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/*
* Copyright (C) 2012 Red Hat, Inc. All rights reserved.
*
* This file is part of the device-mapper userspace tools.
*
* This copyrighted material is made available to anyone wishing to use,
* modify, copy, or redistribute it subject to the terms and conditions
* of the GNU General Public License v.2.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software Foundation,
* Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <stdio.h>
#include <unistd.h>
#include <errno.h>
#include <stdarg.h>
#include <syslog.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <limits.h> /* For PATH_MAX for musl libc */
#include "lvm2app.h"
#include "configure.h" /* for LVM_PATH */
#define KMSG_DEV_PATH "/dev/kmsg"
#define LVM_CONF_USE_LVMETAD "global/use_lvmetad"
#define UNIT_TARGET_LOCAL_FS "local-fs.target"
#define UNIT_TARGET_REMOTE_FS "remote-fs.target"
static char unit_path[PATH_MAX];
static char target_path[PATH_MAX];
static char message[PATH_MAX + 3]; /* +3 for '<n>' where n is the log level */
static int kmsg_fd = -1;
enum {
UNIT_EARLY,
UNIT_MAIN,
UNIT_NET
};
static const char *unit_names[] = {
[UNIT_EARLY] = "lvm2-activation-early.service",
[UNIT_MAIN] = "lvm2-activation.service",
[UNIT_NET] = "lvm2-activation-net.service"
};
__attribute__ ((format(printf, 2, 3)))
static void kmsg(int log_level, const char *format, ...)
{
va_list ap;
int n;
snprintf(message, 4, "<%d>", log_level);
va_start(ap, format);
n = vsnprintf(message + 3, PATH_MAX, format, ap);
va_end(ap);
if (kmsg_fd < 0 || (n < 0 || ((unsigned) n + 1 > PATH_MAX)))
return;
/* The n+4: +3 for "<n>" prefix and +1 for '\0' suffix */
(void) write(kmsg_fd, message, n + 4);
}
static int lvm_uses_lvmetad(void)
{
lvm_t lvm;
int r;
if (!(lvm = lvm_init(NULL))) {
kmsg(LOG_ERR, "LVM: Failed to initialize library context for activation generator.\n");
return 0;
}
r = lvm_config_find_bool(lvm, LVM_CONF_USE_LVMETAD, 0);
lvm_quit(lvm);
return r;
}
static int register_unit_with_target(const char *dir, const char *unit, const char *target)
{
int r = 1;
if (dm_snprintf(target_path, PATH_MAX, "%s/%s.wants", dir, target) < 0) {
r = 0; goto out;
}
(void) dm_prepare_selinux_context(target_path, S_IFDIR);
if (mkdir(target_path, 0755) < 0 && errno != EEXIST) {
kmsg(LOG_ERR, "LVM: Failed to create target directory %s: %m.\n", target_path);
r = 0; goto out;
}
if (dm_snprintf(target_path, PATH_MAX, "%s/%s.wants/%s", dir, target, unit) < 0) {
r = 0; goto out;
}
(void) dm_prepare_selinux_context(target_path, S_IFLNK);
if (symlink(unit_path, target_path) < 0) {
kmsg(LOG_ERR, "LVM: Failed to create symlink for unit %s: %m.\n", unit);
r = 0;
}
out:
dm_prepare_selinux_context(NULL, 0);
return r;
}
static int generate_unit(const char *dir, int unit)
{
FILE *f;
const char *unit_name = unit_names[unit];
const char *target_name = unit == UNIT_NET ? UNIT_TARGET_REMOTE_FS : UNIT_TARGET_LOCAL_FS;
if (dm_snprintf(unit_path, PATH_MAX, "%s/%s", dir, unit_name) < 0)
return 0;
if (!(f = fopen(unit_path, "wxe"))) {
kmsg(LOG_ERR, "LVM: Failed to create unit file %s: %m.\n", unit_name);
return 0;
}
fputs("# Automatically generated by lvm2-activation-generator.\n"
"#\n"
"# This unit is responsible for direct activation of LVM2 logical volumes\n"
"# if lvmetad daemon is not used (global/use_lvmetad=0 lvm.conf setting),\n"
"# hence volume autoactivation is not applicable.\n"
"# Direct LVM2 activation requires udev to be settled!\n\n"
"[Unit]\n"
"Description=Activation of LVM2 logical volumes\n"
"Documentation=man:lvm2-activation-generator(8)\n"
"SourcePath=/etc/lvm/lvm.conf\n"
"DefaultDependencies=no\n", f);
if (unit == UNIT_NET) {
fprintf(f, "After=%s iscsi.service fcoe.service\n"
"Before=remote-fs.target shutdown.target\n\n"
"[Service]\n"
"ExecStartPre=/usr/bin/udevadm settle\n", unit_names[UNIT_MAIN]);
} else {
if (unit == UNIT_EARLY) {
fputs("After=systemd-udev-settle.service\n"
"Before=cryptsetup.target\n", f);
} else
fprintf(f, "After= %s cryptsetup.target\n", unit_names[UNIT_EARLY]);
fputs("Before=local-fs.target shutdown.target\n"
"Wants=systemd-udev-settle.service\n\n"
"[Service]\n", f);
}
fputs("ExecStart=" LVM_PATH " vgchange -aay --sysinit --ignoreskippedcluster\n"
"Type=oneshot\n", f);
if (fclose(f) < 0) {
kmsg(LOG_ERR, "LVM: Failed to write unit file %s: %m.\n", unit_name);
return 0;
}
if (!register_unit_with_target(dir, unit_name, target_name)) {
kmsg(LOG_ERR, "LVM: Failed to register unit %s with target %s.\n", unit_name, target_name);
return 0;
}
return 1;
}
int main(int argc, char *argv[])
{
const char *dir;
int r = EXIT_SUCCESS;
mode_t old_mask;
kmsg_fd = open(KMSG_DEV_PATH, O_WRONLY|O_NOCTTY);
if (argc != 4) {
kmsg(LOG_ERR, "LVM: Incorrect number of arguments for activation generator.\n");
r = EXIT_FAILURE; goto out;
}
/* If lvmetad used, rely on autoactivation instead of direct activation. */
if (lvm_uses_lvmetad())
goto out;
dir = argv[1];
/* mark lvm2-activation.*.service as world-accessible */
old_mask = umask(0022);
if (!generate_unit(dir, UNIT_EARLY) ||
!generate_unit(dir, UNIT_MAIN) ||
!generate_unit(dir, UNIT_NET))
r = EXIT_FAILURE;
umask(old_mask);
out:
if (r)
kmsg(LOG_ERR, "LVM: Activation generator failed.\n");
if (kmsg_fd != -1)
(void) close(kmsg_fd);
return r;
}
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