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/jbd2.h>
  25 #include <linux/slab.h>
  26 #include <linux/init.h>
  27 #include <linux/blkdev.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/proc_fs.h>
  38 #include <linux/ctype.h>
  39 #include <linux/log2.h>
  40 #include <linux/crc16.h>
  41 #include <linux/cleancache.h>
  42 #include <asm/uaccess.h>
  43
  44 #include <linux/kthread.h>
  45 #include <linux/freezer.h>
  46
  47 #include "ext4.h"
  48 #include "ext4_extents.h"       /* Needed for trace points definition */
  49 #include "ext4_jbd2.h"
  50 #include "xattr.h"
  51 #include "acl.h"
  52 #include "mballoc.h"
  53
  54 #define CREATE_TRACE_POINTS
  55 #include <trace/events/ext4.h>
  56
  57 static struct proc_dir_entry *ext4_proc_root;
  58 static struct kset *ext4_kset;
  59 static struct ext4_lazy_init *ext4_li_info;
  60 static struct mutex ext4_li_mtx;
  61 static struct ext4_features *ext4_feat;
  62 static int ext4_mballoc_ready;
  63
  64 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
  65                              unsigned long journal_devnum);
  66 static int ext4_show_options(struct seq_file *seq, struct dentry *root);
  67 static int ext4_commit_super(struct super_block *sb, int sync);
  68 static void ext4_mark_recovery_complete(struct super_block *sb,
  69                                         struct ext4_super_block *es);
  70 static void ext4_clear_journal_err(struct super_block *sb,
  71                                    struct ext4_super_block *es);
  72 static int ext4_sync_fs(struct super_block *sb, int wait);
  73 static int ext4_remount(struct super_block *sb, int *flags, char *data);
  74 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
  75 static int ext4_unfreeze(struct super_block *sb);
  76 static int ext4_freeze(struct super_block *sb);
  77 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
  78                        const char *dev_name, void *data);
  79 static inline int ext2_feature_set_ok(struct super_block *sb);
  80 static inline int ext3_feature_set_ok(struct super_block *sb);
  81 static int ext4_feature_set_ok(struct super_block *sb, int readonly);
  82 static void ext4_destroy_lazyinit_thread(void);
  83 static void ext4_unregister_li_request(struct super_block *sb);
  84 static void ext4_clear_request_list(void);
  85 static int ext4_reserve_clusters(struct ext4_sb_info *, ext4_fsblk_t);
  86
  87 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
  88 static struct file_system_type ext2_fs_type = {
  89         .owner          = THIS_MODULE,
  90         .name           = "ext2",
  91         .mount          = ext4_mount,
  92         .kill_sb        = kill_block_super,
  93         .fs_flags       = FS_REQUIRES_DEV,
  94 };
  95 MODULE_ALIAS_FS("ext2");
  96 MODULE_ALIAS("ext2");
  97 #define IS_EXT2_SB(sb) ((sb)->s_bdev->bd_holder == &ext2_fs_type)
  98 #else
  99 #define IS_EXT2_SB(sb) (0)
 100 #endif
 101
 102
 103 #if !defined(CONFIG_EXT3_FS) && !defined(CONFIG_EXT3_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
 104 static struct file_system_type ext3_fs_type = {
 105         .owner          = THIS_MODULE,
 106         .name           = "ext3",
 107         .mount          = ext4_mount,
 108         .kill_sb        = kill_block_super,
 109         .fs_flags       = FS_REQUIRES_DEV,
 110 };
 111 MODULE_ALIAS_FS("ext3");
 112 MODULE_ALIAS("ext3");
 113 #define IS_EXT3_SB(sb) ((sb)->s_bdev->bd_holder == &ext3_fs_type)
 114 #else
 115 #define IS_EXT3_SB(sb) (0)
 116 #endif
 117
 118 static int ext4_verify_csum_type(struct super_block *sb,
 119                                  struct ext4_super_block *es)
 120 {
 121         if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
 122                                         EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
 123                 return 1;
 124
 125         return es->s_checksum_type == EXT4_CRC32C_CHKSUM;
 126 }
 127
 128 static __le32 ext4_superblock_csum(struct super_block *sb,
 129                                    struct ext4_super_block *es)
 130 {
 131         struct ext4_sb_info *sbi = EXT4_SB(sb);
 132         int offset = offsetof(struct ext4_super_block, s_checksum);
 133         __u32 csum;
 134
 135         csum = ext4_chksum(sbi, ~0, (char *)es, offset);
 136
 137         return cpu_to_le32(csum);
 138 }
 139
 140 static int ext4_superblock_csum_verify(struct super_block *sb,
 141                                        struct ext4_super_block *es)
 142 {
 143         if (!ext4_has_metadata_csum(sb))
 144                 return 1;
 145
 146         return es->s_checksum == ext4_superblock_csum(sb, es);
 147 }
 148
 149 void ext4_superblock_csum_set(struct super_block *sb)
 150 {
 151         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 152
 153         if (!ext4_has_metadata_csum(sb))
 154                 return;
 155
 156         es->s_checksum = ext4_superblock_csum(sb, es);
 157 }
 158
 159 void *ext4_kvmalloc(size_t size, gfp_t flags)
 160 {
 161         void *ret;
 162
 163         ret = kmalloc(size, flags | __GFP_NOWARN);
 164         if (!ret)
 165                 ret = __vmalloc(size, flags, PAGE_KERNEL);
 166         return ret;
 167 }
 168
 169 void *ext4_kvzalloc(size_t size, gfp_t flags)
 170 {
 171         void *ret;
 172
 173         ret = kzalloc(size, flags | __GFP_NOWARN);
 174         if (!ret)
 175                 ret = __vmalloc(size, flags | __GFP_ZERO, PAGE_KERNEL);
 176         return ret;
 177 }
 178
 179 void ext4_kvfree(void *ptr)
 180 {
 181         if (is_vmalloc_addr(ptr))
 182                 vfree(ptr);
 183         else
 184                 kfree(ptr);
 185
 186 }
 187
 188 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
 189                                struct ext4_group_desc *bg)
 190 {
 191         return le32_to_cpu(bg->bg_block_bitmap_lo) |
 192                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 193                  (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
 194 }
 195
 196 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
 197                                struct ext4_group_desc *bg)
 198 {
 199         return le32_to_cpu(bg->bg_inode_bitmap_lo) |
 200                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 201                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
 202 }
 203
 204 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
 205                               struct ext4_group_desc *bg)
 206 {
 207         return le32_to_cpu(bg->bg_inode_table_lo) |
 208                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 209                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
 210 }
 211
 212 __u32 ext4_free_group_clusters(struct super_block *sb,
 213                                struct ext4_group_desc *bg)
 214 {
 215         return le16_to_cpu(bg->bg_free_blocks_count_lo) |
 216                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 217                  (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
 218 }
 219
 220 __u32 ext4_free_inodes_count(struct super_block *sb,
 221                               struct ext4_group_desc *bg)
 222 {
 223         return le16_to_cpu(bg->bg_free_inodes_count_lo) |
 224                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 225                  (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
 226 }
 227
 228 __u32 ext4_used_dirs_count(struct super_block *sb,
 229                               struct ext4_group_desc *bg)
 230 {
 231         return le16_to_cpu(bg->bg_used_dirs_count_lo) |
 232                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 233                  (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
 234 }
 235
 236 __u32 ext4_itable_unused_count(struct super_block *sb,
 237                               struct ext4_group_desc *bg)
 238 {
 239         return le16_to_cpu(bg->bg_itable_unused_lo) |
 240                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 241                  (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
 242 }
 243
 244 void ext4_block_bitmap_set(struct super_block *sb,
 245                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 246 {
 247         bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
 248         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 249                 bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
 250 }
 251
 252 void ext4_inode_bitmap_set(struct super_block *sb,
 253                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 254 {
 255         bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
 256         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 257                 bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
 258 }
 259
 260 void ext4_inode_table_set(struct super_block *sb,
 261                           struct ext4_group_desc *bg, ext4_fsblk_t blk)
 262 {
 263         bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
 264         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 265                 bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
 266 }
 267
 268 void ext4_free_group_clusters_set(struct super_block *sb,
 269                                   struct ext4_group_desc *bg, __u32 count)
 270 {
 271         bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
 272         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 273                 bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
 274 }
 275
 276 void ext4_free_inodes_set(struct super_block *sb,
 277                           struct ext4_group_desc *bg, __u32 count)
 278 {
 279         bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
 280         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 281                 bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
 282 }
 283
 284 void ext4_used_dirs_set(struct super_block *sb,
 285                           struct ext4_group_desc *bg, __u32 count)
 286 {
 287         bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
 288         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 289                 bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
 290 }
 291
 292 void ext4_itable_unused_set(struct super_block *sb,
 293                           struct ext4_group_desc *bg, __u32 count)
 294 {
 295         bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
 296         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 297                 bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
 298 }
 299
 300
 301 static void __save_error_info(struct super_block *sb, const char *func,
 302                             unsigned int line)
 303 {
 304         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 305
 306         EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
 307         es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
 308         es->s_last_error_time = cpu_to_le32(get_seconds());
 309         strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
 310         es->s_last_error_line = cpu_to_le32(line);
 311         if (!es->s_first_error_time) {
 312                 es->s_first_error_time = es->s_last_error_time;
 313                 strncpy(es->s_first_error_func, func,
 314                         sizeof(es->s_first_error_func));
 315                 es->s_first_error_line = cpu_to_le32(line);
 316                 es->s_first_error_ino = es->s_last_error_ino;
 317                 es->s_first_error_block = es->s_last_error_block;
 318         }
 319         /*
 320          * Start the daily error reporting function if it hasn't been
 321          * started already
 322          */
 323         if (!es->s_error_count)
 324                 mod_timer(&EXT4_SB(sb)->s_err_report, jiffies + 24*60*60*HZ);
 325         le32_add_cpu(&es->s_error_count, 1);
 326 }
 327
 328 static void save_error_info(struct super_block *sb, const char *func,
 329                             unsigned int line)
 330 {
 331         __save_error_info(sb, func, line);
 332         ext4_commit_super(sb, 1);
 333 }
 334
 335 /*
 336  * The del_gendisk() function uninitializes the disk-specific data
 337  * structures, including the bdi structure, without telling anyone
 338  * else.  Once this happens, any attempt to call mark_buffer_dirty()
 339  * (for example, by ext4_commit_super), will cause a kernel OOPS.
 340  * This is a kludge to prevent these oops until we can put in a proper
 341  * hook in del_gendisk() to inform the VFS and file system layers.
 342  */
 343 static int block_device_ejected(struct super_block *sb)
 344 {
 345         struct inode *bd_inode = sb->s_bdev->bd_inode;
 346         struct backing_dev_info *bdi = bd_inode->i_mapping->backing_dev_info;
 347
 348         return bdi->dev == NULL;
 349 }
 350
 351 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
 352 {
 353         struct super_block              *sb = journal->j_private;
 354         struct ext4_sb_info             *sbi = EXT4_SB(sb);
 355         int                             error = is_journal_aborted(journal);
 356         struct ext4_journal_cb_entry    *jce;
 357
 358         BUG_ON(txn->t_state == T_FINISHED);
 359         spin_lock(&sbi->s_md_lock);
 360         while (!list_empty(&txn->t_private_list)) {
 361                 jce = list_entry(txn->t_private_list.next,
 362                                  struct ext4_journal_cb_entry, jce_list);
 363                 list_del_init(&jce->jce_list);
 364                 spin_unlock(&sbi->s_md_lock);
 365                 jce->jce_func(sb, jce, error);
 366                 spin_lock(&sbi->s_md_lock);
 367         }
 368         spin_unlock(&sbi->s_md_lock);
 369 }
 370
 371 /* Deal with the reporting of failure conditions on a filesystem such as
 372  * inconsistencies detected or read IO failures.
 373  *
 374  * On ext2, we can store the error state of the filesystem in the
 375  * superblock.  That is not possible on ext4, because we may have other
 376  * write ordering constraints on the superblock which prevent us from
 377  * writing it out straight away; and given that the journal is about to
 378  * be aborted, we can't rely on the current, or future, transactions to
 379  * write out the superblock safely.
 380  *
 381  * We'll just use the jbd2_journal_abort() error code to record an error in
 382  * the journal instead.  On recovery, the journal will complain about
 383  * that error until we've noted it down and cleared it.
 384  */
 385
 386 static void ext4_handle_error(struct super_block *sb)
 387 {
 388         if (sb->s_flags & MS_RDONLY)
 389                 return;
 390
 391         if (!test_opt(sb, ERRORS_CONT)) {
 392                 journal_t *journal = EXT4_SB(sb)->s_journal;
 393
 394                 EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
 395                 if (journal)
 396                         jbd2_journal_abort(journal, -EIO);
 397         }
 398         if (test_opt(sb, ERRORS_RO)) {
 399                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 400                 /*
 401                  * Make sure updated value of ->s_mount_flags will be visible
 402                  * before ->s_flags update
 403                  */
 404                 smp_wmb();
 405                 sb->s_flags |= MS_RDONLY;
 406         }
 407         if (test_opt(sb, ERRORS_PANIC))
 408                 panic("EXT4-fs (device %s): panic forced after error\n",
 409                         sb->s_id);
 410 }
 411
 412 #define ext4_error_ratelimit(sb)                                        \
 413                 ___ratelimit(&(EXT4_SB(sb)->s_err_ratelimit_state),     \
 414                              "EXT4-fs error")
 415
 416 void __ext4_error(struct super_block *sb, const char *function,
 417                   unsigned int line, const char *fmt, ...)
 418 {
 419         struct va_format vaf;
 420         va_list args;
 421
 422         if (ext4_error_ratelimit(sb)) {
 423                 va_start(args, fmt);
 424                 vaf.fmt = fmt;
 425                 vaf.va = &args;
 426                 printk(KERN_CRIT
 427                        "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
 428                        sb->s_id, function, line, current->comm, &vaf);
 429                 va_end(args);
 430         }
 431         save_error_info(sb, function, line);
 432         ext4_handle_error(sb);
 433 }
 434
 435 void __ext4_error_inode(struct inode *inode, const char *function,
 436                         unsigned int line, ext4_fsblk_t block,
 437                         const char *fmt, ...)
 438 {
 439         va_list args;
 440         struct va_format vaf;
 441         struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
 442
 443         es->s_last_error_ino = cpu_to_le32(inode->i_ino);
 444         es->s_last_error_block = cpu_to_le64(block);
 445         if (ext4_error_ratelimit(inode->i_sb)) {
 446                 va_start(args, fmt);
 447                 vaf.fmt = fmt;
 448                 vaf.va = &args;
 449                 if (block)
 450                         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
 451                                "inode #%lu: block %llu: comm %s: %pV\n",
 452                                inode->i_sb->s_id, function, line, inode->i_ino,
 453                                block, current->comm, &vaf);
 454                 else
 455                         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
 456                                "inode #%lu: comm %s: %pV\n",
 457                                inode->i_sb->s_id, function, line, inode->i_ino,
 458                                current->comm, &vaf);
 459                 va_end(args);
 460         }
 461         save_error_info(inode->i_sb, function, line);
 462         ext4_handle_error(inode->i_sb);
 463 }
 464
 465 void __ext4_error_file(struct file *file, const char *function,
 466                        unsigned int line, ext4_fsblk_t block,
 467                        const char *fmt, ...)
 468 {
 469         va_list args;
 470         struct va_format vaf;
 471         struct ext4_super_block *es;
 472         struct inode *inode = file_inode(file);
 473         char pathname[80], *path;
 474
 475         es = EXT4_SB(inode->i_sb)->s_es;
 476         es->s_last_error_ino = cpu_to_le32(inode->i_ino);
 477         if (ext4_error_ratelimit(inode->i_sb)) {
 478                 path = d_path(&(file->f_path), pathname, sizeof(pathname));
 479                 if (IS_ERR(path))
 480                         path = "(unknown)";
 481                 va_start(args, fmt);
 482                 vaf.fmt = fmt;
 483                 vaf.va = &args;
 484                 if (block)
 485                         printk(KERN_CRIT
 486                                "EXT4-fs error (device %s): %s:%d: inode #%lu: "
 487                                "block %llu: comm %s: path %s: %pV\n",
 488                                inode->i_sb->s_id, function, line, inode->i_ino,
 489                                block, current->comm, path, &vaf);
 490                 else
 491                         printk(KERN_CRIT
 492                                "EXT4-fs error (device %s): %s:%d: inode #%lu: "
 493                                "comm %s: path %s: %pV\n",
 494                                inode->i_sb->s_id, function, line, inode->i_ino,
 495                                current->comm, path, &vaf);
 496                 va_end(args);
 497         }
 498         save_error_info(inode->i_sb, function, line);
 499         ext4_handle_error(inode->i_sb);
 500 }
 501
 502 const char *ext4_decode_error(struct super_block *sb, int errno,
 503                               char nbuf[16])
 504 {
 505         char *errstr = NULL;
 506
 507         switch (errno) {
 508         case -EIO:
 509                 errstr = "IO failure";
 510                 break;
 511         case -ENOMEM:
 512                 errstr = "Out of memory";
 513                 break;
 514         case -EROFS:
 515                 if (!sb || (EXT4_SB(sb)->s_journal &&
 516                             EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
 517                         errstr = "Journal has aborted";
 518                 else
 519                         errstr = "Readonly filesystem";
 520                 break;
 521         default:
 522                 /* If the caller passed in an extra buffer for unknown
 523                  * errors, textualise them now.  Else we just return
 524                  * NULL. */
 525                 if (nbuf) {
 526                         /* Check for truncated error codes... */
 527                         if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
 528                                 errstr = nbuf;
 529                 }
 530                 break;
 531         }
 532
 533         return errstr;
 534 }
 535
 536 /* __ext4_std_error decodes expected errors from journaling functions
 537  * automatically and invokes the appropriate error response.  */
 538
 539 void __ext4_std_error(struct super_block *sb, const char *function,
 540                       unsigned int line, int errno)
 541 {
 542         char nbuf[16];
 543         const char *errstr;
 544
 545         /* Special case: if the error is EROFS, and we're not already
 546          * inside a transaction, then there's really no point in logging
 547          * an error. */
 548         if (errno == -EROFS && journal_current_handle() == NULL &&
 549             (sb->s_flags & MS_RDONLY))
 550                 return;
 551
 552         if (ext4_error_ratelimit(sb)) {
 553                 errstr = ext4_decode_error(sb, errno, nbuf);
 554                 printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
 555                        sb->s_id, function, line, errstr);
 556         }
 557
 558         save_error_info(sb, function, line);
 559         ext4_handle_error(sb);
 560 }
 561
 562 /*
 563  * ext4_abort is a much stronger failure handler than ext4_error.  The
 564  * abort function may be used to deal with unrecoverable failures such
 565  * as journal IO errors or ENOMEM at a critical moment in log management.
 566  *
 567  * We unconditionally force the filesystem into an ABORT|READONLY state,
 568  * unless the error response on the fs has been set to panic in which
 569  * case we take the easy way out and panic immediately.
 570  */
 571
 572 void __ext4_abort(struct super_block *sb, const char *function,
 573                 unsigned int line, const char *fmt, ...)
 574 {
 575         va_list args;
 576
 577         save_error_info(sb, function, line);
 578         va_start(args, fmt);
 579         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: ", sb->s_id,
 580                function, line);
 581         vprintk(fmt, args);
 582         printk("\n");
 583         va_end(args);
 584
 585         if ((sb->s_flags & MS_RDONLY) == 0) {
 586                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 587                 EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
 588                 /*
 589                  * Make sure updated value of ->s_mount_flags will be visible
 590                  * before ->s_flags update
 591                  */
 592                 smp_wmb();
 593                 sb->s_flags |= MS_RDONLY;
 594                 if (EXT4_SB(sb)->s_journal)
 595                         jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
 596                 save_error_info(sb, function, line);
 597         }
 598         if (test_opt(sb, ERRORS_PANIC))
 599                 panic("EXT4-fs panic from previous error\n");
 600 }
 601
 602 void __ext4_msg(struct super_block *sb,
 603                 const char *prefix, const char *fmt, ...)
 604 {
 605         struct va_format vaf;
 606         va_list args;
 607
 608         if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state), "EXT4-fs"))
 609                 return;
 610
 611         va_start(args, fmt);
 612         vaf.fmt = fmt;
 613         vaf.va = &args;
 614         printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
 615         va_end(args);
 616 }
 617
 618 void __ext4_warning(struct super_block *sb, const char *function,
 619                     unsigned int line, const char *fmt, ...)
 620 {
 621         struct va_format vaf;
 622         va_list args;
 623
 624         if (!___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state),
 625                           "EXT4-fs warning"))
 626                 return;
 627
 628         va_start(args, fmt);
 629         vaf.fmt = fmt;
 630         vaf.va = &args;
 631         printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
 632                sb->s_id, function, line, &vaf);
 633         va_end(args);
 634 }
 635
 636 void __ext4_grp_locked_error(const char *function, unsigned int line,
 637                              struct super_block *sb, ext4_group_t grp,
 638                              unsigned long ino, ext4_fsblk_t block,
 639                              const char *fmt, ...)
 640 __releases(bitlock)
 641 __acquires(bitlock)
 642 {
 643         struct va_format vaf;
 644         va_list args;
 645         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 646
 647         es->s_last_error_ino = cpu_to_le32(ino);
 648         es->s_last_error_block = cpu_to_le64(block);
 649         __save_error_info(sb, function, line);
 650
 651         if (ext4_error_ratelimit(sb)) {
 652                 va_start(args, fmt);
 653                 vaf.fmt = fmt;
 654                 vaf.va = &args;
 655                 printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
 656                        sb->s_id, function, line, grp);
 657                 if (ino)
 658                         printk(KERN_CONT "inode %lu: ", ino);
 659                 if (block)
 660                         printk(KERN_CONT "block %llu:",
 661                                (unsigned long long) block);
 662                 printk(KERN_CONT "%pV\n", &vaf);
 663                 va_end(args);
 664         }
 665
 666         if (test_opt(sb, ERRORS_CONT)) {
 667                 ext4_commit_super(sb, 0);
 668                 return;
 669         }
 670
 671         ext4_unlock_group(sb, grp);
 672         ext4_handle_error(sb);
 673         /*
 674          * We only get here in the ERRORS_RO case; relocking the group
 675          * may be dangerous, but nothing bad will happen since the
 676          * filesystem will have already been marked read/only and the
 677          * journal has been aborted.  We return 1 as a hint to callers
 678          * who might what to use the return value from
 679          * ext4_grp_locked_error() to distinguish between the
 680          * ERRORS_CONT and ERRORS_RO case, and perhaps return more
 681          * aggressively from the ext4 function in question, with a
 682          * more appropriate error code.
 683          */
 684         ext4_lock_group(sb, grp);
 685         return;
 686 }
 687
 688 void ext4_update_dynamic_rev(struct super_block *sb)
 689 {
 690         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 691
 692         if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
 693                 return;
 694
 695         ext4_warning(sb,
 696                      "updating to rev %d because of new feature flag, "
 697                      "running e2fsck is recommended",
 698                      EXT4_DYNAMIC_REV);
 699
 700         es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
 701         es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
 702         es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
 703         /* leave es->s_feature_*compat flags alone */
 704         /* es->s_uuid will be set by e2fsck if empty */
 705
 706         /*
 707          * The rest of the superblock fields should be zero, and if not it
 708          * means they are likely already in use, so leave them alone.  We
 709          * can leave it up to e2fsck to clean up any inconsistencies there.
 710          */
 711 }
 712
 713 /*
 714  * Open the external journal device
 715  */
 716 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
 717 {
 718         struct block_device *bdev;
 719         char b[BDEVNAME_SIZE];
 720
 721         bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
 722         if (IS_ERR(bdev))
 723                 goto fail;
 724         return bdev;
 725
 726 fail:
 727         ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
 728                         __bdevname(dev, b), PTR_ERR(bdev));
 729         return NULL;
 730 }
 731
 732 /*
 733  * Release the journal device
 734  */
 735 static void ext4_blkdev_put(struct block_device *bdev)
 736 {
 737         blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
 738 }
 739
 740 static void ext4_blkdev_remove(struct ext4_sb_info *sbi)
 741 {
 742         struct block_device *bdev;
 743         bdev = sbi->journal_bdev;
 744         if (bdev) {
 745                 ext4_blkdev_put(bdev);
 746                 sbi->journal_bdev = NULL;
 747         }
 748 }
 749
 750 static inline struct inode *orphan_list_entry(struct list_head *l)
 751 {
 752         return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
 753 }
 754
 755 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
 756 {
 757         struct list_head *l;
 758
 759         ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
 760                  le32_to_cpu(sbi->s_es->s_last_orphan));
 761
 762         printk(KERN_ERR "sb_info orphan list:\n");
 763         list_for_each(l, &sbi->s_orphan) {
 764                 struct inode *inode = orphan_list_entry(l);
 765                 printk(KERN_ERR "  "
 766                        "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
 767                        inode->i_sb->s_id, inode->i_ino, inode,
 768                        inode->i_mode, inode->i_nlink,
 769                        NEXT_ORPHAN(inode));
 770         }
 771 }
 772
 773 static void ext4_put_super(struct super_block *sb)
 774 {
 775         struct ext4_sb_info *sbi = EXT4_SB(sb);
 776         struct ext4_super_block *es = sbi->s_es;
 777         int i, err;
 778
 779         ext4_unregister_li_request(sb);
 780         dquot_disable(sb, -1, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
 781
 782         flush_workqueue(sbi->rsv_conversion_wq);
 783         destroy_workqueue(sbi->rsv_conversion_wq);
 784
 785         if (sbi->s_journal) {
 786                 err = jbd2_journal_destroy(sbi->s_journal);
 787                 sbi->s_journal = NULL;
 788                 if (err < 0)
 789                         ext4_abort(sb, "Couldn't clean up the journal");
 790         }
 791
 792         ext4_es_unregister_shrinker(sbi);
 793         del_timer_sync(&sbi->s_err_report);
 794         ext4_release_system_zone(sb);
 795         ext4_mb_release(sb);
 796         ext4_ext_release(sb);
 797         ext4_xattr_put_super(sb);
 798
 799         if (!(sb->s_flags & MS_RDONLY)) {
 800                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
 801                 es->s_state = cpu_to_le16(sbi->s_mount_state);
 802         }
 803         if (!(sb->s_flags & MS_RDONLY))
 804                 ext4_commit_super(sb, 1);
 805
 806         if (sbi->s_proc) {
 807                 remove_proc_entry("options", sbi->s_proc);
 808                 remove_proc_entry(sb->s_id, ext4_proc_root);
 809         }
 810         kobject_del(&sbi->s_kobj);
 811
 812         for (i = 0; i < sbi->s_gdb_count; i++)
 813                 brelse(sbi->s_group_desc[i]);
 814         ext4_kvfree(sbi->s_group_desc);
 815         ext4_kvfree(sbi->s_flex_groups);
 816         percpu_counter_destroy(&sbi->s_freeclusters_counter);
 817         percpu_counter_destroy(&sbi->s_freeinodes_counter);
 818         percpu_counter_destroy(&sbi->s_dirs_counter);
 819         percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
 820         brelse(sbi->s_sbh);
 821 #ifdef CONFIG_QUOTA
 822         for (i = 0; i < EXT4_MAXQUOTAS; i++)
 823                 kfree(sbi->s_qf_names[i]);
 824 #endif
 825
 826         /* Debugging code just in case the in-memory inode orphan list
 827          * isn't empty.  The on-disk one can be non-empty if we've
 828          * detected an error and taken the fs readonly, but the
 829          * in-memory list had better be clean by this point. */
 830         if (!list_empty(&sbi->s_orphan))
 831                 dump_orphan_list(sb, sbi);
 832         J_ASSERT(list_empty(&sbi->s_orphan));
 833
 834         invalidate_bdev(sb->s_bdev);
 835         if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
 836                 /*
 837                  * Invalidate the journal device's buffers.  We don't want them
 838                  * floating about in memory - the physical journal device may
 839                  * hotswapped, and it breaks the `ro-after' testing code.
 840                  */
 841                 sync_blockdev(sbi->journal_bdev);
 842                 invalidate_bdev(sbi->journal_bdev);
 843                 ext4_blkdev_remove(sbi);
 844         }
 845         if (sbi->s_mb_cache) {
 846                 ext4_xattr_destroy_cache(sbi->s_mb_cache);
 847                 sbi->s_mb_cache = NULL;
 848         }
 849         if (sbi->s_mmp_tsk)
 850                 kthread_stop(sbi->s_mmp_tsk);
 851         sb->s_fs_info = NULL;
 852         /*
 853          * Now that we are completely done shutting down the
 854          * superblock, we need to actually destroy the kobject.
 855          */
 856         kobject_put(&sbi->s_kobj);
 857         wait_for_completion(&sbi->s_kobj_unregister);
 858         if (sbi->s_chksum_driver)
 859                 crypto_free_shash(sbi->s_chksum_driver);
 860         kfree(sbi->s_blockgroup_lock);
 861         kfree(sbi);
 862 }
 863
 864 static struct kmem_cache *ext4_inode_cachep;
 865
 866 /*
 867  * Called inside transaction, so use GFP_NOFS
 868  */
 869 static struct inode *ext4_alloc_inode(struct super_block *sb)
 870 {
 871         struct ext4_inode_info *ei;
 872
 873         ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
 874         if (!ei)
 875                 return NULL;
 876
 877         ei->vfs_inode.i_version = 1;
 878         spin_lock_init(&ei->i_raw_lock);
 879         INIT_LIST_HEAD(&ei->i_prealloc_list);
 880         spin_lock_init(&ei->i_prealloc_lock);
 881         ext4_es_init_tree(&ei->i_es_tree);
 882         rwlock_init(&ei->i_es_lock);
 883         INIT_LIST_HEAD(&ei->i_es_lru);
 884         ei->i_es_all_nr = 0;
 885         ei->i_es_lru_nr = 0;
 886         ei->i_touch_when = 0;
 887         ei->i_reserved_data_blocks = 0;
 888         ei->i_reserved_meta_blocks = 0;
 889         ei->i_allocated_meta_blocks = 0;
 890         ei->i_da_metadata_calc_len = 0;
 891         ei->i_da_metadata_calc_last_lblock = 0;
 892         spin_lock_init(&(ei->i_block_reservation_lock));
 893 #ifdef CONFIG_QUOTA
 894         ei->i_reserved_quota = 0;
 895 #endif
 896         ei->jinode = NULL;
 897         INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
 898         spin_lock_init(&ei->i_completed_io_lock);
 899         ei->i_sync_tid = 0;
 900         ei->i_datasync_tid = 0;
 901         atomic_set(&ei->i_ioend_count, 0);
 902         atomic_set(&ei->i_unwritten, 0);
 903         INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
 904
 905         return &ei->vfs_inode;
 906 }
 907
 908 static int ext4_drop_inode(struct inode *inode)
 909 {
 910         int drop = generic_drop_inode(inode);
 911
 912         trace_ext4_drop_inode(inode, drop);
 913         return drop;
 914 }
 915
 916 static void ext4_i_callback(struct rcu_head *head)
 917 {
 918         struct inode *inode = container_of(head, struct inode, i_rcu);
 919         kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
 920 }
 921
 922 static void ext4_destroy_inode(struct inode *inode)
 923 {
 924         if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
 925                 ext4_msg(inode->i_sb, KERN_ERR,
 926                          "Inode %lu (%p): orphan list check failed!",
 927                          inode->i_ino, EXT4_I(inode));
 928                 print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
 929                                 EXT4_I(inode), sizeof(struct ext4_inode_info),
 930                                 true);
 931                 dump_stack();
 932         }
 933         call_rcu(&inode->i_rcu, ext4_i_callback);
 934 }
 935
 936 static void init_once(void *foo)
 937 {
 938         struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
 939
 940         INIT_LIST_HEAD(&ei->i_orphan);
 941         init_rwsem(&ei->xattr_sem);
 942         init_rwsem(&ei->i_data_sem);
 943         inode_init_once(&ei->vfs_inode);
 944 }
 945
 946 static int __init init_inodecache(void)
 947 {
 948         ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
 949                                              sizeof(struct ext4_inode_info),
 950                                              0, (SLAB_RECLAIM_ACCOUNT|
 951                                                 SLAB_MEM_SPREAD),
 952                                              init_once);
 953         if (ext4_inode_cachep == NULL)
 954                 return -ENOMEM;
 955         return 0;
 956 }
 957
 958 static void destroy_inodecache(void)
 959 {
 960         /*
 961          * Make sure all delayed rcu free inodes are flushed before we
 962          * destroy cache.
 963          */
 964         rcu_barrier();
 965         kmem_cache_destroy(ext4_inode_cachep);
 966 }
 967
 968 void ext4_clear_inode(struct inode *inode)
 969 {
 970         invalidate_inode_buffers(inode);
 971         clear_inode(inode);
 972         dquot_drop(inode);
 973         ext4_discard_preallocations(inode);
 974         ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
 975         ext4_es_lru_del(inode);
 976         if (EXT4_I(inode)->jinode) {
 977                 jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
 978                                                EXT4_I(inode)->jinode);
 979                 jbd2_free_inode(EXT4_I(inode)->jinode);
 980                 EXT4_I(inode)->jinode = NULL;
 981         }
 982 }
 983
 984 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
 985                                         u64 ino, u32 generation)
 986 {
 987         struct inode *inode;
 988
 989         if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
 990                 return ERR_PTR(-ESTALE);
 991         if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
 992                 return ERR_PTR(-ESTALE);
 993
 994         /* iget isn't really right if the inode is currently unallocated!!
 995          *
 996          * ext4_read_inode will return a bad_inode if the inode had been
 997          * deleted, so we should be safe.
 998          *
 999          * Currently we don't know the generation for parent directory, so
1000          * a generation of 0 means "accept any"
1001          */
1002         inode = ext4_iget_normal(sb, ino);
1003         if (IS_ERR(inode))
1004                 return ERR_CAST(inode);
1005         if (generation && inode->i_generation != generation) {
1006                 iput(inode);
1007                 return ERR_PTR(-ESTALE);
1008         }
1009
1010         return inode;
1011 }
1012
1013 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1014                                         int fh_len, int fh_type)
1015 {
1016         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1017                                     ext4_nfs_get_inode);
1018 }
1019
1020 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1021                                         int fh_len, int fh_type)
1022 {
1023         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1024                                     ext4_nfs_get_inode);
1025 }
1026
1027 /*
1028  * Try to release metadata pages (indirect blocks, directories) which are
1029  * mapped via the block device.  Since these pages could have journal heads
1030  * which would prevent try_to_free_buffers() from freeing them, we must use
1031  * jbd2 layer's try_to_free_buffers() function to release them.
1032  */
1033 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1034                                  gfp_t wait)
1035 {
1036         journal_t *journal = EXT4_SB(sb)->s_journal;
1037
1038         WARN_ON(PageChecked(page));
1039         if (!page_has_buffers(page))
1040                 return 0;
1041         if (journal)
1042                 return jbd2_journal_try_to_free_buffers(journal, page,
1043                                                         wait & ~__GFP_WAIT);
1044         return try_to_free_buffers(page);
1045 }
1046
1047 #ifdef CONFIG_QUOTA
1048 #define QTYPE2NAME(t) ((t) == USRQUOTA ? "user" : "group")
1049 #define QTYPE2MOPT(on, t) ((t) == USRQUOTA?((on)##USRJQUOTA):((on)##GRPJQUOTA))
1050
1051 static int ext4_write_dquot(struct dquot *dquot);
1052 static int ext4_acquire_dquot(struct dquot *dquot);
1053 static int ext4_release_dquot(struct dquot *dquot);
1054 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1055 static int ext4_write_info(struct super_block *sb, int type);
1056 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1057                          struct path *path);
1058 static int ext4_quota_on_sysfile(struct super_block *sb, int type,
1059                                  int format_id);
1060 static int ext4_quota_off(struct super_block *sb, int type);
1061 static int ext4_quota_off_sysfile(struct super_block *sb, int type);
1062 static int ext4_quota_on_mount(struct super_block *sb, int type);
1063 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1064                                size_t len, loff_t off);
1065 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1066                                 const char *data, size_t len, loff_t off);
1067 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1068                              unsigned int flags);
1069 static int ext4_enable_quotas(struct super_block *sb);
1070
1071 static const struct dquot_operations ext4_quota_operations = {
1072         .get_reserved_space = ext4_get_reserved_space,
1073         .write_dquot    = ext4_write_dquot,
1074         .acquire_dquot  = ext4_acquire_dquot,
1075         .release_dquot  = ext4_release_dquot,
1076         .mark_dirty     = ext4_mark_dquot_dirty,
1077         .write_info     = ext4_write_info,
1078         .alloc_dquot    = dquot_alloc,
1079         .destroy_dquot  = dquot_destroy,
1080 };
1081
1082 static const struct quotactl_ops ext4_qctl_operations = {
1083         .quota_on       = ext4_quota_on,
1084         .quota_off      = ext4_quota_off,
1085         .quota_sync     = dquot_quota_sync,
1086         .get_info       = dquot_get_dqinfo,
1087         .set_info       = dquot_set_dqinfo,
1088         .get_dqblk      = dquot_get_dqblk,
1089         .set_dqblk      = dquot_set_dqblk
1090 };
1091
1092 static const struct quotactl_ops ext4_qctl_sysfile_operations = {
1093         .quota_on_meta  = ext4_quota_on_sysfile,
1094         .quota_off      = ext4_quota_off_sysfile,
1095         .quota_sync     = dquot_quota_sync,
1096         .get_info       = dquot_get_dqinfo,
1097         .set_info       = dquot_set_dqinfo,
1098         .get_dqblk      = dquot_get_dqblk,
1099         .set_dqblk      = dquot_set_dqblk
1100 };
1101 #endif
1102
1103 static const struct super_operations ext4_sops = {
1104         .alloc_inode    = ext4_alloc_inode,
1105         .destroy_inode  = ext4_destroy_inode,
1106         .write_inode    = ext4_write_inode,
1107         .dirty_inode    = ext4_dirty_inode,
1108         .drop_inode     = ext4_drop_inode,
1109         .evict_inode    = ext4_evict_inode,
1110         .put_super      = ext4_put_super,
1111         .sync_fs        = ext4_sync_fs,
1112         .freeze_fs      = ext4_freeze,
1113         .unfreeze_fs    = ext4_unfreeze,
1114         .statfs         = ext4_statfs,
1115         .remount_fs     = ext4_remount,
1116         .show_options   = ext4_show_options,
1117 #ifdef CONFIG_QUOTA
1118         .quota_read     = ext4_quota_read,
1119         .quota_write    = ext4_quota_write,
1120 #endif
1121         .bdev_try_to_free_page = bdev_try_to_free_page,
1122 };
1123
1124 static const struct export_operations ext4_export_ops = {
1125         .fh_to_dentry = ext4_fh_to_dentry,
1126         .fh_to_parent = ext4_fh_to_parent,
1127         .get_parent = ext4_get_parent,
1128 };
1129
1130 enum {
1131         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1132         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1133         Opt_nouid32, Opt_debug, Opt_removed,
1134         Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1135         Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1136         Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1137         Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1138         Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1139         Opt_data_err_abort, Opt_data_err_ignore,
1140         Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1141         Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1142         Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1143         Opt_usrquota, Opt_grpquota, Opt_i_version,
1144         Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_mblk_io_submit,
1145         Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1146         Opt_inode_readahead_blks, Opt_journal_ioprio,
1147         Opt_dioread_nolock, Opt_dioread_lock,
1148         Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1149         Opt_max_dir_size_kb,
1150 };
1151
1152 static const match_table_t tokens = {
1153         {Opt_bsd_df, "bsddf"},
1154         {Opt_minix_df, "minixdf"},
1155         {Opt_grpid, "grpid"},
1156         {Opt_grpid, "bsdgroups"},
1157         {Opt_nogrpid, "nogrpid"},
1158         {Opt_nogrpid, "sysvgroups"},
1159         {Opt_resgid, "resgid=%u"},
1160         {Opt_resuid, "resuid=%u"},
1161         {Opt_sb, "sb=%u"},
1162         {Opt_err_cont, "errors=continue"},
1163         {Opt_err_panic, "errors=panic"},
1164         {Opt_err_ro, "errors=remount-ro"},
1165         {Opt_nouid32, "nouid32"},
1166         {Opt_debug, "debug"},
1167         {Opt_removed, "oldalloc"},
1168         {Opt_removed, "orlov"},
1169         {Opt_user_xattr, "user_xattr"},
1170         {Opt_nouser_xattr, "nouser_xattr"},
1171         {Opt_acl, "acl"},
1172         {Opt_noacl, "noacl"},
1173         {Opt_noload, "norecovery"},
1174         {Opt_noload, "noload"},
1175         {Opt_removed, "nobh"},
1176         {Opt_removed, "bh"},
1177         {Opt_commit, "commit=%u"},
1178         {Opt_min_batch_time, "min_batch_time=%u"},
1179         {Opt_max_batch_time, "max_batch_time=%u"},
1180         {Opt_journal_dev, "journal_dev=%u"},
1181         {Opt_journal_path, "journal_path=%s"},
1182         {Opt_journal_checksum, "journal_checksum"},
1183         {Opt_journal_async_commit, "journal_async_commit"},
1184         {Opt_abort, "abort"},
1185         {Opt_data_journal, "data=journal"},
1186         {Opt_data_ordered, "data=ordered"},
1187         {Opt_data_writeback, "data=writeback"},
1188         {Opt_data_err_abort, "data_err=abort"},
1189         {Opt_data_err_ignore, "data_err=ignore"},
1190         {Opt_offusrjquota, "usrjquota="},
1191         {Opt_usrjquota, "usrjquota=%s"},
1192         {Opt_offgrpjquota, "grpjquota="},
1193         {Opt_grpjquota, "grpjquota=%s"},
1194         {Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1195         {Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1196         {Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1197         {Opt_grpquota, "grpquota"},
1198         {Opt_noquota, "noquota"},
1199         {Opt_quota, "quota"},
1200         {Opt_usrquota, "usrquota"},
1201         {Opt_barrier, "barrier=%u"},
1202         {Opt_barrier, "barrier"},
1203         {Opt_nobarrier, "nobarrier"},
1204         {Opt_i_version, "i_version"},
1205         {Opt_stripe, "stripe=%u"},
1206         {Opt_delalloc, "delalloc"},
1207         {Opt_nodelalloc, "nodelalloc"},
1208         {Opt_removed, "mblk_io_submit"},
1209         {Opt_removed, "nomblk_io_submit"},
1210         {Opt_block_validity, "block_validity"},
1211         {Opt_noblock_validity, "noblock_validity"},
1212         {Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1213         {Opt_journal_ioprio, "journal_ioprio=%u"},
1214         {Opt_auto_da_alloc, "auto_da_alloc=%u"},
1215         {Opt_auto_da_alloc, "auto_da_alloc"},
1216         {Opt_noauto_da_alloc, "noauto_da_alloc"},
1217         {Opt_dioread_nolock, "dioread_nolock"},
1218         {Opt_dioread_lock, "dioread_lock"},
1219         {Opt_discard, "discard"},
1220         {Opt_nodiscard, "nodiscard"},
1221         {Opt_init_itable, "init_itable=%u"},
1222         {Opt_init_itable, "init_itable"},
1223         {Opt_noinit_itable, "noinit_itable"},
1224         {Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1225         {Opt_removed, "check=none"},    /* mount option from ext2/3 */
1226         {Opt_removed, "nocheck"},       /* mount option from ext2/3 */
1227         {Opt_removed, "reservation"},   /* mount option from ext2/3 */
1228         {Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1229         {Opt_removed, "journal=%u"},    /* mount option from ext2/3 */
1230         {Opt_err, NULL},
1231 };
1232
1233 static ext4_fsblk_t get_sb_block(void **data)
1234 {
1235         ext4_fsblk_t    sb_block;
1236         char            *options = (char *) *data;
1237
1238         if (!options || strncmp(options, "sb=", 3) != 0)
1239                 return 1;       /* Default location */
1240
1241         options += 3;
1242         /* TODO: use simple_strtoll with >32bit ext4 */
1243         sb_block = simple_strtoul(options, &options, 0);
1244         if (*options && *options != ',') {
1245                 printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1246                        (char *) *data);
1247                 return 1;
1248         }
1249         if (*options == ',')
1250                 options++;
1251         *data = (void *) options;
1252
1253         return sb_block;
1254 }
1255
1256 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1257 static char deprecated_msg[] = "Mount option \"%s\" will be removed by %s\n"
1258         "Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1259
1260 #ifdef CONFIG_QUOTA
1261 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1262 {
1263         struct ext4_sb_info *sbi = EXT4_SB(sb);
1264         char *qname;
1265         int ret = -1;
1266
1267         if (sb_any_quota_loaded(sb) &&
1268                 !sbi->s_qf_names[qtype]) {
1269                 ext4_msg(sb, KERN_ERR,
1270                         "Cannot change journaled "
1271                         "quota options when quota turned on");
1272                 return -1;
1273         }
1274         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA)) {
1275                 ext4_msg(sb, KERN_ERR, "Cannot set journaled quota options "
1276                          "when QUOTA feature is enabled");
1277                 return -1;
1278         }
1279         qname = match_strdup(args);
1280         if (!qname) {
1281                 ext4_msg(sb, KERN_ERR,
1282                         "Not enough memory for storing quotafile name");
1283                 return -1;
1284         }
1285         if (sbi->s_qf_names[qtype]) {
1286                 if (strcmp(sbi->s_qf_names[qtype], qname) == 0)
1287                         ret = 1;
1288                 else
1289                         ext4_msg(sb, KERN_ERR,
1290                                  "%s quota file already specified",
1291                                  QTYPE2NAME(qtype));
1292                 goto errout;
1293         }
1294         if (strchr(qname, '/')) {
1295                 ext4_msg(sb, KERN_ERR,
1296                         "quotafile must be on filesystem root");
1297                 goto errout;
1298         }
1299         sbi->s_qf_names[qtype] = qname;
1300         set_opt(sb, QUOTA);
1301         return 1;
1302 errout:
1303         kfree(qname);
1304         return ret;
1305 }
1306
1307 static int clear_qf_name(struct super_block *sb, int qtype)
1308 {
1309
1310         struct ext4_sb_info *sbi = EXT4_SB(sb);
1311
1312         if (sb_any_quota_loaded(sb) &&
1313                 sbi->s_qf_names[qtype]) {
1314                 ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1315                         " when quota turned on");
1316                 return -1;
1317         }
1318         kfree(sbi->s_qf_names[qtype]);
1319         sbi->s_qf_names[qtype] = NULL;
1320         return 1;
1321 }
1322 #endif
1323
1324 #define MOPT_SET        0x0001
1325 #define MOPT_CLEAR      0x0002
1326 #define MOPT_NOSUPPORT  0x0004
1327 #define MOPT_EXPLICIT   0x0008
1328 #define MOPT_CLEAR_ERR  0x0010
1329 #define MOPT_GTE0       0x0020
1330 #ifdef CONFIG_QUOTA
1331 #define MOPT_Q          0
1332 #define MOPT_QFMT       0x0040
1333 #else
1334 #define MOPT_Q          MOPT_NOSUPPORT
1335 #define MOPT_QFMT       MOPT_NOSUPPORT
1336 #endif
1337 #define MOPT_DATAJ      0x0080
1338 #define MOPT_NO_EXT2    0x0100
1339 #define MOPT_NO_EXT3    0x0200
1340 #define MOPT_EXT4_ONLY  (MOPT_NO_EXT2 | MOPT_NO_EXT3)
1341 #define MOPT_STRING     0x0400
1342
1343 static const struct mount_opts {
1344         int     token;
1345         int     mount_opt;
1346         int     flags;
1347 } ext4_mount_opts[] = {
1348         {Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1349         {Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1350         {Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1351         {Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1352         {Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1353         {Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1354         {Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1355          MOPT_EXT4_ONLY | MOPT_SET},
1356         {Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1357          MOPT_EXT4_ONLY | MOPT_CLEAR},
1358         {Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1359         {Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1360         {Opt_delalloc, EXT4_MOUNT_DELALLOC,
1361          MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1362         {Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1363          MOPT_EXT4_ONLY | MOPT_CLEAR},
1364         {Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1365          MOPT_EXT4_ONLY | MOPT_SET},
1366         {Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1367                                     EXT4_MOUNT_JOURNAL_CHECKSUM),
1368          MOPT_EXT4_ONLY | MOPT_SET},
1369         {Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1370         {Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1371         {Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1372         {Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1373         {Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
1374          MOPT_NO_EXT2 | MOPT_SET},
1375         {Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
1376          MOPT_NO_EXT2 | MOPT_CLEAR},
1377         {Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1378         {Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1379         {Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1380         {Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1381         {Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1382         {Opt_commit, 0, MOPT_GTE0},
1383         {Opt_max_batch_time, 0, MOPT_GTE0},
1384         {Opt_min_batch_time, 0, MOPT_GTE0},
1385         {Opt_inode_readahead_blks, 0, MOPT_GTE0},
1386         {Opt_init_itable, 0, MOPT_GTE0},
1387         {Opt_stripe, 0, MOPT_GTE0},
1388         {Opt_resuid, 0, MOPT_GTE0},
1389         {Opt_resgid, 0, MOPT_GTE0},
1390         {Opt_journal_dev, 0, MOPT_GTE0},
1391         {Opt_journal_path, 0, MOPT_STRING},
1392         {Opt_journal_ioprio, 0, MOPT_GTE0},
1393         {Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1394         {Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1395         {Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
1396          MOPT_NO_EXT2 | MOPT_DATAJ},
1397         {Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1398         {Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1399 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1400         {Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1401         {Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1402 #else
1403         {Opt_acl, 0, MOPT_NOSUPPORT},
1404         {Opt_noacl, 0, MOPT_NOSUPPORT},
1405 #endif
1406         {Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1407         {Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1408         {Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1409         {Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1410                                                         MOPT_SET | MOPT_Q},
1411         {Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1412                                                         MOPT_SET | MOPT_Q},
1413         {Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1414                        EXT4_MOUNT_GRPQUOTA), MOPT_CLEAR | MOPT_Q},
1415         {Opt_usrjquota, 0, MOPT_Q},
1416         {Opt_grpjquota, 0, MOPT_Q},
1417         {Opt_offusrjquota, 0, MOPT_Q},
1418         {Opt_offgrpjquota, 0, MOPT_Q},
1419         {Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1420         {Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1421         {Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1422         {Opt_max_dir_size_kb, 0, MOPT_GTE0},
1423         {Opt_err, 0, 0}
1424 };
1425
1426 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1427                             substring_t *args, unsigned long *journal_devnum,
1428                             unsigned int *journal_ioprio, int is_remount)
1429 {
1430         struct ext4_sb_info *sbi = EXT4_SB(sb);
1431         const struct mount_opts *m;
1432         kuid_t uid;
1433         kgid_t gid;
1434         int arg = 0;
1435
1436 #ifdef CONFIG_QUOTA
1437         if (token == Opt_usrjquota)
1438                 return set_qf_name(sb, USRQUOTA, &args[0]);
1439         else if (token == Opt_grpjquota)
1440                 return set_qf_name(sb, GRPQUOTA, &args[0]);
1441         else if (token == Opt_offusrjquota)
1442                 return clear_qf_name(sb, USRQUOTA);
1443         else if (token == Opt_offgrpjquota)
1444                 return clear_qf_name(sb, GRPQUOTA);
1445 #endif
1446         switch (token) {
1447         case Opt_noacl:
1448         case Opt_nouser_xattr:
1449                 ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1450                 break;
1451         case Opt_sb:
1452                 return 1;       /* handled by get_sb_block() */
1453         case Opt_removed:
1454                 ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
1455                 return 1;
1456         case Opt_abort:
1457                 sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1458                 return 1;
1459         case Opt_i_version:
1460                 sb->s_flags |= MS_I_VERSION;
1461                 return 1;
1462         }
1463
1464         for (m = ext4_mount_opts; m->token != Opt_err; m++)
1465                 if (token == m->token)
1466                         break;
1467
1468         if (m->token == Opt_err) {
1469                 ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1470                          "or missing value", opt);
1471                 return -1;
1472         }
1473
1474         if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
1475                 ext4_msg(sb, KERN_ERR,
1476                          "Mount option \"%s\" incompatible with ext2", opt);
1477                 return -1;
1478         }
1479         if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
1480                 ext4_msg(sb, KERN_ERR,
1481                          "Mount option \"%s\" incompatible with ext3", opt);
1482                 return -1;
1483         }
1484
1485         if (args->from && !(m->flags & MOPT_STRING) && match_int(args, &arg))
1486                 return -1;
1487         if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1488                 return -1;
1489         if (m->flags & MOPT_EXPLICIT)
1490                 set_opt2(sb, EXPLICIT_DELALLOC);
1491         if (m->flags & MOPT_CLEAR_ERR)
1492                 clear_opt(sb, ERRORS_MASK);
1493         if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1494                 ext4_msg(sb, KERN_ERR, "Cannot change quota "
1495                          "options when quota turned on");
1496                 return -1;
1497         }
1498
1499         if (m->flags & MOPT_NOSUPPORT) {
1500                 ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1501         } else if (token == Opt_commit) {
1502                 if (arg == 0)
1503                         arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1504                 sbi->s_commit_interval = HZ * arg;
1505         } else if (token == Opt_max_batch_time) {
1506                 sbi->s_max_batch_time = arg;
1507         } else if (token == Opt_min_batch_time) {
1508                 sbi->s_min_batch_time = arg;
1509         } else if (token == Opt_inode_readahead_blks) {
1510                 if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
1511                         ext4_msg(sb, KERN_ERR,
1512                                  "EXT4-fs: inode_readahead_blks must be "
1513                                  "0 or a power of 2 smaller than 2^31");
1514                         return -1;
1515                 }
1516                 sbi->s_inode_readahead_blks = arg;
1517         } else if (token == Opt_init_itable) {
1518                 set_opt(sb, INIT_INODE_TABLE);
1519                 if (!args->from)
1520                         arg = EXT4_DEF_LI_WAIT_MULT;
1521                 sbi->s_li_wait_mult = arg;
1522         } else if (token == Opt_max_dir_size_kb) {
1523                 sbi->s_max_dir_size_kb = arg;
1524         } else if (token == Opt_stripe) {
1525                 sbi->s_stripe = arg;
1526         } else if (token == Opt_resuid) {
1527                 uid = make_kuid(current_user_ns(), arg);
1528                 if (!uid_valid(uid)) {
1529                         ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
1530                         return -1;
1531                 }
1532                 sbi->s_resuid = uid;
1533         } else if (token == Opt_resgid) {
1534                 gid = make_kgid(current_user_ns(), arg);
1535                 if (!gid_valid(gid)) {
1536                         ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
1537                         return -1;
1538                 }
1539                 sbi->s_resgid = gid;
1540         } else if (token == Opt_journal_dev) {
1541                 if (is_remount) {
1542                         ext4_msg(sb, KERN_ERR,
1543                                  "Cannot specify journal on remount");
1544                         return -1;
1545                 }
1546                 *journal_devnum = arg;
1547         } else if (token == Opt_journal_path) {
1548                 char *journal_path;
1549                 struct inode *journal_inode;
1550                 struct path path;
1551                 int error;
1552
1553                 if (is_remount) {
1554                         ext4_msg(sb, KERN_ERR,
1555                                  "Cannot specify journal on remount");
1556                         return -1;
1557                 }
1558                 journal_path = match_strdup(&args[0]);
1559                 if (!journal_path) {
1560                         ext4_msg(sb, KERN_ERR, "error: could not dup "
1561                                 "journal device string");
1562                         return -1;
1563                 }
1564
1565                 error = kern_path(journal_path, LOOKUP_FOLLOW, &path);
1566                 if (error) {
1567                         ext4_msg(sb, KERN_ERR, "error: could not find "
1568                                 "journal device path: error %d", error);
1569                         kfree(journal_path);
1570                         return -1;
1571                 }
1572
1573                 journal_inode = path.dentry->d_inode;
1574                 if (!S_ISBLK(journal_inode->i_mode)) {
1575                         ext4_msg(sb, KERN_ERR, "error: journal path %s "
1576                                 "is not a block device", journal_path);
1577                         path_put(&path);
1578                         kfree(journal_path);
1579                         return -1;
1580                 }
1581
1582                 *journal_devnum = new_encode_dev(journal_inode->i_rdev);
1583                 path_put(&path);
1584                 kfree(journal_path);
1585         } else if (token == Opt_journal_ioprio) {
1586                 if (arg > 7) {
1587                         ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
1588                                  " (must be 0-7)");
1589                         return -1;
1590                 }
1591                 *journal_ioprio =
1592                         IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
1593         } else if (m->flags & MOPT_DATAJ) {
1594                 if (is_remount) {
1595                         if (!sbi->s_journal)
1596                                 ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
1597                         else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
1598                                 ext4_msg(sb, KERN_ERR,
1599                                          "Cannot change data mode on remount");
1600                                 return -1;
1601                         }
1602                 } else {
1603                         clear_opt(sb, DATA_FLAGS);
1604                         sbi->s_mount_opt |= m->mount_opt;
1605                 }
1606 #ifdef CONFIG_QUOTA
1607         } else if (m->flags & MOPT_QFMT) {
1608                 if (sb_any_quota_loaded(sb) &&
1609                     sbi->s_jquota_fmt != m->mount_opt) {
1610                         ext4_msg(sb, KERN_ERR, "Cannot change journaled "
1611                                  "quota options when quota turned on");
1612                         return -1;
1613                 }
1614                 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
1615                                                EXT4_FEATURE_RO_COMPAT_QUOTA)) {
1616                         ext4_msg(sb, KERN_ERR,
1617                                  "Cannot set journaled quota options "
1618                                  "when QUOTA feature is enabled");
1619                         return -1;
1620                 }
1621                 sbi->s_jquota_fmt = m->mount_opt;
1622 #endif
1623         } else {
1624                 if (!args->from)
1625                         arg = 1;
1626                 if (m->flags & MOPT_CLEAR)
1627                         arg = !arg;
1628                 else if (unlikely(!(m->flags & MOPT_SET))) {
1629                         ext4_msg(sb, KERN_WARNING,
1630                                  "buggy handling of option %s", opt);
1631                         WARN_ON(1);
1632                         return -1;
1633                 }
1634                 if (arg != 0)
1635                         sbi->s_mount_opt |= m->mount_opt;
1636                 else
1637                         sbi->s_mount_opt &= ~m->mount_opt;
1638         }
1639         return 1;
1640 }
1641
1642 static int parse_options(char *options, struct super_block *sb,
1643                          unsigned long *journal_devnum,
1644                          unsigned int *journal_ioprio,
1645                          int is_remount)
1646 {
1647         struct ext4_sb_info *sbi = EXT4_SB(sb);
1648         char *p;
1649         substring_t args[MAX_OPT_ARGS];
1650         int token;
1651
1652         if (!options)
1653                 return 1;
1654
1655         while ((p = strsep(&options, ",")) != NULL) {
1656                 if (!*p)
1657                         continue;
1658                 /*
1659                  * Initialize args struct so we know whether arg was
1660                  * found; some options take optional arguments.
1661                  */
1662                 args[0].to = args[0].from = NULL;
1663                 token = match_token(p, tokens, args);
1664                 if (handle_mount_opt(sb, p, token, args, journal_devnum,
1665                                      journal_ioprio, is_remount) < 0)
1666                         return 0;
1667         }
1668 #ifdef CONFIG_QUOTA
1669         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
1670             (test_opt(sb, USRQUOTA) || test_opt(sb, GRPQUOTA))) {
1671                 ext4_msg(sb, KERN_ERR, "Cannot set quota options when QUOTA "
1672                          "feature is enabled");
1673                 return 0;
1674         }
1675         if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1676                 if (test_opt(sb, USRQUOTA) && sbi->s_qf_names[USRQUOTA])
1677                         clear_opt(sb, USRQUOTA);
1678
1679                 if (test_opt(sb, GRPQUOTA) && sbi->s_qf_names[GRPQUOTA])
1680                         clear_opt(sb, GRPQUOTA);
1681
1682                 if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
1683                         ext4_msg(sb, KERN_ERR, "old and new quota "
1684                                         "format mixing");
1685                         return 0;
1686                 }
1687
1688                 if (!sbi->s_jquota_fmt) {
1689                         ext4_msg(sb, KERN_ERR, "journaled quota format "
1690                                         "not specified");
1691                         return 0;
1692                 }
1693         }
1694 #endif
1695         if (test_opt(sb, DIOREAD_NOLOCK)) {
1696                 int blocksize =
1697                         BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
1698
1699                 if (blocksize < PAGE_CACHE_SIZE) {
1700                         ext4_msg(sb, KERN_ERR, "can't mount with "
1701                                  "dioread_nolock if block size != PAGE_SIZE");
1702                         return 0;
1703                 }
1704         }
1705         return 1;
1706 }
1707
1708 static inline void ext4_show_quota_options(struct seq_file *seq,
1709                                            struct super_block *sb)
1710 {
1711 #if defined(CONFIG_QUOTA)
1712         struct ext4_sb_info *sbi = EXT4_SB(sb);
1713
1714         if (sbi->s_jquota_fmt) {
1715                 char *fmtname = "";
1716
1717                 switch (sbi->s_jquota_fmt) {
1718                 case QFMT_VFS_OLD:
1719                         fmtname = "vfsold";
1720                         break;
1721                 case QFMT_VFS_V0:
1722                         fmtname = "vfsv0";
1723                         break;
1724                 case QFMT_VFS_V1:
1725                         fmtname = "vfsv1";
1726                         break;
1727                 }
1728                 seq_printf(seq, ",jqfmt=%s", fmtname);
1729         }
1730
1731         if (sbi->s_qf_names[USRQUOTA])
1732                 seq_printf(seq, ",usrjquota=%s", sbi->s_qf_names[USRQUOTA]);
1733
1734         if (sbi->s_qf_names[GRPQUOTA])
1735                 seq_printf(seq, ",grpjquota=%s", sbi->s_qf_names[GRPQUOTA]);
1736 #endif
1737 }
1738
1739 static const char *token2str(int token)
1740 {
1741         const struct match_token *t;
1742
1743         for (t = tokens; t->token != Opt_err; t++)
1744                 if (t->token == token && !strchr(t->pattern, '='))
1745                         break;
1746         return t->pattern;
1747 }
1748
1749 /*
1750  * Show an option if
1751  *  - it's set to a non-default value OR
1752  *  - if the per-sb default is different from the global default
1753  */
1754 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
1755                               int nodefs)
1756 {
1757         struct ext4_sb_info *sbi = EXT4_SB(sb);
1758         struct ext4_super_block *es = sbi->s_es;
1759         int def_errors, def_mount_opt = nodefs ? 0 : sbi->s_def_mount_opt;
1760         const struct mount_opts *m;
1761         char sep = nodefs ? '\n' : ',';
1762
1763 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
1764 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
1765
1766         if (sbi->s_sb_block != 1)
1767                 SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
1768
1769         for (m = ext4_mount_opts; m->token != Opt_err; m++) {
1770                 int want_set = m->flags & MOPT_SET;
1771                 if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
1772                     (m->flags & MOPT_CLEAR_ERR))
1773                         continue;
1774                 if (!(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
1775                         continue; /* skip if same as the default */
1776                 if ((want_set &&
1777                      (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
1778                     (!want_set && (sbi->s_mount_opt & m->mount_opt)))
1779                         continue; /* select Opt_noFoo vs Opt_Foo */
1780                 SEQ_OPTS_PRINT("%s", token2str(m->token));
1781         }
1782
1783         if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
1784             le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
1785                 SEQ_OPTS_PRINT("resuid=%u",
1786                                 from_kuid_munged(&init_user_ns, sbi->s_resuid));
1787         if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
1788             le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
1789                 SEQ_OPTS_PRINT("resgid=%u",
1790                                 from_kgid_munged(&init_user_ns, sbi->s_resgid));
1791         def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
1792         if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
1793                 SEQ_OPTS_PUTS("errors=remount-ro");
1794         if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
1795                 SEQ_OPTS_PUTS("errors=continue");
1796         if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
1797                 SEQ_OPTS_PUTS("errors=panic");
1798         if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
1799                 SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
1800         if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
1801                 SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
1802         if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
1803                 SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
1804         if (sb->s_flags & MS_I_VERSION)
1805                 SEQ_OPTS_PUTS("i_version");
1806         if (nodefs || sbi->s_stripe)
1807                 SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
1808         if (EXT4_MOUNT_DATA_FLAGS & (sbi->s_mount_opt ^ def_mount_opt)) {
1809                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
1810                         SEQ_OPTS_PUTS("data=journal");
1811                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
1812                         SEQ_OPTS_PUTS("data=ordered");
1813                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
1814                         SEQ_OPTS_PUTS("data=writeback");
1815         }
1816         if (nodefs ||
1817             sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
1818                 SEQ_OPTS_PRINT("inode_readahead_blks=%u",
1819                                sbi->s_inode_readahead_blks);
1820
1821         if (nodefs || (test_opt(sb, INIT_INODE_TABLE) &&
1822                        (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
1823                 SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
1824         if (nodefs || sbi->s_max_dir_size_kb)
1825                 SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
1826
1827         ext4_show_quota_options(seq, sb);
1828         return 0;
1829 }
1830
1831 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
1832 {
1833         return _ext4_show_options(seq, root->d_sb, 0);
1834 }
1835
1836 static int options_seq_show(struct seq_file *seq, void *offset)
1837 {
1838         struct super_block *sb = seq->private;
1839         int rc;
1840
1841         seq_puts(seq, (sb->s_flags & MS_RDONLY) ? "ro" : "rw");
1842         rc = _ext4_show_options(seq, sb, 1);
1843         seq_puts(seq, "\n");
1844         return rc;
1845 }
1846
1847 static int options_open_fs(struct inode *inode, struct file *file)
1848 {
1849         return single_open(file, options_seq_show, PDE_DATA(inode));
1850 }
1851
1852 static const struct file_operations ext4_seq_options_fops = {
1853         .owner = THIS_MODULE,
1854         .open = options_open_fs,
1855         .read = seq_read,
1856         .llseek = seq_lseek,
1857         .release = single_release,
1858 };
1859
1860 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
1861                             int read_only)
1862 {
1863         struct ext4_sb_info *sbi = EXT4_SB(sb);
1864         int res = 0;
1865
1866         if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
1867                 ext4_msg(sb, KERN_ERR, "revision level too high, "
1868                          "forcing read-only mode");
1869                 res = MS_RDONLY;
1870         }
1871         if (read_only)
1872                 goto done;
1873         if (!(sbi->s_mount_state & EXT4_VALID_FS))
1874                 ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
1875                          "running e2fsck is recommended");
1876         else if (sbi->s_mount_state & EXT4_ERROR_FS)
1877                 ext4_msg(sb, KERN_WARNING,
1878                          "warning: mounting fs with errors, "
1879                          "running e2fsck is recommended");
1880         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
1881                  le16_to_cpu(es->s_mnt_count) >=
1882                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
1883                 ext4_msg(sb, KERN_WARNING,
1884                          "warning: maximal mount count reached, "
1885                          "running e2fsck is recommended");
1886         else if (le32_to_cpu(es->s_checkinterval) &&
1887                 (le32_to_cpu(es->s_lastcheck) +
1888                         le32_to_cpu(es->s_checkinterval) <= get_seconds()))
1889                 ext4_msg(sb, KERN_WARNING,
1890                          "warning: checktime reached, "
1891                          "running e2fsck is recommended");
1892         if (!sbi->s_journal)
1893                 es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
1894         if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
1895                 es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
1896         le16_add_cpu(&es->s_mnt_count, 1);
1897         es->s_mtime = cpu_to_le32(get_seconds());
1898         ext4_update_dynamic_rev(sb);
1899         if (sbi->s_journal)
1900                 EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
1901
1902         ext4_commit_super(sb, 1);
1903 done:
1904         if (test_opt(sb, DEBUG))
1905                 printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
1906                                 "bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
1907                         sb->s_blocksize,
1908                         sbi->s_groups_count,
1909                         EXT4_BLOCKS_PER_GROUP(sb),
1910                         EXT4_INODES_PER_GROUP(sb),
1911                         sbi->s_mount_opt, sbi->s_mount_opt2);
1912
1913         cleancache_init_fs(sb);
1914         return res;
1915 }
1916
1917 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
1918 {
1919         struct ext4_sb_info *sbi = EXT4_SB(sb);
1920         struct flex_groups *new_groups;
1921         int size;
1922
1923         if (!sbi->s_log_groups_per_flex)
1924                 return 0;
1925
1926         size = ext4_flex_group(sbi, ngroup - 1) + 1;
1927         if (size <= sbi->s_flex_groups_allocated)
1928                 return 0;
1929
1930         size = roundup_pow_of_two(size * sizeof(struct flex_groups));
1931         new_groups = ext4_kvzalloc(size, GFP_KERNEL);
1932         if (!new_groups) {
1933                 ext4_msg(sb, KERN_ERR, "not enough memory for %d flex groups",
1934                          size / (int) sizeof(struct flex_groups));
1935                 return -ENOMEM;
1936         }
1937
1938         if (sbi->s_flex_groups) {
1939                 memcpy(new_groups, sbi->s_flex_groups,
1940                        (sbi->s_flex_groups_allocated *
1941                         sizeof(struct flex_groups)));
1942                 ext4_kvfree(sbi->s_flex_groups);
1943         }
1944         sbi->s_flex_groups = new_groups;
1945         sbi->s_flex_groups_allocated = size / sizeof(struct flex_groups);
1946         return 0;
1947 }
1948
1949 static int ext4_fill_flex_info(struct super_block *sb)
1950 {
1951         struct ext4_sb_info *sbi = EXT4_SB(sb);
1952         struct ext4_group_desc *gdp = NULL;
1953         ext4_group_t flex_group;
1954         int i, err;
1955
1956         sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
1957         if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
1958                 sbi->s_log_groups_per_flex = 0;
1959                 return 1;
1960         }
1961
1962         err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
1963         if (err)
1964                 goto failed;
1965
1966         for (i = 0; i < sbi->s_groups_count; i++) {
1967                 gdp = ext4_get_group_desc(sb, i, NULL);
1968
1969                 flex_group = ext4_flex_group(sbi, i);
1970                 atomic_add(ext4_free_inodes_count(sb, gdp),
1971                            &sbi->s_flex_groups[flex_group].free_inodes);
1972                 atomic64_add(ext4_free_group_clusters(sb, gdp),
1973                              &sbi->s_flex_groups[flex_group].free_clusters);
1974                 atomic_add(ext4_used_dirs_count(sb, gdp),
1975                            &sbi->s_flex_groups[flex_group].used_dirs);
1976         }
1977
1978         return 1;
1979 failed:
1980         return 0;
1981 }
1982
1983 static __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 block_group,
1984                                    struct ext4_group_desc *gdp)
1985 {
1986         int offset;
1987         __u16 crc = 0;
1988         __le32 le_group = cpu_to_le32(block_group);
1989
1990         if (ext4_has_metadata_csum(sbi->s_sb)) {
1991                 /* Use new metadata_csum algorithm */
1992                 __le16 save_csum;
1993                 __u32 csum32;
1994
1995                 save_csum = gdp->bg_checksum;
1996                 gdp->bg_checksum = 0;
1997                 csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
1998                                      sizeof(le_group));
1999                 csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp,
2000                                      sbi->s_desc_size);
2001                 gdp->bg_checksum = save_csum;
2002
2003                 crc = csum32 & 0xFFFF;
2004                 goto out;
2005         }
2006
2007         /* old crc16 code */
2008         if (!(sbi->s_es->s_feature_ro_compat &
2009               cpu_to_le32(EXT4_FEATURE_RO_COMPAT_GDT_CSUM)))
2010                 return 0;
2011
2012         offset = offsetof(struct ext4_group_desc, bg_checksum);
2013
2014         crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2015         crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2016         crc = crc16(crc, (__u8 *)gdp, offset);
2017         offset += sizeof(gdp->bg_checksum); /* skip checksum */
2018         /* for checksum of struct ext4_group_desc do the rest...*/
2019         if ((sbi->s_es->s_feature_incompat &
2020              cpu_to_le32(EXT4_FEATURE_INCOMPAT_64BIT)) &&
2021             offset < le16_to_cpu(sbi->s_es->s_desc_size))
2022                 crc = crc16(crc, (__u8 *)gdp + offset,
2023                             le16_to_cpu(sbi->s_es->s_desc_size) -
2024                                 offset);
2025
2026 out:
2027         return cpu_to_le16(crc);
2028 }
2029
2030 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2031                                 struct ext4_group_desc *gdp)
2032 {
2033         if (ext4_has_group_desc_csum(sb) &&
2034             (gdp->bg_checksum != ext4_group_desc_csum(EXT4_SB(sb),
2035                                                       block_group, gdp)))
2036                 return 0;
2037
2038         return 1;
2039 }
2040
2041 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2042                               struct ext4_group_desc *gdp)
2043 {
2044         if (!ext4_has_group_desc_csum(sb))
2045                 return;
2046         gdp->bg_checksum = ext4_group_desc_csum(EXT4_SB(sb), block_group, gdp);
2047 }
2048
2049 /* Called at mount-time, super-block is locked */
2050 static int ext4_check_descriptors(struct super_block *sb,
2051                                   ext4_group_t *first_not_zeroed)
2052 {
2053         struct ext4_sb_info *sbi = EXT4_SB(sb);
2054         ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2055         ext4_fsblk_t last_block;
2056         ext4_fsblk_t block_bitmap;
2057         ext4_fsblk_t inode_bitmap;
2058         ext4_fsblk_t inode_table;
2059         int flexbg_flag = 0;
2060         ext4_group_t i, grp = sbi->s_groups_count;
2061
2062         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
2063                 flexbg_flag = 1;
2064
2065         ext4_debug("Checking group descriptors");
2066
2067         for (i = 0; i < sbi->s_groups_count; i++) {
2068                 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2069
2070                 if (i == sbi->s_groups_count - 1 || flexbg_flag)
2071                         last_block = ext4_blocks_count(sbi->s_es) - 1;
2072                 else
2073                         last_block = first_block +
2074                                 (EXT4_BLOCKS_PER_GROUP(sb) - 1);
2075
2076                 if ((grp == sbi->s_groups_count) &&
2077                    !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2078                         grp = i;
2079
2080                 block_bitmap = ext4_block_bitmap(sb, gdp);
2081                 if (block_bitmap < first_block || block_bitmap > last_block) {
2082                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2083                                "Block bitmap for group %u not in group "
2084                                "(block %llu)!", i, block_bitmap);
2085                         return 0;
2086                 }
2087                 inode_bitmap = ext4_inode_bitmap(sb, gdp);
2088                 if (inode_bitmap < first_block || inode_bitmap > last_block) {
2089                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2090                                "Inode bitmap for group %u not in group "
2091                                "(block %llu)!", i, inode_bitmap);
2092                         return 0;
2093                 }
2094                 inode_table = ext4_inode_table(sb, gdp);
2095                 if (inode_table < first_block ||
2096                     inode_table + sbi->s_itb_per_group - 1 > last_block) {
2097                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2098                                "Inode table for group %u not in group "
2099                                "(block %llu)!", i, inode_table);
2100                         return 0;
2101                 }
2102                 ext4_lock_group(sb, i);
2103                 if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2104                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2105                                  "Checksum for group %u failed (%u!=%u)",
2106                                  i, le16_to_cpu(ext4_group_desc_csum(sbi, i,
2107                                      gdp)), le16_to_cpu(gdp->bg_checksum));
2108                         if (!(sb->s_flags & MS_RDONLY)) {
2109                                 ext4_unlock_group(sb, i);
2110                                 return 0;
2111                         }
2112                 }
2113                 ext4_unlock_group(sb, i);
2114                 if (!flexbg_flag)
2115                         first_block += EXT4_BLOCKS_PER_GROUP(sb);
2116         }
2117         if (NULL != first_not_zeroed)
2118                 *first_not_zeroed = grp;
2119         return 1;
2120 }
2121
2122 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2123  * the superblock) which were deleted from all directories, but held open by
2124  * a process at the time of a crash.  We walk the list and try to delete these
2125  * inodes at recovery time (only with a read-write filesystem).
2126  *
2127  * In order to keep the orphan inode chain consistent during traversal (in
2128  * case of crash during recovery), we link each inode into the superblock
2129  * orphan list_head and handle it the same way as an inode deletion during
2130  * normal operation (which journals the operations for us).
2131  *
2132  * We only do an iget() and an iput() on each inode, which is very safe if we
2133  * accidentally point at an in-use or already deleted inode.  The worst that
2134  * can happen in this case is that we get a "bit already cleared" message from
2135  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2136  * e2fsck was run on this filesystem, and it must have already done the orphan
2137  * inode cleanup for us, so we can safely abort without any further action.
2138  */
2139 static void ext4_orphan_cleanup(struct super_block *sb,
2140                                 struct ext4_super_block *es)
2141 {
2142         unsigned int s_flags = sb->s_flags;
2143         int nr_orphans = 0, nr_truncates = 0;
2144 #ifdef CONFIG_QUOTA
2145         int i;
2146 #endif
2147         if (!es->s_last_orphan) {
2148                 jbd_debug(4, "no orphan inodes to clean up\n");
2149                 return;
2150         }
2151
2152         if (bdev_read_only(sb->s_bdev)) {
2153                 ext4_msg(sb, KERN_ERR, "write access "
2154                         "unavailable, skipping orphan cleanup");
2155                 return;
2156         }
2157
2158         /* Check if feature set would not allow a r/w mount */
2159         if (!ext4_feature_set_ok(sb, 0)) {
2160                 ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2161                          "unknown ROCOMPAT features");
2162                 return;
2163         }
2164
2165         if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2166                 /* don't clear list on RO mount w/ errors */
2167                 if (es->s_last_orphan && !(s_flags & MS_RDONLY)) {
2168                         ext4_msg(sb, KERN_INFO, "Errors on filesystem, "
2169                                   "clearing orphan list.\n");
2170                         es->s_last_orphan = 0;
2171                 }
2172                 jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2173                 return;
2174         }
2175
2176         if (s_flags & MS_RDONLY) {
2177                 ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2178                 sb->s_flags &= ~MS_RDONLY;
2179         }
2180 #ifdef CONFIG_QUOTA
2181         /* Needed for iput() to work correctly and not trash data */
2182         sb->s_flags |= MS_ACTIVE;
2183         /* Turn on quotas so that they are updated correctly */
2184         for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2185                 if (EXT4_SB(sb)->s_qf_names[i]) {
2186                         int ret = ext4_quota_on_mount(sb, i);
2187                         if (ret < 0)
2188                                 ext4_msg(sb, KERN_ERR,
2189                                         "Cannot turn on journaled "
2190                                         "quota: error %d", ret);
2191                 }
2192         }
2193 #endif
2194
2195         while (es->s_last_orphan) {
2196                 struct inode *inode;
2197
2198                 inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2199                 if (IS_ERR(inode)) {
2200                         es->s_last_orphan = 0;
2201                         break;
2202                 }
2203
2204                 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2205                 dquot_initialize(inode);
2206                 if (inode->i_nlink) {
2207                         if (test_opt(sb, DEBUG))
2208                                 ext4_msg(sb, KERN_DEBUG,
2209                                         "%s: truncating inode %lu to %lld bytes",
2210                                         __func__, inode->i_ino, inode->i_size);
2211                         jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2212                                   inode->i_ino, inode->i_size);
2213                         mutex_lock(&inode->i_mutex);
2214                         truncate_inode_pages(inode->i_mapping, inode->i_size);
2215                         ext4_truncate(inode);
2216                         mutex_unlock(&inode->i_mutex);
2217                         nr_truncates++;
2218                 } else {
2219                         if (test_opt(sb, DEBUG))
2220                                 ext4_msg(sb, KERN_DEBUG,
2221                                         "%s: deleting unreferenced inode %lu",
2222                                         __func__, inode->i_ino);
2223                         jbd_debug(2, "deleting unreferenced inode %lu\n",
2224                                   inode->i_ino);
2225                         nr_orphans++;
2226                 }
2227                 iput(inode);  /* The delete magic happens here! */
2228         }
2229
2230 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2231
2232         if (nr_orphans)
2233                 ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2234                        PLURAL(nr_orphans));
2235         if (nr_truncates)
2236                 ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2237                        PLURAL(nr_truncates));
2238 #ifdef CONFIG_QUOTA
2239         /* Turn quotas off */
2240         for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2241                 if (sb_dqopt(sb)->files[i])
2242                         dquot_quota_off(sb, i);
2243         }
2244 #endif
2245         sb->s_flags = s_flags; /* Restore MS_RDONLY status */
2246 }
2247
2248 /*
2249  * Maximal extent format file size.
2250  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2251  * extent format containers, within a sector_t, and within i_blocks
2252  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2253  * so that won't be a limiting factor.
2254  *
2255  * However there is other limiting factor. We do store extents in the form
2256  * of starting block and length, hence the resulting length of the extent
2257  * covering maximum file size must fit into on-disk format containers as
2258  * well. Given that length is always by 1 unit bigger than max unit (because
2259  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2260  *
2261  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2262  */
2263 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2264 {
2265         loff_t res;
2266         loff_t upper_limit = MAX_LFS_FILESIZE;
2267
2268         /* small i_blocks in vfs inode? */
2269         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2270                 /*
2271                  * CONFIG_LBDAF is not enabled implies the inode
2272                  * i_block represent total blocks in 512 bytes
2273                  * 32 == size of vfs inode i_blocks * 8
2274                  */
2275                 upper_limit = (1LL << 32) - 1;
2276
2277                 /* total blocks in file system block size */
2278                 upper_limit >>= (blkbits - 9);
2279                 upper_limit <<= blkbits;
2280         }
2281
2282         /*
2283          * 32-bit extent-start container, ee_block. We lower the maxbytes
2284          * by one fs block, so ee_len can cover the extent of maximum file
2285          * size
2286          */
2287         res = (1LL << 32) - 1;
2288         res <<= blkbits;
2289
2290         /* Sanity check against vm- & vfs- imposed limits */
2291         if (res > upper_limit)
2292                 res = upper_limit;
2293
2294         return res;
2295 }
2296
2297 /*
2298  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2299  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2300  * We need to be 1 filesystem block less than the 2^48 sector limit.
2301  */
2302 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2303 {
2304         loff_t res = EXT4_NDIR_BLOCKS;
2305         int meta_blocks;
2306         loff_t upper_limit;
2307         /* This is calculated to be the largest file size for a dense, block
2308          * mapped file such that the file's total number of 512-byte sectors,
2309          * including data and all indirect blocks, does not exceed (2^48 - 1).
2310          *
2311          * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2312          * number of 512-byte sectors of the file.
2313          */
2314
2315         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2316                 /*
2317                  * !has_huge_files or CONFIG_LBDAF not enabled implies that
2318                  * the inode i_block field represents total file blocks in
2319                  * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2320                  */
2321                 upper_limit = (1LL << 32) - 1;
2322
2323                 /* total blocks in file system block size */
2324                 upper_limit >>= (bits - 9);
2325
2326         } else {
2327                 /*
2328                  * We use 48 bit ext4_inode i_blocks
2329                  * With EXT4_HUGE_FILE_FL set the i_blocks
2330                  * represent total number of blocks in
2331                  * file system block size
2332                  */
2333                 upper_limit = (1LL << 48) - 1;
2334
2335         }
2336
2337         /* indirect blocks */
2338         meta_blocks = 1;
2339         /* double indirect blocks */
2340         meta_blocks += 1 + (1LL << (bits-2));
2341         /* tripple indirect blocks */
2342         meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2343
2344         upper_limit -= meta_blocks;
2345         upper_limit <<= bits;
2346
2347         res += 1LL << (bits-2);
2348         res += 1LL << (2*(bits-2));
2349         res += 1LL << (3*(bits-2));
2350         res <<= bits;
2351         if (res > upper_limit)
2352                 res = upper_limit;
2353
2354         if (res > MAX_LFS_FILESIZE)
2355                 res = MAX_LFS_FILESIZE;
2356
2357         return res;
2358 }
2359
2360 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2361                                    ext4_fsblk_t logical_sb_block, int nr)
2362 {
2363         struct ext4_sb_info *sbi = EXT4_SB(sb);
2364         ext4_group_t bg, first_meta_bg;
2365         int has_super = 0;
2366
2367         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2368
2369         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG) ||
2370             nr < first_meta_bg)
2371                 return logical_sb_block + nr + 1;
2372         bg = sbi->s_desc_per_block * nr;
2373         if (ext4_bg_has_super(sb, bg))
2374                 has_super = 1;
2375
2376         /*
2377          * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
2378          * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
2379          * on modern mke2fs or blksize > 1k on older mke2fs) then we must
2380          * compensate.
2381          */
2382         if (sb->s_blocksize == 1024 && nr == 0 &&
2383             le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block) == 0)
2384                 has_super++;
2385
2386         return (has_super + ext4_group_first_block_no(sb, bg));
2387 }
2388
2389 /**
2390  * ext4_get_stripe_size: Get the stripe size.
2391  * @sbi: In memory super block info
2392  *
2393  * If we have specified it via mount option, then
2394  * use the mount option value. If the value specified at mount time is
2395  * greater than the blocks per group use the super block value.
2396  * If the super block value is greater than blocks per group return 0.
2397  * Allocator needs it be less than blocks per group.
2398  *
2399  */
2400 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2401 {
2402         unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2403         unsigned long stripe_width =
2404                         le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2405         int ret;
2406
2407         if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2408                 ret = sbi->s_stripe;
2409         else if (stripe_width <= sbi->s_blocks_per_group)
2410                 ret = stripe_width;
2411         else if (stride <= sbi->s_blocks_per_group)
2412                 ret = stride;
2413         else
2414                 ret = 0;
2415
2416         /*
2417          * If the stripe width is 1, this makes no sense and
2418          * we set it to 0 to turn off stripe handling code.
2419          */
2420         if (ret <= 1)
2421                 ret = 0;
2422
2423         return ret;
2424 }
2425
2426 /* sysfs supprt */
2427
2428 struct ext4_attr {
2429         struct attribute attr;
2430         ssize_t (*show)(struct ext4_attr *, struct ext4_sb_info *, char *);
2431         ssize_t (*store)(struct ext4_attr *, struct ext4_sb_info *,
2432                          const char *, size_t);
2433         union {
2434                 int offset;
2435                 int deprecated_val;
2436         } u;
2437 };
2438
2439 static int parse_strtoull(const char *buf,
2440                 unsigned long long max, unsigned long long *value)
2441 {
2442         int ret;
2443
2444         ret = kstrtoull(skip_spaces(buf), 0, value);
2445         if (!ret && *value > max)
2446                 ret = -EINVAL;
2447         return ret;
2448 }
2449
2450 static ssize_t delayed_allocation_blocks_show(struct ext4_attr *a,
2451                                               struct ext4_sb_info *sbi,
2452                                               char *buf)
2453 {
2454         return snprintf(buf, PAGE_SIZE, "%llu\n",
2455                 (s64) EXT4_C2B(sbi,
2456                         percpu_counter_sum(&sbi->s_dirtyclusters_counter)));
2457 }
2458
2459 static ssize_t session_write_kbytes_show(struct ext4_attr *a,
2460                                          struct ext4_sb_info *sbi, char *buf)
2461 {
2462         struct super_block *sb = sbi->s_buddy_cache->i_sb;
2463
2464         if (!sb->s_bdev->bd_part)
2465                 return snprintf(buf, PAGE_SIZE, "0\n");
2466         return snprintf(buf, PAGE_SIZE, "%lu\n",
2467                         (part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2468                          sbi->s_sectors_written_start) >> 1);
2469 }
2470
2471 static ssize_t lifetime_write_kbytes_show(struct ext4_attr *a,
2472                                           struct ext4_sb_info *sbi, char *buf)
2473 {
2474         struct super_block *sb = sbi->s_buddy_cache->i_sb;
2475
2476         if (!sb->s_bdev->bd_part)
2477                 return snprintf(buf, PAGE_SIZE, "0\n");
2478         return snprintf(buf, PAGE_SIZE, "%llu\n",
2479                         (unsigned long long)(sbi->s_kbytes_written +
2480                         ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2481                           EXT4_SB(sb)->s_sectors_written_start) >> 1)));
2482 }
2483
2484 static ssize_t inode_readahead_blks_store(struct ext4_attr *a,
2485                                           struct ext4_sb_info *sbi,
2486                                           const char *buf, size_t count)
2487 {
2488         unsigned long t;
2489         int ret;
2490
2491         ret = kstrtoul(skip_spaces(buf), 0, &t);
2492         if (ret)
2493                 return ret;
2494
2495         if (t && (!is_power_of_2(t) || t > 0x40000000))
2496                 return -EINVAL;
2497
2498         sbi->s_inode_readahead_blks = t;
2499         return count;
2500 }
2501
2502 static ssize_t sbi_ui_show(struct ext4_attr *a,
2503                            struct ext4_sb_info *sbi, char *buf)
2504 {
2505         unsigned int *ui = (unsigned int *) (((char *) sbi) + a->u.offset);
2506
2507         return snprintf(buf, PAGE_SIZE, "%u\n", *ui);
2508 }
2509
2510 static ssize_t sbi_ui_store(struct ext4_attr *a,
2511                             struct ext4_sb_info *sbi,
2512                             const char *buf, size_t count)
2513 {
2514         unsigned int *ui = (unsigned int *) (((char *) sbi) + a->u.offset);
2515         unsigned long t;
2516         int ret;
2517
2518         ret = kstrtoul(skip_spaces(buf), 0, &t);
2519         if (ret)
2520                 return ret;
2521         *ui = t;
2522         return count;
2523 }
2524
2525 static ssize_t es_ui_show(struct ext4_attr *a,
2526                            struct ext4_sb_info *sbi, char *buf)
2527 {
2528
2529         unsigned int *ui = (unsigned int *) (((char *) sbi->s_es) +
2530                            a->u.offset);
2531
2532         return snprintf(buf, PAGE_SIZE, "%u\n", *ui);
2533 }
2534
2535 static ssize_t reserved_clusters_show(struct ext4_attr *a,
2536                                   struct ext4_sb_info *sbi, char *buf)
2537 {
2538         return snprintf(buf, PAGE_SIZE, "%llu\n",
2539                 (unsigned long long) atomic64_read(&sbi->s_resv_clusters));
2540 }
2541
2542 static ssize_t reserved_clusters_store(struct ext4_attr *a,
2543                                    struct ext4_sb_info *sbi,
2544                                    const char *buf, size_t count)
2545 {
2546         unsigned long long val;
2547         int ret;
2548
2549         if (parse_strtoull(buf, -1ULL, &val))
2550                 return -EINVAL;
2551         ret = ext4_reserve_clusters(sbi, val);
2552
2553         return ret ? ret : count;
2554 }
2555
2556 static ssize_t trigger_test_error(struct ext4_attr *a,
2557                                   struct ext4_sb_info *sbi,
2558                                   const char *buf, size_t count)
2559 {
2560         int len = count;
2561
2562         if (!capable(CAP_SYS_ADMIN))
2563                 return -EPERM;
2564
2565         if (len && buf[len-1] == '\n')
2566                 len--;
2567
2568         if (len)
2569                 ext4_error(sbi->s_sb, "%.*s", len, buf);
2570         return count;
2571 }
2572
2573 static ssize_t sbi_deprecated_show(struct ext4_attr *a,
2574                                    struct ext4_sb_info *sbi, char *buf)
2575 {
2576         return snprintf(buf, PAGE_SIZE, "%d\n", a->u.deprecated_val);
2577 }
2578
2579 #define EXT4_ATTR_OFFSET(_name,_mode,_show,_store,_elname) \
2580 static struct ext4_attr ext4_attr_##_name = {                   \
2581         .attr = {.name = __stringify(_name), .mode = _mode },   \
2582         .show   = _show,                                        \
2583         .store  = _store,                                       \
2584         .u = {                                                  \
2585                 .offset = offsetof(struct ext4_sb_info, _elname),\
2586         },                                                      \
2587 }
2588
2589 #define EXT4_ATTR_OFFSET_ES(_name,_mode,_show,_store,_elname)           \
2590 static struct ext4_attr ext4_attr_##_name = {                           \
2591         .attr = {.name = __stringify(_name), .mode = _mode },           \
2592         .show   = _show,                                                \
2593         .store  = _store,                                               \
2594         .u = {                                                          \
2595                 .offset = offsetof(struct ext4_super_block, _elname),   \
2596         },                                                              \
2597 }
2598
2599 #define EXT4_ATTR(name, mode, show, store) \
2600 static struct ext4_attr ext4_attr_##name = __ATTR(name, mode, show, store)
2601
2602 #define EXT4_INFO_ATTR(name) EXT4_ATTR(name, 0444, NULL, NULL)
2603 #define EXT4_RO_ATTR(name) EXT4_ATTR(name, 0444, name##_show, NULL)
2604 #define EXT4_RW_ATTR(name) EXT4_ATTR(name, 0644, name##_show, name##_store)
2605
2606 #define EXT4_RO_ATTR_ES_UI(name, elname)        \
2607         EXT4_ATTR_OFFSET_ES(name, 0444, es_ui_show, NULL, elname)
2608 #define EXT4_RW_ATTR_SBI_UI(name, elname)       \
2609         EXT4_ATTR_OFFSET(name, 0644, sbi_ui_show, sbi_ui_store, elname)
2610
2611 #define ATTR_LIST(name) &ext4_attr_##name.attr
2612 #define EXT4_DEPRECATED_ATTR(_name, _val)       \
2613 static struct ext4_attr ext4_attr_##_name = {                   \
2614         .attr = {.name = __stringify(_name), .mode = 0444 },    \
2615         .show   = sbi_deprecated_show,                          \
2616         .u = {                                                  \
2617                 .deprecated_val = _val,                         \
2618         },                                                      \
2619 }
2620
2621 EXT4_RO_ATTR(delayed_allocation_blocks);
2622 EXT4_RO_ATTR(session_write_kbytes);
2623 EXT4_RO_ATTR(lifetime_write_kbytes);
2624 EXT4_RW_ATTR(reserved_clusters);
2625 EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, sbi_ui_show,
2626                  inode_readahead_blks_store, s_inode_readahead_blks);
2627 EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal);
2628 EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats);
2629 EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan);
2630 EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan);
2631 EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs);
2632 EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request);
2633 EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc);
2634 EXT4_DEPRECATED_ATTR(max_writeback_mb_bump, 128);
2635 EXT4_RW_ATTR_SBI_UI(extent_max_zeroout_kb, s_extent_max_zeroout_kb);
2636 EXT4_ATTR(trigger_fs_error, 0200, NULL, trigger_test_error);
2637 EXT4_RW_ATTR_SBI_UI(err_ratelimit_interval_ms, s_err_ratelimit_state.interval);
2638 EXT4_RW_ATTR_SBI_UI(err_ratelimit_burst, s_err_ratelimit_state.burst);
2639 EXT4_RW_ATTR_SBI_UI(warning_ratelimit_interval_ms, s_warning_ratelimit_state.interval);
2640 EXT4_RW_ATTR_SBI_UI(warning_ratelimit_burst, s_warning_ratelimit_state.burst);
2641 EXT4_RW_ATTR_SBI_UI(msg_ratelimit_interval_ms, s_msg_ratelimit_state.interval);
2642 EXT4_RW_ATTR_SBI_UI(msg_ratelimit_burst, s_msg_ratelimit_state.burst);
2643 EXT4_RO_ATTR_ES_UI(errors_count, s_error_count);
2644 EXT4_RO_ATTR_ES_UI(first_error_time, s_first_error_time);
2645 EXT4_RO_ATTR_ES_UI(last_error_time, s_last_error_time);
2646
2647 static struct attribute *ext4_attrs[] = {
2648         ATTR_LIST(delayed_allocation_blocks),
2649         ATTR_LIST(session_write_kbytes),
2650         ATTR_LIST(lifetime_write_kbytes),
2651         ATTR_LIST(reserved_clusters),
2652         ATTR_LIST(inode_readahead_blks),
2653         ATTR_LIST(inode_goal),
2654         ATTR_LIST(mb_stats),
2655         ATTR_LIST(mb_max_to_scan),
2656         ATTR_LIST(mb_min_to_scan),
2657         ATTR_LIST(mb_order2_req),
2658         ATTR_LIST(mb_stream_req),
2659         ATTR_LIST(mb_group_prealloc),
2660         ATTR_LIST(max_writeback_mb_bump),
2661         ATTR_LIST(extent_max_zeroout_kb),
2662         ATTR_LIST(trigger_fs_error),
2663         ATTR_LIST(err_ratelimit_interval_ms),
2664         ATTR_LIST(err_ratelimit_burst),
2665         ATTR_LIST(warning_ratelimit_interval_ms),
2666         ATTR_LIST(warning_ratelimit_burst),
2667         ATTR_LIST(msg_ratelimit_interval_ms),
2668         ATTR_LIST(msg_ratelimit_burst),
2669         ATTR_LIST(errors_count),
2670         ATTR_LIST(first_error_time),
2671         ATTR_LIST(last_error_time),
2672         NULL,
2673 };
2674
2675 /* Features this copy of ext4 supports */
2676 EXT4_INFO_ATTR(lazy_itable_init);
2677 EXT4_INFO_ATTR(batched_discard);
2678 EXT4_INFO_ATTR(meta_bg_resize);
2679
2680 static struct attribute *ext4_feat_attrs[] = {
2681         ATTR_LIST(lazy_itable_init),
2682         ATTR_LIST(batched_discard),
2683         ATTR_LIST(meta_bg_resize),
2684         NULL,
2685 };
2686
2687 static ssize_t ext4_attr_show(struct kobject *kobj,
2688                               struct attribute *attr, char *buf)
2689 {
2690         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2691                                                 s_kobj);
2692         struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2693
2694         return a->show ? a->show(a, sbi, buf) : 0;
2695 }
2696
2697 static ssize_t ext4_attr_store(struct kobject *kobj,
2698                                struct attribute *attr,
2699                                const char *buf, size_t len)
2700 {
2701         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2702                                                 s_kobj);
2703         struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2704
2705         return a->store ? a->store(a, sbi, buf, len) : 0;
2706 }
2707
2708 static void ext4_sb_release(struct kobject *kobj)
2709 {
2710         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2711                                                 s_kobj);
2712         complete(&sbi->s_kobj_unregister);
2713 }
2714
2715 static const struct sysfs_ops ext4_attr_ops = {
2716         .show   = ext4_attr_show,
2717         .store  = ext4_attr_store,
2718 };
2719
2720 static struct kobj_type ext4_ktype = {
2721         .default_attrs  = ext4_attrs,
2722         .sysfs_ops      = &ext4_attr_ops,
2723         .release        = ext4_sb_release,
2724 };
2725
2726 static void ext4_feat_release(struct kobject *kobj)
2727 {
2728         complete(&ext4_feat->f_kobj_unregister);
2729 }
2730
2731 static ssize_t ext4_feat_show(struct kobject *kobj,
2732                               struct attribute *attr, char *buf)
2733 {
2734         return snprintf(buf, PAGE_SIZE, "supported\n");
2735 }
2736
2737 /*
2738  * We can not use ext4_attr_show/store because it relies on the kobject
2739  * being embedded in the ext4_sb_info structure which is definitely not
2740  * true in this case.
2741  */
2742 static const struct sysfs_ops ext4_feat_ops = {
2743         .show   = ext4_feat_show,
2744         .store  = NULL,
2745 };
2746
2747 static struct kobj_type ext4_feat_ktype = {
2748         .default_attrs  = ext4_feat_attrs,
2749         .sysfs_ops      = &ext4_feat_ops,
2750         .release        = ext4_feat_release,
2751 };
2752
2753 /*
2754  * Check whether this filesystem can be mounted based on
2755  * the features present and the RDONLY/RDWR mount requested.
2756  * Returns 1 if this filesystem can be mounted as requested,
2757  * 0 if it cannot be.
2758  */
2759 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2760 {
2761         if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT4_FEATURE_INCOMPAT_SUPP)) {
2762                 ext4_msg(sb, KERN_ERR,
2763                         "Couldn't mount because of "
2764                         "unsupported optional features (%x)",
2765                         (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2766                         ~EXT4_FEATURE_INCOMPAT_SUPP));
2767                 return 0;
2768         }
2769
2770         if (readonly)
2771                 return 1;
2772
2773         /* Check that feature set is OK for a read-write mount */
2774         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT4_FEATURE_RO_COMPAT_SUPP)) {
2775                 ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2776                          "unsupported optional features (%x)",
2777                          (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2778                                 ~EXT4_FEATURE_RO_COMPAT_SUPP));
2779                 return 0;
2780         }
2781         /*
2782          * Large file size enabled file system can only be mounted
2783          * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2784          */
2785         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) {
2786                 if (sizeof(blkcnt_t) < sizeof(u64)) {
2787                         ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2788                                  "cannot be mounted RDWR without "
2789                                  "CONFIG_LBDAF");
2790                         return 0;
2791                 }
2792         }
2793         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_BIGALLOC) &&
2794             !EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)) {
2795                 ext4_msg(sb, KERN_ERR,
2796                          "Can't support bigalloc feature without "
2797                          "extents feature\n");
2798                 return 0;
2799         }
2800
2801 #ifndef CONFIG_QUOTA
2802         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
2803             !readonly) {
2804                 ext4_msg(sb, KERN_ERR,
2805                          "Filesystem with quota feature cannot be mounted RDWR "
2806                          "without CONFIG_QUOTA");
2807                 return 0;
2808         }
2809 #endif  /* CONFIG_QUOTA */
2810         return 1;
2811 }
2812
2813 /*
2814  * This function is called once a day if we have errors logged
2815  * on the file system
2816  */
2817 static void print_daily_error_info(unsigned long arg)
2818 {
2819         struct super_block *sb = (struct super_block *) arg;
2820         struct ext4_sb_info *sbi;
2821         struct ext4_super_block *es;
2822
2823         sbi = EXT4_SB(sb);
2824         es = sbi->s_es;
2825
2826         if (es->s_error_count)
2827                 /* fsck newer than v1.41.13 is needed to clean this condition. */
2828                 ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
2829                          le32_to_cpu(es->s_error_count));
2830         if (es->s_first_error_time) {
2831                 printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %u: %.*s:%d",
2832                        sb->s_id, le32_to_cpu(es->s_first_error_time),
2833                        (int) sizeof(es->s_first_error_func),
2834                        es->s_first_error_func,
2835                        le32_to_cpu(es->s_first_error_line));
2836                 if (es->s_first_error_ino)
2837                         printk(": inode %u",
2838                                le32_to_cpu(es->s_first_error_ino));
2839                 if (es->s_first_error_block)
2840                         printk(": block %llu", (unsigned long long)
2841                                le64_to_cpu(es->s_first_error_block));
2842                 printk("\n");
2843         }
2844         if (es->s_last_error_time) {
2845                 printk(KERN_NOTICE "EXT4-fs (%s): last error at time %u: %.*s:%d",
2846                        sb->s_id, le32_to_cpu(es->s_last_error_time),
2847                        (int) sizeof(es->s_last_error_func),
2848                        es->s_last_error_func,
2849                        le32_to_cpu(es->s_last_error_line));
2850                 if (es->s_last_error_ino)
2851                         printk(": inode %u",
2852                                le32_to_cpu(es->s_last_error_ino));
2853                 if (es->s_last_error_block)
2854                         printk(": block %llu", (unsigned long long)
2855                                le64_to_cpu(es->s_last_error_block));
2856                 printk("\n");
2857         }
2858         mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2859 }
2860
2861 /* Find next suitable group and run ext4_init_inode_table */
2862 static int ext4_run_li_request(struct ext4_li_request *elr)
2863 {
2864         struct ext4_group_desc *gdp = NULL;
2865         ext4_group_t group, ngroups;
2866         struct super_block *sb;
2867         unsigned long timeout = 0;
2868         int ret = 0;
2869
2870         sb = elr->lr_super;
2871         ngroups = EXT4_SB(sb)->s_groups_count;
2872
2873         sb_start_write(sb);
2874         for (group = elr->lr_next_group; group < ngroups; group++) {
2875                 gdp = ext4_get_group_desc(sb, group, NULL);
2876                 if (!gdp) {
2877                         ret = 1;
2878                         break;
2879                 }
2880
2881                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2882                         break;
2883         }
2884
2885         if (group >= ngroups)
2886                 ret = 1;
2887
2888         if (!ret) {
2889                 timeout = jiffies;
2890                 ret = ext4_init_inode_table(sb, group,
2891                                             elr->lr_timeout ? 0 : 1);
2892                 if (elr->lr_timeout == 0) {
2893                         timeout = (jiffies - timeout) *
2894                                   elr->lr_sbi->s_li_wait_mult;
2895                         elr->lr_timeout = timeout;
2896                 }
2897                 elr->lr_next_sched = jiffies + elr->lr_timeout;
2898                 elr->lr_next_group = group + 1;
2899         }
2900         sb_end_write(sb);
2901
2902         return ret;
2903 }
2904
2905 /*
2906  * Remove lr_request from the list_request and free the
2907  * request structure. Should be called with li_list_mtx held
2908  */
2909 static void ext4_remove_li_request(struct ext4_li_request *elr)
2910 {
2911         struct ext4_sb_info *sbi;
2912
2913         if (!elr)
2914                 return;
2915
2916         sbi = elr->lr_sbi;
2917
2918         list_del(&elr->lr_request);
2919         sbi->s_li_request = NULL;
2920         kfree(elr);
2921 }
2922
2923 static void ext4_unregister_li_request(struct super_block *sb)
2924 {
2925         mutex_lock(&ext4_li_mtx);
2926         if (!ext4_li_info) {
2927                 mutex_unlock(&ext4_li_mtx);
2928                 return;
2929         }
2930
2931         mutex_lock(&ext4_li_info->li_list_mtx);
2932         ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
2933         mutex_unlock(&ext4_li_info->li_list_mtx);
2934         mutex_unlock(&ext4_li_mtx);
2935 }
2936
2937 static struct task_struct *ext4_lazyinit_task;
2938
2939 /*
2940  * This is the function where ext4lazyinit thread lives. It walks
2941  * through the request list searching for next scheduled filesystem.
2942  * When such a fs is found, run the lazy initialization request
2943  * (ext4_rn_li_request) and keep track of the time spend in this
2944  * function. Based on that time we compute next schedule time of
2945  * the request. When walking through the list is complete, compute
2946  * next waking time and put itself into sleep.
2947  */
2948 static int ext4_lazyinit_thread(void *arg)
2949 {
2950         struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
2951         struct list_head *pos, *n;
2952         struct ext4_li_request *elr;
2953         unsigned long next_wakeup, cur;
2954
2955         BUG_ON(NULL == eli);
2956
2957 cont_thread:
2958         while (true) {
2959                 next_wakeup = MAX_JIFFY_OFFSET;
2960
2961                 mutex_lock(&eli->li_list_mtx);
2962                 if (list_empty(&eli->li_request_list)) {
2963                         mutex_unlock(&eli->li_list_mtx);
2964                         goto exit_thread;
2965                 }
2966
2967                 list_for_each_safe(pos, n, &eli->li_request_list) {
2968                         elr = list_entry(pos, struct ext4_li_request,
2969                                          lr_request);
2970
2971                         if (time_after_eq(jiffies, elr->lr_next_sched)) {
2972                                 if (ext4_run_li_request(elr) != 0) {
2973                                         /* error, remove the lazy_init job */
2974                                         ext4_remove_li_request(elr);
2975                                         continue;
2976                                 }
2977                         }
2978
2979                         if (time_before(elr->lr_next_sched, next_wakeup))
2980                                 next_wakeup = elr->lr_next_sched;
2981                 }
2982                 mutex_unlock(&eli->li_list_mtx);
2983
2984                 try_to_freeze();
2985
2986                 cur = jiffies;
2987                 if ((time_after_eq(cur, next_wakeup)) ||
2988                     (MAX_JIFFY_OFFSET == next_wakeup)) {
2989                         cond_resched();
2990                         continue;
2991                 }
2992
2993                 schedule_timeout_interruptible(next_wakeup - cur);
2994
2995                 if (kthread_should_stop()) {
2996                         ext4_clear_request_list();
2997                         goto exit_thread;
2998                 }
2999         }
3000
3001 exit_thread:
3002         /*
3003          * It looks like the request list is empty, but we need
3004          * to check it under the li_list_mtx lock, to prevent any
3005          * additions into it, and of course we should lock ext4_li_mtx
3006          * to atomically free the list and ext4_li_info, because at
3007          * this point another ext4 filesystem could be registering
3008          * new one.
3009          */
3010         mutex_lock(&ext4_li_mtx);
3011         mutex_lock(&eli->li_list_mtx);
3012         if (!list_empty(&eli->li_request_list)) {
3013                 mutex_unlock(&eli->li_list_mtx);
3014                 mutex_unlock(&ext4_li_mtx);
3015                 goto cont_thread;
3016         }
3017         mutex_unlock(&eli->li_list_mtx);
3018         kfree(ext4_li_info);
3019         ext4_li_info = NULL;
3020         mutex_unlock(&ext4_li_mtx);
3021
3022         return 0;
3023 }
3024
3025 static void ext4_clear_request_list(void)
3026 {
3027         struct list_head *pos, *n;
3028         struct ext4_li_request *elr;
3029
3030         mutex_lock(&ext4_li_info->li_list_mtx);
3031         list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
3032                 elr = list_entry(pos, struct ext4_li_request,
3033                                  lr_request);
3034                 ext4_remove_li_request(elr);
3035         }
3036         mutex_unlock(&ext4_li_info->li_list_mtx);
3037 }
3038
3039 static int ext4_run_lazyinit_thread(void)
3040 {
3041         ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
3042                                          ext4_li_info, "ext4lazyinit");
3043         if (IS_ERR(ext4_lazyinit_task)) {
3044                 int err = PTR_ERR(ext4_lazyinit_task);
3045                 ext4_clear_request_list();
3046                 kfree(ext4_li_info);
3047                 ext4_li_info = NULL;
3048                 printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
3049                                  "initialization thread\n",
3050                                  err);
3051                 return err;
3052         }
3053         ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
3054         return 0;
3055 }
3056
3057 /*
3058  * Check whether it make sense to run itable init. thread or not.
3059  * If there is at least one uninitialized inode table, return
3060  * corresponding group number, else the loop goes through all
3061  * groups and return total number of groups.
3062  */
3063 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3064 {
3065         ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3066         struct ext4_group_desc *gdp = NULL;
3067
3068         for (group = 0; group < ngroups; group++) {
3069                 gdp = ext4_get_group_desc(sb, group, NULL);
3070                 if (!gdp)
3071                         continue;
3072
3073                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3074                         break;
3075         }
3076
3077         return group;
3078 }
3079
3080 static int ext4_li_info_new(void)
3081 {
3082         struct ext4_lazy_init *eli = NULL;
3083
3084         eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3085         if (!eli)
3086                 return -ENOMEM;
3087
3088         INIT_LIST_HEAD(&eli->li_request_list);
3089         mutex_init(&eli->li_list_mtx);
3090
3091         eli->li_state |= EXT4_LAZYINIT_QUIT;
3092
3093         ext4_li_info = eli;
3094
3095         return 0;
3096 }
3097
3098 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3099                                             ext4_group_t start)
3100 {
3101         struct ext4_sb_info *sbi = EXT4_SB(sb);
3102         struct ext4_li_request *elr;
3103
3104         elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3105         if (!elr)
3106                 return NULL;
3107
3108         elr->lr_super = sb;
3109         elr->lr_sbi = sbi;
3110         elr->lr_next_group = start;
3111
3112         /*
3113          * Randomize first schedule time of the request to
3114          * spread the inode table initialization requests
3115          * better.
3116          */
3117         elr->lr_next_sched = jiffies + (prandom_u32() %
3118                                 (EXT4_DEF_LI_MAX_START_DELAY * HZ));
3119         return elr;
3120 }
3121
3122 int ext4_register_li_request(struct super_block *sb,
3123                              ext4_group_t first_not_zeroed)
3124 {
3125         struct ext4_sb_info *sbi = EXT4_SB(sb);
3126         struct ext4_li_request *elr = NULL;
3127         ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
3128         int ret = 0;
3129
3130         mutex_lock(&ext4_li_mtx);
3131         if (sbi->s_li_request != NULL) {
3132                 /*
3133                  * Reset timeout so it can be computed again, because
3134                  * s_li_wait_mult might have changed.
3135                  */
3136                 sbi->s_li_request->lr_timeout = 0;
3137                 goto out;
3138         }
3139
3140         if (first_not_zeroed == ngroups ||
3141             (sb->s_flags & MS_RDONLY) ||
3142             !test_opt(sb, INIT_INODE_TABLE))
3143                 goto out;
3144
3145         elr = ext4_li_request_new(sb, first_not_zeroed);
3146         if (!elr) {
3147                 ret = -ENOMEM;
3148                 goto out;
3149         }
3150
3151         if (NULL == ext4_li_info) {
3152                 ret = ext4_li_info_new();
3153                 if (ret)
3154                         goto out;
3155         }
3156
3157         mutex_lock(&ext4_li_info->li_list_mtx);
3158         list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3159         mutex_unlock(&ext4_li_info->li_list_mtx);
3160
3161         sbi->s_li_request = elr;
3162         /*
3163          * set elr to NULL here since it has been inserted to
3164          * the request_list and the removal and free of it is
3165          * handled by ext4_clear_request_list from now on.
3166          */
3167         elr = NULL;
3168
3169         if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3170                 ret = ext4_run_lazyinit_thread();
3171                 if (ret)
3172                         goto out;
3173         }
3174 out:
3175         mutex_unlock(&ext4_li_mtx);
3176         if (ret)
3177                 kfree(elr);
3178         return ret;
3179 }
3180
3181 /*
3182  * We do not need to lock anything since this is called on
3183  * module unload.
3184  */
3185 static void ext4_destroy_lazyinit_thread(void)
3186 {
3187         /*
3188          * If thread exited earlier
3189          * there's nothing to be done.
3190          */
3191         if (!ext4_li_info || !ext4_lazyinit_task)
3192                 return;
3193
3194         kthread_stop(ext4_lazyinit_task);
3195 }
3196
3197 static int set_journal_csum_feature_set(struct super_block *sb)
3198 {
3199         int ret = 1;
3200         int compat, incompat;
3201         struct ext4_sb_info *sbi = EXT4_SB(sb);
3202
3203         if (ext4_has_metadata_csum(sb)) {
3204                 /* journal checksum v3 */
3205                 compat = 0;
3206                 incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
3207         } else {
3208                 /* journal checksum v1 */
3209                 compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3210                 incompat = 0;
3211         }
3212
3213         jbd2_journal_clear_features(sbi->s_journal,
3214                         JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3215                         JBD2_FEATURE_INCOMPAT_CSUM_V3 |
3216                         JBD2_FEATURE_INCOMPAT_CSUM_V2);
3217         if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3218                 ret = jbd2_journal_set_features(sbi->s_journal,
3219                                 compat, 0,
3220                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3221                                 incompat);
3222         } else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3223                 ret = jbd2_journal_set_features(sbi->s_journal,
3224                                 compat, 0,
3225                                 incompat);
3226                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3227                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3228         } else {
3229                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3230                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3231         }
3232
3233         return ret;
3234 }
3235
3236 /*
3237  * Note: calculating the overhead so we can be compatible with
3238  * historical BSD practice is quite difficult in the face of
3239  * clusters/bigalloc.  This is because multiple metadata blocks from
3240  * different block group can end up in the same allocation cluster.
3241  * Calculating the exact overhead in the face of clustered allocation
3242  * requires either O(all block bitmaps) in memory or O(number of block
3243  * groups**2) in time.  We will still calculate the superblock for
3244  * older file systems --- and if we come across with a bigalloc file
3245  * system with zero in s_overhead_clusters the estimate will be close to
3246  * correct especially for very large cluster sizes --- but for newer
3247  * file systems, it's better to calculate this figure once at mkfs
3248  * time, and store it in the superblock.  If the superblock value is
3249  * present (even for non-bigalloc file systems), we will use it.
3250  */
3251 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3252                           char *buf)
3253 {
3254         struct ext4_sb_info     *sbi = EXT4_SB(sb);
3255         struct ext4_group_desc  *gdp;
3256         ext4_fsblk_t            first_block, last_block, b;
3257         ext4_group_t            i, ngroups = ext4_get_groups_count(sb);
3258         int                     s, j, count = 0;
3259
3260         if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_BIGALLOC))
3261                 return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3262                         sbi->s_itb_per_group + 2);
3263
3264         first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3265                 (grp * EXT4_BLOCKS_PER_GROUP(sb));
3266         last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3267         for (i = 0; i < ngroups; i++) {
3268                 gdp = ext4_get_group_desc(sb, i, NULL);
3269                 b = ext4_block_bitmap(sb, gdp);
3270                 if (b >= first_block && b <= last_block) {
3271                         ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3272                         count++;
3273                 }
3274                 b = ext4_inode_bitmap(sb, gdp);
3275                 if (b >= first_block && b <= last_block) {
3276                         ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3277                         count++;
3278                 }
3279                 b = ext4_inode_table(sb, gdp);
3280                 if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3281                         for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3282                                 int c = EXT4_B2C(sbi, b - first_block);
3283                                 ext4_set_bit(c, buf);
3284                                 count++;
3285                         }
3286                 if (i != grp)
3287                         continue;
3288                 s = 0;
3289                 if (ext4_bg_has_super(sb, grp)) {
3290                         ext4_set_bit(s++, buf);
3291                         count++;
3292                 }
3293                 for (j = ext4_bg_num_gdb(sb, grp); j > 0; j--) {
3294                         ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3295                         count++;
3296                 }
3297         }
3298         if (!count)
3299                 return 0;
3300         return EXT4_CLUSTERS_PER_GROUP(sb) -
3301                 ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3302 }
3303
3304 /*
3305  * Compute the overhead and stash it in sbi->s_overhead
3306  */
3307 int ext4_calculate_overhead(struct super_block *sb)
3308 {
3309         struct ext4_sb_info *sbi = EXT4_SB(sb);
3310         struct ext4_super_block *es = sbi->s_es;
3311         ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3312         ext4_fsblk_t overhead = 0;
3313         char *buf = (char *) get_zeroed_page(GFP_KERNEL);
3314
3315         if (!buf)
3316                 return -ENOMEM;
3317
3318         /*
3319          * Compute the overhead (FS structures).  This is constant
3320          * for a given filesystem unless the number of block groups
3321          * changes so we cache the previous value until it does.
3322          */
3323
3324         /*
3325          * All of the blocks before first_data_block are overhead
3326          */
3327         overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3328
3329         /*
3330          * Add the overhead found in each block group
3331          */
3332         for (i = 0; i < ngroups; i++) {
3333                 int blks;
3334
3335                 blks = count_overhead(sb, i, buf);
3336                 overhead += blks;
3337                 if (blks)
3338                         memset(buf, 0, PAGE_SIZE);
3339                 cond_resched();
3340         }
3341         /* Add the journal blocks as well */
3342         if (sbi->s_journal)
3343                 overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_maxlen);
3344
3345         sbi->s_overhead = overhead;
3346         smp_wmb();
3347         free_page((unsigned long) buf);
3348         return 0;
3349 }
3350
3351
3352 static ext4_fsblk_t ext4_calculate_resv_clusters(struct super_block *sb)
3353 {
3354         ext4_fsblk_t resv_clusters;
3355
3356         /*
3357          * There's no need to reserve anything when we aren't using extents.
3358          * The space estimates are exact, there are no unwritten extents,
3359          * hole punching doesn't need new metadata... This is needed especially
3360          * to keep ext2/3 backward compatibility.
3361          */
3362         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS))
3363                 return 0;
3364         /*
3365          * By default we reserve 2% or 4096 clusters, whichever is smaller.
3366          * This should cover the situations where we can not afford to run
3367          * out of space like for example punch hole, or converting
3368          * unwritten extents in delalloc path. In most cases such
3369          * allocation would require 1, or 2 blocks, higher numbers are
3370          * very rare.
3371          */
3372         resv_clusters = ext4_blocks_count(EXT4_SB(sb)->s_es) >>
3373                         EXT4_SB(sb)->s_cluster_bits;
3374
3375         do_div(resv_clusters, 50);
3376         resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
3377
3378         return resv_clusters;
3379 }
3380
3381
3382 static int ext4_reserve_clusters(struct ext4_sb_info *sbi, ext4_fsblk_t count)
3383 {
3384         ext4_fsblk_t clusters = ext4_blocks_count(sbi->s_es) >>
3385                                 sbi->s_cluster_bits;
3386
3387         if (count >= clusters)
3388                 return -EINVAL;
3389
3390         atomic64_set(&sbi->s_resv_clusters, count);
3391         return 0;
3392 }
3393
3394 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3395 {
3396         char *orig_data = kstrdup(data, GFP_KERNEL);
3397         struct buffer_head *bh;
3398         struct ext4_super_block *es = NULL;
3399         struct ext4_sb_info *sbi;
3400         ext4_fsblk_t block;
3401         ext4_fsblk_t sb_block = get_sb_block(&data);
3402         ext4_fsblk_t logical_sb_block;
3403         unsigned long offset = 0;
3404         unsigned long journal_devnum = 0;
3405         unsigned long def_mount_opts;
3406         struct inode *root;
3407         char *cp;
3408         const char *descr;
3409         int ret = -ENOMEM;
3410         int blocksize, clustersize;
3411         unsigned int db_count;
3412         unsigned int i;
3413         int needs_recovery, has_huge_files, has_bigalloc;
3414         __u64 blocks_count;
3415         int err = 0;
3416         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3417         ext4_group_t first_not_zeroed;
3418
3419         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3420         if (!sbi)
3421                 goto out_free_orig;
3422
3423         sbi->s_blockgroup_lock =
3424                 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3425         if (!sbi->s_blockgroup_lock) {
3426                 kfree(sbi);
3427                 goto out_free_orig;
3428         }
3429         sb->s_fs_info = sbi;
3430         sbi->s_sb = sb;
3431         sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3432         sbi->s_sb_block = sb_block;
3433         if (sb->s_bdev->bd_part)
3434                 sbi->s_sectors_written_start =
3435                         part_stat_read(sb->s_bdev->bd_part, sectors[1]);
3436
3437         /* Cleanup superblock name */
3438         for (cp = sb->s_id; (cp = strchr(cp, '/'));)
3439                 *cp = '!';
3440
3441         /* -EINVAL is default */
3442         ret = -EINVAL;
3443         blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3444         if (!blocksize) {
3445                 ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3446                 goto out_fail;
3447         }
3448
3449         /*
3450          * The ext4 superblock will not be buffer aligned for other than 1kB
3451          * block sizes.  We need to calculate the offset from buffer start.
3452          */
3453         if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3454                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3455                 offset = do_div(logical_sb_block, blocksize);
3456         } else {
3457                 logical_sb_block = sb_block;
3458         }
3459
3460         if (!(bh = sb_bread_unmovable(sb, logical_sb_block))) {
3461                 ext4_msg(sb, KERN_ERR, "unable to read superblock");
3462                 goto out_fail;
3463         }
3464         /*
3465          * Note: s_es must be initialized as soon as possible because
3466          *       some ext4 macro-instructions depend on its value
3467          */
3468         es = (struct ext4_super_block *) (bh->b_data + offset);
3469         sbi->s_es = es;
3470         sb->s_magic = le16_to_cpu(es->s_magic);
3471         if (sb->s_magic != EXT4_SUPER_MAGIC)
3472                 goto cantfind_ext4;
3473         sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3474
3475         /* Warn if metadata_csum and gdt_csum are both set. */
3476         if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3477                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
3478             EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_GDT_CSUM))
3479                 ext4_warning(sb, KERN_INFO "metadata_csum and uninit_bg are "
3480                              "redundant flags; please run fsck.");
3481
3482         /* Check for a known checksum algorithm */
3483         if (!ext4_verify_csum_type(sb, es)) {
3484                 ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3485                          "unknown checksum algorithm.");
3486                 silent = 1;
3487                 goto cantfind_ext4;
3488         }
3489
3490         /* Load the checksum driver */
3491         if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3492                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
3493                 sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3494                 if (IS_ERR(sbi->s_chksum_driver)) {
3495                         ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3496                         ret = PTR_ERR(sbi->s_chksum_driver);
3497                         sbi->s_chksum_driver = NULL;
3498                         goto failed_mount;
3499                 }
3500         }
3501
3502         /* Check superblock checksum */
3503         if (!ext4_superblock_csum_verify(sb, es)) {
3504                 ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3505                          "invalid superblock checksum.  Run e2fsck?");
3506                 silent = 1;
3507                 goto cantfind_ext4;
3508         }
3509
3510         /* Precompute checksum seed for all metadata */
3511         if (ext4_has_metadata_csum(sb))
3512                 sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3513                                                sizeof(es->s_uuid));
3514
3515         /* Set defaults before we parse the mount options */
3516         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3517         set_opt(sb, INIT_INODE_TABLE);
3518         if (def_mount_opts & EXT4_DEFM_DEBUG)
3519                 set_opt(sb, DEBUG);
3520         if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3521                 set_opt(sb, GRPID);
3522         if (def_mount_opts & EXT4_DEFM_UID16)
3523                 set_opt(sb, NO_UID32);
3524         /* xattr user namespace & acls are now defaulted on */
3525         set_opt(sb, XATTR_USER);
3526 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3527         set_opt(sb, POSIX_ACL);
3528 #endif
3529         if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3530                 set_opt(sb, JOURNAL_DATA);
3531         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3532                 set_opt(sb, ORDERED_DATA);
3533         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3534                 set_opt(sb, WRITEBACK_DATA);
3535
3536         if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3537                 set_opt(sb, ERRORS_PANIC);
3538         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3539                 set_opt(sb, ERRORS_CONT);
3540         else
3541                 set_opt(sb, ERRORS_RO);
3542         /* block_validity enabled by default; disable with noblock_validity */
3543         set_opt(sb, BLOCK_VALIDITY);
3544         if (def_mount_opts & EXT4_DEFM_DISCARD)
3545                 set_opt(sb, DISCARD);
3546
3547         sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3548         sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3549         sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3550         sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3551         sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3552
3553         if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3554                 set_opt(sb, BARRIER);
3555
3556         /*
3557          * enable delayed allocation by default
3558          * Use -o nodelalloc to turn it off
3559          */
3560         if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
3561             ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3562                 set_opt(sb, DELALLOC);
3563
3564         /*
3565          * set default s_li_wait_mult for lazyinit, for the case there is
3566          * no mount option specified.
3567          */
3568         sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3569
3570         if (!parse_options((char *) sbi->s_es->s_mount_opts, sb,
3571                            &journal_devnum, &journal_ioprio, 0)) {
3572                 ext4_msg(sb, KERN_WARNING,
3573                          "failed to parse options in superblock: %s",
3574                          sbi->s_es->s_mount_opts);
3575         }
3576         sbi->s_def_mount_opt = sbi->s_mount_opt;
3577         if (!parse_options((char *) data, sb, &journal_devnum,
3578                            &journal_ioprio, 0))
3579                 goto failed_mount;
3580
3581         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3582                 printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3583                             "with data=journal disables delayed "
3584                             "allocation and O_DIRECT support!\n");
3585                 if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3586                         ext4_msg(sb, KERN_ERR, "can't mount with "
3587                                  "both data=journal and delalloc");
3588                         goto failed_mount;
3589                 }
3590                 if (test_opt(sb, DIOREAD_NOLOCK)) {
3591                         ext4_msg(sb, KERN_ERR, "can't mount with "
3592                                  "both data=journal and dioread_nolock");
3593                         goto failed_mount;
3594                 }
3595                 if (test_opt(sb, DELALLOC))
3596                         clear_opt(sb, DELALLOC);
3597         }
3598
3599         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
3600                 (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
3601
3602         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3603             (EXT4_HAS_COMPAT_FEATURE(sb, ~0U) ||
3604              EXT4_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
3605              EXT4_HAS_INCOMPAT_FEATURE(sb, ~0U)))
3606                 ext4_msg(sb, KERN_WARNING,
3607                        "feature flags set on rev 0 fs, "
3608                        "running e2fsck is recommended");
3609
3610         if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
3611                 set_opt2(sb, HURD_COMPAT);
3612                 if (EXT4_HAS_INCOMPAT_FEATURE(sb,
3613                                               EXT4_FEATURE_INCOMPAT_64BIT)) {
3614                         ext4_msg(sb, KERN_ERR,
3615                                  "The Hurd can't support 64-bit file systems");
3616                         goto failed_mount;
3617                 }
3618         }
3619
3620         if (IS_EXT2_SB(sb)) {
3621                 if (ext2_feature_set_ok(sb))
3622                         ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3623                                  "using the ext4 subsystem");
3624                 else {
3625                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3626                                  "to feature incompatibilities");
3627                         goto failed_mount;
3628                 }
3629         }
3630
3631         if (IS_EXT3_SB(sb)) {
3632                 if (ext3_feature_set_ok(sb))
3633                         ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3634                                  "using the ext4 subsystem");
3635                 else {
3636                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3637                                  "to feature incompatibilities");
3638                         goto failed_mount;
3639                 }
3640         }
3641
3642         /*
3643          * Check feature flags regardless of the revision level, since we
3644          * previously didn't change the revision level when setting the flags,
3645          * so there is a chance incompat flags are set on a rev 0 filesystem.
3646          */
3647         if (!ext4_feature_set_ok(sb, (sb->s_flags & MS_RDONLY)))
3648                 goto failed_mount;
3649
3650         blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3651         if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3652             blocksize > EXT4_MAX_BLOCK_SIZE) {
3653                 ext4_msg(sb, KERN_ERR,
3654                        "Unsupported filesystem blocksize %d", blocksize);
3655                 goto failed_mount;
3656         }
3657
3658         if (sb->s_blocksize != blocksize) {
3659                 /* Validate the filesystem blocksize */
3660                 if (!sb_set_blocksize(sb, blocksize)) {
3661                         ext4_msg(sb, KERN_ERR, "bad block size %d",
3662                                         blocksize);
3663                         goto failed_mount;
3664                 }
3665
3666                 brelse(bh);
3667                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3668                 offset = do_div(logical_sb_block, blocksize);
3669                 bh = sb_bread_unmovable(sb, logical_sb_block);
3670                 if (!bh) {
3671                         ext4_msg(sb, KERN_ERR,
3672                                "Can't read superblock on 2nd try");
3673                         goto failed_mount;
3674                 }
3675                 es = (struct ext4_super_block *)(bh->b_data + offset);
3676                 sbi->s_es = es;
3677                 if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
3678                         ext4_msg(sb, KERN_ERR,
3679                                "Magic mismatch, very weird!");
3680                         goto failed_mount;
3681                 }
3682         }
3683
3684         has_huge_files = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3685                                 EXT4_FEATURE_RO_COMPAT_HUGE_FILE);
3686         sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
3687                                                       has_huge_files);
3688         sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
3689
3690         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3691                 sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3692                 sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3693         } else {
3694                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3695                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3696                 if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3697                     (!is_power_of_2(sbi->s_inode_size)) ||
3698                     (sbi->s_inode_size > blocksize)) {
3699                         ext4_msg(sb, KERN_ERR,
3700                                "unsupported inode size: %d",
3701                                sbi->s_inode_size);
3702                         goto failed_mount;
3703                 }
3704                 if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
3705                         sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
3706         }
3707
3708         sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
3709         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT)) {
3710                 if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
3711                     sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
3712                     !is_power_of_2(sbi->s_desc_size)) {
3713                         ext4_msg(sb, KERN_ERR,
3714                                "unsupported descriptor size %lu",
3715                                sbi->s_desc_size);
3716                         goto failed_mount;
3717                 }
3718         } else
3719                 sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
3720
3721         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
3722         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
3723         if (EXT4_INODE_SIZE(sb) == 0 || EXT4_INODES_PER_GROUP(sb) == 0)
3724                 goto cantfind_ext4;
3725
3726         sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
3727         if (sbi->s_inodes_per_block == 0)
3728                 goto cantfind_ext4;
3729         sbi->s_itb_per_group = sbi->s_inodes_per_group /
3730                                         sbi->s_inodes_per_block;
3731         sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
3732         sbi->s_sbh = bh;
3733         sbi->s_mount_state = le16_to_cpu(es->s_state);
3734         sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
3735         sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
3736
3737         for (i = 0; i < 4; i++)
3738                 sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
3739         sbi->s_def_hash_version = es->s_def_hash_version;
3740         if (EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_DIR_INDEX)) {
3741                 i = le32_to_cpu(es->s_flags);
3742                 if (i & EXT2_FLAGS_UNSIGNED_HASH)
3743                         sbi->s_hash_unsigned = 3;
3744                 else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
3745 #ifdef __CHAR_UNSIGNED__
3746                         if (!(sb->s_flags & MS_RDONLY))
3747                                 es->s_flags |=
3748                                         cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
3749                         sbi->s_hash_unsigned = 3;
3750 #else
3751                         if (!(sb->s_flags & MS_RDONLY))
3752                                 es->s_flags |=
3753                                         cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
3754 #endif
3755                 }
3756         }
3757
3758         /* Handle clustersize */
3759         clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
3760         has_bigalloc = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3761                                 EXT4_FEATURE_RO_COMPAT_BIGALLOC);
3762         if (has_bigalloc) {
3763                 if (clustersize < blocksize) {
3764                         ext4_msg(sb, KERN_ERR,
3765                                  "cluster size (%d) smaller than "
3766                                  "block size (%d)", clustersize, blocksize);
3767                         goto failed_mount;
3768                 }
3769                 sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
3770                         le32_to_cpu(es->s_log_block_size);
3771                 sbi->s_clusters_per_group =
3772                         le32_to_cpu(es->s_clusters_per_group);
3773                 if (sbi->s_clusters_per_group > blocksize * 8) {
3774                         ext4_msg(sb, KERN_ERR,
3775                                  "#clusters per group too big: %lu",
3776                                  sbi->s_clusters_per_group);
3777                         goto failed_mount;
3778                 }
3779                 if (sbi->s_blocks_per_group !=
3780                     (sbi->s_clusters_per_group * (clustersize / blocksize))) {
3781                         ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
3782                                  "clusters per group (%lu) inconsistent",
3783                                  sbi->s_blocks_per_group,
3784                                  sbi->s_clusters_per_group);
3785                         goto failed_mount;
3786                 }
3787         } else {
3788                 if (clustersize != blocksize) {
3789                         ext4_warning(sb, "fragment/cluster size (%d) != "
3790                                      "block size (%d)", clustersize,
3791                                      blocksize);
3792                         clustersize = blocksize;
3793                 }
3794                 if (sbi->s_blocks_per_group > blocksize * 8) {
3795                         ext4_msg(sb, KERN_ERR,
3796                                  "#blocks per group too big: %lu",
3797                                  sbi->s_blocks_per_group);
3798                         goto failed_mount;
3799                 }
3800                 sbi->s_clusters_per_group = sbi->s_blocks_per_group;
3801                 sbi->s_cluster_bits = 0;
3802         }
3803         sbi->s_cluster_ratio = clustersize / blocksize;
3804
3805         if (sbi->s_inodes_per_group > blocksize * 8) {
3806                 ext4_msg(sb, KERN_ERR,
3807                        "#inodes per group too big: %lu",
3808                        sbi->s_inodes_per_group);
3809                 goto failed_mount;
3810         }
3811
3812         /* Do we have standard group size of clustersize * 8 blocks ? */
3813         if (sbi->s_blocks_per_group == clustersize << 3)
3814                 set_opt2(sb, STD_GROUP_SIZE);
3815
3816         /*
3817          * Test whether we have more sectors than will fit in sector_t,
3818          * and whether the max offset is addressable by the page cache.
3819          */
3820         err = generic_check_addressable(sb->s_blocksize_bits,
3821                                         ext4_blocks_count(es));
3822         if (err) {
3823                 ext4_msg(sb, KERN_ERR, "filesystem"
3824                          " too large to mount safely on this system");
3825                 if (sizeof(sector_t) < 8)
3826                         ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
3827                 goto failed_mount;
3828         }
3829
3830         if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
3831                 goto cantfind_ext4;
3832
3833         /* check blocks count against device size */
3834         blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
3835         if (blocks_count && ext4_blocks_count(es) > blocks_count) {
3836                 ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
3837                        "exceeds size of device (%llu blocks)",
3838                        ext4_blocks_count(es), blocks_count);
3839                 goto failed_mount;
3840         }
3841
3842         /*
3843          * It makes no sense for the first data block to be beyond the end
3844          * of the filesystem.
3845          */
3846         if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
3847                 ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
3848                          "block %u is beyond end of filesystem (%llu)",
3849                          le32_to_cpu(es->s_first_data_block),
3850                          ext4_blocks_count(es));
3851                 goto failed_mount;
3852         }
3853         blocks_count = (ext4_blocks_count(es) -
3854                         le32_to_cpu(es->s_first_data_block) +
3855                         EXT4_BLOCKS_PER_GROUP(sb) - 1);
3856         do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
3857         if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
3858                 ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
3859                        "(block count %llu, first data block %u, "
3860                        "blocks per group %lu)", sbi->s_groups_count,
3861                        ext4_blocks_count(es),
3862                        le32_to_cpu(es->s_first_data_block),
3863                        EXT4_BLOCKS_PER_GROUP(sb));
3864                 goto failed_mount;
3865         }
3866         sbi->s_groups_count = blocks_count;
3867         sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
3868                         (EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
3869         db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
3870                    EXT4_DESC_PER_BLOCK(sb);
3871         sbi->s_group_desc = ext4_kvmalloc(db_count *
3872                                           sizeof(struct buffer_head *),
3873                                           GFP_KERNEL);
3874         if (sbi->s_group_desc == NULL) {
3875                 ext4_msg(sb, KERN_ERR, "not enough memory");
3876                 ret = -ENOMEM;
3877                 goto failed_mount;
3878         }
3879
3880         if (ext4_proc_root)
3881                 sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root);
3882
3883         if (sbi->s_proc)
3884                 proc_create_data("options", S_IRUGO, sbi->s_proc,
3885                                  &ext4_seq_options_fops, sb);
3886
3887         bgl_lock_init(sbi->s_blockgroup_lock);
3888
3889         for (i = 0; i < db_count; i++) {
3890                 block = descriptor_loc(sb, logical_sb_block, i);
3891                 sbi->s_group_desc[i] = sb_bread_unmovable(sb, block);
3892                 if (!sbi->s_group_desc[i]) {
3893                         ext4_msg(sb, KERN_ERR,
3894                                "can't read group descriptor %d", i);
3895                         db_count = i;
3896                         goto failed_mount2;
3897                 }
3898         }
3899         if (!ext4_check_descriptors(sb, &first_not_zeroed)) {
3900                 ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
3901                 goto failed_mount2;
3902         }
3903
3904         sbi->s_gdb_count = db_count;
3905         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
3906         spin_lock_init(&sbi->s_next_gen_lock);
3907
3908         init_timer(&sbi->s_err_report);
3909         sbi->s_err_report.function = print_daily_error_info;
3910         sbi->s_err_report.data = (unsigned long) sb;
3911
3912         /* Register extent status tree shrinker */
3913         if (ext4_es_register_shrinker(sbi))
3914                 goto failed_mount3;
3915
3916         sbi->s_stripe = ext4_get_stripe_size(sbi);
3917         sbi->s_extent_max_zeroout_kb = 32;
3918
3919         /*
3920          * set up enough so that it can read an inode
3921          */
3922         sb->s_op = &ext4_sops;
3923         sb->s_export_op = &ext4_export_ops;
3924         sb->s_xattr = ext4_xattr_handlers;
3925 #ifdef CONFIG_QUOTA
3926         sb->dq_op = &ext4_quota_operations;
3927         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
3928                 sb->s_qcop = &ext4_qctl_sysfile_operations;
3929         else
3930                 sb->s_qcop = &ext4_qctl_operations;
3931 #endif
3932         memcpy(sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
3933
3934         INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
3935         mutex_init(&sbi->s_orphan_lock);
3936
3937         sb->s_root = NULL;
3938
3939         needs_recovery = (es->s_last_orphan != 0 ||
3940                           EXT4_HAS_INCOMPAT_FEATURE(sb,
3941                                     EXT4_FEATURE_INCOMPAT_RECOVER));
3942
3943         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_MMP) &&
3944             !(sb->s_flags & MS_RDONLY))
3945                 if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
3946                         goto failed_mount3;
3947
3948         /*
3949          * The first inode we look at is the journal inode.  Don't try
3950          * root first: it may be modified in the journal!
3951          */
3952         if (!test_opt(sb, NOLOAD) &&
3953             EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
3954                 if (ext4_load_journal(sb, es, journal_devnum))
3955                         goto failed_mount3;
3956         } else if (test_opt(sb, NOLOAD) && !(sb->s_flags & MS_RDONLY) &&
3957               EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
3958                 ext4_msg(sb, KERN_ERR, "required journal recovery "
3959                        "suppressed and not mounted read-only");
3960                 goto failed_mount_wq;
3961         } else {
3962                 clear_opt(sb, DATA_FLAGS);
3963                 sbi->s_journal = NULL;
3964                 needs_recovery = 0;
3965                 goto no_journal;
3966         }
3967
3968         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT) &&
3969             !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
3970                                        JBD2_FEATURE_INCOMPAT_64BIT)) {
3971                 ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
3972                 goto failed_mount_wq;
3973         }
3974
3975         if (!set_journal_csum_feature_set(sb)) {
3976                 ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
3977                          "feature set");
3978                 goto failed_mount_wq;
3979         }
3980
3981         /* We have now updated the journal if required, so we can
3982          * validate the data journaling mode. */
3983         switch (test_opt(sb, DATA_FLAGS)) {
3984         case 0:
3985                 /* No mode set, assume a default based on the journal
3986                  * capabilities: ORDERED_DATA if the journal can
3987                  * cope, else JOURNAL_DATA
3988                  */
3989                 if (jbd2_journal_check_available_features
3990                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
3991                         set_opt(sb, ORDERED_DATA);
3992                 else
3993                         set_opt(sb, JOURNAL_DATA);
3994                 break;
3995
3996         case EXT4_MOUNT_ORDERED_DATA:
3997         case EXT4_MOUNT_WRITEBACK_DATA:
3998                 if (!jbd2_journal_check_available_features
3999                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4000                         ext4_msg(sb, KERN_ERR, "Journal does not support "
4001                                "requested data journaling mode");
4002                         goto failed_mount_wq;
4003                 }
4004         default:
4005                 break;
4006         }
4007         set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4008
4009         sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
4010
4011 no_journal:
4012         if (ext4_mballoc_ready) {
4013                 sbi->s_mb_cache = ext4_xattr_create_cache(sb->s_id);
4014                 if (!sbi->s_mb_cache) {
4015                         ext4_msg(sb, KERN_ERR, "Failed to create an mb_cache");
4016                         goto failed_mount_wq;
4017                 }
4018         }
4019
4020         /*
4021          * Get the # of file system overhead blocks from the
4022          * superblock if present.
4023          */
4024         if (es->s_overhead_clusters)
4025                 sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
4026         else {
4027                 err = ext4_calculate_overhead(sb);
4028                 if (err)
4029                         goto failed_mount_wq;
4030         }
4031
4032         /*
4033          * The maximum number of concurrent works can be high and
4034          * concurrency isn't really necessary.  Limit it to 1.
4035          */
4036         EXT4_SB(sb)->rsv_conversion_wq =
4037                 alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
4038         if (!EXT4_SB(sb)->rsv_conversion_wq) {
4039                 printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
4040                 ret = -ENOMEM;
4041                 goto failed_mount4;
4042         }
4043
4044         /*
4045          * The jbd2_journal_load will have done any necessary log recovery,
4046          * so we can safely mount the rest of the filesystem now.
4047          */
4048
4049         root = ext4_iget(sb, EXT4_ROOT_INO);
4050         if (IS_ERR(root)) {
4051                 ext4_msg(sb, KERN_ERR, "get root inode failed");
4052                 ret = PTR_ERR(root);
4053                 root = NULL;
4054                 goto failed_mount4;
4055         }
4056         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
4057                 ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
4058                 iput(root);
4059                 goto failed_mount4;
4060         }
4061         sb->s_root = d_make_root(root);
4062         if (!sb->s_root) {
4063                 ext4_msg(sb, KERN_ERR, "get root dentry failed");
4064                 ret = -ENOMEM;
4065                 goto failed_mount4;
4066         }
4067
4068         if (ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY))
4069                 sb->s_flags |= MS_RDONLY;
4070
4071         /* determine the minimum size of new large inodes, if present */
4072         if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
4073                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4074                                                      EXT4_GOOD_OLD_INODE_SIZE;
4075                 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
4076                                        EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE)) {
4077                         if (sbi->s_want_extra_isize <
4078                             le16_to_cpu(es->s_want_extra_isize))
4079                                 sbi->s_want_extra_isize =
4080                                         le16_to_cpu(es->s_want_extra_isize);
4081                         if (sbi->s_want_extra_isize <
4082                             le16_to_cpu(es->s_min_extra_isize))
4083                                 sbi->s_want_extra_isize =
4084                                         le16_to_cpu(es->s_min_extra_isize);
4085                 }
4086         }
4087         /* Check if enough inode space is available */
4088         if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
4089                                                         sbi->s_inode_size) {
4090                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4091                                                        EXT4_GOOD_OLD_INODE_SIZE;
4092                 ext4_msg(sb, KERN_INFO, "required extra inode space not"
4093                          "available");
4094         }
4095
4096         err = ext4_reserve_clusters(sbi, ext4_calculate_resv_clusters(sb));
4097         if (err) {
4098                 ext4_msg(sb, KERN_ERR, "failed to reserve %llu clusters for "
4099                          "reserved pool", ext4_calculate_resv_clusters(sb));
4100                 goto failed_mount4a;
4101         }
4102
4103         err = ext4_setup_system_zone(sb);
4104         if (err) {
4105                 ext4_msg(sb, KERN_ERR, "failed to initialize system "
4106                          "zone (%d)", err);
4107                 goto failed_mount4a;
4108         }
4109
4110         ext4_ext_init(sb);
4111         err = ext4_mb_init(sb);
4112         if (err) {
4113                 ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
4114                          err);
4115                 goto failed_mount5;
4116         }
4117
4118         block = ext4_count_free_clusters(sb);
4119         ext4_free_blocks_count_set(sbi->s_es,
4120                                    EXT4_C2B(sbi, block));
4121         err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
4122                                   GFP_KERNEL);
4123         if (!err) {
4124                 unsigned long freei = ext4_count_free_inodes(sb);
4125                 sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
4126                 err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
4127                                           GFP_KERNEL);
4128         }
4129         if (!err)
4130                 err = percpu_counter_init(&sbi->s_dirs_counter,
4131                                           ext4_count_dirs(sb), GFP_KERNEL);
4132         if (!err)
4133                 err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
4134                                           GFP_KERNEL);
4135         if (err) {
4136                 ext4_msg(sb, KERN_ERR, "insufficient memory");
4137                 goto failed_mount6;
4138         }
4139
4140         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
4141                 if (!ext4_fill_flex_info(sb)) {
4142                         ext4_msg(sb, KERN_ERR,
4143                                "unable to initialize "
4144                                "flex_bg meta info!");
4145                         goto failed_mount6;
4146                 }
4147
4148         err = ext4_register_li_request(sb, first_not_zeroed);
4149         if (err)
4150                 goto failed_mount6;
4151
4152         sbi->s_kobj.kset = ext4_kset;
4153         init_completion(&sbi->s_kobj_unregister);
4154         err = kobject_init_and_add(&sbi->s_kobj, &ext4_ktype, NULL,
4155                                    "%s", sb->s_id);
4156         if (err)
4157                 goto failed_mount7;
4158
4159 #ifdef CONFIG_QUOTA
4160         /* Enable quota usage during mount. */
4161         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
4162             !(sb->s_flags & MS_RDONLY)) {
4163                 err = ext4_enable_quotas(sb);
4164                 if (err)
4165                         goto failed_mount8;
4166         }
4167 #endif  /* CONFIG_QUOTA */
4168
4169         EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
4170         ext4_orphan_cleanup(sb, es);
4171         EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
4172         if (needs_recovery) {
4173                 ext4_msg(sb, KERN_INFO, "recovery complete");
4174                 ext4_mark_recovery_complete(sb, es);
4175         }
4176         if (EXT4_SB(sb)->s_journal) {
4177                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
4178                         descr = " journalled data mode";
4179                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
4180                         descr = " ordered data mode";
4181                 else
4182                         descr = " writeback data mode";
4183         } else
4184                 descr = "out journal";
4185
4186         if (test_opt(sb, DISCARD)) {
4187                 struct request_queue *q = bdev_get_queue(sb->s_bdev);
4188                 if (!blk_queue_discard(q))
4189                         ext4_msg(sb, KERN_WARNING,
4190                                  "mounting with \"discard\" option, but "
4191                                  "the device does not support discard");
4192         }
4193
4194         ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
4195                  "Opts: %s%s%s", descr, sbi->s_es->s_mount_opts,
4196                  *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
4197
4198         if (es->s_error_count)
4199                 mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
4200
4201         /* Enable message ratelimiting. Default is 10 messages per 5 secs. */
4202         ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
4203         ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
4204         ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
4205
4206         kfree(orig_data);
4207         return 0;
4208
4209 cantfind_ext4:
4210         if (!silent)
4211                 ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
4212         goto failed_mount;
4213
4214 #ifdef CONFIG_QUOTA
4215 failed_mount8:
4216         kobject_del(&sbi->s_kobj);
4217 #endif
4218 failed_mount7:
4219         ext4_unregister_li_request(sb);
4220 failed_mount6:
4221         ext4_mb_release(sb);
4222         if (sbi->s_flex_groups)
4223                 ext4_kvfree(sbi->s_flex_groups);
4224         percpu_counter_destroy(&sbi->s_freeclusters_counter);
4225         percpu_counter_destroy(&sbi->s_freeinodes_counter);
4226         percpu_counter_destroy(&sbi->s_dirs_counter);
4227         percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4228 failed_mount5:
4229         ext4_ext_release(sb);
4230         ext4_release_system_zone(sb);
4231 failed_mount4a:
4232         dput(sb->s_root);
4233         sb->s_root = NULL;
4234 failed_mount4:
4235         ext4_msg(sb, KERN_ERR, "mount failed");
4236         if (EXT4_SB(sb)->rsv_conversion_wq)
4237                 destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4238 failed_mount_wq:
4239         if (sbi->s_journal) {
4240                 jbd2_journal_destroy(sbi->s_journal);
4241                 sbi->s_journal = NULL;
4242         }
4243         ext4_es_unregister_shrinker(sbi);
4244 failed_mount3:
4245         del_timer_sync(&sbi->s_err_report);
4246         if (sbi->s_mmp_tsk)
4247                 kthread_stop(sbi->s_mmp_tsk);
4248 failed_mount2:
4249         for (i = 0; i < db_count; i++)
4250                 brelse(sbi->s_group_desc[i]);
4251         ext4_kvfree(sbi->s_group_desc);
4252 failed_mount:
4253         if (sbi->s_chksum_driver)
4254                 crypto_free_shash(sbi->s_chksum_driver);
4255         if (sbi->s_proc) {
4256                 remove_proc_entry("options", sbi->s_proc);
4257                 remove_proc_entry(sb->s_id, ext4_proc_root);
4258         }
4259 #ifdef CONFIG_QUOTA
4260         for (i = 0; i < EXT4_MAXQUOTAS; i++)
4261                 kfree(sbi->s_qf_names[i]);
4262 #endif
4263         ext4_blkdev_remove(sbi);
4264         brelse(bh);
4265 out_fail:
4266         sb->s_fs_info = NULL;
4267         kfree(sbi->s_blockgroup_lock);
4268         kfree(sbi);
4269 out_free_orig:
4270         kfree(orig_data);
4271         return err ? err : ret;
4272 }
4273
4274 /*
4275  * Setup any per-fs journal parameters now.  We'll do this both on
4276  * initial mount, once the journal has been initialised but before we've
4277  * done any recovery; and again on any subsequent remount.
4278  */
4279 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4280 {
4281         struct ext4_sb_info *sbi = EXT4_SB(sb);
4282
4283         journal->j_commit_interval = sbi->s_commit_interval;
4284         journal->j_min_batch_time = sbi->s_min_batch_time;
4285         journal->j_max_batch_time = sbi->s_max_batch_time;
4286
4287         write_lock(&journal->j_state_lock);
4288         if (test_opt(sb, BARRIER))
4289                 journal->j_flags |= JBD2_BARRIER;
4290         else
4291                 journal->j_flags &= ~JBD2_BARRIER;
4292         if (test_opt(sb, DATA_ERR_ABORT))
4293                 journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4294         else
4295                 journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4296         write_unlock(&journal->j_state_lock);
4297 }
4298
4299 static journal_t *ext4_get_journal(struct super_block *sb,
4300                                    unsigned int journal_inum)
4301 {
4302         struct inode *journal_inode;
4303         journal_t *journal;
4304
4305         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4306
4307         /* First, test for the existence of a valid inode on disk.  Bad
4308          * things happen if we iget() an unused inode, as the subsequent
4309          * iput() will try to delete it. */
4310
4311         journal_inode = ext4_iget(sb, journal_inum);
4312         if (IS_ERR(journal_inode)) {
4313                 ext4_msg(sb, KERN_ERR, "no journal found");
4314                 return NULL;
4315         }
4316         if (!journal_inode->i_nlink) {
4317                 make_bad_inode(journal_inode);
4318                 iput(journal_inode);
4319                 ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4320                 return NULL;
4321         }
4322
4323         jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4324                   journal_inode, journal_inode->i_size);
4325         if (!S_ISREG(journal_inode->i_mode)) {
4326                 ext4_msg(sb, KERN_ERR, "invalid journal inode");
4327                 iput(journal_inode);
4328                 return NULL;
4329         }
4330
4331         journal = jbd2_journal_init_inode(journal_inode);
4332         if (!journal) {
4333                 ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4334                 iput(journal_inode);
4335                 return NULL;
4336         }
4337         journal->j_private = sb;
4338         ext4_init_journal_params(sb, journal);
4339         return journal;
4340 }
4341
4342 static journal_t *ext4_get_dev_journal(struct super_block *sb,
4343                                        dev_t j_dev)
4344 {
4345         struct buffer_head *bh;
4346         journal_t *journal;
4347         ext4_fsblk_t start;
4348         ext4_fsblk_t len;
4349         int hblock, blocksize;
4350         ext4_fsblk_t sb_block;
4351         unsigned long offset;
4352         struct ext4_super_block *es;
4353         struct block_device *bdev;
4354
4355         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4356
4357         bdev = ext4_blkdev_get(j_dev, sb);
4358         if (bdev == NULL)
4359                 return NULL;
4360
4361         blocksize = sb->s_blocksize;
4362         hblock = bdev_logical_block_size(bdev);
4363         if (blocksize < hblock) {
4364                 ext4_msg(sb, KERN_ERR,
4365                         "blocksize too small for journal device");
4366                 goto out_bdev;
4367         }
4368
4369         sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4370         offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4371         set_blocksize(bdev, blocksize);
4372         if (!(bh = __bread(bdev, sb_block, blocksize))) {
4373                 ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4374                        "external journal");
4375                 goto out_bdev;
4376         }
4377
4378         es = (struct ext4_super_block *) (bh->b_data + offset);
4379         if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4380             !(le32_to_cpu(es->s_feature_incompat) &
4381               EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4382                 ext4_msg(sb, KERN_ERR, "external journal has "
4383                                         "bad superblock");
4384                 brelse(bh);
4385                 goto out_bdev;
4386         }
4387
4388         if ((le32_to_cpu(es->s_feature_ro_compat) &
4389              EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
4390             es->s_checksum != ext4_superblock_csum(sb, es)) {
4391                 ext4_msg(sb, KERN_ERR, "external journal has "
4392                                        "corrupt superblock");
4393                 brelse(bh);
4394                 goto out_bdev;
4395         }
4396
4397         if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4398                 ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4399                 brelse(bh);
4400                 goto out_bdev;
4401         }
4402
4403         len = ext4_blocks_count(es);
4404         start = sb_block + 1;
4405         brelse(bh);     /* we're done with the superblock */
4406
4407         journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4408                                         start, len, blocksize);
4409         if (!journal) {
4410                 ext4_msg(sb, KERN_ERR, "failed to create device journal");
4411                 goto out_bdev;
4412         }
4413         journal->j_private = sb;
4414         ll_rw_block(READ | REQ_META | REQ_PRIO, 1, &journal->j_sb_buffer);
4415         wait_on_buffer(journal->j_sb_buffer);
4416         if (!buffer_uptodate(journal->j_sb_buffer)) {
4417                 ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4418                 goto out_journal;
4419         }
4420         if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4421                 ext4_msg(sb, KERN_ERR, "External journal has more than one "
4422                                         "user (unsupported) - %d",
4423                         be32_to_cpu(journal->j_superblock->s_nr_users));
4424                 goto out_journal;
4425         }
4426         EXT4_SB(sb)->journal_bdev = bdev;
4427         ext4_init_journal_params(sb, journal);
4428         return journal;
4429
4430 out_journal:
4431         jbd2_journal_destroy(journal);
4432 out_bdev:
4433         ext4_blkdev_put(bdev);
4434         return NULL;
4435 }
4436
4437 static int ext4_load_journal(struct super_block *sb,
4438                              struct ext4_super_block *es,
4439                              unsigned long journal_devnum)
4440 {
4441         journal_t *journal;
4442         unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4443         dev_t journal_dev;
4444         int err = 0;
4445         int really_read_only;
4446
4447         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4448
4449         if (journal_devnum &&
4450             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4451                 ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4452                         "numbers have changed");
4453                 journal_dev = new_decode_dev(journal_devnum);
4454         } else
4455                 journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4456
4457         really_read_only = bdev_read_only(sb->s_bdev);
4458
4459         /*
4460          * Are we loading a blank journal or performing recovery after a
4461          * crash?  For recovery, we need to check in advance whether we
4462          * can get read-write access to the device.
4463          */
4464         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
4465                 if (sb->s_flags & MS_RDONLY) {
4466                         ext4_msg(sb, KERN_INFO, "INFO: recovery "
4467                                         "required on readonly filesystem");
4468                         if (really_read_only) {
4469                                 ext4_msg(sb, KERN_ERR, "write access "
4470                                         "unavailable, cannot proceed");
4471                                 return -EROFS;
4472                         }
4473                         ext4_msg(sb, KERN_INFO, "write access will "
4474                                "be enabled during recovery");
4475                 }
4476         }
4477
4478         if (journal_inum && journal_dev) {
4479                 ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4480                        "and inode journals!");
4481                 return -EINVAL;
4482         }
4483
4484         if (journal_inum) {
4485                 if (!(journal = ext4_get_journal(sb, journal_inum)))
4486                         return -EINVAL;
4487         } else {
4488                 if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4489                         return -EINVAL;
4490         }
4491
4492         if (!(journal->j_flags & JBD2_BARRIER))
4493                 ext4_msg(sb, KERN_INFO, "barriers disabled");
4494
4495         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER))
4496                 err = jbd2_journal_wipe(journal, !really_read_only);
4497         if (!err) {
4498                 char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4499                 if (save)
4500                         memcpy(save, ((char *) es) +
4501                                EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4502                 err = jbd2_journal_load(journal);
4503                 if (save)
4504                         memcpy(((char *) es) + EXT4_S_ERR_START,
4505                                save, EXT4_S_ERR_LEN);
4506                 kfree(save);
4507         }
4508
4509         if (err) {
4510                 ext4_msg(sb, KERN_ERR, "error loading journal");
4511                 jbd2_journal_destroy(journal);
4512                 return err;
4513         }
4514
4515         EXT4_SB(sb)->s_journal = journal;
4516         ext4_clear_journal_err(sb, es);
4517
4518         if (!really_read_only && journal_devnum &&
4519             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4520                 es->s_journal_dev = cpu_to_le32(journal_devnum);
4521
4522                 /* Make sure we flush the recovery flag to disk. */
4523                 ext4_commit_super(sb, 1);
4524         }
4525
4526         return 0;
4527 }
4528
4529 static int ext4_commit_super(struct super_block *sb, int sync)
4530 {
4531         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4532         struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4533         int error = 0;
4534
4535         if (!sbh || block_device_ejected(sb))
4536                 return error;
4537         if (buffer_write_io_error(sbh)) {
4538                 /*
4539                  * Oh, dear.  A previous attempt to write the
4540                  * superblock failed.  This could happen because the
4541                  * USB device was yanked out.  Or it could happen to
4542                  * be a transient write error and maybe the block will
4543                  * be remapped.  Nothing we can do but to retry the
4544                  * write and hope for the best.
4545                  */
4546                 ext4_msg(sb, KERN_ERR, "previous I/O error to "
4547                        "superblock detected");
4548                 clear_buffer_write_io_error(sbh);
4549                 set_buffer_uptodate(sbh);
4550         }
4551         /*
4552          * If the file system is mounted read-only, don't update the
4553          * superblock write time.  This avoids updating the superblock
4554          * write time when we are mounting the root file system
4555          * read/only but we need to replay the journal; at that point,
4556          * for people who are east of GMT and who make their clock
4557          * tick in localtime for Windows bug-for-bug compatibility,
4558          * the clock is set in the future, and this will cause e2fsck
4559          * to complain and force a full file system check.
4560          */
4561         if (!(sb->s_flags & MS_RDONLY))
4562                 es->s_wtime = cpu_to_le32(get_seconds());
4563         if (sb->s_bdev->bd_part)
4564                 es->s_kbytes_written =
4565                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
4566                             ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
4567                               EXT4_SB(sb)->s_sectors_written_start) >> 1));
4568         else
4569                 es->s_kbytes_written =
4570                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
4571         if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeclusters_counter))
4572                 ext4_free_blocks_count_set(es,
4573                         EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
4574                                 &EXT4_SB(sb)->s_freeclusters_counter)));
4575         if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeinodes_counter))
4576                 es->s_free_inodes_count =
4577                         cpu_to_le32(percpu_counter_sum_positive(
4578                                 &EXT4_SB(sb)->s_freeinodes_counter));
4579         BUFFER_TRACE(sbh, "marking dirty");
4580         ext4_superblock_csum_set(sb);
4581         mark_buffer_dirty(sbh);
4582         if (sync) {
4583                 error = sync_dirty_buffer(sbh);
4584                 if (error)
4585                         return error;
4586
4587                 error = buffer_write_io_error(sbh);
4588                 if (error) {
4589                         ext4_msg(sb, KERN_ERR, "I/O error while writing "
4590                                "superblock");
4591                         clear_buffer_write_io_error(sbh);
4592                         set_buffer_uptodate(sbh);
4593                 }
4594         }
4595         return error;
4596 }
4597
4598 /*
4599  * Have we just finished recovery?  If so, and if we are mounting (or
4600  * remounting) the filesystem readonly, then we will end up with a
4601  * consistent fs on disk.  Record that fact.
4602  */
4603 static void ext4_mark_recovery_complete(struct super_block *sb,
4604                                         struct ext4_super_block *es)
4605 {
4606         journal_t *journal = EXT4_SB(sb)->s_journal;
4607
4608         if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
4609                 BUG_ON(journal != NULL);
4610                 return;
4611         }
4612         jbd2_journal_lock_updates(journal);
4613         if (jbd2_journal_flush(journal) < 0)
4614                 goto out;
4615
4616         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER) &&
4617             sb->s_flags & MS_RDONLY) {
4618                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4619                 ext4_commit_super(sb, 1);
4620         }
4621
4622 out:
4623         jbd2_journal_unlock_updates(journal);
4624 }
4625
4626 /*
4627  * If we are mounting (or read-write remounting) a filesystem whose journal
4628  * has recorded an error from a previous lifetime, move that error to the
4629  * main filesystem now.
4630  */
4631 static void ext4_clear_journal_err(struct super_block *sb,
4632                                    struct ext4_super_block *es)
4633 {
4634         journal_t *journal;
4635         int j_errno;
4636         const char *errstr;
4637
4638         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4639
4640         journal = EXT4_SB(sb)->s_journal;
4641
4642         /*
4643          * Now check for any error status which may have been recorded in the
4644          * journal by a prior ext4_error() or ext4_abort()
4645          */
4646
4647         j_errno = jbd2_journal_errno(journal);
4648         if (j_errno) {
4649                 char nbuf[16];
4650
4651                 errstr = ext4_decode_error(sb, j_errno, nbuf);
4652                 ext4_warning(sb, "Filesystem error recorded "
4653                              "from previous mount: %s", errstr);
4654                 ext4_warning(sb, "Marking fs in need of filesystem check.");
4655
4656                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
4657                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
4658                 ext4_commit_super(sb, 1);
4659
4660                 jbd2_journal_clear_err(journal);
4661                 jbd2_journal_update_sb_errno(journal);
4662         }
4663 }
4664
4665 /*
4666  * Force the running and committing transactions to commit,
4667  * and wait on the commit.
4668  */
4669 int ext4_force_commit(struct super_block *sb)
4670 {
4671         journal_t *journal;
4672
4673         if (sb->s_flags & MS_RDONLY)
4674                 return 0;
4675
4676         journal = EXT4_SB(sb)->s_journal;
4677         return ext4_journal_force_commit(journal);
4678 }
4679
4680 static int ext4_sync_fs(struct super_block *sb, int wait)
4681 {
4682         int ret = 0;
4683         tid_t target;
4684         bool needs_barrier = false;
4685         struct ext4_sb_info *sbi = EXT4_SB(sb);
4686
4687         trace_ext4_sync_fs(sb, wait);
4688         flush_workqueue(sbi->rsv_conversion_wq);
4689         /*
4690          * Writeback quota in non-journalled quota case - journalled quota has
4691          * no dirty dquots
4692          */
4693         dquot_writeback_dquots(sb, -1);
4694         /*
4695          * Data writeback is possible w/o journal transaction, so barrier must
4696          * being sent at the end of the function. But we can skip it if
4697          * transaction_commit will do it for us.
4698          */
4699         if (sbi->s_journal) {
4700                 target = jbd2_get_latest_transaction(sbi->s_journal);
4701                 if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
4702                     !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
4703                         needs_barrier = true;
4704
4705                 if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
4706                         if (wait)
4707                                 ret = jbd2_log_wait_commit(sbi->s_journal,
4708                                                            target);
4709                 }
4710         } else if (wait && test_opt(sb, BARRIER))
4711                 needs_barrier = true;
4712         if (needs_barrier) {
4713                 int err;
4714                 err = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
4715                 if (!ret)
4716                         ret = err;
4717         }
4718
4719         return ret;
4720 }
4721
4722 /*
4723  * LVM calls this function before a (read-only) snapshot is created.  This
4724  * gives us a chance to flush the journal completely and mark the fs clean.
4725  *
4726  * Note that only this function cannot bring a filesystem to be in a clean
4727  * state independently. It relies on upper layer to stop all data & metadata
4728  * modifications.
4729  */
4730 static int ext4_freeze(struct super_block *sb)
4731 {
4732         int error = 0;
4733         journal_t *journal;
4734
4735         if (sb->s_flags & MS_RDONLY)
4736                 return 0;
4737
4738         journal = EXT4_SB(sb)->s_journal;
4739
4740         if (journal) {
4741                 /* Now we set up the journal barrier. */
4742                 jbd2_journal_lock_updates(journal);
4743
4744                 /*
4745                  * Don't clear the needs_recovery flag if we failed to
4746                  * flush the journal.
4747                  */
4748                 error = jbd2_journal_flush(journal);
4749                 if (error < 0)
4750                         goto out;
4751         }
4752
4753         /* Journal blocked and flushed, clear needs_recovery flag. */
4754         EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4755         error = ext4_commit_super(sb, 1);
4756 out:
4757         if (journal)
4758                 /* we rely on upper layer to stop further updates */
4759                 jbd2_journal_unlock_updates(journal);
4760         return error;
4761 }
4762
4763 /*
4764  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
4765  * flag here, even though the filesystem is not technically dirty yet.
4766  */
4767 static int ext4_unfreeze(struct super_block *sb)
4768 {
4769         if (sb->s_flags & MS_RDONLY)
4770                 return 0;
4771
4772         /* Reset the needs_recovery flag before the fs is unlocked. */
4773         EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4774         ext4_commit_super(sb, 1);
4775         return 0;
4776 }
4777
4778 /*
4779  * Structure to save mount options for ext4_remount's benefit
4780  */
4781 struct ext4_mount_options {
4782         unsigned long s_mount_opt;
4783         unsigned long s_mount_opt2;
4784         kuid_t s_resuid;
4785         kgid_t s_resgid;
4786         unsigned long s_commit_interval;
4787         u32 s_min_batch_time, s_max_batch_time;
4788 #ifdef CONFIG_QUOTA
4789         int s_jquota_fmt;
4790         char *s_qf_names[EXT4_MAXQUOTAS];
4791 #endif
4792 };
4793
4794 static int ext4_remount(struct super_block *sb, int *flags, char *data)
4795 {
4796         struct ext4_super_block *es;
4797         struct ext4_sb_info *sbi = EXT4_SB(sb);
4798         unsigned long old_sb_flags;
4799         struct ext4_mount_options old_opts;
4800         int enable_quota = 0;
4801         ext4_group_t g;
4802         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4803         int err = 0;
4804 #ifdef CONFIG_QUOTA
4805         int i, j;
4806 #endif
4807         char *orig_data = kstrdup(data, GFP_KERNEL);
4808
4809         /* Store the original options */
4810         old_sb_flags = sb->s_flags;
4811         old_opts.s_mount_opt = sbi->s_mount_opt;
4812         old_opts.s_mount_opt2 = sbi->s_mount_opt2;
4813         old_opts.s_resuid = sbi->s_resuid;
4814         old_opts.s_resgid = sbi->s_resgid;
4815         old_opts.s_commit_interval = sbi->s_commit_interval;
4816         old_opts.s_min_batch_time = sbi->s_min_batch_time;
4817         old_opts.s_max_batch_time = sbi->s_max_batch_time;
4818 #ifdef CONFIG_QUOTA
4819         old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
4820         for (i = 0; i < EXT4_MAXQUOTAS; i++)
4821                 if (sbi->s_qf_names[i]) {
4822                         old_opts.s_qf_names[i] = kstrdup(sbi->s_qf_names[i],
4823                                                          GFP_KERNEL);
4824                         if (!old_opts.s_qf_names[i]) {
4825                                 for (j = 0; j < i; j++)
4826                                         kfree(old_opts.s_qf_names[j]);
4827                                 kfree(orig_data);
4828                                 return -ENOMEM;
4829                         }
4830                 } else
4831                         old_opts.s_qf_names[i] = NULL;
4832 #endif
4833         if (sbi->s_journal && sbi->s_journal->j_task->io_context)
4834                 journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
4835
4836         /*
4837          * Allow the "check" option to be passed as a remount option.
4838          */
4839         if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
4840                 err = -EINVAL;
4841                 goto restore_opts;
4842         }
4843
4844         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
4845                 if (test_opt2(sb, EXPLICIT_DELALLOC)) {
4846                         ext4_msg(sb, KERN_ERR, "can't mount with "
4847                                  "both data=journal and delalloc");
4848                         err = -EINVAL;
4849                         goto restore_opts;
4850                 }
4851                 if (test_opt(sb, DIOREAD_NOLOCK)) {
4852                         ext4_msg(sb, KERN_ERR, "can't mount with "
4853                                  "both data=journal and dioread_nolock");
4854                         err = -EINVAL;
4855                         goto restore_opts;
4856                 }
4857         }
4858
4859         if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
4860                 ext4_abort(sb, "Abort forced by user");
4861
4862         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
4863                 (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
4864
4865         es = sbi->s_es;
4866
4867         if (sbi->s_journal) {
4868                 ext4_init_journal_params(sb, sbi->s_journal);
4869                 set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4870         }
4871
4872         if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY)) {
4873                 if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
4874                         err = -EROFS;
4875                         goto restore_opts;
4876                 }
4877
4878                 if (*flags & MS_RDONLY) {
4879                         err = sync_filesystem(sb);
4880                         if (err < 0)
4881                                 goto restore_opts;
4882                         err = dquot_suspend(sb, -1);
4883                         if (err < 0)
4884                                 goto restore_opts;
4885
4886                         /*
4887                          * First of all, the unconditional stuff we have to do
4888                          * to disable replay of the journal when we next remount
4889                          */
4890                         sb->s_flags |= MS_RDONLY;
4891
4892                         /*
4893                          * OK, test if we are remounting a valid rw partition
4894                          * readonly, and if so set the rdonly flag and then
4895                          * mark the partition as valid again.
4896                          */
4897                         if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
4898                             (sbi->s_mount_state & EXT4_VALID_FS))
4899                                 es->s_state = cpu_to_le16(sbi->s_mount_state);
4900
4901                         if (sbi->s_journal)
4902                                 ext4_mark_recovery_complete(sb, es);
4903                 } else {
4904                         /* Make sure we can mount this feature set readwrite */
4905                         if (!ext4_feature_set_ok(sb, 0)) {
4906                                 err = -EROFS;
4907                                 goto restore_opts;
4908                         }
4909                         /*
4910                          * Make sure the group descriptor checksums
4911                          * are sane.  If they aren't, refuse to remount r/w.
4912                          */
4913                         for (g = 0; g < sbi->s_groups_count; g++) {
4914                                 struct ext4_group_desc *gdp =
4915                                         ext4_get_group_desc(sb, g, NULL);
4916
4917                                 if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
4918                                         ext4_msg(sb, KERN_ERR,
4919                "ext4_remount: Checksum for group %u failed (%u!=%u)",
4920                 g, le16_to_cpu(ext4_group_desc_csum(sbi, g, gdp)),
4921                                                le16_to_cpu(gdp->bg_checksum));
4922                                         err = -EINVAL;
4923                                         goto restore_opts;
4924                                 }
4925                         }
4926
4927                         /*
4928                          * If we have an unprocessed orphan list hanging
4929                          * around from a previously readonly bdev mount,
4930                          * require a full umount/remount for now.
4931                          */
4932                         if (es->s_last_orphan) {
4933                                 ext4_msg(sb, KERN_WARNING, "Couldn't "
4934                                        "remount RDWR because of unprocessed "
4935                                        "orphan inode list.  Please "
4936                                        "umount/remount instead");
4937                                 err = -EINVAL;
4938                                 goto restore_opts;
4939                         }
4940
4941                         /*
4942                          * Mounting a RDONLY partition read-write, so reread
4943                          * and store the current valid flag.  (It may have
4944                          * been changed by e2fsck since we originally mounted
4945                          * the partition.)
4946                          */
4947                         if (sbi->s_journal)
4948                                 ext4_clear_journal_err(sb, es);
4949                         sbi->s_mount_state = le16_to_cpu(es->s_state);
4950                         if (!ext4_setup_super(sb, es, 0))
4951                                 sb->s_flags &= ~MS_RDONLY;
4952                         if (EXT4_HAS_INCOMPAT_FEATURE(sb,
4953                                                      EXT4_FEATURE_INCOMPAT_MMP))
4954                                 if (ext4_multi_mount_protect(sb,
4955                                                 le64_to_cpu(es->s_mmp_block))) {
4956                                         err = -EROFS;
4957                                         goto restore_opts;
4958                                 }
4959                         enable_quota = 1;
4960                 }
4961         }
4962
4963         /*
4964          * Reinitialize lazy itable initialization thread based on
4965          * current settings
4966          */
4967         if ((sb->s_flags & MS_RDONLY) || !test_opt(sb, INIT_INODE_TABLE))
4968                 ext4_unregister_li_request(sb);
4969         else {
4970                 ext4_group_t first_not_zeroed;
4971                 first_not_zeroed = ext4_has_uninit_itable(sb);
4972                 ext4_register_li_request(sb, first_not_zeroed);
4973         }
4974
4975         ext4_setup_system_zone(sb);
4976         if (sbi->s_journal == NULL && !(old_sb_flags & MS_RDONLY))
4977                 ext4_commit_super(sb, 1);
4978
4979 #ifdef CONFIG_QUOTA
4980         /* Release old quota file names */
4981         for (i = 0; i < EXT4_MAXQUOTAS; i++)
4982                 kfree(old_opts.s_qf_names[i]);
4983         if (enable_quota) {
4984                 if (sb_any_quota_suspended(sb))
4985                         dquot_resume(sb, -1);
4986                 else if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
4987                                         EXT4_FEATURE_RO_COMPAT_QUOTA)) {
4988                         err = ext4_enable_quotas(sb);
4989                         if (err)
4990                                 goto restore_opts;
4991                 }
4992         }
4993 #endif
4994
4995         ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
4996         kfree(orig_data);
4997         return 0;
4998
4999 restore_opts:
5000         sb->s_flags = old_sb_flags;
5001         sbi->s_mount_opt = old_opts.s_mount_opt;
5002         sbi->s_mount_opt2 = old_opts.s_mount_opt2;
5003         sbi->s_resuid = old_opts.s_resuid;
5004         sbi->s_resgid = old_opts.s_resgid;
5005         sbi->s_commit_interval = old_opts.s_commit_interval;
5006         sbi->s_min_batch_time = old_opts.s_min_batch_time;
5007         sbi->s_max_batch_time = old_opts.s_max_batch_time;
5008 #ifdef CONFIG_QUOTA
5009         sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
5010         for (i = 0; i < EXT4_MAXQUOTAS; i++) {
5011                 kfree(sbi->s_qf_names[i]);
5012                 sbi->s_qf_names[i] = old_opts.s_qf_names[i];
5013         }
5014 #endif
5015         kfree(orig_data);
5016         return err;
5017 }
5018
5019 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
5020 {
5021         struct super_block *sb = dentry->d_sb;
5022         struct ext4_sb_info *sbi = EXT4_SB(sb);
5023         struct ext4_super_block *es = sbi->s_es;
5024         ext4_fsblk_t overhead = 0, resv_blocks;
5025         u64 fsid;
5026         s64 bfree;
5027         resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
5028
5029         if (!test_opt(sb, MINIX_DF))
5030                 overhead = sbi->s_overhead;
5031
5032         buf->f_type = EXT4_SUPER_MAGIC;
5033         buf->f_bsize = sb->s_blocksize;
5034         buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
5035         bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
5036                 percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
5037         /* prevent underflow in case that few free space is available */
5038         buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
5039         buf->f_bavail = buf->f_bfree -
5040                         (ext4_r_blocks_count(es) + resv_blocks);
5041         if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
5042                 buf->f_bavail = 0;
5043         buf->f_files = le32_to_cpu(es->s_inodes_count);
5044         buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
5045         buf->f_namelen = EXT4_NAME_LEN;
5046         fsid = le64_to_cpup((void *)es->s_uuid) ^
5047                le64_to_cpup((void *)es->s_uuid + sizeof(u64));
5048         buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
5049         buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
5050
5051         return 0;
5052 }
5053
5054 /* Helper function for writing quotas on sync - we need to start transaction
5055  * before quota file is locked for write. Otherwise the are possible deadlocks:
5056  * Process 1                         Process 2
5057  * ext4_create()                     quota_sync()
5058  *   jbd2_journal_start()                  write_dquot()
5059  *   dquot_initialize()                         down(dqio_mutex)
5060  *     down(dqio_mutex)                    jbd2_journal_start()
5061  *
5062  */
5063
5064 #ifdef CONFIG_QUOTA
5065
5066 static inline struct inode *dquot_to_inode(struct dquot *dquot)
5067 {
5068         return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
5069 }
5070
5071 static int ext4_write_dquot(struct dquot *dquot)
5072 {
5073         int ret, err;
5074         handle_t *handle;
5075         struct inode *inode;
5076
5077         inode = dquot_to_inode(dquot);
5078         handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
5079                                     EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
5080         if (IS_ERR(handle))
5081                 return PTR_ERR(handle);
5082         ret = dquot_commit(dquot);
5083         err = ext4_journal_stop(handle);
5084         if (!ret)
5085                 ret = err;
5086         return ret;
5087 }
5088
5089 static int ext4_acquire_dquot(struct dquot *dquot)
5090 {
5091         int ret, err;
5092         handle_t *handle;
5093
5094         handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5095                                     EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
5096         if (IS_ERR(handle))
5097                 return PTR_ERR(handle);
5098         ret = dquot_acquire(dquot);
5099         err = ext4_journal_stop(handle);
5100         if (!ret)
5101                 ret = err;
5102         return ret;
5103 }
5104
5105 static int ext4_release_dquot(struct dquot *dquot)
5106 {
5107         int ret, err;
5108         handle_t *handle;
5109
5110         handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5111                                     EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
5112         if (IS_ERR(handle)) {
5113                 /* Release dquot anyway to avoid endless cycle in dqput() */
5114                 dquot_release(dquot);
5115                 return PTR_ERR(handle);
5116         }
5117         ret = dquot_release(dquot);
5118         err = ext4_journal_stop(handle);
5119         if (!ret)
5120                 ret = err;
5121         return ret;
5122 }
5123
5124 static int ext4_mark_dquot_dirty(struct dquot *dquot)
5125 {
5126         struct super_block *sb = dquot->dq_sb;
5127         struct ext4_sb_info *sbi = EXT4_SB(sb);
5128
5129         /* Are we journaling quotas? */
5130         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) ||
5131             sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
5132                 dquot_mark_dquot_dirty(dquot);
5133                 return ext4_write_dquot(dquot);
5134         } else {
5135                 return dquot_mark_dquot_dirty(dquot);
5136         }
5137 }
5138
5139 static int ext4_write_info(struct super_block *sb, int type)
5140 {
5141         int ret, err;
5142         handle_t *handle;
5143
5144         /* Data block + inode block */
5145         handle = ext4_journal_start(sb->s_root->d_inode, EXT4_HT_QUOTA, 2);
5146         if (IS_ERR(handle))
5147                 return PTR_ERR(handle);
5148         ret = dquot_commit_info(sb, type);
5149         err = ext4_journal_stop(handle);
5150         if (!ret)
5151                 ret = err;
5152         return ret;
5153 }
5154
5155 /*
5156  * Turn on quotas during mount time - we need to find
5157  * the quota file and such...
5158  */
5159 static int ext4_quota_on_mount(struct super_block *sb, int type)
5160 {
5161         return dquot_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
5162                                         EXT4_SB(sb)->s_jquota_fmt, type);
5163 }
5164
5165 /*
5166  * Standard function to be called on quota_on
5167  */
5168 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
5169                          struct path *path)
5170 {
5171         int err;
5172
5173         if (!test_opt(sb, QUOTA))
5174                 return -EINVAL;
5175
5176         /* Quotafile not on the same filesystem? */
5177         if (path->dentry->d_sb != sb)
5178                 return -EXDEV;
5179         /* Journaling quota? */
5180         if (EXT4_SB(sb)->s_qf_names[type]) {
5181                 /* Quotafile not in fs root? */
5182                 if (path->dentry->d_parent != sb->s_root)
5183                         ext4_msg(sb, KERN_WARNING,
5184                                 "Quota file not on filesystem root. "
5185                                 "Journaled quota will not work");
5186         }
5187
5188         /*
5189          * When we journal data on quota file, we have to flush journal to see
5190          * all updates to the file when we bypass pagecache...
5191          */
5192         if (EXT4_SB(sb)->s_journal &&
5193             ext4_should_journal_data(path->dentry->d_inode)) {
5194                 /*
5195                  * We don't need to lock updates but journal_flush() could
5196                  * otherwise be livelocked...
5197                  */
5198                 jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
5199                 err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
5200                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
5201                 if (err)
5202                         return err;
5203         }
5204
5205         return dquot_quota_on(sb, type, format_id, path);
5206 }
5207
5208 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
5209                              unsigned int flags)
5210 {
5211         int err;
5212         struct inode *qf_inode;
5213         unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5214                 le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5215                 le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum)
5216         };
5217
5218         BUG_ON(!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA));
5219
5220         if (!qf_inums[type])
5221                 return -EPERM;
5222
5223         qf_inode = ext4_iget(sb, qf_inums[type]);
5224         if (IS_ERR(qf_inode)) {
5225                 ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
5226                 return PTR_ERR(qf_inode);
5227         }
5228
5229         /* Don't account quota for quota files to avoid recursion */
5230         qf_inode->i_flags |= S_NOQUOTA;
5231         err = dquot_enable(qf_inode, type, format_id, flags);
5232         iput(qf_inode);
5233
5234         return err;
5235 }
5236
5237 /* Enable usage tracking for all quota types. */
5238 static int ext4_enable_quotas(struct super_block *sb)
5239 {
5240         int type, err = 0;
5241         unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5242                 le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5243                 le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum)
5244         };
5245
5246         sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE;
5247         for (type = 0; type < EXT4_MAXQUOTAS; type++) {
5248                 if (qf_inums[type]) {
5249                         err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
5250                                                 DQUOT_USAGE_ENABLED);
5251                         if (err) {
5252                                 ext4_warning(sb,
5253                                         "Failed to enable quota tracking "
5254                                         "(type=%d, err=%d). Please run "
5255                                         "e2fsck to fix.", type, err);
5256                                 return err;
5257                         }
5258                 }
5259         }
5260         return 0;
5261 }
5262
5263 /*
5264  * quota_on function that is used when QUOTA feature is set.
5265  */
5266 static int ext4_quota_on_sysfile(struct super_block *sb, int type,
5267                                  int format_id)
5268 {
5269         if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
5270                 return -EINVAL;
5271
5272         /*
5273          * USAGE was enabled at mount time. Only need to enable LIMITS now.
5274          */
5275         return ext4_quota_enable(sb, type, format_id, DQUOT_LIMITS_ENABLED);
5276 }
5277
5278 static int ext4_quota_off(struct super_block *sb, int type)
5279 {
5280         struct inode *inode = sb_dqopt(sb)->files[type];
5281         handle_t *handle;
5282
5283         /* Force all delayed allocation blocks to be allocated.
5284          * Caller already holds s_umount sem */
5285         if (test_opt(sb, DELALLOC))
5286                 sync_filesystem(sb);
5287
5288         if (!inode)
5289                 goto out;
5290
5291         /* Update modification times of quota files when userspace can
5292          * start looking at them */
5293         handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5294         if (IS_ERR(handle))
5295                 goto out;
5296         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
5297         ext4_mark_inode_dirty(handle, inode);
5298         ext4_journal_stop(handle);
5299
5300 out:
5301         return dquot_quota_off(sb, type);
5302 }
5303
5304 /*
5305  * quota_off function that is used when QUOTA feature is set.
5306  */
5307 static int ext4_quota_off_sysfile(struct super_block *sb, int type)
5308 {
5309         if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
5310                 return -EINVAL;
5311
5312         /* Disable only the limits. */
5313         return dquot_disable(sb, type, DQUOT_LIMITS_ENABLED);
5314 }
5315
5316 /* Read data from quotafile - avoid pagecache and such because we cannot afford
5317  * acquiring the locks... As quota files are never truncated and quota code
5318  * itself serializes the operations (and no one else should touch the files)
5319  * we don't have to be afraid of races */
5320 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
5321                                size_t len, loff_t off)
5322 {
5323         struct inode *inode = sb_dqopt(sb)->files[type];
5324         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5325         int offset = off & (sb->s_blocksize - 1);
5326         int tocopy;
5327         size_t toread;
5328         struct buffer_head *bh;
5329         loff_t i_size = i_size_read(inode);
5330
5331         if (off > i_size)
5332                 return 0;
5333         if (off+len > i_size)
5334                 len = i_size-off;
5335         toread = len;
5336         while (toread > 0) {
5337                 tocopy = sb->s_blocksize - offset < toread ?
5338                                 sb->s_blocksize - offset : toread;
5339                 bh = ext4_bread(NULL, inode, blk, 0);
5340                 if (IS_ERR(bh))
5341                         return PTR_ERR(bh);
5342                 if (!bh)        /* A hole? */
5343                         memset(data, 0, tocopy);
5344                 else
5345                         memcpy(data, bh->b_data+offset, tocopy);
5346                 brelse(bh);
5347                 offset = 0;
5348                 toread -= tocopy;
5349                 data += tocopy;
5350                 blk++;
5351         }
5352         return len;
5353 }
5354
5355 /* Write to quotafile (we know the transaction is already started and has
5356  * enough credits) */
5357 static ssize_t ext4_quota_write(struct super_block *sb, int type,
5358                                 const char *data, size_t len, loff_t off)
5359 {
5360         struct inode *inode = sb_dqopt(sb)->files[type];
5361         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5362         int err, offset = off & (sb->s_blocksize - 1);
5363         struct buffer_head *bh;
5364         handle_t *handle = journal_current_handle();
5365
5366         if (EXT4_SB(sb)->s_journal && !handle) {
5367                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5368                         " cancelled because transaction is not started",
5369                         (unsigned long long)off, (unsigned long long)len);
5370                 return -EIO;
5371         }
5372         /*
5373          * Since we account only one data block in transaction credits,
5374          * then it is impossible to cross a block boundary.
5375          */
5376         if (sb->s_blocksize - offset < len) {
5377                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5378                         " cancelled because not block aligned",
5379                         (unsigned long long)off, (unsigned long long)len);
5380                 return -EIO;
5381         }
5382
5383         bh = ext4_bread(handle, inode, blk, 1);
5384         if (IS_ERR(bh))
5385                 return PTR_ERR(bh);
5386         if (!bh)
5387                 goto out;
5388         BUFFER_TRACE(bh, "get write access");
5389         err = ext4_journal_get_write_access(handle, bh);
5390         if (err) {
5391                 brelse(bh);
5392                 return err;
5393         }
5394         lock_buffer(bh);
5395         memcpy(bh->b_data+offset, data, len);
5396         flush_dcache_page(bh->b_page);
5397         unlock_buffer(bh);
5398         err = ext4_handle_dirty_metadata(handle, NULL, bh);
5399         brelse(bh);
5400 out:
5401         if (inode->i_size < off + len) {
5402                 i_size_write(inode, off + len);
5403                 EXT4_I(inode)->i_disksize = inode->i_size;
5404                 ext4_mark_inode_dirty(handle, inode);
5405         }
5406         return len;
5407 }
5408
5409 #endif
5410
5411 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
5412                        const char *dev_name, void *data)
5413 {
5414         return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
5415 }
5416
5417 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
5418 static inline void register_as_ext2(void)
5419 {
5420         int err = register_filesystem(&ext2_fs_type);
5421         if (err)
5422                 printk(KERN_WARNING
5423                        "EXT4-fs: Unable to register as ext2 (%d)\n", err);
5424 }
5425
5426 static inline void unregister_as_ext2(void)
5427 {
5428         unregister_filesystem(&ext2_fs_type);
5429 }
5430
5431 static inline int ext2_feature_set_ok(struct super_block *sb)
5432 {
5433         if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP))
5434                 return 0;
5435         if (sb->s_flags & MS_RDONLY)
5436                 return 1;
5437         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))
5438                 return 0;
5439         return 1;
5440 }
5441 #else
5442 static inline void register_as_ext2(void) { }
5443 static inline void unregister_as_ext2(void) { }
5444 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
5445 #endif
5446
5447 #if !defined(CONFIG_EXT3_FS) && !defined(CONFIG_EXT3_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
5448 static inline void register_as_ext3(void)
5449 {
5450         int err = register_filesystem(&ext3_fs_type);
5451         if (err)
5452                 printk(KERN_WARNING
5453                        "EXT4-fs: Unable to register as ext3 (%d)\n", err);
5454 }
5455
5456 static inline void unregister_as_ext3(void)
5457 {
5458         unregister_filesystem(&ext3_fs_type);
5459 }
5460
5461 static inline int ext3_feature_set_ok(struct super_block *sb)
5462 {
5463         if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT3_FEATURE_INCOMPAT_SUPP))
5464                 return 0;
5465         if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
5466                 return 0;
5467         if (sb->s_flags & MS_RDONLY)
5468                 return 1;
5469         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT3_FEATURE_RO_COMPAT_SUPP))
5470                 return 0;
5471         return 1;
5472 }
5473 #else
5474 static inline void register_as_ext3(void) { }
5475 static inline void unregister_as_ext3(void) { }
5476 static inline int ext3_feature_set_ok(struct super_block *sb) { return 0; }
5477 #endif
5478
5479 static struct file_system_type ext4_fs_type = {
5480         .owner          = THIS_MODULE,
5481         .name           = "ext4",
5482         .mount          = ext4_mount,
5483         .kill_sb        = kill_block_super,
5484         .fs_flags       = FS_REQUIRES_DEV,
5485 };
5486 MODULE_ALIAS_FS("ext4");
5487
5488 static int __init ext4_init_feat_adverts(void)
5489 {
5490         struct ext4_features *ef;
5491         int ret = -ENOMEM;
5492
5493         ef = kzalloc(sizeof(struct ext4_features), GFP_KERNEL);
5494         if (!ef)
5495                 goto out;
5496
5497         ef->f_kobj.kset = ext4_kset;
5498         init_completion(&ef->f_kobj_unregister);
5499         ret = kobject_init_and_add(&ef->f_kobj, &ext4_feat_ktype, NULL,
5500                                    "features");
5501         if (ret) {
5502                 kfree(ef);
5503                 goto out;
5504         }
5505
5506         ext4_feat = ef;
5507         ret = 0;
5508 out:
5509         return ret;
5510 }
5511
5512 static void ext4_exit_feat_adverts(void)
5513 {
5514         kobject_put(&ext4_feat->f_kobj);
5515         wait_for_completion(&ext4_feat->f_kobj_unregister);
5516         kfree(ext4_feat);
5517 }
5518
5519 /* Shared across all ext4 file systems */
5520 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
5521 struct mutex ext4__aio_mutex[EXT4_WQ_HASH_SZ];
5522
5523 static int __init ext4_init_fs(void)
5524 {
5525         int i, err;
5526
5527         ext4_li_info = NULL;
5528         mutex_init(&ext4_li_mtx);
5529
5530         /* Build-time check for flags consistency */
5531         ext4_check_flag_values();
5532
5533         for (i = 0; i < EXT4_WQ_HASH_SZ; i++) {
5534                 mutex_init(&ext4__aio_mutex[i]);
5535                 init_waitqueue_head(&ext4__ioend_wq[i]);
5536         }
5537
5538         err = ext4_init_es();
5539         if (err)
5540                 return err;
5541
5542         err = ext4_init_pageio();
5543         if (err)
5544                 goto out7;
5545
5546         err = ext4_init_system_zone();
5547         if (err)
5548                 goto out6;
5549         ext4_kset = kset_create_and_add("ext4", NULL, fs_kobj);
5550         if (!ext4_kset) {
5551                 err = -ENOMEM;
5552                 goto out5;
5553         }
5554         ext4_proc_root = proc_mkdir("fs/ext4", NULL);
5555
5556         err = ext4_init_feat_adverts();
5557         if (err)
5558                 goto out4;
5559
5560         err = ext4_init_mballoc();
5561         if (err)
5562                 goto out2;
5563         else
5564                 ext4_mballoc_ready = 1;
5565         err = init_inodecache();
5566         if (err)
5567                 goto out1;
5568         register_as_ext3();
5569         register_as_ext2();
5570         err = register_filesystem(&ext4_fs_type);
5571         if (err)
5572                 goto out;
5573
5574         return 0;
5575 out:
5576         unregister_as_ext2();
5577         unregister_as_ext3();
5578         destroy_inodecache();
5579 out1:
5580         ext4_mballoc_ready = 0;
5581         ext4_exit_mballoc();
5582 out2:
5583         ext4_exit_feat_adverts();
5584 out4:
5585         if (ext4_proc_root)
5586                 remove_proc_entry("fs/ext4", NULL);
5587         kset_unregister(ext4_kset);
5588 out5:
5589         ext4_exit_system_zone();
5590 out6:
5591         ext4_exit_pageio();
5592 out7:
5593         ext4_exit_es();
5594
5595         return err;
5596 }
5597
5598 static void __exit ext4_exit_fs(void)
5599 {
5600         ext4_destroy_lazyinit_thread();
5601         unregister_as_ext2();
5602         unregister_as_ext3();
5603         unregister_filesystem(&ext4_fs_type);
5604         destroy_inodecache();
5605         ext4_exit_mballoc();
5606         ext4_exit_feat_adverts();
5607         remove_proc_entry("fs/ext4", NULL);
5608         kset_unregister(ext4_kset);
5609         ext4_exit_system_zone();
5610         ext4_exit_pageio();
5611         ext4_exit_es();
5612 }
5613
5614 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
5615 MODULE_DESCRIPTION("Fourth Extended Filesystem");
5616 MODULE_LICENSE("GPL");
5617 module_init(ext4_init_fs)
5618 module_exit(ext4_exit_fs)