Re: [PATCH net-next] rxrpc: Make service connection lookup always check for retry

From: David Miller
Date: Tue Sep 05 2017 - 17:42:01 EST


From: David Howells <dhowells@xxxxxxxxxx>
Date: Mon, 04 Sep 2017 15:28:28 +0100

> When an RxRPC service packet comes in, the target connection is looked up
> by an rb-tree search under RCU and a read-locked seqlock; the seqlock retry
> check is, however, currently skipped if we got a match, but probably
> shouldn't be in case the connection we found gets replaced whilst we're
> doing a search.
>
> Make the lookup procedure always go through need_seqretry(), even if the
> lookup was successful. This makes sure we always pick up on a write-lock
> event.
>
> On the other hand, since we don't take a ref on the object, but rely on RCU
> to prevent its destruction after dropping the seqlock, I'm not sure this is
> necessary.
>
> Signed-off-by: David Howells <dhowells@xxxxxxxxxx>

Applied, thanks David.