partitions/ibm: use bdev_nr_sectors instead of open coding it

Use the proper helper to read the block device size and switch various
places to pass the size in terms of sectors which is more practical.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20211019062024.2171074-4-hch@lst.de
[axboe: fix comment typo]
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block/partitions/ibm.c

@@ -198,7 +198,7 @@ static int find_lnx1_partitions(struct parsed_partitions *state,
 				char name[],
 				union label_t *label,
 				sector_t labelsect,
-				loff_t i_size,
+				sector_t nr_sectors,
 				dasd_information2_t *info)
 {
 	loff_t offset, geo_size, size;
@@ -213,14 +213,14 @@ static int find_lnx1_partitions(struct parsed_partitions *state,
 	} else {
 		/*
 		 * Formated w/o large volume support. If the sanity check
-		 * 'size based on geo == size based on i_size' is true, then
+		 * 'size based on geo == size based on nr_sectors' is true, then
 		 * we can safely assume that we know the formatted size of
 		 * the disk, otherwise we need additional information
 		 * that we can only get from a real DASD device.
 		 */
 		geo_size = geo->cylinders * geo->heads
 			* geo->sectors * secperblk;
-		size = i_size >> 9;
+		size = nr_sectors;
 		if (size != geo_size) {
 			if (!info) {
 				strlcat(state->pp_buf, "\n", PAGE_SIZE);
@@ -229,7 +229,7 @@ static int find_lnx1_partitions(struct parsed_partitions *state,
 			if (!strcmp(info->type, "ECKD"))
 				if (geo_size < size)
 					size = geo_size;
-			/* else keep size based on i_size */
+			/* else keep size based on nr_sectors */
 		}
 	}
 	/* first and only partition starts in the first block after the label */
@@ -293,7 +293,8 @@ int ibm_partition(struct parsed_partitions *state)
 	struct gendisk *disk = state->disk;
 	struct block_device *bdev = disk->part0;
 	int blocksize, res;
-	loff_t i_size, offset, size;
+	loff_t offset, size;
+	sector_t nr_sectors;
 	dasd_information2_t *info;
 	struct hd_geometry *geo;
 	char type[5] = {0,};
@@ -308,8 +309,8 @@ int ibm_partition(struct parsed_partitions *state)
 	blocksize = bdev_logical_block_size(bdev);
 	if (blocksize <= 0)
 		goto out_symbol;
-	i_size = i_size_read(bdev->bd_inode);
-	if (i_size == 0)
+	nr_sectors = bdev_nr_sectors(bdev);
+	if (nr_sectors == 0)
 		goto out_symbol;
 	info = kmalloc(sizeof(dasd_information2_t), GFP_KERNEL);
 	if (info == NULL)
@@ -336,7 +337,7 @@ int ibm_partition(struct parsed_partitions *state)
 						   label);
 		} else if (!strncmp(type, "LNX1", 4)) {
 			res = find_lnx1_partitions(state, geo, blocksize, name,
-						   label, labelsect, i_size,
+						   label, labelsect, nr_sectors,
 						   info);
 		} else if (!strncmp(type, "CMS1", 4)) {
 			res = find_cms1_partitions(state, geo, blocksize, name,
@@ -353,7 +354,7 @@ int ibm_partition(struct parsed_partitions *state)
 		res = 1;
 		if (info->format == DASD_FORMAT_LDL) {
 			strlcat(state->pp_buf, "(nonl)", PAGE_SIZE);
-			size = i_size >> 9;
+			size = nr_sectors;
 			offset = (info->label_block + 1) * (blocksize >> 9);
 			put_partition(state, 1, offset, size-offset);
 			strlcat(state->pp_buf, "\n", PAGE_SIZE);