Commit be324177 authored by Jarod Wilson's avatar Jarod Wilson Committed by Jens Axboe
Browse files

block: export blkdev_reread_part() and __blkdev_reread_part() 



This patch exports blkdev_reread_part() for block drivers, also
introduce __blkdev_reread_part().

For some drivers, such as loop, reread of partitions can be run
from the release path, and bd_mutex may already be held prior to
calling ioctl_by_bdev(bdev, BLKRRPART, 0), so introduce
__blkdev_reread_part for use in such cases.

CC: Christoph Hellwig <hch@lst.de>
CC: Jens Axboe <axboe@kernel.dk>
CC: Tejun Heo <tj@kernel.org>
CC: Alexander Viro <viro@zeniv.linux.org.uk>
CC: Markus Pargmann <mpa@pengutronix.de>
CC: Stefan Weinhuber <wein@de.ibm.com>
CC: Stefan Haberland <stefan.haberland@de.ibm.com>
CC: Sebastian Ott <sebott@linux.vnet.ibm.com>
CC: Fabian Frederick <fabf@skynet.be>
CC: Ming Lei <ming.lei@canonical.com>
CC: David Herrmann <dh.herrmann@gmail.com>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: Peter Zijlstra <peterz@infradead.org>
CC: nbd-general@lists.sourceforge.net
CC: linux-s390@vger.kernel.org
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarJarod Wilson <jarod@redhat.com>
Signed-off-by: default avatarMing Lei <ming.lei@canonical.com>
Signed-off-by: default avatarJens Axboe <axboe@fb.com>
parent 343df3c7

block/ioctl.c

+25 −3
Original line number Diff line number Diff line
@@ -150,21 +150,43 @@ static int blkpg_ioctl(struct block_device *bdev, struct blkpg_ioctl_arg __user 
	}

}



static int blkdev_reread_part(struct block_device *bdev)

/*

 * This is an exported API for the block driver, and will not

 * acquire bd_mutex. This API should be used in case that

 * caller has held bd_mutex already.

 */

int __blkdev_reread_part(struct block_device *bdev)

{

	struct gendisk *disk = bdev->bd_disk;

	int res;



	if (!disk_part_scan_enabled(disk) || bdev != bdev->bd_contains)

		return -EINVAL;

	if (!capable(CAP_SYS_ADMIN))

		return -EACCES;



	lockdep_assert_held(&bdev->bd_mutex);



	return rescan_partitions(disk, bdev);

}

EXPORT_SYMBOL(__blkdev_reread_part);



/*

 * This is an exported API for the block driver, and will

 * try to acquire bd_mutex. If bd_mutex has been held already

 * in current context, please call __blkdev_reread_part().

 */

int blkdev_reread_part(struct block_device *bdev)

{

	int res;



	if (!mutex_trylock(&bdev->bd_mutex))

		return -EBUSY;

	res = rescan_partitions(disk, bdev);

	res = __blkdev_reread_part(bdev);

	mutex_unlock(&bdev->bd_mutex);



	return res;

}

EXPORT_SYMBOL(blkdev_reread_part);



static int blk_ioctl_discard(struct block_device *bdev, uint64_t start,

			     uint64_t len, int secure)

include/linux/fs.h

+3 −0
Original line number Diff line number Diff line
@@ -2279,6 +2279,9 @@ extern struct block_device *blkdev_get_by_path(const char *path, fmode_t mode, 
extern struct block_device *blkdev_get_by_dev(dev_t dev, fmode_t mode,

					      void *holder);

extern void blkdev_put(struct block_device *bdev, fmode_t mode);

extern int __blkdev_reread_part(struct block_device *bdev);

extern int blkdev_reread_part(struct block_device *bdev);



#ifdef CONFIG_SYSFS

extern int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk);

extern void bd_unlink_disk_holder(struct block_device *bdev,

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