diff --git a/fs/cramfs/inode.c b/fs/cramfs/inode.c
index 2be65269a987..666aa380011e 100644
--- a/fs/cramfs/inode.c
+++ b/fs/cramfs/inode.c
@@ -209,7 +209,7 @@ static void *cramfs_blkdev_read(struct super_block *sb, unsigned int offset,
 		return read_buffers[i] + blk_offset;
 	}
 
-	devsize = mapping->host->i_size >> PAGE_SHIFT;
+	devsize = bdev_nr_bytes(sb->s_bdev) >> PAGE_SHIFT;
 
 	/* Ok, read in BLKS_PER_BUF pages completely first. */
 	for (i = 0; i < BLKS_PER_BUF; i++) {