Commit 2d8d40af authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller

pkt_sched: fq: do not hold qdisc lock while allocating memory

Resizing fq hash table allocates memory while holding qdisc spinlock,
with BH disabled.

This is definitely not good, as allocation might sleep.

We can drop the lock and get it when needed, we hold RTNL so no other
changes can happen at the same time.
Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Fixes: afe4fd06 ("pkt_sched: fq: Fair Queue packet scheduler")
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent d85ea93f
...@@ -601,6 +601,7 @@ static int fq_resize(struct Qdisc *sch, u32 log) ...@@ -601,6 +601,7 @@ static int fq_resize(struct Qdisc *sch, u32 log)
{ {
struct fq_sched_data *q = qdisc_priv(sch); struct fq_sched_data *q = qdisc_priv(sch);
struct rb_root *array; struct rb_root *array;
void *old_fq_root;
u32 idx; u32 idx;
if (q->fq_root && log == q->fq_trees_log) if (q->fq_root && log == q->fq_trees_log)
...@@ -615,13 +616,19 @@ static int fq_resize(struct Qdisc *sch, u32 log) ...@@ -615,13 +616,19 @@ static int fq_resize(struct Qdisc *sch, u32 log)
for (idx = 0; idx < (1U << log); idx++) for (idx = 0; idx < (1U << log); idx++)
array[idx] = RB_ROOT; array[idx] = RB_ROOT;
if (q->fq_root) { sch_tree_lock(sch);
fq_rehash(q, q->fq_root, q->fq_trees_log, array, log);
fq_free(q->fq_root); old_fq_root = q->fq_root;
} if (old_fq_root)
fq_rehash(q, old_fq_root, q->fq_trees_log, array, log);
q->fq_root = array; q->fq_root = array;
q->fq_trees_log = log; q->fq_trees_log = log;
sch_tree_unlock(sch);
fq_free(old_fq_root);
return 0; return 0;
} }
...@@ -697,9 +704,11 @@ static int fq_change(struct Qdisc *sch, struct nlattr *opt) ...@@ -697,9 +704,11 @@ static int fq_change(struct Qdisc *sch, struct nlattr *opt)
q->flow_refill_delay = usecs_to_jiffies(usecs_delay); q->flow_refill_delay = usecs_to_jiffies(usecs_delay);
} }
if (!err) if (!err) {
sch_tree_unlock(sch);
err = fq_resize(sch, fq_log); err = fq_resize(sch, fq_log);
sch_tree_lock(sch);
}
while (sch->q.qlen > sch->limit) { while (sch->q.qlen > sch->limit) {
struct sk_buff *skb = fq_dequeue(sch); struct sk_buff *skb = fq_dequeue(sch);
......
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