Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 92c63902 authored by Mikulas Patocka's avatar Mikulas Patocka Committed by Alasdair G Kergon
Browse files

dm: remove dm_request loop 



Remove queue_io return value and a loop in dm_request.

IO may be submitted to a worker thread with queue_io().  queue_io() sets
DMF_QUEUE_IO_TO_THREAD so that all further IO is queued for the thread. When
the thread finishes its work, it clears DMF_QUEUE_IO_TO_THREAD and from this
point on, requests are submitted from dm_request again. This will be used
for processing barriers.

Remove the loop in dm_request. queue_io() can submit I/Os to the worker thread
even if DMF_QUEUE_IO_TO_THREAD was not set.

Signed-off-by: default avatarMikulas Patocka <mpatocka@redhat.com>
Signed-off-by: default avatarAlasdair G Kergon <agk@redhat.com>
parent 3b00b203

drivers/md/dm.c

+7 −15
Original line number Diff line number Diff line
@@ -436,21 +436,18 @@ static void end_io_acct(struct dm_io *io) 
/*

 * Add the bio to the list of deferred io.

 */

static int queue_io(struct mapped_device *md, struct bio *bio)

static void queue_io(struct mapped_device *md, struct bio *bio)

{

	down_write(&md->io_lock);



	if (!test_bit(DMF_QUEUE_IO_TO_THREAD, &md->flags)) {

		up_write(&md->io_lock);

		return 1;

	}



	spin_lock_irq(&md->deferred_lock);

	bio_list_add(&md->deferred, bio);

	spin_unlock_irq(&md->deferred_lock);



	if (!test_and_set_bit(DMF_QUEUE_IO_TO_THREAD, &md->flags))

		queue_work(md->wq, &md->work);



	up_write(&md->io_lock);

	return 0;		/* deferred successfully */

}



/*
@@ -953,7 +950,7 @@ static int dm_request(struct request_queue *q, struct bio *bio) 
	 * If we're suspended or the thread is processing barriers

	 * we have to queue this io for later.

	 */

	while (test_bit(DMF_QUEUE_IO_TO_THREAD, &md->flags)) {

	if (unlikely(test_bit(DMF_QUEUE_IO_TO_THREAD, &md->flags))) {

		up_read(&md->io_lock);



		if (unlikely(test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags)) &&
@@ -962,14 +959,9 @@ static int dm_request(struct request_queue *q, struct bio *bio) 
			return 0;

		}



		if (!queue_io(md, bio))

			return 0;

		queue_io(md, bio);



		/*

		 * We're in a while loop, because someone could suspend

		 * before we get to the following read lock.

		 */

		down_read(&md->io_lock);

		return 0;

	}



	__split_and_process_bio(md, bio);