Commit 825cac27 authored by Seth Howell's avatar Seth Howell Committed by Ben Walker
Browse files

rdma.c: Create a single point of entry for qpair disconnect 



Since there are multiple events/conditions that can trigger a qpair
disconnection, we need to funnel them to a single point of entry. If
more than one of these events occurs, we can ignore all but the first
since once a disconnect starts, it can't be stopped.

Change-Id: I749c9087a25779fcd5e3fe6685583a610ad983d3
Signed-off-by: default avatarSeth Howell <seth.howell@intel.com>
Reviewed-on: https://review.gerrithub.io/c/443305


Tested-by: default avatarSPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: default avatarBen Walker <benjamin.walker@intel.com>
parent 0699216f

lib/nvmf/rdma.c

+20 −46
Original line number Diff line number Diff line
@@ -339,14 +339,11 @@ struct spdk_nvmf_rdma_qpair { 
	struct spdk_nvmf_rdma_wr		drain_send_wr;

	struct spdk_nvmf_rdma_wr		drain_recv_wr;



	/* Reference counter for how many unprocessed messages

	 * from other threads are currently outstanding. The

	 * qpair cannot be destroyed until this is 0. This is

	 * atomically incremented from any thread, but only

	 * decremented and read from the thread that owns this

	 * qpair.

	/* There are several ways a disconnect can start on a qpair

	 * and they are not all mutually exclusive. It is important

	 * that we only initialize one of these paths.

	 */

	uint32_t				refcnt;

	bool					disconnect_started;

};



struct spdk_nvmf_rdma_poller {
@@ -407,26 +404,6 @@ struct spdk_nvmf_rdma_transport { 
	TAILQ_HEAD(, spdk_nvmf_rdma_port)	ports;

};



static inline void

spdk_nvmf_rdma_qpair_inc_refcnt(struct spdk_nvmf_rdma_qpair *rqpair)

{

	__sync_fetch_and_add(&rqpair->refcnt, 1);

}



static inline uint32_t

spdk_nvmf_rdma_qpair_dec_refcnt(struct spdk_nvmf_rdma_qpair *rqpair)

{

	uint32_t old_refcnt, new_refcnt;



	do {

		old_refcnt = rqpair->refcnt;

		assert(old_refcnt > 0);

		new_refcnt = old_refcnt - 1;

	} while (__sync_bool_compare_and_swap(&rqpair->refcnt, old_refcnt, new_refcnt) == false);



	return new_refcnt;

}



static inline int

spdk_nvmf_rdma_check_ibv_state(enum ibv_qp_state state)

{
@@ -626,10 +603,6 @@ spdk_nvmf_rdma_qpair_destroy(struct spdk_nvmf_rdma_qpair *rqpair) 
{

	int qd;



	if (rqpair->refcnt != 0) {

		return;

	}



	spdk_trace_record(TRACE_RDMA_QP_DESTROY, 0, 0, (uintptr_t)rqpair->cm_id, 0);



	qd = spdk_nvmf_rdma_cur_queue_depth(rqpair);
@@ -2239,17 +2212,12 @@ static void 
_nvmf_rdma_qpair_disconnect(void *ctx)

{

	struct spdk_nvmf_qpair *qpair = ctx;

	struct spdk_nvmf_rdma_qpair *rqpair;



	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);



	spdk_nvmf_rdma_qpair_dec_refcnt(rqpair);



	spdk_nvmf_qpair_disconnect(qpair, NULL, NULL);

}



static void

_nvmf_rdma_disconnect_retry(void *ctx)

_nvmf_rdma_try_disconnect(void *ctx)

{

	struct spdk_nvmf_qpair *qpair = ctx;

	struct spdk_nvmf_poll_group *group;
@@ -2264,13 +2232,22 @@ _nvmf_rdma_disconnect_retry(void *ctx) 
	if (group == NULL) {

		/* The qpair hasn't been assigned to a group yet, so we can't

		 * process a disconnect. Send a message to ourself and try again. */

		spdk_thread_send_msg(spdk_get_thread(), _nvmf_rdma_disconnect_retry, qpair);

		spdk_thread_send_msg(spdk_get_thread(), _nvmf_rdma_try_disconnect, qpair);

		return;

	}



	spdk_thread_send_msg(group->thread, _nvmf_rdma_qpair_disconnect, qpair);

}



static inline void

spdk_nvmf_rdma_start_disconnect(struct spdk_nvmf_rdma_qpair *rqpair)

{

	if (__sync_bool_compare_and_swap(&rqpair->disconnect_started, false, true)) {

		_nvmf_rdma_try_disconnect(&rqpair->qpair);

	}

}





static int

nvmf_rdma_disconnect(struct rdma_cm_event *evt)

{
@@ -2293,9 +2270,8 @@ nvmf_rdma_disconnect(struct rdma_cm_event *evt) 
	spdk_trace_record(TRACE_RDMA_QP_DISCONNECT, 0, 0, (uintptr_t)rqpair->cm_id, 0);



	spdk_nvmf_rdma_update_ibv_state(rqpair);

	spdk_nvmf_rdma_qpair_inc_refcnt(rqpair);



	_nvmf_rdma_disconnect_retry(qpair);

	spdk_nvmf_rdma_start_disconnect(rqpair);



	return 0;

}
@@ -2426,8 +2402,7 @@ spdk_nvmf_process_ib_event(struct spdk_nvmf_rdma_device *device) 
		spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0,

				  (uintptr_t)rqpair->cm_id, event.event_type);

		spdk_nvmf_rdma_update_ibv_state(rqpair);

		spdk_nvmf_rdma_qpair_inc_refcnt(rqpair);

		_nvmf_rdma_disconnect_retry(&rqpair->qpair);

		spdk_nvmf_rdma_start_disconnect(rqpair);

		break;

	case IBV_EVENT_QP_LAST_WQE_REACHED:

		/* This event only occurs for shared receive queues, which are not currently supported. */
@@ -2443,8 +2418,7 @@ spdk_nvmf_process_ib_event(struct spdk_nvmf_rdma_device *device) 
				  (uintptr_t)rqpair->cm_id, event.event_type);

		state = spdk_nvmf_rdma_update_ibv_state(rqpair);

		if (state == IBV_QPS_ERR) {

			spdk_nvmf_rdma_qpair_inc_refcnt(rqpair);

			_nvmf_rdma_disconnect_retry(&rqpair->qpair);

			spdk_nvmf_rdma_start_disconnect(rqpair);

		}

		break;

	case IBV_EVENT_QP_REQ_ERR:
@@ -2859,7 +2833,7 @@ spdk_nvmf_rdma_poller_poll(struct spdk_nvmf_rdma_transport *rtransport, 


			if (rqpair->qpair.state == SPDK_NVMF_QPAIR_ACTIVE) {

				/* Disconnect the connection. */

				spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);

				spdk_nvmf_rdma_start_disconnect(rqpair);

			}

			continue;

		}
@@ -2920,7 +2894,7 @@ spdk_nvmf_rdma_poller_poll(struct spdk_nvmf_rdma_transport *rtransport, 
			rqpair = rdma_recv->qpair;

			/* The qpair should not send more requests than are allowed per qpair. */

			if (rqpair->current_recv_depth >= rqpair->max_queue_depth) {

				spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);

				spdk_nvmf_rdma_start_disconnect(rqpair);

			} else {

				rqpair->current_recv_depth++;

			}