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net/mlx5: Add a locked flag to node removal functions
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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 <[email protected]>
Reviewed-by: Maor Gottlieb <[email protected]>
Reviewed-by: Mark Bloch <[email protected]>
Signed-off-by: Saeed Mahameed <[email protected]>
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Eli Britstein authored and Saeed Mahameed committed Mar 11, 2019
1 parent e7aafc8 commit 476d61b
Showing 1 changed file with 44 additions and 42 deletions.
86 changes: 44 additions & 42 deletions drivers/net/ethernet/mellanox/mlx5/core/fs_core.c
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Original file line number Diff line number Diff line change
Expand Up @@ -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);
}
}
Expand All @@ -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;

Expand All @@ -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;
}

Expand Down Expand Up @@ -867,15 +869,15 @@ 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);

memcpy(&rule->dest_attr, dest, sizeof(*dest));
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;
}
Expand Down Expand Up @@ -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;
Expand Down Expand Up @@ -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);
Expand Down Expand Up @@ -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);
}
Expand Down Expand Up @@ -1611,15 +1613,15 @@ 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;
}

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;
Expand Down Expand Up @@ -1661,8 +1663,8 @@ try_add_to_existing_fg(struct mlx5_flow_table *ft,
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;
}
Expand Down Expand Up @@ -1698,19 +1700,19 @@ try_add_to_existing_fg(struct mlx5_flow_table *ft,

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);
return ERR_PTR(err);
}

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);
Expand Down Expand Up @@ -1752,7 +1754,7 @@ _mlx5_add_flow_rules(struct mlx5_flow_table *ft,
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);
Expand All @@ -1767,7 +1769,7 @@ _mlx5_add_flow_rules(struct mlx5_flow_table *ft,
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;
}

Expand All @@ -1783,12 +1785,12 @@ _mlx5_add_flow_rules(struct mlx5_flow_table *ft,
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)
Expand All @@ -1807,17 +1809,17 @@ _mlx5_add_flow_rules(struct mlx5_flow_table *ft,
}

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);
}

Expand Down Expand Up @@ -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);
Expand Down Expand Up @@ -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);
Expand All @@ -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);
}
Expand Down Expand Up @@ -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);
}
}

Expand Down

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