linux/fs/ext4/super.c
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   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
  57static struct proc_dir_entry *ext4_proc_root;
  58static struct kset *ext4_kset;
  59static struct ext4_lazy_init *ext4_li_info;
  60static struct mutex ext4_li_mtx;
  61static struct ext4_features *ext4_feat;
  62static int ext4_mballoc_ready;
  63
  64static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
  65                             unsigned long journal_devnum);
  66static int ext4_show_options(struct seq_file *seq, struct dentry *root);
  67static int ext4_commit_super(struct super_block *sb, int sync);
  68static void ext4_mark_recovery_complete(struct super_block *sb,
  69                                        struct ext4_super_block *es);
  70static void ext4_clear_journal_err(struct super_block *sb,
  71                                   struct ext4_super_block *es);
  72static int ext4_sync_fs(struct super_block *sb, int wait);
  73static int ext4_remount(struct super_block *sb, int *flags, char *data);
  74static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
  75static int ext4_unfreeze(struct super_block *sb);
  76static int ext4_freeze(struct super_block *sb);
  77static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
  78                       const char *dev_name, void *data);
  79static inline int ext2_feature_set_ok(struct super_block *sb);
  80static inline int ext3_feature_set_ok(struct super_block *sb);
  81static int ext4_feature_set_ok(struct super_block *sb, int readonly);
  82static void ext4_destroy_lazyinit_thread(void);
  83static void ext4_unregister_li_request(struct super_block *sb);
  84static void ext4_clear_request_list(void);
  85static int ext4_reserve_clusters(struct ext4_sb_info *, ext4_fsblk_t);
  86
  87#if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
  88static struct file_system_type ext2_fs_type = {
  89        .owner          = THIS_MODULE,
  90        .name           = "ext2",
  91        .mount          = ext4_mount,
  92        .kill_sb        = kill_block_super,
  93        .fs_flags       = FS_REQUIRES_DEV,
  94};
  95MODULE_ALIAS_FS("ext2");
  96MODULE_ALIAS("ext2");
  97#define IS_EXT2_SB(sb) ((sb)->s_bdev->bd_holder == &ext2_fs_type)
  98#else
  99#define IS_EXT2_SB(sb) (0)
 100#endif
 101
 102
 103#if !defined(CONFIG_EXT3_FS) && !defined(CONFIG_EXT3_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
 104static struct file_system_type ext3_fs_type = {
 105        .owner          = THIS_MODULE,
 106        .name           = "ext3",
 107        .mount          = ext4_mount,
 108        .kill_sb        = kill_block_super,
 109        .fs_flags       = FS_REQUIRES_DEV,
 110};
 111MODULE_ALIAS_FS("ext3");
 112MODULE_ALIAS("ext3");
 113#define IS_EXT3_SB(sb) ((sb)->s_bdev->bd_holder == &ext3_fs_type)
 114#else
 115#define IS_EXT3_SB(sb) (0)
 116#endif
 117
 118static int ext4_verify_csum_type(struct super_block *sb,
 119                                 struct ext4_super_block *es)
 120{
 121        if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
 122                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
 123                return 1;
 124
 125        return es->s_checksum_type == EXT4_CRC32C_CHKSUM;
 126}
 127
 128static __le32 ext4_superblock_csum(struct super_block *sb,
 129                                   struct ext4_super_block *es)
 130{
 131        struct ext4_sb_info *sbi = EXT4_SB(sb);
 132        int offset = offsetof(struct ext4_super_block, s_checksum);
 133        __u32 csum;
 134
 135        csum = ext4_chksum(sbi, ~0, (char *)es, offset);
 136
 137        return cpu_to_le32(csum);
 138}
 139
 140static int ext4_superblock_csum_verify(struct super_block *sb,
 141                                       struct ext4_super_block *es)
 142{
 143        if (!ext4_has_metadata_csum(sb))
 144                return 1;
 145
 146        return es->s_checksum == ext4_superblock_csum(sb, es);
 147}
 148
 149void ext4_superblock_csum_set(struct super_block *sb)
 150{
 151        struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 152
 153        if (!ext4_has_metadata_csum(sb))
 154                return;
 155
 156        es->s_checksum = ext4_superblock_csum(sb, es);
 157}
 158
 159void *ext4_kvmalloc(size_t size, gfp_t flags)
 160{
 161        void *ret;
 162
 163        ret = kmalloc(size, flags | __GFP_NOWARN);
 164        if (!ret)
 165                ret = __vmalloc(size, flags, PAGE_KERNEL);
 166        return ret;
 167}
 168
 169void *ext4_kvzalloc(size_t size, gfp_t flags)
 170{
 171        void *ret;
 172
 173        ret = kzalloc(size, flags | __GFP_NOWARN);
 174        if (!ret)
 175                ret = __vmalloc(size, flags | __GFP_ZERO, PAGE_KERNEL);
 176        return ret;
 177}
 178
 179ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
 180                               struct ext4_group_desc *bg)
 181{
 182        return le32_to_cpu(bg->bg_block_bitmap_lo) |
 183                (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 184                 (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
 185}
 186
 187ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
 188                               struct ext4_group_desc *bg)
 189{
 190        return le32_to_cpu(bg->bg_inode_bitmap_lo) |
 191                (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 192                 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
 193}
 194
 195ext4_fsblk_t ext4_inode_table(struct super_block *sb,
 196                              struct ext4_group_desc *bg)
 197{
 198        return le32_to_cpu(bg->bg_inode_table_lo) |
 199                (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 200                 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
 201}
 202
 203__u32 ext4_free_group_clusters(struct super_block *sb,
 204                               struct ext4_group_desc *bg)
 205{
 206        return le16_to_cpu(bg->bg_free_blocks_count_lo) |
 207                (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 208                 (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
 209}
 210
 211__u32 ext4_free_inodes_count(struct super_block *sb,
 212                              struct ext4_group_desc *bg)
 213{
 214        return le16_to_cpu(bg->bg_free_inodes_count_lo) |
 215                (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 216                 (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
 217}
 218
 219__u32 ext4_used_dirs_count(struct super_block *sb,
 220                              struct ext4_group_desc *bg)
 221{
 222        return le16_to_cpu(bg->bg_used_dirs_count_lo) |
 223                (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 224                 (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
 225}
 226
 227__u32 ext4_itable_unused_count(struct super_block *sb,
 228                              struct ext4_group_desc *bg)
 229{
 230        return le16_to_cpu(bg->bg_itable_unused_lo) |
 231                (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 232                 (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
 233}
 234
 235void ext4_block_bitmap_set(struct super_block *sb,
 236                           struct ext4_group_desc *bg, ext4_fsblk_t blk)
 237{
 238        bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
 239        if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 240                bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
 241}
 242
 243void ext4_inode_bitmap_set(struct super_block *sb,
 244                           struct ext4_group_desc *bg, ext4_fsblk_t blk)
 245{
 246        bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
 247        if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 248                bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
 249}
 250
 251void ext4_inode_table_set(struct super_block *sb,
 252                          struct ext4_group_desc *bg, ext4_fsblk_t blk)
 253{
 254        bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
 255        if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 256                bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
 257}
 258
 259void ext4_free_group_clusters_set(struct super_block *sb,
 260                                  struct ext4_group_desc *bg, __u32 count)
 261{
 262        bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
 263        if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 264                bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
 265}
 266
 267void ext4_free_inodes_set(struct super_block *sb,
 268                          struct ext4_group_desc *bg, __u32 count)
 269{
 270        bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
 271        if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 272                bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
 273}
 274
 275void ext4_used_dirs_set(struct super_block *sb,
 276                          struct ext4_group_desc *bg, __u32 count)
 277{
 278        bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
 279        if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 280                bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
 281}
 282
 283void ext4_itable_unused_set(struct super_block *sb,
 284                          struct ext4_group_desc *bg, __u32 count)
 285{
 286        bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
 287        if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 288                bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
 289}
 290
 291
 292static void __save_error_info(struct super_block *sb, const char *func,
 293                            unsigned int line)
 294{
 295        struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 296
 297        EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
 298        es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
 299        es->s_last_error_time = cpu_to_le32(get_seconds());
 300        strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
 301        es->s_last_error_line = cpu_to_le32(line);
 302        if (!es->s_first_error_time) {
 303                es->s_first_error_time = es->s_last_error_time;
 304                strncpy(es->s_first_error_func, func,
 305                        sizeof(es->s_first_error_func));
 306                es->s_first_error_line = cpu_to_le32(line);
 307                es->s_first_error_ino = es->s_last_error_ino;
 308                es->s_first_error_block = es->s_last_error_block;
 309        }
 310        /*
 311         * Start the daily error reporting function if it hasn't been
 312         * started already
 313         */
 314        if (!es->s_error_count)
 315                mod_timer(&EXT4_SB(sb)->s_err_report, jiffies + 24*60*60*HZ);
 316        le32_add_cpu(&es->s_error_count, 1);
 317}
 318
 319static void save_error_info(struct super_block *sb, const char *func,
 320                            unsigned int line)
 321{
 322        __save_error_info(sb, func, line);
 323        ext4_commit_super(sb, 1);
 324}
 325
 326/*
 327 * The del_gendisk() function uninitializes the disk-specific data
 328 * structures, including the bdi structure, without telling anyone
 329 * else.  Once this happens, any attempt to call mark_buffer_dirty()
 330 * (for example, by ext4_commit_super), will cause a kernel OOPS.
 331 * This is a kludge to prevent these oops until we can put in a proper
 332 * hook in del_gendisk() to inform the VFS and file system layers.
 333 */
 334static int block_device_ejected(struct super_block *sb)
 335{
 336        struct inode *bd_inode = sb->s_bdev->bd_inode;
 337        struct backing_dev_info *bdi = inode_to_bdi(bd_inode);
 338
 339        return bdi->dev == NULL;
 340}
 341
 342static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
 343{
 344        struct super_block              *sb = journal->j_private;
 345        struct ext4_sb_info             *sbi = EXT4_SB(sb);
 346        int                             error = is_journal_aborted(journal);
 347        struct ext4_journal_cb_entry    *jce;
 348
 349        BUG_ON(txn->t_state == T_FINISHED);
 350        spin_lock(&sbi->s_md_lock);
 351        while (!list_empty(&txn->t_private_list)) {
 352                jce = list_entry(txn->t_private_list.next,
 353                                 struct ext4_journal_cb_entry, jce_list);
 354                list_del_init(&jce->jce_list);
 355                spin_unlock(&sbi->s_md_lock);
 356                jce->jce_func(sb, jce, error);
 357                spin_lock(&sbi->s_md_lock);
 358        }
 359        spin_unlock(&sbi->s_md_lock);
 360}
 361
 362/* Deal with the reporting of failure conditions on a filesystem such as
 363 * inconsistencies detected or read IO failures.
 364 *
 365 * On ext2, we can store the error state of the filesystem in the
 366 * superblock.  That is not possible on ext4, because we may have other
 367 * write ordering constraints on the superblock which prevent us from
 368 * writing it out straight away; and given that the journal is about to
 369 * be aborted, we can't rely on the current, or future, transactions to
 370 * write out the superblock safely.
 371 *
 372 * We'll just use the jbd2_journal_abort() error code to record an error in
 373 * the journal instead.  On recovery, the journal will complain about
 374 * that error until we've noted it down and cleared it.
 375 */
 376
 377static void ext4_handle_error(struct super_block *sb)
 378{
 379        if (sb->s_flags & MS_RDONLY)
 380                return;
 381
 382        if (!test_opt(sb, ERRORS_CONT)) {
 383                journal_t *journal = EXT4_SB(sb)->s_journal;
 384
 385                EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
 386                if (journal)
 387                        jbd2_journal_abort(journal, -EIO);
 388        }
 389        if (test_opt(sb, ERRORS_RO)) {
 390                ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 391                /*
 392                 * Make sure updated value of ->s_mount_flags will be visible
 393                 * before ->s_flags update
 394                 */
 395                smp_wmb();
 396                sb->s_flags |= MS_RDONLY;
 397        }
 398        if (test_opt(sb, ERRORS_PANIC))
 399                panic("EXT4-fs (device %s): panic forced after error\n",
 400                        sb->s_id);
 401}
 402
 403#define ext4_error_ratelimit(sb)                                        \
 404                ___ratelimit(&(EXT4_SB(sb)->s_err_ratelimit_state),     \
 405                             "EXT4-fs error")
 406
 407void __ext4_error(struct super_block *sb, const char *function,
 408                  unsigned int line, const char *fmt, ...)
 409{
 410        struct va_format vaf;
 411        va_list args;
 412
 413        if (ext4_error_ratelimit(sb)) {
 414                va_start(args, fmt);
 415                vaf.fmt = fmt;
 416                vaf.va = &args;
 417                printk(KERN_CRIT
 418                       "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
 419                       sb->s_id, function, line, current->comm, &vaf);
 420                va_end(args);
 421        }
 422        save_error_info(sb, function, line);
 423        ext4_handle_error(sb);
 424}
 425
 426void __ext4_error_inode(struct inode *inode, const char *function,
 427                        unsigned int line, ext4_fsblk_t block,
 428                        const char *fmt, ...)
 429{
 430        va_list args;
 431        struct va_format vaf;
 432        struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
 433
 434        es->s_last_error_ino = cpu_to_le32(inode->i_ino);
 435        es->s_last_error_block = cpu_to_le64(block);
 436        if (ext4_error_ratelimit(inode->i_sb)) {
 437                va_start(args, fmt);
 438                vaf.fmt = fmt;
 439                vaf.va = &args;
 440                if (block)
 441                        printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
 442                               "inode #%lu: block %llu: comm %s: %pV\n",
 443                               inode->i_sb->s_id, function, line, inode->i_ino,
 444                               block, current->comm, &vaf);
 445                else
 446                        printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
 447                               "inode #%lu: comm %s: %pV\n",
 448                               inode->i_sb->s_id, function, line, inode->i_ino,
 449                               current->comm, &vaf);
 450                va_end(args);
 451        }
 452        save_error_info(inode->i_sb, function, line);
 453        ext4_handle_error(inode->i_sb);
 454}
 455
 456void __ext4_error_file(struct file *file, const char *function,
 457                       unsigned int line, ext4_fsblk_t block,
 458                       const char *fmt, ...)
 459{
 460        va_list args;
 461        struct va_format vaf;
 462        struct ext4_super_block *es;
 463        struct inode *inode = file_inode(file);
 464        char pathname[80], *path;
 465
 466        es = EXT4_SB(inode->i_sb)->s_es;
 467        es->s_last_error_ino = cpu_to_le32(inode->i_ino);
 468        if (ext4_error_ratelimit(inode->i_sb)) {
 469                path = d_path(&(file->f_path), pathname, sizeof(pathname));
 470                if (IS_ERR(path))
 471                        path = "(unknown)";
 472                va_start(args, fmt);
 473                vaf.fmt = fmt;
 474                vaf.va = &args;
 475                if (block)
 476                        printk(KERN_CRIT
 477                               "EXT4-fs error (device %s): %s:%d: inode #%lu: "
 478                               "block %llu: comm %s: path %s: %pV\n",
 479                               inode->i_sb->s_id, function, line, inode->i_ino,
 480                               block, current->comm, path, &vaf);
 481                else
 482                        printk(KERN_CRIT
 483                               "EXT4-fs error (device %s): %s:%d: inode #%lu: "
 484                               "comm %s: path %s: %pV\n",
 485                               inode->i_sb->s_id, function, line, inode->i_ino,
 486                               current->comm, path, &vaf);
 487                va_end(args);
 488        }
 489        save_error_info(inode->i_sb, function, line);
 490        ext4_handle_error(inode->i_sb);
 491}
 492
 493const char *ext4_decode_error(struct super_block *sb, int errno,
 494                              char nbuf[16])
 495{
 496        char *errstr = NULL;
 497
 498        switch (errno) {
 499        case -EIO:
 500                errstr = "IO failure";
 501                break;
 502        case -ENOMEM:
 503                errstr = "Out of memory";
 504                break;
 505        case -EROFS:
 506                if (!sb || (EXT4_SB(sb)->s_journal &&
 507                            EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
 508                        errstr = "Journal has aborted";
 509                else
 510                        errstr = "Readonly filesystem";
 511                break;
 512        default:
 513                /* If the caller passed in an extra buffer for unknown
 514                 * errors, textualise them now.  Else we just return
 515                 * NULL. */
 516                if (nbuf) {
 517                        /* Check for truncated error codes... */
 518                        if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
 519                                errstr = nbuf;
 520                }
 521                break;
 522        }
 523
 524        return errstr;
 525}
 526
 527/* __ext4_std_error decodes expected errors from journaling functions
 528 * automatically and invokes the appropriate error response.  */
 529
 530void __ext4_std_error(struct super_block *sb, const char *function,
 531                      unsigned int line, int errno)
 532{
 533        char nbuf[16];
 534        const char *errstr;
 535
 536        /* Special case: if the error is EROFS, and we're not already
 537         * inside a transaction, then there's really no point in logging
 538         * an error. */
 539        if (errno == -EROFS && journal_current_handle() == NULL &&
 540            (sb->s_flags & MS_RDONLY))
 541                return;
 542
 543        if (ext4_error_ratelimit(sb)) {
 544                errstr = ext4_decode_error(sb, errno, nbuf);
 545                printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
 546                       sb->s_id, function, line, errstr);
 547        }
 548
 549        save_error_info(sb, function, line);
 550        ext4_handle_error(sb);
 551}
 552
 553/*
 554 * ext4_abort is a much stronger failure handler than ext4_error.  The
 555 * abort function may be used to deal with unrecoverable failures such
 556 * as journal IO errors or ENOMEM at a critical moment in log management.
 557 *
 558 * We unconditionally force the filesystem into an ABORT|READONLY state,
 559 * unless the error response on the fs has been set to panic in which
 560 * case we take the easy way out and panic immediately.
 561 */
 562
 563void __ext4_abort(struct super_block *sb, const char *function,
 564                unsigned int line, const char *fmt, ...)
 565{
 566        va_list args;
 567
 568        save_error_info(sb, function, line);
 569        va_start(args, fmt);
 570        printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: ", sb->s_id,
 571               function, line);
 572        vprintk(fmt, args);
 573        printk("\n");
 574        va_end(args);
 575
 576        if ((sb->s_flags & MS_RDONLY) == 0) {
 577                ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 578                EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
 579                /*
 580                 * Make sure updated value of ->s_mount_flags will be visible
 581                 * before ->s_flags update
 582                 */
 583                smp_wmb();
 584                sb->s_flags |= MS_RDONLY;
 585                if (EXT4_SB(sb)->s_journal)
 586                        jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
 587                save_error_info(sb, function, line);
 588        }
 589        if (test_opt(sb, ERRORS_PANIC))
 590                panic("EXT4-fs panic from previous error\n");
 591}
 592
 593void __ext4_msg(struct super_block *sb,
 594                const char *prefix, const char *fmt, ...)
 595{
 596        struct va_format vaf;
 597        va_list args;
 598
 599        if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state), "EXT4-fs"))
 600                return;
 601
 602        va_start(args, fmt);
 603        vaf.fmt = fmt;
 604        vaf.va = &args;
 605        printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
 606        va_end(args);
 607}
 608
 609void __ext4_warning(struct super_block *sb, const char *function,
 610                    unsigned int line, const char *fmt, ...)
 611{
 612        struct va_format vaf;
 613        va_list args;
 614
 615        if (!___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state),
 616                          "EXT4-fs warning"))
 617                return;
 618
 619        va_start(args, fmt);
 620        vaf.fmt = fmt;
 621        vaf.va = &args;
 622        printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
 623               sb->s_id, function, line, &vaf);
 624        va_end(args);
 625}
 626
 627void __ext4_grp_locked_error(const char *function, unsigned int line,
 628                             struct super_block *sb, ext4_group_t grp,
 629                             unsigned long ino, ext4_fsblk_t block,
 630                             const char *fmt, ...)
 631__releases(bitlock)
 632__acquires(bitlock)
 633{
 634        struct va_format vaf;
 635        va_list args;
 636        struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 637
 638        es->s_last_error_ino = cpu_to_le32(ino);
 639        es->s_last_error_block = cpu_to_le64(block);
 640        __save_error_info(sb, function, line);
 641
 642        if (ext4_error_ratelimit(sb)) {
 643                va_start(args, fmt);
 644                vaf.fmt = fmt;
 645                vaf.va = &args;
 646                printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
 647                       sb->s_id, function, line, grp);
 648                if (ino)
 649                        printk(KERN_CONT "inode %lu: ", ino);
 650                if (block)
 651                        printk(KERN_CONT "block %llu:",
 652                               (unsigned long long) block);
 653                printk(KERN_CONT "%pV\n", &vaf);
 654                va_end(args);
 655        }
 656
 657        if (test_opt(sb, ERRORS_CONT)) {
 658                ext4_commit_super(sb, 0);
 659                return;
 660        }
 661
 662        ext4_unlock_group(sb, grp);
 663        ext4_handle_error(sb);
 664        /*
 665         * We only get here in the ERRORS_RO case; relocking the group
 666         * may be dangerous, but nothing bad will happen since the
 667         * filesystem will have already been marked read/only and the
 668         * journal has been aborted.  We return 1 as a hint to callers
 669         * who might what to use the return value from
 670         * ext4_grp_locked_error() to distinguish between the
 671         * ERRORS_CONT and ERRORS_RO case, and perhaps return more
 672         * aggressively from the ext4 function in question, with a
 673         * more appropriate error code.
 674         */
 675        ext4_lock_group(sb, grp);
 676        return;
 677}
 678
 679void ext4_update_dynamic_rev(struct super_block *sb)
 680{
 681        struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 682
 683        if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
 684                return;
 685
 686        ext4_warning(sb,
 687                     "updating to rev %d because of new feature flag, "
 688                     "running e2fsck is recommended",
 689                     EXT4_DYNAMIC_REV);
 690
 691        es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
 692        es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
 693        es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
 694        /* leave es->s_feature_*compat flags alone */
 695        /* es->s_uuid will be set by e2fsck if empty */
 696
 697        /*
 698         * The rest of the superblock fields should be zero, and if not it
 699         * means they are likely already in use, so leave them alone.  We
 700         * can leave it up to e2fsck to clean up any inconsistencies there.
 701         */
 702}
 703
 704/*
 705 * Open the external journal device
 706 */
 707static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
 708{
 709        struct block_device *bdev;
 710        char b[BDEVNAME_SIZE];
 711
 712        bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
 713        if (IS_ERR(bdev))
 714                goto fail;
 715        return bdev;
 716
 717fail:
 718        ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
 719                        __bdevname(dev, b), PTR_ERR(bdev));
 720        return NULL;
 721}
 722
 723/*
 724 * Release the journal device
 725 */
 726static void ext4_blkdev_put(struct block_device *bdev)
 727{
 728        blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
 729}
 730
 731static void ext4_blkdev_remove(struct ext4_sb_info *sbi)
 732{
 733        struct block_device *bdev;
 734        bdev = sbi->journal_bdev;
 735        if (bdev) {
 736                ext4_blkdev_put(bdev);
 737                sbi->journal_bdev = NULL;
 738        }
 739}
 740
 741static inline struct inode *orphan_list_entry(struct list_head *l)
 742{
 743        return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
 744}
 745
 746static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
 747{
 748        struct list_head *l;
 749
 750        ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
 751                 le32_to_cpu(sbi->s_es->s_last_orphan));
 752
 753        printk(KERN_ERR "sb_info orphan list:\n");
 754        list_for_each(l, &sbi->s_orphan) {
 755                struct inode *inode = orphan_list_entry(l);
 756                printk(KERN_ERR "  "
 757                       "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
 758                       inode->i_sb->s_id, inode->i_ino, inode,
 759                       inode->i_mode, inode->i_nlink,
 760                       NEXT_ORPHAN(inode));
 761        }
 762}
 763
 764static void ext4_put_super(struct super_block *sb)
 765{
 766        struct ext4_sb_info *sbi = EXT4_SB(sb);
 767        struct ext4_super_block *es = sbi->s_es;
 768        int i, err;
 769
 770        ext4_unregister_li_request(sb);
 771        dquot_disable(sb, -1, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
 772
 773        flush_workqueue(sbi->rsv_conversion_wq);
 774        destroy_workqueue(sbi->rsv_conversion_wq);
 775
 776        if (sbi->s_journal) {
 777                err = jbd2_journal_destroy(sbi->s_journal);
 778                sbi->s_journal = NULL;
 779                if (err < 0)
 780                        ext4_abort(sb, "Couldn't clean up the journal");
 781        }
 782
 783        ext4_es_unregister_shrinker(sbi);
 784        del_timer_sync(&sbi->s_err_report);
 785        ext4_release_system_zone(sb);
 786        ext4_mb_release(sb);
 787        ext4_ext_release(sb);
 788        ext4_xattr_put_super(sb);
 789
 790        if (!(sb->s_flags & MS_RDONLY)) {
 791                EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
 792                es->s_state = cpu_to_le16(sbi->s_mount_state);
 793        }
 794        if (!(sb->s_flags & MS_RDONLY))
 795                ext4_commit_super(sb, 1);
 796
 797        if (sbi->s_proc) {
 798                remove_proc_entry("options", sbi->s_proc);
 799                remove_proc_entry(sb->s_id, ext4_proc_root);
 800        }
 801        kobject_del(&sbi->s_kobj);
 802
 803        for (i = 0; i < sbi->s_gdb_count; i++)
 804                brelse(sbi->s_group_desc[i]);
 805        kvfree(sbi->s_group_desc);
 806        kvfree(sbi->s_flex_groups);
 807        percpu_counter_destroy(&sbi->s_freeclusters_counter);
 808        percpu_counter_destroy(&sbi->s_freeinodes_counter);
 809        percpu_counter_destroy(&sbi->s_dirs_counter);
 810        percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
 811        brelse(sbi->s_sbh);
 812#ifdef CONFIG_QUOTA
 813        for (i = 0; i < EXT4_MAXQUOTAS; i++)
 814                kfree(sbi->s_qf_names[i]);
 815#endif
 816
 817        /* Debugging code just in case the in-memory inode orphan list
 818         * isn't empty.  The on-disk one can be non-empty if we've
 819         * detected an error and taken the fs readonly, but the
 820         * in-memory list had better be clean by this point. */
 821        if (!list_empty(&sbi->s_orphan))
 822                dump_orphan_list(sb, sbi);
 823        J_ASSERT(list_empty(&sbi->s_orphan));
 824
 825        invalidate_bdev(sb->s_bdev);
 826        if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
 827                /*
 828                 * Invalidate the journal device's buffers.  We don't want them
 829                 * floating about in memory - the physical journal device may
 830                 * hotswapped, and it breaks the `ro-after' testing code.
 831                 */
 832                sync_blockdev(sbi->journal_bdev);
 833                invalidate_bdev(sbi->journal_bdev);
 834                ext4_blkdev_remove(sbi);
 835        }
 836        if (sbi->s_mb_cache) {
 837                ext4_xattr_destroy_cache(sbi->s_mb_cache);
 838                sbi->s_mb_cache = NULL;
 839        }
 840        if (sbi->s_mmp_tsk)
 841                kthread_stop(sbi->s_mmp_tsk);
 842        sb->s_fs_info = NULL;
 843        /*
 844         * Now that we are completely done shutting down the
 845         * superblock, we need to actually destroy the kobject.
 846         */
 847        kobject_put(&sbi->s_kobj);
 848        wait_for_completion(&sbi->s_kobj_unregister);
 849        if (sbi->s_chksum_driver)
 850                crypto_free_shash(sbi->s_chksum_driver);
 851        kfree(sbi->s_blockgroup_lock);
 852        kfree(sbi);
 853}
 854
 855static struct kmem_cache *ext4_inode_cachep;
 856
 857/*
 858 * Called inside transaction, so use GFP_NOFS
 859 */
 860static struct inode *ext4_alloc_inode(struct super_block *sb)
 861{
 862        struct ext4_inode_info *ei;
 863
 864        ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
 865        if (!ei)
 866                return NULL;
 867
 868        ei->vfs_inode.i_version = 1;
 869        spin_lock_init(&ei->i_raw_lock);
 870        INIT_LIST_HEAD(&ei->i_prealloc_list);
 871        spin_lock_init(&ei->i_prealloc_lock);
 872        ext4_es_init_tree(&ei->i_es_tree);
 873        rwlock_init(&ei->i_es_lock);
 874        INIT_LIST_HEAD(&ei->i_es_list);
 875        ei->i_es_all_nr = 0;
 876        ei->i_es_shk_nr = 0;
 877        ei->i_es_shrink_lblk = 0;
 878        ei->i_reserved_data_blocks = 0;
 879        ei->i_reserved_meta_blocks = 0;
 880        ei->i_allocated_meta_blocks = 0;
 881        ei->i_da_metadata_calc_len = 0;
 882        ei->i_da_metadata_calc_last_lblock = 0;
 883        spin_lock_init(&(ei->i_block_reservation_lock));
 884#ifdef CONFIG_QUOTA
 885        ei->i_reserved_quota = 0;
 886        memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
 887#endif
 888        ei->jinode = NULL;
 889        INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
 890        spin_lock_init(&ei->i_completed_io_lock);
 891        ei->i_sync_tid = 0;
 892        ei->i_datasync_tid = 0;
 893        atomic_set(&ei->i_ioend_count, 0);
 894        atomic_set(&ei->i_unwritten, 0);
 895        INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
 896
 897        return &ei->vfs_inode;
 898}
 899
 900static int ext4_drop_inode(struct inode *inode)
 901{
 902        int drop = generic_drop_inode(inode);
 903
 904        trace_ext4_drop_inode(inode, drop);
 905        return drop;
 906}
 907
 908static void ext4_i_callback(struct rcu_head *head)
 909{
 910        struct inode *inode = container_of(head, struct inode, i_rcu);
 911        kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
 912}
 913
 914static void ext4_destroy_inode(struct inode *inode)
 915{
 916        if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
 917                ext4_msg(inode->i_sb, KERN_ERR,
 918                         "Inode %lu (%p): orphan list check failed!",
 919                         inode->i_ino, EXT4_I(inode));
 920                print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
 921                                EXT4_I(inode), sizeof(struct ext4_inode_info),
 922                                true);
 923                dump_stack();
 924        }
 925        call_rcu(&inode->i_rcu, ext4_i_callback);
 926}
 927
 928static void init_once(void *foo)
 929{
 930        struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
 931
 932        INIT_LIST_HEAD(&ei->i_orphan);
 933        init_rwsem(&ei->xattr_sem);
 934        init_rwsem(&ei->i_data_sem);
 935        inode_init_once(&ei->vfs_inode);
 936}
 937
 938static int __init init_inodecache(void)
 939{
 940        ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
 941                                             sizeof(struct ext4_inode_info),
 942                                             0, (SLAB_RECLAIM_ACCOUNT|
 943                                                SLAB_MEM_SPREAD),
 944                                             init_once);
 945        if (ext4_inode_cachep == NULL)
 946                return -ENOMEM;
 947        return 0;
 948}
 949
 950static void destroy_inodecache(void)
 951{
 952        /*
 953         * Make sure all delayed rcu free inodes are flushed before we
 954         * destroy cache.
 955         */
 956        rcu_barrier();
 957        kmem_cache_destroy(ext4_inode_cachep);
 958}
 959
 960void ext4_clear_inode(struct inode *inode)
 961{
 962        invalidate_inode_buffers(inode);
 963        clear_inode(inode);
 964        dquot_drop(inode);
 965        ext4_discard_preallocations(inode);
 966        ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
 967        if (EXT4_I(inode)->jinode) {
 968                jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
 969                                               EXT4_I(inode)->jinode);
 970                jbd2_free_inode(EXT4_I(inode)->jinode);
 971                EXT4_I(inode)->jinode = NULL;
 972        }
 973}
 974
 975static struct inode *ext4_nfs_get_inode(struct super_block *sb,
 976                                        u64 ino, u32 generation)
 977{
 978        struct inode *inode;
 979
 980        if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
 981                return ERR_PTR(-ESTALE);
 982        if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
 983                return ERR_PTR(-ESTALE);
 984
 985        /* iget isn't really right if the inode is currently unallocated!!
 986         *
 987         * ext4_read_inode will return a bad_inode if the inode had been
 988         * deleted, so we should be safe.
 989         *
 990         * Currently we don't know the generation for parent directory, so
 991         * a generation of 0 means "accept any"
 992         */
 993        inode = ext4_iget_normal(sb, ino);
 994        if (IS_ERR(inode))
 995                return ERR_CAST(inode);
 996        if (generation && inode->i_generation != generation) {
 997                iput(inode);
 998                return ERR_PTR(-ESTALE);
 999        }
1000
1001        return inode;
1002}
1003
1004static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1005                                        int fh_len, int fh_type)
1006{
1007        return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1008                                    ext4_nfs_get_inode);
1009}
1010
1011static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1012                                        int fh_len, int fh_type)
1013{
1014        return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1015                                    ext4_nfs_get_inode);
1016}
1017
1018/*
1019 * Try to release metadata pages (indirect blocks, directories) which are
1020 * mapped via the block device.  Since these pages could have journal heads
1021 * which would prevent try_to_free_buffers() from freeing them, we must use
1022 * jbd2 layer's try_to_free_buffers() function to release them.
1023 */
1024static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1025                                 gfp_t wait)
1026{
1027        journal_t *journal = EXT4_SB(sb)->s_journal;
1028
1029        WARN_ON(PageChecked(page));
1030        if (!page_has_buffers(page))
1031                return 0;
1032        if (journal)
1033                return jbd2_journal_try_to_free_buffers(journal, page,
1034                                                        wait & ~__GFP_WAIT);
1035        return try_to_free_buffers(page);
1036}
1037
1038#ifdef CONFIG_QUOTA
1039#define QTYPE2NAME(t) ((t) == USRQUOTA ? "user" : "group")
1040#define QTYPE2MOPT(on, t) ((t) == USRQUOTA?((on)##USRJQUOTA):((on)##GRPJQUOTA))
1041
1042static int ext4_write_dquot(struct dquot *dquot);
1043static int ext4_acquire_dquot(struct dquot *dquot);
1044static int ext4_release_dquot(struct dquot *dquot);
1045static int ext4_mark_dquot_dirty(struct dquot *dquot);
1046static int ext4_write_info(struct super_block *sb, int type);
1047static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1048                         struct path *path);
1049static int ext4_quota_off(struct super_block *sb, int type);
1050static int ext4_quota_on_mount(struct super_block *sb, int type);
1051static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1052                               size_t len, loff_t off);
1053static ssize_t ext4_quota_write(struct super_block *sb, int type,
1054                                const char *data, size_t len, loff_t off);
1055static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1056                             unsigned int flags);
1057static int ext4_enable_quotas(struct super_block *sb);
1058
1059static struct dquot **ext4_get_dquots(struct inode *inode)
1060{
1061        return EXT4_I(inode)->i_dquot;
1062}
1063
1064static const struct dquot_operations ext4_quota_operations = {
1065        .get_reserved_space = ext4_get_reserved_space,
1066        .write_dquot    = ext4_write_dquot,
1067        .acquire_dquot  = ext4_acquire_dquot,
1068        .release_dquot  = ext4_release_dquot,
1069        .mark_dirty     = ext4_mark_dquot_dirty,
1070        .write_info     = ext4_write_info,
1071        .alloc_dquot    = dquot_alloc,
1072        .destroy_dquot  = dquot_destroy,
1073};
1074
1075static const struct quotactl_ops ext4_qctl_operations = {
1076        .quota_on       = ext4_quota_on,
1077        .quota_off      = ext4_quota_off,
1078        .quota_sync     = dquot_quota_sync,
1079        .get_info       = dquot_get_dqinfo,
1080        .set_info       = dquot_set_dqinfo,
1081        .get_dqblk      = dquot_get_dqblk,
1082        .set_dqblk      = dquot_set_dqblk
1083};
1084#endif
1085
1086static const struct super_operations ext4_sops = {
1087        .alloc_inode    = ext4_alloc_inode,
1088        .destroy_inode  = ext4_destroy_inode,
1089        .write_inode    = ext4_write_inode,
1090        .dirty_inode    = ext4_dirty_inode,
1091        .drop_inode     = ext4_drop_inode,
1092        .evict_inode    = ext4_evict_inode,
1093        .put_super      = ext4_put_super,
1094        .sync_fs        = ext4_sync_fs,
1095        .freeze_fs      = ext4_freeze,
1096        .unfreeze_fs    = ext4_unfreeze,
1097        .statfs         = ext4_statfs,
1098        .remount_fs     = ext4_remount,
1099        .show_options   = ext4_show_options,
1100#ifdef CONFIG_QUOTA
1101        .quota_read     = ext4_quota_read,
1102        .quota_write    = ext4_quota_write,
1103        .get_dquots     = ext4_get_dquots,
1104#endif
1105        .bdev_try_to_free_page = bdev_try_to_free_page,
1106};
1107
1108static const struct export_operations ext4_export_ops = {
1109        .fh_to_dentry = ext4_fh_to_dentry,
1110        .fh_to_parent = ext4_fh_to_parent,
1111        .get_parent = ext4_get_parent,
1112};
1113
1114enum {
1115        Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1116        Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1117        Opt_nouid32, Opt_debug, Opt_removed,
1118        Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1119        Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1120        Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1121        Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1122        Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1123        Opt_data_err_abort, Opt_data_err_ignore,
1124        Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1125        Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1126        Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1127        Opt_usrquota, Opt_grpquota, Opt_i_version, Opt_dax,
1128        Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_mblk_io_submit,
1129        Opt_lazytime, Opt_nolazytime,
1130        Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1131        Opt_inode_readahead_blks, Opt_journal_ioprio,
1132        Opt_dioread_nolock, Opt_dioread_lock,
1133        Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1134        Opt_max_dir_size_kb, Opt_nojournal_checksum,
1135};
1136
1137static const match_table_t tokens = {
1138        {Opt_bsd_df, "bsddf"},
1139        {Opt_minix_df, "minixdf"},
1140        {Opt_grpid, "grpid"},
1141        {Opt_grpid, "bsdgroups"},
1142        {Opt_nogrpid, "nogrpid"},
1143        {Opt_nogrpid, "sysvgroups"},
1144        {Opt_resgid, "resgid=%u"},
1145        {Opt_resuid, "resuid=%u"},
1146        {Opt_sb, "sb=%u"},
1147        {Opt_err_cont, "errors=continue"},
1148        {Opt_err_panic, "errors=panic"},
1149        {Opt_err_ro, "errors=remount-ro"},
1150        {Opt_nouid32, "nouid32"},
1151        {Opt_debug, "debug"},
1152        {Opt_removed, "oldalloc"},
1153        {Opt_removed, "orlov"},
1154        {Opt_user_xattr, "user_xattr"},
1155        {Opt_nouser_xattr, "nouser_xattr"},
1156        {Opt_acl, "acl"},
1157        {Opt_noacl, "noacl"},
1158        {Opt_noload, "norecovery"},
1159        {Opt_noload, "noload"},
1160        {Opt_removed, "nobh"},
1161        {Opt_removed, "bh"},
1162        {Opt_commit, "commit=%u"},
1163        {Opt_min_batch_time, "min_batch_time=%u"},
1164        {Opt_max_batch_time, "max_batch_time=%u"},
1165        {Opt_journal_dev, "journal_dev=%u"},
1166        {Opt_journal_path, "journal_path=%s"},
1167        {Opt_journal_checksum, "journal_checksum"},
1168        {Opt_nojournal_checksum, "nojournal_checksum"},
1169        {Opt_journal_async_commit, "journal_async_commit"},
1170        {Opt_abort, "abort"},
1171        {Opt_data_journal, "data=journal"},
1172        {Opt_data_ordered, "data=ordered"},
1173        {Opt_data_writeback, "data=writeback"},
1174        {Opt_data_err_abort, "data_err=abort"},
1175        {Opt_data_err_ignore, "data_err=ignore"},
1176        {Opt_offusrjquota, "usrjquota="},
1177        {Opt_usrjquota, "usrjquota=%s"},
1178        {Opt_offgrpjquota, "grpjquota="},
1179        {Opt_grpjquota, "grpjquota=%s"},
1180        {Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1181        {Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1182        {Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1183        {Opt_grpquota, "grpquota"},
1184        {Opt_noquota, "noquota"},
1185        {Opt_quota, "quota"},
1186        {Opt_usrquota, "usrquota"},
1187        {Opt_barrier, "barrier=%u"},
1188        {Opt_barrier, "barrier"},
1189        {Opt_nobarrier, "nobarrier"},
1190        {Opt_i_version, "i_version"},
1191        {Opt_dax, "dax"},
1192        {Opt_stripe, "stripe=%u"},
1193        {Opt_delalloc, "delalloc"},
1194        {Opt_lazytime, "lazytime"},
1195        {Opt_nolazytime, "nolazytime"},
1196        {Opt_nodelalloc, "nodelalloc"},
1197        {Opt_removed, "mblk_io_submit"},
1198        {Opt_removed, "nomblk_io_submit"},
1199        {Opt_block_validity, "block_validity"},
1200        {Opt_noblock_validity, "noblock_validity"},
1201        {Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1202        {Opt_journal_ioprio, "journal_ioprio=%u"},
1203        {Opt_auto_da_alloc, "auto_da_alloc=%u"},
1204        {Opt_auto_da_alloc, "auto_da_alloc"},
1205        {Opt_noauto_da_alloc, "noauto_da_alloc"},
1206        {Opt_dioread_nolock, "dioread_nolock"},
1207        {Opt_dioread_lock, "dioread_lock"},
1208        {Opt_discard, "discard"},
1209        {Opt_nodiscard, "nodiscard"},
1210        {Opt_init_itable, "init_itable=%u"},
1211        {Opt_init_itable, "init_itable"},
1212        {Opt_noinit_itable, "noinit_itable"},
1213        {Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1214        {Opt_removed, "check=none"},    /* mount option from ext2/3 */
1215        {Opt_removed, "nocheck"},       /* mount option from ext2/3 */
1216        {Opt_removed, "reservation"},   /* mount option from ext2/3 */
1217        {Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1218        {Opt_removed, "journal=%u"},    /* mount option from ext2/3 */
1219        {Opt_err, NULL},
1220};
1221
1222static ext4_fsblk_t get_sb_block(void **data)
1223{
1224        ext4_fsblk_t    sb_block;
1225        char            *options = (char *) *data;
1226
1227        if (!options || strncmp(options, "sb=", 3) != 0)
1228                return 1;       /* Default location */
1229
1230        options += 3;
1231        /* TODO: use simple_strtoll with >32bit ext4 */
1232        sb_block = simple_strtoul(options, &options, 0);
1233        if (*options && *options != ',') {
1234                printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1235                       (char *) *data);
1236                return 1;
1237        }
1238        if (*options == ',')
1239                options++;
1240        *data = (void *) options;
1241
1242        return sb_block;
1243}
1244
1245#define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1246static char deprecated_msg[] = "Mount option \"%s\" will be removed by %s\n"
1247        "Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1248
1249#ifdef CONFIG_QUOTA
1250static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1251{
1252        struct ext4_sb_info *sbi = EXT4_SB(sb);
1253        char *qname;
1254        int ret = -1;
1255
1256        if (sb_any_quota_loaded(sb) &&
1257                !sbi->s_qf_names[qtype]) {
1258                ext4_msg(sb, KERN_ERR,
1259                        "Cannot change journaled "
1260                        "quota options when quota turned on");
1261                return -1;
1262        }
1263        if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA)) {
1264                ext4_msg(sb, KERN_ERR, "Cannot set journaled quota options "
1265                         "when QUOTA feature is enabled");
1266                return -1;
1267        }
1268        qname = match_strdup(args);
1269        if (!qname) {
1270                ext4_msg(sb, KERN_ERR,
1271                        "Not enough memory for storing quotafile name");
1272                return -1;
1273        }
1274        if (sbi->s_qf_names[qtype]) {
1275                if (strcmp(sbi->s_qf_names[qtype], qname) == 0)
1276                        ret = 1;
1277                else
1278                        ext4_msg(sb, KERN_ERR,
1279                                 "%s quota file already specified",
1280                                 QTYPE2NAME(qtype));
1281                goto errout;
1282        }
1283        if (strchr(qname, '/')) {
1284                ext4_msg(sb, KERN_ERR,
1285                        "quotafile must be on filesystem root");
1286                goto errout;
1287        }
1288        sbi->s_qf_names[qtype] = qname;
1289        set_opt(sb, QUOTA);
1290        return 1;
1291errout:
1292        kfree(qname);
1293        return ret;
1294}
1295
1296static int clear_qf_name(struct super_block *sb, int qtype)
1297{
1298
1299        struct ext4_sb_info *sbi = EXT4_SB(sb);
1300
1301        if (sb_any_quota_loaded(sb) &&
1302                sbi->s_qf_names[qtype]) {
1303                ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1304                        " when quota turned on");
1305                return -1;
1306        }
1307        kfree(sbi->s_qf_names[qtype]);
1308        sbi->s_qf_names[qtype] = NULL;
1309        return 1;
1310}
1311#endif
1312
1313#define MOPT_SET        0x0001
1314#define MOPT_CLEAR      0x0002
1315#define MOPT_NOSUPPORT  0x0004
1316#define MOPT_EXPLICIT   0x0008
1317#define MOPT_CLEAR_ERR  0x0010
1318#define MOPT_GTE0       0x0020
1319#ifdef CONFIG_QUOTA
1320#define MOPT_Q          0
1321#define MOPT_QFMT       0x0040
1322#else
1323#define MOPT_Q          MOPT_NOSUPPORT
1324#define MOPT_QFMT       MOPT_NOSUPPORT
1325#endif
1326#define MOPT_DATAJ      0x0080
1327#define MOPT_NO_EXT2    0x0100
1328#define MOPT_NO_EXT3    0x0200
1329#define MOPT_EXT4_ONLY  (MOPT_NO_EXT2 | MOPT_NO_EXT3)
1330#define MOPT_STRING     0x0400
1331
1332static const struct mount_opts {
1333        int     token;
1334        int     mount_opt;
1335        int     flags;
1336} ext4_mount_opts[] = {
1337        {Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1338        {Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1339        {Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1340        {Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1341        {Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1342        {Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1343        {Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1344         MOPT_EXT4_ONLY | MOPT_SET},
1345        {Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1346         MOPT_EXT4_ONLY | MOPT_CLEAR},
1347        {Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1348        {Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1349        {Opt_delalloc, EXT4_MOUNT_DELALLOC,
1350         MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1351        {Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1352         MOPT_EXT4_ONLY | MOPT_CLEAR},
1353        {Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1354         MOPT_EXT4_ONLY | MOPT_CLEAR},
1355        {Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1356         MOPT_EXT4_ONLY | MOPT_SET},
1357        {Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1358                                    EXT4_MOUNT_JOURNAL_CHECKSUM),
1359         MOPT_EXT4_ONLY | MOPT_SET},
1360        {Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1361        {Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1362        {Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1363        {Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1364        {Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
1365         MOPT_NO_EXT2 | MOPT_SET},
1366        {Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
1367         MOPT_NO_EXT2 | MOPT_CLEAR},
1368        {Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1369        {Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1370        {Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1371        {Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1372        {Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1373        {Opt_commit, 0, MOPT_GTE0},
1374        {Opt_max_batch_time, 0, MOPT_GTE0},
1375        {Opt_min_batch_time, 0, MOPT_GTE0},
1376        {Opt_inode_readahead_blks, 0, MOPT_GTE0},
1377        {Opt_init_itable, 0, MOPT_GTE0},
1378        {Opt_dax, EXT4_MOUNT_DAX, MOPT_SET},
1379        {Opt_stripe, 0, MOPT_GTE0},
1380        {Opt_resuid, 0, MOPT_GTE0},
1381        {Opt_resgid, 0, MOPT_GTE0},
1382        {Opt_journal_dev, 0, MOPT_GTE0},
1383        {Opt_journal_path, 0, MOPT_STRING},
1384        {Opt_journal_ioprio, 0, MOPT_GTE0},
1385        {Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1386        {Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1387        {Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
1388         MOPT_NO_EXT2 | MOPT_DATAJ},
1389        {Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1390        {Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1391#ifdef CONFIG_EXT4_FS_POSIX_ACL
1392        {Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1393        {Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1394#else
1395        {Opt_acl, 0, MOPT_NOSUPPORT},
1396        {Opt_noacl, 0, MOPT_NOSUPPORT},
1397#endif
1398        {Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1399        {Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1400        {Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1401        {Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1402                                                        MOPT_SET | MOPT_Q},
1403        {Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1404                                                        MOPT_SET | MOPT_Q},
1405        {Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1406                       EXT4_MOUNT_GRPQUOTA), MOPT_CLEAR | MOPT_Q},
1407        {Opt_usrjquota, 0, MOPT_Q},
1408        {Opt_grpjquota, 0, MOPT_Q},
1409        {Opt_offusrjquota, 0, MOPT_Q},
1410        {Opt_offgrpjquota, 0, MOPT_Q},
1411        {Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1412        {Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1413        {Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1414        {Opt_max_dir_size_kb, 0, MOPT_GTE0},
1415        {Opt_err, 0, 0}
1416};
1417
1418static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1419                            substring_t *args, unsigned long *journal_devnum,
1420                            unsigned int *journal_ioprio, int is_remount)
1421{
1422        struct ext4_sb_info *sbi = EXT4_SB(sb);
1423        const struct mount_opts *m;
1424        kuid_t uid;
1425        kgid_t gid;
1426        int arg = 0;
1427
1428#ifdef CONFIG_QUOTA
1429        if (token == Opt_usrjquota)
1430                return set_qf_name(sb, USRQUOTA, &args[0]);
1431        else if (token == Opt_grpjquota)
1432                return set_qf_name(sb, GRPQUOTA, &args[0]);
1433        else if (token == Opt_offusrjquota)
1434                return clear_qf_name(sb, USRQUOTA);
1435        else if (token == Opt_offgrpjquota)
1436                return clear_qf_name(sb, GRPQUOTA);
1437#endif
1438        switch (token) {
1439        case Opt_noacl:
1440        case Opt_nouser_xattr:
1441                ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1442                break;
1443        case Opt_sb:
1444                return 1;       /* handled by get_sb_block() */
1445        case Opt_removed:
1446                ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
1447                return 1;
1448        case Opt_abort:
1449                sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1450                return 1;
1451        case Opt_i_version:
1452                sb->s_flags |= MS_I_VERSION;
1453                return 1;
1454        case Opt_lazytime:
1455                sb->s_flags |= MS_LAZYTIME;
1456                return 1;
1457        case Opt_nolazytime:
1458                sb->s_flags &= ~MS_LAZYTIME;
1459                return 1;
1460        }
1461
1462        for (m = ext4_mount_opts; m->token != Opt_err; m++)
1463                if (token == m->token)
1464                        break;
1465
1466        if (m->token == Opt_err) {
1467                ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1468                         "or missing value", opt);
1469                return -1;
1470        }
1471
1472        if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
1473                ext4_msg(sb, KERN_ERR,
1474                         "Mount option \"%s\" incompatible with ext2", opt);
1475                return -1;
1476        }
1477        if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
1478                ext4_msg(sb, KERN_ERR,
1479                         "Mount option \"%s\" incompatible with ext3", opt);
1480                return -1;
1481        }
1482
1483        if (args->from && !(m->flags & MOPT_STRING) && match_int(args, &arg))
1484                return -1;
1485        if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1486                return -1;
1487        if (m->flags & MOPT_EXPLICIT)
1488                set_opt2(sb, EXPLICIT_DELALLOC);
1489        if (m->flags & MOPT_CLEAR_ERR)
1490                clear_opt(sb, ERRORS_MASK);
1491        if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1492                ext4_msg(sb, KERN_ERR, "Cannot change quota "
1493                         "options when quota turned on");
1494                return -1;
1495        }
1496
1497        if (m->flags & MOPT_NOSUPPORT) {
1498                ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1499        } else if (token == Opt_commit) {
1500                if (arg == 0)
1501                        arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1502                sbi->s_commit_interval = HZ * arg;
1503        } else if (token == Opt_max_batch_time) {
1504                sbi->s_max_batch_time = arg;
1505        } else if (token == Opt_min_batch_time) {
1506                sbi->s_min_batch_time = arg;
1507        } else if (token == Opt_inode_readahead_blks) {
1508                if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
1509                        ext4_msg(sb, KERN_ERR,
1510                                 "EXT4-fs: inode_readahead_blks must be "
1511                                 "0 or a power of 2 smaller than 2^31");
1512                        return -1;
1513                }
1514                sbi->s_inode_readahead_blks = arg;
1515        } else if (token == Opt_init_itable) {
1516                set_opt(sb, INIT_INODE_TABLE);
1517                if (!args->from)
1518                        arg = EXT4_DEF_LI_WAIT_MULT;
1519                sbi->s_li_wait_mult = arg;
1520        } else if (token == Opt_max_dir_size_kb) {
1521                sbi->s_max_dir_size_kb = arg;
1522        } else if (token == Opt_stripe) {
1523                sbi->s_stripe = arg;
1524        } else if (token == Opt_resuid) {
1525                uid = make_kuid(current_user_ns(), arg);
1526                if (!uid_valid(uid)) {
1527                        ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
1528                        return -1;
1529                }
1530                sbi->s_resuid = uid;
1531        } else if (token == Opt_resgid) {
1532                gid = make_kgid(current_user_ns(), arg);
1533                if (!gid_valid(gid)) {
1534                        ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
1535                        return -1;
1536                }
1537                sbi->s_resgid = gid;
1538        } else if (token == Opt_journal_dev) {
1539                if (is_remount) {
1540                        ext4_msg(sb, KERN_ERR,
1541                                 "Cannot specify journal on remount");
1542                        return -1;
1543                }
1544                *journal_devnum = arg;
1545        } else if (token == Opt_journal_path) {
1546                char *journal_path;
1547                struct inode *journal_inode;
1548                struct path path;
1549                int error;
1550
1551                if (is_remount) {
1552                        ext4_msg(sb, KERN_ERR,
1553                                 "Cannot specify journal on remount");
1554                        return -1;
1555                }
1556                journal_path = match_strdup(&args[0]);
1557                if (!journal_path) {
1558                        ext4_msg(sb, KERN_ERR, "error: could not dup "
1559                                "journal device string");
1560                        return -1;
1561                }
1562
1563                error = kern_path(journal_path, LOOKUP_FOLLOW, &path);
1564                if (error) {
1565                        ext4_msg(sb, KERN_ERR, "error: could not find "
1566                                "journal device path: error %d", error);
1567                        kfree(journal_path);
1568                        return -1;
1569                }
1570
1571                journal_inode = path.dentry->d_inode;
1572                if (!S_ISBLK(journal_inode->i_mode)) {
1573                        ext4_msg(sb, KERN_ERR, "error: journal path %s "
1574                                "is not a block device", journal_path);
1575                        path_put(&path);
1576                        kfree(journal_path);
1577                        return -1;
1578                }
1579
1580                *journal_devnum = new_encode_dev(journal_inode->i_rdev);
1581                path_put(&path);
1582                kfree(journal_path);
1583        } else if (token == Opt_journal_ioprio) {
1584                if (arg > 7) {
1585                        ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
1586                                 " (must be 0-7)");
1587                        return -1;
1588                }
1589                *journal_ioprio =
1590                        IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
1591        } else if (m->flags & MOPT_DATAJ) {
1592                if (is_remount) {
1593                        if (!sbi->s_journal)
1594                                ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
1595                        else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
1596                                ext4_msg(sb, KERN_ERR,
1597                                         "Cannot change data mode on remount");
1598                                return -1;
1599                        }
1600                } else {
1601                        clear_opt(sb, DATA_FLAGS);
1602                        sbi->s_mount_opt |= m->mount_opt;
1603                }
1604#ifdef CONFIG_QUOTA
1605        } else if (m->flags & MOPT_QFMT) {
1606                if (sb_any_quota_loaded(sb) &&
1607                    sbi->s_jquota_fmt != m->mount_opt) {
1608                        ext4_msg(sb, KERN_ERR, "Cannot change journaled "
1609                                 "quota options when quota turned on");
1610                        return -1;
1611                }
1612                if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
1613                                               EXT4_FEATURE_RO_COMPAT_QUOTA)) {
1614                        ext4_msg(sb, KERN_ERR,
1615                                 "Cannot set journaled quota options "
1616                                 "when QUOTA feature is enabled");
1617                        return -1;
1618                }
1619                sbi->s_jquota_fmt = m->mount_opt;
1620#endif
1621#ifndef CONFIG_FS_DAX
1622        } else if (token == Opt_dax) {
1623                ext4_msg(sb, KERN_INFO, "dax option not supported");
1624                return -1;
1625#endif
1626        } else {
1627                if (!args->from)
1628                        arg = 1;
1629                if (m->flags & MOPT_CLEAR)
1630                        arg = !arg;
1631                else if (unlikely(!(m->flags & MOPT_SET))) {
1632                        ext4_msg(sb, KERN_WARNING,
1633                                 "buggy handling of option %s", opt);
1634                        WARN_ON(1);
1635                        return -1;
1636                }
1637                if (arg != 0)
1638                        sbi->s_mount_opt |= m->mount_opt;
1639                else
1640                        sbi->s_mount_opt &= ~m->mount_opt;
1641        }
1642        return 1;
1643}
1644
1645static int parse_options(char *options, struct super_block *sb,
1646                         unsigned long *journal_devnum,
1647                         unsigned int *journal_ioprio,
1648                         int is_remount)
1649{
1650        struct ext4_sb_info *sbi = EXT4_SB(sb);
1651        char *p;
1652        substring_t args[MAX_OPT_ARGS];
1653        int token;
1654
1655        if (!options)
1656                return 1;
1657
1658        while ((p = strsep(&options, ",")) != NULL) {
1659                if (!*p)
1660                        continue;
1661                /*
1662                 * Initialize args struct so we know whether arg was
1663                 * found; some options take optional arguments.
1664                 */
1665                args[0].to = args[0].from = NULL;
1666                token = match_token(p, tokens, args);
1667                if (handle_mount_opt(sb, p, token, args, journal_devnum,
1668                                     journal_ioprio, is_remount) < 0)
1669                        return 0;
1670        }
1671#ifdef CONFIG_QUOTA
1672        if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
1673            (test_opt(sb, USRQUOTA) || test_opt(sb, GRPQUOTA))) {
1674                ext4_msg(sb, KERN_ERR, "Cannot set quota options when QUOTA "
1675                         "feature is enabled");
1676                return 0;
1677        }
1678        if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1679                if (test_opt(sb, USRQUOTA) && sbi->s_qf_names[USRQUOTA])
1680                        clear_opt(sb, USRQUOTA);
1681
1682                if (test_opt(sb, GRPQUOTA) && sbi->s_qf_names[GRPQUOTA])
1683                        clear_opt(sb, GRPQUOTA);
1684
1685                if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
1686                        ext4_msg(sb, KERN_ERR, "old and new quota "
1687                                        "format mixing");
1688                        return 0;
1689                }
1690
1691                if (!sbi->s_jquota_fmt) {
1692                        ext4_msg(sb, KERN_ERR, "journaled quota format "
1693                                        "not specified");
1694                        return 0;
1695                }
1696        }
1697#endif
1698        if (test_opt(sb, DIOREAD_NOLOCK)) {
1699                int blocksize =
1700                        BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
1701
1702                if (blocksize < PAGE_CACHE_SIZE) {
1703                        ext4_msg(sb, KERN_ERR, "can't mount with "
1704                                 "dioread_nolock if block size != PAGE_SIZE");
1705                        return 0;
1706                }
1707        }
1708        if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
1709            test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
1710                ext4_msg(sb, KERN_ERR, "can't mount with journal_async_commit "
1711                         "in data=ordered mode");
1712                return 0;
1713        }
1714        return 1;
1715}
1716
1717static inline void ext4_show_quota_options(struct seq_file *seq,
1718                                           struct super_block *sb)
1719{
1720#if defined(CONFIG_QUOTA)
1721        struct ext4_sb_info *sbi = EXT4_SB(sb);
1722
1723        if (sbi->s_jquota_fmt) {
1724                char *fmtname = "";
1725
1726                switch (sbi->s_jquota_fmt) {
1727                case QFMT_VFS_OLD:
1728                        fmtname = "vfsold";
1729                        break;
1730                case QFMT_VFS_V0:
1731                        fmtname = "vfsv0";
1732                        break;
1733                case QFMT_VFS_V1:
1734                        fmtname = "vfsv1";
1735                        break;
1736                }
1737                seq_printf(seq, ",jqfmt=%s", fmtname);
1738        }
1739
1740        if (sbi->s_qf_names[USRQUOTA])
1741                seq_printf(seq, ",usrjquota=%s", sbi->s_qf_names[USRQUOTA]);
1742
1743        if (sbi->s_qf_names[GRPQUOTA])
1744                seq_printf(seq, ",grpjquota=%s", sbi->s_qf_names[GRPQUOTA]);
1745#endif
1746}
1747
1748static const char *token2str(int token)
1749{
1750        const struct match_token *t;
1751
1752        for (t = tokens; t->token != Opt_err; t++)
1753                if (t->token == token && !strchr(t->pattern, '='))
1754                        break;
1755        return t->pattern;
1756}
1757
1758/*
1759 * Show an option if
1760 *  - it's set to a non-default value OR
1761 *  - if the per-sb default is different from the global default
1762 */
1763static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
1764                              int nodefs)
1765{
1766        struct ext4_sb_info *sbi = EXT4_SB(sb);
1767        struct ext4_super_block *es = sbi->s_es;
1768        int def_errors, def_mount_opt = nodefs ? 0 : sbi->s_def_mount_opt;
1769        const struct mount_opts *m;
1770        char sep = nodefs ? '\n' : ',';
1771
1772#define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
1773#define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
1774
1775        if (sbi->s_sb_block != 1)
1776                SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
1777
1778        for (m = ext4_mount_opts; m->token != Opt_err; m++) {
1779                int want_set = m->flags & MOPT_SET;
1780                if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
1781                    (m->flags & MOPT_CLEAR_ERR))
1782                        continue;
1783                if (!(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
1784                        continue; /* skip if same as the default */
1785                if ((want_set &&
1786                     (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
1787                    (!want_set && (sbi->s_mount_opt & m->mount_opt)))
1788                        continue; /* select Opt_noFoo vs Opt_Foo */
1789                SEQ_OPTS_PRINT("%s", token2str(m->token));
1790        }
1791
1792        if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
1793            le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
1794                SEQ_OPTS_PRINT("resuid=%u",
1795                                from_kuid_munged(&init_user_ns, sbi->s_resuid));
1796        if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
1797            le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
1798                SEQ_OPTS_PRINT("resgid=%u",
1799                                from_kgid_munged(&init_user_ns, sbi->s_resgid));
1800        def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
1801        if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
1802                SEQ_OPTS_PUTS("errors=remount-ro");
1803        if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
1804                SEQ_OPTS_PUTS("errors=continue");
1805        if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
1806                SEQ_OPTS_PUTS("errors=panic");
1807        if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
1808                SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
1809        if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
1810                SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
1811        if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
1812                SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
1813        if (sb->s_flags & MS_I_VERSION)
1814                SEQ_OPTS_PUTS("i_version");
1815        if (nodefs || sbi->s_stripe)
1816                SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
1817        if (EXT4_MOUNT_DATA_FLAGS & (sbi->s_mount_opt ^ def_mount_opt)) {
1818                if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
1819                        SEQ_OPTS_PUTS("data=journal");
1820                else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
1821                        SEQ_OPTS_PUTS("data=ordered");
1822                else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
1823                        SEQ_OPTS_PUTS("data=writeback");
1824        }
1825        if (nodefs ||
1826            sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
1827                SEQ_OPTS_PRINT("inode_readahead_blks=%u",
1828                               sbi->s_inode_readahead_blks);
1829
1830        if (nodefs || (test_opt(sb, INIT_INODE_TABLE) &&
1831                       (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
1832                SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
1833        if (nodefs || sbi->s_max_dir_size_kb)
1834                SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
1835
1836        ext4_show_quota_options(seq, sb);
1837        return 0;
1838}
1839
1840static int ext4_show_options(struct seq_file *seq, struct dentry *root)
1841{
1842        return _ext4_show_options(seq, root->d_sb, 0);
1843}
1844
1845static int options_seq_show(struct seq_file *seq, void *offset)
1846{
1847        struct super_block *sb = seq->private;
1848        int rc;
1849
1850        seq_puts(seq, (sb->s_flags & MS_RDONLY) ? "ro" : "rw");
1851        rc = _ext4_show_options(seq, sb, 1);
1852        seq_puts(seq, "\n");
1853        return rc;
1854}
1855
1856static int options_open_fs(struct inode *inode, struct file *file)
1857{
1858        return single_open(file, options_seq_show, PDE_DATA(inode));
1859}
1860
1861static const struct file_operations ext4_seq_options_fops = {
1862        .owner = THIS_MODULE,
1863        .open = options_open_fs,
1864        .read = seq_read,
1865        .llseek = seq_lseek,
1866        .release = single_release,
1867};
1868
1869static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
1870                            int read_only)
1871{
1872        struct ext4_sb_info *sbi = EXT4_SB(sb);
1873        int res = 0;
1874
1875        if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
1876                ext4_msg(sb, KERN_ERR, "revision level too high, "
1877                         "forcing read-only mode");
1878                res = MS_RDONLY;
1879        }
1880        if (read_only)
1881                goto done;
1882        if (!(sbi->s_mount_state & EXT4_VALID_FS))
1883                ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
1884                         "running e2fsck is recommended");
1885        else if (sbi->s_mount_state & EXT4_ERROR_FS)
1886                ext4_msg(sb, KERN_WARNING,
1887                         "warning: mounting fs with errors, "
1888                         "running e2fsck is recommended");
1889        else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
1890                 le16_to_cpu(es->s_mnt_count) >=
1891                 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
1892                ext4_msg(sb, KERN_WARNING,
1893                         "warning: maximal mount count reached, "
1894                         "running e2fsck is recommended");
1895        else if (le32_to_cpu(es->s_checkinterval) &&
1896                (le32_to_cpu(es->s_lastcheck) +
1897                        le32_to_cpu(es->s_checkinterval) <= get_seconds()))
1898                ext4_msg(sb, KERN_WARNING,
1899                         "warning: checktime reached, "
1900                         "running e2fsck is recommended");
1901        if (!sbi->s_journal)
1902                es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
1903        if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
1904                es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
1905        le16_add_cpu(&es->s_mnt_count, 1);
1906        es->s_mtime = cpu_to_le32(get_seconds());
1907        ext4_update_dynamic_rev(sb);
1908        if (sbi->s_journal)
1909                EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
1910
1911        ext4_commit_super(sb, 1);
1912done:
1913        if (test_opt(sb, DEBUG))
1914                printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
1915                                "bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
1916                        sb->s_blocksize,
1917                        sbi->s_groups_count,
1918                        EXT4_BLOCKS_PER_GROUP(sb),
1919                        EXT4_INODES_PER_GROUP(sb),
1920                        sbi->s_mount_opt, sbi->s_mount_opt2);
1921
1922        cleancache_init_fs(sb);
1923        return res;
1924}
1925
1926int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
1927{
1928        struct ext4_sb_info *sbi = EXT4_SB(sb);
1929        struct flex_groups *new_groups;
1930        int size;
1931
1932        if (!sbi->s_log_groups_per_flex)
1933                return 0;
1934
1935        size = ext4_flex_group(sbi, ngroup - 1) + 1;
1936        if (size <= sbi->s_flex_groups_allocated)
1937                return 0;
1938
1939        size = roundup_pow_of_two(size * sizeof(struct flex_groups));
1940        new_groups = ext4_kvzalloc(size, GFP_KERNEL);
1941        if (!new_groups) {
1942                ext4_msg(sb, KERN_ERR, "not enough memory for %d flex groups",
1943                         size / (int) sizeof(struct flex_groups));
1944                return -ENOMEM;
1945        }
1946
1947        if (sbi->s_flex_groups) {
1948                memcpy(new_groups, sbi->s_flex_groups,
1949                       (sbi->s_flex_groups_allocated *
1950                        sizeof(struct flex_groups)));
1951                kvfree(sbi->s_flex_groups);
1952        }
1953        sbi->s_flex_groups = new_groups;
1954        sbi->s_flex_groups_allocated = size / sizeof(struct flex_groups);
1955        return 0;
1956}
1957
1958static int ext4_fill_flex_info(struct super_block *sb)
1959{
1960        struct ext4_sb_info *sbi = EXT4_SB(sb);
1961        struct ext4_group_desc *gdp = NULL;
1962        ext4_group_t flex_group;
1963        int i, err;
1964
1965        sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
1966        if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
1967                sbi->s_log_groups_per_flex = 0;
1968                return 1;
1969        }
1970
1971        err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
1972        if (err)
1973                goto failed;
1974
1975        for (i = 0; i < sbi->s_groups_count; i++) {
1976                gdp = ext4_get_group_desc(sb, i, NULL);
1977
1978                flex_group = ext4_flex_group(sbi, i);
1979                atomic_add(ext4_free_inodes_count(sb, gdp),
1980                           &sbi->s_flex_groups[flex_group].free_inodes);
1981                atomic64_add(ext4_free_group_clusters(sb, gdp),
1982                             &sbi->s_flex_groups[flex_group].free_clusters);
1983                atomic_add(ext4_used_dirs_count(sb, gdp),
1984                           &sbi->s_flex_groups[flex_group].used_dirs);
1985        }
1986
1987        return 1;
1988failed:
1989        return 0;
1990}
1991
1992static __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 block_group,
1993                                   struct ext4_group_desc *gdp)
1994{
1995        int offset;
1996        __u16 crc = 0;
1997        __le32 le_group = cpu_to_le32(block_group);
1998
1999        if (ext4_has_metadata_csum(sbi->s_sb)) {
2000                /* Use new metadata_csum algorithm */
2001                __le16 save_csum;
2002                __u32 csum32;
2003
2004                save_csum = gdp->bg_checksum;
2005                gdp->bg_checksum = 0;
2006                csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
2007                                     sizeof(le_group));
2008                csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp,
2009                                     sbi->s_desc_size);
2010                gdp->bg_checksum = save_csum;
2011
2012                crc = csum32 & 0xFFFF;
2013                goto out;
2014        }
2015
2016        /* old crc16 code */
2017        if (!(sbi->s_es->s_feature_ro_compat &
2018              cpu_to_le32(EXT4_FEATURE_RO_COMPAT_GDT_CSUM)))
2019                return 0;
2020
2021        offset = offsetof(struct ext4_group_desc, bg_checksum);
2022
2023        crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2024        crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2025        crc = crc16(crc, (__u8 *)gdp, offset);
2026        offset += sizeof(gdp->bg_checksum); /* skip checksum */
2027        /* for checksum of struct ext4_group_desc do the rest...*/
2028        if ((sbi->s_es->s_feature_incompat &
2029             cpu_to_le32(EXT4_FEATURE_INCOMPAT_64BIT)) &&
2030            offset < le16_to_cpu(sbi->s_es->s_desc_size))
2031                crc = crc16(crc, (__u8 *)gdp + offset,
2032                            le16_to_cpu(sbi->s_es->s_desc_size) -
2033                                offset);
2034
2035out:
2036        return cpu_to_le16(crc);
2037}
2038
2039int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2040                                struct ext4_group_desc *gdp)
2041{
2042        if (ext4_has_group_desc_csum(sb) &&
2043            (gdp->bg_checksum != ext4_group_desc_csum(EXT4_SB(sb),
2044                                                      block_group, gdp)))
2045                return 0;
2046
2047        return 1;
2048}
2049
2050void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2051                              struct ext4_group_desc *gdp)
2052{
2053        if (!ext4_has_group_desc_csum(sb))
2054                return;
2055        gdp->bg_checksum = ext4_group_desc_csum(EXT4_SB(sb), block_group, gdp);
2056}
2057
2058/* Called at mount-time, super-block is locked */
2059static int ext4_check_descriptors(struct super_block *sb,
2060                                  ext4_group_t *first_not_zeroed)
2061{
2062        struct ext4_sb_info *sbi = EXT4_SB(sb);
2063        ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2064        ext4_fsblk_t last_block;
2065        ext4_fsblk_t block_bitmap;
2066        ext4_fsblk_t inode_bitmap;
2067        ext4_fsblk_t inode_table;
2068        int flexbg_flag = 0;
2069        ext4_group_t i, grp = sbi->s_groups_count;
2070
2071        if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
2072                flexbg_flag = 1;
2073
2074        ext4_debug("Checking group descriptors");
2075
2076        for (i = 0; i < sbi->s_groups_count; i++) {
2077                struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2078
2079                if (i == sbi->s_groups_count - 1 || flexbg_flag)
2080                        last_block = ext4_blocks_count(sbi->s_es) - 1;
2081                else
2082                        last_block = first_block +
2083                                (EXT4_BLOCKS_PER_GROUP(sb) - 1);
2084
2085                if ((grp == sbi->s_groups_count) &&
2086                   !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2087                        grp = i;
2088
2089                block_bitmap = ext4_block_bitmap(sb, gdp);
2090                if (block_bitmap < first_block || block_bitmap > last_block) {
2091                        ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2092                               "Block bitmap for group %u not in group "
2093                               "(block %llu)!", i, block_bitmap);
2094                        return 0;
2095                }
2096                inode_bitmap = ext4_inode_bitmap(sb, gdp);
2097                if (inode_bitmap < first_block || inode_bitmap > last_block) {
2098                        ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2099                               "Inode bitmap for group %u not in group "
2100                               "(block %llu)!", i, inode_bitmap);
2101                        return 0;
2102                }
2103                inode_table = ext4_inode_table(sb, gdp);
2104                if (inode_table < first_block ||
2105                    inode_table + sbi->s_itb_per_group - 1 > last_block) {
2106                        ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2107                               "Inode table for group %u not in group "
2108                               "(block %llu)!", i, inode_table);
2109                        return 0;
2110                }
2111                ext4_lock_group(sb, i);
2112                if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2113                        ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2114                                 "Checksum for group %u failed (%u!=%u)",
2115                                 i, le16_to_cpu(ext4_group_desc_csum(sbi, i,
2116                                     gdp)), le16_to_cpu(gdp->bg_checksum));
2117                        if (!(sb->s_flags & MS_RDONLY)) {
2118                                ext4_unlock_group(sb, i);
2119                                return 0;
2120                        }
2121                }
2122                ext4_unlock_group(sb, i);
2123                if (!flexbg_flag)
2124                        first_block += EXT4_BLOCKS_PER_GROUP(sb);
2125        }
2126        if (NULL != first_not_zeroed)
2127                *first_not_zeroed = grp;
2128        return 1;
2129}
2130
2131/* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2132 * the superblock) which were deleted from all directories, but held open by
2133 * a process at the time of a crash.  We walk the list and try to delete these
2134 * inodes at recovery time (only with a read-write filesystem).
2135 *
2136 * In order to keep the orphan inode chain consistent during traversal (in
2137 * case of crash during recovery), we link each inode into the superblock
2138 * orphan list_head and handle it the same way as an inode deletion during
2139 * normal operation (which journals the operations for us).
2140 *
2141 * We only do an iget() and an iput() on each inode, which is very safe if we
2142 * accidentally point at an in-use or already deleted inode.  The worst that
2143 * can happen in this case is that we get a "bit already cleared" message from
2144 * ext4_free_inode().  The only reason we would point at a wrong inode is if
2145 * e2fsck was run on this filesystem, and it must have already done the orphan
2146 * inode cleanup for us, so we can safely abort without any further action.
2147 */
2148static void ext4_orphan_cleanup(struct super_block *sb,
2149                                struct ext4_super_block *es)
2150{
2151        unsigned int s_flags = sb->s_flags;
2152        int nr_orphans = 0, nr_truncates = 0;
2153#ifdef CONFIG_QUOTA
2154        int i;
2155#endif
2156        if (!es->s_last_orphan) {
2157                jbd_debug(4, "no orphan inodes to clean up\n");
2158                return;
2159        }
2160
2161        if (bdev_read_only(sb->s_bdev)) {
2162                ext4_msg(sb, KERN_ERR, "write access "
2163                        "unavailable, skipping orphan cleanup");
2164                return;
2165        }
2166
2167        /* Check if feature set would not allow a r/w mount */
2168        if (!ext4_feature_set_ok(sb, 0)) {
2169                ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2170                         "unknown ROCOMPAT features");
2171                return;
2172        }
2173
2174        if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2175                /* don't clear list on RO mount w/ errors */
2176                if (es->s_last_orphan && !(s_flags & MS_RDONLY)) {
2177                        ext4_msg(sb, KERN_INFO, "Errors on filesystem, "
2178                                  "clearing orphan list.\n");
2179                        es->s_last_orphan = 0;
2180                }
2181                jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2182                return;
2183        }
2184
2185        if (s_flags & MS_RDONLY) {
2186                ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2187                sb->s_flags &= ~MS_RDONLY;
2188        }
2189#ifdef CONFIG_QUOTA
2190        /* Needed for iput() to work correctly and not trash data */
2191        sb->s_flags |= MS_ACTIVE;
2192        /* Turn on quotas so that they are updated correctly */
2193        for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2194                if (EXT4_SB(sb)->s_qf_names[i]) {
2195                        int ret = ext4_quota_on_mount(sb, i);
2196                        if (ret < 0)
2197                                ext4_msg(sb, KERN_ERR,
2198                                        "Cannot turn on journaled "
2199                                        "quota: error %d", ret);
2200                }
2201        }
2202#endif
2203
2204        while (es->s_last_orphan) {
2205                struct inode *inode;
2206
2207                inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2208                if (IS_ERR(inode)) {
2209                        es->s_last_orphan = 0;
2210                        break;
2211                }
2212
2213                list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2214                dquot_initialize(inode);
2215                if (inode->i_nlink) {
2216                        if (test_opt(sb, DEBUG))
2217                                ext4_msg(sb, KERN_DEBUG,
2218                                        "%s: truncating inode %lu to %lld bytes",
2219                                        __func__, inode->i_ino, inode->i_size);
2220                        jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2221                                  inode->i_ino, inode->i_size);
2222                        mutex_lock(&inode->i_mutex);
2223                        truncate_inode_pages(inode->i_mapping, inode->i_size);
2224                        ext4_truncate(inode);
2225                        mutex_unlock(&inode->i_mutex);
2226                        nr_truncates++;
2227                } else {
2228                        if (test_opt(sb, DEBUG))
2229                                ext4_msg(sb, KERN_DEBUG,
2230                                        "%s: deleting unreferenced inode %lu",
2231                                        __func__, inode->i_ino);
2232                        jbd_debug(2, "deleting unreferenced inode %lu\n",
2233                                  inode->i_ino);
2234                        nr_orphans++;
2235                }
2236                iput(inode);  /* The delete magic happens here! */
2237        }
2238
2239#define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2240
2241        if (nr_orphans)
2242                ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2243                       PLURAL(nr_orphans));
2244        if (nr_truncates)
2245                ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2246                       PLURAL(nr_truncates));
2247#ifdef CONFIG_QUOTA
2248        /* Turn quotas off */
2249        for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2250                if (sb_dqopt(sb)->files[i])
2251                        dquot_quota_off(sb, i);
2252        }
2253#endif
2254        sb->s_flags = s_flags; /* Restore MS_RDONLY status */
2255}
2256
2257/*
2258 * Maximal extent format file size.
2259 * Resulting logical blkno at s_maxbytes must fit in our on-disk
2260 * extent format containers, within a sector_t, and within i_blocks
2261 * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2262 * so that won't be a limiting factor.
2263 *
2264 * However there is other limiting factor. We do store extents in the form
2265 * of starting block and length, hence the resulting length of the extent
2266 * covering maximum file size must fit into on-disk format containers as
2267 * well. Given that length is always by 1 unit bigger than max unit (because
2268 * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2269 *
2270 * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2271 */
2272static loff_t ext4_max_size(int blkbits, int has_huge_files)
2273{
2274        loff_t res;
2275        loff_t upper_limit = MAX_LFS_FILESIZE;
2276
2277        /* small i_blocks in vfs inode? */
2278        if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2279                /*
2280                 * CONFIG_LBDAF is not enabled implies the inode
2281                 * i_block represent total blocks in 512 bytes
2282                 * 32 == size of vfs inode i_blocks * 8
2283                 */
2284                upper_limit = (1LL << 32) - 1;
2285
2286                /* total blocks in file system block size */
2287                upper_limit >>= (blkbits - 9);
2288                upper_limit <<= blkbits;
2289        }
2290
2291        /*
2292         * 32-bit extent-start container, ee_block. We lower the maxbytes
2293         * by one fs block, so ee_len can cover the extent of maximum file
2294         * size
2295         */
2296        res = (1LL << 32) - 1;
2297        res <<= blkbits;
2298
2299        /* Sanity check against vm- & vfs- imposed limits */
2300        if (res > upper_limit)
2301                res = upper_limit;
2302
2303        return res;
2304}
2305
2306/*
2307 * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2308 * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2309 * We need to be 1 filesystem block less than the 2^48 sector limit.
2310 */
2311static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2312{
2313        loff_t res = EXT4_NDIR_BLOCKS;
2314        int meta_blocks;
2315        loff_t upper_limit;
2316        /* This is calculated to be the largest file size for a dense, block
2317         * mapped file such that the file's total number of 512-byte sectors,
2318         * including data and all indirect blocks, does not exceed (2^48 - 1).
2319         *
2320         * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2321         * number of 512-byte sectors of the file.
2322         */
2323
2324        if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2325                /*
2326                 * !has_huge_files or CONFIG_LBDAF not enabled implies that
2327                 * the inode i_block field represents total file blocks in
2328                 * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2329                 */
2330                upper_limit = (1LL << 32) - 1;
2331
2332                /* total blocks in file system block size */
2333                upper_limit >>= (bits - 9);
2334
2335        } else {
2336                /*
2337                 * We use 48 bit ext4_inode i_blocks
2338                 * With EXT4_HUGE_FILE_FL set the i_blocks
2339                 * represent total number of blocks in
2340                 * file system block size
2341                 */
2342                upper_limit = (1LL << 48) - 1;
2343
2344        }
2345
2346        /* indirect blocks */
2347        meta_blocks = 1;
2348        /* double indirect blocks */
2349        meta_blocks += 1 + (1LL << (bits-2));
2350        /* tripple indirect blocks */
2351        meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2352
2353        upper_limit -= meta_blocks;
2354        upper_limit <<= bits;
2355
2356        res += 1LL << (bits-2);
2357        res += 1LL << (2*(bits-2));
2358        res += 1LL << (3*(bits-2));
2359        res <<= bits;
2360        if (res > upper_limit)
2361                res = upper_limit;
2362
2363        if (res > MAX_LFS_FILESIZE)
2364                res = MAX_LFS_FILESIZE;
2365
2366        return res;
2367}
2368
2369static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2370                                   ext4_fsblk_t logical_sb_block, int nr)
2371{
2372        struct ext4_sb_info *sbi = EXT4_SB(sb);
2373        ext4_group_t bg, first_meta_bg;
2374        int has_super = 0;
2375
2376        first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2377
2378        if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG) ||
2379            nr < first_meta_bg)
2380                return logical_sb_block + nr + 1;
2381        bg = sbi->s_desc_per_block * nr;
2382        if (ext4_bg_has_super(sb, bg))
2383                has_super = 1;
2384
2385        /*
2386         * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
2387         * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
2388         * on modern mke2fs or blksize > 1k on older mke2fs) then we must
2389         * compensate.
2390         */
2391        if (sb->s_blocksize == 1024 && nr == 0 &&
2392            le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block) == 0)
2393                has_super++;
2394
2395        return (has_super + ext4_group_first_block_no(sb, bg));
2396}
2397
2398/**
2399 * ext4_get_stripe_size: Get the stripe size.
2400 * @sbi: In memory super block info
2401 *
2402 * If we have specified it via mount option, then
2403 * use the mount option value. If the value specified at mount time is
2404 * greater than the blocks per group use the super block value.
2405 * If the super block value is greater than blocks per group return 0.
2406 * Allocator needs it be less than blocks per group.
2407 *
2408 */
2409static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2410{
2411        unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2412        unsigned long stripe_width =
2413                        le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2414        int ret;
2415
2416        if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2417                ret = sbi->s_stripe;
2418        else if (stripe_width <= sbi->s_blocks_per_group)
2419                ret = stripe_width;
2420        else if (stride <= sbi->s_blocks_per_group)
2421                ret = stride;
2422        else
2423                ret = 0;
2424
2425        /*
2426         * If the stripe width is 1, this makes no sense and
2427         * we set it to 0 to turn off stripe handling code.
2428         */
2429        if (ret <= 1)
2430                ret = 0;
2431
2432        return ret;
2433}
2434
2435/* sysfs supprt */
2436
2437struct ext4_attr {
2438        struct attribute attr;
2439        ssize_t (*show)(struct ext4_attr *, struct ext4_sb_info *, char *);
2440        ssize_t (*store)(struct ext4_attr *, struct ext4_sb_info *,
2441                         const char *, size_t);
2442        union {
2443                int offset;
2444                int deprecated_val;
2445        } u;
2446};
2447
2448static int parse_strtoull(const char *buf,
2449                unsigned long long max, unsigned long long *value)
2450{
2451        int ret;
2452
2453        ret = kstrtoull(skip_spaces(buf), 0, value);
2454        if (!ret && *value > max)
2455                ret = -EINVAL;
2456        return ret;
2457}
2458
2459static ssize_t delayed_allocation_blocks_show(struct ext4_attr *a,
2460                                              struct ext4_sb_info *sbi,
2461                                              char *buf)
2462{
2463        return snprintf(buf, PAGE_SIZE, "%llu\n",
2464                (s64) EXT4_C2B(sbi,
2465                        percpu_counter_sum(&sbi->s_dirtyclusters_counter)));
2466}
2467
2468static ssize_t session_write_kbytes_show(struct ext4_attr *a,
2469                                         struct ext4_sb_info *sbi, char *buf)
2470{
2471        struct super_block *sb = sbi->s_buddy_cache->i_sb;
2472
2473        if (!sb->s_bdev->bd_part)
2474                return snprintf(buf, PAGE_SIZE, "0\n");
2475        return snprintf(buf, PAGE_SIZE, "%lu\n",
2476                        (part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2477                         sbi->s_sectors_written_start) >> 1);
2478}
2479
2480static ssize_t lifetime_write_kbytes_show(struct ext4_attr *a,
2481                                          struct ext4_sb_info *sbi, char *buf)
2482{
2483        struct super_block *sb = sbi->s_buddy_cache->i_sb;
2484
2485        if (!sb->s_bdev->bd_part)
2486                return snprintf(buf, PAGE_SIZE, "0\n");
2487        return snprintf(buf, PAGE_SIZE, "%llu\n",
2488                        (unsigned long long)(sbi->s_kbytes_written +
2489                        ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2490                          EXT4_SB(sb)->s_sectors_written_start) >> 1)));
2491}
2492
2493static ssize_t inode_readahead_blks_store(struct ext4_attr *a,
2494                                          struct ext4_sb_info *sbi,
2495                                          const char *buf, size_t count)
2496{
2497        unsigned long t;
2498        int ret;
2499
2500        ret = kstrtoul(skip_spaces(buf), 0, &t);
2501        if (ret)
2502                return ret;
2503
2504        if (t && (!is_power_of_2(t) || t > 0x40000000))
2505                return -EINVAL;
2506
2507        sbi->s_inode_readahead_blks = t;
2508        return count;
2509}
2510
2511static ssize_t sbi_ui_show(struct ext4_attr *a,
2512                           struct ext4_sb_info *sbi, char *buf)
2513{
2514        unsigned int *ui = (unsigned int *) (((char *) sbi) + a->u.offset);
2515
2516        return snprintf(buf, PAGE_SIZE, "%u\n", *ui);
2517}
2518
2519static ssize_t sbi_ui_store(struct ext4_attr *a,
2520                            struct ext4_sb_info *sbi,
2521                            const char *buf, size_t count)
2522{
2523        unsigned int *ui = (unsigned int *) (((char *) sbi) + a->u.offset);
2524        unsigned long t;
2525        int ret;
2526
2527        ret = kstrtoul(skip_spaces(buf), 0, &t);
2528        if (ret)
2529                return ret;
2530        *ui = t;
2531        return count;
2532}
2533
2534static ssize_t es_ui_show(struct ext4_attr *a,
2535                           struct ext4_sb_info *sbi, char *buf)
2536{
2537
2538        unsigned int *ui = (unsigned int *) (((char *) sbi->s_es) +
2539                           a->u.offset);
2540
2541        return snprintf(buf, PAGE_SIZE, "%u\n", *ui);
2542}
2543
2544static ssize_t reserved_clusters_show(struct ext4_attr *a,
2545                                  struct ext4_sb_info *sbi, char *buf)
2546{
2547        return snprintf(buf, PAGE_SIZE, "%llu\n",
2548                (unsigned long long) atomic64_read(&sbi->s_resv_clusters));
2549}
2550
2551static ssize_t reserved_clusters_store(struct ext4_attr *a,
2552                                   struct ext4_sb_info *sbi,
2553                                   const char *buf, size_t count)
2554{
2555        unsigned long long val;
2556        int ret;
2557
2558        if (parse_strtoull(buf, -1ULL, &val))
2559                return -EINVAL;
2560        ret = ext4_reserve_clusters(sbi, val);
2561
2562        return ret ? ret : count;
2563}
2564
2565static ssize_t trigger_test_error(struct ext4_attr *a,
2566                                  struct ext4_sb_info *sbi,
2567                                  const char *buf, size_t count)
2568{
2569        int len = count;
2570
2571        if (!capable(CAP_SYS_ADMIN))
2572                return -EPERM;
2573
2574        if (len && buf[len-1] == '\n')
2575                len--;
2576
2577        if (len)
2578                ext4_error(sbi->s_sb, "%.*s", len, buf);
2579        return count;
2580}
2581
2582static ssize_t sbi_deprecated_show(struct ext4_attr *a,
2583                                   struct ext4_sb_info *sbi, char *buf)
2584{
2585        return snprintf(buf, PAGE_SIZE, "%d\n", a->u.deprecated_val);
2586}
2587
2588#define EXT4_ATTR_OFFSET(_name,_mode,_show,_store,_elname) \
2589static struct ext4_attr ext4_attr_##_name = {                   \
2590        .attr = {.name = __stringify(_name), .mode = _mode },   \
2591        .show   = _show,                                        \
2592        .store  = _store,                                       \
2593        .u = {                                                  \
2594                .offset = offsetof(struct ext4_sb_info, _elname),\
2595        },                                                      \
2596}
2597
2598#define EXT4_ATTR_OFFSET_ES(_name,_mode,_show,_store,_elname)           \
2599static struct ext4_attr ext4_attr_##_name = {                           \
2600        .attr = {.name = __stringify(_name), .mode = _mode },           \
2601        .show   = _show,                                                \
2602        .store  = _store,                                               \
2603        .u = {                                                          \
2604                .offset = offsetof(struct ext4_super_block, _elname),   \
2605        },                                                              \
2606}
2607
2608#define EXT4_ATTR(name, mode, show, store) \
2609static struct ext4_attr ext4_attr_##name = __ATTR(name, mode, show, store)
2610
2611#define EXT4_INFO_ATTR(name) EXT4_ATTR(name, 0444, NULL, NULL)
2612#define EXT4_RO_ATTR(name) EXT4_ATTR(name, 0444, name##_show, NULL)
2613#define EXT4_RW_ATTR(name) EXT4_ATTR(name, 0644, name##_show, name##_store)
2614
2615#define EXT4_RO_ATTR_ES_UI(name, elname)        \
2616        EXT4_ATTR_OFFSET_ES(name, 0444, es_ui_show, NULL, elname)
2617#define EXT4_RW_ATTR_SBI_UI(name, elname)       \
2618        EXT4_ATTR_OFFSET(name, 0644, sbi_ui_show, sbi_ui_store, elname)
2619
2620#define ATTR_LIST(name) &ext4_attr_##name.attr
2621#define EXT4_DEPRECATED_ATTR(_name, _val)       \
2622static struct ext4_attr ext4_attr_##_name = {                   \
2623        .attr = {.name = __stringify(_name), .mode = 0444 },    \
2624        .show   = sbi_deprecated_show,                          \
2625        .u = {                                                  \
2626                .deprecated_val = _val,                         \
2627        },                                                      \
2628}
2629
2630EXT4_RO_ATTR(delayed_allocation_blocks);
2631EXT4_RO_ATTR(session_write_kbytes);
2632EXT4_RO_ATTR(lifetime_write_kbytes);
2633EXT4_RW_ATTR(reserved_clusters);
2634EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, sbi_ui_show,
2635                 inode_readahead_blks_store, s_inode_readahead_blks);
2636EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal);
2637EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats);
2638EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan);
2639EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan);
2640EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs);
2641EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request);
2642EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc);
2643EXT4_DEPRECATED_ATTR(max_writeback_mb_bump, 128);
2644EXT4_RW_ATTR_SBI_UI(extent_max_zeroout_kb, s_extent_max_zeroout_kb);
2645EXT4_ATTR(trigger_fs_error, 0200, NULL, trigger_test_error);
2646EXT4_RW_ATTR_SBI_UI(err_ratelimit_interval_ms, s_err_ratelimit_state.interval);
2647EXT4_RW_ATTR_SBI_UI(err_ratelimit_burst, s_err_ratelimit_state.burst);
2648EXT4_RW_ATTR_SBI_UI(warning_ratelimit_interval_ms, s_warning_ratelimit_state.interval);
2649EXT4_RW_ATTR_SBI_UI(warning_ratelimit_burst, s_warning_ratelimit_state.burst);
2650EXT4_RW_ATTR_SBI_UI(msg_ratelimit_interval_ms, s_msg_ratelimit_state.interval);
2651EXT4_RW_ATTR_SBI_UI(msg_ratelimit_burst, s_msg_ratelimit_state.burst);
2652EXT4_RO_ATTR_ES_UI(errors_count, s_error_count);
2653EXT4_RO_ATTR_ES_UI(first_error_time, s_first_error_time);
2654EXT4_RO_ATTR_ES_UI(last_error_time, s_last_error_time);
2655
2656static struct attribute *ext4_attrs[] = {
2657        ATTR_LIST(delayed_allocation_blocks),
2658        ATTR_LIST(session_write_kbytes),
2659        ATTR_LIST(lifetime_write_kbytes),
2660        ATTR_LIST(reserved_clusters),
2661        ATTR_LIST(inode_readahead_blks),
2662        ATTR_LIST(inode_goal),
2663        ATTR_LIST(mb_stats),
2664        ATTR_LIST(mb_max_to_scan),
2665        ATTR_LIST(mb_min_to_scan),
2666        ATTR_LIST(mb_order2_req),
2667        ATTR_LIST(mb_stream_req),
2668        ATTR_LIST(mb_group_prealloc),
2669        ATTR_LIST(max_writeback_mb_bump),
2670        ATTR_LIST(extent_max_zeroout_kb),
2671        ATTR_LIST(trigger_fs_error),
2672        ATTR_LIST(err_ratelimit_interval_ms),
2673        ATTR_LIST(err_ratelimit_burst),
2674        ATTR_LIST(warning_ratelimit_interval_ms),
2675        ATTR_LIST(warning_ratelimit_burst),
2676        ATTR_LIST(msg_ratelimit_interval_ms),
2677        ATTR_LIST(msg_ratelimit_burst),
2678        ATTR_LIST(errors_count),
2679        ATTR_LIST(first_error_time),
2680        ATTR_LIST(last_error_time),
2681        NULL,
2682};
2683
2684/* Features this copy of ext4 supports */
2685EXT4_INFO_ATTR(lazy_itable_init);
2686EXT4_INFO_ATTR(batched_discard);
2687EXT4_INFO_ATTR(meta_bg_resize);
2688
2689static struct attribute *ext4_feat_attrs[] = {
2690        ATTR_LIST(lazy_itable_init),
2691        ATTR_LIST(batched_discard),
2692        ATTR_LIST(meta_bg_resize),
2693        NULL,
2694};
2695
2696static ssize_t ext4_attr_show(struct kobject *kobj,
2697                              struct attribute *attr, char *buf)
2698{
2699        struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2700                                                s_kobj);
2701        struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2702
2703        return a->show ? a->show(a, sbi, buf) : 0;
2704}
2705
2706static ssize_t ext4_attr_store(struct kobject *kobj,
2707                               struct attribute *attr,
2708                               const char *buf, size_t len)
2709{
2710        struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2711                                                s_kobj);
2712        struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2713
2714        return a->store ? a->store(a, sbi, buf, len) : 0;
2715}
2716
2717static void ext4_sb_release(struct kobject *kobj)
2718{
2719        struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2720                                                s_kobj);
2721        complete(&sbi->s_kobj_unregister);
2722}
2723
2724static const struct sysfs_ops ext4_attr_ops = {
2725        .show   = ext4_attr_show,
2726        .store  = ext4_attr_store,
2727};
2728
2729static struct kobj_type ext4_ktype = {
2730        .default_attrs  = ext4_attrs,
2731        .sysfs_ops      = &ext4_attr_ops,
2732        .release        = ext4_sb_release,
2733};
2734
2735static void ext4_feat_release(struct kobject *kobj)
2736{
2737        complete(&ext4_feat->f_kobj_unregister);
2738}
2739
2740static ssize_t ext4_feat_show(struct kobject *kobj,
2741                              struct attribute *attr, char *buf)
2742{
2743        return snprintf(buf, PAGE_SIZE, "supported\n");
2744}
2745
2746/*
2747 * We can not use ext4_attr_show/store because it relies on the kobject
2748 * being embedded in the ext4_sb_info structure which is definitely not
2749 * true in this case.
2750 */
2751static const struct sysfs_ops ext4_feat_ops = {
2752        .show   = ext4_feat_show,
2753        .store  = NULL,
2754};
2755
2756static struct kobj_type ext4_feat_ktype = {
2757        .default_attrs  = ext4_feat_attrs,
2758        .sysfs_ops      = &ext4_feat_ops,
2759        .release        = ext4_feat_release,
2760};
2761
2762/*
2763 * Check whether this filesystem can be mounted based on
2764 * the features present and the RDONLY/RDWR mount requested.
2765 * Returns 1 if this filesystem can be mounted as requested,
2766 * 0 if it cannot be.
2767 */
2768static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2769{
2770        if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT4_FEATURE_INCOMPAT_SUPP)) {
2771                ext4_msg(sb, KERN_ERR,
2772                        "Couldn't mount because of "
2773                        "unsupported optional features (%x)",
2774                        (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2775                        ~EXT4_FEATURE_INCOMPAT_SUPP));
2776                return 0;
2777        }
2778
2779        if (readonly)
2780                return 1;
2781
2782        if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_READONLY)) {
2783                ext4_msg(sb, KERN_INFO, "filesystem is read-only");
2784                sb->s_flags |= MS_RDONLY;
2785                return 1;
2786        }
2787
2788        /* Check that feature set is OK for a read-write mount */
2789        if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT4_FEATURE_RO_COMPAT_SUPP)) {
2790                ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2791                         "unsupported optional features (%x)",
2792                         (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2793                                ~EXT4_FEATURE_RO_COMPAT_SUPP));
2794                return 0;
2795        }
2796        /*
2797         * Large file size enabled file system can only be mounted
2798         * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2799         */
2800        if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) {
2801                if (sizeof(blkcnt_t) < sizeof(u64)) {
2802                        ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2803                                 "cannot be mounted RDWR without "
2804                                 "CONFIG_LBDAF");
2805                        return 0;
2806                }
2807        }
2808        if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_BIGALLOC) &&
2809            !EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)) {
2810                ext4_msg(sb, KERN_ERR,
2811                         "Can't support bigalloc feature without "
2812                         "extents feature\n");
2813                return 0;
2814        }
2815
2816#ifndef CONFIG_QUOTA
2817        if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
2818            !readonly) {
2819                ext4_msg(sb, KERN_ERR,
2820                         "Filesystem with quota feature cannot be mounted RDWR "
2821                         "without CONFIG_QUOTA");
2822                return 0;
2823        }
2824#endif  /* CONFIG_QUOTA */
2825        return 1;
2826}
2827
2828/*
2829 * This function is called once a day if we have errors logged
2830 * on the file system
2831 */
2832static void print_daily_error_info(unsigned long arg)
2833{
2834        struct super_block *sb = (struct super_block *) arg;
2835        struct ext4_sb_info *sbi;
2836        struct ext4_super_block *es;
2837
2838        sbi = EXT4_SB(sb);
2839        es = sbi->s_es;
2840
2841        if (es->s_error_count)
2842                /* fsck newer than v1.41.13 is needed to clean this condition. */
2843                ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
2844                         le32_to_cpu(es->s_error_count));
2845        if (es->s_first_error_time) {
2846                printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %u: %.*s:%d",
2847                       sb->s_id, le32_to_cpu(es->s_first_error_time),
2848                       (int) sizeof(es->s_first_error_func),
2849                       es->s_first_error_func,
2850                       le32_to_cpu(es->s_first_error_line));
2851                if (es->s_first_error_ino)
2852                        printk(": inode %u",
2853                               le32_to_cpu(es->s_first_error_ino));
2854                if (es->s_first_error_block)
2855                        printk(": block %llu", (unsigned long long)
2856                               le64_to_cpu(es->s_first_error_block));
2857                printk("\n");
2858        }
2859        if (es->s_last_error_time) {
2860                printk(KERN_NOTICE "EXT4-fs (%s): last error at time %u: %.*s:%d",
2861                       sb->s_id, le32_to_cpu(es->s_last_error_time),
2862                       (int) sizeof(es->s_last_error_func),
2863                       es->s_last_error_func,
2864                       le32_to_cpu(es->s_last_error_line));
2865                if (es->s_last_error_ino)
2866                        printk(": inode %u",
2867                               le32_to_cpu(es->s_last_error_ino));
2868                if (es->s_last_error_block)
2869                        printk(": block %llu", (unsigned long long)
2870                               le64_to_cpu(es->s_last_error_block));
2871                printk("\n");
2872        }
2873        mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2874}
2875
2876/* Find next suitable group and run ext4_init_inode_table */
2877static int ext4_run_li_request(struct ext4_li_request *elr)
2878{
2879        struct ext4_group_desc *gdp = NULL;
2880        ext4_group_t group, ngroups;
2881        struct super_block *sb;
2882        unsigned long timeout = 0;
2883        int ret = 0;
2884
2885        sb = elr->lr_super;
2886        ngroups = EXT4_SB(sb)->s_groups_count;
2887
2888        sb_start_write(sb);
2889        for (group = elr->lr_next_group; group < ngroups; group++) {
2890                gdp = ext4_get_group_desc(sb, group, NULL);
2891                if (!gdp) {
2892                        ret = 1;
2893                        break;
2894                }
2895
2896                if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2897                        break;
2898        }
2899
2900        if (group >= ngroups)
2901                ret = 1;
2902
2903        if (!ret) {
2904                timeout = jiffies;
2905                ret = ext4_init_inode_table(sb, group,
2906                                            elr->lr_timeout ? 0 : 1);
2907                if (elr->lr_timeout == 0) {
2908                        timeout = (jiffies - timeout) *
2909                                  elr->lr_sbi->s_li_wait_mult;
2910                        elr->lr_timeout = timeout;
2911                }
2912                elr->lr_next_sched = jiffies + elr->lr_timeout;
2913                elr->lr_next_group = group + 1;
2914        }
2915        sb_end_write(sb);
2916
2917        return ret;
2918}
2919
2920/*
2921 * Remove lr_request from the list_request and free the
2922 * request structure. Should be called with li_list_mtx held
2923 */
2924static void ext4_remove_li_request(struct ext4_li_request *elr)
2925{
2926        struct ext4_sb_info *sbi;
2927
2928        if (!elr)
2929                return;
2930
2931        sbi = elr->lr_sbi;
2932
2933        list_del(&elr->lr_request);
2934        sbi->s_li_request = NULL;
2935        kfree(elr);
2936}
2937
2938static void ext4_unregister_li_request(struct super_block *sb)
2939{
2940        mutex_lock(&ext4_li_mtx);
2941        if (!ext4_li_info) {
2942                mutex_unlock(&ext4_li_mtx);
2943                return;
2944        }
2945
2946        mutex_lock(&ext4_li_info->li_list_mtx);
2947        ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
2948        mutex_unlock(&ext4_li_info->li_list_mtx);
2949        mutex_unlock(&ext4_li_mtx);
2950}
2951
2952static struct task_struct *ext4_lazyinit_task;
2953
2954/*
2955 * This is the function where ext4lazyinit thread lives. It walks
2956 * through the request list searching for next scheduled filesystem.
2957 * When such a fs is found, run the lazy initialization request
2958 * (ext4_rn_li_request) and keep track of the time spend in this
2959 * function. Based on that time we compute next schedule time of
2960 * the request. When walking through the list is complete, compute
2961 * next waking time and put itself into sleep.
2962 */
2963static int ext4_lazyinit_thread(void *arg)
2964{
2965        struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
2966        struct list_head *pos, *n;
2967        struct ext4_li_request *elr;
2968        unsigned long next_wakeup, cur;
2969
2970        BUG_ON(NULL == eli);
2971
2972cont_thread:
2973        while (true) {
2974                next_wakeup = MAX_JIFFY_OFFSET;
2975
2976                mutex_lock(&eli->li_list_mtx);
2977                if (list_empty(&eli->li_request_list)) {
2978                        mutex_unlock(&eli->li_list_mtx);
2979                        goto exit_thread;
2980                }
2981
2982                list_for_each_safe(pos, n, &eli->li_request_list) {
2983                        elr = list_entry(pos, struct ext4_li_request,
2984                                         lr_request);
2985
2986                        if (time_after_eq(jiffies, elr->lr_next_sched)) {
2987                                if (ext4_run_li_request(elr) != 0) {
2988                                        /* error, remove the lazy_init job */
2989                                        ext4_remove_li_request(elr);
2990                                        continue;
2991                                }
2992                        }
2993
2994                        if (time_before(elr->lr_next_sched, next_wakeup))
2995                                next_wakeup = elr->lr_next_sched;
2996                }
2997                mutex_unlock(&eli->li_list_mtx);
2998
2999                try_to_freeze();
3000
3001                cur = jiffies;
3002                if ((time_after_eq(cur, next_wakeup)) ||
3003                    (MAX_JIFFY_OFFSET == next_wakeup)) {
3004                        cond_resched();
3005                        continue;
3006                }
3007
3008                schedule_timeout_interruptible(next_wakeup - cur);
3009
3010                if (kthread_should_stop()) {
3011                        ext4_clear_request_list();
3012                        goto exit_thread;
3013                }
3014        }
3015
3016exit_thread:
3017        /*
3018         * It looks like the request list is empty, but we need
3019         * to check it under the li_list_mtx lock, to prevent any
3020         * additions into it, and of course we should lock ext4_li_mtx
3021         * to atomically free the list and ext4_li_info, because at
3022         * this point another ext4 filesystem could be registering
3023         * new one.
3024         */
3025        mutex_lock(&ext4_li_mtx);
3026        mutex_lock(&eli->li_list_mtx);
3027        if (!list_empty(&eli->li_request_list)) {
3028                mutex_unlock(&eli->li_list_mtx);
3029                mutex_unlock(&ext4_li_mtx);
3030                goto cont_thread;
3031        }
3032        mutex_unlock(&eli->li_list_mtx);
3033        kfree(ext4_li_info);
3034        ext4_li_info = NULL;
3035        mutex_unlock(&ext4_li_mtx);
3036
3037        return 0;
3038}
3039
3040static void ext4_clear_request_list(void)
3041{
3042        struct list_head *pos, *n;
3043        struct ext4_li_request *elr;
3044
3045        mutex_lock(&ext4_li_info->li_list_mtx);
3046        list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
3047                elr = list_entry(pos, struct ext4_li_request,
3048                                 lr_request);
3049                ext4_remove_li_request(elr);
3050        }
3051        mutex_unlock(&ext4_li_info->li_list_mtx);
3052}
3053
3054static int ext4_run_lazyinit_thread(void)
3055{
3056        ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
3057                                         ext4_li_info, "ext4lazyinit");
3058        if (IS_ERR(ext4_lazyinit_task)) {
3059                int err = PTR_ERR(ext4_lazyinit_task);
3060                ext4_clear_request_list();
3061                kfree(ext4_li_info);
3062                ext4_li_info = NULL;
3063                printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
3064                                 "initialization thread\n",
3065                                 err);
3066                return err;
3067        }
3068        ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
3069        return 0;
3070}
3071
3072/*
3073 * Check whether it make sense to run itable init. thread or not.
3074 * If there is at least one uninitialized inode table, return
3075 * corresponding group number, else the loop goes through all
3076 * groups and return total number of groups.
3077 */
3078static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3079{
3080        ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3081        struct ext4_group_desc *gdp = NULL;
3082
3083        for (group = 0; group < ngroups; group++) {
3084                gdp = ext4_get_group_desc(sb, group, NULL);
3085                if (!gdp)
3086                        continue;
3087
3088                if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3089                        break;
3090        }
3091
3092        return group;
3093}
3094
3095static int ext4_li_info_new(void)
3096{
3097        struct ext4_lazy_init *eli = NULL;
3098
3099        eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3100        if (!eli)
3101                return -ENOMEM;
3102
3103        INIT_LIST_HEAD(&eli->li_request_list);
3104        mutex_init(&eli->li_list_mtx);
3105
3106        eli->li_state |= EXT4_LAZYINIT_QUIT;
3107
3108        ext4_li_info = eli;
3109
3110        return 0;
3111}
3112
3113static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3114                                            ext4_group_t start)
3115{
3116        struct ext4_sb_info *sbi = EXT4_SB(sb);
3117        struct ext4_li_request *elr;
3118
3119        elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3120        if (!elr)
3121                return NULL;
3122
3123        elr->lr_super = sb;
3124        elr->lr_sbi = sbi;
3125        elr->lr_next_group = start;
3126
3127        /*
3128         * Randomize first schedule time of the request to
3129         * spread the inode table initialization requests
3130         * better.
3131         */
3132        elr->lr_next_sched = jiffies + (prandom_u32() %
3133                                (EXT4_DEF_LI_MAX_START_DELAY * HZ));
3134        return elr;
3135}
3136
3137int ext4_register_li_request(struct super_block *sb,
3138                             ext4_group_t first_not_zeroed)
3139{
3140        struct ext4_sb_info *sbi = EXT4_SB(sb);
3141        struct ext4_li_request *elr = NULL;
3142        ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
3143        int ret = 0;
3144
3145        mutex_lock(&ext4_li_mtx);
3146        if (sbi->s_li_request != NULL) {
3147                /*
3148                 * Reset timeout so it can be computed again, because
3149                 * s_li_wait_mult might have changed.
3150                 */
3151                sbi->s_li_request->lr_timeout = 0;
3152                goto out;
3153        }
3154
3155        if (first_not_zeroed == ngroups ||
3156            (sb->s_flags & MS_RDONLY) ||
3157            !test_opt(sb, INIT_INODE_TABLE))
3158                goto out;
3159
3160        elr = ext4_li_request_new(sb, first_not_zeroed);
3161        if (!elr) {
3162                ret = -ENOMEM;
3163                goto out;
3164        }
3165
3166        if (NULL == ext4_li_info) {
3167                ret = ext4_li_info_new();
3168                if (ret)
3169                        goto out;
3170        }
3171
3172        mutex_lock(&ext4_li_info->li_list_mtx);
3173        list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3174        mutex_unlock(&ext4_li_info->li_list_mtx);
3175
3176        sbi->s_li_request = elr;
3177        /*
3178         * set elr to NULL here since it has been inserted to
3179         * the request_list and the removal and free of it is
3180         * handled by ext4_clear_request_list from now on.
3181         */
3182        elr = NULL;
3183
3184        if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3185                ret = ext4_run_lazyinit_thread();
3186                if (ret)
3187                        goto out;
3188        }
3189out:
3190        mutex_unlock(&ext4_li_mtx);
3191        if (ret)
3192                kfree(elr);
3193        return ret;
3194}
3195
3196/*
3197 * We do not need to lock anything since this is called on
3198 * module unload.
3199 */
3200static void ext4_destroy_lazyinit_thread(void)
3201{
3202        /*
3203         * If thread exited earlier
3204         * there's nothing to be done.
3205         */
3206        if (!ext4_li_info || !ext4_lazyinit_task)
3207                return;
3208
3209        kthread_stop(ext4_lazyinit_task);
3210}
3211
3212static int set_journal_csum_feature_set(struct super_block *sb)
3213{
3214        int ret = 1;
3215        int compat, incompat;
3216        struct ext4_sb_info *sbi = EXT4_SB(sb);
3217
3218        if (ext4_has_metadata_csum(sb)) {
3219                /* journal checksum v3 */
3220                compat = 0;
3221                incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
3222        } else {
3223                /* journal checksum v1 */
3224                compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3225                incompat = 0;
3226        }
3227
3228        jbd2_journal_clear_features(sbi->s_journal,
3229                        JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3230                        JBD2_FEATURE_INCOMPAT_CSUM_V3 |
3231                        JBD2_FEATURE_INCOMPAT_CSUM_V2);
3232        if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3233                ret = jbd2_journal_set_features(sbi->s_journal,
3234                                compat, 0,
3235                                JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3236                                incompat);
3237        } else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3238                ret = jbd2_journal_set_features(sbi->s_journal,
3239                                compat, 0,
3240                                incompat);
3241                jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3242                                JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3243        } else {
3244                jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3245                                JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3246        }
3247
3248        return ret;
3249}
3250
3251/*
3252 * Note: calculating the overhead so we can be compatible with
3253 * historical BSD practice is quite difficult in the face of
3254 * clusters/bigalloc.  This is because multiple metadata blocks from
3255 * different block group can end up in the same allocation cluster.
3256 * Calculating the exact overhead in the face of clustered allocation
3257 * requires either O(all block bitmaps) in memory or O(number of block
3258 * groups**2) in time.  We will still calculate the superblock for
3259 * older file systems --- and if we come across with a bigalloc file
3260 * system with zero in s_overhead_clusters the estimate will be close to
3261 * correct especially for very large cluster sizes --- but for newer
3262 * file systems, it's better to calculate this figure once at mkfs
3263 * time, and store it in the superblock.  If the superblock value is
3264 * present (even for non-bigalloc file systems), we will use it.
3265 */
3266static int count_overhead(struct super_block *sb, ext4_group_t grp,
3267                          char *buf)
3268{
3269        struct ext4_sb_info     *sbi = EXT4_SB(sb);
3270        struct ext4_group_desc  *gdp;
3271        ext4_fsblk_t            first_block, last_block, b;
3272        ext4_group_t            i, ngroups = ext4_get_groups_count(sb);
3273        int                     s, j, count = 0;
3274
3275        if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_BIGALLOC))
3276                return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3277                        sbi->s_itb_per_group + 2);
3278
3279        first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3280                (grp * EXT4_BLOCKS_PER_GROUP(sb));
3281        last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3282        for (i = 0; i < ngroups; i++) {
3283                gdp = ext4_get_group_desc(sb, i, NULL);
3284                b = ext4_block_bitmap(sb, gdp);
3285                if (b >= first_block && b <= last_block) {
3286                        ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3287                        count++;
3288                }
3289                b = ext4_inode_bitmap(sb, gdp);
3290                if (b >= first_block && b <= last_block) {
3291                        ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3292                        count++;
3293                }
3294                b = ext4_inode_table(sb, gdp);
3295                if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3296                        for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3297                                int c = EXT4_B2C(sbi, b - first_block);
3298                                ext4_set_bit(c, buf);
3299                                count++;
3300                        }
3301                if (i != grp)
3302                        continue;
3303                s = 0;
3304                if (ext4_bg_has_super(sb, grp)) {
3305                        ext4_set_bit(s++, buf);
3306                        count++;
3307                }
3308                for (j = ext4_bg_num_gdb(sb, grp); j > 0; j--) {
3309                        ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3310                        count++;
3311                }
3312        }
3313        if (!count)
3314                return 0;
3315        return EXT4_CLUSTERS_PER_GROUP(sb) -
3316                ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3317}
3318
3319/*
3320 * Compute the overhead and stash it in sbi->s_overhead
3321 */
3322int ext4_calculate_overhead(struct super_block *sb)
3323{
3324        struct ext4_sb_info *sbi = EXT4_SB(sb);
3325        struct ext4_super_block *es = sbi->s_es;
3326        ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3327        ext4_fsblk_t overhead = 0;
3328        char *buf = (char *) get_zeroed_page(GFP_NOFS);
3329
3330        if (!buf)
3331                return -ENOMEM;
3332
3333        /*
3334         * Compute the overhead (FS structures).  This is constant
3335         * for a given filesystem unless the number of block groups
3336         * changes so we cache the previous value until it does.
3337         */
3338
3339        /*
3340         * All of the blocks before first_data_block are overhead
3341         */
3342        overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3343
3344        /*
3345         * Add the overhead found in each block group
3346         */
3347        for (i = 0; i < ngroups; i++) {
3348                int blks;
3349
3350                blks = count_overhead(sb, i, buf);
3351                overhead += blks;
3352                if (blks)
3353                        memset(buf, 0, PAGE_SIZE);
3354                cond_resched();
3355        }
3356        /* Add the internal journal blocks as well */
3357        if (sbi->s_journal && !sbi->journal_bdev)
3358                overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_maxlen);
3359
3360        sbi->s_overhead = overhead;
3361        smp_wmb();
3362        free_page((unsigned long) buf);
3363        return 0;
3364}
3365
3366
3367static ext4_fsblk_t ext4_calculate_resv_clusters(struct super_block *sb)
3368{
3369        ext4_fsblk_t resv_clusters;
3370
3371        /*
3372         * There's no need to reserve anything when we aren't using extents.
3373         * The space estimates are exact, there are no unwritten extents,
3374         * hole punching doesn't need new metadata... This is needed especially
3375         * to keep ext2/3 backward compatibility.
3376         */
3377        if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS))
3378                return 0;
3379        /*
3380         * By default we reserve 2% or 4096 clusters, whichever is smaller.
3381         * This should cover the situations where we can not afford to run
3382         * out of space like for example punch hole, or converting
3383         * unwritten extents in delalloc path. In most cases such
3384         * allocation would require 1, or 2 blocks, higher numbers are
3385         * very rare.
3386         */
3387        resv_clusters = ext4_blocks_count(EXT4_SB(sb)->s_es) >>
3388                        EXT4_SB(sb)->s_cluster_bits;
3389
3390        do_div(resv_clusters, 50);
3391        resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
3392
3393        return resv_clusters;
3394}
3395
3396
3397static int ext4_reserve_clusters(struct ext4_sb_info *sbi, ext4_fsblk_t count)
3398{
3399        ext4_fsblk_t clusters = ext4_blocks_count(sbi->s_es) >>
3400                                sbi->s_cluster_bits;
3401
3402        if (count >= clusters)
3403                return -EINVAL;
3404
3405        atomic64_set(&sbi->s_resv_clusters, count);
3406        return 0;
3407}
3408
3409static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3410{
3411        char *orig_data = kstrdup(data, GFP_KERNEL);
3412        struct buffer_head *bh;
3413        struct ext4_super_block *es = NULL;
3414        struct ext4_sb_info *sbi;
3415        ext4_fsblk_t block;
3416        ext4_fsblk_t sb_block = get_sb_block(&data);
3417        ext4_fsblk_t logical_sb_block;
3418        unsigned long offset = 0;
3419        unsigned long journal_devnum = 0;
3420        unsigned long def_mount_opts;
3421        struct inode *root;
3422        char *cp;
3423        const char *descr;
3424        int ret = -ENOMEM;
3425        int blocksize, clustersize;
3426        unsigned int db_count;
3427        unsigned int i;
3428        int needs_recovery, has_huge_files, has_bigalloc;
3429        __u64 blocks_count;
3430        int err = 0;
3431        unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3432        ext4_group_t first_not_zeroed;
3433
3434        sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3435        if (!sbi)
3436                goto out_free_orig;
3437
3438        sbi->s_blockgroup_lock =
3439                kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3440        if (!sbi->s_blockgroup_lock) {
3441                kfree(sbi);
3442                goto out_free_orig;
3443        }
3444        sb->s_fs_info = sbi;
3445        sbi->s_sb = sb;
3446        sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3447        sbi->s_sb_block = sb_block;
3448        if (sb->s_bdev->bd_part)
3449                sbi->s_sectors_written_start =
3450                        part_stat_read(sb->s_bdev->bd_part, sectors[1]);
3451
3452        /* Cleanup superblock name */
3453        for (cp = sb->s_id; (cp = strchr(cp, '/'));)
3454                *cp = '!';
3455
3456        /* -EINVAL is default */
3457        ret = -EINVAL;
3458        blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3459        if (!blocksize) {
3460                ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3461                goto out_fail;
3462        }
3463
3464        /*
3465         * The ext4 superblock will not be buffer aligned for other than 1kB
3466         * block sizes.  We need to calculate the offset from buffer start.
3467         */
3468        if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3469                logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3470                offset = do_div(logical_sb_block, blocksize);
3471        } else {
3472                logical_sb_block = sb_block;
3473        }
3474
3475        if (!(bh = sb_bread_unmovable(sb, logical_sb_block))) {
3476                ext4_msg(sb, KERN_ERR, "unable to read superblock");
3477                goto out_fail;
3478        }
3479        /*
3480         * Note: s_es must be initialized as soon as possible because
3481         *       some ext4 macro-instructions depend on its value
3482         */
3483        es = (struct ext4_super_block *) (bh->b_data + offset);
3484        sbi->s_es = es;
3485        sb->s_magic = le16_to_cpu(es->s_magic);
3486        if (sb->s_magic != EXT4_SUPER_MAGIC)
3487                goto cantfind_ext4;
3488        sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3489
3490        /* Warn if metadata_csum and gdt_csum are both set. */
3491        if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3492                                       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
3493            EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_GDT_CSUM))
3494                ext4_warning(sb, "metadata_csum and uninit_bg are "
3495                             "redundant flags; please run fsck.");
3496
3497        /* Check for a known checksum algorithm */
3498        if (!ext4_verify_csum_type(sb, es)) {
3499                ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3500                         "unknown checksum algorithm.");
3501                silent = 1;
3502                goto cantfind_ext4;
3503        }
3504
3505        /* Load the checksum driver */
3506        if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3507                                       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
3508                sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3509                if (IS_ERR(sbi->s_chksum_driver)) {
3510                        ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3511                        ret = PTR_ERR(sbi->s_chksum_driver);
3512                        sbi->s_chksum_driver = NULL;
3513                        goto failed_mount;
3514                }
3515        }
3516
3517        /* Check superblock checksum */
3518        if (!ext4_superblock_csum_verify(sb, es)) {
3519                ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3520                         "invalid superblock checksum.  Run e2fsck?");
3521                silent = 1;
3522                goto cantfind_ext4;
3523        }
3524
3525        /* Precompute checksum seed for all metadata */
3526        if (ext4_has_metadata_csum(sb))
3527                sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3528                                               sizeof(es->s_uuid));
3529
3530        /* Set defaults before we parse the mount options */
3531        def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3532        set_opt(sb, INIT_INODE_TABLE);
3533        if (def_mount_opts & EXT4_DEFM_DEBUG)
3534                set_opt(sb, DEBUG);
3535        if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3536                set_opt(sb, GRPID);
3537        if (def_mount_opts & EXT4_DEFM_UID16)
3538                set_opt(sb, NO_UID32);
3539        /* xattr user namespace & acls are now defaulted on */
3540        set_opt(sb, XATTR_USER);
3541#ifdef CONFIG_EXT4_FS_POSIX_ACL
3542        set_opt(sb, POSIX_ACL);
3543#endif
3544        /* don't forget to enable journal_csum when metadata_csum is enabled. */
3545        if (ext4_has_metadata_csum(sb))
3546                set_opt(sb, JOURNAL_CHECKSUM);
3547
3548        if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3549                set_opt(sb, JOURNAL_DATA);
3550        else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3551                set_opt(sb, ORDERED_DATA);
3552        else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3553                set_opt(sb, WRITEBACK_DATA);
3554
3555        if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3556                set_opt(sb, ERRORS_PANIC);
3557        else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3558                set_opt(sb, ERRORS_CONT);
3559        else
3560                set_opt(sb, ERRORS_RO);
3561        /* block_validity enabled by default; disable with noblock_validity */
3562        set_opt(sb, BLOCK_VALIDITY);
3563        if (def_mount_opts & EXT4_DEFM_DISCARD)
3564                set_opt(sb, DISCARD);
3565
3566        sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3567        sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3568        sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3569        sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3570        sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3571
3572        if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3573                set_opt(sb, BARRIER);
3574
3575        /*
3576         * enable delayed allocation by default
3577         * Use -o nodelalloc to turn it off
3578         */
3579        if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
3580            ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3581                set_opt(sb, DELALLOC);
3582
3583        /*
3584         * set default s_li_wait_mult for lazyinit, for the case there is
3585         * no mount option specified.
3586         */
3587        sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3588
3589        if (!parse_options((char *) sbi->s_es->s_mount_opts, sb,
3590                           &journal_devnum, &journal_ioprio, 0)) {
3591                ext4_msg(sb, KERN_WARNING,
3592                         "failed to parse options in superblock: %s",
3593                         sbi->s_es->s_mount_opts);
3594        }
3595        sbi->s_def_mount_opt = sbi->s_mount_opt;
3596        if (!parse_options((char *) data, sb, &journal_devnum,
3597                           &journal_ioprio, 0))
3598                goto failed_mount;
3599
3600        if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3601                printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3602                            "with data=journal disables delayed "
3603                            "allocation and O_DIRECT support!\n");
3604                if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3605                        ext4_msg(sb, KERN_ERR, "can't mount with "
3606                                 "both data=journal and delalloc");
3607                        goto failed_mount;
3608                }
3609                if (test_opt(sb, DIOREAD_NOLOCK)) {
3610                        ext4_msg(sb, KERN_ERR, "can't mount with "
3611                                 "both data=journal and dioread_nolock");
3612                        goto failed_mount;
3613                }
3614                if (test_opt(sb, DAX)) {
3615                        ext4_msg(sb, KERN_ERR, "can't mount with "
3616                                 "both data=journal and dax");
3617                        goto failed_mount;
3618                }
3619                if (test_opt(sb, DELALLOC))
3620                        clear_opt(sb, DELALLOC);
3621        }
3622
3623        sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
3624                (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
3625
3626        if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3627            (EXT4_HAS_COMPAT_FEATURE(sb, ~0U) ||
3628             EXT4_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
3629             EXT4_HAS_INCOMPAT_FEATURE(sb, ~0U)))
3630                ext4_msg(sb, KERN_WARNING,
3631                       "feature flags set on rev 0 fs, "
3632                       "running e2fsck is recommended");
3633
3634        if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
3635                set_opt2(sb, HURD_COMPAT);
3636                if (EXT4_HAS_INCOMPAT_FEATURE(sb,
3637                                              EXT4_FEATURE_INCOMPAT_64BIT)) {
3638                        ext4_msg(sb, KERN_ERR,
3639                                 "The Hurd can't support 64-bit file systems");
3640                        goto failed_mount;
3641                }
3642        }
3643
3644        if (IS_EXT2_SB(sb)) {
3645                if (ext2_feature_set_ok(sb))
3646                        ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3647                                 "using the ext4 subsystem");
3648                else {
3649                        ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3650                                 "to feature incompatibilities");
3651                        goto failed_mount;
3652                }
3653        }
3654
3655        if (IS_EXT3_SB(sb)) {
3656                if (ext3_feature_set_ok(sb))
3657                        ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3658                                 "using the ext4 subsystem");
3659                else {
3660                        ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3661                                 "to feature incompatibilities");
3662                        goto failed_mount;
3663                }
3664        }
3665
3666        /*
3667         * Check feature flags regardless of the revision level, since we
3668         * previously didn't change the revision level when setting the flags,
3669         * so there is a chance incompat flags are set on a rev 0 filesystem.
3670         */
3671        if (!ext4_feature_set_ok(sb, (sb->s_flags & MS_RDONLY)))
3672                goto failed_mount;
3673
3674        blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3675        if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3676            blocksize > EXT4_MAX_BLOCK_SIZE) {
3677                ext4_msg(sb, KERN_ERR,
3678                       "Unsupported filesystem blocksize %d", blocksize);
3679                goto failed_mount;
3680        }
3681
3682        if (sbi->s_mount_opt & EXT4_MOUNT_DAX) {
3683                if (blocksize != PAGE_SIZE) {
3684                        ext4_msg(sb, KERN_ERR,
3685                                        "error: unsupported blocksize for dax");
3686                        goto failed_mount;
3687                }
3688                if (!sb->s_bdev->bd_disk->fops->direct_access) {
3689                        ext4_msg(sb, KERN_ERR,
3690                                        "error: device does not support dax");
3691                        goto failed_mount;
3692                }
3693        }
3694
3695        if (sb->s_blocksize != blocksize) {
3696                /* Validate the filesystem blocksize */
3697                if (!sb_set_blocksize(sb, blocksize)) {
3698                        ext4_msg(sb, KERN_ERR, "bad block size %d",
3699                                        blocksize);
3700                        goto failed_mount;
3701                }
3702
3703                brelse(bh);
3704                logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3705                offset = do_div(logical_sb_block, blocksize);
3706                bh = sb_bread_unmovable(sb, logical_sb_block);
3707                if (!bh) {
3708                        ext4_msg(sb, KERN_ERR,
3709                               "Can't read superblock on 2nd try");
3710                        goto failed_mount;
3711                }
3712                es = (struct ext4_super_block *)(bh->b_data + offset);
3713                sbi->s_es = es;
3714                if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
3715                        ext4_msg(sb, KERN_ERR,
3716                               "Magic mismatch, very weird!");
3717                        goto failed_mount;
3718                }
3719        }
3720
3721        has_huge_files = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3722                                EXT4_FEATURE_RO_COMPAT_HUGE_FILE);
3723        sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
3724                                                      has_huge_files);
3725        sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
3726
3727        if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3728                sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3729                sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3730        } else {
3731                sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3732                sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3733                if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3734                    (!is_power_of_2(sbi->s_inode_size)) ||
3735                    (sbi->s_inode_size > blocksize)) {
3736                        ext4_msg(sb, KERN_ERR,
3737                               "unsupported inode size: %d",
3738                               sbi->s_inode_size);
3739                        goto failed_mount;
3740                }
3741                if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
3742                        sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
3743        }
3744
3745        sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
3746        if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT)) {
3747                if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
3748                    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
3749                    !is_power_of_2(sbi->s_desc_size)) {
3750                        ext4_msg(sb, KERN_ERR,
3751                               "unsupported descriptor size %lu",
3752                               sbi->s_desc_size);
3753                        goto failed_mount;
3754                }
3755        } else
3756                sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
3757
3758        sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
3759        sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
3760        if (EXT4_INODE_SIZE(sb) == 0 || EXT4_INODES_PER_GROUP(sb) == 0)
3761                goto cantfind_ext4;
3762
3763        sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
3764        if (sbi->s_inodes_per_block == 0)
3765                goto cantfind_ext4;
3766        sbi->s_itb_per_group = sbi->s_inodes_per_group /
3767                                        sbi->s_inodes_per_block;
3768        sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
3769        sbi->s_sbh = bh;
3770        sbi->s_mount_state = le16_to_cpu(es->s_state);
3771        sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
3772        sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
3773
3774        for (i = 0; i < 4; i++)
3775                sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
3776        sbi->s_def_hash_version = es->s_def_hash_version;
3777        if (EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_DIR_INDEX)) {
3778                i = le32_to_cpu(es->s_flags);
3779                if (i & EXT2_FLAGS_UNSIGNED_HASH)
3780                        sbi->s_hash_unsigned = 3;
3781                else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
3782#ifdef __CHAR_UNSIGNED__
3783                        if (!(sb->s_flags & MS_RDONLY))
3784                                es->s_flags |=
3785                                        cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
3786                        sbi->s_hash_unsigned = 3;
3787#else
3788                        if (!(sb->s_flags & MS_RDONLY))
3789                                es->s_flags |=
3790                                        cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
3791#endif
3792                }
3793        }
3794
3795        /* Handle clustersize */
3796        clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
3797        has_bigalloc = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3798                                EXT4_FEATURE_RO_COMPAT_BIGALLOC);
3799        if (has_bigalloc) {
3800                if (clustersize < blocksize) {
3801                        ext4_msg(sb, KERN_ERR,
3802                                 "cluster size (%d) smaller than "
3803                                 "block size (%d)", clustersize, blocksize);
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        sbi->s_group_desc = ext4_kvmalloc(db_count *
3909                                          sizeof(struct buffer_head *),
3910                                          GFP_KERNEL);
3911        if (sbi->s_group_desc == NULL) {
3912                ext4_msg(sb, KERN_ERR, "not enough memory");
3913                ret = -ENOMEM;
3914                goto failed_mount;
3915        }
3916
3917        if (ext4_proc_root)
3918                sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root);
3919
3920        if (sbi->s_proc)
3921                proc_create_data("options", S_IRUGO, sbi->s_proc,
3922                                 &ext4_seq_options_fops, sb);
3923
3924        bgl_lock_init(sbi->s_blockgroup_lock);
3925
3926        for (i = 0; i < db_count; i++) {
3927                block = descriptor_loc(sb, logical_sb_block, i);
3928                sbi->s_group_desc[i] = sb_bread_unmovable(sb, block);
3929                if (!sbi->s_group_desc[i]) {
3930                        ext4_msg(sb, KERN_ERR,
3931                               "can't read group descriptor %d", i);
3932                        db_count = i;
3933                        goto failed_mount2;
3934                }
3935        }
3936        if (!ext4_check_descriptors(sb, &first_not_zeroed)) {
3937                ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
3938                goto failed_mount2;
3939        }
3940
3941        sbi->s_gdb_count = db_count;
3942        get_random_bytes(&sbi->s_next_generation, sizeof(u32));
3943        spin_lock_init(&sbi->s_next_gen_lock);
3944
3945        setup_timer(&sbi->s_err_report, print_daily_error_info,
3946                (unsigned long) sb);
3947
3948        /* Register extent status tree shrinker */
3949        if (ext4_es_register_shrinker(sbi))
3950                goto failed_mount3;
3951
3952        sbi->s_stripe = ext4_get_stripe_size(sbi);
3953        sbi->s_extent_max_zeroout_kb = 32;
3954
3955        /*
3956         * set up enough so that it can read an inode
3957         */
3958        sb->s_op = &ext4_sops;
3959        sb->s_export_op = &ext4_export_ops;
3960        sb->s_xattr = ext4_xattr_handlers;
3961#ifdef CONFIG_QUOTA
3962        sb->dq_op = &ext4_quota_operations;
3963        if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
3964                sb->s_qcop = &dquot_quotactl_sysfile_ops;
3965        else
3966                sb->s_qcop = &ext4_qctl_operations;
3967        sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP;
3968#endif
3969        memcpy(sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
3970
3971        INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
3972        mutex_init(&sbi->s_orphan_lock);
3973
3974        sb->s_root = NULL;
3975
3976        needs_recovery = (es->s_last_orphan != 0 ||
3977                          EXT4_HAS_INCOMPAT_FEATURE(sb,
3978                                    EXT4_FEATURE_INCOMPAT_RECOVER));
3979
3980        if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_MMP) &&
3981            !(sb->s_flags & MS_RDONLY))
3982                if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
3983                        goto failed_mount3a;
3984
3985        /*
3986         * The first inode we look at is the journal inode.  Don't try
3987         * root first: it may be modified in the journal!
3988         */
3989        if (!test_opt(sb, NOLOAD) &&
3990            EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
3991                if (ext4_load_journal(sb, es, journal_devnum))
3992                        goto failed_mount3a;
3993        } else if (test_opt(sb, NOLOAD) && !(sb->s_flags & MS_RDONLY) &&
3994              EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
3995                ext4_msg(sb, KERN_ERR, "required journal recovery "
3996                       "suppressed and not mounted read-only");
3997                goto failed_mount_wq;
3998        } else {
3999                clear_opt(sb, DATA_FLAGS);
4000                sbi->s_journal = NULL;
4001                needs_recovery = 0;
4002                goto no_journal;
4003        }
4004
4005        if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT) &&
4006            !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4007                                       JBD2_FEATURE_INCOMPAT_64BIT)) {
4008                ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
4009                goto failed_mount_wq;
4010        }
4011
4012        if (!set_journal_csum_feature_set(sb)) {
4013                ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
4014                         "feature set");
4015                goto failed_mount_wq;
4016        }
4017
4018        /* We have now updated the journal if required, so we can
4019         * validate the data journaling mode. */
4020        switch (test_opt(sb, DATA_FLAGS)) {
4021        case 0:
4022                /* No mode set, assume a default based on the journal
4023                 * capabilities: ORDERED_DATA if the journal can
4024                 * cope, else JOURNAL_DATA
4025                 */
4026                if (jbd2_journal_check_available_features
4027                    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
4028                        set_opt(sb, ORDERED_DATA);
4029                else
4030                        set_opt(sb, JOURNAL_DATA);
4031                break;
4032
4033        case EXT4_MOUNT_ORDERED_DATA:
4034        case EXT4_MOUNT_WRITEBACK_DATA:
4035                if (!jbd2_journal_check_available_features
4036                    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4037                        ext4_msg(sb, KERN_ERR, "Journal does not support "
4038                               "requested data journaling mode");
4039                        goto failed_mount_wq;
4040                }
4041        default:
4042                break;
4043        }
4044        set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4045
4046        sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
4047
4048no_journal:
4049        if (ext4_mballoc_ready) {
4050                sbi->s_mb_cache = ext4_xattr_create_cache(sb->s_id);
4051                if (!sbi->s_mb_cache) {
4052                        ext4_msg(sb, KERN_ERR, "Failed to create an mb_cache");
4053                        goto failed_mount_wq;
4054                }
4055        }
4056
4057        /*
4058         * Get the # of file system overhead blocks from the
4059         * superblock if present.
4060         */
4061        if (es->s_overhead_clusters)
4062                sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
4063        else {
4064                err = ext4_calculate_overhead(sb);
4065                if (err)
4066                        goto failed_mount_wq;
4067        }
4068
4069        /*
4070         * The maximum number of concurrent works can be high and
4071         * concurrency isn't really necessary.  Limit it to 1.
4072         */
4073        EXT4_SB(sb)->rsv_conversion_wq =
4074                alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
4075        if (!EXT4_SB(sb)->rsv_conversion_wq) {
4076                printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
4077                ret = -ENOMEM;
4078                goto failed_mount4;
4079        }
4080
4081        /*
4082         * The jbd2_journal_load will have done any necessary log recovery,
4083         * so we can safely mount the rest of the filesystem now.
4084         */
4085
4086        root = ext4_iget(sb, EXT4_ROOT_INO);
4087        if (IS_ERR(root)) {
4088                ext4_msg(sb, KERN_ERR, "get root inode failed");
4089                ret = PTR_ERR(root);
4090                root = NULL;
4091                goto failed_mount4;
4092        }
4093        if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
4094                ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
4095                iput(root);
4096                goto failed_mount4;
4097        }
4098        sb->s_root = d_make_root(root);
4099        if (!sb->s_root) {
4100                ext4_msg(sb, KERN_ERR, "get root dentry failed");
4101                ret = -ENOMEM;
4102                goto failed_mount4;
4103        }
4104
4105        if (ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY))
4106                sb->s_flags |= MS_RDONLY;
4107
4108        /* determine the minimum size of new large inodes, if present */
4109        if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
4110                sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4111                                                     EXT4_GOOD_OLD_INODE_SIZE;
4112                if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
4113                                       EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE)) {
4114                        if (sbi->s_want_extra_isize <
4115                            le16_to_cpu(es->s_want_extra_isize))
4116                                sbi->s_want_extra_isize =
4117                                        le16_to_cpu(es->s_want_extra_isize);
4118                        if (sbi->s_want_extra_isize <
4119                            le16_to_cpu(es->s_min_extra_isize))
4120                                sbi->s_want_extra_isize =
4121                                        le16_to_cpu(es->s_min_extra_isize);
4122                }
4123        }
4124        /* Check if enough inode space is available */
4125        if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
4126                                                        sbi->s_inode_size) {
4127                sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4128                                                       EXT4_GOOD_OLD_INODE_SIZE;
4129                ext4_msg(sb, KERN_INFO, "required extra inode space not"
4130                         "available");
4131        }
4132
4133        err = ext4_reserve_clusters(sbi, ext4_calculate_resv_clusters(sb));
4134        if (err) {
4135                ext4_msg(sb, KERN_ERR, "failed to reserve %llu clusters for "
4136                         "reserved pool", ext4_calculate_resv_clusters(sb));
4137                goto failed_mount4a;
4138        }
4139
4140        err = ext4_setup_system_zone(sb);
4141        if (err) {
4142                ext4_msg(sb, KERN_ERR, "failed to initialize system "
4143                         "zone (%d)", err);
4144                goto failed_mount4a;
4145        }
4146
4147        ext4_ext_init(sb);
4148        err = ext4_mb_init(sb);
4149        if (err) {
4150                ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
4151                         err);
4152                goto failed_mount5;
4153        }
4154
4155        block = ext4_count_free_clusters(sb);
4156        ext4_free_blocks_count_set(sbi->s_es, 
4157                                   EXT4_C2B(sbi, block));
4158        err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
4159                                  GFP_KERNEL);
4160        if (!err) {
4161                unsigned long freei = ext4_count_free_inodes(sb);
4162                sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
4163                err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
4164                                          GFP_KERNEL);
4165        }
4166        if (!err)
4167                err = percpu_counter_init(&sbi->s_dirs_counter,
4168                                          ext4_count_dirs(sb), GFP_KERNEL);
4169        if (!err)
4170                err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
4171                                          GFP_KERNEL);
4172        if (err) {
4173                ext4_msg(sb, KERN_ERR, "insufficient memory");
4174                goto failed_mount6;
4175        }
4176
4177        if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
4178                if (!ext4_fill_flex_info(sb)) {
4179                        ext4_msg(sb, KERN_ERR,
4180                               "unable to initialize "
4181                               "flex_bg meta info!");
4182                        goto failed_mount6;
4183                }
4184
4185        err = ext4_register_li_request(sb, first_not_zeroed);
4186        if (err)
4187                goto failed_mount6;
4188
4189        sbi->s_kobj.kset = ext4_kset;
4190        init_completion(&sbi->s_kobj_unregister);
4191        err = kobject_init_and_add(&sbi->s_kobj, &ext4_ktype, NULL,
4192                                   "%s", sb->s_id);
4193        if (err)
4194                goto failed_mount7;
4195
4196#ifdef CONFIG_QUOTA
4197        /* Enable quota usage during mount. */
4198        if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
4199            !(sb->s_flags & MS_RDONLY)) {
4200                err = ext4_enable_quotas(sb);
4201                if (err)
4202                        goto failed_mount8;
4203        }
4204#endif  /* CONFIG_QUOTA */
4205
4206        EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
4207        ext4_orphan_cleanup(sb, es);
4208        EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
4209        if (needs_recovery) {
4210                ext4_msg(sb, KERN_INFO, "recovery complete");
4211                ext4_mark_recovery_complete(sb, es);
4212        }
4213        if (EXT4_SB(sb)->s_journal) {
4214                if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
4215                        descr = " journalled data mode";
4216                else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
4217                        descr = " ordered data mode";
4218                else
4219                        descr = " writeback data mode";
4220        } else
4221                descr = "out journal";
4222
4223        if (test_opt(sb, DISCARD)) {
4224                struct request_queue *q = bdev_get_queue(sb->s_bdev);
4225                if (!blk_queue_discard(q))
4226                        ext4_msg(sb, KERN_WARNING,
4227                                 "mounting with \"discard\" option, but "
4228                                 "the device does not support discard");
4229        }
4230
4231        ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
4232                 "Opts: %s%s%s", descr, sbi->s_es->s_mount_opts,
4233                 *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
4234
4235        if (es->s_error_count)
4236                mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
4237
4238        /* Enable message ratelimiting. Default is 10 messages per 5 secs. */
4239        ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
4240        ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
4241        ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
4242
4243        kfree(orig_data);
4244        return 0;
4245
4246cantfind_ext4:
4247        if (!silent)
4248                ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
4249        goto failed_mount;
4250
4251#ifdef CONFIG_QUOTA
4252failed_mount8:
4253        kobject_del(&sbi->s_kobj);
4254#endif
4255failed_mount7:
4256        ext4_unregister_li_request(sb);
4257failed_mount6:
4258        ext4_mb_release(sb);
4259        if (sbi->s_flex_groups)
4260                kvfree(sbi->s_flex_groups);
4261        percpu_counter_destroy(&sbi->s_freeclusters_counter);
4262        percpu_counter_destroy(&sbi->s_freeinodes_counter);
4263        percpu_counter_destroy(&sbi->s_dirs_counter);
4264        percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4265failed_mount5:
4266        ext4_ext_release(sb);
4267        ext4_release_system_zone(sb);
4268failed_mount4a:
4269        dput(sb->s_root);
4270        sb->s_root = NULL;
4271failed_mount4:
4272        ext4_msg(sb, KERN_ERR, "mount failed");
4273        if (EXT4_SB(sb)->rsv_conversion_wq)
4274                destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4275failed_mount_wq:
4276        if (sbi->s_journal) {
4277                jbd2_journal_destroy(sbi->s_journal);
4278                sbi->s_journal = NULL;
4279        }
4280failed_mount3a:
4281        ext4_es_unregister_shrinker(sbi);
4282failed_mount3:
4283        del_timer_sync(&sbi->s_err_report);
4284        if (sbi->s_mmp_tsk)
4285                kthread_stop(sbi->s_mmp_tsk);
4286failed_mount2:
4287        for (i = 0; i < db_count; i++)
4288                brelse(sbi->s_group_desc[i]);
4289        kvfree(sbi->s_group_desc);
4290failed_mount:
4291        if (sbi->s_chksum_driver)
4292                crypto_free_shash(sbi->s_chksum_driver);
4293        if (sbi->s_proc) {
4294                remove_proc_entry("options", sbi->s_proc);
4295                remove_proc_entry(sb->s_id, ext4_proc_root);
4296        }
4297#ifdef CONFIG_QUOTA
4298        for (i = 0; i < EXT4_MAXQUOTAS; i++)
4299                kfree(sbi->s_qf_names[i]);
4300#endif
4301        ext4_blkdev_remove(sbi);
4302        brelse(bh);
4303out_fail:
4304        sb->s_fs_info = NULL;
4305        kfree(sbi->s_blockgroup_lock);
4306        kfree(sbi);
4307out_free_orig:
4308        kfree(orig_data);
4309        return err ? err : ret;
4310}
4311
4312/*
4313 * Setup any per-fs journal parameters now.  We'll do this both on
4314 * initial mount, once the journal has been initialised but before we've
4315 * done any recovery; and again on any subsequent remount.
4316 */
4317static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4318{
4319        struct ext4_sb_info *sbi = EXT4_SB(sb);
4320
4321        journal->j_commit_interval = sbi->s_commit_interval;
4322        journal->j_min_batch_time = sbi->s_min_batch_time;
4323        journal->j_max_batch_time = sbi->s_max_batch_time;
4324
4325        write_lock(&journal->j_state_lock);
4326        if (test_opt(sb, BARRIER))
4327                journal->j_flags |= JBD2_BARRIER;
4328        else
4329                journal->j_flags &= ~JBD2_BARRIER;
4330        if (test_opt(sb, DATA_ERR_ABORT))
4331                journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4332        else
4333                journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4334        write_unlock(&journal->j_state_lock);
4335}
4336
4337static journal_t *ext4_get_journal(struct super_block *sb,
4338                                   unsigned int journal_inum)
4339{
4340        struct inode *journal_inode;
4341        journal_t *journal;
4342
4343        BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4344
4345        /* First, test for the existence of a valid inode on disk.  Bad
4346         * things happen if we iget() an unused inode, as the subsequent
4347         * iput() will try to delete it. */
4348
4349        journal_inode = ext4_iget(sb, journal_inum);
4350        if (IS_ERR(journal_inode)) {
4351                ext4_msg(sb, KERN_ERR, "no journal found");
4352                return NULL;
4353        }
4354        if (!journal_inode->i_nlink) {
4355                make_bad_inode(journal_inode);
4356                iput(journal_inode);
4357                ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4358                return NULL;
4359        }
4360
4361        jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4362                  journal_inode, journal_inode->i_size);
4363        if (!S_ISREG(journal_inode->i_mode)) {
4364                ext4_msg(sb, KERN_ERR, "invalid journal inode");
4365                iput(journal_inode);
4366                return NULL;
4367        }
4368
4369        journal = jbd2_journal_init_inode(journal_inode);
4370        if (!journal) {
4371                ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4372                iput(journal_inode);
4373                return NULL;
4374        }
4375        journal->j_private = sb;
4376        ext4_init_journal_params(sb, journal);
4377        return journal;
4378}
4379
4380static journal_t *ext4_get_dev_journal(struct super_block *sb,
4381                                       dev_t j_dev)
4382{
4383        struct buffer_head *bh;
4384        journal_t *journal;
4385        ext4_fsblk_t start;
4386        ext4_fsblk_t len;
4387        int hblock, blocksize;
4388        ext4_fsblk_t sb_block;
4389        unsigned long offset;
4390        struct ext4_super_block *es;
4391        struct block_device *bdev;
4392
4393        BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4394
4395        bdev = ext4_blkdev_get(j_dev, sb);
4396        if (bdev == NULL)
4397                return NULL;
4398
4399        blocksize = sb->s_blocksize;
4400        hblock = bdev_logical_block_size(bdev);
4401        if (blocksize < hblock) {
4402                ext4_msg(sb, KERN_ERR,
4403                        "blocksize too small for journal device");
4404                goto out_bdev;
4405        }
4406
4407        sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4408        offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4409        set_blocksize(bdev, blocksize);
4410        if (!(bh = __bread(bdev, sb_block, blocksize))) {
4411                ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4412                       "external journal");
4413                goto out_bdev;
4414        }
4415
4416        es = (struct ext4_super_block *) (bh->b_data + offset);
4417        if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4418            !(le32_to_cpu(es->s_feature_incompat) &
4419              EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4420                ext4_msg(sb, KERN_ERR, "external journal has "
4421                                        "bad superblock");
4422                brelse(bh);
4423                goto out_bdev;
4424        }
4425
4426        if ((le32_to_cpu(es->s_feature_ro_compat) &
4427             EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
4428            es->s_checksum != ext4_superblock_csum(sb, es)) {
4429                ext4_msg(sb, KERN_ERR, "external journal has "
4430                                       "corrupt superblock");
4431                brelse(bh);
4432                goto out_bdev;
4433        }
4434
4435        if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4436                ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4437                brelse(bh);
4438                goto out_bdev;
4439        }
4440
4441        len = ext4_blocks_count(es);
4442        start = sb_block + 1;
4443        brelse(bh);     /* we're done with the superblock */
4444
4445        journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4446                                        start, len, blocksize);
4447        if (!journal) {
4448                ext4_msg(sb, KERN_ERR, "failed to create device journal");
4449                goto out_bdev;
4450        }
4451        journal->j_private = sb;
4452        ll_rw_block(READ | REQ_META | REQ_PRIO, 1, &journal->j_sb_buffer);
4453        wait_on_buffer(journal->j_sb_buffer);
4454        if (!buffer_uptodate(journal->j_sb_buffer)) {
4455                ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4456                goto out_journal;
4457        }
4458        if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4459                ext4_msg(sb, KERN_ERR, "External journal has more than one "
4460                                        "user (unsupported) - %d",
4461                        be32_to_cpu(journal->j_superblock->s_nr_users));
4462                goto out_journal;
4463        }
4464        EXT4_SB(sb)->journal_bdev = bdev;
4465        ext4_init_journal_params(sb, journal);
4466        return journal;
4467
4468out_journal:
4469        jbd2_journal_destroy(journal);
4470out_bdev:
4471        ext4_blkdev_put(bdev);
4472        return NULL;
4473}
4474
4475static int ext4_load_journal(struct super_block *sb,
4476                             struct ext4_super_block *es,
4477                             unsigned long journal_devnum)
4478{
4479        journal_t *journal;
4480        unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4481        dev_t journal_dev;
4482        int err = 0;
4483        int really_read_only;
4484
4485        BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4486
4487        if (journal_devnum &&
4488            journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4489                ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4490                        "numbers have changed");
4491                journal_dev = new_decode_dev(journal_devnum);
4492        } else
4493                journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4494
4495        really_read_only = bdev_read_only(sb->s_bdev);
4496
4497        /*
4498         * Are we loading a blank journal or performing recovery after a
4499         * crash?  For recovery, we need to check in advance whether we
4500         * can get read-write access to the device.
4501         */
4502        if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
4503                if (sb->s_flags & MS_RDONLY) {
4504                        ext4_msg(sb, KERN_INFO, "INFO: recovery "
4505                                        "required on readonly filesystem");
4506                        if (really_read_only) {
4507                                ext4_msg(sb, KERN_ERR, "write access "
4508                                        "unavailable, cannot proceed");
4509                                return -EROFS;
4510                        }
4511                        ext4_msg(sb, KERN_INFO, "write access will "
4512                               "be enabled during recovery");
4513                }
4514        }
4515
4516        if (journal_inum && journal_dev) {
4517                ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4518                       "and inode journals!");
4519                return -EINVAL;
4520        }
4521
4522        if (journal_inum) {
4523                if (!(journal = ext4_get_journal(sb, journal_inum)))
4524                        return -EINVAL;
4525        } else {
4526                if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4527                        return -EINVAL;
4528        }
4529
4530        if (!(journal->j_flags & JBD2_BARRIER))
4531                ext4_msg(sb, KERN_INFO, "barriers disabled");
4532
4533        if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER))
4534                err = jbd2_journal_wipe(journal, !really_read_only);
4535        if (!err) {
4536                char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4537                if (save)
4538                        memcpy(save, ((char *) es) +
4539                               EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4540                err = jbd2_journal_load(journal);
4541                if (save)
4542                        memcpy(((char *) es) + EXT4_S_ERR_START,
4543                               save, EXT4_S_ERR_LEN);
4544                kfree(save);
4545        }
4546
4547        if (err) {
4548                ext4_msg(sb, KERN_ERR, "error loading journal");
4549                jbd2_journal_destroy(journal);
4550                return err;
4551        }
4552
4553        EXT4_SB(sb)->s_journal = journal;
4554        ext4_clear_journal_err(sb, es);
4555
4556        if (!really_read_only && journal_devnum &&
4557            journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4558                es->s_journal_dev = cpu_to_le32(journal_devnum);
4559
4560                /* Make sure we flush the recovery flag to disk. */
4561                ext4_commit_super(sb, 1);
4562        }
4563
4564        return 0;
4565}
4566
4567static int ext4_commit_super(struct super_block *sb, int sync)
4568{
4569        struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4570        struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4571        int error = 0;
4572
4573        if (!sbh || block_device_ejected(sb))
4574                return error;
4575        if (buffer_write_io_error(sbh)) {
4576                /*
4577                 * Oh, dear.  A previous attempt to write the
4578                 * superblock failed.  This could happen because the
4579                 * USB device was yanked out.  Or it could happen to
4580                 * be a transient write error and maybe the block will
4581                 * be remapped.  Nothing we can do but to retry the
4582                 * write and hope for the best.
4583                 */
4584                ext4_msg(sb, KERN_ERR, "previous I/O error to "
4585                       "superblock detected");
4586                clear_buffer_write_io_error(sbh);
4587                set_buffer_uptodate(sbh);
4588        }
4589        /*
4590         * If the file system is mounted read-only, don't update the
4591         * superblock write time.  This avoids updating the superblock
4592         * write time when we are mounting the root file system
4593         * read/only but we need to replay the journal; at that point,
4594         * for people who are east of GMT and who make their clock
4595         * tick in localtime for Windows bug-for-bug compatibility,
4596         * the clock is set in the future, and this will cause e2fsck
4597         * to complain and force a full file system check.
4598         */
4599        if (!(sb->s_flags & MS_RDONLY))
4600                es->s_wtime = cpu_to_le32(get_seconds());
4601        if (sb->s_bdev->bd_part)
4602                es->s_kbytes_written =
4603                        cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
4604                            ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
4605                              EXT4_SB(sb)->s_sectors_written_start) >> 1));
4606        else
4607                es->s_kbytes_written =
4608                        cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
4609        if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeclusters_counter))
4610                ext4_free_blocks_count_set(es,
4611                        EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
4612                                &EXT4_SB(sb)->s_freeclusters_counter)));
4613        if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeinodes_counter))
4614                es->s_free_inodes_count =
4615                        cpu_to_le32(percpu_counter_sum_positive(
4616                                &EXT4_SB(sb)->s_freeinodes_counter));
4617        BUFFER_TRACE(sbh, "marking dirty");
4618        ext4_superblock_csum_set(sb);
4619        mark_buffer_dirty(sbh);
4620        if (sync) {
4621                error = sync_dirty_buffer(sbh);
4622                if (error)
4623                        return error;
4624
4625                error = buffer_write_io_error(sbh);
4626                if (error) {
4627                        ext4_msg(sb, KERN_ERR, "I/O error while writing "
4628                               "superblock");
4629                        clear_buffer_write_io_error(sbh);
4630                        set_buffer_uptodate(sbh);
4631                }
4632        }
4633        return error;
4634}
4635
4636/*
4637 * Have we just finished recovery?  If so, and if we are mounting (or
4638 * remounting) the filesystem readonly, then we will end up with a
4639 * consistent fs on disk.  Record that fact.
4640 */
4641static void ext4_mark_recovery_complete(struct super_block *sb,
4642                                        struct ext4_super_block *es)
4643{
4644        journal_t *journal = EXT4_SB(sb)->s_journal;
4645
4646        if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
4647                BUG_ON(journal != NULL);
4648                return;
4649        }
4650        jbd2_journal_lock_updates(journal);
4651        if (jbd2_journal_flush(journal) < 0)
4652                goto out;
4653
4654        if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER) &&
4655            sb->s_flags & MS_RDONLY) {
4656                EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4657                ext4_commit_super(sb, 1);
4658        }
4659
4660out:
4661        jbd2_journal_unlock_updates(journal);
4662}
4663
4664/*
4665 * If we are mounting (or read-write remounting) a filesystem whose journal
4666 * has recorded an error from a previous lifetime, move that error to the
4667 * main filesystem now.
4668 */
4669static void ext4_clear_journal_err(struct super_block *sb,
4670                                   struct ext4_super_block *es)
4671{
4672        journal_t *journal;
4673        int j_errno;
4674        const char *errstr;
4675
4676        BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4677
4678        journal = EXT4_SB(sb)->s_journal;
4679
4680        /*
4681         * Now check for any error status which may have been recorded in the
4682         * journal by a prior ext4_error() or ext4_abort()
4683         */
4684
4685        j_errno = jbd2_journal_errno(journal);
4686        if (j_errno) {
4687                char nbuf[16];
4688
4689                errstr = ext4_decode_error(sb, j_errno, nbuf);
4690                ext4_warning(sb, "Filesystem error recorded "
4691                             "from previous mount: %s", errstr);
4692                ext4_warning(sb, "Marking fs in need of filesystem check.");
4693
4694                EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
4695                es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
4696                ext4_commit_super(sb, 1);
4697
4698                jbd2_journal_clear_err(journal);
4699                jbd2_journal_update_sb_errno(journal);
4700        }
4701}
4702
4703/*
4704 * Force the running and committing transactions to commit,
4705 * and wait on the commit.
4706 */
4707int ext4_force_commit(struct super_block *sb)
4708{
4709        journal_t *journal;
4710
4711        if (sb->s_flags & MS_RDONLY)
4712                return 0;
4713
4714        journal = EXT4_SB(sb)->s_journal;
4715        return ext4_journal_force_commit(journal);
4716}
4717
4718static int ext4_sync_fs(struct super_block *sb, int wait)
4719{
4720        int ret = 0;
4721        tid_t target;
4722        bool needs_barrier = false;
4723        struct ext4_sb_info *sbi = EXT4_SB(sb);
4724
4725        trace_ext4_sync_fs(sb, wait);
4726        flush_workqueue(sbi->rsv_conversion_wq);
4727        /*
4728         * Writeback quota in non-journalled quota case - journalled quota has
4729         * no dirty dquots
4730         */
4731        dquot_writeback_dquots(sb, -1);
4732        /*
4733         * Data writeback is possible w/o journal transaction, so barrier must
4734         * being sent at the end of the function. But we can skip it if
4735         * transaction_commit will do it for us.
4736         */
4737        if (sbi->s_journal) {
4738                target = jbd2_get_latest_transaction(sbi->s_journal);
4739                if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
4740                    !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
4741                        needs_barrier = true;
4742
4743                if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
4744                        if (wait)
4745                                ret = jbd2_log_wait_commit(sbi->s_journal,
4746                                                           target);
4747                }
4748        } else if (wait && test_opt(sb, BARRIER))
4749                needs_barrier = true;
4750        if (needs_barrier) {
4751                int err;
4752                err = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
4753                if (!ret)
4754                        ret = err;
4755        }
4756
4757        return ret;
4758}
4759
4760/*
4761 * LVM calls this function before a (read-only) snapshot is created.  This
4762 * gives us a chance to flush the journal completely and mark the fs clean.
4763 *
4764 * Note that only this function cannot bring a filesystem to be in a clean
4765 * state independently. It relies on upper layer to stop all data & metadata
4766 * modifications.
4767 */
4768static int ext4_freeze(struct super_block *sb)
4769{
4770        int error = 0;
4771        journal_t *journal;
4772
4773        if (sb->s_flags & MS_RDONLY)
4774                return 0;
4775
4776        journal = EXT4_SB(sb)->s_journal;
4777
4778        if (journal) {
4779                /* Now we set up the journal barrier. */
4780                jbd2_journal_lock_updates(journal);
4781
4782                /*
4783                 * Don't clear the needs_recovery flag if we failed to
4784                 * flush the journal.
4785                 */
4786                error = jbd2_journal_flush(journal);
4787                if (error < 0)
4788                        goto out;
4789        }
4790
4791        /* Journal blocked and flushed, clear needs_recovery flag. */
4792        EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4793        error = ext4_commit_super(sb, 1);
4794out:
4795        if (journal)
4796                /* we rely on upper layer to stop further updates */
4797                jbd2_journal_unlock_updates(journal);
4798        return error;
4799}
4800
4801/*
4802 * Called by LVM after the snapshot is done.  We need to reset the RECOVER
4803 * flag here, even though the filesystem is not technically dirty yet.
4804 */
4805static int ext4_unfreeze(struct super_block *sb)
4806{
4807        if (sb->s_flags & MS_RDONLY)
4808                return 0;
4809
4810        /* Reset the needs_recovery flag before the fs is unlocked. */
4811        EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4812        ext4_commit_super(sb, 1);
4813        return 0;
4814}
4815
4816/*
4817 * Structure to save mount options for ext4_remount's benefit
4818 */
4819struct ext4_mount_options {
4820        unsigned long s_mount_opt;
4821        unsigned long s_mount_opt2;
4822        kuid_t s_resuid;
4823        kgid_t s_resgid;
4824        unsigned long s_commit_interval;
4825        u32 s_min_batch_time, s_max_batch_time;
4826#ifdef CONFIG_QUOTA
4827        int s_jquota_fmt;
4828        char *s_qf_names[EXT4_MAXQUOTAS];
4829#endif
4830};
4831
4832static int ext4_remount(struct super_block *sb, int *flags, char *data)
4833{
4834        struct ext4_super_block *es;
4835        struct ext4_sb_info *sbi = EXT4_SB(sb);
4836        unsigned long old_sb_flags;
4837        struct ext4_mount_options old_opts;
4838        int enable_quota = 0;
4839        ext4_group_t g;
4840        unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4841        int err = 0;
4842#ifdef CONFIG_QUOTA
4843        int i, j;
4844#endif
4845        char *orig_data = kstrdup(data, GFP_KERNEL);
4846
4847        /* Store the original options */
4848        old_sb_flags = sb->s_flags;
4849        old_opts.s_mount_opt = sbi->s_mount_opt;
4850        old_opts.s_mount_opt2 = sbi->s_mount_opt2;
4851        old_opts.s_resuid = sbi->s_resuid;
4852        old_opts.s_resgid = sbi->s_resgid;
4853        old_opts.s_commit_interval = sbi->s_commit_interval;
4854        old_opts.s_min_batch_time = sbi->s_min_batch_time;
4855        old_opts.s_max_batch_time = sbi->s_max_batch_time;
4856#ifdef CONFIG_QUOTA
4857        old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
4858        for (i = 0; i < EXT4_MAXQUOTAS; i++)
4859                if (sbi->s_qf_names[i]) {
4860                        old_opts.s_qf_names[i] = kstrdup(sbi->s_qf_names[i],
4861                                                         GFP_KERNEL);
4862                        if (!old_opts.s_qf_names[i]) {
4863                                for (j = 0; j < i; j++)
4864                                        kfree(old_opts.s_qf_names[j]);
4865                                kfree(orig_data);
4866                                return -ENOMEM;
4867                        }
4868                } else
4869                        old_opts.s_qf_names[i] = NULL;
4870#endif
4871        if (sbi->s_journal && sbi->s_journal->j_task->io_context)
4872                journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
4873
4874        if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
4875                err = -EINVAL;
4876                goto restore_opts;
4877        }
4878
4879        if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
4880            test_opt(sb, JOURNAL_CHECKSUM)) {
4881                ext4_msg(sb, KERN_ERR, "changing journal_checksum "
4882                         "during remount not supported; ignoring");
4883                sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
4884        }
4885
4886        if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
4887                if (test_opt2(sb, EXPLICIT_DELALLOC)) {
4888                        ext4_msg(sb, KERN_ERR, "can't mount with "
4889                                 "both data=journal and delalloc");
4890                        err = -EINVAL;
4891                        goto restore_opts;
4892                }
4893                if (test_opt(sb, DIOREAD_NOLOCK)) {
4894                        ext4_msg(sb, KERN_ERR, "can't mount with "
4895                                 "both data=journal and dioread_nolock");
4896                        err = -EINVAL;
4897                        goto restore_opts;
4898                }
4899                if (test_opt(sb, DAX)) {
4900                        ext4_msg(sb, KERN_ERR, "can't mount with "
4901                                 "both data=journal and dax");
4902                        err = -EINVAL;
4903                        goto restore_opts;
4904                }
4905        }
4906
4907        if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_DAX) {
4908                ext4_msg(sb, KERN_WARNING, "warning: refusing change of "
4909                        "dax flag with busy inodes while remounting");
4910                sbi->s_mount_opt ^= EXT4_MOUNT_DAX;
4911        }
4912
4913        if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
4914                ext4_abort(sb, "Abort forced by user");
4915
4916        sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
4917                (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
4918
4919        es = sbi->s_es;
4920
4921        if (sbi->s_journal) {
4922                ext4_init_journal_params(sb, sbi->s_journal);
4923                set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4924        }
4925
4926        if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY)) {
4927                if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
4928                        err = -EROFS;
4929                        goto restore_opts;
4930                }
4931
4932                if (*flags & MS_RDONLY) {
4933                        err = sync_filesystem(sb);
4934                        if (err < 0)
4935                                goto restore_opts;
4936                        err = dquot_suspend(sb, -1);
4937                        if (err < 0)
4938                                goto restore_opts;
4939
4940                        /*
4941                         * First of all, the unconditional stuff we have to do
4942                         * to disable replay of the journal when we next remount
4943                         */
4944                        sb->s_flags |= MS_RDONLY;
4945
4946                        /*
4947                         * OK, test if we are remounting a valid rw partition
4948                         * readonly, and if so set the rdonly flag and then
4949                         * mark the partition as valid again.
4950                         */
4951                        if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
4952                            (sbi->s_mount_state & EXT4_VALID_FS))
4953                                es->s_state = cpu_to_le16(sbi->s_mount_state);
4954
4955                        if (sbi->s_journal)
4956                                ext4_mark_recovery_complete(sb, es);
4957                } else {
4958                        /* Make sure we can mount this feature set readwrite */
4959                        if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
4960                                        EXT4_FEATURE_RO_COMPAT_READONLY) ||
4961                            !ext4_feature_set_ok(sb, 0)) {
4962                                err = -EROFS;
4963                                goto restore_opts;
4964                        }
4965                        /*
4966                         * Make sure the group descriptor checksums
4967                         * are sane.  If they aren't, refuse to remount r/w.
4968                         */
4969                        for (g = 0; g < sbi->s_groups_count; g++) {
4970                                struct ext4_group_desc *gdp =
4971                                        ext4_get_group_desc(sb, g, NULL);
4972
4973                                if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
4974                                        ext4_msg(sb, KERN_ERR,
4975               "ext4_remount: Checksum for group %u failed (%u!=%u)",
4976                g, le16_to_cpu(ext4_group_desc_csum(sbi, g, gdp)),
4977                                               le16_to_cpu(gdp->bg_checksum));
4978                                        err = -EINVAL;
4979                                        goto restore_opts;
4980                                }
4981                        }
4982
4983                        /*
4984                         * If we have an unprocessed orphan list hanging
4985                         * around from a previously readonly bdev mount,
4986                         * require a full umount/remount for now.
4987                         */
4988                        if (es->s_last_orphan) {
4989                                ext4_msg(sb, KERN_WARNING, "Couldn't "
4990                                       "remount RDWR because of unprocessed "
4991                                       "orphan inode list.  Please "
4992                                       "umount/remount instead");
4993                                err = -EINVAL;
4994                                goto restore_opts;
4995                        }
4996
4997                        /*
4998                         * Mounting a RDONLY partition read-write, so reread
4999                         * and store the current valid flag.  (It may have
5000                         * been changed by e2fsck since we originally mounted
5001                         * the partition.)
5002                         */
5003                        if (sbi->s_journal)
5004                                ext4_clear_journal_err(sb, es);
5005                        sbi->s_mount_state = le16_to_cpu(es->s_state);
5006                        if (!ext4_setup_super(sb, es, 0))
5007                                sb->s_flags &= ~MS_RDONLY;
5008                        if (EXT4_HAS_INCOMPAT_FEATURE(sb,
5009                                                     EXT4_FEATURE_INCOMPAT_MMP))
5010                                if (ext4_multi_mount_protect(sb,
5011                                                le64_to_cpu(es->s_mmp_block))) {
5012                                        err = -EROFS;
5013                                        goto restore_opts;
5014                                }
5015                        enable_quota = 1;
5016                }
5017        }
5018
5019        /*
5020         * Reinitialize lazy itable initialization thread based on
5021         * current settings
5022         */
5023        if ((sb->s_flags & MS_RDONLY) || !test_opt(sb, INIT_INODE_TABLE))
5024                ext4_unregister_li_request(sb);
5025        else {
5026                ext4_group_t first_not_zeroed;
5027                first_not_zeroed = ext4_has_uninit_itable(sb);
5028                ext4_register_li_request(sb, first_not_zeroed);
5029        }
5030
5031        ext4_setup_system_zone(sb);
5032        if (sbi->s_journal == NULL && !(old_sb_flags & MS_RDONLY))
5033                ext4_commit_super(sb, 1);
5034
5035#ifdef CONFIG_QUOTA
5036        /* Release old quota file names */
5037        for (i = 0; i < EXT4_MAXQUOTAS; i++)
5038                kfree(old_opts.s_qf_names[i]);
5039        if (enable_quota) {
5040                if (sb_any_quota_suspended(sb))
5041                        dquot_resume(sb, -1);
5042                else if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
5043                                        EXT4_FEATURE_RO_COMPAT_QUOTA)) {
5044                        err = ext4_enable_quotas(sb);
5045                        if (err)
5046                                goto restore_opts;
5047                }
5048        }
5049#endif
5050
5051        *flags = (*flags & ~MS_LAZYTIME) | (sb->s_flags & MS_LAZYTIME);
5052        ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
5053        kfree(orig_data);
5054        return 0;
5055
5056restore_opts:
5057        sb->s_flags = old_sb_flags;
5058        sbi->s_mount_opt = old_opts.s_mount_opt;
5059        sbi->s_mount_opt2 = old_opts.s_mount_opt2;
5060        sbi->s_resuid = old_opts.s_resuid;
5061        sbi->s_resgid = old_opts.s_resgid;
5062        sbi->s_commit_interval = old_opts.s_commit_interval;
5063        sbi->s_min_batch_time = old_opts.s_min_batch_time;
5064        sbi->s_max_batch_time = old_opts.s_max_batch_time;
5065#ifdef CONFIG_QUOTA
5066        sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
5067        for (i = 0; i < EXT4_MAXQUOTAS; i++) {
5068                kfree(sbi->s_qf_names[i]);
5069                sbi->s_qf_names[i] = old_opts.s_qf_names[i];
5070        }
5071#endif
5072        kfree(orig_data);
5073        return err;
5074}
5075
5076static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
5077{
5078        struct super_block *sb = dentry->d_sb;
5079        struct ext4_sb_info *sbi = EXT4_SB(sb);
5080        struct ext4_super_block *es = sbi->s_es;
5081        ext4_fsblk_t overhead = 0, resv_blocks;
5082        u64 fsid;
5083        s64 bfree;
5084        resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
5085
5086        if (!test_opt(sb, MINIX_DF))
5087                overhead = sbi->s_overhead;
5088
5089        buf->f_type = EXT4_SUPER_MAGIC;
5090        buf->f_bsize = sb->s_blocksize;
5091        buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
5092        bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
5093                percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
5094        /* prevent underflow in case that few free space is available */
5095        buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
5096        buf->f_bavail = buf->f_bfree -
5097                        (ext4_r_blocks_count(es) + resv_blocks);
5098        if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
5099                buf->f_bavail = 0;
5100        buf->f_files = le32_to_cpu(es->s_inodes_count);
5101        buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
5102        buf->f_namelen = EXT4_NAME_LEN;
5103        fsid = le64_to_cpup((void *)es->s_uuid) ^
5104               le64_to_cpup((void *)es->s_uuid + sizeof(u64));
5105        buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
5106        buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
5107
5108        return 0;
5109}
5110
5111/* Helper function for writing quotas on sync - we need to start transaction
5112 * before quota file is locked for write. Otherwise the are possible deadlocks:
5113 * Process 1                         Process 2
5114 * ext4_create()                     quota_sync()
5115 *   jbd2_journal_start()                  write_dquot()
5116 *   dquot_initialize()                         down(dqio_mutex)
5117 *     down(dqio_mutex)                    jbd2_journal_start()
5118 *
5119 */
5120
5121#ifdef CONFIG_QUOTA
5122
5123static inline struct inode *dquot_to_inode(struct dquot *dquot)
5124{
5125        return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
5126}
5127
5128static int ext4_write_dquot(struct dquot *dquot)
5129{
5130        int ret, err;
5131        handle_t *handle;
5132        struct inode *inode;
5133
5134        inode = dquot_to_inode(dquot);
5135        handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
5136                                    EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
5137        if (IS_ERR(handle))
5138                return PTR_ERR(handle);
5139        ret = dquot_commit(dquot);
5140        err = ext4_journal_stop(handle);
5141        if (!ret)
5142                ret = err;
5143        return ret;
5144}
5145
5146static int ext4_acquire_dquot(struct dquot *dquot)
5147{
5148        int ret, err;
5149        handle_t *handle;
5150
5151        handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5152                                    EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
5153        if (IS_ERR(handle))
5154                return PTR_ERR(handle);
5155        ret = dquot_acquire(dquot);
5156        err = ext4_journal_stop(handle);
5157        if (!ret)
5158                ret = err;
5159        return ret;
5160}
5161
5162static int ext4_release_dquot(struct dquot *dquot)
5163{
5164        int ret, err;
5165        handle_t *handle;
5166
5167        handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5168                                    EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
5169        if (IS_ERR(handle)) {
5170                /* Release dquot anyway to avoid endless cycle in dqput() */
5171                dquot_release(dquot);
5172                return PTR_ERR(handle);
5173        }
5174        ret = dquot_release(dquot);
5175        err = ext4_journal_stop(handle);
5176        if (!ret)
5177                ret = err;
5178        return ret;
5179}
5180
5181static int ext4_mark_dquot_dirty(struct dquot *dquot)
5182{
5183        struct super_block *sb = dquot->dq_sb;
5184        struct ext4_sb_info *sbi = EXT4_SB(sb);
5185
5186        /* Are we journaling quotas? */
5187        if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) ||
5188            sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
5189                dquot_mark_dquot_dirty(dquot);
5190                return ext4_write_dquot(dquot);
5191        } else {
5192                return dquot_mark_dquot_dirty(dquot);
5193        }
5194}
5195
5196static int ext4_write_info(struct super_block *sb, int type)
5197{
5198        int ret, err;
5199        handle_t *handle;
5200
5201        /* Data block + inode block */
5202        handle = ext4_journal_start(sb->s_root->d_inode, EXT4_HT_QUOTA, 2);
5203        if (IS_ERR(handle))
5204                return PTR_ERR(handle);
5205        ret = dquot_commit_info(sb, type);
5206        err = ext4_journal_stop(handle);
5207        if (!ret)
5208                ret = err;
5209        return ret;
5210}
5211
5212/*
5213 * Turn on quotas during mount time - we need to find
5214 * the quota file and such...
5215 */
5216static int ext4_quota_on_mount(struct super_block *sb, int type)
5217{
5218        return dquot_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
5219                                        EXT4_SB(sb)->s_jquota_fmt, type);
5220}
5221
5222/*
5223 * Standard function to be called on quota_on
5224 */
5225static int ext4_quota_on(struct super_block *sb, int type, int format_id,
5226                         struct path *path)
5227{
5228        int err;
5229
5230        if (!test_opt(sb, QUOTA))
5231                return -EINVAL;
5232
5233        /* Quotafile not on the same filesystem? */
5234        if (path->dentry->d_sb != sb)
5235                return -EXDEV;
5236        /* Journaling quota? */
5237        if (EXT4_SB(sb)->s_qf_names[type]) {
5238                /* Quotafile not in fs root? */
5239                if (path->dentry->d_parent != sb->s_root)
5240                        ext4_msg(sb, KERN_WARNING,
5241                                "Quota file not on filesystem root. "
5242                                "Journaled quota will not work");
5243        }
5244
5245        /*
5246         * When we journal data on quota file, we have to flush journal to see
5247         * all updates to the file when we bypass pagecache...
5248         */
5249        if (EXT4_SB(sb)->s_journal &&
5250            ext4_should_journal_data(path->dentry->d_inode)) {
5251                /*
5252                 * We don't need to lock updates but journal_flush() could
5253                 * otherwise be livelocked...
5254                 */
5255                jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
5256                err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
5257                jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
5258                if (err)
5259                        return err;
5260        }
5261
5262        return dquot_quota_on(sb, type, format_id, path);
5263}
5264
5265static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
5266                             unsigned int flags)
5267{
5268        int err;
5269        struct inode *qf_inode;
5270        unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5271                le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5272                le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum)
5273        };
5274
5275        BUG_ON(!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA));
5276
5277        if (!qf_inums[type])
5278                return -EPERM;
5279
5280        qf_inode = ext4_iget(sb, qf_inums[type]);
5281        if (IS_ERR(qf_inode)) {
5282                ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
5283                return PTR_ERR(qf_inode);
5284        }
5285
5286        /* Don't account quota for quota files to avoid recursion */
5287        qf_inode->i_flags |= S_NOQUOTA;
5288        err = dquot_enable(qf_inode, type, format_id, flags);
5289        iput(qf_inode);
5290
5291        return err;
5292}
5293
5294/* Enable usage tracking for all quota types. */
5295static int ext4_enable_quotas(struct super_block *sb)
5296{
5297        int type, err = 0;
5298        unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5299                le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5300                le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum)
5301        };
5302
5303        sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE;
5304        for (type = 0; type < EXT4_MAXQUOTAS; type++) {
5305                if (qf_inums[type]) {
5306                        err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
5307                                                DQUOT_USAGE_ENABLED);
5308                        if (err) {
5309                                ext4_warning(sb,
5310                                        "Failed to enable quota tracking "
5311                                        "(type=%d, err=%d). Please run "
5312                                        "e2fsck to fix.", type, err);
5313                                return err;
5314                        }
5315                }
5316        }
5317        return 0;
5318}
5319
5320static int ext4_quota_off(struct super_block *sb, int type)
5321{
5322        struct inode *inode = sb_dqopt(sb)->files[type];
5323        handle_t *handle;
5324
5325        /* Force all delayed allocation blocks to be allocated.
5326         * Caller already holds s_umount sem */
5327        if (test_opt(sb, DELALLOC))
5328                sync_filesystem(sb);
5329
5330        if (!inode)
5331                goto out;
5332
5333        /* Update modification times of quota files when userspace can
5334         * start looking at them */
5335        handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5336        if (IS_ERR(handle))
5337                goto out;
5338        inode->i_mtime = inode->i_ctime = CURRENT_TIME;
5339        ext4_mark_inode_dirty(handle, inode);
5340        ext4_journal_stop(handle);
5341
5342out:
5343        return dquot_quota_off(sb, type);
5344}
5345
5346/* Read data from quotafile - avoid pagecache and such because we cannot afford
5347 * acquiring the locks... As quota files are never truncated and quota code
5348 * itself serializes the operations (and no one else should touch the files)
5349 * we don't have to be afraid of races */
5350static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
5351                               size_t len, loff_t off)
5352{
5353        struct inode *inode = sb_dqopt(sb)->files[type];
5354        ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5355        int offset = off & (sb->s_blocksize - 1);
5356        int tocopy;
5357        size_t toread;
5358        struct buffer_head *bh;
5359        loff_t i_size = i_size_read(inode);
5360
5361        if (off > i_size)
5362                return 0;
5363        if (off+len > i_size)
5364                len = i_size-off;
5365        toread = len;
5366        while (toread > 0) {
5367                tocopy = sb->s_blocksize - offset < toread ?
5368                                sb->s_blocksize - offset : toread;
5369                bh = ext4_bread(NULL, inode, blk, 0);
5370                if (IS_ERR(bh))
5371                        return PTR_ERR(bh);
5372                if (!bh)        /* A hole? */
5373                        memset(data, 0, tocopy);
5374                else
5375                        memcpy(data, bh->b_data+offset, tocopy);
5376                brelse(bh);
5377                offset = 0;
5378                toread -= tocopy;
5379                data += tocopy;
5380                blk++;
5381        }
5382        return len;
5383}
5384
5385/* Write to quotafile (we know the transaction is already started and has
5386 * enough credits) */
5387static ssize_t ext4_quota_write(struct super_block *sb, int type,
5388                                const char *data, size_t len, loff_t off)
5389{
5390        struct inode *inode = sb_dqopt(sb)->files[type];
5391        ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5392        int err, offset = off & (sb->s_blocksize - 1);
5393        struct buffer_head *bh;
5394        handle_t *handle = journal_current_handle();
5395
5396        if (EXT4_SB(sb)->s_journal && !handle) {
5397                ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5398                        " cancelled because transaction is not started",
5399                        (unsigned long long)off, (unsigned long long)len);
5400                return -EIO;
5401        }
5402        /*
5403         * Since we account only one data block in transaction credits,
5404         * then it is impossible to cross a block boundary.
5405         */
5406        if (sb->s_blocksize - offset < len) {
5407                ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5408                        " cancelled because not block aligned",
5409                        (unsigned long long)off, (unsigned long long)len);
5410                return -EIO;
5411        }
5412
5413        bh = ext4_bread(handle, inode, blk, 1);
5414        if (IS_ERR(bh))
5415                return PTR_ERR(bh);
5416        if (!bh)
5417                goto out;
5418        BUFFER_TRACE(bh, "get write access");
5419        err = ext4_journal_get_write_access(handle, bh);
5420        if (err) {
5421                brelse(bh);
5422                return err;
5423        }
5424        lock_buffer(bh);
5425        memcpy(bh->b_data+offset, data, len);
5426        flush_dcache_page(bh->b_page);
5427        unlock_buffer(bh);
5428        err = ext4_handle_dirty_metadata(handle, NULL, bh);
5429        brelse(bh);
5430out:
5431        if (inode->i_size < off + len) {
5432                i_size_write(inode, off + len);
5433                EXT4_I(inode)->i_disksize = inode->i_size;
5434                ext4_mark_inode_dirty(handle, inode);
5435        }
5436        return len;
5437}
5438
5439#endif
5440
5441static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
5442                       const char *dev_name, void *data)
5443{
5444        return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
5445}
5446
5447#if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
5448static inline void register_as_ext2(void)
5449{
5450        int err = register_filesystem(&ext2_fs_type);
5451        if (err)
5452                printk(KERN_WARNING
5453                       "EXT4-fs: Unable to register as ext2 (%d)\n", err);
5454}
5455
5456static inline void unregister_as_ext2(void)
5457{
5458        unregister_filesystem(&ext2_fs_type);
5459}
5460
5461static inline int ext2_feature_set_ok(struct super_block *sb)
5462{
5463        if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP))
5464                return 0;
5465        if (sb->s_flags & MS_RDONLY)
5466                return 1;
5467        if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))
5468                return 0;
5469        return 1;
5470}
5471#else
5472static inline void register_as_ext2(void) { }
5473static inline void unregister_as_ext2(void) { }
5474static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
5475#endif
5476
5477#if !defined(CONFIG_EXT3_FS) && !defined(CONFIG_EXT3_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
5478static inline void register_as_ext3(void)
5479{
5480        int err = register_filesystem(&ext3_fs_type);
5481        if (err)
5482                printk(KERN_WARNING
5483                       "EXT4-fs: Unable to register as ext3 (%d)\n", err);
5484}
5485
5486static inline void unregister_as_ext3(void)
5487{
5488        unregister_filesystem(&ext3_fs_type);
5489}
5490
5491static inline int ext3_feature_set_ok(struct super_block *sb)
5492{
5493        if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT3_FEATURE_INCOMPAT_SUPP))
5494                return 0;
5495        if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
5496                return 0;
5497        if (sb->s_flags & MS_RDONLY)
5498                return 1;
5499        if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT3_FEATURE_RO_COMPAT_SUPP))
5500                return 0;
5501        return 1;
5502}
5503#else
5504static inline void register_as_ext3(void) { }
5505static inline void unregister_as_ext3(void) { }
5506static inline int ext3_feature_set_ok(struct super_block *sb) { return 0; }
5507#endif
5508
5509static struct file_system_type ext4_fs_type = {
5510        .owner          = THIS_MODULE,
5511        .name           = "ext4",
5512        .mount          = ext4_mount,
5513        .kill_sb        = kill_block_super,
5514        .fs_flags       = FS_REQUIRES_DEV,
5515};
5516MODULE_ALIAS_FS("ext4");
5517
5518static int __init ext4_init_feat_adverts(void)
5519{
5520        struct ext4_features *ef;
5521        int ret = -ENOMEM;
5522
5523        ef = kzalloc(sizeof(struct ext4_features), GFP_KERNEL);
5524        if (!ef)
5525                goto out;
5526
5527        ef->f_kobj.kset = ext4_kset;
5528        init_completion(&ef->f_kobj_unregister);
5529        ret = kobject_init_and_add(&ef->f_kobj, &ext4_feat_ktype, NULL,
5530                                   "features");
5531        if (ret) {
5532                kfree(ef);
5533                goto out;
5534        }
5535
5536        ext4_feat = ef;
5537        ret = 0;
5538out:
5539        return ret;
5540}
5541
5542static void ext4_exit_feat_adverts(void)
5543{
5544        kobject_put(&ext4_feat->f_kobj);
5545        wait_for_completion(&ext4_feat->f_kobj_unregister);
5546        kfree(ext4_feat);
5547}
5548
5549/* Shared across all ext4 file systems */
5550wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
5551struct mutex ext4__aio_mutex[EXT4_WQ_HASH_SZ];
5552
5553static int __init ext4_init_fs(void)
5554{
5555        int i, err;
5556
5557        ext4_li_info = NULL;
5558        mutex_init(&ext4_li_mtx);
5559
5560        /* Build-time check for flags consistency */
5561        ext4_check_flag_values();
5562
5563        for (i = 0; i < EXT4_WQ_HASH_SZ; i++) {
5564                mutex_init(&ext4__aio_mutex[i]);
5565                init_waitqueue_head(&ext4__ioend_wq[i]);
5566        }
5567
5568        err = ext4_init_es();
5569        if (err)
5570                return err;
5571
5572        err = ext4_init_pageio();
5573        if (err)
5574                goto out7;
5575
5576        err = ext4_init_system_zone();
5577        if (err)
5578                goto out6;
5579        ext4_kset = kset_create_and_add("ext4", NULL, fs_kobj);
5580        if (!ext4_kset) {
5581                err = -ENOMEM;
5582                goto out5;
5583        }
5584        ext4_proc_root = proc_mkdir("fs/ext4", NULL);
5585
5586        err = ext4_init_feat_adverts();
5587        if (err)
5588                goto out4;
5589
5590        err = ext4_init_mballoc();
5591        if (err)
5592                goto out2;
5593        else
5594                ext4_mballoc_ready = 1;
5595        err = init_inodecache();
5596        if (err)
5597                goto out1;
5598        register_as_ext3();
5599        register_as_ext2();
5600        err = register_filesystem(&ext4_fs_type);
5601        if (err)
5602                goto out;
5603
5604        return 0;
5605out:
5606        unregister_as_ext2();
5607        unregister_as_ext3();
5608        destroy_inodecache();
5609out1:
5610        ext4_mballoc_ready = 0;
5611        ext4_exit_mballoc();
5612out2:
5613        ext4_exit_feat_adverts();
5614out4:
5615        if (ext4_proc_root)
5616                remove_proc_entry("fs/ext4", NULL);
5617        kset_unregister(ext4_kset);
5618out5:
5619        ext4_exit_system_zone();
5620out6:
5621        ext4_exit_pageio();
5622out7:
5623        ext4_exit_es();
5624
5625        return err;
5626}
5627
5628static void __exit ext4_exit_fs(void)
5629{
5630        ext4_destroy_lazyinit_thread();
5631        unregister_as_ext2();
5632        unregister_as_ext3();
5633        unregister_filesystem(&ext4_fs_type);
5634        destroy_inodecache();
5635        ext4_exit_mballoc();
5636        ext4_exit_feat_adverts();
5637        remove_proc_entry("fs/ext4", NULL);
5638        kset_unregister(ext4_kset);
5639        ext4_exit_system_zone();
5640        ext4_exit_pageio();
5641        ext4_exit_es();
5642}
5643
5644MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
5645MODULE_DESCRIPTION("Fourth Extended Filesystem");
5646MODULE_LICENSE("GPL");
5647module_init(ext4_init_fs)
5648module_exit(ext4_exit_fs)
5649