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

[Yonghong Song]

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 <y...@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