This is a note to let you know that I've just added the patch titled
bonding: refine bond_fold_stats() wrap detection
to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
bonding-refine-bond_fold_stats-wrap-detection.patch
and it can be found in the queue-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From foo@baz Mon Mar 19 09:58:12 CET 2018
From: Eric Dumazet <edumazet@xxxxxxxxxx>
Date: Wed, 29 Mar 2017 10:45:44 -0700
Subject: bonding: refine bond_fold_stats() wrap detection
From: Eric Dumazet <edumazet@xxxxxxxxxx>
[ Upstream commit 142c6594acbcc32391af9c15f8cd65c6c177698f ]
Some device drivers reset their stats at down/up events, possibly
fooling bonding stats, since they operate with relative deltas.
It is nearly not possible to fix drivers, since some of them compute the
tx/rx counters based on per rx/tx queue stats, and the queues can be
reconfigured (ethtool -L) between the down/up sequence.
Lets avoid accumulating 'negative' values that render bonding stats
useless.
It is better to lose small deltas, assuming the bonding stats are
fetched at a reasonable frequency.
Fixes: 5f0c5f73e5ef ("bonding: make global bonding stats more reliable")
Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/net/bonding/bond_main.c | 11 ++++++++---
1 file changed, 8 insertions(+), 3 deletions(-)
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -3276,12 +3276,17 @@ static void bond_fold_stats(struct rtnl_
for (i = 0; i < sizeof(*_res) / sizeof(u64); i++) {
u64 nv = new[i];
u64 ov = old[i];
+ s64 delta = nv - ov;
/* detects if this particular field is 32bit only */
if (((nv | ov) >> 32) == 0)
- res[i] += (u32)nv - (u32)ov;
- else
- res[i] += nv - ov;
+ delta = (s64)(s32)((u32)nv - (u32)ov);
+
+ /* filter anomalies, some drivers reset their stats
+ * at down/up events.
+ */
+ if (delta > 0)
+ res[i] += delta;
}
}
Patches currently in stable-queue which might be from edumazet@xxxxxxxxxx are
queue-4.4/selinux-check-for-address-length-in-selinux_socket_bind.patch
queue-4.4/bonding-refine-bond_fold_stats-wrap-detection.patch