#include "efivars.h"
#include "fd-util.h"
#include "fileio.h"
+#include "fs-util.h"
#include "fstab-util.h"
#include "generator.h"
#include "gpt.h"
if (r < 0)
return log_error_errno(r, "Failed to determine block device of /usr file system: %m");
if (r == 0) {
- log_debug("Neither root nor /usr file system are on a (single) block device.");
- return 0;
+ _cleanup_free_ char *p = NULL;
+ mode_t m;
+
+ /* If the root mount has been replaced by some form of volatile file system (overlayfs), the
+ * original root block device node is symlinked in /run/systemd/volatile-root. Let's read that
+ * here. */
+ r = readlink_malloc("/run/systemd/volatile-root", &p);
+ if (r == -ENOENT) {
+ log_debug("Neither root nor /usr file system are on a (single) block device.");
+ return 0;
+ }
+ if (r < 0)
+ return log_error_errno(r, "Failed to read symlink /run/systemd/volatile-root: %m");
+
+ r = device_path_parse_major_minor(p, &m, &devno);
+ if (r < 0)
+ return log_error_errno(r, "Failed to parse major/minor device node: %m");
+ if (!S_ISBLK(m))
+ return log_error_errno(SYNTHETIC_ERRNO(ENOTBLK), "Volatile root device is of wrong type.");
}
}