Commit 9771a96a authored by Geliang Tang's avatar Geliang Tang Committed by Jakub Kicinski
Browse files

mptcp: sched: split get_subflow interface into two 



get_retrans() interface of the burst packet scheduler invokes a sleeping
function mptcp_pm_subflow_chk_stale(), which calls __lock_sock_fast().
So get_retrans() interface should be set with BPF_F_SLEEPABLE flag in
BPF. But get_send() interface of this scheduler can't be set with
BPF_F_SLEEPABLE flag since it's invoked in ack_update_msk() under mptcp
data lock.

So this patch has to split get_subflow() interface of packet scheduer into
two interfaces: get_send() and get_retrans(). Then we can set get_retrans()
interface alone with BPF_F_SLEEPABLE flag.

Signed-off-by: default avatarGeliang Tang <tanggeliang@kylinos.cn>
Reviewed-by: default avatarMat Martineau <martineau@kernel.org>
Signed-off-by: default avatarMatthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250221-net-next-mptcp-pm-misc-cleanup-3-v1-8-2b70ab1cee79@kernel.org


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 7720790f

include/net/mptcp.h

+3 −2
Original line number Diff line number Diff line
@@ -103,13 +103,14 @@ struct mptcp_out_options { 
#define MPTCP_SUBFLOWS_MAX	8



struct mptcp_sched_data {

	bool	reinject;

	u8	subflows;

	struct mptcp_subflow_context *contexts[MPTCP_SUBFLOWS_MAX];

};



struct mptcp_sched_ops {

	int (*get_subflow)(struct mptcp_sock *msk,

	int (*get_send)(struct mptcp_sock *msk,

			struct mptcp_sched_data *data);

	int (*get_retrans)(struct mptcp_sock *msk,

			   struct mptcp_sched_data *data);



	char			name[MPTCP_SCHED_NAME_MAX];

net/mptcp/sched.c

+24 −11
Original line number Diff line number Diff line
@@ -16,13 +16,25 @@ 
static DEFINE_SPINLOCK(mptcp_sched_list_lock);

static LIST_HEAD(mptcp_sched_list);



static int mptcp_sched_default_get_subflow(struct mptcp_sock *msk,

static int mptcp_sched_default_get_send(struct mptcp_sock *msk,

					struct mptcp_sched_data *data)

{

	struct sock *ssk;



	ssk = data->reinject ? mptcp_subflow_get_retrans(msk) :

			       mptcp_subflow_get_send(msk);

	ssk = mptcp_subflow_get_send(msk);

	if (!ssk)

		return -EINVAL;



	mptcp_subflow_set_scheduled(mptcp_subflow_ctx(ssk), true);

	return 0;

}



static int mptcp_sched_default_get_retrans(struct mptcp_sock *msk,

					   struct mptcp_sched_data *data)

{

	struct sock *ssk;



	ssk = mptcp_subflow_get_retrans(msk);

	if (!ssk)

		return -EINVAL;
@@ -31,7 +43,8 @@ static int mptcp_sched_default_get_subflow(struct mptcp_sock *msk, 
}



static struct mptcp_sched_ops mptcp_sched_default = {

	.get_subflow	= mptcp_sched_default_get_subflow,

	.get_send	= mptcp_sched_default_get_send,

	.get_retrans	= mptcp_sched_default_get_retrans,

	.name		= "default",

	.owner		= THIS_MODULE,

};
@@ -73,7 +86,7 @@ void mptcp_get_available_schedulers(char *buf, size_t maxlen) 


int mptcp_register_scheduler(struct mptcp_sched_ops *sched)

{

	if (!sched->get_subflow)

	if (!sched->get_send)

		return -EINVAL;



	spin_lock(&mptcp_sched_list_lock);
@@ -164,10 +177,9 @@ int mptcp_sched_get_send(struct mptcp_sock *msk) 
			return 0;

	}



	data.reinject = false;

	if (msk->sched == &mptcp_sched_default || !msk->sched)

		return mptcp_sched_default_get_subflow(msk, &data);

	return msk->sched->get_subflow(msk, &data);

		return mptcp_sched_default_get_send(msk, &data);

	return msk->sched->get_send(msk, &data);

}



int mptcp_sched_get_retrans(struct mptcp_sock *msk)
@@ -186,8 +198,9 @@ int mptcp_sched_get_retrans(struct mptcp_sock *msk) 
			return 0;

	}



	data.reinject = true;

	if (msk->sched == &mptcp_sched_default || !msk->sched)

		return mptcp_sched_default_get_subflow(msk, &data);

	return msk->sched->get_subflow(msk, &data);

		return mptcp_sched_default_get_retrans(msk, &data);

	if (msk->sched->get_retrans)

		return msk->sched->get_retrans(msk, &data);

	return msk->sched->get_send(msk, &data);

}