From: Toke Høiland-Jørgensen toke@redhat.com
[ Upstream commit 4976e3c683f328bc6f2edef555a4ffee6524486f ]
The logic in cake_select_tin() was getting a bit hairy, and it turns out we can simplify it quite a bit. This also allows us to get rid of one of the two diffserv parsing functions, which has the added benefit that already-zeroed DSCP fields won't get re-written.
Suggested-by: Kevin Darbyshire-Bryant ldir@darbyshire-bryant.me.uk Signed-off-by: Toke Høiland-Jørgensen toke@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/sched/sch_cake.c | 44 ++++++++++++++++---------------------------- 1 file changed, 16 insertions(+), 28 deletions(-)
--- a/net/sched/sch_cake.c +++ b/net/sched/sch_cake.c @@ -1508,20 +1508,6 @@ static unsigned int cake_drop(struct Qdi return idx + (tin << 16); }
-static void cake_wash_diffserv(struct sk_buff *skb) -{ - switch (skb->protocol) { - case htons(ETH_P_IP): - ipv4_change_dsfield(ip_hdr(skb), INET_ECN_MASK, 0); - break; - case htons(ETH_P_IPV6): - ipv6_change_dsfield(ipv6_hdr(skb), INET_ECN_MASK, 0); - break; - default: - break; - } -} - static u8 cake_handle_diffserv(struct sk_buff *skb, u16 wash) { int wlen = skb_network_offset(skb); @@ -1564,25 +1550,27 @@ static struct cake_tin_data *cake_select { struct cake_sched_data *q = qdisc_priv(sch); u32 tin; + u8 dscp; + + /* Tin selection: Default to diffserv-based selection, allow overriding + * using firewall marks or skb->priority. + */ + dscp = cake_handle_diffserv(skb, + q->rate_flags & CAKE_FLAG_WASH); + + if (q->tin_mode == CAKE_DIFFSERV_BESTEFFORT) + tin = 0;
- if (TC_H_MAJ(skb->priority) == sch->handle && - TC_H_MIN(skb->priority) > 0 && - TC_H_MIN(skb->priority) <= q->tin_cnt) { + else if (TC_H_MAJ(skb->priority) == sch->handle && + TC_H_MIN(skb->priority) > 0 && + TC_H_MIN(skb->priority) <= q->tin_cnt) tin = q->tin_order[TC_H_MIN(skb->priority) - 1];
- if (q->rate_flags & CAKE_FLAG_WASH) - cake_wash_diffserv(skb); - } else if (q->tin_mode != CAKE_DIFFSERV_BESTEFFORT) { - /* extract the Diffserv Precedence field, if it exists */ - /* and clear DSCP bits if washing */ - tin = q->tin_index[cake_handle_diffserv(skb, - q->rate_flags & CAKE_FLAG_WASH)]; + else { + tin = q->tin_index[dscp]; + if (unlikely(tin >= q->tin_cnt)) tin = 0; - } else { - tin = 0; - if (q->rate_flags & CAKE_FLAG_WASH) - cake_wash_diffserv(skb); }
return &q->tins[tin];