svcrdma: Fix another Receive buffer leak

[ Upstream commit 64d26422516b2e347b32e6d9b1d40b3c19a62aae ]

During a connection tear down, the Receive queue is flushed before
the device resources are freed. Typically, all the Receives flush
with IB_WR_FLUSH_ERR.

However, any pending successful Receives flush with IB_WR_SUCCESS,
and the server automatically posts a fresh Receive to replace the
completing one. This happens even after the connection has closed
and the RQ is drained. Receives that are posted after the RQ is
drained appear never to complete, causing a Receive resource leak.
The leaked Receive buffer is left DMA-mapped.

To prevent these late-posted recv_ctxt's from leaking, block new
Receive posting after XPT_CLOSE is set.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c
index efa5fcb5793f710cdd6d8eabe5a1353849f44db9..952b8f190850030d0d27af39a04963d848c427c9 100644 (file)
--- a/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c
+++ b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c
@@ -265,6 +265,8 @@ static int svc_rdma_post_recv(struct svcxprt_rdma *rdma)
 {
        struct svc_rdma_recv_ctxt *ctxt;
 
+       if (test_bit(XPT_CLOSE, &rdma->sc_xprt.xpt_flags))
+               return 0;
        ctxt = svc_rdma_recv_ctxt_get(rdma);
        if (!ctxt)
                return -ENOMEM;