Re: [PATCH -next] packet: remove unused variable 'status' in __packet_lookup_frame_in_block

From: Willem de Bruijn
Date: Mon Jun 10 2019 - 09:10:49 EST


On Mon, Jun 10, 2019 at 8:17 AM Mao Wenan <maowenan@xxxxxxxxxx> wrote:
>
> The variable 'status' in __packet_lookup_frame_in_block() is never used since
> introduction in commit f6fb8f100b80 ("af-packet: TPACKET_V3 flexible buffer
> implementation."), we can remove it.
> And when __packet_lookup_frame_in_block() calls prb_retire_current_block(),
> it can pass macro TP_STATUS_KERNEL instead of 0.
>
> Signed-off-by: Mao Wenan <maowenan@xxxxxxxxxx>
> ---
> net/packet/af_packet.c | 5 ++---
> 1 file changed, 2 insertions(+), 3 deletions(-)
>
> diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
> index a29d66d..fb1a79c 100644
> --- a/net/packet/af_packet.c
> +++ b/net/packet/af_packet.c
> @@ -1003,7 +1003,6 @@ static void prb_fill_curr_block(char *curr,
> /* Assumes caller has the sk->rx_queue.lock */
> static void *__packet_lookup_frame_in_block(struct packet_sock *po,
> struct sk_buff *skb,
> - int status,
> unsigned int len
> )
> {
> @@ -1046,7 +1045,7 @@ static void *__packet_lookup_frame_in_block(struct packet_sock *po,
> }
>
> /* Ok, close the current block */
> - prb_retire_current_block(pkc, po, 0);
> + prb_retire_current_block(pkc, po, TP_STATUS_KERNEL);

I don't think that 0 is intended to mean TP_STATUS_KERNEL here.

prb_retire_current_block calls prb_close_block which sets status to

TP_STATUS_USER | stat

where stat is 0 or TP_STATUS_BLK_TMO.