xenstored: support running in minios stubdom

A previous versions of this patch has been sent to xen-devel. See
http://lists.xensource.com/archives/html/xen-devel/2009-03/msg01655.html

Signed-off-by: Diego Ongaro <diego.ongaro@citrix.com>
Signed-off-by: Alex Zeffertt <alex.zeffertt@eu.citrix.com>
Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Cc: Ian Jackson <ian.jackson@eu.citrix.com>
Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Committed-by: Ian Jackson <Ian.Jackson@eu.citrix.com>

1 files changed, 10 insertions, 78 deletions

diff --git a/tools/xenstore/xenstored_core.c b/tools/xenstore/xenstored_core.c
index 4b12cf27cc..a762db714f 100644
--- a/tools/xenstore/xenstored_core.c
+++ b/tools/xenstore/xenstored_core.c
@@ -224,7 +224,6 @@ static void reopen_log(void)
 	}
 }
 
-
 static bool write_messages(struct connection *conn)
 {
 	int ret;
@@ -327,7 +326,8 @@ static int initialize_set(fd_set *inset, fd_set *outset, int sock, int ro_sock,
 		set_fd(sock, inset, &max);
 	if (ro_sock != -1)
 		set_fd(ro_sock, inset, &max);
-	set_fd(reopen_log_pipe[0], inset, &max);
+	if (reopen_log_pipe[0] != -1)
+		set_fd(reopen_log_pipe[0], inset, &max);
 
 	if (xce_handle != NULL)
 		set_fd(xc_evtchn_fd(xce_handle), inset, &max);
@@ -1664,53 +1664,6 @@ static void corrupt(struct connection *conn, const char *fmt, ...)
 }
 
 
-static void write_pidfile(const char *pidfile)
-{
-	char buf[100];
-	int len;
-	int fd;
-
-	fd = open(pidfile, O_RDWR | O_CREAT, 0600);
-	if (fd == -1)
-		barf_perror("Opening pid file %s", pidfile);
-
-	/* We exit silently if daemon already running. */
-	if (lockf(fd, F_TLOCK, 0) == -1)
-		exit(0);
-
-	len = snprintf(buf, sizeof(buf), "%ld\n", (long)getpid());
-	if (write(fd, buf, len) != len)
-		barf_perror("Writing pid file %s", pidfile);
-}
-
-/* Stevens. */
-static void daemonize(void)
-{
-	pid_t pid;
-
-	/* Separate from our parent via fork, so init inherits us. */
-	if ((pid = fork()) < 0)
-		barf_perror("Failed to fork daemon");
-	if (pid != 0)
-		exit(0);
-
-	/* Session leader so ^C doesn't whack us. */
-	setsid();
-
-	/* Let session leader exit so child cannot regain CTTY */
-	if ((pid = fork()) < 0)
-		barf_perror("Failed to fork daemon");
-	if (pid != 0)
-		exit(0);
-
-	/* Move off any mount points we might be in. */
-	if (chdir("/") == -1)
-		barf_perror("Failed to chdir");
-
-	/* Discard our parent's old-fashioned umask prejudices. */
-	umask(0);
-}
-
 #ifdef NO_SOCKETS
 static void init_sockets(int **psock, int **pro_sock)
 {
@@ -1874,20 +1827,10 @@ int main(int argc, char *argv[])
 
 	reopen_log();
 
-	/* make sure xenstored directory exists */
-	if (mkdir(xs_daemon_rundir(), 0755)) {
-		if (errno != EEXIST) {
-			perror("error: mkdir daemon rundir");
-			exit(-1);
-		}
-	}
-
-	if (mkdir(xs_daemon_rootdir(), 0755)) {
-		if (errno != EEXIST) {
-			perror("error: mkdir daemon rootdir");
-			exit(-1);
-		}
-	}
+	/* make sure xenstored directories exist */
+	/* Errors ignored here, will be reported when we open files */
+	mkdir(xs_daemon_rundir(), 0755);
+	mkdir(xs_daemon_rootdir(), 0755);
 
 	if (dofork) {
 		openlog("xenstored", 0, LOG_DAEMON);
@@ -1904,10 +1847,7 @@ int main(int argc, char *argv[])
 	signal(SIGPIPE, SIG_IGN);
 
 	init_sockets(&sock, &ro_sock);
-
-	if (pipe(reopen_log_pipe)) {
-		barf_perror("pipe");
-	}
+	init_pipe(reopen_log_pipe);
 
 	/* Setup the database */
 	setup_structure();
@@ -1925,16 +1865,8 @@ int main(int argc, char *argv[])
 	}
 
 	/* redirect to /dev/null now we're ready to accept connections */
-	if (dofork) {
-		int devnull = open("/dev/null", O_RDWR);
-		if (devnull == -1)
-			barf_perror("Could not open /dev/null\n");
-		dup2(devnull, STDIN_FILENO);
-		dup2(devnull, STDOUT_FILENO);
-		dup2(devnull, STDERR_FILENO);
-		close(devnull);
-		xprintf = trace;
-	}
+	if (dofork)
+		finish_daemonize();
 
 	signal(SIGHUP, trigger_reopen_log);
 
@@ -1957,7 +1889,7 @@ int main(int argc, char *argv[])
 			barf_perror("Select failed");
 		}
 
-		if (FD_ISSET(reopen_log_pipe[0], &inset)) {
+		if (reopen_log_pipe[0] != -1 && FD_ISSET(reopen_log_pipe[0], &inset)) {
 			char c;
 			if (read(reopen_log_pipe[0], &c, 1) != 1)
 				barf_perror("read failed");