Re: [net][PATCH v2 2/2] RDS: Fix the atomicity for congestion map update

From: David Miller
Date: Sat Apr 16 2016 - 19:01:54 EST


From: Santosh Shilimkar <santosh.shilimkar@xxxxxxxxxx>
Date: Thu, 14 Apr 2016 10:43:27 -0700

> Two different threads with different rds sockets may be in
> rds_recv_rcvbuf_delta() via receive path. If their ports
> both map to the same word in the congestion map, then
> using non-atomic ops to update it could cause the map to
> be incorrect. Lets use atomics to avoid such an issue.
>
> Full credit to Wengang <wen.gang.wang@xxxxxxxxxx> for
> finding the issue, analysing it and also pointing out
> to offending code with spin lock based fix.
>
> Reviewed-by: Leon Romanovsky <leon@xxxxxxx>
> Signed-off-by: Wengang Wang <wen.gang.wang@xxxxxxxxxx>
> Signed-off-by: Santosh Shilimkar <santosh.shilimkar@xxxxxxxxxx>

Applied.