Re: [PATCH v3 11/11] NFS replace cross device with cross filesystem check in copy_file_range

[Matthew Wilcox <willy@xxxxxxxxxxxxx>]

On Thu, Oct 25, 2018 at 05:51:47PM -0400, Olga Kornievskaia wrote:
> -	if (file_in->f_inode->i_sb != file_out->f_inode->i_sb)
> +	if (file_in->f_inode->i_sb->s_type != file_out->f_inode->i_sb->s_type)

Isn't it simpler to do:

	if (file_in->f_inode->i_sb->s_type != &nfs4_fs_type)

But now I've done some grepping, and I wonder whether it's possible
/ desirable to also copy between inodes on a nfs4_remote_fs_type,
nfs4_remote_referral_fs_type, nfs4_referral_fs_type or nfs4_xdev_fs_type.
I haven't kept up with NFS development for a while, so maybe none of
those are possible.