> On Aug 17, 2020, at 11:19 AM, Chuck Lever <chuck.lever@xxxxxxxxxx> wrote: > > 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? Hi Anna, can you grab this for v5.9-rc ? > 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, > > -- Chuck Lever
