Date: Tue, 25 Sep 2012 22:10:14 +0000 (UTC) From: Ed Maste <emaste@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r240938 - head/sys/net Message-ID: <201209252210.q8PMAEx5003950@svn.freebsd.org>
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Author: emaste Date: Tue Sep 25 22:10:14 2012 New Revision: 240938 URL: http://svn.freebsd.org/changeset/base/240938 Log: Avoid INVARIANTS panic destroying an in-use tap(4) The requirement (implied by the KASSERT in tap_destroy) that the tap is closed isn't valid; destroy_dev will block in devdrn while other threads are in d_* functions. Note: if_tun had the same issue, addressed in SVN revisions r186391, r186483 and r186497. The use of the condvar there appears to be redundant with the functionality provided by destroy_dev. Sponsored by: ADARA Networks Reviewed by: dwhite MFC after: 2 weeks Modified: head/sys/net/if_tap.c head/sys/net/if_tapvar.h Modified: head/sys/net/if_tap.c ============================================================================== --- head/sys/net/if_tap.c Tue Sep 25 21:33:36 2012 (r240937) +++ head/sys/net/if_tap.c Tue Sep 25 22:10:14 2012 (r240938) @@ -213,14 +213,10 @@ tap_destroy(struct tap_softc *tp) { struct ifnet *ifp = tp->tap_ifp; - /* Unlocked read. */ - KASSERT(!(tp->tap_flags & TAP_OPEN), - ("%s flags is out of sync", ifp->if_xname)); - CURVNET_SET(ifp->if_vnet); + destroy_dev(tp->tap_dev); seldrain(&tp->tap_rsel); knlist_destroy(&tp->tap_rsel.si_note); - destroy_dev(tp->tap_dev); ether_ifdetach(ifp); if_free(ifp); Modified: head/sys/net/if_tapvar.h ============================================================================== --- head/sys/net/if_tapvar.h Tue Sep 25 21:33:36 2012 (r240937) +++ head/sys/net/if_tapvar.h Tue Sep 25 22:10:14 2012 (r240938) @@ -64,6 +64,7 @@ struct tap_softc { SLIST_ENTRY(tap_softc) tap_next; /* next device in chain */ struct cdev *tap_dev; struct mtx tap_mtx; /* per-softc mutex */ + struct cv tap_cv; /* protect ref'd dev destroy */ }; #endif /* !_NET_IF_TAPVAR_H_ */
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