linux/net/sunrpc/xprtrdma
Chuck Lever 1e091c3bbf svcrdma: Ignore source port when computing DRC hash
The DRC appears to be effectively empty after an RPC/RDMA transport
reconnect. The problem is that each connection uses a different
source port, which defeats the DRC hash.

Clients always have to disconnect before they send retransmissions
to reset the connection's credit accounting, thus every retransmit
on NFS/RDMA will miss the DRC.

An NFS/RDMA client's IP source port is meaningless for RDMA
transports. The transport layer typically sets the source port value
on the connection to a random ephemeral port. The server already
ignores it for the "secure port" check. See commit 16e4d93f6d
("NFSD: Ignore client's source port on RDMA transports").

The Linux NFS server's DRC resolves XID collisions from the same
source IP address by using the checksum of the first 200 bytes of
the RPC call header.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Cc: stable@vger.kernel.org # v4.14+
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2019-06-19 16:40:40 -04:00
..
backchannel.c xprtrdma: Aggregate the inline settings in struct rpcrdma_ep 2019-04-25 15:39:16 -04:00
frwr_ops.c xprtrdma: Remove pr_err() call sites from completion handlers 2019-04-25 15:40:09 -04:00
Makefile xprtrdma: Remove support for FMR memory registration 2019-01-02 12:05:17 -05:00
module.c NFS client updates for Linux 4.18 2018-06-12 10:09:03 -07:00
rpc_rdma.c xprtrdma: Aggregate the inline settings in struct rpcrdma_ep 2019-04-25 15:39:16 -04:00
svc_rdma.c sunrpc: remove svc_rdma_bc_class 2018-12-27 21:01:41 -05:00
svc_rdma_backchannel.c SUNRPC: Refactor xprt_request_wait_receive() 2019-04-25 14:18:12 -04:00
svc_rdma_recvfrom.c svcrdma: Remove syslog warnings in work completion handlers 2019-02-06 15:37:15 -05:00
svc_rdma_rw.c svcrdma: Remove syslog warnings in work completion handlers 2019-02-06 15:37:15 -05:00
svc_rdma_sendto.c svcrdma: Remove syslog warnings in work completion handlers 2019-02-06 15:37:15 -05:00
svc_rdma_transport.c svcrdma: Ignore source port when computing DRC hash 2019-06-19 16:40:40 -04:00
transport.c xprtrdma: Eliminate struct rpcrdma_create_data_internal 2019-04-25 15:39:40 -04:00
verbs.c xprtrdma: Update comments that reference ib_drain_qp 2019-04-25 15:40:31 -04:00
xprt_rdma.h xprtrdma: Remove stale comment 2019-04-25 15:42:04 -04:00