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;
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                 __le16 save_csum;
2041                 __u32 csum32;
2042
2043                 save_csum = gdp->bg_checksum;
2044                 gdp->bg_checksum = 0;
2045                 csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
2046                                      sizeof(le_group));
2047                 csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp,
2048                                      sbi->s_desc_size);
2049                 gdp->bg_checksum = save_csum;
2050
2051                 crc = csum32 & 0xFFFF;
2052                 goto out;
2053         }
2054
2055         /* old crc16 code */
2056         if (!ext4_has_feature_gdt_csum(sb))
2057                 return 0;
2058
2059         offset = offsetof(struct ext4_group_desc, bg_checksum);
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_group_t *first_not_zeroed)
2097 {
2098         struct ext4_sb_info *sbi = EXT4_SB(sb);
2099         ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2100         ext4_fsblk_t last_block;
2101         ext4_fsblk_t block_bitmap;
2102         ext4_fsblk_t inode_bitmap;
2103         ext4_fsblk_t inode_table;
2104         int flexbg_flag = 0;
2105         ext4_group_t i, grp = sbi->s_groups_count;
2106
2107         if (ext4_has_feature_flex_bg(sb))
2108                 flexbg_flag = 1;
2109
2110         ext4_debug("Checking group descriptors");
2111
2112         for (i = 0; i < sbi->s_groups_count; i++) {
2113                 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2114
2115                 if (i == sbi->s_groups_count - 1 || flexbg_flag)
2116                         last_block = ext4_blocks_count(sbi->s_es) - 1;
2117                 else
2118                         last_block = first_block +
2119                                 (EXT4_BLOCKS_PER_GROUP(sb) - 1);
2120
2121                 if ((grp == sbi->s_groups_count) &&
2122                    !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2123                         grp = i;
2124
2125                 block_bitmap = ext4_block_bitmap(sb, gdp);
2126                 if (block_bitmap < first_block || block_bitmap > last_block) {
2127                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2128                                "Block bitmap for group %u not in group "
2129                                "(block %llu)!", i, block_bitmap);
2130                         return 0;
2131                 }
2132                 inode_bitmap = ext4_inode_bitmap(sb, gdp);
2133                 if (inode_bitmap < first_block || inode_bitmap > last_block) {
2134                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2135                                "Inode bitmap for group %u not in group "
2136                                "(block %llu)!", i, inode_bitmap);
2137                         return 0;
2138                 }
2139                 inode_table = ext4_inode_table(sb, gdp);
2140                 if (inode_table < first_block ||
2141                     inode_table + sbi->s_itb_per_group - 1 > last_block) {
2142                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2143                                "Inode table for group %u not in group "
2144                                "(block %llu)!", i, inode_table);
2145                         return 0;
2146                 }
2147                 ext4_lock_group(sb, i);
2148                 if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2149                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2150                                  "Checksum for group %u failed (%u!=%u)",
2151                                  i, le16_to_cpu(ext4_group_desc_csum(sb, i,
2152                                      gdp)), le16_to_cpu(gdp->bg_checksum));
2153                         if (!(sb->s_flags & MS_RDONLY)) {
2154                                 ext4_unlock_group(sb, i);
2155                                 return 0;
2156                         }
2157                 }
2158                 ext4_unlock_group(sb, i);
2159                 if (!flexbg_flag)
2160                         first_block += EXT4_BLOCKS_PER_GROUP(sb);
2161         }
2162         if (NULL != first_not_zeroed)
2163                 *first_not_zeroed = grp;
2164         return 1;
2165 }
2166
2167 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2168  * the superblock) which were deleted from all directories, but held open by
2169  * a process at the time of a crash.  We walk the list and try to delete these
2170  * inodes at recovery time (only with a read-write filesystem).
2171  *
2172  * In order to keep the orphan inode chain consistent during traversal (in
2173  * case of crash during recovery), we link each inode into the superblock
2174  * orphan list_head and handle it the same way as an inode deletion during
2175  * normal operation (which journals the operations for us).
2176  *
2177  * We only do an iget() and an iput() on each inode, which is very safe if we
2178  * accidentally point at an in-use or already deleted inode.  The worst that
2179  * can happen in this case is that we get a "bit already cleared" message from
2180  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2181  * e2fsck was run on this filesystem, and it must have already done the orphan
2182  * inode cleanup for us, so we can safely abort without any further action.
2183  */
2184 static void ext4_orphan_cleanup(struct super_block *sb,
2185                                 struct ext4_super_block *es)
2186 {
2187         unsigned int s_flags = sb->s_flags;
2188         int nr_orphans = 0, nr_truncates = 0;
2189 #ifdef CONFIG_QUOTA
2190         int i;
2191 #endif
2192         if (!es->s_last_orphan) {
2193                 jbd_debug(4, "no orphan inodes to clean up\n");
2194                 return;
2195         }
2196
2197         if (bdev_read_only(sb->s_bdev)) {
2198                 ext4_msg(sb, KERN_ERR, "write access "
2199                         "unavailable, skipping orphan cleanup");
2200                 return;
2201         }
2202
2203         /* Check if feature set would not allow a r/w mount */
2204         if (!ext4_feature_set_ok(sb, 0)) {
2205                 ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2206                          "unknown ROCOMPAT features");
2207                 return;
2208         }
2209
2210         if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2211                 /* don't clear list on RO mount w/ errors */
2212                 if (es->s_last_orphan && !(s_flags & MS_RDONLY)) {
2213                         ext4_msg(sb, KERN_INFO, "Errors on filesystem, "
2214                                   "clearing orphan list.\n");
2215                         es->s_last_orphan = 0;
2216                 }
2217                 jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2218                 return;
2219         }
2220
2221         if (s_flags & MS_RDONLY) {
2222                 ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2223                 sb->s_flags &= ~MS_RDONLY;
2224         }
2225 #ifdef CONFIG_QUOTA
2226         /* Needed for iput() to work correctly and not trash data */
2227         sb->s_flags |= MS_ACTIVE;
2228         /* Turn on quotas so that they are updated correctly */
2229         for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2230                 if (EXT4_SB(sb)->s_qf_names[i]) {
2231                         int ret = ext4_quota_on_mount(sb, i);
2232                         if (ret < 0)
2233                                 ext4_msg(sb, KERN_ERR,
2234                                         "Cannot turn on journaled "
2235                                         "quota: error %d", ret);
2236                 }
2237         }
2238 #endif
2239
2240         while (es->s_last_orphan) {
2241                 struct inode *inode;
2242
2243                 inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2244                 if (IS_ERR(inode)) {
2245                         es->s_last_orphan = 0;
2246                         break;
2247                 }
2248
2249                 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2250                 dquot_initialize(inode);
2251                 if (inode->i_nlink) {
2252                         if (test_opt(sb, DEBUG))
2253                                 ext4_msg(sb, KERN_DEBUG,
2254                                         "%s: truncating inode %lu to %lld bytes",
2255                                         __func__, inode->i_ino, inode->i_size);
2256                         jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2257                                   inode->i_ino, inode->i_size);
2258                         mutex_lock(&inode->i_mutex);
2259                         truncate_inode_pages(inode->i_mapping, inode->i_size);
2260                         ext4_truncate(inode);
2261                         mutex_unlock(&inode->i_mutex);
2262                         nr_truncates++;
2263                 } else {
2264                         if (test_opt(sb, DEBUG))
2265                                 ext4_msg(sb, KERN_DEBUG,
2266                                         "%s: deleting unreferenced inode %lu",
2267                                         __func__, inode->i_ino);
2268                         jbd_debug(2, "deleting unreferenced inode %lu\n",
2269                                   inode->i_ino);
2270                         nr_orphans++;
2271                 }
2272                 iput(inode);  /* The delete magic happens here! */
2273         }
2274
2275 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2276
2277         if (nr_orphans)
2278                 ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2279                        PLURAL(nr_orphans));
2280         if (nr_truncates)
2281                 ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2282                        PLURAL(nr_truncates));
2283 #ifdef CONFIG_QUOTA
2284         /* Turn quotas off */
2285         for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2286                 if (sb_dqopt(sb)->files[i])
2287                         dquot_quota_off(sb, i);
2288         }
2289 #endif
2290         sb->s_flags = s_flags; /* Restore MS_RDONLY status */
2291 }
2292
2293 /*
2294  * Maximal extent format file size.
2295  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2296  * extent format containers, within a sector_t, and within i_blocks
2297  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2298  * so that won't be a limiting factor.
2299  *
2300  * However there is other limiting factor. We do store extents in the form
2301  * of starting block and length, hence the resulting length of the extent
2302  * covering maximum file size must fit into on-disk format containers as
2303  * well. Given that length is always by 1 unit bigger than max unit (because
2304  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2305  *
2306  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2307  */
2308 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2309 {
2310         loff_t res;
2311         loff_t upper_limit = MAX_LFS_FILESIZE;
2312
2313         /* small i_blocks in vfs inode? */
2314         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2315                 /*
2316                  * CONFIG_LBDAF is not enabled implies the inode
2317                  * i_block represent total blocks in 512 bytes
2318                  * 32 == size of vfs inode i_blocks * 8
2319                  */
2320                 upper_limit = (1LL << 32) - 1;
2321
2322                 /* total blocks in file system block size */
2323                 upper_limit >>= (blkbits - 9);
2324                 upper_limit <<= blkbits;
2325         }
2326
2327         /*
2328          * 32-bit extent-start container, ee_block. We lower the maxbytes
2329          * by one fs block, so ee_len can cover the extent of maximum file
2330          * size
2331          */
2332         res = (1LL << 32) - 1;
2333         res <<= blkbits;
2334
2335         /* Sanity check against vm- & vfs- imposed limits */
2336         if (res > upper_limit)
2337                 res = upper_limit;
2338
2339         return res;
2340 }
2341
2342 /*
2343  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2344  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2345  * We need to be 1 filesystem block less than the 2^48 sector limit.
2346  */
2347 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2348 {
2349         loff_t res = EXT4_NDIR_BLOCKS;
2350         int meta_blocks;
2351         loff_t upper_limit;
2352         /* This is calculated to be the largest file size for a dense, block
2353          * mapped file such that the file's total number of 512-byte sectors,
2354          * including data and all indirect blocks, does not exceed (2^48 - 1).
2355          *
2356          * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2357          * number of 512-byte sectors of the file.
2358          */
2359
2360         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2361                 /*
2362                  * !has_huge_files or CONFIG_LBDAF not enabled implies that
2363                  * the inode i_block field represents total file blocks in
2364                  * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2365                  */
2366                 upper_limit = (1LL << 32) - 1;
2367
2368                 /* total blocks in file system block size */
2369                 upper_limit >>= (bits - 9);
2370
2371         } else {
2372                 /*
2373                  * We use 48 bit ext4_inode i_blocks
2374                  * With EXT4_HUGE_FILE_FL set the i_blocks
2375                  * represent total number of blocks in
2376                  * file system block size
2377                  */
2378                 upper_limit = (1LL << 48) - 1;
2379
2380         }
2381
2382         /* indirect blocks */
2383         meta_blocks = 1;
2384         /* double indirect blocks */
2385         meta_blocks += 1 + (1LL << (bits-2));
2386         /* tripple indirect blocks */
2387         meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2388
2389         upper_limit -= meta_blocks;
2390         upper_limit <<= bits;
2391
2392         res += 1LL << (bits-2);
2393         res += 1LL << (2*(bits-2));
2394         res += 1LL << (3*(bits-2));
2395         res <<= bits;
2396         if (res > upper_limit)
2397                 res = upper_limit;
2398
2399         if (res > MAX_LFS_FILESIZE)
2400                 res = MAX_LFS_FILESIZE;
2401
2402         return res;
2403 }
2404
2405 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2406                                    ext4_fsblk_t logical_sb_block, int nr)
2407 {
2408         struct ext4_sb_info *sbi = EXT4_SB(sb);
2409         ext4_group_t bg, first_meta_bg;
2410         int has_super = 0;
2411
2412         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2413
2414         if (!ext4_has_feature_meta_bg(sb) || nr < first_meta_bg)
2415                 return logical_sb_block + nr + 1;
2416         bg = sbi->s_desc_per_block * nr;
2417         if (ext4_bg_has_super(sb, bg))
2418                 has_super = 1;
2419
2420         /*
2421          * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
2422          * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
2423          * on modern mke2fs or blksize > 1k on older mke2fs) then we must
2424          * compensate.
2425          */
2426         if (sb->s_blocksize == 1024 && nr == 0 &&
2427             le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block) == 0)
2428                 has_super++;
2429
2430         return (has_super + ext4_group_first_block_no(sb, bg));
2431 }
2432
2433 /**
2434  * ext4_get_stripe_size: Get the stripe size.
2435  * @sbi: In memory super block info
2436  *
2437  * If we have specified it via mount option, then
2438  * use the mount option value. If the value specified at mount time is
2439  * greater than the blocks per group use the super block value.
2440  * If the super block value is greater than blocks per group return 0.
2441  * Allocator needs it be less than blocks per group.
2442  *
2443  */
2444 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2445 {
2446         unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2447         unsigned long stripe_width =
2448                         le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2449         int ret;
2450
2451         if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2452                 ret = sbi->s_stripe;
2453         else if (stripe_width <= sbi->s_blocks_per_group)
2454                 ret = stripe_width;
2455         else if (stride <= sbi->s_blocks_per_group)
2456                 ret = stride;
2457         else
2458                 ret = 0;
2459
2460         /*
2461          * If the stripe width is 1, this makes no sense and
2462          * we set it to 0 to turn off stripe handling code.
2463          */
2464         if (ret <= 1)
2465                 ret = 0;
2466
2467         return ret;
2468 }
2469
2470 /*
2471  * Check whether this filesystem can be mounted based on
2472  * the features present and the RDONLY/RDWR mount requested.
2473  * Returns 1 if this filesystem can be mounted as requested,
2474  * 0 if it cannot be.
2475  */
2476 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2477 {
2478         if (ext4_has_unknown_ext4_incompat_features(sb)) {
2479                 ext4_msg(sb, KERN_ERR,
2480                         "Couldn't mount because of "
2481                         "unsupported optional features (%x)",
2482                         (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2483                         ~EXT4_FEATURE_INCOMPAT_SUPP));
2484                 return 0;
2485         }
2486
2487         if (readonly)
2488                 return 1;
2489
2490         if (ext4_has_feature_readonly(sb)) {
2491                 ext4_msg(sb, KERN_INFO, "filesystem is read-only");
2492                 sb->s_flags |= MS_RDONLY;
2493                 return 1;
2494         }
2495
2496         /* Check that feature set is OK for a read-write mount */
2497         if (ext4_has_unknown_ext4_ro_compat_features(sb)) {
2498                 ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2499                          "unsupported optional features (%x)",
2500                          (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2501                                 ~EXT4_FEATURE_RO_COMPAT_SUPP));
2502                 return 0;
2503         }
2504         /*
2505          * Large file size enabled file system can only be mounted
2506          * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2507          */
2508         if (ext4_has_feature_huge_file(sb)) {
2509                 if (sizeof(blkcnt_t) < sizeof(u64)) {
2510                         ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2511                                  "cannot be mounted RDWR without "
2512                                  "CONFIG_LBDAF");
2513                         return 0;
2514                 }
2515         }
2516         if (ext4_has_feature_bigalloc(sb) && !ext4_has_feature_extents(sb)) {
2517                 ext4_msg(sb, KERN_ERR,
2518                          "Can't support bigalloc feature without "
2519                          "extents feature\n");
2520                 return 0;
2521         }
2522
2523 #ifndef CONFIG_QUOTA
2524         if (ext4_has_feature_quota(sb) && !readonly) {
2525                 ext4_msg(sb, KERN_ERR,
2526                          "Filesystem with quota feature cannot be mounted RDWR "
2527                          "without CONFIG_QUOTA");
2528                 return 0;
2529         }
2530 #endif  /* CONFIG_QUOTA */
2531         return 1;
2532 }
2533
2534 /*
2535  * This function is called once a day if we have errors logged
2536  * on the file system
2537  */
2538 static void print_daily_error_info(unsigned long arg)
2539 {
2540         struct super_block *sb = (struct super_block *) arg;
2541         struct ext4_sb_info *sbi;
2542         struct ext4_super_block *es;
2543
2544         sbi = EXT4_SB(sb);
2545         es = sbi->s_es;
2546
2547         if (es->s_error_count)
2548                 /* fsck newer than v1.41.13 is needed to clean this condition. */
2549                 ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
2550                          le32_to_cpu(es->s_error_count));
2551         if (es->s_first_error_time) {
2552                 printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %u: %.*s:%d",
2553                        sb->s_id, le32_to_cpu(es->s_first_error_time),
2554                        (int) sizeof(es->s_first_error_func),
2555                        es->s_first_error_func,
2556                        le32_to_cpu(es->s_first_error_line));
2557                 if (es->s_first_error_ino)
2558                         printk(": inode %u",
2559                                le32_to_cpu(es->s_first_error_ino));
2560                 if (es->s_first_error_block)
2561                         printk(": block %llu", (unsigned long long)
2562                                le64_to_cpu(es->s_first_error_block));
2563                 printk("\n");
2564         }
2565         if (es->s_last_error_time) {
2566                 printk(KERN_NOTICE "EXT4-fs (%s): last error at time %u: %.*s:%d",
2567                        sb->s_id, le32_to_cpu(es->s_last_error_time),
2568                        (int) sizeof(es->s_last_error_func),
2569                        es->s_last_error_func,
2570                        le32_to_cpu(es->s_last_error_line));
2571                 if (es->s_last_error_ino)
2572                         printk(": inode %u",
2573                                le32_to_cpu(es->s_last_error_ino));
2574                 if (es->s_last_error_block)
2575                         printk(": block %llu", (unsigned long long)
2576                                le64_to_cpu(es->s_last_error_block));
2577                 printk("\n");
2578         }
2579         mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2580 }
2581
2582 /* Find next suitable group and run ext4_init_inode_table */
2583 static int ext4_run_li_request(struct ext4_li_request *elr)
2584 {
2585         struct ext4_group_desc *gdp = NULL;
2586         ext4_group_t group, ngroups;
2587         struct super_block *sb;
2588         unsigned long timeout = 0;
2589         int ret = 0;
2590
2591         sb = elr->lr_super;
2592         ngroups = EXT4_SB(sb)->s_groups_count;
2593
2594         sb_start_write(sb);
2595         for (group = elr->lr_next_group; group < ngroups; group++) {
2596                 gdp = ext4_get_group_desc(sb, group, NULL);
2597                 if (!gdp) {
2598                         ret = 1;
2599                         break;
2600                 }
2601
2602                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2603                         break;
2604         }
2605
2606         if (group >= ngroups)
2607                 ret = 1;
2608
2609         if (!ret) {
2610                 timeout = jiffies;
2611                 ret = ext4_init_inode_table(sb, group,
2612                                             elr->lr_timeout ? 0 : 1);
2613                 if (elr->lr_timeout == 0) {
2614                         timeout = (jiffies - timeout) *
2615                                   elr->lr_sbi->s_li_wait_mult;
2616                         elr->lr_timeout = timeout;
2617                 }
2618                 elr->lr_next_sched = jiffies + elr->lr_timeout;
2619                 elr->lr_next_group = group + 1;
2620         }
2621         sb_end_write(sb);
2622
2623         return ret;
2624 }
2625
2626 /*
2627  * Remove lr_request from the list_request and free the
2628  * request structure. Should be called with li_list_mtx held
2629  */
2630 static void ext4_remove_li_request(struct ext4_li_request *elr)
2631 {
2632         struct ext4_sb_info *sbi;
2633
2634         if (!elr)
2635                 return;
2636
2637         sbi = elr->lr_sbi;
2638
2639         list_del(&elr->lr_request);
2640         sbi->s_li_request = NULL;
2641         kfree(elr);
2642 }
2643
2644 static void ext4_unregister_li_request(struct super_block *sb)
2645 {
2646         mutex_lock(&ext4_li_mtx);
2647         if (!ext4_li_info) {
2648                 mutex_unlock(&ext4_li_mtx);
2649                 return;
2650         }
2651
2652         mutex_lock(&ext4_li_info->li_list_mtx);
2653         ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
2654         mutex_unlock(&ext4_li_info->li_list_mtx);
2655         mutex_unlock(&ext4_li_mtx);
2656 }
2657
2658 static struct task_struct *ext4_lazyinit_task;
2659
2660 /*
2661  * This is the function where ext4lazyinit thread lives. It walks
2662  * through the request list searching for next scheduled filesystem.
2663  * When such a fs is found, run the lazy initialization request
2664  * (ext4_rn_li_request) and keep track of the time spend in this
2665  * function. Based on that time we compute next schedule time of
2666  * the request. When walking through the list is complete, compute
2667  * next waking time and put itself into sleep.
2668  */
2669 static int ext4_lazyinit_thread(void *arg)
2670 {
2671         struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
2672         struct list_head *pos, *n;
2673         struct ext4_li_request *elr;
2674         unsigned long next_wakeup, cur;
2675
2676         BUG_ON(NULL == eli);
2677
2678 cont_thread:
2679         while (true) {
2680                 next_wakeup = MAX_JIFFY_OFFSET;
2681
2682                 mutex_lock(&eli->li_list_mtx);
2683                 if (list_empty(&eli->li_request_list)) {
2684                         mutex_unlock(&eli->li_list_mtx);
2685                         goto exit_thread;
2686                 }
2687
2688                 list_for_each_safe(pos, n, &eli->li_request_list) {
2689                         elr = list_entry(pos, struct ext4_li_request,
2690                                          lr_request);
2691
2692                         if (time_after_eq(jiffies, elr->lr_next_sched)) {
2693                                 if (ext4_run_li_request(elr) != 0) {
2694                                         /* error, remove the lazy_init job */
2695                                         ext4_remove_li_request(elr);
2696                                         continue;
2697                                 }
2698                         }
2699
2700                         if (time_before(elr->lr_next_sched, next_wakeup))
2701                                 next_wakeup = elr->lr_next_sched;
2702                 }
2703                 mutex_unlock(&eli->li_list_mtx);
2704
2705                 try_to_freeze();
2706
2707                 cur = jiffies;
2708                 if ((time_after_eq(cur, next_wakeup)) ||
2709                     (MAX_JIFFY_OFFSET == next_wakeup)) {
2710                         cond_resched();
2711                         continue;
2712                 }
2713
2714                 schedule_timeout_interruptible(next_wakeup - cur);
2715
2716                 if (kthread_should_stop()) {
2717                         ext4_clear_request_list();
2718                         goto exit_thread;
2719                 }
2720         }
2721
2722 exit_thread:
2723         /*
2724          * It looks like the request list is empty, but we need
2725          * to check it under the li_list_mtx lock, to prevent any
2726          * additions into it, and of course we should lock ext4_li_mtx
2727          * to atomically free the list and ext4_li_info, because at
2728          * this point another ext4 filesystem could be registering
2729          * new one.
2730          */
2731         mutex_lock(&ext4_li_mtx);
2732         mutex_lock(&eli->li_list_mtx);
2733         if (!list_empty(&eli->li_request_list)) {
2734                 mutex_unlock(&eli->li_list_mtx);
2735                 mutex_unlock(&ext4_li_mtx);
2736                 goto cont_thread;
2737         }
2738         mutex_unlock(&eli->li_list_mtx);
2739         kfree(ext4_li_info);
2740         ext4_li_info = NULL;
2741         mutex_unlock(&ext4_li_mtx);
2742
2743         return 0;
2744 }
2745
2746 static void ext4_clear_request_list(void)
2747 {
2748         struct list_head *pos, *n;
2749         struct ext4_li_request *elr;
2750
2751         mutex_lock(&ext4_li_info->li_list_mtx);
2752         list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
2753                 elr = list_entry(pos, struct ext4_li_request,
2754                                  lr_request);
2755                 ext4_remove_li_request(elr);
2756         }
2757         mutex_unlock(&ext4_li_info->li_list_mtx);
2758 }
2759
2760 static int ext4_run_lazyinit_thread(void)
2761 {
2762         ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
2763                                          ext4_li_info, "ext4lazyinit");
2764         if (IS_ERR(ext4_lazyinit_task)) {
2765                 int err = PTR_ERR(ext4_lazyinit_task);
2766                 ext4_clear_request_list();
2767                 kfree(ext4_li_info);
2768                 ext4_li_info = NULL;
2769                 printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
2770                                  "initialization thread\n",
2771                                  err);
2772                 return err;
2773         }
2774         ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
2775         return 0;
2776 }
2777
2778 /*
2779  * Check whether it make sense to run itable init. thread or not.
2780  * If there is at least one uninitialized inode table, return
2781  * corresponding group number, else the loop goes through all
2782  * groups and return total number of groups.
2783  */
2784 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
2785 {
2786         ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
2787         struct ext4_group_desc *gdp = NULL;
2788
2789         for (group = 0; group < ngroups; group++) {
2790                 gdp = ext4_get_group_desc(sb, group, NULL);
2791                 if (!gdp)
2792                         continue;
2793
2794                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2795                         break;
2796         }
2797
2798         return group;
2799 }
2800
2801 static int ext4_li_info_new(void)
2802 {
2803         struct ext4_lazy_init *eli = NULL;
2804
2805         eli = kzalloc(sizeof(*eli), GFP_KERNEL);
2806         if (!eli)
2807                 return -ENOMEM;
2808
2809         INIT_LIST_HEAD(&eli->li_request_list);
2810         mutex_init(&eli->li_list_mtx);
2811
2812         eli->li_state |= EXT4_LAZYINIT_QUIT;
2813
2814         ext4_li_info = eli;
2815
2816         return 0;
2817 }
2818
2819 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
2820                                             ext4_group_t start)
2821 {
2822         struct ext4_sb_info *sbi = EXT4_SB(sb);
2823         struct ext4_li_request *elr;
2824
2825         elr = kzalloc(sizeof(*elr), GFP_KERNEL);
2826         if (!elr)
2827                 return NULL;
2828
2829         elr->lr_super = sb;
2830         elr->lr_sbi = sbi;
2831         elr->lr_next_group = start;
2832
2833         /*
2834          * Randomize first schedule time of the request to
2835          * spread the inode table initialization requests
2836          * better.
2837          */
2838         elr->lr_next_sched = jiffies + (prandom_u32() %
2839                                 (EXT4_DEF_LI_MAX_START_DELAY * HZ));
2840         return elr;
2841 }
2842
2843 int ext4_register_li_request(struct super_block *sb,
2844                              ext4_group_t first_not_zeroed)
2845 {
2846         struct ext4_sb_info *sbi = EXT4_SB(sb);
2847         struct ext4_li_request *elr = NULL;
2848         ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
2849         int ret = 0;
2850
2851         mutex_lock(&ext4_li_mtx);
2852         if (sbi->s_li_request != NULL) {
2853                 /*
2854                  * Reset timeout so it can be computed again, because
2855                  * s_li_wait_mult might have changed.
2856                  */
2857                 sbi->s_li_request->lr_timeout = 0;
2858                 goto out;
2859         }
2860
2861         if (first_not_zeroed == ngroups ||
2862             (sb->s_flags & MS_RDONLY) ||
2863             !test_opt(sb, INIT_INODE_TABLE))
2864                 goto out;
2865
2866         elr = ext4_li_request_new(sb, first_not_zeroed);
2867         if (!elr) {
2868                 ret = -ENOMEM;
2869                 goto out;
2870         }
2871
2872         if (NULL == ext4_li_info) {
2873                 ret = ext4_li_info_new();
2874                 if (ret)
2875                         goto out;
2876         }
2877
2878         mutex_lock(&ext4_li_info->li_list_mtx);
2879         list_add(&elr->lr_request, &ext4_li_info->li_request_list);
2880         mutex_unlock(&ext4_li_info->li_list_mtx);
2881
2882         sbi->s_li_request = elr;
2883         /*
2884          * set elr to NULL here since it has been inserted to
2885          * the request_list and the removal and free of it is
2886          * handled by ext4_clear_request_list from now on.
2887          */
2888         elr = NULL;
2889
2890         if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
2891                 ret = ext4_run_lazyinit_thread();
2892                 if (ret)
2893                         goto out;
2894         }
2895 out:
2896         mutex_unlock(&ext4_li_mtx);
2897         if (ret)
2898                 kfree(elr);
2899         return ret;
2900 }
2901
2902 /*
2903  * We do not need to lock anything since this is called on
2904  * module unload.
2905  */
2906 static void ext4_destroy_lazyinit_thread(void)
2907 {
2908         /*
2909          * If thread exited earlier
2910          * there's nothing to be done.
2911          */
2912         if (!ext4_li_info || !ext4_lazyinit_task)
2913                 return;
2914
2915         kthread_stop(ext4_lazyinit_task);
2916 }
2917
2918 static int set_journal_csum_feature_set(struct super_block *sb)
2919 {
2920         int ret = 1;
2921         int compat, incompat;
2922         struct ext4_sb_info *sbi = EXT4_SB(sb);
2923
2924         if (ext4_has_metadata_csum(sb)) {
2925                 /* journal checksum v3 */
2926                 compat = 0;
2927                 incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
2928         } else {
2929                 /* journal checksum v1 */
2930                 compat = JBD2_FEATURE_COMPAT_CHECKSUM;
2931                 incompat = 0;
2932         }
2933
2934         jbd2_journal_clear_features(sbi->s_journal,
2935                         JBD2_FEATURE_COMPAT_CHECKSUM, 0,
2936                         JBD2_FEATURE_INCOMPAT_CSUM_V3 |
2937                         JBD2_FEATURE_INCOMPAT_CSUM_V2);
2938         if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
2939                 ret = jbd2_journal_set_features(sbi->s_journal,
2940                                 compat, 0,
2941                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
2942                                 incompat);
2943         } else if (test_opt(sb, JOURNAL_CHECKSUM)) {
2944                 ret = jbd2_journal_set_features(sbi->s_journal,
2945                                 compat, 0,
2946                                 incompat);
2947                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
2948                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
2949         } else {
2950                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
2951                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
2952         }
2953
2954         return ret;
2955 }
2956
2957 /*
2958  * Note: calculating the overhead so we can be compatible with
2959  * historical BSD practice is quite difficult in the face of
2960  * clusters/bigalloc.  This is because multiple metadata blocks from
2961  * different block group can end up in the same allocation cluster.
2962  * Calculating the exact overhead in the face of clustered allocation
2963  * requires either O(all block bitmaps) in memory or O(number of block
2964  * groups**2) in time.  We will still calculate the superblock for
2965  * older file systems --- and if we come across with a bigalloc file
2966  * system with zero in s_overhead_clusters the estimate will be close to
2967  * correct especially for very large cluster sizes --- but for newer
2968  * file systems, it's better to calculate this figure once at mkfs
2969  * time, and store it in the superblock.  If the superblock value is
2970  * present (even for non-bigalloc file systems), we will use it.
2971  */
2972 static int count_overhead(struct super_block *sb, ext4_group_t grp,
2973                           char *buf)
2974 {
2975         struct ext4_sb_info     *sbi = EXT4_SB(sb);
2976         struct ext4_group_desc  *gdp;
2977         ext4_fsblk_t            first_block, last_block, b;
2978         ext4_group_t            i, ngroups = ext4_get_groups_count(sb);
2979         int                     s, j, count = 0;
2980
2981         if (!ext4_has_feature_bigalloc(sb))
2982                 return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
2983                         sbi->s_itb_per_group + 2);
2984
2985         first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
2986                 (grp * EXT4_BLOCKS_PER_GROUP(sb));
2987         last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
2988         for (i = 0; i < ngroups; i++) {
2989                 gdp = ext4_get_group_desc(sb, i, NULL);
2990                 b = ext4_block_bitmap(sb, gdp);
2991                 if (b >= first_block && b <= last_block) {
2992                         ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
2993                         count++;
2994                 }
2995                 b = ext4_inode_bitmap(sb, gdp);
2996                 if (b >= first_block && b <= last_block) {
2997                         ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
2998                         count++;
2999                 }
3000                 b = ext4_inode_table(sb, gdp);
3001                 if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3002                         for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3003                                 int c = EXT4_B2C(sbi, b - first_block);
3004                                 ext4_set_bit(c, buf);
3005                                 count++;
3006                         }
3007                 if (i != grp)
3008                         continue;
3009                 s = 0;
3010                 if (ext4_bg_has_super(sb, grp)) {
3011                         ext4_set_bit(s++, buf);
3012                         count++;
3013                 }
3014                 for (j = ext4_bg_num_gdb(sb, grp); j > 0; j--) {
3015                         ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3016                         count++;
3017                 }
3018         }
3019         if (!count)
3020                 return 0;
3021         return EXT4_CLUSTERS_PER_GROUP(sb) -
3022                 ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3023 }
3024
3025 /*
3026  * Compute the overhead and stash it in sbi->s_overhead
3027  */
3028 int ext4_calculate_overhead(struct super_block *sb)
3029 {
3030         struct ext4_sb_info *sbi = EXT4_SB(sb);
3031         struct ext4_super_block *es = sbi->s_es;
3032         ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3033         ext4_fsblk_t overhead = 0;
3034         char *buf = (char *) get_zeroed_page(GFP_NOFS);
3035
3036         if (!buf)
3037                 return -ENOMEM;
3038
3039         /*
3040          * Compute the overhead (FS structures).  This is constant
3041          * for a given filesystem unless the number of block groups
3042          * changes so we cache the previous value until it does.
3043          */
3044
3045         /*
3046          * All of the blocks before first_data_block are overhead
3047          */
3048         overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3049
3050         /*
3051          * Add the overhead found in each block group
3052          */
3053         for (i = 0; i < ngroups; i++) {
3054                 int blks;
3055
3056                 blks = count_overhead(sb, i, buf);
3057                 overhead += blks;
3058                 if (blks)
3059                         memset(buf, 0, PAGE_SIZE);
3060                 cond_resched();
3061         }
3062         /* Add the internal journal blocks as well */
3063         if (sbi->s_journal && !sbi->journal_bdev)
3064                 overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_maxlen);
3065
3066         sbi->s_overhead = overhead;
3067         smp_wmb();
3068         free_page((unsigned long) buf);
3069         return 0;
3070 }
3071
3072 static void ext4_set_resv_clusters(struct super_block *sb)
3073 {
3074         ext4_fsblk_t resv_clusters;
3075         struct ext4_sb_info *sbi = EXT4_SB(sb);
3076
3077         /*
3078          * There's no need to reserve anything when we aren't using extents.
3079          * The space estimates are exact, there are no unwritten extents,
3080          * hole punching doesn't need new metadata... This is needed especially
3081          * to keep ext2/3 backward compatibility.
3082          */
3083         if (!ext4_has_feature_extents(sb))
3084                 return;
3085         /*
3086          * By default we reserve 2% or 4096 clusters, whichever is smaller.
3087          * This should cover the situations where we can not afford to run
3088          * out of space like for example punch hole, or converting
3089          * unwritten extents in delalloc path. In most cases such
3090          * allocation would require 1, or 2 blocks, higher numbers are
3091          * very rare.
3092          */
3093         resv_clusters = (ext4_blocks_count(sbi->s_es) >>
3094                          sbi->s_cluster_bits);
3095
3096         do_div(resv_clusters, 50);
3097         resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
3098
3099         atomic64_set(&sbi->s_resv_clusters, resv_clusters);
3100 }
3101
3102 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3103 {
3104         char *orig_data = kstrdup(data, GFP_KERNEL);
3105         struct buffer_head *bh;
3106         struct ext4_super_block *es = NULL;
3107         struct ext4_sb_info *sbi;
3108         ext4_fsblk_t block;
3109         ext4_fsblk_t sb_block = get_sb_block(&data);
3110         ext4_fsblk_t logical_sb_block;
3111         unsigned long offset = 0;
3112         unsigned long journal_devnum = 0;
3113         unsigned long def_mount_opts;
3114         struct inode *root;
3115         const char *descr;
3116         int ret = -ENOMEM;
3117         int blocksize, clustersize;
3118         unsigned int db_count;
3119         unsigned int i;
3120         int needs_recovery, has_huge_files, has_bigalloc;
3121         __u64 blocks_count;
3122         int err = 0;
3123         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3124         ext4_group_t first_not_zeroed;
3125
3126         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3127         if (!sbi)
3128                 goto out_free_orig;
3129
3130         sbi->s_blockgroup_lock =
3131                 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3132         if (!sbi->s_blockgroup_lock) {
3133                 kfree(sbi);
3134                 goto out_free_orig;
3135         }
3136         sb->s_fs_info = sbi;
3137         sbi->s_sb = sb;
3138         sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3139         sbi->s_sb_block = sb_block;
3140         if (sb->s_bdev->bd_part)
3141                 sbi->s_sectors_written_start =
3142                         part_stat_read(sb->s_bdev->bd_part, sectors[1]);
3143
3144         /* Cleanup superblock name */
3145         strreplace(sb->s_id, '/', '!');
3146
3147         /* -EINVAL is default */
3148         ret = -EINVAL;
3149         blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3150         if (!blocksize) {
3151                 ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3152                 goto out_fail;
3153         }
3154
3155         /*
3156          * The ext4 superblock will not be buffer aligned for other than 1kB
3157          * block sizes.  We need to calculate the offset from buffer start.
3158          */
3159         if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3160                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3161                 offset = do_div(logical_sb_block, blocksize);
3162         } else {
3163                 logical_sb_block = sb_block;
3164         }
3165
3166         if (!(bh = sb_bread_unmovable(sb, logical_sb_block))) {
3167                 ext4_msg(sb, KERN_ERR, "unable to read superblock");
3168                 goto out_fail;
3169         }
3170         /*
3171          * Note: s_es must be initialized as soon as possible because
3172          *       some ext4 macro-instructions depend on its value
3173          */
3174         es = (struct ext4_super_block *) (bh->b_data + offset);
3175         sbi->s_es = es;
3176         sb->s_magic = le16_to_cpu(es->s_magic);
3177         if (sb->s_magic != EXT4_SUPER_MAGIC)
3178                 goto cantfind_ext4;
3179         sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3180
3181         /* Warn if metadata_csum and gdt_csum are both set. */
3182         if (ext4_has_feature_metadata_csum(sb) &&
3183             ext4_has_feature_gdt_csum(sb))
3184                 ext4_warning(sb, "metadata_csum and uninit_bg are "
3185                              "redundant flags; please run fsck.");
3186
3187         /* Check for a known checksum algorithm */
3188         if (!ext4_verify_csum_type(sb, es)) {
3189                 ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3190                          "unknown checksum algorithm.");
3191                 silent = 1;
3192                 goto cantfind_ext4;
3193         }
3194
3195         /* Load the checksum driver */
3196         if (ext4_has_feature_metadata_csum(sb)) {
3197                 sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3198                 if (IS_ERR(sbi->s_chksum_driver)) {
3199                         ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3200                         ret = PTR_ERR(sbi->s_chksum_driver);
3201                         sbi->s_chksum_driver = NULL;
3202                         goto failed_mount;
3203                 }
3204         }
3205
3206         /* Check superblock checksum */
3207         if (!ext4_superblock_csum_verify(sb, es)) {
3208                 ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3209                          "invalid superblock checksum.  Run e2fsck?");
3210                 silent = 1;
3211                 ret = -EFSBADCRC;
3212                 goto cantfind_ext4;
3213         }
3214
3215         /* Precompute checksum seed for all metadata */
3216         if (ext4_has_feature_csum_seed(sb))
3217                 sbi->s_csum_seed = le32_to_cpu(es->s_checksum_seed);
3218         else if (ext4_has_metadata_csum(sb))
3219                 sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3220                                                sizeof(es->s_uuid));
3221
3222         /* Set defaults before we parse the mount options */
3223         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3224         set_opt(sb, INIT_INODE_TABLE);
3225         if (def_mount_opts & EXT4_DEFM_DEBUG)
3226                 set_opt(sb, DEBUG);
3227         if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3228                 set_opt(sb, GRPID);
3229         if (def_mount_opts & EXT4_DEFM_UID16)
3230                 set_opt(sb, NO_UID32);
3231         /* xattr user namespace & acls are now defaulted on */
3232         set_opt(sb, XATTR_USER);
3233 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3234         set_opt(sb, POSIX_ACL);
3235 #endif
3236         /* don't forget to enable journal_csum when metadata_csum is enabled. */
3237         if (ext4_has_metadata_csum(sb))
3238                 set_opt(sb, JOURNAL_CHECKSUM);
3239
3240         if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3241                 set_opt(sb, JOURNAL_DATA);
3242         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3243                 set_opt(sb, ORDERED_DATA);
3244         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3245                 set_opt(sb, WRITEBACK_DATA);
3246
3247         if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3248                 set_opt(sb, ERRORS_PANIC);
3249         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3250                 set_opt(sb, ERRORS_CONT);
3251         else
3252                 set_opt(sb, ERRORS_RO);
3253         /* block_validity enabled by default; disable with noblock_validity */
3254         set_opt(sb, BLOCK_VALIDITY);
3255         if (def_mount_opts & EXT4_DEFM_DISCARD)
3256                 set_opt(sb, DISCARD);
3257
3258         sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3259         sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3260         sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3261         sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3262         sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3263
3264         if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3265                 set_opt(sb, BARRIER);
3266
3267         /*
3268          * enable delayed allocation by default
3269          * Use -o nodelalloc to turn it off
3270          */
3271         if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
3272             ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3273                 set_opt(sb, DELALLOC);
3274
3275         /*
3276          * set default s_li_wait_mult for lazyinit, for the case there is
3277          * no mount option specified.
3278          */
3279         sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3280
3281         if (!parse_options((char *) sbi->s_es->s_mount_opts, sb,
3282                            &journal_devnum, &journal_ioprio, 0)) {
3283                 ext4_msg(sb, KERN_WARNING,
3284                          "failed to parse options in superblock: %s",
3285                          sbi->s_es->s_mount_opts);
3286         }
3287         sbi->s_def_mount_opt = sbi->s_mount_opt;
3288         if (!parse_options((char *) data, sb, &journal_devnum,
3289                            &journal_ioprio, 0))
3290                 goto failed_mount;
3291
3292         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3293                 printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3294                             "with data=journal disables delayed "
3295                             "allocation and O_DIRECT support!\n");
3296                 if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3297                         ext4_msg(sb, KERN_ERR, "can't mount with "
3298                                  "both data=journal and delalloc");
3299                         goto failed_mount;
3300                 }
3301                 if (test_opt(sb, DIOREAD_NOLOCK)) {
3302                         ext4_msg(sb, KERN_ERR, "can't mount with "
3303                                  "both data=journal and dioread_nolock");
3304                         goto failed_mount;
3305                 }
3306                 if (test_opt(sb, DAX)) {
3307                         ext4_msg(sb, KERN_ERR, "can't mount with "
3308                                  "both data=journal and dax");
3309                         goto failed_mount;
3310                 }
3311                 if (test_opt(sb, DELALLOC))
3312                         clear_opt(sb, DELALLOC);
3313         } else {
3314                 sb->s_iflags |= SB_I_CGROUPWB;
3315         }
3316
3317         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
3318                 (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
3319
3320         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3321             (ext4_has_compat_features(sb) ||
3322              ext4_has_ro_compat_features(sb) ||
3323              ext4_has_incompat_features(sb)))
3324                 ext4_msg(sb, KERN_WARNING,
3325                        "feature flags set on rev 0 fs, "
3326                        "running e2fsck is recommended");
3327
3328         if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
3329                 set_opt2(sb, HURD_COMPAT);
3330                 if (ext4_has_feature_64bit(sb)) {
3331                         ext4_msg(sb, KERN_ERR,
3332                                  "The Hurd can't support 64-bit file systems");
3333                         goto failed_mount;
3334                 }
3335         }
3336
3337         if (IS_EXT2_SB(sb)) {
3338                 if (ext2_feature_set_ok(sb))
3339                         ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3340                                  "using the ext4 subsystem");
3341                 else {
3342                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3343                                  "to feature incompatibilities");
3344                         goto failed_mount;
3345                 }
3346         }
3347
3348         if (IS_EXT3_SB(sb)) {
3349                 if (ext3_feature_set_ok(sb))
3350                         ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3351                                  "using the ext4 subsystem");
3352                 else {
3353                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3354                                  "to feature incompatibilities");
3355                         goto failed_mount;
3356                 }
3357         }
3358
3359         /*
3360          * Check feature flags regardless of the revision level, since we
3361          * previously didn't change the revision level when setting the flags,
3362          * so there is a chance incompat flags are set on a rev 0 filesystem.
3363          */
3364         if (!ext4_feature_set_ok(sb, (sb->s_flags & MS_RDONLY)))
3365                 goto failed_mount;
3366
3367         blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3368         if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3369             blocksize > EXT4_MAX_BLOCK_SIZE) {
3370                 ext4_msg(sb, KERN_ERR,
3371                        "Unsupported filesystem blocksize %d", blocksize);
3372                 goto failed_mount;
3373         }
3374
3375         if (sbi->s_mount_opt & EXT4_MOUNT_DAX) {
3376                 if (blocksize != PAGE_SIZE) {
3377                         ext4_msg(sb, KERN_ERR,
3378                                         "error: unsupported blocksize for dax");
3379                         goto failed_mount;
3380                 }
3381                 if (!sb->s_bdev->bd_disk->fops->direct_access) {
3382                         ext4_msg(sb, KERN_ERR,
3383                                         "error: device does not support dax");
3384                         goto failed_mount;
3385                 }
3386         }
3387
3388         if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) {
3389                 ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
3390                          es->s_encryption_level);
3391                 goto failed_mount;
3392         }
3393
3394         if (sb->s_blocksize != blocksize) {
3395                 /* Validate the filesystem blocksize */
3396                 if (!sb_set_blocksize(sb, blocksize)) {
3397                         ext4_msg(sb, KERN_ERR, "bad block size %d",
3398                                         blocksize);
3399                         goto failed_mount;
3400                 }
3401
3402                 brelse(bh);
3403                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3404                 offset = do_div(logical_sb_block, blocksize);
3405                 bh = sb_bread_unmovable(sb, logical_sb_block);
3406                 if (!bh) {
3407                         ext4_msg(sb, KERN_ERR,
3408                                "Can't read superblock on 2nd try");
3409                         goto failed_mount;
3410                 }
3411                 es = (struct ext4_super_block *)(bh->b_data + offset);
3412                 sbi->s_es = es;
3413                 if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
3414                         ext4_msg(sb, KERN_ERR,
3415                                "Magic mismatch, very weird!");
3416                         goto failed_mount;
3417                 }
3418         }
3419
3420         has_huge_files = ext4_has_feature_huge_file(sb);
3421         sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
3422                                                       has_huge_files);
3423         sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
3424
3425         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3426                 sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3427                 sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3428         } else {
3429                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3430                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3431                 if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3432                     (!is_power_of_2(sbi->s_inode_size)) ||
3433                     (sbi->s_inode_size > blocksize)) {
3434                         ext4_msg(sb, KERN_ERR,
3435                                "unsupported inode size: %d",
3436                                sbi->s_inode_size);
3437                         goto failed_mount;
3438                 }
3439                 if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
3440                         sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
3441         }
3442
3443         sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
3444         if (ext4_has_feature_64bit(sb)) {
3445                 if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
3446                     sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
3447                     !is_power_of_2(sbi->s_desc_size)) {
3448                         ext4_msg(sb, KERN_ERR,
3449                                "unsupported descriptor size %lu",
3450                                sbi->s_desc_size);
3451                         goto failed_mount;
3452                 }
3453         } else
3454                 sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
3455
3456         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
3457         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
3458         if (EXT4_INODE_SIZE(sb) == 0 || EXT4_INODES_PER_GROUP(sb) == 0)
3459                 goto cantfind_ext4;
3460
3461         sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
3462         if (sbi->s_inodes_per_block == 0)
3463                 goto cantfind_ext4;
3464         sbi->s_itb_per_group = sbi->s_inodes_per_group /
3465                                         sbi->s_inodes_per_block;
3466         sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
3467         sbi->s_sbh = bh;
3468         sbi->s_mount_state = le16_to_cpu(es->s_state);
3469         sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
3470         sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
3471
3472         for (i = 0; i < 4; i++)
3473                 sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
3474         sbi->s_def_hash_version = es->s_def_hash_version;
3475         if (ext4_has_feature_dir_index(sb)) {
3476                 i = le32_to_cpu(es->s_flags);
3477                 if (i & EXT2_FLAGS_UNSIGNED_HASH)
3478                         sbi->s_hash_unsigned = 3;
3479                 else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
3480 #ifdef __CHAR_UNSIGNED__
3481                         if (!(sb->s_flags & MS_RDONLY))
3482                                 es->s_flags |=
3483                                         cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
3484                         sbi->s_hash_unsigned = 3;
3485 #else
3486                         if (!(sb->s_flags & MS_RDONLY))
3487                                 es->s_flags |=
3488                                         cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
3489 #endif
3490                 }
3491         }
3492
3493         /* Handle clustersize */
3494         clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
3495         has_bigalloc = ext4_has_feature_bigalloc(sb);
3496         if (has_bigalloc) {
3497                 if (clustersize < blocksize) {
3498                         ext4_msg(sb, KERN_ERR,
3499                                  "cluster size (%d) smaller than "
3500                                  "block size (%d)", clustersize, blocksize);
3501                         goto failed_mount;
3502                 }
3503                 sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
3504                         le32_to_cpu(es->s_log_block_size);
3505                 sbi->s_clusters_per_group =
3506                         le32_to_cpu(es->s_clusters_per_group);
3507                 if (sbi->s_clusters_per_group > blocksize * 8) {
3508                         ext4_msg(sb, KERN_ERR,
3509                                  "#clusters per group too big: %lu",
3510                                  sbi->s_clusters_per_group);
3511                         goto failed_mount;
3512                 }
3513                 if (sbi->s_blocks_per_group !=
3514                     (sbi->s_clusters_per_group * (clustersize / blocksize))) {
3515                         ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
3516                                  "clusters per group (%lu) inconsistent",
3517                                  sbi->s_blocks_per_group,
3518                                  sbi->s_clusters_per_group);
3519                         goto failed_mount;
3520                 }
3521         } else {
3522                 if (clustersize != blocksize) {
3523                         ext4_warning(sb, "fragment/cluster size (%d) != "
3524                                      "block size (%d)", clustersize,
3525                                      blocksize);
3526                         clustersize = blocksize;
3527                 }
3528                 if (sbi->s_blocks_per_group > blocksize * 8) {
3529                         ext4_msg(sb, KERN_ERR,
3530                                  "#blocks per group too big: %lu",
3531                                  sbi->s_blocks_per_group);
3532                         goto failed_mount;
3533                 }
3534                 sbi->s_clusters_per_group = sbi->s_blocks_per_group;
3535                 sbi->s_cluster_bits = 0;
3536         }
3537         sbi->s_cluster_ratio = clustersize / blocksize;
3538
3539         if (sbi->s_inodes_per_group > blocksize * 8) {
3540                 ext4_msg(sb, KERN_ERR,
3541                        "#inodes per group too big: %lu",
3542                        sbi->s_inodes_per_group);
3543                 goto failed_mount;
3544         }
3545
3546         /* Do we have standard group size of clustersize * 8 blocks ? */
3547         if (sbi->s_blocks_per_group == clustersize << 3)
3548                 set_opt2(sb, STD_GROUP_SIZE);
3549
3550         /*
3551          * Test whether we have more sectors than will fit in sector_t,
3552          * and whether the max offset is addressable by the page cache.
3553          */
3554         err = generic_check_addressable(sb->s_blocksize_bits,
3555                                         ext4_blocks_count(es));
3556         if (err) {
3557                 ext4_msg(sb, KERN_ERR, "filesystem"
3558                          " too large to mount safely on this system");
3559                 if (sizeof(sector_t) < 8)
3560                         ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
3561                 goto failed_mount;
3562         }
3563
3564         if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
3565                 goto cantfind_ext4;
3566
3567         /* check blocks count against device size */
3568         blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
3569         if (blocks_count && ext4_blocks_count(es) > blocks_count) {
3570                 ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
3571                        "exceeds size of device (%llu blocks)",
3572                        ext4_blocks_count(es), blocks_count);
3573                 goto failed_mount;
3574         }
3575
3576         /*
3577          * It makes no sense for the first data block to be beyond the end
3578          * of the filesystem.
3579          */
3580         if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
3581                 ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
3582                          "block %u is beyond end of filesystem (%llu)",
3583                          le32_to_cpu(es->s_first_data_block),
3584                          ext4_blocks_count(es));
3585                 goto failed_mount;
3586         }
3587         blocks_count = (ext4_blocks_count(es) -
3588                         le32_to_cpu(es->s_first_data_block) +
3589                         EXT4_BLOCKS_PER_GROUP(sb) - 1);
3590         do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
3591         if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
3592                 ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
3593                        "(block count %llu, first data block %u, "
3594                        "blocks per group %lu)", sbi->s_groups_count,
3595                        ext4_blocks_count(es),
3596                        le32_to_cpu(es->s_first_data_block),
3597                        EXT4_BLOCKS_PER_GROUP(sb));
3598                 goto failed_mount;
3599         }
3600         sbi->s_groups_count = blocks_count;
3601         sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
3602                         (EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
3603         db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
3604                    EXT4_DESC_PER_BLOCK(sb);
3605         sbi->s_group_desc = ext4_kvmalloc(db_count *
3606                                           sizeof(struct buffer_head *),
3607                                           GFP_KERNEL);
3608         if (sbi->s_group_desc == NULL) {
3609                 ext4_msg(sb, KERN_ERR, "not enough memory");
3610                 ret = -ENOMEM;
3611                 goto failed_mount;
3612         }
3613
3614         bgl_lock_init(sbi->s_blockgroup_lock);
3615
3616         for (i = 0; i < db_count; i++) {
3617                 block = descriptor_loc(sb, logical_sb_block, i);
3618                 sbi->s_group_desc[i] = sb_bread_unmovable(sb, block);
3619                 if (!sbi->s_group_desc[i]) {
3620                         ext4_msg(sb, KERN_ERR,
3621                                "can't read group descriptor %d", i);
3622                         db_count = i;
3623                         goto failed_mount2;
3624                 }
3625         }
3626         if (!ext4_check_descriptors(sb, &first_not_zeroed)) {
3627                 ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
3628                 ret = -EFSCORRUPTED;
3629                 goto failed_mount2;
3630         }
3631
3632         sbi->s_gdb_count = db_count;
3633         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
3634         spin_lock_init(&sbi->s_next_gen_lock);
3635
3636         setup_timer(&sbi->s_err_report, print_daily_error_info,
3637                 (unsigned long) sb);
3638
3639         /* Register extent status tree shrinker */
3640         if (ext4_es_register_shrinker(sbi))
3641                 goto failed_mount3;
3642
3643         sbi->s_stripe = ext4_get_stripe_size(sbi);
3644         sbi->s_extent_max_zeroout_kb = 32;
3645
3646         /*
3647          * set up enough so that it can read an inode
3648          */
3649         sb->s_op = &ext4_sops;
3650         sb->s_export_op = &ext4_export_ops;
3651         sb->s_xattr = ext4_xattr_handlers;
3652 #ifdef CONFIG_QUOTA
3653         sb->dq_op = &ext4_quota_operations;
3654         if (ext4_has_feature_quota(sb))
3655                 sb->s_qcop = &dquot_quotactl_sysfile_ops;
3656         else
3657                 sb->s_qcop = &ext4_qctl_operations;
3658         sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP;
3659 #endif
3660         memcpy(sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
3661
3662         INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
3663         mutex_init(&sbi->s_orphan_lock);
3664
3665         sb->s_root = NULL;
3666
3667         needs_recovery = (es->s_last_orphan != 0 ||
3668                           ext4_has_feature_journal_needs_recovery(sb));
3669
3670         if (ext4_has_feature_mmp(sb) && !(sb->s_flags & MS_RDONLY))
3671                 if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
3672                         goto failed_mount3a;
3673
3674         /*
3675          * The first inode we look at is the journal inode.  Don't try
3676          * root first: it may be modified in the journal!
3677          */
3678         if (!test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) {
3679                 if (ext4_load_journal(sb, es, journal_devnum))
3680                         goto failed_mount3a;
3681         } else if (test_opt(sb, NOLOAD) && !(sb->s_flags & MS_RDONLY) &&
3682                    ext4_has_feature_journal_needs_recovery(sb)) {
3683                 ext4_msg(sb, KERN_ERR, "required journal recovery "
3684                        "suppressed and not mounted read-only");
3685                 goto failed_mount_wq;
3686         } else {
3687                 /* Nojournal mode, all journal mount options are illegal */
3688                 if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM)) {
3689                         ext4_msg(sb, KERN_ERR, "can't mount with "
3690                                  "journal_checksum, fs mounted w/o journal");
3691                         goto failed_mount_wq;
3692                 }
3693                 if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3694                         ext4_msg(sb, KERN_ERR, "can't mount with "
3695                                  "journal_async_commit, fs mounted w/o journal");
3696                         goto failed_mount_wq;
3697                 }
3698                 if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
3699                         ext4_msg(sb, KERN_ERR, "can't mount with "
3700                                  "commit=%lu, fs mounted w/o journal",
3701                                  sbi->s_commit_interval / HZ);
3702                         goto failed_mount_wq;
3703                 }
3704                 if (EXT4_MOUNT_DATA_FLAGS &
3705                     (sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
3706                         ext4_msg(sb, KERN_ERR, "can't mount with "
3707                                  "data=, fs mounted w/o journal");
3708                         goto failed_mount_wq;
3709                 }
3710                 sbi->s_def_mount_opt &= EXT4_MOUNT_JOURNAL_CHECKSUM;
3711                 clear_opt(sb, JOURNAL_CHECKSUM);
3712                 clear_opt(sb, DATA_FLAGS);
3713                 sbi->s_journal = NULL;
3714                 needs_recovery = 0;
3715                 goto no_journal;
3716         }
3717
3718         if (ext4_has_feature_64bit(sb) &&
3719             !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
3720                                        JBD2_FEATURE_INCOMPAT_64BIT)) {
3721                 ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
3722                 goto failed_mount_wq;
3723         }
3724
3725         if (!set_journal_csum_feature_set(sb)) {
3726                 ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
3727                          "feature set");
3728                 goto failed_mount_wq;
3729         }
3730
3731         /* We have now updated the journal if required, so we can
3732          * validate the data journaling mode. */
3733         switch (test_opt(sb, DATA_FLAGS)) {
3734         case 0:
3735                 /* No mode set, assume a default based on the journal
3736                  * capabilities: ORDERED_DATA if the journal can
3737                  * cope, else JOURNAL_DATA
3738                  */
3739                 if (jbd2_journal_check_available_features
3740                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
3741                         set_opt(sb, ORDERED_DATA);
3742                 else
3743                         set_opt(sb, JOURNAL_DATA);
3744                 break;
3745
3746         case EXT4_MOUNT_ORDERED_DATA:
3747         case EXT4_MOUNT_WRITEBACK_DATA:
3748                 if (!jbd2_journal_check_available_features
3749                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
3750                         ext4_msg(sb, KERN_ERR, "Journal does not support "
3751                                "requested data journaling mode");
3752                         goto failed_mount_wq;
3753                 }
3754         default:
3755                 break;
3756         }
3757         set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
3758
3759         sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
3760
3761 no_journal:
3762         if (ext4_mballoc_ready) {
3763                 sbi->s_mb_cache = ext4_xattr_create_cache(sb->s_id);
3764                 if (!sbi->s_mb_cache) {
3765                         ext4_msg(sb, KERN_ERR, "Failed to create an mb_cache");
3766                         goto failed_mount_wq;
3767                 }
3768         }
3769
3770         if ((DUMMY_ENCRYPTION_ENABLED(sbi) || ext4_has_feature_encrypt(sb)) &&
3771             (blocksize != PAGE_CACHE_SIZE)) {
3772                 ext4_msg(sb, KERN_ERR,
3773                          "Unsupported blocksize for fs encryption");
3774                 goto failed_mount_wq;
3775         }
3776
3777         if (DUMMY_ENCRYPTION_ENABLED(sbi) && !(sb->s_flags & MS_RDONLY) &&
3778             !ext4_has_feature_encrypt(sb)) {
3779                 ext4_set_feature_encrypt(sb);
3780                 ext4_commit_super(sb, 1);
3781         }
3782
3783         /*
3784          * Get the # of file system overhead blocks from the
3785          * superblock if present.
3786          */
3787         if (es->s_overhead_clusters)
3788                 sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
3789         else {
3790                 err = ext4_calculate_overhead(sb);
3791                 if (err)
3792                         goto failed_mount_wq;
3793         }
3794
3795         /*
3796          * The maximum number of concurrent works can be high and
3797          * concurrency isn't really necessary.  Limit it to 1.
3798          */
3799         EXT4_SB(sb)->rsv_conversion_wq =
3800                 alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
3801         if (!EXT4_SB(sb)->rsv_conversion_wq) {
3802                 printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
3803                 ret = -ENOMEM;
3804                 goto failed_mount4;
3805         }
3806
3807         /*
3808          * The jbd2_journal_load will have done any necessary log recovery,
3809          * so we can safely mount the rest of the filesystem now.
3810          */
3811
3812         root = ext4_iget(sb, EXT4_ROOT_INO);
3813         if (IS_ERR(root)) {
3814                 ext4_msg(sb, KERN_ERR, "get root inode failed");
3815                 ret = PTR_ERR(root);
3816                 root = NULL;
3817                 goto failed_mount4;
3818         }
3819         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
3820                 ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
3821                 iput(root);
3822                 goto failed_mount4;
3823         }
3824         sb->s_root = d_make_root(root);
3825         if (!sb->s_root) {
3826                 ext4_msg(sb, KERN_ERR, "get root dentry failed");
3827                 ret = -ENOMEM;
3828                 goto failed_mount4;
3829         }
3830
3831         if (ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY))
3832                 sb->s_flags |= MS_RDONLY;
3833
3834         /* determine the minimum size of new large inodes, if present */
3835         if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
3836                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
3837                                                      EXT4_GOOD_OLD_INODE_SIZE;
3838                 if (ext4_has_feature_extra_isize(sb)) {
3839                         if (sbi->s_want_extra_isize <
3840                             le16_to_cpu(es->s_want_extra_isize))
3841                                 sbi->s_want_extra_isize =
3842                                         le16_to_cpu(es->s_want_extra_isize);
3843                         if (sbi->s_want_extra_isize <
3844                             le16_to_cpu(es->s_min_extra_isize))
3845                                 sbi->s_want_extra_isize =
3846                                         le16_to_cpu(es->s_min_extra_isize);
3847                 }
3848         }
3849         /* Check if enough inode space is available */
3850         if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
3851                                                         sbi->s_inode_size) {
3852                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
3853                                                        EXT4_GOOD_OLD_INODE_SIZE;
3854                 ext4_msg(sb, KERN_INFO, "required extra inode space not"
3855                          "available");
3856         }
3857
3858         ext4_set_resv_clusters(sb);
3859
3860         err = ext4_setup_system_zone(sb);
3861         if (err) {
3862                 ext4_msg(sb, KERN_ERR, "failed to initialize system "
3863                          "zone (%d)", err);
3864                 goto failed_mount4a;
3865         }
3866
3867         ext4_ext_init(sb);
3868         err = ext4_mb_init(sb);
3869         if (err) {
3870                 ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
3871                          err);
3872                 goto failed_mount5;
3873         }
3874
3875         block = ext4_count_free_clusters(sb);
3876         ext4_free_blocks_count_set(sbi->s_es,
3877                                    EXT4_C2B(sbi, block));
3878         err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
3879                                   GFP_KERNEL);
3880         if (!err) {
3881                 unsigned long freei = ext4_count_free_inodes(sb);
3882                 sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
3883                 err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
3884                                           GFP_KERNEL);
3885         }
3886         if (!err)
3887                 err = percpu_counter_init(&sbi->s_dirs_counter,
3888                                           ext4_count_dirs(sb), GFP_KERNEL);
3889         if (!err)
3890                 err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
3891                                           GFP_KERNEL);
3892         if (err) {
3893                 ext4_msg(sb, KERN_ERR, "insufficient memory");
3894                 goto failed_mount6;
3895         }
3896
3897         if (ext4_has_feature_flex_bg(sb))
3898                 if (!ext4_fill_flex_info(sb)) {
3899                         ext4_msg(sb, KERN_ERR,
3900                                "unable to initialize "
3901                                "flex_bg meta info!");
3902                         goto failed_mount6;
3903                 }
3904
3905         err = ext4_register_li_request(sb, first_not_zeroed);
3906         if (err)
3907                 goto failed_mount6;
3908
3909         err = ext4_register_sysfs(sb);
3910         if (err)
3911                 goto failed_mount7;
3912
3913 #ifdef CONFIG_QUOTA
3914         /* Enable quota usage during mount. */
3915         if (ext4_has_feature_quota(sb) && !(sb->s_flags & MS_RDONLY)) {
3916                 err = ext4_enable_quotas(sb);
3917                 if (err)
3918                         goto failed_mount8;
3919         }
3920 #endif  /* CONFIG_QUOTA */
3921
3922         EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
3923         ext4_orphan_cleanup(sb, es);
3924         EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
3925         if (needs_recovery) {
3926                 ext4_msg(sb, KERN_INFO, "recovery complete");
3927                 ext4_mark_recovery_complete(sb, es);
3928         }
3929         if (EXT4_SB(sb)->s_journal) {
3930                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
3931                         descr = " journalled data mode";
3932                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
3933                         descr = " ordered data mode";
3934                 else
3935                         descr = " writeback data mode";
3936         } else
3937                 descr = "out journal";
3938
3939         if (test_opt(sb, DISCARD)) {
3940                 struct request_queue *q = bdev_get_queue(sb->s_bdev);
3941                 if (!blk_queue_discard(q))
3942                         ext4_msg(sb, KERN_WARNING,
3943                                  "mounting with \"discard\" option, but "
3944                                  "the device does not support discard");
3945         }
3946
3947         if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
3948                 ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
3949                          "Opts: %s%s%s", descr, sbi->s_es->s_mount_opts,
3950                          *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
3951
3952         if (es->s_error_count)
3953                 mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
3954
3955         /* Enable message ratelimiting. Default is 10 messages per 5 secs. */
3956         ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
3957         ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
3958         ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
3959
3960         kfree(orig_data);
3961         return 0;
3962
3963 cantfind_ext4:
3964         if (!silent)
3965                 ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
3966         goto failed_mount;
3967
3968 #ifdef CONFIG_QUOTA
3969 failed_mount8:
3970         ext4_unregister_sysfs(sb);
3971 #endif
3972 failed_mount7:
3973         ext4_unregister_li_request(sb);
3974 failed_mount6:
3975         ext4_mb_release(sb);
3976         if (sbi->s_flex_groups)
3977                 kvfree(sbi->s_flex_groups);
3978         percpu_counter_destroy(&sbi->s_freeclusters_counter);
3979         percpu_counter_destroy(&sbi->s_freeinodes_counter);
3980         percpu_counter_destroy(&sbi->s_dirs_counter);
3981         percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
3982 failed_mount5:
3983         ext4_ext_release(sb);
3984         ext4_release_system_zone(sb);
3985 failed_mount4a:
3986         dput(sb->s_root);
3987         sb->s_root = NULL;
3988 failed_mount4:
3989         ext4_msg(sb, KERN_ERR, "mount failed");
3990         if (EXT4_SB(sb)->rsv_conversion_wq)
3991                 destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
3992 failed_mount_wq:
3993         if (sbi->s_journal) {
3994                 jbd2_journal_destroy(sbi->s_journal);
3995                 sbi->s_journal = NULL;
3996         }
3997 failed_mount3a:
3998         ext4_es_unregister_shrinker(sbi);
3999 failed_mount3:
4000         del_timer_sync(&sbi->s_err_report);
4001         if (sbi->s_mmp_tsk)
4002                 kthread_stop(sbi->s_mmp_tsk);
4003 failed_mount2:
4004         for (i = 0; i < db_count; i++)
4005                 brelse(sbi->s_group_desc[i]);
4006         kvfree(sbi->s_group_desc);
4007 failed_mount:
4008         if (sbi->s_chksum_driver)
4009                 crypto_free_shash(sbi->s_chksum_driver);
4010 #ifdef CONFIG_QUOTA
4011         for (i = 0; i < EXT4_MAXQUOTAS; i++)
4012                 kfree(sbi->s_qf_names[i]);
4013 #endif
4014         ext4_blkdev_remove(sbi);
4015         brelse(bh);
4016 out_fail:
4017         sb->s_fs_info = NULL;
4018         kfree(sbi->s_blockgroup_lock);
4019         kfree(sbi);
4020 out_free_orig:
4021         kfree(orig_data);
4022         return err ? err : ret;
4023 }
4024
4025 /*
4026  * Setup any per-fs journal parameters now.  We'll do this both on
4027  * initial mount, once the journal has been initialised but before we've
4028  * done any recovery; and again on any subsequent remount.
4029  */
4030 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4031 {
4032         struct ext4_sb_info *sbi = EXT4_SB(sb);
4033
4034         journal->j_commit_interval = sbi->s_commit_interval;
4035         journal->j_min_batch_time = sbi->s_min_batch_time;
4036         journal->j_max_batch_time = sbi->s_max_batch_time;
4037
4038         write_lock(&journal->j_state_lock);
4039         if (test_opt(sb, BARRIER))
4040                 journal->j_flags |= JBD2_BARRIER;
4041         else
4042                 journal->j_flags &= ~JBD2_BARRIER;
4043         if (test_opt(sb, DATA_ERR_ABORT))
4044                 journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4045         else
4046                 journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4047         write_unlock(&journal->j_state_lock);
4048 }
4049
4050 static journal_t *ext4_get_journal(struct super_block *sb,
4051                                    unsigned int journal_inum)
4052 {
4053         struct inode *journal_inode;
4054         journal_t *journal;
4055
4056         BUG_ON(!ext4_has_feature_journal(sb));
4057
4058         /* First, test for the existence of a valid inode on disk.  Bad
4059          * things happen if we iget() an unused inode, as the subsequent
4060          * iput() will try to delete it. */
4061
4062         journal_inode = ext4_iget(sb, journal_inum);
4063         if (IS_ERR(journal_inode)) {
4064                 ext4_msg(sb, KERN_ERR, "no journal found");
4065                 return NULL;
4066         }
4067         if (!journal_inode->i_nlink) {
4068                 make_bad_inode(journal_inode);
4069                 iput(journal_inode);
4070                 ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4071                 return NULL;
4072         }
4073
4074         jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4075                   journal_inode, journal_inode->i_size);
4076         if (!S_ISREG(journal_inode->i_mode)) {
4077                 ext4_msg(sb, KERN_ERR, "invalid journal inode");
4078                 iput(journal_inode);
4079                 return NULL;
4080         }
4081
4082         journal = jbd2_journal_init_inode(journal_inode);
4083         if (!journal) {
4084                 ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4085                 iput(journal_inode);
4086                 return NULL;
4087         }
4088         journal->j_private = sb;
4089         ext4_init_journal_params(sb, journal);
4090         return journal;
4091 }
4092
4093 static journal_t *ext4_get_dev_journal(struct super_block *sb,
4094                                        dev_t j_dev)
4095 {
4096         struct buffer_head *bh;
4097         journal_t *journal;
4098         ext4_fsblk_t start;
4099         ext4_fsblk_t len;
4100         int hblock, blocksize;
4101         ext4_fsblk_t sb_block;
4102         unsigned long offset;
4103         struct ext4_super_block *es;
4104         struct block_device *bdev;
4105
4106         BUG_ON(!ext4_has_feature_journal(sb));
4107
4108         bdev = ext4_blkdev_get(j_dev, sb);
4109         if (bdev == NULL)
4110                 return NULL;
4111
4112         blocksize = sb->s_blocksize;
4113         hblock = bdev_logical_block_size(bdev);
4114         if (blocksize < hblock) {
4115                 ext4_msg(sb, KERN_ERR,
4116                         "blocksize too small for journal device");
4117                 goto out_bdev;
4118         }
4119
4120         sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4121         offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4122         set_blocksize(bdev, blocksize);
4123         if (!(bh = __bread(bdev, sb_block, blocksize))) {
4124                 ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4125                        "external journal");
4126                 goto out_bdev;
4127         }
4128
4129         es = (struct ext4_super_block *) (bh->b_data + offset);
4130         if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4131             !(le32_to_cpu(es->s_feature_incompat) &
4132               EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4133                 ext4_msg(sb, KERN_ERR, "external journal has "
4134                                         "bad superblock");
4135                 brelse(bh);
4136                 goto out_bdev;
4137         }
4138
4139         if ((le32_to_cpu(es->s_feature_ro_compat) &
4140              EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
4141             es->s_checksum != ext4_superblock_csum(sb, es)) {
4142                 ext4_msg(sb, KERN_ERR, "external journal has "
4143                                        "corrupt superblock");
4144                 brelse(bh);
4145                 goto out_bdev;
4146         }
4147
4148         if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4149                 ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4150                 brelse(bh);
4151                 goto out_bdev;
4152         }
4153
4154         len = ext4_blocks_count(es);
4155         start = sb_block + 1;
4156         brelse(bh);     /* we're done with the superblock */
4157
4158         journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4159                                         start, len, blocksize);
4160         if (!journal) {
4161                 ext4_msg(sb, KERN_ERR, "failed to create device journal");
4162                 goto out_bdev;
4163         }
4164         journal->j_private = sb;
4165         ll_rw_block(READ | REQ_META | REQ_PRIO, 1, &journal->j_sb_buffer);
4166         wait_on_buffer(journal->j_sb_buffer);
4167         if (!buffer_uptodate(journal->j_sb_buffer)) {
4168                 ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4169                 goto out_journal;
4170         }
4171         if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4172                 ext4_msg(sb, KERN_ERR, "External journal has more than one "
4173                                         "user (unsupported) - %d",
4174                         be32_to_cpu(journal->j_superblock->s_nr_users));
4175                 goto out_journal;
4176         }
4177         EXT4_SB(sb)->journal_bdev = bdev;
4178         ext4_init_journal_params(sb, journal);
4179         return journal;
4180
4181 out_journal:
4182         jbd2_journal_destroy(journal);
4183 out_bdev:
4184         ext4_blkdev_put(bdev);
4185         return NULL;
4186 }
4187
4188 static int ext4_load_journal(struct super_block *sb,
4189                              struct ext4_super_block *es,
4190                              unsigned long journal_devnum)
4191 {
4192         journal_t *journal;
4193         unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4194         dev_t journal_dev;
4195         int err = 0;
4196         int really_read_only;
4197
4198         BUG_ON(!ext4_has_feature_journal(sb));
4199
4200         if (journal_devnum &&
4201             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4202                 ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4203                         "numbers have changed");
4204                 journal_dev = new_decode_dev(journal_devnum);
4205         } else
4206                 journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4207
4208         really_read_only = bdev_read_only(sb->s_bdev);
4209
4210         /*
4211          * Are we loading a blank journal or performing recovery after a
4212          * crash?  For recovery, we need to check in advance whether we
4213          * can get read-write access to the device.
4214          */
4215         if (ext4_has_feature_journal_needs_recovery(sb)) {
4216                 if (sb->s_flags & MS_RDONLY) {
4217                         ext4_msg(sb, KERN_INFO, "INFO: recovery "
4218                                         "required on readonly filesystem");
4219                         if (really_read_only) {
4220                                 ext4_msg(sb, KERN_ERR, "write access "
4221                                         "unavailable, cannot proceed");
4222                                 return -EROFS;
4223                         }
4224                         ext4_msg(sb, KERN_INFO, "write access will "
4225                                "be enabled during recovery");
4226                 }
4227         }
4228
4229         if (journal_inum && journal_dev) {
4230                 ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4231                        "and inode journals!");
4232                 return -EINVAL;
4233         }
4234
4235         if (journal_inum) {
4236                 if (!(journal = ext4_get_journal(sb, journal_inum)))
4237                         return -EINVAL;
4238         } else {
4239                 if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4240                         return -EINVAL;
4241         }
4242
4243         if (!(journal->j_flags & JBD2_BARRIER))
4244                 ext4_msg(sb, KERN_INFO, "barriers disabled");
4245
4246         if (!ext4_has_feature_journal_needs_recovery(sb))
4247                 err = jbd2_journal_wipe(journal, !really_read_only);
4248         if (!err) {
4249                 char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4250                 if (save)
4251                         memcpy(save, ((char *) es) +
4252                                EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4253                 err = jbd2_journal_load(journal);
4254                 if (save)
4255                         memcpy(((char *) es) + EXT4_S_ERR_START,
4256                                save, EXT4_S_ERR_LEN);
4257                 kfree(save);
4258         }
4259
4260         if (err) {
4261                 ext4_msg(sb, KERN_ERR, "error loading journal");
4262                 jbd2_journal_destroy(journal);
4263                 return err;
4264         }
4265
4266         EXT4_SB(sb)->s_journal = journal;
4267         ext4_clear_journal_err(sb, es);
4268
4269         if (!really_read_only && journal_devnum &&
4270             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4271                 es->s_journal_dev = cpu_to_le32(journal_devnum);
4272
4273                 /* Make sure we flush the recovery flag to disk. */
4274                 ext4_commit_super(sb, 1);
4275         }
4276
4277         return 0;
4278 }
4279
4280 static int ext4_commit_super(struct super_block *sb, int sync)
4281 {
4282         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4283         struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4284         int error = 0;
4285
4286         if (!sbh || block_device_ejected(sb))
4287                 return error;
4288         if (buffer_write_io_error(sbh)) {
4289                 /*
4290                  * Oh, dear.  A previous attempt to write the
4291                  * superblock failed.  This could happen because the
4292                  * USB device was yanked out.  Or it could happen to
4293                  * be a transient write error and maybe the block will
4294                  * be remapped.  Nothing we can do but to retry the
4295                  * write and hope for the best.
4296                  */
4297                 ext4_msg(sb, KERN_ERR, "previous I/O error to "
4298                        "superblock detected");
4299                 clear_buffer_write_io_error(sbh);
4300                 set_buffer_uptodate(sbh);
4301         }
4302         /*
4303          * If the file system is mounted read-only, don't update the
4304          * superblock write time.  This avoids updating the superblock
4305          * write time when we are mounting the root file system
4306          * read/only but we need to replay the journal; at that point,
4307          * for people who are east of GMT and who make their clock
4308          * tick in localtime for Windows bug-for-bug compatibility,
4309          * the clock is set in the future, and this will cause e2fsck
4310          * to complain and force a full file system check.
4311          */
4312         if (!(sb->s_flags & MS_RDONLY))
4313                 es->s_wtime = cpu_to_le32(get_seconds());
4314         if (sb->s_bdev->bd_part)
4315                 es->s_kbytes_written =
4316                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
4317                             ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
4318                               EXT4_SB(sb)->s_sectors_written_start) >> 1));
4319         else
4320                 es->s_kbytes_written =
4321                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
4322         if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeclusters_counter))
4323                 ext4_free_blocks_count_set(es,
4324                         EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
4325                                 &EXT4_SB(sb)->s_freeclusters_counter)));
4326         if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeinodes_counter))
4327                 es->s_free_inodes_count =
4328                         cpu_to_le32(percpu_counter_sum_positive(
4329                                 &EXT4_SB(sb)->s_freeinodes_counter));
4330         BUFFER_TRACE(sbh, "marking dirty");
4331         ext4_superblock_csum_set(sb);
4332         mark_buffer_dirty(sbh);
4333         if (sync) {
4334                 error = __sync_dirty_buffer(sbh,
4335                         test_opt(sb, BARRIER) ? WRITE_FUA : WRITE_SYNC);
4336                 if (error)
4337                         return error;
4338
4339                 error = buffer_write_io_error(sbh);
4340                 if (error) {
4341                         ext4_msg(sb, KERN_ERR, "I/O error while writing "
4342                                "superblock");
4343                         clear_buffer_write_io_error(sbh);
4344                         set_buffer_uptodate(sbh);
4345                 }
4346         }
4347         return error;
4348 }
4349
4350 /*
4351  * Have we just finished recovery?  If so, and if we are mounting (or
4352  * remounting) the filesystem readonly, then we will end up with a
4353  * consistent fs on disk.  Record that fact.
4354  */
4355 static void ext4_mark_recovery_complete(struct super_block *sb,
4356                                         struct ext4_super_block *es)
4357 {
4358         journal_t *journal = EXT4_SB(sb)->s_journal;
4359
4360         if (!ext4_has_feature_journal(sb)) {
4361                 BUG_ON(journal != NULL);
4362                 return;
4363         }
4364         jbd2_journal_lock_updates(journal);
4365         if (jbd2_journal_flush(journal) < 0)
4366                 goto out;
4367
4368         if (ext4_has_feature_journal_needs_recovery(sb) &&
4369             sb->s_flags & MS_RDONLY) {
4370                 ext4_clear_feature_journal_needs_recovery(sb);
4371                 ext4_commit_super(sb, 1);
4372         }
4373
4374 out:
4375         jbd2_journal_unlock_updates(journal);
4376 }
4377
4378 /*
4379  * If we are mounting (or read-write remounting) a filesystem whose journal
4380  * has recorded an error from a previous lifetime, move that error to the
4381  * main filesystem now.
4382  */
4383 static void ext4_clear_journal_err(struct super_block *sb,
4384                                    struct ext4_super_block *es)
4385 {
4386         journal_t *journal;
4387         int j_errno;
4388         const char *errstr;
4389
4390         BUG_ON(!ext4_has_feature_journal(sb));
4391
4392         journal = EXT4_SB(sb)->s_journal;
4393
4394         /*
4395          * Now check for any error status which may have been recorded in the
4396          * journal by a prior ext4_error() or ext4_abort()
4397          */
4398
4399         j_errno = jbd2_journal_errno(journal);
4400         if (j_errno) {
4401                 char nbuf[16];
4402
4403                 errstr = ext4_decode_error(sb, j_errno, nbuf);
4404                 ext4_warning(sb, "Filesystem error recorded "
4405                              "from previous mount: %s", errstr);
4406                 ext4_warning(sb, "Marking fs in need of filesystem check.");
4407
4408                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
4409                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
4410                 ext4_commit_super(sb, 1);
4411
4412                 jbd2_journal_clear_err(journal);
4413                 jbd2_journal_update_sb_errno(journal);
4414         }
4415 }
4416
4417 /*
4418  * Force the running and committing transactions to commit,
4419  * and wait on the commit.
4420  */
4421 int ext4_force_commit(struct super_block *sb)
4422 {
4423         journal_t *journal;
4424
4425         if (sb->s_flags & MS_RDONLY)
4426                 return 0;
4427
4428         journal = EXT4_SB(sb)->s_journal;
4429         return ext4_journal_force_commit(journal);
4430 }
4431
4432 static int ext4_sync_fs(struct super_block *sb, int wait)
4433 {
4434         int ret = 0;
4435         tid_t target;
4436         bool needs_barrier = false;
4437         struct ext4_sb_info *sbi = EXT4_SB(sb);
4438
4439         trace_ext4_sync_fs(sb, wait);
4440         flush_workqueue(sbi->rsv_conversion_wq);
4441         /*
4442          * Writeback quota in non-journalled quota case - journalled quota has
4443          * no dirty dquots
4444          */
4445         dquot_writeback_dquots(sb, -1);
4446         /*
4447          * Data writeback is possible w/o journal transaction, so barrier must
4448          * being sent at the end of the function. But we can skip it if
4449          * transaction_commit will do it for us.
4450          */
4451         if (sbi->s_journal) {
4452                 target = jbd2_get_latest_transaction(sbi->s_journal);
4453                 if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
4454                     !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
4455                         needs_barrier = true;
4456
4457                 if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
4458                         if (wait)
4459                                 ret = jbd2_log_wait_commit(sbi->s_journal,
4460                                                            target);
4461                 }
4462         } else if (wait && test_opt(sb, BARRIER))
4463                 needs_barrier = true;
4464         if (needs_barrier) {
4465                 int err;
4466                 err = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
4467                 if (!ret)
4468                         ret = err;
4469         }
4470
4471         return ret;
4472 }
4473
4474 /*
4475  * LVM calls this function before a (read-only) snapshot is created.  This
4476  * gives us a chance to flush the journal completely and mark the fs clean.
4477  *
4478  * Note that only this function cannot bring a filesystem to be in a clean
4479  * state independently. It relies on upper layer to stop all data & metadata
4480  * modifications.
4481  */
4482 static int ext4_freeze(struct super_block *sb)
4483 {
4484         int error = 0;
4485         journal_t *journal;
4486
4487         if (sb->s_flags & MS_RDONLY)
4488                 return 0;
4489
4490         journal = EXT4_SB(sb)->s_journal;
4491
4492         if (journal) {
4493                 /* Now we set up the journal barrier. */
4494                 jbd2_journal_lock_updates(journal);
4495
4496                 /*
4497                  * Don't clear the needs_recovery flag if we failed to
4498                  * flush the journal.
4499                  */
4500                 error = jbd2_journal_flush(journal);
4501                 if (error < 0)
4502                         goto out;
4503
4504                 /* Journal blocked and flushed, clear needs_recovery flag. */
4505                 ext4_clear_feature_journal_needs_recovery(sb);
4506         }
4507
4508         error = ext4_commit_super(sb, 1);
4509 out:
4510         if (journal)
4511                 /* we rely on upper layer to stop further updates */
4512                 jbd2_journal_unlock_updates(journal);
4513         return error;
4514 }
4515
4516 /*
4517  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
4518  * flag here, even though the filesystem is not technically dirty yet.
4519  */
4520 static int ext4_unfreeze(struct super_block *sb)
4521 {
4522         if (sb->s_flags & MS_RDONLY)
4523                 return 0;
4524
4525         if (EXT4_SB(sb)->s_journal) {
4526                 /* Reset the needs_recovery flag before the fs is unlocked. */
4527                 ext4_set_feature_journal_needs_recovery(sb);
4528         }
4529
4530         ext4_commit_super(sb, 1);
4531         return 0;
4532 }
4533
4534 /*
4535  * Structure to save mount options for ext4_remount's benefit
4536  */
4537 struct ext4_mount_options {
4538         unsigned long s_mount_opt;
4539         unsigned long s_mount_opt2;
4540         kuid_t s_resuid;
4541         kgid_t s_resgid;
4542         unsigned long s_commit_interval;
4543         u32 s_min_batch_time, s_max_batch_time;
4544 #ifdef CONFIG_QUOTA
4545         int s_jquota_fmt;
4546         char *s_qf_names[EXT4_MAXQUOTAS];
4547 #endif
4548 };
4549
4550 static int ext4_remount(struct super_block *sb, int *flags, char *data)
4551 {
4552         struct ext4_super_block *es;
4553         struct ext4_sb_info *sbi = EXT4_SB(sb);
4554         unsigned long old_sb_flags;
4555         struct ext4_mount_options old_opts;
4556         int enable_quota = 0;
4557         ext4_group_t g;
4558         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4559         int err = 0;
4560 #ifdef CONFIG_QUOTA
4561         int i, j;
4562 #endif
4563         char *orig_data = kstrdup(data, GFP_KERNEL);
4564
4565         /* Store the original options */
4566         old_sb_flags = sb->s_flags;
4567         old_opts.s_mount_opt = sbi->s_mount_opt;
4568         old_opts.s_mount_opt2 = sbi->s_mount_opt2;
4569         old_opts.s_resuid = sbi->s_resuid;
4570         old_opts.s_resgid = sbi->s_resgid;
4571         old_opts.s_commit_interval = sbi->s_commit_interval;
4572         old_opts.s_min_batch_time = sbi->s_min_batch_time;
4573         old_opts.s_max_batch_time = sbi->s_max_batch_time;
4574 #ifdef CONFIG_QUOTA
4575         old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
4576         for (i = 0; i < EXT4_MAXQUOTAS; i++)
4577                 if (sbi->s_qf_names[i]) {
4578                         old_opts.s_qf_names[i] = kstrdup(sbi->s_qf_names[i],
4579                                                          GFP_KERNEL);
4580                         if (!old_opts.s_qf_names[i]) {
4581                                 for (j = 0; j < i; j++)
4582                                         kfree(old_opts.s_qf_names[j]);
4583                                 kfree(orig_data);
4584                                 return -ENOMEM;
4585                         }
4586                 } else
4587                         old_opts.s_qf_names[i] = NULL;
4588 #endif
4589         if (sbi->s_journal && sbi->s_journal->j_task->io_context)
4590                 journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
4591
4592         if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
4593                 err = -EINVAL;
4594                 goto restore_opts;
4595         }
4596
4597         if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
4598             test_opt(sb, JOURNAL_CHECKSUM)) {
4599                 ext4_msg(sb, KERN_ERR, "changing journal_checksum "
4600                          "during remount not supported; ignoring");
4601                 sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
4602         }
4603
4604         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
4605                 if (test_opt2(sb, EXPLICIT_DELALLOC)) {
4606                         ext4_msg(sb, KERN_ERR, "can't mount with "
4607                                  "both data=journal and delalloc");
4608                         err = -EINVAL;
4609                         goto restore_opts;
4610                 }
4611                 if (test_opt(sb, DIOREAD_NOLOCK)) {
4612                         ext4_msg(sb, KERN_ERR, "can't mount with "
4613                                  "both data=journal and dioread_nolock");
4614                         err = -EINVAL;
4615                         goto restore_opts;
4616                 }
4617                 if (test_opt(sb, DAX)) {
4618                         ext4_msg(sb, KERN_ERR, "can't mount with "
4619                                  "both data=journal and dax");
4620                         err = -EINVAL;
4621                         goto restore_opts;
4622                 }
4623         }
4624
4625         if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_DAX) {
4626                 ext4_msg(sb, KERN_WARNING, "warning: refusing change of "
4627                         "dax flag with busy inodes while remounting");
4628                 sbi->s_mount_opt ^= EXT4_MOUNT_DAX;
4629         }
4630
4631         if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
4632                 ext4_abort(sb, "Abort forced by user");
4633
4634         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
4635                 (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
4636
4637         es = sbi->s_es;
4638
4639         if (sbi->s_journal) {
4640                 ext4_init_journal_params(sb, sbi->s_journal);
4641                 set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4642         }
4643
4644         if (*flags & MS_LAZYTIME)
4645                 sb->s_flags |= MS_LAZYTIME;
4646
4647         if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY)) {
4648                 if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
4649                         err = -EROFS;
4650                         goto restore_opts;
4651                 }
4652
4653                 if (*flags & MS_RDONLY) {
4654                         err = sync_filesystem(sb);
4655                         if (err < 0)
4656                                 goto restore_opts;
4657                         err = dquot_suspend(sb, -1);
4658                         if (err < 0)
4659                                 goto restore_opts;
4660
4661                         /*
4662                          * First of all, the unconditional stuff we have to do
4663                          * to disable replay of the journal when we next remount
4664                          */
4665                         sb->s_flags |= MS_RDONLY;
4666
4667                         /*
4668                          * OK, test if we are remounting a valid rw partition
4669                          * readonly, and if so set the rdonly flag and then
4670                          * mark the partition as valid again.
4671                          */
4672                         if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
4673                             (sbi->s_mount_state & EXT4_VALID_FS))
4674                                 es->s_state = cpu_to_le16(sbi->s_mount_state);
4675
4676                         if (sbi->s_journal)
4677                                 ext4_mark_recovery_complete(sb, es);
4678                 } else {
4679                         /* Make sure we can mount this feature set readwrite */
4680                         if (ext4_has_feature_readonly(sb) ||
4681                             !ext4_feature_set_ok(sb, 0)) {
4682                                 err = -EROFS;
4683                                 goto restore_opts;
4684                         }
4685                         /*
4686                          * Make sure the group descriptor checksums
4687                          * are sane.  If they aren't, refuse to remount r/w.
4688                          */
4689                         for (g = 0; g < sbi->s_groups_count; g++) {
4690                                 struct ext4_group_desc *gdp =
4691                                         ext4_get_group_desc(sb, g, NULL);
4692
4693                                 if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
4694                                         ext4_msg(sb, KERN_ERR,
4695                "ext4_remount: Checksum for group %u failed (%u!=%u)",
4696                 g, le16_to_cpu(ext4_group_desc_csum(sb, g, gdp)),
4697                                                le16_to_cpu(gdp->bg_checksum));
4698                                         err = -EFSBADCRC;
4699                                         goto restore_opts;
4700                                 }
4701                         }
4702
4703                         /*
4704                          * If we have an unprocessed orphan list hanging
4705                          * around from a previously readonly bdev mount,
4706                          * require a full umount/remount for now.
4707                          */
4708                         if (es->s_last_orphan) {
4709                                 ext4_msg(sb, KERN_WARNING, "Couldn't "
4710                                        "remount RDWR because of unprocessed "
4711                                        "orphan inode list.  Please "
4712                                        "umount/remount instead");
4713                                 err = -EINVAL;
4714                                 goto restore_opts;
4715                         }
4716
4717                         /*
4718                          * Mounting a RDONLY partition read-write, so reread
4719                          * and store the current valid flag.  (It may have
4720                          * been changed by e2fsck since we originally mounted
4721                          * the partition.)
4722                          */
4723                         if (sbi->s_journal)
4724                                 ext4_clear_journal_err(sb, es);
4725                         sbi->s_mount_state = le16_to_cpu(es->s_state);
4726                         if (!ext4_setup_super(sb, es, 0))
4727                                 sb->s_flags &= ~MS_RDONLY;
4728                         if (ext4_has_feature_mmp(sb))
4729                                 if (ext4_multi_mount_protect(sb,
4730                                                 le64_to_cpu(es->s_mmp_block))) {
4731                                         err = -EROFS;
4732                                         goto restore_opts;
4733                                 }
4734                         enable_quota = 1;
4735                 }
4736         }
4737
4738         /*
4739          * Reinitialize lazy itable initialization thread based on
4740          * current settings
4741          */
4742         if ((sb->s_flags & MS_RDONLY) || !test_opt(sb, INIT_INODE_TABLE))
4743                 ext4_unregister_li_request(sb);
4744         else {
4745                 ext4_group_t first_not_zeroed;
4746                 first_not_zeroed = ext4_has_uninit_itable(sb);
4747                 ext4_register_li_request(sb, first_not_zeroed);
4748         }
4749
4750         ext4_setup_system_zone(sb);
4751         if (sbi->s_journal == NULL && !(old_sb_flags & MS_RDONLY))
4752                 ext4_commit_super(sb, 1);
4753
4754 #ifdef CONFIG_QUOTA
4755         /* Release old quota file names */
4756         for (i = 0; i < EXT4_MAXQUOTAS; i++)
4757                 kfree(old_opts.s_qf_names[i]);
4758         if (enable_quota) {
4759                 if (sb_any_quota_suspended(sb))
4760                         dquot_resume(sb, -1);
4761                 else if (ext4_has_feature_quota(sb)) {
4762                         err = ext4_enable_quotas(sb);
4763                         if (err)
4764                                 goto restore_opts;
4765                 }
4766         }
4767 #endif
4768
4769         *flags = (*flags & ~MS_LAZYTIME) | (sb->s_flags & MS_LAZYTIME);
4770         ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
4771         kfree(orig_data);
4772         return 0;
4773
4774 restore_opts:
4775         sb->s_flags = old_sb_flags;
4776         sbi->s_mount_opt = old_opts.s_mount_opt;
4777         sbi->s_mount_opt2 = old_opts.s_mount_opt2;
4778         sbi->s_resuid = old_opts.s_resuid;
4779         sbi->s_resgid = old_opts.s_resgid;
4780         sbi->s_commit_interval = old_opts.s_commit_interval;
4781         sbi->s_min_batch_time = old_opts.s_min_batch_time;
4782         sbi->s_max_batch_time = old_opts.s_max_batch_time;
4783 #ifdef CONFIG_QUOTA
4784         sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
4785         for (i = 0; i < EXT4_MAXQUOTAS; i++) {
4786                 kfree(sbi->s_qf_names[i]);
4787                 sbi->s_qf_names[i] = old_opts.s_qf_names[i];
4788         }
4789 #endif
4790         kfree(orig_data);
4791         return err;
4792 }
4793
4794 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
4795 {
4796         struct super_block *sb = dentry->d_sb;
4797         struct ext4_sb_info *sbi = EXT4_SB(sb);
4798         struct ext4_super_block *es = sbi->s_es;
4799         ext4_fsblk_t overhead = 0, resv_blocks;
4800         u64 fsid;
4801         s64 bfree;
4802         resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
4803
4804         if (!test_opt(sb, MINIX_DF))
4805                 overhead = sbi->s_overhead;
4806
4807         buf->f_type = EXT4_SUPER_MAGIC;
4808         buf->f_bsize = sb->s_blocksize;
4809         buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
4810         bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
4811                 percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
4812         /* prevent underflow in case that few free space is available */
4813         buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
4814         buf->f_bavail = buf->f_bfree -
4815                         (ext4_r_blocks_count(es) + resv_blocks);
4816         if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
4817                 buf->f_bavail = 0;
4818         buf->f_files = le32_to_cpu(es->s_inodes_count);
4819         buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
4820         buf->f_namelen = EXT4_NAME_LEN;
4821         fsid = le64_to_cpup((void *)es->s_uuid) ^
4822                le64_to_cpup((void *)es->s_uuid + sizeof(u64));
4823         buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
4824         buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
4825
4826         return 0;
4827 }
4828
4829 /* Helper function for writing quotas on sync - we need to start transaction
4830  * before quota file is locked for write. Otherwise the are possible deadlocks:
4831  * Process 1                         Process 2
4832  * ext4_create()                     quota_sync()
4833  *   jbd2_journal_start()                  write_dquot()
4834  *   dquot_initialize()                         down(dqio_mutex)
4835  *     down(dqio_mutex)                    jbd2_journal_start()
4836  *
4837  */
4838
4839 #ifdef CONFIG_QUOTA
4840
4841 static inline struct inode *dquot_to_inode(struct dquot *dquot)
4842 {
4843         return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
4844 }
4845
4846 static int ext4_write_dquot(struct dquot *dquot)
4847 {
4848         int ret, err;
4849         handle_t *handle;
4850         struct inode *inode;
4851
4852         inode = dquot_to_inode(dquot);
4853         handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
4854                                     EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
4855         if (IS_ERR(handle))
4856                 return PTR_ERR(handle);
4857         ret = dquot_commit(dquot);
4858         err = ext4_journal_stop(handle);
4859         if (!ret)
4860                 ret = err;
4861         return ret;
4862 }
4863
4864 static int ext4_acquire_dquot(struct dquot *dquot)
4865 {
4866         int ret, err;
4867         handle_t *handle;
4868
4869         handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
4870                                     EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
4871         if (IS_ERR(handle))
4872                 return PTR_ERR(handle);
4873         ret = dquot_acquire(dquot);
4874         err = ext4_journal_stop(handle);
4875         if (!ret)
4876                 ret = err;
4877         return ret;
4878 }
4879
4880 static int ext4_release_dquot(struct dquot *dquot)
4881 {
4882         int ret, err;
4883         handle_t *handle;
4884
4885         handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
4886                                     EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
4887         if (IS_ERR(handle)) {
4888                 /* Release dquot anyway to avoid endless cycle in dqput() */
4889                 dquot_release(dquot);
4890                 return PTR_ERR(handle);
4891         }
4892         ret = dquot_release(dquot);
4893         err = ext4_journal_stop(handle);
4894         if (!ret)
4895                 ret = err;
4896         return ret;
4897 }
4898
4899 static int ext4_mark_dquot_dirty(struct dquot *dquot)
4900 {
4901         struct super_block *sb = dquot->dq_sb;
4902         struct ext4_sb_info *sbi = EXT4_SB(sb);
4903
4904         /* Are we journaling quotas? */
4905         if (ext4_has_feature_quota(sb) ||
4906             sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
4907                 dquot_mark_dquot_dirty(dquot);
4908                 return ext4_write_dquot(dquot);
4909         } else {
4910                 return dquot_mark_dquot_dirty(dquot);
4911         }
4912 }
4913
4914 static int ext4_write_info(struct super_block *sb, int type)
4915 {
4916         int ret, err;
4917         handle_t *handle;
4918
4919         /* Data block + inode block */
4920         handle = ext4_journal_start(d_inode(sb->s_root), EXT4_HT_QUOTA, 2);
4921         if (IS_ERR(handle))
4922                 return PTR_ERR(handle);
4923         ret = dquot_commit_info(sb, type);
4924         err = ext4_journal_stop(handle);
4925         if (!ret)
4926                 ret = err;
4927         return ret;
4928 }
4929
4930 /*
4931  * Turn on quotas during mount time - we need to find
4932  * the quota file and such...
4933  */
4934 static int ext4_quota_on_mount(struct super_block *sb, int type)
4935 {
4936         return dquot_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
4937                                         EXT4_SB(sb)->s_jquota_fmt, type);
4938 }
4939
4940 static void lockdep_set_quota_inode(struct inode *inode, int subclass)
4941 {
4942         struct ext4_inode_info *ei = EXT4_I(inode);
4943
4944         /* The first argument of lockdep_set_subclass has to be
4945          * *exactly* the same as the argument to init_rwsem() --- in
4946          * this case, in init_once() --- or lockdep gets unhappy
4947          * because the name of the lock is set using the
4948          * stringification of the argument to init_rwsem().
4949          */
4950         (void) ei;      /* shut up clang warning if !CONFIG_LOCKDEP */
4951         lockdep_set_subclass(&ei->i_data_sem, subclass);
4952 }
4953
4954 /*
4955  * Standard function to be called on quota_on
4956  */
4957 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
4958                          struct path *path)
4959 {
4960         int err;
4961
4962         if (!test_opt(sb, QUOTA))
4963                 return -EINVAL;
4964
4965         /* Quotafile not on the same filesystem? */
4966         if (path->dentry->d_sb != sb)
4967                 return -EXDEV;
4968         /* Journaling quota? */
4969         if (EXT4_SB(sb)->s_qf_names[type]) {
4970                 /* Quotafile not in fs root? */
4971                 if (path->dentry->d_parent != sb->s_root)
4972                         ext4_msg(sb, KERN_WARNING,
4973                                 "Quota file not on filesystem root. "
4974                                 "Journaled quota will not work");
4975         }
4976
4977         /*
4978          * When we journal data on quota file, we have to flush journal to see
4979          * all updates to the file when we bypass pagecache...
4980          */
4981         if (EXT4_SB(sb)->s_journal &&
4982             ext4_should_journal_data(d_inode(path->dentry))) {
4983                 /*
4984                  * We don't need to lock updates but journal_flush() could
4985                  * otherwise be livelocked...
4986                  */
4987                 jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
4988                 err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
4989                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
4990                 if (err)
4991                         return err;
4992         }
4993         lockdep_set_quota_inode(path->dentry->d_inode, I_DATA_SEM_QUOTA);
4994         err = dquot_quota_on(sb, type, format_id, path);
4995         if (err)
4996                 lockdep_set_quota_inode(path->dentry->d_inode,
4997                                              I_DATA_SEM_NORMAL);
4998         return err;
4999 }
5000
5001 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
5002                              unsigned int flags)
5003 {
5004         int err;
5005         struct inode *qf_inode;
5006         unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5007                 le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5008                 le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum)
5009         };
5010
5011         BUG_ON(!ext4_has_feature_quota(sb));
5012
5013         if (!qf_inums[type])
5014                 return -EPERM;
5015
5016         qf_inode = ext4_iget(sb, qf_inums[type]);
5017         if (IS_ERR(qf_inode)) {
5018                 ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
5019                 return PTR_ERR(qf_inode);
5020         }
5021
5022         /* Don't account quota for quota files to avoid recursion */
5023         qf_inode->i_flags |= S_NOQUOTA;
5024         lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);
5025         err = dquot_enable(qf_inode, type, format_id, flags);
5026         iput(qf_inode);
5027         if (err)
5028                 lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);
5029
5030         return err;
5031 }
5032
5033 /* Enable usage tracking for all quota types. */
5034 static int ext4_enable_quotas(struct super_block *sb)
5035 {
5036         int type, err = 0;
5037         unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5038                 le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5039                 le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum)
5040         };
5041
5042         sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE;
5043         for (type = 0; type < EXT4_MAXQUOTAS; type++) {
5044                 if (qf_inums[type]) {
5045                         err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
5046                                                 DQUOT_USAGE_ENABLED);
5047                         if (err) {
5048                                 ext4_warning(sb,
5049                                         "Failed to enable quota tracking "
5050                                         "(type=%d, err=%d). Please run "
5051                                         "e2fsck to fix.", type, err);
5052                                 return err;
5053                         }
5054                 }
5055         }
5056         return 0;
5057 }
5058
5059 static int ext4_quota_off(struct super_block *sb, int type)
5060 {
5061         struct inode *inode = sb_dqopt(sb)->files[type];
5062         handle_t *handle;
5063
5064         /* Force all delayed allocation blocks to be allocated.
5065          * Caller already holds s_umount sem */
5066         if (test_opt(sb, DELALLOC))
5067                 sync_filesystem(sb);
5068
5069         if (!inode)
5070                 goto out;
5071
5072         /* Update modification times of quota files when userspace can
5073          * start looking at them */
5074         handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5075         if (IS_ERR(handle))
5076                 goto out;
5077         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
5078         ext4_mark_inode_dirty(handle, inode);
5079         ext4_journal_stop(handle);
5080
5081 out:
5082         return dquot_quota_off(sb, type);
5083 }
5084
5085 /* Read data from quotafile - avoid pagecache and such because we cannot afford
5086  * acquiring the locks... As quota files are never truncated and quota code
5087  * itself serializes the operations (and no one else should touch the files)
5088  * we don't have to be afraid of races */
5089 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
5090                                size_t len, loff_t off)
5091 {
5092         struct inode *inode = sb_dqopt(sb)->files[type];
5093         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5094         int offset = off & (sb->s_blocksize - 1);
5095         int tocopy;
5096         size_t toread;
5097         struct buffer_head *bh;
5098         loff_t i_size = i_size_read(inode);
5099
5100         if (off > i_size)
5101                 return 0;
5102         if (off+len > i_size)
5103                 len = i_size-off;
5104         toread = len;
5105         while (toread > 0) {
5106                 tocopy = sb->s_blocksize - offset < toread ?
5107                                 sb->s_blocksize - offset : toread;
5108                 bh = ext4_bread(NULL, inode, blk, 0);
5109                 if (IS_ERR(bh))
5110                         return PTR_ERR(bh);
5111                 if (!bh)        /* A hole? */
5112                         memset(data, 0, tocopy);
5113                 else
5114                         memcpy(data, bh->b_data+offset, tocopy);
5115                 brelse(bh);
5116                 offset = 0;
5117                 toread -= tocopy;
5118                 data += tocopy;
5119                 blk++;
5120         }
5121         return len;
5122 }
5123
5124 /* Write to quotafile (we know the transaction is already started and has
5125  * enough credits) */
5126 static ssize_t ext4_quota_write(struct super_block *sb, int type,
5127                                 const char *data, size_t len, loff_t off)
5128 {
5129         struct inode *inode = sb_dqopt(sb)->files[type];
5130         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5131         int err, offset = off & (sb->s_blocksize - 1);
5132         int retries = 0;
5133         struct buffer_head *bh;
5134         handle_t *handle = journal_current_handle();
5135
5136         if (EXT4_SB(sb)->s_journal && !handle) {
5137                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5138                         " cancelled because transaction is not started",
5139                         (unsigned long long)off, (unsigned long long)len);
5140                 return -EIO;
5141         }
5142         /*
5143          * Since we account only one data block in transaction credits,
5144          * then it is impossible to cross a block boundary.
5145          */
5146         if (sb->s_blocksize - offset < len) {
5147                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5148                         " cancelled because not block aligned",
5149                         (unsigned long long)off, (unsigned long long)len);
5150                 return -EIO;
5151         }
5152
5153         do {
5154                 bh = ext4_bread(handle, inode, blk,
5155                                 EXT4_GET_BLOCKS_CREATE |
5156                                 EXT4_GET_BLOCKS_METADATA_NOFAIL);
5157         } while (IS_ERR(bh) && (PTR_ERR(bh) == -ENOSPC) &&
5158                  ext4_should_retry_alloc(inode->i_sb, &retries));
5159         if (IS_ERR(bh))
5160                 return PTR_ERR(bh);
5161         if (!bh)
5162                 goto out;
5163         BUFFER_TRACE(bh, "get write access");
5164         err = ext4_journal_get_write_access(handle, bh);
5165         if (err) {
5166                 brelse(bh);
5167                 return err;
5168         }
5169         lock_buffer(bh);
5170         memcpy(bh->b_data+offset, data, len);
5171         flush_dcache_page(bh->b_page);
5172         unlock_buffer(bh);
5173         err = ext4_handle_dirty_metadata(handle, NULL, bh);
5174         brelse(bh);
5175 out:
5176         if (inode->i_size < off + len) {
5177                 i_size_write(inode, off + len);
5178                 EXT4_I(inode)->i_disksize = inode->i_size;
5179                 ext4_mark_inode_dirty(handle, inode);
5180         }
5181         return len;
5182 }
5183
5184 #endif
5185
5186 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
5187                        const char *dev_name, void *data)
5188 {
5189         return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
5190 }
5191
5192 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
5193 static inline void register_as_ext2(void)
5194 {
5195         int err = register_filesystem(&ext2_fs_type);
5196         if (err)
5197                 printk(KERN_WARNING
5198                        "EXT4-fs: Unable to register as ext2 (%d)\n", err);
5199 }
5200
5201 static inline void unregister_as_ext2(void)
5202 {
5203         unregister_filesystem(&ext2_fs_type);
5204 }
5205
5206 static inline int ext2_feature_set_ok(struct super_block *sb)
5207 {
5208         if (ext4_has_unknown_ext2_incompat_features(sb))
5209                 return 0;
5210         if (sb->s_flags & MS_RDONLY)
5211                 return 1;
5212         if (ext4_has_unknown_ext2_ro_compat_features(sb))
5213                 return 0;
5214         return 1;
5215 }
5216 #else
5217 static inline void register_as_ext2(void) { }
5218 static inline void unregister_as_ext2(void) { }
5219 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
5220 #endif
5221
5222 static inline void register_as_ext3(void)
5223 {
5224         int err = register_filesystem(&ext3_fs_type);
5225         if (err)
5226                 printk(KERN_WARNING
5227                        "EXT4-fs: Unable to register as ext3 (%d)\n", err);
5228 }
5229
5230 static inline void unregister_as_ext3(void)
5231 {
5232         unregister_filesystem(&ext3_fs_type);
5233 }
5234
5235 static inline int ext3_feature_set_ok(struct super_block *sb)
5236 {
5237         if (ext4_has_unknown_ext3_incompat_features(sb))
5238                 return 0;
5239         if (!ext4_has_feature_journal(sb))
5240                 return 0;
5241         if (sb->s_flags & MS_RDONLY)
5242                 return 1;
5243         if (ext4_has_unknown_ext3_ro_compat_features(sb))
5244                 return 0;
5245         return 1;
5246 }
5247
5248 static struct file_system_type ext4_fs_type = {
5249         .owner          = THIS_MODULE,
5250         .name           = "ext4",
5251         .mount          = ext4_mount,
5252         .kill_sb        = kill_block_super,
5253         .fs_flags       = FS_REQUIRES_DEV,
5254 };
5255 MODULE_ALIAS_FS("ext4");
5256
5257 /* Shared across all ext4 file systems */
5258 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
5259 struct mutex ext4__aio_mutex[EXT4_WQ_HASH_SZ];
5260
5261 static int __init ext4_init_fs(void)
5262 {
5263         int i, err;
5264
5265         ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
5266         ext4_li_info = NULL;
5267         mutex_init(&ext4_li_mtx);
5268
5269         /* Build-time check for flags consistency */
5270         ext4_check_flag_values();
5271
5272         for (i = 0; i < EXT4_WQ_HASH_SZ; i++) {
5273                 mutex_init(&ext4__aio_mutex[i]);
5274                 init_waitqueue_head(&ext4__ioend_wq[i]);
5275         }
5276
5277         err = ext4_init_es();
5278         if (err)
5279                 return err;
5280
5281         err = ext4_init_pageio();
5282         if (err)
5283                 goto out5;
5284
5285         err = ext4_init_system_zone();
5286         if (err)
5287                 goto out4;
5288
5289         err = ext4_init_sysfs();
5290         if (err)
5291                 goto out3;
5292
5293         err = ext4_init_mballoc();
5294         if (err)
5295                 goto out2;
5296         else
5297                 ext4_mballoc_ready = 1;
5298         err = init_inodecache();
5299         if (err)
5300                 goto out1;
5301         register_as_ext3();
5302         register_as_ext2();
5303         err = register_filesystem(&ext4_fs_type);
5304         if (err)
5305                 goto out;
5306
5307         return 0;
5308 out:
5309         unregister_as_ext2();
5310         unregister_as_ext3();
5311         destroy_inodecache();
5312 out1:
5313         ext4_mballoc_ready = 0;
5314         ext4_exit_mballoc();
5315 out2:
5316         ext4_exit_sysfs();
5317 out3:
5318         ext4_exit_system_zone();
5319 out4:
5320         ext4_exit_pageio();
5321 out5:
5322         ext4_exit_es();
5323
5324         return err;
5325 }
5326
5327 static void __exit ext4_exit_fs(void)
5328 {
5329         ext4_exit_crypto();
5330         ext4_destroy_lazyinit_thread();
5331         unregister_as_ext2();
5332         unregister_as_ext3();
5333         unregister_filesystem(&ext4_fs_type);
5334         destroy_inodecache();
5335         ext4_exit_mballoc();
5336         ext4_exit_sysfs();
5337         ext4_exit_system_zone();
5338         ext4_exit_pageio();
5339         ext4_exit_es();
5340 }
5341
5342 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
5343 MODULE_DESCRIPTION("Fourth Extended Filesystem");
5344 MODULE_LICENSE("GPL");
5345 module_init(ext4_init_fs)
5346 module_exit(ext4_exit_fs)