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* [PATCH v2 net] bonding: only set speed/duplex to unknown, if getting speed failed
@ 2026-02-03 14:11 Thomas Bogendoerfer
  2026-02-03 18:34 ` Jay Vosburgh
                   ` (3 more replies)
  0 siblings, 4 replies; 5+ messages in thread
From: Thomas Bogendoerfer @ 2026-02-03 14:11 UTC (permalink / raw)
  To: Jay Vosburgh, Andrew Lunn, David S. Miller, Eric Dumazet,
	Jakub Kicinski, Paolo Abeni, Weiping Pan, netdev, linux-kernel

bond_update_speed_duplex() first set speed/duplex to unknown and
then asks slave driver for current speed/duplex. Since getting
speed/duplex might take longer there is a race, where this false state
is visible by /proc/net/bonding. With commit 691b2bf14946 ("bonding:
 update port speed when getting bond speed") this race gets more visible,
if user space is calling ethtool on a regular base.

Fix this by only setting speed/duplex to unknown, if link speed is
really unknown/unusable.

Fixes: 98f41f694f46 ("bonding:update speed/duplex for NETDEV_CHANGE")
Signed-off-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
v2: corrected fixes tag
v1: https://lore.kernel.org/all/20260130111904.144024-1-tbogendoerfer@suse.de/

 drivers/net/bonding/bond_main.c | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index e7caf400a59c..4cdf89b21ca0 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -791,26 +791,29 @@ static int bond_update_speed_duplex(struct slave *slave)
 	struct ethtool_link_ksettings ecmd;
 	int res;
 
-	slave->speed = SPEED_UNKNOWN;
-	slave->duplex = DUPLEX_UNKNOWN;
-
 	res = __ethtool_get_link_ksettings(slave_dev, &ecmd);
 	if (res < 0)
-		return 1;
+		goto speed_duplex_unknown;
 	if (ecmd.base.speed == 0 || ecmd.base.speed == ((__u32)-1))
-		return 1;
+		goto speed_duplex_unknown;
 	switch (ecmd.base.duplex) {
 	case DUPLEX_FULL:
 	case DUPLEX_HALF:
 		break;
 	default:
-		return 1;
+		goto speed_duplex_unknown;
 	}
 
 	slave->speed = ecmd.base.speed;
 	slave->duplex = ecmd.base.duplex;
 
 	return 0;
+
+speed_duplex_unknown:
+	slave->speed = SPEED_UNKNOWN;
+	slave->duplex = DUPLEX_UNKNOWN;
+
+	return 1;
 }
 
 const char *bond_slave_link_status(s8 link)
-- 
2.43.0


^ permalink raw reply related	[flat|nested] 5+ messages in thread

end of thread, other threads:[~2026-02-05 21:00 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2026-02-03 14:11 [PATCH v2 net] bonding: only set speed/duplex to unknown, if getting speed failed Thomas Bogendoerfer
2026-02-03 18:34 ` Jay Vosburgh
2026-02-03 18:48 ` Nikolay Aleksandrov
2026-02-04  1:12 ` Hangbin Liu
2026-02-05 21:00 ` patchwork-bot+netdevbpf

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