pkt_sched: Annotate uninitialized var in sfq_enqueue()
[safe/jmp/linux-2.6] / net / sched / sch_htb.c
index d14f020..5070643 100644 (file)
@@ -84,12 +84,12 @@ struct htb_class {
        unsigned int children;
        struct htb_class *parent;       /* parent class */
 
+       int prio;               /* these two are used only by leaves... */
+       int quantum;            /* but stored for parent-to-leaf return */
+
        union {
                struct htb_class_leaf {
                        struct Qdisc *q;
-                       int prio;
-                       int aprio;
-                       int quantum;
                        int deficit[TC_HTB_MAXDEPTH];
                        struct list_head drop_list;
                } leaf;
@@ -123,19 +123,8 @@ struct htb_class {
        psched_tdiff_t mbuffer; /* max wait time */
        long tokens, ctokens;   /* current number of tokens */
        psched_time_t t_c;      /* checkpoint time */
-
-       int prio;               /* For parent to leaf return possible here */
-       int quantum;            /* we do backup. Finally full replacement  */
-                               /* of un.leaf originals should be done. */
 };
 
-static inline long L2T(struct htb_class *cl, struct qdisc_rate_table *rate,
-                          int size)
-{
-       long result = qdisc_l2t(rate, size);
-       return result;
-}
-
 struct htb_sched {
        struct Qdisc_class_hash clhash;
        struct list_head drops[TC_HTB_NUMPRIO];/* active leaves (for drops) */
@@ -152,9 +141,6 @@ struct htb_sched {
        /* time of nearest event per level (row) */
        psched_time_t near_ev_cache[TC_HTB_MAXDEPTH];
 
-       /* whether we hit non-work conserving class during this dequeue; we use */
-       int nwc_hit;            /* this to disable mindelay complaint in dequeue */
-
        int defcls;             /* class where unclassified flows go to */
 
        /* filters for qdisc itself */
@@ -527,10 +513,10 @@ static inline void htb_activate(struct htb_sched *q, struct htb_class *cl)
        WARN_ON(cl->level || !cl->un.leaf.q || !cl->un.leaf.q->q.qlen);
 
        if (!cl->prio_activity) {
-               cl->prio_activity = 1 << (cl->un.leaf.aprio = cl->un.leaf.prio);
+               cl->prio_activity = 1 << cl->prio;
                htb_activate_prios(q, cl);
                list_add_tail(&cl->un.leaf.drop_list,
-                             q->drops + cl->un.leaf.aprio);
+                             q->drops + cl->prio);
        }
 }
 
@@ -551,7 +537,7 @@ static inline void htb_deactivate(struct htb_sched *q, struct htb_class *cl)
 
 static int htb_enqueue(struct sk_buff *skb, struct Qdisc *sch)
 {
-       int ret;
+       int uninitialized_var(ret);
        struct htb_sched *q = qdisc_priv(sch);
        struct htb_class *cl = htb_classify(skb, sch, &ret);
 
@@ -591,45 +577,30 @@ static int htb_enqueue(struct sk_buff *skb, struct Qdisc *sch)
        return NET_XMIT_SUCCESS;
 }
 
-/* TODO: requeuing packet charges it to policers again !! */
-static int htb_requeue(struct sk_buff *skb, struct Qdisc *sch)
+static inline void htb_accnt_tokens(struct htb_class *cl, int bytes, long diff)
 {
-       int ret;
-       struct htb_sched *q = qdisc_priv(sch);
-       struct htb_class *cl = htb_classify(skb, sch, &ret);
-       struct sk_buff *tskb;
+       long toks = diff + cl->tokens;
 
-       if (cl == HTB_DIRECT) {
-               /* enqueue to helper queue */
-               if (q->direct_queue.qlen < q->direct_qlen) {
-                       __skb_queue_head(&q->direct_queue, skb);
-               } else {
-                       __skb_queue_head(&q->direct_queue, skb);
-                       tskb = __skb_dequeue_tail(&q->direct_queue);
-                       kfree_skb(tskb);
-                       sch->qstats.drops++;
-                       return NET_XMIT_CN;
-               }
-#ifdef CONFIG_NET_CLS_ACT
-       } else if (!cl) {
-               if (ret & __NET_XMIT_BYPASS)
-                       sch->qstats.drops++;
-               kfree_skb(skb);
-               return ret;
-#endif
-       } else if ((ret = cl->un.leaf.q->ops->requeue(skb, cl->un.leaf.q)) !=
-                  NET_XMIT_SUCCESS) {
-               if (net_xmit_drop_count(ret)) {
-                       sch->qstats.drops++;
-                       cl->qstats.drops++;
-               }
-               return ret;
-       } else
-               htb_activate(q, cl);
+       if (toks > cl->buffer)
+               toks = cl->buffer;
+       toks -= (long) qdisc_l2t(cl->rate, bytes);
+       if (toks <= -cl->mbuffer)
+               toks = 1 - cl->mbuffer;
 
-       sch->q.qlen++;
-       sch->qstats.requeues++;
-       return NET_XMIT_SUCCESS;
+       cl->tokens = toks;
+}
+
+static inline void htb_accnt_ctokens(struct htb_class *cl, int bytes, long diff)
+{
+       long toks = diff + cl->ctokens;
+
+       if (toks > cl->cbuffer)
+               toks = cl->cbuffer;
+       toks -= (long) qdisc_l2t(cl->ceil, bytes);
+       if (toks <= -cl->mbuffer)
+               toks = 1 - cl->mbuffer;
+
+       cl->ctokens = toks;
 }
 
 /**
@@ -647,26 +618,20 @@ static void htb_charge_class(struct htb_sched *q, struct htb_class *cl,
                             int level, struct sk_buff *skb)
 {
        int bytes = qdisc_pkt_len(skb);
-       long toks, diff;
        enum htb_cmode old_mode;
-
-#define HTB_ACCNT(T,B,R) toks = diff + cl->T; \
-       if (toks > cl->B) toks = cl->B; \
-       toks -= L2T(cl, cl->R, bytes); \
-       if (toks <= -cl->mbuffer) toks = 1-cl->mbuffer; \
-       cl->T = toks
+       long diff;
 
        while (cl) {
                diff = psched_tdiff_bounded(q->now, cl->t_c, cl->mbuffer);
                if (cl->level >= level) {
                        if (cl->level == level)
                                cl->xstats.lends++;
-                       HTB_ACCNT(tokens, buffer, rate);
+                       htb_accnt_tokens(cl, bytes, diff);
                } else {
                        cl->xstats.borrows++;
                        cl->tokens += diff;     /* we moved t_c; update tokens */
                }
-               HTB_ACCNT(ctokens, cbuffer, ceil);
+               htb_accnt_ctokens(cl, bytes, diff);
                cl->t_c = q->now;
 
                old_mode = cl->cmode;
@@ -733,14 +698,14 @@ static struct rb_node *htb_id_find_next_upper(int prio, struct rb_node *n,
        while (n) {
                struct htb_class *cl =
                    rb_entry(n, struct htb_class, node[prio]);
-               if (id == cl->common.classid)
-                       return n;
 
                if (id > cl->common.classid) {
                        n = n->rb_right;
-               } else {
+               } else if (id < cl->common.classid) {
                        r = n;
                        n = n->rb_left;
+               } else {
+                       return n;
                }
        }
        return r;
@@ -761,7 +726,7 @@ static struct htb_class *htb_lookup_leaf(struct rb_root *tree, int prio,
                u32 *pid;
        } stk[TC_HTB_MAXDEPTH], *sp = stk;
 
-       WARN_ON(!tree->rb_node);
+       BUG_ON(!tree->rb_node);
        sp->root = tree->rb_node;
        sp->pptr = pptr;
        sp->pid = pid;
@@ -781,9 +746,10 @@ static struct htb_class *htb_lookup_leaf(struct rb_root *tree, int prio,
                                *sp->pptr = (*sp->pptr)->rb_left;
                        if (sp > stk) {
                                sp--;
-                               WARN_ON(!*sp->pptr);
-                               if (!*sp->pptr)
+                               if (!*sp->pptr) {
+                                       WARN_ON(1);
                                        return NULL;
+                               }
                                htb_next_rb_node(sp->pptr);
                        }
                } else {
@@ -814,8 +780,7 @@ static struct sk_buff *htb_dequeue_tree(struct htb_sched *q, int prio,
 
        do {
 next:
-               WARN_ON(!cl);
-               if (!cl)
+               if (unlikely(!cl))
                        return NULL;
 
                /* class can be empty - it is unlikely but can be true if leaf
@@ -849,7 +814,7 @@ next:
                               cl->common.classid);
                        cl->warned = 1;
                }
-               q->nwc_hit++;
+
                htb_next_rb_node((level ? cl->parent->un.inner.ptr : q->
                                  ptr[0]) + prio);
                cl = htb_lookup_leaf(q->row[level] + prio, prio,
@@ -861,7 +826,7 @@ next:
        if (likely(skb != NULL)) {
                cl->un.leaf.deficit[level] -= qdisc_pkt_len(skb);
                if (cl->un.leaf.deficit[level] < 0) {
-                       cl->un.leaf.deficit[level] += cl->un.leaf.quantum;
+                       cl->un.leaf.deficit[level] += cl->quantum;
                        htb_next_rb_node((level ? cl->parent->un.inner.ptr : q->
                                          ptr[0]) + prio);
                }
@@ -894,7 +859,7 @@ static struct sk_buff *htb_dequeue(struct Qdisc *sch)
        q->now = psched_get_time();
 
        next_event = q->now + 5 * PSCHED_TICKS_PER_SEC;
-       q->nwc_hit = 0;
+
        for (level = 0; level < TC_HTB_MAXDEPTH; level++) {
                /* common case optimization - skip event handler quickly */
                int m;
@@ -1095,8 +1060,8 @@ static int htb_dump_class(struct Qdisc *sch, unsigned long arg,
        opt.buffer = cl->buffer;
        opt.ceil = cl->ceil->rate;
        opt.cbuffer = cl->cbuffer;
-       opt.quantum = cl->un.leaf.quantum;
-       opt.prio = cl->un.leaf.prio;
+       opt.quantum = cl->quantum;
+       opt.prio = cl->prio;
        opt.level = cl->level;
        NLA_PUT(skb, TCA_HTB_PARMS, sizeof(opt), &opt);
 
@@ -1141,7 +1106,9 @@ static int htb_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
                    == NULL)
                        return -ENOBUFS;
                sch_tree_lock(sch);
-               if ((*old = xchg(&cl->un.leaf.q, new)) != NULL) {
+               *old = cl->un.leaf.q;
+               cl->un.leaf.q = new;
+               if (*old != NULL) {
                        qdisc_tree_decrease_qlen(*old, (*old)->q.qlen);
                        qdisc_reset(*old);
                }
@@ -1198,8 +1165,6 @@ static void htb_parent_to_leaf(struct htb_sched *q, struct htb_class *cl,
        memset(&parent->un.inner, 0, sizeof(parent->un.inner));
        INIT_LIST_HEAD(&parent->un.leaf.drop_list);
        parent->un.leaf.q = new_q ? new_q : &noop_qdisc;
-       parent->un.leaf.quantum = parent->quantum;
-       parent->un.leaf.prio = parent->prio;
        parent->tokens = parent->buffer;
        parent->ctokens = parent->cbuffer;
        parent->t_c = psched_get_time();
@@ -1371,9 +1336,14 @@ static int htb_change_class(struct Qdisc *sch, u32 classid,
                if ((cl = kzalloc(sizeof(*cl), GFP_KERNEL)) == NULL)
                        goto failure;
 
-               gen_new_estimator(&cl->bstats, &cl->rate_est,
-                                 qdisc_root_sleeping_lock(sch),
-                                 tca[TCA_RATE] ? : &est.nla);
+               err = gen_new_estimator(&cl->bstats, &cl->rate_est,
+                                       qdisc_root_sleeping_lock(sch),
+                                       tca[TCA_RATE] ? : &est.nla);
+               if (err) {
+                       kfree(cl);
+                       goto failure;
+               }
+
                cl->refcnt = 1;
                cl->children = 0;
                INIT_LIST_HEAD(&cl->un.leaf.drop_list);
@@ -1425,37 +1395,36 @@ static int htb_change_class(struct Qdisc *sch, u32 classid,
                if (parent)
                        parent->children++;
        } else {
-               if (tca[TCA_RATE])
-                       gen_replace_estimator(&cl->bstats, &cl->rate_est,
-                                             qdisc_root_sleeping_lock(sch),
-                                             tca[TCA_RATE]);
+               if (tca[TCA_RATE]) {
+                       err = gen_replace_estimator(&cl->bstats, &cl->rate_est,
+                                                   qdisc_root_sleeping_lock(sch),
+                                                   tca[TCA_RATE]);
+                       if (err)
+                               return err;
+               }
                sch_tree_lock(sch);
        }
 
        /* it used to be a nasty bug here, we have to check that node
           is really leaf before changing cl->un.leaf ! */
        if (!cl->level) {
-               cl->un.leaf.quantum = rtab->rate.rate / q->rate2quantum;
-               if (!hopt->quantum && cl->un.leaf.quantum < 1000) {
+               cl->quantum = rtab->rate.rate / q->rate2quantum;
+               if (!hopt->quantum && cl->quantum < 1000) {
                        printk(KERN_WARNING
                               "HTB: quantum of class %X is small. Consider r2q change.\n",
                               cl->common.classid);
-                       cl->un.leaf.quantum = 1000;
+                       cl->quantum = 1000;
                }
-               if (!hopt->quantum && cl->un.leaf.quantum > 200000) {
+               if (!hopt->quantum && cl->quantum > 200000) {
                        printk(KERN_WARNING
                               "HTB: quantum of class %X is big. Consider r2q change.\n",
                               cl->common.classid);
-                       cl->un.leaf.quantum = 200000;
+                       cl->quantum = 200000;
                }
                if (hopt->quantum)
-                       cl->un.leaf.quantum = hopt->quantum;
-               if ((cl->un.leaf.prio = hopt->prio) >= TC_HTB_NUMPRIO)
-                       cl->un.leaf.prio = TC_HTB_NUMPRIO - 1;
-
-               /* backup for htb_parent_to_leaf */
-               cl->quantum = cl->un.leaf.quantum;
-               cl->prio = cl->un.leaf.prio;
+                       cl->quantum = hopt->quantum;
+               if ((cl->prio = hopt->prio) >= TC_HTB_NUMPRIO)
+                       cl->prio = TC_HTB_NUMPRIO - 1;
        }
 
        cl->buffer = hopt->buffer;
@@ -1565,7 +1534,7 @@ static struct Qdisc_ops htb_qdisc_ops __read_mostly = {
        .priv_size      =       sizeof(struct htb_sched),
        .enqueue        =       htb_enqueue,
        .dequeue        =       htb_dequeue,
-       .requeue        =       htb_requeue,
+       .peek           =       qdisc_peek_dequeued,
        .drop           =       htb_drop,
        .init           =       htb_init,
        .reset          =       htb_reset,