nbd: refactor size updates

Merge nbd_size_set and nbd_size_update into a single function that also
updates the nbd_config fields.  This new function takes the device size
in bytes as the first argument, and the blocksize as the second argument,
simplifying the calculations required in most callers.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Author: Christoph Hellwig

drivers/block/nbd.c

@@ -296,44 +296,37 @@ static void nbd_size_clear(struct nbd_device *nbd)
 	}
 }
 
-static void nbd_size_update(struct nbd_device *nbd)
+static void nbd_set_size(struct nbd_device *nbd, loff_t bytesize,
+		loff_t blksize)
 {
-	struct nbd_config *config = nbd->config;
-	sector_t nr_sectors = config->bytesize >> 9;
 	struct block_device *bdev;
 
+	nbd->config->bytesize = bytesize;
+	nbd->config->blksize = blksize;
+
 	if (!nbd->task_recv)
 		return;
 
-	if (config->flags & NBD_FLAG_SEND_TRIM) {
-		nbd->disk->queue->limits.discard_granularity = config->blksize;
-		nbd->disk->queue->limits.discard_alignment = config->blksize;
+	if (nbd->config->flags & NBD_FLAG_SEND_TRIM) {
+		nbd->disk->queue->limits.discard_granularity = blksize;
+		nbd->disk->queue->limits.discard_alignment = blksize;
 		blk_queue_max_discard_sectors(nbd->disk->queue, UINT_MAX);
 	}
-	blk_queue_logical_block_size(nbd->disk->queue, config->blksize);
-	blk_queue_physical_block_size(nbd->disk->queue, config->blksize);
+	blk_queue_logical_block_size(nbd->disk->queue, blksize);
+	blk_queue_physical_block_size(nbd->disk->queue, blksize);
 
-	set_capacity(nbd->disk, nr_sectors);
+	set_capacity(nbd->disk, bytesize >> 9);
 	bdev = bdget_disk(nbd->disk, 0);
 	if (bdev) {
 		if (bdev->bd_disk)
-			bd_set_nr_sectors(bdev, nr_sectors);
+			bd_set_nr_sectors(bdev, bytesize >> 9);
 		else
 			set_bit(GD_NEED_PART_SCAN, &nbd->disk->state);
 		bdput(bdev);
 	}
 	kobject_uevent(&nbd_to_dev(nbd)->kobj, KOBJ_CHANGE);
 }
 
-static void nbd_size_set(struct nbd_device *nbd, loff_t blocksize,
-			 loff_t nr_blocks)
-{
-	struct nbd_config *config = nbd->config;
-	config->blksize = blocksize;
-	config->bytesize = blocksize * nr_blocks;
-	nbd_size_update(nbd);
-}
-
 static void nbd_complete_rq(struct request *req)
 {
 	struct nbd_cmd *cmd = blk_mq_rq_to_pdu(req);
@@ -1311,7 +1304,7 @@ static int nbd_start_device(struct nbd_device *nbd)
 		args->index = i;
 		queue_work(nbd->recv_workq, &args->work);
 	}
-	nbd_size_update(nbd);
+	nbd_set_size(nbd, config->bytesize, config->blksize);
 	return error;
 }
 
@@ -1390,15 +1383,14 @@ static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *nbd,
 			arg = NBD_DEF_BLKSIZE;
 		if (!nbd_is_valid_blksize(arg))
 			return -EINVAL;
-		nbd_size_set(nbd, arg,
-			     div_s64(config->bytesize, arg));
+		nbd_set_size(nbd, config->bytesize, arg);
 		return 0;
 	case NBD_SET_SIZE:
-		nbd_size_set(nbd, config->blksize,
-			     div_s64(arg, config->blksize));
+		nbd_set_size(nbd, arg, config->blksize);
 		return 0;
 	case NBD_SET_SIZE_BLOCKS:
-		nbd_size_set(nbd, config->blksize, arg);
+		nbd_set_size(nbd, arg * config->blksize,
+			     config->blksize);
 		return 0;
 	case NBD_SET_TIMEOUT:
 		nbd_set_cmd_timeout(nbd, arg);
@@ -1828,7 +1820,7 @@ static int nbd_genl_size_set(struct genl_info *info, struct nbd_device *nbd)
 	}
 
 	if (bytes != config->bytesize || bsize != config->blksize)
-		nbd_size_set(nbd, bsize, div64_u64(bytes, bsize));
+		nbd_set_size(nbd, bytes, bsize);
 	return 0;
 }