block: pass inclusive 'lend' parameter to truncate_inode_pages_range

The 'lend' parameter of truncate_inode_pages_range is required to be
inclusive, so follow the rule.

This patch fixes one memory corruption triggered by discard.

Cc: <[email protected]>
Cc: Dmitry Monakhov <[email protected]>
Fixes: 351499a ("block: Invalidate cache on discard v2")
Reviewed-by: Bart Van Assche <[email protected]>
Signed-off-by: Ming Lei <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>

Author: Ming Lei

block/ioctl.c

@@ -225,7 +225,7 @@ static int blk_ioctl_discard(struct block_device *bdev, fmode_t mode,
 
 	if (start + len > i_size_read(bdev->bd_inode))
 		return -EINVAL;
-	truncate_inode_pages_range(mapping, start, start + len);
+	truncate_inode_pages_range(mapping, start, start + len - 1);
 	return blkdev_issue_discard(bdev, start >> 9, len >> 9,
 				    GFP_KERNEL, flags);
 }