rpc: share one xps between all backchannels
The spec allows backchannels for multiple clients to share the same tcp
connection. When that happens, we need to use the same xprt for all of
them. Similarly, we need the same xps.
This fixes list corruption introduced by the multipath code.
Cc: stable@vger.kernel.org
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Acked-by: Trond Myklebust <trondmy@primarydata.com>
diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index b33721d..2808d55 100644
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -452,10 +452,20 @@
struct rpc_clnt *clnt = NULL;
struct rpc_xprt_switch *xps;
- xps = xprt_switch_alloc(xprt, GFP_KERNEL);
- if (xps == NULL) {
- xprt_put(xprt);
- return ERR_PTR(-ENOMEM);
+ if (args->bc_xprt && args->bc_xprt->xpt_bc_xps) {
+ WARN_ON(args->protocol != XPRT_TRANSPORT_BC_TCP);
+ xps = args->bc_xprt->xpt_bc_xps;
+ xprt_switch_get(xps);
+ } else {
+ xps = xprt_switch_alloc(xprt, GFP_KERNEL);
+ if (xps == NULL) {
+ xprt_put(xprt);
+ return ERR_PTR(-ENOMEM);
+ }
+ if (xprt->bc_xprt) {
+ xprt_switch_get(xps);
+ xprt->bc_xprt->xpt_bc_xps = xps;
+ }
}
clnt = rpc_new_client(args, xps, xprt, NULL);
if (IS_ERR(clnt))