Beispiel #1
0
/*
 * The request function that just remaps the bio built up by
 * dm_merge_bvec.
 */
static int dm_request(request_queue_t *q, struct bio *bio)
{
	int r;
	int rw = bio_data_dir(bio);
	struct mapped_device *md = q->queuedata;

	/*
	 * There is no use in forwarding any barrier request since we can't
	 * guarantee it is (or can be) handled by the targets correctly.
	 */
	if (unlikely(bio_barrier(bio))) {
		bio_endio(bio, bio->bi_size, -EOPNOTSUPP);
		return 0;
	}

	down_read(&md->io_lock);

	disk_stat_inc(dm_disk(md), ios[rw]);
	disk_stat_add(dm_disk(md), sectors[rw], bio_sectors(bio));

	/*
	 * If we're suspended we have to queue
	 * this io for later.
	 */
	while (test_bit(DMF_BLOCK_IO, &md->flags)) {
		up_read(&md->io_lock);

		if (bio_rw(bio) == READA) {
			bio_io_error(bio, bio->bi_size);
			return 0;
		}

		r = queue_io(md, bio);
		if (r < 0) {
			bio_io_error(bio, bio->bi_size);
			return 0;

		} else if (r == 0)
			return 0;	/* deferred successfully */

		/*
		 * We're in a while loop, because someone could suspend
		 * before we get to the following read lock.
		 */
		down_read(&md->io_lock);
	}

	__split_bio(md, bio);
	up_read(&md->io_lock);
	return 0;
}
Beispiel #2
0
/*
 * The request function that just remaps the bio built up by
 * dm_merge_bvec.
 */
static int dm_request(request_queue_t *q, struct bio *bio)
{
	int r;
	int rw = bio_data_dir(bio);
	struct mapped_device *md = q->queuedata;

	down_read(&md->io_lock);

	disk_stat_inc(dm_disk(md), ios[rw]);
	disk_stat_add(dm_disk(md), sectors[rw], bio_sectors(bio));

	/*
	 * If we're suspended we have to queue
	 * this io for later.
	 */
	while (test_bit(DMF_BLOCK_IO, &md->flags)) {
		up_read(&md->io_lock);

		if (bio_rw(bio) == READA) {
			bio_io_error(bio, bio->bi_size);
			return 0;
		}

		r = queue_io(md, bio);
		if (r < 0) {
			bio_io_error(bio, bio->bi_size);
			return 0;

		} else if (r == 0)
			return 0;	/* deferred successfully */

		/*
		 * We're in a while loop, because someone could suspend
		 * before we get to the following read lock.
		 */
		down_read(&md->io_lock);
	}

	__split_bio(md, bio);
	up_read(&md->io_lock);
	return 0;
}