diff options
| author |  Christoph Hellwig <hch@lst.de>
| 2022-03-30 07:29:06 +0200 |
|---|---|---|
| committer |  Jens Axboe <axboe@kernel.dk>
| 2022-04-18 06:54:09 -0600 |
| commit | dbdc1be32591af023db2812706f01e6cd2f42bfc (patch) | |
| tree | ecdb59b4ebcdc9bb0f1eea5e086aa9ea0e3c733f /include/linux/blkdev.h | |
| parent | zram: cleanup zram_remove (diff) | |
| download | linux-dbdc1be32591af023db2812706f01e6cd2f42bfc.tar.gz linux-dbdc1be32591af023db2812706f01e6cd2f42bfc.tar.bz2 linux-dbdc1be32591af023db2812706f01e6cd2f42bfc.zip | |
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 <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20220330052917.2566582-5-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'include/linux/blkdev.h')
| -rw-r--r-- | include/linux/blkdev.h | 15 |
1 files changed, 15 insertions, 0 deletions
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. |