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Commit 2c485362 authored by Martin Devera's avatar Martin Devera Committed by Stephen Hemminger
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[NET]: Fix jiffies races in net/sched/sch_htb.c

parent 3c23a204
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net/sched/sch_htb.c
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......@@ -9,6 +9,8 @@
* Authors: Martin Devera, <devik@cdi.cz>
*
* Credits (in time order) for older HTB versions:
* Stef Coene <stef.coene@docum.org>
* HTB support at LARTC mailing list
* Ondrej Kraus, <krauso@barr.cz>
* found missing INIT_QDISC(htb)
* Vladimir Smelhaus, Aamer Akhter, Bert Hubert
......@@ -19,7 +21,7 @@
* created test case so that I was able to fix nasty bug
* and many others. thanks.
*
* $Id: sch_htb.c,v 1.17 2003/01/29 09:22:18 devik Exp devik $
* $Id: sch_htb.c,v 1.20 2003/06/18 19:55:49 devik Exp devik $
*/
#include <linux/config.h>
#include <linux/module.h>
......@@ -71,7 +73,7 @@
#define HTB_HYSTERESIS 1/* whether to use mode hysteresis for speedup */
#define HTB_QLOCK(S) spin_lock_bh(&(S)->dev->queue_lock)
#define HTB_QUNLOCK(S) spin_unlock_bh(&(S)->dev->queue_lock)
#define HTB_VER 0x3000a /* major must be matched with number suplied by TC as version */
#define HTB_VER 0x3000c /* major must be matched with number suplied by TC as version */
#if HTB_VER >> 16 != TC_HTB_PROTOVER
#error "Mismatched sch_htb.c and pkt_sch.h"
......@@ -217,6 +219,9 @@ struct htb_sched
/* time of nearest event per level (row) */
unsigned long near_ev_cache[TC_HTB_MAXDEPTH];
/* cached value of jiffies in dequeue */
unsigned long jiffies;
/* whether we hit non-work conserving class during this dequeue; we use */
int nwc_hit; /* this to disable mindelay complaint in dequeue */
......@@ -336,7 +341,7 @@ static void htb_next_rb_node(struct rb_node **n);
static void htb_debug_dump (struct htb_sched *q)
{
int i,p;
printk(KERN_DEBUG "htb*g j=%lu\n",jiffies);
printk(KERN_DEBUG "htb*g j=%lu lj=%lu\n",jiffies,q->jiffies);
/* rows */
for (i=TC_HTB_MAXDEPTH-1;i>=0;i--) {
printk(KERN_DEBUG "htb*r%d m=%x",i,q->row_mask[i]);
......@@ -419,8 +424,8 @@ static void htb_add_to_wait_tree (struct htb_sched *q,
if ((delay <= 0 || delay > cl->mbuffer) && net_ratelimit())
printk(KERN_ERR "HTB: suspicious delay in wait_tree d=%ld cl=%X h=%d\n",delay,cl->classid,debug_hint);
#endif
cl->pq_key = jiffies + PSCHED_US2JIFFIE(delay);
if (cl->pq_key == jiffies)
cl->pq_key = q->jiffies + PSCHED_US2JIFFIE(delay);
if (cl->pq_key == q->jiffies)
cl->pq_key++;
/* update the nearest event cache */
......@@ -587,7 +592,7 @@ htb_class_mode(struct htb_class *cl,long *diff)
long toks;
if ((toks = (cl->ctokens + *diff)) < (
#ifdef HTB_HYSTERESIS
#if HTB_HYSTERESIS
cl->cmode != HTB_CANT_SEND ? -cl->cbuffer :
#endif
0)) {
......@@ -595,7 +600,7 @@ htb_class_mode(struct htb_class *cl,long *diff)
return HTB_CANT_SEND;
}
if ((toks = (cl->tokens + *diff)) >= (
#ifdef HTB_HYSTERESIS
#if HTB_HYSTERESIS
cl->cmode == HTB_CAN_SEND ? -cl->buffer :
#endif
0))
......@@ -798,7 +803,7 @@ static void htb_charge_class(struct htb_sched *q,struct htb_class *cl,
cl->classid, diff,
(unsigned long long) q->now,
(unsigned long long) cl->t_c,
jiffies);
q->jiffies);
diff = 1000;
}
#endif
......@@ -841,6 +846,7 @@ static void htb_charge_class(struct htb_sched *q,struct htb_class *cl,
*
* Scans event queue for pending events and applies them. Returns jiffies to
* next pending event (0 for no event in pq).
* Note: Aplied are events whose have cl->pq_key <= jiffies.
*/
static long htb_do_events(struct htb_sched *q,int level)
{
......@@ -855,9 +861,9 @@ static long htb_do_events(struct htb_sched *q,int level)
while (p->rb_left) p = p->rb_left;
cl = rb_entry(p, struct htb_class, pq_node);
if (cl->pq_key - (jiffies+1) < 0x80000000) {
HTB_DBG(8,3,"htb_do_ev_ret delay=%ld\n",cl->pq_key - jiffies);
return cl->pq_key - jiffies;
if (cl->pq_key - (q->jiffies+1) < 0x80000000) {
HTB_DBG(8,3,"htb_do_ev_ret delay=%ld\n",cl->pq_key - q->jiffies);
return cl->pq_key - q->jiffies;
}
htb_safe_rb_erase(p,q->wait_pq+level);
diff = PSCHED_TDIFF_SAFE(q->now, cl->t_c, (u32)cl->mbuffer, 0);
......@@ -868,7 +874,7 @@ static long htb_do_events(struct htb_sched *q,int level)
cl->classid, diff,
(unsigned long long) q->now,
(unsigned long long) cl->t_c,
jiffies);
q->jiffies);
diff = 1000;
}
#endif
......@@ -975,7 +981,8 @@ static void htb_delay_by(struct Qdisc *sch,long delay)
printk(KERN_INFO "HTB delay %ld > 5sec\n", delay);
delay = 5*HZ;
}
mod_timer(&q->timer, jiffies + delay);
/* why don't use jiffies here ? because expires can be in past */
mod_timer(&q->timer, q->jiffies + delay);
sch->flags |= TCQ_F_THROTTLED;
sch->stats.overlimits++;
HTB_DBG(3,1,"htb_deq t_delay=%ld\n",delay);
......@@ -991,6 +998,7 @@ static struct sk_buff *htb_dequeue(struct Qdisc *sch)
int evs_used = 0;
#endif
q->jiffies = jiffies;
HTB_DBG(3,1,"htb_deq dircnt=%d qlen=%d\n",skb_queue_len(&q->direct_queue),
sch->q.qlen);
......@@ -1010,14 +1018,14 @@ static struct sk_buff *htb_dequeue(struct Qdisc *sch)
/* common case optimization - skip event handler quickly */
int m;
long delay;
if (jiffies - q->near_ev_cache[level] < 0x80000000 || 0) {
if (q->jiffies - q->near_ev_cache[level] < 0x80000000 || 0) {
delay = htb_do_events(q,level);
q->near_ev_cache[level] += delay ? delay : HZ;
q->near_ev_cache[level] = q->jiffies + (delay ? delay : HZ);
#ifdef HTB_DEBUG
evs_used++;
#endif
} else
delay = q->near_ev_cache[level] - jiffies;
delay = q->near_ev_cache[level] - q->jiffies;
if (delay && min_delay > delay)
min_delay = delay;
......@@ -1036,8 +1044,8 @@ static struct sk_buff *htb_dequeue(struct Qdisc *sch)
#ifdef HTB_DEBUG
if (!q->nwc_hit && min_delay >= 10*HZ && net_ratelimit()) {
if (min_delay == LONG_MAX) {
printk(KERN_ERR "HTB: dequeue bug (%d), report it please !\n",
evs_used);
printk(KERN_ERR "HTB: dequeue bug (%d,%lu,%lu), report it please !\n",
evs_used,q->jiffies,jiffies);
htb_debug_dump(q);
} else
printk(KERN_WARNING "HTB: mindelay=%ld, some class has "
......@@ -1046,7 +1054,7 @@ static struct sk_buff *htb_dequeue(struct Qdisc *sch)
#endif
htb_delay_by (sch,min_delay > 5*HZ ? 5*HZ : min_delay);
fin:
HTB_DBG(3,1,"htb_deq_end %s j=%lu skb=%p\n",sch->dev->name,jiffies,skb);
HTB_DBG(3,1,"htb_deq_end %s j=%lu skb=%p\n",sch->dev->name,q->jiffies,skb);
return skb;
}
......@@ -1409,7 +1417,7 @@ static int htb_change_class(struct Qdisc *sch, u32 classid,
parent = parentid == TC_H_ROOT ? NULL : htb_find (parentid,sch);
hopt = RTA_DATA(tb[TCA_HTB_PARMS-1]);
HTB_DBG(0,1,"htb_chg cl=%p, clid=%X, opt/prio=%d, rate=%u, buff=%d, quant=%d\n", cl,cl?cl->classid:0,(int)hopt->prio,hopt->rate.rate,hopt->buffer,hopt->quantum);
HTB_DBG(0,1,"htb_chg cl=%p(%X), clid=%X, parid=%X, opt/prio=%d, rate=%u, buff=%d, quant=%d\n", cl,cl?cl->classid:0,classid,parentid,(int)hopt->prio,hopt->rate.rate,hopt->buffer,hopt->quantum);
rtab = qdisc_get_rtab(&hopt->rate, tb[TCA_HTB_RTAB-1]);
ctab = qdisc_get_rtab(&hopt->ceil, tb[TCA_HTB_CTAB-1]);
if (!rtab || !ctab) goto failure;
......
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