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>

12 files changed, 55 insertions, 69 deletions

diff --git a/block/bio-integrity.c b/block/bio-integrity.c
index 9ffd7e289554..c3e5abcfdc98 100644
--- a/block/bio-integrity.c
+++ b/block/bio-integrity.c
@@ -140,7 +140,7 @@ int bio_integrity_add_page(struct bio *bio, struct page *page,
 	iv = bip->bip_vec + bip->bip_vcnt;
 
 	if (bip->bip_vcnt &&
-	    bvec_gap_to_prev(bio->bi_disk->queue,
+	    bvec_gap_to_prev(bio->bi_bdev->bd_disk->queue,
 			     &bip->bip_vec[bip->bip_vcnt - 1], offset))
 		return 0;
 
@@ -162,7 +162,7 @@ EXPORT_SYMBOL(bio_integrity_add_page);
 static blk_status_t bio_integrity_process(struct bio *bio,
 		struct bvec_iter *proc_iter, integrity_processing_fn *proc_fn)
 {
-	struct blk_integrity *bi = blk_get_integrity(bio->bi_disk);
+	struct blk_integrity *bi = blk_get_integrity(bio->bi_bdev->bd_disk);
 	struct blk_integrity_iter iter;
 	struct bvec_iter bviter;
 	struct bio_vec bv;
@@ -171,7 +171,7 @@ static blk_status_t bio_integrity_process(struct bio *bio,
 	void *prot_buf = page_address(bip->bip_vec->bv_page) +
 		bip->bip_vec->bv_offset;
 
-	iter.disk_name = bio->bi_disk->disk_name;
+	iter.disk_name = bio->bi_bdev->bd_disk->disk_name;
 	iter.interval = 1 << bi->interval_exp;
 	iter.seed = proc_iter->bi_sector;
 	iter.prot_buf = prot_buf;
@@ -208,8 +208,8 @@ static blk_status_t bio_integrity_process(struct bio *bio,
 bool bio_integrity_prep(struct bio *bio)
 {
 	struct bio_integrity_payload *bip;
-	struct blk_integrity *bi = blk_get_integrity(bio->bi_disk);
-	struct request_queue *q = bio->bi_disk->queue;
+	struct blk_integrity *bi = blk_get_integrity(bio->bi_bdev->bd_disk);
+	struct request_queue *q = bio->bi_bdev->bd_disk->queue;
 	void *buf;
 	unsigned long start, end;
 	unsigned int len, nr_pages;
@@ -329,7 +329,7 @@ static void bio_integrity_verify_fn(struct work_struct *work)
 	struct bio_integrity_payload *bip =
 		container_of(work, struct bio_integrity_payload, bip_work);
 	struct bio *bio = bip->bip_bio;
-	struct blk_integrity *bi = blk_get_integrity(bio->bi_disk);
+	struct blk_integrity *bi = blk_get_integrity(bio->bi_bdev->bd_disk);
 
 	/*
 	 * At the moment verify is called bio's iterator was advanced
@@ -355,7 +355,7 @@ static void bio_integrity_verify_fn(struct work_struct *work)
  */
 bool __bio_integrity_endio(struct bio *bio)
 {
-	struct blk_integrity *bi = blk_get_integrity(bio->bi_disk);
+	struct blk_integrity *bi = blk_get_integrity(bio->bi_bdev->bd_disk);
 	struct bio_integrity_payload *bip = bio_integrity(bio);
 
 	if (bio_op(bio) == REQ_OP_READ && !bio->bi_status &&
@@ -381,7 +381,7 @@ bool __bio_integrity_endio(struct bio *bio)
 void bio_integrity_advance(struct bio *bio, unsigned int bytes_done)
 {
 	struct bio_integrity_payload *bip = bio_integrity(bio);
-	struct blk_integrity *bi = blk_get_integrity(bio->bi_disk);
+	struct blk_integrity *bi = blk_get_integrity(bio->bi_bdev->bd_disk);
 	unsigned bytes = bio_integrity_bytes(bi, bytes_done >> 9);
 
 	bip->bip_iter.bi_sector += bytes_done >> 9;
@@ -397,7 +397,7 @@ void bio_integrity_advance(struct bio *bio, unsigned int bytes_done)
 void bio_integrity_trim(struct bio *bio)
 {
 	struct bio_integrity_payload *bip = bio_integrity(bio);
-	struct blk_integrity *bi = blk_get_integrity(bio->bi_disk);
+	struct blk_integrity *bi = blk_get_integrity(bio->bi_bdev->bd_disk);
 
 	bip->bip_iter.bi_size = bio_integrity_bytes(bi, bio_sectors(bio));
 }
diff --git a/block/bio.c b/block/bio.c
index 1f2cc1fbe283..0b70ade17da6 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -607,16 +607,7 @@ void bio_truncate(struct bio *bio, unsigned new_size)
  */
 void guard_bio_eod(struct bio *bio)
 {
-	sector_t maxsector;
-	struct block_device *part;
-
-	rcu_read_lock();
-	part = __disk_get_part(bio->bi_disk, bio->bi_partno);
-	if (part)
-		maxsector = bdev_nr_sectors(part);
-	else	
-		maxsector = get_capacity(bio->bi_disk);
-	rcu_read_unlock();
+	sector_t maxsector = bdev_nr_sectors(bio->bi_bdev);
 
 	if (!maxsector)
 		return;
@@ -676,11 +667,10 @@ void __bio_clone_fast(struct bio *bio, struct bio *bio_src)
 	BUG_ON(bio->bi_pool && BVEC_POOL_IDX(bio));
 
 	/*
-	 * most users will be overriding ->bi_disk with a new target,
+	 * most users will be overriding ->bi_bdev with a new target,
 	 * so we don't set nor calculate new physical/hw segment counts here
 	 */
-	bio->bi_disk = bio_src->bi_disk;
-	bio->bi_partno = bio_src->bi_partno;
+	bio->bi_bdev = bio_src->bi_bdev;
 	bio_set_flag(bio, BIO_CLONED);
 	if (bio_flagged(bio_src, BIO_THROTTLED))
 		bio_set_flag(bio, BIO_THROTTLED);
@@ -730,7 +720,7 @@ EXPORT_SYMBOL(bio_clone_fast);
 
 const char *bio_devname(struct bio *bio, char *buf)
 {
-	return disk_name(bio->bi_disk, bio->bi_partno, buf);
+	return bdevname(bio->bi_bdev, buf);
 }
 EXPORT_SYMBOL(bio_devname);
 
@@ -1037,7 +1027,7 @@ static int __bio_iov_append_get_pages(struct bio *bio, struct iov_iter *iter)
 {
 	unsigned short nr_pages = bio->bi_max_vecs - bio->bi_vcnt;
 	unsigned short entries_left = bio->bi_max_vecs - bio->bi_vcnt;
-	struct request_queue *q = bio->bi_disk->queue;
+	struct request_queue *q = bio->bi_bdev->bd_disk->queue;
 	unsigned int max_append_sectors = queue_max_zone_append_sectors(q);
 	struct bio_vec *bv = bio->bi_io_vec + bio->bi_vcnt;
 	struct page **pages = (struct page **)bv;
@@ -1145,7 +1135,8 @@ static void submit_bio_wait_endio(struct bio *bio)
  */
 int submit_bio_wait(struct bio *bio)
 {
-	DECLARE_COMPLETION_ONSTACK_MAP(done, bio->bi_disk->lockdep_map);
+	DECLARE_COMPLETION_ONSTACK_MAP(done,
+			bio->bi_bdev->bd_disk->lockdep_map);
 	unsigned long hang_check;
 
 	bio->bi_private = &done;
@@ -1422,8 +1413,8 @@ again:
 	if (!bio_integrity_endio(bio))
 		return;
 
-	if (bio->bi_disk)
-		rq_qos_done_bio(bio->bi_disk->queue, bio);
+	if (bio->bi_bdev)
+		rq_qos_done_bio(bio->bi_bdev->bd_disk->queue, bio);
 
 	/*
 	 * Need to have a real endio function for chained bios, otherwise
@@ -1438,8 +1429,8 @@ again:
 		goto again;
 	}
 
-	if (bio->bi_disk && bio_flagged(bio, BIO_TRACE_COMPLETION)) {
-		trace_block_bio_complete(bio->bi_disk->queue, bio);
+	if (bio->bi_bdev && bio_flagged(bio, BIO_TRACE_COMPLETION)) {
+		trace_block_bio_complete(bio->bi_bdev->bd_disk->queue, bio);
 		bio_clear_flag(bio, BIO_TRACE_COMPLETION);
 	}
 
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 031114d454a6..3465d6ee708e 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -1800,7 +1800,8 @@ static inline struct blkcg_gq *blkg_tryget_closest(struct bio *bio,
 	struct blkcg_gq *blkg, *ret_blkg = NULL;
 
 	rcu_read_lock();
-	blkg = blkg_lookup_create(css_to_blkcg(css), bio->bi_disk->queue);
+	blkg = blkg_lookup_create(css_to_blkcg(css),
+				  bio->bi_bdev->bd_disk->queue);
 	while (blkg) {
 		if (blkg_tryget(blkg)) {
 			ret_blkg = blkg;
@@ -1836,8 +1837,8 @@ void bio_associate_blkg_from_css(struct bio *bio,
 	if (css && css->parent) {
 		bio->bi_blkg = blkg_tryget_closest(bio, css);
 	} else {
-		blkg_get(bio->bi_disk->queue->root_blkg);
-		bio->bi_blkg = bio->bi_disk->queue->root_blkg;
+		blkg_get(bio->bi_bdev->bd_disk->queue->root_blkg);
+		bio->bi_blkg = bio->bi_bdev->bd_disk->queue->root_blkg;
 	}
 }
 EXPORT_SYMBOL_GPL(bio_associate_blkg_from_css);
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);
 
diff --git a/block/blk-crypto-fallback.c b/block/blk-crypto-fallback.c
index c162b754efbd..8f1e18176731 100644
--- a/block/blk-crypto-fallback.c
+++ b/block/blk-crypto-fallback.c
@@ -167,7 +167,7 @@ static struct bio *blk_crypto_clone_bio(struct bio *bio_src)
 	bio = bio_alloc_bioset(GFP_NOIO, bio_segments(bio_src), NULL);
 	if (!bio)
 		return NULL;
-	bio->bi_disk		= bio_src->bi_disk;
+	bio->bi_bdev		= bio_src->bi_bdev;
 	bio->bi_opf		= bio_src->bi_opf;
 	bio->bi_ioprio		= bio_src->bi_ioprio;
 	bio->bi_write_hint	= bio_src->bi_write_hint;
diff --git a/block/blk-crypto.c b/block/blk-crypto.c
index 5da43f0973b4..09fcb18fa778 100644
--- a/block/blk-crypto.c
+++ b/block/blk-crypto.c
@@ -280,7 +280,7 @@ bool __blk_crypto_bio_prep(struct bio **bio_ptr)
 	 * Success if device supports the encryption context, or if we succeeded
 	 * in falling back to the crypto API.
 	 */
-	if (blk_ksm_crypto_cfg_supported(bio->bi_disk->queue->ksm,
+	if (blk_ksm_crypto_cfg_supported(bio->bi_bdev->bd_disk->queue->ksm,
 					 &bc_key->crypto_cfg))
 		return true;
 
diff --git a/block/blk-merge.c b/block/blk-merge.c
index 808768f6b174..ffb4aa0ea68b 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -298,14 +298,13 @@ split:
  * Split a bio into two bios, chain the two bios, submit the second half and
  * store a pointer to the first half in *@bio. If the second bio is still too
  * big it will be split by a recursive call to this function. Since this
- * function may allocate a new bio from @bio->bi_disk->queue->bio_split, it is
- * the responsibility of the caller to ensure that
- * @bio->bi_disk->queue->bio_split is only released after processing of the
- * split bio has finished.
+ * function may allocate a new bio from q->bio_split, it is the responsibility
+ * of the caller to ensure that q->bio_split is only released after processing
+ * of the split bio has finished.
  */
 void __blk_queue_split(struct bio **bio, unsigned int *nr_segs)
 {
-	struct request_queue *q = (*bio)->bi_disk->queue;
+	struct request_queue *q = (*bio)->bi_bdev->bd_disk->queue;
 	struct bio *split = NULL;
 
 	switch (bio_op(*bio)) {
@@ -358,9 +357,9 @@ void __blk_queue_split(struct bio **bio, unsigned int *nr_segs)
  *
  * Split a bio into two bios, chains the two bios, submit the second half and
  * store a pointer to the first half in *@bio. Since this function may allocate
- * a new bio from @bio->bi_disk->queue->bio_split, it is the responsibility of
- * the caller to ensure that @bio->bi_disk->queue->bio_split is only released
- * after processing of the split bio has finished.
+ * a new bio from q->bio_split, it is the responsibility of the caller to ensure
+ * that q->bio_split is only released after processing of the split bio has
+ * finished.
  */
 void blk_queue_split(struct bio **bio)
 {
@@ -866,7 +865,7 @@ bool blk_rq_merge_ok(struct request *rq, struct bio *bio)
 		return false;
 
 	/* must be same device */
-	if (rq->rq_disk != bio->bi_disk)
+	if (rq->rq_disk != bio->bi_bdev->bd_disk)
 		return false;
 
 	/* only merge integrity protected bio into ditto rq */
diff --git a/block/blk-mq.c b/block/blk-mq.c
index f285a9123a8b..74b17b396f4c 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -2128,7 +2128,7 @@ static void blk_add_rq_to_plug(struct blk_plug *plug, struct request *rq)
  */
 blk_qc_t blk_mq_submit_bio(struct bio *bio)
 {
-	struct request_queue *q = bio->bi_disk->queue;
+	struct request_queue *q = bio->bi_bdev->bd_disk->queue;
 	const int is_sync = op_is_sync(bio->bi_opf);
 	const int is_flush_fua = op_is_flush(bio->bi_opf);
 	struct blk_mq_alloc_data data = {
diff --git a/block/blk-throttle.c b/block/blk-throttle.c
index d52cac9f3a7c..b1b22d863bdf 100644
--- a/block/blk-throttle.c
+++ b/block/blk-throttle.c
@@ -2178,7 +2178,7 @@ static inline void throtl_update_latency_buckets(struct throtl_data *td)
 
 bool blk_throtl_bio(struct bio *bio)
 {
-	struct request_queue *q = bio->bi_disk->queue;
+	struct request_queue *q = bio->bi_bdev->bd_disk->queue;
 	struct blkcg_gq *blkg = bio->bi_blkg;
 	struct throtl_qnode *qn = NULL;
 	struct throtl_grp *tg = blkg_to_tg(blkg);
diff --git a/block/blk.h b/block/blk.h
index 7550364c326c..10ab7c0d0766 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -202,8 +202,6 @@ static inline void elevator_exit(struct request_queue *q,
 	__elevator_exit(q, e);
 }
 
-struct block_device *__disk_get_part(struct gendisk *disk, int partno);
-
 ssize_t part_size_show(struct device *dev, struct device_attribute *attr,
 		char *buf);
 ssize_t part_stat_show(struct device *dev, struct device_attribute *attr,
diff --git a/block/bounce.c b/block/bounce.c
index d3f51acd6e3b..a22a8a1942b2 100644
--- a/block/bounce.c
+++ b/block/bounce.c
@@ -246,7 +246,7 @@ static struct bio *bounce_clone_bio(struct bio *bio_src, gfp_t gfp_mask,
 	bio = bio_alloc_bioset(gfp_mask, bio_segments(bio_src), bs);
 	if (!bio)
 		return NULL;
-	bio->bi_disk		= bio_src->bi_disk;
+	bio->bi_bdev		= bio_src->bi_bdev;
 	bio->bi_opf		= bio_src->bi_opf;
 	bio->bi_ioprio		= bio_src->bi_ioprio;
 	bio->bi_write_hint	= bio_src->bi_write_hint;
diff --git a/block/genhd.c b/block/genhd.c
index ca5d880af512..e536d0b4bbae 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -161,7 +161,7 @@ static void part_in_flight_rw(struct block_device *part,
 		inflight[1] = 0;
 }
 
-struct block_device *__disk_get_part(struct gendisk *disk, int partno)
+static struct block_device *__disk_get_part(struct gendisk *disk, int partno)
 {
 	struct disk_part_tbl *ptbl = rcu_dereference(disk->part_tbl);