Commit f0b870df authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jens Axboe
Browse files

block: remove (__)blkdev_reread_part as an exported API 



In general drivers should never mess with partition tables directly.
Unfortunately s390 and loop do for somewhat historic reasons, but they
can use bdev_disk_changed directly instead when we export it as they
satisfy the sanity checks we have in __blkdev_reread_part.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: Stefan Haberland <sth@linux.ibm.com>	[dasd]
Reviewed-by: default avatarJan Kara <jack@suse.cz>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 142fe8f4

block/ioctl.c

+5 −30
Original line number Diff line number Diff line
@@ -155,46 +155,21 @@ static int blkpg_ioctl(struct block_device *bdev, struct blkpg_ioctl_arg __user 
	}

}



/*

 * 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)

static int blkdev_reread_part(struct block_device *bdev)

{

	int ret;



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

		return -EINVAL;

	if (!capable(CAP_SYS_ADMIN))

		return -EACCES;



	lockdep_assert_held(&bdev->bd_mutex);



	return bdev_disk_changed(bdev, false);

}

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().

 *

 * Make sure the held locks in current context aren't required

 * in open()/close() handler and I/O path for avoiding ABBA deadlock:

 * - bd_mutex is held before calling block driver's open/close

 *   handler

 * - reading partition table may submit I/O to the block device

 */

int blkdev_reread_part(struct block_device *bdev)

{

	int res;



	mutex_lock(&bdev->bd_mutex);

	res = __blkdev_reread_part(bdev);

	ret = bdev_disk_changed(bdev, false);

	mutex_unlock(&bdev->bd_mutex);



	return res;

	return ret;

}

EXPORT_SYMBOL(blkdev_reread_part);



static int blk_ioctl_discard(struct block_device *bdev, fmode_t mode,

		unsigned long arg, unsigned long flags)

drivers/block/loop.c

+8 −5
Original line number Diff line number Diff line
@@ -640,7 +640,9 @@ static void loop_reread_partitions(struct loop_device *lo, 
{

	int rc;



	rc = blkdev_reread_part(bdev);

	mutex_lock(&bdev->bd_mutex);

	rc = bdev_disk_changed(bdev, false);

	mutex_unlock(&bdev->bd_mutex);

	if (rc)

		pr_warn("%s: partition scan of loop%d (%s) failed (rc=%d)\n",

			__func__, lo->lo_number, lo->lo_file_name, rc);
@@ -1164,10 +1166,11 @@ out_unlock: 
		 * must be at least one and it can only become zero when the

		 * current holder is released.

		 */

		if (release)

			err = __blkdev_reread_part(bdev);

		else

			err = blkdev_reread_part(bdev);

		if (!release)

			mutex_lock(&bdev->bd_mutex);

		err = bdev_disk_changed(bdev, false);

		if (!release)

			mutex_unlock(&bdev->bd_mutex);

		if (err)

			pr_warn("%s: partition scan of loop%d failed (rc=%d)\n",

				__func__, lo_number, err);

drivers/s390/block/dasd_genhd.c

+3 −1
Original line number Diff line number Diff line
@@ -116,7 +116,9 @@ int dasd_scan_partitions(struct dasd_block *block) 
		return -ENODEV;

	}



	rc = blkdev_reread_part(bdev);

	mutex_lock(&bdev->bd_mutex);

	rc = bdev_disk_changed(bdev, false);

	mutex_unlock(&bdev->bd_mutex);

	if (rc)

		DBF_DEV_EVENT(DBF_ERR, block->base,

				"scan partitions error, rc %d", rc);

fs/block_dev.c

+7 −0
Original line number Diff line number Diff line
@@ -1513,6 +1513,8 @@ int bdev_disk_changed(struct block_device *bdev, bool invalidate) 
	struct gendisk *disk = bdev->bd_disk;

	int ret;



	lockdep_assert_held(&bdev->bd_mutex);



rescan:

	ret = blk_drop_partitions(disk, bdev);

	if (ret)
@@ -1540,6 +1542,11 @@ rescan: 


	return ret;

}

/*

 * Only exported for for loop and dasd for historic reasons.  Don't use in new

 * code!

 */

EXPORT_SYMBOL_GPL(bdev_disk_changed);



/*

 * bd_mutex locking:

include/linux/fs.h

+0 −2
Original line number Diff line number Diff line
@@ -2632,8 +2632,6 @@ extern void bd_finish_claiming(struct block_device *bdev, 
extern void bd_abort_claiming(struct block_device *bdev,

			      struct block_device *whole, 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);

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