Btrfs: remove redundant r/o check for superblock

mnt_want_write() and mnt_want_write_file() will check sb->s_flags with
MS_RDONLY, and we don't need to do it ourselves.

Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com>

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index c1f4975..b8034dc 100644 (file)
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -1381,14 +1381,10 @@ static noinline int btrfs_ioctl_snap_create_transid(struct file *file,
                                                    u64 *transid,
                                                    bool readonly)
 {
-       struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
        struct file *src_file;
        int namelen;
        int ret = 0;
 
-       if (root->fs_info->sb->s_flags & MS_RDONLY)
-               return -EROFS;
-
        ret = mnt_want_write_file(file);
        if (ret)
                goto out;
@@ -3269,9 +3265,6 @@ static long btrfs_ioctl_balance(struct file *file, void __user *arg)
        if (!capable(CAP_SYS_ADMIN))
                return -EPERM;
 
-       if (fs_info->sb->s_flags & MS_RDONLY)
-               return -EROFS;
-
        ret = mnt_want_write(file->f_path.mnt);
        if (ret)
                return ret;