Refactor cgclear to use new recursive delete

Let's rework cgroup_config_unload_controller to use the brand new recursive
removal of groups. It saves *lot of* fopen() and fclose() calls:

On my (semi-broken) Fedora 11 with 196 running processes and 3 cgroup
hierarchies, the old cgclear does 668 open("*/tasks"). With the
optimized cgclear, I can see just 22 open("*/tasks") calls.

Signed-off-by: Jan Safranek <jsafrane@redhat.com>
Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com>

diff --git a/src/config.c b/src/config.c
index b996b8d85e8f15da47e409992d5de5b9c423a430..da2c268aa706f6b4c3e03fe79d5fce4191e6c015 100644 (file)
--- a/src/config.c
+++ b/src/config.c
@@ -493,105 +493,27 @@ err_mnt:
        return error;
 }
 
-static int cgroup_cleanup_cgroup_controller_files(struct cgroup_file_info info,
-                                               char *root_path, char *ctrl)
-{
-       void *task_handle;
-       pid_t pid;
-       char *rel_path = NULL;
-       int error;
-       int ret;
-
-
-       rel_path = info.full_path + strlen(root_path) - 1;
-
-       if (!strncmp(rel_path, "/", strlen(rel_path)))
-               return 0;
-
-       error = cgroup_get_task_begin(rel_path, ctrl,
-                                       &task_handle, &pid);
-
-       if (error && error != ECGEOF)
-               return error;
-
-       while (error != ECGEOF) {
-               ret = cgroup_attach_task_pid(NULL, pid);
-
-               if (ret) {
-                       cgroup_get_task_end(&task_handle);
-                       return ret;
-               }
-               error = cgroup_get_task_next(&task_handle, &pid);
-
-               if (error && error != ECGEOF) {
-                       cgroup_get_task_end(&task_handle);
-                       return error;
-               }
-       }
-
-       cgroup_get_task_end(&task_handle);
-
-       error = rmdir(info.full_path);
-       if (error) {
-               last_errno = errno;
-               return ECGOTHER;
-       }
-
-       return 0;
-}
-
 static int cgroup_config_unload_controller(struct cgroup_mount_point mount_info)
 {
-       struct cgroup_file_info info;
-       void *tree_handle;
-       int lvl;
-       int ret = 0, error;
-       char *root_path = NULL;
-
-       error = cgroup_walk_tree_begin(mount_info.name, "/", 0, &tree_handle,
-                                                       &info, &lvl);
-
-       if (error && error != ECGEOF)
-               return error;
-
-       root_path = strdup(info.full_path);
+       int ret, error;
+       struct cgroup *cgroup = NULL;
+       struct cgroup_controller *cgc = NULL;
 
-       if (!root_path) {
-               cgroup_walk_tree_end(&tree_handle);
-               last_errno = errno;
-               return ECGOTHER;
-       }
+       cgroup = cgroup_new_cgroup(".");
+       if (cgroup == NULL)
+               return ECGFAIL;
 
-       ret = cgroup_walk_tree_set_flags(&tree_handle,
-                               CGROUP_WALK_TYPE_POST_DIR);
-
-       if (ret) {
-               cgroup_walk_tree_end(&tree_handle);
+       cgc = cgroup_add_controller(cgroup, mount_info.name);
+       if (cgc == NULL) {
+               ret = ECGFAIL;
                goto out_error;
        }
 
-       while (error != ECGEOF) {
-               if (info.type == CGROUP_FILE_TYPE_DIR) {
-                       ret = cgroup_cleanup_cgroup_controller_files(info,
-                                               root_path, mount_info.name);
-
-                       if (ret) {
-                               cgroup_walk_tree_end(&tree_handle);
-                               goto out_error;
-                       }
-               }
-
-               error = cgroup_walk_tree_next(0, &tree_handle, &info, lvl);
+       ret = cgroup_delete_cgroup_ext(cgroup, CGFLAG_DELETE_RECURSIVE);
+       if (ret != 0)
+               goto out_error;
 
-               if (error && error != ECGEOF) {
-                       ret = error;
-                       cgroup_walk_tree_end(&tree_handle);
-                       goto out_error;
-               }
-       }
-       cgroup_walk_tree_end(&tree_handle);
        error = umount(mount_info.path);
-
        if (error) {
                last_errno = errno;
                ret = ECGOTHER;
@@ -599,14 +521,14 @@ static int cgroup_config_unload_controller(struct cgroup_mount_point mount_info)
        }
 
        error = rmdir(mount_info.path);
-
        if (error) {
                last_errno = errno;
                ret = ECGOTHER;
        }
 
 out_error:
-       free(root_path);
+       if (cgroup)
+               cgroup_free(&cgroup);
        return ret;
 }