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 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
 180                                struct ext4_group_desc *bg)
 181 {
 182         return le32_to_cpu(bg->bg_block_bitmap_lo) |
 183                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 184                  (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
 185 }
 186
 187 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
 188                                struct ext4_group_desc *bg)
 189 {
 190         return le32_to_cpu(bg->bg_inode_bitmap_lo) |
 191                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 192                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
 193 }
 194
 195 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
 196                               struct ext4_group_desc *bg)
 197 {
 198         return le32_to_cpu(bg->bg_inode_table_lo) |
 199                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 200                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
 201 }
 202
 203 __u32 ext4_free_group_clusters(struct super_block *sb,
 204                                struct ext4_group_desc *bg)
 205 {
 206         return le16_to_cpu(bg->bg_free_blocks_count_lo) |
 207                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 208                  (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
 209 }
 210
 211 __u32 ext4_free_inodes_count(struct super_block *sb,
 212                               struct ext4_group_desc *bg)
 213 {
 214         return le16_to_cpu(bg->bg_free_inodes_count_lo) |
 215                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 216                  (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
 217 }
 218
 219 __u32 ext4_used_dirs_count(struct super_block *sb,
 220                               struct ext4_group_desc *bg)
 221 {
 222         return le16_to_cpu(bg->bg_used_dirs_count_lo) |
 223                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 224                  (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
 225 }
 226
 227 __u32 ext4_itable_unused_count(struct super_block *sb,
 228                               struct ext4_group_desc *bg)
 229 {
 230         return le16_to_cpu(bg->bg_itable_unused_lo) |
 231                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 232                  (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
 233 }
 234
 235 void ext4_block_bitmap_set(struct super_block *sb,
 236                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 237 {
 238         bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
 239         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 240                 bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
 241 }
 242
 243 void ext4_inode_bitmap_set(struct super_block *sb,
 244                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 245 {
 246         bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
 247         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 248                 bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
 249 }
 250
 251 void ext4_inode_table_set(struct super_block *sb,
 252                           struct ext4_group_desc *bg, ext4_fsblk_t blk)
 253 {
 254         bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
 255         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 256                 bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
 257 }
 258
 259 void ext4_free_group_clusters_set(struct super_block *sb,
 260                                   struct ext4_group_desc *bg, __u32 count)
 261 {
 262         bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
 263         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 264                 bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
 265 }
 266
 267 void ext4_free_inodes_set(struct super_block *sb,
 268                           struct ext4_group_desc *bg, __u32 count)
 269 {
 270         bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
 271         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 272                 bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
 273 }
 274
 275 void ext4_used_dirs_set(struct super_block *sb,
 276                           struct ext4_group_desc *bg, __u32 count)
 277 {
 278         bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
 279         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 280                 bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
 281 }
 282
 283 void ext4_itable_unused_set(struct super_block *sb,
 284                           struct ext4_group_desc *bg, __u32 count)
 285 {
 286         bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
 287         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 288                 bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
 289 }
 290
 291
 292 static void __save_error_info(struct super_block *sb, const char *func,
 293                             unsigned int line)
 294 {
 295         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 296
 297         EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
 298         es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
 299         es->s_last_error_time = cpu_to_le32(get_seconds());
 300         strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
 301         es->s_last_error_line = cpu_to_le32(line);
 302         if (!es->s_first_error_time) {
 303                 es->s_first_error_time = es->s_last_error_time;
 304                 strncpy(es->s_first_error_func, func,
 305                         sizeof(es->s_first_error_func));
 306                 es->s_first_error_line = cpu_to_le32(line);
 307                 es->s_first_error_ino = es->s_last_error_ino;
 308                 es->s_first_error_block = es->s_last_error_block;
 309         }
 310         /*
 311          * Start the daily error reporting function if it hasn't been
 312          * started already
 313          */
 314         if (!es->s_error_count)
 315                 mod_timer(&EXT4_SB(sb)->s_err_report, jiffies + 24*60*60*HZ);
 316         le32_add_cpu(&es->s_error_count, 1);
 317 }
 318
 319 static void save_error_info(struct super_block *sb, const char *func,
 320                             unsigned int line)
 321 {
 322         __save_error_info(sb, func, line);
 323         ext4_commit_super(sb, 1);
 324 }
 325
 326 /*
 327  * The del_gendisk() function uninitializes the disk-specific data
 328  * structures, including the bdi structure, without telling anyone
 329  * else.  Once this happens, any attempt to call mark_buffer_dirty()
 330  * (for example, by ext4_commit_super), will cause a kernel OOPS.
 331  * This is a kludge to prevent these oops until we can put in a proper
 332  * hook in del_gendisk() to inform the VFS and file system layers.
 333  */
 334 static int block_device_ejected(struct super_block *sb)
 335 {
 336         struct inode *bd_inode = sb->s_bdev->bd_inode;
 337         struct backing_dev_info *bdi = inode_to_bdi(bd_inode);
 338
 339         return bdi->dev == NULL;
 340 }
 341
 342 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
 343 {
 344         struct super_block              *sb = journal->j_private;
 345         struct ext4_sb_info             *sbi = EXT4_SB(sb);
 346         int                             error = is_journal_aborted(journal);
 347         struct ext4_journal_cb_entry    *jce;
 348
 349         BUG_ON(txn->t_state == T_FINISHED);
 350         spin_lock(&sbi->s_md_lock);
 351         while (!list_empty(&txn->t_private_list)) {
 352                 jce = list_entry(txn->t_private_list.next,
 353                                  struct ext4_journal_cb_entry, jce_list);
 354                 list_del_init(&jce->jce_list);
 355                 spin_unlock(&sbi->s_md_lock);
 356                 jce->jce_func(sb, jce, error);
 357                 spin_lock(&sbi->s_md_lock);
 358         }
 359         spin_unlock(&sbi->s_md_lock);
 360 }
 361
 362 /* Deal with the reporting of failure conditions on a filesystem such as
 363  * inconsistencies detected or read IO failures.
 364  *
 365  * On ext2, we can store the error state of the filesystem in the
 366  * superblock.  That is not possible on ext4, because we may have other
 367  * write ordering constraints on the superblock which prevent us from
 368  * writing it out straight away; and given that the journal is about to
 369  * be aborted, we can't rely on the current, or future, transactions to
 370  * write out the superblock safely.
 371  *
 372  * We'll just use the jbd2_journal_abort() error code to record an error in
 373  * the journal instead.  On recovery, the journal will complain about
 374  * that error until we've noted it down and cleared it.
 375  */
 376
 377 static void ext4_handle_error(struct super_block *sb)
 378 {
 379         if (sb->s_flags & MS_RDONLY)
 380                 return;
 381
 382         if (!test_opt(sb, ERRORS_CONT)) {
 383                 journal_t *journal = EXT4_SB(sb)->s_journal;
 384
 385                 EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
 386                 if (journal)
 387                         jbd2_journal_abort(journal, -EIO);
 388         }
 389         if (test_opt(sb, ERRORS_RO)) {
 390                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 391                 /*
 392                  * Make sure updated value of ->s_mount_flags will be visible
 393                  * before ->s_flags update
 394                  */
 395                 smp_wmb();
 396                 sb->s_flags |= MS_RDONLY;
 397         }
 398         if (test_opt(sb, ERRORS_PANIC))
 399                 panic("EXT4-fs (device %s): panic forced after error\n",
 400                         sb->s_id);
 401 }
 402
 403 #define ext4_error_ratelimit(sb)                                        \
 404                 ___ratelimit(&(EXT4_SB(sb)->s_err_ratelimit_state),     \
 405                              "EXT4-fs error")
 406
 407 void __ext4_error(struct super_block *sb, const char *function,
 408                   unsigned int line, const char *fmt, ...)
 409 {
 410         struct va_format vaf;
 411         va_list args;
 412
 413         if (ext4_error_ratelimit(sb)) {
 414                 va_start(args, fmt);
 415                 vaf.fmt = fmt;
 416                 vaf.va = &args;
 417                 printk(KERN_CRIT
 418                        "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
 419                        sb->s_id, function, line, current->comm, &vaf);
 420                 va_end(args);
 421         }
 422         save_error_info(sb, function, line);
 423         ext4_handle_error(sb);
 424 }
 425
 426 void __ext4_error_inode(struct inode *inode, const char *function,
 427                         unsigned int line, ext4_fsblk_t block,
 428                         const char *fmt, ...)
 429 {
 430         va_list args;
 431         struct va_format vaf;
 432         struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
 433
 434         es->s_last_error_ino = cpu_to_le32(inode->i_ino);
 435         es->s_last_error_block = cpu_to_le64(block);
 436         if (ext4_error_ratelimit(inode->i_sb)) {
 437                 va_start(args, fmt);
 438                 vaf.fmt = fmt;
 439                 vaf.va = &args;
 440                 if (block)
 441                         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
 442                                "inode #%lu: block %llu: comm %s: %pV\n",
 443                                inode->i_sb->s_id, function, line, inode->i_ino,
 444                                block, current->comm, &vaf);
 445                 else
 446                         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
 447                                "inode #%lu: comm %s: %pV\n",
 448                                inode->i_sb->s_id, function, line, inode->i_ino,
 449                                current->comm, &vaf);
 450                 va_end(args);
 451         }
 452         save_error_info(inode->i_sb, function, line);
 453         ext4_handle_error(inode->i_sb);
 454 }
 455
 456 void __ext4_error_file(struct file *file, const char *function,
 457                        unsigned int line, ext4_fsblk_t block,
 458                        const char *fmt, ...)
 459 {
 460         va_list args;
 461         struct va_format vaf;
 462         struct ext4_super_block *es;
 463         struct inode *inode = file_inode(file);
 464         char pathname[80], *path;
 465
 466         es = EXT4_SB(inode->i_sb)->s_es;
 467         es->s_last_error_ino = cpu_to_le32(inode->i_ino);
 468         if (ext4_error_ratelimit(inode->i_sb)) {
 469                 path = d_path(&(file->f_path), pathname, sizeof(pathname));
 470                 if (IS_ERR(path))
 471                         path = "(unknown)";
 472                 va_start(args, fmt);
 473                 vaf.fmt = fmt;
 474                 vaf.va = &args;
 475                 if (block)
 476                         printk(KERN_CRIT
 477                                "EXT4-fs error (device %s): %s:%d: inode #%lu: "
 478                                "block %llu: comm %s: path %s: %pV\n",
 479                                inode->i_sb->s_id, function, line, inode->i_ino,
 480                                block, current->comm, path, &vaf);
 481                 else
 482                         printk(KERN_CRIT
 483                                "EXT4-fs error (device %s): %s:%d: inode #%lu: "
 484                                "comm %s: path %s: %pV\n",
 485                                inode->i_sb->s_id, function, line, inode->i_ino,
 486                                current->comm, path, &vaf);
 487                 va_end(args);
 488         }
 489         save_error_info(inode->i_sb, function, line);
 490         ext4_handle_error(inode->i_sb);
 491 }
 492
 493 const char *ext4_decode_error(struct super_block *sb, int errno,
 494                               char nbuf[16])
 495 {
 496         char *errstr = NULL;
 497
 498         switch (errno) {
 499         case -EIO:
 500                 errstr = "IO failure";
 501                 break;
 502         case -ENOMEM:
 503                 errstr = "Out of memory";
 504                 break;
 505         case -EROFS:
 506                 if (!sb || (EXT4_SB(sb)->s_journal &&
 507                             EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
 508                         errstr = "Journal has aborted";
 509                 else
 510                         errstr = "Readonly filesystem";
 511                 break;
 512         default:
 513                 /* If the caller passed in an extra buffer for unknown
 514                  * errors, textualise them now.  Else we just return
 515                  * NULL. */
 516                 if (nbuf) {
 517                         /* Check for truncated error codes... */
 518                         if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
 519                                 errstr = nbuf;
 520                 }
 521                 break;
 522         }
 523
 524         return errstr;
 525 }
 526
 527 /* __ext4_std_error decodes expected errors from journaling functions
 528  * automatically and invokes the appropriate error response.  */
 529
 530 void __ext4_std_error(struct super_block *sb, const char *function,
 531                       unsigned int line, int errno)
 532 {
 533         char nbuf[16];
 534         const char *errstr;
 535
 536         /* Special case: if the error is EROFS, and we're not already
 537          * inside a transaction, then there's really no point in logging
 538          * an error. */
 539         if (errno == -EROFS && journal_current_handle() == NULL &&
 540             (sb->s_flags & MS_RDONLY))
 541                 return;
 542
 543         if (ext4_error_ratelimit(sb)) {
 544                 errstr = ext4_decode_error(sb, errno, nbuf);
 545                 printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
 546                        sb->s_id, function, line, errstr);
 547         }
 548
 549         save_error_info(sb, function, line);
 550         ext4_handle_error(sb);
 551 }
 552
 553 /*
 554  * ext4_abort is a much stronger failure handler than ext4_error.  The
 555  * abort function may be used to deal with unrecoverable failures such
 556  * as journal IO errors or ENOMEM at a critical moment in log management.
 557  *
 558  * We unconditionally force the filesystem into an ABORT|READONLY state,
 559  * unless the error response on the fs has been set to panic in which
 560  * case we take the easy way out and panic immediately.
 561  */
 562
 563 void __ext4_abort(struct super_block *sb, const char *function,
 564                 unsigned int line, const char *fmt, ...)
 565 {
 566         va_list args;
 567
 568         save_error_info(sb, function, line);
 569         va_start(args, fmt);
 570         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: ", sb->s_id,
 571                function, line);
 572         vprintk(fmt, args);
 573         printk("\n");
 574         va_end(args);
 575
 576         if ((sb->s_flags & MS_RDONLY) == 0) {
 577                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 578                 EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
 579                 /*
 580                  * Make sure updated value of ->s_mount_flags will be visible
 581                  * before ->s_flags update
 582                  */
 583                 smp_wmb();
 584                 sb->s_flags |= MS_RDONLY;
 585                 if (EXT4_SB(sb)->s_journal)
 586                         jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
 587                 save_error_info(sb, function, line);
 588         }
 589         if (test_opt(sb, ERRORS_PANIC))
 590                 panic("EXT4-fs panic from previous error\n");
 591 }
 592
 593 void __ext4_msg(struct super_block *sb,
 594                 const char *prefix, const char *fmt, ...)
 595 {
 596         struct va_format vaf;
 597         va_list args;
 598
 599         if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state), "EXT4-fs"))
 600                 return;
 601
 602         va_start(args, fmt);
 603         vaf.fmt = fmt;
 604         vaf.va = &args;
 605         printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
 606         va_end(args);
 607 }
 608
 609 void __ext4_warning(struct super_block *sb, const char *function,
 610                     unsigned int line, const char *fmt, ...)
 611 {
 612         struct va_format vaf;
 613         va_list args;
 614
 615         if (!___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state),
 616                           "EXT4-fs warning"))
 617                 return;
 618
 619         va_start(args, fmt);
 620         vaf.fmt = fmt;
 621         vaf.va = &args;
 622         printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
 623                sb->s_id, function, line, &vaf);
 624         va_end(args);
 625 }
 626
 627 void __ext4_grp_locked_error(const char *function, unsigned int line,
 628                              struct super_block *sb, ext4_group_t grp,
 629                              unsigned long ino, ext4_fsblk_t block,
 630                              const char *fmt, ...)
 631 __releases(bitlock)
 632 __acquires(bitlock)
 633 {
 634         struct va_format vaf;
 635         va_list args;
 636         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 637
 638         es->s_last_error_ino = cpu_to_le32(ino);
 639         es->s_last_error_block = cpu_to_le64(block);
 640         __save_error_info(sb, function, line);
 641
 642         if (ext4_error_ratelimit(sb)) {
 643                 va_start(args, fmt);
 644                 vaf.fmt = fmt;
 645                 vaf.va = &args;
 646                 printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
 647                        sb->s_id, function, line, grp);
 648                 if (ino)
 649                         printk(KERN_CONT "inode %lu: ", ino);
 650                 if (block)
 651                         printk(KERN_CONT "block %llu:",
 652                                (unsigned long long) block);
 653                 printk(KERN_CONT "%pV\n", &vaf);
 654                 va_end(args);
 655         }
 656
 657         if (test_opt(sb, ERRORS_CONT)) {
 658                 ext4_commit_super(sb, 0);
 659                 return;
 660         }
 661
 662         ext4_unlock_group(sb, grp);
 663         ext4_handle_error(sb);
 664         /*
 665          * We only get here in the ERRORS_RO case; relocking the group
 666          * may be dangerous, but nothing bad will happen since the
 667          * filesystem will have already been marked read/only and the
 668          * journal has been aborted.  We return 1 as a hint to callers
 669          * who might what to use the return value from
 670          * ext4_grp_locked_error() to distinguish between the
 671          * ERRORS_CONT and ERRORS_RO case, and perhaps return more
 672          * aggressively from the ext4 function in question, with a
 673          * more appropriate error code.
 674          */
 675         ext4_lock_group(sb, grp);
 676         return;
 677 }
 678
 679 void ext4_update_dynamic_rev(struct super_block *sb)
 680 {
 681         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 682
 683         if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
 684                 return;
 685
 686         ext4_warning(sb,
 687                      "updating to rev %d because of new feature flag, "
 688                      "running e2fsck is recommended",
 689                      EXT4_DYNAMIC_REV);
 690
 691         es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
 692         es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
 693         es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
 694         /* leave es->s_feature_*compat flags alone */
 695         /* es->s_uuid will be set by e2fsck if empty */
 696
 697         /*
 698          * The rest of the superblock fields should be zero, and if not it
 699          * means they are likely already in use, so leave them alone.  We
 700          * can leave it up to e2fsck to clean up any inconsistencies there.
 701          */
 702 }
 703
 704 /*
 705  * Open the external journal device
 706  */
 707 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
 708 {
 709         struct block_device *bdev;
 710         char b[BDEVNAME_SIZE];
 711
 712         bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
 713         if (IS_ERR(bdev))
 714                 goto fail;
 715         return bdev;
 716
 717 fail:
 718         ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
 719                         __bdevname(dev, b), PTR_ERR(bdev));
 720         return NULL;
 721 }
 722
 723 /*
 724  * Release the journal device
 725  */
 726 static void ext4_blkdev_put(struct block_device *bdev)
 727 {
 728         blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
 729 }
 730
 731 static void ext4_blkdev_remove(struct ext4_sb_info *sbi)
 732 {
 733         struct block_device *bdev;
 734         bdev = sbi->journal_bdev;
 735         if (bdev) {
 736                 ext4_blkdev_put(bdev);
 737                 sbi->journal_bdev = NULL;
 738         }
 739 }
 740
 741 static inline struct inode *orphan_list_entry(struct list_head *l)
 742 {
 743         return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
 744 }
 745
 746 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
 747 {
 748         struct list_head *l;
 749
 750         ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
 751                  le32_to_cpu(sbi->s_es->s_last_orphan));
 752
 753         printk(KERN_ERR "sb_info orphan list:\n");
 754         list_for_each(l, &sbi->s_orphan) {
 755                 struct inode *inode = orphan_list_entry(l);
 756                 printk(KERN_ERR "  "
 757                        "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
 758                        inode->i_sb->s_id, inode->i_ino, inode,
 759                        inode->i_mode, inode->i_nlink,
 760                        NEXT_ORPHAN(inode));
 761         }
 762 }
 763
 764 static void ext4_put_super(struct super_block *sb)
 765 {
 766         struct ext4_sb_info *sbi = EXT4_SB(sb);
 767         struct ext4_super_block *es = sbi->s_es;
 768         int i, err;
 769
 770         ext4_unregister_li_request(sb);
 771         dquot_disable(sb, -1, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
 772
 773         flush_workqueue(sbi->rsv_conversion_wq);
 774         destroy_workqueue(sbi->rsv_conversion_wq);
 775
 776         if (sbi->s_journal) {
 777                 err = jbd2_journal_destroy(sbi->s_journal);
 778                 sbi->s_journal = NULL;
 779                 if (err < 0)
 780                         ext4_abort(sb, "Couldn't clean up the journal");
 781         }
 782
 783         ext4_es_unregister_shrinker(sbi);
 784         del_timer_sync(&sbi->s_err_report);
 785         ext4_release_system_zone(sb);
 786         ext4_mb_release(sb);
 787         ext4_ext_release(sb);
 788         ext4_xattr_put_super(sb);
 789
 790         if (!(sb->s_flags & MS_RDONLY)) {
 791                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
 792                 es->s_state = cpu_to_le16(sbi->s_mount_state);
 793         }
 794         if (!(sb->s_flags & MS_RDONLY))
 795                 ext4_commit_super(sb, 1);
 796
 797         if (sbi->s_proc) {
 798                 remove_proc_entry("options", sbi->s_proc);
 799                 remove_proc_entry(sb->s_id, ext4_proc_root);
 800         }
 801         kobject_del(&sbi->s_kobj);
 802
 803         for (i = 0; i < sbi->s_gdb_count; i++)
 804                 brelse(sbi->s_group_desc[i]);
 805         kvfree(sbi->s_group_desc);
 806         kvfree(sbi->s_flex_groups);
 807         percpu_counter_destroy(&sbi->s_freeclusters_counter);
 808         percpu_counter_destroy(&sbi->s_freeinodes_counter);
 809         percpu_counter_destroy(&sbi->s_dirs_counter);
 810         percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
 811         brelse(sbi->s_sbh);
 812 #ifdef CONFIG_QUOTA
 813         for (i = 0; i < EXT4_MAXQUOTAS; i++)
 814                 kfree(sbi->s_qf_names[i]);
 815 #endif
 816
 817         /* Debugging code just in case the in-memory inode orphan list
 818          * isn't empty.  The on-disk one can be non-empty if we've
 819          * detected an error and taken the fs readonly, but the
 820          * in-memory list had better be clean by this point. */
 821         if (!list_empty(&sbi->s_orphan))
 822                 dump_orphan_list(sb, sbi);
 823         J_ASSERT(list_empty(&sbi->s_orphan));
 824
 825         invalidate_bdev(sb->s_bdev);
 826         if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
 827                 /*
 828                  * Invalidate the journal device's buffers.  We don't want them
 829                  * floating about in memory - the physical journal device may
 830                  * hotswapped, and it breaks the `ro-after' testing code.
 831                  */
 832                 sync_blockdev(sbi->journal_bdev);
 833                 invalidate_bdev(sbi->journal_bdev);
 834                 ext4_blkdev_remove(sbi);
 835         }
 836         if (sbi->s_mb_cache) {
 837                 ext4_xattr_destroy_cache(sbi->s_mb_cache);
 838                 sbi->s_mb_cache = NULL;
 839         }
 840         if (sbi->s_mmp_tsk)
 841                 kthread_stop(sbi->s_mmp_tsk);
 842         sb->s_fs_info = NULL;
 843         /*
 844          * Now that we are completely done shutting down the
 845          * superblock, we need to actually destroy the kobject.
 846          */
 847         kobject_put(&sbi->s_kobj);
 848         wait_for_completion(&sbi->s_kobj_unregister);
 849         if (sbi->s_chksum_driver)
 850                 crypto_free_shash(sbi->s_chksum_driver);
 851         kfree(sbi->s_blockgroup_lock);
 852         kfree(sbi);
 853 }
 854
 855 static struct kmem_cache *ext4_inode_cachep;
 856
 857 /*
 858  * Called inside transaction, so use GFP_NOFS
 859  */
 860 static struct inode *ext4_alloc_inode(struct super_block *sb)
 861 {
 862         struct ext4_inode_info *ei;
 863
 864         ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
 865         if (!ei)
 866                 return NULL;
 867
 868         ei->vfs_inode.i_version = 1;
 869         spin_lock_init(&ei->i_raw_lock);
 870         INIT_LIST_HEAD(&ei->i_prealloc_list);
 871         spin_lock_init(&ei->i_prealloc_lock);
 872         ext4_es_init_tree(&ei->i_es_tree);
 873         rwlock_init(&ei->i_es_lock);
 874         INIT_LIST_HEAD(&ei->i_es_list);
 875         ei->i_es_all_nr = 0;
 876         ei->i_es_shk_nr = 0;
 877         ei->i_es_shrink_lblk = 0;
 878         ei->i_reserved_data_blocks = 0;
 879         ei->i_reserved_meta_blocks = 0;
 880         ei->i_allocated_meta_blocks = 0;
 881         ei->i_da_metadata_calc_len = 0;
 882         ei->i_da_metadata_calc_last_lblock = 0;
 883         spin_lock_init(&(ei->i_block_reservation_lock));
 884 #ifdef CONFIG_QUOTA
 885         ei->i_reserved_quota = 0;
 886         memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
 887 #endif
 888         ei->jinode = NULL;
 889         INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
 890         spin_lock_init(&ei->i_completed_io_lock);
 891         ei->i_sync_tid = 0;
 892         ei->i_datasync_tid = 0;
 893         atomic_set(&ei->i_ioend_count, 0);
 894         atomic_set(&ei->i_unwritten, 0);
 895         INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
 896
 897         return &ei->vfs_inode;
 898 }
 899
 900 static int ext4_drop_inode(struct inode *inode)
 901 {
 902         int drop = generic_drop_inode(inode);
 903
 904         trace_ext4_drop_inode(inode, drop);
 905         return drop;
 906 }
 907
 908 static void ext4_i_callback(struct rcu_head *head)
 909 {
 910         struct inode *inode = container_of(head, struct inode, i_rcu);
 911         kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
 912 }
 913
 914 static void ext4_destroy_inode(struct inode *inode)
 915 {
 916         if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
 917                 ext4_msg(inode->i_sb, KERN_ERR,
 918                          "Inode %lu (%p): orphan list check failed!",
 919                          inode->i_ino, EXT4_I(inode));
 920                 print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
 921                                 EXT4_I(inode), sizeof(struct ext4_inode_info),
 922                                 true);
 923                 dump_stack();
 924         }
 925         call_rcu(&inode->i_rcu, ext4_i_callback);
 926 }
 927
 928 static void init_once(void *foo)
 929 {
 930         struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
 931
 932         INIT_LIST_HEAD(&ei->i_orphan);
 933         init_rwsem(&ei->xattr_sem);
 934         init_rwsem(&ei->i_data_sem);
 935         inode_init_once(&ei->vfs_inode);
 936 }
 937
 938 static int __init init_inodecache(void)
 939 {
 940         ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
 941                                              sizeof(struct ext4_inode_info),
 942                                              0, (SLAB_RECLAIM_ACCOUNT|
 943                                                 SLAB_MEM_SPREAD),
 944                                              init_once);
 945         if (ext4_inode_cachep == NULL)
 946                 return -ENOMEM;
 947         return 0;
 948 }
 949
 950 static void destroy_inodecache(void)
 951 {
 952         /*
 953          * Make sure all delayed rcu free inodes are flushed before we
 954          * destroy cache.
 955          */
 956         rcu_barrier();
 957         kmem_cache_destroy(ext4_inode_cachep);
 958 }
 959
 960 void ext4_clear_inode(struct inode *inode)
 961 {
 962         invalidate_inode_buffers(inode);
 963         clear_inode(inode);
 964         dquot_drop(inode);
 965         ext4_discard_preallocations(inode);
 966         ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
 967         if (EXT4_I(inode)->jinode) {
 968                 jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
 969                                                EXT4_I(inode)->jinode);
 970                 jbd2_free_inode(EXT4_I(inode)->jinode);
 971                 EXT4_I(inode)->jinode = NULL;
 972         }
 973 }
 974
 975 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
 976                                         u64 ino, u32 generation)
 977 {
 978         struct inode *inode;
 979
 980         if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
 981                 return ERR_PTR(-ESTALE);
 982         if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
 983                 return ERR_PTR(-ESTALE);
 984
 985         /* iget isn't really right if the inode is currently unallocated!!
 986          *
 987          * ext4_read_inode will return a bad_inode if the inode had been
 988          * deleted, so we should be safe.
 989          *
 990          * Currently we don't know the generation for parent directory, so
 991          * a generation of 0 means "accept any"
 992          */
 993         inode = ext4_iget_normal(sb, ino);
 994         if (IS_ERR(inode))
 995                 return ERR_CAST(inode);
 996         if (generation && inode->i_generation != generation) {
 997                 iput(inode);
 998                 return ERR_PTR(-ESTALE);
 999         }
1000
1001         return inode;
1002 }
1003
1004 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1005                                         int fh_len, int fh_type)
1006 {
1007         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1008                                     ext4_nfs_get_inode);
1009 }
1010
1011 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1012                                         int fh_len, int fh_type)
1013 {
1014         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1015                                     ext4_nfs_get_inode);
1016 }
1017
1018 /*
1019  * Try to release metadata pages (indirect blocks, directories) which are
1020  * mapped via the block device.  Since these pages could have journal heads
1021  * which would prevent try_to_free_buffers() from freeing them, we must use
1022  * jbd2 layer's try_to_free_buffers() function to release them.
1023  */
1024 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1025                                  gfp_t wait)
1026 {
1027         journal_t *journal = EXT4_SB(sb)->s_journal;
1028
1029         WARN_ON(PageChecked(page));
1030         if (!page_has_buffers(page))
1031                 return 0;
1032         if (journal)
1033                 return jbd2_journal_try_to_free_buffers(journal, page,
1034                                                         wait & ~__GFP_WAIT);
1035         return try_to_free_buffers(page);
1036 }
1037
1038 #ifdef CONFIG_QUOTA
1039 #define QTYPE2NAME(t) ((t) == USRQUOTA ? "user" : "group")
1040 #define QTYPE2MOPT(on, t) ((t) == USRQUOTA?((on)##USRJQUOTA):((on)##GRPJQUOTA))
1041
1042 static int ext4_write_dquot(struct dquot *dquot);
1043 static int ext4_acquire_dquot(struct dquot *dquot);
1044 static int ext4_release_dquot(struct dquot *dquot);
1045 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1046 static int ext4_write_info(struct super_block *sb, int type);
1047 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1048                          struct path *path);
1049 static int ext4_quota_off(struct super_block *sb, int type);
1050 static int ext4_quota_on_mount(struct super_block *sb, int type);
1051 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1052                                size_t len, loff_t off);
1053 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1054                                 const char *data, size_t len, loff_t off);
1055 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1056                              unsigned int flags);
1057 static int ext4_enable_quotas(struct super_block *sb);
1058
1059 static struct dquot **ext4_get_dquots(struct inode *inode)
1060 {
1061         return EXT4_I(inode)->i_dquot;
1062 }
1063
1064 static const struct dquot_operations ext4_quota_operations = {
1065         .get_reserved_space = ext4_get_reserved_space,
1066         .write_dquot    = ext4_write_dquot,
1067         .acquire_dquot  = ext4_acquire_dquot,
1068         .release_dquot  = ext4_release_dquot,
1069         .mark_dirty     = ext4_mark_dquot_dirty,
1070         .write_info     = ext4_write_info,
1071         .alloc_dquot    = dquot_alloc,
1072         .destroy_dquot  = dquot_destroy,
1073 };
1074
1075 static const struct quotactl_ops ext4_qctl_operations = {
1076         .quota_on       = ext4_quota_on,
1077         .quota_off      = ext4_quota_off,
1078         .quota_sync     = dquot_quota_sync,
1079         .get_info       = dquot_get_dqinfo,
1080         .set_info       = dquot_set_dqinfo,
1081         .get_dqblk      = dquot_get_dqblk,
1082         .set_dqblk      = dquot_set_dqblk
1083 };
1084 #endif
1085
1086 static const struct super_operations ext4_sops = {
1087         .alloc_inode    = ext4_alloc_inode,
1088         .destroy_inode  = ext4_destroy_inode,
1089         .write_inode    = ext4_write_inode,
1090         .dirty_inode    = ext4_dirty_inode,
1091         .drop_inode     = ext4_drop_inode,
1092         .evict_inode    = ext4_evict_inode,
1093         .put_super      = ext4_put_super,
1094         .sync_fs        = ext4_sync_fs,
1095         .freeze_fs      = ext4_freeze,
1096         .unfreeze_fs    = ext4_unfreeze,
1097         .statfs         = ext4_statfs,
1098         .remount_fs     = ext4_remount,
1099         .show_options   = ext4_show_options,
1100 #ifdef CONFIG_QUOTA
1101         .quota_read     = ext4_quota_read,
1102         .quota_write    = ext4_quota_write,
1103         .get_dquots     = ext4_get_dquots,
1104 #endif
1105         .bdev_try_to_free_page = bdev_try_to_free_page,
1106 };
1107
1108 static const struct export_operations ext4_export_ops = {
1109         .fh_to_dentry = ext4_fh_to_dentry,
1110         .fh_to_parent = ext4_fh_to_parent,
1111         .get_parent = ext4_get_parent,
1112 };
1113
1114 enum {
1115         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1116         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1117         Opt_nouid32, Opt_debug, Opt_removed,
1118         Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1119         Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1120         Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1121         Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1122         Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1123         Opt_data_err_abort, Opt_data_err_ignore,
1124         Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1125         Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1126         Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1127         Opt_usrquota, Opt_grpquota, Opt_i_version,
1128         Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_mblk_io_submit,
1129         Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1130         Opt_inode_readahead_blks, Opt_journal_ioprio,
1131         Opt_dioread_nolock, Opt_dioread_lock,
1132         Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1133         Opt_max_dir_size_kb, Opt_nojournal_checksum,
1134 };
1135
1136 static const match_table_t tokens = {
1137         {Opt_bsd_df, "bsddf"},
1138         {Opt_minix_df, "minixdf"},
1139         {Opt_grpid, "grpid"},
1140         {Opt_grpid, "bsdgroups"},
1141         {Opt_nogrpid, "nogrpid"},
1142         {Opt_nogrpid, "sysvgroups"},
1143         {Opt_resgid, "resgid=%u"},
1144         {Opt_resuid, "resuid=%u"},
1145         {Opt_sb, "sb=%u"},
1146         {Opt_err_cont, "errors=continue"},
1147         {Opt_err_panic, "errors=panic"},
1148         {Opt_err_ro, "errors=remount-ro"},
1149         {Opt_nouid32, "nouid32"},
1150         {Opt_debug, "debug"},
1151         {Opt_removed, "oldalloc"},
1152         {Opt_removed, "orlov"},
1153         {Opt_user_xattr, "user_xattr"},
1154         {Opt_nouser_xattr, "nouser_xattr"},
1155         {Opt_acl, "acl"},
1156         {Opt_noacl, "noacl"},
1157         {Opt_noload, "norecovery"},
1158         {Opt_noload, "noload"},
1159         {Opt_removed, "nobh"},
1160         {Opt_removed, "bh"},
1161         {Opt_commit, "commit=%u"},
1162         {Opt_min_batch_time, "min_batch_time=%u"},
1163         {Opt_max_batch_time, "max_batch_time=%u"},
1164         {Opt_journal_dev, "journal_dev=%u"},
1165         {Opt_journal_path, "journal_path=%s"},
1166         {Opt_journal_checksum, "journal_checksum"},
1167         {Opt_nojournal_checksum, "nojournal_checksum"},
1168         {Opt_journal_async_commit, "journal_async_commit"},
1169         {Opt_abort, "abort"},
1170         {Opt_data_journal, "data=journal"},
1171         {Opt_data_ordered, "data=ordered"},
1172         {Opt_data_writeback, "data=writeback"},
1173         {Opt_data_err_abort, "data_err=abort"},
1174         {Opt_data_err_ignore, "data_err=ignore"},
1175         {Opt_offusrjquota, "usrjquota="},
1176         {Opt_usrjquota, "usrjquota=%s"},
1177         {Opt_offgrpjquota, "grpjquota="},
1178         {Opt_grpjquota, "grpjquota=%s"},
1179         {Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1180         {Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1181         {Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1182         {Opt_grpquota, "grpquota"},
1183         {Opt_noquota, "noquota"},
1184         {Opt_quota, "quota"},
1185         {Opt_usrquota, "usrquota"},
1186         {Opt_barrier, "barrier=%u"},
1187         {Opt_barrier, "barrier"},
1188         {Opt_nobarrier, "nobarrier"},
1189         {Opt_i_version, "i_version"},
1190         {Opt_stripe, "stripe=%u"},
1191         {Opt_delalloc, "delalloc"},
1192         {Opt_nodelalloc, "nodelalloc"},
1193         {Opt_removed, "mblk_io_submit"},
1194         {Opt_removed, "nomblk_io_submit"},
1195         {Opt_block_validity, "block_validity"},
1196         {Opt_noblock_validity, "noblock_validity"},
1197         {Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1198         {Opt_journal_ioprio, "journal_ioprio=%u"},
1199         {Opt_auto_da_alloc, "auto_da_alloc=%u"},
1200         {Opt_auto_da_alloc, "auto_da_alloc"},
1201         {Opt_noauto_da_alloc, "noauto_da_alloc"},
1202         {Opt_dioread_nolock, "dioread_nolock"},
1203         {Opt_dioread_lock, "dioread_lock"},
1204         {Opt_discard, "discard"},
1205         {Opt_nodiscard, "nodiscard"},
1206         {Opt_init_itable, "init_itable=%u"},
1207         {Opt_init_itable, "init_itable"},
1208         {Opt_noinit_itable, "noinit_itable"},
1209         {Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1210         {Opt_removed, "check=none"},    /* mount option from ext2/3 */
1211         {Opt_removed, "nocheck"},       /* mount option from ext2/3 */
1212         {Opt_removed, "reservation"},   /* mount option from ext2/3 */
1213         {Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1214         {Opt_removed, "journal=%u"},    /* mount option from ext2/3 */
1215         {Opt_err, NULL},
1216 };
1217
1218 static ext4_fsblk_t get_sb_block(void **data)
1219 {
1220         ext4_fsblk_t    sb_block;
1221         char            *options = (char *) *data;
1222
1223         if (!options || strncmp(options, "sb=", 3) != 0)
1224                 return 1;       /* Default location */
1225
1226         options += 3;
1227         /* TODO: use simple_strtoll with >32bit ext4 */
1228         sb_block = simple_strtoul(options, &options, 0);
1229         if (*options && *options != ',') {
1230                 printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1231                        (char *) *data);
1232                 return 1;
1233         }
1234         if (*options == ',')
1235                 options++;
1236         *data = (void *) options;
1237
1238         return sb_block;
1239 }
1240
1241 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1242 static char deprecated_msg[] = "Mount option \"%s\" will be removed by %s\n"
1243         "Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1244
1245 #ifdef CONFIG_QUOTA
1246 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1247 {
1248         struct ext4_sb_info *sbi = EXT4_SB(sb);
1249         char *qname;
1250         int ret = -1;
1251
1252         if (sb_any_quota_loaded(sb) &&
1253                 !sbi->s_qf_names[qtype]) {
1254                 ext4_msg(sb, KERN_ERR,
1255                         "Cannot change journaled "
1256                         "quota options when quota turned on");
1257                 return -1;
1258         }
1259         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA)) {
1260                 ext4_msg(sb, KERN_ERR, "Cannot set journaled quota options "
1261                          "when QUOTA feature is enabled");
1262                 return -1;
1263         }
1264         qname = match_strdup(args);
1265         if (!qname) {
1266                 ext4_msg(sb, KERN_ERR,
1267                         "Not enough memory for storing quotafile name");
1268                 return -1;
1269         }
1270         if (sbi->s_qf_names[qtype]) {
1271                 if (strcmp(sbi->s_qf_names[qtype], qname) == 0)
1272                         ret = 1;
1273                 else
1274                         ext4_msg(sb, KERN_ERR,
1275                                  "%s quota file already specified",
1276                                  QTYPE2NAME(qtype));
1277                 goto errout;
1278         }
1279         if (strchr(qname, '/')) {
1280                 ext4_msg(sb, KERN_ERR,
1281                         "quotafile must be on filesystem root");
1282                 goto errout;
1283         }
1284         sbi->s_qf_names[qtype] = qname;
1285         set_opt(sb, QUOTA);
1286         return 1;
1287 errout:
1288         kfree(qname);
1289         return ret;
1290 }
1291
1292 static int clear_qf_name(struct super_block *sb, int qtype)
1293 {
1294
1295         struct ext4_sb_info *sbi = EXT4_SB(sb);
1296
1297         if (sb_any_quota_loaded(sb) &&
1298                 sbi->s_qf_names[qtype]) {
1299                 ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1300                         " when quota turned on");
1301                 return -1;
1302         }
1303         kfree(sbi->s_qf_names[qtype]);
1304         sbi->s_qf_names[qtype] = NULL;
1305         return 1;
1306 }
1307 #endif
1308
1309 #define MOPT_SET        0x0001
1310 #define MOPT_CLEAR      0x0002
1311 #define MOPT_NOSUPPORT  0x0004
1312 #define MOPT_EXPLICIT   0x0008
1313 #define MOPT_CLEAR_ERR  0x0010
1314 #define MOPT_GTE0       0x0020
1315 #ifdef CONFIG_QUOTA
1316 #define MOPT_Q          0
1317 #define MOPT_QFMT       0x0040
1318 #else
1319 #define MOPT_Q          MOPT_NOSUPPORT
1320 #define MOPT_QFMT       MOPT_NOSUPPORT
1321 #endif
1322 #define MOPT_DATAJ      0x0080
1323 #define MOPT_NO_EXT2    0x0100
1324 #define MOPT_NO_EXT3    0x0200
1325 #define MOPT_EXT4_ONLY  (MOPT_NO_EXT2 | MOPT_NO_EXT3)
1326 #define MOPT_STRING     0x0400
1327
1328 static const struct mount_opts {
1329         int     token;
1330         int     mount_opt;
1331         int     flags;
1332 } ext4_mount_opts[] = {
1333         {Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1334         {Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1335         {Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1336         {Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1337         {Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1338         {Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1339         {Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1340          MOPT_EXT4_ONLY | MOPT_SET},
1341         {Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1342          MOPT_EXT4_ONLY | MOPT_CLEAR},
1343         {Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1344         {Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1345         {Opt_delalloc, EXT4_MOUNT_DELALLOC,
1346          MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1347         {Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1348          MOPT_EXT4_ONLY | MOPT_CLEAR},
1349         {Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1350          MOPT_EXT4_ONLY | MOPT_CLEAR},
1351         {Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1352          MOPT_EXT4_ONLY | MOPT_SET},
1353         {Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1354                                     EXT4_MOUNT_JOURNAL_CHECKSUM),
1355          MOPT_EXT4_ONLY | MOPT_SET},
1356         {Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1357         {Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1358         {Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1359         {Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1360         {Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
1361          MOPT_NO_EXT2 | MOPT_SET},
1362         {Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
1363          MOPT_NO_EXT2 | MOPT_CLEAR},
1364         {Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1365         {Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1366         {Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1367         {Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1368         {Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1369         {Opt_commit, 0, MOPT_GTE0},
1370         {Opt_max_batch_time, 0, MOPT_GTE0},
1371         {Opt_min_batch_time, 0, MOPT_GTE0},
1372         {Opt_inode_readahead_blks, 0, MOPT_GTE0},
1373         {Opt_init_itable, 0, MOPT_GTE0},
1374         {Opt_stripe, 0, MOPT_GTE0},
1375         {Opt_resuid, 0, MOPT_GTE0},
1376         {Opt_resgid, 0, MOPT_GTE0},
1377         {Opt_journal_dev, 0, MOPT_GTE0},
1378         {Opt_journal_path, 0, MOPT_STRING},
1379         {Opt_journal_ioprio, 0, MOPT_GTE0},
1380         {Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1381         {Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1382         {Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
1383          MOPT_NO_EXT2 | MOPT_DATAJ},
1384         {Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1385         {Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1386 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1387         {Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1388         {Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1389 #else
1390         {Opt_acl, 0, MOPT_NOSUPPORT},
1391         {Opt_noacl, 0, MOPT_NOSUPPORT},
1392 #endif
1393         {Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1394         {Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1395         {Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1396         {Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1397                                                         MOPT_SET | MOPT_Q},
1398         {Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1399                                                         MOPT_SET | MOPT_Q},
1400         {Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1401                        EXT4_MOUNT_GRPQUOTA), MOPT_CLEAR | MOPT_Q},
1402         {Opt_usrjquota, 0, MOPT_Q},
1403         {Opt_grpjquota, 0, MOPT_Q},
1404         {Opt_offusrjquota, 0, MOPT_Q},
1405         {Opt_offgrpjquota, 0, MOPT_Q},
1406         {Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1407         {Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1408         {Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1409         {Opt_max_dir_size_kb, 0, MOPT_GTE0},
1410         {Opt_err, 0, 0}
1411 };
1412
1413 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1414                             substring_t *args, unsigned long *journal_devnum,
1415                             unsigned int *journal_ioprio, int is_remount)
1416 {
1417         struct ext4_sb_info *sbi = EXT4_SB(sb);
1418         const struct mount_opts *m;
1419         kuid_t uid;
1420         kgid_t gid;
1421         int arg = 0;
1422
1423 #ifdef CONFIG_QUOTA
1424         if (token == Opt_usrjquota)
1425                 return set_qf_name(sb, USRQUOTA, &args[0]);
1426         else if (token == Opt_grpjquota)
1427                 return set_qf_name(sb, GRPQUOTA, &args[0]);
1428         else if (token == Opt_offusrjquota)
1429                 return clear_qf_name(sb, USRQUOTA);
1430         else if (token == Opt_offgrpjquota)
1431                 return clear_qf_name(sb, GRPQUOTA);
1432 #endif
1433         switch (token) {
1434         case Opt_noacl:
1435         case Opt_nouser_xattr:
1436                 ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1437                 break;
1438         case Opt_sb:
1439                 return 1;       /* handled by get_sb_block() */
1440         case Opt_removed:
1441                 ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
1442                 return 1;
1443         case Opt_abort:
1444                 sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1445                 return 1;
1446         case Opt_i_version:
1447                 sb->s_flags |= MS_I_VERSION;
1448                 return 1;
1449         }
1450
1451         for (m = ext4_mount_opts; m->token != Opt_err; m++)
1452                 if (token == m->token)
1453                         break;
1454
1455         if (m->token == Opt_err) {
1456                 ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1457                          "or missing value", opt);
1458                 return -1;
1459         }
1460
1461         if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
1462                 ext4_msg(sb, KERN_ERR,
1463                          "Mount option \"%s\" incompatible with ext2", opt);
1464                 return -1;
1465         }
1466         if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
1467                 ext4_msg(sb, KERN_ERR,
1468                          "Mount option \"%s\" incompatible with ext3", opt);
1469                 return -1;
1470         }
1471
1472         if (args->from && !(m->flags & MOPT_STRING) && match_int(args, &arg))
1473                 return -1;
1474         if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1475                 return -1;
1476         if (m->flags & MOPT_EXPLICIT)
1477                 set_opt2(sb, EXPLICIT_DELALLOC);
1478         if (m->flags & MOPT_CLEAR_ERR)
1479                 clear_opt(sb, ERRORS_MASK);
1480         if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1481                 ext4_msg(sb, KERN_ERR, "Cannot change quota "
1482                          "options when quota turned on");
1483                 return -1;
1484         }
1485
1486         if (m->flags & MOPT_NOSUPPORT) {
1487                 ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1488         } else if (token == Opt_commit) {
1489                 if (arg == 0)
1490                         arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1491                 sbi->s_commit_interval = HZ * arg;
1492         } else if (token == Opt_max_batch_time) {
1493                 sbi->s_max_batch_time = arg;
1494         } else if (token == Opt_min_batch_time) {
1495                 sbi->s_min_batch_time = arg;
1496         } else if (token == Opt_inode_readahead_blks) {
1497                 if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
1498                         ext4_msg(sb, KERN_ERR,
1499                                  "EXT4-fs: inode_readahead_blks must be "
1500                                  "0 or a power of 2 smaller than 2^31");
1501                         return -1;
1502                 }
1503                 sbi->s_inode_readahead_blks = arg;
1504         } else if (token == Opt_init_itable) {
1505                 set_opt(sb, INIT_INODE_TABLE);
1506                 if (!args->from)
1507                         arg = EXT4_DEF_LI_WAIT_MULT;
1508                 sbi->s_li_wait_mult = arg;
1509         } else if (token == Opt_max_dir_size_kb) {
1510                 sbi->s_max_dir_size_kb = arg;
1511         } else if (token == Opt_stripe) {
1512                 sbi->s_stripe = arg;
1513         } else if (token == Opt_resuid) {
1514                 uid = make_kuid(current_user_ns(), arg);
1515                 if (!uid_valid(uid)) {
1516                         ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
1517                         return -1;
1518                 }
1519                 sbi->s_resuid = uid;
1520         } else if (token == Opt_resgid) {
1521                 gid = make_kgid(current_user_ns(), arg);
1522                 if (!gid_valid(gid)) {
1523                         ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
1524                         return -1;
1525                 }
1526                 sbi->s_resgid = gid;
1527         } else if (token == Opt_journal_dev) {
1528                 if (is_remount) {
1529                         ext4_msg(sb, KERN_ERR,
1530                                  "Cannot specify journal on remount");
1531                         return -1;
1532                 }
1533                 *journal_devnum = arg;
1534         } else if (token == Opt_journal_path) {
1535                 char *journal_path;
1536                 struct inode *journal_inode;
1537                 struct path path;
1538                 int error;
1539
1540                 if (is_remount) {
1541                         ext4_msg(sb, KERN_ERR,
1542                                  "Cannot specify journal on remount");
1543                         return -1;
1544                 }
1545                 journal_path = match_strdup(&args[0]);
1546                 if (!journal_path) {
1547                         ext4_msg(sb, KERN_ERR, "error: could not dup "
1548                                 "journal device string");
1549                         return -1;
1550                 }
1551
1552                 error = kern_path(journal_path, LOOKUP_FOLLOW, &path);
1553                 if (error) {
1554                         ext4_msg(sb, KERN_ERR, "error: could not find "
1555                                 "journal device path: error %d", error);
1556                         kfree(journal_path);
1557                         return -1;
1558                 }
1559
1560                 journal_inode = path.dentry->d_inode;
1561                 if (!S_ISBLK(journal_inode->i_mode)) {
1562                         ext4_msg(sb, KERN_ERR, "error: journal path %s "
1563                                 "is not a block device", journal_path);
1564                         path_put(&path);
1565                         kfree(journal_path);
1566                         return -1;
1567                 }
1568
1569                 *journal_devnum = new_encode_dev(journal_inode->i_rdev);
1570                 path_put(&path);
1571                 kfree(journal_path);
1572         } else if (token == Opt_journal_ioprio) {
1573                 if (arg > 7) {
1574                         ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
1575                                  " (must be 0-7)");
1576                         return -1;
1577                 }
1578                 *journal_ioprio =
1579                         IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
1580         } else if (m->flags & MOPT_DATAJ) {
1581                 if (is_remount) {
1582                         if (!sbi->s_journal)
1583                                 ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
1584                         else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
1585                                 ext4_msg(sb, KERN_ERR,
1586                                          "Cannot change data mode on remount");
1587                                 return -1;
1588                         }
1589                 } else {
1590                         clear_opt(sb, DATA_FLAGS);
1591                         sbi->s_mount_opt |= m->mount_opt;
1592                 }
1593 #ifdef CONFIG_QUOTA
1594         } else if (m->flags & MOPT_QFMT) {
1595                 if (sb_any_quota_loaded(sb) &&
1596                     sbi->s_jquota_fmt != m->mount_opt) {
1597                         ext4_msg(sb, KERN_ERR, "Cannot change journaled "
1598                                  "quota options when quota turned on");
1599                         return -1;
1600                 }
1601                 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
1602                                                EXT4_FEATURE_RO_COMPAT_QUOTA)) {
1603                         ext4_msg(sb, KERN_ERR,
1604                                  "Cannot set journaled quota options "
1605                                  "when QUOTA feature is enabled");
1606                         return -1;
1607                 }
1608                 sbi->s_jquota_fmt = m->mount_opt;
1609 #endif
1610         } else {
1611                 if (!args->from)
1612                         arg = 1;
1613                 if (m->flags & MOPT_CLEAR)
1614                         arg = !arg;
1615                 else if (unlikely(!(m->flags & MOPT_SET))) {
1616                         ext4_msg(sb, KERN_WARNING,
1617                                  "buggy handling of option %s", opt);
1618                         WARN_ON(1);
1619                         return -1;
1620                 }
1621                 if (arg != 0)
1622                         sbi->s_mount_opt |= m->mount_opt;
1623                 else
1624                         sbi->s_mount_opt &= ~m->mount_opt;
1625         }
1626         return 1;
1627 }
1628
1629 static int parse_options(char *options, struct super_block *sb,
1630                          unsigned long *journal_devnum,
1631                          unsigned int *journal_ioprio,
1632                          int is_remount)
1633 {
1634         struct ext4_sb_info *sbi = EXT4_SB(sb);
1635         char *p;
1636         substring_t args[MAX_OPT_ARGS];
1637         int token;
1638
1639         if (!options)
1640                 return 1;
1641
1642         while ((p = strsep(&options, ",")) != NULL) {
1643                 if (!*p)
1644                         continue;
1645                 /*
1646                  * Initialize args struct so we know whether arg was
1647                  * found; some options take optional arguments.
1648                  */
1649                 args[0].to = args[0].from = NULL;
1650                 token = match_token(p, tokens, args);
1651                 if (handle_mount_opt(sb, p, token, args, journal_devnum,
1652                                      journal_ioprio, is_remount) < 0)
1653                         return 0;
1654         }
1655 #ifdef CONFIG_QUOTA
1656         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
1657             (test_opt(sb, USRQUOTA) || test_opt(sb, GRPQUOTA))) {
1658                 ext4_msg(sb, KERN_ERR, "Cannot set quota options when QUOTA "
1659                          "feature is enabled");
1660                 return 0;
1661         }
1662         if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1663                 if (test_opt(sb, USRQUOTA) && sbi->s_qf_names[USRQUOTA])
1664                         clear_opt(sb, USRQUOTA);
1665
1666                 if (test_opt(sb, GRPQUOTA) && sbi->s_qf_names[GRPQUOTA])
1667                         clear_opt(sb, GRPQUOTA);
1668
1669                 if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
1670                         ext4_msg(sb, KERN_ERR, "old and new quota "
1671                                         "format mixing");
1672                         return 0;
1673                 }
1674
1675                 if (!sbi->s_jquota_fmt) {
1676                         ext4_msg(sb, KERN_ERR, "journaled quota format "
1677                                         "not specified");
1678                         return 0;
1679                 }
1680         }
1681 #endif
1682         if (test_opt(sb, DIOREAD_NOLOCK)) {
1683                 int blocksize =
1684                         BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
1685
1686                 if (blocksize < PAGE_CACHE_SIZE) {
1687                         ext4_msg(sb, KERN_ERR, "can't mount with "
1688                                  "dioread_nolock if block size != PAGE_SIZE");
1689                         return 0;
1690                 }
1691         }
1692         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
1693             test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
1694                 ext4_msg(sb, KERN_ERR, "can't mount with journal_async_commit "
1695                          "in data=ordered mode");
1696                 return 0;
1697         }
1698         return 1;
1699 }
1700
1701 static inline void ext4_show_quota_options(struct seq_file *seq,
1702                                            struct super_block *sb)
1703 {
1704 #if defined(CONFIG_QUOTA)
1705         struct ext4_sb_info *sbi = EXT4_SB(sb);
1706
1707         if (sbi->s_jquota_fmt) {
1708                 char *fmtname = "";
1709
1710                 switch (sbi->s_jquota_fmt) {
1711                 case QFMT_VFS_OLD:
1712                         fmtname = "vfsold";
1713                         break;
1714                 case QFMT_VFS_V0:
1715                         fmtname = "vfsv0";
1716                         break;
1717                 case QFMT_VFS_V1:
1718                         fmtname = "vfsv1";
1719                         break;
1720                 }
1721                 seq_printf(seq, ",jqfmt=%s", fmtname);
1722         }
1723
1724         if (sbi->s_qf_names[USRQUOTA])
1725                 seq_printf(seq, ",usrjquota=%s", sbi->s_qf_names[USRQUOTA]);
1726
1727         if (sbi->s_qf_names[GRPQUOTA])
1728                 seq_printf(seq, ",grpjquota=%s", sbi->s_qf_names[GRPQUOTA]);
1729 #endif
1730 }
1731
1732 static const char *token2str(int token)
1733 {
1734         const struct match_token *t;
1735
1736         for (t = tokens; t->token != Opt_err; t++)
1737                 if (t->token == token && !strchr(t->pattern, '='))
1738                         break;
1739         return t->pattern;
1740 }
1741
1742 /*
1743  * Show an option if
1744  *  - it's set to a non-default value OR
1745  *  - if the per-sb default is different from the global default
1746  */
1747 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
1748                               int nodefs)
1749 {
1750         struct ext4_sb_info *sbi = EXT4_SB(sb);
1751         struct ext4_super_block *es = sbi->s_es;
1752         int def_errors, def_mount_opt = nodefs ? 0 : sbi->s_def_mount_opt;
1753         const struct mount_opts *m;
1754         char sep = nodefs ? '\n' : ',';
1755
1756 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
1757 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
1758
1759         if (sbi->s_sb_block != 1)
1760                 SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
1761
1762         for (m = ext4_mount_opts; m->token != Opt_err; m++) {
1763                 int want_set = m->flags & MOPT_SET;
1764                 if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
1765                     (m->flags & MOPT_CLEAR_ERR))
1766                         continue;
1767                 if (!(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
1768                         continue; /* skip if same as the default */
1769                 if ((want_set &&
1770                      (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
1771                     (!want_set && (sbi->s_mount_opt & m->mount_opt)))
1772                         continue; /* select Opt_noFoo vs Opt_Foo */
1773                 SEQ_OPTS_PRINT("%s", token2str(m->token));
1774         }
1775
1776         if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
1777             le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
1778                 SEQ_OPTS_PRINT("resuid=%u",
1779                                 from_kuid_munged(&init_user_ns, sbi->s_resuid));
1780         if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
1781             le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
1782                 SEQ_OPTS_PRINT("resgid=%u",
1783                                 from_kgid_munged(&init_user_ns, sbi->s_resgid));
1784         def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
1785         if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
1786                 SEQ_OPTS_PUTS("errors=remount-ro");
1787         if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
1788                 SEQ_OPTS_PUTS("errors=continue");
1789         if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
1790                 SEQ_OPTS_PUTS("errors=panic");
1791         if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
1792                 SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
1793         if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
1794                 SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
1795         if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
1796                 SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
1797         if (sb->s_flags & MS_I_VERSION)
1798                 SEQ_OPTS_PUTS("i_version");
1799         if (nodefs || sbi->s_stripe)
1800                 SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
1801         if (EXT4_MOUNT_DATA_FLAGS & (sbi->s_mount_opt ^ def_mount_opt)) {
1802                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
1803                         SEQ_OPTS_PUTS("data=journal");
1804                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
1805                         SEQ_OPTS_PUTS("data=ordered");
1806                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
1807                         SEQ_OPTS_PUTS("data=writeback");
1808         }
1809         if (nodefs ||
1810             sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
1811                 SEQ_OPTS_PRINT("inode_readahead_blks=%u",
1812                                sbi->s_inode_readahead_blks);
1813
1814         if (nodefs || (test_opt(sb, INIT_INODE_TABLE) &&
1815                        (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
1816                 SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
1817         if (nodefs || sbi->s_max_dir_size_kb)
1818                 SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
1819
1820         ext4_show_quota_options(seq, sb);
1821         return 0;
1822 }
1823
1824 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
1825 {
1826         return _ext4_show_options(seq, root->d_sb, 0);
1827 }
1828
1829 static int options_seq_show(struct seq_file *seq, void *offset)
1830 {
1831         struct super_block *sb = seq->private;
1832         int rc;
1833
1834         seq_puts(seq, (sb->s_flags & MS_RDONLY) ? "ro" : "rw");
1835         rc = _ext4_show_options(seq, sb, 1);
1836         seq_puts(seq, "\n");
1837         return rc;
1838 }
1839
1840 static int options_open_fs(struct inode *inode, struct file *file)
1841 {
1842         return single_open(file, options_seq_show, PDE_DATA(inode));
1843 }
1844
1845 static const struct file_operations ext4_seq_options_fops = {
1846         .owner = THIS_MODULE,
1847         .open = options_open_fs,
1848         .read = seq_read,
1849         .llseek = seq_lseek,
1850         .release = single_release,
1851 };
1852
1853 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
1854                             int read_only)
1855 {
1856         struct ext4_sb_info *sbi = EXT4_SB(sb);
1857         int res = 0;
1858
1859         if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
1860                 ext4_msg(sb, KERN_ERR, "revision level too high, "
1861                          "forcing read-only mode");
1862                 res = MS_RDONLY;
1863         }
1864         if (read_only)
1865                 goto done;
1866         if (!(sbi->s_mount_state & EXT4_VALID_FS))
1867                 ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
1868                          "running e2fsck is recommended");
1869         else if (sbi->s_mount_state & EXT4_ERROR_FS)
1870                 ext4_msg(sb, KERN_WARNING,
1871                          "warning: mounting fs with errors, "
1872                          "running e2fsck is recommended");
1873         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
1874                  le16_to_cpu(es->s_mnt_count) >=
1875                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
1876                 ext4_msg(sb, KERN_WARNING,
1877                          "warning: maximal mount count reached, "
1878                          "running e2fsck is recommended");
1879         else if (le32_to_cpu(es->s_checkinterval) &&
1880                 (le32_to_cpu(es->s_lastcheck) +
1881                         le32_to_cpu(es->s_checkinterval) <= get_seconds()))
1882                 ext4_msg(sb, KERN_WARNING,
1883                          "warning: checktime reached, "
1884                          "running e2fsck is recommended");
1885         if (!sbi->s_journal)
1886                 es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
1887         if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
1888                 es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
1889         le16_add_cpu(&es->s_mnt_count, 1);
1890         es->s_mtime = cpu_to_le32(get_seconds());
1891         ext4_update_dynamic_rev(sb);
1892         if (sbi->s_journal)
1893                 EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
1894
1895         ext4_commit_super(sb, 1);
1896 done:
1897         if (test_opt(sb, DEBUG))
1898                 printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
1899                                 "bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
1900                         sb->s_blocksize,
1901                         sbi->s_groups_count,
1902                         EXT4_BLOCKS_PER_GROUP(sb),
1903                         EXT4_INODES_PER_GROUP(sb),
1904                         sbi->s_mount_opt, sbi->s_mount_opt2);
1905
1906         cleancache_init_fs(sb);
1907         return res;
1908 }
1909
1910 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
1911 {
1912         struct ext4_sb_info *sbi = EXT4_SB(sb);
1913         struct flex_groups *new_groups;
1914         int size;
1915
1916         if (!sbi->s_log_groups_per_flex)
1917                 return 0;
1918
1919         size = ext4_flex_group(sbi, ngroup - 1) + 1;
1920         if (size <= sbi->s_flex_groups_allocated)
1921                 return 0;
1922
1923         size = roundup_pow_of_two(size * sizeof(struct flex_groups));
1924         new_groups = ext4_kvzalloc(size, GFP_KERNEL);
1925         if (!new_groups) {
1926                 ext4_msg(sb, KERN_ERR, "not enough memory for %d flex groups",
1927                          size / (int) sizeof(struct flex_groups));
1928                 return -ENOMEM;
1929         }
1930
1931         if (sbi->s_flex_groups) {
1932                 memcpy(new_groups, sbi->s_flex_groups,
1933                        (sbi->s_flex_groups_allocated *
1934                         sizeof(struct flex_groups)));
1935                 kvfree(sbi->s_flex_groups);
1936         }
1937         sbi->s_flex_groups = new_groups;
1938         sbi->s_flex_groups_allocated = size / sizeof(struct flex_groups);
1939         return 0;
1940 }
1941
1942 static int ext4_fill_flex_info(struct super_block *sb)
1943 {
1944         struct ext4_sb_info *sbi = EXT4_SB(sb);
1945         struct ext4_group_desc *gdp = NULL;
1946         ext4_group_t flex_group;
1947         int i, err;
1948
1949         sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
1950         if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
1951                 sbi->s_log_groups_per_flex = 0;
1952                 return 1;
1953         }
1954
1955         err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
1956         if (err)
1957                 goto failed;
1958
1959         for (i = 0; i < sbi->s_groups_count; i++) {
1960                 gdp = ext4_get_group_desc(sb, i, NULL);
1961
1962                 flex_group = ext4_flex_group(sbi, i);
1963                 atomic_add(ext4_free_inodes_count(sb, gdp),
1964                            &sbi->s_flex_groups[flex_group].free_inodes);
1965                 atomic64_add(ext4_free_group_clusters(sb, gdp),
1966                              &sbi->s_flex_groups[flex_group].free_clusters);
1967                 atomic_add(ext4_used_dirs_count(sb, gdp),
1968                            &sbi->s_flex_groups[flex_group].used_dirs);
1969         }
1970
1971         return 1;
1972 failed:
1973         return 0;
1974 }
1975
1976 static __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 block_group,
1977                                    struct ext4_group_desc *gdp)
1978 {
1979         int offset;
1980         __u16 crc = 0;
1981         __le32 le_group = cpu_to_le32(block_group);
1982
1983         if (ext4_has_metadata_csum(sbi->s_sb)) {
1984                 /* Use new metadata_csum algorithm */
1985                 __le16 save_csum;
1986                 __u32 csum32;
1987
1988                 save_csum = gdp->bg_checksum;
1989                 gdp->bg_checksum = 0;
1990                 csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
1991                                      sizeof(le_group));
1992                 csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp,
1993                                      sbi->s_desc_size);
1994                 gdp->bg_checksum = save_csum;
1995
1996                 crc = csum32 & 0xFFFF;
1997                 goto out;
1998         }
1999
2000         /* old crc16 code */
2001         if (!(sbi->s_es->s_feature_ro_compat &
2002               cpu_to_le32(EXT4_FEATURE_RO_COMPAT_GDT_CSUM)))
2003                 return 0;
2004
2005         offset = offsetof(struct ext4_group_desc, bg_checksum);
2006
2007         crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2008         crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2009         crc = crc16(crc, (__u8 *)gdp, offset);
2010         offset += sizeof(gdp->bg_checksum); /* skip checksum */
2011         /* for checksum of struct ext4_group_desc do the rest...*/
2012         if ((sbi->s_es->s_feature_incompat &
2013              cpu_to_le32(EXT4_FEATURE_INCOMPAT_64BIT)) &&
2014             offset < le16_to_cpu(sbi->s_es->s_desc_size))
2015                 crc = crc16(crc, (__u8 *)gdp + offset,
2016                             le16_to_cpu(sbi->s_es->s_desc_size) -
2017                                 offset);
2018
2019 out:
2020         return cpu_to_le16(crc);
2021 }
2022
2023 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2024                                 struct ext4_group_desc *gdp)
2025 {
2026         if (ext4_has_group_desc_csum(sb) &&
2027             (gdp->bg_checksum != ext4_group_desc_csum(EXT4_SB(sb),
2028                                                       block_group, gdp)))
2029                 return 0;
2030
2031         return 1;
2032 }
2033
2034 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2035                               struct ext4_group_desc *gdp)
2036 {
2037         if (!ext4_has_group_desc_csum(sb))
2038                 return;
2039         gdp->bg_checksum = ext4_group_desc_csum(EXT4_SB(sb), block_group, gdp);
2040 }
2041
2042 /* Called at mount-time, super-block is locked */
2043 static int ext4_check_descriptors(struct super_block *sb,
2044                                   ext4_group_t *first_not_zeroed)
2045 {
2046         struct ext4_sb_info *sbi = EXT4_SB(sb);
2047         ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2048         ext4_fsblk_t last_block;
2049         ext4_fsblk_t block_bitmap;
2050         ext4_fsblk_t inode_bitmap;
2051         ext4_fsblk_t inode_table;
2052         int flexbg_flag = 0;
2053         ext4_group_t i, grp = sbi->s_groups_count;
2054
2055         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
2056                 flexbg_flag = 1;
2057
2058         ext4_debug("Checking group descriptors");
2059
2060         for (i = 0; i < sbi->s_groups_count; i++) {
2061                 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2062
2063                 if (i == sbi->s_groups_count - 1 || flexbg_flag)
2064                         last_block = ext4_blocks_count(sbi->s_es) - 1;
2065                 else
2066                         last_block = first_block +
2067                                 (EXT4_BLOCKS_PER_GROUP(sb) - 1);
2068
2069                 if ((grp == sbi->s_groups_count) &&
2070                    !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2071                         grp = i;
2072
2073                 block_bitmap = ext4_block_bitmap(sb, gdp);
2074                 if (block_bitmap < first_block || block_bitmap > last_block) {
2075                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2076                                "Block bitmap for group %u not in group "
2077                                "(block %llu)!", i, block_bitmap);
2078                         return 0;
2079                 }
2080                 inode_bitmap = ext4_inode_bitmap(sb, gdp);
2081                 if (inode_bitmap < first_block || inode_bitmap > last_block) {
2082                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2083                                "Inode bitmap for group %u not in group "
2084                                "(block %llu)!", i, inode_bitmap);
2085                         return 0;
2086                 }
2087                 inode_table = ext4_inode_table(sb, gdp);
2088                 if (inode_table < first_block ||
2089                     inode_table + sbi->s_itb_per_group - 1 > last_block) {
2090                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2091                                "Inode table for group %u not in group "
2092                                "(block %llu)!", i, inode_table);
2093                         return 0;
2094                 }
2095                 ext4_lock_group(sb, i);
2096                 if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2097                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2098                                  "Checksum for group %u failed (%u!=%u)",
2099                                  i, le16_to_cpu(ext4_group_desc_csum(sbi, i,
2100                                      gdp)), le16_to_cpu(gdp->bg_checksum));
2101                         if (!(sb->s_flags & MS_RDONLY)) {
2102                                 ext4_unlock_group(sb, i);
2103                                 return 0;
2104                         }
2105                 }
2106                 ext4_unlock_group(sb, i);
2107                 if (!flexbg_flag)
2108                         first_block += EXT4_BLOCKS_PER_GROUP(sb);
2109         }
2110         if (NULL != first_not_zeroed)
2111                 *first_not_zeroed = grp;
2112         return 1;
2113 }
2114
2115 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2116  * the superblock) which were deleted from all directories, but held open by
2117  * a process at the time of a crash.  We walk the list and try to delete these
2118  * inodes at recovery time (only with a read-write filesystem).
2119  *
2120  * In order to keep the orphan inode chain consistent during traversal (in
2121  * case of crash during recovery), we link each inode into the superblock
2122  * orphan list_head and handle it the same way as an inode deletion during
2123  * normal operation (which journals the operations for us).
2124  *
2125  * We only do an iget() and an iput() on each inode, which is very safe if we
2126  * accidentally point at an in-use or already deleted inode.  The worst that
2127  * can happen in this case is that we get a "bit already cleared" message from
2128  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2129  * e2fsck was run on this filesystem, and it must have already done the orphan
2130  * inode cleanup for us, so we can safely abort without any further action.
2131  */
2132 static void ext4_orphan_cleanup(struct super_block *sb,
2133                                 struct ext4_super_block *es)
2134 {
2135         unsigned int s_flags = sb->s_flags;
2136         int nr_orphans = 0, nr_truncates = 0;
2137 #ifdef CONFIG_QUOTA
2138         int i;
2139 #endif
2140         if (!es->s_last_orphan) {
2141                 jbd_debug(4, "no orphan inodes to clean up\n");
2142                 return;
2143         }
2144
2145         if (bdev_read_only(sb->s_bdev)) {
2146                 ext4_msg(sb, KERN_ERR, "write access "
2147                         "unavailable, skipping orphan cleanup");
2148                 return;
2149         }
2150
2151         /* Check if feature set would not allow a r/w mount */
2152         if (!ext4_feature_set_ok(sb, 0)) {
2153                 ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2154                          "unknown ROCOMPAT features");
2155                 return;
2156         }
2157
2158         if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2159                 /* don't clear list on RO mount w/ errors */
2160                 if (es->s_last_orphan && !(s_flags & MS_RDONLY)) {
2161                         ext4_msg(sb, KERN_INFO, "Errors on filesystem, "
2162                                   "clearing orphan list.\n");
2163                         es->s_last_orphan = 0;
2164                 }
2165                 jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2166                 return;
2167         }
2168
2169         if (s_flags & MS_RDONLY) {
2170                 ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2171                 sb->s_flags &= ~MS_RDONLY;
2172         }
2173 #ifdef CONFIG_QUOTA
2174         /* Needed for iput() to work correctly and not trash data */
2175         sb->s_flags |= MS_ACTIVE;
2176         /* Turn on quotas so that they are updated correctly */
2177         for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2178                 if (EXT4_SB(sb)->s_qf_names[i]) {
2179                         int ret = ext4_quota_on_mount(sb, i);
2180                         if (ret < 0)
2181                                 ext4_msg(sb, KERN_ERR,
2182                                         "Cannot turn on journaled "
2183                                         "quota: error %d", ret);
2184                 }
2185         }
2186 #endif
2187
2188         while (es->s_last_orphan) {
2189                 struct inode *inode;
2190
2191                 inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2192                 if (IS_ERR(inode)) {
2193                         es->s_last_orphan = 0;
2194                         break;
2195                 }
2196
2197                 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2198                 dquot_initialize(inode);
2199                 if (inode->i_nlink) {
2200                         if (test_opt(sb, DEBUG))
2201                                 ext4_msg(sb, KERN_DEBUG,
2202                                         "%s: truncating inode %lu to %lld bytes",
2203                                         __func__, inode->i_ino, inode->i_size);
2204                         jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2205                                   inode->i_ino, inode->i_size);
2206                         mutex_lock(&inode->i_mutex);
2207                         truncate_inode_pages(inode->i_mapping, inode->i_size);
2208                         ext4_truncate(inode);
2209                         mutex_unlock(&inode->i_mutex);
2210                         nr_truncates++;
2211                 } else {
2212                         if (test_opt(sb, DEBUG))
2213                                 ext4_msg(sb, KERN_DEBUG,
2214                                         "%s: deleting unreferenced inode %lu",
2215                                         __func__, inode->i_ino);
2216                         jbd_debug(2, "deleting unreferenced inode %lu\n",
2217                                   inode->i_ino);
2218                         nr_orphans++;
2219                 }
2220                 iput(inode);  /* The delete magic happens here! */
2221         }
2222
2223 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2224
2225         if (nr_orphans)
2226                 ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2227                        PLURAL(nr_orphans));
2228         if (nr_truncates)
2229                 ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2230                        PLURAL(nr_truncates));
2231 #ifdef CONFIG_QUOTA
2232         /* Turn quotas off */
2233         for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2234                 if (sb_dqopt(sb)->files[i])
2235                         dquot_quota_off(sb, i);
2236         }
2237 #endif
2238         sb->s_flags = s_flags; /* Restore MS_RDONLY status */
2239 }
2240
2241 /*
2242  * Maximal extent format file size.
2243  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2244  * extent format containers, within a sector_t, and within i_blocks
2245  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2246  * so that won't be a limiting factor.
2247  *
2248  * However there is other limiting factor. We do store extents in the form
2249  * of starting block and length, hence the resulting length of the extent
2250  * covering maximum file size must fit into on-disk format containers as
2251  * well. Given that length is always by 1 unit bigger than max unit (because
2252  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2253  *
2254  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2255  */
2256 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2257 {
2258         loff_t res;
2259         loff_t upper_limit = MAX_LFS_FILESIZE;
2260
2261         /* small i_blocks in vfs inode? */
2262         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2263                 /*
2264                  * CONFIG_LBDAF is not enabled implies the inode
2265                  * i_block represent total blocks in 512 bytes
2266                  * 32 == size of vfs inode i_blocks * 8
2267                  */
2268                 upper_limit = (1LL << 32) - 1;
2269
2270                 /* total blocks in file system block size */
2271                 upper_limit >>= (blkbits - 9);
2272                 upper_limit <<= blkbits;
2273         }
2274
2275         /*
2276          * 32-bit extent-start container, ee_block. We lower the maxbytes
2277          * by one fs block, so ee_len can cover the extent of maximum file
2278          * size
2279          */
2280         res = (1LL << 32) - 1;
2281         res <<= blkbits;
2282
2283         /* Sanity check against vm- & vfs- imposed limits */
2284         if (res > upper_limit)
2285                 res = upper_limit;
2286
2287         return res;
2288 }
2289
2290 /*
2291  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2292  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2293  * We need to be 1 filesystem block less than the 2^48 sector limit.
2294  */
2295 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2296 {
2297         loff_t res = EXT4_NDIR_BLOCKS;
2298         int meta_blocks;
2299         loff_t upper_limit;
2300         /* This is calculated to be the largest file size for a dense, block
2301          * mapped file such that the file's total number of 512-byte sectors,
2302          * including data and all indirect blocks, does not exceed (2^48 - 1).
2303          *
2304          * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2305          * number of 512-byte sectors of the file.
2306          */
2307
2308         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2309                 /*
2310                  * !has_huge_files or CONFIG_LBDAF not enabled implies that
2311                  * the inode i_block field represents total file blocks in
2312                  * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2313                  */
2314                 upper_limit = (1LL << 32) - 1;
2315
2316                 /* total blocks in file system block size */
2317                 upper_limit >>= (bits - 9);
2318
2319         } else {
2320                 /*
2321                  * We use 48 bit ext4_inode i_blocks
2322                  * With EXT4_HUGE_FILE_FL set the i_blocks
2323                  * represent total number of blocks in
2324                  * file system block size
2325                  */
2326                 upper_limit = (1LL << 48) - 1;
2327
2328         }
2329
2330         /* indirect blocks */
2331         meta_blocks = 1;
2332         /* double indirect blocks */
2333         meta_blocks += 1 + (1LL << (bits-2));
2334         /* tripple indirect blocks */
2335         meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2336
2337         upper_limit -= meta_blocks;
2338         upper_limit <<= bits;
2339
2340         res += 1LL << (bits-2);
2341         res += 1LL << (2*(bits-2));
2342         res += 1LL << (3*(bits-2));
2343         res <<= bits;
2344         if (res > upper_limit)
2345                 res = upper_limit;
2346
2347         if (res > MAX_LFS_FILESIZE)
2348                 res = MAX_LFS_FILESIZE;
2349
2350         return res;
2351 }
2352
2353 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2354                                    ext4_fsblk_t logical_sb_block, int nr)
2355 {
2356         struct ext4_sb_info *sbi = EXT4_SB(sb);
2357         ext4_group_t bg, first_meta_bg;
2358         int has_super = 0;
2359
2360         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2361
2362         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG) ||
2363             nr < first_meta_bg)
2364                 return logical_sb_block + nr + 1;
2365         bg = sbi->s_desc_per_block * nr;
2366         if (ext4_bg_has_super(sb, bg))
2367                 has_super = 1;
2368
2369         /*
2370          * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
2371          * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
2372          * on modern mke2fs or blksize > 1k on older mke2fs) then we must
2373          * compensate.
2374          */
2375         if (sb->s_blocksize == 1024 && nr == 0 &&
2376             le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block) == 0)
2377                 has_super++;
2378
2379         return (has_super + ext4_group_first_block_no(sb, bg));
2380 }
2381
2382 /**
2383  * ext4_get_stripe_size: Get the stripe size.
2384  * @sbi: In memory super block info
2385  *
2386  * If we have specified it via mount option, then
2387  * use the mount option value. If the value specified at mount time is
2388  * greater than the blocks per group use the super block value.
2389  * If the super block value is greater than blocks per group return 0.
2390  * Allocator needs it be less than blocks per group.
2391  *
2392  */
2393 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2394 {
2395         unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2396         unsigned long stripe_width =
2397                         le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2398         int ret;
2399
2400         if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2401                 ret = sbi->s_stripe;
2402         else if (stripe_width <= sbi->s_blocks_per_group)
2403                 ret = stripe_width;
2404         else if (stride <= sbi->s_blocks_per_group)
2405                 ret = stride;
2406         else
2407                 ret = 0;
2408
2409         /*
2410          * If the stripe width is 1, this makes no sense and
2411          * we set it to 0 to turn off stripe handling code.
2412          */
2413         if (ret <= 1)
2414                 ret = 0;
2415
2416         return ret;
2417 }
2418
2419 /* sysfs supprt */
2420
2421 struct ext4_attr {
2422         struct attribute attr;
2423         ssize_t (*show)(struct ext4_attr *, struct ext4_sb_info *, char *);
2424         ssize_t (*store)(struct ext4_attr *, struct ext4_sb_info *,
2425                          const char *, size_t);
2426         union {
2427                 int offset;
2428                 int deprecated_val;
2429         } u;
2430 };
2431
2432 static int parse_strtoull(const char *buf,
2433                 unsigned long long max, unsigned long long *value)
2434 {
2435         int ret;
2436
2437         ret = kstrtoull(skip_spaces(buf), 0, value);
2438         if (!ret && *value > max)
2439                 ret = -EINVAL;
2440         return ret;
2441 }
2442
2443 static ssize_t delayed_allocation_blocks_show(struct ext4_attr *a,
2444                                               struct ext4_sb_info *sbi,
2445                                               char *buf)
2446 {
2447         return snprintf(buf, PAGE_SIZE, "%llu\n",
2448                 (s64) EXT4_C2B(sbi,
2449                         percpu_counter_sum(&sbi->s_dirtyclusters_counter)));
2450 }
2451
2452 static ssize_t session_write_kbytes_show(struct ext4_attr *a,
2453                                          struct ext4_sb_info *sbi, char *buf)
2454 {
2455         struct super_block *sb = sbi->s_buddy_cache->i_sb;
2456
2457         if (!sb->s_bdev->bd_part)
2458                 return snprintf(buf, PAGE_SIZE, "0\n");
2459         return snprintf(buf, PAGE_SIZE, "%lu\n",
2460                         (part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2461                          sbi->s_sectors_written_start) >> 1);
2462 }
2463
2464 static ssize_t lifetime_write_kbytes_show(struct ext4_attr *a,
2465                                           struct ext4_sb_info *sbi, char *buf)
2466 {
2467         struct super_block *sb = sbi->s_buddy_cache->i_sb;
2468
2469         if (!sb->s_bdev->bd_part)
2470                 return snprintf(buf, PAGE_SIZE, "0\n");
2471         return snprintf(buf, PAGE_SIZE, "%llu\n",
2472                         (unsigned long long)(sbi->s_kbytes_written +
2473                         ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2474                           EXT4_SB(sb)->s_sectors_written_start) >> 1)));
2475 }
2476
2477 static ssize_t inode_readahead_blks_store(struct ext4_attr *a,
2478                                           struct ext4_sb_info *sbi,
2479                                           const char *buf, size_t count)
2480 {
2481         unsigned long t;
2482         int ret;
2483
2484         ret = kstrtoul(skip_spaces(buf), 0, &t);
2485         if (ret)
2486                 return ret;
2487
2488         if (t && (!is_power_of_2(t) || t > 0x40000000))
2489                 return -EINVAL;
2490
2491         sbi->s_inode_readahead_blks = t;
2492         return count;
2493 }
2494
2495 static ssize_t sbi_ui_show(struct ext4_attr *a,
2496                            struct ext4_sb_info *sbi, char *buf)
2497 {
2498         unsigned int *ui = (unsigned int *) (((char *) sbi) + a->u.offset);
2499
2500         return snprintf(buf, PAGE_SIZE, "%u\n", *ui);
2501 }
2502
2503 static ssize_t sbi_ui_store(struct ext4_attr *a,
2504                             struct ext4_sb_info *sbi,
2505                             const char *buf, size_t count)
2506 {
2507         unsigned int *ui = (unsigned int *) (((char *) sbi) + a->u.offset);
2508         unsigned long t;
2509         int ret;
2510
2511         ret = kstrtoul(skip_spaces(buf), 0, &t);
2512         if (ret)
2513                 return ret;
2514         *ui = t;
2515         return count;
2516 }
2517
2518 static ssize_t es_ui_show(struct ext4_attr *a,
2519                            struct ext4_sb_info *sbi, char *buf)
2520 {
2521
2522         unsigned int *ui = (unsigned int *) (((char *) sbi->s_es) +
2523                            a->u.offset);
2524
2525         return snprintf(buf, PAGE_SIZE, "%u\n", *ui);
2526 }
2527
2528 static ssize_t reserved_clusters_show(struct ext4_attr *a,
2529                                   struct ext4_sb_info *sbi, char *buf)
2530 {
2531         return snprintf(buf, PAGE_SIZE, "%llu\n",
2532                 (unsigned long long) atomic64_read(&sbi->s_resv_clusters));
2533 }
2534
2535 static ssize_t reserved_clusters_store(struct ext4_attr *a,
2536                                    struct ext4_sb_info *sbi,
2537                                    const char *buf, size_t count)
2538 {
2539         unsigned long long val;
2540         int ret;
2541
2542         if (parse_strtoull(buf, -1ULL, &val))
2543                 return -EINVAL;
2544         ret = ext4_reserve_clusters(sbi, val);
2545
2546         return ret ? ret : count;
2547 }
2548
2549 static ssize_t trigger_test_error(struct ext4_attr *a,
2550                                   struct ext4_sb_info *sbi,
2551                                   const char *buf, size_t count)
2552 {
2553         int len = count;
2554
2555         if (!capable(CAP_SYS_ADMIN))
2556                 return -EPERM;
2557
2558         if (len && buf[len-1] == '\n')
2559                 len--;
2560
2561         if (len)
2562                 ext4_error(sbi->s_sb, "%.*s", len, buf);
2563         return count;
2564 }
2565
2566 static ssize_t sbi_deprecated_show(struct ext4_attr *a,
2567                                    struct ext4_sb_info *sbi, char *buf)
2568 {
2569         return snprintf(buf, PAGE_SIZE, "%d\n", a->u.deprecated_val);
2570 }
2571
2572 #define EXT4_ATTR_OFFSET(_name,_mode,_show,_store,_elname) \
2573 static struct ext4_attr ext4_attr_##_name = {                   \
2574         .attr = {.name = __stringify(_name), .mode = _mode },   \
2575         .show   = _show,                                        \
2576         .store  = _store,                                       \
2577         .u = {                                                  \
2578                 .offset = offsetof(struct ext4_sb_info, _elname),\
2579         },                                                      \
2580 }
2581
2582 #define EXT4_ATTR_OFFSET_ES(_name,_mode,_show,_store,_elname)           \
2583 static struct ext4_attr ext4_attr_##_name = {                           \
2584         .attr = {.name = __stringify(_name), .mode = _mode },           \
2585         .show   = _show,                                                \
2586         .store  = _store,                                               \
2587         .u = {                                                          \
2588                 .offset = offsetof(struct ext4_super_block, _elname),   \
2589         },                                                              \
2590 }
2591
2592 #define EXT4_ATTR(name, mode, show, store) \
2593 static struct ext4_attr ext4_attr_##name = __ATTR(name, mode, show, store)
2594
2595 #define EXT4_INFO_ATTR(name) EXT4_ATTR(name, 0444, NULL, NULL)
2596 #define EXT4_RO_ATTR(name) EXT4_ATTR(name, 0444, name##_show, NULL)
2597 #define EXT4_RW_ATTR(name) EXT4_ATTR(name, 0644, name##_show, name##_store)
2598
2599 #define EXT4_RO_ATTR_ES_UI(name, elname)        \
2600         EXT4_ATTR_OFFSET_ES(name, 0444, es_ui_show, NULL, elname)
2601 #define EXT4_RW_ATTR_SBI_UI(name, elname)       \
2602         EXT4_ATTR_OFFSET(name, 0644, sbi_ui_show, sbi_ui_store, elname)
2603
2604 #define ATTR_LIST(name) &ext4_attr_##name.attr
2605 #define EXT4_DEPRECATED_ATTR(_name, _val)       \
2606 static struct ext4_attr ext4_attr_##_name = {                   \
2607         .attr = {.name = __stringify(_name), .mode = 0444 },    \
2608         .show   = sbi_deprecated_show,                          \
2609         .u = {                                                  \
2610                 .deprecated_val = _val,                         \
2611         },                                                      \
2612 }
2613
2614 EXT4_RO_ATTR(delayed_allocation_blocks);
2615 EXT4_RO_ATTR(session_write_kbytes);
2616 EXT4_RO_ATTR(lifetime_write_kbytes);
2617 EXT4_RW_ATTR(reserved_clusters);
2618 EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, sbi_ui_show,
2619                  inode_readahead_blks_store, s_inode_readahead_blks);
2620 EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal);
2621 EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats);
2622 EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan);
2623 EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan);
2624 EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs);
2625 EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request);
2626 EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc);
2627 EXT4_DEPRECATED_ATTR(max_writeback_mb_bump, 128);
2628 EXT4_RW_ATTR_SBI_UI(extent_max_zeroout_kb, s_extent_max_zeroout_kb);
2629 EXT4_ATTR(trigger_fs_error, 0200, NULL, trigger_test_error);
2630 EXT4_RW_ATTR_SBI_UI(err_ratelimit_interval_ms, s_err_ratelimit_state.interval);
2631 EXT4_RW_ATTR_SBI_UI(err_ratelimit_burst, s_err_ratelimit_state.burst);
2632 EXT4_RW_ATTR_SBI_UI(warning_ratelimit_interval_ms, s_warning_ratelimit_state.interval);
2633 EXT4_RW_ATTR_SBI_UI(warning_ratelimit_burst, s_warning_ratelimit_state.burst);
2634 EXT4_RW_ATTR_SBI_UI(msg_ratelimit_interval_ms, s_msg_ratelimit_state.interval);
2635 EXT4_RW_ATTR_SBI_UI(msg_ratelimit_burst, s_msg_ratelimit_state.burst);
2636 EXT4_RO_ATTR_ES_UI(errors_count, s_error_count);
2637 EXT4_RO_ATTR_ES_UI(first_error_time, s_first_error_time);
2638 EXT4_RO_ATTR_ES_UI(last_error_time, s_last_error_time);
2639
2640 static struct attribute *ext4_attrs[] = {
2641         ATTR_LIST(delayed_allocation_blocks),
2642         ATTR_LIST(session_write_kbytes),
2643         ATTR_LIST(lifetime_write_kbytes),
2644         ATTR_LIST(reserved_clusters),
2645         ATTR_LIST(inode_readahead_blks),
2646         ATTR_LIST(inode_goal),
2647         ATTR_LIST(mb_stats),
2648         ATTR_LIST(mb_max_to_scan),
2649         ATTR_LIST(mb_min_to_scan),
2650         ATTR_LIST(mb_order2_req),
2651         ATTR_LIST(mb_stream_req),
2652         ATTR_LIST(mb_group_prealloc),
2653         ATTR_LIST(max_writeback_mb_bump),
2654         ATTR_LIST(extent_max_zeroout_kb),
2655         ATTR_LIST(trigger_fs_error),
2656         ATTR_LIST(err_ratelimit_interval_ms),
2657         ATTR_LIST(err_ratelimit_burst),
2658         ATTR_LIST(warning_ratelimit_interval_ms),
2659         ATTR_LIST(warning_ratelimit_burst),
2660         ATTR_LIST(msg_ratelimit_interval_ms),
2661         ATTR_LIST(msg_ratelimit_burst),
2662         ATTR_LIST(errors_count),
2663         ATTR_LIST(first_error_time),
2664         ATTR_LIST(last_error_time),
2665         NULL,
2666 };
2667
2668 /* Features this copy of ext4 supports */
2669 EXT4_INFO_ATTR(lazy_itable_init);
2670 EXT4_INFO_ATTR(batched_discard);
2671 EXT4_INFO_ATTR(meta_bg_resize);
2672
2673 static struct attribute *ext4_feat_attrs[] = {
2674         ATTR_LIST(lazy_itable_init),
2675         ATTR_LIST(batched_discard),
2676         ATTR_LIST(meta_bg_resize),
2677         NULL,
2678 };
2679
2680 static ssize_t ext4_attr_show(struct kobject *kobj,
2681                               struct attribute *attr, char *buf)
2682 {
2683         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2684                                                 s_kobj);
2685         struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2686
2687         return a->show ? a->show(a, sbi, buf) : 0;
2688 }
2689
2690 static ssize_t ext4_attr_store(struct kobject *kobj,
2691                                struct attribute *attr,
2692                                const char *buf, size_t len)
2693 {
2694         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2695                                                 s_kobj);
2696         struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2697
2698         return a->store ? a->store(a, sbi, buf, len) : 0;
2699 }
2700
2701 static void ext4_sb_release(struct kobject *kobj)
2702 {
2703         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2704                                                 s_kobj);
2705         complete(&sbi->s_kobj_unregister);
2706 }
2707
2708 static const struct sysfs_ops ext4_attr_ops = {
2709         .show   = ext4_attr_show,
2710         .store  = ext4_attr_store,
2711 };
2712
2713 static struct kobj_type ext4_ktype = {
2714         .default_attrs  = ext4_attrs,
2715         .sysfs_ops      = &ext4_attr_ops,
2716         .release        = ext4_sb_release,
2717 };
2718
2719 static void ext4_feat_release(struct kobject *kobj)
2720 {
2721         complete(&ext4_feat->f_kobj_unregister);
2722 }
2723
2724 static ssize_t ext4_feat_show(struct kobject *kobj,
2725                               struct attribute *attr, char *buf)
2726 {
2727         return snprintf(buf, PAGE_SIZE, "supported\n");
2728 }
2729
2730 /*
2731  * We can not use ext4_attr_show/store because it relies on the kobject
2732  * being embedded in the ext4_sb_info structure which is definitely not
2733  * true in this case.
2734  */
2735 static const struct sysfs_ops ext4_feat_ops = {
2736         .show   = ext4_feat_show,
2737         .store  = NULL,
2738 };
2739
2740 static struct kobj_type ext4_feat_ktype = {
2741         .default_attrs  = ext4_feat_attrs,
2742         .sysfs_ops      = &ext4_feat_ops,
2743         .release        = ext4_feat_release,
2744 };
2745
2746 /*
2747  * Check whether this filesystem can be mounted based on
2748  * the features present and the RDONLY/RDWR mount requested.
2749  * Returns 1 if this filesystem can be mounted as requested,
2750  * 0 if it cannot be.
2751  */
2752 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2753 {
2754         if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT4_FEATURE_INCOMPAT_SUPP)) {
2755                 ext4_msg(sb, KERN_ERR,
2756                         "Couldn't mount because of "
2757                         "unsupported optional features (%x)",
2758                         (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2759                         ~EXT4_FEATURE_INCOMPAT_SUPP));
2760                 return 0;
2761         }
2762
2763         if (readonly)
2764                 return 1;
2765
2766         /* Check that feature set is OK for a read-write mount */
2767         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT4_FEATURE_RO_COMPAT_SUPP)) {
2768                 ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2769                          "unsupported optional features (%x)",
2770                          (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2771                                 ~EXT4_FEATURE_RO_COMPAT_SUPP));
2772                 return 0;
2773         }
2774         /*
2775          * Large file size enabled file system can only be mounted
2776          * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2777          */
2778         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) {
2779                 if (sizeof(blkcnt_t) < sizeof(u64)) {
2780                         ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2781                                  "cannot be mounted RDWR without "
2782                                  "CONFIG_LBDAF");
2783                         return 0;
2784                 }
2785         }
2786         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_BIGALLOC) &&
2787             !EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)) {
2788                 ext4_msg(sb, KERN_ERR,
2789                          "Can't support bigalloc feature without "
2790                          "extents feature\n");
2791                 return 0;
2792         }
2793
2794 #ifndef CONFIG_QUOTA
2795         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
2796             !readonly) {
2797                 ext4_msg(sb, KERN_ERR,
2798                          "Filesystem with quota feature cannot be mounted RDWR "
2799                          "without CONFIG_QUOTA");
2800                 return 0;
2801         }
2802 #endif  /* CONFIG_QUOTA */
2803         return 1;
2804 }
2805
2806 /*
2807  * This function is called once a day if we have errors logged
2808  * on the file system
2809  */
2810 static void print_daily_error_info(unsigned long arg)
2811 {
2812         struct super_block *sb = (struct super_block *) arg;
2813         struct ext4_sb_info *sbi;
2814         struct ext4_super_block *es;
2815
2816         sbi = EXT4_SB(sb);
2817         es = sbi->s_es;
2818
2819         if (es->s_error_count)
2820                 /* fsck newer than v1.41.13 is needed to clean this condition. */
2821                 ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
2822                          le32_to_cpu(es->s_error_count));
2823         if (es->s_first_error_time) {
2824                 printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %u: %.*s:%d",
2825                        sb->s_id, le32_to_cpu(es->s_first_error_time),
2826                        (int) sizeof(es->s_first_error_func),
2827                        es->s_first_error_func,
2828                        le32_to_cpu(es->s_first_error_line));
2829                 if (es->s_first_error_ino)
2830                         printk(": inode %u",
2831                                le32_to_cpu(es->s_first_error_ino));
2832                 if (es->s_first_error_block)
2833                         printk(": block %llu", (unsigned long long)
2834                                le64_to_cpu(es->s_first_error_block));
2835                 printk("\n");
2836         }
2837         if (es->s_last_error_time) {
2838                 printk(KERN_NOTICE "EXT4-fs (%s): last error at time %u: %.*s:%d",
2839                        sb->s_id, le32_to_cpu(es->s_last_error_time),
2840                        (int) sizeof(es->s_last_error_func),
2841                        es->s_last_error_func,
2842                        le32_to_cpu(es->s_last_error_line));
2843                 if (es->s_last_error_ino)
2844                         printk(": inode %u",
2845                                le32_to_cpu(es->s_last_error_ino));
2846                 if (es->s_last_error_block)
2847                         printk(": block %llu", (unsigned long long)
2848                                le64_to_cpu(es->s_last_error_block));
2849                 printk("\n");
2850         }
2851         mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2852 }
2853
2854 /* Find next suitable group and run ext4_init_inode_table */
2855 static int ext4_run_li_request(struct ext4_li_request *elr)
2856 {
2857         struct ext4_group_desc *gdp = NULL;
2858         ext4_group_t group, ngroups;
2859         struct super_block *sb;
2860         unsigned long timeout = 0;
2861         int ret = 0;
2862
2863         sb = elr->lr_super;
2864         ngroups = EXT4_SB(sb)->s_groups_count;
2865
2866         sb_start_write(sb);
2867         for (group = elr->lr_next_group; group < ngroups; group++) {
2868                 gdp = ext4_get_group_desc(sb, group, NULL);
2869                 if (!gdp) {
2870                         ret = 1;
2871                         break;
2872                 }
2873
2874                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2875                         break;
2876         }
2877
2878         if (group >= ngroups)
2879                 ret = 1;
2880
2881         if (!ret) {
2882                 timeout = jiffies;
2883                 ret = ext4_init_inode_table(sb, group,
2884                                             elr->lr_timeout ? 0 : 1);
2885                 if (elr->lr_timeout == 0) {
2886                         timeout = (jiffies - timeout) *
2887                                   elr->lr_sbi->s_li_wait_mult;
2888                         elr->lr_timeout = timeout;
2889                 }
2890                 elr->lr_next_sched = jiffies + elr->lr_timeout;
2891                 elr->lr_next_group = group + 1;
2892         }
2893         sb_end_write(sb);
2894
2895         return ret;
2896 }
2897
2898 /*
2899  * Remove lr_request from the list_request and free the
2900  * request structure. Should be called with li_list_mtx held
2901  */
2902 static void ext4_remove_li_request(struct ext4_li_request *elr)
2903 {
2904         struct ext4_sb_info *sbi;
2905
2906         if (!elr)
2907                 return;
2908
2909         sbi = elr->lr_sbi;
2910
2911         list_del(&elr->lr_request);
2912         sbi->s_li_request = NULL;
2913         kfree(elr);
2914 }
2915
2916 static void ext4_unregister_li_request(struct super_block *sb)
2917 {
2918         mutex_lock(&ext4_li_mtx);
2919         if (!ext4_li_info) {
2920                 mutex_unlock(&ext4_li_mtx);
2921                 return;
2922         }
2923
2924         mutex_lock(&ext4_li_info->li_list_mtx);
2925         ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
2926         mutex_unlock(&ext4_li_info->li_list_mtx);
2927         mutex_unlock(&ext4_li_mtx);
2928 }
2929
2930 static struct task_struct *ext4_lazyinit_task;
2931
2932 /*
2933  * This is the function where ext4lazyinit thread lives. It walks
2934  * through the request list searching for next scheduled filesystem.
2935  * When such a fs is found, run the lazy initialization request
2936  * (ext4_rn_li_request) and keep track of the time spend in this
2937  * function. Based on that time we compute next schedule time of
2938  * the request. When walking through the list is complete, compute
2939  * next waking time and put itself into sleep.
2940  */
2941 static int ext4_lazyinit_thread(void *arg)
2942 {
2943         struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
2944         struct list_head *pos, *n;
2945         struct ext4_li_request *elr;
2946         unsigned long next_wakeup, cur;
2947
2948         BUG_ON(NULL == eli);
2949
2950 cont_thread:
2951         while (true) {
2952                 next_wakeup = MAX_JIFFY_OFFSET;
2953
2954                 mutex_lock(&eli->li_list_mtx);
2955                 if (list_empty(&eli->li_request_list)) {
2956                         mutex_unlock(&eli->li_list_mtx);
2957                         goto exit_thread;
2958                 }
2959
2960                 list_for_each_safe(pos, n, &eli->li_request_list) {
2961                         elr = list_entry(pos, struct ext4_li_request,
2962                                          lr_request);
2963
2964                         if (time_after_eq(jiffies, elr->lr_next_sched)) {
2965                                 if (ext4_run_li_request(elr) != 0) {
2966                                         /* error, remove the lazy_init job */
2967                                         ext4_remove_li_request(elr);
2968                                         continue;
2969                                 }
2970                         }
2971
2972                         if (time_before(elr->lr_next_sched, next_wakeup))
2973                                 next_wakeup = elr->lr_next_sched;
2974                 }
2975                 mutex_unlock(&eli->li_list_mtx);
2976
2977                 try_to_freeze();
2978
2979                 cur = jiffies;
2980                 if ((time_after_eq(cur, next_wakeup)) ||
2981                     (MAX_JIFFY_OFFSET == next_wakeup)) {
2982                         cond_resched();
2983                         continue;
2984                 }
2985
2986                 schedule_timeout_interruptible(next_wakeup - cur);
2987
2988                 if (kthread_should_stop()) {
2989                         ext4_clear_request_list();
2990                         goto exit_thread;
2991                 }
2992         }
2993
2994 exit_thread:
2995         /*
2996          * It looks like the request list is empty, but we need
2997          * to check it under the li_list_mtx lock, to prevent any
2998          * additions into it, and of course we should lock ext4_li_mtx
2999          * to atomically free the list and ext4_li_info, because at
3000          * this point another ext4 filesystem could be registering
3001          * new one.
3002          */
3003         mutex_lock(&ext4_li_mtx);
3004         mutex_lock(&eli->li_list_mtx);
3005         if (!list_empty(&eli->li_request_list)) {
3006                 mutex_unlock(&eli->li_list_mtx);
3007                 mutex_unlock(&ext4_li_mtx);
3008                 goto cont_thread;
3009         }
3010         mutex_unlock(&eli->li_list_mtx);
3011         kfree(ext4_li_info);
3012         ext4_li_info = NULL;
3013         mutex_unlock(&ext4_li_mtx);
3014
3015         return 0;
3016 }
3017
3018 static void ext4_clear_request_list(void)
3019 {
3020         struct list_head *pos, *n;
3021         struct ext4_li_request *elr;
3022
3023         mutex_lock(&ext4_li_info->li_list_mtx);
3024         list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
3025                 elr = list_entry(pos, struct ext4_li_request,
3026                                  lr_request);
3027                 ext4_remove_li_request(elr);
3028         }
3029         mutex_unlock(&ext4_li_info->li_list_mtx);
3030 }
3031
3032 static int ext4_run_lazyinit_thread(void)
3033 {
3034         ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
3035                                          ext4_li_info, "ext4lazyinit");
3036         if (IS_ERR(ext4_lazyinit_task)) {
3037                 int err = PTR_ERR(ext4_lazyinit_task);
3038                 ext4_clear_request_list();
3039                 kfree(ext4_li_info);
3040                 ext4_li_info = NULL;
3041                 printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
3042                                  "initialization thread\n",
3043                                  err);
3044                 return err;
3045         }
3046         ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
3047         return 0;
3048 }
3049
3050 /*
3051  * Check whether it make sense to run itable init. thread or not.
3052  * If there is at least one uninitialized inode table, return
3053  * corresponding group number, else the loop goes through all
3054  * groups and return total number of groups.
3055  */
3056 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3057 {
3058         ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3059         struct ext4_group_desc *gdp = NULL;
3060
3061         for (group = 0; group < ngroups; group++) {
3062                 gdp = ext4_get_group_desc(sb, group, NULL);
3063                 if (!gdp)
3064                         continue;
3065
3066                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3067                         break;
3068         }
3069
3070         return group;
3071 }
3072
3073 static int ext4_li_info_new(void)
3074 {
3075         struct ext4_lazy_init *eli = NULL;
3076
3077         eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3078         if (!eli)
3079                 return -ENOMEM;
3080
3081         INIT_LIST_HEAD(&eli->li_request_list);
3082         mutex_init(&eli->li_list_mtx);
3083
3084         eli->li_state |= EXT4_LAZYINIT_QUIT;
3085
3086         ext4_li_info = eli;
3087
3088         return 0;
3089 }
3090
3091 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3092                                             ext4_group_t start)
3093 {
3094         struct ext4_sb_info *sbi = EXT4_SB(sb);
3095         struct ext4_li_request *elr;
3096
3097         elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3098         if (!elr)
3099                 return NULL;
3100
3101         elr->lr_super = sb;
3102         elr->lr_sbi = sbi;
3103         elr->lr_next_group = start;
3104
3105         /*
3106          * Randomize first schedule time of the request to
3107          * spread the inode table initialization requests
3108          * better.
3109          */
3110         elr->lr_next_sched = jiffies + (prandom_u32() %
3111                                 (EXT4_DEF_LI_MAX_START_DELAY * HZ));
3112         return elr;
3113 }
3114
3115 int ext4_register_li_request(struct super_block *sb,
3116                              ext4_group_t first_not_zeroed)
3117 {
3118         struct ext4_sb_info *sbi = EXT4_SB(sb);
3119         struct ext4_li_request *elr = NULL;
3120         ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
3121         int ret = 0;
3122
3123         mutex_lock(&ext4_li_mtx);
3124         if (sbi->s_li_request != NULL) {
3125                 /*
3126                  * Reset timeout so it can be computed again, because
3127                  * s_li_wait_mult might have changed.
3128                  */
3129                 sbi->s_li_request->lr_timeout = 0;
3130                 goto out;
3131         }
3132
3133         if (first_not_zeroed == ngroups ||
3134             (sb->s_flags & MS_RDONLY) ||
3135             !test_opt(sb, INIT_INODE_TABLE))
3136                 goto out;
3137
3138         elr = ext4_li_request_new(sb, first_not_zeroed);
3139         if (!elr) {
3140                 ret = -ENOMEM;
3141                 goto out;
3142         }
3143
3144         if (NULL == ext4_li_info) {
3145                 ret = ext4_li_info_new();
3146                 if (ret)
3147                         goto out;
3148         }
3149
3150         mutex_lock(&ext4_li_info->li_list_mtx);
3151         list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3152         mutex_unlock(&ext4_li_info->li_list_mtx);
3153
3154         sbi->s_li_request = elr;
3155         /*
3156          * set elr to NULL here since it has been inserted to
3157          * the request_list and the removal and free of it is
3158          * handled by ext4_clear_request_list from now on.
3159          */
3160         elr = NULL;
3161
3162         if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3163                 ret = ext4_run_lazyinit_thread();
3164                 if (ret)
3165                         goto out;
3166         }
3167 out:
3168         mutex_unlock(&ext4_li_mtx);
3169         if (ret)
3170                 kfree(elr);
3171         return ret;
3172 }
3173
3174 /*
3175  * We do not need to lock anything since this is called on
3176  * module unload.
3177  */
3178 static void ext4_destroy_lazyinit_thread(void)
3179 {
3180         /*
3181          * If thread exited earlier
3182          * there's nothing to be done.
3183          */
3184         if (!ext4_li_info || !ext4_lazyinit_task)
3185                 return;
3186
3187         kthread_stop(ext4_lazyinit_task);
3188 }
3189
3190 static int set_journal_csum_feature_set(struct super_block *sb)
3191 {
3192         int ret = 1;
3193         int compat, incompat;
3194         struct ext4_sb_info *sbi = EXT4_SB(sb);
3195
3196         if (ext4_has_metadata_csum(sb)) {
3197                 /* journal checksum v3 */
3198                 compat = 0;
3199                 incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
3200         } else {
3201                 /* journal checksum v1 */
3202                 compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3203                 incompat = 0;
3204         }
3205
3206         jbd2_journal_clear_features(sbi->s_journal,
3207                         JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3208                         JBD2_FEATURE_INCOMPAT_CSUM_V3 |
3209                         JBD2_FEATURE_INCOMPAT_CSUM_V2);
3210         if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3211                 ret = jbd2_journal_set_features(sbi->s_journal,
3212                                 compat, 0,
3213                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3214                                 incompat);
3215         } else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3216                 ret = jbd2_journal_set_features(sbi->s_journal,
3217                                 compat, 0,
3218                                 incompat);
3219                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3220                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3221         } else {
3222                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3223                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3224         }
3225
3226         return ret;
3227 }
3228
3229 /*
3230  * Note: calculating the overhead so we can be compatible with
3231  * historical BSD practice is quite difficult in the face of
3232  * clusters/bigalloc.  This is because multiple metadata blocks from
3233  * different block group can end up in the same allocation cluster.
3234  * Calculating the exact overhead in the face of clustered allocation
3235  * requires either O(all block bitmaps) in memory or O(number of block
3236  * groups**2) in time.  We will still calculate the superblock for
3237  * older file systems --- and if we come across with a bigalloc file
3238  * system with zero in s_overhead_clusters the estimate will be close to
3239  * correct especially for very large cluster sizes --- but for newer
3240  * file systems, it's better to calculate this figure once at mkfs
3241  * time, and store it in the superblock.  If the superblock value is
3242  * present (even for non-bigalloc file systems), we will use it.
3243  */
3244 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3245                           char *buf)
3246 {
3247         struct ext4_sb_info     *sbi = EXT4_SB(sb);
3248         struct ext4_group_desc  *gdp;
3249         ext4_fsblk_t            first_block, last_block, b;
3250         ext4_group_t            i, ngroups = ext4_get_groups_count(sb);
3251         int                     s, j, count = 0;
3252
3253         if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_BIGALLOC))
3254                 return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3255                         sbi->s_itb_per_group + 2);
3256
3257         first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3258                 (grp * EXT4_BLOCKS_PER_GROUP(sb));
3259         last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3260         for (i = 0; i < ngroups; i++) {
3261                 gdp = ext4_get_group_desc(sb, i, NULL);
3262                 b = ext4_block_bitmap(sb, gdp);
3263                 if (b >= first_block && b <= last_block) {
3264                         ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3265                         count++;
3266                 }
3267                 b = ext4_inode_bitmap(sb, gdp);
3268                 if (b >= first_block && b <= last_block) {
3269                         ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3270                         count++;
3271                 }
3272                 b = ext4_inode_table(sb, gdp);
3273                 if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3274                         for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3275                                 int c = EXT4_B2C(sbi, b - first_block);
3276                                 ext4_set_bit(c, buf);
3277                                 count++;
3278                         }
3279                 if (i != grp)
3280                         continue;
3281                 s = 0;
3282                 if (ext4_bg_has_super(sb, grp)) {
3283                         ext4_set_bit(s++, buf);
3284                         count++;
3285                 }
3286                 for (j = ext4_bg_num_gdb(sb, grp); j > 0; j--) {
3287                         ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3288                         count++;
3289                 }
3290         }
3291         if (!count)
3292                 return 0;
3293         return EXT4_CLUSTERS_PER_GROUP(sb) -
3294                 ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3295 }
3296
3297 /*
3298  * Compute the overhead and stash it in sbi->s_overhead
3299  */
3300 int ext4_calculate_overhead(struct super_block *sb)
3301 {
3302         struct ext4_sb_info *sbi = EXT4_SB(sb);
3303         struct ext4_super_block *es = sbi->s_es;
3304         ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3305         ext4_fsblk_t overhead = 0;
3306         char *buf = (char *) get_zeroed_page(GFP_NOFS);
3307
3308         if (!buf)
3309                 return -ENOMEM;
3310
3311         /*
3312          * Compute the overhead (FS structures).  This is constant
3313          * for a given filesystem unless the number of block groups
3314          * changes so we cache the previous value until it does.
3315          */
3316
3317         /*
3318          * All of the blocks before first_data_block are overhead
3319          */
3320         overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3321
3322         /*
3323          * Add the overhead found in each block group
3324          */
3325         for (i = 0; i < ngroups; i++) {
3326                 int blks;
3327
3328                 blks = count_overhead(sb, i, buf);
3329                 overhead += blks;
3330                 if (blks)
3331                         memset(buf, 0, PAGE_SIZE);
3332                 cond_resched();
3333         }
3334         /* Add the internal journal blocks as well */
3335         if (sbi->s_journal && !sbi->journal_bdev)
3336                 overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_maxlen);
3337
3338         sbi->s_overhead = overhead;
3339         smp_wmb();
3340         free_page((unsigned long) buf);
3341         return 0;
3342 }
3343
3344
3345 static ext4_fsblk_t ext4_calculate_resv_clusters(struct super_block *sb)
3346 {
3347         ext4_fsblk_t resv_clusters;
3348
3349         /*
3350          * There's no need to reserve anything when we aren't using extents.
3351          * The space estimates are exact, there are no unwritten extents,
3352          * hole punching doesn't need new metadata... This is needed especially
3353          * to keep ext2/3 backward compatibility.
3354          */
3355         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS))
3356                 return 0;
3357         /*
3358          * By default we reserve 2% or 4096 clusters, whichever is smaller.
3359          * This should cover the situations where we can not afford to run
3360          * out of space like for example punch hole, or converting
3361          * unwritten extents in delalloc path. In most cases such
3362          * allocation would require 1, or 2 blocks, higher numbers are
3363          * very rare.
3364          */
3365         resv_clusters = ext4_blocks_count(EXT4_SB(sb)->s_es) >>
3366                         EXT4_SB(sb)->s_cluster_bits;
3367
3368         do_div(resv_clusters, 50);
3369         resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
3370
3371         return resv_clusters;
3372 }
3373
3374
3375 static int ext4_reserve_clusters(struct ext4_sb_info *sbi, ext4_fsblk_t count)
3376 {
3377         ext4_fsblk_t clusters = ext4_blocks_count(sbi->s_es) >>
3378                                 sbi->s_cluster_bits;
3379
3380         if (count >= clusters)
3381                 return -EINVAL;
3382
3383         atomic64_set(&sbi->s_resv_clusters, count);
3384         return 0;
3385 }
3386
3387 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3388 {
3389         char *orig_data = kstrdup(data, GFP_KERNEL);
3390         struct buffer_head *bh;
3391         struct ext4_super_block *es = NULL;
3392         struct ext4_sb_info *sbi;
3393         ext4_fsblk_t block;
3394         ext4_fsblk_t sb_block = get_sb_block(&data);
3395         ext4_fsblk_t logical_sb_block;
3396         unsigned long offset = 0;
3397         unsigned long journal_devnum = 0;
3398         unsigned long def_mount_opts;
3399         struct inode *root;
3400         char *cp;
3401         const char *descr;
3402         int ret = -ENOMEM;
3403         int blocksize, clustersize;
3404         unsigned int db_count;
3405         unsigned int i;
3406         int needs_recovery, has_huge_files, has_bigalloc;
3407         __u64 blocks_count;
3408         int err = 0;
3409         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3410         ext4_group_t first_not_zeroed;
3411
3412         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3413         if (!sbi)
3414                 goto out_free_orig;
3415
3416         sbi->s_blockgroup_lock =
3417                 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3418         if (!sbi->s_blockgroup_lock) {
3419                 kfree(sbi);
3420                 goto out_free_orig;
3421         }
3422         sb->s_fs_info = sbi;
3423         sbi->s_sb = sb;
3424         sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3425         sbi->s_sb_block = sb_block;
3426         if (sb->s_bdev->bd_part)
3427                 sbi->s_sectors_written_start =
3428                         part_stat_read(sb->s_bdev->bd_part, sectors[1]);
3429
3430         /* Cleanup superblock name */
3431         for (cp = sb->s_id; (cp = strchr(cp, '/'));)
3432                 *cp = '!';
3433
3434         /* -EINVAL is default */
3435         ret = -EINVAL;
3436         blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3437         if (!blocksize) {
3438                 ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3439                 goto out_fail;
3440         }
3441
3442         /*
3443          * The ext4 superblock will not be buffer aligned for other than 1kB
3444          * block sizes.  We need to calculate the offset from buffer start.
3445          */
3446         if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3447                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3448                 offset = do_div(logical_sb_block, blocksize);
3449         } else {
3450                 logical_sb_block = sb_block;
3451         }
3452
3453         if (!(bh = sb_bread_unmovable(sb, logical_sb_block))) {
3454                 ext4_msg(sb, KERN_ERR, "unable to read superblock");
3455                 goto out_fail;
3456         }
3457         /*
3458          * Note: s_es must be initialized as soon as possible because
3459          *       some ext4 macro-instructions depend on its value
3460          */
3461         es = (struct ext4_super_block *) (bh->b_data + offset);
3462         sbi->s_es = es;
3463         sb->s_magic = le16_to_cpu(es->s_magic);
3464         if (sb->s_magic != EXT4_SUPER_MAGIC)
3465                 goto cantfind_ext4;
3466         sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3467
3468         /* Warn if metadata_csum and gdt_csum are both set. */
3469         if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3470                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
3471             EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_GDT_CSUM))
3472                 ext4_warning(sb, "metadata_csum and uninit_bg are "
3473                              "redundant flags; please run fsck.");
3474
3475         /* Check for a known checksum algorithm */
3476         if (!ext4_verify_csum_type(sb, es)) {
3477                 ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3478                          "unknown checksum algorithm.");
3479                 silent = 1;
3480                 goto cantfind_ext4;
3481         }
3482
3483         /* Load the checksum driver */
3484         if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3485                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
3486                 sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3487                 if (IS_ERR(sbi->s_chksum_driver)) {
3488                         ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3489                         ret = PTR_ERR(sbi->s_chksum_driver);
3490                         sbi->s_chksum_driver = NULL;
3491                         goto failed_mount;
3492                 }
3493         }
3494
3495         /* Check superblock checksum */
3496         if (!ext4_superblock_csum_verify(sb, es)) {
3497                 ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3498                          "invalid superblock checksum.  Run e2fsck?");
3499                 silent = 1;
3500                 goto cantfind_ext4;
3501         }
3502
3503         /* Precompute checksum seed for all metadata */
3504         if (ext4_has_metadata_csum(sb))
3505                 sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3506                                                sizeof(es->s_uuid));
3507
3508         /* Set defaults before we parse the mount options */
3509         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3510         set_opt(sb, INIT_INODE_TABLE);
3511         if (def_mount_opts & EXT4_DEFM_DEBUG)
3512                 set_opt(sb, DEBUG);
3513         if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3514                 set_opt(sb, GRPID);
3515         if (def_mount_opts & EXT4_DEFM_UID16)
3516                 set_opt(sb, NO_UID32);
3517         /* xattr user namespace & acls are now defaulted on */
3518         set_opt(sb, XATTR_USER);
3519 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3520         set_opt(sb, POSIX_ACL);
3521 #endif
3522         /* don't forget to enable journal_csum when metadata_csum is enabled. */
3523         if (ext4_has_metadata_csum(sb))
3524                 set_opt(sb, JOURNAL_CHECKSUM);
3525
3526         if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3527                 set_opt(sb, JOURNAL_DATA);
3528         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3529                 set_opt(sb, ORDERED_DATA);
3530         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3531                 set_opt(sb, WRITEBACK_DATA);
3532
3533         if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3534                 set_opt(sb, ERRORS_PANIC);
3535         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3536                 set_opt(sb, ERRORS_CONT);
3537         else
3538                 set_opt(sb, ERRORS_RO);
3539         /* block_validity enabled by default; disable with noblock_validity */
3540         set_opt(sb, BLOCK_VALIDITY);
3541         if (def_mount_opts & EXT4_DEFM_DISCARD)
3542                 set_opt(sb, DISCARD);
3543
3544         sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3545         sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3546         sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3547         sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3548         sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3549
3550         if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3551                 set_opt(sb, BARRIER);
3552
3553         /*
3554          * enable delayed allocation by default
3555          * Use -o nodelalloc to turn it off
3556          */
3557         if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
3558             ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3559                 set_opt(sb, DELALLOC);
3560
3561         /*
3562          * set default s_li_wait_mult for lazyinit, for the case there is
3563          * no mount option specified.
3564          */
3565         sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3566
3567         if (!parse_options((char *) sbi->s_es->s_mount_opts, sb,
3568                            &journal_devnum, &journal_ioprio, 0)) {
3569                 ext4_msg(sb, KERN_WARNING,
3570                          "failed to parse options in superblock: %s",
3571                          sbi->s_es->s_mount_opts);
3572         }
3573         sbi->s_def_mount_opt = sbi->s_mount_opt;
3574         if (!parse_options((char *) data, sb, &journal_devnum,
3575                            &journal_ioprio, 0))
3576                 goto failed_mount;
3577
3578         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3579                 printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3580                             "with data=journal disables delayed "
3581                             "allocation and O_DIRECT support!\n");
3582                 if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3583                         ext4_msg(sb, KERN_ERR, "can't mount with "
3584                                  "both data=journal and delalloc");
3585                         goto failed_mount;
3586                 }
3587                 if (test_opt(sb, DIOREAD_NOLOCK)) {
3588                         ext4_msg(sb, KERN_ERR, "can't mount with "
3589                                  "both data=journal and dioread_nolock");
3590                         goto failed_mount;
3591                 }
3592                 if (test_opt(sb, DELALLOC))
3593                         clear_opt(sb, DELALLOC);
3594         }
3595
3596         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
3597                 (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
3598
3599         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3600             (EXT4_HAS_COMPAT_FEATURE(sb, ~0U) ||
3601              EXT4_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
3602              EXT4_HAS_INCOMPAT_FEATURE(sb, ~0U)))
3603                 ext4_msg(sb, KERN_WARNING,
3604                        "feature flags set on rev 0 fs, "
3605                        "running e2fsck is recommended");
3606
3607         if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
3608                 set_opt2(sb, HURD_COMPAT);
3609                 if (EXT4_HAS_INCOMPAT_FEATURE(sb,
3610                                               EXT4_FEATURE_INCOMPAT_64BIT)) {
3611                         ext4_msg(sb, KERN_ERR,
3612                                  "The Hurd can't support 64-bit file systems");
3613                         goto failed_mount;
3614                 }
3615         }
3616
3617         if (IS_EXT2_SB(sb)) {
3618                 if (ext2_feature_set_ok(sb))
3619                         ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3620                                  "using the ext4 subsystem");
3621                 else {
3622                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3623                                  "to feature incompatibilities");
3624                         goto failed_mount;
3625                 }
3626         }
3627
3628         if (IS_EXT3_SB(sb)) {
3629                 if (ext3_feature_set_ok(sb))
3630                         ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3631                                  "using the ext4 subsystem");
3632                 else {
3633                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3634                                  "to feature incompatibilities");
3635                         goto failed_mount;
3636                 }
3637         }
3638
3639         /*
3640          * Check feature flags regardless of the revision level, since we
3641          * previously didn't change the revision level when setting the flags,
3642          * so there is a chance incompat flags are set on a rev 0 filesystem.
3643          */
3644         if (!ext4_feature_set_ok(sb, (sb->s_flags & MS_RDONLY)))
3645                 goto failed_mount;
3646
3647         blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3648         if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3649             blocksize > EXT4_MAX_BLOCK_SIZE) {
3650                 ext4_msg(sb, KERN_ERR,
3651                        "Unsupported filesystem blocksize %d", blocksize);
3652                 goto failed_mount;
3653         }
3654
3655         if (sb->s_blocksize != blocksize) {
3656                 /* Validate the filesystem blocksize */
3657                 if (!sb_set_blocksize(sb, blocksize)) {
3658                         ext4_msg(sb, KERN_ERR, "bad block size %d",
3659                                         blocksize);
3660                         goto failed_mount;
3661                 }
3662
3663                 brelse(bh);
3664                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3665                 offset = do_div(logical_sb_block, blocksize);
3666                 bh = sb_bread_unmovable(sb, logical_sb_block);
3667                 if (!bh) {
3668                         ext4_msg(sb, KERN_ERR,
3669                                "Can't read superblock on 2nd try");
3670                         goto failed_mount;
3671                 }
3672                 es = (struct ext4_super_block *)(bh->b_data + offset);
3673                 sbi->s_es = es;
3674                 if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
3675                         ext4_msg(sb, KERN_ERR,
3676                                "Magic mismatch, very weird!");
3677                         goto failed_mount;
3678                 }
3679         }
3680
3681         has_huge_files = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3682                                 EXT4_FEATURE_RO_COMPAT_HUGE_FILE);
3683         sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
3684                                                       has_huge_files);
3685         sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
3686
3687         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3688                 sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3689                 sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3690         } else {
3691                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3692                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3693                 if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3694                     (!is_power_of_2(sbi->s_inode_size)) ||
3695                     (sbi->s_inode_size > blocksize)) {
3696                         ext4_msg(sb, KERN_ERR,
3697                                "unsupported inode size: %d",
3698                                sbi->s_inode_size);
3699                         goto failed_mount;
3700                 }
3701                 if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
3702                         sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
3703         }
3704
3705         sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
3706         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT)) {
3707                 if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
3708                     sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
3709                     !is_power_of_2(sbi->s_desc_size)) {
3710                         ext4_msg(sb, KERN_ERR,
3711                                "unsupported descriptor size %lu",
3712                                sbi->s_desc_size);
3713                         goto failed_mount;
3714                 }
3715         } else
3716                 sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
3717
3718         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
3719         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
3720         if (EXT4_INODE_SIZE(sb) == 0 || EXT4_INODES_PER_GROUP(sb) == 0)
3721                 goto cantfind_ext4;
3722
3723         sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
3724         if (sbi->s_inodes_per_block == 0)
3725                 goto cantfind_ext4;
3726         sbi->s_itb_per_group = sbi->s_inodes_per_group /
3727                                         sbi->s_inodes_per_block;
3728         sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
3729         sbi->s_sbh = bh;
3730         sbi->s_mount_state = le16_to_cpu(es->s_state);
3731         sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
3732         sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
3733
3734         for (i = 0; i < 4; i++)
3735                 sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
3736         sbi->s_def_hash_version = es->s_def_hash_version;
3737         if (EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_DIR_INDEX)) {
3738                 i = le32_to_cpu(es->s_flags);
3739                 if (i & EXT2_FLAGS_UNSIGNED_HASH)
3740                         sbi->s_hash_unsigned = 3;
3741                 else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
3742 #ifdef __CHAR_UNSIGNED__
3743                         if (!(sb->s_flags & MS_RDONLY))
3744                                 es->s_flags |=
3745                                         cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
3746                         sbi->s_hash_unsigned = 3;
3747 #else
3748                         if (!(sb->s_flags & MS_RDONLY))
3749                                 es->s_flags |=
3750                                         cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
3751 #endif
3752                 }
3753         }
3754
3755         /* Handle clustersize */
3756         clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
3757         has_bigalloc = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3758                                 EXT4_FEATURE_RO_COMPAT_BIGALLOC);
3759         if (has_bigalloc) {
3760                 if (clustersize < blocksize) {
3761                         ext4_msg(sb, KERN_ERR,
3762                                  "cluster size (%d) smaller than "
3763                                  "block size (%d)", clustersize, blocksize);
3764                         goto failed_mount;
3765                 }
3766                 sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
3767                         le32_to_cpu(es->s_log_block_size);
3768                 sbi->s_clusters_per_group =
3769                         le32_to_cpu(es->s_clusters_per_group);
3770                 if (sbi->s_clusters_per_group > blocksize * 8) {
3771                         ext4_msg(sb, KERN_ERR,
3772                                  "#clusters per group too big: %lu",
3773                                  sbi->s_clusters_per_group);
3774                         goto failed_mount;
3775                 }
3776                 if (sbi->s_blocks_per_group !=
3777                     (sbi->s_clusters_per_group * (clustersize / blocksize))) {
3778                         ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
3779                                  "clusters per group (%lu) inconsistent",
3780                                  sbi->s_blocks_per_group,
3781                                  sbi->s_clusters_per_group);
3782                         goto failed_mount;
3783                 }
3784         } else {
3785                 if (clustersize != blocksize) {
3786                         ext4_warning(sb, "fragment/cluster size (%d) != "
3787                                      "block size (%d)", clustersize,
3788                                      blocksize);
3789                         clustersize = blocksize;
3790                 }
3791                 if (sbi->s_blocks_per_group > blocksize * 8) {
3792                         ext4_msg(sb, KERN_ERR,
3793                                  "#blocks per group too big: %lu",
3794                                  sbi->s_blocks_per_group);
3795                         goto failed_mount;
3796                 }
3797                 sbi->s_clusters_per_group = sbi->s_blocks_per_group;
3798                 sbi->s_cluster_bits = 0;
3799         }
3800         sbi->s_cluster_ratio = clustersize / blocksize;
3801
3802         if (sbi->s_inodes_per_group > blocksize * 8) {
3803                 ext4_msg(sb, KERN_ERR,
3804                        "#inodes per group too big: %lu",
3805                        sbi->s_inodes_per_group);
3806                 goto failed_mount;
3807         }
3808
3809         /* Do we have standard group size of clustersize * 8 blocks ? */
3810         if (sbi->s_blocks_per_group == clustersize << 3)
3811                 set_opt2(sb, STD_GROUP_SIZE);
3812
3813         /*
3814          * Test whether we have more sectors than will fit in sector_t,
3815          * and whether the max offset is addressable by the page cache.
3816          */
3817         err = generic_check_addressable(sb->s_blocksize_bits,
3818                                         ext4_blocks_count(es));
3819         if (err) {
3820                 ext4_msg(sb, KERN_ERR, "filesystem"
3821                          " too large to mount safely on this system");
3822                 if (sizeof(sector_t) < 8)
3823                         ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
3824                 goto failed_mount;
3825         }
3826
3827         if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
3828                 goto cantfind_ext4;
3829
3830         /* check blocks count against device size */
3831         blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
3832         if (blocks_count && ext4_blocks_count(es) > blocks_count) {
3833                 ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
3834                        "exceeds size of device (%llu blocks)",
3835                        ext4_blocks_count(es), blocks_count);
3836                 goto failed_mount;
3837         }
3838
3839         /*
3840          * It makes no sense for the first data block to be beyond the end
3841          * of the filesystem.
3842          */
3843         if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
3844                 ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
3845                          "block %u is beyond end of filesystem (%llu)",
3846                          le32_to_cpu(es->s_first_data_block),
3847                          ext4_blocks_count(es));
3848                 goto failed_mount;
3849         }
3850         blocks_count = (ext4_blocks_count(es) -
3851                         le32_to_cpu(es->s_first_data_block) +
3852                         EXT4_BLOCKS_PER_GROUP(sb) - 1);
3853         do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
3854         if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
3855                 ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
3856                        "(block count %llu, first data block %u, "
3857                        "blocks per group %lu)", sbi->s_groups_count,
3858                        ext4_blocks_count(es),
3859                        le32_to_cpu(es->s_first_data_block),
3860                        EXT4_BLOCKS_PER_GROUP(sb));
3861                 goto failed_mount;
3862         }
3863         sbi->s_groups_count = blocks_count;
3864         sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
3865                         (EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
3866         db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
3867                    EXT4_DESC_PER_BLOCK(sb);
3868         sbi->s_group_desc = ext4_kvmalloc(db_count *
3869                                           sizeof(struct buffer_head *),
3870                                           GFP_KERNEL);
3871         if (sbi->s_group_desc == NULL) {
3872                 ext4_msg(sb, KERN_ERR, "not enough memory");
3873                 ret = -ENOMEM;
3874                 goto failed_mount;
3875         }
3876
3877         if (ext4_proc_root)
3878                 sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root);
3879
3880         if (sbi->s_proc)
3881                 proc_create_data("options", S_IRUGO, sbi->s_proc,
3882                                  &ext4_seq_options_fops, sb);
3883
3884         bgl_lock_init(sbi->s_blockgroup_lock);
3885
3886         for (i = 0; i < db_count; i++) {
3887                 block = descriptor_loc(sb, logical_sb_block, i);
3888                 sbi->s_group_desc[i] = sb_bread_unmovable(sb, block);
3889                 if (!sbi->s_group_desc[i]) {
3890                         ext4_msg(sb, KERN_ERR,
3891                                "can't read group descriptor %d", i);
3892                         db_count = i;
3893                         goto failed_mount2;
3894                 }
3895         }
3896         if (!ext4_check_descriptors(sb, &first_not_zeroed)) {
3897                 ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
3898                 goto failed_mount2;
3899         }
3900
3901         sbi->s_gdb_count = db_count;
3902         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
3903         spin_lock_init(&sbi->s_next_gen_lock);
3904
3905         init_timer(&sbi->s_err_report);
3906         sbi->s_err_report.function = print_daily_error_info;
3907         sbi->s_err_report.data = (unsigned long) sb;
3908
3909         /* Register extent status tree shrinker */
3910         if (ext4_es_register_shrinker(sbi))
3911                 goto failed_mount3;
3912
3913         sbi->s_stripe = ext4_get_stripe_size(sbi);
3914         sbi->s_extent_max_zeroout_kb = 32;
3915
3916         /*
3917          * set up enough so that it can read an inode
3918          */
3919         sb->s_op = &ext4_sops;
3920         sb->s_export_op = &ext4_export_ops;
3921         sb->s_xattr = ext4_xattr_handlers;
3922 #ifdef CONFIG_QUOTA
3923         sb->dq_op = &ext4_quota_operations;
3924         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
3925                 sb->s_qcop = &dquot_quotactl_sysfile_ops;
3926         else
3927                 sb->s_qcop = &ext4_qctl_operations;
3928         sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP;
3929 #endif
3930         memcpy(sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
3931
3932         INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
3933         mutex_init(&sbi->s_orphan_lock);
3934
3935         sb->s_root = NULL;
3936
3937         needs_recovery = (es->s_last_orphan != 0 ||
3938                           EXT4_HAS_INCOMPAT_FEATURE(sb,
3939                                     EXT4_FEATURE_INCOMPAT_RECOVER));
3940
3941         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_MMP) &&
3942             !(sb->s_flags & MS_RDONLY))
3943                 if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
3944                         goto failed_mount3a;
3945
3946         /*
3947          * The first inode we look at is the journal inode.  Don't try
3948          * root first: it may be modified in the journal!
3949          */
3950         if (!test_opt(sb, NOLOAD) &&
3951             EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
3952                 if (ext4_load_journal(sb, es, journal_devnum))
3953                         goto failed_mount3a;
3954         } else if (test_opt(sb, NOLOAD) && !(sb->s_flags & MS_RDONLY) &&
3955               EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
3956                 ext4_msg(sb, KERN_ERR, "required journal recovery "
3957                        "suppressed and not mounted read-only");
3958                 goto failed_mount_wq;
3959         } else {
3960                 clear_opt(sb, DATA_FLAGS);
3961                 sbi->s_journal = NULL;
3962                 needs_recovery = 0;
3963                 goto no_journal;
3964         }
3965
3966         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT) &&
3967             !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
3968                                        JBD2_FEATURE_INCOMPAT_64BIT)) {
3969                 ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
3970                 goto failed_mount_wq;
3971         }
3972
3973         if (!set_journal_csum_feature_set(sb)) {
3974                 ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
3975                          "feature set");
3976                 goto failed_mount_wq;
3977         }
3978
3979         /* We have now updated the journal if required, so we can
3980          * validate the data journaling mode. */
3981         switch (test_opt(sb, DATA_FLAGS)) {
3982         case 0:
3983                 /* No mode set, assume a default based on the journal
3984                  * capabilities: ORDERED_DATA if the journal can
3985                  * cope, else JOURNAL_DATA
3986                  */
3987                 if (jbd2_journal_check_available_features
3988                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
3989                         set_opt(sb, ORDERED_DATA);
3990                 else
3991                         set_opt(sb, JOURNAL_DATA);
3992                 break;
3993
3994         case EXT4_MOUNT_ORDERED_DATA:
3995         case EXT4_MOUNT_WRITEBACK_DATA:
3996                 if (!jbd2_journal_check_available_features
3997                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
3998                         ext4_msg(sb, KERN_ERR, "Journal does not support "
3999                                "requested data journaling mode");
4000                         goto failed_mount_wq;
4001                 }
4002         default:
4003                 break;
4004         }
4005         set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4006
4007         sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
4008
4009 no_journal:
4010         if (ext4_mballoc_ready) {
4011                 sbi->s_mb_cache = ext4_xattr_create_cache(sb->s_id);
4012                 if (!sbi->s_mb_cache) {
4013                         ext4_msg(sb, KERN_ERR, "Failed to create an mb_cache");
4014                         goto failed_mount_wq;
4015                 }
4016         }
4017
4018         /*
4019          * Get the # of file system overhead blocks from the
4020          * superblock if present.
4021          */
4022         if (es->s_overhead_clusters)
4023                 sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
4024         else {
4025                 err = ext4_calculate_overhead(sb);
4026                 if (err)
4027                         goto failed_mount_wq;
4028         }
4029
4030         /*
4031          * The maximum number of concurrent works can be high and
4032          * concurrency isn't really necessary.  Limit it to 1.
4033          */
4034         EXT4_SB(sb)->rsv_conversion_wq =
4035                 alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
4036         if (!EXT4_SB(sb)->rsv_conversion_wq) {
4037                 printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
4038                 ret = -ENOMEM;
4039                 goto failed_mount4;
4040         }
4041
4042         /*
4043          * The jbd2_journal_load will have done any necessary log recovery,
4044          * so we can safely mount the rest of the filesystem now.
4045          */
4046
4047         root = ext4_iget(sb, EXT4_ROOT_INO);
4048         if (IS_ERR(root)) {
4049                 ext4_msg(sb, KERN_ERR, "get root inode failed");
4050                 ret = PTR_ERR(root);
4051                 root = NULL;
4052                 goto failed_mount4;
4053         }
4054         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
4055                 ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
4056                 iput(root);
4057                 goto failed_mount4;
4058         }
4059         sb->s_root = d_make_root(root);
4060         if (!sb->s_root) {
4061                 ext4_msg(sb, KERN_ERR, "get root dentry failed");
4062                 ret = -ENOMEM;
4063                 goto failed_mount4;
4064         }
4065
4066         if (ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY))
4067                 sb->s_flags |= MS_RDONLY;
4068
4069         /* determine the minimum size of new large inodes, if present */
4070         if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
4071                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4072                                                      EXT4_GOOD_OLD_INODE_SIZE;
4073                 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
4074                                        EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE)) {
4075                         if (sbi->s_want_extra_isize <
4076                             le16_to_cpu(es->s_want_extra_isize))
4077                                 sbi->s_want_extra_isize =
4078                                         le16_to_cpu(es->s_want_extra_isize);
4079                         if (sbi->s_want_extra_isize <
4080                             le16_to_cpu(es->s_min_extra_isize))
4081                                 sbi->s_want_extra_isize =
4082                                         le16_to_cpu(es->s_min_extra_isize);
4083                 }
4084         }
4085         /* Check if enough inode space is available */
4086         if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
4087                                                         sbi->s_inode_size) {
4088                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4089                                                        EXT4_GOOD_OLD_INODE_SIZE;
4090                 ext4_msg(sb, KERN_INFO, "required extra inode space not"
4091                          "available");
4092         }
4093
4094         err = ext4_reserve_clusters(sbi, ext4_calculate_resv_clusters(sb));
4095         if (err) {
4096                 ext4_msg(sb, KERN_ERR, "failed to reserve %llu clusters for "
4097                          "reserved pool", ext4_calculate_resv_clusters(sb));
4098                 goto failed_mount4a;
4099         }
4100
4101         err = ext4_setup_system_zone(sb);
4102         if (err) {
4103                 ext4_msg(sb, KERN_ERR, "failed to initialize system "
4104                          "zone (%d)", err);
4105                 goto failed_mount4a;
4106         }
4107
4108         ext4_ext_init(sb);
4109         err = ext4_mb_init(sb);
4110         if (err) {
4111                 ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
4112                          err);
4113                 goto failed_mount5;
4114         }
4115
4116         block = ext4_count_free_clusters(sb);
4117         ext4_free_blocks_count_set(sbi->s_es,
4118                                    EXT4_C2B(sbi, block));
4119         err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
4120                                   GFP_KERNEL);
4121         if (!err) {
4122                 unsigned long freei = ext4_count_free_inodes(sb);
4123                 sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
4124                 err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
4125                                           GFP_KERNEL);
4126         }
4127         if (!err)
4128                 err = percpu_counter_init(&sbi->s_dirs_counter,
4129                                           ext4_count_dirs(sb), GFP_KERNEL);
4130         if (!err)
4131                 err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
4132                                           GFP_KERNEL);
4133         if (err) {
4134                 ext4_msg(sb, KERN_ERR, "insufficient memory");
4135                 goto failed_mount6;
4136         }
4137
4138         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
4139                 if (!ext4_fill_flex_info(sb)) {
4140                         ext4_msg(sb, KERN_ERR,
4141                                "unable to initialize "
4142                                "flex_bg meta info!");
4143                         goto failed_mount6;
4144                 }
4145
4146         err = ext4_register_li_request(sb, first_not_zeroed);
4147         if (err)
4148                 goto failed_mount6;
4149
4150         sbi->s_kobj.kset = ext4_kset;
4151         init_completion(&sbi->s_kobj_unregister);
4152         err = kobject_init_and_add(&sbi->s_kobj, &ext4_ktype, NULL,
4153                                    "%s", sb->s_id);
4154         if (err)
4155                 goto failed_mount7;
4156
4157 #ifdef CONFIG_QUOTA
4158         /* Enable quota usage during mount. */
4159         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
4160             !(sb->s_flags & MS_RDONLY)) {
4161                 err = ext4_enable_quotas(sb);
4162                 if (err)
4163                         goto failed_mount8;
4164         }
4165 #endif  /* CONFIG_QUOTA */
4166
4167         EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
4168         ext4_orphan_cleanup(sb, es);
4169         EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
4170         if (needs_recovery) {
4171                 ext4_msg(sb, KERN_INFO, "recovery complete");
4172                 ext4_mark_recovery_complete(sb, es);
4173         }
4174         if (EXT4_SB(sb)->s_journal) {
4175                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
4176                         descr = " journalled data mode";
4177                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
4178                         descr = " ordered data mode";
4179                 else
4180                         descr = " writeback data mode";
4181         } else
4182                 descr = "out journal";
4183
4184         if (test_opt(sb, DISCARD)) {
4185                 struct request_queue *q = bdev_get_queue(sb->s_bdev);
4186                 if (!blk_queue_discard(q))
4187                         ext4_msg(sb, KERN_WARNING,
4188                                  "mounting with \"discard\" option, but "
4189                                  "the device does not support discard");
4190         }
4191
4192         ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
4193                  "Opts: %s%s%s", descr, sbi->s_es->s_mount_opts,
4194                  *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
4195
4196         if (es->s_error_count)
4197                 mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
4198
4199         /* Enable message ratelimiting. Default is 10 messages per 5 secs. */
4200         ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
4201         ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
4202         ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
4203
4204         kfree(orig_data);
4205         return 0;
4206
4207 cantfind_ext4:
4208         if (!silent)
4209                 ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
4210         goto failed_mount;
4211
4212 #ifdef CONFIG_QUOTA
4213 failed_mount8:
4214         kobject_del(&sbi->s_kobj);
4215 #endif
4216 failed_mount7:
4217         ext4_unregister_li_request(sb);
4218 failed_mount6:
4219         ext4_mb_release(sb);
4220         if (sbi->s_flex_groups)
4221                 kvfree(sbi->s_flex_groups);
4222         percpu_counter_destroy(&sbi->s_freeclusters_counter);
4223         percpu_counter_destroy(&sbi->s_freeinodes_counter);
4224         percpu_counter_destroy(&sbi->s_dirs_counter);
4225         percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4226 failed_mount5:
4227         ext4_ext_release(sb);
4228         ext4_release_system_zone(sb);
4229 failed_mount4a:
4230         dput(sb->s_root);
4231         sb->s_root = NULL;
4232 failed_mount4:
4233         ext4_msg(sb, KERN_ERR, "mount failed");
4234         if (EXT4_SB(sb)->rsv_conversion_wq)
4235                 destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4236 failed_mount_wq:
4237         if (sbi->s_journal) {
4238                 jbd2_journal_destroy(sbi->s_journal);
4239                 sbi->s_journal = NULL;
4240         }
4241 failed_mount3a:
4242         ext4_es_unregister_shrinker(sbi);
4243 failed_mount3:
4244         del_timer_sync(&sbi->s_err_report);
4245         if (sbi->s_mmp_tsk)
4246                 kthread_stop(sbi->s_mmp_tsk);
4247 failed_mount2:
4248         for (i = 0; i < db_count; i++)
4249                 brelse(sbi->s_group_desc[i]);
4250         kvfree(sbi->s_group_desc);
4251 failed_mount:
4252         if (sbi->s_chksum_driver)
4253                 crypto_free_shash(sbi->s_chksum_driver);
4254         if (sbi->s_proc) {
4255                 remove_proc_entry("options", sbi->s_proc);
4256                 remove_proc_entry(sb->s_id, ext4_proc_root);
4257         }
4258 #ifdef CONFIG_QUOTA
4259         for (i = 0; i < EXT4_MAXQUOTAS; i++)
4260                 kfree(sbi->s_qf_names[i]);
4261 #endif
4262         ext4_blkdev_remove(sbi);
4263         brelse(bh);
4264 out_fail:
4265         sb->s_fs_info = NULL;
4266         kfree(sbi->s_blockgroup_lock);
4267         kfree(sbi);
4268 out_free_orig:
4269         kfree(orig_data);
4270         return err ? err : ret;
4271 }
4272
4273 /*
4274  * Setup any per-fs journal parameters now.  We'll do this both on
4275  * initial mount, once the journal has been initialised but before we've
4276  * done any recovery; and again on any subsequent remount.
4277  */
4278 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4279 {
4280         struct ext4_sb_info *sbi = EXT4_SB(sb);
4281
4282         journal->j_commit_interval = sbi->s_commit_interval;
4283         journal->j_min_batch_time = sbi->s_min_batch_time;
4284         journal->j_max_batch_time = sbi->s_max_batch_time;
4285
4286         write_lock(&journal->j_state_lock);
4287         if (test_opt(sb, BARRIER))
4288                 journal->j_flags |= JBD2_BARRIER;
4289         else
4290                 journal->j_flags &= ~JBD2_BARRIER;
4291         if (test_opt(sb, DATA_ERR_ABORT))
4292                 journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4293         else
4294                 journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4295         write_unlock(&journal->j_state_lock);
4296 }
4297
4298 static journal_t *ext4_get_journal(struct super_block *sb,
4299                                    unsigned int journal_inum)
4300 {
4301         struct inode *journal_inode;
4302         journal_t *journal;
4303
4304         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4305
4306         /* First, test for the existence of a valid inode on disk.  Bad
4307          * things happen if we iget() an unused inode, as the subsequent
4308          * iput() will try to delete it. */
4309
4310         journal_inode = ext4_iget(sb, journal_inum);
4311         if (IS_ERR(journal_inode)) {
4312                 ext4_msg(sb, KERN_ERR, "no journal found");
4313                 return NULL;
4314         }
4315         if (!journal_inode->i_nlink) {
4316                 make_bad_inode(journal_inode);
4317                 iput(journal_inode);
4318                 ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4319                 return NULL;
4320         }
4321
4322         jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4323                   journal_inode, journal_inode->i_size);
4324         if (!S_ISREG(journal_inode->i_mode)) {
4325                 ext4_msg(sb, KERN_ERR, "invalid journal inode");
4326                 iput(journal_inode);
4327                 return NULL;
4328         }
4329
4330         journal = jbd2_journal_init_inode(journal_inode);
4331         if (!journal) {
4332                 ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4333                 iput(journal_inode);
4334                 return NULL;
4335         }
4336         journal->j_private = sb;
4337         ext4_init_journal_params(sb, journal);
4338         return journal;
4339 }
4340
4341 static journal_t *ext4_get_dev_journal(struct super_block *sb,
4342                                        dev_t j_dev)
4343 {
4344         struct buffer_head *bh;
4345         journal_t *journal;
4346         ext4_fsblk_t start;
4347         ext4_fsblk_t len;
4348         int hblock, blocksize;
4349         ext4_fsblk_t sb_block;
4350         unsigned long offset;
4351         struct ext4_super_block *es;
4352         struct block_device *bdev;
4353
4354         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4355
4356         bdev = ext4_blkdev_get(j_dev, sb);
4357         if (bdev == NULL)
4358                 return NULL;
4359
4360         blocksize = sb->s_blocksize;
4361         hblock = bdev_logical_block_size(bdev);
4362         if (blocksize < hblock) {
4363                 ext4_msg(sb, KERN_ERR,
4364                         "blocksize too small for journal device");
4365                 goto out_bdev;
4366         }
4367
4368         sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4369         offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4370         set_blocksize(bdev, blocksize);
4371         if (!(bh = __bread(bdev, sb_block, blocksize))) {
4372                 ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4373                        "external journal");
4374                 goto out_bdev;
4375         }
4376
4377         es = (struct ext4_super_block *) (bh->b_data + offset);
4378         if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4379             !(le32_to_cpu(es->s_feature_incompat) &
4380               EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4381                 ext4_msg(sb, KERN_ERR, "external journal has "
4382                                         "bad superblock");
4383                 brelse(bh);
4384                 goto out_bdev;
4385         }
4386
4387         if ((le32_to_cpu(es->s_feature_ro_compat) &
4388              EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
4389             es->s_checksum != ext4_superblock_csum(sb, es)) {
4390                 ext4_msg(sb, KERN_ERR, "external journal has "
4391                                        "corrupt superblock");
4392                 brelse(bh);
4393                 goto out_bdev;
4394         }
4395
4396         if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4397                 ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4398                 brelse(bh);
4399                 goto out_bdev;
4400         }
4401
4402         len = ext4_blocks_count(es);
4403         start = sb_block + 1;
4404         brelse(bh);     /* we're done with the superblock */
4405
4406         journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4407                                         start, len, blocksize);
4408         if (!journal) {
4409                 ext4_msg(sb, KERN_ERR, "failed to create device journal");
4410                 goto out_bdev;
4411         }
4412         journal->j_private = sb;
4413         ll_rw_block(READ | REQ_META | REQ_PRIO, 1, &journal->j_sb_buffer);
4414         wait_on_buffer(journal->j_sb_buffer);
4415         if (!buffer_uptodate(journal->j_sb_buffer)) {
4416                 ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4417                 goto out_journal;
4418         }
4419         if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4420                 ext4_msg(sb, KERN_ERR, "External journal has more than one "
4421                                         "user (unsupported) - %d",
4422                         be32_to_cpu(journal->j_superblock->s_nr_users));
4423                 goto out_journal;
4424         }
4425         EXT4_SB(sb)->journal_bdev = bdev;
4426         ext4_init_journal_params(sb, journal);
4427         return journal;
4428
4429 out_journal:
4430         jbd2_journal_destroy(journal);
4431 out_bdev:
4432         ext4_blkdev_put(bdev);
4433         return NULL;
4434 }
4435
4436 static int ext4_load_journal(struct super_block *sb,
4437                              struct ext4_super_block *es,
4438                              unsigned long journal_devnum)
4439 {
4440         journal_t *journal;
4441         unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4442         dev_t journal_dev;
4443         int err = 0;
4444         int really_read_only;
4445
4446         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4447
4448         if (journal_devnum &&
4449             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4450                 ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4451                         "numbers have changed");
4452                 journal_dev = new_decode_dev(journal_devnum);
4453         } else
4454                 journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4455
4456         really_read_only = bdev_read_only(sb->s_bdev);
4457
4458         /*
4459          * Are we loading a blank journal or performing recovery after a
4460          * crash?  For recovery, we need to check in advance whether we
4461          * can get read-write access to the device.
4462          */
4463         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
4464                 if (sb->s_flags & MS_RDONLY) {
4465                         ext4_msg(sb, KERN_INFO, "INFO: recovery "
4466                                         "required on readonly filesystem");
4467                         if (really_read_only) {
4468                                 ext4_msg(sb, KERN_ERR, "write access "
4469                                         "unavailable, cannot proceed");
4470                                 return -EROFS;
4471                         }
4472                         ext4_msg(sb, KERN_INFO, "write access will "
4473                                "be enabled during recovery");
4474                 }
4475         }
4476
4477         if (journal_inum && journal_dev) {
4478                 ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4479                        "and inode journals!");
4480                 return -EINVAL;
4481         }
4482
4483         if (journal_inum) {
4484                 if (!(journal = ext4_get_journal(sb, journal_inum)))
4485                         return -EINVAL;
4486         } else {
4487                 if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4488                         return -EINVAL;
4489         }
4490
4491         if (!(journal->j_flags & JBD2_BARRIER))
4492                 ext4_msg(sb, KERN_INFO, "barriers disabled");
4493
4494         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER))
4495                 err = jbd2_journal_wipe(journal, !really_read_only);
4496         if (!err) {
4497                 char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4498                 if (save)
4499                         memcpy(save, ((char *) es) +
4500                                EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4501                 err = jbd2_journal_load(journal);
4502                 if (save)
4503                         memcpy(((char *) es) + EXT4_S_ERR_START,
4504                                save, EXT4_S_ERR_LEN);
4505                 kfree(save);
4506         }
4507
4508         if (err) {
4509                 ext4_msg(sb, KERN_ERR, "error loading journal");
4510                 jbd2_journal_destroy(journal);
4511                 return err;
4512         }
4513
4514         EXT4_SB(sb)->s_journal = journal;
4515         ext4_clear_journal_err(sb, es);
4516
4517         if (!really_read_only && journal_devnum &&
4518             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4519                 es->s_journal_dev = cpu_to_le32(journal_devnum);
4520
4521                 /* Make sure we flush the recovery flag to disk. */
4522                 ext4_commit_super(sb, 1);
4523         }
4524
4525         return 0;
4526 }
4527
4528 static int ext4_commit_super(struct super_block *sb, int sync)
4529 {
4530         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4531         struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4532         int error = 0;
4533
4534         if (!sbh || block_device_ejected(sb))
4535                 return error;
4536         if (buffer_write_io_error(sbh)) {
4537                 /*
4538                  * Oh, dear.  A previous attempt to write the
4539                  * superblock failed.  This could happen because the
4540                  * USB device was yanked out.  Or it could happen to
4541                  * be a transient write error and maybe the block will
4542                  * be remapped.  Nothing we can do but to retry the
4543                  * write and hope for the best.
4544                  */
4545                 ext4_msg(sb, KERN_ERR, "previous I/O error to "
4546                        "superblock detected");
4547                 clear_buffer_write_io_error(sbh);
4548                 set_buffer_uptodate(sbh);
4549         }
4550         /*
4551          * If the file system is mounted read-only, don't update the
4552          * superblock write time.  This avoids updating the superblock
4553          * write time when we are mounting the root file system
4554          * read/only but we need to replay the journal; at that point,
4555          * for people who are east of GMT and who make their clock
4556          * tick in localtime for Windows bug-for-bug compatibility,
4557          * the clock is set in the future, and this will cause e2fsck
4558          * to complain and force a full file system check.
4559          */
4560         if (!(sb->s_flags & MS_RDONLY))
4561                 es->s_wtime = cpu_to_le32(get_seconds());
4562         if (sb->s_bdev->bd_part)
4563                 es->s_kbytes_written =
4564                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
4565                             ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
4566                               EXT4_SB(sb)->s_sectors_written_start) >> 1));
4567         else
4568                 es->s_kbytes_written =
4569                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
4570         if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeclusters_counter))
4571                 ext4_free_blocks_count_set(es,
4572                         EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
4573                                 &EXT4_SB(sb)->s_freeclusters_counter)));
4574         if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeinodes_counter))
4575                 es->s_free_inodes_count =
4576                         cpu_to_le32(percpu_counter_sum_positive(
4577                                 &EXT4_SB(sb)->s_freeinodes_counter));
4578         BUFFER_TRACE(sbh, "marking dirty");
4579         ext4_superblock_csum_set(sb);
4580         mark_buffer_dirty(sbh);
4581         if (sync) {
4582                 error = sync_dirty_buffer(sbh);
4583                 if (error)
4584                         return error;
4585
4586                 error = buffer_write_io_error(sbh);
4587                 if (error) {
4588                         ext4_msg(sb, KERN_ERR, "I/O error while writing "
4589                                "superblock");
4590                         clear_buffer_write_io_error(sbh);
4591                         set_buffer_uptodate(sbh);
4592                 }
4593         }
4594         return error;
4595 }
4596
4597 /*
4598  * Have we just finished recovery?  If so, and if we are mounting (or
4599  * remounting) the filesystem readonly, then we will end up with a
4600  * consistent fs on disk.  Record that fact.
4601  */
4602 static void ext4_mark_recovery_complete(struct super_block *sb,
4603                                         struct ext4_super_block *es)
4604 {
4605         journal_t *journal = EXT4_SB(sb)->s_journal;
4606
4607         if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
4608                 BUG_ON(journal != NULL);
4609                 return;
4610         }
4611         jbd2_journal_lock_updates(journal);
4612         if (jbd2_journal_flush(journal) < 0)
4613                 goto out;
4614
4615         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER) &&
4616             sb->s_flags & MS_RDONLY) {
4617                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4618                 ext4_commit_super(sb, 1);
4619         }
4620
4621 out:
4622         jbd2_journal_unlock_updates(journal);
4623 }
4624
4625 /*
4626  * If we are mounting (or read-write remounting) a filesystem whose journal
4627  * has recorded an error from a previous lifetime, move that error to the
4628  * main filesystem now.
4629  */
4630 static void ext4_clear_journal_err(struct super_block *sb,
4631                                    struct ext4_super_block *es)
4632 {
4633         journal_t *journal;
4634         int j_errno;
4635         const char *errstr;
4636
4637         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4638
4639         journal = EXT4_SB(sb)->s_journal;
4640
4641         /*
4642          * Now check for any error status which may have been recorded in the
4643          * journal by a prior ext4_error() or ext4_abort()
4644          */
4645
4646         j_errno = jbd2_journal_errno(journal);
4647         if (j_errno) {
4648                 char nbuf[16];
4649
4650                 errstr = ext4_decode_error(sb, j_errno, nbuf);
4651                 ext4_warning(sb, "Filesystem error recorded "
4652                              "from previous mount: %s", errstr);
4653                 ext4_warning(sb, "Marking fs in need of filesystem check.");
4654
4655                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
4656                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
4657                 ext4_commit_super(sb, 1);
4658
4659                 jbd2_journal_clear_err(journal);
4660                 jbd2_journal_update_sb_errno(journal);
4661         }
4662 }
4663
4664 /*
4665  * Force the running and committing transactions to commit,
4666  * and wait on the commit.
4667  */
4668 int ext4_force_commit(struct super_block *sb)
4669 {
4670         journal_t *journal;
4671
4672         if (sb->s_flags & MS_RDONLY)
4673                 return 0;
4674
4675         journal = EXT4_SB(sb)->s_journal;
4676         return ext4_journal_force_commit(journal);
4677 }
4678
4679 static int ext4_sync_fs(struct super_block *sb, int wait)
4680 {
4681         int ret = 0;
4682         tid_t target;
4683         bool needs_barrier = false;
4684         struct ext4_sb_info *sbi = EXT4_SB(sb);
4685
4686         trace_ext4_sync_fs(sb, wait);
4687         flush_workqueue(sbi->rsv_conversion_wq);
4688         /*
4689          * Writeback quota in non-journalled quota case - journalled quota has
4690          * no dirty dquots
4691          */
4692         dquot_writeback_dquots(sb, -1);
4693         /*
4694          * Data writeback is possible w/o journal transaction, so barrier must
4695          * being sent at the end of the function. But we can skip it if
4696          * transaction_commit will do it for us.
4697          */
4698         if (sbi->s_journal) {
4699                 target = jbd2_get_latest_transaction(sbi->s_journal);
4700                 if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
4701                     !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
4702                         needs_barrier = true;
4703
4704                 if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
4705                         if (wait)
4706                                 ret = jbd2_log_wait_commit(sbi->s_journal,
4707                                                            target);
4708                 }
4709         } else if (wait && test_opt(sb, BARRIER))
4710                 needs_barrier = true;
4711         if (needs_barrier) {
4712                 int err;
4713                 err = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
4714                 if (!ret)
4715                         ret = err;
4716         }
4717
4718         return ret;
4719 }
4720
4721 /*
4722  * LVM calls this function before a (read-only) snapshot is created.  This
4723  * gives us a chance to flush the journal completely and mark the fs clean.
4724  *
4725  * Note that only this function cannot bring a filesystem to be in a clean
4726  * state independently. It relies on upper layer to stop all data & metadata
4727  * modifications.
4728  */
4729 static int ext4_freeze(struct super_block *sb)
4730 {
4731         int error = 0;
4732         journal_t *journal;
4733
4734         if (sb->s_flags & MS_RDONLY)
4735                 return 0;
4736
4737         journal = EXT4_SB(sb)->s_journal;
4738
4739         if (journal) {
4740                 /* Now we set up the journal barrier. */
4741                 jbd2_journal_lock_updates(journal);
4742
4743                 /*
4744                  * Don't clear the needs_recovery flag if we failed to
4745                  * flush the journal.
4746                  */
4747                 error = jbd2_journal_flush(journal);
4748                 if (error < 0)
4749                         goto out;
4750         }
4751
4752         /* Journal blocked and flushed, clear needs_recovery flag. */
4753         EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4754         error = ext4_commit_super(sb, 1);
4755 out:
4756         if (journal)
4757                 /* we rely on upper layer to stop further updates */
4758                 jbd2_journal_unlock_updates(journal);
4759         return error;
4760 }
4761
4762 /*
4763  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
4764  * flag here, even though the filesystem is not technically dirty yet.
4765  */
4766 static int ext4_unfreeze(struct super_block *sb)
4767 {
4768         if (sb->s_flags & MS_RDONLY)
4769                 return 0;
4770
4771         /* Reset the needs_recovery flag before the fs is unlocked. */
4772         EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4773         ext4_commit_super(sb, 1);
4774         return 0;
4775 }
4776
4777 /*
4778  * Structure to save mount options for ext4_remount's benefit
4779  */
4780 struct ext4_mount_options {
4781         unsigned long s_mount_opt;
4782         unsigned long s_mount_opt2;
4783         kuid_t s_resuid;
4784         kgid_t s_resgid;
4785         unsigned long s_commit_interval;
4786         u32 s_min_batch_time, s_max_batch_time;
4787 #ifdef CONFIG_QUOTA
4788         int s_jquota_fmt;
4789         char *s_qf_names[EXT4_MAXQUOTAS];
4790 #endif
4791 };
4792
4793 static int ext4_remount(struct super_block *sb, int *flags, char *data)
4794 {
4795         struct ext4_super_block *es;
4796         struct ext4_sb_info *sbi = EXT4_SB(sb);
4797         unsigned long old_sb_flags;
4798         struct ext4_mount_options old_opts;
4799         int enable_quota = 0;
4800         ext4_group_t g;
4801         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4802         int err = 0;
4803 #ifdef CONFIG_QUOTA
4804         int i, j;
4805 #endif
4806         char *orig_data = kstrdup(data, GFP_KERNEL);
4807
4808         /* Store the original options */
4809         old_sb_flags = sb->s_flags;
4810         old_opts.s_mount_opt = sbi->s_mount_opt;
4811         old_opts.s_mount_opt2 = sbi->s_mount_opt2;
4812         old_opts.s_resuid = sbi->s_resuid;
4813         old_opts.s_resgid = sbi->s_resgid;
4814         old_opts.s_commit_interval = sbi->s_commit_interval;
4815         old_opts.s_min_batch_time = sbi->s_min_batch_time;
4816         old_opts.s_max_batch_time = sbi->s_max_batch_time;
4817 #ifdef CONFIG_QUOTA
4818         old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
4819         for (i = 0; i < EXT4_MAXQUOTAS; i++)
4820                 if (sbi->s_qf_names[i]) {
4821                         old_opts.s_qf_names[i] = kstrdup(sbi->s_qf_names[i],
4822                                                          GFP_KERNEL);
4823                         if (!old_opts.s_qf_names[i]) {
4824                                 for (j = 0; j < i; j++)
4825                                         kfree(old_opts.s_qf_names[j]);
4826                                 kfree(orig_data);
4827                                 return -ENOMEM;
4828                         }
4829                 } else
4830                         old_opts.s_qf_names[i] = NULL;
4831 #endif
4832         if (sbi->s_journal && sbi->s_journal->j_task->io_context)
4833                 journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
4834
4835         /*
4836          * Allow the "check" option to be passed as a remount option.
4837          */
4838         if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
4839                 err = -EINVAL;
4840                 goto restore_opts;
4841         }
4842
4843         if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
4844             test_opt(sb, JOURNAL_CHECKSUM)) {
4845                 ext4_msg(sb, KERN_ERR, "changing journal_checksum "
4846                          "during remount not supported");
4847                 err = -EINVAL;
4848                 goto restore_opts;
4849         }
4850
4851         if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
4852             test_opt(sb, JOURNAL_CHECKSUM)) {
4853                 ext4_msg(sb, KERN_ERR, "changing journal_checksum "
4854                          "during remount not supported");
4855                 err = -EINVAL;
4856                 goto restore_opts;
4857         }
4858
4859         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
4860                 if (test_opt2(sb, EXPLICIT_DELALLOC)) {
4861                         ext4_msg(sb, KERN_ERR, "can't mount with "
4862                                  "both data=journal and delalloc");
4863                         err = -EINVAL;
4864                         goto restore_opts;
4865                 }
4866                 if (test_opt(sb, DIOREAD_NOLOCK)) {
4867                         ext4_msg(sb, KERN_ERR, "can't mount with "
4868                                  "both data=journal and dioread_nolock");
4869                         err = -EINVAL;
4870                         goto restore_opts;
4871                 }
4872         }
4873
4874         if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
4875                 ext4_abort(sb, "Abort forced by user");
4876
4877         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
4878                 (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
4879
4880         es = sbi->s_es;
4881
4882         if (sbi->s_journal) {
4883                 ext4_init_journal_params(sb, sbi->s_journal);
4884                 set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4885         }
4886
4887         if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY)) {
4888                 if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
4889                         err = -EROFS;
4890                         goto restore_opts;
4891                 }
4892
4893                 if (*flags & MS_RDONLY) {
4894                         err = sync_filesystem(sb);
4895                         if (err < 0)
4896                                 goto restore_opts;
4897                         err = dquot_suspend(sb, -1);
4898                         if (err < 0)
4899                                 goto restore_opts;
4900
4901                         /*
4902                          * First of all, the unconditional stuff we have to do
4903                          * to disable replay of the journal when we next remount
4904                          */
4905                         sb->s_flags |= MS_RDONLY;
4906
4907                         /*
4908                          * OK, test if we are remounting a valid rw partition
4909                          * readonly, and if so set the rdonly flag and then
4910                          * mark the partition as valid again.
4911                          */
4912                         if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
4913                             (sbi->s_mount_state & EXT4_VALID_FS))
4914                                 es->s_state = cpu_to_le16(sbi->s_mount_state);
4915
4916                         if (sbi->s_journal)
4917                                 ext4_mark_recovery_complete(sb, es);
4918                 } else {
4919                         /* Make sure we can mount this feature set readwrite */
4920                         if (!ext4_feature_set_ok(sb, 0)) {
4921                                 err = -EROFS;
4922                                 goto restore_opts;
4923                         }
4924                         /*
4925                          * Make sure the group descriptor checksums
4926                          * are sane.  If they aren't, refuse to remount r/w.
4927                          */
4928                         for (g = 0; g < sbi->s_groups_count; g++) {
4929                                 struct ext4_group_desc *gdp =
4930                                         ext4_get_group_desc(sb, g, NULL);
4931
4932                                 if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
4933                                         ext4_msg(sb, KERN_ERR,
4934                "ext4_remount: Checksum for group %u failed (%u!=%u)",
4935                 g, le16_to_cpu(ext4_group_desc_csum(sbi, g, gdp)),
4936                                                le16_to_cpu(gdp->bg_checksum));
4937                                         err = -EINVAL;
4938                                         goto restore_opts;
4939                                 }
4940                         }
4941
4942                         /*
4943                          * If we have an unprocessed orphan list hanging
4944                          * around from a previously readonly bdev mount,
4945                          * require a full umount/remount for now.
4946                          */
4947                         if (es->s_last_orphan) {
4948                                 ext4_msg(sb, KERN_WARNING, "Couldn't "
4949                                        "remount RDWR because of unprocessed "
4950                                        "orphan inode list.  Please "
4951                                        "umount/remount instead");
4952                                 err = -EINVAL;
4953                                 goto restore_opts;
4954                         }
4955
4956                         /*
4957                          * Mounting a RDONLY partition read-write, so reread
4958                          * and store the current valid flag.  (It may have
4959                          * been changed by e2fsck since we originally mounted
4960                          * the partition.)
4961                          */
4962                         if (sbi->s_journal)
4963                                 ext4_clear_journal_err(sb, es);
4964                         sbi->s_mount_state = le16_to_cpu(es->s_state);
4965                         if (!ext4_setup_super(sb, es, 0))
4966                                 sb->s_flags &= ~MS_RDONLY;
4967                         if (EXT4_HAS_INCOMPAT_FEATURE(sb,
4968                                                      EXT4_FEATURE_INCOMPAT_MMP))
4969                                 if (ext4_multi_mount_protect(sb,
4970                                                 le64_to_cpu(es->s_mmp_block))) {
4971                                         err = -EROFS;
4972                                         goto restore_opts;
4973                                 }
4974                         enable_quota = 1;
4975                 }
4976         }
4977
4978         /*
4979          * Reinitialize lazy itable initialization thread based on
4980          * current settings
4981          */
4982         if ((sb->s_flags & MS_RDONLY) || !test_opt(sb, INIT_INODE_TABLE))
4983                 ext4_unregister_li_request(sb);
4984         else {
4985                 ext4_group_t first_not_zeroed;
4986                 first_not_zeroed = ext4_has_uninit_itable(sb);
4987                 ext4_register_li_request(sb, first_not_zeroed);
4988         }
4989
4990         ext4_setup_system_zone(sb);
4991         if (sbi->s_journal == NULL && !(old_sb_flags & MS_RDONLY))
4992                 ext4_commit_super(sb, 1);
4993
4994 #ifdef CONFIG_QUOTA
4995         /* Release old quota file names */
4996         for (i = 0; i < EXT4_MAXQUOTAS; i++)
4997                 kfree(old_opts.s_qf_names[i]);
4998         if (enable_quota) {
4999                 if (sb_any_quota_suspended(sb))
5000                         dquot_resume(sb, -1);
5001                 else if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
5002                                         EXT4_FEATURE_RO_COMPAT_QUOTA)) {
5003                         err = ext4_enable_quotas(sb);
5004                         if (err)
5005                                 goto restore_opts;
5006                 }
5007         }
5008 #endif
5009
5010         ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
5011         kfree(orig_data);
5012         return 0;
5013
5014 restore_opts:
5015         sb->s_flags = old_sb_flags;
5016         sbi->s_mount_opt = old_opts.s_mount_opt;
5017         sbi->s_mount_opt2 = old_opts.s_mount_opt2;
5018         sbi->s_resuid = old_opts.s_resuid;
5019         sbi->s_resgid = old_opts.s_resgid;
5020         sbi->s_commit_interval = old_opts.s_commit_interval;
5021         sbi->s_min_batch_time = old_opts.s_min_batch_time;
5022         sbi->s_max_batch_time = old_opts.s_max_batch_time;
5023 #ifdef CONFIG_QUOTA
5024         sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
5025         for (i = 0; i < EXT4_MAXQUOTAS; i++) {
5026                 kfree(sbi->s_qf_names[i]);
5027                 sbi->s_qf_names[i] = old_opts.s_qf_names[i];
5028         }
5029 #endif
5030         kfree(orig_data);
5031         return err;
5032 }
5033
5034 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
5035 {
5036         struct super_block *sb = dentry->d_sb;
5037         struct ext4_sb_info *sbi = EXT4_SB(sb);
5038         struct ext4_super_block *es = sbi->s_es;
5039         ext4_fsblk_t overhead = 0, resv_blocks;
5040         u64 fsid;
5041         s64 bfree;
5042         resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
5043
5044         if (!test_opt(sb, MINIX_DF))
5045                 overhead = sbi->s_overhead;
5046
5047         buf->f_type = EXT4_SUPER_MAGIC;
5048         buf->f_bsize = sb->s_blocksize;
5049         buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
5050         bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
5051                 percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
5052         /* prevent underflow in case that few free space is available */
5053         buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
5054         buf->f_bavail = buf->f_bfree -
5055                         (ext4_r_blocks_count(es) + resv_blocks);
5056         if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
5057                 buf->f_bavail = 0;
5058         buf->f_files = le32_to_cpu(es->s_inodes_count);
5059         buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
5060         buf->f_namelen = EXT4_NAME_LEN;
5061         fsid = le64_to_cpup((void *)es->s_uuid) ^
5062                le64_to_cpup((void *)es->s_uuid + sizeof(u64));
5063         buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
5064         buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
5065
5066         return 0;
5067 }
5068
5069 /* Helper function for writing quotas on sync - we need to start transaction
5070  * before quota file is locked for write. Otherwise the are possible deadlocks:
5071  * Process 1                         Process 2
5072  * ext4_create()                     quota_sync()
5073  *   jbd2_journal_start()                  write_dquot()
5074  *   dquot_initialize()                         down(dqio_mutex)
5075  *     down(dqio_mutex)                    jbd2_journal_start()
5076  *
5077  */
5078
5079 #ifdef CONFIG_QUOTA
5080
5081 static inline struct inode *dquot_to_inode(struct dquot *dquot)
5082 {
5083         return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
5084 }
5085
5086 static int ext4_write_dquot(struct dquot *dquot)
5087 {
5088         int ret, err;
5089         handle_t *handle;
5090         struct inode *inode;
5091
5092         inode = dquot_to_inode(dquot);
5093         handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
5094                                     EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
5095         if (IS_ERR(handle))
5096                 return PTR_ERR(handle);
5097         ret = dquot_commit(dquot);
5098         err = ext4_journal_stop(handle);
5099         if (!ret)
5100                 ret = err;
5101         return ret;
5102 }
5103
5104 static int ext4_acquire_dquot(struct dquot *dquot)
5105 {
5106         int ret, err;
5107         handle_t *handle;
5108
5109         handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5110                                     EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
5111         if (IS_ERR(handle))
5112                 return PTR_ERR(handle);
5113         ret = dquot_acquire(dquot);
5114         err = ext4_journal_stop(handle);
5115         if (!ret)
5116                 ret = err;
5117         return ret;
5118 }
5119
5120 static int ext4_release_dquot(struct dquot *dquot)
5121 {
5122         int ret, err;
5123         handle_t *handle;
5124
5125         handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5126                                     EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
5127         if (IS_ERR(handle)) {
5128                 /* Release dquot anyway to avoid endless cycle in dqput() */
5129                 dquot_release(dquot);
5130                 return PTR_ERR(handle);
5131         }
5132         ret = dquot_release(dquot);
5133         err = ext4_journal_stop(handle);
5134         if (!ret)
5135                 ret = err;
5136         return ret;
5137 }
5138
5139 static int ext4_mark_dquot_dirty(struct dquot *dquot)
5140 {
5141         struct super_block *sb = dquot->dq_sb;
5142         struct ext4_sb_info *sbi = EXT4_SB(sb);
5143
5144         /* Are we journaling quotas? */
5145         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) ||
5146             sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
5147                 dquot_mark_dquot_dirty(dquot);
5148                 return ext4_write_dquot(dquot);
5149         } else {
5150                 return dquot_mark_dquot_dirty(dquot);
5151         }
5152 }
5153
5154 static int ext4_write_info(struct super_block *sb, int type)
5155 {
5156         int ret, err;
5157         handle_t *handle;
5158
5159         /* Data block + inode block */
5160         handle = ext4_journal_start(sb->s_root->d_inode, EXT4_HT_QUOTA, 2);
5161         if (IS_ERR(handle))
5162                 return PTR_ERR(handle);
5163         ret = dquot_commit_info(sb, type);
5164         err = ext4_journal_stop(handle);
5165         if (!ret)
5166                 ret = err;
5167         return ret;
5168 }
5169
5170 /*
5171  * Turn on quotas during mount time - we need to find
5172  * the quota file and such...
5173  */
5174 static int ext4_quota_on_mount(struct super_block *sb, int type)
5175 {
5176         return dquot_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
5177                                         EXT4_SB(sb)->s_jquota_fmt, type);
5178 }
5179
5180 /*
5181  * Standard function to be called on quota_on
5182  */
5183 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
5184                          struct path *path)
5185 {
5186         int err;
5187
5188         if (!test_opt(sb, QUOTA))
5189                 return -EINVAL;
5190
5191         /* Quotafile not on the same filesystem? */
5192         if (path->dentry->d_sb != sb)
5193                 return -EXDEV;
5194         /* Journaling quota? */
5195         if (EXT4_SB(sb)->s_qf_names[type]) {
5196                 /* Quotafile not in fs root? */
5197                 if (path->dentry->d_parent != sb->s_root)
5198                         ext4_msg(sb, KERN_WARNING,
5199                                 "Quota file not on filesystem root. "
5200                                 "Journaled quota will not work");
5201         }
5202
5203         /*
5204          * When we journal data on quota file, we have to flush journal to see
5205          * all updates to the file when we bypass pagecache...
5206          */
5207         if (EXT4_SB(sb)->s_journal &&
5208             ext4_should_journal_data(path->dentry->d_inode)) {
5209                 /*
5210                  * We don't need to lock updates but journal_flush() could
5211                  * otherwise be livelocked...
5212                  */
5213                 jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
5214                 err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
5215                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
5216                 if (err)
5217                         return err;
5218         }
5219
5220         return dquot_quota_on(sb, type, format_id, path);
5221 }
5222
5223 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
5224                              unsigned int flags)
5225 {
5226         int err;
5227         struct inode *qf_inode;
5228         unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5229                 le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5230                 le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum)
5231         };
5232
5233         BUG_ON(!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA));
5234
5235         if (!qf_inums[type])
5236                 return -EPERM;
5237
5238         qf_inode = ext4_iget(sb, qf_inums[type]);
5239         if (IS_ERR(qf_inode)) {
5240                 ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
5241                 return PTR_ERR(qf_inode);
5242         }
5243
5244         /* Don't account quota for quota files to avoid recursion */
5245         qf_inode->i_flags |= S_NOQUOTA;
5246         err = dquot_enable(qf_inode, type, format_id, flags);
5247         iput(qf_inode);
5248
5249         return err;
5250 }
5251
5252 /* Enable usage tracking for all quota types. */
5253 static int ext4_enable_quotas(struct super_block *sb)
5254 {
5255         int type, err = 0;
5256         unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5257                 le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5258                 le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum)
5259         };
5260
5261         sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE;
5262         for (type = 0; type < EXT4_MAXQUOTAS; type++) {
5263                 if (qf_inums[type]) {
5264                         err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
5265                                                 DQUOT_USAGE_ENABLED);
5266                         if (err) {
5267                                 ext4_warning(sb,
5268                                         "Failed to enable quota tracking "
5269                                         "(type=%d, err=%d). Please run "
5270                                         "e2fsck to fix.", type, err);
5271                                 return err;
5272                         }
5273                 }
5274         }
5275         return 0;
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 /* Read data from quotafile - avoid pagecache and such because we cannot afford
5305  * acquiring the locks... As quota files are never truncated and quota code
5306  * itself serializes the operations (and no one else should touch the files)
5307  * we don't have to be afraid of races */
5308 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
5309                                size_t len, loff_t off)
5310 {
5311         struct inode *inode = sb_dqopt(sb)->files[type];
5312         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5313         int offset = off & (sb->s_blocksize - 1);
5314         int tocopy;
5315         size_t toread;
5316         struct buffer_head *bh;
5317         loff_t i_size = i_size_read(inode);
5318
5319         if (off > i_size)
5320                 return 0;
5321         if (off+len > i_size)
5322                 len = i_size-off;
5323         toread = len;
5324         while (toread > 0) {
5325                 tocopy = sb->s_blocksize - offset < toread ?
5326                                 sb->s_blocksize - offset : toread;
5327                 bh = ext4_bread(NULL, inode, blk, 0);
5328                 if (IS_ERR(bh))
5329                         return PTR_ERR(bh);
5330                 if (!bh)        /* A hole? */
5331                         memset(data, 0, tocopy);
5332                 else
5333                         memcpy(data, bh->b_data+offset, tocopy);
5334                 brelse(bh);
5335                 offset = 0;
5336                 toread -= tocopy;
5337                 data += tocopy;
5338                 blk++;
5339         }
5340         return len;
5341 }
5342
5343 /* Write to quotafile (we know the transaction is already started and has
5344  * enough credits) */
5345 static ssize_t ext4_quota_write(struct super_block *sb, int type,
5346                                 const char *data, size_t len, loff_t off)
5347 {
5348         struct inode *inode = sb_dqopt(sb)->files[type];
5349         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5350         int err, offset = off & (sb->s_blocksize - 1);
5351         struct buffer_head *bh;
5352         handle_t *handle = journal_current_handle();
5353
5354         if (EXT4_SB(sb)->s_journal && !handle) {
5355                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5356                         " cancelled because transaction is not started",
5357                         (unsigned long long)off, (unsigned long long)len);
5358                 return -EIO;
5359         }
5360         /*
5361          * Since we account only one data block in transaction credits,
5362          * then it is impossible to cross a block boundary.
5363          */
5364         if (sb->s_blocksize - offset < len) {
5365                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5366                         " cancelled because not block aligned",
5367                         (unsigned long long)off, (unsigned long long)len);
5368                 return -EIO;
5369         }
5370
5371         bh = ext4_bread(handle, inode, blk, 1);
5372         if (IS_ERR(bh))
5373                 return PTR_ERR(bh);
5374         if (!bh)
5375                 goto out;
5376         BUFFER_TRACE(bh, "get write access");
5377         err = ext4_journal_get_write_access(handle, bh);
5378         if (err) {
5379                 brelse(bh);
5380                 return err;
5381         }
5382         lock_buffer(bh);
5383         memcpy(bh->b_data+offset, data, len);
5384         flush_dcache_page(bh->b_page);
5385         unlock_buffer(bh);
5386         err = ext4_handle_dirty_metadata(handle, NULL, bh);
5387         brelse(bh);
5388 out:
5389         if (inode->i_size < off + len) {
5390                 i_size_write(inode, off + len);
5391                 EXT4_I(inode)->i_disksize = inode->i_size;
5392                 ext4_mark_inode_dirty(handle, inode);
5393         }
5394         return len;
5395 }
5396
5397 #endif
5398
5399 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
5400                        const char *dev_name, void *data)
5401 {
5402         return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
5403 }
5404
5405 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
5406 static inline void register_as_ext2(void)
5407 {
5408         int err = register_filesystem(&ext2_fs_type);
5409         if (err)
5410                 printk(KERN_WARNING
5411                        "EXT4-fs: Unable to register as ext2 (%d)\n", err);
5412 }
5413
5414 static inline void unregister_as_ext2(void)
5415 {
5416         unregister_filesystem(&ext2_fs_type);
5417 }
5418
5419 static inline int ext2_feature_set_ok(struct super_block *sb)
5420 {
5421         if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP))
5422                 return 0;
5423         if (sb->s_flags & MS_RDONLY)
5424                 return 1;
5425         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))
5426                 return 0;
5427         return 1;
5428 }
5429 #else
5430 static inline void register_as_ext2(void) { }
5431 static inline void unregister_as_ext2(void) { }
5432 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
5433 #endif
5434
5435 #if !defined(CONFIG_EXT3_FS) && !defined(CONFIG_EXT3_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
5436 static inline void register_as_ext3(void)
5437 {
5438         int err = register_filesystem(&ext3_fs_type);
5439         if (err)
5440                 printk(KERN_WARNING
5441                        "EXT4-fs: Unable to register as ext3 (%d)\n", err);
5442 }
5443
5444 static inline void unregister_as_ext3(void)
5445 {
5446         unregister_filesystem(&ext3_fs_type);
5447 }
5448
5449 static inline int ext3_feature_set_ok(struct super_block *sb)
5450 {
5451         if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT3_FEATURE_INCOMPAT_SUPP))
5452                 return 0;
5453         if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
5454                 return 0;
5455         if (sb->s_flags & MS_RDONLY)
5456                 return 1;
5457         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT3_FEATURE_RO_COMPAT_SUPP))
5458                 return 0;
5459         return 1;
5460 }
5461 #else
5462 static inline void register_as_ext3(void) { }
5463 static inline void unregister_as_ext3(void) { }
5464 static inline int ext3_feature_set_ok(struct super_block *sb) { return 0; }
5465 #endif
5466
5467 static struct file_system_type ext4_fs_type = {
5468         .owner          = THIS_MODULE,
5469         .name           = "ext4",
5470         .mount          = ext4_mount,
5471         .kill_sb        = kill_block_super,
5472         .fs_flags       = FS_REQUIRES_DEV,
5473 };
5474 MODULE_ALIAS_FS("ext4");
5475
5476 static int __init ext4_init_feat_adverts(void)
5477 {
5478         struct ext4_features *ef;
5479         int ret = -ENOMEM;
5480
5481         ef = kzalloc(sizeof(struct ext4_features), GFP_KERNEL);
5482         if (!ef)
5483                 goto out;
5484
5485         ef->f_kobj.kset = ext4_kset;
5486         init_completion(&ef->f_kobj_unregister);
5487         ret = kobject_init_and_add(&ef->f_kobj, &ext4_feat_ktype, NULL,
5488                                    "features");
5489         if (ret) {
5490                 kfree(ef);
5491                 goto out;
5492         }
5493
5494         ext4_feat = ef;
5495         ret = 0;
5496 out:
5497         return ret;
5498 }
5499
5500 static void ext4_exit_feat_adverts(void)
5501 {
5502         kobject_put(&ext4_feat->f_kobj);
5503         wait_for_completion(&ext4_feat->f_kobj_unregister);
5504         kfree(ext4_feat);
5505 }
5506
5507 /* Shared across all ext4 file systems */
5508 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
5509 struct mutex ext4__aio_mutex[EXT4_WQ_HASH_SZ];
5510
5511 static int __init ext4_init_fs(void)
5512 {
5513         int i, err;
5514
5515         ext4_li_info = NULL;
5516         mutex_init(&ext4_li_mtx);
5517
5518         /* Build-time check for flags consistency */
5519         ext4_check_flag_values();
5520
5521         for (i = 0; i < EXT4_WQ_HASH_SZ; i++) {
5522                 mutex_init(&ext4__aio_mutex[i]);
5523                 init_waitqueue_head(&ext4__ioend_wq[i]);
5524         }
5525
5526         err = ext4_init_es();
5527         if (err)
5528                 return err;
5529
5530         err = ext4_init_pageio();
5531         if (err)
5532                 goto out7;
5533
5534         err = ext4_init_system_zone();
5535         if (err)
5536                 goto out6;
5537         ext4_kset = kset_create_and_add("ext4", NULL, fs_kobj);
5538         if (!ext4_kset) {
5539                 err = -ENOMEM;
5540                 goto out5;
5541         }
5542         ext4_proc_root = proc_mkdir("fs/ext4", NULL);
5543
5544         err = ext4_init_feat_adverts();
5545         if (err)
5546                 goto out4;
5547
5548         err = ext4_init_mballoc();
5549         if (err)
5550                 goto out2;
5551         else
5552                 ext4_mballoc_ready = 1;
5553         err = init_inodecache();
5554         if (err)
5555                 goto out1;
5556         register_as_ext3();
5557         register_as_ext2();
5558         err = register_filesystem(&ext4_fs_type);
5559         if (err)
5560                 goto out;
5561
5562         return 0;
5563 out:
5564         unregister_as_ext2();
5565         unregister_as_ext3();
5566         destroy_inodecache();
5567 out1:
5568         ext4_mballoc_ready = 0;
5569         ext4_exit_mballoc();
5570 out2:
5571         ext4_exit_feat_adverts();
5572 out4:
5573         if (ext4_proc_root)
5574                 remove_proc_entry("fs/ext4", NULL);
5575         kset_unregister(ext4_kset);
5576 out5:
5577         ext4_exit_system_zone();
5578 out6:
5579         ext4_exit_pageio();
5580 out7:
5581         ext4_exit_es();
5582
5583         return err;
5584 }
5585
5586 static void __exit ext4_exit_fs(void)
5587 {
5588         ext4_destroy_lazyinit_thread();
5589         unregister_as_ext2();
5590         unregister_as_ext3();
5591         unregister_filesystem(&ext4_fs_type);
5592         destroy_inodecache();
5593         ext4_exit_mballoc();
5594         ext4_exit_feat_adverts();
5595         remove_proc_entry("fs/ext4", NULL);
5596         kset_unregister(ext4_kset);
5597         ext4_exit_system_zone();
5598         ext4_exit_pageio();
5599         ext4_exit_es();
5600 }
5601
5602 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
5603 MODULE_DESCRIPTION("Fourth Extended Filesystem");
5604 MODULE_LICENSE("GPL");
5605 module_init(ext4_init_fs)
5606 module_exit(ext4_exit_fs)