fs/cifs: keep guid when assigning fid to fileinfo

When we open a durable handle we give a Globally Unique
Identifier (GUID) to the server which we must keep for later reference
e.g. when reopening persistent handles on reconnection.

Without this the GUID generated for a new persistent handle was lost and
16 zero bytes were used instead on re-opening.
Signed-off-by: NAurelien Aptel <aaptel@suse.com>
CC: Stable <stable@vger.kernel.org>
Signed-off-by: NSteve French <smfrench@gmail.com>

fs/cifs/smb2ops.c

@@ -541,6 +541,7 @@ smb2_set_fid(struct cifsFileInfo *cfile, struct cifs_fid *fid, __u32 oplock)
 	server->ops->set_oplock_level(cinode, oplock, fid->epoch,
 				      &fid->purge_cache);
 	cinode->can_cache_brlcks = CIFS_CACHE_WRITE(cinode);
+	memcpy(cfile->fid.create_guid, fid->create_guid, 16);
 }
 
 static void