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>

10 files changed, 18 insertions, 20 deletions

diff --git a/drivers/block/brd.c b/drivers/block/brd.c
index 104b71c..006e1cb 100644
--- a/drivers/block/brd.c
+++ b/drivers/block/brd.c
@@ -294,14 +294,13 @@ out:
 
 static blk_qc_t brd_make_request(struct request_queue *q, struct bio *bio)
 {
-	struct block_device *bdev = bio->bi_bdev;
-	struct brd_device *brd = bdev->bd_disk->private_data;
+	struct brd_device *brd = bio->bi_disk->private_data;
 	struct bio_vec bvec;
 	sector_t sector;
 	struct bvec_iter iter;
 
 	sector = bio->bi_iter.bi_sector;
-	if (bio_end_sector(bio) > get_capacity(bdev->bd_disk))
+	if (bio_end_sector(bio) > get_capacity(bio->bi_disk))
 		goto io_error;
 
 	bio_for_each_segment(bvec, bio, iter) {
diff --git a/drivers/block/drbd/drbd_actlog.c b/drivers/block/drbd/drbd_actlog.c
index e02c45c..5f0eaee 100644
--- a/drivers/block/drbd/drbd_actlog.c
+++ b/drivers/block/drbd/drbd_actlog.c
@@ -151,7 +151,7 @@ static int _drbd_md_sync_page_io(struct drbd_device *device,
 	op_flags |= REQ_SYNC;
 
 	bio = bio_alloc_drbd(GFP_NOIO);
-	bio->bi_bdev = bdev->md_bdev;
+	bio_set_dev(bio, bdev->md_bdev);
 	bio->bi_iter.bi_sector = sector;
 	err = -EIO;
 	if (bio_add_page(bio, device->md_io.page, size, 0) != size)
diff --git a/drivers/block/drbd/drbd_bitmap.c b/drivers/block/drbd/drbd_bitmap.c
index 809fd24..bd97908 100644
--- a/drivers/block/drbd/drbd_bitmap.c
+++ b/drivers/block/drbd/drbd_bitmap.c
@@ -1019,7 +1019,7 @@ static void bm_page_io_async(struct drbd_bm_aio_ctx *ctx, int page_nr) __must_ho
 		bm_store_page_idx(page, page_nr);
 	} else
 		page = b->bm_pages[page_nr];
-	bio->bi_bdev = device->ldev->md_bdev;
+	bio_set_dev(bio, device->ldev->md_bdev);
 	bio->bi_iter.bi_sector = on_disk_sector;
 	/* bio_add_page of a single page to an empty bio will always succeed,
 	 * according to api.  Do we want to assert that? */
diff --git a/drivers/block/drbd/drbd_int.h b/drivers/block/drbd/drbd_int.h
index d17b6e6..819f9d0 100644
--- a/drivers/block/drbd/drbd_int.h
+++ b/drivers/block/drbd/drbd_int.h
@@ -1628,8 +1628,8 @@ static inline void drbd_generic_make_request(struct drbd_device *device,
 					     int fault_type, struct bio *bio)
 {
 	__release(local);
-	if (!bio->bi_bdev) {
-		drbd_err(device, "drbd_generic_make_request: bio->bi_bdev == NULL\n");
+	if (!bio->bi_disk) {
+		drbd_err(device, "drbd_generic_make_request: bio->bi_disk == NULL\n");
 		bio->bi_status = BLK_STS_IOERR;
 		bio_endio(bio);
 		return;
diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c
index c7e95e6..ece6e5d 100644
--- a/drivers/block/drbd/drbd_receiver.c
+++ b/drivers/block/drbd/drbd_receiver.c
@@ -1265,7 +1265,7 @@ static void submit_one_flush(struct drbd_device *device, struct issue_flush_cont
 
 	octx->device = device;
 	octx->ctx = ctx;
-	bio->bi_bdev = device->ldev->backing_bdev;
+	bio_set_dev(bio, device->ldev->backing_bdev);
 	bio->bi_private = octx;
 	bio->bi_end_io = one_flush_endio;
 	bio->bi_opf = REQ_OP_FLUSH | REQ_PREFLUSH;
@@ -1548,7 +1548,7 @@ next_bio:
 	}
 	/* > peer_req->i.sector, unless this is the first bio */
 	bio->bi_iter.bi_sector = sector;
-	bio->bi_bdev = device->ldev->backing_bdev;
+	bio_set_dev(bio, device->ldev->backing_bdev);
 	bio_set_op_attrs(bio, op, op_flags);
 	bio->bi_private = peer_req;
 	bio->bi_end_io = drbd_peer_request_endio;
diff --git a/drivers/block/drbd/drbd_req.c b/drivers/block/drbd/drbd_req.c
index 8d6b5d1..447c975 100644
--- a/drivers/block/drbd/drbd_req.c
+++ b/drivers/block/drbd/drbd_req.c
@@ -1179,7 +1179,7 @@ drbd_submit_req_private_bio(struct drbd_request *req)
 	else
 		type = DRBD_FAULT_DT_RD;
 
-	bio->bi_bdev = device->ldev->backing_bdev;
+	bio_set_dev(bio, device->ldev->backing_bdev);
 
 	/* State may have changed since we grabbed our reference on the
 	 * ->ldev member. Double check, and short-circuit to endio.
diff --git a/drivers/block/drbd/drbd_worker.c b/drivers/block/drbd/drbd_worker.c
index 1d8726a..c268d88 100644
--- a/drivers/block/drbd/drbd_worker.c
+++ b/drivers/block/drbd/drbd_worker.c
@@ -1513,7 +1513,7 @@ int w_restart_disk_io(struct drbd_work *w, int cancel)
 		drbd_al_begin_io(device, &req->i);
 
 	drbd_req_make_private_bio(req, req->master_bio);
-	req->private_bio->bi_bdev = device->ldev->backing_bdev;
+	bio_set_dev(req->private_bio, device->ldev->backing_bdev);
 	generic_make_request(req->private_bio);
 
 	return 0;
diff --git a/drivers/block/floppy.c b/drivers/block/floppy.c
index 9c00f29..60c086a 100644
--- a/drivers/block/floppy.c
+++ b/drivers/block/floppy.c
@@ -4134,7 +4134,7 @@ static int __floppy_read_block_0(struct block_device *bdev, int drive)
 	cbdata.drive = drive;
 
 	bio_init(&bio, &bio_vec, 1);
-	bio.bi_bdev = bdev;
+	bio_set_dev(&bio, bdev);
 	bio_add_page(&bio, page, size, 0);
 
 	bio.bi_iter.bi_sector = 0;
diff --git a/drivers/block/pktcdvd.c b/drivers/block/pktcdvd.c
index 6b8b097..6797479 100644
--- a/drivers/block/pktcdvd.c
+++ b/drivers/block/pktcdvd.c
@@ -1028,7 +1028,7 @@ static void pkt_gather_data(struct pktcdvd_device *pd, struct packet_data *pkt)
 		bio = pkt->r_bios[f];
 		bio_reset(bio);
 		bio->bi_iter.bi_sector = pkt->sector + f * (CD_FRAMESIZE >> 9);
-		bio->bi_bdev = pd->bdev;
+		bio_set_dev(bio, pd->bdev);
 		bio->bi_end_io = pkt_end_io_read;
 		bio->bi_private = pkt;
 
@@ -1122,7 +1122,7 @@ static int pkt_start_recovery(struct packet_data *pkt)
 	pkt->sector = new_sector;
 
 	bio_reset(pkt->bio);
-	pkt->bio->bi_bdev = pd->bdev;
+	bio_set_set(pkt->bio, pd->bdev);
 	bio_set_op_attrs(pkt->bio, REQ_OP_WRITE, 0);
 	pkt->bio->bi_iter.bi_sector = new_sector;
 	pkt->bio->bi_iter.bi_size = pkt->frames * CD_FRAMESIZE;
@@ -1267,7 +1267,7 @@ static void pkt_start_write(struct pktcdvd_device *pd, struct packet_data *pkt)
 
 	bio_reset(pkt->w_bio);
 	pkt->w_bio->bi_iter.bi_sector = pkt->sector;
-	pkt->w_bio->bi_bdev = pd->bdev;
+	bio_set_dev(pkt->w_bio, pd->bdev);
 	pkt->w_bio->bi_end_io = pkt_end_io_packet_write;
 	pkt->w_bio->bi_private = pkt;
 
@@ -2314,7 +2314,7 @@ static void pkt_make_request_read(struct pktcdvd_device *pd, struct bio *bio)
 
 	psd->pd = pd;
 	psd->bio = bio;
-	cloned_bio->bi_bdev = pd->bdev;
+	bio_set_dev(cloned_bio, pd->bdev);
 	cloned_bio->bi_private = psd;
 	cloned_bio->bi_end_io = pkt_end_io_read_cloned;
 	pd->stats.secs_r += bio_sectors(bio);
@@ -2415,8 +2415,7 @@ static blk_qc_t pkt_make_request(struct request_queue *q, struct bio *bio)
 
 	pd = q->queuedata;
 	if (!pd) {
-		pr_err("%s incorrect request queue\n",
-		       bdevname(bio->bi_bdev, b));
+		pr_err("%s incorrect request queue\n", bio_devname(bio, b));
 		goto end_io;
 	}
 
diff --git a/drivers/block/xen-blkback/blkback.c b/drivers/block/xen-blkback/blkback.c
index 5f3a813..987d665 100644
--- a/drivers/block/xen-blkback/blkback.c
+++ b/drivers/block/xen-blkback/blkback.c
@@ -1363,7 +1363,7 @@ static int dispatch_rw_block_io(struct xen_blkif_ring *ring,
 				goto fail_put_bio;
 
 			biolist[nbio++] = bio;
-			bio->bi_bdev    = preq.bdev;
+			bio_set_dev(bio, preq.bdev);
 			bio->bi_private = pending_req;
 			bio->bi_end_io  = end_block_io_op;
 			bio->bi_iter.bi_sector  = preq.sector_number;
@@ -1382,7 +1382,7 @@ static int dispatch_rw_block_io(struct xen_blkif_ring *ring,
 			goto fail_put_bio;
 
 		biolist[nbio++] = bio;
-		bio->bi_bdev    = preq.bdev;
+		bio_set_dev(bio, preq.bdev);
 		bio->bi_private = pending_req;
 		bio->bi_end_io  = end_block_io_op;
 		bio_set_op_attrs(bio, operation, operation_flags);