Author: trasz
Date: Sun Oct 18 14:34:13 2015
New Revision: 289511
URL: https://svnweb.freebsd.org/changeset/base/289511
Log:
MFC r286237:
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.
Sponsored by: The FreeBSD Foundation
Modified:
stable/10/sys/geom/geom_dev.c
Directory Properties:
stable/10/ (props changed)
Modified: stable/10/sys/geom/geom_dev.c
==============================================================================
--- stable/10/sys/geom/geom_dev.c Sun Oct 18 14:31:54 2015
(r289510)
+++ stable/10/sys/geom/geom_dev.c Sun Oct 18 14:34:13 2015
(r289511)
@@ -399,6 +399,20 @@ 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-stable-10@freebsd.org mailing list
https://lists.freebsd.org/mailman/listinfo/svn-src-stable-10
To unsubscribe, send any mail to "svn-src-stable-10-unsubscr...@freebsd.org"
