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Subject: [PATCH v1 00/11] NFS/RDMA client side connection overhaul
From:   Chuck Lever <chuck.lever@oracle.com>
To:     linux-rdma@vger.kernel.org, linux-nfs@vger.kernel.org
Date:   Fri, 21 Feb 2020 17:00:06 -0500
Message-ID: <20200221214906.2072.32572.stgit@manet.1015granger.net>
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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