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authorChuck Lever <chuck.lever@oracle.com>2021-07-19 17:48:10 +0300
committerAnna Schumaker <Anna.Schumaker@Netapp.com>2021-08-09 23:32:27 +0300
commit823c73d0c539a0c1740c7929a7aad3f844e69d70 (patch)
tree804ce5076c58ad5ccf1dd9486834883e04b3487e /net/sunrpc/clnt.c
parentaede517207b2bf4e5176492ce3be0e45feb581bd (diff)
downloadlinux-823c73d0c539a0c1740c7929a7aad3f844e69d70.tar.xz
SUNRPC: Unset RPC_TASK_NO_RETRANS_TIMEOUT for NULL RPCs
In some rare failure modes, the server is actually reading the transport, but then just dropping the requests on the floor. TCP_USER_TIMEOUT cannot detect that case. Prevent such a stuck server from pinning client resources indefinitely by ensuring that certain idempotent requests (such as NULL) can time out even if the connection is still operational. Otherwise rpc_bind_new_program(), gss_destroy_cred(), or rpc_clnt_test_and_add_xprt() can wait forever. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Diffstat (limited to 'net/sunrpc/clnt.c')
-rw-r--r--net/sunrpc/clnt.c15
1 files changed, 14 insertions, 1 deletions
diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index ca2000d8cf64..d34737a8a68a 100644
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -2694,6 +2694,18 @@ static const struct rpc_procinfo rpcproc_null = {
.p_decode = rpcproc_decode_null,
};
+static void
+rpc_null_call_prepare(struct rpc_task *task, void *data)
+{
+ task->tk_flags &= ~RPC_TASK_NO_RETRANS_TIMEOUT;
+ rpc_call_start(task);
+}
+
+static const struct rpc_call_ops rpc_null_ops = {
+ .rpc_call_prepare = rpc_null_call_prepare,
+ .rpc_call_done = rpc_default_callback,
+};
+
static
struct rpc_task *rpc_call_null_helper(struct rpc_clnt *clnt,
struct rpc_xprt *xprt, struct rpc_cred *cred, int flags,
@@ -2707,7 +2719,7 @@ struct rpc_task *rpc_call_null_helper(struct rpc_clnt *clnt,
.rpc_xprt = xprt,
.rpc_message = &msg,
.rpc_op_cred = cred,
- .callback_ops = (ops != NULL) ? ops : &rpc_default_ops,
+ .callback_ops = ops ?: &rpc_null_ops,
.callback_data = data,
.flags = flags | RPC_TASK_SOFT | RPC_TASK_SOFTCONN |
RPC_TASK_NULLCREDS,
@@ -2758,6 +2770,7 @@ static void rpc_cb_add_xprt_release(void *calldata)
}
static const struct rpc_call_ops rpc_cb_add_xprt_call_ops = {
+ .rpc_call_prepare = rpc_null_call_prepare,
.rpc_call_done = rpc_cb_add_xprt_done,
.rpc_release = rpc_cb_add_xprt_release,
};