Commit a954ea81 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jens Axboe
Browse files

block: remove ->bd_contains 



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: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: default avatarJan Kara <jack@suse.cz>
Reviewed-by: default avatarHannes Reinecke <hare@suse.de>
Acked-by: default avatarTejun Heo <tj@kernel.org>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 22ae8ce8

drivers/block/loop.c

+1 −1
Original line number Diff line number Diff line
@@ -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;

drivers/scsi/scsicam.c

+1 −1
Original line number Diff line number Diff line
@@ -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;

fs/block_dev.c

+8 −14
Original line number Diff line number Diff line
@@ -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;
@@ -1347,9 +1346,7 @@ 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)
@@ -1389,7 +1386,6 @@ 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 (!(disk->flags & GENHD_FL_UP) ||

			    !bdev->bd_part || !bdev->bd_part->nr_sects) {
@@ -1405,7 +1401,7 @@ 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);
@@ -1423,7 +1419,6 @@ 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;

}
@@ -1670,8 +1665,7 @@ 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);
@@ -1690,6 +1684,7 @@ 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;



		/*
@@ -1700,13 +1695,12 @@ 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);

include/linux/blk_types.h

+3 −1
Original line number Diff line number Diff line
@@ -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)