Add code to initialize rb tree nodes, and check for double deletion. This is not a real fix, but I can make it trap sometimes and may be a bandaid for: http://bugzilla.kernel.org/show_bug.cgi?id=6681 Signed-off-by: Stephen Hemminger <shemminger@xxxxxxxx> --- net/sched/sch_htb.c | 34 +++++++++++++++++++++++++++------- 1 files changed, 27 insertions(+), 7 deletions(-) diff --git a/net/sched/sch_htb.c b/net/sched/sch_htb.c index 7853c6f..3f3e9df 100644 --- a/net/sched/sch_htb.c +++ b/net/sched/sch_htb.c @@ -366,7 +366,7 @@ static void htb_add_to_wait_tree(struct * When we are past last key we return NULL. * Average complexity is 2 steps per call. */ -static void htb_next_rb_node(struct rb_node **n) +static inline void htb_next_rb_node(struct rb_node **n) { *n = rb_next(*n); } @@ -388,6 +388,18 @@ static inline void htb_add_class_to_row( } } +/* If this triggers, it is a bug in this code, but it need not be fatal */ +static void htb_safe_rb_erase(struct rb_node *rb, struct rb_root *root) +{ + if (RB_EMPTY_NODE(rb)) { + WARN_ON(1); + } else { + rb_erase(rb, root); + RB_CLEAR_NODE(rb); + } +} + + /** * htb_remove_class_from_row - removes class from its row * @@ -401,10 +413,12 @@ static inline void htb_remove_class_from while (mask) { int prio = ffz(~mask); + mask &= ~(1 << prio); if (q->ptr[cl->level][prio] == cl->node + prio) htb_next_rb_node(q->ptr[cl->level] + prio); - rb_erase(cl->node + prio, q->row[cl->level] + prio); + + htb_safe_rb_erase(cl->node + prio, q->row[cl->level] + prio); if (!q->row[cl->level][prio].rb_node) m |= 1 << prio; } @@ -472,7 +486,7 @@ static void htb_deactivate_prios(struct p->un.inner.ptr[prio] = NULL; } - rb_erase(cl->node + prio, p->un.inner.feed + prio); + htb_safe_rb_erase(cl->node + prio, p->un.inner.feed + prio); if (!p->un.inner.feed[prio].rb_node) mask |= 1 << prio; @@ -739,7 +753,7 @@ #define HTB_ACCNT(T,B,R) toks = diff + c htb_change_class_mode(q, cl, &diff); if (old_mode != cl->cmode) { if (old_mode != HTB_CAN_SEND) - rb_erase(&cl->pq_node, q->wait_pq + cl->level); + htb_safe_rb_erase(&cl->pq_node, q->wait_pq + cl->level); if (cl->cmode != HTB_CAN_SEND) htb_add_to_wait_tree(q, cl, diff); } @@ -782,7 +796,7 @@ static long htb_do_events(struct htb_sch if (time_after(cl->pq_key, q->jiffies)) { return cl->pq_key - q->jiffies; } - rb_erase(p, q->wait_pq + level); + htb_safe_rb_erase(p, q->wait_pq + level); diff = PSCHED_TDIFF_SAFE(q->now, cl->t_c, (u32) cl->mbuffer); htb_change_class_mode(q, cl, &diff); if (cl->cmode != HTB_CAN_SEND) @@ -1279,7 +1293,7 @@ static void htb_destroy_class(struct Qdi htb_deactivate(q, cl); if (cl->cmode != HTB_CAN_SEND) - rb_erase(&cl->pq_node, q->wait_pq + cl->level); + htb_safe_rb_erase(&cl->pq_node, q->wait_pq + cl->level); kfree(cl); } @@ -1370,6 +1384,8 @@ static int htb_change_class(struct Qdisc if (!cl) { /* new class */ struct Qdisc *new_q; + int prio; + /* check for valid classid */ if (!classid || TC_H_MAJ(classid ^ sch->handle) || htb_find(classid, sch)) @@ -1389,6 +1405,10 @@ static int htb_change_class(struct Qdisc INIT_HLIST_NODE(&cl->hlist); INIT_LIST_HEAD(&cl->children); INIT_LIST_HEAD(&cl->un.leaf.drop_list); + RB_CLEAR_NODE(&cl->pq_node); + + for (prio = 0; prio < TC_HTB_NUMPRIO; prio++) + RB_CLEAR_NODE(&cl->node[prio]); /* create leaf qdisc early because it uses kmalloc(GFP_KERNEL) so that can't be used inside of sch_tree_lock @@ -1404,7 +1424,7 @@ static int htb_change_class(struct Qdisc /* remove from evt list because of level change */ if (parent->cmode != HTB_CAN_SEND) { - rb_erase(&parent->pq_node, q->wait_pq); + htb_safe_rb_erase(&parent->pq_node, q->wait_pq); parent->cmode = HTB_CAN_SEND; } parent->level = (parent->parent ? parent->parent->level -- 1.4.0 _______________________________________________ LARTC mailing list LARTC@xxxxxxxxxxxxxxx http://mailman.ds9a.nl/cgi-bin/mailman/listinfo/lartc
