SPGridView 2013 Data Permissions

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SharePoint

Hello everyone,
I am implementing a SPGridView in sharepoint 2013 as a visual web part. Reading a document list and binding it's data to spgridview now the issue that i want to resolve is :
I am using form based authentication for my web application. when a system admin login then he would be able to see documents uploaded with all operations specified for that document list but when a user other than system admin login to site then he just can see documents uploaded to that doc list no operations should be able on that web part.
the problem is when i delete my site members in permission settings of that document library from where I'm reading my data and bind to gridview and login as other users instead admin then it's not showing me spgridview data because i have delete the members those have permissions to that doc library and most importantly not showing home page saying that this site has not shared with you.