mptcp: use mptcp worker for path management

We can re-use the existing work queue to handle path management
instead of a dedicated work queue.  Just move pm_worker to protocol.c,
call it from the mptcp worker and get rid of the msk lock (already held).
Signed-off-by: Florian Westphal <fw@strlen.de>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/mptcp/pm.c

@@ -10,8 +10,6 @@
 #include <net/mptcp.h>
 #include "protocol.h"
 
-static struct workqueue_struct *pm_wq;
-
 /* path manager command handlers */
 
 int mptcp_pm_announce_addr(struct mptcp_sock *msk,
@@ -78,7 +76,7 @@ static bool mptcp_pm_schedule_work(struct mptcp_sock *msk,
 		return false;
 
 	msk->pm.status |= BIT(new_status);
-	if (queue_work(pm_wq, &msk->pm.work))
+	if (schedule_work(&msk->work))
 		sock_hold((struct sock *)msk);
 	return true;
 }
@@ -181,35 +179,6 @@ int mptcp_pm_get_local_id(struct mptcp_sock *msk, struct sock_common *skc)
 	return mptcp_pm_nl_get_local_id(msk, skc);
 }
 
-static void pm_worker(struct work_struct *work)
-{
-	struct mptcp_pm_data *pm = container_of(work, struct mptcp_pm_data,
-						work);
-	struct mptcp_sock *msk = container_of(pm, struct mptcp_sock, pm);
-	struct sock *sk = (struct sock *)msk;
-
-	lock_sock(sk);
-	spin_lock_bh(&msk->pm.lock);
-
-	pr_debug("msk=%p status=%x", msk, pm->status);
-	if (pm->status & BIT(MPTCP_PM_ADD_ADDR_RECEIVED)) {
-		pm->status &= ~BIT(MPTCP_PM_ADD_ADDR_RECEIVED);
-		mptcp_pm_nl_add_addr_received(msk);
-	}
-	if (pm->status & BIT(MPTCP_PM_ESTABLISHED)) {
-		pm->status &= ~BIT(MPTCP_PM_ESTABLISHED);
-		mptcp_pm_nl_fully_established(msk);
-	}
-	if (pm->status & BIT(MPTCP_PM_SUBFLOW_ESTABLISHED)) {
-		pm->status &= ~BIT(MPTCP_PM_SUBFLOW_ESTABLISHED);
-		mptcp_pm_nl_subflow_established(msk);
-	}
-
-	spin_unlock_bh(&msk->pm.lock);
-	release_sock(sk);
-	sock_put(sk);
-}
-
 void mptcp_pm_data_init(struct mptcp_sock *msk)
 {
 	msk->pm.add_addr_signaled = 0;
@@ -223,22 +192,11 @@ void mptcp_pm_data_init(struct mptcp_sock *msk)
 	msk->pm.status = 0;
 
 	spin_lock_init(&msk->pm.lock);
-	INIT_WORK(&msk->pm.work, pm_worker);
 
 	mptcp_pm_nl_data_init(msk);
 }
 
-void mptcp_pm_close(struct mptcp_sock *msk)
-{
-	if (cancel_work_sync(&msk->pm.work))
-		sock_put((struct sock *)msk);
-}
-
 void __init mptcp_pm_init(void)
 {
-	pm_wq = alloc_workqueue("pm_wq", WQ_UNBOUND | WQ_MEM_RECLAIM, 8);
-	if (!pm_wq)
-		panic("Failed to allocate workqueue");
-
 	mptcp_pm_nl_init();
 }

net/mptcp/protocol.c

@@ -1214,6 +1214,29 @@ static unsigned int mptcp_sync_mss(struct sock *sk, u32 pmtu)
 	return 0;
 }
 
+static void pm_work(struct mptcp_sock *msk)
+{
+	struct mptcp_pm_data *pm = &msk->pm;
+
+	spin_lock_bh(&msk->pm.lock);
+
+	pr_debug("msk=%p status=%x", msk, pm->status);
+	if (pm->status & BIT(MPTCP_PM_ADD_ADDR_RECEIVED)) {
+		pm->status &= ~BIT(MPTCP_PM_ADD_ADDR_RECEIVED);
+		mptcp_pm_nl_add_addr_received(msk);
+	}
+	if (pm->status & BIT(MPTCP_PM_ESTABLISHED)) {
+		pm->status &= ~BIT(MPTCP_PM_ESTABLISHED);
+		mptcp_pm_nl_fully_established(msk);
+	}
+	if (pm->status & BIT(MPTCP_PM_SUBFLOW_ESTABLISHED)) {
+		pm->status &= ~BIT(MPTCP_PM_SUBFLOW_ESTABLISHED);
+		mptcp_pm_nl_subflow_established(msk);
+	}
+
+	spin_unlock_bh(&msk->pm.lock);
+}
+
 static void mptcp_worker(struct work_struct *work)
 {
 	struct mptcp_sock *msk = container_of(work, struct mptcp_sock, work);
@@ -1230,6 +1253,9 @@ static void mptcp_worker(struct work_struct *work)
 	__mptcp_flush_join_list(msk);
 	__mptcp_move_skbs(msk);
 
+	if (msk->pm.status)
+		pm_work(msk);
+
 	if (test_and_clear_bit(MPTCP_WORK_EOF, &msk->flags))
 		mptcp_check_for_eof(msk);
 
@@ -1420,7 +1446,6 @@ static void mptcp_close(struct sock *sk, long timeout)
 	}
 
 	mptcp_cancel_work(sk);
-	mptcp_pm_close(msk);
 
 	__skb_queue_purge(&sk->sk_receive_queue);
 

net/mptcp/protocol.h

@@ -174,8 +174,6 @@ struct mptcp_pm_data {
 	u8		local_addr_max;
 	u8		subflows_max;
 	u8		status;
-
-	struct		work_struct work;
 };
 
 struct mptcp_data_frag {
@@ -412,7 +410,6 @@ void mptcp_crypto_hmac_sha(u64 key1, u64 key2, u8 *msg, int len, void *hmac);
 
 void __init mptcp_pm_init(void);
 void mptcp_pm_data_init(struct mptcp_sock *msk);
-void mptcp_pm_close(struct mptcp_sock *msk);
 void mptcp_pm_new_connection(struct mptcp_sock *msk, int server_side);
 void mptcp_pm_fully_established(struct mptcp_sock *msk);
 bool mptcp_pm_allow_new_subflow(struct mptcp_sock *msk);