svn commit: r206470 - head/sys/net
Bjoern A. Zeeb
bz at FreeBSD.org
Sun Apr 11 11:51:45 UTC 2010
Author: bz
Date: Sun Apr 11 11:51:44 2010
New Revision: 206470
URL: http://svn.freebsd.org/changeset/base/206470
Log:
In if_detach_internal() we cannot hold the af_data lock over the
dom_ifdetach() calls as they might sleep for callout_drain().
Do as we do in if_attachdomain1() [r121470] and handle
if_afdata_initialized earlier and call dom_ifdetach() unlocked.
Discussed with: rwatson
MFC after: 10 days
Modified:
head/sys/net/if.c
Modified: head/sys/net/if.c
==============================================================================
--- head/sys/net/if.c Sun Apr 11 11:49:24 2010 (r206469)
+++ head/sys/net/if.c Sun Apr 11 11:51:44 2010 (r206470)
@@ -897,14 +897,20 @@ if_detach_internal(struct ifnet *ifp, in
devctl_notify("IFNET", ifp->if_xname, "DETACH", NULL);
if_delgroups(ifp);
+ /*
+ * We cannot hold the lock over dom_ifdetach calls as they might
+ * sleep, for example trying to drain a callout, thus open up the
+ * theoretical race with re-attaching.
+ */
IF_AFDATA_LOCK(ifp);
- for (dp = domains; ifp->if_afdata_initialized > 0 && dp; dp = dp->dom_next) {
+ i = ifp->if_afdata_initialized;
+ ifp->if_afdata_initialized = 0;
+ IF_AFDATA_UNLOCK(ifp);
+ for (dp = domains; i > 0 && dp; dp = dp->dom_next) {
if (dp->dom_ifdetach && ifp->if_afdata[dp->dom_family])
(*dp->dom_ifdetach)(ifp,
ifp->if_afdata[dp->dom_family]);
}
- ifp->if_afdata_initialized = 0;
- IF_AFDATA_UNLOCK(ifp);
}
#ifdef VIMAGE
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