of the filesystem now.
3880          */
3881
3882         root = ext4_iget(sb, EXT4_ROOT_INO);
3883         if (IS_ERR(root)) {
3884                 ext4_msg(sb, KERN_ERR, "get root inode failed");
3885                 ret = PTR_ERR(root);
3886                 root = NULL;
3887                 goto failed_mount4;
3888         }
3889         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
3890                 ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
3891                 iput(root);
3892                 goto failed_mount4;
3893         }
3894         sb->s_root = d_make_root(root);
3895         if (!sb->s_root) {
3896                 ext4_msg(sb, KERN_ERR, "get root dentry failed");
3897                 ret = -ENOMEM;
3898                 goto failed_mount4;
3899         }
3900
3901         if (ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY))
3902                 sb->s_flags |= MS_RDONLY;
3903
3904         /* determine the minimum size of new large inodes, if present */
3905         if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
3906                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
3907                                                      EXT4_GOOD_OLD_INODE_SIZE;
3908                 if (ext4_has_feature_extra_isize(sb)) {
3909                         if (sbi->s_want_extra_isize <
3910                             le16_to_cpu(es->s_want_extra_isize))
3911                                 sbi->s_want_extra_isize =
3912                                         le16_to_cpu(es->s_want_extra_isize);
3913                         if (sbi->s_want_extra_isize <
3914                             le16_to_cpu(es->s_min_extra_isize))
3915                                 sbi->s_want_extra_isize =
3916                                         le16_to_cpu(es->s_min_extra_isize);
3917                 }
3918         }
3919         /* Check if enough inode space is available */
3920         if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
3921                                                         sbi->s_inode_size) {
3922                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
3923                                                        EXT4_GOOD_OLD_INODE_SIZE;
3924                 ext4_msg(sb, KERN_INFO, "required extra inode space not"
3925                          "available");
3926         }
3927
3928         ext4_set_resv_clusters(sb);
3929
3930         err = ext4_setup_system_zone(sb);
3931         if (err) {
3932                 ext4_msg(sb, KERN_ERR, "failed to initialize system "
3933                          "zone (%d)", err);
3934                 goto failed_mount4a;
3935         }
3936
3937         ext4_ext_init(sb);
3938         err = ext4_mb_init(sb);
3939         if (err) {
3940                 ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
3941                          err);
3942                 goto failed_mount5;
3943         }
3944
3945         block = ext4_count_free_clusters(sb);
3946         ext4_free_blocks_count_set(sbi->s_es,
3947                                    EXT4_C2B(sbi, block));
3948         err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
3949                                   GFP_KERNEL);
3950         if (!err) {
3951                 unsigned long freei = ext4_count_free_inodes(sb);
3952                 sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
3953                 err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
3954                                           GFP_KERNEL);
3955         }
3956         if (!err)
3957                 err = percpu_counter_init(&sbi->s_dirs_counter,
3958                                           ext4_count_dirs(sb), GFP_KERNEL);
3959         if (!err)
3960                 err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
3961                                           GFP_KERNEL);
3962         if (err) {
3963                 ext4_msg(sb, KERN_ERR, "insufficient memory");
3964                 goto failed_mount6;
3965         }
3966
3967         if (ext4_has_feature_flex_bg(sb))
3968                 if (!ext4_fill_flex_info(sb)) {
3969                         ext4_msg(sb, KERN_ERR,
3970                                "unable to initialize "
3971                                "flex_bg meta info!");
3972                         goto failed_mount6;
3973                 }
3974
3975         err = ext4_register_li_request(sb, first_not_zeroed);
3976         if (err)
3977                 goto failed_mount6;
3978
3979         err = ext4_register_sysfs(sb);
3980         if (err)
3981                 goto failed_mount7;
3982
3983 #ifdef CONFIG_QUOTA
3984         /* Enable quota usage during mount. */
3985         if (ext4_has_feature_quota(sb) && !(sb->s_flags & MS_RDONLY)) {
3986                 err = ext4_enable_quotas(sb);
3987                 if (err)
3988                         goto failed_mount8;
3989         }
3990 #endif  /* CONFIG_QUOTA */
3991
3992         EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
3993         ext4_orphan_cleanup(sb, es);
3994         EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
3995         if (needs_recovery) {
3996                 ext4_msg(sb, KERN_INFO, "recovery complete");
3997                 ext4_mark_recovery_complete(sb, es);
3998         }
3999         if (EXT4_SB(sb)->s_journal) {
4000                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
4001                         descr = " journalled data mode";
4002                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
4003                         descr = " ordered data mode";
4004                 else
4005                         descr = " writeback data mode";
4006         } else
4007                 descr = "out journal";
4008
4009         if (test_opt(sb, DISCARD)) {
4010                 struct request_queue *q = bdev_get_queue(sb->s_bdev);
4011                 if (!blk_queue_discard(q))
4012                         ext4_msg(sb, KERN_WARNING,
4013                                  "mounting with \"discard\" option, but "
4014                                  "the device does not support discard");
4015         }
4016
4017         if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
4018                 ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
4019                          "Opts: %.*s%s%s", descr,
4020                          (int) sizeof(sbi->s_es->s_mount_opts),
4021                          sbi->s_es->s_mount_opts,
4022                          *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
4023
4024         if (es->s_error_count)
4025                 mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
4026
4027         /* Enable message ratelimiting. Default is 10 messages per 5 secs. */
4028         ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
4029         ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
4030         ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
4031
4032         kfree(orig_data);
4033         return 0;
4034
4035 cantfind_ext4:
4036         if (!silent)
4037                 ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
4038         goto failed_mount;
4039
4040 #ifdef CONFIG_QUOTA
4041 failed_mount8:
4042         ext4_unregister_sysfs(sb);
4043 #endif
4044 failed_mount7:
4045         ext4_unregister_li_request(sb);
4046 failed_mount6:
4047         ext4_mb_release(sb);
4048         if (sbi->s_flex_groups)
4049                 kvfree(sbi->s_flex_groups);
4050         percpu_counter_destroy(&sbi->s_freeclusters_counter);
4051         percpu_counter_destroy(&sbi->s_freeinodes_counter);
4052         percpu_counter_destroy(&sbi->s_dirs_counter);
4053         percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4054 failed_mount5:
4055         ext4_ext_release(sb);
4056         ext4_release_system_zone(sb);
4057 failed_mount4a:
4058         dput(sb->s_root);
4059         sb->s_root = NULL;
4060 failed_mount4:
4061         ext4_msg(sb, KERN_ERR, "mount failed");
4062         if (EXT4_SB(sb)->rsv_conversion_wq)
4063                 destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4064 failed_mount_wq:
4065         if (sbi->s_journal) {
4066                 jbd2_journal_destroy(sbi->s_journal);
4067                 sbi->s_journal = NULL;
4068         }
4069 failed_mount3a:
4070         ext4_es_unregister_shrinker(sbi);
4071 failed_mount3:
4072         del_timer_sync(&sbi->s_err_report);
4073         if (sbi->s_mmp_tsk)
4074                 kthread_stop(sbi->s_mmp_tsk);
4075 failed_mount2:
4076         for (i = 0; i < db_count; i++)
4077                 brelse(sbi->s_group_desc[i]);
4078         kvfree(sbi->s_group_desc);
4079 failed_mount:
4080         if (sbi->s_chksum_driver)
4081                 crypto_free_shash(sbi->s_chksum_driver);
4082 #ifdef CONFIG_QUOTA
4083         for (i = 0; i < EXT4_MAXQUOTAS; i++)
4084                 kfree(sbi->s_qf_names[i]);
4085 #endif
4086         ext4_blkdev_remove(sbi);
4087         brelse(bh);
4088 out_fail:
4089         sb->s_fs_info = NULL;
4090         kfree(sbi->s_blockgroup_lock);
4091 out_free_base:
4092         kfree(sbi);
4093         kfree(orig_data);
4094         return err ? err : ret;
4095 }
4096
4097 /*
4098  * Setup any per-fs journal parameters now.  We'll do this both on
4099  * initial mount, once the journal has been initialised but before we've
4100  * done any recovery; and again on any subsequent remount.
4101  */
4102 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4103 {
4104         struct ext4_sb_info *sbi = EXT4_SB(sb);
4105
4106         journal->j_commit_interval = sbi->s_commit_interval;
4107         journal->j_min_batch_time = sbi->s_min_batch_time;
4108         journal->j_max_batch_time = sbi->s_max_batch_time;
4109
4110         write_lock(&journal->j_state_lock);
4111         if (test_opt(sb, BARRIER))
4112                 journal->j_flags |= JBD2_BARRIER;
4113         else
4114                 journal->j_flags &= ~JBD2_BARRIER;
4115         if (test_opt(sb, DATA_ERR_ABORT))
4116                 journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4117         else
4118                 journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4119         write_unlock(&journal->j_state_lock);
4120 }
4121
4122 static journal_t *ext4_get_journal(struct super_block *sb,
4123                                    unsigned int journal_inum)
4124 {
4125         struct inode *journal_inode;
4126         journal_t *journal;
4127
4128         BUG_ON(!ext4_has_feature_journal(sb));
4129
4130         /* First, test for the existence of a valid inode on disk.  Bad
4131          * things happen if we iget() an unused inode, as the subsequent
4132          * iput() will try to delete it. */
4133
4134         journal_inode = ext4_iget(sb, journal_inum);
4135         if (IS_ERR(journal_inode)) {
4136                 ext4_msg(sb, KERN_ERR, "no journal found");
4137                 return NULL;
4138         }
4139         if (!journal_inode->i_nlink) {
4140                 make_bad_inode(journal_inode);
4141                 iput(journal_inode);
4142                 ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4143                 return NULL;
4144         }
4145
4146         jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4147                   journal_inode, journal_inode->i_size);
4148         if (!S_ISREG(journal_inode->i_mode)) {
4149                 ext4_msg(sb, KERN_ERR, "invalid journal inode");
4150                 iput(journal_inode);
4151                 return NULL;
4152         }
4153
4154         journal = jbd2_journal_init_inode(journal_inode);
4155         if (!journal) {
4156                 ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4157                 iput(journal_inode);
4158                 return NULL;
4159         }
4160         journal->j_private = sb;
4161         ext4_init_journal_params(sb, journal);
4162         return journal;
4163 }
4164
4165 static journal_t *ext4_get_dev_journal(struct super_block *sb,
4166                                        dev_t j_dev)
4167 {
4168         struct buffer_head *bh;
4169         journal_t *journal;
4170         ext4_fsblk_t start;
4171         ext4_fsblk_t len;
4172         int hblock, blocksize;
4173         ext4_fsblk_t sb_block;
4174         unsigned long offset;
4175         struct ext4_super_block *es;
4176         struct block_device *bdev;
4177
4178         BUG_ON(!ext4_has_feature_journal(sb));
4179
4180         bdev = ext4_blkdev_get(j_dev, sb);
4181         if (bdev == NULL)
4182                 return NULL;
4183
4184         blocksize = sb->s_blocksize;
4185         hblock = bdev_logical_block_size(bdev);
4186         if (blocksize < hblock) {
4187                 ext4_msg(sb, KERN_ERR,
4188                         "blocksize too small for journal device");
4189                 goto out_bdev;
4190         }
4191
4192         sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4193         offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4194         set_blocksize(bdev, blocksize);
4195         if (!(bh = __bread(bdev, sb_block, blocksize))) {
4196                 ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4197                        "external journal");
4198                 goto out_bdev;
4199         }
4200
4201         es = (struct ext4_super_block *) (bh->b_data + offset);
4202         if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4203             !(le32_to_cpu(es->s_feature_incompat) &
4204               EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4205                 ext4_msg(sb, KERN_ERR, "external journal has "
4206                                         "bad superblock");
4207                 brelse(bh);
4208                 goto out_bdev;
4209         }
4210
4211         if ((le32_to_cpu(es->s_feature_ro_compat) &
4212              EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
4213             es->s_checksum != ext4_superblock_csum(sb, es)) {
4214                 ext4_msg(sb, KERN_ERR, "external journal has "
4215                                        "corrupt superblock");
4216                 brelse(bh);
4217                 goto out_bdev;
4218         }
4219
4220         if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4221                 ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4222                 brelse(bh);
4223                 goto out_bdev;
4224         }
4225
4226         len = ext4_blocks_count(es);
4227         start = sb_block + 1;
4228         brelse(bh);     /* we're done with the superblock */
4229
4230         journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4231                                         start, len, blocksize);
4232         if (!journal) {
4233                 ext4_msg(sb, KERN_ERR, "failed to create device journal");
4234                 goto out_bdev;
4235         }
4236         journal->j_private = sb;
4237         ll_rw_block(READ | REQ_META | REQ_PRIO, 1, &journal->j_sb_buffer);
4238         wait_on_buffer(journal->j_sb_buffer);
4239         if (!buffer_uptodate(journal->j_sb_buffer)) {
4240                 ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4241                 goto out_journal;
4242         }
4243         if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4244                 ext4_msg(sb, KERN_ERR, "External journal has more than one "
4245                                         "user (unsupported) - %d",
4246                         be32_to_cpu(journal->j_superblock->s_nr_users));
4247                 goto out_journal;
4248         }
4249         EXT4_SB(sb)->journal_bdev = bdev;
4250         ext4_init_journal_params(sb, journal);
4251         return journal;
4252
4253 out_journal:
4254         jbd2_journal_destroy(journal);
4255 out_bdev:
4256         ext4_blkdev_put(bdev);
4257         return NULL;
4258 }
4259
4260 static int ext4_load_journal(struct super_block *sb,
4261                              struct ext4_super_block *es,
4262                              unsigned long journal_devnum)
4263 {
4264         journal_t *journal;
4265         unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4266         dev_t journal_dev;
4267         int err = 0;
4268         int really_read_only;
4269
4270         BUG_ON(!ext4_has_feature_journal(sb));
4271
4272         if (journal_devnum &&
4273             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4274                 ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4275                         "numbers have changed");
4276                 journal_dev = new_decode_dev(journal_devnum);
4277         } else
4278                 journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4279
4280         really_read_only = bdev_read_only(sb->s_bdev);
4281
4282         /*
4283          * Are we loading a blank journal or performing recovery after a
4284          * crash?  For recovery, we need to check in advance whether we
4285          * can get read-write access to the device.
4286          */
4287         if (ext4_has_feature_journal_needs_recovery(sb)) {
4288                 if (sb->s_flags & MS_RDONLY) {
4289                         ext4_msg(sb, KERN_INFO, "INFO: recovery "
4290                                         "required on readonly filesystem");
4291                         if (really_read_only) {
4292                                 ext4_msg(sb, KERN_ERR, "write access "
4293                                         "unavailable, cannot proceed");
4294                                 return -EROFS;
4295                         }
4296                         ext4_msg(sb, KERN_INFO, "write access will "
4297                                "be enabled during recovery");
4298                 }
4299         }
4300
4301         if (journal_inum && journal_dev) {
4302                 ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4303                        "and inode journals!");
4304                 return -EINVAL;
4305         }
4306
4307         if (journal_inum) {
4308                 if (!(journal = ext4_get_journal(sb, journal_inum)))
4309                         return -EINVAL;
4310         } else {
4311                 if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4312                         return -EINVAL;
4313         }
4314
4315         if (!(journal->j_flags & JBD2_BARRIER))
4316                 ext4_msg(sb, KERN_INFO, "barriers disabled");
4317
4318         if (!ext4_has_feature_journal_needs_recovery(sb))
4319                 err = jbd2_journal_wipe(journal, !really_read_only);
4320         if (!err) {
4321                 char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4322                 if (save)
4323                         memcpy(save, ((char *) es) +
4324                                EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4325                 err = jbd2_journal_load(journal);
4326                 if (save)
4327                         memcpy(((char *) es) + EXT4_S_ERR_START,
4328                                save, EXT4_S_ERR_LEN);
4329                 kfree(save);
4330         }
4331
4332         if (err) {
4333                 ext4_msg(sb, KERN_ERR, "error loading journal");
4334                 jbd2_journal_destroy(journal);
4335                 return err;
4336         }
4337
4338         EXT4_SB(sb)->s_journal = journal;
4339         ext4_clear_journal_err(sb, es);
4340
4341         if (!really_read_only && journal_devnum &&
4342             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4343                 es->s_journal_dev = cpu_to_le32(journal_devnum);
4344
4345                 /* Make sure we flush the recovery flag to disk. */
4346                 ext4_commit_super(sb, 1);
4347         }
4348
4349         return 0;
4350 }
4351
4352 static int ext4_commit_super(struct super_block *sb, int sync)
4353 {
4354         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4355         struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4356         int error = 0;
4357
4358         if (!sbh || block_device_ejected(sb))
4359                 return error;
4360         if (buffer_write_io_error(sbh)) {
4361                 /*
4362                  * Oh, dear.  A previous attempt to write the
4363                  * superblock failed.  This could happen because the
4364                  * USB device was yanked out.  Or it could happen to
4365                  * be a transient write error and maybe the block will
4366                  * be remapped.  Nothing we can do but to retry the
4367                  * write and hope for the best.
4368                  */
4369                 ext4_msg(sb, KERN_ERR, "previous I/O error to "
4370                        "superblock detected");
4371                 clear_buffer_write_io_error(sbh);
4372                 set_buffer_uptodate(sbh);
4373         }
4374         /*
4375          * If the file system is mounted read-only, don't update the
4376          * superblock write time.  This avoids updating the superblock
4377          * write time when we are mounting the root file system
4378          * read/only but we need to replay the journal; at that point,
4379          * for people who are east of GMT and who make their clock
4380          * tick in localtime for Windows bug-for-bug compatibility,
4381          * the clock is set in the future, and this will cause e2fsck
4382          * to complain and force a full file system check.
4383          */
4384         if (!(sb->s_flags & MS_RDONLY))
4385                 es->s_wtime = cpu_to_le32(get_seconds());
4386         if (sb->s_bdev->bd_part)
4387                 es->s_kbytes_written =
4388                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
4389                             ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
4390                               EXT4_SB(sb)->s_sectors_written_start) >> 1));
4391         else
4392                 es->s_kbytes_written =
4393                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
4394         if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeclusters_counter))
4395                 ext4_free_blocks_count_set(es,
4396                         EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
4397                                 &EXT4_SB(sb)->s_freeclusters_counter)));
4398         if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeinodes_counter))
4399                 es->s_free_inodes_count =
4400                         cpu_to_le32(percpu_counter_sum_positive(
4401                                 &EXT4_SB(sb)->s_freeinodes_counter));
4402         BUFFER_TRACE(sbh, "marking dirty");
4403         ext4_superblock_csum_set(sb);
4404         mark_buffer_dirty(sbh);
4405         if (sync) {
4406                 error = __sync_dirty_buffer(sbh,
4407                         test_opt(sb, BARRIER) ? WRITE_FUA : WRITE_SYNC);
4408                 if (error)
4409                         return error;
4410
4411                 error = buffer_write_io_error(sbh);
4412                 if (error) {
4413                         ext4_msg(sb, KERN_ERR, "I/O error while writing "
4414                                "superblock");
4415                         clear_buffer_write_io_error(sbh);
4416                         set_buffer_uptodate(sbh);
4417                 }
4418         }
4419         return error;
4420 }
4421
4422 /*
4423  * Have we just finished recovery?  If so, and if we are mounting (or
4424  * remounting) the filesystem readonly, then we will end up with a
4425  * consistent fs on disk.  Record that fact.
4426  */
4427 static void ext4_mark_recovery_complete(struct super_block *sb,
4428                                         struct ext4_super_block *es)
4429 {
4430         journal_t *journal = EXT4_SB(sb)->s_journal;
4431
4432         if (!ext4_has_feature_journal(sb)) {
4433                 BUG_ON(journal != NULL);
4434                 return;
4435         }
4436         jbd2_journal_lock_updates(journal);
4437         if (jbd2_journal_flush(journal) < 0)
4438                 goto out;
4439
4440         if (ext4_has_feature_journal_needs_recovery(sb) &&
4441             sb->s_flags & MS_RDONLY) {
4442                 ext4_clear_feature_journal_needs_recovery(sb);
4443                 ext4_commit_super(sb, 1);
4444         }
4445
4446 out:
4447         jbd2_journal_unlock_updates(journal);
4448 }
4449
4450 /*
4451  * If we are mounting (or read-write remounting) a filesystem whose journal
4452  * has recorded an error from a previous lifetime, move that error to the
4453  * main filesystem now.
4454  */
4455 static void ext4_clear_journal_err(struct super_block *sb,
4456                                    struct ext4_super_block *es)
4457 {
4458         journal_t *journal;
4459         int j_errno;
4460         const char *errstr;
4461
4462         BUG_ON(!ext4_has_feature_journal(sb));
4463
4464         journal = EXT4_SB(sb)->s_journal;
4465
4466         /*
4467          * Now check for any error status which may have been recorded in the
4468          * journal by a prior ext4_error() or ext4_abort()
4469          */
4470
4471         j_errno = jbd2_journal_errno(journal);
4472         if (j_errno) {
4473                 char nbuf[16];
4474
4475                 errstr = ext4_decode_error(sb, j_errno, nbuf);
4476                 ext4_warning(sb, "Filesystem error recorded "
4477                              "from previous mount: %s", errstr);
4478                 ext4_warning(sb, "Marking fs in need of filesystem check.");
4479
4480                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
4481                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
4482                 ext4_commit_super(sb, 1);
4483
4484                 jbd2_journal_clear_err(journal);
4485                 jbd2_journal_update_sb_errno(journal);
4486         }
4487 }
4488
4489 /*
4490  * Force the running and committing transactions to commit,
4491  * and wait on the commit.
4492  */
4493 int ext4_force_commit(struct super_block *sb)
4494 {
4495         journal_t *journal;
4496
4497         if (sb->s_flags & MS_RDONLY)
4498                 return 0;
4499
4500         journal = EXT4_SB(sb)->s_journal;
4501         return ext4_journal_force_commit(journal);
4502 }
4503
4504 static int ext4_sync_fs(struct super_block *sb, int wait)
4505 {
4506         int ret = 0;
4507         tid_t target;
4508         bool needs_barrier = false;
4509         struct ext4_sb_info *sbi = EXT4_SB(sb);
4510
4511         trace_ext4_sync_fs(sb, wait);
4512         flush_workqueue(sbi->rsv_conversion_wq);
4513         /*
4514          * Writeback quota in non-journalled quota case - journalled quota has
4515          * no dirty dquots
4516          */
4517         dquot_writeback_dquots(sb, -1);
4518         /*
4519          * Data writeback is possible w/o journal transaction, so barrier must
4520          * being sent at the end of the function. But we can skip it if
4521          * transaction_commit will do it for us.
4522          */
4523         if (sbi->s_journal) {
4524                 target = jbd2_get_latest_transaction(sbi->s_journal);
4525                 if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
4526                     !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
4527                         needs_barrier = true;
4528
4529                 if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
4530                         if (wait)
4531                                 ret = jbd2_log_wait_commit(sbi->s_journal,
4532                                                            target);
4533                 }
4534         } else if (wait && test_opt(sb, BARRIER))
4535                 needs_barrier = true;
4536         if (needs_barrier) {
4537                 int err;
4538                 err = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
4539                 if (!ret)
4540                         ret = err;
4541         }
4542
4543         return ret;
4544 }
4545
4546 /*
4547  * LVM calls this function before a (read-only) snapshot is created.  This
4548  * gives us a chance to flush the journal completely and mark the fs clean.
4549  *
4550  * Note that only this function cannot bring a filesystem to be in a clean
4551  * state independently. It relies on upper layer to stop all data & metadata
4552  * modifications.
4553  */
4554 static int ext4_freeze(struct super_block *sb)
4555 {
4556         int error = 0;
4557         journal_t *journal;
4558
4559         if (sb->s_flags & MS_RDONLY)
4560                 return 0;
4561
4562         journal = EXT4_SB(sb)->s_journal;
4563
4564         if (journal) {
4565                 /* Now we set up the journal barrier. */
4566                 jbd2_journal_lock_updates(journal);
4567
4568                 /*
4569                  * Don't clear the needs_recovery flag if we failed to
4570                  * flush the journal.
4571                  */
4572                 error = jbd2_journal_flush(journal);
4573                 if (error < 0)
4574                         goto out;
4575
4576                 /* Journal blocked and flushed, clear needs_recovery flag. */
4577                 ext4_clear_feature_journal_needs_recovery(sb);
4578         }
4579
4580         error = ext4_commit_super(sb, 1);
4581 out:
4582         if (journal)
4583                 /* we rely on upper layer to stop further updates */
4584                 jbd2_journal_unlock_updates(journal);
4585         return error;
4586 }
4587
4588 /*
4589  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
4590  * flag here, even though the filesystem is not technically dirty yet.
4591  */
4592 static int ext4_unfreeze(struct super_block *sb)
4593 {
4594         if (sb->s_flags & MS_RDONLY)
4595                 return 0;
4596
4597         if (EXT4_SB(sb)->s_journal) {
4598                 /* Reset the needs_recovery flag before the fs is unlocked. */
4599                 ext4_set_feature_journal_needs_recovery(sb);
4600         }
4601
4602         ext4_commit_super(sb, 1);
4603         return 0;
4604 }
4605
4606 /*
4607  * Structure to save mount options for ext4_remount's benefit
4608  */
4609 struct ext4_mount_options {
4610         unsigned long s_mount_opt;
4611         unsigned long s_mount_opt2;
4612         kuid_t s_resuid;
4613         kgid_t s_resgid;
4614         unsigned long s_commit_interval;
4615         u32 s_min_batch_time, s_max_batch_time;
4616 #ifdef CONFIG_QUOTA
4617         int s_jquota_fmt;
4618         char *s_qf_names[EXT4_MAXQUOTAS];
4619 #endif
4620 };
4621
4622 static int ext4_remount(struct super_block *sb, int *flags, char *data)
4623 {
4624         struct ext4_super_block *es;
4625         struct ext4_sb_info *sbi = EXT4_SB(sb);
4626         unsigned long old_sb_flags;
4627         struct ext4_mount_options old_opts;
4628         int enable_quota = 0;
4629         ext4_group_t g;
4630         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4631         int err = 0;
4632 #ifdef CONFIG_QUOTA
4633         int i, j;
4634 #endif
4635         char *orig_data = kstrdup(data, GFP_KERNEL);
4636
4637         /* Store the original options */
4638         old_sb_flags = sb->s_flags;
4639         old_opts.s_mount_opt = sbi->s_mount_opt;
4640         old_opts.s_mount_opt2 = sbi->s_mount_opt2;
4641         old_opts.s_resuid = sbi->s_resuid;
4642         old_opts.s_resgid = sbi->s_resgid;
4643         old_opts.s_commit_interval = sbi->s_commit_interval;
4644         old_opts.s_min_batch_time = sbi->s_min_batch_time;
4645         old_opts.s_max_batch_time = sbi->s_max_batch_time;
4646 #ifdef CONFIG_QUOTA
4647         old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
4648         for (i = 0; i < EXT4_MAXQUOTAS; i++)
4649                 if (sbi->s_qf_names[i]) {
4650                         old_opts.s_qf_names[i] = kstrdup(sbi->s_qf_names[i],
4651                                                          GFP_KERNEL);
4652                         if (!old_opts.s_qf_names[i]) {
4653                                 for (j = 0; j < i; j++)
4654                                         kfree(old_opts.s_qf_names[j]);
4655                                 kfree(orig_data);
4656                                 return -ENOMEM;
4657                         }
4658                 } else
4659                         old_opts.s_qf_names[i] = NULL;
4660 #endif
4661         if (sbi->s_journal && sbi->s_journal->j_task->io_context)
4662                 journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
4663
4664         if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
4665                 err = -EINVAL;
4666                 goto restore_opts;
4667         }
4668
4669         if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
4670             test_opt(sb, JOURNAL_CHECKSUM)) {
4671                 ext4_msg(sb, KERN_ERR, "changing journal_checksum "
4672                          "during remount not supported; ignoring");
4673                 sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
4674         }
4675
4676         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
4677                 if (test_opt2(sb, EXPLICIT_DELALLOC)) {
4678                         ext4_msg(sb, KERN_ERR, "can't mount with "
4679                                  "both data=journal and delalloc");
4680                         err = -EINVAL;
4681                         goto restore_opts;
4682                 }
4683                 if (test_opt(sb, DIOREAD_NOLOCK)) {
4684                         ext4_msg(sb, KERN_ERR, "can't mount with "
4685                                  "both data=journal and dioread_nolock");
4686                         err = -EINVAL;
4687                         goto restore_opts;
4688                 }
4689                 if (test_opt(sb, DAX)) {
4690                         ext4_msg(sb, KERN_ERR, "can't mount with "
4691                                  "both data=journal and dax");
4692                         err = -EINVAL;
4693                         goto restore_opts;
4694                 }
4695         }
4696
4697         if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_DAX) {
4698                 ext4_msg(sb, KERN_WARNING, "warning: refusing change of "
4699                         "dax flag with busy inodes while remounting");
4700                 sbi->s_mount_opt ^= EXT4_MOUNT_DAX;
4701         }
4702
4703         if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
4704                 ext4_abort(sb, "Abort forced by user");
4705
4706         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
4707                 (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
4708
4709         es = sbi->s_es;
4710
4711         if (sbi->s_journal) {
4712                 ext4_init_journal_params(sb, sbi->s_journal);
4713                 set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4714         }
4715
4716         if (*flags & MS_LAZYTIME)
4717                 sb->s_flags |= MS_LAZYTIME;
4718
4719         if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY)) {
4720                 if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
4721                         err = -EROFS;
4722                         goto restore_opts;
4723                 }
4724
4725                 if (*flags & MS_RDONLY) {
4726                         err = sync_filesystem(sb);
4727                         if (err < 0)
4728                                 goto restore_opts;
4729                         err = dquot_suspend(sb, -1);
4730                         if (err < 0)
4731                                 goto restore_opts;
4732
4733                         /*
4734                          * First of all, the unconditional stuff we have to do
4735                          * to disable replay of the journal when we next remount
4736                          */
4737                         sb->s_flags |= MS_RDONLY;
4738
4739                         /*
4740                          * OK, test if we are remounting a valid rw partition
4741                          * readonly, and if so set the rdonly flag and then
4742                          * mark the partition as valid again.
4743                          */
4744                         if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
4745                             (sbi->s_mount_state & EXT4_VALID_FS))
4746                                 es->s_state = cpu_to_le16(sbi->s_mount_state);
4747
4748                         if (sbi->s_journal)
4749                                 ext4_mark_recovery_complete(sb, es);
4750                 } else {
4751                         /* Make sure we can mount this feature set readwrite */
4752                         if (ext4_has_feature_readonly(sb) ||
4753                             !ext4_feature_set_ok(sb, 0)) {
4754                                 err = -EROFS;
4755                                 goto restore_opts;
4756                         }
4757                         /*
4758                          * Make sure the group descriptor checksums
4759                          * are sane.  If they aren't, refuse to remount r/w.
4760                          */
4761                         for (g = 0; g < sbi->s_groups_count; g++) {
4762                                 struct ext4_group_desc *gdp =
4763                                         ext4_get_group_desc(sb, g, NULL);
4764
4765                                 if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
4766                                         ext4_msg(sb, KERN_ERR,
4767                "ext4_remount: Checksum for group %u failed (%u!=%u)",
4768                 g, le16_to_cpu(ext4_group_desc_csum(sb, g, gdp)),
4769                                                le16_to_cpu(gdp->bg_checksum));
4770                                         err = -EFSBADCRC;
4771                                         goto restore_opts;
4772                                 }
4773                         }
4774
4775                         /*
4776                          * If we have an unprocessed orphan list hanging
4777                          * around from a previously readonly bdev mount,
4778                          * require a full umount/remount for now.
4779                          */
4780                         if (es->s_last_orphan) {
4781                                 ext4_msg(sb, KERN_WARNING, "Couldn't "
4782                                        "remount RDWR because of unprocessed "
4783                                        "orphan inode list.  Please "
4784                                        "umount/remount instead");
4785                                 err = -EINVAL;
4786                                 goto restore_opts;
4787                         }
4788
4789                         /*
4790                          * Mounting a RDONLY partition read-write, so reread
4791                          * and store the current valid flag.  (It may have
4792                          * been changed by e2fsck since we originally mounted
4793                          * the partition.)
4794                          */
4795                         if (sbi->s_journal)
4796                                 ext4_clear_journal_err(sb, es);
4797                         sbi->s_mount_state = le16_to_cpu(es->s_state);
4798                         if (!ext4_setup_super(sb, es, 0))
4799                                 sb->s_flags &= ~MS_RDONLY;
4800                         if (ext4_has_feature_mmp(sb))
4801                                 if (ext4_multi_mount_protect(sb,
4802                                                 le64_to_cpu(es->s_mmp_block))) {
4803                                         err = -EROFS;
4804                                         goto restore_opts;
4805                                 }
4806                         enable_quota = 1;
4807                 }
4808         }
4809
4810         /*
4811          * Reinitialize lazy itable initialization thread based on
4812          * current settings
4813          */
4814         if ((sb->s_flags & MS_RDONLY) || !test_opt(sb, INIT_INODE_TABLE))
4815                 ext4_unregister_li_request(sb);
4816         else {
4817                 ext4_group_t first_not_zeroed;
4818                 first_not_zeroed = ext4_has_uninit_itable(sb);
4819                 ext4_register_li_request(sb, first_not_zeroed);
4820         }
4821
4822         ext4_setup_system_zone(sb);
4823         if (sbi->s_journal == NULL && !(old_sb_flags & MS_RDONLY))
4824                 ext4_commit_super(sb, 1);
4825
4826 #ifdef CONFIG_QUOTA
4827         /* Release old quota file names */
4828         for (i = 0; i < EXT4_MAXQUOTAS; i++)
4829                 kfree(old_opts.s_qf_names[i]);
4830         if (enable_quota) {
4831                 if (sb_any_quota_suspended(sb))
4832                         dquot_resume(sb, -1);
4833                 else if (ext4_has_feature_quota(sb)) {
4834                         err = ext4_enable_quotas(sb);
4835                         if (err)
4836                                 goto restore_opts;
4837                 }
4838         }
4839 #endif
4840
4841         *flags = (*flags & ~MS_LAZYTIME) | (sb->s_flags & MS_LAZYTIME);
4842         ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
4843         kfree(orig_data);
4844         return 0;
4845
4846 restore_opts:
4847         sb->s_flags = old_sb_flags;
4848         sbi->s_mount_opt = old_opts.s_mount_opt;
4849         sbi->s_mount_opt2 = old_opts.s_mount_opt2;
4850         sbi->s_resuid = old_opts.s_resuid;
4851         sbi->s_resgid = old_opts.s_resgid;
4852         sbi->s_commit_interval = old_opts.s_commit_interval;
4853         sbi->s_min_batch_time = old_opts.s_min_batch_time;
4854         sbi->s_max_batch_time = old_opts.s_max_batch_time;
4855 #ifdef CONFIG_QUOTA
4856         sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
4857         for (i = 0; i < EXT4_MAXQUOTAS; i++) {
4858                 kfree(sbi->s_qf_names[i]);
4859                 sbi->s_qf_names[i] = old_opts.s_qf_names[i];
4860         }
4861 #endif
4862         kfree(orig_data);
4863         return err;
4864 }
4865
4866 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
4867 {
4868         struct super_block *sb = dentry->d_sb;
4869         struct ext4_sb_info *sbi = EXT4_SB(sb);
4870         struct ext4_super_block *es = sbi->s_es;
4871         ext4_fsblk_t overhead = 0, resv_blocks;
4872         u64 fsid;
4873         s64 bfree;
4874         resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
4875
4876         if (!test_opt(sb, MINIX_DF))
4877                 overhead = sbi->s_overhead;
4878
4879         buf->f_type = EXT4_SUPER_MAGIC;
4880         buf->f_bsize = sb->s_blocksize;
4881         buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
4882         bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
4883                 percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
4884         /* prevent underflow in case that few free space is available */
4885         buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
4886         buf->f_bavail = buf->f_bfree -
4887                         (ext4_r_blocks_count(es) + resv_blocks);
4888         if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
4889                 buf->f_bavail = 0;
4890         buf->f_files = le32_to_cpu(es->s_inodes_count);
4891         buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
4892         buf->f_namelen = EXT4_NAME_LEN;
4893         fsid = le64_to_cpup((void *)es->s_uuid) ^
4894                le64_to_cpup((void *)es->s_uuid + sizeof(u64));
4895         buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
4896         buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
4897
4898         return 0;
4899 }
4900
4901 /* Helper function for writing quotas on sync - we need to start transaction
4902  * before quota file is locked for write. Otherwise the are possible deadlocks:
4903  * Process 1                         Process 2
4904  * ext4_create()                     quota_sync()
4905  *   jbd2_journal_start()                  write_dquot()
4906  *   dquot_initialize()                         down(dqio_mutex)
4907  *     down(dqio_mutex)                    jbd2_journal_start()
4908  *
4909  */
4910
4911 #ifdef CONFIG_QUOTA
4912
4913 static inline struct inode *dquot_to_inode(struct dquot *dquot)
4914 {
4915         return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
4916 }
4917
4918 static int ext4_write_dquot(struct dquot *dquot)
4919 {
4920         int ret, err;
4921         handle_t *handle;
4922         struct inode *inode;
4923
4924         inode = dquot_to_inode(dquot);
4925         handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
4926                                     EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
4927         if (IS_ERR(handle))
4928                 return PTR_ERR(handle);
4929         ret = dquot_commit(dquot);
4930         err = ext4_journal_stop(handle);
4931         if (!ret)
4932                 ret = err;
4933         return ret;
4934 }
4935
4936 static int ext4_acquire_dquot(struct dquot *dquot)
4937 {
4938         int ret, err;
4939         handle_t *handle;
4940
4941         handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
4942                                     EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
4943         if (IS_ERR(handle))
4944                 return PTR_ERR(handle);
4945         ret = dquot_acquire(dquot);
4946         err = ext4_journal_stop(handle);
4947         if (!ret)
4948                 ret = err;
4949         return ret;
4950 }
4951
4952 static int ext4_release_dquot(struct dquot *dquot)
4953 {
4954         int ret, err;
4955         handle_t *handle;
4956
4957         handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
4958                                     EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
4959         if (IS_ERR(handle)) {
4960                 /* Release dquot anyway to avoid endless cycle in dqput() */
4961                 dquot_release(dquot);
4962                 return PTR_ERR(handle);
4963         }
4964         ret = dquot_release(dquot);
4965         err = ext4_journal_stop(handle);
4966         if (!ret)
4967                 ret = err;
4968         return ret;
4969 }
4970
4971 static int ext4_mark_dquot_dirty(struct dquot *dquot)
4972 {
4973         struct super_block *sb = dquot->dq_sb;
4974         struct ext4_sb_info *sbi = EXT4_SB(sb);
4975
4976         /* Are we journaling quotas? */
4977         if (ext4_has_feature_quota(sb) ||
4978             sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
4979                 dquot_mark_dquot_dirty(dquot);
4980                 return ext4_write_dquot(dquot);
4981         } else {
4982                 return dquot_mark_dquot_dirty(dquot);
4983         }
4984 }
4985
4986 static int ext4_write_info(struct super_block *sb, int type)
4987 {
4988         int ret, err;
4989         handle_t *handle;
4990
4991         /* Data block + inode block */
4992         handle = ext4_journal_start(d_inode(sb->s_root), EXT4_HT_QUOTA, 2);
4993         if (IS_ERR(handle))
4994                 return PTR_ERR(handle);
4995         ret = dquot_commit_info(sb, type);
4996         err = ext4_journal_stop(handle);
4997         if (!ret)
4998                 ret = err;
4999         return ret;
5000 }
5001
5002 /*
5003  * Turn on quotas during mount time - we need to find
5004  * the quota file and such...
5005  */
5006 static int ext4_quota_on_mount(struct super_block *sb, int type)
5007 {
5008         return dquot_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
5009                                         EXT4_SB(sb)->s_jquota_fmt, type);
5010 }
5011
5012 static void lockdep_set_quota_inode(struct inode *inode, int subclass)
5013 {
5014         struct ext4_inode_info *ei = EXT4_I(inode);
5015
5016         /* The first argument of lockdep_set_subclass has to be
5017          * *exactly* the same as the argument to init_rwsem() --- in
5018          * this case, in init_once() --- or lockdep gets unhappy
5019          * because the name of the lock is set using the
5020          * stringification of the argument to init_rwsem().
5021          */
5022         (void) ei;      /* shut up clang warning if !CONFIG_LOCKDEP */
5023         lockdep_set_subclass(&ei->i_data_sem, subclass);
5024 }
5025
5026 /*
5027  * Standard function to be called on quota_on
5028  */
5029 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
5030                          struct path *path)
5031 {
5032         int err;
5033
5034         if (!test_opt(sb, QUOTA))
5035                 return -EINVAL;
5036
5037         /* Quotafile not on the same filesystem? */
5038         if (path->dentry->d_sb != sb)
5039                 return -EXDEV;
5040         /* Journaling quota? */
5041         if (EXT4_SB(sb)->s_qf_names[type]) {
5042                 /* Quotafile not in fs root? */
5043                 if (path->dentry->d_parent != sb->s_root)
5044                         ext4_msg(sb, KERN_WARNING,
5045                                 "Quota file not on filesystem root. "
5046                                 "Journaled quota will not work");
5047         }
5048
5049         /*
5050          * When we journal data on quota file, we have to flush journal to see
5051          * all updates to the file when we bypass pagecache...
5052          */
5053         if (EXT4_SB(sb)->s_journal &&
5054             ext4_should_journal_data(d_inode(path->dentry))) {
5055                 /*
5056                  * We don't need to lock updates but journal_flush() could
5057                  * otherwise be livelocked...
5058                  */
5059                 jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
5060                 err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
5061                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
5062                 if (err)
5063                         return err;
5064         }
5065         lockdep_set_quota_inode(path->dentry->d_inode, I_DATA_SEM_QUOTA);
5066         err = dquot_quota_on(sb, type, format_id, path);
5067         if (err)
5068                 lockdep_set_quota_inode(path->dentry->d_inode,
5069                                              I_DATA_SEM_NORMAL);
5070         return err;
5071 }
5072
5073 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
5074                              unsigned int flags)
5075 {
5076         int err;
5077         struct inode *qf_inode;
5078         unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5079                 le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5080                 le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum)
5081         };
5082
5083         BUG_ON(!ext4_has_feature_quota(sb));
5084
5085         if (!qf_inums[type])
5086                 return -EPERM;
5087
5088         qf_inode = ext4_iget(sb, qf_inums[type]);
5089         if (IS_ERR(qf_inode)) {
5090                 ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
5091                 return PTR_ERR(qf_inode);
5092         }
5093
5094         /* Don't account quota for quota files to avoid recursion */
5095         qf_inode->i_flags |= S_NOQUOTA;
5096         lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);
5097         err = dquot_enable(qf_inode, type, format_id, flags);
5098         iput(qf_inode);
5099         if (err)
5100                 lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);
5101
5102         return err;
5103 }
5104
5105 /* Enable usage tracking for all quota types. */
5106 static int ext4_enable_quotas(struct super_block *sb)
5107 {
5108         int type, err = 0;
5109         unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5110                 le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5111                 le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum)
5112         };
5113
5114         sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE;
5115         for (type = 0; type < EXT4_MAXQUOTAS; type++) {
5116                 if (qf_inums[type]) {
5117                         err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
5118                                                 DQUOT_USAGE_ENABLED);
5119                         if (err) {
5120                                 ext4_warning(sb,
5121                                         "Failed to enable quota tracking "
5122                                         "(type=%d, err=%d). Please run "
5123                                         "e2fsck to fix.", type, err);
5124                                 return err;
5125                         }
5126                 }
5127         }
5128         return 0;
5129 }
5130
5131 static int ext4_quota_off(struct super_block *sb, int type)
5132 {
5133         struct inode *inode = sb_dqopt(sb)->files[type];
5134         handle_t *handle;
5135
5136         /* Force all delayed allocation blocks to be allocated.
5137          * Caller already holds s_umount sem */
5138         if (test_opt(sb, DELALLOC))
5139                 sync_filesystem(sb);
5140
5141         if (!inode)
5142                 goto out;
5143
5144         /* Update modification times of quota files when userspace can
5145          * start looking at them */
5146         handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5147         if (IS_ERR(handle))
5148                 goto out;
5149         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
5150         ext4_mark_inode_dirty(handle, inode);
5151         ext4_journal_stop(handle);
5152
5153 out:
5154         return dquot_quota_off(sb, type);
5155 }
5156
5157 /* Read data from quotafile - avoid pagecache and such because we cannot afford
5158  * acquiring the locks... As quota files are never truncated and quota code
5159  * itself serializes the operations (and no one else should touch the files)
5160  * we don't have to be afraid of races */
5161 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
5162                                size_t len, loff_t off)
5163 {
5164         struct inode *inode = sb_dqopt(sb)->files[type];
5165         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5166         int offset = off & (sb->s_blocksize - 1);
5167         int tocopy;
5168         size_t toread;
5169         struct buffer_head *bh;
5170         loff_t i_size = i_size_read(inode);
5171
5172         if (off > i_size)
5173                 return 0;
5174         if (off+len > i_size)
5175                 len = i_size-off;
5176         toread = len;
5177         while (toread > 0) {
5178                 tocopy = sb->s_blocksize - offset < toread ?
5179                                 sb->s_blocksize - offset : toread;
5180                 bh = ext4_bread(NULL, inode, blk, 0);
5181                 if (IS_ERR(bh))
5182                         return PTR_ERR(bh);
5183                 if (!bh)        /* A hole? */
5184                         memset(data, 0, tocopy);
5185                 else
5186                         memcpy(data, bh->b_data+offset, tocopy);
5187                 brelse(bh);
5188                 offset = 0;
5189                 toread -= tocopy;
5190                 data += tocopy;
5191                 blk++;
5192         }
5193         return len;
5194 }
5195
5196 /* Write to quotafile (we know the transaction is already started and has
5197  * enough credits) */
5198 static ssize_t ext4_quota_write(struct super_block *sb, int type,
5199                                 const char *data, size_t len, loff_t off)
5200 {
5201         struct inode *inode = sb_dqopt(sb)->files[type];
5202         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5203         int err, offset = off & (sb->s_blocksize - 1);
5204         int retries = 0;
5205         struct buffer_head *bh;
5206         handle_t *handle = journal_current_handle();
5207
5208         if (EXT4_SB(sb)->s_journal && !handle) {
5209                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5210                         " cancelled because transaction is not started",
5211                         (unsigned long long)off, (unsigned long long)len);
5212                 return -EIO;
5213         }
5214         /*
5215          * Since we account only one data block in transaction credits,
5216          * then it is impossible to cross a block boundary.
5217          */
5218         if (sb->s_blocksize - offset < len) {
5219                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5220                         " cancelled because not block aligned",
5221                         (unsigned long long)off, (unsigned long long)len);
5222                 return -EIO;
5223         }
5224
5225         do {
5226                 bh = ext4_bread(handle, inode, blk,
5227                                 EXT4_GET_BLOCKS_CREATE |
5228                                 EXT4_GET_BLOCKS_METADATA_NOFAIL);
5229         } while (IS_ERR(bh) && (PTR_ERR(bh) == -ENOSPC) &&
5230                  ext4_should_retry_alloc(inode->i_sb, &retries));
5231         if (IS_ERR(bh))
5232                 return PTR_ERR(bh);
5233         if (!bh)
5234                 goto out;
5235         BUFFER_TRACE(bh, "get write access");
5236         err = ext4_journal_get_write_access(handle, bh);
5237         if (err) {
5238                 brelse(bh);
5239                 return err;
5240         }
5241         lock_buffer(bh);
5242         memcpy(bh->b_data+offset, data, len);
5243         flush_dcache_page(bh->b_page);
5244         unlock_buffer(bh);
5245         err = ext4_handle_dirty_metadata(handle, NULL, bh);
5246         brelse(bh);
5247 out:
5248         if (inode->i_size < off + len) {
5249                 i_size_write(inode, off + len);
5250                 EXT4_I(inode)->i_disksize = inode->i_size;
5251                 ext4_mark_inode_dirty(handle, inode);
5252         }
5253         return len;
5254 }
5255
5256 #endif
5257
5258 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
5259                        const char *dev_name, void *data)
5260 {
5261         return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
5262 }
5263
5264 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
5265 static inline void register_as_ext2(void)
5266 {
5267         int err = register_filesystem(&ext2_fs_type);
5268         if (err)
5269                 printk(KERN_WARNING
5270                        "EXT4-fs: Unable to register as ext2 (%d)\n", err);
5271 }
5272
5273 static inline void unregister_as_ext2(void)
5274 {
5275         unregister_filesystem(&ext2_fs_type);
5276 }
5277
5278 static inline int ext2_feature_set_ok(struct super_block *sb)
5279 {
5280         if (ext4_has_unknown_ext2_incompat_features(sb))
5281                 return 0;
5282         if (sb->s_flags & MS_RDONLY)
5283                 return 1;
5284         if (ext4_has_unknown_ext2_ro_compat_features(sb))
5285                 return 0;
5286         return 1;
5287 }
5288 #else
5289 static inline void register_as_ext2(void) { }
5290 static inline void unregister_as_ext2(void) { }
5291 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
5292 #endif
5293
5294 static inline void register_as_ext3(void)
5295 {
5296         int err = register_filesystem(&ext3_fs_type);
5297         if (err)
5298                 printk(KERN_WARNING
5299                        "EXT4-fs: Unable to register as ext3 (%d)\n", err);
5300 }
5301
5302 static inline void unregister_as_ext3(void)
5303 {
5304         unregister_filesystem(&ext3_fs_type);
5305 }
5306
5307 static inline int ext3_feature_set_ok(struct super_block *sb)
5308 {
5309         if (ext4_has_unknown_ext3_incompat_features(sb))
5310                 return 0;
5311         if (!ext4_has_feature_journal(sb))
5312                 return 0;
5313         if (sb->s_flags & MS_RDONLY)
5314                 return 1;
5315         if (ext4_has_unknown_ext3_ro_compat_features(sb))
5316                 return 0;
5317         return 1;
5318 }
5319
5320 static struct file_system_type ext4_fs_type = {
5321         .owner          = THIS_MODULE,
5322         .name           = "ext4",
5323         .mount          = ext4_mount,
5324         .kill_sb        = kill_block_super,
5325         .fs_flags       = FS_REQUIRES_DEV,
5326 };
5327 MODULE_ALIAS_FS("ext4");
5328
5329 /* Shared across all ext4 file systems */
5330 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
5331 struct mutex ext4__aio_mutex[EXT4_WQ_HASH_SZ];
5332
5333 static int __init ext4_init_fs(void)
5334 {
5335         int i, err;
5336
5337         ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
5338         ext4_li_info = NULL;
5339         mutex_init(&ext4_li_mtx);
5340
5341         /* Build-time check for flags consistency */
5342         ext4_check_flag_values();
5343
5344         for (i = 0; i < EXT4_WQ_HASH_SZ; i++) {
5345                 mutex_init(&ext4__aio_mutex[i]);
5346                 init_waitqueue_head(&ext4__ioend_wq[i]);
5347         }
5348
5349         err = ext4_init_es();
5350         if (err)
5351                 return err;
5352
5353         err = ext4_init_pageio();
5354         if (err)
5355                 goto out5;
5356
5357         err = ext4_init_system_zone();
5358         if (err)
5359                 goto out4;
5360
5361         err = ext4_init_sysfs();
5362         if (err)
5363                 goto out3;
5364
5365         err = ext4_init_mballoc();
5366         if (err)
5367                 goto out2;
5368         else
5369                 ext4_mballoc_ready = 1;
5370         err = init_inodecache();
5371         if (err)
5372                 goto out1;
5373         register_as_ext3();
5374         register_as_ext2();
5375         err = register_filesystem(&ext4_fs_type);
5376         if (err)
5377                 goto out;
5378
5379         return 0;
5380 out:
5381         unregister_as_ext2();
5382         unregister_as_ext3();
5383         destroy_inodecache();
5384 out1:
5385         ext4_mballoc_ready = 0;
5386         ext4_exit_mballoc();
5387 out2:
5388         ext4_exit_sysfs();
5389 out3:
5390         ext4_exit_system_zone();
5391 out4:
5392         ext4_exit_pageio();
5393 out5:
5394         ext4_exit_es();
5395
5396         return err;
5397 }
5398
5399 static void __exit ext4_exit_fs(void)
5400 {
5401         ext4_exit_crypto();
5402         ext4_destroy_lazyinit_thread();
5403         unregister_as_ext2();
5404         unregister_as_ext3();
5405         unregister_filesystem(&ext4_fs_type);
5406         destroy_inodecache();
5407         ext4_exit_mballoc();
5408         ext4_exit_sysfs();
5409         ext4_exit_system_zone();
5410         ext4_exit_pageio();
5411         ext4_exit_es();
5412 }
5413
5414 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
5415 MODULE_DESCRIPTION("Fourth Extended Filesystem");
5416 MODULE_LICENSE("GPL");
5417 module_init(ext4_init_fs)
5418 module_exit(ext4_exit_fs)