mptcp: refine memory scheduling

Similar to commit 7c80b038d23e ("net: fix sk_wmem_schedule() and
sk_rmem_schedule() errors"), let the MPTCP receive path schedule
exactly the required amount of memory.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index b4b4ca8..d77ca57 100644 (file)
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -323,9 +323,10 @@ static bool mptcp_rmem_schedule(struct sock *sk, struct sock *ssk, int size)
        struct mptcp_sock *msk = mptcp_sk(sk);
        int amt, amount;
 
-       if (size < msk->rmem_fwd_alloc)
+       if (size <= msk->rmem_fwd_alloc)
                return true;
 
+       size -= msk->rmem_fwd_alloc;
        amt = sk_mem_pages(size);
        amount = amt << PAGE_SHIFT;
        if (!__sk_mem_raise_allocated(sk, size, amt, SK_MEM_RECV))