block: replace bi_bdev with a gendisk pointer and partitions index

This way we don't need a block_device structure to submit I/O.  The
block_device has different life time rules from the gendisk and
request_queue and is usually only available when the block device node
is open.  Other callers need to explicitly create one (e.g. the lightnvm
passthrough code, or the new nvme multipathing code).

For the actual I/O path all that we need is the gendisk, which exists
once per block device.  But given that the block layer also does
partition remapping we additionally need a partition index, which is
used for said remapping in generic_make_request.

Note that all the block drivers generally want request_queue or
sometimes the gendisk, so this removes a layer of indirection all
over the stack.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

1 files changed, 8 insertions, 8 deletions

diff --git a/drivers/md/dm-snap.c b/drivers/md/dm-snap.c
index 1ba41048b438..1113b42e1eda 100644
--- a/drivers/md/dm-snap.c
+++ b/drivers/md/dm-snap.c
@@ -1663,7 +1663,7 @@ __find_pending_exception(struct dm_snapshot *s,
 static void remap_exception(struct dm_snapshot *s, struct dm_exception *e,
 			    struct bio *bio, chunk_t chunk)
 {
-	bio->bi_bdev = s->cow->bdev;
+	bio_set_dev(bio, s->cow->bdev);
 	bio->bi_iter.bi_sector =
 		chunk_to_sector(s->store, dm_chunk_number(e->new_chunk) +
 				(chunk - e->old_chunk)) +
@@ -1681,7 +1681,7 @@ static int snapshot_map(struct dm_target *ti, struct bio *bio)
 	init_tracked_chunk(bio);
 
 	if (bio->bi_opf & REQ_PREFLUSH) {
-		bio->bi_bdev = s->cow->bdev;
+		bio_set_dev(bio, s->cow->bdev);
 		return DM_MAPIO_REMAPPED;
 	}
 
@@ -1769,7 +1769,7 @@ static int snapshot_map(struct dm_target *ti, struct bio *bio)
 			goto out;
 		}
 	} else {
-		bio->bi_bdev = s->origin->bdev;
+		bio_set_dev(bio, s->origin->bdev);
 		track_chunk(s, bio, chunk);
 	}
 
@@ -1802,9 +1802,9 @@ static int snapshot_merge_map(struct dm_target *ti, struct bio *bio)
 
 	if (bio->bi_opf & REQ_PREFLUSH) {
 		if (!dm_bio_get_target_bio_nr(bio))
-			bio->bi_bdev = s->origin->bdev;
+			bio_set_dev(bio, s->origin->bdev);
 		else
-			bio->bi_bdev = s->cow->bdev;
+			bio_set_dev(bio, s->cow->bdev);
 		return DM_MAPIO_REMAPPED;
 	}
 
@@ -1824,7 +1824,7 @@ static int snapshot_merge_map(struct dm_target *ti, struct bio *bio)
 		    chunk >= s->first_merging_chunk &&
 		    chunk < (s->first_merging_chunk +
 			     s->num_merging_chunks)) {
-			bio->bi_bdev = s->origin->bdev;
+			bio_set_dev(bio, s->origin->bdev);
 			bio_list_add(&s->bios_queued_during_merge, bio);
 			r = DM_MAPIO_SUBMITTED;
 			goto out_unlock;
@@ -1838,7 +1838,7 @@ static int snapshot_merge_map(struct dm_target *ti, struct bio *bio)
 	}
 
 redirect_to_origin:
-	bio->bi_bdev = s->origin->bdev;
+	bio_set_dev(bio, s->origin->bdev);
 
 	if (bio_data_dir(bio) == WRITE) {
 		up_write(&s->lock);
@@ -2285,7 +2285,7 @@ static int origin_map(struct dm_target *ti, struct bio *bio)
 	struct dm_origin *o = ti->private;
 	unsigned available_sectors;
 
-	bio->bi_bdev = o->dev->bdev;
+	bio_set_dev(bio, o->dev->bdev);
 
 	if (unlikely(bio->bi_opf & REQ_PREFLUSH))
 		return DM_MAPIO_REMAPPED;