Commit b1a61970 authored by Pawel Wodkowski's avatar Pawel Wodkowski Committed by Jim Harris
Browse files

vhost-scsi: change removed flag into small state machine 



Introduce EMPTY, PRESENT and REMOVED states for Vhost SCSI targets. This
does not introduce any functional changes but opens a way to stop using
both removed flag and spdk_scsi_dev pointer as indicator if device is
removed or not.

Change-Id: Iecd76ffe9e8121cc1359b1e268eb21679d13598e
Signed-off-by: default avatarPawel Wodkowski <pawelx.wodkowski@intel.com>
Reviewed-on: https://review.gerrithub.io/c/spdk/spdk/+/447070


Tested-by: default avatarSPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: default avatarBen Walker <benjamin.walker@intel.com>
Reviewed-by: default avatarJim Harris <james.r.harris@intel.com>
Reviewed-by: default avatarShuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>
parent b9b1c959

lib/vhost/vhost_scsi.c

+32 −13
Original line number Diff line number Diff line
@@ -67,9 +67,23 @@ 
#define VIRTIO_SCSI_EVENTQ   1

#define VIRTIO_SCSI_REQUESTQ   2



enum spdk_scsi_dev_vhost_status {

	/* Target ID is empty. */

	VHOST_SCSI_DEV_EMPTY,



	/* Target ID occupied. */

	VHOST_SCSI_DEV_PRESENT,



	/* Target ID is occupied but removal is in progress. */

	VHOST_SCSI_DEV_REMOVING,



	/* In session - device (SCSI target) seen but removed. */

	VHOST_SCSI_DEV_REMOVED,

};



struct spdk_scsi_dev_vhost_state {

	struct spdk_scsi_dev *dev;

	bool removed;

	enum spdk_scsi_dev_vhost_status status;

	spdk_vhost_event_fn remove_cb;

	void *remove_ctx;

};
@@ -167,6 +181,8 @@ remove_scsi_tgt(struct spdk_vhost_scsi_dev *svdev, 


	dev = state->dev;

	state->dev = NULL;

	assert(state->status == VHOST_SCSI_DEV_REMOVING);

	state->status = VHOST_SCSI_DEV_EMPTY;

	spdk_scsi_dev_destruct(dev);

	if (state->remove_cb) {

		state->remove_cb(&svdev->vdev, state->remove_ctx);
@@ -219,10 +235,11 @@ process_removed_devs(struct spdk_vhost_scsi_session *svsession) 
		state = &svsession->scsi_dev_state[i];

		dev = state->dev;



		if (dev && state->removed && !spdk_scsi_dev_has_pending_tasks(dev)) {

		if (dev && state->status == VHOST_SCSI_DEV_REMOVING && !spdk_scsi_dev_has_pending_tasks(dev)) {

			/* detach the device from this session */

			spdk_scsi_dev_free_io_channels(dev);

			state->dev = NULL;

			state->status = VHOST_SCSI_DEV_REMOVED;

			/* try to detach it globally */

			spdk_vhost_lock();

			spdk_vhost_dev_foreach_session(&svsession->svdev->vdev,
@@ -374,11 +391,11 @@ spdk_vhost_scsi_task_init_target(struct spdk_vhost_scsi_task *task, const __u8 * 


	state = &svsession->scsi_dev_state[lun[1]];

	task->scsi_dev = state->dev;

	if (state->dev == NULL || svsession->scsi_dev_state[lun[1]].removed) {

	if (state->dev == NULL || state->status != VHOST_SCSI_DEV_PRESENT) {

		/* If dev has been hotdetached, return 0 to allow sending

		 * additional hotremove event via sense codes.

		 */

		return svsession->scsi_dev_state[lun[1]].removed ? 0 : -1;

		return state->status != VHOST_SCSI_DEV_EMPTY ? 0 : -1;

	}



	task->scsi.target_port = spdk_scsi_dev_find_port_by_id(task->scsi_dev, 0);
@@ -923,10 +940,10 @@ spdk_vhost_scsi_session_add_tgt(struct spdk_vhost_dev *vdev, 


		/* unset the SCSI target so that all I/O to it will be rejected */

		svsession->scsi_dev_state[scsi_tgt_num].dev = NULL;

		/* unset the removed flag so that we won't reply with SCSI hotremove

		/* Set status to EMPTY so that we won't reply with SCSI hotremove

		 * sense codes - the device hasn't ever been added.

		 */

		svsession->scsi_dev_state[scsi_tgt_num].removed = false;

		svsession->scsi_dev_state[scsi_tgt_num].status = VHOST_SCSI_DEV_EMPTY;



		/* Return with no error. We'll continue allocating io_channels for

		 * other sessions on this device in hopes they succeed. The sessions
@@ -1000,12 +1017,13 @@ spdk_vhost_scsi_dev_add_tgt(struct spdk_vhost_dev *vdev, int scsi_tgt_num, 
	lun_id_list[0] = 0;

	bdev_names_list[0] = (char *)bdev_name;



	state->removed = false;

	state->status = VHOST_SCSI_DEV_PRESENT;

	state->dev = spdk_scsi_dev_construct(target_name, bdev_names_list, lun_id_list, 1,

					     SPDK_SPC_PROTOCOL_IDENTIFIER_SAS,

					     spdk_vhost_scsi_lun_hotremove, svdev);



	if (state->dev == NULL) {

		state->status = VHOST_SCSI_DEV_EMPTY;

		SPDK_ERRLOG("Couldn't create spdk SCSI target '%s' using bdev '%s' in controller: %s\n",

			    target_name, bdev_name, vdev->name);

		return -EINVAL;
@@ -1043,8 +1061,8 @@ spdk_vhost_scsi_session_remove_tgt(struct spdk_vhost_dev *vdev, 
	/* Mark the target for removal */

	svsession = (struct spdk_vhost_scsi_session *)vsession;

	state = &svsession->scsi_dev_state[scsi_tgt_num];

	assert(!state->removed);

	state->removed = true;

	assert(state->status == VHOST_SCSI_DEV_PRESENT);

	state->status = VHOST_SCSI_DEV_REMOVING;



	/* If the session isn't currently polled, unset the dev straight away */

	if (vsession->lcore == -1) {
@@ -1087,7 +1105,8 @@ spdk_vhost_scsi_dev_remove_tgt(struct spdk_vhost_dev *vdev, unsigned scsi_tgt_nu 
		return -ENODEV;

	}



	if (scsi_dev_state->removed) {

	assert(scsi_dev_state->status != VHOST_SCSI_DEV_EMPTY);

	if (scsi_dev_state->status != VHOST_SCSI_DEV_PRESENT) {

		SPDK_WARNLOG("%s: 'Target %u' has been already marked to hotremove.\n",

			     vdev->name, scsi_tgt_num);

		return -EBUSY;
@@ -1095,7 +1114,7 @@ spdk_vhost_scsi_dev_remove_tgt(struct spdk_vhost_dev *vdev, unsigned scsi_tgt_nu 


	scsi_dev_state->remove_cb = cb_fn;

	scsi_dev_state->remove_ctx = cb_arg;

	scsi_dev_state->removed = true;

	scsi_dev_state->status = VHOST_SCSI_DEV_REMOVING;



	spdk_vhost_dev_foreach_session(vdev, spdk_vhost_scsi_session_remove_tgt,

				       (void *)(uintptr_t)scsi_tgt_num);
@@ -1273,10 +1292,10 @@ spdk_vhost_scsi_start_cb(struct spdk_vhost_dev *vdev, 
			SPDK_ERRLOG("%s: failed to alloc io_channel for SCSI target %"PRIu32"\n", vdev->name, i);

			/* unset the SCSI target so that all I/O to it will be rejected */

			svsession->scsi_dev_state[i].dev = NULL;

			/* unset the removed flag so that we won't reply with SCSI hotremove

			/* set EMPTY state so that we won't reply with SCSI hotremove

			 * sense codes - the device hasn't ever been added.

			 */

			svsession->scsi_dev_state[i].removed = false;

			svsession->scsi_dev_state[i].status = VHOST_SCSI_DEV_EMPTY;

			continue;

		}

	}