kernfs: convert kernfs_node->id from union kernfs_node_id to u64

kernfs_node->id is currently a union kernfs_node_id which represents
either a 32bit (ino, gen) pair or u64 value.  I can't see much value
in the usage of the union - all that's needed is a 64bit ID which the
current code is already limited to.  Using a union makes the code
unnecessarily complicated and prevents using 64bit ino without adding
practical benefits.

This patch drops union kernfs_node_id and makes kernfs_node->id a u64.
ino is stored in the lower 32bits and gen upper.  Accessors -
kernfs[_id]_ino() and kernfs[_id]_gen() - are added to retrieve the
ino and gen.  This simplifies ID handling less cumbersome and will
allow using 64bit inos on supported archs.

This patch doesn't make any functional changes.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Alexei Starovoitov <ast@kernel.org>

2 files changed, 2 insertions, 2 deletions

diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c
index 5e28718928ca..912e761cd17a 100644
--- a/kernel/bpf/helpers.c
+++ b/kernel/bpf/helpers.c
@@ -317,7 +317,7 @@ BPF_CALL_0(bpf_get_current_cgroup_id)
 {
 	struct cgroup *cgrp = task_dfl_cgroup(current);
 
-	return cgrp->kn->id.id;
+	return cgrp->kn->id;
 }
 
 const struct bpf_func_proto bpf_get_current_cgroup_id_proto = {
diff --git a/kernel/bpf/local_storage.c b/kernel/bpf/local_storage.c
index addd6fdceec8..5d867f6d7204 100644
--- a/kernel/bpf/local_storage.c
+++ b/kernel/bpf/local_storage.c
@@ -569,7 +569,7 @@ void bpf_cgroup_storage_link(struct bpf_cgroup_storage *storage,
 		return;
 
 	storage->key.attach_type = type;
-	storage->key.cgroup_inode_id = cgroup->kn->id.id;
+	storage->key.cgroup_inode_id = cgroup->kn->id;
 
 	map = storage->map;