On Wed, Dec 12, 2018 at 01:55:28PM -0500, Olga Kornievskaia wrote: > On Wed, Dec 12, 2018 at 6:31 AM Luis Henriques <lhenriques@xxxxxxxx> wrote: > > I was wondering if, with the above check, it would make sense to also > > have an extra patch changing some filesystems (ceph, nfs and cifs) to > > simply return -EOPNOTSUPP (instead of -EINVAL) when inode_in == > > inode_out. Something like the diff below (not tested!). > > +++ b/fs/nfs/nfs4file.c > > @@ -136,7 +136,7 @@ static ssize_t nfs4_copy_file_range(struct file *file_in, loff_t pos_in, > > ssize_t ret; > > > > if (file_inode(file_in) == file_inode(file_out)) > > - return -EINVAL; > > + return -EOPNOTSUPP; > > Please don't change the NFS bits. This is against the NFS > specifications. RFC 7862 15.2.3 > > (snippet) > SAVED_FH and CURRENT_FH must be different files. If SAVED_FH and > CURRENT_FH refer to the same file, the operation MUST fail with > NFS4ERR_INVAL. I don't see how that applies. That refers to a requirement _in the protocol_ that determines what the server MUST do if the client sends it two FHs which refer to the same file. What we're talking about here is how a Linux filesystem behaves when receiving a copy_file_range() referring to the same file. As long as the Linux filesystem doesn't react by sending out one of these invalid protocol messages, I don't see the problem.
