btrfs: add read-only check to sysfs handler of features

We don't want to trigger the change on a read-only filesystem, similar
to what the label handler does.

Signed-off-by: David Sterba <dsterba@suse.cz>

diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c
index 539e7b5e3f86a83059f070409fdb36749a958ce4..6a6bb600b1ff43375490980f4dfc46e4b16601c2 100644 (file)
--- a/fs/btrfs/sysfs.c
+++ b/fs/btrfs/sysfs.c
@@ -120,6 +120,9 @@ static ssize_t btrfs_feature_attr_store(struct kobject *kobj,
        if (!fs_info)
                return -EPERM;
 
+       if (fs_info->sb->s_flags & MS_RDONLY)
+               return -EROFS;
+
        ret = kstrtoul(skip_spaces(buf), 0, &val);
        if (ret)
                return ret;