Add option for transient etc

ostreedev · Aug 7, 2023 · 5370cc8 · 5370cc8
1 parent c9a38df
commit 5370cc8
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Showing 2 changed files with 18 additions and 10 deletions.
diff --git a/man/ostree-prepare-root.xml b/man/ostree-prepare-root.xml
@@ -114,6 +114,13 @@ License along with this library. If not, see <https://www.gnu.org/licenses/>.
                 <listitem><para>A boolean value; the default is false.  If this is set to <literal>true</literal>, then the <literal>/sysroot</literal> mount point is mounted read-only.</para></listitem>
           </varlistentry>
         </variablelist>
+
+        <variablelist>
+            <varlistentry>
+                <term><varname>sysroot.etc</varname></term>
+                <listitem><para>A string value; the default is persitent.  If this is set to <literal>transient</literal>, then the <literal>/sysroot</literal> mount point is mounted transiently i.e. a non-persistent location.</para></listitem>
+          </varlistentry>
+        </variablelist>
     </refsect1>
 
 

diff --git a/src/switchroot/ostree-prepare-root.c b/src/switchroot/ostree-prepare-root.c
@@ -330,8 +330,10 @@ load_composefs_config (GError **error)
 static gboolean
 find_etc (const char **out_path, GError **error)
 {
+  struct stat stbuf;
+
   // Look for /etc
-  if (fstatat (AT_FDCWD, "etc") == 0)
+  if (!glnx_fstatat_allow_noent (AT_FDCWD, "etc", &stbuf, AT_SYMLINK_NOFOLLOW, error))
     {
       *out_path = "etc";
       return TRUE;
@@ -342,7 +344,7 @@ find_etc (const char **out_path, GError **error)
     }
 
   // Look for /usr/etc
-  if (fstatat (AT_FDCWD, "usr/etc") == 0)
+  if (!glnx_fstatat_allow_noent (AT_FDCWD, "usr/etc", &stbuf, AT_SYMLINK_NOFOLLOW, error))
     {
       *out_path = "usr/etc";
       return TRUE;
@@ -352,7 +354,7 @@ find_etc (const char **out_path, GError **error)
       return glnx_throw_errno_prefix (error, "failed to stat etc");
     }
   *out_path = NULL;
-  return TRUE;
+  return FALSE;
 }
 
 int
@@ -600,9 +602,9 @@ main (int argc, char *argv[])
 
   g_autofree char *etc_config = NULL;
   if (!ot_keyfile_get_value_with_default (config, SYSROOT_KEY, ETC_KEY, "persistent", &etc_config,
-                                          error))
+                                          &error))
     errx (EXIT_FAILURE, "failed to parse %s.%s: %s", SYSROOT_KEY, ETC_KEY, error->message);
-  bool etc_transient = FALSE;
+  bool etc_transient = false;
   if (g_str_equal (etc_config, "persistent"))
     etc_transient = false;
   else if (g_str_equal (etc_config, "transient"))
@@ -634,11 +636,10 @@ main (int argc, char *argv[])
           if (!find_etc (&etc_lower, &error))
             errx (EXIT_FAILURE, "Failed to find etc: %s", error->message);
 
-          if (etc_lower)
-            {
-              g_autofree char etc_ovl_options
-                = g_strdup_printf ("lowerdir=%s,upperdir=%s,workdir=%s", etc_lower, upper, work);
-              if (g_str_equal (""))
+          g_autofree char *etc_ovl_options
+              = g_strdup_printf ("lowerdir=%s,upperdir=%s,workdir=%s", etc_lower, upper, work);
+          if (mount ("overlay", TMP_SYSROOT "/etc", "overlay", MS_SILENT, etc_ovl_options) < 0)
+            err (EXIT_FAILURE, "failed to mount transient etc overlayfs");
         }
       else
         {