From 308047dd99abd1689e79333cead1adbacef26bc7 Mon Sep 17 00:00:00 2001
From: Eric Dumazet <edumazet@google.com>
Date: Mon, 18 Oct 2021 17:34:01 -0700
Subject: [PATCH 048/158] net: sched: fix logic error in qdisc_run_begin()
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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>
Tested-by: Ido Schimmel <idosch@nvidia.com>
Acked-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Tested-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
include/net/sch_generic.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
Index: linux-5.15.19-rt29/include/net/sch_generic.h
===================================================================
@ linux-5.15.19-rt29/include/net/sch_generic.h:220 @ static inline bool qdisc_run_begin(struc
*/
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)