141 lines
4.4 KiB
C
141 lines
4.4 KiB
C
/* SPDX-License-Identifier: LGPL-2.1+ */
|
|
|
|
#include <sys/mount.h>
|
|
|
|
#include "alloc-util.h"
|
|
#include "fs-util.h"
|
|
#include "mkdir.h"
|
|
#include "mount-util.h"
|
|
#include "stat-util.h"
|
|
#include "volatile-util.h"
|
|
#include "string-util.h"
|
|
#include "path-util.h"
|
|
|
|
static int make_volatile(const char *path) {
|
|
_cleanup_free_ char *old_usr = NULL;
|
|
int r;
|
|
|
|
r = path_is_mount_point(path, NULL, AT_SYMLINK_FOLLOW);
|
|
if (r < 0)
|
|
return log_error_errno(r, "Couldn't determine whether %s is a mount point: %m", path);
|
|
if (r == 0) {
|
|
log_error("%s is not a mount point.", path);
|
|
return -EINVAL;
|
|
}
|
|
|
|
r = path_is_temporary_fs(path);
|
|
if (r < 0)
|
|
return log_error_errno(r, "Couldn't determine whether %s is a temporary file system: %m", path);
|
|
if (r > 0) {
|
|
log_info("%s already is a temporary file system.", path);
|
|
return 0;
|
|
}
|
|
|
|
r = chase_symlinks("/usr", path, CHASE_PREFIX_ROOT, &old_usr);
|
|
if (r < 0)
|
|
return log_error_errno(r, "/usr not available in old root: %m");
|
|
|
|
r = mkdir_p("/run/systemd/volatile-sysroot", 0700);
|
|
if (r < 0)
|
|
return log_error_errno(r, "Couldn't generate volatile sysroot directory: %m");
|
|
|
|
r = mount_verbose(LOG_ERR, "tmpfs", "/run/systemd/volatile-sysroot", "tmpfs", MS_STRICTATIME, "mode=755");
|
|
if (r < 0)
|
|
goto finish_rmdir;
|
|
|
|
if (mkdir("/run/systemd/volatile-sysroot/usr", 0755) < 0) {
|
|
r = -errno;
|
|
goto finish_umount;
|
|
}
|
|
|
|
r = mount_verbose(LOG_ERR, old_usr, "/run/systemd/volatile-sysroot/usr", NULL, MS_BIND|MS_REC, NULL);
|
|
if (r < 0)
|
|
goto finish_umount;
|
|
|
|
r = bind_remount_recursive("/run/systemd/volatile-sysroot/usr", true, NULL);
|
|
if (r < 0)
|
|
goto finish_umount;
|
|
|
|
r = umount_recursive(path, 0);
|
|
if (r < 0) {
|
|
log_error_errno(r, "Failed to unmount %s: %m", path);
|
|
goto finish_umount;
|
|
}
|
|
|
|
if (mount(NULL, "/", NULL, MS_SLAVE|MS_REC, NULL) < 0)
|
|
log_warning_errno(errno, "Failed to remount %s MS_SLAVE|MS_REC: %m", path);
|
|
|
|
r = mount_verbose(LOG_ERR, "/run/systemd/volatile-sysroot", path, NULL, MS_MOVE, NULL);
|
|
|
|
finish_umount:
|
|
(void) umount_recursive("/run/systemd/volatile-sysroot", 0);
|
|
|
|
finish_rmdir:
|
|
(void) rmdir("/run/systemd/volatile-sysroot");
|
|
|
|
return r;
|
|
}
|
|
|
|
int main(int argc, char *argv[]) {
|
|
VolatileMode m = _VOLATILE_MODE_INVALID;
|
|
const char *path;
|
|
int r;
|
|
|
|
log_set_target(LOG_TARGET_AUTO);
|
|
log_parse_environment();
|
|
log_open();
|
|
|
|
if (argc > 3) {
|
|
log_error("Too many arguments. Expected directory and mode.");
|
|
r = -EINVAL;
|
|
goto finish;
|
|
}
|
|
|
|
r = query_volatile_mode(&m);
|
|
if (r < 0) {
|
|
log_error_errno(r, "Failed to determine volatile mode from kernel command line.");
|
|
goto finish;
|
|
}
|
|
if (r == 0 && argc >= 2) {
|
|
/* The kernel command line always wins. However if nothing was set there, the argument passed here wins instead. */
|
|
m = volatile_mode_from_string(argv[1]);
|
|
if (m < 0) {
|
|
log_error("Couldn't parse volatile mode: %s", argv[1]);
|
|
r = -EINVAL;
|
|
goto finish;
|
|
}
|
|
}
|
|
|
|
if (argc < 3)
|
|
path = "/sysroot";
|
|
else {
|
|
path = argv[2];
|
|
|
|
if (isempty(path)) {
|
|
log_error("Directory name cannot be empty.");
|
|
r = -EINVAL;
|
|
goto finish;
|
|
}
|
|
if (!path_is_absolute(path)) {
|
|
log_error("Directory must be specified as absolute path.");
|
|
r = -EINVAL;
|
|
goto finish;
|
|
}
|
|
if (path_equal(path, "/")) {
|
|
log_error("Directory cannot be the root directory.");
|
|
r = -EINVAL;
|
|
goto finish;
|
|
}
|
|
}
|
|
|
|
if (m != VOLATILE_YES) {
|
|
r = 0;
|
|
goto finish;
|
|
}
|
|
|
|
r = make_volatile(path);
|
|
|
|
finish:
|
|
return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
|
|
}
|