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_sync_fs_nojournal(struct super_block *sb, int wait);
  74 static int ext4_remount(struct super_block *sb, int *flags, char *data);
  75 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
  76 static int ext4_unfreeze(struct super_block *sb);
  77 static int ext4_freeze(struct super_block *sb);
  78 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
  79                        const char *dev_name, void *data);
  80 static inline int ext2_feature_set_ok(struct super_block *sb);
  81 static inline int ext3_feature_set_ok(struct super_block *sb);
  82 static int ext4_feature_set_ok(struct super_block *sb, int readonly);
  83 static void ext4_destroy_lazyinit_thread(void);
  84 static void ext4_unregister_li_request(struct super_block *sb);
  85 static void ext4_clear_request_list(void);
  86 static int ext4_reserve_clusters(struct ext4_sb_info *, ext4_fsblk_t);
  87
  88 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
  89 static struct file_system_type ext2_fs_type = {
  90         .owner          = THIS_MODULE,
  91         .name           = "ext2",
  92         .mount          = ext4_mount,
  93         .kill_sb        = kill_block_super,
  94         .fs_flags       = FS_REQUIRES_DEV,
  95 };
  96 MODULE_ALIAS_FS("ext2");
  97 MODULE_ALIAS("ext2");
  98 #define IS_EXT2_SB(sb) ((sb)->s_bdev->bd_holder == &ext2_fs_type)
  99 #else
 100 #define IS_EXT2_SB(sb) (0)
 101 #endif
 102
 103
 104 #if !defined(CONFIG_EXT3_FS) && !defined(CONFIG_EXT3_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
 105 static struct file_system_type ext3_fs_type = {
 106         .owner          = THIS_MODULE,
 107         .name           = "ext3",
 108         .mount          = ext4_mount,
 109         .kill_sb        = kill_block_super,
 110         .fs_flags       = FS_REQUIRES_DEV,
 111 };
 112 MODULE_ALIAS_FS("ext3");
 113 MODULE_ALIAS("ext3");
 114 #define IS_EXT3_SB(sb) ((sb)->s_bdev->bd_holder == &ext3_fs_type)
 115 #else
 116 #define IS_EXT3_SB(sb) (0)
 117 #endif
 118
 119 static int ext4_verify_csum_type(struct super_block *sb,
 120                                  struct ext4_super_block *es)
 121 {
 122         if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
 123                                         EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
 124                 return 1;
 125
 126         return es->s_checksum_type == EXT4_CRC32C_CHKSUM;
 127 }
 128
 129 static __le32 ext4_superblock_csum(struct super_block *sb,
 130                                    struct ext4_super_block *es)
 131 {
 132         struct ext4_sb_info *sbi = EXT4_SB(sb);
 133         int offset = offsetof(struct ext4_super_block, s_checksum);
 134         __u32 csum;
 135
 136         csum = ext4_chksum(sbi, ~0, (char *)es, offset);
 137
 138         return cpu_to_le32(csum);
 139 }
 140
 141 static int ext4_superblock_csum_verify(struct super_block *sb,
 142                                        struct ext4_super_block *es)
 143 {
 144         if (!ext4_has_metadata_csum(sb))
 145                 return 1;
 146
 147         return es->s_checksum == ext4_superblock_csum(sb, es);
 148 }
 149
 150 void ext4_superblock_csum_set(struct super_block *sb)
 151 {
 152         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 153
 154         if (!ext4_has_metadata_csum(sb))
 155                 return;
 156
 157         es->s_checksum = ext4_superblock_csum(sb, es);
 158 }
 159
 160 void *ext4_kvmalloc(size_t size, gfp_t flags)
 161 {
 162         void *ret;
 163
 164         ret = kmalloc(size, flags | __GFP_NOWARN);
 165         if (!ret)
 166                 ret = __vmalloc(size, flags, PAGE_KERNEL);
 167         return ret;
 168 }
 169
 170 void *ext4_kvzalloc(size_t size, gfp_t flags)
 171 {
 172         void *ret;
 173
 174         ret = kzalloc(size, flags | __GFP_NOWARN);
 175         if (!ret)
 176                 ret = __vmalloc(size, flags | __GFP_ZERO, PAGE_KERNEL);
 177         return ret;
 178 }
 179
 180 void ext4_kvfree(void *ptr)
 181 {
 182         if (is_vmalloc_addr(ptr))
 183                 vfree(ptr);
 184         else
 185                 kfree(ptr);
 186
 187 }
 188
 189 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
 190                                struct ext4_group_desc *bg)
 191 {
 192         return le32_to_cpu(bg->bg_block_bitmap_lo) |
 193                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 194                  (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
 195 }
 196
 197 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
 198                                struct ext4_group_desc *bg)
 199 {
 200         return le32_to_cpu(bg->bg_inode_bitmap_lo) |
 201                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 202                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
 203 }
 204
 205 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
 206                               struct ext4_group_desc *bg)
 207 {
 208         return le32_to_cpu(bg->bg_inode_table_lo) |
 209                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 210                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
 211 }
 212
 213 __u32 ext4_free_group_clusters(struct super_block *sb,
 214                                struct ext4_group_desc *bg)
 215 {
 216         return le16_to_cpu(bg->bg_free_blocks_count_lo) |
 217                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 218                  (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
 219 }
 220
 221 __u32 ext4_free_inodes_count(struct super_block *sb,
 222                               struct ext4_group_desc *bg)
 223 {
 224         return le16_to_cpu(bg->bg_free_inodes_count_lo) |
 225                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 226                  (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
 227 }
 228
 229 __u32 ext4_used_dirs_count(struct super_block *sb,
 230                               struct ext4_group_desc *bg)
 231 {
 232         return le16_to_cpu(bg->bg_used_dirs_count_lo) |
 233                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 234                  (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
 235 }
 236
 237 __u32 ext4_itable_unused_count(struct super_block *sb,
 238                               struct ext4_group_desc *bg)
 239 {
 240         return le16_to_cpu(bg->bg_itable_unused_lo) |
 241                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 242                  (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
 243 }
 244
 245 void ext4_block_bitmap_set(struct super_block *sb,
 246                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 247 {
 248         bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
 249         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 250                 bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
 251 }
 252
 253 void ext4_inode_bitmap_set(struct super_block *sb,
 254                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 255 {
 256         bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
 257         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 258                 bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
 259 }
 260
 261 void ext4_inode_table_set(struct super_block *sb,
 262                           struct ext4_group_desc *bg, ext4_fsblk_t blk)
 263 {
 264         bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
 265         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 266                 bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
 267 }
 268
 269 void ext4_free_group_clusters_set(struct super_block *sb,
 270                                   struct ext4_group_desc *bg, __u32 count)
 271 {
 272         bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
 273         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 274                 bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
 275 }
 276
 277 void ext4_free_inodes_set(struct super_block *sb,
 278                           struct ext4_group_desc *bg, __u32 count)
 279 {
 280         bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
 281         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 282                 bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
 283 }
 284
 285 void ext4_used_dirs_set(struct super_block *sb,
 286                           struct ext4_group_desc *bg, __u32 count)
 287 {
 288         bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
 289         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 290                 bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
 291 }
 292
 293 void ext4_itable_unused_set(struct super_block *sb,
 294                           struct ext4_group_desc *bg, __u32 count)
 295 {
 296         bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
 297         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 298                 bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
 299 }
 300
 301
 302 static void __save_error_info(struct super_block *sb, const char *func,
 303                             unsigned int line)
 304 {
 305         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 306
 307         EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
 308         es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
 309         es->s_last_error_time = cpu_to_le32(get_seconds());
 310         strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
 311         es->s_last_error_line = cpu_to_le32(line);
 312         if (!es->s_first_error_time) {
 313                 es->s_first_error_time = es->s_last_error_time;
 314                 strncpy(es->s_first_error_func, func,
 315                         sizeof(es->s_first_error_func));
 316                 es->s_first_error_line = cpu_to_le32(line);
 317                 es->s_first_error_ino = es->s_last_error_ino;
 318                 es->s_first_error_block = es->s_last_error_block;
 319         }
 320         /*
 321          * Start the daily error reporting function if it hasn't been
 322          * started already
 323          */
 324         if (!es->s_error_count)
 325                 mod_timer(&EXT4_SB(sb)->s_err_report, jiffies + 24*60*60*HZ);
 326         le32_add_cpu(&es->s_error_count, 1);
 327 }
 328
 329 static void save_error_info(struct super_block *sb, const char *func,
 330                             unsigned int line)
 331 {
 332         __save_error_info(sb, func, line);
 333         ext4_commit_super(sb, 1);
 334 }
 335
 336 /*
 337  * The del_gendisk() function uninitializes the disk-specific data
 338  * structures, including the bdi structure, without telling anyone
 339  * else.  Once this happens, any attempt to call mark_buffer_dirty()
 340  * (for example, by ext4_commit_super), will cause a kernel OOPS.
 341  * This is a kludge to prevent these oops until we can put in a proper
 342  * hook in del_gendisk() to inform the VFS and file system layers.
 343  */
 344 static int block_device_ejected(struct super_block *sb)
 345 {
 346         struct inode *bd_inode = sb->s_bdev->bd_inode;
 347         struct backing_dev_info *bdi = bd_inode->i_mapping->backing_dev_info;
 348
 349         return bdi->dev == NULL;
 350 }
 351
 352 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
 353 {
 354         struct super_block              *sb = journal->j_private;
 355         struct ext4_sb_info             *sbi = EXT4_SB(sb);
 356         int                             error = is_journal_aborted(journal);
 357         struct ext4_journal_cb_entry    *jce;
 358
 359         BUG_ON(txn->t_state == T_FINISHED);
 360         spin_lock(&sbi->s_md_lock);
 361         while (!list_empty(&txn->t_private_list)) {
 362                 jce = list_entry(txn->t_private_list.next,
 363                                  struct ext4_journal_cb_entry, jce_list);
 364                 list_del_init(&jce->jce_list);
 365                 spin_unlock(&sbi->s_md_lock);
 366                 jce->jce_func(sb, jce, error);
 367                 spin_lock(&sbi->s_md_lock);
 368         }
 369         spin_unlock(&sbi->s_md_lock);
 370 }
 371
 372 /* Deal with the reporting of failure conditions on a filesystem such as
 373  * inconsistencies detected or read IO failures.
 374  *
 375  * On ext2, we can store the error state of the filesystem in the
 376  * superblock.  That is not possible on ext4, because we may have other
 377  * write ordering constraints on the superblock which prevent us from
 378  * writing it out straight away; and given that the journal is about to
 379  * be aborted, we can't rely on the current, or future, transactions to
 380  * write out the superblock safely.
 381  *
 382  * We'll just use the jbd2_journal_abort() error code to record an error in
 383  * the journal instead.  On recovery, the journal will complain about
 384  * that error until we've noted it down and cleared it.
 385  */
 386
 387 static void ext4_handle_error(struct super_block *sb)
 388 {
 389         if (sb->s_flags & MS_RDONLY)
 390                 return;
 391
 392         if (!test_opt(sb, ERRORS_CONT)) {
 393                 journal_t *journal = EXT4_SB(sb)->s_journal;
 394
 395                 EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
 396                 if (journal)
 397                         jbd2_journal_abort(journal, -EIO);
 398         }
 399         if (test_opt(sb, ERRORS_RO)) {
 400                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 401                 /*
 402                  * Make sure updated value of ->s_mount_flags will be visible
 403                  * before ->s_flags update
 404                  */
 405                 smp_wmb();
 406                 sb->s_flags |= MS_RDONLY;
 407         }
 408         if (test_opt(sb, ERRORS_PANIC)) {
 409                 if (EXT4_SB(sb)->s_journal &&
 410                   !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
 411                         return;
 412                 panic("EXT4-fs (device %s): panic forced after error\n",
 413                         sb->s_id);
 414         }
 415 }
 416
 417 #define ext4_error_ratelimit(sb)                                        \
 418                 ___ratelimit(&(EXT4_SB(sb)->s_err_ratelimit_state),     \
 419                              "EXT4-fs error")
 420
 421 void __ext4_error(struct super_block *sb, const char *function,
 422                   unsigned int line, const char *fmt, ...)
 423 {
 424         struct va_format vaf;
 425         va_list args;
 426
 427         if (ext4_error_ratelimit(sb)) {
 428                 va_start(args, fmt);
 429                 vaf.fmt = fmt;
 430                 vaf.va = &args;
 431                 printk(KERN_CRIT
 432                        "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
 433                        sb->s_id, function, line, current->comm, &vaf);
 434                 va_end(args);
 435         }
 436         save_error_info(sb, function, line);
 437         ext4_handle_error(sb);
 438 }
 439
 440 void __ext4_error_inode(struct inode *inode, const char *function,
 441                         unsigned int line, ext4_fsblk_t block,
 442                         const char *fmt, ...)
 443 {
 444         va_list args;
 445         struct va_format vaf;
 446         struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
 447
 448         es->s_last_error_ino = cpu_to_le32(inode->i_ino);
 449         es->s_last_error_block = cpu_to_le64(block);
 450         if (ext4_error_ratelimit(inode->i_sb)) {
 451                 va_start(args, fmt);
 452                 vaf.fmt = fmt;
 453                 vaf.va = &args;
 454                 if (block)
 455                         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
 456                                "inode #%lu: block %llu: comm %s: %pV\n",
 457                                inode->i_sb->s_id, function, line, inode->i_ino,
 458                                block, current->comm, &vaf);
 459                 else
 460                         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
 461                                "inode #%lu: comm %s: %pV\n",
 462                                inode->i_sb->s_id, function, line, inode->i_ino,
 463                                current->comm, &vaf);
 464                 va_end(args);
 465         }
 466         save_error_info(inode->i_sb, function, line);
 467         ext4_handle_error(inode->i_sb);
 468 }
 469
 470 void __ext4_error_file(struct file *file, const char *function,
 471                        unsigned int line, ext4_fsblk_t block,
 472                        const char *fmt, ...)
 473 {
 474         va_list args;
 475         struct va_format vaf;
 476         struct ext4_super_block *es;
 477         struct inode *inode = file_inode(file);
 478         char pathname[80], *path;
 479
 480         es = EXT4_SB(inode->i_sb)->s_es;
 481         es->s_last_error_ino = cpu_to_le32(inode->i_ino);
 482         if (ext4_error_ratelimit(inode->i_sb)) {
 483                 path = d_path(&(file->f_path), pathname, sizeof(pathname));
 484                 if (IS_ERR(path))
 485                         path = "(unknown)";
 486                 va_start(args, fmt);
 487                 vaf.fmt = fmt;
 488                 vaf.va = &args;
 489                 if (block)
 490                         printk(KERN_CRIT
 491                                "EXT4-fs error (device %s): %s:%d: inode #%lu: "
 492                                "block %llu: comm %s: path %s: %pV\n",
 493                                inode->i_sb->s_id, function, line, inode->i_ino,
 494                                block, current->comm, path, &vaf);
 495                 else
 496                         printk(KERN_CRIT
 497                                "EXT4-fs error (device %s): %s:%d: inode #%lu: "
 498                                "comm %s: path %s: %pV\n",
 499                                inode->i_sb->s_id, function, line, inode->i_ino,
 500                                current->comm, path, &vaf);
 501                 va_end(args);
 502         }
 503         save_error_info(inode->i_sb, function, line);
 504         ext4_handle_error(inode->i_sb);
 505 }
 506
 507 const char *ext4_decode_error(struct super_block *sb, int errno,
 508                               char nbuf[16])
 509 {
 510         char *errstr = NULL;
 511
 512         switch (errno) {
 513         case -EIO:
 514                 errstr = "IO failure";
 515                 break;
 516         case -ENOMEM:
 517                 errstr = "Out of memory";
 518                 break;
 519         case -EROFS:
 520                 if (!sb || (EXT4_SB(sb)->s_journal &&
 521                             EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
 522                         errstr = "Journal has aborted";
 523                 else
 524                         errstr = "Readonly filesystem";
 525                 break;
 526         default:
 527                 /* If the caller passed in an extra buffer for unknown
 528                  * errors, textualise them now.  Else we just return
 529                  * NULL. */
 530                 if (nbuf) {
 531                         /* Check for truncated error codes... */
 532                         if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
 533                                 errstr = nbuf;
 534                 }
 535                 break;
 536         }
 537
 538         return errstr;
 539 }
 540
 541 /* __ext4_std_error decodes expected errors from journaling functions
 542  * automatically and invokes the appropriate error response.  */
 543
 544 void __ext4_std_error(struct super_block *sb, const char *function,
 545                       unsigned int line, int errno)
 546 {
 547         char nbuf[16];
 548         const char *errstr;
 549
 550         /* Special case: if the error is EROFS, and we're not already
 551          * inside a transaction, then there's really no point in logging
 552          * an error. */
 553         if (errno == -EROFS && journal_current_handle() == NULL &&
 554             (sb->s_flags & MS_RDONLY))
 555                 return;
 556
 557         if (ext4_error_ratelimit(sb)) {
 558                 errstr = ext4_decode_error(sb, errno, nbuf);
 559                 printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
 560                        sb->s_id, function, line, errstr);
 561         }
 562
 563         save_error_info(sb, function, line);
 564         ext4_handle_error(sb);
 565 }
 566
 567 /*
 568  * ext4_abort is a much stronger failure handler than ext4_error.  The
 569  * abort function may be used to deal with unrecoverable failures such
 570  * as journal IO errors or ENOMEM at a critical moment in log management.
 571  *
 572  * We unconditionally force the filesystem into an ABORT|READONLY state,
 573  * unless the error response on the fs has been set to panic in which
 574  * case we take the easy way out and panic immediately.
 575  */
 576
 577 void __ext4_abort(struct super_block *sb, const char *function,
 578                 unsigned int line, const char *fmt, ...)
 579 {
 580         va_list args;
 581
 582         save_error_info(sb, function, line);
 583         va_start(args, fmt);
 584         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: ", sb->s_id,
 585                function, line);
 586         vprintk(fmt, args);
 587         printk("\n");
 588         va_end(args);
 589
 590         if ((sb->s_flags & MS_RDONLY) == 0) {
 591                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 592                 EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
 593                 /*
 594                  * Make sure updated value of ->s_mount_flags will be visible
 595                  * before ->s_flags update
 596                  */
 597                 smp_wmb();
 598                 sb->s_flags |= MS_RDONLY;
 599                 if (EXT4_SB(sb)->s_journal)
 600                         jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
 601                 save_error_info(sb, function, line);
 602         }
 603         if (test_opt(sb, ERRORS_PANIC)) {
 604                 if (EXT4_SB(sb)->s_journal &&
 605                   !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
 606                         return;
 607                 panic("EXT4-fs panic from previous error\n");
 608         }
 609 }
 610
 611 void __ext4_msg(struct super_block *sb,
 612                 const char *prefix, const char *fmt, ...)
 613 {
 614         struct va_format vaf;
 615         va_list args;
 616
 617         if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state), "EXT4-fs"))
 618                 return;
 619
 620         va_start(args, fmt);
 621         vaf.fmt = fmt;
 622         vaf.va = &args;
 623         printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
 624         va_end(args);
 625 }
 626
 627 void __ext4_warning(struct super_block *sb, const char *function,
 628                     unsigned int line, const char *fmt, ...)
 629 {
 630         struct va_format vaf;
 631         va_list args;
 632
 633         if (!___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state),
 634                           "EXT4-fs warning"))
 635                 return;
 636
 637         va_start(args, fmt);
 638         vaf.fmt = fmt;
 639         vaf.va = &args;
 640         printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
 641                sb->s_id, function, line, &vaf);
 642         va_end(args);
 643 }
 644
 645 void __ext4_grp_locked_error(const char *function, unsigned int line,
 646                              struct super_block *sb, ext4_group_t grp,
 647                              unsigned long ino, ext4_fsblk_t block,
 648                              const char *fmt, ...)
 649 __releases(bitlock)
 650 __acquires(bitlock)
 651 {
 652         struct va_format vaf;
 653         va_list args;
 654         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 655
 656         es->s_last_error_ino = cpu_to_le32(ino);
 657         es->s_last_error_block = cpu_to_le64(block);
 658         __save_error_info(sb, function, line);
 659
 660         if (ext4_error_ratelimit(sb)) {
 661                 va_start(args, fmt);
 662                 vaf.fmt = fmt;
 663                 vaf.va = &args;
 664                 printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
 665                        sb->s_id, function, line, grp);
 666                 if (ino)
 667                         printk(KERN_CONT "inode %lu: ", ino);
 668                 if (block)
 669                         printk(KERN_CONT "block %llu:",
 670                                (unsigned long long) block);
 671                 printk(KERN_CONT "%pV\n", &vaf);
 672                 va_end(args);
 673         }
 674
 675         if (test_opt(sb, ERRORS_CONT)) {
 676                 ext4_commit_super(sb, 0);
 677                 return;
 678         }
 679
 680         ext4_unlock_group(sb, grp);
 681         ext4_handle_error(sb);
 682         /*
 683          * We only get here in the ERRORS_RO case; relocking the group
 684          * may be dangerous, but nothing bad will happen since the
 685          * filesystem will have already been marked read/only and the
 686          * journal has been aborted.  We return 1 as a hint to callers
 687          * who might what to use the return value from
 688          * ext4_grp_locked_error() to distinguish between the
 689          * ERRORS_CONT and ERRORS_RO case, and perhaps return more
 690          * aggressively from the ext4 function in question, with a
 691          * more appropriate error code.
 692          */
 693         ext4_lock_group(sb, grp);
 694         return;
 695 }
 696
 697 void ext4_update_dynamic_rev(struct super_block *sb)
 698 {
 699         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 700
 701         if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
 702                 return;
 703
 704         ext4_warning(sb,
 705                      "updating to rev %d because of new feature flag, "
 706                      "running e2fsck is recommended",
 707                      EXT4_DYNAMIC_REV);
 708
 709         es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
 710         es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
 711         es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
 712         /* leave es->s_feature_*compat flags alone */
 713         /* es->s_uuid will be set by e2fsck if empty */
 714
 715         /*
 716          * The rest of the superblock fields should be zero, and if not it
 717          * means they are likely already in use, so leave them alone.  We
 718          * can leave it up to e2fsck to clean up any inconsistencies there.
 719          */
 720 }
 721
 722 /*
 723  * Open the external journal device
 724  */
 725 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
 726 {
 727         struct block_device *bdev;
 728         char b[BDEVNAME_SIZE];
 729
 730         bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
 731         if (IS_ERR(bdev))
 732                 goto fail;
 733         return bdev;
 734
 735 fail:
 736         ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
 737                         __bdevname(dev, b), PTR_ERR(bdev));
 738         return NULL;
 739 }
 740
 741 /*
 742  * Release the journal device
 743  */
 744 static void ext4_blkdev_put(struct block_device *bdev)
 745 {
 746         blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
 747 }
 748
 749 static void ext4_blkdev_remove(struct ext4_sb_info *sbi)
 750 {
 751         struct block_device *bdev;
 752         bdev = sbi->journal_bdev;
 753         if (bdev) {
 754                 ext4_blkdev_put(bdev);
 755                 sbi->journal_bdev = NULL;
 756         }
 757 }
 758
 759 static inline struct inode *orphan_list_entry(struct list_head *l)
 760 {
 761         return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
 762 }
 763
 764 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
 765 {
 766         struct list_head *l;
 767
 768         ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
 769                  le32_to_cpu(sbi->s_es->s_last_orphan));
 770
 771         printk(KERN_ERR "sb_info orphan list:\n");
 772         list_for_each(l, &sbi->s_orphan) {
 773                 struct inode *inode = orphan_list_entry(l);
 774                 printk(KERN_ERR "  "
 775                        "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
 776                        inode->i_sb->s_id, inode->i_ino, inode,
 777                        inode->i_mode, inode->i_nlink,
 778                        NEXT_ORPHAN(inode));
 779         }
 780 }
 781
 782 static void ext4_put_super(struct super_block *sb)
 783 {
 784         struct ext4_sb_info *sbi = EXT4_SB(sb);
 785         struct ext4_super_block *es = sbi->s_es;
 786         int i, err;
 787
 788         ext4_unregister_li_request(sb);
 789         dquot_disable(sb, -1, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
 790
 791         flush_workqueue(sbi->rsv_conversion_wq);
 792         destroy_workqueue(sbi->rsv_conversion_wq);
 793
 794         if (sbi->s_journal) {
 795                 err = jbd2_journal_destroy(sbi->s_journal);
 796                 sbi->s_journal = NULL;
 797                 if (err < 0)
 798                         ext4_abort(sb, "Couldn't clean up the journal");
 799         }
 800
 801         ext4_es_unregister_shrinker(sbi);
 802         del_timer_sync(&sbi->s_err_report);
 803         ext4_release_system_zone(sb);
 804         ext4_mb_release(sb);
 805         ext4_ext_release(sb);
 806         ext4_xattr_put_super(sb);
 807
 808         if (!(sb->s_flags & MS_RDONLY)) {
 809                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
 810                 es->s_state = cpu_to_le16(sbi->s_mount_state);
 811         }
 812         if (!(sb->s_flags & MS_RDONLY))
 813                 ext4_commit_super(sb, 1);
 814
 815         if (sbi->s_proc) {
 816                 remove_proc_entry("options", sbi->s_proc);
 817                 remove_proc_entry(sb->s_id, ext4_proc_root);
 818         }
 819         kobject_del(&sbi->s_kobj);
 820
 821         for (i = 0; i < sbi->s_gdb_count; i++)
 822                 brelse(sbi->s_group_desc[i]);
 823         ext4_kvfree(sbi->s_group_desc);
 824         ext4_kvfree(sbi->s_flex_groups);
 825         percpu_counter_destroy(&sbi->s_freeclusters_counter);
 826         percpu_counter_destroy(&sbi->s_freeinodes_counter);
 827         percpu_counter_destroy(&sbi->s_dirs_counter);
 828         percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
 829         percpu_counter_destroy(&sbi->s_extent_cache_cnt);
 830         brelse(sbi->s_sbh);
 831 #ifdef CONFIG_QUOTA
 832         for (i = 0; i < MAXQUOTAS; i++)
 833                 kfree(sbi->s_qf_names[i]);
 834 #endif
 835
 836         /* Debugging code just in case the in-memory inode orphan list
 837          * isn't empty.  The on-disk one can be non-empty if we've
 838          * detected an error and taken the fs readonly, but the
 839          * in-memory list had better be clean by this point. */
 840         if (!list_empty(&sbi->s_orphan))
 841                 dump_orphan_list(sb, sbi);
 842         J_ASSERT(list_empty(&sbi->s_orphan));
 843
 844         sync_blockdev(sb->s_bdev);
 845         invalidate_bdev(sb->s_bdev);
 846         if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
 847                 /*
 848                  * Invalidate the journal device's buffers.  We don't want them
 849                  * floating about in memory - the physical journal device may
 850                  * hotswapped, and it breaks the `ro-after' testing code.
 851                  */
 852                 sync_blockdev(sbi->journal_bdev);
 853                 invalidate_bdev(sbi->journal_bdev);
 854                 ext4_blkdev_remove(sbi);
 855         }
 856         if (sbi->s_mb_cache) {
 857                 ext4_xattr_destroy_cache(sbi->s_mb_cache);
 858                 sbi->s_mb_cache = NULL;
 859         }
 860         if (sbi->s_mmp_tsk)
 861                 kthread_stop(sbi->s_mmp_tsk);
 862         sb->s_fs_info = NULL;
 863         /*
 864          * Now that we are completely done shutting down the
 865          * superblock, we need to actually destroy the kobject.
 866          */
 867         kobject_put(&sbi->s_kobj);
 868         wait_for_completion(&sbi->s_kobj_unregister);
 869         if (sbi->s_chksum_driver)
 870                 crypto_free_shash(sbi->s_chksum_driver);
 871         kfree(sbi->s_blockgroup_lock);
 872         kfree(sbi);
 873 }
 874
 875 static struct kmem_cache *ext4_inode_cachep;
 876
 877 /*
 878  * Called inside transaction, so use GFP_NOFS
 879  */
 880 static struct inode *ext4_alloc_inode(struct super_block *sb)
 881 {
 882         struct ext4_inode_info *ei;
 883
 884         ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
 885         if (!ei)
 886                 return NULL;
 887
 888         ei->vfs_inode.i_version = 1;
 889         spin_lock_init(&ei->i_raw_lock);
 890         INIT_LIST_HEAD(&ei->i_prealloc_list);
 891         spin_lock_init(&ei->i_prealloc_lock);
 892         ext4_es_init_tree(&ei->i_es_tree);
 893         rwlock_init(&ei->i_es_lock);
 894         INIT_LIST_HEAD(&ei->i_es_lru);
 895         ei->i_es_lru_nr = 0;
 896         ei->i_touch_when = 0;
 897         ei->i_reserved_data_blocks = 0;
 898         ei->i_reserved_meta_blocks = 0;
 899         ei->i_allocated_meta_blocks = 0;
 900         ei->i_da_metadata_calc_len = 0;
 901         ei->i_da_metadata_calc_last_lblock = 0;
 902         spin_lock_init(&(ei->i_block_reservation_lock));
 903 #ifdef CONFIG_QUOTA
 904         ei->i_reserved_quota = 0;
 905 #endif
 906         ei->jinode = NULL;
 907         INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
 908         spin_lock_init(&ei->i_completed_io_lock);
 909         ei->i_sync_tid = 0;
 910         ei->i_datasync_tid = 0;
 911         atomic_set(&ei->i_ioend_count, 0);
 912         atomic_set(&ei->i_unwritten, 0);
 913         INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
 914
 915         return &ei->vfs_inode;
 916 }
 917
 918 static int ext4_drop_inode(struct inode *inode)
 919 {
 920         int drop = generic_drop_inode(inode);
 921
 922         trace_ext4_drop_inode(inode, drop);
 923         return drop;
 924 }
 925
 926 static void ext4_i_callback(struct rcu_head *head)
 927 {
 928         struct inode *inode = container_of(head, struct inode, i_rcu);
 929         kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
 930 }
 931
 932 static void ext4_destroy_inode(struct inode *inode)
 933 {
 934         if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
 935                 ext4_msg(inode->i_sb, KERN_ERR,
 936                          "Inode %lu (%p): orphan list check failed!",
 937                          inode->i_ino, EXT4_I(inode));
 938                 print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
 939                                 EXT4_I(inode), sizeof(struct ext4_inode_info),
 940                                 true);
 941                 dump_stack();
 942         }
 943         call_rcu(&inode->i_rcu, ext4_i_callback);
 944 }
 945
 946 static void init_once(void *foo)
 947 {
 948         struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
 949
 950         INIT_LIST_HEAD(&ei->i_orphan);
 951         init_rwsem(&ei->xattr_sem);
 952         init_rwsem(&ei->i_data_sem);
 953         inode_init_once(&ei->vfs_inode);
 954 }
 955
 956 static int __init init_inodecache(void)
 957 {
 958         ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
 959                                              sizeof(struct ext4_inode_info),
 960                                              0, (SLAB_RECLAIM_ACCOUNT|
 961                                                 SLAB_MEM_SPREAD),
 962                                              init_once);
 963         if (ext4_inode_cachep == NULL)
 964                 return -ENOMEM;
 965         return 0;
 966 }
 967
 968 static void destroy_inodecache(void)
 969 {
 970         /*
 971          * Make sure all delayed rcu free inodes are flushed before we
 972          * destroy cache.
 973          */
 974         rcu_barrier();
 975         kmem_cache_destroy(ext4_inode_cachep);
 976 }
 977
 978 void ext4_clear_inode(struct inode *inode)
 979 {
 980         invalidate_inode_buffers(inode);
 981         clear_inode(inode);
 982         dquot_drop(inode);
 983         ext4_discard_preallocations(inode);
 984         ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
 985         ext4_es_lru_del(inode);
 986         if (EXT4_I(inode)->jinode) {
 987                 jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
 988                                                EXT4_I(inode)->jinode);
 989                 jbd2_free_inode(EXT4_I(inode)->jinode);
 990                 EXT4_I(inode)->jinode = NULL;
 991         }
 992 }
 993
 994 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
 995                                         u64 ino, u32 generation)
 996 {
 997         struct inode *inode;
 998
 999         if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
1000                 return ERR_PTR(-ESTALE);
1001         if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
1002                 return ERR_PTR(-ESTALE);
1003
1004         /* iget isn't really right if the inode is currently unallocated!!
1005          *
1006          * ext4_read_inode will return a bad_inode if the inode had been
1007          * deleted, so we should be safe.
1008          *
1009          * Currently we don't know the generation for parent directory, so
1010          * a generation of 0 means "accept any"
1011          */
1012         inode = ext4_iget_normal(sb, ino);
1013         if (IS_ERR(inode))
1014                 return ERR_CAST(inode);
1015         if (generation && inode->i_generation != generation) {
1016                 iput(inode);
1017                 return ERR_PTR(-ESTALE);
1018         }
1019
1020         return inode;
1021 }
1022
1023 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1024                                         int fh_len, int fh_type)
1025 {
1026         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1027                                     ext4_nfs_get_inode);
1028 }
1029
1030 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1031                                         int fh_len, int fh_type)
1032 {
1033         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1034                                     ext4_nfs_get_inode);
1035 }
1036
1037 /*
1038  * Try to release metadata pages (indirect blocks, directories) which are
1039  * mapped via the block device.  Since these pages could have journal heads
1040  * which would prevent try_to_free_buffers() from freeing them, we must use
1041  * jbd2 layer's try_to_free_buffers() function to release them.
1042  */
1043 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1044                                  gfp_t wait)
1045 {
1046         journal_t *journal = EXT4_SB(sb)->s_journal;
1047
1048         WARN_ON(PageChecked(page));
1049         if (!page_has_buffers(page))
1050                 return 0;
1051         if (journal)
1052                 return jbd2_journal_try_to_free_buffers(journal, page,
1053                                                         wait & ~__GFP_WAIT);
1054         return try_to_free_buffers(page);
1055 }
1056
1057 #ifdef CONFIG_QUOTA
1058 #define QTYPE2NAME(t) ((t) == USRQUOTA ? "user" : "group")
1059 #define QTYPE2MOPT(on, t) ((t) == USRQUOTA?((on)##USRJQUOTA):((on)##GRPJQUOTA))
1060
1061 static int ext4_write_dquot(struct dquot *dquot);
1062 static int ext4_acquire_dquot(struct dquot *dquot);
1063 static int ext4_release_dquot(struct dquot *dquot);
1064 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1065 static int ext4_write_info(struct super_block *sb, int type);
1066 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1067                          struct path *path);
1068 static int ext4_quota_on_sysfile(struct super_block *sb, int type,
1069                                  int format_id);
1070 static int ext4_quota_off(struct super_block *sb, int type);
1071 static int ext4_quota_off_sysfile(struct super_block *sb, int type);
1072 static int ext4_quota_on_mount(struct super_block *sb, int type);
1073 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1074                                size_t len, loff_t off);
1075 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1076                                 const char *data, size_t len, loff_t off);
1077 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1078                              unsigned int flags);
1079 static int ext4_enable_quotas(struct super_block *sb);
1080
1081 static const struct dquot_operations ext4_quota_operations = {
1082         .get_reserved_space = ext4_get_reserved_space,
1083         .write_dquot    = ext4_write_dquot,
1084         .acquire_dquot  = ext4_acquire_dquot,
1085         .release_dquot  = ext4_release_dquot,
1086         .mark_dirty     = ext4_mark_dquot_dirty,
1087         .write_info     = ext4_write_info,
1088         .alloc_dquot    = dquot_alloc,
1089         .destroy_dquot  = dquot_destroy,
1090 };
1091
1092 static const struct quotactl_ops ext4_qctl_operations = {
1093         .quota_on       = ext4_quota_on,
1094         .quota_off      = ext4_quota_off,
1095         .quota_sync     = dquot_quota_sync,
1096         .get_info       = dquot_get_dqinfo,
1097         .set_info       = dquot_set_dqinfo,
1098         .get_dqblk      = dquot_get_dqblk,
1099         .set_dqblk      = dquot_set_dqblk
1100 };
1101
1102 static const struct quotactl_ops ext4_qctl_sysfile_operations = {
1103         .quota_on_meta  = ext4_quota_on_sysfile,
1104         .quota_off      = ext4_quota_off_sysfile,
1105         .quota_sync     = dquot_quota_sync,
1106         .get_info       = dquot_get_dqinfo,
1107         .set_info       = dquot_set_dqinfo,
1108         .get_dqblk      = dquot_get_dqblk,
1109         .set_dqblk      = dquot_set_dqblk
1110 };
1111 #endif
1112
1113 static const struct super_operations ext4_sops = {
1114         .alloc_inode    = ext4_alloc_inode,
1115         .destroy_inode  = ext4_destroy_inode,
1116         .write_inode    = ext4_write_inode,
1117         .dirty_inode    = ext4_dirty_inode,
1118         .drop_inode     = ext4_drop_inode,
1119         .evict_inode    = ext4_evict_inode,
1120         .put_super      = ext4_put_super,
1121         .sync_fs        = ext4_sync_fs,
1122         .freeze_fs      = ext4_freeze,
1123         .unfreeze_fs    = ext4_unfreeze,
1124         .statfs         = ext4_statfs,
1125         .remount_fs     = ext4_remount,
1126         .show_options   = ext4_show_options,
1127 #ifdef CONFIG_QUOTA
1128         .quota_read     = ext4_quota_read,
1129         .quota_write    = ext4_quota_write,
1130 #endif
1131         .bdev_try_to_free_page = bdev_try_to_free_page,
1132 };
1133
1134 static const struct super_operations ext4_nojournal_sops = {
1135         .alloc_inode    = ext4_alloc_inode,
1136         .destroy_inode  = ext4_destroy_inode,
1137         .write_inode    = ext4_write_inode,
1138         .dirty_inode    = ext4_dirty_inode,
1139         .drop_inode     = ext4_drop_inode,
1140         .evict_inode    = ext4_evict_inode,
1141         .sync_fs        = ext4_sync_fs_nojournal,
1142         .put_super      = ext4_put_super,
1143         .statfs         = ext4_statfs,
1144         .remount_fs     = ext4_remount,
1145         .show_options   = ext4_show_options,
1146 #ifdef CONFIG_QUOTA
1147         .quota_read     = ext4_quota_read,
1148         .quota_write    = ext4_quota_write,
1149 #endif
1150         .bdev_try_to_free_page = bdev_try_to_free_page,
1151 };
1152
1153 static const struct export_operations ext4_export_ops = {
1154         .fh_to_dentry = ext4_fh_to_dentry,
1155         .fh_to_parent = ext4_fh_to_parent,
1156         .get_parent = ext4_get_parent,
1157 };
1158
1159 enum {
1160         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1161         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1162         Opt_nouid32, Opt_debug, Opt_removed,
1163         Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1164         Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1165         Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1166         Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1167         Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1168         Opt_data_err_abort, Opt_data_err_ignore,
1169         Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1170         Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1171         Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1172         Opt_usrquota, Opt_grpquota, Opt_i_version,
1173         Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_mblk_io_submit,
1174         Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1175         Opt_inode_readahead_blks, Opt_journal_ioprio,
1176         Opt_dioread_nolock, Opt_dioread_lock,
1177         Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1178         Opt_max_dir_size_kb,
1179 };
1180
1181 static const match_table_t tokens = {
1182         {Opt_bsd_df, "bsddf"},
1183         {Opt_minix_df, "minixdf"},
1184         {Opt_grpid, "grpid"},
1185         {Opt_grpid, "bsdgroups"},
1186         {Opt_nogrpid, "nogrpid"},
1187         {Opt_nogrpid, "sysvgroups"},
1188         {Opt_resgid, "resgid=%u"},
1189         {Opt_resuid, "resuid=%u"},
1190         {Opt_sb, "sb=%u"},
1191         {Opt_err_cont, "errors=continue"},
1192         {Opt_err_panic, "errors=panic"},
1193         {Opt_err_ro, "errors=remount-ro"},
1194         {Opt_nouid32, "nouid32"},
1195         {Opt_debug, "debug"},
1196         {Opt_removed, "oldalloc"},
1197         {Opt_removed, "orlov"},
1198         {Opt_user_xattr, "user_xattr"},
1199         {Opt_nouser_xattr, "nouser_xattr"},
1200         {Opt_acl, "acl"},
1201         {Opt_noacl, "noacl"},
1202         {Opt_noload, "norecovery"},
1203         {Opt_noload, "noload"},
1204         {Opt_removed, "nobh"},
1205         {Opt_removed, "bh"},
1206         {Opt_commit, "commit=%u"},
1207         {Opt_min_batch_time, "min_batch_time=%u"},
1208         {Opt_max_batch_time, "max_batch_time=%u"},
1209         {Opt_journal_dev, "journal_dev=%u"},
1210         {Opt_journal_path, "journal_path=%s"},
1211         {Opt_journal_checksum, "journal_checksum"},
1212         {Opt_journal_async_commit, "journal_async_commit"},
1213         {Opt_abort, "abort"},
1214         {Opt_data_journal, "data=journal"},
1215         {Opt_data_ordered, "data=ordered"},
1216         {Opt_data_writeback, "data=writeback"},
1217         {Opt_data_err_abort, "data_err=abort"},
1218         {Opt_data_err_ignore, "data_err=ignore"},
1219         {Opt_offusrjquota, "usrjquota="},
1220         {Opt_usrjquota, "usrjquota=%s"},
1221         {Opt_offgrpjquota, "grpjquota="},
1222         {Opt_grpjquota, "grpjquota=%s"},
1223         {Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1224         {Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1225         {Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1226         {Opt_grpquota, "grpquota"},
1227         {Opt_noquota, "noquota"},
1228         {Opt_quota, "quota"},
1229         {Opt_usrquota, "usrquota"},
1230         {Opt_barrier, "barrier=%u"},
1231         {Opt_barrier, "barrier"},
1232         {Opt_nobarrier, "nobarrier"},
1233         {Opt_i_version, "i_version"},
1234         {Opt_stripe, "stripe=%u"},
1235         {Opt_delalloc, "delalloc"},
1236         {Opt_nodelalloc, "nodelalloc"},
1237         {Opt_removed, "mblk_io_submit"},
1238         {Opt_removed, "nomblk_io_submit"},
1239         {Opt_block_validity, "block_validity"},
1240         {Opt_noblock_validity, "noblock_validity"},
1241         {Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1242         {Opt_journal_ioprio, "journal_ioprio=%u"},
1243         {Opt_auto_da_alloc, "auto_da_alloc=%u"},
1244         {Opt_auto_da_alloc, "auto_da_alloc"},
1245         {Opt_noauto_da_alloc, "noauto_da_alloc"},
1246         {Opt_dioread_nolock, "dioread_nolock"},
1247         {Opt_dioread_lock, "dioread_lock"},
1248         {Opt_discard, "discard"},
1249         {Opt_nodiscard, "nodiscard"},
1250         {Opt_init_itable, "init_itable=%u"},
1251         {Opt_init_itable, "init_itable"},
1252         {Opt_noinit_itable, "noinit_itable"},
1253         {Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1254         {Opt_removed, "check=none"},    /* mount option from ext2/3 */
1255         {Opt_removed, "nocheck"},       /* mount option from ext2/3 */
1256         {Opt_removed, "reservation"},   /* mount option from ext2/3 */
1257         {Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1258         {Opt_removed, "journal=%u"},    /* mount option from ext2/3 */
1259         {Opt_err, NULL},
1260 };
1261
1262 static ext4_fsblk_t get_sb_block(void **data)
1263 {
1264         ext4_fsblk_t    sb_block;
1265         char            *options = (char *) *data;
1266
1267         if (!options || strncmp(options, "sb=", 3) != 0)
1268                 return 1;       /* Default location */
1269
1270         options += 3;
1271         /* TODO: use simple_strtoll with >32bit ext4 */
1272         sb_block = simple_strtoul(options, &options, 0);
1273         if (*options && *options != ',') {
1274                 printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1275                        (char *) *data);
1276                 return 1;
1277         }
1278         if (*options == ',')
1279                 options++;
1280         *data = (void *) options;
1281
1282         return sb_block;
1283 }
1284
1285 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1286 static char deprecated_msg[] = "Mount option \"%s\" will be removed by %s\n"
1287         "Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1288
1289 #ifdef CONFIG_QUOTA
1290 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1291 {
1292         struct ext4_sb_info *sbi = EXT4_SB(sb);
1293         char *qname;
1294         int ret = -1;
1295
1296         if (sb_any_quota_loaded(sb) &&
1297                 !sbi->s_qf_names[qtype]) {
1298                 ext4_msg(sb, KERN_ERR,
1299                         "Cannot change journaled "
1300                         "quota options when quota turned on");
1301                 return -1;
1302         }
1303         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA)) {
1304                 ext4_msg(sb, KERN_ERR, "Cannot set journaled quota options "
1305                          "when QUOTA feature is enabled");
1306                 return -1;
1307         }
1308         qname = match_strdup(args);
1309         if (!qname) {
1310                 ext4_msg(sb, KERN_ERR,
1311                         "Not enough memory for storing quotafile name");
1312                 return -1;
1313         }
1314         if (sbi->s_qf_names[qtype]) {
1315                 if (strcmp(sbi->s_qf_names[qtype], qname) == 0)
1316                         ret = 1;
1317                 else
1318                         ext4_msg(sb, KERN_ERR,
1319                                  "%s quota file already specified",
1320                                  QTYPE2NAME(qtype));
1321                 goto errout;
1322         }
1323         if (strchr(qname, '/')) {
1324                 ext4_msg(sb, KERN_ERR,
1325                         "quotafile must be on filesystem root");
1326                 goto errout;
1327         }
1328         sbi->s_qf_names[qtype] = qname;
1329         set_opt(sb, QUOTA);
1330         return 1;
1331 errout:
1332         kfree(qname);
1333         return ret;
1334 }
1335
1336 static int clear_qf_name(struct super_block *sb, int qtype)
1337 {
1338
1339         struct ext4_sb_info *sbi = EXT4_SB(sb);
1340
1341         if (sb_any_quota_loaded(sb) &&
1342                 sbi->s_qf_names[qtype]) {
1343                 ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1344                         " when quota turned on");
1345                 return -1;
1346         }
1347         kfree(sbi->s_qf_names[qtype]);
1348         sbi->s_qf_names[qtype] = NULL;
1349         return 1;
1350 }
1351 #endif
1352
1353 #define MOPT_SET        0x0001
1354 #define MOPT_CLEAR      0x0002
1355 #define MOPT_NOSUPPORT  0x0004
1356 #define MOPT_EXPLICIT   0x0008
1357 #define MOPT_CLEAR_ERR  0x0010
1358 #define MOPT_GTE0       0x0020
1359 #ifdef CONFIG_QUOTA
1360 #define MOPT_Q          0
1361 #define MOPT_QFMT       0x0040
1362 #else
1363 #define MOPT_Q          MOPT_NOSUPPORT
1364 #define MOPT_QFMT       MOPT_NOSUPPORT
1365 #endif
1366 #define MOPT_DATAJ      0x0080
1367 #define MOPT_NO_EXT2    0x0100
1368 #define MOPT_NO_EXT3    0x0200
1369 #define MOPT_EXT4_ONLY  (MOPT_NO_EXT2 | MOPT_NO_EXT3)
1370 #define MOPT_STRING     0x0400
1371
1372 static const struct mount_opts {
1373         int     token;
1374         int     mount_opt;
1375         int     flags;
1376 } ext4_mount_opts[] = {
1377         {Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1378         {Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1379         {Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1380         {Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1381         {Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1382         {Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1383         {Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1384          MOPT_EXT4_ONLY | MOPT_SET},
1385         {Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1386          MOPT_EXT4_ONLY | MOPT_CLEAR},
1387         {Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1388         {Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1389         {Opt_delalloc, EXT4_MOUNT_DELALLOC,
1390          MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1391         {Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1392          MOPT_EXT4_ONLY | MOPT_CLEAR},
1393         {Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1394          MOPT_EXT4_ONLY | MOPT_SET},
1395         {Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1396                                     EXT4_MOUNT_JOURNAL_CHECKSUM),
1397          MOPT_EXT4_ONLY | MOPT_SET},
1398         {Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1399         {Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1400         {Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1401         {Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1402         {Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
1403          MOPT_NO_EXT2 | MOPT_SET},
1404         {Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
1405          MOPT_NO_EXT2 | MOPT_CLEAR},
1406         {Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1407         {Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1408         {Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1409         {Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1410         {Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1411         {Opt_commit, 0, MOPT_GTE0},
1412         {Opt_max_batch_time, 0, MOPT_GTE0},
1413         {Opt_min_batch_time, 0, MOPT_GTE0},
1414         {Opt_inode_readahead_blks, 0, MOPT_GTE0},
1415         {Opt_init_itable, 0, MOPT_GTE0},
1416         {Opt_stripe, 0, MOPT_GTE0},
1417         {Opt_resuid, 0, MOPT_GTE0},
1418         {Opt_resgid, 0, MOPT_GTE0},
1419         {Opt_journal_dev, 0, MOPT_GTE0},
1420         {Opt_journal_path, 0, MOPT_STRING},
1421         {Opt_journal_ioprio, 0, MOPT_GTE0},
1422         {Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1423         {Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1424         {Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
1425          MOPT_NO_EXT2 | MOPT_DATAJ},
1426         {Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1427         {Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1428 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1429         {Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1430         {Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1431 #else
1432         {Opt_acl, 0, MOPT_NOSUPPORT},
1433         {Opt_noacl, 0, MOPT_NOSUPPORT},
1434 #endif
1435         {Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1436         {Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1437         {Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1438         {Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1439                                                         MOPT_SET | MOPT_Q},
1440         {Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1441                                                         MOPT_SET | MOPT_Q},
1442         {Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1443                        EXT4_MOUNT_GRPQUOTA), MOPT_CLEAR | MOPT_Q},
1444         {Opt_usrjquota, 0, MOPT_Q},
1445         {Opt_grpjquota, 0, MOPT_Q},
1446         {Opt_offusrjquota, 0, MOPT_Q},
1447         {Opt_offgrpjquota, 0, MOPT_Q},
1448         {Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1449         {Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1450         {Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1451         {Opt_max_dir_size_kb, 0, MOPT_GTE0},
1452         {Opt_err, 0, 0}
1453 };
1454
1455 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1456                             substring_t *args, unsigned long *journal_devnum,
1457                             unsigned int *journal_ioprio, int is_remount)
1458 {
1459         struct ext4_sb_info *sbi = EXT4_SB(sb);
1460         const struct mount_opts *m;
1461         kuid_t uid;
1462         kgid_t gid;
1463         int arg = 0;
1464
1465 #ifdef CONFIG_QUOTA
1466         if (token == Opt_usrjquota)
1467                 return set_qf_name(sb, USRQUOTA, &args[0]);
1468         else if (token == Opt_grpjquota)
1469                 return set_qf_name(sb, GRPQUOTA, &args[0]);
1470         else if (token == Opt_offusrjquota)
1471                 return clear_qf_name(sb, USRQUOTA);
1472         else if (token == Opt_offgrpjquota)
1473                 return clear_qf_name(sb, GRPQUOTA);
1474 #endif
1475         switch (token) {
1476         case Opt_noacl:
1477         case Opt_nouser_xattr:
1478                 ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1479                 break;
1480         case Opt_sb:
1481                 return 1;       /* handled by get_sb_block() */
1482         case Opt_removed:
1483                 ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
1484                 return 1;
1485         case Opt_abort:
1486                 sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1487                 return 1;
1488         case Opt_i_version:
1489                 sb->s_flags |= MS_I_VERSION;
1490                 return 1;
1491         }
1492
1493         for (m = ext4_mount_opts; m->token != Opt_err; m++)
1494                 if (token == m->token)
1495                         break;
1496
1497         if (m->token == Opt_err) {
1498                 ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1499                          "or missing value", opt);
1500                 return -1;
1501         }
1502
1503         if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
1504                 ext4_msg(sb, KERN_ERR,
1505                          "Mount option \"%s\" incompatible with ext2", opt);
1506                 return -1;
1507         }
1508         if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
1509                 ext4_msg(sb, KERN_ERR,
1510                          "Mount option \"%s\" incompatible with ext3", opt);
1511                 return -1;
1512         }
1513
1514         if (args->from && !(m->flags & MOPT_STRING) && match_int(args, &arg))
1515                 return -1;
1516         if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1517                 return -1;
1518         if (m->flags & MOPT_EXPLICIT)
1519                 set_opt2(sb, EXPLICIT_DELALLOC);
1520         if (m->flags & MOPT_CLEAR_ERR)
1521                 clear_opt(sb, ERRORS_MASK);
1522         if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1523                 ext4_msg(sb, KERN_ERR, "Cannot change quota "
1524                          "options when quota turned on");
1525                 return -1;
1526         }
1527
1528         if (m->flags & MOPT_NOSUPPORT) {
1529                 ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1530         } else if (token == Opt_commit) {
1531                 if (arg == 0)
1532                         arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1533                 sbi->s_commit_interval = HZ * arg;
1534         } else if (token == Opt_max_batch_time) {
1535                 sbi->s_max_batch_time = arg;
1536         } else if (token == Opt_min_batch_time) {
1537                 sbi->s_min_batch_time = arg;
1538         } else if (token == Opt_inode_readahead_blks) {
1539                 if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
1540                         ext4_msg(sb, KERN_ERR,
1541                                  "EXT4-fs: inode_readahead_blks must be "
1542                                  "0 or a power of 2 smaller than 2^31");
1543                         return -1;
1544                 }
1545                 sbi->s_inode_readahead_blks = arg;
1546         } else if (token == Opt_init_itable) {
1547                 set_opt(sb, INIT_INODE_TABLE);
1548                 if (!args->from)
1549                         arg = EXT4_DEF_LI_WAIT_MULT;
1550                 sbi->s_li_wait_mult = arg;
1551         } else if (token == Opt_max_dir_size_kb) {
1552                 sbi->s_max_dir_size_kb = arg;
1553         } else if (token == Opt_stripe) {
1554                 sbi->s_stripe = arg;
1555         } else if (token == Opt_resuid) {
1556                 uid = make_kuid(current_user_ns(), arg);
1557                 if (!uid_valid(uid)) {
1558                         ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
1559                         return -1;
1560                 }
1561                 sbi->s_resuid = uid;
1562         } else if (token == Opt_resgid) {
1563                 gid = make_kgid(current_user_ns(), arg);
1564                 if (!gid_valid(gid)) {
1565                         ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
1566                         return -1;
1567                 }
1568                 sbi->s_resgid = gid;
1569         } else if (token == Opt_journal_dev) {
1570                 if (is_remount) {
1571                         ext4_msg(sb, KERN_ERR,
1572                                  "Cannot specify journal on remount");
1573                         return -1;
1574                 }
1575                 *journal_devnum = arg;
1576         } else if (token == Opt_journal_path) {
1577                 char *journal_path;
1578                 struct inode *journal_inode;
1579                 struct path path;
1580                 int error;
1581
1582                 if (is_remount) {
1583                         ext4_msg(sb, KERN_ERR,
1584                                  "Cannot specify journal on remount");
1585                         return -1;
1586                 }
1587                 journal_path = match_strdup(&args[0]);
1588                 if (!journal_path) {
1589                         ext4_msg(sb, KERN_ERR, "error: could not dup "
1590                                 "journal device string");
1591                         return -1;
1592                 }
1593
1594                 error = kern_path(journal_path, LOOKUP_FOLLOW, &path);
1595                 if (error) {
1596                         ext4_msg(sb, KERN_ERR, "error: could not find "
1597                                 "journal device path: error %d", error);
1598                         kfree(journal_path);
1599                         return -1;
1600                 }
1601
1602                 journal_inode = path.dentry->d_inode;
1603                 if (!S_ISBLK(journal_inode->i_mode)) {
1604                         ext4_msg(sb, KERN_ERR, "error: journal path %s "
1605                                 "is not a block device", journal_path);
1606                         path_put(&path);
1607                         kfree(journal_path);
1608                         return -1;
1609                 }
1610
1611                 *journal_devnum = new_encode_dev(journal_inode->i_rdev);
1612                 path_put(&path);
1613                 kfree(journal_path);
1614         } else if (token == Opt_journal_ioprio) {
1615                 if (arg > 7) {
1616                         ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
1617                                  " (must be 0-7)");
1618                         return -1;
1619                 }
1620                 *journal_ioprio =
1621                         IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
1622         } else if (m->flags & MOPT_DATAJ) {
1623                 if (is_remount) {
1624                         if (!sbi->s_journal)
1625                                 ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
1626                         else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
1627                                 ext4_msg(sb, KERN_ERR,
1628                                          "Cannot change data mode on remount");
1629                                 return -1;
1630                         }
1631                 } else {
1632                         clear_opt(sb, DATA_FLAGS);
1633                         sbi->s_mount_opt |= m->mount_opt;
1634                 }
1635 #ifdef CONFIG_QUOTA
1636         } else if (m->flags & MOPT_QFMT) {
1637                 if (sb_any_quota_loaded(sb) &&
1638                     sbi->s_jquota_fmt != m->mount_opt) {
1639                         ext4_msg(sb, KERN_ERR, "Cannot change journaled "
1640                                  "quota options when quota turned on");
1641                         return -1;
1642                 }
1643                 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
1644                                                EXT4_FEATURE_RO_COMPAT_QUOTA)) {
1645                         ext4_msg(sb, KERN_ERR,
1646                                  "Cannot set journaled quota options "
1647                                  "when QUOTA feature is enabled");
1648                         return -1;
1649                 }
1650                 sbi->s_jquota_fmt = m->mount_opt;
1651 #endif
1652         } else {
1653                 if (!args->from)
1654                         arg = 1;
1655                 if (m->flags & MOPT_CLEAR)
1656                         arg = !arg;
1657                 else if (unlikely(!(m->flags & MOPT_SET))) {
1658                         ext4_msg(sb, KERN_WARNING,
1659                                  "buggy handling of option %s", opt);
1660                         WARN_ON(1);
1661                         return -1;
1662                 }
1663                 if (arg != 0)
1664                         sbi->s_mount_opt |= m->mount_opt;
1665                 else
1666                         sbi->s_mount_opt &= ~m->mount_opt;
1667         }
1668         return 1;
1669 }
1670
1671 static int parse_options(char *options, struct super_block *sb,
1672                          unsigned long *journal_devnum,
1673                          unsigned int *journal_ioprio,
1674                          int is_remount)
1675 {
1676         struct ext4_sb_info *sbi = EXT4_SB(sb);
1677         char *p;
1678         substring_t args[MAX_OPT_ARGS];
1679         int token;
1680
1681         if (!options)
1682                 return 1;
1683
1684         while ((p = strsep(&options, ",")) != NULL) {
1685                 if (!*p)
1686                         continue;
1687                 /*
1688                  * Initialize args struct so we know whether arg was
1689                  * found; some options take optional arguments.
1690                  */
1691                 args[0].to = args[0].from = NULL;
1692                 token = match_token(p, tokens, args);
1693                 if (handle_mount_opt(sb, p, token, args, journal_devnum,
1694                                      journal_ioprio, is_remount) < 0)
1695                         return 0;
1696         }
1697 #ifdef CONFIG_QUOTA
1698         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
1699             (test_opt(sb, USRQUOTA) || test_opt(sb, GRPQUOTA))) {
1700                 ext4_msg(sb, KERN_ERR, "Cannot set quota options when QUOTA "
1701                          "feature is enabled");
1702                 return 0;
1703         }
1704         if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1705                 if (test_opt(sb, USRQUOTA) && sbi->s_qf_names[USRQUOTA])
1706                         clear_opt(sb, USRQUOTA);
1707
1708                 if (test_opt(sb, GRPQUOTA) && sbi->s_qf_names[GRPQUOTA])
1709                         clear_opt(sb, GRPQUOTA);
1710
1711                 if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
1712                         ext4_msg(sb, KERN_ERR, "old and new quota "
1713                                         "format mixing");
1714                         return 0;
1715                 }
1716
1717                 if (!sbi->s_jquota_fmt) {
1718                         ext4_msg(sb, KERN_ERR, "journaled quota format "
1719                                         "not specified");
1720                         return 0;
1721                 }
1722         }
1723 #endif
1724         if (test_opt(sb, DIOREAD_NOLOCK)) {
1725                 int blocksize =
1726                         BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
1727
1728                 if (blocksize < PAGE_CACHE_SIZE) {
1729                         ext4_msg(sb, KERN_ERR, "can't mount with "
1730                                  "dioread_nolock if block size != PAGE_SIZE");
1731                         return 0;
1732                 }
1733         }
1734         return 1;
1735 }
1736
1737 static inline void ext4_show_quota_options(struct seq_file *seq,
1738                                            struct super_block *sb)
1739 {
1740 #if defined(CONFIG_QUOTA)
1741         struct ext4_sb_info *sbi = EXT4_SB(sb);
1742
1743         if (sbi->s_jquota_fmt) {
1744                 char *fmtname = "";
1745
1746                 switch (sbi->s_jquota_fmt) {
1747                 case QFMT_VFS_OLD:
1748                         fmtname = "vfsold";
1749                         break;
1750                 case QFMT_VFS_V0:
1751                         fmtname = "vfsv0";
1752                         break;
1753                 case QFMT_VFS_V1:
1754                         fmtname = "vfsv1";
1755                         break;
1756                 }
1757                 seq_printf(seq, ",jqfmt=%s", fmtname);
1758         }
1759
1760         if (sbi->s_qf_names[USRQUOTA])
1761                 seq_show_option(seq, "usrjquota", sbi->s_qf_names[USRQUOTA]);
1762
1763         if (sbi->s_qf_names[GRPQUOTA])
1764                 seq_show_option(seq, "grpjquota", sbi->s_qf_names[GRPQUOTA]);
1765 #endif
1766 }
1767
1768 static const char *token2str(int token)
1769 {
1770         const struct match_token *t;
1771
1772         for (t = tokens; t->token != Opt_err; t++)
1773                 if (t->token == token && !strchr(t->pattern, '='))
1774                         break;
1775         return t->pattern;
1776 }
1777
1778 /*
1779  * Show an option if
1780  *  - it's set to a non-default value OR
1781  *  - if the per-sb default is different from the global default
1782  */
1783 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
1784                               int nodefs)
1785 {
1786         struct ext4_sb_info *sbi = EXT4_SB(sb);
1787         struct ext4_super_block *es = sbi->s_es;
1788         int def_errors, def_mount_opt = nodefs ? 0 : sbi->s_def_mount_opt;
1789         const struct mount_opts *m;
1790         char sep = nodefs ? '\n' : ',';
1791
1792 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
1793 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
1794
1795         if (sbi->s_sb_block != 1)
1796                 SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
1797
1798         for (m = ext4_mount_opts; m->token != Opt_err; m++) {
1799                 int want_set = m->flags & MOPT_SET;
1800                 if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
1801                     (m->flags & MOPT_CLEAR_ERR))
1802                         continue;
1803                 if (!(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
1804                         continue; /* skip if same as the default */
1805                 if ((want_set &&
1806                      (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
1807                     (!want_set && (sbi->s_mount_opt & m->mount_opt)))
1808                         continue; /* select Opt_noFoo vs Opt_Foo */
1809                 SEQ_OPTS_PRINT("%s", token2str(m->token));
1810         }
1811
1812         if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
1813             le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
1814                 SEQ_OPTS_PRINT("resuid=%u",
1815                                 from_kuid_munged(&init_user_ns, sbi->s_resuid));
1816         if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
1817             le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
1818                 SEQ_OPTS_PRINT("resgid=%u",
1819                                 from_kgid_munged(&init_user_ns, sbi->s_resgid));
1820         def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
1821         if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
1822                 SEQ_OPTS_PUTS("errors=remount-ro");
1823         if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
1824                 SEQ_OPTS_PUTS("errors=continue");
1825         if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
1826                 SEQ_OPTS_PUTS("errors=panic");
1827         if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
1828                 SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
1829         if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
1830                 SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
1831         if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
1832                 SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
1833         if (sb->s_flags & MS_I_VERSION)
1834                 SEQ_OPTS_PUTS("i_version");
1835         if (nodefs || sbi->s_stripe)
1836                 SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
1837         if (EXT4_MOUNT_DATA_FLAGS & (sbi->s_mount_opt ^ def_mount_opt)) {
1838                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
1839                         SEQ_OPTS_PUTS("data=journal");
1840                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
1841                         SEQ_OPTS_PUTS("data=ordered");
1842                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
1843                         SEQ_OPTS_PUTS("data=writeback");
1844         }
1845         if (nodefs ||
1846             sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
1847                 SEQ_OPTS_PRINT("inode_readahead_blks=%u",
1848                                sbi->s_inode_readahead_blks);
1849
1850         if (nodefs || (test_opt(sb, INIT_INODE_TABLE) &&
1851                        (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
1852                 SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
1853         if (nodefs || sbi->s_max_dir_size_kb)
1854                 SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
1855
1856         ext4_show_quota_options(seq, sb);
1857         return 0;
1858 }
1859
1860 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
1861 {
1862         return _ext4_show_options(seq, root->d_sb, 0);
1863 }
1864
1865 static int options_seq_show(struct seq_file *seq, void *offset)
1866 {
1867         struct super_block *sb = seq->private;
1868         int rc;
1869
1870         seq_puts(seq, (sb->s_flags & MS_RDONLY) ? "ro" : "rw");
1871         rc = _ext4_show_options(seq, sb, 1);
1872         seq_puts(seq, "\n");
1873         return rc;
1874 }
1875
1876 static int options_open_fs(struct inode *inode, struct file *file)
1877 {
1878         return single_open(file, options_seq_show, PDE_DATA(inode));
1879 }
1880
1881 static const struct file_operations ext4_seq_options_fops = {
1882         .owner = THIS_MODULE,
1883         .open = options_open_fs,
1884         .read = seq_read,
1885         .llseek = seq_lseek,
1886         .release = single_release,
1887 };
1888
1889 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
1890                             int read_only)
1891 {
1892         struct ext4_sb_info *sbi = EXT4_SB(sb);
1893         int res = 0;
1894
1895         if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
1896                 ext4_msg(sb, KERN_ERR, "revision level too high, "
1897                          "forcing read-only mode");
1898                 res = MS_RDONLY;
1899         }
1900         if (read_only)
1901                 goto done;
1902         if (!(sbi->s_mount_state & EXT4_VALID_FS))
1903                 ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
1904                          "running e2fsck is recommended");
1905         else if (sbi->s_mount_state & EXT4_ERROR_FS)
1906                 ext4_msg(sb, KERN_WARNING,
1907                          "warning: mounting fs with errors, "
1908                          "running e2fsck is recommended");
1909         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
1910                  le16_to_cpu(es->s_mnt_count) >=
1911                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
1912                 ext4_msg(sb, KERN_WARNING,
1913                          "warning: maximal mount count reached, "
1914                          "running e2fsck is recommended");
1915         else if (le32_to_cpu(es->s_checkinterval) &&
1916                 (le32_to_cpu(es->s_lastcheck) +
1917                         le32_to_cpu(es->s_checkinterval) <= get_seconds()))
1918                 ext4_msg(sb, KERN_WARNING,
1919                          "warning: checktime reached, "
1920                          "running e2fsck is recommended");
1921         if (!sbi->s_journal)
1922                 es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
1923         if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
1924                 es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
1925         le16_add_cpu(&es->s_mnt_count, 1);
1926         es->s_mtime = cpu_to_le32(get_seconds());
1927         ext4_update_dynamic_rev(sb);
1928         if (sbi->s_journal)
1929                 EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
1930
1931         ext4_commit_super(sb, 1);
1932 done:
1933         if (test_opt(sb, DEBUG))
1934                 printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
1935                                 "bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
1936                         sb->s_blocksize,
1937                         sbi->s_groups_count,
1938                         EXT4_BLOCKS_PER_GROUP(sb),
1939                         EXT4_INODES_PER_GROUP(sb),
1940                         sbi->s_mount_opt, sbi->s_mount_opt2);
1941
1942         cleancache_init_fs(sb);
1943         return res;
1944 }
1945
1946 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
1947 {
1948         struct ext4_sb_info *sbi = EXT4_SB(sb);
1949         struct flex_groups *new_groups;
1950         int size;
1951
1952         if (!sbi->s_log_groups_per_flex)
1953                 return 0;
1954
1955         size = ext4_flex_group(sbi, ngroup - 1) + 1;
1956         if (size <= sbi->s_flex_groups_allocated)
1957                 return 0;
1958
1959         size = roundup_pow_of_two(size * sizeof(struct flex_groups));
1960         new_groups = ext4_kvzalloc(size, GFP_KERNEL);
1961         if (!new_groups) {
1962                 ext4_msg(sb, KERN_ERR, "not enough memory for %d flex groups",
1963                          size / (int) sizeof(struct flex_groups));
1964                 return -ENOMEM;
1965         }
1966
1967         if (sbi->s_flex_groups) {
1968                 memcpy(new_groups, sbi->s_flex_groups,
1969                        (sbi->s_flex_groups_allocated *
1970                         sizeof(struct flex_groups)));
1971                 ext4_kvfree(sbi->s_flex_groups);
1972         }
1973         sbi->s_flex_groups = new_groups;
1974         sbi->s_flex_groups_allocated = size / sizeof(struct flex_groups);
1975         return 0;
1976 }
1977
1978 static int ext4_fill_flex_info(struct super_block *sb)
1979 {
1980         struct ext4_sb_info *sbi = EXT4_SB(sb);
1981         struct ext4_group_desc *gdp = NULL;
1982         ext4_group_t flex_group;
1983         int i, err;
1984
1985         sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
1986         if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
1987                 sbi->s_log_groups_per_flex = 0;
1988                 return 1;
1989         }
1990
1991         err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
1992         if (err)
1993                 goto failed;
1994
1995         for (i = 0; i < sbi->s_groups_count; i++) {
1996                 gdp = ext4_get_group_desc(sb, i, NULL);
1997
1998                 flex_group = ext4_flex_group(sbi, i);
1999                 atomic_add(ext4_free_inodes_count(sb, gdp),
2000                            &sbi->s_flex_groups[flex_group].free_inodes);
2001                 atomic64_add(ext4_free_group_clusters(sb, gdp),
2002                              &sbi->s_flex_groups[flex_group].free_clusters);
2003                 atomic_add(ext4_used_dirs_count(sb, gdp),
2004                            &sbi->s_flex_groups[flex_group].used_dirs);
2005         }
2006
2007         return 1;
2008 failed:
2009         return 0;
2010 }
2011
2012 static __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 block_group,
2013                                    struct ext4_group_desc *gdp)
2014 {
2015         int offset;
2016         __u16 crc = 0;
2017         __le32 le_group = cpu_to_le32(block_group);
2018
2019         if (ext4_has_metadata_csum(sbi->s_sb)) {
2020                 /* Use new metadata_csum algorithm */
2021                 __le16 save_csum;
2022                 __u32 csum32;
2023
2024                 save_csum = gdp->bg_checksum;
2025                 gdp->bg_checksum = 0;
2026                 csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
2027                                      sizeof(le_group));
2028                 csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp,
2029                                      sbi->s_desc_size);
2030                 gdp->bg_checksum = save_csum;
2031
2032                 crc = csum32 & 0xFFFF;
2033                 goto out;
2034         }
2035
2036         /* old crc16 code */
2037         if (!(sbi->s_es->s_feature_ro_compat &
2038               cpu_to_le32(EXT4_FEATURE_RO_COMPAT_GDT_CSUM)))
2039                 return 0;
2040
2041         offset = offsetof(struct ext4_group_desc, bg_checksum);
2042
2043         crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2044         crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2045         crc = crc16(crc, (__u8 *)gdp, offset);
2046         offset += sizeof(gdp->bg_checksum); /* skip checksum */
2047         /* for checksum of struct ext4_group_desc do the rest...*/
2048         if ((sbi->s_es->s_feature_incompat &
2049              cpu_to_le32(EXT4_FEATURE_INCOMPAT_64BIT)) &&
2050             offset < le16_to_cpu(sbi->s_es->s_desc_size))
2051                 crc = crc16(crc, (__u8 *)gdp + offset,
2052                             le16_to_cpu(sbi->s_es->s_desc_size) -
2053                                 offset);
2054
2055 out:
2056         return cpu_to_le16(crc);
2057 }
2058
2059 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2060                                 struct ext4_group_desc *gdp)
2061 {
2062         if (ext4_has_group_desc_csum(sb) &&
2063             (gdp->bg_checksum != ext4_group_desc_csum(EXT4_SB(sb),
2064                                                       block_group, gdp)))
2065                 return 0;
2066
2067         return 1;
2068 }
2069
2070 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2071                               struct ext4_group_desc *gdp)
2072 {
2073         if (!ext4_has_group_desc_csum(sb))
2074                 return;
2075         gdp->bg_checksum = ext4_group_desc_csum(EXT4_SB(sb), block_group, gdp);
2076 }
2077
2078 /* Called at mount-time, super-block is locked */
2079 static int ext4_check_descriptors(struct super_block *sb,
2080                                   ext4_fsblk_t sb_block,
2081                                   ext4_group_t *first_not_zeroed)
2082 {
2083         struct ext4_sb_info *sbi = EXT4_SB(sb);
2084         ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2085         ext4_fsblk_t last_block;
2086         ext4_fsblk_t block_bitmap;
2087         ext4_fsblk_t inode_bitmap;
2088         ext4_fsblk_t inode_table;
2089         int flexbg_flag = 0;
2090         ext4_group_t i, grp = sbi->s_groups_count;
2091
2092         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
2093                 flexbg_flag = 1;
2094
2095         ext4_debug("Checking group descriptors");
2096
2097         for (i = 0; i < sbi->s_groups_count; i++) {
2098                 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2099
2100                 if (i == sbi->s_groups_count - 1 || flexbg_flag)
2101                         last_block = ext4_blocks_count(sbi->s_es) - 1;
2102                 else
2103                         last_block = first_block +
2104                                 (EXT4_BLOCKS_PER_GROUP(sb) - 1);
2105
2106                 if ((grp == sbi->s_groups_count) &&
2107                    !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2108                         grp = i;
2109
2110                 block_bitmap = ext4_block_bitmap(sb, gdp);
2111                 if (block_bitmap == sb_block) {
2112                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2113                                  "Block bitmap for group %u overlaps "
2114                                  "superblock", i);
2115                 }
2116                 if (block_bitmap < first_block || block_bitmap > last_block) {
2117                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2118                                "Block bitmap for group %u not in group "
2119                                "(block %llu)!", i, block_bitmap);
2120                         return 0;
2121                 }
2122                 inode_bitmap = ext4_inode_bitmap(sb, gdp);
2123                 if (inode_bitmap == sb_block) {
2124                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2125                                  "Inode bitmap for group %u overlaps "
2126                                  "superblock", i);
2127                 }
2128                 if (inode_bitmap < first_block || inode_bitmap > last_block) {
2129                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2130                                "Inode bitmap for group %u not in group "
2131                                "(block %llu)!", i, inode_bitmap);
2132                         return 0;
2133                 }
2134                 inode_table = ext4_inode_table(sb, gdp);
2135                 if (inode_table == sb_block) {
2136                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2137                                  "Inode table for group %u overlaps "
2138                                  "superblock", i);
2139                 }
2140                 if (inode_table < first_block ||
2141                     inode_table + sbi->s_itb_per_group - 1 > last_block) {
2142                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2143                                "Inode table for group %u not in group "
2144                                "(block %llu)!", i, inode_table);
2145                         return 0;
2146                 }
2147                 ext4_lock_group(sb, i);
2148                 if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2149                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2150                                  "Checksum for group %u failed (%u!=%u)",
2151                                  i, le16_to_cpu(ext4_group_desc_csum(sbi, i,
2152                                      gdp)), le16_to_cpu(gdp->bg_checksum));
2153                         if (!(sb->s_flags & MS_RDONLY)) {
2154                                 ext4_unlock_group(sb, i);
2155                                 return 0;
2156                         }
2157                 }
2158                 ext4_unlock_group(sb, i);
2159                 if (!flexbg_flag)
2160                         first_block += EXT4_BLOCKS_PER_GROUP(sb);
2161         }
2162         if (NULL != first_not_zeroed)
2163                 *first_not_zeroed = grp;
2164
2165         ext4_free_blocks_count_set(sbi->s_es,
2166                                    EXT4_C2B(sbi, ext4_count_free_clusters(sb)));
2167         sbi->s_es->s_free_inodes_count =cpu_to_le32(ext4_count_free_inodes(sb));
2168         return 1;
2169 }
2170
2171 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2172  * the superblock) which were deleted from all directories, but held open by
2173  * a process at the time of a crash.  We walk the list and try to delete these
2174  * inodes at recovery time (only with a read-write filesystem).
2175  *
2176  * In order to keep the orphan inode chain consistent during traversal (in
2177  * case of crash during recovery), we link each inode into the superblock
2178  * orphan list_head and handle it the same way as an inode deletion during
2179  * normal operation (which journals the operations for us).
2180  *
2181  * We only do an iget() and an iput() on each inode, which is very safe if we
2182  * accidentally point at an in-use or already deleted inode.  The worst that
2183  * can happen in this case is that we get a "bit already cleared" message from
2184  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2185  * e2fsck was run on this filesystem, and it must have already done the orphan
2186  * inode cleanup for us, so we can safely abort without any further action.
2187  */
2188 static void ext4_orphan_cleanup(struct super_block *sb,
2189                                 struct ext4_super_block *es)
2190 {
2191         unsigned int s_flags = sb->s_flags;
2192         int nr_orphans = 0, nr_truncates = 0;
2193 #ifdef CONFIG_QUOTA
2194         int i;
2195 #endif
2196         if (!es->s_last_orphan) {
2197                 jbd_debug(4, "no orphan inodes to clean up\n");
2198                 return;
2199         }
2200
2201         if (bdev_read_only(sb->s_bdev)) {
2202                 ext4_msg(sb, KERN_ERR, "write access "
2203                         "unavailable, skipping orphan cleanup");
2204                 return;
2205         }
2206
2207         /* Check if feature set would not allow a r/w mount */
2208         if (!ext4_feature_set_ok(sb, 0)) {
2209                 ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2210                          "unknown ROCOMPAT features");
2211                 return;
2212         }
2213
2214         if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2215                 /* don't clear list on RO mount w/ errors */
2216                 if (es->s_last_orphan && !(s_flags & MS_RDONLY)) {
2217                         jbd_debug(1, "Errors on filesystem, "
2218                                   "clearing orphan list.\n");
2219                         es->s_last_orphan = 0;
2220                 }
2221                 jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2222                 return;
2223         }
2224
2225         if (s_flags & MS_RDONLY) {
2226                 ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2227                 sb->s_flags &= ~MS_RDONLY;
2228         }
2229 #ifdef CONFIG_QUOTA
2230         /* Needed for iput() to work correctly and not trash data */
2231         sb->s_flags |= MS_ACTIVE;
2232         /* Turn on quotas so that they are updated correctly */
2233         for (i = 0; i < MAXQUOTAS; i++) {
2234                 if (EXT4_SB(sb)->s_qf_names[i]) {
2235                         int ret = ext4_quota_on_mount(sb, i);
2236                         if (ret < 0)
2237                                 ext4_msg(sb, KERN_ERR,
2238                                         "Cannot turn on journaled "
2239                                         "quota: error %d", ret);
2240                 }
2241         }
2242 #endif
2243
2244         while (es->s_last_orphan) {
2245                 struct inode *inode;
2246
2247                 /*
2248                  * We may have encountered an error during cleanup; if
2249                  * so, skip the rest.
2250                  */
2251                 if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2252                         jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2253                         es->s_last_orphan = 0;
2254                         break;
2255                 }
2256
2257                 inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2258                 if (IS_ERR(inode)) {
2259                         es->s_last_orphan = 0;
2260                         break;
2261                 }
2262
2263                 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2264                 dquot_initialize(inode);
2265                 if (inode->i_nlink) {
2266                         if (test_opt(sb, DEBUG))
2267                                 ext4_msg(sb, KERN_DEBUG,
2268                                         "%s: truncating inode %lu to %lld bytes",
2269                                         __func__, inode->i_ino, inode->i_size);
2270                         jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2271                                   inode->i_ino, inode->i_size);
2272                         mutex_lock(&inode->i_mutex);
2273                         truncate_inode_pages(inode->i_mapping, inode->i_size);
2274                         ext4_truncate(inode);
2275                         mutex_unlock(&inode->i_mutex);
2276                         nr_truncates++;
2277                 } else {
2278                         if (test_opt(sb, DEBUG))
2279                                 ext4_msg(sb, KERN_DEBUG,
2280                                         "%s: deleting unreferenced inode %lu",
2281                                         __func__, inode->i_ino);
2282                         jbd_debug(2, "deleting unreferenced inode %lu\n",
2283                                   inode->i_ino);
2284                         nr_orphans++;
2285                 }
2286                 iput(inode);  /* The delete magic happens here! */
2287         }
2288
2289 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2290
2291         if (nr_orphans)
2292                 ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2293                        PLURAL(nr_orphans));
2294         if (nr_truncates)
2295                 ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2296                        PLURAL(nr_truncates));
2297 #ifdef CONFIG_QUOTA
2298         /* Turn quotas off */
2299         for (i = 0; i < MAXQUOTAS; i++) {
2300                 if (sb_dqopt(sb)->files[i])
2301                         dquot_quota_off(sb, i);
2302         }
2303 #endif
2304         sb->s_flags = s_flags; /* Restore MS_RDONLY status */
2305 }
2306
2307 /*
2308  * Maximal extent format file size.
2309  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2310  * extent format containers, within a sector_t, and within i_blocks
2311  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2312  * so that won't be a limiting factor.
2313  *
2314  * However there is other limiting factor. We do store extents in the form
2315  * of starting block and length, hence the resulting length of the extent
2316  * covering maximum file size must fit into on-disk format containers as
2317  * well. Given that length is always by 1 unit bigger than max unit (because
2318  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2319  *
2320  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2321  */
2322 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2323 {
2324         loff_t res;
2325         loff_t upper_limit = MAX_LFS_FILESIZE;
2326
2327         /* small i_blocks in vfs inode? */
2328         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2329                 /*
2330                  * CONFIG_LBDAF is not enabled implies the inode
2331                  * i_block represent total blocks in 512 bytes
2332                  * 32 == size of vfs inode i_blocks * 8
2333                  */
2334                 upper_limit = (1LL << 32) - 1;
2335
2336                 /* total blocks in file system block size */
2337                 upper_limit >>= (blkbits - 9);
2338                 upper_limit <<= blkbits;
2339         }
2340
2341         /*
2342          * 32-bit extent-start container, ee_block. We lower the maxbytes
2343          * by one fs block, so ee_len can cover the extent of maximum file
2344          * size
2345          */
2346         res = (1LL << 32) - 1;
2347         res <<= blkbits;
2348
2349         /* Sanity check against vm- & vfs- imposed limits */
2350         if (res > upper_limit)
2351                 res = upper_limit;
2352
2353         return res;
2354 }
2355
2356 /*
2357  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2358  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2359  * We need to be 1 filesystem block less than the 2^48 sector limit.
2360  */
2361 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2362 {
2363         loff_t res = EXT4_NDIR_BLOCKS;
2364         int meta_blocks;
2365         loff_t upper_limit;
2366         /* This is calculated to be the largest file size for a dense, block
2367          * mapped file such that the file's total number of 512-byte sectors,
2368          * including data and all indirect blocks, does not exceed (2^48 - 1).
2369          *
2370          * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2371          * number of 512-byte sectors of the file.
2372          */
2373
2374         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2375                 /*
2376                  * !has_huge_files or CONFIG_LBDAF not enabled implies that
2377                  * the inode i_block field represents total file blocks in
2378                  * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2379                  */
2380                 upper_limit = (1LL << 32) - 1;
2381
2382                 /* total blocks in file system block size */
2383                 upper_limit >>= (bits - 9);
2384
2385         } else {
2386                 /*
2387                  * We use 48 bit ext4_inode i_blocks
2388                  * With EXT4_HUGE_FILE_FL set the i_blocks
2389                  * represent total number of blocks in
2390                  * file system block size
2391                  */
2392                 upper_limit = (1LL << 48) - 1;
2393
2394         }
2395
2396         /* indirect blocks */
2397         meta_blocks = 1;
2398         /* double indirect blocks */
2399         meta_blocks += 1 + (1LL << (bits-2));
2400         /* tripple indirect blocks */
2401         meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2402
2403         upper_limit -= meta_blocks;
2404         upper_limit <<= bits;
2405
2406         res += 1LL << (bits-2);
2407         res += 1LL << (2*(bits-2));
2408         res += 1LL << (3*(bits-2));
2409         res <<= bits;
2410         if (res > upper_limit)
2411                 res = upper_limit;
2412
2413         if (res > MAX_LFS_FILESIZE)
2414                 res = MAX_LFS_FILESIZE;
2415
2416         return res;
2417 }
2418
2419 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2420                                    ext4_fsblk_t logical_sb_block, int nr)
2421 {
2422         struct ext4_sb_info *sbi = EXT4_SB(sb);
2423         ext4_group_t bg, first_meta_bg;
2424         int has_super = 0;
2425
2426         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2427
2428         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG) ||
2429             nr < first_meta_bg)
2430                 return logical_sb_block + nr + 1;
2431         bg = sbi->s_desc_per_block * nr;
2432         if (ext4_bg_has_super(sb, bg))
2433                 has_super = 1;
2434
2435         /*
2436          * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
2437          * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
2438          * on modern mke2fs or blksize > 1k on older mke2fs) then we must
2439          * compensate.
2440          */
2441         if (sb->s_blocksize == 1024 && nr == 0 &&
2442             le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block) == 0)
2443                 has_super++;
2444
2445         return (has_super + ext4_group_first_block_no(sb, bg));
2446 }
2447
2448 /**
2449  * ext4_get_stripe_size: Get the stripe size.
2450  * @sbi: In memory super block info
2451  *
2452  * If we have specified it via mount option, then
2453  * use the mount option value. If the value specified at mount time is
2454  * greater than the blocks per group use the super block value.
2455  * If the super block value is greater than blocks per group return 0.
2456  * Allocator needs it be less than blocks per group.
2457  *
2458  */
2459 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2460 {
2461         unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2462         unsigned long stripe_width =
2463                         le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2464         int ret;
2465
2466         if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2467                 ret = sbi->s_stripe;
2468         else if (stripe_width <= sbi->s_blocks_per_group)
2469                 ret = stripe_width;
2470         else if (stride <= sbi->s_blocks_per_group)
2471                 ret = stride;
2472         else
2473                 ret = 0;
2474
2475         /*
2476          * If the stripe width is 1, this makes no sense and
2477          * we set it to 0 to turn off stripe handling code.
2478          */
2479         if (ret <= 1)
2480                 ret = 0;
2481
2482         return ret;
2483 }
2484
2485 /* sysfs supprt */
2486
2487 struct ext4_attr {
2488         struct attribute attr;
2489         ssize_t (*show)(struct ext4_attr *, struct ext4_sb_info *, char *);
2490         ssize_t (*store)(struct ext4_attr *, struct ext4_sb_info *,
2491                          const char *, size_t);
2492         union {
2493                 int offset;
2494                 int deprecated_val;
2495         } u;
2496 };
2497
2498 static int parse_strtoull(const char *buf,
2499                 unsigned long long max, unsigned long long *value)
2500 {
2501         int ret;
2502
2503         ret = kstrtoull(skip_spaces(buf), 0, value);
2504         if (!ret && *value > max)
2505                 ret = -EINVAL;
2506         return ret;
2507 }
2508
2509 static ssize_t delayed_allocation_blocks_show(struct ext4_attr *a,
2510                                               struct ext4_sb_info *sbi,
2511                                               char *buf)
2512 {
2513         return snprintf(buf, PAGE_SIZE, "%llu\n",
2514                 (s64) EXT4_C2B(sbi,
2515                         percpu_counter_sum(&sbi->s_dirtyclusters_counter)));
2516 }
2517
2518 static ssize_t session_write_kbytes_show(struct ext4_attr *a,
2519                                          struct ext4_sb_info *sbi, char *buf)
2520 {
2521         struct super_block *sb = sbi->s_buddy_cache->i_sb;
2522
2523         if (!sb->s_bdev->bd_part)
2524                 return snprintf(buf, PAGE_SIZE, "0\n");
2525         return snprintf(buf, PAGE_SIZE, "%lu\n",
2526                         (part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2527                          sbi->s_sectors_written_start) >> 1);
2528 }
2529
2530 static ssize_t lifetime_write_kbytes_show(struct ext4_attr *a,
2531                                           struct ext4_sb_info *sbi, char *buf)
2532 {
2533         struct super_block *sb = sbi->s_buddy_cache->i_sb;
2534
2535         if (!sb->s_bdev->bd_part)
2536                 return snprintf(buf, PAGE_SIZE, "0\n");
2537         return snprintf(buf, PAGE_SIZE, "%llu\n",
2538                         (unsigned long long)(sbi->s_kbytes_written +
2539                         ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2540                           EXT4_SB(sb)->s_sectors_written_start) >> 1)));
2541 }
2542
2543 static ssize_t inode_readahead_blks_store(struct ext4_attr *a,
2544                                           struct ext4_sb_info *sbi,
2545                                           const char *buf, size_t count)
2546 {
2547         unsigned long t;
2548         int ret;
2549
2550         ret = kstrtoul(skip_spaces(buf), 0, &t);
2551         if (ret)
2552                 return ret;
2553
2554         if (t && (!is_power_of_2(t) || t > 0x40000000))
2555                 return -EINVAL;
2556
2557         sbi->s_inode_readahead_blks = t;
2558         return count;
2559 }
2560
2561 static ssize_t sbi_ui_show(struct ext4_attr *a,
2562                            struct ext4_sb_info *sbi, char *buf)
2563 {
2564         unsigned int *ui = (unsigned int *) (((char *) sbi) + a->u.offset);
2565
2566         return snprintf(buf, PAGE_SIZE, "%u\n", *ui);
2567 }
2568
2569 static ssize_t sbi_ui_store(struct ext4_attr *a,
2570                             struct ext4_sb_info *sbi,
2571                             const char *buf, size_t count)
2572 {
2573         unsigned int *ui = (unsigned int *) (((char *) sbi) + a->u.offset);
2574         unsigned long t;
2575         int ret;
2576
2577         ret = kstrtoul(skip_spaces(buf), 0, &t);
2578         if (ret)
2579                 return ret;
2580         *ui = t;
2581         return count;
2582 }
2583
2584 static ssize_t reserved_clusters_show(struct ext4_attr *a,
2585                                   struct ext4_sb_info *sbi, char *buf)
2586 {
2587         return snprintf(buf, PAGE_SIZE, "%llu\n",
2588                 (unsigned long long) atomic64_read(&sbi->s_resv_clusters));
2589 }
2590
2591 static ssize_t reserved_clusters_store(struct ext4_attr *a,
2592                                    struct ext4_sb_info *sbi,
2593                                    const char *buf, size_t count)
2594 {
2595         unsigned long long val;
2596         int ret;
2597
2598         if (parse_strtoull(buf, -1ULL, &val))
2599                 return -EINVAL;
2600         ret = ext4_reserve_clusters(sbi, val);
2601
2602         return ret ? ret : count;
2603 }
2604
2605 static ssize_t trigger_test_error(struct ext4_attr *a,
2606                                   struct ext4_sb_info *sbi,
2607                                   const char *buf, size_t count)
2608 {
2609         int len = count;
2610
2611         if (!capable(CAP_SYS_ADMIN))
2612                 return -EPERM;
2613
2614         if (len && buf[len-1] == '\n')
2615                 len--;
2616
2617         if (len)
2618                 ext4_error(sbi->s_sb, "%.*s", len, buf);
2619         return count;
2620 }
2621
2622 static ssize_t sbi_deprecated_show(struct ext4_attr *a,
2623                                    struct ext4_sb_info *sbi, char *buf)
2624 {
2625         return snprintf(buf, PAGE_SIZE, "%d\n", a->u.deprecated_val);
2626 }
2627
2628 #define EXT4_ATTR_OFFSET(_name,_mode,_show,_store,_elname) \
2629 static struct ext4_attr ext4_attr_##_name = {                   \
2630         .attr = {.name = __stringify(_name), .mode = _mode },   \
2631         .show   = _show,                                        \
2632         .store  = _store,                                       \
2633         .u = {                                                  \
2634                 .offset = offsetof(struct ext4_sb_info, _elname),\
2635         },                                                      \
2636 }
2637 #define EXT4_ATTR(name, mode, show, store) \
2638 static struct ext4_attr ext4_attr_##name = __ATTR(name, mode, show, store)
2639
2640 #define EXT4_INFO_ATTR(name) EXT4_ATTR(name, 0444, NULL, NULL)
2641 #define EXT4_RO_ATTR(name) EXT4_ATTR(name, 0444, name##_show, NULL)
2642 #define EXT4_RW_ATTR(name) EXT4_ATTR(name, 0644, name##_show, name##_store)
2643 #define EXT4_RW_ATTR_SBI_UI(name, elname)       \
2644         EXT4_ATTR_OFFSET(name, 0644, sbi_ui_show, sbi_ui_store, elname)
2645 #define ATTR_LIST(name) &ext4_attr_##name.attr
2646 #define EXT4_DEPRECATED_ATTR(_name, _val)       \
2647 static struct ext4_attr ext4_attr_##_name = {                   \
2648         .attr = {.name = __stringify(_name), .mode = 0444 },    \
2649         .show   = sbi_deprecated_show,                          \
2650         .u = {                                                  \
2651                 .deprecated_val = _val,                         \
2652         },                                                      \
2653 }
2654
2655 EXT4_RO_ATTR(delayed_allocation_blocks);
2656 EXT4_RO_ATTR(session_write_kbytes);
2657 EXT4_RO_ATTR(lifetime_write_kbytes);
2658 EXT4_RW_ATTR(reserved_clusters);
2659 EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, sbi_ui_show,
2660                  inode_readahead_blks_store, s_inode_readahead_blks);
2661 EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal);
2662 EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats);
2663 EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan);
2664 EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan);
2665 EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs);
2666 EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request);
2667 EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc);
2668 EXT4_DEPRECATED_ATTR(max_writeback_mb_bump, 128);
2669 EXT4_RW_ATTR_SBI_UI(extent_max_zeroout_kb, s_extent_max_zeroout_kb);
2670 EXT4_ATTR(trigger_fs_error, 0200, NULL, trigger_test_error);
2671 EXT4_RW_ATTR_SBI_UI(err_ratelimit_interval_ms, s_err_ratelimit_state.interval);
2672 EXT4_RW_ATTR_SBI_UI(err_ratelimit_burst, s_err_ratelimit_state.burst);
2673 EXT4_RW_ATTR_SBI_UI(warning_ratelimit_interval_ms, s_warning_ratelimit_state.interval);
2674 EXT4_RW_ATTR_SBI_UI(warning_ratelimit_burst, s_warning_ratelimit_state.burst);
2675 EXT4_RW_ATTR_SBI_UI(msg_ratelimit_interval_ms, s_msg_ratelimit_state.interval);
2676 EXT4_RW_ATTR_SBI_UI(msg_ratelimit_burst, s_msg_ratelimit_state.burst);
2677
2678 static struct attribute *ext4_attrs[] = {
2679         ATTR_LIST(delayed_allocation_blocks),
2680         ATTR_LIST(session_write_kbytes),
2681         ATTR_LIST(lifetime_write_kbytes),
2682         ATTR_LIST(reserved_clusters),
2683         ATTR_LIST(inode_readahead_blks),
2684         ATTR_LIST(inode_goal),
2685         ATTR_LIST(mb_stats),
2686         ATTR_LIST(mb_max_to_scan),
2687         ATTR_LIST(mb_min_to_scan),
2688         ATTR_LIST(mb_order2_req),
2689         ATTR_LIST(mb_stream_req),
2690         ATTR_LIST(mb_group_prealloc),
2691         ATTR_LIST(max_writeback_mb_bump),
2692         ATTR_LIST(extent_max_zeroout_kb),
2693         ATTR_LIST(trigger_fs_error),
2694         ATTR_LIST(err_ratelimit_interval_ms),
2695         ATTR_LIST(err_ratelimit_burst),
2696         ATTR_LIST(warning_ratelimit_interval_ms),
2697         ATTR_LIST(warning_ratelimit_burst),
2698         ATTR_LIST(msg_ratelimit_interval_ms),
2699         ATTR_LIST(msg_ratelimit_burst),
2700         NULL,
2701 };
2702
2703 /* Features this copy of ext4 supports */
2704 EXT4_INFO_ATTR(lazy_itable_init);
2705 EXT4_INFO_ATTR(batched_discard);
2706 EXT4_INFO_ATTR(meta_bg_resize);
2707
2708 static struct attribute *ext4_feat_attrs[] = {
2709         ATTR_LIST(lazy_itable_init),
2710         ATTR_LIST(batched_discard),
2711         ATTR_LIST(meta_bg_resize),
2712         NULL,
2713 };
2714
2715 static ssize_t ext4_attr_show(struct kobject *kobj,
2716                               struct attribute *attr, char *buf)
2717 {
2718         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2719                                                 s_kobj);
2720         struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2721
2722         return a->show ? a->show(a, sbi, buf) : 0;
2723 }
2724
2725 static ssize_t ext4_attr_store(struct kobject *kobj,
2726                                struct attribute *attr,
2727                                const char *buf, size_t len)
2728 {
2729         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2730                                                 s_kobj);
2731         struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2732
2733         return a->store ? a->store(a, sbi, buf, len) : 0;
2734 }
2735
2736 static void ext4_sb_release(struct kobject *kobj)
2737 {
2738         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2739                                                 s_kobj);
2740         complete(&sbi->s_kobj_unregister);
2741 }
2742
2743 static const struct sysfs_ops ext4_attr_ops = {
2744         .show   = ext4_attr_show,
2745         .store  = ext4_attr_store,
2746 };
2747
2748 static struct kobj_type ext4_ktype = {
2749         .default_attrs  = ext4_attrs,
2750         .sysfs_ops      = &ext4_attr_ops,
2751         .release        = ext4_sb_release,
2752 };
2753
2754 static void ext4_feat_release(struct kobject *kobj)
2755 {
2756         complete(&ext4_feat->f_kobj_unregister);
2757 }
2758
2759 static struct kobj_type ext4_feat_ktype = {
2760         .default_attrs  = ext4_feat_attrs,
2761         .sysfs_ops      = &ext4_attr_ops,
2762         .release        = ext4_feat_release,
2763 };
2764
2765 /*
2766  * Check whether this filesystem can be mounted based on
2767  * the features present and the RDONLY/RDWR mount requested.
2768  * Returns 1 if this filesystem can be mounted as requested,
2769  * 0 if it cannot be.
2770  */
2771 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2772 {
2773         if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT4_FEATURE_INCOMPAT_SUPP)) {
2774                 ext4_msg(sb, KERN_ERR,
2775                         "Couldn't mount because of "
2776                         "unsupported optional features (%x)",
2777                         (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2778                         ~EXT4_FEATURE_INCOMPAT_SUPP));
2779                 return 0;
2780         }
2781
2782         if (readonly)
2783                 return 1;
2784
2785         /* Check that feature set is OK for a read-write mount */
2786         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT4_FEATURE_RO_COMPAT_SUPP)) {
2787                 ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2788                          "unsupported optional features (%x)",
2789                          (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2790                                 ~EXT4_FEATURE_RO_COMPAT_SUPP));
2791                 return 0;
2792         }
2793         /*
2794          * Large file size enabled file system can only be mounted
2795          * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2796          */
2797         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) {
2798                 if (sizeof(blkcnt_t) < sizeof(u64)) {
2799                         ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2800                                  "cannot be mounted RDWR without "
2801                                  "CONFIG_LBDAF");
2802                         return 0;
2803                 }
2804         }
2805         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_BIGALLOC) &&
2806             !EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)) {
2807                 ext4_msg(sb, KERN_ERR,
2808                          "Can't support bigalloc feature without "
2809                          "extents feature\n");
2810                 return 0;
2811         }
2812
2813 #ifndef CONFIG_QUOTA
2814         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
2815             !readonly) {
2816                 ext4_msg(sb, KERN_ERR,
2817                          "Filesystem with quota feature cannot be mounted RDWR "
2818                          "without CONFIG_QUOTA");
2819                 return 0;
2820         }
2821 #endif  /* CONFIG_QUOTA */
2822         return 1;
2823 }
2824
2825 /*
2826  * This function is called once a day if we have errors logged
2827  * on the file system
2828  */
2829 static void print_daily_error_info(unsigned long arg)
2830 {
2831         struct super_block *sb = (struct super_block *) arg;
2832         struct ext4_sb_info *sbi;
2833         struct ext4_super_block *es;
2834
2835         sbi = EXT4_SB(sb);
2836         es = sbi->s_es;
2837
2838         if (es->s_error_count)
2839                 /* fsck newer than v1.41.13 is needed to clean this condition. */
2840                 ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
2841                          le32_to_cpu(es->s_error_count));
2842         if (es->s_first_error_time) {
2843                 printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %u: %.*s:%d",
2844                        sb->s_id, le32_to_cpu(es->s_first_error_time),
2845                        (int) sizeof(es->s_first_error_func),
2846                        es->s_first_error_func,
2847                        le32_to_cpu(es->s_first_error_line));
2848                 if (es->s_first_error_ino)
2849                         printk(": inode %u",
2850                                le32_to_cpu(es->s_first_error_ino));
2851                 if (es->s_first_error_block)
2852                         printk(": block %llu", (unsigned long long)
2853                                le64_to_cpu(es->s_first_error_block));
2854                 printk("\n");
2855         }
2856         if (es->s_last_error_time) {
2857                 printk(KERN_NOTICE "EXT4-fs (%s): last error at time %u: %.*s:%d",
2858                        sb->s_id, le32_to_cpu(es->s_last_error_time),
2859                        (int) sizeof(es->s_last_error_func),
2860                        es->s_last_error_func,
2861                        le32_to_cpu(es->s_last_error_line));
2862                 if (es->s_last_error_ino)
2863                         printk(": inode %u",
2864                                le32_to_cpu(es->s_last_error_ino));
2865                 if (es->s_last_error_block)
2866                         printk(": block %llu", (unsigned long long)
2867                                le64_to_cpu(es->s_last_error_block));
2868                 printk("\n");
2869         }
2870         mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2871 }
2872
2873 /* Find next suitable group and run ext4_init_inode_table */
2874 static int ext4_run_li_request(struct ext4_li_request *elr)
2875 {
2876         struct ext4_group_desc *gdp = NULL;
2877         ext4_group_t group, ngroups;
2878         struct super_block *sb;
2879         unsigned long timeout = 0;
2880         int ret = 0;
2881
2882         sb = elr->lr_super;
2883         ngroups = EXT4_SB(sb)->s_groups_count;
2884
2885         sb_start_write(sb);
2886         for (group = elr->lr_next_group; group < ngroups; group++) {
2887                 gdp = ext4_get_group_desc(sb, group, NULL);
2888                 if (!gdp) {
2889                         ret = 1;
2890                         break;
2891                 }
2892
2893                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2894                         break;
2895         }
2896
2897         if (group >= ngroups)
2898                 ret = 1;
2899
2900         if (!ret) {
2901                 timeout = jiffies;
2902                 ret = ext4_init_inode_table(sb, group,
2903                                             elr->lr_timeout ? 0 : 1);
2904                 if (elr->lr_timeout == 0) {
2905                         timeout = (jiffies - timeout) *
2906                                   elr->lr_sbi->s_li_wait_mult;
2907                         elr->lr_timeout = timeout;
2908                 }
2909                 elr->lr_next_sched = jiffies + elr->lr_timeout;
2910                 elr->lr_next_group = group + 1;
2911         }
2912         sb_end_write(sb);
2913
2914         return ret;
2915 }
2916
2917 /*
2918  * Remove lr_request from the list_request and free the
2919  * request structure. Should be called with li_list_mtx held
2920  */
2921 static void ext4_remove_li_request(struct ext4_li_request *elr)
2922 {
2923         struct ext4_sb_info *sbi;
2924
2925         if (!elr)
2926                 return;
2927
2928         sbi = elr->lr_sbi;
2929
2930         list_del(&elr->lr_request);
2931         sbi->s_li_request = NULL;
2932         kfree(elr);
2933 }
2934
2935 static void ext4_unregister_li_request(struct super_block *sb)
2936 {
2937         mutex_lock(&ext4_li_mtx);
2938         if (!ext4_li_info) {
2939                 mutex_unlock(&ext4_li_mtx);
2940                 return;
2941         }
2942
2943         mutex_lock(&ext4_li_info->li_list_mtx);
2944         ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
2945         mutex_unlock(&ext4_li_info->li_list_mtx);
2946         mutex_unlock(&ext4_li_mtx);
2947 }
2948
2949 static struct task_struct *ext4_lazyinit_task;
2950
2951 /*
2952  * This is the function where ext4lazyinit thread lives. It walks
2953  * through the request list searching for next scheduled filesystem.
2954  * When such a fs is found, run the lazy initialization request
2955  * (ext4_rn_li_request) and keep track of the time spend in this
2956  * function. Based on that time we compute next schedule time of
2957  * the request. When walking through the list is complete, compute
2958  * next waking time and put itself into sleep.
2959  */
2960 static int ext4_lazyinit_thread(void *arg)
2961 {
2962         struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
2963         struct list_head *pos, *n;
2964         struct ext4_li_request *elr;
2965         unsigned long next_wakeup, cur;
2966
2967         BUG_ON(NULL == eli);
2968
2969 cont_thread:
2970         while (true) {
2971                 next_wakeup = MAX_JIFFY_OFFSET;
2972
2973                 mutex_lock(&eli->li_list_mtx);
2974                 if (list_empty(&eli->li_request_list)) {
2975                         mutex_unlock(&eli->li_list_mtx);
2976                         goto exit_thread;
2977                 }
2978
2979                 list_for_each_safe(pos, n, &eli->li_request_list) {
2980                         elr = list_entry(pos, struct ext4_li_request,
2981                                          lr_request);
2982
2983                         if (time_after_eq(jiffies, elr->lr_next_sched)) {
2984                                 if (ext4_run_li_request(elr) != 0) {
2985                                         /* error, remove the lazy_init job */
2986                                         ext4_remove_li_request(elr);
2987                                         continue;
2988                                 }
2989                         }
2990
2991                         if (time_before(elr->lr_next_sched, next_wakeup))
2992                                 next_wakeup = elr->lr_next_sched;
2993                 }
2994                 mutex_unlock(&eli->li_list_mtx);
2995
2996                 try_to_freeze();
2997
2998                 cur = jiffies;
2999                 if ((time_after_eq(cur, next_wakeup)) ||
3000                     (MAX_JIFFY_OFFSET == next_wakeup)) {
3001                         cond_resched();
3002                         continue;
3003                 }
3004
3005                 schedule_timeout_interruptible(next_wakeup - cur);
3006
3007                 if (kthread_should_stop()) {
3008                         ext4_clear_request_list();
3009                         goto exit_thread;
3010                 }
3011         }
3012
3013 exit_thread:
3014         /*
3015          * It looks like the request list is empty, but we need
3016          * to check it under the li_list_mtx lock, to prevent any
3017          * additions into it, and of course we should lock ext4_li_mtx
3018          * to atomically free the list and ext4_li_info, because at
3019          * this point another ext4 filesystem could be registering
3020          * new one.
3021          */
3022         mutex_lock(&ext4_li_mtx);
3023         mutex_lock(&eli->li_list_mtx);
3024         if (!list_empty(&eli->li_request_list)) {
3025                 mutex_unlock(&eli->li_list_mtx);
3026                 mutex_unlock(&ext4_li_mtx);
3027                 goto cont_thread;
3028         }
3029         mutex_unlock(&eli->li_list_mtx);
3030         kfree(ext4_li_info);
3031         ext4_li_info = NULL;
3032         mutex_unlock(&ext4_li_mtx);
3033
3034         return 0;
3035 }
3036
3037 static void ext4_clear_request_list(void)
3038 {
3039         struct list_head *pos, *n;
3040         struct ext4_li_request *elr;
3041
3042         mutex_lock(&ext4_li_info->li_list_mtx);
3043         list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
3044                 elr = list_entry(pos, struct ext4_li_request,
3045                                  lr_request);
3046                 ext4_remove_li_request(elr);
3047         }
3048         mutex_unlock(&ext4_li_info->li_list_mtx);
3049 }
3050
3051 static int ext4_run_lazyinit_thread(void)
3052 {
3053         ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
3054                                          ext4_li_info, "ext4lazyinit");
3055         if (IS_ERR(ext4_lazyinit_task)) {
3056                 int err = PTR_ERR(ext4_lazyinit_task);
3057                 ext4_clear_request_list();
3058                 kfree(ext4_li_info);
3059                 ext4_li_info = NULL;
3060                 printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
3061                                  "initialization thread\n",
3062                                  err);
3063                 return err;
3064         }
3065         ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
3066         return 0;
3067 }
3068
3069 /*
3070  * Check whether it make sense to run itable init. thread or not.
3071  * If there is at least one uninitialized inode table, return
3072  * corresponding group number, else the loop goes through all
3073  * groups and return total number of groups.
3074  */
3075 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3076 {
3077         ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3078         struct ext4_group_desc *gdp = NULL;
3079
3080         for (group = 0; group < ngroups; group++) {
3081                 gdp = ext4_get_group_desc(sb, group, NULL);
3082                 if (!gdp)
3083                         continue;
3084
3085                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3086                         break;
3087         }
3088
3089         return group;
3090 }
3091
3092 static int ext4_li_info_new(void)
3093 {
3094         struct ext4_lazy_init *eli = NULL;
3095
3096         eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3097         if (!eli)
3098                 return -ENOMEM;
3099
3100         INIT_LIST_HEAD(&eli->li_request_list);
3101         mutex_init(&eli->li_list_mtx);
3102
3103         eli->li_state |= EXT4_LAZYINIT_QUIT;
3104
3105         ext4_li_info = eli;
3106
3107         return 0;
3108 }
3109
3110 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3111                                             ext4_group_t start)
3112 {
3113         struct ext4_sb_info *sbi = EXT4_SB(sb);
3114         struct ext4_li_request *elr;
3115
3116         elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3117         if (!elr)
3118                 return NULL;
3119
3120         elr->lr_super = sb;
3121         elr->lr_sbi = sbi;
3122         elr->lr_next_group = start;
3123
3124         /*
3125          * Randomize first schedule time of the request to
3126          * spread the inode table initialization requests
3127          * better.
3128          */
3129         elr->lr_next_sched = jiffies + (prandom_u32() %
3130                                 (EXT4_DEF_LI_MAX_START_DELAY * HZ));
3131         return elr;
3132 }
3133
3134 int ext4_register_li_request(struct super_block *sb,
3135                              ext4_group_t first_not_zeroed)
3136 {
3137         struct ext4_sb_info *sbi = EXT4_SB(sb);
3138         struct ext4_li_request *elr = NULL;
3139         ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
3140         int ret = 0;
3141
3142         mutex_lock(&ext4_li_mtx);
3143         if (sbi->s_li_request != NULL) {
3144                 /*
3145                  * Reset timeout so it can be computed again, because
3146                  * s_li_wait_mult might have changed.
3147                  */
3148                 sbi->s_li_request->lr_timeout = 0;
3149                 goto out;
3150         }
3151
3152         if (first_not_zeroed == ngroups ||
3153             (sb->s_flags & MS_RDONLY) ||
3154             !test_opt(sb, INIT_INODE_TABLE))
3155                 goto out;
3156
3157         elr = ext4_li_request_new(sb, first_not_zeroed);
3158         if (!elr) {
3159                 ret = -ENOMEM;
3160                 goto out;
3161         }
3162
3163         if (NULL == ext4_li_info) {
3164                 ret = ext4_li_info_new();
3165                 if (ret)
3166                         goto out;
3167         }
3168
3169         mutex_lock(&ext4_li_info->li_list_mtx);
3170         list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3171         mutex_unlock(&ext4_li_info->li_list_mtx);
3172
3173         sbi->s_li_request = elr;
3174         /*
3175          * set elr to NULL here since it has been inserted to
3176          * the request_list and the removal and free of it is
3177          * handled by ext4_clear_request_list from now on.
3178          */
3179         elr = NULL;
3180
3181         if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3182                 ret = ext4_run_lazyinit_thread();
3183                 if (ret)
3184                         goto out;
3185         }
3186 out:
3187         mutex_unlock(&ext4_li_mtx);
3188         if (ret)
3189                 kfree(elr);
3190         return ret;
3191 }
3192
3193 /*
3194  * We do not need to lock anything since this is called on
3195  * module unload.
3196  */
3197 static void ext4_destroy_lazyinit_thread(void)
3198 {
3199         /*
3200          * If thread exited earlier
3201          * there's nothing to be done.
3202          */
3203         if (!ext4_li_info || !ext4_lazyinit_task)
3204                 return;
3205
3206         kthread_stop(ext4_lazyinit_task);
3207 }
3208
3209 static int set_journal_csum_feature_set(struct super_block *sb)
3210 {
3211         int ret = 1;
3212         int compat, incompat;
3213         struct ext4_sb_info *sbi = EXT4_SB(sb);
3214
3215         if (ext4_has_metadata_csum(sb)) {
3216                 /* journal checksum v3 */
3217                 compat = 0;
3218                 incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
3219         } else {
3220                 /* journal checksum v1 */
3221                 compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3222                 incompat = 0;
3223         }
3224
3225         if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3226                 ret = jbd2_journal_set_features(sbi->s_journal,
3227                                 compat, 0,
3228                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3229                                 incompat);
3230         } else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3231                 ret = jbd2_journal_set_features(sbi->s_journal,
3232                                 compat, 0,
3233                                 incompat);
3234                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3235                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3236         } else {
3237                 jbd2_journal_clear_features(sbi->s_journal,
3238                                 JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3239                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3240                                 JBD2_FEATURE_INCOMPAT_CSUM_V3 |
3241                                 JBD2_FEATURE_INCOMPAT_CSUM_V2);
3242         }
3243
3244         return ret;
3245 }
3246
3247 /*
3248  * Note: calculating the overhead so we can be compatible with
3249  * historical BSD practice is quite difficult in the face of
3250  * clusters/bigalloc.  This is because multiple metadata blocks from
3251  * different block group can end up in the same allocation cluster.
3252  * Calculating the exact overhead in the face of clustered allocation
3253  * requires either O(all block bitmaps) in memory or O(number of block
3254  * groups**2) in time.  We will still calculate the superblock for
3255  * older file systems --- and if we come across with a bigalloc file
3256  * system with zero in s_overhead_clusters the estimate will be close to
3257  * correct especially for very large cluster sizes --- but for newer
3258  * file systems, it's better to calculate this figure once at mkfs
3259  * time, and store it in the superblock.  If the superblock value is
3260  * present (even for non-bigalloc file systems), we will use it.
3261  */
3262 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3263                           char *buf)
3264 {
3265         struct ext4_sb_info     *sbi = EXT4_SB(sb);
3266         struct ext4_group_desc  *gdp;
3267         ext4_fsblk_t            first_block, last_block, b;
3268         ext4_group_t            i, ngroups = ext4_get_groups_count(sb);
3269         int                     s, j, count = 0;
3270
3271         if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_BIGALLOC))
3272                 return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3273                         sbi->s_itb_per_group + 2);
3274
3275         first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3276                 (grp * EXT4_BLOCKS_PER_GROUP(sb));
3277         last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3278         for (i = 0; i < ngroups; i++) {
3279                 gdp = ext4_get_group_desc(sb, i, NULL);
3280                 b = ext4_block_bitmap(sb, gdp);
3281                 if (b >= first_block && b <= last_block) {
3282                         ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3283                         count++;
3284                 }
3285                 b = ext4_inode_bitmap(sb, gdp);
3286                 if (b >= first_block && b <= last_block) {
3287                         ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3288                         count++;
3289                 }
3290                 b = ext4_inode_table(sb, gdp);
3291                 if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3292                         for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3293                                 int c = EXT4_B2C(sbi, b - first_block);
3294                                 ext4_set_bit(c, buf);
3295                                 count++;
3296                         }
3297                 if (i != grp)
3298                         continue;
3299                 s = 0;
3300                 if (ext4_bg_has_super(sb, grp)) {
3301                         ext4_set_bit(s++, buf);
3302                         count++;
3303                 }
3304                 for (j = ext4_bg_num_gdb(sb, grp); j > 0; j--) {
3305                         ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3306                         count++;
3307                 }
3308         }
3309         if (!count)
3310                 return 0;
3311         return EXT4_CLUSTERS_PER_GROUP(sb) -
3312                 ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3313 }
3314
3315 /*
3316  * Compute the overhead and stash it in sbi->s_overhead
3317  */
3318 int ext4_calculate_overhead(struct super_block *sb)
3319 {
3320         struct ext4_sb_info *sbi = EXT4_SB(sb);
3321         struct ext4_super_block *es = sbi->s_es;
3322         ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3323         ext4_fsblk_t overhead = 0;
3324         char *buf = (char *) get_zeroed_page(GFP_KERNEL);
3325
3326         if (!buf)
3327                 return -ENOMEM;
3328
3329         /*
3330          * Compute the overhead (FS structures).  This is constant
3331          * for a given filesystem unless the number of block groups
3332          * changes so we cache the previous value until it does.
3333          */
3334
3335         /*
3336          * All of the blocks before first_data_block are overhead
3337          */
3338         overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3339
3340         /*
3341          * Add the overhead found in each block group
3342          */
3343         for (i = 0; i < ngroups; i++) {
3344                 int blks;
3345
3346                 blks = count_overhead(sb, i, buf);
3347                 overhead += blks;
3348                 if (blks)
3349                         memset(buf, 0, PAGE_SIZE);
3350                 cond_resched();
3351         }
3352         /* Add the journal blocks as well */
3353         if (sbi->s_journal)
3354                 overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_maxlen);
3355
3356         sbi->s_overhead = overhead;
3357         smp_wmb();
3358         free_page((unsigned long) buf);
3359         return 0;
3360 }
3361
3362
3363 static ext4_fsblk_t ext4_calculate_resv_clusters(struct super_block *sb)
3364 {
3365         ext4_fsblk_t resv_clusters;
3366
3367         /*
3368          * There's no need to reserve anything when we aren't using extents.
3369          * The space estimates are exact, there are no unwritten extents,
3370          * hole punching doesn't need new metadata... This is needed especially
3371          * to keep ext2/3 backward compatibility.
3372          */
3373         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS))
3374                 return 0;
3375         /*
3376          * By default we reserve 2% or 4096 clusters, whichever is smaller.
3377          * This should cover the situations where we can not afford to run
3378          * out of space like for example punch hole, or converting
3379          * unwritten extents in delalloc path. In most cases such
3380          * allocation would require 1, or 2 blocks, higher numbers are
3381          * very rare.
3382          */
3383         resv_clusters = ext4_blocks_count(EXT4_SB(sb)->s_es) >>
3384                         EXT4_SB(sb)->s_cluster_bits;
3385
3386         do_div(resv_clusters, 50);
3387         resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
3388
3389         return resv_clusters;
3390 }
3391
3392
3393 static int ext4_reserve_clusters(struct ext4_sb_info *sbi, ext4_fsblk_t count)
3394 {
3395         ext4_fsblk_t clusters = ext4_blocks_count(sbi->s_es) >>
3396                                 sbi->s_cluster_bits;
3397
3398         if (count >= clusters)
3399                 return -EINVAL;
3400
3401         atomic64_set(&sbi->s_resv_clusters, count);
3402         return 0;
3403 }
3404
3405 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3406 {
3407         char *orig_data = kstrdup(data, GFP_KERNEL);
3408         struct buffer_head *bh;
3409         struct ext4_super_block *es = NULL;
3410         struct ext4_sb_info *sbi;
3411         ext4_fsblk_t block;
3412         ext4_fsblk_t sb_block = get_sb_block(&data);
3413         ext4_fsblk_t logical_sb_block;
3414         unsigned long offset = 0;
3415         unsigned long journal_devnum = 0;
3416         unsigned long def_mount_opts;
3417         struct inode *root;
3418         char *cp;
3419         const char *descr;
3420         int ret = -ENOMEM;
3421         int blocksize, clustersize;
3422         unsigned int db_count;
3423         unsigned int i;
3424         int needs_recovery, has_huge_files, has_bigalloc;
3425         __u64 blocks_count;
3426         int err = 0;
3427         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3428         ext4_group_t first_not_zeroed;
3429
3430         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3431         if (!sbi)
3432                 goto out_free_orig;
3433
3434         sbi->s_blockgroup_lock =
3435                 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3436         if (!sbi->s_blockgroup_lock) {
3437                 kfree(sbi);
3438                 goto out_free_orig;
3439         }
3440         sb->s_fs_info = sbi;
3441         sbi->s_sb = sb;
3442         sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3443         sbi->s_sb_block = sb_block;
3444         if (sb->s_bdev->bd_part)
3445                 sbi->s_sectors_written_start =
3446                         part_stat_read(sb->s_bdev->bd_part, sectors[1]);
3447
3448         /* Cleanup superblock name */
3449         for (cp = sb->s_id; (cp = strchr(cp, '/'));)
3450                 *cp = '!';
3451
3452         /* -EINVAL is default */
3453         ret = -EINVAL;
3454         blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3455         if (!blocksize) {
3456                 ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3457                 goto out_fail;
3458         }
3459
3460         /*
3461          * The ext4 superblock will not be buffer aligned for other than 1kB
3462          * block sizes.  We need to calculate the offset from buffer start.
3463          */
3464         if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3465                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3466                 offset = do_div(logical_sb_block, blocksize);
3467         } else {
3468                 logical_sb_block = sb_block;
3469         }
3470
3471         if (!(bh = sb_bread(sb, logical_sb_block))) {
3472                 ext4_msg(sb, KERN_ERR, "unable to read superblock");
3473                 goto out_fail;
3474         }
3475         /*
3476          * Note: s_es must be initialized as soon as possible because
3477          *       some ext4 macro-instructions depend on its value
3478          */
3479         es = (struct ext4_super_block *) (bh->b_data + offset);
3480         sbi->s_es = es;
3481         sb->s_magic = le16_to_cpu(es->s_magic);
3482         if (sb->s_magic != EXT4_SUPER_MAGIC)
3483                 goto cantfind_ext4;
3484         sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3485
3486         /* Warn if metadata_csum and gdt_csum are both set. */
3487         if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3488                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
3489             EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_GDT_CSUM))
3490                 ext4_warning(sb, KERN_INFO "metadata_csum and uninit_bg are "
3491                              "redundant flags; please run fsck.");
3492
3493         /* Check for a known checksum algorithm */
3494         if (!ext4_verify_csum_type(sb, es)) {
3495                 ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3496                          "unknown checksum algorithm.");
3497                 silent = 1;
3498                 goto cantfind_ext4;
3499         }
3500
3501         /* Load the checksum driver */
3502         if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3503                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
3504                 sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3505                 if (IS_ERR(sbi->s_chksum_driver)) {
3506                         ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3507                         ret = PTR_ERR(sbi->s_chksum_driver);
3508                         sbi->s_chksum_driver = NULL;
3509                         goto failed_mount;
3510                 }
3511         }
3512
3513         /* Check superblock checksum */
3514         if (!ext4_superblock_csum_verify(sb, es)) {
3515                 ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3516                          "invalid superblock checksum.  Run e2fsck?");
3517                 silent = 1;
3518                 goto cantfind_ext4;
3519         }
3520
3521         /* Precompute checksum seed for all metadata */
3522         if (ext4_has_metadata_csum(sb))
3523                 sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3524                                                sizeof(es->s_uuid));
3525
3526         /* Set defaults before we parse the mount options */
3527         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3528         set_opt(sb, INIT_INODE_TABLE);
3529         if (def_mount_opts & EXT4_DEFM_DEBUG)
3530                 set_opt(sb, DEBUG);
3531         if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3532                 set_opt(sb, GRPID);
3533         if (def_mount_opts & EXT4_DEFM_UID16)
3534                 set_opt(sb, NO_UID32);
3535         /* xattr user namespace & acls are now defaulted on */
3536         set_opt(sb, XATTR_USER);
3537 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3538         set_opt(sb, POSIX_ACL);
3539 #endif
3540         /* don't forget to enable journal_csum when metadata_csum is enabled. */
3541         if (ext4_has_metadata_csum(sb))
3542                 set_opt(sb, JOURNAL_CHECKSUM);
3543
3544         if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3545                 set_opt(sb, JOURNAL_DATA);
3546         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3547                 set_opt(sb, ORDERED_DATA);
3548         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3549                 set_opt(sb, WRITEBACK_DATA);
3550
3551         if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3552                 set_opt(sb, ERRORS_PANIC);
3553         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3554                 set_opt(sb, ERRORS_CONT);
3555         else
3556                 set_opt(sb, ERRORS_RO);
3557         if (def_mount_opts & EXT4_DEFM_BLOCK_VALIDITY)
3558                 set_opt(sb, BLOCK_VALIDITY);
3559         if (def_mount_opts & EXT4_DEFM_DISCARD)
3560                 set_opt(sb, DISCARD);
3561
3562         sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3563         sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3564         sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3565         sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3566         sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3567
3568         if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3569                 set_opt(sb, BARRIER);
3570
3571         /*
3572          * enable delayed allocation by default
3573          * Use -o nodelalloc to turn it off
3574          */
3575         if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
3576             ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3577                 set_opt(sb, DELALLOC);
3578
3579         /*
3580          * set default s_li_wait_mult for lazyinit, for the case there is
3581          * no mount option specified.
3582          */
3583         sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3584
3585         if (!parse_options((char *) sbi->s_es->s_mount_opts, sb,
3586                            &journal_devnum, &journal_ioprio, 0)) {
3587                 ext4_msg(sb, KERN_WARNING,
3588                          "failed to parse options in superblock: %s",
3589                          sbi->s_es->s_mount_opts);
3590         }
3591         sbi->s_def_mount_opt = sbi->s_mount_opt;
3592         if (!parse_options((char *) data, sb, &journal_devnum,
3593                            &journal_ioprio, 0))
3594                 goto failed_mount;
3595
3596         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3597                 printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3598                             "with data=journal disables delayed "
3599                             "allocation and O_DIRECT support!\n");
3600                 if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3601                         ext4_msg(sb, KERN_ERR, "can't mount with "
3602                                  "both data=journal and delalloc");
3603                         goto failed_mount;
3604                 }
3605                 if (test_opt(sb, DIOREAD_NOLOCK)) {
3606                         ext4_msg(sb, KERN_ERR, "can't mount with "
3607                                  "both data=journal and dioread_nolock");
3608                         goto failed_mount;
3609                 }
3610                 if (test_opt(sb, DELALLOC))
3611                         clear_opt(sb, DELALLOC);
3612         }
3613
3614         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
3615                 (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
3616
3617         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3618             (EXT4_HAS_COMPAT_FEATURE(sb, ~0U) ||
3619              EXT4_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
3620              EXT4_HAS_INCOMPAT_FEATURE(sb, ~0U)))
3621                 ext4_msg(sb, KERN_WARNING,
3622                        "feature flags set on rev 0 fs, "
3623                        "running e2fsck is recommended");
3624
3625         if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
3626                 set_opt2(sb, HURD_COMPAT);
3627                 if (EXT4_HAS_INCOMPAT_FEATURE(sb,
3628                                               EXT4_FEATURE_INCOMPAT_64BIT)) {
3629                         ext4_msg(sb, KERN_ERR,
3630                                  "The Hurd can't support 64-bit file systems");
3631                         goto failed_mount;
3632                 }
3633         }
3634
3635         if (IS_EXT2_SB(sb)) {
3636                 if (ext2_feature_set_ok(sb))
3637                         ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3638                                  "using the ext4 subsystem");
3639                 else {
3640                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3641                                  "to feature incompatibilities");
3642                         goto failed_mount;
3643                 }
3644         }
3645
3646         if (IS_EXT3_SB(sb)) {
3647                 if (ext3_feature_set_ok(sb))
3648                         ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3649                                  "using the ext4 subsystem");
3650                 else {
3651                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3652                                  "to feature incompatibilities");
3653                         goto failed_mount;
3654                 }
3655         }
3656
3657         /*
3658          * Check feature flags regardless of the revision level, since we
3659          * previously didn't change the revision level when setting the flags,
3660          * so there is a chance incompat flags are set on a rev 0 filesystem.
3661          */
3662         if (!ext4_feature_set_ok(sb, (sb->s_flags & MS_RDONLY)))
3663                 goto failed_mount;
3664
3665         blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3666         if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3667             blocksize > EXT4_MAX_BLOCK_SIZE) {
3668                 ext4_msg(sb, KERN_ERR,
3669                        "Unsupported filesystem blocksize %d (%d log_block_size)",
3670                          blocksize, le32_to_cpu(es->s_log_block_size));
3671                 goto failed_mount;
3672         }
3673         if (le32_to_cpu(es->s_log_block_size) >
3674             (EXT4_MAX_BLOCK_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
3675                 ext4_msg(sb, KERN_ERR,
3676                          "Invalid log block size: %u",
3677                          le32_to_cpu(es->s_log_block_size));
3678                 goto failed_mount;
3679         }
3680
3681         if (le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) > (blocksize / 4)) {
3682                 ext4_msg(sb, KERN_ERR,
3683                          "Number of reserved GDT blocks insanely large: %d",
3684                          le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks));
3685                 goto failed_mount;
3686         }
3687
3688         if (sb->s_blocksize != blocksize) {
3689                 /* Validate the filesystem blocksize */
3690                 if (!sb_set_blocksize(sb, blocksize)) {
3691                         ext4_msg(sb, KERN_ERR, "bad block size %d",
3692                                         blocksize);
3693                         goto failed_mount;
3694                 }
3695
3696                 brelse(bh);
3697                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3698                 offset = do_div(logical_sb_block, blocksize);
3699                 bh = sb_bread(sb, logical_sb_block);
3700                 if (!bh) {
3701                         ext4_msg(sb, KERN_ERR,
3702                                "Can't read superblock on 2nd try");
3703                         goto failed_mount;
3704                 }
3705                 es = (struct ext4_super_block *)(bh->b_data + offset);
3706                 sbi->s_es = es;
3707                 if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
3708                         ext4_msg(sb, KERN_ERR,
3709                                "Magic mismatch, very weird!");
3710                         goto failed_mount;
3711                 }
3712         }
3713
3714         has_huge_files = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3715                                 EXT4_FEATURE_RO_COMPAT_HUGE_FILE);
3716         sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
3717                                                       has_huge_files);
3718         sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
3719
3720         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3721                 sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3722                 sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3723         } else {
3724                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3725                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3726                 if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3727                     (!is_power_of_2(sbi->s_inode_size)) ||
3728                     (sbi->s_inode_size > blocksize)) {
3729                         ext4_msg(sb, KERN_ERR,
3730                                "unsupported inode size: %d",
3731                                sbi->s_inode_size);
3732                         goto failed_mount;
3733                 }
3734                 if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
3735                         sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
3736         }
3737
3738         sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
3739         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT)) {
3740                 if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
3741                     sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
3742                     !is_power_of_2(sbi->s_desc_size)) {
3743                         ext4_msg(sb, KERN_ERR,
3744                                "unsupported descriptor size %lu",
3745                                sbi->s_desc_size);
3746                         goto failed_mount;
3747                 }
3748         } else
3749                 sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
3750
3751         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
3752         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
3753         if (EXT4_INODE_SIZE(sb) == 0 || EXT4_INODES_PER_GROUP(sb) == 0)
3754                 goto cantfind_ext4;
3755
3756         sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
3757         if (sbi->s_inodes_per_block == 0)
3758                 goto cantfind_ext4;
3759         sbi->s_itb_per_group = sbi->s_inodes_per_group /
3760                                         sbi->s_inodes_per_block;
3761         sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
3762         sbi->s_sbh = bh;
3763         sbi->s_mount_state = le16_to_cpu(es->s_state);
3764         sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
3765         sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
3766
3767         for (i = 0; i < 4; i++)
3768                 sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
3769         sbi->s_def_hash_version = es->s_def_hash_version;
3770         if (EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_DIR_INDEX)) {
3771                 i = le32_to_cpu(es->s_flags);
3772                 if (i & EXT2_FLAGS_UNSIGNED_HASH)
3773                         sbi->s_hash_unsigned = 3;
3774                 else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
3775 #ifdef __CHAR_UNSIGNED__
3776                         if (!(sb->s_flags & MS_RDONLY))
3777                                 es->s_flags |=
3778                                         cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
3779                         sbi->s_hash_unsigned = 3;
3780 #else
3781                         if (!(sb->s_flags & MS_RDONLY))
3782                                 es->s_flags |=
3783                                         cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
3784 #endif
3785                 }
3786         }
3787
3788         /* Handle clustersize */
3789         clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
3790         has_bigalloc = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3791                                 EXT4_FEATURE_RO_COMPAT_BIGALLOC);
3792         if (has_bigalloc) {
3793                 if (clustersize < blocksize) {
3794                         ext4_msg(sb, KERN_ERR,
3795                                  "cluster size (%d) smaller than "
3796                                  "block size (%d)", clustersize, blocksize);
3797                         goto failed_mount;
3798                 }
3799                 if (le32_to_cpu(es->s_log_cluster_size) >
3800                     (EXT4_MAX_CLUSTER_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
3801                         ext4_msg(sb, KERN_ERR,
3802                                  "Invalid log cluster size: %u",
3803                                  le32_to_cpu(es->s_log_cluster_size));
3804                         goto failed_mount;
3805                 }
3806                 sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
3807                         le32_to_cpu(es->s_log_block_size);
3808                 sbi->s_clusters_per_group =
3809                         le32_to_cpu(es->s_clusters_per_group);
3810                 if (sbi->s_clusters_per_group > blocksize * 8) {
3811                         ext4_msg(sb, KERN_ERR,
3812                                  "#clusters per group too big: %lu",
3813                                  sbi->s_clusters_per_group);
3814                         goto failed_mount;
3815                 }
3816                 if (sbi->s_blocks_per_group !=
3817                     (sbi->s_clusters_per_group * (clustersize / blocksize))) {
3818                         ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
3819                                  "clusters per group (%lu) inconsistent",
3820                                  sbi->s_blocks_per_group,
3821                                  sbi->s_clusters_per_group);
3822                         goto failed_mount;
3823                 }
3824         } else {
3825                 if (clustersize != blocksize) {
3826                         ext4_warning(sb, "fragment/cluster size (%d) != "
3827                                      "block size (%d)", clustersize,
3828                                      blocksize);
3829                         clustersize = blocksize;
3830                 }
3831                 if (sbi->s_blocks_per_group > blocksize * 8) {
3832                         ext4_msg(sb, KERN_ERR,
3833                                  "#blocks per group too big: %lu",
3834                                  sbi->s_blocks_per_group);
3835                         goto failed_mount;
3836                 }
3837                 sbi->s_clusters_per_group = sbi->s_blocks_per_group;
3838                 sbi->s_cluster_bits = 0;
3839         }
3840         sbi->s_cluster_ratio = clustersize / blocksize;
3841
3842         if (sbi->s_inodes_per_group > blocksize * 8) {
3843                 ext4_msg(sb, KERN_ERR,
3844                        "#inodes per group too big: %lu",
3845                        sbi->s_inodes_per_group);
3846                 goto failed_mount;
3847         }
3848
3849         /* Do we have standard group size of clustersize * 8 blocks ? */
3850         if (sbi->s_blocks_per_group == clustersize << 3)
3851                 set_opt2(sb, STD_GROUP_SIZE);
3852
3853         /*
3854          * Test whether we have more sectors than will fit in sector_t,
3855          * and whether the max offset is addressable by the page cache.
3856          */
3857         err = generic_check_addressable(sb->s_blocksize_bits,
3858                                         ext4_blocks_count(es));
3859         if (err) {
3860                 ext4_msg(sb, KERN_ERR, "filesystem"
3861                          " too large to mount safely on this system");
3862                 if (sizeof(sector_t) < 8)
3863                         ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
3864                 goto failed_mount;
3865         }
3866
3867         if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
3868                 goto cantfind_ext4;
3869
3870         /* check blocks count against device size */
3871         blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
3872         if (blocks_count && ext4_blocks_count(es) > blocks_count) {
3873                 ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
3874                        "exceeds size of device (%llu blocks)",
3875                        ext4_blocks_count(es), blocks_count);
3876                 goto failed_mount;
3877         }
3878
3879         /*
3880          * It makes no sense for the first data block to be beyond the end
3881          * of the filesystem.
3882          */
3883         if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
3884                 ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
3885                          "block %u is beyond end of filesystem (%llu)",
3886                          le32_to_cpu(es->s_first_data_block),
3887                          ext4_blocks_count(es));
3888                 goto failed_mount;
3889         }
3890         blocks_count = (ext4_blocks_count(es) -
3891                         le32_to_cpu(es->s_first_data_block) +
3892                         EXT4_BLOCKS_PER_GROUP(sb) - 1);
3893         do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
3894         if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
3895                 ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
3896                        "(block count %llu, first data block %u, "
3897                        "blocks per group %lu)", sbi->s_groups_count,
3898                        ext4_blocks_count(es),
3899                        le32_to_cpu(es->s_first_data_block),
3900                        EXT4_BLOCKS_PER_GROUP(sb));
3901                 goto failed_mount;
3902         }
3903         sbi->s_groups_count = blocks_count;
3904         sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
3905                         (EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
3906         db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
3907                    EXT4_DESC_PER_BLOCK(sb);
3908         if (EXT4_HAS_INCOMPAT_FEATURE(sb,EXT4_FEATURE_INCOMPAT_META_BG)) {
3909                 if (le32_to_cpu(es->s_first_meta_bg) >= db_count) {
3910                         ext4_msg(sb, KERN_WARNING,
3911                                  "first meta block group too large: %u "
3912                                  "(group descriptor block count %u)",
3913                                  le32_to_cpu(es->s_first_meta_bg), db_count);
3914                         goto failed_mount;
3915                 }
3916         }
3917         sbi->s_group_desc = ext4_kvmalloc(db_count *
3918                                           sizeof(struct buffer_head *),
3919                                           GFP_KERNEL);
3920         if (sbi->s_group_desc == NULL) {
3921                 ext4_msg(sb, KERN_ERR, "not enough memory");
3922                 ret = -ENOMEM;
3923                 goto failed_mount;
3924         }
3925
3926         if (ext4_proc_root)
3927                 sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root);
3928
3929         if (sbi->s_proc)
3930                 proc_create_data("options", S_IRUGO, sbi->s_proc,
3931                                  &ext4_seq_options_fops, sb);
3932
3933         bgl_lock_init(sbi->s_blockgroup_lock);
3934
3935         for (i = 0; i < db_count; i++) {
3936                 block = descriptor_loc(sb, logical_sb_block, i);
3937                 sbi->s_group_desc[i] = sb_bread(sb, block);
3938                 if (!sbi->s_group_desc[i]) {
3939                         ext4_msg(sb, KERN_ERR,
3940                                "can't read group descriptor %d", i);
3941                         db_count = i;
3942                         goto failed_mount2;
3943                 }
3944         }
3945         if (!ext4_check_descriptors(sb, logical_sb_block, &first_not_zeroed)) {
3946                 ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
3947                 goto failed_mount2;
3948         }
3949         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
3950                 if (!ext4_fill_flex_info(sb)) {
3951                         ext4_msg(sb, KERN_ERR,
3952                                "unable to initialize "
3953                                "flex_bg meta info!");
3954                         goto failed_mount2;
3955                 }
3956
3957         sbi->s_gdb_count = db_count;
3958         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
3959         spin_lock_init(&sbi->s_next_gen_lock);
3960
3961         init_timer(&sbi->s_err_report);
3962         sbi->s_err_report.function = print_daily_error_info;
3963         sbi->s_err_report.data = (unsigned long) sb;
3964
3965         /* Register extent status tree shrinker */
3966         ext4_es_register_shrinker(sbi);
3967
3968         err = percpu_counter_init(&sbi->s_freeclusters_counter,
3969                         ext4_count_free_clusters(sb));
3970         if (!err) {
3971                 err = percpu_counter_init(&sbi->s_freeinodes_counter,
3972                                 ext4_count_free_inodes(sb));
3973         }
3974         if (!err) {
3975                 err = percpu_counter_init(&sbi->s_dirs_counter,
3976                                 ext4_count_dirs(sb));
3977         }
3978         if (!err) {
3979                 err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0);
3980         }
3981         if (!err) {
3982                 err = percpu_counter_init(&sbi->s_extent_cache_cnt, 0);
3983         }
3984         if (err) {
3985                 ext4_msg(sb, KERN_ERR, "insufficient memory");
3986                 goto failed_mount3;
3987         }
3988
3989         sbi->s_stripe = ext4_get_stripe_size(sbi);
3990         sbi->s_extent_max_zeroout_kb = 32;
3991
3992         /*
3993          * set up enough so that it can read an inode
3994          */
3995         if (!test_opt(sb, NOLOAD) &&
3996             EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
3997                 sb->s_op = &ext4_sops;
3998         else
3999                 sb->s_op = &ext4_nojournal_sops;
4000         sb->s_export_op = &ext4_export_ops;
4001         sb->s_xattr = ext4_xattr_handlers;
4002 #ifdef CONFIG_QUOTA
4003         sb->dq_op = &ext4_quota_operations;
4004         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
4005                 sb->s_qcop = &ext4_qctl_sysfile_operations;
4006         else
4007                 sb->s_qcop = &ext4_qctl_operations;
4008 #endif
4009         memcpy(sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
4010
4011         INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
4012         mutex_init(&sbi->s_orphan_lock);
4013
4014         sb->s_root = NULL;
4015
4016         needs_recovery = (es->s_last_orphan != 0 ||
4017                           EXT4_HAS_INCOMPAT_FEATURE(sb,
4018                                     EXT4_FEATURE_INCOMPAT_RECOVER));
4019
4020         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_MMP) &&
4021             !(sb->s_flags & MS_RDONLY))
4022                 if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
4023                         goto failed_mount3;
4024
4025         /*
4026          * The first inode we look at is the journal inode.  Don't try
4027          * root first: it may be modified in the journal!
4028          */
4029         if (!test_opt(sb, NOLOAD) &&
4030             EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
4031                 if (ext4_load_journal(sb, es, journal_devnum))
4032                         goto failed_mount3;
4033         } else if (test_opt(sb, NOLOAD) && !(sb->s_flags & MS_RDONLY) &&
4034               EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
4035                 ext4_msg(sb, KERN_ERR, "required journal recovery "
4036                        "suppressed and not mounted read-only");
4037                 goto failed_mount_wq;
4038         } else {
4039                 clear_opt(sb, DATA_FLAGS);
4040                 sbi->s_journal = NULL;
4041                 needs_recovery = 0;
4042                 goto no_journal;
4043         }
4044
4045         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT) &&
4046             !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4047                                        JBD2_FEATURE_INCOMPAT_64BIT)) {
4048                 ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
4049                 goto failed_mount_wq;
4050         }
4051
4052         if (!set_journal_csum_feature_set(sb)) {
4053                 ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
4054                          "feature set");
4055                 goto failed_mount_wq;
4056         }
4057
4058         /* We have now updated the journal if required, so we can
4059          * validate the data journaling mode. */
4060         switch (test_opt(sb, DATA_FLAGS)) {
4061         case 0:
4062                 /* No mode set, assume a default based on the journal
4063                  * capabilities: ORDERED_DATA if the journal can
4064                  * cope, else JOURNAL_DATA
4065                  */
4066                 if (jbd2_journal_check_available_features
4067                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
4068                         set_opt(sb, ORDERED_DATA);
4069                 else
4070                         set_opt(sb, JOURNAL_DATA);
4071                 break;
4072
4073         case EXT4_MOUNT_ORDERED_DATA:
4074         case EXT4_MOUNT_WRITEBACK_DATA:
4075                 if (!jbd2_journal_check_available_features
4076                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4077                         ext4_msg(sb, KERN_ERR, "Journal does not support "
4078                                "requested data journaling mode");
4079                         goto failed_mount_wq;
4080                 }
4081         default:
4082                 break;
4083         }
4084         set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4085
4086         sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
4087
4088         /*
4089          * The journal may have updated the bg summary counts, so we
4090          * need to update the global counters.
4091          */
4092         percpu_counter_set(&sbi->s_freeclusters_counter,
4093                            ext4_count_free_clusters(sb));
4094         percpu_counter_set(&sbi->s_freeinodes_counter,
4095                            ext4_count_free_inodes(sb));
4096         percpu_counter_set(&sbi->s_dirs_counter,
4097                            ext4_count_dirs(sb));
4098         percpu_counter_set(&sbi->s_dirtyclusters_counter, 0);
4099
4100 no_journal:
4101         if (ext4_mballoc_ready) {
4102                 sbi->s_mb_cache = ext4_xattr_create_cache(sb->s_id);
4103                 if (!sbi->s_mb_cache) {
4104                         ext4_msg(sb, KERN_ERR, "Failed to create an mb_cache");
4105                         goto failed_mount_wq;
4106                 }
4107         }
4108
4109         /*
4110          * Get the # of file system overhead blocks from the
4111          * superblock if present.
4112          */
4113         if (es->s_overhead_clusters)
4114                 sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
4115         else {
4116                 err = ext4_calculate_overhead(sb);
4117                 if (err)
4118                         goto failed_mount_wq;
4119         }
4120
4121         /*
4122          * The maximum number of concurrent works can be high and
4123          * concurrency isn't really necessary.  Limit it to 1.
4124          */
4125         EXT4_SB(sb)->rsv_conversion_wq =
4126                 alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
4127         if (!EXT4_SB(sb)->rsv_conversion_wq) {
4128                 printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
4129                 ret = -ENOMEM;
4130                 goto failed_mount4;
4131         }
4132
4133         /*
4134          * The jbd2_journal_load will have done any necessary log recovery,
4135          * so we can safely mount the rest of the filesystem now.
4136          */
4137
4138         root = ext4_iget(sb, EXT4_ROOT_INO);
4139         if (IS_ERR(root)) {
4140                 ext4_msg(sb, KERN_ERR, "get root inode failed");
4141                 ret = PTR_ERR(root);
4142                 root = NULL;
4143                 goto failed_mount4;
4144         }
4145         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
4146                 ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
4147                 iput(root);
4148                 goto failed_mount4;
4149         }
4150         sb->s_root = d_make_root(root);
4151         if (!sb->s_root) {
4152                 ext4_msg(sb, KERN_ERR, "get root dentry failed");
4153                 ret = -ENOMEM;
4154                 goto failed_mount4;
4155         }
4156
4157         if (ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY))
4158                 sb->s_flags |= MS_RDONLY;
4159
4160         /* determine the minimum size of new large inodes, if present */
4161         if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
4162                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4163                                                      EXT4_GOOD_OLD_INODE_SIZE;
4164                 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
4165                                        EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE)) {
4166                         if (sbi->s_want_extra_isize <
4167                             le16_to_cpu(es->s_want_extra_isize))
4168                                 sbi->s_want_extra_isize =
4169                                         le16_to_cpu(es->s_want_extra_isize);
4170                         if (sbi->s_want_extra_isize <
4171                             le16_to_cpu(es->s_min_extra_isize))
4172                                 sbi->s_want_extra_isize =
4173                                         le16_to_cpu(es->s_min_extra_isize);
4174                 }
4175         }
4176         /* Check if enough inode space is available */
4177         if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
4178                                                         sbi->s_inode_size) {
4179                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4180                                                        EXT4_GOOD_OLD_INODE_SIZE;
4181                 ext4_msg(sb, KERN_INFO, "required extra inode space not"
4182                          "available");
4183         }
4184
4185         err = ext4_reserve_clusters(sbi, ext4_calculate_resv_clusters(sb));
4186         if (err) {
4187                 ext4_msg(sb, KERN_ERR, "failed to reserve %llu clusters for "
4188                          "reserved pool", ext4_calculate_resv_clusters(sb));
4189                 goto failed_mount4a;
4190         }
4191
4192         err = ext4_setup_system_zone(sb);
4193         if (err) {
4194                 ext4_msg(sb, KERN_ERR, "failed to initialize system "
4195                          "zone (%d)", err);
4196                 goto failed_mount4a;
4197         }
4198
4199         ext4_ext_init(sb);
4200         err = ext4_mb_init(sb);
4201         if (err) {
4202                 ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
4203                          err);
4204                 goto failed_mount5;
4205         }
4206
4207         err = ext4_register_li_request(sb, first_not_zeroed);
4208         if (err)
4209                 goto failed_mount6;
4210
4211         sbi->s_kobj.kset = ext4_kset;
4212         init_completion(&sbi->s_kobj_unregister);
4213         err = kobject_init_and_add(&sbi->s_kobj, &ext4_ktype, NULL,
4214                                    "%s", sb->s_id);
4215         if (err)
4216                 goto failed_mount7;
4217
4218 #ifdef CONFIG_QUOTA
4219         /* Enable quota usage during mount. */
4220         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
4221             !(sb->s_flags & MS_RDONLY)) {
4222                 err = ext4_enable_quotas(sb);
4223                 if (err)
4224                         goto failed_mount8;
4225         }
4226 #endif  /* CONFIG_QUOTA */
4227
4228         EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
4229         ext4_orphan_cleanup(sb, es);
4230         EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
4231         if (needs_recovery) {
4232                 ext4_msg(sb, KERN_INFO, "recovery complete");
4233                 ext4_mark_recovery_complete(sb, es);
4234         }
4235         if (EXT4_SB(sb)->s_journal) {
4236                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
4237                         descr = " journalled data mode";
4238                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
4239                         descr = " ordered data mode";
4240                 else
4241                         descr = " writeback data mode";
4242         } else
4243                 descr = "out journal";
4244
4245         if (test_opt(sb, DISCARD)) {
4246                 struct request_queue *q = bdev_get_queue(sb->s_bdev);
4247                 if (!blk_queue_discard(q))
4248                         ext4_msg(sb, KERN_WARNING,
4249                                  "mounting with \"discard\" option, but "
4250                                  "the device does not support discard");
4251         }
4252
4253         ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
4254                  "Opts: %s%s%s", descr, sbi->s_es->s_mount_opts,
4255                  *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
4256
4257         if (es->s_error_count)
4258                 mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
4259
4260         /* Enable message ratelimiting. Default is 10 messages per 5 secs. */
4261         ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
4262         ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
4263         ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
4264
4265         kfree(orig_data);
4266         return 0;
4267
4268 cantfind_ext4:
4269         if (!silent)
4270                 ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
4271         goto failed_mount;
4272
4273 #ifdef CONFIG_QUOTA
4274 failed_mount8:
4275         kobject_del(&sbi->s_kobj);
4276 #endif
4277 failed_mount7:
4278         ext4_unregister_li_request(sb);
4279 failed_mount6:
4280         ext4_mb_release(sb);
4281 failed_mount5:
4282         ext4_ext_release(sb);
4283         ext4_release_system_zone(sb);
4284 failed_mount4a:
4285         dput(sb->s_root);
4286         sb->s_root = NULL;
4287 failed_mount4:
4288         ext4_msg(sb, KERN_ERR, "mount failed");
4289         if (EXT4_SB(sb)->rsv_conversion_wq)
4290                 destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4291 failed_mount_wq:
4292         if (sbi->s_journal) {
4293                 jbd2_journal_destroy(sbi->s_journal);
4294                 sbi->s_journal = NULL;
4295         }
4296 failed_mount3:
4297         ext4_es_unregister_shrinker(sbi);
4298         del_timer_sync(&sbi->s_err_report);
4299         if (sbi->s_flex_groups)
4300                 ext4_kvfree(sbi->s_flex_groups);
4301         percpu_counter_destroy(&sbi->s_freeclusters_counter);
4302         percpu_counter_destroy(&sbi->s_freeinodes_counter);
4303         percpu_counter_destroy(&sbi->s_dirs_counter);
4304         percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4305         percpu_counter_destroy(&sbi->s_extent_cache_cnt);
4306         if (sbi->s_mmp_tsk)
4307                 kthread_stop(sbi->s_mmp_tsk);
4308 failed_mount2:
4309         for (i = 0; i < db_count; i++)
4310                 brelse(sbi->s_group_desc[i]);
4311         ext4_kvfree(sbi->s_group_desc);
4312 failed_mount:
4313         if (sbi->s_chksum_driver)
4314                 crypto_free_shash(sbi->s_chksum_driver);
4315         if (sbi->s_proc) {
4316                 remove_proc_entry("options", sbi->s_proc);
4317                 remove_proc_entry(sb->s_id, ext4_proc_root);
4318         }
4319 #ifdef CONFIG_QUOTA
4320         for (i = 0; i < MAXQUOTAS; i++)
4321                 kfree(sbi->s_qf_names[i]);
4322 #endif
4323         ext4_blkdev_remove(sbi);
4324         brelse(bh);
4325 out_fail:
4326         sb->s_fs_info = NULL;
4327         kfree(sbi->s_blockgroup_lock);
4328         kfree(sbi);
4329 out_free_orig:
4330         kfree(orig_data);
4331         return err ? err : ret;
4332 }
4333
4334 /*
4335  * Setup any per-fs journal parameters now.  We'll do this both on
4336  * initial mount, once the journal has been initialised but before we've
4337  * done any recovery; and again on any subsequent remount.
4338  */
4339 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4340 {
4341         struct ext4_sb_info *sbi = EXT4_SB(sb);
4342
4343         journal->j_commit_interval = sbi->s_commit_interval;
4344         journal->j_min_batch_time = sbi->s_min_batch_time;
4345         journal->j_max_batch_time = sbi->s_max_batch_time;
4346
4347         write_lock(&journal->j_state_lock);
4348         if (test_opt(sb, BARRIER))
4349                 journal->j_flags |= JBD2_BARRIER;
4350         else
4351                 journal->j_flags &= ~JBD2_BARRIER;
4352         if (test_opt(sb, DATA_ERR_ABORT))
4353                 journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4354         else
4355                 journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4356         write_unlock(&journal->j_state_lock);
4357 }
4358
4359 static journal_t *ext4_get_journal(struct super_block *sb,
4360                                    unsigned int journal_inum)
4361 {
4362         struct inode *journal_inode;
4363         journal_t *journal;
4364
4365         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4366
4367         /* First, test for the existence of a valid inode on disk.  Bad
4368          * things happen if we iget() an unused inode, as the subsequent
4369          * iput() will try to delete it. */
4370
4371         journal_inode = ext4_iget(sb, journal_inum);
4372         if (IS_ERR(journal_inode)) {
4373                 ext4_msg(sb, KERN_ERR, "no journal found");
4374                 return NULL;
4375         }
4376         if (!journal_inode->i_nlink) {
4377                 make_bad_inode(journal_inode);
4378                 iput(journal_inode);
4379                 ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4380                 return NULL;
4381         }
4382
4383         jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4384                   journal_inode, journal_inode->i_size);
4385         if (!S_ISREG(journal_inode->i_mode)) {
4386                 ext4_msg(sb, KERN_ERR, "invalid journal inode");
4387                 iput(journal_inode);
4388                 return NULL;
4389         }
4390
4391         journal = jbd2_journal_init_inode(journal_inode);
4392         if (!journal) {
4393                 ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4394                 iput(journal_inode);
4395                 return NULL;
4396         }
4397         journal->j_private = sb;
4398         ext4_init_journal_params(sb, journal);
4399         return journal;
4400 }
4401
4402 static journal_t *ext4_get_dev_journal(struct super_block *sb,
4403                                        dev_t j_dev)
4404 {
4405         struct buffer_head *bh;
4406         journal_t *journal;
4407         ext4_fsblk_t start;
4408         ext4_fsblk_t len;
4409         int hblock, blocksize;
4410         ext4_fsblk_t sb_block;
4411         unsigned long offset;
4412         struct ext4_super_block *es;
4413         struct block_device *bdev;
4414
4415         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4416
4417         bdev = ext4_blkdev_get(j_dev, sb);
4418         if (bdev == NULL)
4419                 return NULL;
4420
4421         blocksize = sb->s_blocksize;
4422         hblock = bdev_logical_block_size(bdev);
4423         if (blocksize < hblock) {
4424                 ext4_msg(sb, KERN_ERR,
4425                         "blocksize too small for journal device");
4426                 goto out_bdev;
4427         }
4428
4429         sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4430         offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4431         set_blocksize(bdev, blocksize);
4432         if (!(bh = __bread(bdev, sb_block, blocksize))) {
4433                 ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4434                        "external journal");
4435                 goto out_bdev;
4436         }
4437
4438         es = (struct ext4_super_block *) (bh->b_data + offset);
4439         if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4440             !(le32_to_cpu(es->s_feature_incompat) &
4441               EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4442                 ext4_msg(sb, KERN_ERR, "external journal has "
4443                                         "bad superblock");
4444                 brelse(bh);
4445                 goto out_bdev;
4446         }
4447
4448         if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4449                 ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4450                 brelse(bh);
4451                 goto out_bdev;
4452         }
4453
4454         len = ext4_blocks_count(es);
4455         start = sb_block + 1;
4456         brelse(bh);     /* we're done with the superblock */
4457
4458         journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4459                                         start, len, blocksize);
4460         if (!journal) {
4461                 ext4_msg(sb, KERN_ERR, "failed to create device journal");
4462                 goto out_bdev;
4463         }
4464         journal->j_private = sb;
4465         ll_rw_block(READ | REQ_META | REQ_PRIO, 1, &journal->j_sb_buffer);
4466         wait_on_buffer(journal->j_sb_buffer);
4467         if (!buffer_uptodate(journal->j_sb_buffer)) {
4468                 ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4469                 goto out_journal;
4470         }
4471         if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4472                 ext4_msg(sb, KERN_ERR, "External journal has more than one "
4473                                         "user (unsupported) - %d",
4474                         be32_to_cpu(journal->j_superblock->s_nr_users));
4475                 goto out_journal;
4476         }
4477         EXT4_SB(sb)->journal_bdev = bdev;
4478         ext4_init_journal_params(sb, journal);
4479         return journal;
4480
4481 out_journal:
4482         jbd2_journal_destroy(journal);
4483 out_bdev:
4484         ext4_blkdev_put(bdev);
4485         return NULL;
4486 }
4487
4488 static int ext4_load_journal(struct super_block *sb,
4489                              struct ext4_super_block *es,
4490                              unsigned long journal_devnum)
4491 {
4492         journal_t *journal;
4493         unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4494         dev_t journal_dev;
4495         int err = 0;
4496         int really_read_only;
4497
4498         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4499
4500         if (journal_devnum &&
4501             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4502                 ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4503                         "numbers have changed");
4504                 journal_dev = new_decode_dev(journal_devnum);
4505         } else
4506                 journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4507
4508         really_read_only = bdev_read_only(sb->s_bdev);
4509
4510         /*
4511          * Are we loading a blank journal or performing recovery after a
4512          * crash?  For recovery, we need to check in advance whether we
4513          * can get read-write access to the device.
4514          */
4515         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
4516                 if (sb->s_flags & MS_RDONLY) {
4517                         ext4_msg(sb, KERN_INFO, "INFO: recovery "
4518                                         "required on readonly filesystem");
4519                         if (really_read_only) {
4520                                 ext4_msg(sb, KERN_ERR, "write access "
4521                                         "unavailable, cannot proceed");
4522                                 return -EROFS;
4523                         }
4524                         ext4_msg(sb, KERN_INFO, "write access will "
4525                                "be enabled during recovery");
4526                 }
4527         }
4528
4529         if (journal_inum && journal_dev) {
4530                 ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4531                        "and inode journals!");
4532                 return -EINVAL;
4533         }
4534
4535         if (journal_inum) {
4536                 if (!(journal = ext4_get_journal(sb, journal_inum)))
4537                         return -EINVAL;
4538         } else {
4539                 if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4540                         return -EINVAL;
4541         }
4542
4543         if (!(journal->j_flags & JBD2_BARRIER))
4544                 ext4_msg(sb, KERN_INFO, "barriers disabled");
4545
4546         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER))
4547                 err = jbd2_journal_wipe(journal, !really_read_only);
4548         if (!err) {
4549                 char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4550                 if (save)
4551                         memcpy(save, ((char *) es) +
4552                                EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4553                 err = jbd2_journal_load(journal);
4554                 if (save)
4555                         memcpy(((char *) es) + EXT4_S_ERR_START,
4556                                save, EXT4_S_ERR_LEN);
4557                 kfree(save);
4558         }
4559
4560         if (err) {
4561                 ext4_msg(sb, KERN_ERR, "error loading journal");
4562                 jbd2_journal_destroy(journal);
4563                 return err;
4564         }
4565
4566         EXT4_SB(sb)->s_journal = journal;
4567         ext4_clear_journal_err(sb, es);
4568
4569         if (!really_read_only && journal_devnum &&
4570             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4571                 es->s_journal_dev = cpu_to_le32(journal_devnum);
4572
4573                 /* Make sure we flush the recovery flag to disk. */
4574                 ext4_commit_super(sb, 1);
4575         }
4576
4577         return 0;
4578 }
4579
4580 static int ext4_commit_super(struct super_block *sb, int sync)
4581 {
4582         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4583         struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4584         int error = 0;
4585
4586         if (!sbh || block_device_ejected(sb))
4587                 return error;
4588         if (buffer_write_io_error(sbh)) {
4589                 /*
4590                  * Oh, dear.  A previous attempt to write the
4591                  * superblock failed.  This could happen because the
4592                  * USB device was yanked out.  Or it could happen to
4593                  * be a transient write error and maybe the block will
4594                  * be remapped.  Nothing we can do but to retry the
4595                  * write and hope for the best.
4596                  */
4597                 ext4_msg(sb, KERN_ERR, "previous I/O error to "
4598                        "superblock detected");
4599                 clear_buffer_write_io_error(sbh);
4600                 set_buffer_uptodate(sbh);
4601         }
4602         /*
4603          * If the file system is mounted read-only, don't update the
4604          * superblock write time.  This avoids updating the superblock
4605          * write time when we are mounting the root file system
4606          * read/only but we need to replay the journal; at that point,
4607          * for people who are east of GMT and who make their clock
4608          * tick in localtime for Windows bug-for-bug compatibility,
4609          * the clock is set in the future, and this will cause e2fsck
4610          * to complain and force a full file system check.
4611          */
4612         if (!(sb->s_flags & MS_RDONLY))
4613                 es->s_wtime = cpu_to_le32(get_seconds());
4614         if (sb->s_bdev->bd_part)
4615                 es->s_kbytes_written =
4616                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
4617                             ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
4618                               EXT4_SB(sb)->s_sectors_written_start) >> 1));
4619         else
4620                 es->s_kbytes_written =
4621                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
4622         ext4_free_blocks_count_set(es,
4623                         EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
4624                                 &EXT4_SB(sb)->s_freeclusters_counter)));
4625         es->s_free_inodes_count =
4626                 cpu_to_le32(percpu_counter_sum_positive(
4627                                 &EXT4_SB(sb)->s_freeinodes_counter));
4628         BUFFER_TRACE(sbh, "marking dirty");
4629         ext4_superblock_csum_set(sb);
4630         mark_buffer_dirty(sbh);
4631         if (sync) {
4632                 error = sync_dirty_buffer(sbh);
4633                 if (error)
4634                         return error;
4635
4636                 error = buffer_write_io_error(sbh);
4637                 if (error) {
4638                         ext4_msg(sb, KERN_ERR, "I/O error while writing "
4639                                "superblock");
4640                         clear_buffer_write_io_error(sbh);
4641                         set_buffer_uptodate(sbh);
4642                 }
4643         }
4644         return error;
4645 }
4646
4647 /*
4648  * Have we just finished recovery?  If so, and if we are mounting (or
4649  * remounting) the filesystem readonly, then we will end up with a
4650  * consistent fs on disk.  Record that fact.
4651  */
4652 static void ext4_mark_recovery_complete(struct super_block *sb,
4653                                         struct ext4_super_block *es)
4654 {
4655         journal_t *journal = EXT4_SB(sb)->s_journal;
4656
4657         if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
4658                 BUG_ON(journal != NULL);
4659                 return;
4660         }
4661         jbd2_journal_lock_updates(journal);
4662         if (jbd2_journal_flush(journal) < 0)
4663                 goto out;
4664
4665         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER) &&
4666             sb->s_flags & MS_RDONLY) {
4667                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4668                 ext4_commit_super(sb, 1);
4669         }
4670
4671 out:
4672         jbd2_journal_unlock_updates(journal);
4673 }
4674
4675 /*
4676  * If we are mounting (or read-write remounting) a filesystem whose journal
4677  * has recorded an error from a previous lifetime, move that error to the
4678  * main filesystem now.
4679  */
4680 static void ext4_clear_journal_err(struct super_block *sb,
4681                                    struct ext4_super_block *es)
4682 {
4683         journal_t *journal;
4684         int j_errno;
4685         const char *errstr;
4686
4687         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4688
4689         journal = EXT4_SB(sb)->s_journal;
4690
4691         /*
4692          * Now check for any error status which may have been recorded in the
4693          * journal by a prior ext4_error() or ext4_abort()
4694          */
4695
4696         j_errno = jbd2_journal_errno(journal);
4697         if (j_errno) {
4698                 char nbuf[16];
4699
4700                 errstr = ext4_decode_error(sb, j_errno, nbuf);
4701                 ext4_warning(sb, "Filesystem error recorded "
4702                              "from previous mount: %s", errstr);
4703                 ext4_warning(sb, "Marking fs in need of filesystem check.");
4704
4705                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
4706                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
4707                 ext4_commit_super(sb, 1);
4708
4709                 jbd2_journal_clear_err(journal);
4710                 jbd2_journal_update_sb_errno(journal);
4711         }
4712 }
4713
4714 /*
4715  * Force the running and committing transactions to commit,
4716  * and wait on the commit.
4717  */
4718 int ext4_force_commit(struct super_block *sb)
4719 {
4720         journal_t *journal;
4721
4722         if (sb->s_flags & MS_RDONLY)
4723                 return 0;
4724
4725         journal = EXT4_SB(sb)->s_journal;
4726         return ext4_journal_force_commit(journal);
4727 }
4728
4729 static int ext4_sync_fs(struct super_block *sb, int wait)
4730 {
4731         int ret = 0;
4732         tid_t target;
4733         bool needs_barrier = false;
4734         struct ext4_sb_info *sbi = EXT4_SB(sb);
4735
4736         trace_ext4_sync_fs(sb, wait);
4737         flush_workqueue(sbi->rsv_conversion_wq);
4738         /*
4739          * Writeback quota in non-journalled quota case - journalled quota has
4740          * no dirty dquots
4741          */
4742         dquot_writeback_dquots(sb, -1);
4743         /*
4744          * Data writeback is possible w/o journal transaction, so barrier must
4745          * being sent at the end of the function. But we can skip it if
4746          * transaction_commit will do it for us.
4747          */
4748         target = jbd2_get_latest_transaction(sbi->s_journal);
4749         if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
4750             !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
4751                 needs_barrier = true;
4752
4753         if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
4754                 if (wait)
4755                         ret = jbd2_log_wait_commit(sbi->s_journal, target);
4756         }
4757         if (needs_barrier) {
4758                 int err;
4759                 err = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
4760                 if (!ret)
4761                         ret = err;
4762         }
4763
4764         return ret;
4765 }
4766
4767 static int ext4_sync_fs_nojournal(struct super_block *sb, int wait)
4768 {
4769         int ret = 0;
4770
4771         trace_ext4_sync_fs(sb, wait);
4772         flush_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4773         dquot_writeback_dquots(sb, -1);
4774         if (wait && test_opt(sb, BARRIER))
4775                 ret = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
4776
4777         return ret;
4778 }
4779
4780 /*
4781  * LVM calls this function before a (read-only) snapshot is created.  This
4782  * gives us a chance to flush the journal completely and mark the fs clean.
4783  *
4784  * Note that only this function cannot bring a filesystem to be in a clean
4785  * state independently. It relies on upper layer to stop all data & metadata
4786  * modifications.
4787  */
4788 static int ext4_freeze(struct super_block *sb)
4789 {
4790         int error = 0;
4791         journal_t *journal;
4792
4793         if (sb->s_flags & MS_RDONLY)
4794                 return 0;
4795
4796         journal = EXT4_SB(sb)->s_journal;
4797
4798         /* Now we set up the journal barrier. */
4799         jbd2_journal_lock_updates(journal);
4800
4801         /*
4802          * Don't clear the needs_recovery flag if we failed to flush
4803          * the journal.
4804          */
4805         error = jbd2_journal_flush(journal);
4806         if (error < 0)
4807                 goto out;
4808
4809         /* Journal blocked and flushed, clear needs_recovery flag. */
4810         EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4811         error = ext4_commit_super(sb, 1);
4812 out:
4813         /* we rely on upper layer to stop further updates */
4814         jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
4815         return error;
4816 }
4817
4818 /*
4819  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
4820  * flag here, even though the filesystem is not technically dirty yet.
4821  */
4822 static int ext4_unfreeze(struct super_block *sb)
4823 {
4824         if (sb->s_flags & MS_RDONLY)
4825                 return 0;
4826
4827         /* Reset the needs_recovery flag before the fs is unlocked. */
4828         EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4829         ext4_commit_super(sb, 1);
4830         return 0;
4831 }
4832
4833 /*
4834  * Structure to save mount options for ext4_remount's benefit
4835  */
4836 struct ext4_mount_options {
4837         unsigned long s_mount_opt;
4838         unsigned long s_mount_opt2;
4839         kuid_t s_resuid;
4840         kgid_t s_resgid;
4841         unsigned long s_commit_interval;
4842         u32 s_min_batch_time, s_max_batch_time;
4843 #ifdef CONFIG_QUOTA
4844         int s_jquota_fmt;
4845         char *s_qf_names[MAXQUOTAS];
4846 #endif
4847 };
4848
4849 static int ext4_remount(struct super_block *sb, int *flags, char *data)
4850 {
4851         struct ext4_super_block *es;
4852         struct ext4_sb_info *sbi = EXT4_SB(sb);
4853         unsigned long old_sb_flags;
4854         struct ext4_mount_options old_opts;
4855         int enable_quota = 0;
4856         ext4_group_t g;
4857         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4858         int err = 0;
4859 #ifdef CONFIG_QUOTA
4860         int i, j;
4861 #endif
4862         char *orig_data = kstrdup(data, GFP_KERNEL);
4863
4864         /* Store the original options */
4865         old_sb_flags = sb->s_flags;
4866         old_opts.s_mount_opt = sbi->s_mount_opt;
4867         old_opts.s_mount_opt2 = sbi->s_mount_opt2;
4868         old_opts.s_resuid = sbi->s_resuid;
4869         old_opts.s_resgid = sbi->s_resgid;
4870         old_opts.s_commit_interval = sbi->s_commit_interval;
4871         old_opts.s_min_batch_time = sbi->s_min_batch_time;
4872         old_opts.s_max_batch_time = sbi->s_max_batch_time;
4873 #ifdef CONFIG_QUOTA
4874         old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
4875         for (i = 0; i < MAXQUOTAS; i++)
4876                 if (sbi->s_qf_names[i]) {
4877                         old_opts.s_qf_names[i] = kstrdup(sbi->s_qf_names[i],
4878                                                          GFP_KERNEL);
4879                         if (!old_opts.s_qf_names[i]) {
4880                                 for (j = 0; j < i; j++)
4881                                         kfree(old_opts.s_qf_names[j]);
4882                                 kfree(orig_data);
4883                                 return -ENOMEM;
4884                         }
4885                 } else
4886                         old_opts.s_qf_names[i] = NULL;
4887 #endif
4888         if (sbi->s_journal && sbi->s_journal->j_task->io_context)
4889                 journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
4890
4891         /*
4892          * Allow the "check" option to be passed as a remount option.
4893          */
4894         if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
4895                 err = -EINVAL;
4896                 goto restore_opts;
4897         }
4898
4899         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
4900                 if (test_opt2(sb, EXPLICIT_DELALLOC)) {
4901                         ext4_msg(sb, KERN_ERR, "can't mount with "
4902                                  "both data=journal and delalloc");
4903                         err = -EINVAL;
4904                         goto restore_opts;
4905                 }
4906                 if (test_opt(sb, DIOREAD_NOLOCK)) {
4907                         ext4_msg(sb, KERN_ERR, "can't mount with "
4908                                  "both data=journal and dioread_nolock");
4909                         err = -EINVAL;
4910                         goto restore_opts;
4911                 }
4912         }
4913
4914         if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
4915                 ext4_abort(sb, "Abort forced by user");
4916
4917         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
4918                 (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
4919
4920         es = sbi->s_es;
4921
4922         if (sbi->s_journal) {
4923                 ext4_init_journal_params(sb, sbi->s_journal);
4924                 set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4925         }
4926
4927         if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY)) {
4928                 if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
4929                         err = -EROFS;
4930                         goto restore_opts;
4931                 }
4932
4933                 if (*flags & MS_RDONLY) {
4934                         err = sync_filesystem(sb);
4935                         if (err < 0)
4936                                 goto restore_opts;
4937                         err = dquot_suspend(sb, -1);
4938                         if (err < 0)
4939                                 goto restore_opts;
4940
4941                         /*
4942                          * First of all, the unconditional stuff we have to do
4943                          * to disable replay of the journal when we next remount
4944                          */
4945                         sb->s_flags |= MS_RDONLY;
4946
4947                         /*
4948                          * OK, test if we are remounting a valid rw partition
4949                          * readonly, and if so set the rdonly flag and then
4950                          * mark the partition as valid again.
4951                          */
4952                         if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
4953                             (sbi->s_mount_state & EXT4_VALID_FS))
4954                                 es->s_state = cpu_to_le16(sbi->s_mount_state);
4955
4956                         if (sbi->s_journal)
4957                                 ext4_mark_recovery_complete(sb, es);
4958                 } else {
4959                         /* Make sure we can mount this feature set readwrite */
4960                         if (!ext4_feature_set_ok(sb, 0)) {
4961                                 err = -EROFS;
4962                                 goto restore_opts;
4963                         }
4964                         /*
4965                          * Make sure the group descriptor checksums
4966                          * are sane.  If they aren't, refuse to remount r/w.
4967                          */
4968                         for (g = 0; g < sbi->s_groups_count; g++) {
4969                                 struct ext4_group_desc *gdp =
4970                                         ext4_get_group_desc(sb, g, NULL);
4971
4972                                 if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
4973                                         ext4_msg(sb, KERN_ERR,
4974                "ext4_remount: Checksum for group %u failed (%u!=%u)",
4975                 g, le16_to_cpu(ext4_group_desc_csum(sbi, g, gdp)),
4976                                                le16_to_cpu(gdp->bg_checksum));
4977                                         err = -EINVAL;
4978                                         goto restore_opts;
4979                                 }
4980                         }
4981
4982                         /*
4983                          * If we have an unprocessed orphan list hanging
4984                          * around from a previously readonly bdev mount,
4985                          * require a full umount/remount for now.
4986                          */
4987                         if (es->s_last_orphan) {
4988                                 ext4_msg(sb, KERN_WARNING, "Couldn't "
4989                                        "remount RDWR because of unprocessed "
4990                                        "orphan inode list.  Please "
4991                                        "umount/remount instead");
4992                                 err = -EINVAL;
4993                                 goto restore_opts;
4994                         }
4995
4996                         /*
4997                          * Mounting a RDONLY partition read-write, so reread
4998                          * and store the current valid flag.  (It may have
4999                          * been changed by e2fsck since we originally mounted
5000                          * the partition.)
5001                          */
5002                         if (sbi->s_journal)
5003                                 ext4_clear_journal_err(sb, es);
5004                         sbi->s_mount_state = le16_to_cpu(es->s_state);
5005                         if (!ext4_setup_super(sb, es, 0))
5006                                 sb->s_flags &= ~MS_RDONLY;
5007                         if (EXT4_HAS_INCOMPAT_FEATURE(sb,
5008                                                      EXT4_FEATURE_INCOMPAT_MMP))
5009                                 if (ext4_multi_mount_protect(sb,
5010                                                 le64_to_cpu(es->s_mmp_block))) {
5011                                         err = -EROFS;
5012                                         goto restore_opts;
5013                                 }
5014                         enable_quota = 1;
5015                 }
5016         }
5017
5018         /*
5019          * Reinitialize lazy itable initialization thread based on
5020          * current settings
5021          */
5022         if ((sb->s_flags & MS_RDONLY) || !test_opt(sb, INIT_INODE_TABLE))
5023                 ext4_unregister_li_request(sb);
5024         else {
5025                 ext4_group_t first_not_zeroed;
5026                 first_not_zeroed = ext4_has_uninit_itable(sb);
5027                 ext4_register_li_request(sb, first_not_zeroed);
5028         }
5029
5030         ext4_setup_system_zone(sb);
5031         if (sbi->s_journal == NULL && !(old_sb_flags & MS_RDONLY))
5032                 ext4_commit_super(sb, 1);
5033
5034 #ifdef CONFIG_QUOTA
5035         /* Release old quota file names */
5036         for (i = 0; i < MAXQUOTAS; i++)
5037                 kfree(old_opts.s_qf_names[i]);
5038         if (enable_quota) {
5039                 if (sb_any_quota_suspended(sb))
5040                         dquot_resume(sb, -1);
5041                 else if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
5042                                         EXT4_FEATURE_RO_COMPAT_QUOTA)) {
5043                         err = ext4_enable_quotas(sb);
5044                         if (err)
5045                                 goto restore_opts;
5046                 }
5047         }
5048 #endif
5049
5050         ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
5051         kfree(orig_data);
5052         return 0;
5053
5054 restore_opts:
5055         sb->s_flags = old_sb_flags;
5056         sbi->s_mount_opt = old_opts.s_mount_opt;
5057         sbi->s_mount_opt2 = old_opts.s_mount_opt2;
5058         sbi->s_resuid = old_opts.s_resuid;
5059         sbi->s_resgid = old_opts.s_resgid;
5060         sbi->s_commit_interval = old_opts.s_commit_interval;
5061         sbi->s_min_batch_time = old_opts.s_min_batch_time;
5062         sbi->s_max_batch_time = old_opts.s_max_batch_time;
5063 #ifdef CONFIG_QUOTA
5064         sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
5065         for (i = 0; i < MAXQUOTAS; i++) {
5066                 kfree(sbi->s_qf_names[i]);
5067                 sbi->s_qf_names[i] = old_opts.s_qf_names[i];
5068         }
5069 #endif
5070         kfree(orig_data);
5071         return err;
5072 }
5073
5074 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
5075 {
5076         struct super_block *sb = dentry->d_sb;
5077         struct ext4_sb_info *sbi = EXT4_SB(sb);
5078         struct ext4_super_block *es = sbi->s_es;
5079         ext4_fsblk_t overhead = 0, resv_blocks;
5080         u64 fsid;
5081         s64 bfree;
5082         resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
5083
5084         if (!test_opt(sb, MINIX_DF))
5085                 overhead = sbi->s_overhead;
5086
5087         buf->f_type = EXT4_SUPER_MAGIC;
5088         buf->f_bsize = sb->s_blocksize;
5089         buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
5090         bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
5091                 percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
5092         /* prevent underflow in case that few free space is available */
5093         buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
5094         buf->f_bavail = buf->f_bfree -
5095                         (ext4_r_blocks_count(es) + resv_blocks);
5096         if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
5097                 buf->f_bavail = 0;
5098         buf->f_files = le32_to_cpu(es->s_inodes_count);
5099         buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
5100         buf->f_namelen = EXT4_NAME_LEN;
5101         fsid = le64_to_cpup((void *)es->s_uuid) ^
5102                le64_to_cpup((void *)es->s_uuid + sizeof(u64));
5103         buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
5104         buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
5105
5106         return 0;
5107 }
5108
5109 /* Helper function for writing quotas on sync - we need to start transaction
5110  * before quota file is locked for write. Otherwise the are possible deadlocks:
5111  * Process 1                         Process 2
5112  * ext4_create()                     quota_sync()
5113  *   jbd2_journal_start()                  write_dquot()
5114  *   dquot_initialize()                         down(dqio_mutex)
5115  *     down(dqio_mutex)                    jbd2_journal_start()
5116  *
5117  */
5118
5119 #ifdef CONFIG_QUOTA
5120
5121 static inline struct inode *dquot_to_inode(struct dquot *dquot)
5122 {
5123         return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
5124 }
5125
5126 static int ext4_write_dquot(struct dquot *dquot)
5127 {
5128         int ret, err;
5129         handle_t *handle;
5130         struct inode *inode;
5131
5132         inode = dquot_to_inode(dquot);
5133         handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
5134                                     EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
5135         if (IS_ERR(handle))
5136                 return PTR_ERR(handle);
5137         ret = dquot_commit(dquot);
5138         err = ext4_journal_stop(handle);
5139         if (!ret)
5140                 ret = err;
5141         return ret;
5142 }
5143
5144 static int ext4_acquire_dquot(struct dquot *dquot)
5145 {
5146         int ret, err;
5147         handle_t *handle;
5148
5149         handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5150                                     EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
5151         if (IS_ERR(handle))
5152                 return PTR_ERR(handle);
5153         ret = dquot_acquire(dquot);
5154         err = ext4_journal_stop(handle);
5155         if (!ret)
5156                 ret = err;
5157         return ret;
5158 }
5159
5160 static int ext4_release_dquot(struct dquot *dquot)
5161 {
5162         int ret, err;
5163         handle_t *handle;
5164
5165         handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5166                                     EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
5167         if (IS_ERR(handle)) {
5168                 /* Release dquot anyway to avoid endless cycle in dqput() */
5169                 dquot_release(dquot);
5170                 return PTR_ERR(handle);
5171         }
5172         ret = dquot_release(dquot);
5173         err = ext4_journal_stop(handle);
5174         if (!ret)
5175                 ret = err;
5176         return ret;
5177 }
5178
5179 static int ext4_mark_dquot_dirty(struct dquot *dquot)
5180 {
5181         struct super_block *sb = dquot->dq_sb;
5182         struct ext4_sb_info *sbi = EXT4_SB(sb);
5183
5184         /* Are we journaling quotas? */
5185         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) ||
5186             sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
5187                 dquot_mark_dquot_dirty(dquot);
5188                 return ext4_write_dquot(dquot);
5189         } else {
5190                 return dquot_mark_dquot_dirty(dquot);
5191         }
5192 }
5193
5194 static int ext4_write_info(struct super_block *sb, int type)
5195 {
5196         int ret, err;
5197         handle_t *handle;
5198
5199         /* Data block + inode block */
5200         handle = ext4_journal_start(sb->s_root->d_inode, EXT4_HT_QUOTA, 2);
5201         if (IS_ERR(handle))
5202                 return PTR_ERR(handle);
5203         ret = dquot_commit_info(sb, type);
5204         err = ext4_journal_stop(handle);
5205         if (!ret)
5206                 ret = err;
5207         return ret;
5208 }
5209
5210 /*
5211  * Turn on quotas during mount time - we need to find
5212  * the quota file and such...
5213  */
5214 static int ext4_quota_on_mount(struct super_block *sb, int type)
5215 {
5216         return dquot_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
5217                                         EXT4_SB(sb)->s_jquota_fmt, type);
5218 }
5219
5220 static void lockdep_set_quota_inode(struct inode *inode, int subclass)
5221 {
5222         struct ext4_inode_info *ei = EXT4_I(inode);
5223
5224         /* The first argument of lockdep_set_subclass has to be
5225          * *exactly* the same as the argument to init_rwsem() --- in
5226          * this case, in init_once() --- or lockdep gets unhappy
5227          * because the name of the lock is set using the
5228          * stringification of the argument to init_rwsem().
5229          */
5230         (void) ei;      /* shut up clang warning if !CONFIG_LOCKDEP */
5231         lockdep_set_subclass(&ei->i_data_sem, subclass);
5232 }
5233
5234 /*
5235  * Standard function to be called on quota_on
5236  */
5237 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
5238                          struct path *path)
5239 {
5240         int err;
5241
5242         if (!test_opt(sb, QUOTA))
5243                 return -EINVAL;
5244
5245         /* Quotafile not on the same filesystem? */
5246         if (path->dentry->d_sb != sb)
5247                 return -EXDEV;
5248         /* Journaling quota? */
5249         if (EXT4_SB(sb)->s_qf_names[type]) {
5250                 /* Quotafile not in fs root? */
5251                 if (path->dentry->d_parent != sb->s_root)
5252                         ext4_msg(sb, KERN_WARNING,
5253                                 "Quota file not on filesystem root. "
5254                                 "Journaled quota will not work");
5255         }
5256
5257         /*
5258          * When we journal data on quota file, we have to flush journal to see
5259          * all updates to the file when we bypass pagecache...
5260          */
5261         if (EXT4_SB(sb)->s_journal &&
5262             ext4_should_journal_data(path->dentry->d_inode)) {
5263                 /*
5264                  * We don't need to lock updates but journal_flush() could
5265                  * otherwise be livelocked...
5266                  */
5267                 jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
5268                 err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
5269                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
5270                 if (err)
5271                         return err;
5272         }
5273         lockdep_set_quota_inode(path->dentry->d_inode, I_DATA_SEM_QUOTA);
5274         err = dquot_quota_on(sb, type, format_id, path);
5275         if (err)
5276                 lockdep_set_quota_inode(path->dentry->d_inode,
5277                                              I_DATA_SEM_NORMAL);
5278         return err;
5279 }
5280
5281 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
5282                              unsigned int flags)
5283 {
5284         int err;
5285         struct inode *qf_inode;
5286         unsigned long qf_inums[MAXQUOTAS] = {
5287                 le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5288                 le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum)
5289         };
5290
5291         BUG_ON(!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA));
5292
5293         if (!qf_inums[type])
5294                 return -EPERM;
5295
5296         qf_inode = ext4_iget(sb, qf_inums[type]);
5297         if (IS_ERR(qf_inode)) {
5298                 ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
5299                 return PTR_ERR(qf_inode);
5300         }
5301
5302         /* Don't account quota for quota files to avoid recursion */
5303         qf_inode->i_flags |= S_NOQUOTA;
5304         lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);
5305         err = dquot_enable(qf_inode, type, format_id, flags);
5306         iput(qf_inode);
5307         if (err)
5308                 lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);
5309
5310         return err;
5311 }
5312
5313 /* Enable usage tracking for all quota types. */
5314 static int ext4_enable_quotas(struct super_block *sb)
5315 {
5316         int type, err = 0;
5317         unsigned long qf_inums[MAXQUOTAS] = {
5318                 le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5319                 le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum)
5320         };
5321
5322         sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE;
5323         for (type = 0; type < MAXQUOTAS; type++) {
5324                 if (qf_inums[type]) {
5325                         err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
5326                                                 DQUOT_USAGE_ENABLED);
5327                         if (err) {
5328                                 ext4_warning(sb,
5329                                         "Failed to enable quota tracking "
5330                                         "(type=%d, err=%d). Please run "
5331                                         "e2fsck to fix.", type, err);
5332                                 return err;
5333                         }
5334                 }
5335         }
5336         return 0;
5337 }
5338
5339 /*
5340  * quota_on function that is used when QUOTA feature is set.
5341  */
5342 static int ext4_quota_on_sysfile(struct super_block *sb, int type,
5343                                  int format_id)
5344 {
5345         if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
5346                 return -EINVAL;
5347
5348         /*
5349          * USAGE was enabled at mount time. Only need to enable LIMITS now.
5350          */
5351         return ext4_quota_enable(sb, type, format_id, DQUOT_LIMITS_ENABLED);
5352 }
5353
5354 static int ext4_quota_off(struct super_block *sb, int type)
5355 {
5356         struct inode *inode = sb_dqopt(sb)->files[type];
5357         handle_t *handle;
5358
5359         /* Force all delayed allocation blocks to be allocated.
5360          * Caller already holds s_umount sem */
5361         if (test_opt(sb, DELALLOC))
5362                 sync_filesystem(sb);
5363
5364         if (!inode)
5365                 goto out;
5366
5367         /* Update modification times of quota files when userspace can
5368          * start looking at them */
5369         handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5370         if (IS_ERR(handle))
5371                 goto out;
5372         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
5373         ext4_mark_inode_dirty(handle, inode);
5374         ext4_journal_stop(handle);
5375
5376 out:
5377         return dquot_quota_off(sb, type);
5378 }
5379
5380 /*
5381  * quota_off function that is used when QUOTA feature is set.
5382  */
5383 static int ext4_quota_off_sysfile(struct super_block *sb, int type)
5384 {
5385         if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
5386                 return -EINVAL;
5387
5388         /* Disable only the limits. */
5389         return dquot_disable(sb, type, DQUOT_LIMITS_ENABLED);
5390 }
5391
5392 /* Read data from quotafile - avoid pagecache and such because we cannot afford
5393  * acquiring the locks... As quota files are never truncated and quota code
5394  * itself serializes the operations (and no one else should touch the files)
5395  * we don't have to be afraid of races */
5396 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
5397                                size_t len, loff_t off)
5398 {
5399         struct inode *inode = sb_dqopt(sb)->files[type];
5400         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5401         int err = 0;
5402         int offset = off & (sb->s_blocksize - 1);
5403         int tocopy;
5404         size_t toread;
5405         struct buffer_head *bh;
5406         loff_t i_size = i_size_read(inode);
5407
5408         if (off > i_size)
5409                 return 0;
5410         if (off+len > i_size)
5411                 len = i_size-off;
5412         toread = len;
5413         while (toread > 0) {
5414                 tocopy = sb->s_blocksize - offset < toread ?
5415                                 sb->s_blocksize - offset : toread;
5416                 bh = ext4_bread(NULL, inode, blk, 0, &err);
5417                 if (err)
5418                         return err;
5419                 if (!bh)        /* A hole? */
5420                         memset(data, 0, tocopy);
5421                 else
5422                         memcpy(data, bh->b_data+offset, tocopy);
5423                 brelse(bh);
5424                 offset = 0;
5425                 toread -= tocopy;
5426                 data += tocopy;
5427                 blk++;
5428         }
5429         return len;
5430 }
5431
5432 /* Write to quotafile (we know the transaction is already started and has
5433  * enough credits) */
5434 static ssize_t ext4_quota_write(struct super_block *sb, int type,
5435                                 const char *data, size_t len, loff_t off)
5436 {
5437         struct inode *inode = sb_dqopt(sb)->files[type];
5438         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5439         int err = 0;
5440         int offset = off & (sb->s_blocksize - 1);
5441         struct buffer_head *bh;
5442         handle_t *handle = journal_current_handle();
5443
5444         if (EXT4_SB(sb)->s_journal && !handle) {
5445                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5446                         " cancelled because transaction is not started",
5447                         (unsigned long long)off, (unsigned long long)len);
5448                 return -EIO;
5449         }
5450         /*
5451          * Since we account only one data block in transaction credits,
5452          * then it is impossible to cross a block boundary.
5453          */
5454         if (sb->s_blocksize - offset < len) {
5455                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5456                         " cancelled because not block aligned",
5457                         (unsigned long long)off, (unsigned long long)len);
5458                 return -EIO;
5459         }
5460
5461         bh = ext4_bread(handle, inode, blk, 1, &err);
5462         if (!bh)
5463                 goto out;
5464         BUFFER_TRACE(bh, "get write access");
5465         err = ext4_journal_get_write_access(handle, bh);
5466         if (err) {
5467                 brelse(bh);
5468                 goto out;
5469         }
5470         lock_buffer(bh);
5471         memcpy(bh->b_data+offset, data, len);
5472         flush_dcache_page(bh->b_page);
5473         unlock_buffer(bh);
5474         err = ext4_handle_dirty_metadata(handle, NULL, bh);
5475         brelse(bh);
5476 out:
5477         if (err)
5478                 return err;
5479         if (inode->i_size < off + len) {
5480                 i_size_write(inode, off + len);
5481                 EXT4_I(inode)->i_disksize = inode->i_size;
5482                 ext4_mark_inode_dirty(handle, inode);
5483         }
5484         return len;
5485 }
5486
5487 #endif
5488
5489 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
5490                        const char *dev_name, void *data)
5491 {
5492         return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
5493 }
5494
5495 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
5496 static inline void register_as_ext2(void)
5497 {
5498         int err = register_filesystem(&ext2_fs_type);
5499         if (err)
5500                 printk(KERN_WARNING
5501                        "EXT4-fs: Unable to register as ext2 (%d)\n", err);
5502 }
5503
5504 static inline void unregister_as_ext2(void)
5505 {
5506         unregister_filesystem(&ext2_fs_type);
5507 }
5508
5509 static inline int ext2_feature_set_ok(struct super_block *sb)
5510 {
5511         if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP))
5512                 return 0;
5513         if (sb->s_flags & MS_RDONLY)
5514                 return 1;
5515         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))
5516                 return 0;
5517         return 1;
5518 }
5519 #else
5520 static inline void register_as_ext2(void) { }
5521 static inline void unregister_as_ext2(void) { }
5522 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
5523 #endif
5524
5525 #if !defined(CONFIG_EXT3_FS) && !defined(CONFIG_EXT3_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
5526 static inline void register_as_ext3(void)
5527 {
5528         int err = register_filesystem(&ext3_fs_type);
5529         if (err)
5530                 printk(KERN_WARNING
5531                        "EXT4-fs: Unable to register as ext3 (%d)\n", err);
5532 }
5533
5534 static inline void unregister_as_ext3(void)
5535 {
5536         unregister_filesystem(&ext3_fs_type);
5537 }
5538
5539 static inline int ext3_feature_set_ok(struct super_block *sb)
5540 {
5541         if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT3_FEATURE_INCOMPAT_SUPP))
5542                 return 0;
5543         if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
5544                 return 0;
5545         if (sb->s_flags & MS_RDONLY)
5546                 return 1;
5547         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT3_FEATURE_RO_COMPAT_SUPP))
5548                 return 0;
5549         return 1;
5550 }
5551 #else
5552 static inline void register_as_ext3(void) { }
5553 static inline void unregister_as_ext3(void) { }
5554 static inline int ext3_feature_set_ok(struct super_block *sb) { return 0; }
5555 #endif
5556
5557 static struct file_system_type ext4_fs_type = {
5558         .owner          = THIS_MODULE,
5559         .name           = "ext4",
5560         .mount          = ext4_mount,
5561         .kill_sb        = kill_block_super,
5562         .fs_flags       = FS_REQUIRES_DEV,
5563 };
5564 MODULE_ALIAS_FS("ext4");
5565
5566 static int __init ext4_init_feat_adverts(void)
5567 {
5568         struct ext4_features *ef;
5569         int ret = -ENOMEM;
5570
5571         ef = kzalloc(sizeof(struct ext4_features), GFP_KERNEL);
5572         if (!ef)
5573                 goto out;
5574
5575         ef->f_kobj.kset = ext4_kset;
5576         init_completion(&ef->f_kobj_unregister);
5577         ret = kobject_init_and_add(&ef->f_kobj, &ext4_feat_ktype, NULL,
5578                                    "features");
5579         if (ret) {
5580                 kfree(ef);
5581                 goto out;
5582         }
5583
5584         ext4_feat = ef;
5585         ret = 0;
5586 out:
5587         return ret;
5588 }
5589
5590 static void ext4_exit_feat_adverts(void)
5591 {
5592         kobject_put(&ext4_feat->f_kobj);
5593         wait_for_completion(&ext4_feat->f_kobj_unregister);
5594         kfree(ext4_feat);
5595 }
5596
5597 /* Shared across all ext4 file systems */
5598 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
5599 struct mutex ext4__aio_mutex[EXT4_WQ_HASH_SZ];
5600
5601 static int __init ext4_init_fs(void)
5602 {
5603         int i, err;
5604
5605         ext4_li_info = NULL;
5606         mutex_init(&ext4_li_mtx);
5607
5608         /* Build-time check for flags consistency */
5609         ext4_check_flag_values();
5610
5611         for (i = 0; i < EXT4_WQ_HASH_SZ; i++) {
5612                 mutex_init(&ext4__aio_mutex[i]);
5613                 init_waitqueue_head(&ext4__ioend_wq[i]);
5614         }
5615
5616         err = ext4_init_es();
5617         if (err)
5618                 return err;
5619
5620         err = ext4_init_pageio();
5621         if (err)
5622                 goto out7;
5623
5624         err = ext4_init_system_zone();
5625         if (err)
5626                 goto out6;
5627         ext4_kset = kset_create_and_add("ext4", NULL, fs_kobj);
5628         if (!ext4_kset) {
5629                 err = -ENOMEM;
5630                 goto out5;
5631         }
5632         ext4_proc_root = proc_mkdir("fs/ext4", NULL);
5633
5634         err = ext4_init_feat_adverts();
5635         if (err)
5636                 goto out4;
5637
5638         err = ext4_init_mballoc();
5639         if (err)
5640                 goto out2;
5641         else
5642                 ext4_mballoc_ready = 1;
5643         err = init_inodecache();
5644         if (err)
5645                 goto out1;
5646         register_as_ext3();
5647         register_as_ext2();
5648         err = register_filesystem(&ext4_fs_type);
5649         if (err)
5650                 goto out;
5651
5652         return 0;
5653 out:
5654         unregister_as_ext2();
5655         unregister_as_ext3();
5656         destroy_inodecache();
5657 out1:
5658         ext4_mballoc_ready = 0;
5659         ext4_exit_mballoc();
5660 out2:
5661         ext4_exit_feat_adverts();
5662 out4:
5663         if (ext4_proc_root)
5664                 remove_proc_entry("fs/ext4", NULL);
5665         kset_unregister(ext4_kset);
5666 out5:
5667         ext4_exit_system_zone();
5668 out6:
5669         ext4_exit_pageio();
5670 out7:
5671         ext4_exit_es();
5672
5673         return err;
5674 }
5675
5676 static void __exit ext4_exit_fs(void)
5677 {
5678         ext4_destroy_lazyinit_thread();
5679         unregister_as_ext2();
5680         unregister_as_ext3();
5681         unregister_filesystem(&ext4_fs_type);
5682         destroy_inodecache();
5683         ext4_exit_mballoc();
5684         ext4_exit_feat_adverts();
5685         remove_proc_entry("fs/ext4", NULL);
5686         kset_unregister(ext4_kset);
5687         ext4_exit_system_zone();
5688         ext4_exit_pageio();
5689         ext4_exit_es();
5690 }
5691
5692 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
5693 MODULE_DESCRIPTION("Fourth Extended Filesystem");
5694 MODULE_LICENSE("GPL");
5695 module_init(ext4_init_fs)
5696 module_exit(ext4_exit_fs)