tmpfiles: add new 'e' action which cleans up a dir without creating it

I wanted to add a config line that would empty a directory
without creating it if doesn't exist. Existing actions don't allow
this.

v2: properly add 'e' to needs_glob() and takes_ownership()

2 files changed, 36 insertions, 42 deletions

diff --git a/man/tmpfiles.d.xml b/man/tmpfiles.d.xml
index cd6d7f626c..957475d2bd 100644
--- a/man/tmpfiles.d.xml
+++ b/man/tmpfiles.d.xml
@@ -168,6 +168,12 @@
           of the directory will be removed when <option>--remove</option> is used.
           </para></listitem>
         </varlistentry>
+
+        <varlistentry>
+          <term><varname>e</varname></term>
+          <listitem><para>Similar to <varname>d</varname>, but the directory will not be
+          created if it does not exist. Lines of this type accept shell-style globs in
+          place of normal path names.</para></listitem>
         </varlistentry>
 
         <varlistentry>
@@ -581,7 +587,7 @@
       unconditionally.</para>
 
       <para>The age field only applies to lines starting with
-      <varname>d</varname>, <varname>D</varname>,
+      <varname>d</varname>, <varname>D</varname>, <varname>e</varname>,
       <varname>v</varname>, <varname>q</varname>,
       <varname>Q</varname>, <varname>C</varname>, <varname>x</varname>
       and <varname>X</varname>. If omitted or set to
@@ -658,7 +664,21 @@ d /var/tmp 1777 root root 30d
       <programlisting># /usr/lib/tmpfiles.d/abrt.conf
 d /var/tmp/abrt 0755 abrt abrt -
 </programlisting>
+    </example>
+
+    <example>
+      <title>Apply clean up during boot and based on time</title>
+
+      <programlisting># /usr/lib/tmpfiles.d/dnf.conf
+r! /var/cache/dnf/*/*/download_lock.pid
+r! /var/cache/dnf/*/*/metadata_lock.pid
+r! /var/lib/dnf/rpmdb_lock.pid
+e  /var/chache/dnf/ - - - 30d
+</programlisting>
 
+     <para>The lock files will be removed during boot. Any files and directories in
+     <filename>/var/chache/dnf/</filename> will be removed after they have not been
+     accessed in 30 days.</para>
     </example>
   </refsect1>
 
diff --git a/src/tmpfiles/tmpfiles.c b/src/tmpfiles/tmpfiles.c
index d868cb5d31..2053d35a67 100644
--- a/src/tmpfiles/tmpfiles.c
+++ b/src/tmpfiles/tmpfiles.c
@@ -94,6 +94,7 @@ typedef enum ItemType {
 
         /* These ones take globs */
         WRITE_FILE = 'w',
+        EMPTY_DIRECTORY = 'e',
         SET_XATTR = 't',
         RECURSIVE_SET_XATTR = 'T',
         SET_ACL = 'a',
@@ -179,6 +180,7 @@ static bool needs_glob(ItemType t) {
                       IGNORE_DIRECTORY_PATH,
                       REMOVE_PATH,
                       RECURSIVE_REMOVE_PATH,
+                      EMPTY_DIRECTORY,
                       ADJUST_MODE,
                       RELABEL_PATH,
                       RECURSIVE_RELABEL_PATH,
@@ -195,6 +197,7 @@ static bool takes_ownership(ItemType t) {
                       CREATE_FILE,
                       TRUNCATE_FILE,
                       CREATE_DIRECTORY,
+                      EMPTY_DIRECTORY,
                       TRUNCATE_DIRECTORY,
                       CREATE_SUBVOLUME,
                       CREATE_SUBVOLUME_INHERIT_QUOTA,
@@ -1217,7 +1220,6 @@ static int create_item(Item *i) {
         case CREATE_SUBVOLUME:
         case CREATE_SUBVOLUME_INHERIT_QUOTA:
         case CREATE_SUBVOLUME_NEW_QUOTA:
-
                 RUN_WITH_UMASK(0000)
                         mkdir_parents_label(i->path, 0755);
 
@@ -1289,6 +1291,9 @@ static int create_item(Item *i) {
                                 log_debug("Quota for subvolume \"%s\" already in place, no change made.", i->path);
                 }
 
+                /* fall through */
+
+        case EMPTY_DIRECTORY:
                 r = path_set_perms(i, i->path);
                 if (q < 0)
                         return q;
@@ -1298,7 +1303,6 @@ static int create_item(Item *i) {
                 break;
 
         case CREATE_FIFO:
-
                 RUN_WITH_UMASK(0000) {
                         mac_selinux_create_file_prepare(i->path, S_IFIFO);
                         r = mkfifo(i->path, i->mode);
@@ -1535,47 +1539,20 @@ static int remove_item_instance(Item *i, const char *instance) {
 }
 
 static int remove_item(Item *i) {
-        int r = 0;
-
         assert(i);
 
         log_debug("Running remove action for entry %c %s", (char) i->type, i->path);
 
         switch (i->type) {
 
-        case CREATE_FILE:
-        case TRUNCATE_FILE:
-        case CREATE_DIRECTORY:
-        case CREATE_SUBVOLUME:
-        case CREATE_SUBVOLUME_INHERIT_QUOTA:
-        case CREATE_SUBVOLUME_NEW_QUOTA:
-        case CREATE_FIFO:
-        case CREATE_SYMLINK:
-        case CREATE_CHAR_DEVICE:
-        case CREATE_BLOCK_DEVICE:
-        case IGNORE_PATH:
-        case IGNORE_DIRECTORY_PATH:
-        case ADJUST_MODE:
-        case RELABEL_PATH:
-        case RECURSIVE_RELABEL_PATH:
-        case WRITE_FILE:
-        case COPY_FILES:
-        case SET_XATTR:
-        case RECURSIVE_SET_XATTR:
-        case SET_ACL:
-        case RECURSIVE_SET_ACL:
-        case SET_ATTRIBUTE:
-        case RECURSIVE_SET_ATTRIBUTE:
-                break;
-
         case REMOVE_PATH:
         case TRUNCATE_DIRECTORY:
         case RECURSIVE_REMOVE_PATH:
-                r = glob_item(i, remove_item_instance, false);
-                break;
-        }
+                return glob_item(i, remove_item_instance, false);
 
-        return r;
+        default:
+                return 0;
+        }
 }
 
 static int clean_item_instance(Item *i, const char* instance) {
@@ -1630,8 +1607,6 @@ static int clean_item_instance(Item *i, const char* instance) {
 }
 
 static int clean_item(Item *i) {
-        int r = 0;
-
         assert(i);
 
         log_debug("Running clean action for entry %c %s", (char) i->type, i->path);
@@ -1641,19 +1616,17 @@ static int clean_item(Item *i) {
         case CREATE_SUBVOLUME:
         case CREATE_SUBVOLUME_INHERIT_QUOTA:
         case CREATE_SUBVOLUME_NEW_QUOTA:
+        case EMPTY_DIRECTORY:
         case TRUNCATE_DIRECTORY:
         case IGNORE_PATH:
         case COPY_FILES:
                 clean_item_instance(i, i->path);
-                break;
+                return 0;
         case IGNORE_DIRECTORY_PATH:
-                r = glob_item(i, clean_item_instance, false);
-                break;
+                return glob_item(i, clean_item_instance, false);
         default:
-                break;
+                return 0;
         }
-
-        return r;
 }
 
 static int process_item_array(ItemArray *array);
@@ -1879,6 +1852,7 @@ static int parse_line(const char *fname, unsigned line, const char *buffer) {
         case CREATE_SUBVOLUME:
         case CREATE_SUBVOLUME_INHERIT_QUOTA:
         case CREATE_SUBVOLUME_NEW_QUOTA:
+        case EMPTY_DIRECTORY:
         case TRUNCATE_DIRECTORY:
         case CREATE_FIFO:
         case IGNORE_PATH: