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xprtrdma: Simplify RPC wake-ups on connect

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Currently, when a connection is established, rpcrdma_conn_upcall
invokes rpcrdma_conn_func and then
wake_up_all(&ep->rep_connect_wait). The former wakes waiting RPCs,
but the connect worker is not done yet, and that leads to races,
double wakes, and difficulty understanding how this logic is
supposed to work.

Instead, collect all the "connection established" logic in the
connect worker (xprt_rdma_connect_worker). A disconnect worker is
retained to handle provider upcalls safely.

Fixes: 254f91e2fa ("xprtrdma: RPC/RDMA must invoke ... ")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
This commit is contained in:
Chuck Lever
2018-10-01 14:26:08 -04:00
committed by Anna Schumaker
parent 316a616e78
commit 31e62d25b5
3 changed files with 54 additions and 50 deletions
Download Patch File Download Diff File Expand all files Collapse all files

42
net/sunrpc/xprtrdma/verbs.c
View File

@@ -108,6 +108,25 @@ rpcrdma_destroy_wq(void)
}
}
/**
* rpcrdma_disconnect_worker - Force a disconnect
* @work: endpoint to be disconnected
*
* Provider callbacks can possibly run in an IRQ context. This function
* is invoked in a worker thread to guarantee that disconnect wake-up
* calls are always done in process context.
*/
static void
rpcrdma_disconnect_worker(struct work_struct *work)
{
struct rpcrdma_ep *ep = container_of(work, struct rpcrdma_ep,
rep_disconnect_worker.work);
struct rpcrdma_xprt *r_xprt =
container_of(ep, struct rpcrdma_xprt, rx_ep);
xprt_force_disconnect(&r_xprt->rx_xprt);
}
static void
rpcrdma_qp_async_error_upcall(struct ib_event *event, void *context)
{
@@ -121,7 +140,7 @@ rpcrdma_qp_async_error_upcall(struct ib_event *event, void *context)
if (ep->rep_connected == 1) {
ep->rep_connected = -EIO;
rpcrdma_conn_func(ep);
schedule_delayed_work(&ep->rep_disconnect_worker, 0);
wake_up_all(&ep->rep_connect_wait);
}
}
@@ -271,13 +290,14 @@ rpcrdma_cm_event_handler(struct rdma_cm_id *id, struct rdma_cm_event *event)
++xprt->connect_cookie;
ep->rep_connected = 1;
rpcrdma_update_connect_private(r_xprt, &event->param.conn);
goto connected;
wake_up_all(&ep->rep_connect_wait);
break;
case RDMA_CM_EVENT_CONNECT_ERROR:
ep->rep_connected = -ENOTCONN;
goto connected;
goto disconnected;
case RDMA_CM_EVENT_UNREACHABLE:
ep->rep_connected = -ENETUNREACH;
goto connected;
goto disconnected;
case RDMA_CM_EVENT_REJECTED:
dprintk("rpcrdma: connection to %s:%s rejected: %s\n",
rpcrdma_addrstr(r_xprt), rpcrdma_portstr(r_xprt),
@@ -285,12 +305,12 @@ rpcrdma_cm_event_handler(struct rdma_cm_id *id, struct rdma_cm_event *event)
ep->rep_connected = -ECONNREFUSED;
if (event->status == IB_CM_REJ_STALE_CONN)
ep->rep_connected = -EAGAIN;
goto connected;
goto disconnected;
case RDMA_CM_EVENT_DISCONNECTED:
++xprt->connect_cookie;
ep->rep_connected = -ECONNABORTED;
connected:
rpcrdma_conn_func(ep);
disconnected:
xprt_force_disconnect(xprt);
wake_up_all(&ep->rep_connect_wait);
break;
default:
@@ -550,7 +570,8 @@ rpcrdma_ep_create(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia,
cdata->max_requests >> 2);
ep->rep_send_count = ep->rep_send_batch;
init_waitqueue_head(&ep->rep_connect_wait);
INIT_DELAYED_WORK(&ep->rep_connect_worker, rpcrdma_connect_worker);
INIT_DELAYED_WORK(&ep->rep_disconnect_worker,
rpcrdma_disconnect_worker);
sendcq = ib_alloc_cq(ia->ri_device, NULL,
ep->rep_attr.cap.max_send_wr + 1,
@@ -623,7 +644,7 @@ out1:
void
rpcrdma_ep_destroy(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia)
{
cancel_delayed_work_sync(&ep->rep_connect_worker);
cancel_delayed_work_sync(&ep->rep_disconnect_worker);
if (ia->ri_id && ia->ri_id->qp) {
rpcrdma_ep_disconnect(ep, ia);
@@ -736,6 +757,7 @@ rpcrdma_ep_connect(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia)
{
struct rpcrdma_xprt *r_xprt = container_of(ia, struct rpcrdma_xprt,
rx_ia);
struct rpc_xprt *xprt = &r_xprt->rx_xprt;
int rc;
retry:
@@ -762,6 +784,8 @@ retry:
}
ep->rep_connected = 0;
xprt_clear_connected(xprt);
rpcrdma_post_recvs(r_xprt, true);
rc = rdma_connect(ia->ri_id, &ep->rep_remote_cma);