libcgroup: cgroup_delete_cgroup_ext was made namespace aware

When namespace is used, a group can have different parents for different
controllers. cgroup_delete_cgroup_ext should reflect that.

Signed-off-by: Jan Safranek <jsafrane@redhat.com>

diff --git a/src/api.c b/src/api.c
index 5987afc3b98836b7c71b34f3d2efe6552db38206..d3aaa45f42e7cebd1507ad982b19ba5e67f27840 100644 (file)
--- a/src/api.c
+++ b/src/api.c
@@ -1689,35 +1689,32 @@ static int cgroup_get_parent_name(struct cgroup *cgroup, char **parent)
 }
 
 /**
- * Find the parent of the specified directory. It returns the parent (the
- * parent is usually name/.. unless name is a mount point.  It is assumed
- * both the cgroup (and, therefore, parent) already exist, and will fail
- * otherwise.
+ * Find the parent of the specified directory. It returns the parent in
+ * hierarchy of given controller (the parent is usually name/.. unless name is
+ * a mount point.  It is assumed both the cgroup (and, therefore, parent)
+ * already exist, and will fail otherwise.
+ *
+ * When namespaces are used, a group can have different parents for different
+ * controllers.
  *
  * @param cgroup The cgroup
+ * @param controller The controller
  * @param parent Output, name of parent's group (if the group has parent) or
  *     NULL, if the provided cgroup is the root group and has no parent.
  *     Caller is responsible to free the returned string!
  * @return 0 on success, >0 on error.
  */
-static int cgroup_find_parent(struct cgroup *cgroup, char **parent)
+static int cgroup_find_parent(struct cgroup *cgroup, char *controller,
+               char **parent)
 {
        char child_path[FILENAME_MAX];
        char *parent_path = NULL;
        struct stat stat_child, stat_parent;
-       char *controller = NULL;
        int ret = 0;
 
        *parent = NULL;
 
-       /* if cgroup has no controllers attached, consider it unconfigured */
-       if (cgroup->controller[0] == NULL) {
-               cgroup_dbg("cgroup_find_parent called on unconfigured group\n");
-               return ECGFAIL;
-       }
-
        pthread_rwlock_rdlock(&cg_mount_table_lock);
-       controller = cgroup->controller[0]->name;
        if (!cg_build_path_locked(cgroup->name, child_path, controller)) {
                pthread_rwlock_unlock(&cg_mount_table_lock);
                return ECGFAIL;
@@ -2033,71 +2030,91 @@ int cgroup_delete_cgroup_ext(struct cgroup *cgroup, int flags)
                        return ECGROUPSUBSYSNOTMOUNTED;
        }
 
-       if (!(flags & CGFLAG_DELETE_EMPTY_ONLY)) {
-               ret = cgroup_find_parent(cgroup, &parent_name);
-               if (ret)
-                       return ret;
-
-               if (parent_name == NULL) {
-                       /*
-                        * Root group is being deleted.
-                        */
-                       if (flags & CGFLAG_DELETE_RECURSIVE) {
-                               /*
-                                * Move all tasks to the root group and do not
-                                * delete it afterwards.
-                                */
-                               parent_name = strdup(".");
-                               if (parent_name == NULL) {
-                                       last_errno = errno;
-                               return ECGOTHER;
-                               }
-                               delete_group = 0;
-                       } else
-                               /*
-                                *  TODO: should it succeed?
-                                */
-                               return 0;
-               }
-       }
-
        /*
         * Remove the group from all controllers.
         */
        for (i = 0; i < cgroup->index; i++) {
                ret = 0;
 
+               /* find parent, it can be different for each controller */
+               if (!(flags & CGFLAG_DELETE_EMPTY_ONLY)) {
+                       ret = cgroup_find_parent(cgroup,
+                                       cgroup->controller[i]->name,
+                                       &parent_name);
+                       if (ret) {
+                               if (first_error == 0) {
+                                       first_errno = last_errno;
+                                       first_error = ret;
+                               }
+                               continue;
+                       }
+                       if (parent_name == NULL) {
+                               /*
+                                * Root group is being deleted.
+                                */
+                               if (flags & CGFLAG_DELETE_RECURSIVE) {
+                                       /*
+                                        * Move all tasks to the root group and
+                                        * do not delete it afterwards.
+                                        */
+                                       parent_name = strdup(".");
+                                       if (parent_name == NULL) {
+                                               if (first_error == 0) {
+                                                       first_errno = errno;
+                                                       first_error = ECGOTHER;
+                                               }
+                                               continue;
+                                       }
+                                       delete_group = 0;
+                               } else
+                                       /*
+                                        * root group is being deleted in non-
+                                        * recursive mode
+                                        */
+                                       continue;
+                       }
+               }
+
                if (parent_name) {
                        /* tasks need to be moved, pre-open target tasks file */
                        if (!cg_build_path(parent_name, parent_path,
-                                       cgroup->controller[i]->name))
+                                       cgroup->controller[i]->name)) {
+                               if (first_error == 0)
+                                       first_error = ECGFAIL;
+                               free(parent_name);
                                continue;
-
+                       }
                        strncat(parent_path, "/tasks", sizeof(parent_path)
                                        - strlen(parent_path));
 
                        parent_tasks = fopen(parent_path, "we");
                        if (!parent_tasks) {
-                               last_errno = errno;
-                               ret = ECGOTHER;
+                               if (first_error == 0) {
+                                       first_errno = errno;
+                                       first_error = ECGOTHER;
+                               }
+                               free(parent_name);
+                               continue;
                        }
                }
-               if (parent_tasks || !parent_name) {
-                       if (flags & CGFLAG_DELETE_RECURSIVE) {
-                               ret = cg_delete_cgroup_controller_recursive(
-                                               cgroup->name,
-                                               cgroup->controller[i]->name,
-                                               parent_tasks, flags,
-                                               delete_group);
-                       } else {
-                               ret = cg_delete_cgroup_controller(cgroup->name,
-                                               cgroup->controller[i]->name,
-                                               parent_tasks, flags);
-                       }
-                       if (parent_tasks)
-                               fclose(parent_tasks);
+               if (flags & CGFLAG_DELETE_RECURSIVE) {
+                       ret = cg_delete_cgroup_controller_recursive(
+                                       cgroup->name,
+                                       cgroup->controller[i]->name,
+                                       parent_tasks, flags,
+                                       delete_group);
+               } else {
+                       ret = cg_delete_cgroup_controller(cgroup->name,
+                                       cgroup->controller[i]->name,
+                                       parent_tasks, flags);
                }
 
+               if (parent_tasks) {
+                       fclose(parent_tasks);
+                       parent_tasks = NULL;
+               }
+               free(parent_name);
+               parent_name = NULL;
                /*
                 * If any of the controller delete fails, remember the first
                 * error code, but continue with next controller and try remove
@@ -2116,7 +2133,6 @@ int cgroup_delete_cgroup_ext(struct cgroup *cgroup, int flags)
        if (first_errno != 0)
                last_errno = first_errno;
 
-       free(parent_name);
        return first_error;
 }