diff options
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/ext4/super.c | 91 |
1 files changed, 49 insertions, 42 deletions
diff --git a/fs/ext4/super.c b/fs/ext4/super.c index de67c3657b83..4037fe0b5a5c 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -2254,6 +2254,49 @@ static struct kobj_type ext4_ktype = { .release = ext4_sb_release, }; +/* + * Check whether this filesystem can be mounted based on + * the features present and the RDONLY/RDWR mount requested. + * Returns 1 if this filesystem can be mounted as requested, + * 0 if it cannot be. + */ +static int ext4_feature_set_ok(struct super_block *sb, int readonly) +{ + if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT4_FEATURE_INCOMPAT_SUPP)) { + ext4_msg(sb, KERN_ERR, + "Couldn't mount because of " + "unsupported optional features (%x)", + (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) & + ~EXT4_FEATURE_INCOMPAT_SUPP)); + return 0; + } + + if (readonly) + return 1; + + /* Check that feature set is OK for a read-write mount */ + if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT4_FEATURE_RO_COMPAT_SUPP)) { + ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of " + "unsupported optional features (%x)", + (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) & + ~EXT4_FEATURE_RO_COMPAT_SUPP)); + return 0; + } + /* + * Large file size enabled file system can only be mounted + * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF + */ + if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) { + if (sizeof(blkcnt_t) < sizeof(u64)) { + ext4_msg(sb, KERN_ERR, "Filesystem with huge files " + "cannot be mounted RDWR without " + "CONFIG_LBDAF"); + return 0; + } + } + return 1; +} + static int ext4_fill_super(struct super_block *sb, void *data, int silent) __releases(kernel_lock) __acquires(kernel_lock) @@ -2275,7 +2318,6 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent) unsigned int db_count; unsigned int i; int needs_recovery, has_huge_files; - int features; __u64 blocks_count; int err; unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO; @@ -2402,39 +2444,9 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent) * previously didn't change the revision level when setting the flags, * so there is a chance incompat flags are set on a rev 0 filesystem. */ - features = EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT4_FEATURE_INCOMPAT_SUPP); - if (features) { - ext4_msg(sb, KERN_ERR, - "Couldn't mount because of " - "unsupported optional features (%x)", - (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) & - ~EXT4_FEATURE_INCOMPAT_SUPP)); - goto failed_mount; - } - features = EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT4_FEATURE_RO_COMPAT_SUPP); - if (!(sb->s_flags & MS_RDONLY) && features) { - ext4_msg(sb, KERN_ERR, - "Couldn't mount RDWR because of " - "unsupported optional features (%x)", - (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) & - ~EXT4_FEATURE_RO_COMPAT_SUPP)); + if (!ext4_feature_set_ok(sb, (sb->s_flags & MS_RDONLY))) goto failed_mount; - } - has_huge_files = EXT4_HAS_RO_COMPAT_FEATURE(sb, - EXT4_FEATURE_RO_COMPAT_HUGE_FILE); - if (has_huge_files) { - /* - * Large file size enabled file system can only be - * mount if kernel is build with CONFIG_LBDAF - */ - if (sizeof(root->i_blocks) < sizeof(u64) && - !(sb->s_flags & MS_RDONLY)) { - ext4_msg(sb, KERN_ERR, "Filesystem with huge " - "files cannot be mounted read-write " - "without CONFIG_LBDAF"); - goto failed_mount; - } - } + blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size); if (blocksize < EXT4_MIN_BLOCK_SIZE || @@ -2470,6 +2482,8 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent) } } + has_huge_files = EXT4_HAS_RO_COMPAT_FEATURE(sb, + EXT4_FEATURE_RO_COMPAT_HUGE_FILE); sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits, has_huge_files); sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files); @@ -3485,18 +3499,11 @@ static int ext4_remount(struct super_block *sb, int *flags, char *data) if (sbi->s_journal) ext4_mark_recovery_complete(sb, es); } else { - int ret; - if ((ret = EXT4_HAS_RO_COMPAT_FEATURE(sb, - ~EXT4_FEATURE_RO_COMPAT_SUPP))) { - ext4_msg(sb, KERN_WARNING, "couldn't " - "remount RDWR because of unsupported " - "optional features (%x)", - (le32_to_cpu(sbi->s_es->s_feature_ro_compat) & - ~EXT4_FEATURE_RO_COMPAT_SUPP)); + /* Make sure we can mount this feature set readwrite */ + if (!ext4_feature_set_ok(sb, 0)) { err = -EROFS; goto restore_opts; } - /* * Make sure the group descriptor checksums * are sane. If they aren't, refuse to remount r/w. |