block: remove bdgrab

All callers are gone, and no one should grab a pure inode reference to
a block device anymore.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJosef Bacik <josef@toxicpanda.com>
Link: https://lore.kernel.org/r/20210722075402.983367-9-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

fs/block_dev.c

@@ -921,21 +921,6 @@ void bdev_add(struct block_device *bdev, dev_t dev)
 	insert_inode_hash(bdev->bd_inode);
 }
 
-/**
- * bdgrab -- Grab a reference to an already referenced block device
- * @bdev:	Block device to grab a reference to.
- *
- * Returns the block_device with an additional reference when successful,
- * or NULL if the inode is already beeing freed.
- */
-struct block_device *bdgrab(struct block_device *bdev)
-{
-	if (!igrab(bdev->bd_inode))
-		return NULL;
-	return bdev;
-}
-EXPORT_SYMBOL(bdgrab);
-
 long nr_blockdev_pages(void)
 {
 	struct inode *inode;

include/linux/blkdev.h

@@ -1984,7 +1984,6 @@ void blkdev_put_no_open(struct block_device *bdev);
 struct block_device *bdev_alloc(struct gendisk *disk, u8 partno);
 void bdev_add(struct block_device *bdev, dev_t dev);
 struct block_device *I_BDEV(struct inode *inode);
-struct block_device *bdgrab(struct block_device *bdev);
 void bdput(struct block_device *);
 int truncate_bdev_range(struct block_device *bdev, fmode_t mode, loff_t lstart,
 		loff_t lend);