diff mbox series

[net-next,1/2] net: sched: fix logic error in qdisc_run_begin()

Message ID 20211021162253.333616-2-eric.dumazet@gmail.com (mailing list archive)
State Superseded
Delegated to: Netdev Maintainers
Headers show
Series tcp: receive path optimizations | expand

Checks

Context Check Description
netdev/apply fail Patch does not apply to net-next
netdev/tree_selection success Clearly marked for net-next

Commit Message

Eric Dumazet Oct. 21, 2021, 4:22 p.m. UTC 
From: Eric Dumazet <edumazet@google.com>

For non TCQ_F_NOLOCK qdisc, qdisc_run_begin() tries to set
__QDISC_STATE_RUNNING and should return true if the bit was not set.

test_and_set_bit() returns old bit value, therefore we need to invert.

Fixes: 29cbcd858283 ("net: sched: Remove Qdisc::running sequence counter")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Ahmed S. Darwish <a.darwish@linutronix.de>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
 include/net/sch_generic.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Eric Dumazet Oct. 21, 2021, 4:24 p.m. UTC | #1 
On Thu, Oct 21, 2021 at 9:23 AM Eric Dumazet <eric.dumazet@gmail.com> wrote:
>
> From: Eric Dumazet <edumazet@google.com>
>
> For non TCQ_F_NOLOCK qdisc, qdisc_run_begin() tries to set
> __QDISC_STATE_RUNNING and should return true if the bit was not set.
>
> test_and_set_bit() returns old bit value, therefore we need to invert.
>
> Fixes: 29cbcd858283 ("net: sched: Remove Qdisc::running sequence counter")
> Signed-off-by: Eric Dumazet <edumazet@google.com>
> Cc: Ahmed S. Darwish <a.darwish@linutronix.de>
> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
> ---

Please disregard, I have accidentally resent this already merged patch.
diff mbox series

Patch

diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h
index baad2ab4d971cd3fdc8d59acdd72d39fa6230370..e0988c56dd8fd7aa3dff6bd971da3c81f1a20626 100644
--- a/include/net/sch_generic.h
+++ b/include/net/sch_generic.h
@@ -217,7 +217,7 @@  static inline bool qdisc_run_begin(struct Qdisc *qdisc)
 		 */
 		return spin_trylock(&qdisc->seqlock);
 	}
-	return test_and_set_bit(__QDISC_STATE_RUNNING, &qdisc->state);
+	return !test_and_set_bit(__QDISC_STATE_RUNNING, &qdisc->state);
 }
 
 static inline void qdisc_run_end(struct Qdisc *qdisc)