[PATCH net 5/5] net/sched: sch_cake: annotate data-races in cake_dump_stats() (V)

[Eric Dumazet <edumazet@google.com>]

cake_dump_stats() runs without qdisc spinlock being held.

In this final patch, I add READ_ONCE()/WRITE_ONCE() annotations
for cparams.target and cparams.interval.

Fixes: 046f6fd5daef ("sched: Add Common Applications Kept Enhanced (cake) qdisc")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: "Toke Høiland-Jørgensen" <toke@toke.dk>
---
 net/sched/sch_cake.c | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/net/sched/sch_cake.c b/net/sched/sch_cake.c
index c3b09f67f0fdbc51d23b3d22df9ab89a716c7e2b..53d90062c32fcf647e4837416e335f4562ab97d9 100644
--- a/net/sched/sch_cake.c
+++ b/net/sched/sch_cake.c
@@ -2356,10 +2356,11 @@ static void cake_set_rate(struct cake_tin_data *b, u64 rate, u32 mtu,
 
 	byte_target_ns = (byte_target * rate_ns) >> rate_shft;
 
-	b->cparams.target = max((byte_target_ns * 3) / 2, target_ns);
-	b->cparams.interval = max(rtt_est_ns +
-				     b->cparams.target - target_ns,
-				     b->cparams.target * 2);
+	WRITE_ONCE(b->cparams.target,
+		   max((byte_target_ns * 3) / 2, target_ns));
+	WRITE_ONCE(b->cparams.interval,
+		   max(rtt_est_ns + b->cparams.target - target_ns,
+		       b->cparams.target * 2));
 	b->cparams.mtu_time = byte_target_ns;
 	b->cparams.p_inc = 1 << 24; /* 1/256 */
 	b->cparams.p_dec = 1 << 20; /* 1/4096 */
@@ -3042,9 +3043,9 @@ static int cake_dump_stats(struct Qdisc *sch, struct gnet_dump *d)
 		PUT_TSTAT_U32(BACKLOG_BYTES, READ_ONCE(b->tin_backlog));
 
 		PUT_TSTAT_U32(TARGET_US,
-			      ktime_to_us(ns_to_ktime(b->cparams.target)));
+			      ktime_to_us(ns_to_ktime(READ_ONCE(b->cparams.target))));
 		PUT_TSTAT_U32(INTERVAL_US,
-			      ktime_to_us(ns_to_ktime(b->cparams.interval)));
+			      ktime_to_us(ns_to_ktime(READ_ONCE(b->cparams.interval))));
 
 		PUT_TSTAT_U32(SENT_PACKETS, READ_ONCE(b->packets));
 		PUT_TSTAT_U32(DROPPED_PACKETS, READ_ONCE(b->tin_dropped));
-- 
2.54.0.rc2.544.gc7ae2d5bb8-goog