Commit 84817d8c authored by Jakub Kicinski's avatar Jakub Kicinski
Browse files

genetlink: push conditional locking into dumpit/done 



Add helpers which take/release the genl mutex based
on family->parallel_ops. Remove the separation between
handling of ops in locked and parallel families.

Future patches would make the duplicated code grow even more.

Reviewed-by: default avatarJohannes Berg <johannes@sipsolutions.net>
Reviewed-by: default avatarJiri Pirko <jiri@nvidia.com>
Link: https://lore.kernel.org/r/20230814214723.2924989-2-kuba@kernel.org


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 479b322e

net/netlink/genetlink.c

+35 −55
Original line number Diff line number Diff line
@@ -52,6 +52,18 @@ static void genl_unlock_all(void) 
	up_write(&cb_lock);

}



static void genl_op_lock(const struct genl_family *family)

{

	if (!family->parallel_ops)

		genl_lock();

}



static void genl_op_unlock(const struct genl_family *family)

{

	if (!family->parallel_ops)

		genl_unlock();

}



static DEFINE_IDR(genl_fam_idr);



/*
@@ -838,11 +850,9 @@ static int genl_start(struct netlink_callback *cb) 


	cb->data = info;

	if (ops->start) {

		if (!ctx->family->parallel_ops)

			genl_lock();

		genl_op_lock(ctx->family);

		rc = ops->start(cb);

		if (!ctx->family->parallel_ops)

			genl_unlock();

		genl_op_unlock(ctx->family);

	}



	if (rc) {
@@ -853,46 +863,34 @@ static int genl_start(struct netlink_callback *cb) 
	return rc;

}



static int genl_lock_dumpit(struct sk_buff *skb, struct netlink_callback *cb)

static int genl_dumpit(struct sk_buff *skb, struct netlink_callback *cb)

{

	const struct genl_split_ops *ops = &genl_dumpit_info(cb)->op;

	const struct genl_dumpit_info *info = genl_dumpit_info(cb);

	const struct genl_split_ops *ops = &info->op;

	int rc;



	genl_lock();

	genl_op_lock(info->family);

	rc = ops->dumpit(skb, cb);

	genl_unlock();

	genl_op_unlock(info->family);

	return rc;

}



static int genl_lock_done(struct netlink_callback *cb)

static int genl_done(struct netlink_callback *cb)

{

	const struct genl_dumpit_info *info = genl_dumpit_info(cb);

	const struct genl_split_ops *ops = &info->op;

	int rc = 0;



	if (ops->done) {

		genl_lock();

		genl_op_lock(info->family);

		rc = ops->done(cb);

		genl_unlock();

		genl_op_unlock(info->family);

	}

	genl_family_rcv_msg_attrs_free(info->attrs);

	genl_dumpit_info_free(info);

	return rc;

}



static int genl_parallel_done(struct netlink_callback *cb)

{

	const struct genl_dumpit_info *info = genl_dumpit_info(cb);

	const struct genl_split_ops *ops = &info->op;

	int rc = 0;



	if (ops->done)

		rc = ops->done(cb);

	genl_family_rcv_msg_attrs_free(info->attrs);

	genl_dumpit_info_free(info);

	return rc;

}



static int genl_family_rcv_msg_dumpit(const struct genl_family *family,

				      struct sk_buff *skb,

				      struct nlmsghdr *nlh,
@@ -901,39 +899,25 @@ static int genl_family_rcv_msg_dumpit(const struct genl_family *family, 
				      int hdrlen, struct net *net)

{

	struct genl_start_context ctx;

	int err;



	ctx.family = family;

	ctx.nlh = nlh;

	ctx.extack = extack;

	ctx.ops = ops;

	ctx.hdrlen = hdrlen;



	if (!family->parallel_ops) {

	struct netlink_dump_control c = {

		.module = family->module,

		.data = &ctx,

		.start = genl_start,

			.dump = genl_lock_dumpit,

			.done = genl_lock_done,

		.dump = genl_dumpit,

		.done = genl_done,

		.extack = extack,

	};

	int err;



		genl_unlock();

		err = __netlink_dump_start(net->genl_sock, skb, nlh, &c);

		genl_lock();

	} else {

		struct netlink_dump_control c = {

			.module = family->module,

			.data = &ctx,

			.start = genl_start,

			.dump = ops->dumpit,

			.done = genl_parallel_done,

			.extack = extack,

		};

	ctx.family = family;

	ctx.nlh = nlh;

	ctx.extack = extack;

	ctx.ops = ops;

	ctx.hdrlen = hdrlen;



	genl_op_unlock(family);

	err = __netlink_dump_start(net->genl_sock, skb, nlh, &c);

	}

	genl_op_lock(family);



	return err;

}
@@ -1065,13 +1049,9 @@ static int genl_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, 
	if (family == NULL)

		return -ENOENT;



	if (!family->parallel_ops)

		genl_lock();



	genl_op_lock(family);

	err = genl_family_rcv_msg(family, skb, nlh, extack);



	if (!family->parallel_ops)

		genl_unlock();

	genl_op_unlock(family);



	return err;

}