According to the NFSv4.2 spec if the input and output file is the
same file, operation should fail with EINVAL. However, linux
copy_file_range() system call has no such restrictions. Therefore,
in such case let's return EOPNOTSUPP and allow VFS to fallback
to doing do_splice_direct(). Also when copy_file_range is called
on an NFSv4.0 or 4.1 mount (ie., a server that doesn't support
COPY functionality), we also need to return EOPNOTSUPP and
fallback to a regular copy.
Fixes xfstest generic/075, generic/091, generic/112, generic/263
for all NFSv4.x versions.
Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
        };
        ssize_t err, err2;
 
-       if (!nfs_server_capable(file_inode(dst), NFS_CAP_COPY))
-               return -EOPNOTSUPP;
-
        src_lock = nfs_get_lock_context(nfs_file_open_context(src));
        if (IS_ERR(src_lock))
                return PTR_ERR(src_lock);
 
                                    struct file *file_out, loff_t pos_out,
                                    size_t count, unsigned int flags)
 {
+       if (!nfs_server_capable(file_inode(file_out), NFS_CAP_COPY))
+               return -EOPNOTSUPP;
        if (file_inode(file_in) == file_inode(file_out))
-               return -EINVAL;
+               return -EOPNOTSUPP;
        return nfs42_proc_copy(file_in, pos_in, file_out, pos_out, count);
 }