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>

11 files changed, 35 insertions, 37 deletions

diff --git a/drivers/md/bcache/debug.c b/drivers/md/bcache/debug.c
index b00fd08d696b..058dd8014428 100644
--- a/drivers/md/bcache/debug.c
+++ b/drivers/md/bcache/debug.c
@@ -114,7 +114,7 @@ void bch_data_verify(struct cached_dev *dc, struct bio *bio)
 	check = bio_kmalloc(GFP_NOIO, bio_segments(bio));
 	if (!check)
 		return;
-	check->bi_disk = bio->bi_disk;
+	check->bi_bdev = bio->bi_bdev;
 	check->bi_opf = REQ_OP_READ;
 	check->bi_iter.bi_sector = bio->bi_iter.bi_sector;
 	check->bi_iter.bi_size = bio->bi_iter.bi_size;
diff --git a/drivers/md/bcache/request.c b/drivers/md/bcache/request.c
index 85b1f2a9b72d..dfc35d6d05ed 100644
--- a/drivers/md/bcache/request.c
+++ b/drivers/md/bcache/request.c
@@ -894,7 +894,8 @@ static int cached_dev_cache_miss(struct btree *b, struct search *s,
 	    !(bio->bi_opf & (REQ_META|REQ_PRIO)) &&
 	    s->iop.c->gc_stats.in_use < CUTOFF_CACHE_READA)
 		reada = min_t(sector_t, dc->readahead >> 9,
-			      get_capacity(bio->bi_disk) - bio_end_sector(bio));
+			      get_capacity(bio->bi_bdev->bd_disk) -
+			      bio_end_sector(bio));
 
 	s->insert_bio_sectors = min(sectors, bio_sectors(bio) + reada);
 
@@ -1167,7 +1168,7 @@ static void quit_max_writeback_rate(struct cache_set *c,
 blk_qc_t cached_dev_submit_bio(struct bio *bio)
 {
 	struct search *s;
-	struct bcache_device *d = bio->bi_disk->private_data;
+	struct bcache_device *d = bio->bi_bdev->bd_disk->private_data;
 	struct cached_dev *dc = container_of(d, struct cached_dev, disk);
 	int rw = bio_data_dir(bio);
 
@@ -1274,7 +1275,7 @@ blk_qc_t flash_dev_submit_bio(struct bio *bio)
 {
 	struct search *s;
 	struct closure *cl;
-	struct bcache_device *d = bio->bi_disk->private_data;
+	struct bcache_device *d = bio->bi_bdev->bd_disk->private_data;
 
 	if (unlikely(d->c && test_bit(CACHE_SET_IO_DISABLE, &d->c->flags))) {
 		bio->bi_status = BLK_STS_IOERR;
diff --git a/drivers/md/dm-bio-record.h b/drivers/md/dm-bio-record.h
index 2ea0360108e1..a3b71350eec8 100644
--- a/drivers/md/dm-bio-record.h
+++ b/drivers/md/dm-bio-record.h
@@ -18,8 +18,7 @@
  */
 
 struct dm_bio_details {
-	struct gendisk *bi_disk;
-	u8 bi_partno;
+	struct block_device *bi_bdev;
 	int __bi_remaining;
 	unsigned long bi_flags;
 	struct bvec_iter bi_iter;
@@ -31,8 +30,7 @@ struct dm_bio_details {
 
 static inline void dm_bio_record(struct dm_bio_details *bd, struct bio *bio)
 {
-	bd->bi_disk = bio->bi_disk;
-	bd->bi_partno = bio->bi_partno;
+	bd->bi_bdev = bio->bi_bdev;
 	bd->bi_flags = bio->bi_flags;
 	bd->bi_iter = bio->bi_iter;
 	bd->__bi_remaining = atomic_read(&bio->__bi_remaining);
@@ -44,8 +42,7 @@ static inline void dm_bio_record(struct dm_bio_details *bd, struct bio *bio)
 
 static inline void dm_bio_restore(struct dm_bio_details *bd, struct bio *bio)
 {
-	bio->bi_disk = bd->bi_disk;
-	bio->bi_partno = bd->bi_partno;
+	bio->bi_bdev = bd->bi_bdev;
 	bio->bi_flags = bd->bi_flags;
 	bio->bi_iter = bd->bi_iter;
 	atomic_set(&bio->__bi_remaining, bd->__bi_remaining);
diff --git a/drivers/md/dm-raid1.c b/drivers/md/dm-raid1.c
index fa09bc4e4c54..b0a82f29a2e4 100644
--- a/drivers/md/dm-raid1.c
+++ b/drivers/md/dm-raid1.c
@@ -145,7 +145,7 @@ static void dispatch_bios(void *context, struct bio_list *bio_list)
 
 struct dm_raid1_bio_record {
 	struct mirror *m;
-	/* if details->bi_disk == NULL, details were not saved */
+	/* if details->bi_bdev == NULL, details were not saved */
 	struct dm_bio_details details;
 	region_t write_region;
 };
@@ -1190,7 +1190,7 @@ static int mirror_map(struct dm_target *ti, struct bio *bio)
 	struct dm_raid1_bio_record *bio_record =
 	  dm_per_bio_data(bio, sizeof(struct dm_raid1_bio_record));
 
-	bio_record->details.bi_disk = NULL;
+	bio_record->details.bi_bdev = NULL;
 
 	if (rw == WRITE) {
 		/* Save region for mirror_end_io() handler */
@@ -1257,7 +1257,7 @@ static int mirror_end_io(struct dm_target *ti, struct bio *bio,
 		goto out;
 
 	if (unlikely(*error)) {
-		if (!bio_record->details.bi_disk) {
+		if (!bio_record->details.bi_bdev) {
 			/*
 			 * There wasn't enough memory to record necessary
 			 * information for a retry or there was no other
@@ -1282,7 +1282,7 @@ static int mirror_end_io(struct dm_target *ti, struct bio *bio,
 			bd = &bio_record->details;
 
 			dm_bio_restore(bd, bio);
-			bio_record->details.bi_disk = NULL;
+			bio_record->details.bi_bdev = NULL;
 			bio->bi_status = 0;
 
 			queue_bio(ms, bio, rw);
@@ -1292,7 +1292,7 @@ static int mirror_end_io(struct dm_target *ti, struct bio *bio,
 	}
 
 out:
-	bio_record->details.bi_disk = NULL;
+	bio_record->details.bi_bdev = NULL;
 
 	return DM_ENDIO_DONE;
 }
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 7bac564f3faa..479ec5bea09e 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -977,16 +977,17 @@ static void clone_endio(struct bio *bio)
 	struct mapped_device *md = tio->io->md;
 	dm_endio_fn endio = tio->ti->type->end_io;
 	struct bio *orig_bio = io->orig_bio;
+	struct request_queue *q = bio->bi_bdev->bd_disk->queue;
 
 	if (unlikely(error == BLK_STS_TARGET)) {
 		if (bio_op(bio) == REQ_OP_DISCARD &&
-		    !bio->bi_disk->queue->limits.max_discard_sectors)
+		    !q->limits.max_discard_sectors)
 			disable_discard(md);
 		else if (bio_op(bio) == REQ_OP_WRITE_SAME &&
-			 !bio->bi_disk->queue->limits.max_write_same_sectors)
+			 !q->limits.max_write_same_sectors)
 			disable_write_same(md);
 		else if (bio_op(bio) == REQ_OP_WRITE_ZEROES &&
-			 !bio->bi_disk->queue->limits.max_write_zeroes_sectors)
+			 !q->limits.max_write_zeroes_sectors)
 			disable_write_zeroes(md);
 	}
 
@@ -996,7 +997,7 @@ static void clone_endio(struct bio *bio)
 	 */
 	if (bio_op(orig_bio) == REQ_OP_ZONE_APPEND) {
 		sector_t written_sector = bio->bi_iter.bi_sector;
-		struct request_queue *q = orig_bio->bi_disk->queue;
+		struct request_queue *q = orig_bio->bi_bdev->bd_disk->queue;
 		u64 mask = (u64)blk_queue_zone_sectors(q) - 1;
 
 		orig_bio->bi_iter.bi_sector += written_sector & mask;
@@ -1422,8 +1423,7 @@ static int __send_empty_flush(struct clone_info *ci)
 	 */
 	bio_init(&flush_bio, NULL, 0);
 	flush_bio.bi_opf = REQ_OP_WRITE | REQ_PREFLUSH | REQ_SYNC;
-	flush_bio.bi_disk = ci->io->md->disk;
-	bio_associate_blkg(&flush_bio);
+	bio_set_dev(&flush_bio, ci->io->md->disk->part0);
 
 	ci->bio = &flush_bio;
 	ci->sector_count = 0;
@@ -1626,7 +1626,7 @@ static blk_qc_t __split_and_process_bio(struct mapped_device *md,
 
 static blk_qc_t dm_submit_bio(struct bio *bio)
 {
-	struct mapped_device *md = bio->bi_disk->private_data;
+	struct mapped_device *md = bio->bi_bdev->bd_disk->private_data;
 	blk_qc_t ret = BLK_QC_T_NONE;
 	int srcu_idx;
 	struct dm_table *map;
diff --git a/drivers/md/md-linear.c b/drivers/md/md-linear.c
index 68cac7d19278..63ed8329a98d 100644
--- a/drivers/md/md-linear.c
+++ b/drivers/md/md-linear.c
@@ -252,7 +252,7 @@ static bool linear_make_request(struct mddev *mddev, struct bio *bio)
 		start_sector + data_offset;
 
 	if (unlikely((bio_op(bio) == REQ_OP_DISCARD) &&
-		     !blk_queue_discard(bio->bi_disk->queue))) {
+		     !blk_queue_discard(bio->bi_bdev->bd_disk->queue))) {
 		/* Just ignore it */
 		bio_endio(bio);
 	} else {
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 04384452a7ab..cf06dbb1aa53 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -486,7 +486,7 @@ static void md_end_io(struct bio *bio)
 static blk_qc_t md_submit_bio(struct bio *bio)
 {
 	const int rw = bio_data_dir(bio);
-	struct mddev *mddev = bio->bi_disk->private_data;
+	struct mddev *mddev = bio->bi_bdev->bd_disk->private_data;
 
 	if (mddev == NULL || mddev->pers == NULL) {
 		bio_io_error(bio);
diff --git a/drivers/md/md.h b/drivers/md/md.h
index 34070ab30a8a..f13290ccc1c2 100644
--- a/drivers/md/md.h
+++ b/drivers/md/md.h
@@ -556,7 +556,7 @@ static inline void md_sync_acct(struct block_device *bdev, unsigned long nr_sect
 
 static inline void md_sync_acct_bio(struct bio *bio, unsigned long nr_sectors)
 {
-	atomic_add(nr_sectors, &bio->bi_disk->sync_io);
+	md_sync_acct(bio->bi_bdev, nr_sectors);
 }
 
 struct md_personality
@@ -793,14 +793,14 @@ static inline void mddev_clear_unsupported_flags(struct mddev *mddev,
 static inline void mddev_check_writesame(struct mddev *mddev, struct bio *bio)
 {
 	if (bio_op(bio) == REQ_OP_WRITE_SAME &&
-	    !bio->bi_disk->queue->limits.max_write_same_sectors)
+	    !bio->bi_bdev->bd_disk->queue->limits.max_write_same_sectors)
 		mddev->queue->limits.max_write_same_sectors = 0;
 }
 
 static inline void mddev_check_write_zeroes(struct mddev *mddev, struct bio *bio)
 {
 	if (bio_op(bio) == REQ_OP_WRITE_ZEROES &&
-	    !bio->bi_disk->queue->limits.max_write_zeroes_sectors)
+	    !bio->bi_bdev->bd_disk->queue->limits.max_write_zeroes_sectors)
 		mddev->queue->limits.max_write_zeroes_sectors = 0;
 }
 
diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index c0347997f6ff..3b19141cdb4b 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -794,13 +794,13 @@ static void flush_bio_list(struct r1conf *conf, struct bio *bio)
 
 	while (bio) { /* submit pending writes */
 		struct bio *next = bio->bi_next;
-		struct md_rdev *rdev = (void *)bio->bi_disk;
+		struct md_rdev *rdev = (void *)bio->bi_bdev;
 		bio->bi_next = NULL;
 		bio_set_dev(bio, rdev->bdev);
 		if (test_bit(Faulty, &rdev->flags)) {
 			bio_io_error(bio);
 		} else if (unlikely((bio_op(bio) == REQ_OP_DISCARD) &&
-				    !blk_queue_discard(bio->bi_disk->queue)))
+				    !blk_queue_discard(bio->bi_bdev->bd_disk->queue)))
 			/* Just ignore it */
 			bio_endio(bio);
 		else
@@ -1520,7 +1520,7 @@ static void raid1_write_request(struct mddev *mddev, struct bio *bio,
 			trace_block_bio_remap(mbio, disk_devt(mddev->gendisk),
 					      r1_bio->sector);
 		/* flush_pending_writes() needs access to the rdev so...*/
-		mbio->bi_disk = (void *)conf->mirrors[i].rdev;
+		mbio->bi_bdev = (void *)conf->mirrors[i].rdev;
 
 		cb = blk_check_plugged(raid1_unplug, mddev, sizeof(*plug));
 		if (cb)
diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index c5d88ef6a45c..be8f14afb6d1 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -882,13 +882,13 @@ static void flush_pending_writes(struct r10conf *conf)
 
 		while (bio) { /* submit pending writes */
 			struct bio *next = bio->bi_next;
-			struct md_rdev *rdev = (void*)bio->bi_disk;
+			struct md_rdev *rdev = (void*)bio->bi_bdev;
 			bio->bi_next = NULL;
 			bio_set_dev(bio, rdev->bdev);
 			if (test_bit(Faulty, &rdev->flags)) {
 				bio_io_error(bio);
 			} else if (unlikely((bio_op(bio) ==  REQ_OP_DISCARD) &&
-					    !blk_queue_discard(bio->bi_disk->queue)))
+					    !blk_queue_discard(bio->bi_bdev->bd_disk->queue)))
 				/* Just ignore it */
 				bio_endio(bio);
 			else
@@ -1075,13 +1075,13 @@ static void raid10_unplug(struct blk_plug_cb *cb, bool from_schedule)
 
 	while (bio) { /* submit pending writes */
 		struct bio *next = bio->bi_next;
-		struct md_rdev *rdev = (void*)bio->bi_disk;
+		struct md_rdev *rdev = (void*)bio->bi_bdev;
 		bio->bi_next = NULL;
 		bio_set_dev(bio, rdev->bdev);
 		if (test_bit(Faulty, &rdev->flags)) {
 			bio_io_error(bio);
 		} else if (unlikely((bio_op(bio) ==  REQ_OP_DISCARD) &&
-				    !blk_queue_discard(bio->bi_disk->queue)))
+				    !blk_queue_discard(bio->bi_bdev->bd_disk->queue)))
 			/* Just ignore it */
 			bio_endio(bio);
 		else
@@ -1253,7 +1253,7 @@ static void raid10_write_one_disk(struct mddev *mddev, struct r10bio *r10_bio,
 		trace_block_bio_remap(mbio, disk_devt(conf->mddev->gendisk),
 				      r10_bio->sector);
 	/* flush_pending_writes() needs access to the rdev so...*/
-	mbio->bi_disk = (void *)rdev;
+	mbio->bi_bdev = (void *)rdev;
 
 	atomic_inc(&r10_bio->remaining);
 
@@ -3003,7 +3003,7 @@ static sector_t raid10_sync_request(struct mddev *mddev, sector_t sector_nr,
 
 	/* Again, very different code for resync and recovery.
 	 * Both must result in an r10bio with a list of bios that
-	 * have bi_end_io, bi_sector, bi_disk set,
+	 * have bi_end_io, bi_sector, bi_bdev set,
 	 * and bi_private set to the r10bio.
 	 * For recovery, we may actually create several r10bios
 	 * with 2 bios in each, that correspond to the bios in the main one.
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 3a90cc0e43ca..f411b9e5c332 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -5310,7 +5310,7 @@ static int in_chunk_boundary(struct mddev *mddev, struct bio *bio)
 	unsigned int chunk_sectors;
 	unsigned int bio_sectors = bio_sectors(bio);
 
-	WARN_ON_ONCE(bio->bi_partno);
+	WARN_ON_ONCE(bio->bi_bdev->bd_partno);
 
 	chunk_sectors = min(conf->chunk_sectors, conf->prev_chunk_sectors);
 	return  chunk_sectors >=