Commit 3486237c authored by Jens Axboe's avatar Jens Axboe
Browse files

iomap: cleanup up iomap_dio_bio_end_io() 



Make the logic a bit easier to follow:

1) Add a release_bio out path, as everybody needs to touch that, and
   have our bio ref check jump there if it's non-zero.
2) Add a kiocb local variable.
3) Add comments for each of the three conditions (sync, inline, or
   async workqueue punt).

No functional changes in this patch.

Reviewed-by: default avatarDarrick J. Wong <djwong@kernel.org>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarDave Chinner <dchinner@redhat.com>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent ccff6d11

fs/iomap/direct-io.c

+31 −15
Original line number Diff line number Diff line
@@ -152,27 +152,43 @@ void iomap_dio_bio_end_io(struct bio *bio) 
{

	struct iomap_dio *dio = bio->bi_private;

	bool should_dirty = (dio->flags & IOMAP_DIO_DIRTY);

	struct kiocb *iocb = dio->iocb;



	if (bio->bi_status)

		iomap_dio_set_error(dio, blk_status_to_errno(bio->bi_status));

	if (!atomic_dec_and_test(&dio->ref))

		goto release_bio;



	if (atomic_dec_and_test(&dio->ref)) {

	/*

	 * Synchronous dio, task itself will handle any completion work

	 * that needs after IO. All we need to do is wake the task.

	 */

	if (dio->wait_for_completion) {

		struct task_struct *waiter = dio->submit.waiter;



		WRITE_ONCE(dio->submit.waiter, NULL);

		blk_wake_io_task(waiter);

		} else if (dio->flags & IOMAP_DIO_WRITE) {

			struct inode *inode = file_inode(dio->iocb->ki_filp);

		goto release_bio;

	}



			WRITE_ONCE(dio->iocb->private, NULL);

			INIT_WORK(&dio->aio.work, iomap_dio_complete_work);

			queue_work(inode->i_sb->s_dio_done_wq, &dio->aio.work);

		} else {

			WRITE_ONCE(dio->iocb->private, NULL);

	/* Read completion can always complete inline. */

	if (!(dio->flags & IOMAP_DIO_WRITE)) {

		WRITE_ONCE(iocb->private, NULL);

		iomap_dio_complete_work(&dio->aio.work);

		}

		goto release_bio;

	}



	/*

	 * Async DIO completion that requires filesystem level completion work

	 * gets punted to a work queue to complete as the operation may require

	 * more IO to be issued to finalise filesystem metadata changes or

	 * guarantee data integrity.

	 */

	WRITE_ONCE(iocb->private, NULL);

	INIT_WORK(&dio->aio.work, iomap_dio_complete_work);

	queue_work(file_inode(iocb->ki_filp)->i_sb->s_dio_done_wq,

			&dio->aio.work);

release_bio:

	if (should_dirty) {

		bio_check_pages_dirty(bio);

	} else {