Re: IPv4/IPv6 sysctl unregistration deadlock
From: Eric W. Biederman <hidden>
Date: 2009-02-26 19:01:12
Stephen Hemminger [off-list ref] writes:
What about something like this: Subject: [PATCH] Avoid race between network down and sysfs
As far as solutions go. That looks like the easiest correct solution. So. Acked-by: "Eric W. Biederman" <redacted> Will -ERESTARTSYS trigger the in kernel restart logic in this case? There are a lot more cases to cover, and I don't I like it long term. Spinning waiting for rtnl_lock feels wrong. Plus it does not help with discovering the problem in new sysfs, sysctl, or proc files. It has the major advantage that we can fix things now.
quoted hunk ↗ jump to hunk
Signed-off-by: Stephen Hemminger <redacted>--- a/net/core/net-sysfs.c 2009-02-26 08:36:18.000000000 -0800 +++ b/net/core/net-sysfs.c 2009-02-26 08:37:51.000000000 -0800@@ -77,7 +77,9 @@ static ssize_t netdev_store(struct devic if (endp == buf) goto err; - rtnl_lock(); + if (!rtnl_trylock()) + return -ERESTARTSYS; + if (dev_isalive(net)) { if ((ret = (*set)(net, new)) == 0) ret = len;