[PATCH] kNFSd: Fix race in svcsock.c

[PATCH] kNFSd: Fix race in svcsock.c

From: Trond Myklebust <trond.myklebust@fys.uio.no>

knfsd needs to disable soft interrupts when calling
csum_partial_copy_to_xdr().

At the moment there's a nasty conflict between the RPC server and
client. The problem arises when you get to xdr_partial_copy_from_skb()
(and the kmap_atomic()); the RPC client can end up calling the same
function from a ->data_ready() soft interrupt, and corrupt any data
the knfsd process may have copied.