Series comparison

-[PATCH mptcp-next v3 00/10] BPF path manager, part 6
+[PATCH mptcp-next v4 0/9] BPF path manager, part 6
 From: Geliang Tang <tanggeliang@kylinos.cn>
+v4:
+ - address Matt's comments in v3.
+ - update pm locks in mptcp_pm_worker.
+ - move the lock inside mptcp_pm_create_subflow_or_signal_addr.
+ - move the lock inside mptcp_pm_nl_add_addr_received.
+ - invoke add_addr_received interface from mptcp_pm_worker.
+ - invoke rm_addr_received interface from mptcp_pm_rm_addr_or_subflow.
+ - simply call mptcp_pm_close_subflow() in mptcp_pm_subflow_check_next.
 v3:
  - merge 'bugfixes for "BPF path manager, part 6, v2"' into this set.
+ - https://patchwork.kernel.org/project/mptcp/cover/cover.1742521397.git.tanggeliang@kylinos.cn/
 v2:
  - address Matt's comments in v1.
  - add add_addr_received and rm_addr_received interfaces.
  - drop subflow_check_next interface.
 ...
 v1:
 - https://patchwork.kernel.org/project/mptcp/cover/cover.1741685260.git.tanggeliang@kylinos.cn/
 New interfaces for struct mptcp_pm_ops.
-Geliang Tang (10):
+Geliang Tang (9):
   Squash to "mptcp: pm: add get_local_id() interface"
   mptcp: pm: add established interfaces
   mptcp: pm: drop is_userspace in subflow_check_next
   mptcp: pm: drop redundant MPTCP_MIB_ADDADDRDROP
-  Squash to "mptcp: pm: add get_local_id() interface"
+  mptcp: pm: add add_addr_received() interface
-  mptcp: pm: add established() interface
+  mptcp: pm: add rm_addr_received() interface
-  mptcp: pm: add subflow_established() interface
+  mptcp: pm: add add_addr_echo() interface
   mptcp: pm: add accept_new_subflow() interface
   mptcp: pm: add allow_new_subflow() interface
-  mptcp: pm: add accept_new_subflow() interface
-  mptcp: pm: add add_addr_received() interface
-  mptcp: pm: add add_addr_echo() interface
-  mptcp: pm: add rm_addr_received() interface
-  mptcp: pm: drop is_userspace in subflow_check_next
- include/net/mptcp.h      |  16 ++++++
+ include/net/mptcp.h      |  15 ++++++
- net/mptcp/pm.c           | 117 ++++++++++++++++++---------------------
+ net/mptcp/pm.c           | 114 ++++++++++++++++++---------------------
- net/mptcp/pm_kernel.c    |  79 ++++++++++++++++++++++----
+ net/mptcp/pm_kernel.c    |  91 +++++++++++++++++++++----------
- net/mptcp/pm_userspace.c |  27 +++++++++
+ net/mptcp/pm_userspace.c |  13 +++++
- net/mptcp/protocol.h     |   4 ++
+ net/mptcp/protocol.h     |   3 +-
  net/mptcp/subflow.c      |   4 +-
-files changed, 171 insertions(+), 76 deletions(-)
+files changed, 148 insertions(+), 92 deletions(-)
 --
 .43.0

-[PATCH mptcp-next v3 02/10] Squash to "mptcp: pm: add get_local_id() interface"
+[PATCH mptcp-next v4 1/9] Squash to "mptcp: pm: add get_local_id() interface"
 From: Geliang Tang <tanggeliang@kylinos.cn>
 Add /* required */ comment for get_local_id and get_priority.
 Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
 ---
  include/net/mptcp.h | 1 +
 file changed, 1 insertion(+)
 diff --git a/include/net/mptcp.h b/include/net/mptcp.h
 index XXXXXXX..XXXXXXX 100644
 --- a/include/net/mptcp.h
 +++ b/include/net/mptcp.h
 @@ -XXX,XX +XXX,XX @@ struct mptcp_sched_ops {
  #define MPTCP_PM_BUF_MAX    (MPTCP_PM_NAME_MAX * MPTCP_PM_MAX)
  struct mptcp_pm_ops {
 +    /* required */
      int (*get_local_id)(struct mptcp_sock *msk,
                  struct mptcp_pm_addr_entry *skc);
      bool (*get_priority)(struct mptcp_sock *msk,
 --
 .43.0

-[PATCH mptcp-next v3 04/10] mptcp: pm: add subflow_established() interface
+[PATCH mptcp-next v4 2/9] mptcp: pm: add established interfaces
 From: Geliang Tang <tanggeliang@kylinos.cn>
-This patch adds a .subflow_established interface for struct mptcp_pm_ops,
+This patch adds .established and .subflow_established interfaces for
-and calls pm->ops->subflow_established in from mptcp_pm_worker(). Then
+struct mptcp_pm_ops, and calls pm->ops->established/subflow_established
-get rid of the corresponding code from __mptcp_pm_kernel_worker().
+in from mptcp_pm_worker(). Then get rid of the corresponding code from
 __mptcp_pm_kernel_worker().
 Since mptcp_pm_addr_send_ack() is a sleepable kfunc, which is invoked
-by mptcp_pm_create_subflow_or_signal_addr(), .subflow_established()
+by mptcp_pm_create_subflow_or_signal_addr(), .established() and
-interface of BPF PM should be invoked by __bpf_prog_enter_sleepable(),
+.subflow_established() interfaces of BPF PM should be invoked by
-which can't be invoked under a lock. This patch unlocks the pm lock
+__bpf_prog_enter_sleepable(), which can't be invoked under a lock.
-before invoking this interface in mptcp_pm_worker(), while holding this
+This patch unlocks the pm lock before invoking this interface in
-lock in mptcp_pm_kernel_subflow_established().
+mptcp_pm_worker(), while holding this lock in mptcp_pm_kernel_established()
 and mptcp_pm_kernel_subflow_established().
 Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
 ---
- include/net/mptcp.h   |  1 +
+ include/net/mptcp.h   |  4 ++++
- net/mptcp/pm.c        | 13 +++++++++++--
+ net/mptcp/pm.c        | 32 ++++++++++++++++++++++++--------
- net/mptcp/pm_kernel.c |  9 ++++-----
+ net/mptcp/pm_kernel.c | 25 +++++++++++--------------
-files changed, 16 insertions(+), 7 deletions(-)
+files changed, 39 insertions(+), 22 deletions(-)
 diff --git a/include/net/mptcp.h b/include/net/mptcp.h
 index XXXXXXX..XXXXXXX 100644
 --- a/include/net/mptcp.h
 +++ b/include/net/mptcp.h
 @@ -XXX,XX +XXX,XX @@ struct mptcp_pm_ops {
+     bool (*get_priority)(struct mptcp_sock *msk,
-     /* optional */
+                  struct mptcp_addr_info *skc);
-     void (*established)(struct mptcp_sock *msk);
 +    /* optional */
 +    void (*established)(struct mptcp_sock *msk);
 +    void (*subflow_established)(struct mptcp_sock *msk);
++
      char            name[MPTCP_PM_NAME_MAX];
      struct module        *owner;
+     struct list_head    list;
 diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
 index XXXXXXX..XXXXXXX 100644
 --- a/net/mptcp/pm.c
 +++ b/net/mptcp/pm.c
+@@ -XXX,XX +XXX,XX @@ void mptcp_pm_fully_established(struct mptcp_sock *msk, const struct sock *ssk)
+      * be sure to serve this event only once.
+      */
+     if (READ_ONCE(pm->work_pending) &&
+-        !(pm->status & BIT(MPTCP_PM_ALREADY_ESTABLISHED)))
++        !(pm->status & BIT(MPTCP_PM_ALREADY_ESTABLISHED)) &&
++        pm->ops->established)
+         mptcp_pm_schedule_work(msk, MPTCP_PM_ESTABLISHED);
+     if ((pm->status & BIT(MPTCP_PM_ALREADY_ESTABLISHED)) == 0)
 @@ -XXX,XX +XXX,XX @@ void mptcp_pm_subflow_established(struct mptcp_sock *msk)
      pr_debug("msk=%p\n", msk);
 -    if (!READ_ONCE(pm->work_pending))
 ...
      spin_lock_bh(&pm->lock);
 @@ -XXX,XX +XXX,XX @@ void mptcp_pm_subflow_check_next(struct mptcp_sock *msk,
          return;
      }
-+    if (!pm->ops->subflow_established)
+-    if (!READ_ONCE(pm->work_pending) && !update_subflows)
-+        return;
++    if (!pm->ops->subflow_established ||
-+
++        (!READ_ONCE(pm->work_pending) && !update_subflows))
-     if (!READ_ONCE(pm->work_pending) && !update_subflows)
+         return;
-         return;
+     spin_lock_bh(&pm->lock);
 @@ -XXX,XX +XXX,XX @@ void mptcp_pm_add_addr_echoed(struct mptcp_sock *msk,
      pr_debug("msk=%p\n", msk);
 -    if (!READ_ONCE(pm->work_pending))
 +    if (!READ_ONCE(pm->work_pending) || !pm->ops->subflow_established)
          return;
      spin_lock_bh(&pm->lock);
 @@ -XXX,XX +XXX,XX @@ void mptcp_pm_worker(struct mptcp_sock *msk)
-         pm->ops->established(msk);
+     if (!(pm->status & MPTCP_PM_WORK_MASK))
-         spin_lock_bh(&pm->lock);
+         return;
-     }
 -    spin_lock_bh(&msk->pm.lock);
 -
      pr_debug("msk=%p status=%x\n", msk, pm->status);
      if (pm->status & BIT(MPTCP_PM_ADD_ADDR_SEND_ACK)) {
 +        spin_lock_bh(&pm->lock);
          pm->status &= ~BIT(MPTCP_PM_ADD_ADDR_SEND_ACK);
          mptcp_pm_addr_send_ack(msk);
 +        spin_unlock_bh(&pm->lock);
      }
      if (pm->status & BIT(MPTCP_PM_RM_ADDR_RECEIVED)) {
 +        spin_lock_bh(&pm->lock);
          pm->status &= ~BIT(MPTCP_PM_RM_ADDR_RECEIVED);
          mptcp_pm_rm_addr_recv(msk);
 +        spin_unlock_bh(&pm->lock);
 +    }
 +    if (pm->status & BIT(MPTCP_PM_ESTABLISHED)) {
 +        spin_lock_bh(&pm->lock);
 +        pm->status &= ~BIT(MPTCP_PM_ESTABLISHED);
 +        spin_unlock_bh(&pm->lock);
 +        pm->ops->established(msk);
 +    }
 +    if (pm->status & BIT(MPTCP_PM_SUBFLOW_ESTABLISHED)) {
++        spin_lock_bh(&pm->lock);
 +        pm->status &= ~BIT(MPTCP_PM_SUBFLOW_ESTABLISHED);
 +        spin_unlock_bh(&pm->lock);
 +        pm->ops->subflow_established(msk);
-+        spin_lock_bh(&pm->lock);
+     }
-+    }
++    spin_lock_bh(&pm->lock);
      __mptcp_pm_kernel_worker(msk);
+-
-     spin_unlock_bh(&msk->pm.lock);
+-    spin_unlock_bh(&msk->pm.lock);
 +    spin_unlock_bh(&pm->lock);
  }
  static void mptcp_pm_ops_init(struct mptcp_sock *msk,
 diff --git a/net/mptcp/pm_kernel.c b/net/mptcp/pm_kernel.c
 index XXXXXXX..XXXXXXX 100644
 --- a/net/mptcp/pm_kernel.c
 +++ b/net/mptcp/pm_kernel.c
-@@ -XXX,XX +XXX,XX @@ static void mptcp_pm_kernel_established(struct mptcp_sock *msk)
+@@ -XXX,XX +XXX,XX @@ static void mptcp_pm_create_subflow_or_signal_addr(struct mptcp_sock *msk)
-     spin_unlock_bh(&msk->pm.lock);
+     local_addr_max = mptcp_pm_get_local_addr_max(msk);
- }
+     subflows_max = mptcp_pm_get_subflows_max(msk);
 +    spin_lock_bh(&msk->pm.lock);
      /* do lazy endpoint usage accounting for the MPC subflows */
      if (unlikely(!(msk->pm.status & BIT(MPTCP_PM_MPC_ENDPOINT_ACCOUNTED))) && msk->first) {
          struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(msk->first);
@@ -XXX,XX +XXX,XX @@ static void mptcp_pm_create_subflow_or_signal_addr(struct mptcp_sock *msk)
           * current address announce will be completed.
           */
          if (msk->pm.addr_signal & BIT(MPTCP_ADD_ADDR_SIGNAL))
 -            return;
 +            goto out;
          if (!select_signal_address(pernet, msk, &local))
              goto subflow;
@@ -XXX,XX +XXX,XX @@ static void mptcp_pm_create_subflow_or_signal_addr(struct mptcp_sock *msk)
           * continuing, and trying to create subflows.
           */
          if (!mptcp_pm_alloc_anno_list(msk, &local.addr))
 -            return;
 +            goto out;
          __clear_bit(local.addr.id, msk->pm.id_avail_bitmap);
          msk->pm.add_addr_signaled++;
@@ -XXX,XX +XXX,XX @@ static void mptcp_pm_create_subflow_or_signal_addr(struct mptcp_sock *msk)
          spin_lock_bh(&msk->pm.lock);
      }
      mptcp_pm_nl_check_work_pending(msk);
 +out:
 +    spin_unlock_bh(&msk->pm.lock);
  }
 -static void mptcp_pm_nl_fully_established(struct mptcp_sock *msk)
 +static void mptcp_pm_kernel_established(struct mptcp_sock *msk)
  {
      mptcp_pm_create_subflow_or_signal_addr(msk);
  }
 -static void mptcp_pm_nl_subflow_established(struct mptcp_sock *msk)
 +static void mptcp_pm_kernel_subflow_established(struct mptcp_sock *msk)
  {
-+    spin_lock_bh(&msk->pm.lock);
      mptcp_pm_create_subflow_or_signal_addr(msk);
-+    spin_unlock_bh(&msk->pm.lock);
+ }
- }
+@@ -XXX,XX +XXX,XX @@ static int mptcp_nl_add_subflow_or_signal_addr(struct net *net,
+         spin_lock_bh(&msk->pm.lock);
- /* Fill all the local addresses into the array addrs[],
+         if (mptcp_addresses_equal(addr, &mpc_addr, addr->port))
              msk->mpc_endpoint_id = addr->id;
 -        mptcp_pm_create_subflow_or_signal_addr(msk);
          spin_unlock_bh(&msk->pm.lock);
 +        mptcp_pm_create_subflow_or_signal_addr(msk);
          release_sock(sk);
  next:
@@ -XXX,XX +XXX,XX @@ static void mptcp_pm_nl_fullmesh(struct mptcp_sock *msk,
      spin_lock_bh(&msk->pm.lock);
      mptcp_pm_rm_subflow(msk, &list);
      __mark_subflow_endp_available(msk, list.ids[0]);
 -    mptcp_pm_create_subflow_or_signal_addr(msk);
      spin_unlock_bh(&msk->pm.lock);
 +    mptcp_pm_create_subflow_or_signal_addr(msk);
  }
  static void mptcp_pm_nl_set_flags_all(struct net *net,
 @@ -XXX,XX +XXX,XX @@ void __mptcp_pm_kernel_worker(struct mptcp_sock *msk)
          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);
 -    }
  }
  static int __net_init pm_nl_init_net(struct net *net)
-@@ -XXX,XX +XXX,XX @@ struct mptcp_pm_ops mptcp_pm_kernel = {
+@@ -XXX,XX +XXX,XX @@ static void mptcp_pm_kernel_init(struct mptcp_sock *msk)
  struct mptcp_pm_ops mptcp_pm_kernel = {
      .get_local_id        = mptcp_pm_kernel_get_local_id,
      .get_priority        = mptcp_pm_kernel_get_priority,
-     .established        = mptcp_pm_kernel_established,
++    .established        = mptcp_pm_kernel_established,
 +    .subflow_established    = mptcp_pm_kernel_subflow_established,
      .init            = mptcp_pm_kernel_init,
      .name            = "kernel",
      .owner            = THIS_MODULE,
 --
 .43.0

-[PATCH mptcp-next v3 10/10] mptcp: pm: drop is_userspace in subflow_check_next
+[PATCH mptcp-next v4 3/9] mptcp: pm: drop is_userspace in subflow_check_next
 From: Geliang Tang <tanggeliang@kylinos.cn>
-In mptcp_pm_subflow_check_next(), instead of reducing "pm->subflows"
+This patch moves mptcp_pm_close_subflow() forward to let it be used by both
-for the in-kernel PM in __mptcp_pm_close_subflow(), this patch moves
+the userspace PM and the in-kernel PM in mptcp_pm_subflow_check_next().Then
-"pm->subflows--;" forward to let it be used by both the userspace PM
+mptcp_pm_is_userspace() here can be dropped.
 and the in-kernel PM. Then mptcp_pm_is_userspace() here can be dropped.
 Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
 ---
- net/mptcp/pm.c | 15 ++++++---------
+ net/mptcp/pm.c | 12 ++----------
-file changed, 6 insertions(+), 9 deletions(-)
+file changed, 2 insertions(+), 10 deletions(-)
 diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
 index XXXXXXX..XXXXXXX 100644
 --- a/net/mptcp/pm.c
 +++ b/net/mptcp/pm.c
 ...
 -            spin_lock_bh(&pm->lock);
 -            pm->subflows--;
 -            spin_unlock_bh(&pm->lock);
 -        }
 -        return;
-+    if (update_subflows) {
+-    }
-+        spin_lock_bh(&pm->lock);
++    if (update_subflows)
-+        pm->subflows--;
++        mptcp_pm_close_subflow(msk);
-+        spin_unlock_bh(&pm->lock);
-     }
+     if (!pm->ops->subflow_established ||
+         (!READ_ONCE(pm->work_pending) && !update_subflows))
      if (!pm->ops->subflow_established)
@@ -XXX,XX +XXX,XX @@ void mptcp_pm_subflow_check_next(struct mptcp_sock *msk,
          return;
      spin_lock_bh(&pm->lock);
 -    if (update_subflows)
 -        __mptcp_pm_close_subflow(msk);
-+    if (update_subflows && msk->pm.subflows < mptcp_pm_get_subflows_max(msk))
-+        WRITE_ONCE(msk->pm.accept_subflow, true);
      /* Even if this subflow is not really established, tell the PM to try
       * to pick the next ones, if possible.
 --
 .43.0

-[PATCH mptcp-next v3 01/10] mptcp: pm: drop redundant MPTCP_MIB_ADDADDRDROP
+[PATCH mptcp-next v4 4/9] mptcp: pm: drop redundant MPTCP_MIB_ADDADDRDROP
 From: Geliang Tang <tanggeliang@kylinos.cn>
 MPTCP_MIB_ADDADDRDROP MIB counter is incremented from both the in-kernel PM
 and the userspace PM. This can be called only once to reduce redundant
 code.
 Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
 ---
  net/mptcp/pm.c | 8 ++++++--
 file changed, 6 insertions(+), 2 deletions(-)
 diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
 index XXXXXXX..XXXXXXX 100644
 --- a/net/mptcp/pm.c
 +++ b/net/mptcp/pm.c
 @@ -XXX,XX +XXX,XX @@ void mptcp_pm_add_addr_received(const struct sock *ssk,
      struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
      struct mptcp_sock *msk = mptcp_sk(subflow->conn);
      struct mptcp_pm_data *pm = &msk->pm;
 +    int ret = 0;
      pr_debug("msk=%p remote_id=%d accept=%d\n", msk, addr->id,
           READ_ONCE(pm->accept_addr));
 @@ -XXX,XX +XXX,XX @@ void mptcp_pm_add_addr_received(const struct sock *ssk,
              mptcp_pm_announce_addr(msk, addr, true);
              mptcp_pm_add_addr_send_ack(msk);
          } else {
 -            __MPTCP_INC_STATS(sock_net((struct sock *)msk), MPTCP_MIB_ADDADDRDROP);
 +            ret = -EINVAL;
          }
      /* id0 should not have a different address */
      } else if ((addr->id == 0 && !mptcp_pm_is_init_remote_addr(msk, addr)) ||
 @@ -XXX,XX +XXX,XX @@ void mptcp_pm_add_addr_received(const struct sock *ssk,
      } else if (mptcp_pm_schedule_work(msk, MPTCP_PM_ADD_ADDR_RECEIVED)) {
          pm->remote = *addr;
      } else {
 -        __MPTCP_INC_STATS(sock_net((struct sock *)msk), MPTCP_MIB_ADDADDRDROP);
 +        ret = -EINVAL;
      }
 +    if (ret)
 +        __MPTCP_INC_STATS(sock_net((struct sock *)msk), MPTCP_MIB_ADDADDRDROP);
 +
      spin_unlock_bh(&pm->lock);
  }
 --
 .43.0

-[PATCH mptcp-next v3 03/10] mptcp: pm: add established() interface
+Deleted patch
-From: Geliang Tang <tanggeliang@kylinos.cn>
-This patch adds a .established interface for struct mptcp_pm_ops, and
-calls pm->ops->established in from mptcp_pm_worker(). Then get rid of
-the corresponding code from __mptcp_pm_kernel_worker().
-Since mptcp_pm_addr_send_ack() is a sleepable kfunc, which is invoked
-by mptcp_pm_create_subflow_or_signal_addr(), .established() interface
-of BPF PM should be invoked by __bpf_prog_enter_sleepable(), which
-can't be invoked under a lock. This patch unlocks the pm lock before
-invoking this interface in mptcp_pm_worker(), while holding this lock
-in mptcp_pm_kernel_established().
-Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
----
- include/net/mptcp.h   | 3 +++
- net/mptcp/pm.c        | 9 ++++++++-
- net/mptcp/pm_kernel.c | 9 ++++-----
-files changed, 15 insertions(+), 6 deletions(-)
-diff --git a/include/net/mptcp.h b/include/net/mptcp.h
-index XXXXXXX..XXXXXXX 100644
---- a/include/net/mptcp.h
-+++ b/include/net/mptcp.h
-@@ -XXX,XX +XXX,XX @@ struct mptcp_pm_ops {
-     bool (*get_priority)(struct mptcp_sock *msk,
-                  struct mptcp_addr_info *skc);
-+    /* optional */
-+    void (*established)(struct mptcp_sock *msk);
-+
-     char            name[MPTCP_PM_NAME_MAX];
-     struct module        *owner;
-     struct list_head    list;
-diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
-index XXXXXXX..XXXXXXX 100644
---- a/net/mptcp/pm.c
-+++ b/net/mptcp/pm.c
-@@ -XXX,XX +XXX,XX @@ void mptcp_pm_fully_established(struct mptcp_sock *msk, const struct sock *ssk)
-      * be sure to serve this event only once.
-      */
-     if (READ_ONCE(pm->work_pending) &&
--        !(pm->status & BIT(MPTCP_PM_ALREADY_ESTABLISHED)))
-+        !(pm->status & BIT(MPTCP_PM_ALREADY_ESTABLISHED)) &&
-+        pm->ops->established)
-         mptcp_pm_schedule_work(msk, MPTCP_PM_ESTABLISHED);
-     if ((pm->status & BIT(MPTCP_PM_ALREADY_ESTABLISHED)) == 0)
-@@ -XXX,XX +XXX,XX @@ void mptcp_pm_worker(struct mptcp_sock *msk)
-         pm->status &= ~BIT(MPTCP_PM_RM_ADDR_RECEIVED);
-         mptcp_pm_rm_addr_recv(msk);
-     }
-+    if (pm->status & BIT(MPTCP_PM_ESTABLISHED)) {
-+        pm->status &= ~BIT(MPTCP_PM_ESTABLISHED);
-+        spin_unlock_bh(&pm->lock);
-+        pm->ops->established(msk);
-+        spin_lock_bh(&pm->lock);
-+    }
-     __mptcp_pm_kernel_worker(msk);
-     spin_unlock_bh(&msk->pm.lock);
-diff --git a/net/mptcp/pm_kernel.c b/net/mptcp/pm_kernel.c
-index XXXXXXX..XXXXXXX 100644
---- a/net/mptcp/pm_kernel.c
-+++ b/net/mptcp/pm_kernel.c
-@@ -XXX,XX +XXX,XX @@ static void mptcp_pm_create_subflow_or_signal_addr(struct mptcp_sock *msk)
-     mptcp_pm_nl_check_work_pending(msk);
- }
--static void mptcp_pm_nl_fully_established(struct mptcp_sock *msk)
-+static void mptcp_pm_kernel_established(struct mptcp_sock *msk)
- {
-+    spin_lock_bh(&msk->pm.lock);
-     mptcp_pm_create_subflow_or_signal_addr(msk);
-+    spin_unlock_bh(&msk->pm.lock);
- }
- static void mptcp_pm_nl_subflow_established(struct mptcp_sock *msk)
-@@ -XXX,XX +XXX,XX @@ void __mptcp_pm_kernel_worker(struct mptcp_sock *msk)
-         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);
-@@ -XXX,XX +XXX,XX @@ static void mptcp_pm_kernel_init(struct mptcp_sock *msk)
- struct mptcp_pm_ops mptcp_pm_kernel = {
-     .get_local_id        = mptcp_pm_kernel_get_local_id,
-     .get_priority        = mptcp_pm_kernel_get_priority,
-+    .established        = mptcp_pm_kernel_established,
-     .init            = mptcp_pm_kernel_init,
-     .name            = "kernel",
-     .owner            = THIS_MODULE,
---
-.43.0

-[PATCH mptcp-next v3 07/10] mptcp: pm: add add_addr_received() interface
+[PATCH mptcp-next v4 5/9] mptcp: pm: add add_addr_received() interface
 From: Geliang Tang <tanggeliang@kylinos.cn>
 This patch adds an optional .add_addr_received interface for struct
-mptcp_pm_ops and invokes it in mptcp_pm_add_addr_received(). A new helper
+mptcp_pm_ops and invokes it in mptcp_pm_worker().
-mptcp_pm_add_addr_recv() is added to allow the MPTCP_PM_ADD_ADDR_RECEIVED
-worker can be invoke from the in-kernel PM.
+This interface is only implemented in the in-kernel PM as a wrapper
 of mptcp_pm_nl_add_addr_received().
 Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
 ---
- include/net/mptcp.h   |  4 ++++
+ include/net/mptcp.h   |  1 +
- net/mptcp/pm.c        |  9 +++++++--
+ net/mptcp/pm.c        | 18 +++++++++++-------
- net/mptcp/pm_kernel.c | 13 +++++++++++++
+ net/mptcp/pm_kernel.c | 24 +++++++++++-------------
- net/mptcp/protocol.h  |  1 +
+ net/mptcp/protocol.h  |  1 -
-files changed, 25 insertions(+), 2 deletions(-)
+files changed, 23 insertions(+), 21 deletions(-)
 diff --git a/include/net/mptcp.h b/include/net/mptcp.h
 index XXXXXXX..XXXXXXX 100644
 --- a/include/net/mptcp.h
 +++ b/include/net/mptcp.h
 @@ -XXX,XX +XXX,XX @@ struct mptcp_pm_ops {
-     bool (*allow_new_subflow)(struct mptcp_sock *msk);
+     /* optional */
-     bool (*accept_new_subflow)(const struct mptcp_sock *msk);
+     void (*established)(struct mptcp_sock *msk);
+     void (*subflow_established)(struct mptcp_sock *msk);
-+    /* optional */
++    void (*add_addr_received)(struct mptcp_sock *msk);
-+    int (*add_addr_received)(struct mptcp_sock *msk,
 +                 const struct mptcp_addr_info *addr);
 +
      char            name[MPTCP_PM_NAME_MAX];
      struct module        *owner;
-     struct list_head    list;
 diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
 index XXXXXXX..XXXXXXX 100644
 --- a/net/mptcp/pm.c
 +++ b/net/mptcp/pm.c
-@@ -XXX,XX +XXX,XX @@ void mptcp_pm_subflow_check_next(struct mptcp_sock *msk,
-     spin_unlock_bh(&pm->lock);
- }
-+bool mptcp_pm_add_addr_recv(struct mptcp_sock *msk)
-+{
-+    return mptcp_pm_schedule_work(msk, MPTCP_PM_ADD_ADDR_RECEIVED);
-+}
-+
- void mptcp_pm_add_addr_received(const struct sock *ssk,
-                 const struct mptcp_addr_info *addr)
- {
 @@ -XXX,XX +XXX,XX @@ void mptcp_pm_add_addr_received(const struct sock *ssk,
             (addr->id > 0 && !READ_ONCE(pm->accept_addr))) {
          mptcp_pm_announce_addr(msk, addr, true);
          mptcp_pm_add_addr_send_ack(msk);
 -    } else if (mptcp_pm_schedule_work(msk, MPTCP_PM_ADD_ADDR_RECEIVED)) {
 -        pm->remote = *addr;
-     } else {
+-    } else {
-         ret = -EINVAL;
+-        ret = -EINVAL;
-+        if (pm->ops->add_addr_received)
++    } else if (pm->ops->add_addr_received) {
-+            ret = pm->ops->add_addr_received(msk, addr);
++        if (mptcp_pm_schedule_work(msk, MPTCP_PM_ADD_ADDR_RECEIVED))
 +            pm->remote = *addr;
 +        else
 +            ret = -EINVAL;
      }
      if (ret)
+@@ -XXX,XX +XXX,XX @@ void mptcp_pm_worker(struct mptcp_sock *msk)
+         return;
+     pr_debug("msk=%p status=%x\n", msk, pm->status);
++    if (pm->status & BIT(MPTCP_PM_ADD_ADDR_RECEIVED)) {
++        spin_lock_bh(&pm->lock);
++        pm->status &= ~BIT(MPTCP_PM_ADD_ADDR_RECEIVED);
++        spin_unlock_bh(&pm->lock);
++        pm->ops->add_addr_received(msk);
++    }
+     if (pm->status & BIT(MPTCP_PM_ADD_ADDR_SEND_ACK)) {
+         spin_lock_bh(&pm->lock);
+         pm->status &= ~BIT(MPTCP_PM_ADD_ADDR_SEND_ACK);
+@@ -XXX,XX +XXX,XX @@ void mptcp_pm_worker(struct mptcp_sock *msk)
+         spin_unlock_bh(&pm->lock);
+         pm->ops->subflow_established(msk);
+     }
+-    spin_lock_bh(&pm->lock);
+-    __mptcp_pm_kernel_worker(msk);
+-    spin_unlock_bh(&pm->lock);
+ }
+ static void mptcp_pm_ops_init(struct mptcp_sock *msk,
 diff --git a/net/mptcp/pm_kernel.c b/net/mptcp/pm_kernel.c
 index XXXXXXX..XXXXXXX 100644
 --- a/net/mptcp/pm_kernel.c
 +++ b/net/mptcp/pm_kernel.c
-@@ -XXX,XX +XXX,XX @@ static bool mptcp_pm_kernel_accept_new_subflow(const struct mptcp_sock *msk)
+@@ -XXX,XX +XXX,XX @@ static void mptcp_pm_nl_add_addr_received(struct mptcp_sock *msk)
-     return READ_ONCE(msk->pm.accept_subflow);
+          msk->pm.add_addr_accepted, add_addr_accept_max,
           msk->pm.remote.family);
 +    spin_lock_bh(&msk->pm.lock);
      remote = msk->pm.remote;
      mptcp_pm_announce_addr(msk, &remote, true);
      mptcp_pm_addr_send_ack(msk);
      if (lookup_subflow_by_daddr(&msk->conn_list, &remote))
 -        return;
 +        goto out;
      /* pick id 0 port, if none is provided the remote address */
      if (!remote.port)
@@ -XXX,XX +XXX,XX @@ static void mptcp_pm_nl_add_addr_received(struct mptcp_sock *msk)
       */
      nr = fill_local_addresses_vec(msk, &remote, locals);
      if (nr == 0)
 -        return;
 +        goto out;
      spin_unlock_bh(&msk->pm.lock);
      for (i = 0; i < nr; i++)
@@ -XXX,XX +XXX,XX @@ static void mptcp_pm_nl_add_addr_received(struct mptcp_sock *msk)
              msk->pm.subflows >= subflows_max)
              WRITE_ONCE(msk->pm.accept_addr, false);
      }
 +out:
 +    spin_unlock_bh(&msk->pm.lock);
  }
-+static int mptcp_pm_kernel_add_addr_received(struct mptcp_sock *msk,
+ void mptcp_pm_nl_rm_addr(struct mptcp_sock *msk, u8 rm_id)
-+                         const struct mptcp_addr_info *addr)
+@@ -XXX,XX +XXX,XX @@ bool mptcp_pm_nl_check_work_pending(struct mptcp_sock *msk)
      return true;
  }
 -/* Called under PM lock */
 -void __mptcp_pm_kernel_worker(struct mptcp_sock *msk)
 -{
 -    struct mptcp_pm_data *pm = &msk->pm;
 -
 -    if (pm->status & BIT(MPTCP_PM_ADD_ADDR_RECEIVED)) {
 -        pm->status &= ~BIT(MPTCP_PM_ADD_ADDR_RECEIVED);
 -        mptcp_pm_nl_add_addr_received(msk);
 -    }
 -}
 -
  static int __net_init pm_nl_init_net(struct net *net)
  {
      struct pm_nl_pernet *pernet = pm_nl_get_pernet(net);
@@ -XXX,XX +XXX,XX @@ static struct pernet_operations mptcp_pm_pernet_ops = {
      .size = sizeof(struct pm_nl_pernet),
  };
 +static void mptcp_pm_kernel_add_addr_received(struct mptcp_sock *msk)
 +{
-+    int ret = 0;
++    mptcp_pm_nl_add_addr_received(msk);
 +
 +    if (mptcp_pm_add_addr_recv(msk))
 +        msk->pm.remote = *addr;
 +    else
 +        ret = -EINVAL;
 +    return ret;
 +}
 +
  static void mptcp_pm_kernel_init(struct mptcp_sock *msk)
  {
      bool subflows_allowed = !!mptcp_pm_get_subflows_max(msk);
 @@ -XXX,XX +XXX,XX @@ struct mptcp_pm_ops mptcp_pm_kernel = {
+     .get_priority        = mptcp_pm_kernel_get_priority,
+     .established        = mptcp_pm_kernel_established,
      .subflow_established    = mptcp_pm_kernel_subflow_established,
-     .allow_new_subflow    = mptcp_pm_kernel_allow_new_subflow,
-     .accept_new_subflow    = mptcp_pm_kernel_accept_new_subflow,
 +    .add_addr_received    = mptcp_pm_kernel_add_addr_received,
      .init            = mptcp_pm_kernel_init,
      .name            = "kernel",
      .owner            = THIS_MODULE,
 diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
 index XXXXXXX..XXXXXXX 100644
 --- a/net/mptcp/protocol.h
 +++ b/net/mptcp/protocol.h
-@@ -XXX,XX +XXX,XX @@ void mptcp_pm_subflow_established(struct mptcp_sock *msk);
+@@ -XXX,XX +XXX,XX @@ void __init mptcp_pm_kernel_register(void);
- bool mptcp_pm_nl_check_work_pending(struct mptcp_sock *msk);
+ void __init mptcp_pm_userspace_register(void);
- void mptcp_pm_subflow_check_next(struct mptcp_sock *msk,
+ void __init mptcp_pm_nl_init(void);
-                  const struct mptcp_subflow_context *subflow);
+ void mptcp_pm_worker(struct mptcp_sock *msk);
-+bool mptcp_pm_add_addr_recv(struct mptcp_sock *msk);
+-void __mptcp_pm_kernel_worker(struct mptcp_sock *msk);
- void mptcp_pm_add_addr_received(const struct sock *ssk,
+ unsigned int mptcp_pm_get_add_addr_signal_max(const struct mptcp_sock *msk);
-                 const struct mptcp_addr_info *addr);
+ unsigned int mptcp_pm_get_add_addr_accept_max(const struct mptcp_sock *msk);
- void mptcp_pm_add_addr_echoed(struct mptcp_sock *msk,
+ unsigned int mptcp_pm_get_subflows_max(const struct mptcp_sock *msk);
 --
 .43.0

-[PATCH mptcp-next v3 09/10] mptcp: pm: add rm_addr_received() interface
+[PATCH mptcp-next v4 6/9] mptcp: pm: add rm_addr_received() interface
 From: Geliang Tang <tanggeliang@kylinos.cn>
 This patch adds an optional .rm_addr_received interface for struct
-mptcp_pm_ops and invokes it in mptcp_pm_worker() without PM lock.
+mptcp_pm_ops and invokes it in mptcp_pm_rm_addr_or_subflow().
 Since mptcp_subflow_shutdown() and mptcp_close_ssk() are sleepable
 kfuncs, .rm_addr_received interface of BPF PM should be invoked by
 __bpf_prog_enter_sleepable(), which can't be invoked under a lock.
 This patch unlocks the pm lock before invoking this interface in
 mptcp_pm_worker(), while holding this lock in mptcp_pm_rm_addr_recv().
-Export mptcp_pm_rm_addr_recv() is to allow the MPTCP_PM_RM_ADDR_RECEIVED
+This interface is only implemented in the in-kernel PM as a wrapper
-worker can be invoke from the in-kernel PM.
+of mptcp_pm_nl_rm_addr().
 With this, mptcp_pm_is_kernel() in mptcp_pm_rm_addr_or_subflow() can be
 dropped.
 Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
 ---
- include/net/mptcp.h   |  1 +
+ include/net/mptcp.h   | 1 +
- net/mptcp/pm.c        | 13 ++++++++++---
+ net/mptcp/pm.c        | 4 ++--
- net/mptcp/pm_kernel.c |  6 ++++++
+ net/mptcp/pm_kernel.c | 6 ++++++
- net/mptcp/protocol.h  |  1 +
+files changed, 9 insertions(+), 2 deletions(-)
 files changed, 18 insertions(+), 3 deletions(-)
 diff --git a/include/net/mptcp.h b/include/net/mptcp.h
 index XXXXXXX..XXXXXXX 100644
 --- a/include/net/mptcp.h
 +++ b/include/net/mptcp.h
 @@ -XXX,XX +XXX,XX @@ struct mptcp_pm_ops {
-     /* optional */
+     void (*established)(struct mptcp_sock *msk);
-     int (*add_addr_received)(struct mptcp_sock *msk,
+     void (*subflow_established)(struct mptcp_sock *msk);
-                  const struct mptcp_addr_info *addr);
+     void (*add_addr_received)(struct mptcp_sock *msk);
-+    void (*rm_addr_received)(struct mptcp_sock *msk);
++    void (*rm_addr_received)(struct mptcp_sock *msk, u8 id);
      char            name[MPTCP_PM_NAME_MAX];
      struct module        *owner;
 diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
 index XXXXXXX..XXXXXXX 100644
 ...
 @@ -XXX,XX +XXX,XX @@ static void mptcp_pm_rm_addr_or_subflow(struct mptcp_sock *msk,
          if (rm_type == MPTCP_MIB_RMADDR) {
              __MPTCP_INC_STATS(sock_net(sk), rm_type);
 -            if (removed && mptcp_pm_is_kernel(msk))
-+            if (removed)
+-                mptcp_pm_nl_rm_addr(msk, rm_id);
-                 mptcp_pm_nl_rm_addr(msk, rm_id);
++            if (removed && msk->pm.ops->rm_addr_received)
 +                msk->pm.ops->rm_addr_received(msk, rm_id);
          }
      }
  }
--static void mptcp_pm_rm_addr_recv(struct mptcp_sock *msk)
-+void mptcp_pm_rm_addr_recv(struct mptcp_sock *msk)
- {
-+    spin_lock_bh(&msk->pm.lock);
-     mptcp_pm_rm_addr_or_subflow(msk, &msk->pm.rm_list_rx, MPTCP_MIB_RMADDR);
-+    spin_unlock_bh(&msk->pm.lock);
- }
- void mptcp_pm_rm_subflow(struct mptcp_sock *msk,
-@@ -XXX,XX +XXX,XX @@ void mptcp_pm_rm_addr_received(struct mptcp_sock *msk,
-     for (i = 0; i < rm_list->nr; i++)
-         mptcp_event_addr_removed(msk, rm_list->ids[i]);
-+    if (!pm->ops->rm_addr_received)
-+        return;
-+
-     spin_lock_bh(&pm->lock);
-     if (mptcp_pm_schedule_work(msk, MPTCP_PM_RM_ADDR_RECEIVED))
-         pm->rm_list_rx = *rm_list;
-@@ -XXX,XX +XXX,XX @@ void mptcp_pm_worker(struct mptcp_sock *msk)
-     }
-     if (pm->status & BIT(MPTCP_PM_RM_ADDR_RECEIVED)) {
-         pm->status &= ~BIT(MPTCP_PM_RM_ADDR_RECEIVED);
--        mptcp_pm_rm_addr_recv(msk);
-+        spin_unlock_bh(&pm->lock);
-+        pm->ops->rm_addr_received(msk);
-+        spin_lock_bh(&pm->lock);
-     }
-     if (pm->status & BIT(MPTCP_PM_ESTABLISHED)) {
-         pm->status &= ~BIT(MPTCP_PM_ESTABLISHED);
 diff --git a/net/mptcp/pm_kernel.c b/net/mptcp/pm_kernel.c
 index XXXXXXX..XXXXXXX 100644
 --- a/net/mptcp/pm_kernel.c
 +++ b/net/mptcp/pm_kernel.c
-@@ -XXX,XX +XXX,XX @@ static int mptcp_pm_kernel_add_addr_received(struct mptcp_sock *msk,
+@@ -XXX,XX +XXX,XX @@ static void mptcp_pm_kernel_add_addr_received(struct mptcp_sock *msk)
-     return ret;
+     mptcp_pm_nl_add_addr_received(msk);
  }
-+static void mptcp_pm_kernel_rm_addr_received(struct mptcp_sock *msk)
++static void mptcp_pm_kernel_rm_addr_received(struct mptcp_sock *msk, u8 id)
 +{
-+    mptcp_pm_rm_addr_recv(msk);
++    mptcp_pm_nl_rm_addr(msk, id);
 +}
 +
  static void mptcp_pm_kernel_init(struct mptcp_sock *msk)
  {
      bool subflows_allowed = !!mptcp_pm_get_subflows_max(msk);
 @@ -XXX,XX +XXX,XX @@ struct mptcp_pm_ops mptcp_pm_kernel = {
-     .accept_new_subflow    = mptcp_pm_kernel_accept_new_subflow,
+     .established        = mptcp_pm_kernel_established,
-     .add_addr_echo        = mptcp_pm_kernel_add_addr_echo,
+     .subflow_established    = mptcp_pm_kernel_subflow_established,
      .add_addr_received    = mptcp_pm_kernel_add_addr_received,
 +    .rm_addr_received    = mptcp_pm_kernel_rm_addr_received,
      .init            = mptcp_pm_kernel_init,
      .name            = "kernel",
      .owner            = THIS_MODULE,
-diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
-index XXXXXXX..XXXXXXX 100644
---- a/net/mptcp/protocol.h
-+++ b/net/mptcp/protocol.h
-@@ -XXX,XX +XXX,XX @@ void mptcp_pm_rm_subflow(struct mptcp_sock *msk,
-              const struct mptcp_rm_list *rm_list);
- void mptcp_pm_rm_addr_received(struct mptcp_sock *msk,
-                    const struct mptcp_rm_list *rm_list);
-+void mptcp_pm_rm_addr_recv(struct mptcp_sock *msk);
- void mptcp_pm_mp_prio_received(struct sock *sk, u8 bkup);
- void mptcp_pm_mp_fail_received(struct sock *sk, u64 fail_seq);
- int mptcp_pm_mp_prio_send_ack(struct mptcp_sock *msk,
 --
 .43.0

-[PATCH mptcp-next v3 08/10] mptcp: pm: add add_addr_echo() interface
+[PATCH mptcp-next v4 7/9] mptcp: pm: add add_addr_echo() interface
 ...
 reasonable to add a mandatory .add_addr_echo interface for struct
 mptcp_pm_ops.
 Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
 ---
- include/net/mptcp.h      |  2 ++
+ include/net/mptcp.h      |  4 ++++
- net/mptcp/pm.c           | 18 +++++-------------
+ net/mptcp/pm.c           | 20 +++++++-------------
  net/mptcp/pm_kernel.c    |  9 +++++++++
  net/mptcp/pm_userspace.c |  7 +++++++
  net/mptcp/protocol.h     |  2 ++
-files changed, 25 insertions(+), 13 deletions(-)
+files changed, 29 insertions(+), 13 deletions(-)
 diff --git a/include/net/mptcp.h b/include/net/mptcp.h
 index XXXXXXX..XXXXXXX 100644
 --- a/include/net/mptcp.h
 +++ b/include/net/mptcp.h
 @@ -XXX,XX +XXX,XX @@ struct mptcp_pm_ops {
-     /* required */
+     void (*add_addr_received)(struct mptcp_sock *msk);
-     bool (*allow_new_subflow)(struct mptcp_sock *msk);
+     void (*rm_addr_received)(struct mptcp_sock *msk, u8 id);
-     bool (*accept_new_subflow)(const struct mptcp_sock *msk);
 +    /* required */
 +    bool (*add_addr_echo)(struct mptcp_sock *msk,
 +                  const struct mptcp_addr_info *addr);
++
-     /* optional */
+     char            name[MPTCP_PM_NAME_MAX];
-     int (*add_addr_received)(struct mptcp_sock *msk,
+     struct module        *owner;
      struct list_head    list;
 diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
 index XXXXXXX..XXXXXXX 100644
 --- a/net/mptcp/pm.c
 +++ b/net/mptcp/pm.c
 @@ -XXX,XX +XXX,XX @@ void mptcp_remote_address(const struct sock_common *skc,
 ...
 -    } else if ((addr->id == 0 && !mptcp_pm_is_init_remote_addr(msk, addr)) ||
 -           (addr->id > 0 && !READ_ONCE(pm->accept_addr))) {
 +    if (pm->ops->add_addr_echo(msk, addr)) {
          mptcp_pm_announce_addr(msk, addr, true);
          mptcp_pm_add_addr_send_ack(msk);
-     } else {
+     } else if (pm->ops->add_addr_received) {
@@ -XXX,XX +XXX,XX @@ void mptcp_pm_add_addr_received(const struct sock *ssk,
              pm->remote = *addr;
          else
              ret = -EINVAL;
 +    } else {
 +        ret = -EINVAL;
      }
      if (ret)
 @@ -XXX,XX +XXX,XX @@ struct mptcp_pm_ops *mptcp_pm_find(const char *name)
  int mptcp_pm_validate(struct mptcp_pm_ops *pm_ops)
  {
-     if (!pm_ops->get_local_id || !pm_ops->get_priority ||
+-    if (!pm_ops->get_local_id || !pm_ops->get_priority) {
--        !pm_ops->allow_new_subflow || !pm_ops->accept_new_subflow) {
++    if (!pm_ops->get_local_id || !pm_ops->get_priority ||
 +        !pm_ops->allow_new_subflow || !pm_ops->accept_new_subflow ||
 +        !pm_ops->add_addr_echo) {
          pr_err("%s does not implement required ops\n", pm_ops->name);
          return -EINVAL;
      }
 diff --git a/net/mptcp/pm_kernel.c b/net/mptcp/pm_kernel.c
 index XXXXXXX..XXXXXXX 100644
 --- a/net/mptcp/pm_kernel.c
 +++ b/net/mptcp/pm_kernel.c
-@@ -XXX,XX +XXX,XX @@ static bool mptcp_pm_kernel_accept_new_subflow(const struct mptcp_sock *msk)
+@@ -XXX,XX +XXX,XX @@ static void mptcp_pm_kernel_rm_addr_received(struct mptcp_sock *msk, u8 id)
-     return READ_ONCE(msk->pm.accept_subflow);
+     mptcp_pm_nl_rm_addr(msk, id);
  }
 +static bool mptcp_pm_kernel_add_addr_echo(struct mptcp_sock *msk,
 +                      const struct mptcp_addr_info *addr)
 +{
 +    /* id0 should not have a different address */
 +    return (addr->id == 0 && !mptcp_pm_is_init_remote_addr(msk, addr)) ||
 +           (addr->id > 0 && !READ_ONCE(msk->pm.accept_addr));
 +}
 +
- static int mptcp_pm_kernel_add_addr_received(struct mptcp_sock *msk,
+ static void mptcp_pm_kernel_init(struct mptcp_sock *msk)
                           const struct mptcp_addr_info *addr)
  {
+     bool subflows_allowed = !!mptcp_pm_get_subflows_max(msk);
 @@ -XXX,XX +XXX,XX @@ struct mptcp_pm_ops mptcp_pm_kernel = {
      .subflow_established    = mptcp_pm_kernel_subflow_established,
-     .allow_new_subflow    = mptcp_pm_kernel_allow_new_subflow,
+     .add_addr_received    = mptcp_pm_kernel_add_addr_received,
-     .accept_new_subflow    = mptcp_pm_kernel_accept_new_subflow,
+     .rm_addr_received    = mptcp_pm_kernel_rm_addr_received,
 +    .add_addr_echo        = mptcp_pm_kernel_add_addr_echo,
-     .add_addr_received    = mptcp_pm_kernel_add_addr_received,
      .init            = mptcp_pm_kernel_init,
      .name            = "kernel",
+     .owner            = THIS_MODULE,
 diff --git a/net/mptcp/pm_userspace.c b/net/mptcp/pm_userspace.c
 index XXXXXXX..XXXXXXX 100644
 --- a/net/mptcp/pm_userspace.c
 +++ b/net/mptcp/pm_userspace.c
-@@ -XXX,XX +XXX,XX @@ static bool mptcp_pm_userspace_accept_new_subflow(const struct mptcp_sock *msk)
+@@ -XXX,XX +XXX,XX @@ int mptcp_userspace_pm_get_addr(u8 id, struct mptcp_pm_addr_entry *addr,
-     return mptcp_userspace_pm_active(msk);
+     return ret;
  }
 +static bool mptcp_pm_userspace_add_addr_echo(struct mptcp_sock *msk,
 +                         const struct mptcp_addr_info *addr)
 +{
 +    return mptcp_userspace_pm_active(msk);
 +}
 +
  static void mptcp_pm_userspace_release(struct mptcp_sock *msk)
  {
      mptcp_userspace_pm_free_local_addr_list(msk);
-@@ -XXX,XX +XXX,XX @@ static struct mptcp_pm_ops mptcp_pm_userspace = {
+@@ -XXX,XX +XXX,XX @@ static void mptcp_pm_userspace_release(struct mptcp_sock *msk)
  static struct mptcp_pm_ops mptcp_pm_userspace = {
      .get_local_id        = mptcp_pm_userspace_get_local_id,
      .get_priority        = mptcp_pm_userspace_get_priority,
-     .allow_new_subflow    = mptcp_pm_userspace_allow_new_subflow,
-     .accept_new_subflow    = mptcp_pm_userspace_accept_new_subflow,
 +    .add_addr_echo        = mptcp_pm_userspace_add_addr_echo,
      .release        = mptcp_pm_userspace_release,
      .name            = "userspace",
      .owner            = THIS_MODULE,
 diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
 ...
  bool mptcp_pm_nl_check_work_pending(struct mptcp_sock *msk);
  void mptcp_pm_subflow_check_next(struct mptcp_sock *msk,
                   const struct mptcp_subflow_context *subflow);
 +bool mptcp_pm_is_init_remote_addr(struct mptcp_sock *msk,
 +                  const struct mptcp_addr_info *remote);
- bool mptcp_pm_add_addr_recv(struct mptcp_sock *msk);
  void mptcp_pm_add_addr_received(const struct sock *ssk,
                  const struct mptcp_addr_info *addr);
+ void mptcp_pm_add_addr_echoed(struct mptcp_sock *msk,
 --
 .43.0

-[PATCH mptcp-next v3 06/10] mptcp: pm: add accept_new_subflow() interface
+[PATCH mptcp-next v4 8/9] mptcp: pm: add accept_new_subflow() interface
 ...
 reasonable to add a mandatory .accept_new_subflow interface for struct
 mptcp_pm_ops.
 Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
 ---
- include/net/mptcp.h      | 1 +
+ include/net/mptcp.h      |  1 +
- net/mptcp/pm.c           | 2 +-
+ net/mptcp/pm.c           | 31 +++++++++++--------------------
- net/mptcp/pm_kernel.c    | 6 ++++++
+ net/mptcp/pm_kernel.c    |  6 ++++++
- net/mptcp/pm_userspace.c | 6 ++++++
+ net/mptcp/pm_userspace.c |  6 ++++++
- net/mptcp/subflow.c      | 4 +---
+ net/mptcp/subflow.c      |  4 +---
-files changed, 15 insertions(+), 4 deletions(-)
+files changed, 25 insertions(+), 23 deletions(-)
 diff --git a/include/net/mptcp.h b/include/net/mptcp.h
 index XXXXXXX..XXXXXXX 100644
 --- a/include/net/mptcp.h
 +++ b/include/net/mptcp.h
 @@ -XXX,XX +XXX,XX @@ struct mptcp_pm_ops {
      /* required */
-     bool (*allow_new_subflow)(struct mptcp_sock *msk);
+     bool (*add_addr_echo)(struct mptcp_sock *msk,
                    const struct mptcp_addr_info *addr);
 +    bool (*accept_new_subflow)(const struct mptcp_sock *msk);
      char            name[MPTCP_PM_NAME_MAX];
      struct module        *owner;
 diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
 index XXXXXXX..XXXXXXX 100644
 --- a/net/mptcp/pm.c
 +++ b/net/mptcp/pm.c
+@@ -XXX,XX +XXX,XX @@ bool mptcp_pm_allow_new_subflow(struct mptcp_sock *msk)
+ {
+     struct mptcp_pm_data *pm = &msk->pm;
+     unsigned int subflows_max;
+-    int ret = 0;
++    bool ret = true;
+-    if (mptcp_pm_is_userspace(msk)) {
+-        if (mptcp_userspace_pm_active(msk)) {
+-            spin_lock_bh(&pm->lock);
+-            pm->subflows++;
+-            spin_unlock_bh(&pm->lock);
+-            return true;
+-        }
++    if (!pm->ops->accept_new_subflow(msk))
+         return false;
+-    }
+-
+-    subflows_max = mptcp_pm_get_subflows_max(msk);
+-    pr_debug("msk=%p subflows=%d max=%d allow=%d\n", msk, pm->subflows,
+-         subflows_max, READ_ONCE(pm->accept_subflow));
++    spin_lock_bh(&pm->lock);
++    if (!mptcp_pm_is_userspace(msk) && READ_ONCE(pm->accept_subflow)) {
++        subflows_max = mptcp_pm_get_subflows_max(msk);
+-    /* try to avoid acquiring the lock below */
+-    if (!READ_ONCE(pm->accept_subflow))
+-        return false;
++        pr_debug("msk=%p subflows=%d max=%d allow=%d\n", msk, pm->subflows,
++             subflows_max, READ_ONCE(pm->accept_subflow));
+-    spin_lock_bh(&pm->lock);
+-    if (READ_ONCE(pm->accept_subflow)) {
+         ret = pm->subflows < subflows_max;
+-        if (ret && ++pm->subflows == subflows_max)
++        if (ret && pm->subflows == subflows_max - 1)
+             WRITE_ONCE(pm->accept_subflow, false);
+     }
++    if (ret)
++        pm->subflows++;
+     spin_unlock_bh(&pm->lock);
+     return ret;
 @@ -XXX,XX +XXX,XX @@ struct mptcp_pm_ops *mptcp_pm_find(const char *name)
  int mptcp_pm_validate(struct mptcp_pm_ops *pm_ops)
  {
      if (!pm_ops->get_local_id || !pm_ops->get_priority ||
--        !pm_ops->allow_new_subflow) {
+-        !pm_ops->add_addr_echo) {
-+        !pm_ops->allow_new_subflow || !pm_ops->accept_new_subflow) {
++        !pm_ops->add_addr_echo || !pm_ops->accept_new_subflow) {
          pr_err("%s does not implement required ops\n", pm_ops->name);
          return -EINVAL;
      }
 diff --git a/net/mptcp/pm_kernel.c b/net/mptcp/pm_kernel.c
 index XXXXXXX..XXXXXXX 100644
 --- a/net/mptcp/pm_kernel.c
 +++ b/net/mptcp/pm_kernel.c
-@@ -XXX,XX +XXX,XX @@ static bool mptcp_pm_kernel_allow_new_subflow(struct mptcp_sock *msk)
+@@ -XXX,XX +XXX,XX @@ static bool mptcp_pm_kernel_add_addr_echo(struct mptcp_sock *msk,
-     return ret;
+            (addr->id > 0 && !READ_ONCE(msk->pm.accept_addr));
  }
 +static bool mptcp_pm_kernel_accept_new_subflow(const struct mptcp_sock *msk)
 +{
 +    return READ_ONCE(msk->pm.accept_subflow);
 +}
 +
  static void mptcp_pm_kernel_init(struct mptcp_sock *msk)
  {
      bool subflows_allowed = !!mptcp_pm_get_subflows_max(msk);
 @@ -XXX,XX +XXX,XX @@ struct mptcp_pm_ops mptcp_pm_kernel = {
-     .established        = mptcp_pm_kernel_established,
+     .add_addr_received    = mptcp_pm_kernel_add_addr_received,
-     .subflow_established    = mptcp_pm_kernel_subflow_established,
+     .rm_addr_received    = mptcp_pm_kernel_rm_addr_received,
-     .allow_new_subflow    = mptcp_pm_kernel_allow_new_subflow,
+     .add_addr_echo        = mptcp_pm_kernel_add_addr_echo,
 +    .accept_new_subflow    = mptcp_pm_kernel_accept_new_subflow,
      .init            = mptcp_pm_kernel_init,
      .name            = "kernel",
      .owner            = THIS_MODULE,
 diff --git a/net/mptcp/pm_userspace.c b/net/mptcp/pm_userspace.c
 index XXXXXXX..XXXXXXX 100644
 --- a/net/mptcp/pm_userspace.c
 +++ b/net/mptcp/pm_userspace.c
-@@ -XXX,XX +XXX,XX @@ static bool mptcp_pm_userspace_allow_new_subflow(struct mptcp_sock *msk)
+@@ -XXX,XX +XXX,XX @@ static bool mptcp_pm_userspace_add_addr_echo(struct mptcp_sock *msk,
-     return false;
+     return mptcp_userspace_pm_active(msk);
  }
 +static bool mptcp_pm_userspace_accept_new_subflow(const struct mptcp_sock *msk)
 +{
 +    return mptcp_userspace_pm_active(msk);
 ...
  {
      mptcp_userspace_pm_free_local_addr_list(msk);
 @@ -XXX,XX +XXX,XX @@ static struct mptcp_pm_ops mptcp_pm_userspace = {
      .get_local_id        = mptcp_pm_userspace_get_local_id,
      .get_priority        = mptcp_pm_userspace_get_priority,
-     .allow_new_subflow    = mptcp_pm_userspace_allow_new_subflow,
+     .add_addr_echo        = mptcp_pm_userspace_add_addr_echo,
 +    .accept_new_subflow    = mptcp_pm_userspace_accept_new_subflow,
      .release        = mptcp_pm_userspace_release,
      .name            = "userspace",
      .owner            = THIS_MODULE,
 diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c
 ...

-[PATCH mptcp-next v3 05/10] mptcp: pm: add allow_new_subflow() interface
+[PATCH mptcp-next v4 9/9] mptcp: pm: add allow_new_subflow() interface
 ...
 reasonable to add a mandatory .allow_new_subflow interface for struct
 mptcp_pm_ops.
 Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
 ---
- include/net/mptcp.h      |  3 +++
+ include/net/mptcp.h   |  3 +++
- net/mptcp/pm.c           | 36 +++---------------------------------
+ net/mptcp/pm.c        | 13 ++-----------
- net/mptcp/pm_kernel.c    | 27 +++++++++++++++++++++++++++
+ net/mptcp/pm_kernel.c | 21 +++++++++++++++++++++
- net/mptcp/pm_userspace.c | 14 ++++++++++++++
+files changed, 26 insertions(+), 11 deletions(-)
 files changed, 47 insertions(+), 33 deletions(-)
 diff --git a/include/net/mptcp.h b/include/net/mptcp.h
 index XXXXXXX..XXXXXXX 100644
 --- a/include/net/mptcp.h
 +++ b/include/net/mptcp.h
 @@ -XXX,XX +XXX,XX @@ struct mptcp_pm_ops {
-     void (*established)(struct mptcp_sock *msk);
+                   const struct mptcp_addr_info *addr);
-     void (*subflow_established)(struct mptcp_sock *msk);
+     bool (*accept_new_subflow)(const struct mptcp_sock *msk);
-+    /* required */
++    /* optional */
 +    bool (*allow_new_subflow)(struct mptcp_sock *msk);
 +
      char            name[MPTCP_PM_NAME_MAX];
      struct module        *owner;
      struct list_head    list;
 diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
 index XXXXXXX..XXXXXXX 100644
 --- a/net/mptcp/pm.c
 +++ b/net/mptcp/pm.c
 @@ -XXX,XX +XXX,XX @@ void mptcp_pm_new_connection(struct mptcp_sock *msk, const struct sock *ssk, int
  bool mptcp_pm_allow_new_subflow(struct mptcp_sock *msk)
  {
--    struct mptcp_pm_data *pm = &msk->pm;
+     struct mptcp_pm_data *pm = &msk->pm;
 -    unsigned int subflows_max;
--    int ret = 0;
+     bool ret = true;
      if (!pm->ops->accept_new_subflow(msk))
          return false;
      spin_lock_bh(&pm->lock);
 -    if (!mptcp_pm_is_userspace(msk) && READ_ONCE(pm->accept_subflow)) {
 -        subflows_max = mptcp_pm_get_subflows_max(msk);
 -
--    if (mptcp_pm_is_userspace(msk)) {
+-        pr_debug("msk=%p subflows=%d max=%d allow=%d\n", msk, pm->subflows,
--        if (mptcp_userspace_pm_active(msk)) {
+-             subflows_max, READ_ONCE(pm->accept_subflow));
 -            spin_lock_bh(&pm->lock);
 -            pm->subflows++;
 -            spin_unlock_bh(&pm->lock);
 -            return true;
 -        }
 -        return false;
 -    }
 -
--    subflows_max = mptcp_pm_get_subflows_max(msk);
--
--    pr_debug("msk=%p subflows=%d max=%d allow=%d\n", msk, pm->subflows,
--         subflows_max, READ_ONCE(pm->accept_subflow));
--
--    /* try to avoid acquiring the lock below */
--    if (!READ_ONCE(pm->accept_subflow))
--        return false;
--
--    spin_lock_bh(&pm->lock);
--    if (READ_ONCE(pm->accept_subflow)) {
 -        ret = pm->subflows < subflows_max;
--        if (ret && ++pm->subflows == subflows_max)
+-        if (ret && pm->subflows == subflows_max - 1)
 -            WRITE_ONCE(pm->accept_subflow, false);
 -    }
--    spin_unlock_bh(&pm->lock);
++    if (pm->ops->allow_new_subflow)
--
++        ret = pm->ops->allow_new_subflow(msk);
--    return ret;
+     if (ret)
-+    return msk->pm.ops->allow_new_subflow(msk);
+         pm->subflows++;
- }
+     spin_unlock_bh(&pm->lock);
  /* return true if the new status bit is currently cleared, that is, this event
@@ -XXX,XX +XXX,XX @@ struct mptcp_pm_ops *mptcp_pm_find(const char *name)
  int mptcp_pm_validate(struct mptcp_pm_ops *pm_ops)
  {
 -    if (!pm_ops->get_local_id || !pm_ops->get_priority) {
 +    if (!pm_ops->get_local_id || !pm_ops->get_priority ||
 +        !pm_ops->allow_new_subflow) {
          pr_err("%s does not implement required ops\n", pm_ops->name);
          return -EINVAL;
      }
 diff --git a/net/mptcp/pm_kernel.c b/net/mptcp/pm_kernel.c
 index XXXXXXX..XXXXXXX 100644
 --- a/net/mptcp/pm_kernel.c
 +++ b/net/mptcp/pm_kernel.c
-@@ -XXX,XX +XXX,XX @@ static struct pernet_operations mptcp_pm_pernet_ops = {
+@@ -XXX,XX +XXX,XX @@ static bool mptcp_pm_kernel_accept_new_subflow(const struct mptcp_sock *msk)
-     .size = sizeof(struct pm_nl_pernet),
+     return READ_ONCE(msk->pm.accept_subflow);
- };
+ }
 +static bool mptcp_pm_kernel_allow_new_subflow(struct mptcp_sock *msk)
 +{
 +    struct mptcp_pm_data *pm = &msk->pm;
 +    unsigned int subflows_max;
-+    int ret = 0;
++    bool ret = false;
 +
 +    subflows_max = mptcp_pm_get_subflows_max(msk);
 +
 +    pr_debug("msk=%p subflows=%d max=%d allow=%d\n", msk, pm->subflows,
 +         subflows_max, READ_ONCE(pm->accept_subflow));
 +
-+    /* try to avoid acquiring the lock below */
-+    if (!READ_ONCE(pm->accept_subflow))
-+        return false;
-+
-+    spin_lock_bh(&pm->lock);
 +    if (READ_ONCE(pm->accept_subflow)) {
 +        ret = pm->subflows < subflows_max;
-+        if (ret && ++pm->subflows == subflows_max)
++        if (ret && pm->subflows == subflows_max - 1)
 +            WRITE_ONCE(pm->accept_subflow, false);
 +    }
-+    spin_unlock_bh(&pm->lock);
 +
 +    return ret;
 +}
 +
  static void mptcp_pm_kernel_init(struct mptcp_sock *msk)
  {
      bool subflows_allowed = !!mptcp_pm_get_subflows_max(msk);
 @@ -XXX,XX +XXX,XX @@ struct mptcp_pm_ops mptcp_pm_kernel = {
-     .get_priority        = mptcp_pm_kernel_get_priority,
+     .rm_addr_received    = mptcp_pm_kernel_rm_addr_received,
-     .established        = mptcp_pm_kernel_established,
+     .add_addr_echo        = mptcp_pm_kernel_add_addr_echo,
-     .subflow_established    = mptcp_pm_kernel_subflow_established,
+     .accept_new_subflow    = mptcp_pm_kernel_accept_new_subflow,
 +    .allow_new_subflow    = mptcp_pm_kernel_allow_new_subflow,
      .init            = mptcp_pm_kernel_init,
      .name            = "kernel",
      .owner            = THIS_MODULE,
-diff --git a/net/mptcp/pm_userspace.c b/net/mptcp/pm_userspace.c
-index XXXXXXX..XXXXXXX 100644
---- a/net/mptcp/pm_userspace.c
-+++ b/net/mptcp/pm_userspace.c
-@@ -XXX,XX +XXX,XX @@ int mptcp_userspace_pm_get_addr(u8 id, struct mptcp_pm_addr_entry *addr,
-     return ret;
- }
-+static bool mptcp_pm_userspace_allow_new_subflow(struct mptcp_sock *msk)
-+{
-+    struct mptcp_pm_data *pm = &msk->pm;
-+
-+    if (mptcp_userspace_pm_active(msk)) {
-+        spin_lock_bh(&pm->lock);
-+        pm->subflows++;
-+        spin_unlock_bh(&pm->lock);
-+        return true;
-+    }
-+    return false;
-+}
-+
- static void mptcp_pm_userspace_release(struct mptcp_sock *msk)
- {
-     mptcp_userspace_pm_free_local_addr_list(msk);
-@@ -XXX,XX +XXX,XX @@ static void mptcp_pm_userspace_release(struct mptcp_sock *msk)
- static struct mptcp_pm_ops mptcp_pm_userspace = {
-     .get_local_id        = mptcp_pm_userspace_get_local_id,
-     .get_priority        = mptcp_pm_userspace_get_priority,
-+    .allow_new_subflow    = mptcp_pm_userspace_allow_new_subflow,
-     .release        = mptcp_pm_userspace_release,
-     .name            = "userspace",
-     .owner            = THIS_MODULE,
 --
 .43.0

From: Geliang Tang <tanggeliang@kylinos.cn>

v3:
 - merge 'bugfixes for "BPF path manager, part 6, v2"' into this set.

v2:
 - address Matt's comments in v1.
 - add add_addr_received and rm_addr_received interfaces.
 - drop subflow_check_next interface.
 - add a "required" or "optional" comment for a group of interfaces in
   struct mptcp_pm_ops.

v1:
- https://patchwork.kernel.org/project/mptcp/cover/cover.1741685260.git.tanggeliang@kylinos.cn/

New interfaces for struct mptcp_pm_ops.

Geliang Tang (10):
  mptcp: pm: drop redundant MPTCP_MIB_ADDADDRDROP
  Squash to "mptcp: pm: add get_local_id() interface"
  mptcp: pm: add established() interface
  mptcp: pm: add subflow_established() interface
  mptcp: pm: add allow_new_subflow() interface
  mptcp: pm: add accept_new_subflow() interface
  mptcp: pm: add add_addr_received() interface
  mptcp: pm: add add_addr_echo() interface
  mptcp: pm: add rm_addr_received() interface
  mptcp: pm: drop is_userspace in subflow_check_next

-- 
2.43.0

From: Geliang Tang <tanggeliang@kylinos.cn>

MPTCP_MIB_ADDADDRDROP MIB counter is incremented from both the in-kernel PM
and the userspace PM. This can be called only once to reduce redundant
code.

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
---
 net/mptcp/pm.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
index XXXXXXX..XXXXXXX 100644
--- a/net/mptcp/pm.c
+++ b/net/mptcp/pm.c
@@ -XXX,XX +XXX,XX @@ void mptcp_pm_add_addr_received(const struct sock *ssk,
 	struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
 	struct mptcp_sock *msk = mptcp_sk(subflow->conn);
 	struct mptcp_pm_data *pm = &msk->pm;
+	int ret = 0;
 
 	pr_debug("msk=%p remote_id=%d accept=%d\n", msk, addr->id,
 		 READ_ONCE(pm->accept_addr));
@@ -XXX,XX +XXX,XX @@ void mptcp_pm_add_addr_received(const struct sock *ssk,
 			mptcp_pm_announce_addr(msk, addr, true);
 			mptcp_pm_add_addr_send_ack(msk);
 		} else {
-			__MPTCP_INC_STATS(sock_net((struct sock *)msk), MPTCP_MIB_ADDADDRDROP);
+			ret = -EINVAL;
 		}
 	/* id0 should not have a different address */
 	} else if ((addr->id == 0 && !mptcp_pm_is_init_remote_addr(msk, addr)) ||
@@ -XXX,XX +XXX,XX @@ void mptcp_pm_add_addr_received(const struct sock *ssk,
 	} else if (mptcp_pm_schedule_work(msk, MPTCP_PM_ADD_ADDR_RECEIVED)) {
 		pm->remote = *addr;
 	} else {
-		__MPTCP_INC_STATS(sock_net((struct sock *)msk), MPTCP_MIB_ADDADDRDROP);
+		ret = -EINVAL;
 	}
 
+	if (ret)
+		__MPTCP_INC_STATS(sock_net((struct sock *)msk), MPTCP_MIB_ADDADDRDROP);
+
 	spin_unlock_bh(&pm->lock);
 }
 
-- 
2.43.0

From: Geliang Tang <tanggeliang@kylinos.cn>

This patch adds a .established interface for struct mptcp_pm_ops, and
calls pm->ops->established in from mptcp_pm_worker(). Then get rid of
the corresponding code from __mptcp_pm_kernel_worker().

Since mptcp_pm_addr_send_ack() is a sleepable kfunc, which is invoked
by mptcp_pm_create_subflow_or_signal_addr(), .established() interface
of BPF PM should be invoked by __bpf_prog_enter_sleepable(), which
can't be invoked under a lock. This patch unlocks the pm lock before
invoking this interface in mptcp_pm_worker(), while holding this lock
in mptcp_pm_kernel_established().

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
---
 include/net/mptcp.h   | 3 +++
 net/mptcp/pm.c        | 9 ++++++++-
 net/mptcp/pm_kernel.c | 9 ++++-----
 3 files changed, 15 insertions(+), 6 deletions(-)

From: Geliang Tang <tanggeliang@kylinos.cn>

This patch adds a .subflow_established interface for struct mptcp_pm_ops,
and calls pm->ops->subflow_established in from mptcp_pm_worker(). Then
get rid of the corresponding code from __mptcp_pm_kernel_worker().

Since mptcp_pm_addr_send_ack() is a sleepable kfunc, which is invoked
by mptcp_pm_create_subflow_or_signal_addr(), .subflow_established()
interface of BPF PM should be invoked by __bpf_prog_enter_sleepable(),
which can't be invoked under a lock. This patch unlocks the pm lock
before invoking this interface in mptcp_pm_worker(), while holding this
lock in mptcp_pm_kernel_subflow_established().

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
---
 include/net/mptcp.h   |  1 +
 net/mptcp/pm.c        | 13 +++++++++++--
 net/mptcp/pm_kernel.c |  9 ++++-----
 3 files changed, 16 insertions(+), 7 deletions(-)

diff --git a/include/net/mptcp.h b/include/net/mptcp.h
index XXXXXXX..XXXXXXX 100644
--- a/include/net/mptcp.h
+++ b/include/net/mptcp.h
@@ -XXX,XX +XXX,XX @@ struct mptcp_pm_ops {
 
 	/* optional */
 	void (*established)(struct mptcp_sock *msk);
+	void (*subflow_established)(struct mptcp_sock *msk);
 
 	char			name[MPTCP_PM_NAME_MAX];
 	struct module		*owner;
diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
index XXXXXXX..XXXXXXX 100644
--- a/net/mptcp/pm.c
+++ b/net/mptcp/pm.c
@@ -XXX,XX +XXX,XX @@ void mptcp_pm_subflow_established(struct mptcp_sock *msk)
 
 	pr_debug("msk=%p\n", msk);
 
-	if (!READ_ONCE(pm->work_pending))
+	if (!READ_ONCE(pm->work_pending) || !pm->ops->subflow_established)
 		return;
 
 	spin_lock_bh(&pm->lock);
@@ -XXX,XX +XXX,XX @@ void mptcp_pm_subflow_check_next(struct mptcp_sock *msk,
 		return;
 	}
 
+	if (!pm->ops->subflow_established)
+		return;
+
 	if (!READ_ONCE(pm->work_pending) && !update_subflows)
 		return;
 
@@ -XXX,XX +XXX,XX @@ void mptcp_pm_add_addr_echoed(struct mptcp_sock *msk,
 
 	pr_debug("msk=%p\n", msk);
 
-	if (!READ_ONCE(pm->work_pending))
+	if (!READ_ONCE(pm->work_pending) || !pm->ops->subflow_established)
 		return;
 
 	spin_lock_bh(&pm->lock);
@@ -XXX,XX +XXX,XX @@ void mptcp_pm_worker(struct mptcp_sock *msk)
 		pm->ops->established(msk);
 		spin_lock_bh(&pm->lock);
 	}
+	if (pm->status & BIT(MPTCP_PM_SUBFLOW_ESTABLISHED)) {
+		pm->status &= ~BIT(MPTCP_PM_SUBFLOW_ESTABLISHED);
+		spin_unlock_bh(&pm->lock);
+		pm->ops->subflow_established(msk);
+		spin_lock_bh(&pm->lock);
+	}
 	__mptcp_pm_kernel_worker(msk);
 
 	spin_unlock_bh(&msk->pm.lock);
diff --git a/net/mptcp/pm_kernel.c b/net/mptcp/pm_kernel.c
index XXXXXXX..XXXXXXX 100644
--- a/net/mptcp/pm_kernel.c
+++ b/net/mptcp/pm_kernel.c
@@ -XXX,XX +XXX,XX @@ static void mptcp_pm_kernel_established(struct mptcp_sock *msk)
 	spin_unlock_bh(&msk->pm.lock);
 }
 
-static void mptcp_pm_nl_subflow_established(struct mptcp_sock *msk)
+static void mptcp_pm_kernel_subflow_established(struct mptcp_sock *msk)
 {
+	spin_lock_bh(&msk->pm.lock);
 	mptcp_pm_create_subflow_or_signal_addr(msk);
+	spin_unlock_bh(&msk->pm.lock);
 }
 
 /* Fill all the local addresses into the array addrs[],
@@ -XXX,XX +XXX,XX @@ void __mptcp_pm_kernel_worker(struct mptcp_sock *msk)
 		pm->status &= ~BIT(MPTCP_PM_ADD_ADDR_RECEIVED);
 		mptcp_pm_nl_add_addr_received(msk);
 	}
-	if (pm->status & BIT(MPTCP_PM_SUBFLOW_ESTABLISHED)) {
-		pm->status &= ~BIT(MPTCP_PM_SUBFLOW_ESTABLISHED);
-		mptcp_pm_nl_subflow_established(msk);
-	}
 }
 
 static int __net_init pm_nl_init_net(struct net *net)
@@ -XXX,XX +XXX,XX @@ struct mptcp_pm_ops mptcp_pm_kernel = {
 	.get_local_id		= mptcp_pm_kernel_get_local_id,
 	.get_priority		= mptcp_pm_kernel_get_priority,
 	.established		= mptcp_pm_kernel_established,
+	.subflow_established	= mptcp_pm_kernel_subflow_established,
 	.init			= mptcp_pm_kernel_init,
 	.name			= "kernel",
 	.owner			= THIS_MODULE,
-- 
2.43.0

From: Geliang Tang <tanggeliang@kylinos.cn>

The helper mptcp_pm_is_userspace() is used to distinguish userspace PM
operations from in-kernel PM in mptcp_pm_allow_new_subflow(). It seems
reasonable to add a mandatory .allow_new_subflow interface for struct
mptcp_pm_ops.

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
---
 include/net/mptcp.h      |  3 +++
 net/mptcp/pm.c           | 36 +++---------------------------------
 net/mptcp/pm_kernel.c    | 27 +++++++++++++++++++++++++++
 net/mptcp/pm_userspace.c | 14 ++++++++++++++
 4 files changed, 47 insertions(+), 33 deletions(-)

diff --git a/include/net/mptcp.h b/include/net/mptcp.h
index XXXXXXX..XXXXXXX 100644
--- a/include/net/mptcp.h
+++ b/include/net/mptcp.h
@@ -XXX,XX +XXX,XX @@ struct mptcp_pm_ops {
 	void (*established)(struct mptcp_sock *msk);
 	void (*subflow_established)(struct mptcp_sock *msk);
 
+	/* required */
+	bool (*allow_new_subflow)(struct mptcp_sock *msk);
+
 	char			name[MPTCP_PM_NAME_MAX];
 	struct module		*owner;
 	struct list_head	list;
diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
index XXXXXXX..XXXXXXX 100644
--- a/net/mptcp/pm.c
+++ b/net/mptcp/pm.c
@@ -XXX,XX +XXX,XX @@ void mptcp_pm_new_connection(struct mptcp_sock *msk, const struct sock *ssk, int
 
 bool mptcp_pm_allow_new_subflow(struct mptcp_sock *msk)
 {
-	struct mptcp_pm_data *pm = &msk->pm;
-	unsigned int subflows_max;
-	int ret = 0;
-
-	if (mptcp_pm_is_userspace(msk)) {
-		if (mptcp_userspace_pm_active(msk)) {
-			spin_lock_bh(&pm->lock);
-			pm->subflows++;
-			spin_unlock_bh(&pm->lock);
-			return true;
-		}
-		return false;
-	}
-
-	subflows_max = mptcp_pm_get_subflows_max(msk);
-
-	pr_debug("msk=%p subflows=%d max=%d allow=%d\n", msk, pm->subflows,
-		 subflows_max, READ_ONCE(pm->accept_subflow));
-
-	/* try to avoid acquiring the lock below */
-	if (!READ_ONCE(pm->accept_subflow))
-		return false;
-
-	spin_lock_bh(&pm->lock);
-	if (READ_ONCE(pm->accept_subflow)) {
-		ret = pm->subflows < subflows_max;
-		if (ret && ++pm->subflows == subflows_max)
-			WRITE_ONCE(pm->accept_subflow, false);
-	}
-	spin_unlock_bh(&pm->lock);
-
-	return ret;
+	return msk->pm.ops->allow_new_subflow(msk);
 }
 
 /* return true if the new status bit is currently cleared, that is, this event
@@ -XXX,XX +XXX,XX @@ struct mptcp_pm_ops *mptcp_pm_find(const char *name)
 
 int mptcp_pm_validate(struct mptcp_pm_ops *pm_ops)
 {
-	if (!pm_ops->get_local_id || !pm_ops->get_priority) {
+	if (!pm_ops->get_local_id || !pm_ops->get_priority ||
+	    !pm_ops->allow_new_subflow) {
 		pr_err("%s does not implement required ops\n", pm_ops->name);
 		return -EINVAL;
 	}
diff --git a/net/mptcp/pm_kernel.c b/net/mptcp/pm_kernel.c
index XXXXXXX..XXXXXXX 100644
--- a/net/mptcp/pm_kernel.c
+++ b/net/mptcp/pm_kernel.c
@@ -XXX,XX +XXX,XX @@ static struct pernet_operations mptcp_pm_pernet_ops = {
 	.size = sizeof(struct pm_nl_pernet),
 };
 
+static bool mptcp_pm_kernel_allow_new_subflow(struct mptcp_sock *msk)
+{
+	struct mptcp_pm_data *pm = &msk->pm;
+	unsigned int subflows_max;
+	int ret = 0;
+
+	subflows_max = mptcp_pm_get_subflows_max(msk);
+
+	pr_debug("msk=%p subflows=%d max=%d allow=%d\n", msk, pm->subflows,
+		 subflows_max, READ_ONCE(pm->accept_subflow));
+
+	/* try to avoid acquiring the lock below */
+	if (!READ_ONCE(pm->accept_subflow))
+		return false;
+
+	spin_lock_bh(&pm->lock);
+	if (READ_ONCE(pm->accept_subflow)) {
+		ret = pm->subflows < subflows_max;
+		if (ret && ++pm->subflows == subflows_max)
+			WRITE_ONCE(pm->accept_subflow, false);
+	}
+	spin_unlock_bh(&pm->lock);
+
+	return ret;
+}
+
 static void mptcp_pm_kernel_init(struct mptcp_sock *msk)
 {
 	bool subflows_allowed = !!mptcp_pm_get_subflows_max(msk);
@@ -XXX,XX +XXX,XX @@ struct mptcp_pm_ops mptcp_pm_kernel = {
 	.get_priority		= mptcp_pm_kernel_get_priority,
 	.established		= mptcp_pm_kernel_established,
 	.subflow_established	= mptcp_pm_kernel_subflow_established,
+	.allow_new_subflow	= mptcp_pm_kernel_allow_new_subflow,
 	.init			= mptcp_pm_kernel_init,
 	.name			= "kernel",
 	.owner			= THIS_MODULE,
diff --git a/net/mptcp/pm_userspace.c b/net/mptcp/pm_userspace.c
index XXXXXXX..XXXXXXX 100644
--- a/net/mptcp/pm_userspace.c
+++ b/net/mptcp/pm_userspace.c
@@ -XXX,XX +XXX,XX @@ int mptcp_userspace_pm_get_addr(u8 id, struct mptcp_pm_addr_entry *addr,
 	return ret;
 }
 
+static bool mptcp_pm_userspace_allow_new_subflow(struct mptcp_sock *msk)
+{
+	struct mptcp_pm_data *pm = &msk->pm;
+
+	if (mptcp_userspace_pm_active(msk)) {
+		spin_lock_bh(&pm->lock);
+		pm->subflows++;
+		spin_unlock_bh(&pm->lock);
+		return true;
+	}
+	return false;
+}
+
 static void mptcp_pm_userspace_release(struct mptcp_sock *msk)
 {
 	mptcp_userspace_pm_free_local_addr_list(msk);
@@ -XXX,XX +XXX,XX @@ static void mptcp_pm_userspace_release(struct mptcp_sock *msk)
 static struct mptcp_pm_ops mptcp_pm_userspace = {
 	.get_local_id		= mptcp_pm_userspace_get_local_id,
 	.get_priority		= mptcp_pm_userspace_get_priority,
+	.allow_new_subflow	= mptcp_pm_userspace_allow_new_subflow,
 	.release		= mptcp_pm_userspace_release,
 	.name			= "userspace",
 	.owner			= THIS_MODULE,
-- 
2.43.0

From: Geliang Tang <tanggeliang@kylinos.cn>

The helper mptcp_pm_is_userspace() is used to distinguish userspace PM
operations from in-kernel PM in mptcp_can_accept_new_subflow(). It seems
reasonable to add a mandatory .accept_new_subflow interface for struct
mptcp_pm_ops.

diff --git a/include/net/mptcp.h b/include/net/mptcp.h
index XXXXXXX..XXXXXXX 100644
--- a/include/net/mptcp.h
+++ b/include/net/mptcp.h
@@ -XXX,XX +XXX,XX @@ struct mptcp_pm_ops {
 
 	/* required */
 	bool (*allow_new_subflow)(struct mptcp_sock *msk);
+	bool (*accept_new_subflow)(const struct mptcp_sock *msk);
 
 	char			name[MPTCP_PM_NAME_MAX];
 	struct module		*owner;
diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
index XXXXXXX..XXXXXXX 100644
--- a/net/mptcp/pm.c
+++ b/net/mptcp/pm.c
@@ -XXX,XX +XXX,XX @@ struct mptcp_pm_ops *mptcp_pm_find(const char *name)
 int mptcp_pm_validate(struct mptcp_pm_ops *pm_ops)
 {
 	if (!pm_ops->get_local_id || !pm_ops->get_priority ||
-	    !pm_ops->allow_new_subflow) {
+	    !pm_ops->allow_new_subflow || !pm_ops->accept_new_subflow) {
 		pr_err("%s does not implement required ops\n", pm_ops->name);
 		return -EINVAL;
 	}
diff --git a/net/mptcp/pm_kernel.c b/net/mptcp/pm_kernel.c
index XXXXXXX..XXXXXXX 100644
--- a/net/mptcp/pm_kernel.c
+++ b/net/mptcp/pm_kernel.c
@@ -XXX,XX +XXX,XX @@ static bool mptcp_pm_kernel_allow_new_subflow(struct mptcp_sock *msk)
 	return ret;
 }
 
+static bool mptcp_pm_kernel_accept_new_subflow(const struct mptcp_sock *msk)
+{
+	return READ_ONCE(msk->pm.accept_subflow);
+}
+
 static void mptcp_pm_kernel_init(struct mptcp_sock *msk)
 {
 	bool subflows_allowed = !!mptcp_pm_get_subflows_max(msk);
@@ -XXX,XX +XXX,XX @@ struct mptcp_pm_ops mptcp_pm_kernel = {
 	.established		= mptcp_pm_kernel_established,
 	.subflow_established	= mptcp_pm_kernel_subflow_established,
 	.allow_new_subflow	= mptcp_pm_kernel_allow_new_subflow,
+	.accept_new_subflow	= mptcp_pm_kernel_accept_new_subflow,
 	.init			= mptcp_pm_kernel_init,
 	.name			= "kernel",
 	.owner			= THIS_MODULE,
diff --git a/net/mptcp/pm_userspace.c b/net/mptcp/pm_userspace.c
index XXXXXXX..XXXXXXX 100644
--- a/net/mptcp/pm_userspace.c
+++ b/net/mptcp/pm_userspace.c
@@ -XXX,XX +XXX,XX @@ static bool mptcp_pm_userspace_allow_new_subflow(struct mptcp_sock *msk)
 	return false;
 }
 
+static bool mptcp_pm_userspace_accept_new_subflow(const struct mptcp_sock *msk)
+{
+	return mptcp_userspace_pm_active(msk);
+}
+
 static void mptcp_pm_userspace_release(struct mptcp_sock *msk)
 {
 	mptcp_userspace_pm_free_local_addr_list(msk);
@@ -XXX,XX +XXX,XX @@ static struct mptcp_pm_ops mptcp_pm_userspace = {
 	.get_local_id		= mptcp_pm_userspace_get_local_id,
 	.get_priority		= mptcp_pm_userspace_get_priority,
 	.allow_new_subflow	= mptcp_pm_userspace_allow_new_subflow,
+	.accept_new_subflow	= mptcp_pm_userspace_accept_new_subflow,
 	.release		= mptcp_pm_userspace_release,
 	.name			= "userspace",
 	.owner			= THIS_MODULE,
diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c
index XXXXXXX..XXXXXXX 100644
--- a/net/mptcp/subflow.c
+++ b/net/mptcp/subflow.c
@@ -XXX,XX +XXX,XX @@ static void subflow_generate_hmac(u64 key1, u64 key2, u32 nonce1, u32 nonce2,
 static bool mptcp_can_accept_new_subflow(const struct mptcp_sock *msk)
 {
 	return mptcp_is_fully_established((void *)msk) &&
-		((mptcp_pm_is_userspace(msk) &&
-		  mptcp_userspace_pm_active(msk)) ||
-		 READ_ONCE(msk->pm.accept_subflow));
+		msk->pm.ops->accept_new_subflow(msk);
 }
 
 /* validate received token and create truncated hmac and nonce for SYN-ACK */
-- 
2.43.0

From: Geliang Tang <tanggeliang@kylinos.cn>

This patch adds an optional .add_addr_received interface for struct
mptcp_pm_ops and invokes it in mptcp_pm_add_addr_received(). A new helper
mptcp_pm_add_addr_recv() is added to allow the MPTCP_PM_ADD_ADDR_RECEIVED
worker can be invoke from the in-kernel PM.

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
---
 include/net/mptcp.h   |  4 ++++
 net/mptcp/pm.c        |  9 +++++++--
 net/mptcp/pm_kernel.c | 13 +++++++++++++
 net/mptcp/protocol.h  |  1 +
 4 files changed, 25 insertions(+), 2 deletions(-)

diff --git a/include/net/mptcp.h b/include/net/mptcp.h
index XXXXXXX..XXXXXXX 100644
--- a/include/net/mptcp.h
+++ b/include/net/mptcp.h
@@ -XXX,XX +XXX,XX @@ struct mptcp_pm_ops {
 	bool (*allow_new_subflow)(struct mptcp_sock *msk);
 	bool (*accept_new_subflow)(const struct mptcp_sock *msk);
 
+	/* optional */
+	int (*add_addr_received)(struct mptcp_sock *msk,
+				 const struct mptcp_addr_info *addr);
+
 	char			name[MPTCP_PM_NAME_MAX];
 	struct module		*owner;
 	struct list_head	list;
diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
index XXXXXXX..XXXXXXX 100644
--- a/net/mptcp/pm.c
+++ b/net/mptcp/pm.c
@@ -XXX,XX +XXX,XX @@ void mptcp_pm_subflow_check_next(struct mptcp_sock *msk,
 	spin_unlock_bh(&pm->lock);
 }
 
+bool mptcp_pm_add_addr_recv(struct mptcp_sock *msk)
+{
+	return mptcp_pm_schedule_work(msk, MPTCP_PM_ADD_ADDR_RECEIVED);
+}
+
 void mptcp_pm_add_addr_received(const struct sock *ssk,
 				const struct mptcp_addr_info *addr)
 {
@@ -XXX,XX +XXX,XX @@ void mptcp_pm_add_addr_received(const struct sock *ssk,
 		   (addr->id > 0 && !READ_ONCE(pm->accept_addr))) {
 		mptcp_pm_announce_addr(msk, addr, true);
 		mptcp_pm_add_addr_send_ack(msk);
-	} else if (mptcp_pm_schedule_work(msk, MPTCP_PM_ADD_ADDR_RECEIVED)) {
-		pm->remote = *addr;
 	} else {
 		ret = -EINVAL;
+		if (pm->ops->add_addr_received)
+			ret = pm->ops->add_addr_received(msk, addr);
 	}
 
 	if (ret)
diff --git a/net/mptcp/pm_kernel.c b/net/mptcp/pm_kernel.c
index XXXXXXX..XXXXXXX 100644
--- a/net/mptcp/pm_kernel.c
+++ b/net/mptcp/pm_kernel.c
@@ -XXX,XX +XXX,XX @@ static bool mptcp_pm_kernel_accept_new_subflow(const struct mptcp_sock *msk)
 	return READ_ONCE(msk->pm.accept_subflow);
 }
 
+static int mptcp_pm_kernel_add_addr_received(struct mptcp_sock *msk,
+					     const struct mptcp_addr_info *addr)
+{
+	int ret = 0;
+
+	if (mptcp_pm_add_addr_recv(msk))
+		msk->pm.remote = *addr;
+	else
+		ret = -EINVAL;
+	return ret;
+}
+
 static void mptcp_pm_kernel_init(struct mptcp_sock *msk)
 {
 	bool subflows_allowed = !!mptcp_pm_get_subflows_max(msk);
@@ -XXX,XX +XXX,XX @@ struct mptcp_pm_ops mptcp_pm_kernel = {
 	.subflow_established	= mptcp_pm_kernel_subflow_established,
 	.allow_new_subflow	= mptcp_pm_kernel_allow_new_subflow,
 	.accept_new_subflow	= mptcp_pm_kernel_accept_new_subflow,
+	.add_addr_received	= mptcp_pm_kernel_add_addr_received,
 	.init			= mptcp_pm_kernel_init,
 	.name			= "kernel",
 	.owner			= THIS_MODULE,
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index XXXXXXX..XXXXXXX 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -XXX,XX +XXX,XX @@ void mptcp_pm_subflow_established(struct mptcp_sock *msk);
 bool mptcp_pm_nl_check_work_pending(struct mptcp_sock *msk);
 void mptcp_pm_subflow_check_next(struct mptcp_sock *msk,
 				 const struct mptcp_subflow_context *subflow);
+bool mptcp_pm_add_addr_recv(struct mptcp_sock *msk);
 void mptcp_pm_add_addr_received(const struct sock *ssk,
 				const struct mptcp_addr_info *addr);
 void mptcp_pm_add_addr_echoed(struct mptcp_sock *msk,
-- 
2.43.0

From: Geliang Tang <tanggeliang@kylinos.cn>

The helper mptcp_pm_is_userspace() is used to distinguish userspace PM
operations from in-kernel PM in mptcp_pm_add_addr_received(). It seems
reasonable to add a mandatory .add_addr_echo interface for struct
mptcp_pm_ops.

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
---
 include/net/mptcp.h      |  2 ++
 net/mptcp/pm.c           | 18 +++++-------------
 net/mptcp/pm_kernel.c    |  9 +++++++++
 net/mptcp/pm_userspace.c |  7 +++++++
 net/mptcp/protocol.h     |  2 ++
 5 files changed, 25 insertions(+), 13 deletions(-)

diff --git a/include/net/mptcp.h b/include/net/mptcp.h
index XXXXXXX..XXXXXXX 100644
--- a/include/net/mptcp.h
+++ b/include/net/mptcp.h
@@ -XXX,XX +XXX,XX @@ struct mptcp_pm_ops {
 	/* required */
 	bool (*allow_new_subflow)(struct mptcp_sock *msk);
 	bool (*accept_new_subflow)(const struct mptcp_sock *msk);
+	bool (*add_addr_echo)(struct mptcp_sock *msk,
+			      const struct mptcp_addr_info *addr);
 
 	/* optional */
 	int (*add_addr_received)(struct mptcp_sock *msk,
diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
index XXXXXXX..XXXXXXX 100644
--- a/net/mptcp/pm.c
+++ b/net/mptcp/pm.c
@@ -XXX,XX +XXX,XX @@ void mptcp_remote_address(const struct sock_common *skc,
 #endif
 }
 
-static bool mptcp_pm_is_init_remote_addr(struct mptcp_sock *msk,
-					 const struct mptcp_addr_info *remote)
+bool mptcp_pm_is_init_remote_addr(struct mptcp_sock *msk,
+				  const struct mptcp_addr_info *remote)
 {
 	struct mptcp_addr_info mpc_remote;
 
@@ -XXX,XX +XXX,XX @@ void mptcp_pm_add_addr_received(const struct sock *ssk,
 
 	spin_lock_bh(&pm->lock);
 
-	if (mptcp_pm_is_userspace(msk)) {
-		if (mptcp_userspace_pm_active(msk)) {
-			mptcp_pm_announce_addr(msk, addr, true);
-			mptcp_pm_add_addr_send_ack(msk);
-		} else {
-			ret = -EINVAL;
-		}
-	/* id0 should not have a different address */
-	} else if ((addr->id == 0 && !mptcp_pm_is_init_remote_addr(msk, addr)) ||
-		   (addr->id > 0 && !READ_ONCE(pm->accept_addr))) {
+	if (pm->ops->add_addr_echo(msk, addr)) {
 		mptcp_pm_announce_addr(msk, addr, true);
 		mptcp_pm_add_addr_send_ack(msk);
 	} else {
@@ -XXX,XX +XXX,XX @@ struct mptcp_pm_ops *mptcp_pm_find(const char *name)
 int mptcp_pm_validate(struct mptcp_pm_ops *pm_ops)
 {
 	if (!pm_ops->get_local_id || !pm_ops->get_priority ||
-	    !pm_ops->allow_new_subflow || !pm_ops->accept_new_subflow) {
+	    !pm_ops->allow_new_subflow || !pm_ops->accept_new_subflow ||
+	    !pm_ops->add_addr_echo) {
 		pr_err("%s does not implement required ops\n", pm_ops->name);
 		return -EINVAL;
 	}
diff --git a/net/mptcp/pm_kernel.c b/net/mptcp/pm_kernel.c
index XXXXXXX..XXXXXXX 100644
--- a/net/mptcp/pm_kernel.c
+++ b/net/mptcp/pm_kernel.c
@@ -XXX,XX +XXX,XX @@ static bool mptcp_pm_kernel_accept_new_subflow(const struct mptcp_sock *msk)
 	return READ_ONCE(msk->pm.accept_subflow);
 }
 
+static bool mptcp_pm_kernel_add_addr_echo(struct mptcp_sock *msk,
+					  const struct mptcp_addr_info *addr)
+{
+	/* id0 should not have a different address */
+	return (addr->id == 0 && !mptcp_pm_is_init_remote_addr(msk, addr)) ||
+	       (addr->id > 0 && !READ_ONCE(msk->pm.accept_addr));
+}
+
 static int mptcp_pm_kernel_add_addr_received(struct mptcp_sock *msk,
 					     const struct mptcp_addr_info *addr)
 {
@@ -XXX,XX +XXX,XX @@ struct mptcp_pm_ops mptcp_pm_kernel = {
 	.subflow_established	= mptcp_pm_kernel_subflow_established,
 	.allow_new_subflow	= mptcp_pm_kernel_allow_new_subflow,
 	.accept_new_subflow	= mptcp_pm_kernel_accept_new_subflow,
+	.add_addr_echo		= mptcp_pm_kernel_add_addr_echo,
 	.add_addr_received	= mptcp_pm_kernel_add_addr_received,
 	.init			= mptcp_pm_kernel_init,
 	.name			= "kernel",
diff --git a/net/mptcp/pm_userspace.c b/net/mptcp/pm_userspace.c
index XXXXXXX..XXXXXXX 100644
--- a/net/mptcp/pm_userspace.c
+++ b/net/mptcp/pm_userspace.c
@@ -XXX,XX +XXX,XX @@ static bool mptcp_pm_userspace_accept_new_subflow(const struct mptcp_sock *msk)
 	return mptcp_userspace_pm_active(msk);
 }
 
+static bool mptcp_pm_userspace_add_addr_echo(struct mptcp_sock *msk,
+					     const struct mptcp_addr_info *addr)
+{
+	return mptcp_userspace_pm_active(msk);
+}
+
 static void mptcp_pm_userspace_release(struct mptcp_sock *msk)
 {
 	mptcp_userspace_pm_free_local_addr_list(msk);
@@ -XXX,XX +XXX,XX @@ static struct mptcp_pm_ops mptcp_pm_userspace = {
 	.get_priority		= mptcp_pm_userspace_get_priority,
 	.allow_new_subflow	= mptcp_pm_userspace_allow_new_subflow,
 	.accept_new_subflow	= mptcp_pm_userspace_accept_new_subflow,
+	.add_addr_echo		= mptcp_pm_userspace_add_addr_echo,
 	.release		= mptcp_pm_userspace_release,
 	.name			= "userspace",
 	.owner			= THIS_MODULE,
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index XXXXXXX..XXXXXXX 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -XXX,XX +XXX,XX @@ void mptcp_pm_subflow_established(struct mptcp_sock *msk);
 bool mptcp_pm_nl_check_work_pending(struct mptcp_sock *msk);
 void mptcp_pm_subflow_check_next(struct mptcp_sock *msk,
 				 const struct mptcp_subflow_context *subflow);
+bool mptcp_pm_is_init_remote_addr(struct mptcp_sock *msk,
+				  const struct mptcp_addr_info *remote);
 bool mptcp_pm_add_addr_recv(struct mptcp_sock *msk);
 void mptcp_pm_add_addr_received(const struct sock *ssk,
 				const struct mptcp_addr_info *addr);
-- 
2.43.0

From: Geliang Tang <tanggeliang@kylinos.cn>

This patch adds an optional .rm_addr_received interface for struct
mptcp_pm_ops and invokes it in mptcp_pm_worker() without PM lock.
Since mptcp_subflow_shutdown() and mptcp_close_ssk() are sleepable
kfuncs, .rm_addr_received interface of BPF PM should be invoked by
__bpf_prog_enter_sleepable(), which can't be invoked under a lock.
This patch unlocks the pm lock before invoking this interface in
mptcp_pm_worker(), while holding this lock in mptcp_pm_rm_addr_recv().

Export mptcp_pm_rm_addr_recv() is to allow the MPTCP_PM_RM_ADDR_RECEIVED
worker can be invoke from the in-kernel PM.

With this, mptcp_pm_is_kernel() in mptcp_pm_rm_addr_or_subflow() can be
dropped.

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
---
 include/net/mptcp.h   |  1 +
 net/mptcp/pm.c        | 13 ++++++++++---
 net/mptcp/pm_kernel.c |  6 ++++++
 net/mptcp/protocol.h  |  1 +
 4 files changed, 18 insertions(+), 3 deletions(-)

From: Geliang Tang <tanggeliang@kylinos.cn>

In mptcp_pm_subflow_check_next(), instead of reducing "pm->subflows"
for the in-kernel PM in __mptcp_pm_close_subflow(), this patch moves
"pm->subflows--;" forward to let it be used by both the userspace PM
and the in-kernel PM. Then mptcp_pm_is_userspace() here can be dropped.

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
---
 net/mptcp/pm.c | 15 ++++++---------
 1 file changed, 6 insertions(+), 9 deletions(-)

diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
index XXXXXXX..XXXXXXX 100644
--- a/net/mptcp/pm.c
+++ b/net/mptcp/pm.c
@@ -XXX,XX +XXX,XX @@ void mptcp_pm_subflow_check_next(struct mptcp_sock *msk,
 	bool update_subflows;
 
 	update_subflows = subflow->request_join || subflow->mp_join;
-	if (mptcp_pm_is_userspace(msk)) {
-		if (update_subflows) {
-			spin_lock_bh(&pm->lock);
-			pm->subflows--;
-			spin_unlock_bh(&pm->lock);
-		}
-		return;
+	if (update_subflows) {
+		spin_lock_bh(&pm->lock);
+		pm->subflows--;
+		spin_unlock_bh(&pm->lock);
 	}
 
 	if (!pm->ops->subflow_established)
@@ -XXX,XX +XXX,XX @@ void mptcp_pm_subflow_check_next(struct mptcp_sock *msk,
 		return;
 
 	spin_lock_bh(&pm->lock);
-	if (update_subflows)
-		__mptcp_pm_close_subflow(msk);
+	if (update_subflows && msk->pm.subflows < mptcp_pm_get_subflows_max(msk))
+		WRITE_ONCE(msk->pm.accept_subflow, true);
 
 	/* Even if this subflow is not really established, tell the PM to try
 	 * to pick the next ones, if possible.
-- 
2.43.0

From: Geliang Tang <tanggeliang@kylinos.cn>

v4:
 - address Matt's comments in v3.
 - update pm locks in mptcp_pm_worker.
 - move the lock inside mptcp_pm_create_subflow_or_signal_addr.
 - move the lock inside mptcp_pm_nl_add_addr_received.
 - invoke add_addr_received interface from mptcp_pm_worker.
 - invoke rm_addr_received interface from mptcp_pm_rm_addr_or_subflow.
 - simply call mptcp_pm_close_subflow() in mptcp_pm_subflow_check_next.

v3:
 - merge 'bugfixes for "BPF path manager, part 6, v2"' into this set.
 - https://patchwork.kernel.org/project/mptcp/cover/cover.1742521397.git.tanggeliang@kylinos.cn/

v1:
- https://patchwork.kernel.org/project/mptcp/cover/cover.1741685260.git.tanggeliang@kylinos.cn/

New interfaces for struct mptcp_pm_ops.

Geliang Tang (9):
  Squash to "mptcp: pm: add get_local_id() interface"
  mptcp: pm: add established interfaces
  mptcp: pm: drop is_userspace in subflow_check_next
  mptcp: pm: drop redundant MPTCP_MIB_ADDADDRDROP
  mptcp: pm: add add_addr_received() interface
  mptcp: pm: add rm_addr_received() interface
  mptcp: pm: add add_addr_echo() interface
  mptcp: pm: add accept_new_subflow() interface
  mptcp: pm: add allow_new_subflow() interface

-- 
2.43.0

From: Geliang Tang <tanggeliang@kylinos.cn>

This patch adds .established and .subflow_established interfaces for
struct mptcp_pm_ops, and calls pm->ops->established/subflow_established
in from mptcp_pm_worker(). Then get rid of the corresponding code from
__mptcp_pm_kernel_worker().

Since mptcp_pm_addr_send_ack() is a sleepable kfunc, which is invoked
by mptcp_pm_create_subflow_or_signal_addr(), .established() and
.subflow_established() interfaces of BPF PM should be invoked by
__bpf_prog_enter_sleepable(), which can't be invoked under a lock.
This patch unlocks the pm lock before invoking this interface in
mptcp_pm_worker(), while holding this lock in mptcp_pm_kernel_established()
and mptcp_pm_kernel_subflow_established().

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
---
 include/net/mptcp.h   |  4 ++++
 net/mptcp/pm.c        | 32 ++++++++++++++++++++++++--------
 net/mptcp/pm_kernel.c | 25 +++++++++++--------------
 3 files changed, 39 insertions(+), 22 deletions(-)

diff --git a/include/net/mptcp.h b/include/net/mptcp.h
index XXXXXXX..XXXXXXX 100644
--- a/include/net/mptcp.h
+++ b/include/net/mptcp.h
@@ -XXX,XX +XXX,XX @@ struct mptcp_pm_ops {
 	bool (*get_priority)(struct mptcp_sock *msk,
 			     struct mptcp_addr_info *skc);
 
+	/* optional */
+	void (*established)(struct mptcp_sock *msk);
+	void (*subflow_established)(struct mptcp_sock *msk);
+
 	char			name[MPTCP_PM_NAME_MAX];
 	struct module		*owner;
 	struct list_head	list;
diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
index XXXXXXX..XXXXXXX 100644
--- a/net/mptcp/pm.c
+++ b/net/mptcp/pm.c
@@ -XXX,XX +XXX,XX @@ void mptcp_pm_fully_established(struct mptcp_sock *msk, const struct sock *ssk)
 	 * be sure to serve this event only once.
 	 */
 	if (READ_ONCE(pm->work_pending) &&
-	    !(pm->status & BIT(MPTCP_PM_ALREADY_ESTABLISHED)))
+	    !(pm->status & BIT(MPTCP_PM_ALREADY_ESTABLISHED)) &&
+	    pm->ops->established)
 		mptcp_pm_schedule_work(msk, MPTCP_PM_ESTABLISHED);
 
 	if ((pm->status & BIT(MPTCP_PM_ALREADY_ESTABLISHED)) == 0)
@@ -XXX,XX +XXX,XX @@ void mptcp_pm_subflow_established(struct mptcp_sock *msk)
 
 	pr_debug("msk=%p\n", msk);
 
-	if (!READ_ONCE(pm->work_pending))
+	if (!READ_ONCE(pm->work_pending) || !pm->ops->subflow_established)
 		return;
 
 	spin_lock_bh(&pm->lock);
@@ -XXX,XX +XXX,XX @@ void mptcp_pm_subflow_check_next(struct mptcp_sock *msk,
 		return;
 	}
 
-	if (!READ_ONCE(pm->work_pending) && !update_subflows)
+	if (!pm->ops->subflow_established ||
+	    (!READ_ONCE(pm->work_pending) && !update_subflows))
 		return;
 
 	spin_lock_bh(&pm->lock);
@@ -XXX,XX +XXX,XX @@ void mptcp_pm_add_addr_echoed(struct mptcp_sock *msk,
 
 	pr_debug("msk=%p\n", msk);
 
-	if (!READ_ONCE(pm->work_pending))
+	if (!READ_ONCE(pm->work_pending) || !pm->ops->subflow_established)
 		return;
 
 	spin_lock_bh(&pm->lock);
@@ -XXX,XX +XXX,XX @@ void mptcp_pm_worker(struct mptcp_sock *msk)
 	if (!(pm->status & MPTCP_PM_WORK_MASK))
 		return;
 
-	spin_lock_bh(&msk->pm.lock);
-
 	pr_debug("msk=%p status=%x\n", msk, pm->status);
 	if (pm->status & BIT(MPTCP_PM_ADD_ADDR_SEND_ACK)) {
+		spin_lock_bh(&pm->lock);
 		pm->status &= ~BIT(MPTCP_PM_ADD_ADDR_SEND_ACK);
 		mptcp_pm_addr_send_ack(msk);
+		spin_unlock_bh(&pm->lock);
 	}
 	if (pm->status & BIT(MPTCP_PM_RM_ADDR_RECEIVED)) {
+		spin_lock_bh(&pm->lock);
 		pm->status &= ~BIT(MPTCP_PM_RM_ADDR_RECEIVED);
 		mptcp_pm_rm_addr_recv(msk);
+		spin_unlock_bh(&pm->lock);
+	}
+	if (pm->status & BIT(MPTCP_PM_ESTABLISHED)) {
+		spin_lock_bh(&pm->lock);
+		pm->status &= ~BIT(MPTCP_PM_ESTABLISHED);
+		spin_unlock_bh(&pm->lock);
+		pm->ops->established(msk);
+	}
+	if (pm->status & BIT(MPTCP_PM_SUBFLOW_ESTABLISHED)) {
+		spin_lock_bh(&pm->lock);
+		pm->status &= ~BIT(MPTCP_PM_SUBFLOW_ESTABLISHED);
+		spin_unlock_bh(&pm->lock);
+		pm->ops->subflow_established(msk);
 	}
+	spin_lock_bh(&pm->lock);
 	__mptcp_pm_kernel_worker(msk);
-
-	spin_unlock_bh(&msk->pm.lock);
+	spin_unlock_bh(&pm->lock);
 }
 
 static void mptcp_pm_ops_init(struct mptcp_sock *msk,
diff --git a/net/mptcp/pm_kernel.c b/net/mptcp/pm_kernel.c
index XXXXXXX..XXXXXXX 100644
--- a/net/mptcp/pm_kernel.c
+++ b/net/mptcp/pm_kernel.c
@@ -XXX,XX +XXX,XX @@ static void mptcp_pm_create_subflow_or_signal_addr(struct mptcp_sock *msk)
 	local_addr_max = mptcp_pm_get_local_addr_max(msk);
 	subflows_max = mptcp_pm_get_subflows_max(msk);
 
+	spin_lock_bh(&msk->pm.lock);
 	/* do lazy endpoint usage accounting for the MPC subflows */
 	if (unlikely(!(msk->pm.status & BIT(MPTCP_PM_MPC_ENDPOINT_ACCOUNTED))) && msk->first) {
 		struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(msk->first);
@@ -XXX,XX +XXX,XX @@ static void mptcp_pm_create_subflow_or_signal_addr(struct mptcp_sock *msk)
 		 * current address announce will be completed.
 		 */
 		if (msk->pm.addr_signal & BIT(MPTCP_ADD_ADDR_SIGNAL))
-			return;
+			goto out;
 
 		if (!select_signal_address(pernet, msk, &local))
 			goto subflow;
@@ -XXX,XX +XXX,XX @@ static void mptcp_pm_create_subflow_or_signal_addr(struct mptcp_sock *msk)
 		 * continuing, and trying to create subflows.
 		 */
 		if (!mptcp_pm_alloc_anno_list(msk, &local.addr))
-			return;
+			goto out;
 
 		__clear_bit(local.addr.id, msk->pm.id_avail_bitmap);
 		msk->pm.add_addr_signaled++;
@@ -XXX,XX +XXX,XX @@ static void mptcp_pm_create_subflow_or_signal_addr(struct mptcp_sock *msk)
 		spin_lock_bh(&msk->pm.lock);
 	}
 	mptcp_pm_nl_check_work_pending(msk);
+out:
+	spin_unlock_bh(&msk->pm.lock);
 }
 
-static void mptcp_pm_nl_fully_established(struct mptcp_sock *msk)
+static void mptcp_pm_kernel_established(struct mptcp_sock *msk)
 {
 	mptcp_pm_create_subflow_or_signal_addr(msk);
 }
 
-static void mptcp_pm_nl_subflow_established(struct mptcp_sock *msk)
+static void mptcp_pm_kernel_subflow_established(struct mptcp_sock *msk)
 {
 	mptcp_pm_create_subflow_or_signal_addr(msk);
 }
@@ -XXX,XX +XXX,XX @@ static int mptcp_nl_add_subflow_or_signal_addr(struct net *net,
 		spin_lock_bh(&msk->pm.lock);
 		if (mptcp_addresses_equal(addr, &mpc_addr, addr->port))
 			msk->mpc_endpoint_id = addr->id;
-		mptcp_pm_create_subflow_or_signal_addr(msk);
 		spin_unlock_bh(&msk->pm.lock);
+		mptcp_pm_create_subflow_or_signal_addr(msk);
 		release_sock(sk);
 
 next:
@@ -XXX,XX +XXX,XX @@ static void mptcp_pm_nl_fullmesh(struct mptcp_sock *msk,
 	spin_lock_bh(&msk->pm.lock);
 	mptcp_pm_rm_subflow(msk, &list);
 	__mark_subflow_endp_available(msk, list.ids[0]);
-	mptcp_pm_create_subflow_or_signal_addr(msk);
 	spin_unlock_bh(&msk->pm.lock);
+	mptcp_pm_create_subflow_or_signal_addr(msk);
 }
 
 static void mptcp_pm_nl_set_flags_all(struct net *net,
@@ -XXX,XX +XXX,XX @@ void __mptcp_pm_kernel_worker(struct mptcp_sock *msk)
 		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);
-	}
 }
 
 static int __net_init pm_nl_init_net(struct net *net)
@@ -XXX,XX +XXX,XX @@ static void mptcp_pm_kernel_init(struct mptcp_sock *msk)
 struct mptcp_pm_ops mptcp_pm_kernel = {
 	.get_local_id		= mptcp_pm_kernel_get_local_id,
 	.get_priority		= mptcp_pm_kernel_get_priority,
+	.established		= mptcp_pm_kernel_established,
+	.subflow_established	= mptcp_pm_kernel_subflow_established,
 	.init			= mptcp_pm_kernel_init,
 	.name			= "kernel",
 	.owner			= THIS_MODULE,
-- 
2.43.0

From: Geliang Tang <tanggeliang@kylinos.cn>

This patch moves mptcp_pm_close_subflow() forward to let it be used by both
the userspace PM and the in-kernel PM in mptcp_pm_subflow_check_next().Then
mptcp_pm_is_userspace() here can be dropped.

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
---
 net/mptcp/pm.c | 12 ++----------
 1 file changed, 2 insertions(+), 10 deletions(-)

diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
index XXXXXXX..XXXXXXX 100644
--- a/net/mptcp/pm.c
+++ b/net/mptcp/pm.c
@@ -XXX,XX +XXX,XX @@ void mptcp_pm_subflow_check_next(struct mptcp_sock *msk,
 	bool update_subflows;
 
 	update_subflows = subflow->request_join || subflow->mp_join;
-	if (mptcp_pm_is_userspace(msk)) {
-		if (update_subflows) {
-			spin_lock_bh(&pm->lock);
-			pm->subflows--;
-			spin_unlock_bh(&pm->lock);
-		}
-		return;
-	}
+	if (update_subflows)
+		mptcp_pm_close_subflow(msk);
 
 	if (!pm->ops->subflow_established ||
 	    (!READ_ONCE(pm->work_pending) && !update_subflows))
 		return;
 
 	spin_lock_bh(&pm->lock);
-	if (update_subflows)
-		__mptcp_pm_close_subflow(msk);
 
 	/* Even if this subflow is not really established, tell the PM to try
 	 * to pick the next ones, if possible.
-- 
2.43.0

From: Geliang Tang <tanggeliang@kylinos.cn>

MPTCP_MIB_ADDADDRDROP MIB counter is incremented from both the in-kernel PM
and the userspace PM. This can be called only once to reduce redundant
code.

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
---
 net/mptcp/pm.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

From: Geliang Tang <tanggeliang@kylinos.cn>

This patch adds an optional .add_addr_received interface for struct
mptcp_pm_ops and invokes it in mptcp_pm_worker().

This interface is only implemented in the in-kernel PM as a wrapper
of mptcp_pm_nl_add_addr_received().

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
---
 include/net/mptcp.h   |  1 +
 net/mptcp/pm.c        | 18 +++++++++++-------
 net/mptcp/pm_kernel.c | 24 +++++++++++-------------
 net/mptcp/protocol.h  |  1 -
 4 files changed, 23 insertions(+), 21 deletions(-)

diff --git a/include/net/mptcp.h b/include/net/mptcp.h
index XXXXXXX..XXXXXXX 100644
--- a/include/net/mptcp.h
+++ b/include/net/mptcp.h
@@ -XXX,XX +XXX,XX @@ struct mptcp_pm_ops {
 	/* optional */
 	void (*established)(struct mptcp_sock *msk);
 	void (*subflow_established)(struct mptcp_sock *msk);
+	void (*add_addr_received)(struct mptcp_sock *msk);
 
 	char			name[MPTCP_PM_NAME_MAX];
 	struct module		*owner;
diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
index XXXXXXX..XXXXXXX 100644
--- a/net/mptcp/pm.c
+++ b/net/mptcp/pm.c
@@ -XXX,XX +XXX,XX @@ void mptcp_pm_add_addr_received(const struct sock *ssk,
 		   (addr->id > 0 && !READ_ONCE(pm->accept_addr))) {
 		mptcp_pm_announce_addr(msk, addr, true);
 		mptcp_pm_add_addr_send_ack(msk);
-	} else if (mptcp_pm_schedule_work(msk, MPTCP_PM_ADD_ADDR_RECEIVED)) {
-		pm->remote = *addr;
-	} else {
-		ret = -EINVAL;
+	} else if (pm->ops->add_addr_received) {
+		if (mptcp_pm_schedule_work(msk, MPTCP_PM_ADD_ADDR_RECEIVED))
+			pm->remote = *addr;
+		else
+			ret = -EINVAL;
 	}
 
 	if (ret)
@@ -XXX,XX +XXX,XX @@ void mptcp_pm_worker(struct mptcp_sock *msk)
 		return;
 
 	pr_debug("msk=%p status=%x\n", msk, pm->status);
+	if (pm->status & BIT(MPTCP_PM_ADD_ADDR_RECEIVED)) {
+		spin_lock_bh(&pm->lock);
+		pm->status &= ~BIT(MPTCP_PM_ADD_ADDR_RECEIVED);
+		spin_unlock_bh(&pm->lock);
+		pm->ops->add_addr_received(msk);
+	}
 	if (pm->status & BIT(MPTCP_PM_ADD_ADDR_SEND_ACK)) {
 		spin_lock_bh(&pm->lock);
 		pm->status &= ~BIT(MPTCP_PM_ADD_ADDR_SEND_ACK);
@@ -XXX,XX +XXX,XX @@ void mptcp_pm_worker(struct mptcp_sock *msk)
 		spin_unlock_bh(&pm->lock);
 		pm->ops->subflow_established(msk);
 	}
-	spin_lock_bh(&pm->lock);
-	__mptcp_pm_kernel_worker(msk);
-	spin_unlock_bh(&pm->lock);
 }
 
 static void mptcp_pm_ops_init(struct mptcp_sock *msk,
diff --git a/net/mptcp/pm_kernel.c b/net/mptcp/pm_kernel.c
index XXXXXXX..XXXXXXX 100644
--- a/net/mptcp/pm_kernel.c
+++ b/net/mptcp/pm_kernel.c
@@ -XXX,XX +XXX,XX @@ static void mptcp_pm_nl_add_addr_received(struct mptcp_sock *msk)
 		 msk->pm.add_addr_accepted, add_addr_accept_max,
 		 msk->pm.remote.family);
 
+	spin_lock_bh(&msk->pm.lock);
 	remote = msk->pm.remote;
 	mptcp_pm_announce_addr(msk, &remote, true);
 	mptcp_pm_addr_send_ack(msk);
 
 	if (lookup_subflow_by_daddr(&msk->conn_list, &remote))
-		return;
+		goto out;
 
 	/* pick id 0 port, if none is provided the remote address */
 	if (!remote.port)
@@ -XXX,XX +XXX,XX @@ static void mptcp_pm_nl_add_addr_received(struct mptcp_sock *msk)
 	 */
 	nr = fill_local_addresses_vec(msk, &remote, locals);
 	if (nr == 0)
-		return;
+		goto out;
 
 	spin_unlock_bh(&msk->pm.lock);
 	for (i = 0; i < nr; i++)
@@ -XXX,XX +XXX,XX @@ static void mptcp_pm_nl_add_addr_received(struct mptcp_sock *msk)
 		    msk->pm.subflows >= subflows_max)
 			WRITE_ONCE(msk->pm.accept_addr, false);
 	}
+out:
+	spin_unlock_bh(&msk->pm.lock);
 }
 
 void mptcp_pm_nl_rm_addr(struct mptcp_sock *msk, u8 rm_id)
@@ -XXX,XX +XXX,XX @@ bool mptcp_pm_nl_check_work_pending(struct mptcp_sock *msk)
 	return true;
 }
 
-/* Called under PM lock */
-void __mptcp_pm_kernel_worker(struct mptcp_sock *msk)
-{
-	struct mptcp_pm_data *pm = &msk->pm;
-
-	if (pm->status & BIT(MPTCP_PM_ADD_ADDR_RECEIVED)) {
-		pm->status &= ~BIT(MPTCP_PM_ADD_ADDR_RECEIVED);
-		mptcp_pm_nl_add_addr_received(msk);
-	}
-}
-
 static int __net_init pm_nl_init_net(struct net *net)
 {
 	struct pm_nl_pernet *pernet = pm_nl_get_pernet(net);
@@ -XXX,XX +XXX,XX @@ static struct pernet_operations mptcp_pm_pernet_ops = {
 	.size = sizeof(struct pm_nl_pernet),
 };
 
+static void mptcp_pm_kernel_add_addr_received(struct mptcp_sock *msk)
+{
+	mptcp_pm_nl_add_addr_received(msk);
+}
+
 static void mptcp_pm_kernel_init(struct mptcp_sock *msk)
 {
 	bool subflows_allowed = !!mptcp_pm_get_subflows_max(msk);
@@ -XXX,XX +XXX,XX @@ struct mptcp_pm_ops mptcp_pm_kernel = {
 	.get_priority		= mptcp_pm_kernel_get_priority,
 	.established		= mptcp_pm_kernel_established,
 	.subflow_established	= mptcp_pm_kernel_subflow_established,
+	.add_addr_received	= mptcp_pm_kernel_add_addr_received,
 	.init			= mptcp_pm_kernel_init,
 	.name			= "kernel",
 	.owner			= THIS_MODULE,
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index XXXXXXX..XXXXXXX 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -XXX,XX +XXX,XX @@ void __init mptcp_pm_kernel_register(void);
 void __init mptcp_pm_userspace_register(void);
 void __init mptcp_pm_nl_init(void);
 void mptcp_pm_worker(struct mptcp_sock *msk);
-void __mptcp_pm_kernel_worker(struct mptcp_sock *msk);
 unsigned int mptcp_pm_get_add_addr_signal_max(const struct mptcp_sock *msk);
 unsigned int mptcp_pm_get_add_addr_accept_max(const struct mptcp_sock *msk);
 unsigned int mptcp_pm_get_subflows_max(const struct mptcp_sock *msk);
-- 
2.43.0

From: Geliang Tang <tanggeliang@kylinos.cn>

This patch adds an optional .rm_addr_received interface for struct
mptcp_pm_ops and invokes it in mptcp_pm_rm_addr_or_subflow().

This interface is only implemented in the in-kernel PM as a wrapper
of mptcp_pm_nl_rm_addr().

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
---
 include/net/mptcp.h   | 1 +
 net/mptcp/pm.c        | 4 ++--
 net/mptcp/pm_kernel.c | 6 ++++++
 3 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/include/net/mptcp.h b/include/net/mptcp.h
index XXXXXXX..XXXXXXX 100644
--- a/include/net/mptcp.h
+++ b/include/net/mptcp.h
@@ -XXX,XX +XXX,XX @@ struct mptcp_pm_ops {
 	void (*established)(struct mptcp_sock *msk);
 	void (*subflow_established)(struct mptcp_sock *msk);
 	void (*add_addr_received)(struct mptcp_sock *msk);
+	void (*rm_addr_received)(struct mptcp_sock *msk, u8 id);
 
 	char			name[MPTCP_PM_NAME_MAX];
 	struct module		*owner;
diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
index XXXXXXX..XXXXXXX 100644
--- a/net/mptcp/pm.c
+++ b/net/mptcp/pm.c
@@ -XXX,XX +XXX,XX @@ static void mptcp_pm_rm_addr_or_subflow(struct mptcp_sock *msk,
 
 		if (rm_type == MPTCP_MIB_RMADDR) {
 			__MPTCP_INC_STATS(sock_net(sk), rm_type);
-			if (removed && mptcp_pm_is_kernel(msk))
-				mptcp_pm_nl_rm_addr(msk, rm_id);
+			if (removed && msk->pm.ops->rm_addr_received)
+				msk->pm.ops->rm_addr_received(msk, rm_id);
 		}
 	}
 }
diff --git a/net/mptcp/pm_kernel.c b/net/mptcp/pm_kernel.c
index XXXXXXX..XXXXXXX 100644
--- a/net/mptcp/pm_kernel.c
+++ b/net/mptcp/pm_kernel.c
@@ -XXX,XX +XXX,XX @@ static void mptcp_pm_kernel_add_addr_received(struct mptcp_sock *msk)
 	mptcp_pm_nl_add_addr_received(msk);
 }
 
+static void mptcp_pm_kernel_rm_addr_received(struct mptcp_sock *msk, u8 id)
+{
+	mptcp_pm_nl_rm_addr(msk, id);
+}
+
 static void mptcp_pm_kernel_init(struct mptcp_sock *msk)
 {
 	bool subflows_allowed = !!mptcp_pm_get_subflows_max(msk);
@@ -XXX,XX +XXX,XX @@ struct mptcp_pm_ops mptcp_pm_kernel = {
 	.established		= mptcp_pm_kernel_established,
 	.subflow_established	= mptcp_pm_kernel_subflow_established,
 	.add_addr_received	= mptcp_pm_kernel_add_addr_received,
+	.rm_addr_received	= mptcp_pm_kernel_rm_addr_received,
 	.init			= mptcp_pm_kernel_init,
 	.name			= "kernel",
 	.owner			= THIS_MODULE,
-- 
2.43.0

From: Geliang Tang <tanggeliang@kylinos.cn>

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
---
 include/net/mptcp.h      |  4 ++++
 net/mptcp/pm.c           | 20 +++++++-------------
 net/mptcp/pm_kernel.c    |  9 +++++++++
 net/mptcp/pm_userspace.c |  7 +++++++
 net/mptcp/protocol.h     |  2 ++
 5 files changed, 29 insertions(+), 13 deletions(-)

diff --git a/include/net/mptcp.h b/include/net/mptcp.h
index XXXXXXX..XXXXXXX 100644
--- a/include/net/mptcp.h
+++ b/include/net/mptcp.h
@@ -XXX,XX +XXX,XX @@ struct mptcp_pm_ops {
 	void (*add_addr_received)(struct mptcp_sock *msk);
 	void (*rm_addr_received)(struct mptcp_sock *msk, u8 id);
 
+	/* required */
+	bool (*add_addr_echo)(struct mptcp_sock *msk,
+			      const struct mptcp_addr_info *addr);
+
 	char			name[MPTCP_PM_NAME_MAX];
 	struct module		*owner;
 	struct list_head	list;
diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
index XXXXXXX..XXXXXXX 100644
--- a/net/mptcp/pm.c
+++ b/net/mptcp/pm.c
@@ -XXX,XX +XXX,XX @@ void mptcp_remote_address(const struct sock_common *skc,
 #endif
 }
 
-static bool mptcp_pm_is_init_remote_addr(struct mptcp_sock *msk,
-					 const struct mptcp_addr_info *remote)
+bool mptcp_pm_is_init_remote_addr(struct mptcp_sock *msk,
+				  const struct mptcp_addr_info *remote)
 {
 	struct mptcp_addr_info mpc_remote;
 
@@ -XXX,XX +XXX,XX @@ void mptcp_pm_add_addr_received(const struct sock *ssk,
 
 	spin_lock_bh(&pm->lock);
 
-	if (mptcp_pm_is_userspace(msk)) {
-		if (mptcp_userspace_pm_active(msk)) {
-			mptcp_pm_announce_addr(msk, addr, true);
-			mptcp_pm_add_addr_send_ack(msk);
-		} else {
-			ret = -EINVAL;
-		}
-	/* id0 should not have a different address */
-	} else if ((addr->id == 0 && !mptcp_pm_is_init_remote_addr(msk, addr)) ||
-		   (addr->id > 0 && !READ_ONCE(pm->accept_addr))) {
+	if (pm->ops->add_addr_echo(msk, addr)) {
 		mptcp_pm_announce_addr(msk, addr, true);
 		mptcp_pm_add_addr_send_ack(msk);
 	} else if (pm->ops->add_addr_received) {
@@ -XXX,XX +XXX,XX @@ void mptcp_pm_add_addr_received(const struct sock *ssk,
 			pm->remote = *addr;
 		else
 			ret = -EINVAL;
+	} else {
+		ret = -EINVAL;
 	}
 
 	if (ret)
@@ -XXX,XX +XXX,XX @@ struct mptcp_pm_ops *mptcp_pm_find(const char *name)
 
 int mptcp_pm_validate(struct mptcp_pm_ops *pm_ops)
 {
-	if (!pm_ops->get_local_id || !pm_ops->get_priority) {
+	if (!pm_ops->get_local_id || !pm_ops->get_priority ||
+	    !pm_ops->add_addr_echo) {
 		pr_err("%s does not implement required ops\n", pm_ops->name);
 		return -EINVAL;
 	}
diff --git a/net/mptcp/pm_kernel.c b/net/mptcp/pm_kernel.c
index XXXXXXX..XXXXXXX 100644
--- a/net/mptcp/pm_kernel.c
+++ b/net/mptcp/pm_kernel.c
@@ -XXX,XX +XXX,XX @@ static void mptcp_pm_kernel_rm_addr_received(struct mptcp_sock *msk, u8 id)
 	mptcp_pm_nl_rm_addr(msk, id);
 }
 
+static bool mptcp_pm_kernel_add_addr_echo(struct mptcp_sock *msk,
+					  const struct mptcp_addr_info *addr)
+{
+	/* id0 should not have a different address */
+	return (addr->id == 0 && !mptcp_pm_is_init_remote_addr(msk, addr)) ||
+	       (addr->id > 0 && !READ_ONCE(msk->pm.accept_addr));
+}
+
 static void mptcp_pm_kernel_init(struct mptcp_sock *msk)
 {
 	bool subflows_allowed = !!mptcp_pm_get_subflows_max(msk);
@@ -XXX,XX +XXX,XX @@ struct mptcp_pm_ops mptcp_pm_kernel = {
 	.subflow_established	= mptcp_pm_kernel_subflow_established,
 	.add_addr_received	= mptcp_pm_kernel_add_addr_received,
 	.rm_addr_received	= mptcp_pm_kernel_rm_addr_received,
+	.add_addr_echo		= mptcp_pm_kernel_add_addr_echo,
 	.init			= mptcp_pm_kernel_init,
 	.name			= "kernel",
 	.owner			= THIS_MODULE,
diff --git a/net/mptcp/pm_userspace.c b/net/mptcp/pm_userspace.c
index XXXXXXX..XXXXXXX 100644
--- a/net/mptcp/pm_userspace.c
+++ b/net/mptcp/pm_userspace.c
@@ -XXX,XX +XXX,XX @@ int mptcp_userspace_pm_get_addr(u8 id, struct mptcp_pm_addr_entry *addr,
 	return ret;
 }
 
+static bool mptcp_pm_userspace_add_addr_echo(struct mptcp_sock *msk,
+					     const struct mptcp_addr_info *addr)
+{
+	return mptcp_userspace_pm_active(msk);
+}
+
 static void mptcp_pm_userspace_release(struct mptcp_sock *msk)
 {
 	mptcp_userspace_pm_free_local_addr_list(msk);
@@ -XXX,XX +XXX,XX @@ static void mptcp_pm_userspace_release(struct mptcp_sock *msk)
 static struct mptcp_pm_ops mptcp_pm_userspace = {
 	.get_local_id		= mptcp_pm_userspace_get_local_id,
 	.get_priority		= mptcp_pm_userspace_get_priority,
+	.add_addr_echo		= mptcp_pm_userspace_add_addr_echo,
 	.release		= mptcp_pm_userspace_release,
 	.name			= "userspace",
 	.owner			= THIS_MODULE,
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index XXXXXXX..XXXXXXX 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -XXX,XX +XXX,XX @@ void mptcp_pm_subflow_established(struct mptcp_sock *msk);
 bool mptcp_pm_nl_check_work_pending(struct mptcp_sock *msk);
 void mptcp_pm_subflow_check_next(struct mptcp_sock *msk,
 				 const struct mptcp_subflow_context *subflow);
+bool mptcp_pm_is_init_remote_addr(struct mptcp_sock *msk,
+				  const struct mptcp_addr_info *remote);
 void mptcp_pm_add_addr_received(const struct sock *ssk,
 				const struct mptcp_addr_info *addr);
 void mptcp_pm_add_addr_echoed(struct mptcp_sock *msk,
-- 
2.43.0

From: Geliang Tang <tanggeliang@kylinos.cn>

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
---
 include/net/mptcp.h      |  1 +
 net/mptcp/pm.c           | 31 +++++++++++--------------------
 net/mptcp/pm_kernel.c    |  6 ++++++
 net/mptcp/pm_userspace.c |  6 ++++++
 net/mptcp/subflow.c      |  4 +---
 5 files changed, 25 insertions(+), 23 deletions(-)

diff --git a/include/net/mptcp.h b/include/net/mptcp.h
index XXXXXXX..XXXXXXX 100644
--- a/include/net/mptcp.h
+++ b/include/net/mptcp.h
@@ -XXX,XX +XXX,XX @@ struct mptcp_pm_ops {
 	/* required */
 	bool (*add_addr_echo)(struct mptcp_sock *msk,
 			      const struct mptcp_addr_info *addr);
+	bool (*accept_new_subflow)(const struct mptcp_sock *msk);
 
 	char			name[MPTCP_PM_NAME_MAX];
 	struct module		*owner;
diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
index XXXXXXX..XXXXXXX 100644
--- a/net/mptcp/pm.c
+++ b/net/mptcp/pm.c
@@ -XXX,XX +XXX,XX @@ bool mptcp_pm_allow_new_subflow(struct mptcp_sock *msk)
 {
 	struct mptcp_pm_data *pm = &msk->pm;
 	unsigned int subflows_max;
-	int ret = 0;
+	bool ret = true;
 
-	if (mptcp_pm_is_userspace(msk)) {
-		if (mptcp_userspace_pm_active(msk)) {
-			spin_lock_bh(&pm->lock);
-			pm->subflows++;
-			spin_unlock_bh(&pm->lock);
-			return true;
-		}
+	if (!pm->ops->accept_new_subflow(msk))
 		return false;
-	}
-
-	subflows_max = mptcp_pm_get_subflows_max(msk);
 
-	pr_debug("msk=%p subflows=%d max=%d allow=%d\n", msk, pm->subflows,
-		 subflows_max, READ_ONCE(pm->accept_subflow));
+	spin_lock_bh(&pm->lock);
+	if (!mptcp_pm_is_userspace(msk) && READ_ONCE(pm->accept_subflow)) {
+		subflows_max = mptcp_pm_get_subflows_max(msk);
 
-	/* try to avoid acquiring the lock below */
-	if (!READ_ONCE(pm->accept_subflow))
-		return false;
+		pr_debug("msk=%p subflows=%d max=%d allow=%d\n", msk, pm->subflows,
+			 subflows_max, READ_ONCE(pm->accept_subflow));
 
-	spin_lock_bh(&pm->lock);
-	if (READ_ONCE(pm->accept_subflow)) {
 		ret = pm->subflows < subflows_max;
-		if (ret && ++pm->subflows == subflows_max)
+		if (ret && pm->subflows == subflows_max - 1)
 			WRITE_ONCE(pm->accept_subflow, false);
 	}
+	if (ret)
+		pm->subflows++;
 	spin_unlock_bh(&pm->lock);
 
 	return ret;
@@ -XXX,XX +XXX,XX @@ struct mptcp_pm_ops *mptcp_pm_find(const char *name)
 int mptcp_pm_validate(struct mptcp_pm_ops *pm_ops)
 {
 	if (!pm_ops->get_local_id || !pm_ops->get_priority ||
-	    !pm_ops->add_addr_echo) {
+	    !pm_ops->add_addr_echo || !pm_ops->accept_new_subflow) {
 		pr_err("%s does not implement required ops\n", pm_ops->name);
 		return -EINVAL;
 	}
diff --git a/net/mptcp/pm_kernel.c b/net/mptcp/pm_kernel.c
index XXXXXXX..XXXXXXX 100644
--- a/net/mptcp/pm_kernel.c
+++ b/net/mptcp/pm_kernel.c
@@ -XXX,XX +XXX,XX @@ static bool mptcp_pm_kernel_add_addr_echo(struct mptcp_sock *msk,
 	       (addr->id > 0 && !READ_ONCE(msk->pm.accept_addr));
 }
 
+static bool mptcp_pm_kernel_accept_new_subflow(const struct mptcp_sock *msk)
+{
+	return READ_ONCE(msk->pm.accept_subflow);
+}
+
 static void mptcp_pm_kernel_init(struct mptcp_sock *msk)
 {
 	bool subflows_allowed = !!mptcp_pm_get_subflows_max(msk);
@@ -XXX,XX +XXX,XX @@ struct mptcp_pm_ops mptcp_pm_kernel = {
 	.add_addr_received	= mptcp_pm_kernel_add_addr_received,
 	.rm_addr_received	= mptcp_pm_kernel_rm_addr_received,
 	.add_addr_echo		= mptcp_pm_kernel_add_addr_echo,
+	.accept_new_subflow	= mptcp_pm_kernel_accept_new_subflow,
 	.init			= mptcp_pm_kernel_init,
 	.name			= "kernel",
 	.owner			= THIS_MODULE,
diff --git a/net/mptcp/pm_userspace.c b/net/mptcp/pm_userspace.c
index XXXXXXX..XXXXXXX 100644
--- a/net/mptcp/pm_userspace.c
+++ b/net/mptcp/pm_userspace.c
@@ -XXX,XX +XXX,XX @@ static bool mptcp_pm_userspace_add_addr_echo(struct mptcp_sock *msk,
 	return mptcp_userspace_pm_active(msk);
 }
 
+static bool mptcp_pm_userspace_accept_new_subflow(const struct mptcp_sock *msk)
+{
+	return mptcp_userspace_pm_active(msk);
+}
+
 static void mptcp_pm_userspace_release(struct mptcp_sock *msk)
 {
 	mptcp_userspace_pm_free_local_addr_list(msk);
@@ -XXX,XX +XXX,XX @@ static struct mptcp_pm_ops mptcp_pm_userspace = {
 	.get_local_id		= mptcp_pm_userspace_get_local_id,
 	.get_priority		= mptcp_pm_userspace_get_priority,
 	.add_addr_echo		= mptcp_pm_userspace_add_addr_echo,
+	.accept_new_subflow	= mptcp_pm_userspace_accept_new_subflow,
 	.release		= mptcp_pm_userspace_release,
 	.name			= "userspace",
 	.owner			= THIS_MODULE,
diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c
index XXXXXXX..XXXXXXX 100644
--- a/net/mptcp/subflow.c
+++ b/net/mptcp/subflow.c
@@ -XXX,XX +XXX,XX @@ static void subflow_generate_hmac(u64 key1, u64 key2, u32 nonce1, u32 nonce2,
 static bool mptcp_can_accept_new_subflow(const struct mptcp_sock *msk)
 {
 	return mptcp_is_fully_established((void *)msk) &&
-		((mptcp_pm_is_userspace(msk) &&
-		  mptcp_userspace_pm_active(msk)) ||
-		 READ_ONCE(msk->pm.accept_subflow));
+		msk->pm.ops->accept_new_subflow(msk);
 }
 
 /* validate received token and create truncated hmac and nonce for SYN-ACK */
-- 
2.43.0

From: Geliang Tang <tanggeliang@kylinos.cn>

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
---
 include/net/mptcp.h   |  3 +++
 net/mptcp/pm.c        | 13 ++-----------
 net/mptcp/pm_kernel.c | 21 +++++++++++++++++++++
 3 files changed, 26 insertions(+), 11 deletions(-)

diff --git a/include/net/mptcp.h b/include/net/mptcp.h
index XXXXXXX..XXXXXXX 100644
--- a/include/net/mptcp.h
+++ b/include/net/mptcp.h
@@ -XXX,XX +XXX,XX @@ struct mptcp_pm_ops {
 			      const struct mptcp_addr_info *addr);
 	bool (*accept_new_subflow)(const struct mptcp_sock *msk);
 
+	/* optional */
+	bool (*allow_new_subflow)(struct mptcp_sock *msk);
+
 	char			name[MPTCP_PM_NAME_MAX];
 	struct module		*owner;
 	struct list_head	list;
diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
index XXXXXXX..XXXXXXX 100644
--- a/net/mptcp/pm.c
+++ b/net/mptcp/pm.c
@@ -XXX,XX +XXX,XX @@ void mptcp_pm_new_connection(struct mptcp_sock *msk, const struct sock *ssk, int
 bool mptcp_pm_allow_new_subflow(struct mptcp_sock *msk)
 {
 	struct mptcp_pm_data *pm = &msk->pm;
-	unsigned int subflows_max;
 	bool ret = true;
 
 	if (!pm->ops->accept_new_subflow(msk))
 		return false;
 
 	spin_lock_bh(&pm->lock);
-	if (!mptcp_pm_is_userspace(msk) && READ_ONCE(pm->accept_subflow)) {
-		subflows_max = mptcp_pm_get_subflows_max(msk);
-
-		pr_debug("msk=%p subflows=%d max=%d allow=%d\n", msk, pm->subflows,
-			 subflows_max, READ_ONCE(pm->accept_subflow));
-
-		ret = pm->subflows < subflows_max;
-		if (ret && pm->subflows == subflows_max - 1)
-			WRITE_ONCE(pm->accept_subflow, false);
-	}
+	if (pm->ops->allow_new_subflow)
+		ret = pm->ops->allow_new_subflow(msk);
 	if (ret)
 		pm->subflows++;
 	spin_unlock_bh(&pm->lock);
diff --git a/net/mptcp/pm_kernel.c b/net/mptcp/pm_kernel.c
index XXXXXXX..XXXXXXX 100644
--- a/net/mptcp/pm_kernel.c
+++ b/net/mptcp/pm_kernel.c
@@ -XXX,XX +XXX,XX @@ static bool mptcp_pm_kernel_accept_new_subflow(const struct mptcp_sock *msk)
 	return READ_ONCE(msk->pm.accept_subflow);
 }
 
+static bool mptcp_pm_kernel_allow_new_subflow(struct mptcp_sock *msk)
+{
+	struct mptcp_pm_data *pm = &msk->pm;
+	unsigned int subflows_max;
+	bool ret = false;
+
+	subflows_max = mptcp_pm_get_subflows_max(msk);
+
+	pr_debug("msk=%p subflows=%d max=%d allow=%d\n", msk, pm->subflows,
+		 subflows_max, READ_ONCE(pm->accept_subflow));
+
+	if (READ_ONCE(pm->accept_subflow)) {
+		ret = pm->subflows < subflows_max;
+		if (ret && pm->subflows == subflows_max - 1)
+			WRITE_ONCE(pm->accept_subflow, false);
+	}
+
+	return ret;
+}
+
 static void mptcp_pm_kernel_init(struct mptcp_sock *msk)
 {
 	bool subflows_allowed = !!mptcp_pm_get_subflows_max(msk);
@@ -XXX,XX +XXX,XX @@ struct mptcp_pm_ops mptcp_pm_kernel = {
 	.rm_addr_received	= mptcp_pm_kernel_rm_addr_received,
 	.add_addr_echo		= mptcp_pm_kernel_add_addr_echo,
 	.accept_new_subflow	= mptcp_pm_kernel_accept_new_subflow,
+	.allow_new_subflow	= mptcp_pm_kernel_allow_new_subflow,
 	.init			= mptcp_pm_kernel_init,
 	.name			= "kernel",
 	.owner			= THIS_MODULE,
-- 
2.43.0