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>

6 files changed, 22 insertions, 20 deletions

diff --git a/fs/btrfs/check-integrity.c b/fs/btrfs/check-integrity.c
index 9d3854839038..fb07e3c22b9a 100644
--- a/fs/btrfs/check-integrity.c
+++ b/fs/btrfs/check-integrity.c
@@ -1635,7 +1635,7 @@ static int btrfsic_read_block(struct btrfsic_state *state,
 		unsigned int j;
 
 		bio = btrfs_io_bio_alloc(num_pages - i);
-		bio->bi_bdev = block_ctx->dev->bdev;
+		bio_set_dev(bio, block_ctx->dev->bdev);
 		bio->bi_iter.bi_sector = dev_bytenr >> 9;
 		bio_set_op_attrs(bio, REQ_OP_READ, 0);
 
@@ -2803,7 +2803,7 @@ static void __btrfsic_submit_bio(struct bio *bio)
 	mutex_lock(&btrfsic_mutex);
 	/* since btrfsic_submit_bio() is also called before
 	 * btrfsic_mount(), this might return NULL */
-	dev_state = btrfsic_dev_state_lookup(bio->bi_bdev->bd_dev);
+	dev_state = btrfsic_dev_state_lookup(bio_dev(bio));
 	if (NULL != dev_state &&
 	    (bio_op(bio) == REQ_OP_WRITE) && bio_has_data(bio)) {
 		unsigned int i = 0;
@@ -2819,10 +2819,10 @@ static void __btrfsic_submit_bio(struct bio *bio)
 		bio_is_patched = 0;
 		if (dev_state->state->print_mask &
 		    BTRFSIC_PRINT_MASK_SUBMIT_BIO_BH)
-			pr_info("submit_bio(rw=%d,0x%x, bi_vcnt=%u, bi_sector=%llu (bytenr %llu), bi_bdev=%p)\n",
+			pr_info("submit_bio(rw=%d,0x%x, bi_vcnt=%u, bi_sector=%llu (bytenr %llu), bi_disk=%p)\n",
 			       bio_op(bio), bio->bi_opf, segs,
 			       (unsigned long long)bio->bi_iter.bi_sector,
-			       dev_bytenr, bio->bi_bdev);
+			       dev_bytenr, bio->bi_disk);
 
 		mapped_datav = kmalloc_array(segs,
 					     sizeof(*mapped_datav), GFP_NOFS);
@@ -2851,8 +2851,8 @@ static void __btrfsic_submit_bio(struct bio *bio)
 	} else if (NULL != dev_state && (bio->bi_opf & REQ_PREFLUSH)) {
 		if (dev_state->state->print_mask &
 		    BTRFSIC_PRINT_MASK_SUBMIT_BIO_BH)
-			pr_info("submit_bio(rw=%d,0x%x FLUSH, bdev=%p)\n",
-			       bio_op(bio), bio->bi_opf, bio->bi_bdev);
+			pr_info("submit_bio(rw=%d,0x%x FLUSH, disk=%p)\n",
+			       bio_op(bio), bio->bi_opf, bio->bi_disk);
 		if (!dev_state->dummy_block_for_bio_bh_flush.is_iodone) {
 			if ((dev_state->state->print_mask &
 			     (BTRFSIC_PRINT_MASK_SUBMIT_BIO_BH |
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 080e2ebb8aa0..0640c27e63e9 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -3499,7 +3499,7 @@ static void write_dev_flush(struct btrfs_device *device)
 
 	bio_reset(bio);
 	bio->bi_end_io = btrfs_end_empty_barrier;
-	bio->bi_bdev = device->bdev;
+	bio_set_dev(bio, device->bdev);
 	bio->bi_opf = REQ_OP_WRITE | REQ_SYNC | REQ_PREFLUSH;
 	init_completion(&device->flush_wait);
 	bio->bi_private = &device->flush_wait;
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 0aff9b278c19..42b12a85ab49 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -2033,7 +2033,7 @@ int repair_io_failure(struct btrfs_fs_info *fs_info, u64 ino, u64 start,
 		bio_put(bio);
 		return -EIO;
 	}
-	bio->bi_bdev = dev->bdev;
+	bio_set_dev(bio, dev->bdev);
 	bio->bi_opf = REQ_OP_WRITE | REQ_SYNC;
 	bio_add_page(bio, page, length, pg_offset);
 
@@ -2335,7 +2335,7 @@ struct bio *btrfs_create_repair_bio(struct inode *inode, struct bio *failed_bio,
 	bio = btrfs_io_bio_alloc(1);
 	bio->bi_end_io = endio_func;
 	bio->bi_iter.bi_sector = failrec->logical >> 9;
-	bio->bi_bdev = fs_info->fs_devices->latest_bdev;
+	bio_set_dev(bio, fs_info->fs_devices->latest_bdev);
 	bio->bi_iter.bi_size = 0;
 	bio->bi_private = data;
 
@@ -2675,7 +2675,7 @@ struct bio *btrfs_bio_alloc(struct block_device *bdev, u64 first_byte)
 	struct bio *bio;
 
 	bio = bio_alloc_bioset(GFP_NOFS, BIO_MAX_PAGES, btrfs_bioset);
-	bio->bi_bdev = bdev;
+	bio_set_dev(bio, bdev);
 	bio->bi_iter.bi_sector = first_byte >> 9;
 	btrfs_io_bio_init(btrfs_io_bio(bio));
 	return bio;
diff --git a/fs/btrfs/raid56.c b/fs/btrfs/raid56.c
index 208638384cd2..d268cb633735 100644
--- a/fs/btrfs/raid56.c
+++ b/fs/btrfs/raid56.c
@@ -1090,7 +1090,8 @@ static int rbio_add_io_page(struct btrfs_raid_bio *rbio,
 		 */
 		if (last_end == disk_start && stripe->dev->bdev &&
 		    !last->bi_status &&
-		    last->bi_bdev == stripe->dev->bdev) {
+		    last->bi_disk == stripe->dev->bdev->bd_disk &&
+		    last->bi_partno == stripe->dev->bdev->bd_partno) {
 			ret = bio_add_page(last, page, PAGE_SIZE, 0);
 			if (ret == PAGE_SIZE)
 				return 0;
@@ -1100,7 +1101,7 @@ static int rbio_add_io_page(struct btrfs_raid_bio *rbio,
 	/* put a new bio on the list */
 	bio = btrfs_io_bio_alloc(bio_max_len >> PAGE_SHIFT ?: 1);
 	bio->bi_iter.bi_size = 0;
-	bio->bi_bdev = stripe->dev->bdev;
+	bio_set_dev(bio, stripe->dev->bdev);
 	bio->bi_iter.bi_sector = disk_start >> 9;
 
 	bio_add_page(bio, page, PAGE_SIZE, 0);
@@ -1347,7 +1348,8 @@ static int find_bio_stripe(struct btrfs_raid_bio *rbio,
 		stripe_start = stripe->physical;
 		if (physical >= stripe_start &&
 		    physical < stripe_start + rbio->stripe_len &&
-		    bio->bi_bdev == stripe->dev->bdev) {
+		    bio->bi_disk == stripe->dev->bdev->bd_disk &&
+		    bio->bi_partno == stripe->dev->bdev->bd_partno) {
 			return i;
 		}
 	}
diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
index 6f1e4c984b94..b0b71e8e4c36 100644
--- a/fs/btrfs/scrub.c
+++ b/fs/btrfs/scrub.c
@@ -1738,7 +1738,7 @@ static void scrub_recheck_block(struct btrfs_fs_info *fs_info,
 
 		WARN_ON(!page->page);
 		bio = btrfs_io_bio_alloc(1);
-		bio->bi_bdev = page->dev->bdev;
+		bio_set_dev(bio, page->dev->bdev);
 
 		bio_add_page(bio, page->page, PAGE_SIZE, 0);
 		if (!retry_failed_mirror && scrub_is_page_on_raid56(page)) {
@@ -1826,7 +1826,7 @@ static int scrub_repair_page_from_good_copy(struct scrub_block *sblock_bad,
 		}
 
 		bio = btrfs_io_bio_alloc(1);
-		bio->bi_bdev = page_bad->dev->bdev;
+		bio_set_dev(bio, page_bad->dev->bdev);
 		bio->bi_iter.bi_sector = page_bad->physical >> 9;
 		bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
 
@@ -1921,7 +1921,7 @@ again:
 
 		bio->bi_private = sbio;
 		bio->bi_end_io = scrub_wr_bio_end_io;
-		bio->bi_bdev = sbio->dev->bdev;
+		bio_set_dev(bio, sbio->dev->bdev);
 		bio->bi_iter.bi_sector = sbio->physical >> 9;
 		bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
 		sbio->status = 0;
@@ -1964,7 +1964,7 @@ static void scrub_wr_submit(struct scrub_ctx *sctx)
 
 	sbio = sctx->wr_curr_bio;
 	sctx->wr_curr_bio = NULL;
-	WARN_ON(!sbio->bio->bi_bdev);
+	WARN_ON(!sbio->bio->bi_disk);
 	scrub_pending_bio_inc(sctx);
 	/* process all writes in a single worker thread. Then the block layer
 	 * orders the requests before sending them to the driver which
@@ -2321,7 +2321,7 @@ again:
 
 		bio->bi_private = sbio;
 		bio->bi_end_io = scrub_bio_end_io;
-		bio->bi_bdev = sbio->dev->bdev;
+		bio_set_dev(bio, sbio->dev->bdev);
 		bio->bi_iter.bi_sector = sbio->physical >> 9;
 		bio_set_op_attrs(bio, REQ_OP_READ, 0);
 		sbio->status = 0;
@@ -4627,7 +4627,7 @@ static int write_page_nocow(struct scrub_ctx *sctx,
 	bio = btrfs_io_bio_alloc(1);
 	bio->bi_iter.bi_size = 0;
 	bio->bi_iter.bi_sector = physical_for_dev_replace >> 9;
-	bio->bi_bdev = dev->bdev;
+	bio_set_dev(bio, dev->bdev);
 	bio->bi_opf = REQ_OP_WRITE | REQ_SYNC;
 	ret = bio_add_page(bio, page, PAGE_SIZE, 0);
 	if (ret != PAGE_SIZE) {
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index e8b9a269fdde..f9f0f474a64f 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -6188,7 +6188,7 @@ static void submit_stripe_bio(struct btrfs_bio *bbio, struct bio *bio,
 		rcu_read_unlock();
 	}
 #endif
-	bio->bi_bdev = dev->bdev;
+	bio_set_dev(bio, dev->bdev);
 
 	btrfs_bio_counter_inc_noblocked(fs_info);