bpf: extend cgroup bpf core to allow multiple cgroup storage types

In order to introduce per-cpu cgroup storage, let's generalize
bpf cgroup core to support multiple cgroup storage types.
Potentially, per-node cgroup storage can be added later.

This commit is mostly a formal change that replaces
cgroup_storage pointer with a array of cgroup_storage pointers.
It doesn't actually introduce a new storage type,
it will be done later.

Each bpf program is now able to have one cgroup storage of each type.

Signed-off-by: Roman Gushchin <guro@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

1 files changed, 9 insertions, 2 deletions

diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index 988a00797bcd..b457fbe7b70b 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -272,6 +272,13 @@ struct bpf_prog_offload {
         u32                     jited_len;
 };
 
+enum bpf_cgroup_storage_type {
+        BPF_CGROUP_STORAGE_SHARED,
+        __BPF_CGROUP_STORAGE_MAX
+};
+
+#define MAX_BPF_CGROUP_STORAGE_TYPE __BPF_CGROUP_STORAGE_MAX
+
 struct bpf_prog_aux {
         atomic_t refcnt;
         u32 used_map_cnt;
@@ -289,7 +296,7 @@ struct bpf_prog_aux {
         struct bpf_prog *prog;
         struct user_struct *user;
         u64 load_time; /* ns since boottime */
-        struct bpf_map *cgroup_storage;
+        struct bpf_map *cgroup_storage[MAX_BPF_CGROUP_STORAGE_TYPE];
         char name[BPF_OBJ_NAME_LEN];
 #ifdef CONFIG_SECURITY
         void *security;
@@ -358,7 +365,7 @@ int bpf_prog_test_run_skb(struct bpf_prog *prog, const union bpf_attr *kattr,
  */
 struct bpf_prog_array_item {
         struct bpf_prog *prog;
-        struct bpf_cgroup_storage *cgroup_storage;
+        struct bpf_cgroup_storage *cgroup_storage[MAX_BPF_CGROUP_STORAGE_TYPE];
 };
 
 struct bpf_prog_array {