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From: Christoph Hellwig <hch@lst.de>
To: Jens Axboe <axboe@kernel.dk>
Cc: linux-bcache@vger.kernel.org, Jan Kara <jack@suse.cz>,
	Mike Snitzer <snitzer@redhat.com>,
	linux-mm@kvack.org,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Jan Kara <jack@suse.com>, Josef Bacik <josef@toxicpanda.com>,
	Coly Li <colyli@suse.de>,
	linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org,
	dm-devel@redhat.com, linux-mtd@lists.infradead.org,
	Johannes Thumshirn <johannes.thumshirn@wdc.com>,
	Tejun Heo <tj@kernel.org>
Subject: [dm-devel] [PATCH 25/44] block: remove ->bd_contains
Date: Thu, 26 Nov 2020 14:04:03 +0100
Message-ID: <20201126130422.92945-26-hch@lst.de> (raw)
In-Reply-To: <20201126130422.92945-1-hch@lst.de>

Now that each hd_struct has a reference to the corresponding
block_device, there is no need for the bd_contains pointer.  Add
a bdev_whole() helper to look up the whole device block_device
struture instead.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Acked-by: Tejun Heo <tj@kernel.org>
---
 drivers/block/loop.c      |  2 +-
 drivers/scsi/scsicam.c    |  2 +-
 fs/block_dev.c            | 22 ++++++++--------------
 include/linux/blk_types.h |  4 +++-
 4 files changed, 13 insertions(+), 17 deletions(-)

diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index 26c7aafba7c5f8..c0df88b3300c41 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -1088,7 +1088,7 @@ static int loop_configure(struct loop_device *lo, fmode_t mode,
 	 * here to avoid changing device under exclusive owner.
 	 */
 	if (!(mode & FMODE_EXCL)) {
-		claimed_bdev = bdev->bd_contains;
+		claimed_bdev = bdev_whole(bdev);
 		error = bd_prepare_to_claim(bdev, claimed_bdev, loop_configure);
 		if (error)
 			goto out_putf;
diff --git a/drivers/scsi/scsicam.c b/drivers/scsi/scsicam.c
index 682cf08ab04153..f1553a453616fd 100644
--- a/drivers/scsi/scsicam.c
+++ b/drivers/scsi/scsicam.c
@@ -32,7 +32,7 @@
  */
 unsigned char *scsi_bios_ptable(struct block_device *dev)
 {
-	struct address_space *mapping = dev->bd_contains->bd_inode->i_mapping;
+	struct address_space *mapping = bdev_whole(dev)->bd_inode->i_mapping;
 	unsigned char *res = NULL;
 	struct page *page;
 
diff --git a/fs/block_dev.c b/fs/block_dev.c
index 07b869c2ade501..73f45ae1d3d50c 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -119,7 +119,7 @@ int truncate_bdev_range(struct block_device *bdev, fmode_t mode,
 	 * under live filesystem.
 	 */
 	if (!(mode & FMODE_EXCL)) {
-		claimed_bdev = bdev->bd_contains;
+		claimed_bdev = bdev_whole(bdev);
 		err = bd_prepare_to_claim(bdev, claimed_bdev,
 					  truncate_bdev_range);
 		if (err)
@@ -880,7 +880,6 @@ struct block_device *bdev_alloc(struct gendisk *disk, u8 partno)
 	spin_lock_init(&bdev->bd_size_lock);
 	bdev->bd_disk = disk;
 	bdev->bd_partno = partno;
-	bdev->bd_contains = NULL;
 	bdev->bd_super = NULL;
 	bdev->bd_inode = inode;
 	bdev->bd_part_count = 0;
@@ -1343,9 +1342,7 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode)
 	int ret;
 
 	if (!bdev->bd_openers) {
-		bdev->bd_contains = bdev;
-
-		if (!bdev->bd_partno) {
+		if (!bdev_is_partition(bdev)) {
 			ret = -ENXIO;
 			bdev->bd_part = disk_get_part(disk, 0);
 			if (!bdev->bd_part)
@@ -1385,7 +1382,6 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode)
 			whole->bd_part_count++;
 			mutex_unlock(&whole->bd_mutex);
 
-			bdev->bd_contains = whole;
 			bdev->bd_part = disk_get_part(disk, bdev->bd_partno);
 			if (!bdev->bd_part || !bdev->bd_part->nr_sects) {
 				__blkdev_put(whole, mode, 1);
@@ -1400,7 +1396,7 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode)
 		if (bdev->bd_bdi == &noop_backing_dev_info)
 			bdev->bd_bdi = bdi_get(disk->queue->backing_dev_info);
 	} else {
-		if (bdev->bd_contains == bdev) {
+		if (!bdev_is_partition(bdev)) {
 			ret = 0;
 			if (bdev->bd_disk->fops->open)
 				ret = bdev->bd_disk->fops->open(bdev, mode);
@@ -1418,7 +1414,6 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode)
  out_clear:
 	disk_put_part(bdev->bd_part);
 	bdev->bd_part = NULL;
-	bdev->bd_contains = NULL;
 	return ret;
 }
 
@@ -1664,8 +1659,7 @@ static void __blkdev_put(struct block_device *bdev, fmode_t mode, int for_part)
 		disk_put_part(bdev->bd_part);
 		bdev->bd_part = NULL;
 		if (bdev_is_partition(bdev))
-			victim = bdev->bd_contains;
-		bdev->bd_contains = NULL;
+			victim = bdev_whole(bdev);
 	} else {
 		if (!bdev_is_partition(bdev) && disk->fops->release)
 			disk->fops->release(disk, mode);
@@ -1684,6 +1678,7 @@ void blkdev_put(struct block_device *bdev, fmode_t mode)
 	mutex_lock(&bdev->bd_mutex);
 
 	if (mode & FMODE_EXCL) {
+		struct block_device *whole = bdev_whole(bdev);
 		bool bdev_free;
 
 		/*
@@ -1694,13 +1689,12 @@ void blkdev_put(struct block_device *bdev, fmode_t mode)
 		spin_lock(&bdev_lock);
 
 		WARN_ON_ONCE(--bdev->bd_holders < 0);
-		WARN_ON_ONCE(--bdev->bd_contains->bd_holders < 0);
+		WARN_ON_ONCE(--whole->bd_holders < 0);
 
-		/* bd_contains might point to self, check in a separate step */
 		if ((bdev_free = !bdev->bd_holders))
 			bdev->bd_holder = NULL;
-		if (!bdev->bd_contains->bd_holders)
-			bdev->bd_contains->bd_holder = NULL;
+		if (!whole->bd_holders)
+			whole->bd_holder = NULL;
 
 		spin_unlock(&bdev_lock);
 
diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
index 9698f459cc65c9..2e0a9bd9688d28 100644
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h
@@ -32,7 +32,6 @@ struct block_device {
 #ifdef CONFIG_SYSFS
 	struct list_head	bd_holder_disks;
 #endif
-	struct block_device *	bd_contains;
 	u8			bd_partno;
 	struct hd_struct *	bd_part;
 	/* number of times partitions within this device have been opened. */
@@ -49,6 +48,9 @@ struct block_device {
 	struct super_block	*bd_fsfreeze_sb;
 } __randomize_layout;
 
+#define bdev_whole(_bdev) \
+	((_bdev)->bd_disk->part0.bdev)
+
 #define bdev_kobj(_bdev) \
 	(&part_to_dev((_bdev)->bd_part)->kobj)
 
-- 
2.29.2

--
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  parent reply index

Thread overview: 89+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-11-26 13:03 [dm-devel] merge struct block_device and struct hd_struct v3 Christoph Hellwig
2020-11-26 13:03 ` [dm-devel] [PATCH 01/44] blk-cgroup: fix a hd_struct leak in blkcg_fill_root_iostats Christoph Hellwig
2020-11-26 13:03 ` [dm-devel] [PATCH 02/44] filemap: consistently use ->f_mapping over ->i_mapping Christoph Hellwig
2020-11-26 13:03 ` [dm-devel] [PATCH 03/44] fs: remove get_super_thawed and get_super_exclusive_thawed Christoph Hellwig
2020-11-26 13:03 ` [dm-devel] [PATCH 04/44] fs: simplify freeze_bdev/thaw_bdev Christoph Hellwig
2020-11-26 14:13   ` Jan Kara
2020-11-26 13:03 ` [dm-devel] [PATCH 05/44] mtip32xx: remove the call to fsync_bdev on removal Christoph Hellwig
2020-11-26 13:03 ` [dm-devel] [PATCH 06/44] zram: do not call set_blocksize Christoph Hellwig
2020-11-26 13:03 ` [dm-devel] [PATCH 07/44] loop: " Christoph Hellwig
2020-11-26 13:03 ` [dm-devel] [PATCH 08/44] dm: simplify flush_bio initialization in __send_empty_flush Christoph Hellwig
2020-11-26 13:03 ` [dm-devel] [PATCH 09/44] dm: remove the block_device reference in struct mapped_device Christoph Hellwig
2020-11-27 10:36   ` Hannes Reinecke
2020-11-26 13:03 ` [dm-devel] [PATCH 10/44] block: remove a duplicate __disk_get_part prototype Christoph Hellwig
2020-11-27 10:36   ` Hannes Reinecke
2020-11-26 13:03 ` [dm-devel] [PATCH 11/44] block: remove a superflous check in blkpg_do_ioctl Christoph Hellwig
2020-11-27 10:37   ` Hannes Reinecke
2020-11-26 13:03 ` [dm-devel] [PATCH 12/44] block: add a bdev_kobj helper Christoph Hellwig
2020-11-26 14:47   ` David Sterba
2020-11-27 12:03   ` Hannes Reinecke
2020-11-26 13:03 ` [dm-devel] [PATCH 13/44] block: use disk_part_iter_exit in disk_part_iter_next Christoph Hellwig
2020-11-27 12:04   ` Hannes Reinecke
2020-11-26 13:03 ` [dm-devel] [PATCH 14/44] block: use put_device in put_disk Christoph Hellwig
2020-11-26 13:03 ` [dm-devel] [PATCH 15/44] block: change the hash used for looking up block devices Christoph Hellwig
2020-11-26 13:03 ` [dm-devel] [PATCH 16/44] init: refactor name_to_dev_t Christoph Hellwig
2020-11-26 13:03 ` [dm-devel] [PATCH 17/44] init: refactor devt_from_partuuid Christoph Hellwig
2020-11-26 13:03 ` [dm-devel] [PATCH 18/44] init: cleanup match_dev_by_uuid and match_dev_by_label Christoph Hellwig
2020-11-26 13:03 ` [dm-devel] [PATCH 19/44] block: refactor __blkdev_put Christoph Hellwig
2020-11-26 13:03 ` [dm-devel] [PATCH 20/44] block: refactor blkdev_get Christoph Hellwig
2020-11-26 14:55   ` Jan Kara
2020-11-26 13:03 ` [dm-devel] [PATCH 21/44] block: move bdput() to the callers of __blkdev_get Christoph Hellwig
2020-11-26 15:05   ` Jan Kara
2020-11-26 13:04 ` [dm-devel] [PATCH 22/44] block: opencode devcgroup_inode_permission Christoph Hellwig
2020-11-26 15:07   ` Jan Kara
2020-11-26 13:04 ` [dm-devel] [PATCH 23/44] block: remove i_bdev Christoph Hellwig
2020-11-26 15:45   ` Jan Kara
2020-11-26 13:04 ` [dm-devel] [PATCH 24/44] block: simplify bdev/disk lookup in blkdev_get Christoph Hellwig
2020-11-26 16:33   ` Jan Kara
2020-11-26 17:42     ` Christoph Hellwig
2020-11-26 13:04 ` Christoph Hellwig [this message]
2020-11-26 13:04 ` [dm-devel] [PATCH 26/44] block: simplify the block device claiming interface Christoph Hellwig
2020-11-26 13:04 ` [dm-devel] [PATCH 27/44] block: simplify part_to_disk Christoph Hellwig
2020-11-26 16:36   ` Jan Kara
2020-11-26 13:04 ` [dm-devel] [PATCH 28/44] block: initialize struct block_device in bdev_alloc Christoph Hellwig
2020-11-26 16:37   ` Jan Kara
2020-11-26 13:04 ` [dm-devel] [PATCH 29/44] block: remove the nr_sects field in struct hd_struct Christoph Hellwig
2020-11-26 16:50   ` Jan Kara
2020-11-26 17:52     ` Christoph Hellwig
2020-11-26 18:04       ` Jan Kara
2020-11-27  9:41         ` Christoph Hellwig
2020-11-26 13:04 ` [dm-devel] [PATCH 30/44] block: move disk stat accounting to struct block_device Christoph Hellwig
2020-11-26 16:53   ` Jan Kara
2020-11-26 13:04 ` [dm-devel] [PATCH 31/44] block: move the start_sect field " Christoph Hellwig
2020-11-26 16:56   ` Jan Kara
2020-11-26 18:02     ` Christoph Hellwig
2020-11-26 13:04 ` [dm-devel] [PATCH 32/44] block: move the partition_meta_info " Christoph Hellwig
2020-11-26 16:58   ` Jan Kara
2020-11-26 13:04 ` [dm-devel] [PATCH 33/44] block: move holder_dir " Christoph Hellwig
2020-11-26 17:00   ` Jan Kara
2020-11-26 13:04 ` [dm-devel] [PATCH 34/44] block: move make_it_fail " Christoph Hellwig
2020-11-26 17:01   ` Jan Kara
2020-11-26 13:04 ` [dm-devel] [PATCH 35/44] block: move the policy field " Christoph Hellwig
2020-11-26 17:03   ` Jan Kara
2020-11-26 13:04 ` [dm-devel] [PATCH 36/44] block: allocate struct hd_struct as part of struct bdev_inode Christoph Hellwig
2020-11-26 17:35   ` Jan Kara
2020-11-26 18:00     ` Jan Kara
2020-11-26 18:02       ` Christoph Hellwig
2020-11-26 13:04 ` [dm-devel] [PATCH 37/44] block: switch partition lookup to use struct block_device Christoph Hellwig
2020-11-26 17:45   ` Jan Kara
2020-11-26 18:22   ` Jan Kara
2020-11-27  9:48     ` Christoph Hellwig
2020-11-27 12:45       ` Jan Kara
2020-11-27 15:36         ` Christoph Hellwig
2020-11-27 17:26           ` Jan Kara
2020-11-26 13:04 ` [dm-devel] [PATCH 38/44] block: remove the partno field from struct hd_struct Christoph Hellwig
2020-11-26 17:46   ` Jan Kara
2020-11-26 13:04 ` [dm-devel] [PATCH 39/44] block: pass a block_device to blk_alloc_devt Christoph Hellwig
2020-11-26 17:47   ` Jan Kara
2020-11-26 13:04 ` [dm-devel] [PATCH 40/44] block: pass a block_device to invalidate_partition Christoph Hellwig
2020-11-26 17:49   ` Jan Kara
2020-11-26 13:04 ` [dm-devel] [PATCH 41/44] block: switch disk_part_iter_* to use a struct block_device Christoph Hellwig
2020-11-27 12:53   ` Jan Kara
2020-11-27 15:24     ` Christoph Hellwig
2020-11-27 17:30       ` Jan Kara
2020-11-26 13:04 ` [dm-devel] [PATCH 42/44] f2fs: remove a few bd_part checks Christoph Hellwig
2020-11-26 13:04 ` [dm-devel] [PATCH 43/44] block: merge struct block_device and struct hd_struct Christoph Hellwig
2020-11-27 13:19   ` Jan Kara
2020-11-27 15:47     ` Christoph Hellwig
2020-11-26 13:04 ` [dm-devel] [PATCH 44/44] block: stop using bdget_disk for partition 0 Christoph Hellwig
2020-11-27 13:22   ` Jan Kara

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