repart: Restore early fstab/crypttab generation (#40473)

fstab/crypttab generation were moved to the late stage to support
'fixate-volume-key' option. This, however, broke the use-case when
fstab/crypttab are put to the generated partition/image.

Fixes #40444

man/repart.d.xml

@@ -884,7 +884,9 @@
         </para>
 
         <para>Note that this setting is only taken into account when <option>--generate-crypttab=</option>
-        is specified on the <command>systemd-repart</command> command line.</para>
+        is specified on the <command>systemd-repart</command> command line. As the crypttab with the expected
+        hashes can only be generated after LUKS volumes are formatted, the crypttab itself cannot be put to
+        the generated volume.</para>
 
         <xi:include href="version-info.xml" xpointer="v256"/></listitem>
       </varlistentry>

src/repart/repart.c

@@ -8501,7 +8501,7 @@ static bool need_crypttab(Context *context) {
         return false;
 }
 
-static int context_crypttab(Context *context) {
+static int context_crypttab(Context *context, bool late) {
         _cleanup_(unlink_and_freep) char *t = NULL;
         _cleanup_fclose_ FILE *f = NULL;
         _cleanup_free_ char *path = NULL;
@@ -8544,7 +8544,7 @@ static int context_crypttab(Context *context) {
                         strempty(p->encrypted_volume->options));
         }
 
-        r = flink_tmpfile(f, t, path, 0);
+        r = flink_tmpfile(f, t, path, late ? LINK_TMPFILE_REPLACE : 0);
         if (r < 0)
                 return log_error_errno(r, "Failed to link temporary file to %s: %m", path);
 
@@ -10755,6 +10755,14 @@ static int run(int argc, char *argv[]) {
         if (r < 0)
                 return r;
 
+        r = context_fstab(context);
+        if (r < 0)
+                return r;
+
+        r = context_crypttab(context, /* late= */ false);
+        if (r < 0)
+                return r;
+
         r = context_update_verity_size(context);
         if (r < 0)
                 return r;
@@ -10810,11 +10818,7 @@ static int run(int argc, char *argv[]) {
         if (r < 0)
                 return r;
 
-        r = context_fstab(context);
-        if (r < 0)
-                return r;
-
-        r = context_crypttab(context);
+        r = context_crypttab(context, /* late= */ true);
         if (r < 0)
                 return r;
 

test/units/TEST-58-REPART.sh

@@ -1997,6 +1997,68 @@ EOF
     losetup -d "$loop"
 }
 
+testcase_fstab_crypttab_in_repart() {
+    local defs imgs root volume
+
+    defs="$(mktemp --directory "/tmp/test-repart.defs.XXXXXXXXXX")"
+    imgs="$(mktemp --directory "/var/tmp/test-repart.imgs.XXXXXXXXXX")"
+    root="$(mktemp --directory "/var/test-repart.root.XXXXXXXXXX")"
+    # shellcheck disable=SC2064
+    trap "rm -rf '$defs' '$imgs' '$root'" RETURN
+    chmod 0755 "$defs"
+
+    echo "*** testcase for including fstab/crypttab into repart created volume ***"
+
+    volume="test-repart-fstab-crypttab-$RANDOM"
+
+    mkdir -p "$root/etc"
+    tee "$defs/root.conf" <<EOF
+[Partition]
+Type=linux-generic
+Format=ext4
+CopyFiles=/etc
+Encrypt=key-file
+EncryptedVolume=$volume
+MountPoint=/mnt/volume
+EOF
+
+    systemd-repart --pretty=yes \
+                   --definitions "$defs" \
+                   --empty=create \
+                   --size=100M \
+                   --seed="$seed" \
+                   --dry-run=no \
+                   --offline="$OFFLINE" \
+                   --generate-fstab="/etc/fstab" \
+                   --generate-crypttab="/etc/crypttab" \
+                   --root="$root" \
+                   "$imgs/fstabcrypttabrepart.img"
+
+    loop="$(losetup -P --show --find "$imgs/fstabcrypttabrepart.img")"
+    udevadm wait --timeout=60 --settle "${loop:?}p1"
+
+    touch "$imgs/empty-password"
+
+    mkdir -p "$imgs/mount"
+
+    systemd-cryptsetup attach "$volume" "${loop}p1" "$imgs/empty-password"
+
+    mount -t ext4 "/dev/mapper/$volume" "$imgs/mount"
+
+    echo "Testing /etc/fstab presence"
+    test -f "$imgs/mount/etc/fstab"
+    grep -q "/mnt/volume" "$imgs/mount/etc/fstab"
+
+    echo "Testing /etc/crypttab presence"
+    test -f "$imgs/mount/etc/crypttab"
+    grep -q "$volume" "$imgs/mount/etc/crypttab"
+
+    umount "$imgs/mount"
+    systemd-cryptsetup detach "$volume"
+
+    losetup -d "$loop"
+}
+
 OFFLINE="yes"
 run_testcases