Subject: Re: [PATCH v12 net-next 1/1] hv_sock: introduce Hyper-V Sockets

From: Rick Jones <[email-masked]>
Date: Tue, 28 Jun 2016 08:42:48 -0700

On 06/28/2016 02:59 AM, Dexuan Cui wrote:
> The idea here is: IMO the syscalls sys_read()/write() shoudn't return
> -ENOMEM, so I have to make sure the buffer allocation succeeds?
>
> I tried to use kmalloc with __GFP_NOFAIL, but I hit a warning in
> in mm/page_alloc.c:
> WARN_ON_ONCE((gfp_flags & __GFP_NOFAIL) && (order > 1));
>
> What error code do you think I should return?
> EAGAIN, ERESTARTSYS, or something else?
>
> May I have your suggestion? Thanks!

What happens as far as errno is concerned when an application makes a 
read() call against a (say TCP) socket associated with a connection 
which has been reset?  Is it limited to those errno values listed in the 
read() manpage, or does it end-up getting an errno value from those 
listed in the recv() manpage?  Or, perhaps even one not (presently) 
listed in either?

rick jones