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Message-ID: <20080804062813.GA4570@ff.dom.local>
Date: Mon, 4 Aug 2008 06:28:13 +0000
From: Jarek Poplawski <jarkao2@...il.com>
To: David Miller <davem@...emloft.net>
Cc: kaber@...sh.net, jussi.kivilinna@...et.fi, netdev@...r.kernel.org
Subject: [PATCH take 2] net_sched: Add qdisc __NET_XMIT_BYPASS flag
On Sun, Aug 03, 2008 at 06:25:24PM -0700, David Miller wrote:
> From: Jarek Poplawski <jarkao2@...il.com>
> Date: Fri, 1 Aug 2008 10:19:29 +0000
>
> > @@ -331,14 +331,14 @@ static inline unsigned int qdisc_pkt_len(struct sk_buff *skb)
> > return qdisc_skb_cb(skb)->pkt_len;
> > }
> >
> > -#ifdef CONFIG_NET_CLS_ACT
> > /* additional qdisc xmit flags */
> > enum net_xmit_qdisc_t {
> > - __NET_XMIT_STOLEN = NET_XMIT_MASK + 1,
> > + __NET_XMIT_STOLEN = NET_XMIT_MASK + 0x1,
> > + __NET_XMIT_BYPASS = NET_XMIT_MASK + 0x2,
> > };
> >
>
> NET_XMIT_MASK + 0x2 is (0xffff + 2) which is 0x10001 and this is very
> much not what you intended.
Thanks for spotting this!
>
> Please just explicitly spell out the bit mask values instead of trying
> to create some false relationship with the mask and these values.
>
> Next, these patches doesn't fix the while problem, in that htb and
> friends are still corrupting the enqueue return value so that TCP is
> going to do the wrong thing still.
These 2 patches aren't supposed to fix these problems:
- the __NET_XMIT_STOLEN patch fixes a problem when a qdiscs passed
upwards NET_XMIT_SUCCESS when eg. an skb was stolen by an action,
to prevent treating this as dropped; then the upper qdiscs couldn't
tell it's not the full NET_XMIT_SUCCESS and counted it as queued,
which was wrong. (BTW, I especially tried to do it with minimal
changes in htb_enqueue() to let you apply your htb patch without
much editing.)
- the __NET_XMIT_BYPASS actually doesn't fix any serious problem, but
lets to remove the mapping from dev_queue_xmit(), and BTW it passes
better information to upper qdiscs too.
Thanks,
Jarek P.
------------------> (take 2)
Subject: net_sched: Add qdisc __NET_XMIT_BYPASS flag
Patrick McHardy <kaber@...sh.net> noticed that it would be nice to
handle NET_XMIT_BYPASS by NET_XMIT_SUCCESS with an internal qdisc flag
__NET_XMIT_BYPASS and to remove the mapping from dev_queue_xmit().
David Miller <davem@...emloft.net> spotted a serious bug in the first
version of this patch.
Signed-off-by: Jarek Poplawski <jarkao2@...il.com>
---
(apply on top of [PATCH] net_sched: Add qdisc __NET_XMIT_STOLEN flag)
include/net/sch_generic.h | 8 ++++----
net/core/dev.c | 1 -
net/sched/sch_atm.c | 2 +-
net/sched/sch_cbq.c | 4 ++--
net/sched/sch_dsmark.c | 2 +-
net/sched/sch_hfsc.c | 4 ++--
net/sched/sch_htb.c | 6 +++---
net/sched/sch_netem.c | 2 +-
net/sched/sch_prio.c | 6 +++---
net/sched/sch_sfq.c | 6 +++---
10 files changed, 20 insertions(+), 21 deletions(-)
diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h
index f139009..b2a1e8f 100644
--- a/include/net/sch_generic.h
+++ b/include/net/sch_generic.h
@@ -331,14 +331,14 @@ static inline unsigned int qdisc_pkt_len(struct sk_buff *skb)
return qdisc_skb_cb(skb)->pkt_len;
}
-#ifdef CONFIG_NET_CLS_ACT
-/* additional qdisc xmit flags */
+/* additional qdisc xmit flags (NET_XMIT_MASK in linux/netdevice.h) */
enum net_xmit_qdisc_t {
- __NET_XMIT_STOLEN = NET_XMIT_MASK + 1,
+ __NET_XMIT_STOLEN = 0x0001FFFF,
+ __NET_XMIT_BYPASS = 0x0002FFFF,
};
+#ifdef CONFIG_NET_CLS_ACT
#define net_xmit_drop_count(e) ((e) & __NET_XMIT_STOLEN ? 0 : 1)
-
#else
#define net_xmit_drop_count(e) (1)
#endif
diff --git a/net/core/dev.c b/net/core/dev.c
index 69320a5..e670504 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -1805,7 +1805,6 @@ gso:
spin_unlock(root_lock);
- rc = rc == NET_XMIT_BYPASS ? NET_XMIT_SUCCESS : rc;
goto out;
}
diff --git a/net/sched/sch_atm.c b/net/sched/sch_atm.c
index 27dd773..43d3725 100644
--- a/net/sched/sch_atm.c
+++ b/net/sched/sch_atm.c
@@ -457,7 +457,7 @@ drop: __maybe_unused
return 0;
}
tasklet_schedule(&p->task);
- return NET_XMIT_BYPASS;
+ return NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
}
/*
diff --git a/net/sched/sch_cbq.c b/net/sched/sch_cbq.c
index 765ae56..4e261ce 100644
--- a/net/sched/sch_cbq.c
+++ b/net/sched/sch_cbq.c
@@ -230,7 +230,7 @@ cbq_classify(struct sk_buff *skb, struct Qdisc *sch, int *qerr)
(cl = cbq_class_lookup(q, prio)) != NULL)
return cl;
- *qerr = NET_XMIT_BYPASS;
+ *qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
for (;;) {
int result = 0;
defmap = head->defaults;
@@ -377,7 +377,7 @@ cbq_enqueue(struct sk_buff *skb, struct Qdisc *sch)
q->rx_class = cl;
#endif
if (cl == NULL) {
- if (ret == NET_XMIT_BYPASS)
+ if (ret & __NET_XMIT_BYPASS)
sch->qstats.drops++;
kfree_skb(skb);
return ret;
diff --git a/net/sched/sch_dsmark.c b/net/sched/sch_dsmark.c
index 7170275..edd1298 100644
--- a/net/sched/sch_dsmark.c
+++ b/net/sched/sch_dsmark.c
@@ -268,7 +268,7 @@ static int dsmark_enqueue(struct sk_buff *skb, struct Qdisc *sch)
drop:
kfree_skb(skb);
sch->qstats.drops++;
- return NET_XMIT_BYPASS;
+ return NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
}
static struct sk_buff *dsmark_dequeue(struct Qdisc *sch)
diff --git a/net/sched/sch_hfsc.c b/net/sched/sch_hfsc.c
index 5cf9ae7..c2b8d9c 100644
--- a/net/sched/sch_hfsc.c
+++ b/net/sched/sch_hfsc.c
@@ -1159,7 +1159,7 @@ hfsc_classify(struct sk_buff *skb, struct Qdisc *sch, int *qerr)
if (cl->level == 0)
return cl;
- *qerr = NET_XMIT_BYPASS;
+ *qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
tcf = q->root.filter_list;
while (tcf && (result = tc_classify(skb, tcf, &res)) >= 0) {
#ifdef CONFIG_NET_CLS_ACT
@@ -1578,7 +1578,7 @@ hfsc_enqueue(struct sk_buff *skb, struct Qdisc *sch)
cl = hfsc_classify(skb, sch, &err);
if (cl == NULL) {
- if (err == NET_XMIT_BYPASS)
+ if (err & __NET_XMIT_BYPASS)
sch->qstats.drops++;
kfree_skb(skb);
return err;
diff --git a/net/sched/sch_htb.c b/net/sched/sch_htb.c
index 538d79b..be35422 100644
--- a/net/sched/sch_htb.c
+++ b/net/sched/sch_htb.c
@@ -214,7 +214,7 @@ static struct htb_class *htb_classify(struct sk_buff *skb, struct Qdisc *sch,
if ((cl = htb_find(skb->priority, sch)) != NULL && cl->level == 0)
return cl;
- *qerr = NET_XMIT_BYPASS;
+ *qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
tcf = q->filter_list;
while (tcf && (result = tc_classify(skb, tcf, &res)) >= 0) {
#ifdef CONFIG_NET_CLS_ACT
@@ -567,7 +567,7 @@ static int htb_enqueue(struct sk_buff *skb, struct Qdisc *sch)
}
#ifdef CONFIG_NET_CLS_ACT
} else if (!cl) {
- if (ret == NET_XMIT_BYPASS)
+ if (ret & __NET_XMIT_BYPASS)
sch->qstats.drops++;
kfree_skb(skb);
return ret;
@@ -612,7 +612,7 @@ static int htb_requeue(struct sk_buff *skb, struct Qdisc *sch)
}
#ifdef CONFIG_NET_CLS_ACT
} else if (!cl) {
- if (ret == NET_XMIT_BYPASS)
+ if (ret & __NET_XMIT_BYPASS)
sch->qstats.drops++;
kfree_skb(skb);
return ret;
diff --git a/net/sched/sch_netem.c b/net/sched/sch_netem.c
index 6cd6f2b..fb0294d 100644
--- a/net/sched/sch_netem.c
+++ b/net/sched/sch_netem.c
@@ -176,7 +176,7 @@ static int netem_enqueue(struct sk_buff *skb, struct Qdisc *sch)
if (count == 0) {
sch->qstats.drops++;
kfree_skb(skb);
- return NET_XMIT_BYPASS;
+ return NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
}
skb_orphan(skb);
diff --git a/net/sched/sch_prio.c b/net/sched/sch_prio.c
index adb1a52..eac1976 100644
--- a/net/sched/sch_prio.c
+++ b/net/sched/sch_prio.c
@@ -38,7 +38,7 @@ prio_classify(struct sk_buff *skb, struct Qdisc *sch, int *qerr)
struct tcf_result res;
int err;
- *qerr = NET_XMIT_BYPASS;
+ *qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
if (TC_H_MAJ(skb->priority) != sch->handle) {
err = tc_classify(skb, q->filter_list, &res);
#ifdef CONFIG_NET_CLS_ACT
@@ -74,7 +74,7 @@ prio_enqueue(struct sk_buff *skb, struct Qdisc *sch)
#ifdef CONFIG_NET_CLS_ACT
if (qdisc == NULL) {
- if (ret == NET_XMIT_BYPASS)
+ if (ret & __NET_XMIT_BYPASS)
sch->qstats.drops++;
kfree_skb(skb);
return ret;
@@ -103,7 +103,7 @@ prio_requeue(struct sk_buff *skb, struct Qdisc* sch)
qdisc = prio_classify(skb, sch, &ret);
#ifdef CONFIG_NET_CLS_ACT
if (qdisc == NULL) {
- if (ret == NET_XMIT_BYPASS)
+ if (ret & __NET_XMIT_BYPASS)
sch->qstats.drops++;
kfree_skb(skb);
return ret;
diff --git a/net/sched/sch_sfq.c b/net/sched/sch_sfq.c
index 3a456e1..6e041d1 100644
--- a/net/sched/sch_sfq.c
+++ b/net/sched/sch_sfq.c
@@ -171,7 +171,7 @@ static unsigned int sfq_classify(struct sk_buff *skb, struct Qdisc *sch,
if (!q->filter_list)
return sfq_hash(q, skb) + 1;
- *qerr = NET_XMIT_BYPASS;
+ *qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
result = tc_classify(skb, q->filter_list, &res);
if (result >= 0) {
#ifdef CONFIG_NET_CLS_ACT
@@ -285,7 +285,7 @@ sfq_enqueue(struct sk_buff *skb, struct Qdisc *sch)
hash = sfq_classify(skb, sch, &ret);
if (hash == 0) {
- if (ret == NET_XMIT_BYPASS)
+ if (ret & __NET_XMIT_BYPASS)
sch->qstats.drops++;
kfree_skb(skb);
return ret;
@@ -339,7 +339,7 @@ sfq_requeue(struct sk_buff *skb, struct Qdisc *sch)
hash = sfq_classify(skb, sch, &ret);
if (hash == 0) {
- if (ret == NET_XMIT_BYPASS)
+ if (ret & __NET_XMIT_BYPASS)
sch->qstats.drops++;
kfree_skb(skb);
return ret;
--
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