machine-id-setup: sync before committing machine-id

sync() before committing a transient machine-id to disk.  This will
ensure that any filesystem changes made by first-boot units will have
been persisted before the first boot is marked as completed.
This commit is contained in:
Harald Seiler 2020-09-06 21:35:33 +02:00
parent 3023f2fead
commit c261a5d014
1 changed files with 13 additions and 1 deletions

View File

@ -202,10 +202,22 @@ finish:
int machine_id_commit(const char *root) {
_cleanup_close_ int fd = -1, initial_mntns_fd = -1;
const char *etc_machine_id;
const char *etc_machine_id, *sync_path;
sd_id128_t id;
int r;
/* Before doing anything, sync everything to ensure any changes by first-boot units are persisted.
*
* First, explicitly sync the file systems we care about and check if it worked. */
FOREACH_STRING(sync_path, "/etc/", "/var/") {
r = syncfs_path(AT_FDCWD, sync_path);
if (r < 0)
return log_error_errno(r, "Cannot sync %s: %m", sync_path);
}
/* Afterwards, sync() the rest too, but we can't check the return value for these. */
sync();
/* Replaces a tmpfs bind mount of /etc/machine-id by a proper file, atomically. For this, the umount is removed
* in a mount namespace, a new file is created at the right place. Afterwards the mount is also removed in the
* original mount namespace, thus revealing the file that was just created. */