Commit d4e19ecc authored by Dariusz Stojaczyk's avatar Dariusz Stojaczyk Committed by Jim Harris
Browse files

vhost: use trylock inside async events body 



This makes the async event body non-blocking
and also fixes potential deadlock scenario:
 * call_external_event() enqueues vhost_event
 * destroy_device() locks g_spdk_vhost_mutex
 * destroy_device() enqueues it's vhost_event
 * reactor dequeues events
  * cb from call_external_event is dequeued first
    * g_spdk_vhost_mutex is locked (deadlock)
 * destroy_device() times out, abort()

Change-Id: If8f51ada3ee5c47ba126f74187a40a285c001c77
Signed-off-by: default avatarDariusz Stojaczyk <dariuszx.stojaczyk@intel.com>
Reviewed-on: https://review.gerrithub.io/380634


Tested-by: default avatarSPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: default avatarJim Harris <james.r.harris@intel.com>
Reviewed-by: default avatarDaniel Verkamp <daniel.verkamp@intel.com>
parent d565f549

lib/vhost/vhost.c

+7 −1
Original line number Diff line number Diff line
@@ -561,8 +561,14 @@ spdk_vhost_event_async_fn(void *arg1, void *arg2) 
{

	struct spdk_vhost_dev_event_ctx *ctx = arg1;

	struct spdk_vhost_dev *vdev;

	struct spdk_event *ev;



	if (pthread_mutex_trylock(&g_spdk_vhost_mutex) != 0) {

		ev = spdk_event_allocate(spdk_env_get_current_core(), spdk_vhost_event_async_fn, arg1, arg2);

		spdk_event_call(ev);

		return;

	}



	pthread_mutex_lock(&g_spdk_vhost_mutex);

	vdev = spdk_vhost_dev_find(ctx->ctrlr_name);

	if (vdev != ctx->vdev) {

		/* vdev has been changed after enqueuing this event */

test/unit/lib/vhost/vhost.c/vhost_ut.c

+1 −0
Original line number Diff line number Diff line
@@ -67,6 +67,7 @@ DEFINE_STUB(spdk_vhost_scsi_controller_construct, int, (void), 0); 
DEFINE_STUB(spdk_vhost_blk_controller_construct, int, (void), 0);

DEFINE_STUB(rte_vhost_set_vhost_vring_last_idx, int,

	    (int vid, uint16_t vring_idx, uint16_t last_avail_idx, uint16_t last_used_idx), 0);

DEFINE_STUB(spdk_env_get_current_core, uint32_t, (void), 0);



static int

test_setup(void)