static int
vdev_disk_physio(struct device *dev, caddr_t data, size_t size,
uint64_t offset, int write)
{
struct bio *bio;
int ret;
bio = alloc_bio();
if (write)
bio->bio_cmd = BIO_WRITE;
else
bio->bio_cmd = BIO_READ;
bio->bio_dev = dev;
bio->bio_data = data;
bio->bio_offset = offset;
bio->bio_bcount = size;
bio->bio_dev->driver->devops->strategy(bio);
ret = bio_wait(bio);
destroy_bio(bio);
return ret;
}
static int
vdev_disk_start_flush(zio_t *zio)
{
vdev_t *vd = zio->io_vd;
struct vdev_disk *dvd = vd->vdev_tsd;
struct bio *bio;
bio = alloc_bio();
bio->bio_cmd = BIO_FLUSH;
bio->bio_dev = dvd->device;
bio->bio_caller1 = zio;
bio->bio_done = vdev_disk_bio_done;
bio->bio_dev->driver->devops->strategy(bio);
return ZIO_PIPELINE_STOP;
}
void multiplex_strategy(struct bio *bio)
{
struct device *dev = bio->bio_dev;
devop_strategy_t strategy = *((devop_strategy_t *)dev->private_data);
uint64_t len = bio->bio_bcount;
bio->bio_offset += bio->bio_dev->offset;
uint64_t offset = bio->bio_offset;
void *buf = bio->bio_data;
assert(strategy != NULL);
if (len <= dev->max_io_size) {
strategy(bio);
return;
}
// It is better to initialize the refcounter beforehand, specially because we can
// trivially determine what is the number going to be. Otherwise, we can have a
// situation in which we bump the refcount to 1, get scheduled out, the bio is
// finished, and when it drops its refcount to 0, we consider the main bio finished.
refcount_init(&bio->bio_refcnt, (len / dev->max_io_size) + !!(len % dev->max_io_size));
while (len > 0) {
uint64_t req_size = MIN(len, dev->max_io_size);
struct bio *b = alloc_bio();
b->bio_bcount = req_size;
b->bio_data = buf;
b->bio_offset = offset;
b->bio_cmd = bio->bio_cmd;
b->bio_dev = bio->bio_dev;
b->bio_caller1 = bio;
b->bio_done = multiplex_bio_done;
strategy(b);
buf += req_size;
offset += req_size;
len -= req_size;
}
}
static int
vdev_disk_start_bio(zio_t *zio)
{
vdev_t *vd = zio->io_vd;
struct vdev_disk *dvd = vd->vdev_tsd;
struct bio *bio;
bio = alloc_bio();
if (zio->io_type == ZIO_TYPE_READ)
bio->bio_cmd = BIO_READ;
else
bio->bio_cmd = BIO_WRITE;
bio->bio_dev = dvd->device;
bio->bio_data = zio->io_data;
bio->bio_offset = zio->io_offset;
bio->bio_bcount = zio->io_size;
bio->bio_caller1 = zio;
bio->bio_done = vdev_disk_bio_done;
bio->bio_dev->driver->devops->strategy(bio);
return ZIO_PIPELINE_STOP;
}
