/*
* 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;
}
/*
* 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;
}