[lxc-devel] [PATCH] daemonized start: exit children on failure, don't return

[Serge Hallyn]

When starting a daemonized container, only the original parent
thread should return to the caller.  The first forked child
immediately exits after forking, but the grandparent child
was in some places returning on error - causing a second instance
of the calling function.

Signed-off-by: Serge Hallyn <serge.hallyn at ubuntu.com>
---
 src/lxc/lxccontainer.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/src/lxc/lxccontainer.c b/src/lxc/lxccontainer.c
index 7708a8c..1c103e8 100644
--- a/src/lxc/lxccontainer.c
+++ b/src/lxc/lxccontainer.c
@@ -712,19 +712,19 @@ static bool do_lxcapi_start(struct lxc_container *c, int useinit, char * const a
 		pid = fork();
 		if (pid < 0) {
 			SYSERROR("Error doing dual-fork");
-			return false;
+			exit(1);
 		}
 		if (pid != 0)
 			exit(0);
 		/* like daemon(), chdir to / and redirect 0,1,2 to /dev/null */
 		if (chdir("/")) {
 			SYSERROR("Error chdir()ing to /.");
-			return false;
+			exit(1);
 		}
 		lxc_check_inherited(conf, true, -1);
 		if (null_stdfds() < 0) {
 			ERROR("failed to close fds");
-			return false;
+			exit(1);
 		}
 		setsid();
 	} else {
@@ -742,6 +742,8 @@ static bool do_lxcapi_start(struct lxc_container *c, int useinit, char * const a
 		if (pid_fp == NULL) {
 			SYSERROR("Failed to create pidfile '%s' for '%s'",
 				 c->pidfile, c->name);
+			if (daemonize)
+				exit(1);
 			return false;
 		}
 
@@ -749,6 +751,8 @@ static bool do_lxcapi_start(struct lxc_container *c, int useinit, char * const a
 			SYSERROR("Failed to write '%s'", c->pidfile);
 			fclose(pid_fp);
 			pid_fp = NULL;
+			if (daemonize)
+				exit(1);
 			return false;
 		}
 
-- 
2.1.4