We check whether a new handle can be started through ext4_journal_check_start() and the function refuses to start the handle when the filesystem is mounted with read-only. But now, when we remount the filesystem with read-only option, already started handles are allowed to be written on disk, but the subsequent metadata modification using the handles are refused by ext4_journal_check_start(). As an example, in ext4_evict_inode(), i_size can be set to 0 using a successfully started handle, but, when we remount the filesystem with read-only option at that time, the subsequent ext4_truncate() will be failed and the filesystem integrity will be damaged. Therefore, we need to permit the metadata modification using already started handles to be proceeded, even if s_flags of the filesystem is set to MS_RDONLY. Kitae found the problem and suggested the solution. Signed-off-by: Kitae Lee <kitae87.lee@xxxxxxxxxxx> Signed-off-by: Daeho Jeong <daeho.jeong@xxxxxxxxxxx> --- fs/ext4/ext4_jbd2.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/ext4/ext4_jbd2.c b/fs/ext4/ext4_jbd2.c index e770c1ee..3b59e11 100644 --- a/fs/ext4/ext4_jbd2.c +++ b/fs/ext4/ext4_jbd2.c @@ -43,7 +43,7 @@ static int ext4_journal_check_start(struct super_block *sb) journal_t *journal; might_sleep(); - if (sb->s_flags & MS_RDONLY) + if (sb->s_flags & MS_RDONLY && ext4_journal_current_handle() == NULL) return -EROFS; WARN_ON(sb->s_writers.frozen == SB_FREEZE_COMPLETE); journal = EXT4_SB(sb)->s_journal; -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
