xprtrdma: Manage MRs in context of a single connection

MRs are now allocated on demand so we can safely throw them away on
disconnect. This way an idle transport can disconnect and it won't
pin hardware MR resources.

Two additional changes:

- Now that all MRs are destroyed on disconnect, there's no need to
  check during header marshaling if a req has MRs to recycle. Each
  req is sent only once per connection, and now rl_registered is
  guaranteed to be empty when rpcrdma_marshal_req is invoked.

- Because MRs are now destroyed in a WQ_MEM_RECLAIM context, they
  also must be allocated in a WQ_MEM_RECLAIM context. This reduces
  the likelihood that device driver memory allocation will trigger
  memory reclaim during NFS writeback.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

1 files changed, 1 insertions, 8 deletions

diff --git a/net/sunrpc/xprtrdma/rpc_rdma.c b/net/sunrpc/xprtrdma/rpc_rdma.c
index 7c125e6cca4f..7b1358284242 100644
--- a/net/sunrpc/xprtrdma/rpc_rdma.c
+++ b/net/sunrpc/xprtrdma/rpc_rdma.c
@@ -363,8 +363,7 @@ static struct rpcrdma_mr_seg *rpcrdma_mr_prepare(struct rpcrdma_xprt *r_xprt,
 out_getmr_err:
 	trace_xprtrdma_nomrs(req);
 	xprt_wait_for_buffer_space(&r_xprt->rx_xprt);
-	if (r_xprt->rx_ep.rep_connected != -ENODEV)
-		schedule_work(&r_xprt->rx_buf.rb_refresh_worker);
+	rpcrdma_mrs_refresh(r_xprt);
 	return ERR_PTR(-EAGAIN);
 }
 
@@ -863,12 +862,6 @@ rpcrdma_marshal_req(struct rpcrdma_xprt *r_xprt, struct rpc_rqst *rqst)
 		rtype = rpcrdma_areadch;
 	}
 
-	/* If this is a retransmit, discard previously registered
-	 * chunks. Very likely the connection has been replaced,
-	 * so these registrations are invalid and unusable.
-	 */
-	frwr_recycle(req);
-
 	/* This implementation supports the following combinations
 	 * of chunk lists in one RPC-over-RDMA Call message:
 	 *