units: add initrd-cryptsetup.target

For encrypted block devices that we need to unlock from the initramfs,
we currently rely on dracut shipping `cryptsetup.target`. This works,
but doesn't cover the case where the encrypted block device requires
networking (i.e. the `remote-cryptsetup.target` version). That target
however is traditionally dynamically enabled.

Instead, let's rework things here by adding a `initrd-cryptsetup.target`
specifically for initramfs encrypted block device setup. This plays the
role of both `cryptsetup.target` and `remote-cryptsetup.target` in the
initramfs.

Then, adapt `systemd-cryptsetup-generator` to hook all generated
services to this new unit when running from the initrd. This is
analogous to `systemd-fstab-generator` hooking all mounts to
`initrd-fs.target`, regardless of whether they're network-backed or not.

1 files changed, 10 insertions, 5 deletions

diff --git a/src/cryptsetup/cryptsetup-generator.c b/src/cryptsetup/cryptsetup-generator.c
index df589ec3e4..13e9f3aedd 100644
--- a/src/cryptsetup/cryptsetup-generator.c
+++ b/src/cryptsetup/cryptsetup-generator.c
@@ -455,10 +455,16 @@ static int create_disk(
                 }
         }
 
+        const char *target;
+        if (in_initrd())
+                target = "initrd-cryptsetup.target";
+        else if (netdev)
+                target = "remote-cryptsetup.target";
+        else
+                target = "cryptsetup.target";
+
         if (!nofail)
-                fprintf(f,
-                        "Before=%s\n",
-                        netdev ? "remote-cryptsetup.target" : "cryptsetup.target");
+                fprintf(f, "Before=%s\n", target);
 
         if (password && !keydev) {
                 r = print_dependencies(f, password);
@@ -521,8 +527,7 @@ static int create_disk(
                 return log_error_errno(r, "Failed to write unit file %s: %m", n);
 
         if (!noauto) {
-                r = generator_add_symlink(arg_dest,
-                                          netdev ? "remote-cryptsetup.target" : "cryptsetup.target",
+                r = generator_add_symlink(arg_dest, target,
                                           nofail ? "wants" : "requires", n);
                 if (r < 0)
                         return r;