Dan Aloni reports that when a server disconnects abruptly, a few memory regions are left DMA mapped. Over time this leak could pin enough I/O resources to slow or even deadlock an NFS/RDMA client. I found that if a transport disconnects before pending Send and FastReg WRs can be posted, the to-be-registered MRs are stranded on the req's rl_registered list and never released -- since they weren't posted, there's no Send completion to DMA unmap them. Reported-by: Dan Aloni <dan@xxxxxxxxxxxx> Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx> --- net/sunrpc/xprtrdma/verbs.c | 2 ++ 1 file changed, 2 insertions(+) Hi Dan, does this help? diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c index 95c66a339e34..53962e41896d 100644 --- a/net/sunrpc/xprtrdma/verbs.c +++ b/net/sunrpc/xprtrdma/verbs.c @@ -936,6 +936,8 @@ static void rpcrdma_req_reset(struct rpcrdma_req *req) rpcrdma_regbuf_dma_unmap(req->rl_sendbuf); rpcrdma_regbuf_dma_unmap(req->rl_recvbuf); + + frwr_reset(req); } /* ASSUMPTION: the rb_allreqs list is stable for the duration,
