]> nv-tegra.nvidia Code Review - linux-2.6.git/blobdiff - net/sched/sch_atm.c
net_sched: factorize qdisc stats handling
[linux-2.6.git] / net / sched / sch_atm.c
index 8e5f70ba3a158b8744bf9396f515c76fd381e91c..943d733409d08316e7bbf81749047c066b63d9bb 100644 (file)
@@ -3,6 +3,7 @@
 /* Written 1998-2000 by Werner Almesberger, EPFL ICA */
 
 #include <linux/module.h>
+#include <linux/slab.h>
 #include <linux/init.h>
 #include <linux/string.h>
 #include <linux/errno.h>
@@ -49,9 +50,9 @@ struct atm_flow_data {
        struct socket           *sock;          /* for closing */
        u32                     classid;        /* x:y type ID */
        int                     ref;            /* reference count */
-       struct gnet_stats_basic bstats;
+       struct gnet_stats_basic_packed  bstats;
        struct gnet_stats_queue qstats;
-       struct atm_flow_data    *next;
+       struct list_head        list;
        struct atm_flow_data    *excess;        /* flow for excess traffic;
                                                   NULL to set CLP instead */
        int                     hdr_len;
@@ -60,34 +61,23 @@ struct atm_flow_data {
 
 struct atm_qdisc_data {
        struct atm_flow_data    link;           /* unclassified skbs go here */
-       struct atm_flow_data    *flows;         /* NB: "link" is also on this
+       struct list_head        flows;          /* NB: "link" is also on this
                                                   list */
-       struct tasklet_struct   task;           /* requeue tasklet */
+       struct tasklet_struct   task;           /* dequeue tasklet */
 };
 
 /* ------------------------- Class/flow operations ------------------------- */
 
-static int find_flow(struct atm_qdisc_data *qdisc, struct atm_flow_data *flow)
-{
-       struct atm_flow_data *walk;
-
-       pr_debug("find_flow(qdisc %p,flow %p)\n", qdisc, flow);
-       for (walk = qdisc->flows; walk; walk = walk->next)
-               if (walk == flow)
-                       return 1;
-       pr_debug("find_flow: not found\n");
-       return 0;
-}
-
 static inline struct atm_flow_data *lookup_flow(struct Qdisc *sch, u32 classid)
 {
        struct atm_qdisc_data *p = qdisc_priv(sch);
        struct atm_flow_data *flow;
 
-       for (flow = p->flows; flow; flow = flow->next)
+       list_for_each_entry(flow, &p->flows, list) {
                if (flow->classid == classid)
-                       break;
-       return flow;
+                       return flow;
+       }
+       return NULL;
 }
 
 static int atm_tc_graft(struct Qdisc *sch, unsigned long arg,
@@ -98,11 +88,12 @@ static int atm_tc_graft(struct Qdisc *sch, unsigned long arg,
 
        pr_debug("atm_tc_graft(sch %p,[qdisc %p],flow %p,new %p,old %p)\n",
                sch, p, flow, new, old);
-       if (!find_flow(p, flow))
+       if (list_empty(&flow->list))
                return -EINVAL;
        if (!new)
                new = &noop_qdisc;
-       *old = xchg(&flow->q, new);
+       *old = flow->q;
+       flow->q = new;
        if (*old)
                qdisc_reset(*old);
        return 0;
@@ -144,25 +135,17 @@ static void atm_tc_put(struct Qdisc *sch, unsigned long cl)
 {
        struct atm_qdisc_data *p = qdisc_priv(sch);
        struct atm_flow_data *flow = (struct atm_flow_data *)cl;
-       struct atm_flow_data **prev;
 
        pr_debug("atm_tc_put(sch %p,[qdisc %p],flow %p)\n", sch, p, flow);
        if (--flow->ref)
                return;
        pr_debug("atm_tc_put: destroying\n");
-       for (prev = &p->flows; *prev; prev = &(*prev)->next)
-               if (*prev == flow)
-                       break;
-       if (!*prev) {
-               printk(KERN_CRIT "atm_tc_put: class %p not found\n", flow);
-               return;
-       }
-       *prev = flow->next;
+       list_del_init(&flow->list);
        pr_debug("atm_tc_put: qdisc %p\n", flow->q);
        qdisc_destroy(flow->q);
        tcf_destroy_chain(&flow->filter_list);
        if (flow->sock) {
-               pr_debug("atm_tc_put: f_count %d\n",
+               pr_debug("atm_tc_put: f_count %ld\n",
                        file_count(flow->sock->file));
                flow->vcc->pop = flow->old_pop;
                sockfd_put(flow->sock);
@@ -259,7 +242,7 @@ static int atm_tc_change(struct Qdisc *sch, u32 classid, u32 parent,
        sock = sockfd_lookup(fd, &error);
        if (!sock)
                return error;   /* f_count++ */
-       pr_debug("atm_tc_change: f_count %d\n", file_count(sock->file));
+       pr_debug("atm_tc_change: f_count %ld\n", file_count(sock->file));
        if (sock->ops->family != PF_ATMSVC && sock->ops->family != PF_ATMPVC) {
                error = -EPROTOTYPE;
                goto err_out;
@@ -272,10 +255,6 @@ static int atm_tc_change(struct Qdisc *sch, u32 classid, u32 parent,
                        error = -EINVAL;
                        goto err_out;
                }
-               if (find_flow(p, flow)) {
-                       error = -EEXIST;
-                       goto err_out;
-               }
        } else {
                int i;
                unsigned long cl;
@@ -296,7 +275,7 @@ static int atm_tc_change(struct Qdisc *sch, u32 classid, u32 parent,
                goto err_out;
        }
        flow->filter_list = NULL;
-       flow->q = qdisc_create_dflt(sch->dev, &pfifo_qdisc_ops, classid);
+       flow->q = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops, classid);
        if (!flow->q)
                flow->q = &noop_qdisc;
        pr_debug("atm_tc_change: qdisc %p\n", flow->q);
@@ -310,8 +289,7 @@ static int atm_tc_change(struct Qdisc *sch, u32 classid, u32 parent,
        flow->classid = classid;
        flow->ref = 1;
        flow->excess = excess;
-       flow->next = p->link.next;
-       p->link.next = flow;
+       list_add(&flow->list, &p->link.list);
        flow->hdr_len = hdr_len;
        if (hdr)
                memcpy(flow->hdr, hdr, hdr_len);
@@ -332,7 +310,7 @@ static int atm_tc_delete(struct Qdisc *sch, unsigned long arg)
        struct atm_flow_data *flow = (struct atm_flow_data *)arg;
 
        pr_debug("atm_tc_delete(sch %p,[qdisc %p],flow %p)\n", sch, p, flow);
-       if (!find_flow(qdisc_priv(sch), flow))
+       if (list_empty(&flow->list))
                return -EINVAL;
        if (flow->filter_list || flow == &p->link)
                return -EBUSY;
@@ -358,12 +336,12 @@ static void atm_tc_walk(struct Qdisc *sch, struct qdisc_walker *walker)
        pr_debug("atm_tc_walk(sch %p,[qdisc %p],walker %p)\n", sch, p, walker);
        if (walker->stop)
                return;
-       for (flow = p->flows; flow; flow = flow->next) {
-               if (walker->count >= walker->skip)
-                       if (walker->fn(sch, (unsigned long)flow, walker) < 0) {
-                               walker->stop = 1;
-                               break;
-                       }
+       list_for_each_entry(flow, &p->flows, list) {
+               if (walker->count >= walker->skip &&
+                   walker->fn(sch, (unsigned long)flow, walker) < 0) {
+                       walker->stop = 1;
+                       break;
+               }
                walker->count++;
        }
 }
@@ -382,16 +360,17 @@ static struct tcf_proto **atm_tc_find_tcf(struct Qdisc *sch, unsigned long cl)
 static int atm_tc_enqueue(struct sk_buff *skb, struct Qdisc *sch)
 {
        struct atm_qdisc_data *p = qdisc_priv(sch);
-       struct atm_flow_data *flow = NULL;      /* @@@ */
+       struct atm_flow_data *flow;
        struct tcf_result res;
        int result;
        int ret = NET_XMIT_POLICED;
 
        pr_debug("atm_tc_enqueue(skb %p,sch %p,[qdisc %p])\n", skb, sch, p);
        result = TC_POLICE_OK;  /* be nice to gcc */
+       flow = NULL;
        if (TC_H_MAJ(skb->priority) != sch->handle ||
-           !(flow = (struct atm_flow_data *)atm_tc_get(sch, skb->priority)))
-               for (flow = p->flows; flow; flow = flow->next)
+           !(flow = (struct atm_flow_data *)atm_tc_get(sch, skb->priority))) {
+               list_for_each_entry(flow, &p->flows, list) {
                        if (flow->filter_list) {
                                result = tc_classify_compat(skb,
                                                            flow->filter_list,
@@ -401,8 +380,13 @@ static int atm_tc_enqueue(struct sk_buff *skb, struct Qdisc *sch)
                                flow = (struct atm_flow_data *)res.class;
                                if (!flow)
                                        flow = lookup_flow(sch, res.classid);
-                               break;
+                               goto done;
                        }
+               }
+               flow = NULL;
+       done:
+               ;               
+       }
        if (!flow)
                flow = &p->link;
        else {
@@ -414,7 +398,7 @@ static int atm_tc_enqueue(struct sk_buff *skb, struct Qdisc *sch)
                case TC_ACT_QUEUED:
                case TC_ACT_STOLEN:
                        kfree_skb(skb);
-                       return NET_XMIT_SUCCESS;
+                       return NET_XMIT_SUCCESS | __NET_XMIT_STOLEN;
                case TC_ACT_SHOT:
                        kfree_skb(skb);
                        goto drop;
@@ -428,18 +412,18 @@ static int atm_tc_enqueue(struct sk_buff *skb, struct Qdisc *sch)
 #endif
        }
 
-       ret = flow->q->enqueue(skb, flow->q);
-       if (ret != 0) {
+       ret = qdisc_enqueue(skb, flow->q);
+       if (ret != NET_XMIT_SUCCESS) {
 drop: __maybe_unused
-               sch->qstats.drops++;
-               if (flow)
-                       flow->qstats.drops++;
+               if (net_xmit_drop_count(ret)) {
+                       sch->qstats.drops++;
+                       if (flow)
+                               flow->qstats.drops++;
+               }
                return ret;
        }
-       sch->bstats.bytes += skb->len;
-       sch->bstats.packets++;
-       flow->bstats.bytes += skb->len;
-       flow->bstats.packets++;
+       qdisc_bstats_update(sch, skb);
+       bstats_update(&flow->bstats, skb);
        /*
         * Okay, this may seem weird. We pretend we've dropped the packet if
         * it goes via ATM. The reason for this is that the outer qdisc
@@ -451,10 +435,10 @@ drop: __maybe_unused
         */
        if (flow == &p->link) {
                sch->q.qlen++;
-               return 0;
+               return NET_XMIT_SUCCESS;
        }
        tasklet_schedule(&p->task);
-       return NET_XMIT_BYPASS;
+       return NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
 }
 
 /*
@@ -472,16 +456,21 @@ static void sch_atm_dequeue(unsigned long data)
        struct sk_buff *skb;
 
        pr_debug("sch_atm_dequeue(sch %p,[qdisc %p])\n", sch, p);
-       for (flow = p->link.next; flow; flow = flow->next)
+       list_for_each_entry(flow, &p->flows, list) {
+               if (flow == &p->link)
+                       continue;
                /*
                 * If traffic is properly shaped, this won't generate nasty
                 * little bursts. Otherwise, it may ... (but that's okay)
                 */
-               while ((skb = flow->q->dequeue(flow->q))) {
-                       if (!atm_may_send(flow->vcc, skb->truesize)) {
-                               (void)flow->q->ops->requeue(skb, flow->q);
+               while ((skb = flow->q->ops->peek(flow->q))) {
+                       if (!atm_may_send(flow->vcc, skb->truesize))
                                break;
-                       }
+
+                       skb = qdisc_dequeue_peeked(flow->q);
+                       if (unlikely(!skb))
+                               break;
+
                        pr_debug("atm_tc_dequeue: sending on class %p\n", flow);
                        /* remove any LL header somebody else has attached */
                        skb_pull(skb, skb_network_offset(skb));
@@ -504,6 +493,7 @@ static void sch_atm_dequeue(unsigned long data)
                        /* atm.atm_options are already set by atm_tc_enqueue */
                        flow->vcc->send(flow->vcc, skb);
                }
+       }
 }
 
 static struct sk_buff *atm_tc_dequeue(struct Qdisc *sch)
@@ -513,27 +503,19 @@ static struct sk_buff *atm_tc_dequeue(struct Qdisc *sch)
 
        pr_debug("atm_tc_dequeue(sch %p,[qdisc %p])\n", sch, p);
        tasklet_schedule(&p->task);
-       skb = p->link.q->dequeue(p->link.q);
+       skb = qdisc_dequeue_peeked(p->link.q);
        if (skb)
                sch->q.qlen--;
        return skb;
 }
 
-static int atm_tc_requeue(struct sk_buff *skb, struct Qdisc *sch)
+static struct sk_buff *atm_tc_peek(struct Qdisc *sch)
 {
        struct atm_qdisc_data *p = qdisc_priv(sch);
-       int ret;
 
-       pr_debug("atm_tc_requeue(skb %p,sch %p,[qdisc %p])\n", skb, sch, p);
-       ret = p->link.q->ops->requeue(skb, p->link.q);
-       if (!ret) {
-               sch->q.qlen++;
-               sch->qstats.requeues++;
-       } else {
-               sch->qstats.drops++;
-               p->link.qstats.drops++;
-       }
-       return ret;
+       pr_debug("atm_tc_peek(sch %p,[qdisc %p])\n", sch, p);
+
+       return p->link.q->ops->peek(p->link.q);
 }
 
 static unsigned int atm_tc_drop(struct Qdisc *sch)
@@ -543,9 +525,10 @@ static unsigned int atm_tc_drop(struct Qdisc *sch)
        unsigned int len;
 
        pr_debug("atm_tc_drop(sch %p,[qdisc %p])\n", sch, p);
-       for (flow = p->flows; flow; flow = flow->next)
+       list_for_each_entry(flow, &p->flows, list) {
                if (flow->q->ops->drop && (len = flow->q->ops->drop(flow->q)))
                        return len;
+       }
        return 0;
 }
 
@@ -554,8 +537,11 @@ static int atm_tc_init(struct Qdisc *sch, struct nlattr *opt)
        struct atm_qdisc_data *p = qdisc_priv(sch);
 
        pr_debug("atm_tc_init(sch %p,[qdisc %p],opt %p)\n", sch, p, opt);
-       p->flows = &p->link;
-       p->link.q = qdisc_create_dflt(sch->dev, &pfifo_qdisc_ops, sch->handle);
+       INIT_LIST_HEAD(&p->flows);
+       INIT_LIST_HEAD(&p->link.list);
+       list_add(&p->link.list, &p->flows);
+       p->link.q = qdisc_create_dflt(sch->dev_queue,
+                                     &pfifo_qdisc_ops, sch->handle);
        if (!p->link.q)
                p->link.q = &noop_qdisc;
        pr_debug("atm_tc_init: link (%p) qdisc %p\n", &p->link, p->link.q);
@@ -564,7 +550,6 @@ static int atm_tc_init(struct Qdisc *sch, struct nlattr *opt)
        p->link.sock = NULL;
        p->link.classid = sch->handle;
        p->link.ref = 1;
-       p->link.next = NULL;
        tasklet_init(&p->task, sch_atm_dequeue, (unsigned long)sch);
        return 0;
 }
@@ -575,7 +560,7 @@ static void atm_tc_reset(struct Qdisc *sch)
        struct atm_flow_data *flow;
 
        pr_debug("atm_tc_reset(sch %p,[qdisc %p])\n", sch, p);
-       for (flow = p->flows; flow; flow = flow->next)
+       list_for_each_entry(flow, &p->flows, list)
                qdisc_reset(flow->q);
        sch->q.qlen = 0;
 }
@@ -583,22 +568,17 @@ static void atm_tc_reset(struct Qdisc *sch)
 static void atm_tc_destroy(struct Qdisc *sch)
 {
        struct atm_qdisc_data *p = qdisc_priv(sch);
-       struct atm_flow_data *flow;
+       struct atm_flow_data *flow, *tmp;
 
        pr_debug("atm_tc_destroy(sch %p,[qdisc %p])\n", sch, p);
-       /* races ? */
-       while ((flow = p->flows)) {
+       list_for_each_entry(flow, &p->flows, list)
                tcf_destroy_chain(&flow->filter_list);
+
+       list_for_each_entry_safe(flow, tmp, &p->flows, list) {
                if (flow->ref > 1)
                        printk(KERN_ERR "atm_destroy: %p->ref = %d\n", flow,
                               flow->ref);
                atm_tc_put(sch, (unsigned long)flow);
-               if (p->flows == flow) {
-                       printk(KERN_ERR "atm_destroy: putting flow %p didn't "
-                              "kill it\n", flow);
-                       p->flows = flow->next;  /* brute force */
-                       break;
-               }
        }
        tasklet_kill(&p->task);
 }
@@ -612,7 +592,7 @@ static int atm_tc_dump_class(struct Qdisc *sch, unsigned long cl,
 
        pr_debug("atm_tc_dump_class(sch %p,[qdisc %p],flow %p,skb %p,tcm %p)\n",
                sch, p, flow, skb, tcm);
-       if (!find_flow(p, flow))
+       if (list_empty(&flow->list))
                return -EINVAL;
        tcm->tcm_handle = flow->classid;
        tcm->tcm_info = flow->q->handle;
@@ -688,7 +668,7 @@ static struct Qdisc_ops atm_qdisc_ops __read_mostly = {
        .priv_size      = sizeof(struct atm_qdisc_data),
        .enqueue        = atm_tc_enqueue,
        .dequeue        = atm_tc_dequeue,
-       .requeue        = atm_tc_requeue,
+       .peek           = atm_tc_peek,
        .drop           = atm_tc_drop,
        .init           = atm_tc_init,
        .reset          = atm_tc_reset,