Function biowait

freebsd/kern/vfs_bio.c:4372–4387

* Wait for a BIO to finish. */

 * Wait for a BIO to finish.
 */
int
biowait(struct bio *bp, const char *wchan)
{
	struct mtx *mtxp;

	mtxp = mtx_pool_find(mtxpool_sleep, bp);
	mtx_lock(mtxp);
	while ((bp->bio_flags & BIO_DONE) == 0)
		msleep(bp, mtxp, PRIBIO, wchan, 0);
	mtx_unlock(mtxp);
	if (bp->bio_error != 0)
		return (bp->bio_error);
	if (!(bp->bio_flags & BIO_ERROR))
		return (0);
	return (EIO);
}

void
biofinish(struct bio *bp, struct devstat *stat, int error)