577  * @holder: holder trying to claim @bdev
578  * @hops: holder ops
580  * Test whether @bdev can be claimed by @holder.
585 static bool bd_may_claim(struct block_device *bdev, void *holder,  in bd_may_claim()  argument
594 		 * The same holder can always re-claim.  in bd_may_claim()
596 		if (bdev->bd_holder == holder) {  in bd_may_claim()
605 	 * If the whole devices holder is set to bd_may_claim, a partition on  in bd_may_claim()
617  * @holder: holder trying to claim @bdev
618  * @hops: holder ops.
621  * holder and waits if another claiming is in progress. return, the caller
627 int bd_prepare_to_claim(struct block_device *bdev, void *holder,  in bd_prepare_to_claim()  argument
632 	if (WARN_ON_ONCE(!holder))  in bd_prepare_to_claim()
637 	if (!bd_may_claim(bdev, holder, hops)) {  in bd_prepare_to_claim()
655 	whole->bd_claiming = holder;  in bd_prepare_to_claim()
661 static void bd_clear_claiming(struct block_device *whole, void *holder)  in bd_clear_claiming()  argument
665 	BUG_ON(whole->bd_claiming != holder);  in bd_clear_claiming()
673  * @holder: holder that has claimed @bdev
674  * @hops: block device holder operations
677  * open by the holder and wake up all waiters for exclusive open to finish.
679 static void bd_finish_claiming(struct block_device *bdev, void *holder,  in bd_finish_claiming()  argument
685 	BUG_ON(!bd_may_claim(bdev, holder, hops));  in bd_finish_claiming()
688 	 * and bd_holder will be set to bd_may_claim before being set to holder  in bd_finish_claiming()
694 	bdev->bd_holder = holder;  in bd_finish_claiming()
697 	bd_clear_claiming(whole, holder);  in bd_finish_claiming()
704  * @holder: holder that has claimed @bdev
710 void bd_abort_claiming(struct block_device *bdev, void *holder)  in bd_abort_claiming()  argument
713 	bd_clear_claiming(bdev_whole(bdev), holder);  in bd_abort_claiming()
718 static void bd_end_claim(struct block_device *bdev, void *holder)  in bd_end_claim()  argument
724 	 * Release a claim on the device.  The holder fields are protected with  in bd_end_claim()
728 	WARN_ON_ONCE(bdev->bd_holder != holder);  in bd_end_claim()
744 	 * If this was the last claim, remove holder link and unblock evpoll if  in bd_end_claim()
745 	 * it was a write holder.  in bd_end_claim()
827 int bdev_permission(dev_t dev, blk_mode_t mode, void *holder)  in bdev_permission()  argument
839 	if (mode & BLK_OPEN_RESTRICT_WRITES && !holder)  in bdev_permission()
846 	if (WARN_ON_ONCE(IS_ERR(holder)))  in bdev_permission()
958  * @holder: exclusive holder identifier
959  * @hops: holder operations
962  * Open the block device. If @holder is not %NULL, the block device is opened
963  * with exclusive access.  Exclusive opens may nest for the same @holder.
971 int bdev_open(struct block_device *bdev, blk_mode_t mode, void *holder,  in bdev_open()  argument
978 	if (holder) {  in bdev_open()
980 		ret = bd_prepare_to_claim(bdev, holder, hops);  in bdev_open()
1006 	if (holder) {  in bdev_open()
1007 		bd_finish_claiming(bdev, holder, hops);  in bdev_open()
1011 		 * holder makes the write_holder state stick until all are  in bdev_open()
1036 	bdev_file->private_data = holder;  in bdev_open()
1042 	if (holder)  in bdev_open()
1043 		bd_abort_claiming(bdev, holder);  in bdev_open()
1079 struct file *bdev_file_open_by_dev(dev_t dev, blk_mode_t mode, void *holder,  in bdev_file_open_by_dev()  argument
1087 	ret = bdev_permission(dev, mode, holder);  in bdev_file_open_by_dev()
1104 	ret = bdev_open(bdev, mode, holder, hops, bdev_file);  in bdev_file_open_by_dev()
1116 				    void *holder,  in bdev_file_open_by_path()  argument
1127 	file = bdev_file_open_by_dev(dev, mode, holder, hops);  in bdev_file_open_by_path()
1142 	void *holder = bdev_file->private_data;  in bd_yield_claim()  local
1146 	if (WARN_ON_ONCE(IS_ERR_OR_NULL(holder)))  in bd_yield_claim()
1150 		bd_end_claim(bdev, holder);  in bd_yield_claim()
1156 	void *holder = bdev_file->private_data;  in bdev_release()  local
1160 	if (IS_ERR(holder))  in bdev_release()
1176 	if (holder)  in bdev_release()
1198  * bdev_yield_claim - give up the holder claim on an open block device
1201  * Yield the holder and any write access for @bdev_file without closing it, so