nilfs2: use bdev_nr_bytes instead of open coding it

Use the proper helper to read the block device size.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Link: https://lore.kernel.org/r/20211018101130.1838532-20-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

fs/nilfs2/ioctl.c

@@ -1107,7 +1107,7 @@ static int nilfs_ioctl_set_alloc_range(struct inode *inode, void __user *argp)
 		goto out;
 
 	ret = -ERANGE;
-	if (range[1] > i_size_read(inode->i_sb->s_bdev->bd_inode))
+	if (range[1] > bdev_nr_bytes(inode->i_sb->s_bdev))
 		goto out;
 
 	segbytes = nilfs->ns_blocks_per_segment * nilfs->ns_blocksize;

fs/nilfs2/super.c

@@ -403,7 +403,7 @@ int nilfs_resize_fs(struct super_block *sb, __u64 newsize)
 	int ret;
 
 	ret = -ERANGE;
-	devsize = i_size_read(sb->s_bdev->bd_inode);
+	devsize = bdev_nr_bytes(sb->s_bdev);
 	if (newsize > devsize)
 		goto out;
 

fs/nilfs2/the_nilfs.c

@@ -489,7 +489,7 @@ static int nilfs_load_super_block(struct the_nilfs *nilfs,
 {
 	struct nilfs_super_block **sbp = nilfs->ns_sbp;
 	struct buffer_head **sbh = nilfs->ns_sbh;
-	u64 sb2off = NILFS_SB2_OFFSET_BYTES(nilfs->ns_bdev->bd_inode->i_size);
+	u64 sb2off = NILFS_SB2_OFFSET_BYTES(bdev_nr_bytes(nilfs->ns_bdev));
 	int valid[2], swp = 0;
 
 	sbp[0] = nilfs_read_super_block(sb, NILFS_SB_OFFSET_BYTES, blocksize,