[PATCH -next 4/5] bpf: Remove map_delete_elem callbacks with -EOPNOTSUPP

[Xiaomeng Zhang <zhangxiaomeng13@xxxxxxxxxx>]

Remove redundant map_delete_elem callbacks with return -EOPNOTSUPP. We can
directly return -EOPNOTSUPP when calling the unimplemented callbacks.

Signed-off-by: Xiaomeng Zhang <zhangxiaomeng13@xxxxxxxxxx>
---
 kernel/bpf/arena.c        | 6 ------
 kernel/bpf/bloom_filter.c | 6 ------
 kernel/bpf/helpers.c      | 5 ++++-
 kernel/bpf/ringbuf.c      | 7 -------
 kernel/bpf/syscall.c      | 5 ++++-
 5 files changed, 8 insertions(+), 21 deletions(-)

diff --git a/kernel/bpf/arena.c b/kernel/bpf/arena.c
index 2c95baa8ece2..50f07bbd33fa 100644
--- a/kernel/bpf/arena.c
+++ b/kernel/bpf/arena.c
@@ -62,11 +62,6 @@ u64 bpf_arena_get_user_vm_start(struct bpf_arena *arena)
 	return arena ? arena->user_vm_start : 0;
 }
 
-static long arena_map_delete_elem(struct bpf_map *map, void *value)
-{
-	return -EOPNOTSUPP;
-}
-
 static int arena_map_get_next_key(struct bpf_map *map, void *key, void *next_key)
 {
 	return -EOPNOTSUPP;
@@ -390,7 +385,6 @@ const struct bpf_map_ops arena_map_ops = {
 	.map_get_next_key = arena_map_get_next_key,
 	.map_lookup_elem = arena_map_lookup_elem,
 	.map_update_elem = arena_map_update_elem,
-	.map_delete_elem = arena_map_delete_elem,
 	.map_check_btf = arena_map_check_btf,
 	.map_mem_usage = arena_map_mem_usage,
 	.map_btf_id = &bpf_arena_map_btf_ids[0],
diff --git a/kernel/bpf/bloom_filter.c b/kernel/bpf/bloom_filter.c
index d8d4dd7b711d..f3bba8ac2532 100644
--- a/kernel/bpf/bloom_filter.c
+++ b/kernel/bpf/bloom_filter.c
@@ -65,11 +65,6 @@ static long bloom_map_push_elem(struct bpf_map *map, void *value, u64 flags)
 	return 0;
 }
 
-static long bloom_map_delete_elem(struct bpf_map *map, void *value)
-{
-	return -EOPNOTSUPP;
-}
-
 static int bloom_map_get_next_key(struct bpf_map *map, void *key, void *next_key)
 {
 	return -EOPNOTSUPP;
@@ -206,7 +201,6 @@ const struct bpf_map_ops bloom_filter_map_ops = {
 	.map_peek_elem = bloom_map_peek_elem,
 	.map_lookup_elem = bloom_map_lookup_elem,
 	.map_update_elem = bloom_map_update_elem,
-	.map_delete_elem = bloom_map_delete_elem,
 	.map_check_btf = bloom_map_check_btf,
 	.map_mem_usage = bloom_map_mem_usage,
 	.map_btf_id = &bpf_bloom_map_btf_ids[0],
diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c
index cb61c06155c8..132c2830c758 100644
--- a/kernel/bpf/helpers.c
+++ b/kernel/bpf/helpers.c
@@ -74,7 +74,10 @@ BPF_CALL_2(bpf_map_delete_elem, struct bpf_map *, map, void *, key)
 {
 	WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_trace_held() &&
 		     !rcu_read_lock_bh_held());
-	return map->ops->map_delete_elem(map, key);
+	if (map->ops->map_delete_elem)
+		return map->ops->map_delete_elem(map, key);
+	else
+		return -EOPNOTSUPP;
 }
 
 const struct bpf_func_proto bpf_map_delete_elem_proto = {
diff --git a/kernel/bpf/ringbuf.c b/kernel/bpf/ringbuf.c
index 1499d8caa9a3..e2d22f10a11f 100644
--- a/kernel/bpf/ringbuf.c
+++ b/kernel/bpf/ringbuf.c
@@ -247,11 +247,6 @@ static long ringbuf_map_update_elem(struct bpf_map *map, void *key, void *value,
 	return -ENOTSUPP;
 }
 
-static long ringbuf_map_delete_elem(struct bpf_map *map, void *key)
-{
-	return -ENOTSUPP;
-}
-
 static int ringbuf_map_get_next_key(struct bpf_map *map, void *key,
 				    void *next_key)
 {
@@ -356,7 +351,6 @@ const struct bpf_map_ops ringbuf_map_ops = {
 	.map_poll = ringbuf_map_poll_kern,
 	.map_lookup_elem = ringbuf_map_lookup_elem,
 	.map_update_elem = ringbuf_map_update_elem,
-	.map_delete_elem = ringbuf_map_delete_elem,
 	.map_get_next_key = ringbuf_map_get_next_key,
 	.map_mem_usage = ringbuf_map_mem_usage,
 	.map_btf_id = &ringbuf_map_btf_ids[0],
@@ -371,7 +365,6 @@ const struct bpf_map_ops user_ringbuf_map_ops = {
 	.map_poll = ringbuf_map_poll_user,
 	.map_lookup_elem = ringbuf_map_lookup_elem,
 	.map_update_elem = ringbuf_map_update_elem,
-	.map_delete_elem = ringbuf_map_delete_elem,
 	.map_get_next_key = ringbuf_map_get_next_key,
 	.map_mem_usage = ringbuf_map_mem_usage,
 	.map_btf_id = &user_ringbuf_map_btf_ids[0],
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index c6f55283f4ff..36eed7016da4 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -1789,7 +1789,10 @@ static int map_delete_elem(union bpf_attr *attr, bpfptr_t uattr)
 	} else if (IS_FD_PROG_ARRAY(map) ||
 		   map->map_type == BPF_MAP_TYPE_STRUCT_OPS) {
 		/* These maps require sleepable context */
-		err = map->ops->map_delete_elem(map, key);
+		if (map->ops->map_delete_elem)
+			err = map->ops->map_delete_elem(map, key);
+		else
+			err = -EOPNOTSUPP;
 		goto out;
 	}
 
-- 
2.34.1