block: store a block_device pointer in struct bio

Replace the gendisk pointer in struct bio with a pointer to the newly
improved struct block device.  From that the gendisk can be trivially
accessed with an extra indirection, but it also allows to directly
look up all information related to partition remapping.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

1 files changed, 17 insertions, 20 deletions

diff --git a/block/blk-core.c b/block/blk-core.c
index 08ff8ca32529..a3a54cd86c9c 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -476,7 +476,7 @@ int blk_queue_enter(struct request_queue *q, blk_mq_req_flags_t flags)
 
 static inline int bio_queue_enter(struct bio *bio)
 {
-	struct request_queue *q = bio->bi_disk->queue;
+	struct request_queue *q = bio->bi_bdev->bd_disk->queue;
 	bool nowait = bio->bi_opf & REQ_NOWAIT;
 	int ret;
 
@@ -712,7 +712,7 @@ static inline bool bio_check_ro(struct bio *bio, struct block_device *part)
 
 static noinline int should_fail_bio(struct bio *bio)
 {
-	if (should_fail_request(bio->bi_disk->part0, bio->bi_iter.bi_size))
+	if (should_fail_request(bdev_whole(bio->bi_bdev), bio->bi_iter.bi_size))
 		return -EIO;
 	return 0;
 }
@@ -741,13 +741,9 @@ static inline int bio_check_eod(struct bio *bio, sector_t maxsector)
  */
 static inline int blk_partition_remap(struct bio *bio)
 {
-	struct block_device *p;
+	struct block_device *p = bio->bi_bdev;
 	int ret = -EIO;
 
-	rcu_read_lock();
-	p = __disk_get_part(bio->bi_disk, bio->bi_partno);
-	if (unlikely(!p))
-		goto out;
 	if (unlikely(should_fail_request(p, bio->bi_iter.bi_size)))
 		goto out;
 	if (unlikely(bio_check_ro(bio, p)))
@@ -761,10 +757,9 @@ static inline int blk_partition_remap(struct bio *bio)
 				      bio->bi_iter.bi_sector -
 				      p->bd_start_sect);
 	}
-	bio->bi_partno = 0;
+	bio->bi_bdev = bdev_whole(p);
 	ret = 0;
 out:
-	rcu_read_unlock();
 	return ret;
 }
 
@@ -805,7 +800,8 @@ static inline blk_status_t blk_check_zone_append(struct request_queue *q,
 
 static noinline_for_stack bool submit_bio_checks(struct bio *bio)
 {
-	struct request_queue *q = bio->bi_disk->queue;
+	struct block_device *bdev = bio->bi_bdev;
+	struct request_queue *q = bdev->bd_disk->queue;
 	blk_status_t status = BLK_STS_IOERR;
 	struct blk_plug *plug;
 
@@ -825,13 +821,13 @@ static noinline_for_stack bool submit_bio_checks(struct bio *bio)
 	if (should_fail_bio(bio))
 		goto end_io;
 
-	if (bio->bi_partno) {
+	if (bio->bi_bdev->bd_partno) {
 		if (unlikely(blk_partition_remap(bio)))
 			goto end_io;
 	} else {
-		if (unlikely(bio_check_ro(bio, bio->bi_disk->part0)))
+		if (unlikely(bio_check_ro(bio, bdev_whole(bdev))))
 			goto end_io;
-		if (unlikely(bio_check_eod(bio, get_capacity(bio->bi_disk))))
+		if (unlikely(bio_check_eod(bio, get_capacity(bdev->bd_disk))))
 			goto end_io;
 	}
 
@@ -924,7 +920,7 @@ end_io:
 
 static blk_qc_t __submit_bio(struct bio *bio)
 {
-	struct gendisk *disk = bio->bi_disk;
+	struct gendisk *disk = bio->bi_bdev->bd_disk;
 	blk_qc_t ret = BLK_QC_T_NONE;
 
 	if (blk_crypto_bio_prep(&bio)) {
@@ -966,7 +962,7 @@ static blk_qc_t __submit_bio_noacct(struct bio *bio)
 	current->bio_list = bio_list_on_stack;
 
 	do {
-		struct request_queue *q = bio->bi_disk->queue;
+		struct request_queue *q = bio->bi_bdev->bd_disk->queue;
 		struct bio_list lower, same;
 
 		if (unlikely(bio_queue_enter(bio) != 0))
@@ -987,7 +983,7 @@ static blk_qc_t __submit_bio_noacct(struct bio *bio)
 		bio_list_init(&lower);
 		bio_list_init(&same);
 		while ((bio = bio_list_pop(&bio_list_on_stack[0])) != NULL)
-			if (q == bio->bi_disk->queue)
+			if (q == bio->bi_bdev->bd_disk->queue)
 				bio_list_add(&same, bio);
 			else
 				bio_list_add(&lower, bio);
@@ -1012,7 +1008,7 @@ static blk_qc_t __submit_bio_noacct_mq(struct bio *bio)
 	current->bio_list = bio_list;
 
 	do {
-		struct gendisk *disk = bio->bi_disk;
+		struct gendisk *disk = bio->bi_bdev->bd_disk;
 
 		if (unlikely(bio_queue_enter(bio) != 0))
 			continue;
@@ -1055,7 +1051,7 @@ blk_qc_t submit_bio_noacct(struct bio *bio)
 		return BLK_QC_T_NONE;
 	}
 
-	if (!bio->bi_disk->fops->submit_bio)
+	if (!bio->bi_bdev->bd_disk->fops->submit_bio)
 		return __submit_bio_noacct_mq(bio);
 	return __submit_bio_noacct(bio);
 }
@@ -1067,7 +1063,7 @@ EXPORT_SYMBOL(submit_bio_noacct);
  *
  * submit_bio() is used to submit I/O requests to block devices.  It is passed a
  * fully set up &struct bio that describes the I/O that needs to be done.  The
- * bio will be send to the device described by the bi_disk and bi_partno fields.
+ * bio will be send to the device described by the bi_bdev field.
  *
  * The success/failure status of the request, along with notification of
  * completion, is delivered asynchronously through the ->bi_end_io() callback
@@ -1087,7 +1083,8 @@ blk_qc_t submit_bio(struct bio *bio)
 		unsigned int count;
 
 		if (unlikely(bio_op(bio) == REQ_OP_WRITE_SAME))
-			count = queue_logical_block_size(bio->bi_disk->queue) >> 9;
+			count = queue_logical_block_size(
+					bio->bi_bdev->bd_disk->queue) >> 9;
 		else
 			count = bio_sectors(bio);