net/mlx5: Add a locked flag to node removal functions

Add a locked flag to the node removal functions to signal if the
parent is already locked from the caller function or not as a pre-step
towards outside lock. Currently always use false with no functional
change.

Signed-off-by: Eli Britstein <elibr@mellanox.com>
Reviewed-by: Maor Gottlieb <maorg@mellanox.com>
Reviewed-by: Mark Bloch <markb@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/fs_core.c b/drivers/net/ethernet/mellanox/mlx5/core/fs_core.c
index 5ff8c5f..42a6952 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlx5/core/fs_core.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/fs_core.c
@@ -263,10 +263,11 @@ static void nested_down_write_ref_node(struct fs_node *node,
        }
 }
 
-static void down_write_ref_node(struct fs_node *node)
+static void down_write_ref_node(struct fs_node *node, bool locked)
 {
        if (node) {
-               down_write(&node->lock);
+               if (!locked)
+                       down_write(&node->lock);
                refcount_inc(&node->refcount);
        }
 }
@@ -277,13 +278,14 @@ static void up_read_ref_node(struct fs_node *node)
        up_read(&node->lock);
 }
 
-static void up_write_ref_node(struct fs_node *node)
+static void up_write_ref_node(struct fs_node *node, bool locked)
 {
        refcount_dec(&node->refcount);
-       up_write(&node->lock);
+       if (!locked)
+               up_write(&node->lock);
 }
 
-static void tree_put_node(struct fs_node *node)
+static void tree_put_node(struct fs_node *node, bool locked)
 {
        struct fs_node *parent_node = node->parent;
 
@@ -294,27 +296,27 @@ static void tree_put_node(struct fs_node *node)
                        /* Only root namespace doesn't have parent and we just
                         * need to free its node.
                         */
-                       down_write_ref_node(parent_node);
+                       down_write_ref_node(parent_node, locked);
                        list_del_init(&node->list);
                        if (node->del_sw_func)
                                node->del_sw_func(node);
-                       up_write_ref_node(parent_node);
+                       up_write_ref_node(parent_node, locked);
                } else {
                        kfree(node);
                }
                node = NULL;
        }
        if (!node && parent_node)
-               tree_put_node(parent_node);
+               tree_put_node(parent_node, locked);
 }
 
-static int tree_remove_node(struct fs_node *node)
+static int tree_remove_node(struct fs_node *node, bool locked)
 {
        if (refcount_read(&node->refcount) > 1) {
                refcount_dec(&node->refcount);
                return -EEXIST;
        }
-       tree_put_node(node);
+       tree_put_node(node, locked);
        return 0;
 }
 
@@ -867,7 +869,7 @@ static int _mlx5_modify_rule_destination(struct mlx5_flow_rule *rule,
        fs_get_obj(fte, rule->node.parent);
        if (!(fte->action.action & MLX5_FLOW_CONTEXT_ACTION_FWD_DEST))
                return -EINVAL;
-       down_write_ref_node(&fte->node);
+       down_write_ref_node(&fte->node, false);
        fs_get_obj(fg, fte->node.parent);
        fs_get_obj(ft, fg->node.parent);
 
@@ -875,7 +877,7 @@ static int _mlx5_modify_rule_destination(struct mlx5_flow_rule *rule,
        root = find_root(&ft->node);
        err = root->cmds->update_fte(get_dev(&ft->node), ft, fg->id,
                                     modify_mask, fte);
-       up_write_ref_node(&fte->node);
+       up_write_ref_node(&fte->node, false);
 
        return err;
 }
@@ -1025,11 +1027,11 @@ static struct mlx5_flow_table *__mlx5_create_flow_table(struct mlx5_flow_namespa
        if (err)
                goto destroy_ft;
        ft->node.active = true;
-       down_write_ref_node(&fs_prio->node);
+       down_write_ref_node(&fs_prio->node, false);
        tree_add_node(&ft->node, &fs_prio->node);
        list_add_flow_table(ft, fs_prio);
        fs_prio->num_ft++;
-       up_write_ref_node(&fs_prio->node);
+       up_write_ref_node(&fs_prio->node, false);
        mutex_unlock(&root->chain_lock);
        trace_mlx5_fs_add_ft(ft);
        return ft;
@@ -1123,17 +1125,17 @@ struct mlx5_flow_group *mlx5_create_flow_group(struct mlx5_flow_table *ft,
        if (ft->autogroup.active)
                return ERR_PTR(-EPERM);
 
-       down_write_ref_node(&ft->node);
+       down_write_ref_node(&ft->node, false);
        fg = alloc_insert_flow_group(ft, match_criteria_enable, match_criteria,
                                     start_index, end_index,
                                     ft->node.children.prev);
-       up_write_ref_node(&ft->node);
+       up_write_ref_node(&ft->node, false);
        if (IS_ERR(fg))
                return fg;
 
        err = root->cmds->create_flow_group(dev, ft, fg_in, &fg->id);
        if (err) {
-               tree_put_node(&fg->node);
+               tree_put_node(&fg->node, false);
                return ERR_PTR(err);
        }
        trace_mlx5_fs_add_fg(fg);
@@ -1530,10 +1532,10 @@ static void free_match_list(struct match_list_head *head)
                struct match_list *iter, *match_tmp;
 
                list_del(&head->first.list);
-               tree_put_node(&head->first.g->node);
+               tree_put_node(&head->first.g->node, false);
                list_for_each_entry_safe(iter, match_tmp, &head->list,
                                         list) {
-                       tree_put_node(&iter->g->node);
+                       tree_put_node(&iter->g->node, false);
                        list_del(&iter->list);
                        kfree(iter);
                }
@@ -1611,7 +1613,7 @@ lookup_fte_locked(struct mlx5_flow_group *g,
                goto out;
        }
        if (!fte_tmp->node.active) {
-               tree_put_node(&fte_tmp->node);
+               tree_put_node(&fte_tmp->node, false);
                fte_tmp = NULL;
                goto out;
        }
@@ -1619,7 +1621,7 @@ lookup_fte_locked(struct mlx5_flow_group *g,
        nested_down_write_ref_node(&fte_tmp->node, FS_LOCK_CHILD);
 out:
        if (take_write)
-               up_write_ref_node(&g->node);
+               up_write_ref_node(&g->node, false);
        else
                up_read_ref_node(&g->node);
        return fte_tmp;
@@ -1661,8 +1663,8 @@ search_again_locked:
                        continue;
                rule = add_rule_fg(g, spec->match_value,
                                   flow_act, dest, dest_num, fte_tmp);
-               up_write_ref_node(&fte_tmp->node);
-               tree_put_node(&fte_tmp->node);
+               up_write_ref_node(&fte_tmp->node, false);
+               tree_put_node(&fte_tmp->node, false);
                kmem_cache_free(steering->ftes_cache, fte);
                return rule;
        }
@@ -1698,7 +1700,7 @@ skip_search:
 
                err = insert_fte(g, fte);
                if (err) {
-                       up_write_ref_node(&g->node);
+                       up_write_ref_node(&g->node, false);
                        if (err == -ENOSPC)
                                continue;
                        kmem_cache_free(steering->ftes_cache, fte);
@@ -1706,11 +1708,11 @@ skip_search:
                }
 
                nested_down_write_ref_node(&fte->node, FS_LOCK_CHILD);
-               up_write_ref_node(&g->node);
+               up_write_ref_node(&g->node, false);
                rule = add_rule_fg(g, spec->match_value,
                                   flow_act, dest, dest_num, fte);
-               up_write_ref_node(&fte->node);
-               tree_put_node(&fte->node);
+               up_write_ref_node(&fte->node, false);
+               tree_put_node(&fte->node, false);
                return rule;
        }
        rule = ERR_PTR(-ENOENT);
@@ -1752,7 +1754,7 @@ search_again_locked:
        err = build_match_list(&match_head, ft, spec);
        if (err) {
                if (take_write)
-                       up_write_ref_node(&ft->node);
+                       up_write_ref_node(&ft->node, false);
                else
                        up_read_ref_node(&ft->node);
                return ERR_PTR(err);
@@ -1767,7 +1769,7 @@ search_again_locked:
        if (!IS_ERR(rule) ||
            (PTR_ERR(rule) != -ENOENT && PTR_ERR(rule) != -EAGAIN)) {
                if (take_write)
-                       up_write_ref_node(&ft->node);
+                       up_write_ref_node(&ft->node, false);
                return rule;
        }
 
@@ -1783,12 +1785,12 @@ search_again_locked:
        g = alloc_auto_flow_group(ft, spec);
        if (IS_ERR(g)) {
                rule = ERR_CAST(g);
-               up_write_ref_node(&ft->node);
+               up_write_ref_node(&ft->node, false);
                return rule;
        }
 
        nested_down_write_ref_node(&g->node, FS_LOCK_PARENT);
-       up_write_ref_node(&ft->node);
+       up_write_ref_node(&ft->node, false);
 
        err = create_auto_flow_group(ft, g);
        if (err)
@@ -1807,17 +1809,17 @@ search_again_locked:
        }
 
        nested_down_write_ref_node(&fte->node, FS_LOCK_CHILD);
-       up_write_ref_node(&g->node);
+       up_write_ref_node(&g->node, false);
        rule = add_rule_fg(g, spec->match_value, flow_act, dest,
                           dest_num, fte);
-       up_write_ref_node(&fte->node);
-       tree_put_node(&fte->node);
-       tree_put_node(&g->node);
+       up_write_ref_node(&fte->node, false);
+       tree_put_node(&fte->node, false);
+       tree_put_node(&g->node, false);
        return rule;
 
 err_release_fg:
-       up_write_ref_node(&g->node);
-       tree_put_node(&g->node);
+       up_write_ref_node(&g->node, false);
+       tree_put_node(&g->node, false);
        return ERR_PTR(err);
 }
 
@@ -1883,7 +1885,7 @@ void mlx5_del_flow_rules(struct mlx5_flow_handle *handle)
        int i;
 
        for (i = handle->num_rules - 1; i >= 0; i--)
-               tree_remove_node(&handle->rule[i]->node);
+               tree_remove_node(&handle->rule[i]->node, false);
        kfree(handle);
 }
 EXPORT_SYMBOL(mlx5_del_flow_rules);
@@ -1986,7 +1988,7 @@ int mlx5_destroy_flow_table(struct mlx5_flow_table *ft)
                mutex_unlock(&root->chain_lock);
                return err;
        }
-       if (tree_remove_node(&ft->node))
+       if (tree_remove_node(&ft->node, false))
                mlx5_core_warn(get_dev(&ft->node), "Flow table %d wasn't destroyed, refcount > 1\n",
                               ft->id);
        mutex_unlock(&root->chain_lock);
@@ -1997,7 +1999,7 @@ EXPORT_SYMBOL(mlx5_destroy_flow_table);
 
 void mlx5_destroy_flow_group(struct mlx5_flow_group *fg)
 {
-       if (tree_remove_node(&fg->node))
+       if (tree_remove_node(&fg->node, false))
                mlx5_core_warn(get_dev(&fg->node), "Flow group %d wasn't destroyed, refcount > 1\n",
                               fg->id);
 }
@@ -2381,8 +2383,8 @@ static void clean_tree(struct fs_node *node)
                tree_get_node(node);
                list_for_each_entry_safe(iter, temp, &node->children, list)
                        clean_tree(iter);
-               tree_put_node(node);
-               tree_remove_node(node);
+               tree_put_node(node, false);
+               tree_remove_node(node, false);
        }
 }