[PATCH bpf-next 03/13] bpf: refactor map_delete_elem()

[Yonghong Song <yhs@fb.com>]

Refactor function map_delete_elem() with a new helper
bpf_map_delete_elem(), which will be used later
for batched lookup_and_delete and delete operations.

Signed-off-by: Yonghong Song <yhs@fb.com>
---
 kernel/bpf/syscall.c | 33 ++++++++++++++++++++-------------
 1 file changed, 20 insertions(+), 13 deletions(-)

diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 3caa0ab3d30d..b8bba499df11 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -992,6 +992,25 @@ static int map_update_elem(union bpf_attr *attr)
 	return err;
 }
 
+static int bpf_map_delete_elem(struct bpf_map *map, void *key)
+{
+	int err;
+
+	if (bpf_map_is_dev_bound(map))
+		return bpf_map_offload_delete_elem(map, key);
+
+	preempt_disable();
+	__this_cpu_inc(bpf_prog_active);
+	rcu_read_lock();
+	err = map->ops->map_delete_elem(map, key);
+	rcu_read_unlock();
+	__this_cpu_dec(bpf_prog_active);
+	preempt_enable();
+	maybe_wait_bpf_programs(map);
+
+	return err;
+}
+
 #define BPF_MAP_DELETE_ELEM_LAST_FIELD key
 
 static int map_delete_elem(union bpf_attr *attr)
@@ -1021,20 +1040,8 @@ static int map_delete_elem(union bpf_attr *attr)
 		goto err_put;
 	}
 
-	if (bpf_map_is_dev_bound(map)) {
-		err = bpf_map_offload_delete_elem(map, key);
-		goto out;
-	}
+	err = bpf_map_delete_elem(map, key);
 
-	preempt_disable();
-	__this_cpu_inc(bpf_prog_active);
-	rcu_read_lock();
-	err = map->ops->map_delete_elem(map, key);
-	rcu_read_unlock();
-	__this_cpu_dec(bpf_prog_active);
-	preempt_enable();
-	maybe_wait_bpf_programs(map);
-out:
 	kfree(key);
 err_put:
 	fdput(f);
-- 
2.17.1