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authorChuck Lever <chuck.lever@oracle.com>2017-04-11 20:23:10 +0300
committerAnna Schumaker <Anna.Schumaker@Netapp.com>2017-04-25 23:12:24 +0300
commitbebd031866caa404c522e91bb6fd0c69be04c707 (patch)
tree5046d400f405f383e1823d140e18c3f878002cec /net/sunrpc
parent91a10c52975a8c89e146a4f740e64cd147ba8e8a (diff)
downloadlinux-bebd031866caa404c522e91bb6fd0c69be04c707.tar.xz
xprtrdma: Support unplugging an HCA from under an NFS mount
The device driver for the underlying physical device associated with an RPC-over-RDMA transport can be removed while RPC-over-RDMA transports are still in use (ie, while NFS filesystems are still mounted and active). The IB core performs a connection event upcall to request that consumers free all RDMA resources associated with a transport. There may be pending RPCs when this occurs. Care must be taken to release associated resources without leaving references that can trigger a subsequent crash if a signal or soft timeout occurs. We rely on the caller of the transport's ->close method to ensure that the previous RPC task has invoked xprt_release but the transport remains write-locked. A DEVICE_REMOVE upcall forces a disconnect then sleeps. When ->close is invoked, it destroys the transport's H/W resources, then wakes the upcall, which completes and allows the core driver unload to continue. BugLink: https://bugzilla.linux-nfs.org/show_bug.cgi?id=266 Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Diffstat (limited to 'net/sunrpc')
-rw-r--r--net/sunrpc/xprtrdma/transport.c29
-rw-r--r--net/sunrpc/xprtrdma/verbs.c74
-rw-r--r--net/sunrpc/xprtrdma/xprt_rdma.h7
3 files changed, 101 insertions, 9 deletions
diff --git a/net/sunrpc/xprtrdma/transport.c b/net/sunrpc/xprtrdma/transport.c
index 83e219d7aba4..62ecbccd9748 100644
--- a/net/sunrpc/xprtrdma/transport.c
+++ b/net/sunrpc/xprtrdma/transport.c
@@ -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
@@ -680,6 +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
@@ -706,6 +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);
diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c
index c8813fb2163f..938fd9e6f308 100644
--- a/net/sunrpc/xprtrdma/verbs.c
+++ b/net/sunrpc/xprtrdma/verbs.c
@@ -69,6 +69,8 @@
/*
* internal functions
*/
+static void rpcrdma_destroy_mrs(struct rpcrdma_buffer *buf);
+static void rpcrdma_dma_unmap_regbuf(struct rpcrdma_regbuf *rb);
static struct workqueue_struct *rpcrdma_receive_wq;
@@ -262,6 +264,21 @@ rpcrdma_conn_upcall(struct rdma_cm_id *id, struct rdma_cm_event *event)
__func__, ep);
complete(&ia->ri_done);
break;
+ case RDMA_CM_EVENT_DEVICE_REMOVAL:
+#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
+ pr_info("rpcrdma: removing device for %pIS:%u\n",
+ sap, rpc_get_port(sap));
+#endif
+ set_bit(RPCRDMA_IAF_REMOVING, &ia->ri_flags);
+ ep->rep_connected = -ENODEV;
+ xprt_force_disconnect(&xprt->rx_xprt);
+ wait_for_completion(&ia->ri_remove_done);
+
+ ia->ri_id = NULL;
+ ia->ri_pd = NULL;
+ ia->ri_device = NULL;
+ /* Return 1 to ensure the core destroys the id. */
+ return 1;
case RDMA_CM_EVENT_ESTABLISHED:
connstate = 1;
ib_query_qp(ia->ri_id->qp, attr,
@@ -291,9 +308,6 @@ rpcrdma_conn_upcall(struct rdma_cm_id *id, struct rdma_cm_event *event)
goto connected;
case RDMA_CM_EVENT_DISCONNECTED:
connstate = -ECONNABORTED;
- goto connected;
- case RDMA_CM_EVENT_DEVICE_REMOVAL:
- connstate = -ENODEV;
connected:
dprintk("RPC: %s: %sconnected\n",
__func__, connstate > 0 ? "" : "dis");
@@ -346,6 +360,7 @@ rpcrdma_create_id(struct rpcrdma_xprt *xprt,
int rc;
init_completion(&ia->ri_done);
+ init_completion(&ia->ri_remove_done);
id = rdma_create_id(&init_net, rpcrdma_conn_upcall, xprt, RDMA_PS_TCP,
IB_QPT_RC);
@@ -469,6 +484,56 @@ out_err:
}
/**
+ * rpcrdma_ia_remove - Handle device driver unload
+ * @ia: interface adapter being removed
+ *
+ * Divest transport H/W resources associated with this adapter,
+ * but allow it to be restored later.
+ */
+void
+rpcrdma_ia_remove(struct rpcrdma_ia *ia)
+{
+ struct rpcrdma_xprt *r_xprt = container_of(ia, struct rpcrdma_xprt,
+ rx_ia);
+ struct rpcrdma_ep *ep = &r_xprt->rx_ep;
+ struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
+ struct rpcrdma_req *req;
+ struct rpcrdma_rep *rep;
+
+ cancel_delayed_work_sync(&buf->rb_refresh_worker);
+
+ /* This is similar to rpcrdma_ep_destroy, but:
+ * - Don't cancel the connect worker.
+ * - Don't call rpcrdma_ep_disconnect, which waits
+ * for another conn upcall, which will deadlock.
+ * - rdma_disconnect is unneeded, the underlying
+ * connection is already gone.
+ */
+ if (ia->ri_id->qp) {
+ ib_drain_qp(ia->ri_id->qp);
+ rdma_destroy_qp(ia->ri_id);
+ ia->ri_id->qp = NULL;
+ }
+ ib_free_cq(ep->rep_attr.recv_cq);
+ ib_free_cq(ep->rep_attr.send_cq);
+
+ /* The ULP is responsible for ensuring all DMA
+ * mappings and MRs are gone.
+ */
+ list_for_each_entry(rep, &buf->rb_recv_bufs, rr_list)
+ rpcrdma_dma_unmap_regbuf(rep->rr_rdmabuf);
+ list_for_each_entry(req, &buf->rb_allreqs, rl_all) {
+ rpcrdma_dma_unmap_regbuf(req->rl_rdmabuf);
+ rpcrdma_dma_unmap_regbuf(req->rl_sendbuf);
+ rpcrdma_dma_unmap_regbuf(req->rl_recvbuf);
+ }
+ rpcrdma_destroy_mrs(buf);
+
+ /* Allow waiters to continue */
+ complete(&ia->ri_remove_done);
+}
+
+/**
* rpcrdma_ia_close - Clean up/close an IA.
* @ia: interface adapter to close
*
@@ -1080,7 +1145,8 @@ rpcrdma_get_mw(struct rpcrdma_xprt *r_xprt)
out_nomws:
dprintk("RPC: %s: no MWs available\n", __func__);
- schedule_delayed_work(&buf->rb_refresh_worker, 0);
+ if (r_xprt->rx_ep.rep_connected != -ENODEV)
+ schedule_delayed_work(&buf->rb_refresh_worker, 0);
/* Allow the reply handler and refresh worker to run */
cond_resched();
diff --git a/net/sunrpc/xprtrdma/xprt_rdma.h b/net/sunrpc/xprtrdma/xprt_rdma.h
index 9d58260533fc..1c5de1af195b 100644
--- a/net/sunrpc/xprtrdma/xprt_rdma.h
+++ b/net/sunrpc/xprtrdma/xprt_rdma.h
@@ -69,6 +69,7 @@ struct rpcrdma_ia {
struct rdma_cm_id *ri_id;
struct ib_pd *ri_pd;
struct completion ri_done;
+ struct completion ri_remove_done;
int ri_async_rc;
unsigned int ri_max_segs;
unsigned int ri_max_frmr_depth;
@@ -78,10 +79,15 @@ struct rpcrdma_ia {
bool ri_reminv_expected;
bool ri_implicit_roundup;
enum ib_mr_type ri_mrtype;
+ unsigned long ri_flags;
struct ib_qp_attr ri_qp_attr;
struct ib_qp_init_attr ri_qp_init_attr;
};
+enum {
+ RPCRDMA_IAF_REMOVING = 0,
+};
+
/*
* RDMA Endpoint -- one per transport instance
*/
@@ -511,6 +517,7 @@ extern unsigned int xprt_rdma_memreg_strategy;
* Interface Adapter calls - xprtrdma/verbs.c
*/
int rpcrdma_ia_open(struct rpcrdma_xprt *xprt, struct sockaddr *addr);
+void rpcrdma_ia_remove(struct rpcrdma_ia *ia);
void rpcrdma_ia_close(struct rpcrdma_ia *);
bool frwr_is_supported(struct rpcrdma_ia *);
bool fmr_is_supported(struct rpcrdma_ia *);