commit: 05738bfce120114037d4f02c67ec740813f94b89
Author: William Hubbs <w.d.hubbs <AT> gmail <DOT> com>
AuthorDate: Wed Apr 12 22:56:30 2017 +0000
Commit: William Hubbs <williamh <AT> gentoo <DOT> org>
CommitDate: Wed Apr 12 22:56:36 2017 +0000
URL: https://gitweb.gentoo.org/proj/openrc.git/commit/?id=05738bfc
init: add re-exec capability
This will allow the re-execution of the init process after upgrading
OpenRC.
man/openrc-shutdown.8 | 7 ++++++-
src/rc/openrc-init.c | 22 +++++++++++++++++++---
src/rc/openrc-shutdown.c | 14 ++++++++++++--
3 files changed, 37 insertions(+), 6 deletions(-)
diff --git a/man/openrc-shutdown.8 b/man/openrc-shutdown.8
index 98ec64a6..eae16ae8 100644
--- a/man/openrc-shutdown.8
+++ b/man/openrc-shutdown.8
@@ -19,11 +19,13 @@
.Op Fl H , -halt
.Op Fl k , -kexec
.Op Fl p , -poweroff
+.Op Fl R , -reexec
.Op Fl r , -reboot
.Sh DESCRIPTION
.Nm
is the utility that communicates with openrc-init(8) to bring down the
-system. The following options affect how the system is brought down:
+system or instruct openrc-init to re-execute itself. It supports the
+following options:
.Bl -tag -width "poweroff"
.It Fl H , -halt
Stop all services, kill all remaining processes and halt the system.
@@ -32,6 +34,9 @@ Stop all services, kill all processes and boot directly into
a new
kernel loaded via kexec(8).
.It Fl p , -poweroff
Stop all services, kill all processes and power off the system.
+.It Fl R , -reexec
+instruct openrc-init to re-exec itself. This should be used after an
+upgrade of OpenRC if you are using openrc-init as your init process.
.It Fl r , -reboot
Stop all services, kill all processes and reboot the system.
.El
diff --git a/src/rc/openrc-init.c b/src/rc/openrc-init.c
index fb3347a4..61052806 100644
--- a/src/rc/openrc-init.c
+++ b/src/rc/openrc-init.c
@@ -20,6 +20,7 @@
#include <errno.h>
#include <signal.h>
+#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
@@ -79,6 +80,12 @@ static void init(const char *default_runlevel)
waitpid(pid, NULL, 0);
}
+static void handle_reexec(char *my_name)
+{
+ execl(my_name, my_name, "reexec", NULL);
+ return;
+}
+
static void handle_shutdown(const char *runlevel, int cmd)
{
pid_t pid;
@@ -123,10 +130,11 @@ static void signal_handler(int sig)
int main(int argc, char **argv)
{
- char *default_runlevel = NULL;
+ char *default_runlevel;
char buf[2048];
int count;
FILE *fifo;
+ bool reexec = false;
struct sigaction sa;
if (getpid() != 1)
@@ -134,16 +142,22 @@ int main(int argc, char **argv)
if (argc > 1)
default_runlevel = argv[1];
+ else
+ default_runlevel = NULL;
+
+ if (default_runlevel && strcmp(default_runlevel, "reexec") == 0)
+ reexec = true;
printf("OpenRC init version %s starting\n", VERSION);
- init(default_runlevel);
+ if (! reexec)
+ init(default_runlevel);
memset(&sa, 0, sizeof(sa));
sa.sa_handler = signal_handler;
sigaction(SIGCHLD, &sa, NULL);
sigaction(SIGINT, &sa, NULL);
reboot(RB_DISABLE_CAD);
- if (mkfifo(RC_INIT_FIFO, 0600) == -1)
+ if (mkfifo(RC_INIT_FIFO, 0600) == -1 && errno != EEXIST)
perror("mkfifo");
for (;;) {
@@ -166,6 +180,8 @@ int main(int argc, char **argv)
handle_shutdown("shutdown", RB_POWER_OFF);
else if (strcmp(buf, "reboot") == 0)
handle_shutdown("reboot", RB_AUTOBOOT);
+ else if (strcmp(buf, "reexec") == 0)
+ handle_reexec(argv[0]);
}
return 0;
}
diff --git a/src/rc/openrc-shutdown.c b/src/rc/openrc-shutdown.c
index 978e8a68..8905d354 100644
--- a/src/rc/openrc-shutdown.c
+++ b/src/rc/openrc-shutdown.c
@@ -35,11 +35,12 @@
const char *applet = NULL;
const char *extraopts = NULL;
-const char *getoptstring = "kpr" getoptstring_COMMON;
+const char *getoptstring = "HkpRr" getoptstring_COMMON;
const struct option longopts[] = {
{ "halt", no_argument, NULL, 'H'},
{ "kexec", no_argument, NULL, 'k'},
{ "poweroff", no_argument, NULL, 'p'},
+ { "reexec", no_argument, NULL, 'R'},
{ "reboot", no_argument, NULL, 'r'},
longopts_COMMON
};
@@ -47,11 +48,13 @@ const char * const longopts_help[] = {
"halt the system",
"reboot the system using kexec",
"power off the system",
+ "re-execute init (use after upgrading)",
"reboot the system",
longopts_help_COMMON
};
const char *usagestring = NULL;
-const char *exclusive = "Select one of --halt, --kexec, --poweroff or
--reboot";
+const char *exclusive = "Select one of "
+"--halt, --kexec, --poweroff, --reexec or --reboot";
static void send_cmd(const char *cmd)
{
@@ -79,6 +82,7 @@ int main(int argc, char **argv)
bool do_kexec = false;
bool do_poweroff = false;
bool do_reboot = false;
+ bool do_reexec = false;
applet = basename_c(argv[0]);
if (geteuid() != 0)
@@ -99,6 +103,10 @@ if (geteuid() != 0)
do_poweroff = true;
cmd_count++;
break;
+ case 'R':
+ do_reexec = true;
+ cmd_count++;
+ break;
case 'r':
do_reboot = true;
cmd_count++;
@@ -118,5 +126,7 @@ if (geteuid() != 0)
send_cmd("poweroff");
else if (do_reboot)
send_cmd("reboot");
+ else if (do_reexec)
+ send_cmd("reexec");
return 0;
}
