From 308047dd99abd1689e79333cead1adbacef26bc7 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Mon, 18 Oct 2021 17:34:01 -0700 Subject: [PATCH 048/158] net: sched: fix logic error in qdisc_run_begin() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Cc: Ahmed S. Darwish Tested-by: Ido Schimmel Acked-by: Sebastian Andrzej Siewior Tested-by: Toke Høiland-Jørgensen Signed-off-by: Jakub Kicinski Signed-off-by: Sebastian Andrzej Siewior --- 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.orig/include/net/sch_generic.h +++ linux-5.15.19-rt29/include/net/sch_generic.h @@ -217,7 +217,7 @@ 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)