net_sched: Add qdisc __NET_XMIT_BYPASS flag

Patrick McHardy <kaber@trash.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@davemloft.net> spotted a serious bug in the first
version of this patch.

Signed-off-by: Jarek Poplawski <jarkao2@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

10 files changed, 19 insertions, 20 deletions

diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h
index f15b045a85e9..a7abfda3e447 100644
--- a/include/net/sch_generic.h
+++ b/include/net/sch_generic.h
@@ -343,14 +343,14 @@ 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 = 0x00010000,
+        __NET_XMIT_BYPASS = 0x00020000,
 };
 
+#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 fc6c9881eca8..01993ad74e76 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 27dd773481bc..43d37256c15e 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 765ae5659000..4e261ce62f48 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 7170275d9f99..edd1298f85f6 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 5cf9ae716118..c2b8d9cce3d2 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 538d79b489ae..be35422711a3 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 6cd6f2bc749e..fb0294d0b55e 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 adb1a52b77d3..eac197610edf 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 3a456e1b829a..6e041d10dbdb 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;