Commit 5d1a2066 authored by Dariusz Stojaczyk's avatar Dariusz Stojaczyk Committed by Jim Harris
Browse files

vhost: added API to call external spdk_events on vdev reactor 



The next step towards fixing synchronization issues between RPC and
vhost controller reactor.

The general idea is to hide spdk_vhost_dev_find declaration, so that
vdev-related functions can't be (incorrectly) called from outside of
the vhost controller reactor. The vdev pointer should only be acquired
via spdk_vhost_call_external_event.

Change-Id: I689226c2271f81624b2651bae3b960b7efb1c01b
Signed-off-by: default avatarDariusz Stojaczyk <dariuszx.stojaczyk@intel.com>
Reviewed-on: https://review.gerrithub.io/371098


Tested-by: default avatarSPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: default avatarDaniel Verkamp <daniel.verkamp@intel.com>
Reviewed-by: default avatarJim Harris <james.r.harris@intel.com>
parent e28f3397

include/spdk/vhost.h

+17 −0
Original line number Diff line number Diff line
@@ -80,4 +80,21 @@ int spdk_vhost_blk_destroy(struct spdk_vhost_dev *dev); 
struct spdk_bdev *spdk_vhost_blk_get_dev(struct spdk_vhost_dev *ctrlr);

bool spdk_vhost_blk_get_readonly(struct spdk_vhost_dev *vdev);



/**

 * Call function on reactor of given vhost controller.

 * If controller is not in use, the event will be called

 * right away on the caller's thread.

 *

 * This function is thread safe.

 *

 * \param ctrlr_name name of the vhost controller to run

 * this event on

 * \param fn function to be called. The first parameter

 * of callback function is either actual spdk_vhost_dev

 * pointer or NULL in case vdev with given name doesn't

 * exist. The second param is user provided argument *arg*.

 * \param arg parameter to be passed to *fn*.

 */

void spdk_vhost_call_external_event(const char *ctrlr_name, spdk_vhost_event_fn fn, void *arg);



#endif /* SPDK_VHOST_H */

lib/vhost/vhost.c

+66 −0
Original line number Diff line number Diff line
@@ -548,6 +548,26 @@ spdk_vhost_event_cb(void *arg1, void *arg2) 
	sem_post(&ctx->sem);

}



static void

spdk_vhost_event_async_fn(void *arg1, void *arg2)

{

	struct spdk_vhost_dev_event_ctx *ctx = arg1;

	struct spdk_vhost_dev *vdev;



	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 */

		vdev = NULL;

	}



	ctx->cb_fn(vdev, arg2);

	pthread_mutex_unlock(&g_spdk_vhost_mutex);



	free(ctx->ctrlr_name);

	free(ctx);

}



int

spdk_vhost_event_send(struct spdk_vhost_dev *vdev, spdk_vhost_event_fn cb_fn, void *arg,

		      unsigned timeout_sec, const char *errmsg)
@@ -585,6 +605,29 @@ spdk_vhost_event_send(struct spdk_vhost_dev *vdev, spdk_vhost_event_fn cb_fn, vo 
	return ev_ctx.response;

}



static int

spdk_vhost_event_async_send(struct spdk_vhost_dev *vdev, spdk_vhost_event_fn cb_fn, void *arg)

{

	struct spdk_vhost_dev_event_ctx *ev_ctx;

	struct spdk_event *ev;



	ev_ctx = calloc(1, sizeof(*ev_ctx));

	if (ev_ctx == NULL) {

		SPDK_ERRLOG("Failed to alloc vhost event.\n");

		return -ENOMEM;

	}



	ev_ctx->vdev = vdev;

	ev_ctx->ctrlr_name = strdup(vdev->name);

	ev_ctx->cb_fn = cb_fn;



	ev = spdk_event_allocate(vdev->lcore, spdk_vhost_event_async_fn, ev_ctx, arg);

	assert(ev);

	spdk_event_call(ev);



	return 0;

}



static void

destroy_device(int vid)

{
@@ -822,4 +865,27 @@ destroy_connection(int vid) 
	pthread_mutex_unlock(&g_spdk_vhost_mutex);

}



void

spdk_vhost_call_external_event(const char *ctrlr_name, spdk_vhost_event_fn fn, void *arg)

{

	struct spdk_vhost_dev *vdev;



	pthread_mutex_lock(&g_spdk_vhost_mutex);

	vdev = spdk_vhost_dev_find(ctrlr_name);



	if (vdev == NULL) {

		pthread_mutex_unlock(&g_spdk_vhost_mutex);

		fn(NULL, arg);

		return;

	}



	if (vdev->lcore == -1) {

		fn(vdev, arg);

	} else {

		spdk_vhost_event_async_send(vdev, fn, arg);

	}



	pthread_mutex_unlock(&g_spdk_vhost_mutex);

}



SPDK_LOG_REGISTER_TRACE_FLAG("vhost_ring", SPDK_TRACE_VHOST_RING)

lib/vhost/vhost_blk.c

+1 −7
Original line number Diff line number Diff line
@@ -451,13 +451,7 @@ bdev_remove_cb(void *remove_ctx) 
{

	struct spdk_vhost_blk_dev *bvdev = remove_ctx;



	if (bvdev->vdev.lcore != -1 && (uint32_t)bvdev->vdev.lcore != spdk_env_get_current_core()) {

		/* Call on proper core. */

		spdk_vhost_event_send(&bvdev->vdev, _bdev_remove_cb, bvdev, 1, "vhost blk hot remove");

		return;

	}



	_bdev_remove_cb(&bvdev->vdev, bvdev);

	spdk_vhost_call_external_event(bvdev->vdev.name, _bdev_remove_cb, bvdev);

}