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: Geliang Tang <tanggeliang@kylinos.cn>
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu 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: Jakub Kicinski <kuba@kernel.org>

diff --git a/include/net/mptcp.h b/include/net/mptcp.h
index 814b5f2e3ed5e3e474a2bac5e4cca5a89abcfe1c..2c85ca92bb1c39989ae08a74ff4ef9b42099e60d 100644 (file)
--- a/include/net/mptcp.h
+++ b/include/net/mptcp.h
@@ -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];

diff --git a/net/mptcp/sched.c b/net/mptcp/sched.c
index df7dbcfa3b71370cc4d7e4e4f16cc1e41a50dddf..94dc4b3ad82f6a462961ae5195b7eba2271d8275 100644 (file)
--- a/net/mptcp/sched.c
+++ b/net/mptcp/sched.c
@@ -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 = 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 = data->reinject ? mptcp_subflow_get_retrans(msk) :
-                              mptcp_subflow_get_send(msk);
+       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);
 }