Author: trasz Date: Mon Aug 3 16:35:18 2015 New Revision: 286237 URL: https://svnweb.freebsd.org/changeset/base/286237
Log: Fix panic that would happen on forcibly unmounting devfs (note that as it is now, devfs ignores MNT_FORCE anyway, so it needs to be modified to trigger the panic) with consumers still opened. Note that this still results in a leak of r/w/e counters. It seems to be harmless, though. If anyone knows a better way to approach this - please tell. Discussed with: kib@, mav@ MFC after: 1 month Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D3050 Modified: head/sys/geom/geom_dev.c Modified: head/sys/geom/geom_dev.c ============================================================================== --- head/sys/geom/geom_dev.c Mon Aug 3 16:30:47 2015 (r286236) +++ head/sys/geom/geom_dev.c Mon Aug 3 16:35:18 2015 (r286237) @@ -401,6 +401,20 @@ g_dev_close(struct cdev *dev, int flags, #else e = 0; #endif + + /* + * The vgonel(9) - caused by eg. forced unmount of devfs - calls + * VOP_CLOSE(9) on devfs vnode without any FREAD or FWRITE flags, + * which would result in zero deltas, which in turn would cause + * panic in g_access(9). + * + * Note that we cannot zero the counters (ie. do "r = cp->acr" + * etc) instead, because the consumer might be opened in another + * devfs instance. + */ + if (r + w + e == 0) + return (EINVAL); + sc = cp->private; mtx_lock(&sc->sc_mtx); sc->sc_open += r + w + e; _______________________________________________ svn-src-head@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
