Commit a66b5aeb authored by Daniel Stodden's avatar Daniel Stodden Committed by Jens Axboe
Browse files

blkfront: Clean up vbd release 



 * Current blkfront_closing is rather a xlvbd_release_gendisk.
   Renamed in preparation of later patches (need the name again).

 * Removed the misleading comment -- this only applied to the backend
   switch handler, and the queue is already flushed btw.

 * Break out the xenbus call, callers know better when to switch
   frontend state.

Signed-off-by: default avatarDaniel Stodden <daniel.stodden@citrix.com>
Signed-off-by: default avatarJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: default avatarJens Axboe <jaxboe@fusionio.com>
parent 9897cb53

drivers/block/xen-blkfront.c

+43 −48
Original line number Diff line number Diff line
@@ -534,6 +534,39 @@ static int xlvbd_alloc_gendisk(blkif_sector_t capacity, 
	return err;

}



static void xlvbd_release_gendisk(struct blkfront_info *info)

{

	unsigned int minor, nr_minors;

	unsigned long flags;



	if (info->rq == NULL)

		return;



	spin_lock_irqsave(&blkif_io_lock, flags);



	/* No more blkif_request(). */

	blk_stop_queue(info->rq);



	/* No more gnttab callback work. */

	gnttab_cancel_free_callback(&info->callback);

	spin_unlock_irqrestore(&blkif_io_lock, flags);



	/* Flush gnttab callback work. Must be done with no locks held. */

	flush_scheduled_work();



	del_gendisk(info->gd);



	minor = info->gd->first_minor;

	nr_minors = info->gd->minors;

	xlbd_release_minors(minor, nr_minors);



	blk_cleanup_queue(info->rq);

	info->rq = NULL;



	put_disk(info->gd);

	info->gd = NULL;

}



static void kick_pending_request_queues(struct blkfront_info *info)

{

	if (!RING_FULL(&info->ring)) {
@@ -994,49 +1027,6 @@ static void blkfront_connect(struct blkfront_info *info) 
	info->is_ready = 1;

}



/**

 * Handle the change of state of the backend to Closing.  We must delete our

 * device-layer structures now, to ensure that writes are flushed through to

 * the backend.  Once is this done, we can switch to Closed in

 * acknowledgement.

 */

static void blkfront_closing(struct blkfront_info *info)

{

	unsigned int minor, nr_minors;

	unsigned long flags;





	if (info->rq == NULL)

		goto out;



	spin_lock_irqsave(&blkif_io_lock, flags);



	/* No more blkif_request(). */

	blk_stop_queue(info->rq);



	/* No more gnttab callback work. */

	gnttab_cancel_free_callback(&info->callback);

	spin_unlock_irqrestore(&blkif_io_lock, flags);



	/* Flush gnttab callback work. Must be done with no locks held. */

	flush_scheduled_work();



	minor = info->gd->first_minor;

	nr_minors = info->gd->minors;

	del_gendisk(info->gd);

	xlbd_release_minors(minor, nr_minors);



	blk_cleanup_queue(info->rq);

	info->rq = NULL;



	put_disk(info->gd);

	info->gd = NULL;



 out:

	if (info->xbdev)

		xenbus_frontend_closed(info->xbdev);

}



/**

 * Callback received when the backend's state changes.

 */
@@ -1073,8 +1063,11 @@ static void blkback_changed(struct xenbus_device *dev, 
		if (info->users > 0)

			xenbus_dev_error(dev, -EBUSY,

					 "Device in use; refusing to close");

		else

			blkfront_closing(info);

		else {

			xlvbd_release_gendisk(info);

			xenbus_frontend_closed(info->xbdev);

		}



		mutex_unlock(&bd->bd_mutex);

		bdput(bd);

		break;
@@ -1130,11 +1123,13 @@ static int blkif_release(struct gendisk *disk, fmode_t mode) 
		struct xenbus_device *dev = info->xbdev;



		if (!dev) {

			blkfront_closing(info);

			xlvbd_release_gendisk(info);

			kfree(info);

		} else if (xenbus_read_driver_state(dev->otherend)

			   == XenbusStateClosing && info->is_ready)

			blkfront_closing(info);

			   == XenbusStateClosing && info->is_ready) {

			xlvbd_release_gendisk(info);

			xenbus_frontend_closed(dev);

		}

	}

	unlock_kernel();

	return 0;

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