Re: [PATCH net] strparser: Remove early eaten to fix full tcp receive buffer stall

[David Miller <davem@davemloft.net>]

From: Doron Roberts-Kedes <doronrk@fb.com>
Date: Tue, 26 Jun 2018 18:33:33 -0700

> On receving an incomplete message, the existing code stores the
> remaining length of the cloned skb in the early_eaten field instead of
> incrementing the value returned by __strp_recv. This defers invocation
> of sock_rfree for the current skb until the next invocation of
> __strp_recv, which returns early_eaten if early_eaten is non-zero.
> 
> This behavior causes a stall when the current message occupies the very
> tail end of a massive skb, and strp_peek/need_bytes indicates that the
> remainder of the current message has yet to arrive on the socket. The
> TCP receive buffer is totally full, causing the TCP window to go to
> zero, so the remainder of the message will never arrive.
> 
> Incrementing the value returned by __strp_recv by the amount otherwise
> stored in early_eaten prevents stalls of this nature.
> 
> Signed-off-by: Doron Roberts-Kedes <doronrk@fb.com>

Applied and queued up for -stable.