[PATCH v1 00/11] NFS/RDMA client side connection overhaul

Chuck Lever
2020-02-21T22:00:14Z

Howdy.

I've had reports (and personal experience) where the Linux NFS/RDMA
client waits for a very long time after a disruption of the network
or NFS server.

There is a disconnect time wait in the Connection Manager which
blocks the RPC/RDMA transport from tearing down a connection for a
few minutes when the remote cannot respond to DREQ messages.

An RPC/RDMA transport has only one slot for connection state, so the
transport is prevented from establishing a fresh connection until
the time wait completes.

This patch series refactors the connection end point data structures
to enable one active and multiple zombie connections. Now, while a
defunct connection is waiting to die, it is separated from the
transport, clearing the way for the immediate creation of a new
connection. Clean-up of the old connection's data structures and
resources then completes in the background.

Well, that's the idea, anyway. Review and comments welcome. Hoping
this can be merged in v5.7.

---

Chuck Lever (11):
xprtrdma: Invoke rpcrdma_ep_create() in the connect worker
xprtrdma: Refactor frwr_init_mr()
xprtrdma: Clean up the post_send path
xprtrdma: Refactor rpcrdma_ep_connect() and rpcrdma_ep_disconnect()
xprtrdma: Allocate Protection Domain in rpcrdma_ep_create()
xprtrdma: Invoke rpcrdma_ia_open in the connect worker
xprtrdma: Remove rpcrdma_ia::ri_flags
xprtrdma: Disconnect on flushed completion
xprtrdma: Merge struct rpcrdma_ia into struct rpcrdma_ep
xprtrdma: Extract sockaddr from struct rdma_cm_id
xprtrdma: kmalloc rpcrdma_ep separate from rpcrdma_xprt

include/trace/events/rpcrdma.h | 97 ++---
net/sunrpc/xprtrdma/backchannel.c | 8
net/sunrpc/xprtrdma/frwr_ops.c | 152 ++++----
net/sunrpc/xprtrdma/rpc_rdma.c | 32 +-
net/sunrpc/xprtrdma/transport.c | 72 +---
net/sunrpc/xprtrdma/verbs.c | 681 ++++++++++++++-----------------------
net/sunrpc/xprtrdma/xprt_rdma.h | 89 ++---
7 files changed, 445 insertions(+), 686 deletions(-)

--
Chuck Lever