Commit e7f67c2b authored by Jens Axboe's avatar Jens Axboe
Browse files

io_uring/bpf_filter: add ref counts to struct io_bpf_filter 



In preparation for allowing inheritance of BPF filters and filter
tables, add a reference count to the filter. This allows multiple tables
to safely include the same filter.

Reviewed-by: default avatarChristian Brauner <brauner@kernel.org>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent e7c30675

io_uring/bpf_filter.c

+7 −0
Original line number Diff line number Diff line
@@ -15,6 +15,7 @@ 
#include "openclose.h"



struct io_bpf_filter {

	refcount_t		refs;

	struct bpf_prog		*prog;

	struct io_bpf_filter	*next;

};
@@ -125,6 +126,11 @@ static void io_free_bpf_filters(struct rcu_head *head) 
			 */

			if (f == &dummy_filter)

				break;



			/* Someone still holds a ref, stop iterating. */

			if (!refcount_dec_and_test(&f->refs))

				break;



			bpf_prog_destroy(f->prog);

			kfree(f);

			f = next;
@@ -298,6 +304,7 @@ int io_register_bpf_filter(struct io_restriction *res, 
		ret = -ENOMEM;

		goto err;

	}

	refcount_set(&filter->refs, 1);

	filter->prog = prog;

	res->bpf_filters = filters;