From dbdc1be32591af023db2812706f01e6cd2f42bfc Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Wed, 30 Mar 2022 07:29:06 +0200 Subject: block: add a disk_openers helper Add a helper that returns the openers for a given gendisk to avoid having drivers poke into disk->part0 to get at this information in a somewhat cumbersome way. Signed-off-by: Christoph Hellwig Reviewed-by: Jan Kara Link: https://lore.kernel.org/r/20220330052917.2566582-5-hch@lst.de Signed-off-by: Jens Axboe --- include/linux/blkdev.h | 15 +++++++++++++++ 1 file changed, 15 insertions(+) (limited to 'include/linux') diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index c9b5925af5a3..436645bde13f 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -176,6 +176,21 @@ static inline bool disk_live(struct gendisk *disk) return !inode_unhashed(disk->part0->bd_inode); } +/** + * disk_openers - returns how many openers are there for a disk + * @disk: disk to check + * + * This returns the number of openers for a disk. Note that this value is only + * stable if disk->open_mutex is held. + * + * Note: Due to a quirk in the block layer open code, each open partition is + * only counted once even if there are multiple openers. + */ +static inline unsigned int disk_openers(struct gendisk *disk) +{ + return disk->part0->bd_openers; +} + /* * The gendisk is refcounted by the part0 block_device, and the bd_device * therein is also used for device model presentation in sysfs. -- cgit v1.2.3