#include <sys/mount.h>
#include "alloc-util.h"
+#include "blockdev-util.h"
+#include "escape.h"
#include "fs-util.h"
#include "main-func.h"
#include "mkdir.h"
#include "mount-util.h"
+#include "mountpoint-util.h"
#include "path-util.h"
#include "stat-util.h"
#include "string-util.h"
_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;
- }
+ assert(path);
- r = chase_symlinks("/usr", path, CHASE_PREFIX_ROOT, &old_usr);
+ r = chase_symlinks("/usr", path, CHASE_PREFIX_ROOT, &old_usr, NULL);
if (r < 0)
return log_error_errno(r, "/usr not available in old root: %m");
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");
+ r = mount_verbose(LOG_ERR, "tmpfs", "/run/systemd/volatile-sysroot", "tmpfs", MS_STRICTATIME, "mode=755" TMPFS_LIMITS_ROOTFS);
if (r < 0)
goto finish_rmdir;
if (mkdir("/run/systemd/volatile-sysroot/usr", 0755) < 0) {
- r = -errno;
+ r = log_error_errno(errno, "Failed to create /usr directory: %m");
goto finish_umount;
}
if (r < 0)
goto finish_umount;
- r = bind_remount_recursive("/run/systemd/volatile-sysroot/usr", true, NULL);
- if (r < 0)
+ r = bind_remount_recursive("/run/systemd/volatile-sysroot/usr", MS_RDONLY, MS_RDONLY, NULL);
+ if (r < 0) {
+ log_error_errno(r, "Failed to remount /usr read-only: %m");
goto finish_umount;
+ }
r = umount_recursive(path, 0);
if (r < 0) {
}
if (mount(NULL, "/", NULL, MS_SLAVE|MS_REC, NULL) < 0)
- log_warning_errno(errno, "Failed to remount %s MS_SLAVE|MS_REC: %m", path);
+ log_warning_errno(errno, "Failed to remount %s MS_SLAVE|MS_REC, ignoring: %m", path);
r = mount_verbose(LOG_ERR, "/run/systemd/volatile-sysroot", path, NULL, MS_MOVE, NULL);
return r;
}
+static int make_overlay(const char *path) {
+ _cleanup_free_ char *escaped_path = NULL;
+ bool tmpfs_mounted = false;
+ const char *options = NULL;
+ int r;
+
+ assert(path);
+
+ r = mkdir_p("/run/systemd/overlay-sysroot", 0700);
+ if (r < 0)
+ return log_error_errno(r, "Couldn't create overlay sysroot directory: %m");
+
+ r = mount_verbose(LOG_ERR, "tmpfs", "/run/systemd/overlay-sysroot", "tmpfs", MS_STRICTATIME, "mode=755" TMPFS_LIMITS_ROOTFS);
+ if (r < 0)
+ goto finish;
+
+ tmpfs_mounted = true;
+
+ if (mkdir("/run/systemd/overlay-sysroot/upper", 0755) < 0) {
+ r = log_error_errno(errno, "Failed to create /run/systemd/overlay-sysroot/upper: %m");
+ goto finish;
+ }
+
+ if (mkdir("/run/systemd/overlay-sysroot/work", 0755) < 0) {
+ r = log_error_errno(errno, "Failed to create /run/systemd/overlay-sysroot/work: %m");
+ goto finish;
+ }
+
+ escaped_path = shell_escape(path, ",:");
+ if (!escaped_path) {
+ r = log_oom();
+ goto finish;
+ }
+
+ options = strjoina("lowerdir=", escaped_path, ",upperdir=/run/systemd/overlay-sysroot/upper,workdir=/run/systemd/overlay-sysroot/work");
+ r = mount_verbose(LOG_ERR, "overlay", path, "overlay", 0, options);
+
+finish:
+ if (tmpfs_mounted)
+ (void) umount_verbose("/run/systemd/overlay-sysroot");
+
+ (void) rmdir("/run/systemd/overlay-sysroot");
+ return r;
+}
+
static int run(int argc, char *argv[]) {
VolatileMode m = _VOLATILE_MODE_INVALID;
const char *path;
+ dev_t devt;
int r;
- log_set_target(LOG_TARGET_AUTO);
- log_parse_environment();
- log_open();
+ log_setup_service();
- if (argc > 3) {
- log_error("Too many arguments. Expected directory and mode.");
- return -EINVAL;
- }
+ if (argc > 3)
+ return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+ "Too many arguments. Expected directory and mode.");
r = query_volatile_mode(&m);
if (r < 0)
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;
- }
+ if (m < 0)
+ return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Couldn't parse volatile mode: %s", argv[1]);
}
if (argc < 3)
else {
path = argv[2];
- if (isempty(path)) {
- log_error("Directory name cannot be empty.");
- return -EINVAL;
- }
- if (!path_is_absolute(path)) {
- log_error("Directory must be specified as absolute path.");
- return -EINVAL;
- }
- if (path_equal(path, "/")) {
- log_error("Directory cannot be the root directory.");
- return -EINVAL;
- }
+ if (isempty(path))
+ return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+ "Directory name cannot be empty.");
+ if (!path_is_absolute(path))
+ return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+ "Directory must be specified as absolute path.");
+ if (path_equal(path, "/"))
+ return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+ "Directory cannot be the root directory.");
}
- if (m != VOLATILE_YES)
+ if (!IN_SET(m, VOLATILE_YES, VOLATILE_OVERLAY))
return 0;
- return make_volatile(path);
+ 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)
+ return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "%s is not a mount point.", path);
+
+ 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;
+ }
+
+ /* We are about to replace the root directory with something else. Later code might want to know what we
+ * replaced here, hence let's save that information as a symlink we can later use. (This is particularly
+ * relevant for the overlayfs case where we'll fully obstruct the view onto the underlying device, hence
+ * querying the backing device node from the file system directly is no longer possible. */
+ r = get_block_device_harder(path, &devt);
+ if (r < 0)
+ return log_error_errno(r, "Failed to determine device major/minor of %s: %m", path);
+ else if (r > 0) {
+ _cleanup_free_ char *dn = NULL;
+
+ r = device_path_make_major_minor(S_IFBLK, devt, &dn);
+ if (r < 0)
+ return log_error_errno(r, "Failed to format device node path: %m");
+
+ if (symlink(dn, "/run/systemd/volatile-root") < 0)
+ log_warning_errno(errno, "Failed to create symlink /run/systemd/volatile-root: %m");
+ }
+
+ if (m == VOLATILE_YES)
+ return make_volatile(path);
+ else {
+ assert(m == VOLATILE_OVERLAY);
+ return make_overlay(path);
+ }
}
DEFINE_MAIN_FUNCTION(run);
projects / thirdparty / systemd.git / blobdiff