cleanup daemonization code

The daemonization init/ready functions have parameters that are never used,
require the caller to keep track of some pipefds that it has no interest in
and which might not be used in some scenarios. Cleanup both functions a bit.

The idea here is also that these two functions might be good points to
insert more systemd init code later (sd_notify()).

Also, statd had a private copy of the daemonization code for unknown
reasons...so make it use the generic version instead.

Signed-off-by: David H?rdeman <david@hardeman.nu>
Signed-off-by: Steve Dickson <steved@redhat.com>

1 files changed, 47 insertions, 45 deletions

diff --git a/support/nfs/mydaemon.c b/support/nfs/mydaemon.c
index e885d60..3391eff 100644
--- a/support/nfs/mydaemon.c
+++ b/support/nfs/mydaemon.c
@@ -46,56 +46,61 @@
 #include <errno.h>
 #include <unistd.h>
 #include <stdio.h>
+#include <stdbool.h>
 #include <stdlib.h>
 #include <string.h>
 #include <xlog.h>
 
+#include "nfslib.h"
+
+static int pipefds[2] = { -1, -1};
+
 /**
- * mydaemon - daemonize, but have parent wait to exit
- * @nochdir:	skip chdir()'ing the child to / after forking if true
- * @noclose:	skip closing stdin/stdout/stderr if true
- * @pipefds:	pointer to 2 element array of pipefds
+ * daemon_init - initial daemon setup
+ * @fg:		whether to run in the foreground
  *
  * This function is like daemon(), but with our own special sauce to delay
  * the exit of the parent until the child is set up properly. A pipe is created
  * between parent and child. The parent process will wait to exit until the
- * child dies or writes a '1' on the pipe signaling that it started
- * successfully.
+ * child dies or writes an int on the pipe signaling its status.
  */
 void
-mydaemon(int nochdir, int noclose, int *pipefds)
+daemon_init(bool fg)
 {
 	int pid, status, tempfd;
 
+	if (fg)
+		return;
+
 	if (pipe(pipefds) < 0) {
 		xlog_err("mydaemon: pipe() failed: errno %d (%s)\n",
 			 errno, strerror(errno));
-		exit(1);
+		exit(EXIT_FAILURE);
 	}
-	if ((pid = fork ()) < 0) {
+
+	pid = fork();
+	if (pid < 0) {
 		xlog_err("mydaemon: fork() failed: errno %d (%s)\n",
 			 errno, strerror(errno));
-		exit(1);
+		exit(EXIT_FAILURE);
 	}
 
-	if (pid != 0) {
-		/*
-		 * Parent. Wait for status from child.
-		 */
+	if (pid > 0) {
+		/* Parent */
 		close(pipefds[1]);
-		if (read(pipefds[0], &status, 1) != 1)
-			exit(1);
-		exit (0);
+		if (read(pipefds[0], &status, sizeof(status)) != sizeof(status))
+			exit(EXIT_FAILURE);
+		exit(status);
 	}
-	/* Child.	*/
+
+	/* Child */
 	close(pipefds[0]);
 	setsid ();
-	if (nochdir == 0) {
-		if (chdir ("/") == -1) {
-			xlog_err("mydaemon: chdir() failed: errno %d (%s)\n",
-				 errno, strerror(errno));
-			exit(1);
-		}
+
+	if (chdir ("/")) {
+		xlog_err("mydaemon: chdir() failed: errno %d (%s)\n",
+			 errno, strerror(errno));
+		exit(EXIT_FAILURE);
 	}
 
 	while (pipefds[1] <= 2) {
@@ -103,41 +108,38 @@ mydaemon(int nochdir, int noclose, int *pipefds)
 		if (pipefds[1] < 0) {
 			xlog_err("mydaemon: dup() failed: errno %d (%s)\n",
 				 errno, strerror(errno));
-			exit(1);
+			exit(EXIT_FAILURE);
 		}
 	}
 
-	if (noclose == 0) {
-		tempfd = open("/dev/null", O_RDWR);
-		if (tempfd >= 0) {
-			dup2(tempfd, 0);
-			dup2(tempfd, 1);
-			dup2(tempfd, 2);
-			close(tempfd);
-		} else {
-			xlog_err("mydaemon: can't open /dev/null: errno %d "
-				 "(%s)\n", errno, strerror(errno));
-			exit(1);
-		}
+	tempfd = open("/dev/null", O_RDWR);
+	if (tempfd < 0) {
+		xlog_err("mydaemon: can't open /dev/null: errno %d "
+			 "(%s)\n", errno, strerror(errno));
+		exit(EXIT_FAILURE);
 	}
 
-	return;
+	dup2(tempfd, 0);
+	dup2(tempfd, 1);
+	dup2(tempfd, 2);
+	dup2(pipefds[1], 3);
+	pipefds[1] = 3;
+	closeall(4);
 }
 
 /**
- * release_parent - tell the parent that it can exit now
- * @pipefds:	pipefd array that was previously passed to mydaemon()
+ * daemon_ready - tell interested parties that the daemon is ready
  *
- * This function tells the parent process of mydaemon() that it's now clear
- * to exit(0).
+ * This function tells e.g. the parent process that the daemon is up
+ * and running.
  */
 void
-release_parent(int *pipefds)
+daemon_ready(void)
 {
-	int status;
+	int status = 0;
 
 	if (pipefds[1] > 0) {
-		if (write(pipefds[1], &status, 1) != 1) {
+		if (write(pipefds[1], &status, sizeof(status)) != sizeof(status)) {
 			xlog_err("WARN: writing to parent pipe failed: errno "
 				 "%d (%s)\n", errno, strerror(errno));
 		}