xprtrdma: Support unplugging an HCA from under an NFS mount

[karo-tx-linux.git] / net / sunrpc / xprtrdma / transport.c

diff --git a/net/sunrpc/xprtrdma/transport.c b/net/sunrpc/xprtrdma/transport.c
index c717f54107768902db7c571ce65f4019624c7bcc..62ecbccd9748e54874059209070ebe4a6b9591e7 100644 (file)
--- a/net/sunrpc/xprtrdma/transport.c
+++ b/net/sunrpc/xprtrdma/transport.c
@@ -66,8 +66,8 @@ static unsigned int xprt_rdma_slot_table_entries = RPCRDMA_DEF_SLOT_TABLE;
 unsigned int xprt_rdma_max_inline_read = RPCRDMA_DEF_INLINE;
 static unsigned int xprt_rdma_max_inline_write = RPCRDMA_DEF_INLINE;
 static unsigned int xprt_rdma_inline_write_padding;
-static unsigned int xprt_rdma_memreg_strategy = RPCRDMA_FRMR;
-               int xprt_rdma_pad_optimize = 0;
+unsigned int xprt_rdma_memreg_strategy         = RPCRDMA_FRMR;
+int xprt_rdma_pad_optimize;
 
 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
 
@@ -396,7 +396,7 @@ xprt_setup_rdma(struct xprt_create *args)
 
        new_xprt = rpcx_to_rdmax(xprt);
 
-       rc = rpcrdma_ia_open(new_xprt, sap, xprt_rdma_memreg_strategy);
+       rc = rpcrdma_ia_open(new_xprt, sap);
        if (rc)
                goto out1;
 
@@ -457,19 +457,33 @@ out1:
        return ERR_PTR(rc);
 }
 
-/*
- * Close a connection, during shutdown or timeout/reconnect
+/**
+ * xprt_rdma_close - Close down RDMA connection
+ * @xprt: generic transport to be closed
+ *
+ * Called during transport shutdown reconnect, or device
+ * removal. Caller holds the transport's write lock.
  */
 static void
 xprt_rdma_close(struct rpc_xprt *xprt)
 {
        struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
+       struct rpcrdma_ep *ep = &r_xprt->rx_ep;
+       struct rpcrdma_ia *ia = &r_xprt->rx_ia;
+
+       dprintk("RPC:       %s: closing xprt %p\n", __func__, xprt);
 
-       dprintk("RPC:       %s: closing\n", __func__);
-       if (r_xprt->rx_ep.rep_connected > 0)
+       if (test_and_clear_bit(RPCRDMA_IAF_REMOVING, &ia->ri_flags)) {
+               xprt_clear_connected(xprt);
+               rpcrdma_ia_remove(ia);
+               return;
+       }
+       if (ep->rep_connected == -ENODEV)
+               return;
+       if (ep->rep_connected > 0)
                xprt->reestablish_timeout = 0;
        xprt_disconnect_done(xprt);
-       rpcrdma_ep_disconnect(&r_xprt->rx_ep, &r_xprt->rx_ia);
+       rpcrdma_ep_disconnect(ep, ia);
 }
 
 static void
@@ -484,6 +498,27 @@ xprt_rdma_set_port(struct rpc_xprt *xprt, u16 port)
        dprintk("RPC:       %s: %u\n", __func__, port);
 }
 
+/**
+ * xprt_rdma_timer - invoked when an RPC times out
+ * @xprt: controlling RPC transport
+ * @task: RPC task that timed out
+ *
+ * Invoked when the transport is still connected, but an RPC
+ * retransmit timeout occurs.
+ *
+ * Since RDMA connections don't have a keep-alive, forcibly
+ * disconnect and retry to connect. This drives full
+ * detection of the network path, and retransmissions of
+ * all pending RPCs.
+ */
+static void
+xprt_rdma_timer(struct rpc_xprt *xprt, struct rpc_task *task)
+{
+       dprintk("RPC: %5u %s: xprt = %p\n", task->tk_pid, __func__, xprt);
+
+       xprt_force_disconnect(xprt);
+}
+
 static void
 xprt_rdma_connect(struct rpc_xprt *xprt, struct rpc_task *task)
 {
@@ -659,6 +694,8 @@ xprt_rdma_free(struct rpc_task *task)
  * xprt_rdma_send_request - marshal and send an RPC request
  * @task: RPC task with an RPC message in rq_snd_buf
  *
+ * Caller holds the transport's write lock.
+ *
  * Return values:
  *        0:   The request has been sent
  * ENOTCONN:   Caller needs to invoke connect logic then call again
@@ -685,6 +722,9 @@ xprt_rdma_send_request(struct rpc_task *task)
        struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
        int rc = 0;
 
+       if (!xprt_connected(xprt))
+               goto drop_connection;
+
        /* On retransmit, remove any previously registered chunks */
        if (unlikely(!list_empty(&req->rl_registered)))
                r_xprt->rx_ia.ri_ops->ro_unmap_safe(r_xprt, req, false);
@@ -776,6 +816,7 @@ static struct rpc_xprt_ops xprt_rdma_procs = {
        .alloc_slot             = xprt_alloc_slot,
        .release_request        = xprt_release_rqst_cong,       /* ditto */
        .set_retrans_timeout    = xprt_set_retrans_timeout_def, /* ditto */
+       .timer                  = xprt_rdma_timer,
        .rpcbind                = rpcb_getport_async,   /* sunrpc/rpcb_clnt.c */
        .set_port               = xprt_rdma_set_port,
        .connect                = xprt_rdma_connect,