bpf, maps: add release callback

Add a release callback for maps that is invoked when the last
reference to its struct file is gone and the struct file about
to be released by vfs. The handler will be used by fd array maps.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Daniel Borkmann 2016-06-15 22:47:12 +02:00 committed by David S. Miller
parent b478af0cd7
commit 61d1b6a42f
2 changed files with 8 additions and 2 deletions

View file

@ -19,7 +19,8 @@ struct bpf_map;
struct bpf_map_ops {
/* funcs callable from userspace (via syscall) */
struct bpf_map *(*map_alloc)(union bpf_attr *attr);
void (*map_free)(struct bpf_map *);
void (*map_release)(struct bpf_map *map, struct file *map_file);
void (*map_free)(struct bpf_map *map);
int (*map_get_next_key)(struct bpf_map *map, void *key, void *next_key);
/* funcs callable from userspace and from eBPF programs */

View file

@ -124,7 +124,12 @@ void bpf_map_put_with_uref(struct bpf_map *map)
static int bpf_map_release(struct inode *inode, struct file *filp)
{
bpf_map_put_with_uref(filp->private_data);
struct bpf_map *map = filp->private_data;
if (map->ops->map_release)
map->ops->map_release(map, filp);
bpf_map_put_with_uref(map);
return 0;
}