From: Eric Dumazet <edumazet@google.com>
Date: Wed, 6 Nov 2019 20:52:40 -0800
Subject: net_sched: gen_estimator: extend packet counter to 64bit
Patch-mainline: v5.5-rc1
Git-commit: 1c8dd9cb4697a425ecb9e9fb8a6c05955642e141
References: bsc#1154353

I forgot to change last_packets field in struct net_rate_estimator.

Without this fix, rate estimators would misbehave after more
than 2^32 packets have been sent.

Another solution would be to be careful and only use the
32 least significant bits of packets counters, but we have
a hole in net_rate_estimator structure and this looks
easier to read/maintain.

Fixes: d0083d98f685 ("net_sched: extend packet counter to 64bit")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 net/core/gen_estimator.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/net/core/gen_estimator.c
+++ b/net/core/gen_estimator.c
@@ -48,7 +48,7 @@ struct net_rate_estimator {
 	u8			intvl_log; /* period : (250ms << intvl_log) */
 
 	seqcount_t		seq;
-	u32			last_packets;
+	u64			last_packets;
 	u64			last_bytes;
 
 	u64			avpps;
@@ -83,7 +83,7 @@ static void est_timer(struct timer_list
 	brate = (b.bytes - est->last_bytes) << (10 - est->ewma_log - est->intvl_log);
 	brate -= (est->avbps >> est->ewma_log);
 
-	rate = (u64)(b.packets - est->last_packets) << (10 - est->ewma_log - est->intvl_log);
+	rate = (b.packets - est->last_packets) << (10 - est->ewma_log - est->intvl_log);
 	rate -= (est->avpps >> est->ewma_log);
 
 	write_seqcount_begin(&est->seq);