mon: fix preforker exit behavior behavior

In 3c5706163b72245768958155d767abf561e6d96d we made exit() not actually
exit so that the leak checking would behave for a non-forking case.
That is only needed for the normal exit case; every other case expects
exit() to actually terminate and not continue execution.

Instead, make a signal_exit() method that signals the parent (if any)
and then lets you return.  exit() goes back to it's usual behavior,
fixing the many other calls in main().

Backport: cuttlefish
Signed-off-by: Sage Weil <sage@inktank.com>
Reviewed-by: Joao Eduardo Luis <joao.luis@inktank.com>
(cherry picked from commit 92d085f7fd6224ffe5b7651c1f83b093f964b5cd)

2 files changed, 7 insertions, 2 deletions

diff --git a/src/ceph_mon.cc b/src/ceph_mon.cc
index 5e820df90f2..a70db47b351 100644
--- a/src/ceph_mon.cc
+++ b/src/ceph_mon.cc
@@ -545,6 +545,7 @@ int main(int argc, const char **argv)
     dout(0) << "ceph-mon: gmon.out should be in " << s << dendl;
   }
 
-  return prefork.exit(0);
+  prefork.signal_exit(0);
+  return 0;
 }
 
diff --git a/src/common/Preforker.h b/src/common/Preforker.h
index bf76e189146..20e8b00be15 100644
--- a/src/common/Preforker.h
+++ b/src/common/Preforker.h
@@ -76,13 +76,17 @@ public:
     return r;
   }
 
-  int exit(int r) {
+  int signal_exit(int r) {
     if (forked) {
       // tell parent
       (void)::write(fd[1], &r, sizeof(r));
     }
     return r;
   }
+  void exit(int r) {
+    signal_exit(r);
+    exit(r);
+  }
 
   void daemonize() {
     assert(forked);