From: Andre Noll <maan@tuebingen.mpg.de>
Date: Sat, 12 Aug 2017 19:32:28 +0000 (+0200)
Subject: server: Deplete close on fork list on exit.
X-Git-Tag: v0.6.2~4^2~20
X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=commitdiff_plain;h=659b46df9a49e0677fd7ff85a9842adac4abec84;ds=sidebyside

server: Deplete close on fork list on exit.

We empty the list in the command handler process by calling
close_listed_fds(), but the server process leaks the memory
allocated for the entries of the close on fork list.

This commit introduces deplete_close_on_fork_list() to empty the
list without closing any file descriptors. It is called from main()
to avoid the leak.

With the patch applied, valgrind --show-reachable=no no longer
complains about possibly lost blocks for the server process.
---

diff --git a/close_on_fork.c b/close_on_fork.c
index 7e0c8e64..28c5eabb 100644
--- a/close_on_fork.c
+++ b/close_on_fork.c
@@ -62,13 +62,7 @@ void del_close_on_fork_list(int fd)
 	}
 }
 
-/**
- * Close all fds in the list and destroy all list entries.
- *
- * This function calls close(3) for each fd in the close-on-fork list
- * and empties the list afterwards.
- */
-void close_listed_fds(void)
+static void deplete_cof_list(bool close_fds)
 {
 	struct close_on_fork *cof, *tmp;
 
@@ -76,8 +70,32 @@ void close_listed_fds(void)
 		return;
 	list_for_each_entry_safe(cof, tmp, &close_on_fork_list, node) {
 		PARA_DEBUG_LOG("closing fd %d\n", cof->fd);
-		close(cof->fd);
+		if (close_fds)
+			close(cof->fd);
 		list_del(&cof->node);
 		free(cof);
 	}
 }
+
+/**
+ * Close all fds in the list and destroy all list entries.
+ *
+ * This function calls close(3) for each fd in the close-on-fork list
+ * and empties the list afterwards.
+ *
+ * \sa \ref deplete_close_on_fork_list().
+ */
+void close_listed_fds(void)
+{
+	deplete_cof_list(true);
+}
+
+/**
+ * Remove all listed fds from the close on fork list.
+ *
+ * This is like \ref close_listed_fds() but does not close the fds.
+ */
+void deplete_close_on_fork_list(void)
+{
+	deplete_cof_list(false);
+}
diff --git a/close_on_fork.h b/close_on_fork.h
index 1bd0cd15..0dcc2b6c 100644
--- a/close_on_fork.h
+++ b/close_on_fork.h
@@ -2,3 +2,4 @@
 void del_close_on_fork_list(int fd);
 void add_close_on_fork_list(int fd);
 void close_listed_fds(void);
+void deplete_close_on_fork_list(void);
diff --git a/server.c b/server.c
index 690f7163..593d92c5 100644
--- a/server.c
+++ b/server.c
@@ -674,6 +674,7 @@ int main(int argc, char *argv[])
 		daemon_set_hooks(NULL, NULL); /* only one process remaining */
 		mutex_destroy(log_mutex);
 		shm_detach(mmd);
+		deplete_close_on_fork_list();
 		if (ret < 0)
 			PARA_EMERG_LOG("%s\n", para_strerror(-ret));
 	} else {