Commit d619f6c2 authored by Tomasz Zawadzki's avatar Tomasz Zawadzki
Browse files

nvmf/tcp: add round-robin poll group assignment for qpairs 



When no optimal poll group exists for a qpair,
assignment for round robin happens in spdk_nvmf_tgt_new_qpair().

RDMA transport implments the logic for this assignment in
nvmf_rdma_get_optimal_poll_group().
TCP relied on the spdk_nvmf_tgt_new_qpair() instead.

This resulted in race condition when looking up and assigning
optimal poll groups - see #2113.

To remedy that, TCP now follows the same pattern as RDMA.
Next patch will improve the sock map lookup to fix the #2113.

Signed-off-by: default avatarTomasz Zawadzki <tomasz.zawadzki@intel.com>
Change-Id: I672d22ac15d06309edf87ece5d30f8e8d1095fbb
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/10270


Community-CI: Broadcom CI <spdk-ci.pdl@broadcom.com>
Tested-by: default avatarSPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: default avatarAleksey Marchuk <alexeymar@mellanox.com>
Reviewed-by: default avatarJim Harris <james.r.harris@intel.com>
parent a1014fcc

lib/nvmf/tcp.c

+52 −2
Original line number Diff line number Diff line
@@ -297,6 +297,8 @@ struct spdk_nvmf_tcp_poll_group { 


	struct spdk_io_channel			*accel_channel;

	struct spdk_nvmf_tcp_control_msg_list	*control_msg_list;



	TAILQ_ENTRY(spdk_nvmf_tcp_poll_group)	link;

};



struct spdk_nvmf_tcp_port {
@@ -315,9 +317,12 @@ struct spdk_nvmf_tcp_transport { 
	struct spdk_nvmf_transport		transport;

	struct tcp_transport_opts               tcp_opts;



	struct spdk_nvmf_tcp_poll_group		*next_pg;



	pthread_mutex_t				lock;



	TAILQ_HEAD(, spdk_nvmf_tcp_port)	ports;

	TAILQ_HEAD(, spdk_nvmf_tcp_poll_group)	poll_groups;

};



static const struct spdk_json_object_decoder tcp_transport_opts_decoder[] = {
@@ -558,6 +563,7 @@ nvmf_tcp_create(struct spdk_nvmf_transport_opts *opts) 
	}



	TAILQ_INIT(&ttransport->ports);

	TAILQ_INIT(&ttransport->poll_groups);



	ttransport->transport.ops = &spdk_nvmf_transport_tcp;
@@ -1211,6 +1217,13 @@ nvmf_tcp_poll_group_create(struct spdk_nvmf_transport *transport) 
		goto cleanup;

	}



	pthread_mutex_lock(&ttransport->lock);

	TAILQ_INSERT_TAIL(&ttransport->poll_groups, tgroup, link);

	if (ttransport->next_pg == NULL) {

		ttransport->next_pg = tgroup;

	}

	pthread_mutex_unlock(&ttransport->lock);



	return &tgroup->group;



cleanup:
@@ -1221,6 +1234,9 @@ cleanup: 
static struct spdk_nvmf_transport_poll_group *

nvmf_tcp_get_optimal_poll_group(struct spdk_nvmf_qpair *qpair)

{

	struct spdk_nvmf_tcp_transport *ttransport;

	struct spdk_nvmf_transport_poll_group *result;

	struct spdk_nvmf_tcp_poll_group **pg;

	struct spdk_nvmf_tcp_qpair *tqpair;

	struct spdk_sock_group *group = NULL;

	int rc;
@@ -1231,13 +1247,34 @@ nvmf_tcp_get_optimal_poll_group(struct spdk_nvmf_qpair *qpair) 
		return spdk_sock_group_get_ctx(group);

	}



	ttransport = SPDK_CONTAINEROF(qpair->transport, struct spdk_nvmf_tcp_transport, transport);



	pthread_mutex_lock(&ttransport->lock);



	if (TAILQ_EMPTY(&ttransport->poll_groups)) {

		pthread_mutex_unlock(&ttransport->lock);

		return NULL;

	}



	pg = &ttransport->next_pg;

	assert(*pg != NULL);



	result = &(*pg)->group;



	*pg = TAILQ_NEXT(*pg, link);

	if (*pg == NULL) {

		*pg = TAILQ_FIRST(&ttransport->poll_groups);

	}



	pthread_mutex_unlock(&ttransport->lock);

	return result;

}



static void

nvmf_tcp_poll_group_destroy(struct spdk_nvmf_transport_poll_group *group)

{

	struct spdk_nvmf_tcp_poll_group *tgroup;

	struct spdk_nvmf_tcp_poll_group *tgroup, *next_tgroup;

	struct spdk_nvmf_tcp_transport *ttransport;



	tgroup = SPDK_CONTAINEROF(group, struct spdk_nvmf_tcp_poll_group, group);

	spdk_sock_group_close(&tgroup->sock_group);
@@ -1249,6 +1286,19 @@ nvmf_tcp_poll_group_destroy(struct spdk_nvmf_transport_poll_group *group) 
		spdk_put_io_channel(tgroup->accel_channel);

	}



	ttransport = SPDK_CONTAINEROF(tgroup->group.transport, struct spdk_nvmf_tcp_transport, transport);



	pthread_mutex_lock(&ttransport->lock);

	next_tgroup = TAILQ_NEXT(tgroup, link);

	TAILQ_REMOVE(&ttransport->poll_groups, tgroup, link);

	if (next_tgroup == NULL) {

		next_tgroup = TAILQ_FIRST(&ttransport->poll_groups);

	}

	if (ttransport->next_pg == tgroup) {

		ttransport->next_pg = next_tgroup;

	}

	pthread_mutex_unlock(&ttransport->lock);



	free(tgroup);

}