[15/20] block: merge struct block_device and struct hd_struct

Commit Message

Christoph Hellwig Nov. 18, 2020, 8:47 a.m. UTC

Instead of having two structures that represent each block device with
different lift time rules merged them into a single one.  This also
greatly simplifies the reference counting rules, as we can use the inode
reference count as the main reference count for the new struct
block_device, with the device model reference front ending it for device
model interaction.  The percpu refcount in struct hd_struct is entirely
gone given that struct block_device must be opened and thus valid for
the duration of the I/O.

Signed-off-by: Christoph Hellwig <[e-mail]>
---
 block/bio.c                        |   6 +-
 block/blk-cgroup.c                 |   9 +-
 block/blk-core.c                   |  85 +++++-----
 block/blk-flush.c                  |   2 +-
 block/blk-lib.c                    |   2 +-
 block/blk-merge.c                  |   6 +-
 block/blk-mq.c                     |  11 +-
 block/blk-mq.h                     |   5 +-
 block/blk.h                        |  39 ++---
 block/genhd.c                      | 240 +++++++++++------------------
 block/ioctl.c                      |   4 +-
 block/partitions/core.c            | 221 ++++++++------------------
 drivers/block/drbd/drbd_receiver.c |   2 +-
 drivers/block/drbd/drbd_worker.c   |   2 +-
 drivers/block/zram/zram_drv.c      |   2 +-
 drivers/md/bcache/request.c        |   4 +-
 drivers/md/dm.c                    |   8 +-
 drivers/md/md.c                    |   4 +-
 drivers/nvme/target/admin-cmd.c    |  20 +--
 drivers/s390/block/dasd.c          |   8 +-
 fs/block_dev.c                     |  77 ++++-----
 fs/ext4/super.c                    |  18 +--
 fs/ext4/sysfs.c                    |  10 +-
 fs/f2fs/checkpoint.c               |   5 +-
 fs/f2fs/f2fs.h                     |   2 +-
 fs/f2fs/super.c                    |   6 +-
 fs/f2fs/sysfs.c                    |   9 --
 include/linux/blk_types.h          |  23 ++-
 include/linux/blkdev.h             |  13 +-
 include/linux/genhd.h              |  67 ++------
 include/linux/part_stat.h          |  17 +-
 init/do_mounts.c                   |  20 +--
 kernel/trace/blktrace.c            |  54 ++-----
 33 files changed, 362 insertions(+), 639 deletions(-)

Comments

Jan Kara Nov. 19, 2020, 2:39 p.m. UTC | #1

On Wed 18-11-20 09:47:55, Christoph Hellwig wrote:
> Instead of having two structures that represent each block device with
> different lift time rules merged them into a single one.  This also
            ^^^ :) life     ^^^^ merge

> greatly simplifies the reference counting rules, as we can use the inode
> reference count as the main reference count for the new struct
> block_device, with the device model reference front ending it for device
> model interaction.  The percpu refcount in struct hd_struct is entirely
> gone given that struct block_device must be opened and thus valid for
> the duration of the I/O.
> 
> Signed-off-by: Christoph Hellwig <[e-mail]>

This patch is kind of difficult to review due to the size of mostly
mechanical changes mixed with not completely mechanical changes. Can we
perhaps split out the mechanical bits? E.g. the rq->part => rq->bdev
renaming is mechanical and notable part of the patch. Similarly the
part->foo => part->bd_foo bits...

Also I'm kind of wondering: AFAIU the new lifetime rules, gendisk holds
bdev reference and bdev is created on gendisk allocation so bdev lifetime is
strictly larger than gendisk lifetime. But what now keeps bdev->bd_disk
reference safe in presence device hot unplug? In most cases we are still
protected by gendisk reference taken in __blkdev_get() but how about
disk->lookup_sem and disk->flags dereferences before we actually grab the
reference?

Also I find it rather non-obvious (although elegant ;) that bdev->bd_device
rules the lifetime of gendisk. Can you perhaps explain this in the
changelog and probably also add somewhere to source a documentation about
the new lifetime rules?

> diff --git a/block/blk.h b/block/blk.h
> index 09cee7024fb43e..90dd2047c6cd29 100644
> --- a/block/blk.h
> +++ b/block/blk.h
> @@ -215,7 +215,15 @@ static inline void elevator_exit(struct request_queue *q,
>  	__elevator_exit(q, e);
>  }
>  
> -struct hd_struct *__disk_get_part(struct gendisk *disk, int partno);
> +static inline struct block_device *__bdget_disk(struct gendisk *disk,
> +		int partno)
> +{
> +	struct disk_part_tbl *ptbl = rcu_dereference(disk->part_tbl);
> +
> +	if (unlikely(partno < 0 || partno >= ptbl->len))
> +		return NULL;
> +	return rcu_dereference(ptbl->part[partno]);
> +}

I understand this is lower-level counterpart of bdget_disk() but it is
confusing to me that this has 'bdget' in the name and returns no bdev
reference. Can we call it like __bdev_from_disk() or something like that?

>  
>  ssize_t part_size_show(struct device *dev, struct device_attribute *attr,
>  		char *buf);


									Honza

Christoph Hellwig Nov. 20, 2020, 9:15 a.m. UTC | #2

On Thu, Nov 19, 2020 at 03:39:21PM +0100, Jan Kara wrote:
> This patch is kind of difficult to review due to the size of mostly
> mechanical changes mixed with not completely mechanical changes. Can we
> perhaps split out the mechanical bits? E.g. the rq->part => rq->bdev
> renaming is mechanical and notable part of the patch. Similarly the
> part->foo => part->bd_foo bits...

We'd end with really weird patches that way.  Never mind that I'm not
even sure how we could mechnically do the renaming.

> 
> Also I'm kind of wondering: AFAIU the new lifetime rules, gendisk holds
> bdev reference and bdev is created on gendisk allocation so bdev lifetime is
> strictly larger than gendisk lifetime. But what now keeps bdev->bd_disk
> reference safe in presence device hot unplug? In most cases we are still
> protected by gendisk reference taken in __blkdev_get() but how about
> disk->lookup_sem and disk->flags dereferences before we actually grab the
> reference?

Good question.  I'll need to think about this a bit more.

> Also I find it rather non-obvious (although elegant ;) that bdev->bd_device
> rules the lifetime of gendisk. Can you perhaps explain this in the
> changelog and probably also add somewhere to source a documentation about
> the new lifetime rules?

Yes.

> > -struct hd_struct *__disk_get_part(struct gendisk *disk, int partno);
> > +static inline struct block_device *__bdget_disk(struct gendisk *disk,
> > +		int partno)
> > +{
> > +	struct disk_part_tbl *ptbl = rcu_dereference(disk->part_tbl);
> > +
> > +	if (unlikely(partno < 0 || partno >= ptbl->len))
> > +		return NULL;
> > +	return rcu_dereference(ptbl->part[partno]);
> > +}
> 
> I understand this is lower-level counterpart of bdget_disk() but it is
> confusing to me that this has 'bdget' in the name and returns no bdev
> reference. Can we call it like __bdev_from_disk() or something like that?

Sure.

Jan Kara Nov. 20, 2020, 10:53 a.m. UTC | #3

On Fri 20-11-20 10:15:46, Christoph Hellwig wrote:
> On Thu, Nov 19, 2020 at 03:39:21PM +0100, Jan Kara wrote:
> > This patch is kind of difficult to review due to the size of mostly
> > mechanical changes mixed with not completely mechanical changes. Can we
> > perhaps split out the mechanical bits? E.g. the rq->part => rq->bdev
> > renaming is mechanical and notable part of the patch. Similarly the
> > part->foo => part->bd_foo bits...
> 
> We'd end with really weird patches that way.  Never mind that I'm not
> even sure how we could mechnically do the renaming.

Well, I believe coccinelle should be able to do the renaming automatically.

> > Also I'm kind of wondering: AFAIU the new lifetime rules, gendisk holds
> > bdev reference and bdev is created on gendisk allocation so bdev lifetime is
> > strictly larger than gendisk lifetime. But what now keeps bdev->bd_disk
> > reference safe in presence device hot unplug? In most cases we are still
> > protected by gendisk reference taken in __blkdev_get() but how about
> > disk->lookup_sem and disk->flags dereferences before we actually grab the
> > reference?
> 
> Good question.  I'll need to think about this a bit more.

My thinking was that you could use

kobject_get_unless_zero(bdev->bd_device->kobj)

and after you hold this reference, you can do everything else safely. In
this case it is really useful that device is embedded in block_dev and
not in gendisk itself...

								Honza

Patch

diff --git a/block/bio.c b/block/bio.c
index 0c5269997434d6..4df1ecd53baf8f 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -608,12 +608,12 @@  void bio_truncate(struct bio *bio, unsigned new_size)
 void guard_bio_eod(struct bio *bio)
 {
 	sector_t maxsector;
-	struct hd_struct *part;
+	struct block_device *part;
 
 	rcu_read_lock();
-	part = __disk_get_part(bio->bi_disk, bio->bi_partno);
+	part = __bdget_disk(bio->bi_disk, bio->bi_partno);
 	if (part)
-		maxsector = bdev_nr_sectors(part->bdev);
+		maxsector = bdev_nr_sectors(part);
 	else
 		maxsector = get_capacity(bio->bi_disk);
 	rcu_read_unlock();
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 4c0ae0f6bce02d..fb5076223f10f2 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -820,9 +820,9 @@  static void blkcg_fill_root_iostats(void)
 
 	class_dev_iter_init(&iter, &block_class, NULL, &disk_type);
 	while ((dev = class_dev_iter_next(&iter))) {
-		struct gendisk *disk = dev_to_disk(dev);
-		struct hd_struct *part = disk_get_part(disk, 0);
-		struct blkcg_gq *blkg = blk_queue_root_blkg(disk->queue);
+		struct block_device *bdev = dev_to_bdev(dev);
+		struct blkcg_gq *blkg =
+			blk_queue_root_blkg(bdev->bd_disk->queue);
 		struct blkg_iostat tmp;
 		int cpu;
 
@@ -830,7 +830,7 @@  static void blkcg_fill_root_iostats(void)
 		for_each_possible_cpu(cpu) {
 			struct disk_stats *cpu_dkstats;
 
-			cpu_dkstats = per_cpu_ptr(part->dkstats, cpu);
+			cpu_dkstats = per_cpu_ptr(bdev->bd_stats, cpu);
 			tmp.ios[BLKG_IOSTAT_READ] +=
 				cpu_dkstats->ios[STAT_READ];
 			tmp.ios[BLKG_IOSTAT_WRITE] +=
@@ -849,7 +849,6 @@  static void blkcg_fill_root_iostats(void)
 			blkg_iostat_set(&blkg->iostat.cur, &tmp);
 			u64_stats_update_end(&blkg->iostat.sync);
 		}
-		disk_put_part(part);
 	}
 }
 
diff --git a/block/blk-core.c b/block/blk-core.c
index 988f45094a387b..192607c98e87c5 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -119,7 +119,7 @@  void blk_rq_init(struct request_queue *q, struct request *rq)
 	rq->tag = BLK_MQ_NO_TAG;
 	rq->internal_tag = BLK_MQ_NO_TAG;
 	rq->start_time_ns = ktime_get_ns();
-	rq->part = NULL;
+	rq->bdev = NULL;
 	refcount_set(&rq->ref, 1);
 	blk_crypto_rq_set_defaults(rq);
 }
@@ -666,9 +666,9 @@  static int __init setup_fail_make_request(char *str)
 }
 __setup("fail_make_request=", setup_fail_make_request);
 
-static bool should_fail_request(struct hd_struct *part, unsigned int bytes)
+static bool should_fail_request(struct block_device *bdev, unsigned int bytes)
 {
-	return part->make_it_fail && should_fail(&fail_make_request, bytes);
+	return bdev->bd_make_it_fail && should_fail(&fail_make_request, bytes);
 }
 
 static int __init fail_make_request_debugfs(void)
@@ -683,19 +683,19 @@  late_initcall(fail_make_request_debugfs);
 
 #else /* CONFIG_FAIL_MAKE_REQUEST */
 
-static inline bool should_fail_request(struct hd_struct *part,
-					unsigned int bytes)
+static inline bool should_fail_request(struct block_device *bdev,
+		unsigned int bytes)
 {
 	return false;
 }
 
 #endif /* CONFIG_FAIL_MAKE_REQUEST */
 
-static inline bool bio_check_ro(struct bio *bio, struct hd_struct *part)
+static inline bool bio_check_ro(struct bio *bio, struct block_device *bdev)
 {
 	const int op = bio_op(bio);
 
-	if (part->policy && op_is_write(op)) {
+	if (bdev->bd_policy && op_is_write(op)) {
 		char b[BDEVNAME_SIZE];
 
 		if (op_is_flush(bio->bi_opf) && !bio_sectors(bio))
@@ -703,7 +703,7 @@  static inline bool bio_check_ro(struct bio *bio, struct hd_struct *part)
 
 		WARN_ONCE(1,
 		       "Trying to write to read-only block-device %s (partno %d)\n",
-			bio_devname(bio, b), part->partno);
+			bio_devname(bio, b), bdev->bd_partno);
 		/* Older lvm-tools actually trigger this */
 		return false;
 	}
@@ -713,7 +713,7 @@  static inline bool bio_check_ro(struct bio *bio, struct hd_struct *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(bio->bi_disk->part0, bio->bi_iter.bi_size))
 		return -EIO;
 	return 0;
 }
@@ -742,11 +742,11 @@  static inline int bio_check_eod(struct bio *bio, sector_t maxsector)
  */
 static inline int blk_partition_remap(struct bio *bio)
 {
-	struct hd_struct *p;
+	struct block_device *p;
 	int ret = -EIO;
 
 	rcu_read_lock();
-	p = __disk_get_part(bio->bi_disk, bio->bi_partno);
+	p = __bdget_disk(bio->bi_disk, bio->bi_partno);
 	if (unlikely(!p))
 		goto out;
 	if (unlikely(should_fail_request(p, bio->bi_iter.bi_size)))
@@ -755,11 +755,11 @@  static inline int blk_partition_remap(struct bio *bio)
 		goto out;
 
 	if (bio_sectors(bio)) {
-		if (bio_check_eod(bio, bdev_nr_sectors(p->bdev)))
+		if (bio_check_eod(bio, bdev_nr_sectors(p)))
 			goto out;
-		bio->bi_iter.bi_sector += p->start_sect;
-		trace_block_bio_remap(bio->bi_disk->queue, bio, part_devt(p),
-				      bio->bi_iter.bi_sector - p->start_sect);
+		bio->bi_iter.bi_sector += p->bd_start_sect;
+		trace_block_bio_remap(bio->bi_disk->queue, bio, p->bd_dev,
+				      bio->bi_iter.bi_sector - p->bd_start_sect);
 	}
 	bio->bi_partno = 0;
 	ret = 0;
@@ -829,7 +829,7 @@  static noinline_for_stack bool submit_bio_checks(struct bio *bio)
 		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, bio->bi_disk->part0)))
 			goto end_io;
 		if (unlikely(bio_check_eod(bio, get_capacity(bio->bi_disk))))
 			goto end_io;
@@ -1201,7 +1201,7 @@  blk_status_t blk_insert_cloned_request(struct request_queue *q, struct request *
 		return ret;
 
 	if (rq->rq_disk &&
-	    should_fail_request(&rq->rq_disk->part0, blk_rq_bytes(rq)))
+	    should_fail_request(rq->rq_disk->part0, blk_rq_bytes(rq)))
 		return BLK_STS_IOERR;
 
 	if (blk_crypto_insert_cloned_request(rq))
@@ -1260,30 +1260,29 @@  unsigned int blk_rq_err_bytes(const struct request *rq)
 }
 EXPORT_SYMBOL_GPL(blk_rq_err_bytes);
 
-static void update_io_ticks(struct hd_struct *part, unsigned long now, bool end)
+static void update_io_ticks(struct block_device *part, unsigned long now,
+		bool end)
 {
 	unsigned long stamp;
 again:
-	stamp = READ_ONCE(part->stamp);
+	stamp = READ_ONCE(part->bd_stamp);
 	if (unlikely(stamp != now)) {
-		if (likely(cmpxchg(&part->stamp, stamp, now) == stamp))
+		if (likely(cmpxchg(&part->bd_stamp, stamp, now) == stamp))
 			__part_stat_add(part, io_ticks, end ? now - stamp : 1);
 	}
-	if (part->partno) {
-		part = &part_to_disk(part)->part0;
+	if (part->bd_partno) {
+		part = part->bd_disk->part0;
 		goto again;
 	}
 }
 
 static void blk_account_io_completion(struct request *req, unsigned int bytes)
 {
-	if (req->part && blk_do_io_stat(req)) {
+	if (req->bdev && blk_do_io_stat(req)) {
 		const int sgrp = op_stat_group(req_op(req));
-		struct hd_struct *part;
 
 		part_stat_lock();
-		part = req->part;
-		part_stat_add(part, sectors[sgrp], bytes >> 9);
+		part_stat_add(req->bdev, sectors[sgrp], bytes >> 9);
 		part_stat_unlock();
 	}
 }
@@ -1295,20 +1294,15 @@  void blk_account_io_done(struct request *req, u64 now)
 	 * normal IO on queueing nor completion.  Accounting the
 	 * containing request is enough.
 	 */
-	if (req->part && blk_do_io_stat(req) &&
+	if (req->bdev && blk_do_io_stat(req) &&
 	    !(req->rq_flags & RQF_FLUSH_SEQ)) {
 		const int sgrp = op_stat_group(req_op(req));
-		struct hd_struct *part;
 
 		part_stat_lock();
-		part = req->part;
-
-		update_io_ticks(part, jiffies, true);
-		part_stat_inc(part, ios[sgrp]);
-		part_stat_add(part, nsecs[sgrp], now - req->start_time_ns);
+		update_io_ticks(req->bdev, jiffies, true);
+		part_stat_inc(req->bdev, ios[sgrp]);
+		part_stat_add(req->bdev, nsecs[sgrp], now - req->start_time_ns);
 		part_stat_unlock();
-
-		hd_struct_put(part);
 	}
 }
 
@@ -1317,15 +1311,15 @@  void blk_account_io_start(struct request *rq)
 	if (!blk_do_io_stat(rq))
 		return;
 
-	rq->part = disk_map_sector_rcu(rq->rq_disk, blk_rq_pos(rq));
+	rq->bdev = disk_map_sector_rcu(rq->rq_disk, blk_rq_pos(rq));
 
 	part_stat_lock();
-	update_io_ticks(rq->part, jiffies, false);
+	update_io_ticks(rq->bdev, jiffies, false);
 	part_stat_unlock();
 }
 
-static unsigned long __part_start_io_acct(struct hd_struct *part,
-					  unsigned int sectors, unsigned int op)
+static unsigned long __part_start_io_acct(struct block_device *part,
+		unsigned int sectors, unsigned int op)
 {
 	const int sgrp = op_stat_group(op);
 	unsigned long now = READ_ONCE(jiffies);
@@ -1340,8 +1334,8 @@  static unsigned long __part_start_io_acct(struct hd_struct *part,
 	return now;
 }
 
-unsigned long part_start_io_acct(struct gendisk *disk, struct hd_struct **part,
-				 struct bio *bio)
+unsigned long part_start_io_acct(struct gendisk *disk,
+		struct block_device **part, struct bio *bio)
 {
 	*part = disk_map_sector_rcu(disk, bio->bi_iter.bi_sector);
 
@@ -1352,11 +1346,11 @@  EXPORT_SYMBOL_GPL(part_start_io_acct);
 unsigned long disk_start_io_acct(struct gendisk *disk, unsigned int sectors,
 				 unsigned int op)
 {
-	return __part_start_io_acct(&disk->part0, sectors, op);
+	return __part_start_io_acct(disk->part0, sectors, op);
 }
 EXPORT_SYMBOL(disk_start_io_acct);
 
-static void __part_end_io_acct(struct hd_struct *part, unsigned int op,
+static void __part_end_io_acct(struct block_device *part, unsigned int op,
 			       unsigned long start_time)
 {
 	const int sgrp = op_stat_group(op);
@@ -1370,18 +1364,17 @@  static void __part_end_io_acct(struct hd_struct *part, unsigned int op,
 	part_stat_unlock();
 }
 
-void part_end_io_acct(struct hd_struct *part, struct bio *bio,
+void part_end_io_acct(struct block_device *part, struct bio *bio,
 		      unsigned long start_time)
 {
 	__part_end_io_acct(part, bio_op(bio), start_time);
-	hd_struct_put(part);
 }
 EXPORT_SYMBOL_GPL(part_end_io_acct);
 
 void disk_end_io_acct(struct gendisk *disk, unsigned int op,
 		      unsigned long start_time)
 {
-	__part_end_io_acct(&disk->part0, op, start_time);
+	__part_end_io_acct(disk->part0, op, start_time);
 }
 EXPORT_SYMBOL(disk_end_io_acct);
 
diff --git a/block/blk-flush.c b/block/blk-flush.c
index e32958f0b68750..9507dcdd58814c 100644
--- a/block/blk-flush.c
+++ b/block/blk-flush.c
@@ -139,7 +139,7 @@  static void blk_flush_queue_rq(struct request *rq, bool add_front)
 
 static void blk_account_io_flush(struct request *rq)
 {
-	struct hd_struct *part = &rq->rq_disk->part0;
+	struct block_device *part = rq->rq_disk->part0;
 
 	part_stat_lock();
 	part_stat_inc(part, ios[STAT_FLUSH]);
diff --git a/block/blk-lib.c b/block/blk-lib.c
index e90614fd8d6a42..752f9c7220622a 100644
--- a/block/blk-lib.c
+++ b/block/blk-lib.c
@@ -65,7 +65,7 @@  int __blkdev_issue_discard(struct block_device *bdev, sector_t sector,
 
 	/* In case the discard request is in a partition */
 	if (bdev_is_partition(bdev))
-		part_offset = bdev->bd_part->start_sect;
+		part_offset = bdev->bd_start_sect;
 
 	while (nr_sects) {
 		sector_t granularity_aligned_lba, req_sects;
diff --git a/block/blk-merge.c b/block/blk-merge.c
index bcf5e458060337..3ec0d322e4a769 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -681,10 +681,8 @@  static void blk_account_io_merge_request(struct request *req)
 {
 	if (blk_do_io_stat(req)) {
 		part_stat_lock();
-		part_stat_inc(req->part, merges[op_stat_group(req_op(req))]);
+		part_stat_inc(req->bdev, merges[op_stat_group(req_op(req))]);
 		part_stat_unlock();
-
-		hd_struct_put(req->part);
 	}
 }
 
@@ -906,7 +904,7 @@  static void blk_account_io_merge_bio(struct request *req)
 		return;
 
 	part_stat_lock();
-	part_stat_inc(req->part, merges[op_stat_group(req_op(req))]);
+	part_stat_inc(req->bdev, merges[op_stat_group(req_op(req))]);
 	part_stat_unlock();
 }
 
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 55bcee5dc0320c..a28475e6405de9 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -95,7 +95,7 @@  static void blk_mq_hctx_clear_pending(struct blk_mq_hw_ctx *hctx,
 }
 
 struct mq_inflight {
-	struct hd_struct *part;
+	struct block_device *part;
 	unsigned int inflight[2];
 };
 
@@ -105,13 +105,14 @@  static bool blk_mq_check_inflight(struct blk_mq_hw_ctx *hctx,
 {
 	struct mq_inflight *mi = priv;
 
-	if (rq->part == mi->part && blk_mq_rq_state(rq) == MQ_RQ_IN_FLIGHT)
+	if (rq->bdev == mi->part && blk_mq_rq_state(rq) == MQ_RQ_IN_FLIGHT)
 		mi->inflight[rq_data_dir(rq)]++;
 
 	return true;
 }
 
-unsigned int blk_mq_in_flight(struct request_queue *q, struct hd_struct *part)
+unsigned int blk_mq_in_flight(struct request_queue *q,
+		struct block_device *part)
 {
 	struct mq_inflight mi = { .part = part };
 
@@ -120,7 +121,7 @@  unsigned int blk_mq_in_flight(struct request_queue *q, struct hd_struct *part)
 	return mi.inflight[0] + mi.inflight[1];
 }
 
-void blk_mq_in_flight_rw(struct request_queue *q, struct hd_struct *part,
+void blk_mq_in_flight_rw(struct request_queue *q, struct block_device *part,
 			 unsigned int inflight[2])
 {
 	struct mq_inflight mi = { .part = part };
@@ -300,7 +301,7 @@  static struct request *blk_mq_rq_ctx_init(struct blk_mq_alloc_data *data,
 	INIT_HLIST_NODE(&rq->hash);
 	RB_CLEAR_NODE(&rq->rb_node);
 	rq->rq_disk = NULL;
-	rq->part = NULL;
+	rq->bdev = NULL;
 #ifdef CONFIG_BLK_RQ_ALLOC_TIME
 	rq->alloc_time_ns = alloc_time_ns;
 #endif
diff --git a/block/blk-mq.h b/block/blk-mq.h
index a52703c98b7736..395fbc6c59d1eb 100644
--- a/block/blk-mq.h
+++ b/block/blk-mq.h
@@ -182,8 +182,9 @@  static inline bool blk_mq_hw_queue_mapped(struct blk_mq_hw_ctx *hctx)
 	return hctx->nr_ctx && hctx->tags;
 }
 
-unsigned int blk_mq_in_flight(struct request_queue *q, struct hd_struct *part);
-void blk_mq_in_flight_rw(struct request_queue *q, struct hd_struct *part,
+unsigned int blk_mq_in_flight(struct request_queue *q,
+		struct block_device *bdev);
+void blk_mq_in_flight_rw(struct request_queue *q, struct block_device *bdev,
 			 unsigned int inflight[2]);
 
 static inline void blk_mq_put_dispatch_budget(struct request_queue *q)
diff --git a/block/blk.h b/block/blk.h
index 09cee7024fb43e..90dd2047c6cd29 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -215,7 +215,15 @@  static inline void elevator_exit(struct request_queue *q,
 	__elevator_exit(q, e);
 }
 
-struct hd_struct *__disk_get_part(struct gendisk *disk, int partno);
+static inline struct block_device *__bdget_disk(struct gendisk *disk,
+		int partno)
+{
+	struct disk_part_tbl *ptbl = rcu_dereference(disk->part_tbl);
+
+	if (unlikely(partno < 0 || partno >= ptbl->len))
+		return NULL;
+	return rcu_dereference(ptbl->part[partno]);
+}
 
 ssize_t part_size_show(struct device *dev, struct device_attribute *attr,
 		char *buf);
@@ -348,44 +356,21 @@  void blk_queue_free_zone_bitmaps(struct request_queue *q);
 static inline void blk_queue_free_zone_bitmaps(struct request_queue *q) {}
 #endif
 
-struct hd_struct *disk_map_sector_rcu(struct gendisk *disk, sector_t sector);
+struct block_device *disk_map_sector_rcu(struct gendisk *disk, sector_t sector);
 
-int blk_alloc_devt(struct hd_struct *part, dev_t *devt);
+int blk_alloc_devt(struct block_device *bdev, dev_t *devt);
 void blk_free_devt(dev_t devt);
 char *disk_name(struct gendisk *hd, int partno, char *buf);
 #define ADDPART_FLAG_NONE	0
 #define ADDPART_FLAG_RAID	1
 #define ADDPART_FLAG_WHOLEDISK	2
-void delete_partition(struct hd_struct *part);
+void delete_partition(struct block_device *part);
 int bdev_add_partition(struct block_device *bdev, int partno,
 		sector_t start, sector_t length);
 int bdev_del_partition(struct block_device *bdev, int partno);
 int bdev_resize_partition(struct block_device *bdev, int partno,
 		sector_t start, sector_t length);
 int disk_expand_part_tbl(struct gendisk *disk, int target);
-int hd_ref_init(struct hd_struct *part);
-
-/* no need to get/put refcount of part0 */
-static inline int hd_struct_try_get(struct hd_struct *part)
-{
-	if (part->partno)
-		return percpu_ref_tryget_live(&part->ref);
-	return 1;
-}
-
-static inline void hd_struct_put(struct hd_struct *part)
-{
-	if (part->partno)
-		percpu_ref_put(&part->ref);
-}
-
-static inline void hd_free_part(struct hd_struct *part)
-{
-	free_percpu(part->dkstats);
-	kfree(part->info);
-	bdput(part->bdev);
-	percpu_ref_exit(&part->ref);
-}
 
 int bio_add_hw_page(struct request_queue *q, struct bio *bio,
 		struct page *page, unsigned int len, unsigned int offset,
diff --git a/block/genhd.c b/block/genhd.c
index e101b6843f7437..a14e2408e3d4e8 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -40,7 +40,7 @@  static void disk_release_events(struct gendisk *disk);
 
 void set_capacity(struct gendisk *disk, sector_t sectors)
 {
-	struct block_device *bdev = disk->part0.bdev;
+	struct block_device *bdev = disk->part0;
 
 	spin_lock(&bdev->bd_size_lock);
 	i_size_write(bdev->bd_inode, (loff_t)sectors << SECTOR_SHIFT);
@@ -93,13 +93,14 @@  const char *bdevname(struct block_device *bdev, char *buf)
 }
 EXPORT_SYMBOL(bdevname);
 
-static void part_stat_read_all(struct hd_struct *part, struct disk_stats *stat)
+static void part_stat_read_all(struct block_device *part,
+		struct disk_stats *stat)
 {
 	int cpu;
 
 	memset(stat, 0, sizeof(struct disk_stats));
 	for_each_possible_cpu(cpu) {
-		struct disk_stats *ptr = per_cpu_ptr(part->dkstats, cpu);
+		struct disk_stats *ptr = per_cpu_ptr(part->bd_stats, cpu);
 		int group;
 
 		for (group = 0; group < NR_STAT_GROUPS; group++) {
@@ -113,7 +114,7 @@  static void part_stat_read_all(struct hd_struct *part, struct disk_stats *stat)
 	}
 }
 
-static unsigned int part_in_flight(struct hd_struct *part)
+static unsigned int part_in_flight(struct block_device *part)
 {
 	unsigned int inflight = 0;
 	int cpu;
@@ -128,7 +129,8 @@  static unsigned int part_in_flight(struct hd_struct *part)
 	return inflight;
 }
 
-static void part_in_flight_rw(struct hd_struct *part, unsigned int inflight[2])
+static void part_in_flight_rw(struct block_device *part,
+		unsigned int inflight[2])
 {
 	int cpu;
 
@@ -144,42 +146,6 @@  static void part_in_flight_rw(struct hd_struct *part, unsigned int inflight[2])
 		inflight[1] = 0;
 }
 
-struct hd_struct *__disk_get_part(struct gendisk *disk, int partno)
-{
-	struct disk_part_tbl *ptbl = rcu_dereference(disk->part_tbl);
-
-	if (unlikely(partno < 0 || partno >= ptbl->len))
-		return NULL;
-	return rcu_dereference(ptbl->part[partno]);
-}
-
-/**
- * disk_get_part - get partition
- * @disk: disk to look partition from
- * @partno: partition number
- *
- * Look for partition @partno from @disk.  If found, increment
- * reference count and return it.
- *
- * CONTEXT:
- * Don't care.
- *
- * RETURNS:
- * Pointer to the found partition on success, NULL if not found.
- */
-struct hd_struct *disk_get_part(struct gendisk *disk, int partno)
-{
-	struct hd_struct *part;
-
-	rcu_read_lock();
-	part = __disk_get_part(disk, partno);
-	if (part)
-		get_device(part_to_dev(part));
-	rcu_read_unlock();
-
-	return part;
-}
-
 /**
  * disk_part_iter_init - initialize partition iterator
  * @piter: iterator to initialize
@@ -224,7 +190,7 @@  EXPORT_SYMBOL_GPL(disk_part_iter_init);
  * CONTEXT:
  * Don't care.
  */
-struct hd_struct *disk_part_iter_next(struct disk_part_iter *piter)
+struct block_device *disk_part_iter_next(struct disk_part_iter *piter)
 {
 	struct disk_part_tbl *ptbl;
 	int inc, end;
@@ -251,19 +217,18 @@  struct hd_struct *disk_part_iter_next(struct disk_part_iter *piter)
 
 	/* iterate to the next partition */
 	for (; piter->idx != end; piter->idx += inc) {
-		struct hd_struct *part;
+		struct block_device *part;
 
 		part = rcu_dereference(ptbl->part[piter->idx]);
 		if (!part)
 			continue;
-		if (!bdev_nr_sectors(part->bdev) &&
+		if (!bdev_nr_sectors(part) &&
 		    !(piter->flags & DISK_PITER_INCL_EMPTY) &&
 		    !(piter->flags & DISK_PITER_INCL_EMPTY_PART0 &&
 		      piter->idx == 0))
 			continue;
 
-		get_device(part_to_dev(part));
-		piter->part = part;
+		piter->part = bdgrab(part);
 		piter->idx += inc;
 		break;
 	}
@@ -285,15 +250,16 @@  EXPORT_SYMBOL_GPL(disk_part_iter_next);
  */
 void disk_part_iter_exit(struct disk_part_iter *piter)
 {
-	disk_put_part(piter->part);
+	if (piter->part)
+		bdput(piter->part);
 	piter->part = NULL;
 }
 EXPORT_SYMBOL_GPL(disk_part_iter_exit);
 
-static inline int sector_in_part(struct hd_struct *part, sector_t sector)
+static inline int sector_in_part(struct block_device *part, sector_t sector)
 {
-	return part->start_sect <= sector &&
-		sector < part->start_sect + bdev_nr_sectors(part->bdev);
+	return part->bd_start_sect <= sector &&
+		sector < part->bd_start_sect + bdev_nr_sectors(part);
 }
 
 /**
@@ -313,36 +279,28 @@  static inline int sector_in_part(struct hd_struct *part, sector_t sector)
  * Found partition on success, part0 is returned if no partition matches
  * or the matched partition is being deleted.
  */
-struct hd_struct *disk_map_sector_rcu(struct gendisk *disk, sector_t sector)
+struct block_device *disk_map_sector_rcu(struct gendisk *disk, sector_t sector)
 {
 	struct disk_part_tbl *ptbl;
-	struct hd_struct *part;
+	struct block_device *part;
 	int i;
 
 	rcu_read_lock();
 	ptbl = rcu_dereference(disk->part_tbl);
 
 	part = rcu_dereference(ptbl->last_lookup);
-	if (part && sector_in_part(part, sector) && hd_struct_try_get(part))
+	if (part && sector_in_part(part, sector))
 		goto out_unlock;
 
 	for (i = 1; i < ptbl->len; i++) {
 		part = rcu_dereference(ptbl->part[i]);
-
 		if (part && sector_in_part(part, sector)) {
-			/*
-			 * only live partition can be cached for lookup,
-			 * so use-after-free on cached & deleting partition
-			 * can be avoided
-			 */
-			if (!hd_struct_try_get(part))
-				break;
 			rcu_assign_pointer(ptbl->last_lookup, part);
 			goto out_unlock;
 		}
 	}
 
-	part = &disk->part0;
+	part = disk->part0;
 out_unlock:
 	rcu_read_unlock();
 	return part;
@@ -560,7 +518,7 @@  static int blk_mangle_minor(int minor)
 
 /**
  * blk_alloc_devt - allocate a dev_t for a partition
- * @part: partition to allocate dev_t for
+ * @bdev: partition to allocate dev_t for
  * @devt: out parameter for resulting dev_t
  *
  * Allocate a dev_t for block device.
@@ -572,14 +530,14 @@  static int blk_mangle_minor(int minor)
  * CONTEXT:
  * Might sleep.
  */
-int blk_alloc_devt(struct hd_struct *part, dev_t *devt)
+int blk_alloc_devt(struct block_device *bdev, dev_t *devt)
 {
-	struct gendisk *disk = part_to_disk(part);
+	struct gendisk *disk = bdev->bd_disk;
 	int idx;
 
 	/* in consecutive minor range? */
-	if (part->partno < disk->minors) {
-		*devt = MKDEV(disk->major, disk->first_minor + part->partno);
+	if (bdev->bd_partno < disk->minors) {
+		*devt = MKDEV(disk->major, disk->first_minor + bdev->bd_partno);
 		return 0;
 	}
 
@@ -636,7 +594,7 @@  static void register_disk(struct device *parent, struct gendisk *disk,
 {
 	struct device *ddev = disk_to_dev(disk);
 	struct disk_part_iter piter;
-	struct hd_struct *part;
+	struct block_device *part;
 	int err;
 
 	ddev->parent = parent;
@@ -668,7 +626,8 @@  static void register_disk(struct device *parent, struct gendisk *disk,
 	 */
 	pm_runtime_set_memalloc_noio(ddev, true);
 
-	disk->part0.holder_dir = kobject_create_and_add("holders", &ddev->kobj);
+	disk->part0->bd_holder_dir =
+		kobject_create_and_add("holders", &ddev->kobj);
 	disk->slave_dir = kobject_create_and_add("slaves", &ddev->kobj);
 
 	if (disk->flags & GENHD_FL_HIDDEN) {
@@ -685,7 +644,7 @@  static void register_disk(struct device *parent, struct gendisk *disk,
 	/* announce possible partitions */
 	disk_part_iter_init(&piter, disk, 0);
 	while ((part = disk_part_iter_next(&piter)))
-		kobject_uevent(&part_to_dev(part)->kobj, KOBJ_ADD);
+		kobject_uevent(bdev_kobj(part), KOBJ_ADD);
 	disk_part_iter_exit(&piter);
 
 	if (disk->queue->backing_dev_info->dev) {
@@ -734,7 +693,7 @@  static void __device_add_disk(struct device *parent, struct gendisk *disk,
 
 	disk->flags |= GENHD_FL_UP;
 
-	retval = blk_alloc_devt(&disk->part0, &devt);
+	retval = blk_alloc_devt(disk->part0, &devt);
 	if (retval) {
 		WARN_ON(1);
 		return;
@@ -761,7 +720,7 @@  static void __device_add_disk(struct device *parent, struct gendisk *disk,
 		ret = bdi_register(bdi, "%u:%u", MAJOR(devt), MINOR(devt));
 		WARN_ON(ret);
 		bdi_set_owner(bdi, dev);
-		bdev_add(disk->part0.bdev, devt);
+		bdev_add(disk->part0, devt);
 	}
 	register_disk(parent, disk, groups);
 	if (register_queue)
@@ -791,14 +750,8 @@  void device_add_disk_no_queue_reg(struct device *parent, struct gendisk *disk)
 }
 EXPORT_SYMBOL(device_add_disk_no_queue_reg);
 
-static void invalidate_partition(struct gendisk *disk, int partno)
+static void invalidate_partition(struct block_device *bdev)
 {
-	struct block_device *bdev;
-
-	bdev = bdget_disk(disk, partno);
-	if (!bdev)
-		return;
-
 	fsync_bdev(bdev);
 	__invalidate_device(bdev, true);
 
@@ -807,7 +760,6 @@  static void invalidate_partition(struct gendisk *disk, int partno)
 	 * as last inode reference is dropped.
 	 */
 	remove_inode_hash(bdev->bd_inode);
-	bdput(bdev);
 }
 
 /**
@@ -832,7 +784,7 @@  static void invalidate_partition(struct gendisk *disk, int partno)
 void del_gendisk(struct gendisk *disk)
 {
 	struct disk_part_iter piter;
-	struct hd_struct *part;
+	struct block_device *part;
 
 	might_sleep();
 
@@ -851,12 +803,12 @@  void del_gendisk(struct gendisk *disk)
 	disk_part_iter_init(&piter, disk,
 			     DISK_PITER_INCL_EMPTY | DISK_PITER_REVERSE);
 	while ((part = disk_part_iter_next(&piter))) {
-		invalidate_partition(disk, part->partno);
+		invalidate_partition(part);
 		delete_partition(part);
 	}
 	disk_part_iter_exit(&piter);
 
-	invalidate_partition(disk, 0);
+	invalidate_partition(disk->part0);
 	set_capacity(disk, 0);
 	disk->flags &= ~GENHD_FL_UP;
 	up_write(&disk->lookup_sem);
@@ -873,11 +825,11 @@  void del_gendisk(struct gendisk *disk)
 
 	blk_unregister_queue(disk);
 
-	kobject_put(disk->part0.holder_dir);
+	kobject_put(disk->part0->bd_holder_dir);
 	kobject_put(disk->slave_dir);
 
-	part_stat_set_all(&disk->part0, 0);
-	disk->part0.stamp = 0;
+	part_stat_set_all(disk->part0, 0);
+	disk->part0->bd_stamp = 0;
 	if (!sysfs_deprecated)
 		sysfs_remove_link(block_depr, dev_name(disk_to_dev(disk)));
 	pm_runtime_set_memalloc_noio(disk_to_dev(disk), false);
@@ -945,13 +897,13 @@  void blk_request_module(dev_t devt)
  */
 struct block_device *bdget_disk(struct gendisk *disk, int partno)
 {
-	struct hd_struct *part;
 	struct block_device *bdev = NULL;
 
-	part = disk_get_part(disk, partno);
-	if (part)
-		bdev = bdget_part(part);
-	disk_put_part(part);
+	rcu_read_lock();
+	bdev = __bdget_disk(disk, partno);
+	if (bdev)
+		bdgrab(bdev);
+	rcu_read_unlock();
 
 	return bdev;
 }
@@ -971,7 +923,7 @@  void __init printk_all_partitions(void)
 	while ((dev = class_dev_iter_next(&iter))) {
 		struct gendisk *disk = dev_to_disk(dev);
 		struct disk_part_iter piter;
-		struct hd_struct *part;
+		struct block_device *part;
 		char name_buf[BDEVNAME_SIZE];
 		char devt_buf[BDEVT_SIZE];
 
@@ -990,13 +942,14 @@  void __init printk_all_partitions(void)
 		 */
 		disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0);
 		while ((part = disk_part_iter_next(&piter))) {
-			bool is_part0 = part == &disk->part0;
+			bool is_part0 = part == disk->part0;
 
 			printk("%s%s %10llu %s %s", is_part0 ? "" : "  ",
-			       bdevt_str(part_devt(part), devt_buf),
-			       bdev_nr_sectors(part->bdev) >> 1
-			       , disk_name(disk, part->partno, name_buf),
-			       part->info ? part->info->uuid : "");
+			       bdevt_str(part->bd_dev, devt_buf),
+			       bdev_nr_sectors(part) >> 1,
+			       disk_name(disk, part->bd_partno, name_buf),
+			       part->bd_meta_info ?
+					part->bd_meta_info->uuid : "");
 			if (is_part0) {
 				if (dev->parent && dev->parent->driver)
 					printk(" driver: %s\n",
@@ -1072,7 +1025,7 @@  static int show_partition(struct seq_file *seqf, void *v)
 {
 	struct gendisk *sgp = v;
 	struct disk_part_iter piter;
-	struct hd_struct *part;
+	struct block_device *part;
 	char buf[BDEVNAME_SIZE];
 
 	/* Don't show non-partitionable removeable devices or empty devices */
@@ -1086,9 +1039,9 @@  static int show_partition(struct seq_file *seqf, void *v)
 	disk_part_iter_init(&piter, sgp, DISK_PITER_INCL_PART0);
 	while ((part = disk_part_iter_next(&piter)))
 		seq_printf(seqf, "%4d  %7d %10llu %s\n",
-			   MAJOR(part_devt(part)), MINOR(part_devt(part)),
-			   bdev_nr_sectors(part->bdev) >> 1,
-			   disk_name(sgp, part->partno, buf));
+			   MAJOR(part->bd_dev), MINOR(part->bd_dev),
+			   bdev_nr_sectors(part) >> 1,
+			   disk_name(sgp, part->bd_partno, buf));
 	disk_part_iter_exit(&piter);
 
 	return 0;
@@ -1167,24 +1120,22 @@  static ssize_t disk_ro_show(struct device *dev,
 ssize_t part_size_show(struct device *dev,
 		       struct device_attribute *attr, char *buf)
 {
-	struct hd_struct *p = dev_to_part(dev);
-
-	return sprintf(buf, "%llu\n", bdev_nr_sectors(p->bdev));
+	return sprintf(buf, "%llu\n", bdev_nr_sectors(dev_to_bdev(dev)));
 }
 
 ssize_t part_stat_show(struct device *dev,
 		       struct device_attribute *attr, char *buf)
 {
-	struct hd_struct *p = dev_to_part(dev);
-	struct request_queue *q = part_to_disk(p)->queue;
+	struct block_device *bdev = dev_to_bdev(dev);
+	struct request_queue *q = bdev->bd_disk->queue;
 	struct disk_stats stat;
 	unsigned int inflight;
 
-	part_stat_read_all(p, &stat);
+	part_stat_read_all(bdev, &stat);
 	if (queue_is_mq(q))
-		inflight = blk_mq_in_flight(q, p);
+		inflight = blk_mq_in_flight(q, bdev);
 	else
-		inflight = part_in_flight(p);
+		inflight = part_in_flight(bdev);
 
 	return sprintf(buf,
 		"%8lu %8lu %8llu %8u "
@@ -1219,14 +1170,14 @@  ssize_t part_stat_show(struct device *dev,
 ssize_t part_inflight_show(struct device *dev, struct device_attribute *attr,
 			   char *buf)
 {
-	struct hd_struct *p = dev_to_part(dev);
-	struct request_queue *q = part_to_disk(p)->queue;
+	struct block_device *bdev = dev_to_bdev(dev);
+	struct request_queue *q = bdev->bd_disk->queue;
 	unsigned int inflight[2];
 
 	if (queue_is_mq(q))
-		blk_mq_in_flight_rw(q, p, inflight);
+		blk_mq_in_flight_rw(q, bdev, inflight);
 	else
-		part_in_flight_rw(p, inflight);
+		part_in_flight_rw(bdev, inflight);
 
 	return sprintf(buf, "%8u %8u\n", inflight[0], inflight[1]);
 }
@@ -1274,16 +1225,14 @@  static DEVICE_ATTR(badblocks, 0644, disk_badblocks_show, disk_badblocks_store);
 ssize_t part_fail_show(struct device *dev,
 		       struct device_attribute *attr, char *buf)
 {
-	struct hd_struct *p = dev_to_part(dev);
-
-	return sprintf(buf, "%d\n", p->make_it_fail);
+	return sprintf(buf, "%d\n", dev_to_bdev(dev)->make_it_fail);
 }
 
 ssize_t part_fail_store(struct device *dev,
 			struct device_attribute *attr,
 			const char *buf, size_t count)
 {
-	struct hd_struct *p = dev_to_part(dev);
+	struct block_device *p = dev_to_bdev(dev);
 	int i;
 
 	if (count > 0 && sscanf(buf, "%d", &i) > 0)
@@ -1444,9 +1393,9 @@  static void disk_release(struct device *dev)
 	disk_release_events(disk);
 	kfree(disk->random);
 	disk_replace_part_tbl(disk, NULL);
-	hd_free_part(&disk->part0);
 	if (disk->queue)
 		blk_put_queue(disk->queue);
+	bdput(disk->part0);
 	kfree(disk);
 }
 struct class block_class = {
@@ -1482,7 +1431,7 @@  static int diskstats_show(struct seq_file *seqf, void *v)
 {
 	struct gendisk *gp = v;
 	struct disk_part_iter piter;
-	struct hd_struct *hd;
+	struct block_device *hd;
 	char buf[BDEVNAME_SIZE];
 	unsigned int inflight;
 	struct disk_stats stat;
@@ -1510,8 +1459,8 @@  static int diskstats_show(struct seq_file *seqf, void *v)
 			   "%lu %lu %lu %u "
 			   "%lu %u"
 			   "\n",
-			   MAJOR(part_devt(hd)), MINOR(part_devt(hd)),
-			   disk_name(gp, hd->partno, buf),
+			   MAJOR(hd->bd_dev), MINOR(hd->bd_dev),
+			   disk_name(gp, hd->bd_partno, buf),
 			   stat.ios[STAT_READ],
 			   stat.merges[STAT_READ],
 			   stat.sectors[STAT_READ],
@@ -1567,9 +1516,9 @@  dev_t blk_lookup_devt(const char *name, int partno)
 	struct device *dev;
 
 	class_dev_iter_init(&iter, &block_class, NULL, &disk_type);
-	while ((dev = class_dev_iter_next(&iter))) {
+	while ((dev = class_dev_iter_next(&iter)) && !devt) {
 		struct gendisk *disk = dev_to_disk(dev);
-		struct hd_struct *part;
+		struct block_device *bdev;
 
 		if (strcmp(dev_name(dev), name))
 			continue;
@@ -1580,15 +1529,13 @@  dev_t blk_lookup_devt(const char *name, int partno)
 			 */
 			devt = MKDEV(MAJOR(dev->devt),
 				     MINOR(dev->devt) + partno);
-			break;
+		} else {
+			rcu_read_lock();
+			bdev = __bdget_disk(disk, partno);
+			if (bdev)
+				devt = bdev->bd_dev;
+			rcu_read_unlock();
 		}
-		part = disk_get_part(disk, partno);
-		if (part) {
-			devt = part_devt(part);
-			disk_put_part(part);
-			break;
-		}
-		disk_put_part(part);
 	}
 	class_dev_iter_exit(&iter);
 	return devt;
@@ -1610,26 +1557,17 @@  struct gendisk *__alloc_disk_node(int minors, int node_id)
 	if (!disk)
 		return NULL;
 
-	disk->part0.bdev = bdev_alloc(disk, 0);
-	if (!disk->part0.bdev)
+	disk->part0 = bdev_alloc(disk, 0);
+	if (!disk->part0)
 		goto out_free_disk;
 
-	disk->part0.dkstats = alloc_percpu(struct disk_stats);
-	if (!disk->part0.dkstats)
-		goto out_bdput;
-
 	init_rwsem(&disk->lookup_sem);
 	disk->node_id = node_id;
 	if (disk_expand_part_tbl(disk, 0))
-		goto out_free_bdstats;
+		goto out_bdput;
 
 	ptbl = rcu_dereference_protected(disk->part_tbl, 1);
-	rcu_assign_pointer(ptbl->part[0], &disk->part0);
-
-	if (hd_ref_init(&disk->part0)) {
-		hd_free_part(&disk->part0);
-		return NULL;
-	}
+	rcu_assign_pointer(ptbl->part[0], disk->part0);
 
 	disk->minors = minors;
 	rand_initialize_disk(disk);
@@ -1638,10 +1576,8 @@  struct gendisk *__alloc_disk_node(int minors, int node_id)
 	device_initialize(disk_to_dev(disk));
 	return disk;
 
-out_free_bdstats:
-	free_percpu(disk->part0.dkstats);
 out_bdput:
-	bdput(disk->part0.bdev);
+	bdput(disk->part0);
 out_free_disk:
 	kfree(disk);
 	return NULL;
@@ -1678,16 +1614,16 @@  static void set_disk_ro_uevent(struct gendisk *gd, int ro)
 void set_disk_ro(struct gendisk *disk, int flag)
 {
 	struct disk_part_iter piter;
-	struct hd_struct *part;
+	struct block_device *part;
 
-	if (disk->part0.policy != flag) {
+	if (disk->part0->bd_policy != flag) {
 		set_disk_ro_uevent(disk, flag);
-		disk->part0.policy = flag;
+		disk->part0->bd_policy = flag;
 	}
 
 	disk_part_iter_init(&piter, disk, DISK_PITER_INCL_EMPTY);
 	while ((part = disk_part_iter_next(&piter)))
-		part->policy = flag;
+		part->bd_policy = flag;
 	disk_part_iter_exit(&piter);
 }
 
@@ -1697,7 +1633,7 @@  int bdev_read_only(struct block_device *bdev)
 {
 	if (!bdev)
 		return 0;
-	return bdev->bd_part->policy;
+	return bdev->bd_policy;
 }
 
 EXPORT_SYMBOL(bdev_read_only);
diff --git a/block/ioctl.c b/block/ioctl.c
index 6b785181344fe1..aa9546e5d6a1bd 100644
--- a/block/ioctl.c
+++ b/block/ioctl.c
@@ -35,7 +35,7 @@  static int blkpg_do_ioctl(struct block_device *bdev,
 	start = p.start >> SECTOR_SHIFT;
 	length = p.length >> SECTOR_SHIFT;
 
-	/* check for fit in a hd_struct */
+	/* check for fit in a sector_t */
 	if (sizeof(sector_t) < sizeof(long long)) {
 		long pstart = start, plength = length;
 
@@ -354,7 +354,7 @@  static int blkdev_roset(struct block_device *bdev, fmode_t mode,
 		if (ret)
 			return ret;
 	}
-	bdev->bd_part->policy = n;
+	bdev->bd_policy = n;
 	return 0;
 }
 
diff --git a/block/partitions/core.c b/block/partitions/core.c
index aae857c22af05d..0269128219decc 100644
--- a/block/partitions/core.c
+++ b/block/partitions/core.c
@@ -182,44 +182,39 @@  static struct parsed_partitions *check_partition(struct gendisk *hd,
 static ssize_t part_partition_show(struct device *dev,
 				   struct device_attribute *attr, char *buf)
 {
-	struct hd_struct *p = dev_to_part(dev);
-
-	return sprintf(buf, "%d\n", p->partno);
+	return sprintf(buf, "%d\n", dev_to_bdev(dev)->bd_partno);
 }
 
 static ssize_t part_start_show(struct device *dev,
 			       struct device_attribute *attr, char *buf)
 {
-	struct hd_struct *p = dev_to_part(dev);
-
-	return sprintf(buf, "%llu\n",(unsigned long long)p->start_sect);
+	return sprintf(buf, "%llu\n", dev_to_bdev(dev)->bd_start_sect);
 }
 
 static ssize_t part_ro_show(struct device *dev,
 			    struct device_attribute *attr, char *buf)
 {
-	struct hd_struct *p = dev_to_part(dev);
-	return sprintf(buf, "%d\n", p->policy ? 1 : 0);
+	return sprintf(buf, "%d\n", dev_to_bdev(dev)->bd_policy ? 1 : 0);
 }
 
 static ssize_t part_alignment_offset_show(struct device *dev,
 					  struct device_attribute *attr, char *buf)
 {
-	struct hd_struct *p = dev_to_part(dev);
+	struct block_device *bdev = dev_to_bdev(dev);
 
 	return sprintf(buf, "%u\n",
-		queue_limit_alignment_offset(&part_to_disk(p)->queue->limits,
-				p->start_sect));
+		queue_limit_alignment_offset(&bdev->bd_disk->queue->limits,
+				bdev->bd_start_sect));
 }
 
 static ssize_t part_discard_alignment_show(struct device *dev,
 					   struct device_attribute *attr, char *buf)
 {
-	struct hd_struct *p = dev_to_part(dev);
+	struct block_device *bdev = dev_to_bdev(dev);
 
 	return sprintf(buf, "%u\n",
-		queue_limit_discard_alignment(&part_to_disk(p)->queue->limits,
-				p->start_sect));
+		queue_limit_discard_alignment(&bdev->bd_disk->queue->limits,
+				bdev->bd_start_sect));
 }
 
 static DEVICE_ATTR(partition, 0444, part_partition_show, NULL);
@@ -264,19 +259,19 @@  static const struct attribute_group *part_attr_groups[] = {
 
 static void part_release(struct device *dev)
 {
-	struct hd_struct *p = dev_to_part(dev);
+	struct block_device *p = dev_to_bdev(dev);
+
 	blk_free_devt(dev->devt);
-	hd_free_part(p);
-	kfree(p);
+	bdput(p);
 }
 
 static int part_uevent(struct device *dev, struct kobj_uevent_env *env)
 {
-	struct hd_struct *part = dev_to_part(dev);
+	struct block_device *part = dev_to_bdev(dev);
 
-	add_uevent_var(env, "PARTN=%u", part->partno);
-	if (part->info && part->info->volname[0])
-		add_uevent_var(env, "PARTNAME=%s", part->info->volname);
+	add_uevent_var(env, "PARTN=%u", part->bd_partno);
+	if (part->bd_meta_info && part->bd_meta_info->volname[0])
+		add_uevent_var(env, "PARTNAME=%s", part->bd_meta_info->volname);
 	return 0;
 }
 
@@ -287,72 +282,28 @@  struct device_type part_type = {
 	.uevent		= part_uevent,
 };
 
-static void hd_struct_free_work(struct work_struct *work)
-{
-	struct hd_struct *part =
-		container_of(to_rcu_work(work), struct hd_struct, rcu_work);
-	struct gendisk *disk = part_to_disk(part);
-
-	/*
-	 * Release the disk reference acquired in delete_partition here.
-	 * We can't release it in hd_struct_free because the final put_device
-	 * needs process context and thus can't be run directly from a
-	 * percpu_ref ->release handler.
-	 */
-	put_device(disk_to_dev(disk));
-
-	part->start_sect = 0;
-	bdev_set_nr_sectors(part->bdev, 0);
-	part_stat_set_all(part, 0);
-	put_device(part_to_dev(part));
-}
-
-static void hd_struct_free(struct percpu_ref *ref)
-{
-	struct hd_struct *part = container_of(ref, struct hd_struct, ref);
-	struct gendisk *disk = part_to_disk(part);
-	struct disk_part_tbl *ptbl =
-		rcu_dereference_protected(disk->part_tbl, 1);
-
-	rcu_assign_pointer(ptbl->last_lookup, NULL);
-
-	INIT_RCU_WORK(&part->rcu_work, hd_struct_free_work);
-	queue_rcu_work(system_wq, &part->rcu_work);
-}
-
-int hd_ref_init(struct hd_struct *part)
-{
-	if (percpu_ref_init(&part->ref, hd_struct_free, 0, GFP_KERNEL))
-		return -ENOMEM;
-	return 0;
-}
-
 /*
  * Must be called either with bd_mutex held, before a disk can be opened or
  * after all disk users are gone.
  */
-void delete_partition(struct hd_struct *part)
+void delete_partition(struct block_device *part)
 {
-	struct gendisk *disk = part_to_disk(part);
+	struct gendisk *disk = part->bd_disk;
 	struct disk_part_tbl *ptbl =
 		rcu_dereference_protected(disk->part_tbl, 1);
 
-	/*
-	 * ->part_tbl is referenced in this part's release handler, so
-	 *  we have to hold the disk device
-	 */
-	get_device(disk_to_dev(disk));
-	rcu_assign_pointer(ptbl->part[part->partno], NULL);
-	kobject_put(part->holder_dir);
+	rcu_assign_pointer(ptbl->part[part->bd_partno], NULL);
+	rcu_assign_pointer(ptbl->last_lookup, NULL);
+	kobject_put(part->bd_holder_dir);
 	device_del(part_to_dev(part));
 
 	/*
 	 * Remove the block device from the inode hash, so that it cannot be
 	 * looked up while waiting for the RCU grace period.
 	 */
-	remove_inode_hash(part->bdev->bd_inode);
+	remove_inode_hash(part->bd_inode);
 
-	percpu_ref_kill(&part->ref);
+	put_device(part_to_dev(part));
 }
 
 static ssize_t whole_disk_show(struct device *dev,
@@ -366,11 +317,11 @@  static DEVICE_ATTR(whole_disk, 0444, whole_disk_show, NULL);
  * Must be called either with bd_mutex held, before a disk can be opened or
  * after all disk users are gone.
  */
-static struct hd_struct *add_partition(struct gendisk *disk, int partno,
+static struct block_device *add_partition(struct gendisk *disk, int partno,
 				sector_t start, sector_t len, int flags,
 				struct partition_meta_info *info)
 {
-	struct hd_struct *p;
+	struct block_device *p;
 	dev_t devt = MKDEV(0, 0);
 	struct device *ddev = disk_to_dev(disk);
 	struct device *pdev;
@@ -404,36 +355,22 @@  static struct hd_struct *add_partition(struct gendisk *disk, int partno,
 	if (ptbl->part[partno])
 		return ERR_PTR(-EBUSY);
 
-	p = kzalloc(sizeof(*p), GFP_KERNEL);
+	p = bdev_alloc(disk, partno);
 	if (!p)
-		return ERR_PTR(-EBUSY);
-
-	err = -ENOMEM;
-	p->dkstats = alloc_percpu(struct disk_stats);
-	if (!p->dkstats)
-		goto out_free;
-
-	p->bdev = bdev_alloc(disk, partno);
-	if (!p->bdev)
-		goto out_free_stats;
-
-	pdev = part_to_dev(p);
+		return ERR_PTR(-ENOMEM);
 
-	p->start_sect = start;
-	bdev_set_nr_sectors(p->bdev, len);
-	p->partno = partno;
-	p->policy = get_disk_ro(disk);
+	p->bd_start_sect = start;
+	bdev_set_nr_sectors(p, len);
+	p->bd_policy = get_disk_ro(disk);
 
 	if (info) {
-		struct partition_meta_info *pinfo;
-
-		pinfo = kzalloc_node(sizeof(*pinfo), GFP_KERNEL, disk->node_id);
-		if (!pinfo)
+		err = -ENOMEM;
+		p->bd_meta_info = kmemdup(info, sizeof(*info), GFP_KERNEL);
+		if (!p->bd_meta_info)
 			goto out_bdput;
-		memcpy(pinfo, info, sizeof(*info));
-		p->info = pinfo;
 	}
 
+	pdev = part_to_dev(p);
 	dname = dev_name(ddev);
 	if (isdigit(dname[strlen(dname) - 1]))
 		dev_set_name(pdev, "%sp%d", dname, partno);
@@ -457,8 +394,8 @@  static struct hd_struct *add_partition(struct gendisk *disk, int partno,
 		goto out_put;
 
 	err = -ENOMEM;
-	p->holder_dir = kobject_create_and_add("holders", &pdev->kobj);
-	if (!p->holder_dir)
+	p->bd_holder_dir = kobject_create_and_add("holders", &pdev->kobj);
+	if (!p->bd_holder_dir)
 		goto out_del;
 
 	dev_set_uevent_suppress(pdev, 0);
@@ -468,15 +405,8 @@  static struct hd_struct *add_partition(struct gendisk *disk, int partno,
 			goto out_del;
 	}
 
-	err = hd_ref_init(p);
-	if (err) {
-		if (flags & ADDPART_FLAG_WHOLEDISK)
-			goto out_remove_file;
-		goto out_del;
-	}
-
 	/* everything is up and running, commence */
-	bdev_add(p->bdev, devt);
+	bdev_add(p, devt);
 	rcu_assign_pointer(ptbl->part[partno], p);
 
 	/* suppress uevent if the disk suppresses it */
@@ -485,19 +415,13 @@  static struct hd_struct *add_partition(struct gendisk *disk, int partno,
 	return p;
 
 out_free_info:
-	kfree(p->info);
+	kfree(p->bd_meta_info);
 out_bdput:
-	bdput(p->bdev);
-out_free_stats:
-	free_percpu(p->dkstats);
-out_free:
-	kfree(p);
+	bdput(p);
 	return ERR_PTR(err);
 
-out_remove_file:
-	device_remove_file(pdev, &dev_attr_whole_disk);
 out_del:
-	kobject_put(p->holder_dir);
+	kobject_put(p->bd_holder_dir);
 	device_del(pdev);
 out_put:
 	put_device(pdev);
@@ -508,14 +432,14 @@  static bool partition_overlaps(struct gendisk *disk, sector_t start,
 		sector_t length, int skip_partno)
 {
 	struct disk_part_iter piter;
-	struct hd_struct *part;
+	struct block_device *part;
 	bool overlap = false;
 
 	disk_part_iter_init(&piter, disk, DISK_PITER_INCL_EMPTY);
 	while ((part = disk_part_iter_next(&piter))) {
-		if (part->partno == skip_partno ||
-		    start >= part->start_sect + bdev_nr_sectors(part->bdev) ||
-		    start + length <= part->start_sect)
+		if (part->bd_partno == skip_partno ||
+		    start >= part->bd_start_sect + bdev_nr_sectors(part) ||
+		    start + length <= part->bd_start_sect)
 			continue;
 		overlap = true;
 		break;
@@ -528,7 +452,7 @@  static bool partition_overlaps(struct gendisk *disk, sector_t start,
 int bdev_add_partition(struct block_device *bdev, int partno,
 		sector_t start, sector_t length)
 {
-	struct hd_struct *part;
+	struct block_device *part;
 
 	mutex_lock(&bdev->bd_mutex);
 	if (partition_overlaps(bdev->bd_disk, start, length, -1)) {
@@ -544,76 +468,59 @@  int bdev_add_partition(struct block_device *bdev, int partno,
 
 int bdev_del_partition(struct block_device *bdev, int partno)
 {
-	struct block_device *bdevp;
-	struct hd_struct *part = NULL;
+	struct block_device *part;
 	int ret;
 
-	bdevp = bdget_disk(bdev->bd_disk, partno);
-	if (!bdevp)
+	part = bdget_disk(bdev->bd_disk, partno);
+	if (!part)
 		return -ENXIO;
 
-	mutex_lock(&bdevp->bd_mutex);
+	mutex_lock(&part->bd_mutex);
 	mutex_lock_nested(&bdev->bd_mutex, 1);
 
-	ret = -ENXIO;
-	part = disk_get_part(bdev->bd_disk, partno);
-	if (!part)
-		goto out_unlock;
-
 	ret = -EBUSY;
-	if (bdevp->bd_openers)
+	if (part->bd_openers)
 		goto out_unlock;
 
-	sync_blockdev(bdevp);
-	invalidate_bdev(bdevp);
+	sync_blockdev(part);
+	invalidate_bdev(part);
 
 	delete_partition(part);
 	ret = 0;
 out_unlock:
 	mutex_unlock(&bdev->bd_mutex);
-	mutex_unlock(&bdevp->bd_mutex);
-	bdput(bdevp);
-	if (part)
-		disk_put_part(part);
+	mutex_unlock(&part->bd_mutex);
+	bdput(part);
 	return ret;
 }
 
 int bdev_resize_partition(struct block_device *bdev, int partno,
 		sector_t start, sector_t length)
 {
-	struct block_device *bdevp;
-	struct hd_struct *part;
+	struct block_device *part;
 	int ret = 0;
 
-	part = disk_get_part(bdev->bd_disk, partno);
+	part = bdget_disk(bdev->bd_disk, partno);
 	if (!part)
 		return -ENXIO;
 
-	ret = -ENOMEM;
-	bdevp = bdget_part(part);
-	if (!bdevp)
-		goto out_put_part;
-
-	mutex_lock(&bdevp->bd_mutex);
+	mutex_lock(&part->bd_mutex);
 	mutex_lock_nested(&bdev->bd_mutex, 1);
-
 	ret = -EINVAL;
-	if (start != part->start_sect)
+	if (start != part->bd_start_sect)
 		goto out_unlock;
 
 	ret = -EBUSY;
 	if (partition_overlaps(bdev->bd_disk, start, length, partno))
 		goto out_unlock;
 
-	bdev_set_nr_sectors(bdevp, length);
+	bdev_set_nr_sectors(part, length);
 
 	ret = 0;
 out_unlock:
-	mutex_unlock(&bdevp->bd_mutex);
+	mutex_unlock(&part->bd_mutex);
 	mutex_unlock(&bdev->bd_mutex);
-	bdput(bdevp);
-out_put_part:
-	disk_put_part(part);
+	bdput(part);
 	return ret;
 }
 
@@ -636,7 +543,7 @@  static bool disk_unlock_native_capacity(struct gendisk *disk)
 int blk_drop_partitions(struct block_device *bdev)
 {
 	struct disk_part_iter piter;
-	struct hd_struct *part;
+	struct block_device *part;
 
 	if (bdev->bd_part_count)
 		return -EBUSY;
@@ -661,7 +568,7 @@  static bool blk_add_partition(struct gendisk *disk, struct block_device *bdev,
 {
 	sector_t size = state->parts[p].size;
 	sector_t from = state->parts[p].from;
-	struct hd_struct *part;
+	struct block_device *part;
 
 	if (!size)
 		return true;
@@ -701,7 +608,7 @@  static bool blk_add_partition(struct gendisk *disk, struct block_device *bdev,
 
 	if (IS_BUILTIN(CONFIG_BLK_DEV_MD) &&
 	    (state->parts[p].flags & ADDPART_FLAG_RAID))
-		md_autodetect_dev(part_to_dev(part)->devt);
+		md_autodetect_dev(part->bd_dev);
 
 	return true;
 }
diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c
index dc333dbe523281..09c86ef3f0fd93 100644
--- a/drivers/block/drbd/drbd_receiver.c
+++ b/drivers/block/drbd/drbd_receiver.c
@@ -2802,7 +2802,7 @@  bool drbd_rs_c_min_rate_throttle(struct drbd_device *device)
 	if (c_min_rate == 0)
 		return false;
 
-	curr_events = (int)part_stat_read_accum(&disk->part0, sectors) -
+	curr_events = (int)part_stat_read_accum(disk->part0, sectors) -
 			atomic_read(&device->rs_sect_ev);
 
 	if (atomic_read(&device->ap_actlog_cnt)
diff --git a/drivers/block/drbd/drbd_worker.c b/drivers/block/drbd/drbd_worker.c
index ba56f3f05312f0..4537559829876e 100644
--- a/drivers/block/drbd/drbd_worker.c
+++ b/drivers/block/drbd/drbd_worker.c
@@ -1678,7 +1678,7 @@  void drbd_rs_controller_reset(struct drbd_device *device)
 	atomic_set(&device->rs_sect_in, 0);
 	atomic_set(&device->rs_sect_ev, 0);
 	device->rs_in_flight = 0;
-	device->rs_last_events = (int)part_stat_read_accum(&disk->part0, sectors);
+	device->rs_last_events = part_stat_read_accum(disk->part0, sectors);
 
 	/* Updating the RCU protected object in place is necessary since
 	   this function gets called from atomic context.
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index 88baa6158eaee1..01757f9578dcb8 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -1687,7 +1687,7 @@  static void zram_reset_device(struct zram *zram)
 	zram->disksize = 0;
 
 	set_capacity_and_notify(zram->disk, 0);
-	part_stat_set_all(&zram->disk->part0, 0);
+	part_stat_set_all(zram->disk->part0, 0);
 
 	up_write(&zram->init_lock);
 	/* I/O operation under all of CPU are done so let's free */
diff --git a/drivers/md/bcache/request.c b/drivers/md/bcache/request.c
index afac8d07c1bd00..85b1f2a9b72d68 100644
--- a/drivers/md/bcache/request.c
+++ b/drivers/md/bcache/request.c
@@ -475,7 +475,7 @@  struct search {
 	unsigned int		read_dirty_data:1;
 	unsigned int		cache_missed:1;
 
-	struct hd_struct	*part;
+	struct block_device	*part;
 	unsigned long		start_time;
 
 	struct btree_op		op;
@@ -1073,7 +1073,7 @@  struct detached_dev_io_private {
 	unsigned long		start_time;
 	bio_end_io_t		*bi_end_io;
 	void			*bi_private;
-	struct hd_struct	*part;
+	struct block_device	*part;
 };
 
 static void detached_dev_end_io(struct bio *bio)
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 83fe1e7f13e6b0..c9438feefe55a3 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -1607,7 +1607,7 @@  static blk_qc_t __split_and_process_bio(struct mapped_device *md,
 				 * (by eliminating DM's splitting and just using bio_split)
 				 */
 				part_stat_lock();
-				__dm_part_stat_sub(&dm_disk(md)->part0,
+				__dm_part_stat_sub(dm_disk(md)->part0,
 						   sectors[op_stat_group(bio_op(bio))], ci.sector_count);
 				part_stat_unlock();
 
@@ -2242,12 +2242,12 @@  EXPORT_SYMBOL_GPL(dm_put);
 static bool md_in_flight_bios(struct mapped_device *md)
 {
 	int cpu;
-	struct hd_struct *part = &dm_disk(md)->part0;
+	struct block_device *bdev = dm_disk(md)->part0;
 	long sum = 0;
 
 	for_each_possible_cpu(cpu) {
-		sum += part_stat_local_read_cpu(part, in_flight[0], cpu);
-		sum += part_stat_local_read_cpu(part, in_flight[1], cpu);
+		sum += part_stat_local_read_cpu(bdev, in_flight[0], cpu);
+		sum += part_stat_local_read_cpu(bdev, in_flight[1], cpu);
 	}
 
 	return sum != 0;
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 7ce6047c856ea2..0065736f05b428 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -464,7 +464,7 @@  struct md_io {
 	bio_end_io_t *orig_bi_end_io;
 	void *orig_bi_private;
 	unsigned long start_time;
-	struct hd_struct *part;
+	struct block_device *part;
 };
 
 static void md_end_io(struct bio *bio)
@@ -8441,7 +8441,7 @@  static int is_mddev_idle(struct mddev *mddev, int init)
 	rcu_read_lock();
 	rdev_for_each_rcu(rdev, mddev) {
 		struct gendisk *disk = rdev->bdev->bd_disk;
-		curr_events = (int)part_stat_read_accum(&disk->part0, sectors) -
+		curr_events = (int)part_stat_read_accum(disk->part0, sectors) -
 			      atomic_read(&disk->sync_io);
 		/* sync IO will cause sync_io to increase before the disk_stats
 		 * as sync_io is counted when a request starts, and
diff --git a/drivers/nvme/target/admin-cmd.c b/drivers/nvme/target/admin-cmd.c
index dca34489a1dc9e..8d90235e4fcc5a 100644
--- a/drivers/nvme/target/admin-cmd.c
+++ b/drivers/nvme/target/admin-cmd.c
@@ -89,12 +89,12 @@  static u16 nvmet_get_smart_log_nsid(struct nvmet_req *req,
 	if (!ns->bdev)
 		goto out;
 
-	host_reads = part_stat_read(ns->bdev->bd_part, ios[READ]);
-	data_units_read = DIV_ROUND_UP(part_stat_read(ns->bdev->bd_part,
-		sectors[READ]), 1000);
-	host_writes = part_stat_read(ns->bdev->bd_part, ios[WRITE]);
-	data_units_written = DIV_ROUND_UP(part_stat_read(ns->bdev->bd_part,
-		sectors[WRITE]), 1000);
+	host_reads = part_stat_read(ns->bdev, ios[READ]);
+	data_units_read =
+		DIV_ROUND_UP(part_stat_read(ns->bdev, sectors[READ]), 1000);
+	host_writes = part_stat_read(ns->bdev, ios[WRITE]);
+	data_units_written =
+		DIV_ROUND_UP(part_stat_read(ns->bdev, sectors[WRITE]), 1000);
 
 	put_unaligned_le64(host_reads, &slog->host_reads[0]);
 	put_unaligned_le64(data_units_read, &slog->data_units_read[0]);
@@ -120,12 +120,12 @@  static u16 nvmet_get_smart_log_all(struct nvmet_req *req,
 		/* we don't have the right data for file backed ns */
 		if (!ns->bdev)
 			continue;
-		host_reads += part_stat_read(ns->bdev->bd_part, ios[READ]);
+		host_reads += part_stat_read(ns->bdev, ios[READ]);
 		data_units_read += DIV_ROUND_UP(
-			part_stat_read(ns->bdev->bd_part, sectors[READ]), 1000);
-		host_writes += part_stat_read(ns->bdev->bd_part, ios[WRITE]);
+			part_stat_read(ns->bdev, sectors[READ]), 1000);
+		host_writes += part_stat_read(ns->bdev, ios[WRITE]);
 		data_units_written += DIV_ROUND_UP(
-			part_stat_read(ns->bdev->bd_part, sectors[WRITE]), 1000);
+			part_stat_read(ns->bdev, sectors[WRITE]), 1000);
 	}
 
 	put_unaligned_le64(host_reads, &slog->host_reads[0]);
diff --git a/drivers/s390/block/dasd.c b/drivers/s390/block/dasd.c
index db24e04ee9781e..1825fa8d05a780 100644
--- a/drivers/s390/block/dasd.c
+++ b/drivers/s390/block/dasd.c
@@ -432,7 +432,7 @@  dasd_state_ready_to_online(struct dasd_device * device)
 {
 	struct gendisk *disk;
 	struct disk_part_iter piter;
-	struct hd_struct *part;
+	struct block_device *part;
 
 	device->state = DASD_STATE_ONLINE;
 	if (device->block) {
@@ -445,7 +445,7 @@  dasd_state_ready_to_online(struct dasd_device * device)
 		disk = device->block->bdev->bd_disk;
 		disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0);
 		while ((part = disk_part_iter_next(&piter)))
-			kobject_uevent(&part_to_dev(part)->kobj, KOBJ_CHANGE);
+			kobject_uevent(bdev_kobj(part), KOBJ_CHANGE);
 		disk_part_iter_exit(&piter);
 	}
 	return 0;
@@ -459,7 +459,7 @@  static int dasd_state_online_to_ready(struct dasd_device *device)
 	int rc;
 	struct gendisk *disk;
 	struct disk_part_iter piter;
-	struct hd_struct *part;
+	struct block_device *part;
 
 	if (device->discipline->online_to_ready) {
 		rc = device->discipline->online_to_ready(device);
@@ -472,7 +472,7 @@  static int dasd_state_online_to_ready(struct dasd_device *device)
 		disk = device->block->bdev->bd_disk;
 		disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0);
 		while ((part = disk_part_iter_next(&piter)))
-			kobject_uevent(&part_to_dev(part)->kobj, KOBJ_CHANGE);
+			kobject_uevent(bdev_kobj(part), KOBJ_CHANGE);
 		disk_part_iter_exit(&piter);
 	}
 	return 0;
diff --git a/fs/block_dev.c b/fs/block_dev.c
index a5a2ac4ca1ce9c..c2da068bd983f4 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -34,6 +34,7 @@ 
 #include <linux/falloc.h>
 #include <linux/uaccess.h>
 #include <linux/suspend.h>
+#include <linux/part_stat.h>
 #include "internal.h"
 
 struct bdev_inode {
@@ -788,23 +789,18 @@  static struct inode *bdev_alloc_inode(struct super_block *sb)
 
 static void bdev_free_inode(struct inode *inode)
 {
+	struct block_device *bdev = I_BDEV(inode);
+
+	kfree(bdev->bd_meta_info);
+	free_percpu(bdev->bd_stats);
 	kmem_cache_free(bdev_cachep, BDEV_I(inode));
 }
 
 static void init_once(void *foo)
 {
 	struct bdev_inode *ei = (struct bdev_inode *) foo;
-	struct block_device *bdev = &ei->bdev;
 
-	memset(bdev, 0, sizeof(*bdev));
-	mutex_init(&bdev->bd_mutex);
-#ifdef CONFIG_SYSFS
-	INIT_LIST_HEAD(&bdev->bd_holder_disks);
-#endif
-	bdev->bd_bdi = &noop_backing_dev_info;
 	inode_init_once(&ei->vfs_inode);
-	/* Initialize mutex for freeze. */
-	mutex_init(&bdev->bd_fsfreeze_mutex);
 }
 
 static void bdev_evict_inode(struct inode *inode)
@@ -876,12 +872,22 @@  struct block_device *bdev_alloc(struct gendisk *disk, u8 partno)
 		return NULL;
 
 	bdev = I_BDEV(inode);
+	memset(bdev, 0, sizeof(*bdev));
 	spin_lock_init(&bdev->bd_size_lock);
+	mutex_init(&bdev->bd_mutex);
+	mutex_init(&bdev->bd_fsfreeze_mutex);
+	bdev->bd_bdi = &noop_backing_dev_info;
 	bdev->bd_disk = disk;
 	bdev->bd_partno = partno;
-	bdev->bd_super = NULL;
 	bdev->bd_inode = inode;
-	bdev->bd_part_count = 0;
+	bdev->bd_stats = alloc_percpu(struct disk_stats);
+	if (!bdev->bd_stats) {
+		iput(inode);
+		return NULL;
+	}
+#ifdef CONFIG_SYSFS
+	INIT_LIST_HEAD(&bdev->bd_holder_disks);
+#endif
 
 	inode->i_mode = S_IFBLK;
 	inode->i_rdev = 0;
@@ -920,11 +926,6 @@  struct block_device *bdgrab(struct block_device *bdev)
 }
 EXPORT_SYMBOL(bdgrab);
 
-struct block_device *bdget_part(struct hd_struct *part)
-{
-	return bdget(part_devt(part));
-}
-
 long nr_blockdev_pages(void)
 {
 	struct inode *inode;
@@ -1201,7 +1202,7 @@  int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk)
 	WARN_ON_ONCE(!bdev->bd_holder);
 
 	/* FIXME: remove the following once add_disk() handles errors */
-	if (WARN_ON(!disk->slave_dir || !bdev->bd_part->holder_dir))
+	if (WARN_ON(!disk->slave_dir || !bdev->bd_holder_dir))
 		goto out_unlock;
 
 	holder = bd_find_holder_disk(bdev, disk);
@@ -1220,24 +1221,24 @@  int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk)
 	holder->disk = disk;
 	holder->refcnt = 1;
 
-	ret = add_symlink(disk->slave_dir, &part_to_dev(bdev->bd_part)->kobj);
+	ret = add_symlink(disk->slave_dir, bdev_kobj(bdev));
 	if (ret)
 		goto out_free;
 
-	ret = add_symlink(bdev->bd_part->holder_dir, &disk_to_dev(disk)->kobj);
+	ret = add_symlink(bdev->bd_holder_dir, &disk_to_dev(disk)->kobj);
 	if (ret)
 		goto out_del;
 	/*
 	 * bdev could be deleted beneath us which would implicitly destroy
 	 * the holder directory.  Hold on to it.
 	 */
-	kobject_get(bdev->bd_part->holder_dir);
+	kobject_get(bdev->bd_holder_dir);
 
 	list_add(&holder->list, &bdev->bd_holder_disks);
 	goto out_unlock;
 
 out_del:
-	del_symlink(disk->slave_dir, &part_to_dev(bdev->bd_part)->kobj);
+	del_symlink(disk->slave_dir, bdev_kobj(bdev));
 out_free:
 	kfree(holder);
 out_unlock:
@@ -1265,10 +1266,10 @@  void bd_unlink_disk_holder(struct block_device *bdev, struct gendisk *disk)
 	holder = bd_find_holder_disk(bdev, disk);
 
 	if (!WARN_ON_ONCE(holder == NULL) && !--holder->refcnt) {
-		del_symlink(disk->slave_dir, &part_to_dev(bdev->bd_part)->kobj);
-		del_symlink(bdev->bd_part->holder_dir,
+		del_symlink(disk->slave_dir, bdev_kobj(bdev));
+		del_symlink(bdev->bd_holder_dir,
 			    &disk_to_dev(disk)->kobj);
-		kobject_put(bdev->bd_part->holder_dir);
+		kobject_put(bdev->bd_holder_dir);
 		list_del_init(&holder->list);
 		kfree(holder);
 	}
@@ -1392,11 +1393,6 @@  static int __blkdev_get(struct block_device *bdev, fmode_t mode, void *holder,
 		first_open = true;
 
 		if (!bdev->bd_partno) {
-			ret = -ENXIO;
-			bdev->bd_part = disk_get_part(disk, 0);
-			if (!bdev->bd_part)
-				goto out_clear;
-
 			ret = 0;
 			if (disk->fops->open) {
 				ret = disk->fops->open(bdev, mode);
@@ -1422,19 +1418,16 @@  static int __blkdev_get(struct block_device *bdev, fmode_t mode, void *holder,
 				bdev_disk_changed(bdev, ret == -ENOMEDIUM);
 
 			if (ret)
-				goto out_clear;
+				goto out_unlock_bdev;
 		} else {
 			BUG_ON(for_part);
 			ret = __blkdev_get(bdev_whole(bdev), mode, NULL, 1);
 			if (ret)
-				goto out_clear;
+				goto out_unlock_bdev;
 			bdgrab(bdev_whole(bdev));
-			bdev->bd_part = disk_get_part(disk, bdev->bd_partno);
-			if (!(disk->flags & GENHD_FL_UP) ||
-			    !bdev->bd_part || !bdev_nr_sectors(bdev)) {
-				ret = -ENXIO;
-				goto out_clear;
-			}
+			ret = -ENXIO;
+			if (!bdev_nr_sectors(bdev))
+				goto out_put_whole;
 			set_init_blocksize(bdev);
 		}
 
@@ -1453,6 +1446,7 @@  static int __blkdev_get(struct block_device *bdev, fmode_t mode, void *holder,
 				goto out_unlock_bdev;
 		}
 	}
+
 	bdev->bd_openers++;
 	if (for_part) {
 		bdev->bd_part_count++;
@@ -1482,11 +1476,8 @@  static int __blkdev_get(struct block_device *bdev, fmode_t mode, void *holder,
 		put_disk_and_module(disk);
 	return 0;
 
- out_clear:
-	disk_put_part(bdev->bd_part);
-	bdev->bd_part = NULL;
-	if (bdev_is_partition(bdev))
-		__blkdev_put(bdev_whole(bdev), mode, 1);
+ out_put_whole:
+	__blkdev_put(bdev_whole(bdev), mode, 1);
  out_unlock_bdev:
 	if (!for_part && (mode & FMODE_EXCL))
 		bd_abort_claiming(bdev, holder);
@@ -1679,8 +1670,6 @@  static void __blkdev_put(struct block_device *bdev, fmode_t mode, int for_part)
 		if (!bdev_is_partition(bdev) && disk->fops->release)
 			disk->fops->release(disk, mode);
 
-		disk_put_part(bdev->bd_part);
-		bdev->bd_part = NULL;
 		if (bdev_is_partition(bdev))
 			victim = bdev_whole(bdev);
 
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 6633b20224d509..c303a0ff0b1701 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -4048,9 +4048,8 @@  static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 	sbi->s_sb = sb;
 	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
 	sbi->s_sb_block = sb_block;
-	if (sb->s_bdev->bd_part)
-		sbi->s_sectors_written_start =
-			part_stat_read(sb->s_bdev->bd_part, sectors[STAT_WRITE]);
+	sbi->s_sectors_written_start =
+		part_stat_read(sb->s_bdev, sectors[STAT_WRITE]);
 
 	/* Cleanup superblock name */
 	strreplace(sb->s_id, '/', '!');
@@ -5509,15 +5508,10 @@  static int ext4_commit_super(struct super_block *sb, int sync)
 	 */
 	if (!(sb->s_flags & SB_RDONLY))
 		ext4_update_tstamp(es, s_wtime);
-	if (sb->s_bdev->bd_part)
-		es->s_kbytes_written =
-			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
-			    ((part_stat_read(sb->s_bdev->bd_part,
-					     sectors[STAT_WRITE]) -
-			      EXT4_SB(sb)->s_sectors_written_start) >> 1));
-	else
-		es->s_kbytes_written =
-			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
+	es->s_kbytes_written =
+		cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
+		    ((part_stat_read(sb->s_bdev, sectors[STAT_WRITE]) -
+		      EXT4_SB(sb)->s_sectors_written_start) >> 1));
 	if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeclusters_counter))
 		ext4_free_blocks_count_set(es,
 			EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
diff --git a/fs/ext4/sysfs.c b/fs/ext4/sysfs.c
index 4e27fe6ed3ae6a..075aa3a19ff5f1 100644
--- a/fs/ext4/sysfs.c
+++ b/fs/ext4/sysfs.c
@@ -62,11 +62,8 @@  static ssize_t session_write_kbytes_show(struct ext4_sb_info *sbi, char *buf)
 {
 	struct super_block *sb = sbi->s_buddy_cache->i_sb;
 
-	if (!sb->s_bdev->bd_part)
-		return snprintf(buf, PAGE_SIZE, "0\n");
 	return snprintf(buf, PAGE_SIZE, "%lu\n",
-			(part_stat_read(sb->s_bdev->bd_part,
-					sectors[STAT_WRITE]) -
+			(part_stat_read(sb->s_bdev, sectors[STAT_WRITE]) -
 			 sbi->s_sectors_written_start) >> 1);
 }
 
@@ -74,12 +71,9 @@  static ssize_t lifetime_write_kbytes_show(struct ext4_sb_info *sbi, char *buf)
 {
 	struct super_block *sb = sbi->s_buddy_cache->i_sb;
 
-	if (!sb->s_bdev->bd_part)
-		return snprintf(buf, PAGE_SIZE, "0\n");
 	return snprintf(buf, PAGE_SIZE, "%llu\n",
 			(unsigned long long)(sbi->s_kbytes_written +
-			((part_stat_read(sb->s_bdev->bd_part,
-					 sectors[STAT_WRITE]) -
+			((part_stat_read(sb->s_bdev, sectors[STAT_WRITE]) -
 			  EXT4_SB(sb)->s_sectors_written_start) >> 1)));
 }
 
diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
index 023462e80e58d5..54a1905af052cc 100644
--- a/fs/f2fs/checkpoint.c
+++ b/fs/f2fs/checkpoint.c
@@ -1395,7 +1395,6 @@  static int do_checkpoint(struct f2fs_sb_info *sbi, struct cp_control *cpc)
 	__u32 crc32 = 0;
 	int i;
 	int cp_payload_blks = __cp_payload(sbi);
-	struct super_block *sb = sbi->sb;
 	struct curseg_info *seg_i = CURSEG_I(sbi, CURSEG_HOT_NODE);
 	u64 kbytes_written;
 	int err;
@@ -1489,9 +1488,7 @@  static int do_checkpoint(struct f2fs_sb_info *sbi, struct cp_control *cpc)
 	start_blk += data_sum_blocks;
 
 	/* Record write statistics in the hot node summary */
-	kbytes_written = sbi->kbytes_written;
-	if (sb->s_bdev->bd_part)
-		kbytes_written += BD_PART_WRITTEN(sbi);
+	kbytes_written = sbi->kbytes_written + BD_PART_WRITTEN(sbi);
 
 	seg_i->journal->info.kbytes_written = cpu_to_le64(kbytes_written);
 
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index cb700d79729680..5f9522d4c727fb 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -1675,7 +1675,7 @@  static inline bool f2fs_is_multi_device(struct f2fs_sb_info *sbi)
  * and the return value is in kbytes. s is of struct f2fs_sb_info.
  */
 #define BD_PART_WRITTEN(s)						 \
-(((u64)part_stat_read((s)->sb->s_bdev->bd_part, sectors[STAT_WRITE]) -   \
+(((u64)part_stat_read((s)->sb->s_bdev, sectors[STAT_WRITE]) -   \
 		(s)->sectors_written_start) >> 1)
 
 static inline void f2fs_update_time(struct f2fs_sb_info *sbi, int type)
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index d4e7fab352bacb..fae92285f561b4 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -3700,10 +3700,8 @@  static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
 	}
 
 	/* For write statistics */
-	if (sb->s_bdev->bd_part)
-		sbi->sectors_written_start =
-			(u64)part_stat_read(sb->s_bdev->bd_part,
-					    sectors[STAT_WRITE]);
+	sbi->sectors_written_start =
+		part_stat_read(sb->s_bdev, sectors[STAT_WRITE]);
 
 	/* Read accumulated write IO statistics if exists */
 	seg_i = CURSEG_I(sbi, CURSEG_HOT_NODE);
diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c
index ec77ccfea923dc..24e876e849c512 100644
--- a/fs/f2fs/sysfs.c
+++ b/fs/f2fs/sysfs.c
@@ -90,11 +90,6 @@  static ssize_t free_segments_show(struct f2fs_attr *a,
 static ssize_t lifetime_write_kbytes_show(struct f2fs_attr *a,
 		struct f2fs_sb_info *sbi, char *buf)
 {
-	struct super_block *sb = sbi->sb;
-
-	if (!sb->s_bdev->bd_part)
-		return sprintf(buf, "0\n");
-
 	return sprintf(buf, "%llu\n",
 			(unsigned long long)(sbi->kbytes_written +
 			BD_PART_WRITTEN(sbi)));
@@ -103,12 +98,8 @@  static ssize_t lifetime_write_kbytes_show(struct f2fs_attr *a,
 static ssize_t features_show(struct f2fs_attr *a,
 		struct f2fs_sb_info *sbi, char *buf)
 {
-	struct super_block *sb = sbi->sb;
 	int len = 0;
 
-	if (!sb->s_bdev->bd_part)
-		return sprintf(buf, "0\n");
-
 	if (f2fs_sb_has_encrypt(sbi))
 		len += scnprintf(buf, PAGE_SIZE - len, "%s",
 						"encryption");
diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
index 453b940b87d8e9..a30559501dfe17 100644
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h
@@ -8,6 +8,7 @@ 
 
 #include <linux/types.h>
 #include <linux/bvec.h>
+#include <linux/device.h>
 #include <linux/ktime.h>
 
 struct bio_set;
@@ -20,7 +21,13 @@  typedef void (bio_end_io_t) (struct bio *);
 struct bio_crypt_ctx;
 
 struct block_device {
+	sector_t		bd_start_sect;
+	unsigned long		bd_stamp;
+	struct disk_stats __percpu *bd_stats;
+	u8			bd_partno;
+	int			bd_policy;
 	dev_t			bd_dev;
+	struct device		bd_device;
 	int			bd_openers;
 	struct inode *		bd_inode;	/* will die */
 	struct super_block *	bd_super;
@@ -32,8 +39,7 @@  struct block_device {
 #ifdef CONFIG_SYSFS
 	struct list_head	bd_holder_disks;
 #endif
-	u8			bd_partno;
-	struct hd_struct *	bd_part;
+	struct kobject		*bd_holder_dir;
 	/* number of times partitions within this device have been opened. */
 	unsigned		bd_part_count;
 
@@ -45,13 +51,22 @@  struct block_device {
 	int			bd_fsfreeze_count;
 	/* Mutex for freeze */
 	struct mutex		bd_fsfreeze_mutex;
+
+	struct partition_meta_info *bd_meta_info;
+#ifdef CONFIG_FAIL_MAKE_REQUEST
+	int			bd_make_it_fail;
+#endif
 } __randomize_layout;
 
 #define bdev_whole(_bdev) \
-	((_bdev)->bd_disk->part0.bdev)
+	((_bdev)->bd_disk->part0)
+
+#define dev_to_bdev(device) \
+	container_of((device), struct block_device, bd_device)
+#define part_to_dev(part)	(&((part)->bd_device))
 
 #define bdev_kobj(_bdev) \
-	(&part_to_dev((_bdev)->bd_part)->kobj)
+	(&part_to_dev((_bdev))->kobj)
 
 /*
  * Block error status values.  See block/blk-core:blk_errors for the details.
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 696b2f9c5529d8..ed40144ab80339 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -191,7 +191,7 @@  struct request {
 	};
 
 	struct gendisk *rq_disk;
-	struct hd_struct *part;
+	struct block_device *bdev;
 #ifdef CONFIG_BLK_RQ_ALLOC_TIME
 	/* Time that the first bio started allocating this request. */
 	u64 alloc_time_ns;
@@ -1488,7 +1488,7 @@  static inline int bdev_alignment_offset(struct block_device *bdev)
 		return -1;
 	if (bdev_is_partition(bdev))
 		return queue_limit_alignment_offset(&q->limits,
-				bdev->bd_part->start_sect);
+				bdev->bd_start_sect);
 	return q->limits.alignment_offset;
 }
 
@@ -1529,7 +1529,7 @@  static inline int bdev_discard_alignment(struct block_device *bdev)
 
 	if (bdev_is_partition(bdev))
 		return queue_limit_discard_alignment(&q->limits,
-				bdev->bd_part->start_sect);
+				bdev->bd_start_sect);
 	return q->limits.discard_alignment;
 }
 
@@ -1943,9 +1943,9 @@  unsigned long disk_start_io_acct(struct gendisk *disk, unsigned int sectors,
 void disk_end_io_acct(struct gendisk *disk, unsigned int op,
 		unsigned long start_time);
 
-unsigned long part_start_io_acct(struct gendisk *disk, struct hd_struct **part,
-				 struct bio *bio);
-void part_end_io_acct(struct hd_struct *part, struct bio *bio,
+unsigned long part_start_io_acct(struct gendisk *disk,
+		struct block_device **part, struct bio *bio);
+void part_end_io_acct(struct block_device *part, struct bio *bio,
 		      unsigned long start_time);
 
 /**
@@ -1996,7 +1996,6 @@  struct block_device *bdev_alloc(struct gendisk *disk, u8 partno);
 void bdev_add(struct block_device *bdev, dev_t dev);
 struct block_device *bdget(dev_t dev);
 struct block_device *I_BDEV(struct inode *inode);
-struct block_device *bdget_part(struct hd_struct *part);
 struct block_device *bdgrab(struct block_device *bdev);
 void bdput(struct block_device *);
 
diff --git a/include/linux/genhd.h b/include/linux/genhd.h
index e01618dfafc05c..6da7bfd6b0bd2a 100644
--- a/include/linux/genhd.h
+++ b/include/linux/genhd.h
@@ -19,11 +19,6 @@ 
 #include <linux/blk_types.h>
 #include <asm/local.h>
 
-#define dev_to_disk(device)	container_of((device), struct gendisk, part0.__dev)
-#define dev_to_part(device)	container_of((device), struct hd_struct, __dev)
-#define disk_to_dev(disk)	(&(disk)->part0.__dev)
-#define part_to_dev(part)	(&((part)->__dev))
-
 extern const struct device_type disk_type;
 extern struct device_type part_type;
 extern struct class block_class;
@@ -50,23 +45,6 @@  struct partition_meta_info {
 	u8 volname[PARTITION_META_INFO_VOLNAMELTH];
 };
 
-struct hd_struct {
-	sector_t start_sect;
-	unsigned long stamp;
-	struct disk_stats __percpu *dkstats;
-	struct percpu_ref ref;
-
-	struct block_device *bdev;
-	struct device __dev;
-	struct kobject *holder_dir;
-	int policy, partno;
-	struct partition_meta_info *info;
-#ifdef CONFIG_FAIL_MAKE_REQUEST
-	int make_it_fail;
-#endif
-	struct rcu_work rcu_work;
-};
-
 /**
  * DOC: genhd capability flags
  *
@@ -141,8 +119,8 @@  enum {
 struct disk_part_tbl {
 	struct rcu_head rcu_head;
 	int len;
-	struct hd_struct __rcu *last_lookup;
-	struct hd_struct __rcu *part[];
+	struct block_device __rcu *last_lookup;
+	struct block_device __rcu *part[];
 };
 
 struct disk_events;
@@ -176,7 +154,7 @@  struct gendisk {
 	 * helpers.
 	 */
 	struct disk_part_tbl __rcu *part_tbl;
-	struct hd_struct part0;
+	struct block_device *part0;
 
 	const struct block_device_operations *fops;
 	struct request_queue *queue;
@@ -202,23 +180,17 @@  struct gendisk {
 	struct lockdep_map lockdep_map;
 };
 
+#define dev_to_disk(device) \
+	(dev_to_bdev(device)->bd_disk)
+#define disk_to_dev(disk) \
+	(part_to_dev((disk)->part0))
+
 #if IS_REACHABLE(CONFIG_CDROM)
 #define disk_to_cdi(disk)	((disk)->cdi)
 #else
 #define disk_to_cdi(disk)	NULL
 #endif
 
-static inline struct gendisk *part_to_disk(struct hd_struct *part)
-{
-	if (likely(part)) {
-		if (part->partno)
-			return dev_to_disk(part_to_dev(part)->parent);
-		else
-			return dev_to_disk(part_to_dev(part));
-	}
-	return NULL;
-}
-
 static inline int disk_max_parts(struct gendisk *disk)
 {
 	if (disk->flags & GENHD_FL_EXT_DEVT)
@@ -237,19 +209,6 @@  static inline dev_t disk_devt(struct gendisk *disk)
 	return MKDEV(disk->major, disk->first_minor);
 }
 
-static inline dev_t part_devt(struct hd_struct *part)
-{
-	return part_to_dev(part)->devt;
-}
-
-extern struct hd_struct *disk_get_part(struct gendisk *disk, int partno);
-
-static inline void disk_put_part(struct hd_struct *part)
-{
-	if (likely(part))
-		put_device(part_to_dev(part));
-}
-
 /*
  * Smarter partition iterator without context limits.
  */
@@ -260,14 +219,14 @@  static inline void disk_put_part(struct hd_struct *part)
 
 struct disk_part_iter {
 	struct gendisk		*disk;
-	struct hd_struct	*part;
+	struct block_device	*part;
 	int			idx;
 	unsigned int		flags;
 };
 
 extern void disk_part_iter_init(struct disk_part_iter *piter,
 				 struct gendisk *disk, unsigned int flags);
-extern struct hd_struct *disk_part_iter_next(struct disk_part_iter *piter);
+struct block_device *disk_part_iter_next(struct disk_part_iter *piter);
 extern void disk_part_iter_exit(struct disk_part_iter *piter);
 extern bool disk_has_partitions(struct gendisk *disk);
 
@@ -291,7 +250,7 @@  extern void set_disk_ro(struct gendisk *disk, int flag);
 
 static inline int get_disk_ro(struct gendisk *disk)
 {
-	return disk->part0.policy;
+	return disk->part0->bd_policy;
 }
 
 extern void disk_block_events(struct gendisk *disk);
@@ -305,7 +264,7 @@  extern void rand_initialize_disk(struct gendisk *disk);
 
 static inline sector_t get_start_sect(struct block_device *bdev)
 {
-	return bdev->bd_part->start_sect;
+	return bdev->bd_start_sect;
 }
 	
 static inline sector_t bdev_nr_sectors(struct block_device *bdev)
@@ -315,7 +274,7 @@  static inline sector_t bdev_nr_sectors(struct block_device *bdev)
 	
 static inline sector_t get_capacity(struct gendisk *disk)
 {
-	return bdev_nr_sectors(disk->part0.bdev);
+	return bdev_nr_sectors(disk->part0);
 }
 
 int bdev_disk_changed(struct block_device *bdev, bool invalidate);
diff --git a/include/linux/part_stat.h b/include/linux/part_stat.h
index 24125778ef3ec7..3b3621b4983a58 100644
--- a/include/linux/part_stat.h
+++ b/include/linux/part_stat.h
@@ -25,26 +25,26 @@  struct disk_stats {
 #define part_stat_unlock()	preempt_enable()
 
 #define part_stat_get_cpu(part, field, cpu)				\
-	(per_cpu_ptr((part)->dkstats, (cpu))->field)
+	(per_cpu_ptr((part)->bd_stats, (cpu))->field)
 
 #define part_stat_get(part, field)					\
 	part_stat_get_cpu(part, field, smp_processor_id())
 
 #define part_stat_read(part, field)					\
 ({									\
-	typeof((part)->dkstats->field) res = 0;				\
+	typeof((part)->bd_stats->field) res = 0;				\
 	unsigned int _cpu;						\
 	for_each_possible_cpu(_cpu)					\
-		res += per_cpu_ptr((part)->dkstats, _cpu)->field;	\
+		res += per_cpu_ptr((part)->bd_stats, _cpu)->field;	\
 	res;								\
 })
 
-static inline void part_stat_set_all(struct hd_struct *part, int value)
+static inline void part_stat_set_all(struct block_device *bdev, int value)
 {
 	int i;
 
 	for_each_possible_cpu(i)
-		memset(per_cpu_ptr(part->dkstats, i), value,
+		memset(per_cpu_ptr(bdev->bd_stats, i), value,
 				sizeof(struct disk_stats));
 }
 
@@ -54,13 +54,12 @@  static inline void part_stat_set_all(struct hd_struct *part, int value)
 	 part_stat_read(part, field[STAT_DISCARD]))
 
 #define __part_stat_add(part, field, addnd)				\
-	__this_cpu_add((part)->dkstats->field, addnd)
+	__this_cpu_add((part)->bd_stats->field, addnd)
 
 #define part_stat_add(part, field, addnd)	do {			\
 	__part_stat_add((part), field, addnd);				\
-	if ((part)->partno)						\
-		__part_stat_add(&part_to_disk((part))->part0,		\
-				field, addnd);				\
+	if ((part)->bd_partno)						\
+		__part_stat_add((part)->bd_disk->part0, field, addnd);	\
 } while (0)
 
 #define part_stat_dec(gendiskp, field)					\
diff --git a/init/do_mounts.c b/init/do_mounts.c
index 5879edf083b318..a78e44ee6adb8d 100644
--- a/init/do_mounts.c
+++ b/init/do_mounts.c
@@ -76,11 +76,11 @@  struct uuidcmp {
  */
 static int match_dev_by_uuid(struct device *dev, const void *data)
 {
+	struct block_device *bdev = dev_to_bdev(dev);
 	const struct uuidcmp *cmp = data;
-	struct hd_struct *part = dev_to_part(dev);
 
-	if (!part->info ||
-	    strncasecmp(cmp->uuid, part->info->uuid, cmp->len))
+	if (!bdev->bd_meta_info ||
+	    strncasecmp(cmp->uuid, bdev->bd_meta_info->uuid, cmp->len))
 		return 0;
 	return 1;
 }
@@ -133,13 +133,13 @@  static dev_t devt_from_partuuid(const char *uuid_str)
 		 * Attempt to find the requested partition by adding an offset
 		 * to the partition number found by UUID.
 		 */
-		struct hd_struct *part;
+		struct block_device *part;
 
-		part = disk_get_part(dev_to_disk(dev),
-				     dev_to_part(dev)->partno + offset);
+		part = bdget_disk(dev_to_disk(dev),
+				  dev_to_bdev(dev)->bd_partno + offset);
 		if (part) {
-			devt = part_devt(part);
-			put_device(part_to_dev(part));
+			devt = part->bd_dev;
+			bdput(part);
 		}
 	} else {
 		devt = dev->devt;
@@ -166,10 +166,10 @@  static dev_t devt_from_partuuid(const char *uuid_str)
  */
 static int match_dev_by_label(struct device *dev, const void *data)
 {
+	struct block_device *bdev = dev_to_bdev(dev);
 	const char *label = data;
-	struct hd_struct *part = dev_to_part(dev);
 
-	if (!part->info || strcmp(label, part->info->volname))
+	if (!bdev->bd_meta_info || strcmp(label, bdev->bd_meta_info->volname))
 		return 0;
 	return 1;
 }
diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index 7076d588a50d69..a482a37848bff7 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -458,14 +458,9 @@  static struct rchan_callbacks blk_relay_callbacks = {
 static void blk_trace_setup_lba(struct blk_trace *bt,
 				struct block_device *bdev)
 {
-	struct hd_struct *part = NULL;
-
-	if (bdev)
-		part = bdev->bd_part;
-
-	if (part) {
-		bt->start_lba = part->start_sect;
-		bt->end_lba = part->start_sect + bdev_nr_sectors(bdev);
+	if (bdev) {
+		bt->start_lba = bdev->bd_start_sect;
+		bt->end_lba = bdev->bd_start_sect + bdev_nr_sectors(bdev);
 	} else {
 		bt->start_lba = 0;
 		bt->end_lba = -1ULL;
@@ -1815,30 +1810,15 @@  static ssize_t blk_trace_mask2str(char *buf, int mask)
 	return p - buf;
 }
 
-static struct request_queue *blk_trace_get_queue(struct block_device *bdev)
-{
-	if (bdev->bd_disk == NULL)
-		return NULL;
-
-	return bdev_get_queue(bdev);
-}
-
 static ssize_t sysfs_blk_trace_attr_show(struct device *dev,
 					 struct device_attribute *attr,
 					 char *buf)
 {
-	struct block_device *bdev = bdget_part(dev_to_part(dev));
-	struct request_queue *q;
+	struct block_device *bdev = dev_to_bdev(dev);
+	struct request_queue *q = bdev_get_queue(bdev);
 	struct blk_trace *bt;
 	ssize_t ret = -ENXIO;
 
-	if (bdev == NULL)
-		goto out;
-
-	q = blk_trace_get_queue(bdev);
-	if (q == NULL)
-		goto out_bdput;
-
 	mutex_lock(&q->debugfs_mutex);
 
 	bt = rcu_dereference_protected(q->blk_trace,
@@ -1861,9 +1841,6 @@  static ssize_t sysfs_blk_trace_attr_show(struct device *dev,
 
 out_unlock_bdev:
 	mutex_unlock(&q->debugfs_mutex);
-out_bdput:
-	bdput(bdev);
-out:
 	return ret;
 }
 
@@ -1871,8 +1848,8 @@  static ssize_t sysfs_blk_trace_attr_store(struct device *dev,
 					  struct device_attribute *attr,
 					  const char *buf, size_t count)
 {
-	struct block_device *bdev;
-	struct request_queue *q;
+	struct block_device *bdev = dev_to_bdev(dev);
+	struct request_queue *q = bdev_get_queue(bdev);
 	struct blk_trace *bt;
 	u64 value;
 	ssize_t ret = -EINVAL;
@@ -1888,17 +1865,10 @@  static ssize_t sysfs_blk_trace_attr_store(struct device *dev,
 				goto out;
 			value = ret;
 		}
-	} else if (kstrtoull(buf, 0, &value))
-		goto out;
-
-	ret = -ENXIO;
-	bdev = bdget_part(dev_to_part(dev));
-	if (bdev == NULL)
-		goto out;
-
-	q = blk_trace_get_queue(bdev);
-	if (q == NULL)
-		goto out_bdput;
+	} else {
+		if (kstrtoull(buf, 0, &value))
+			goto out;
+	}
 
 	mutex_lock(&q->debugfs_mutex);
 
@@ -1936,8 +1906,6 @@  static ssize_t sysfs_blk_trace_attr_store(struct device *dev,
 
 out_unlock_bdev:
 	mutex_unlock(&q->debugfs_mutex);
-out_bdput:
-	bdput(bdev);
 out:
 	return ret ? ret : count;
 }