Commit 3f74e064 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jens Axboe
Browse files

nbd: refactor device removal 



Share common code for the synchronous and workqueue based device removal,
and remove the pointless use of refcount_dec_and_mutex_lock.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20210811124428.2368491-3-hch@lst.de


Reviewed-by: default avatarJosef Bacik <josef@toxicpanda.com>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 68c9417b

drivers/block/nbd.c

+13 −24
Original line number Diff line number Diff line
@@ -259,48 +259,37 @@ static void nbd_notify_destroy_completion(struct nbd_device *nbd) 
		complete(nbd->destroy_complete);

}



static void nbd_dev_remove_work(struct work_struct *work)

static void nbd_dev_remove(struct nbd_device *nbd)

{

	struct nbd_device *nbd =

		container_of(work, struct nbd_device, remove_work);



	nbd_del_disk(nbd);



	mutex_lock(&nbd_index_mutex);

	/*

	 * Remove from idr after del_gendisk() completes,

	 * so if the same id is reused, the following

	 * add_disk() will succeed.

	 * Remove from idr after del_gendisk() completes, so if the same ID is

	 * reused, the following add_disk() will succeed.

	 */

	mutex_lock(&nbd_index_mutex);

	idr_remove(&nbd_index_idr, nbd->index);



	nbd_notify_destroy_completion(nbd);

	mutex_unlock(&nbd_index_mutex);



	kfree(nbd);

}



static void nbd_dev_remove(struct nbd_device *nbd)

static void nbd_dev_remove_work(struct work_struct *work)

{

	/* Call del_gendisk() asynchrounously to prevent deadlock */

	if (test_bit(NBD_DESTROY_ON_DISCONNECT, &nbd->flags)) {

		queue_work(nbd_del_wq, &nbd->remove_work);

		return;

	}



	nbd_del_disk(nbd);

	idr_remove(&nbd_index_idr, nbd->index);

	nbd_notify_destroy_completion(nbd);

	kfree(nbd);

	nbd_dev_remove(container_of(work, struct nbd_device, remove_work));

}



static void nbd_put(struct nbd_device *nbd)

{

	if (refcount_dec_and_mutex_lock(&nbd->refs,

					&nbd_index_mutex)) {

	if (!refcount_dec_and_test(&nbd->refs))

		return;



	/* Call del_gendisk() asynchrounously to prevent deadlock */

	if (test_bit(NBD_DESTROY_ON_DISCONNECT, &nbd->flags))

		queue_work(nbd_del_wq, &nbd->remove_work);

	else

		nbd_dev_remove(nbd);

		mutex_unlock(&nbd_index_mutex);

	}

}



static int nbd_disconnected(struct nbd_config *config)