mptcp: pm: rename 'subflows' to 'extra_subflows'

A few variables linked to the Path-Managers are confusing, and it would
help current and future developers, to clarify them.

One of them is 'subflows', which in fact represents the number of extra
subflows: all the additional subflows created after the initial one, and
not the total number of subflows.

While at it, add an additional name for the corresponding variable in
MPTCP INFO: mptcpi_extra_subflows. Not to break the current uAPI, the
new name is added as a 'define' pointing to the former name. This will
then also help userspace devs.

No functional changes intended.

Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250925-net-next-mptcp-c-flag-laminar-v1-5-ad126cc47c6b@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/include/uapi/linux/mptcp.h b/include/uapi/linux/mptcp.h
index 15eef878690b8556af21be8d959b6a2c9fe617d3..f807c8dba56e7eb278fce0ad3184de3d0e24399b 100644 (file)
--- a/include/uapi/linux/mptcp.h
+++ b/include/uapi/linux/mptcp.h
@@ -42,6 +42,7 @@
 
 struct mptcp_info {
        __u8    mptcpi_subflows;
+       #define mptcpi_extra_subflows mptcpi_subflows
        __u8    mptcpi_add_addr_signal;
        __u8    mptcpi_add_addr_accepted;
        __u8    mptcpi_subflows_max;

diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
index 584cab90aa6eff4c01cdf4ca4d3dce8894829920..332e96bdadc0b936704188e5c9666cba97817b16 100644 (file)
--- a/net/mptcp/pm.c
+++ b/net/mptcp/pm.c
@@ -489,7 +489,7 @@ bool mptcp_pm_allow_new_subflow(struct mptcp_sock *msk)
        if (mptcp_pm_is_userspace(msk)) {
                if (mptcp_userspace_pm_active(msk)) {
                        spin_lock_bh(&pm->lock);
-                       pm->subflows++;
+                       pm->extra_subflows++;
                        spin_unlock_bh(&pm->lock);
                        return true;
                }
@@ -498,8 +498,9 @@ bool mptcp_pm_allow_new_subflow(struct mptcp_sock *msk)
 
        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));
+       pr_debug("msk=%p subflows=%d max=%d allow=%d\n", msk,
+                pm->extra_subflows, subflows_max,
+                READ_ONCE(pm->accept_subflow));
 
        /* try to avoid acquiring the lock below */
        if (!READ_ONCE(pm->accept_subflow))
@@ -507,8 +508,8 @@ bool mptcp_pm_allow_new_subflow(struct mptcp_sock *msk)
 
        spin_lock_bh(&pm->lock);
        if (READ_ONCE(pm->accept_subflow)) {
-               ret = pm->subflows < subflows_max;
-               if (ret && ++pm->subflows == subflows_max)
+               ret = pm->extra_subflows < subflows_max;
+               if (ret && ++pm->extra_subflows == subflows_max)
                        WRITE_ONCE(pm->accept_subflow, false);
        }
        spin_unlock_bh(&pm->lock);
@@ -594,7 +595,7 @@ void mptcp_pm_subflow_check_next(struct mptcp_sock *msk,
        if (mptcp_pm_is_userspace(msk)) {
                if (update_subflows) {
                        spin_lock_bh(&pm->lock);
-                       pm->subflows--;
+                       pm->extra_subflows--;
                        spin_unlock_bh(&pm->lock);
                }
                return;

diff --git a/net/mptcp/pm_kernel.c b/net/mptcp/pm_kernel.c
index a82c077b8a20ccda2b4fc3cf7a55141bd01760f2..20bee6fc06259a0211782c94c1693ffe79dae1b6 100644 (file)
--- a/net/mptcp/pm_kernel.c
+++ b/net/mptcp/pm_kernel.c
@@ -175,7 +175,7 @@ fill_remote_addr(struct mptcp_sock *msk, struct mptcp_addr_info *local,
        if (!mptcp_pm_addr_families_match(sk, local, &remote))
                return 0;
 
-       msk->pm.subflows++;
+       msk->pm.extra_subflows++;
        *addrs = remote;
 
        return 1;
@@ -218,10 +218,10 @@ fill_remote_addresses_fullmesh(struct mptcp_sock *msk,
 
                /* forbid creating multiple address towards this id */
                __set_bit(addrs[i].id, unavail_id);
-               msk->pm.subflows++;
+               msk->pm.extra_subflows++;
                i++;
 
-               if (msk->pm.subflows >= subflows_max)
+               if (msk->pm.extra_subflows >= subflows_max)
                        break;
        }
 
@@ -313,7 +313,7 @@ static void mptcp_pm_create_subflow_or_signal_addr(struct mptcp_sock *msk)
        pr_debug("local %d:%d signal %d:%d subflows %d:%d\n",
                 msk->pm.local_addr_used, local_addr_max,
                 msk->pm.add_addr_signaled, add_addr_signal_max,
-                msk->pm.subflows, subflows_max);
+                msk->pm.extra_subflows, subflows_max);
 
        /* check first for announce */
        if (msk->pm.add_addr_signaled < add_addr_signal_max) {
@@ -353,7 +353,7 @@ static void mptcp_pm_create_subflow_or_signal_addr(struct mptcp_sock *msk)
 subflow:
        /* check if should create a new subflow */
        while (msk->pm.local_addr_used < local_addr_max &&
-              msk->pm.subflows < subflows_max) {
+              msk->pm.extra_subflows < subflows_max) {
                struct mptcp_addr_info addrs[MPTCP_PM_ADDR_MAX];
                bool fullmesh;
                int i, nr;
@@ -441,10 +441,10 @@ fill_local_addresses_vec_fullmesh(struct mptcp_sock *msk,
                if (is_id0)
                        local->addr.id = 0;
 
-               msk->pm.subflows++;
+               msk->pm.extra_subflows++;
                i++;
 
-               if (msk->pm.subflows >= subflows_max)
+               if (msk->pm.extra_subflows >= subflows_max)
                        break;
        }
        rcu_read_unlock();
@@ -483,10 +483,10 @@ fill_local_addresses_vec_c_flag(struct mptcp_sock *msk,
                        continue;
 
                msk->pm.local_addr_used++;
-               msk->pm.subflows++;
+               msk->pm.extra_subflows++;
                i++;
 
-               if (msk->pm.subflows >= subflows_max)
+               if (msk->pm.extra_subflows >= subflows_max)
                        break;
        }
 
@@ -510,7 +510,7 @@ fill_local_address_any(struct mptcp_sock *msk, struct mptcp_addr_info *remote,
        if (!mptcp_pm_addr_families_match(sk, &local->addr, remote))
                return 0;
 
-       msk->pm.subflows++;
+       msk->pm.extra_subflows++;
 
        return 1;
 }
@@ -586,7 +586,7 @@ static void mptcp_pm_nl_add_addr_received(struct mptcp_sock *msk)
                if (remote.id)
                        msk->pm.add_addr_accepted++;
                if (msk->pm.add_addr_accepted >= add_addr_accept_max ||
-                   msk->pm.subflows >= subflows_max)
+                   msk->pm.extra_subflows >= subflows_max)
                        WRITE_ONCE(msk->pm.accept_addr, false);
        }
 }
@@ -1427,7 +1427,7 @@ bool mptcp_pm_nl_check_work_pending(struct mptcp_sock *msk)
 {
        struct pm_nl_pernet *pernet = pm_nl_get_pernet_from_msk(msk);
 
-       if (msk->pm.subflows == mptcp_pm_get_subflows_max(msk) ||
+       if (msk->pm.extra_subflows == mptcp_pm_get_subflows_max(msk) ||
            (find_next_and_bit(pernet->id_bitmap, msk->pm.id_avail_bitmap,
                               MPTCP_PM_MAX_ADDR_ID + 1, 0) == MPTCP_PM_MAX_ADDR_ID + 1)) {
                WRITE_ONCE(msk->pm.work_pending, false);

diff --git a/net/mptcp/pm_userspace.c b/net/mptcp/pm_userspace.c
index a715dcbe0146ed0c055d071c63257047a90a9afd..8cbc1920afb492a03eff84317b08684ee58c6bc9 100644 (file)
--- a/net/mptcp/pm_userspace.c
+++ b/net/mptcp/pm_userspace.c
@@ -419,7 +419,7 @@ int mptcp_pm_nl_subflow_create_doit(struct sk_buff *skb, struct genl_info *info)
        if (err)
                mptcp_userspace_pm_delete_local_addr(msk, &entry);
        else
-               msk->pm.subflows++;
+               msk->pm.extra_subflows++;
        spin_unlock_bh(&msk->pm.lock);
 
  create_err:

diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index cbe54331e5c745989af50409d9cb79c6d90a8201..ca68f9a7580149e43139ec6cc61a1e0b966e7a22 100644 (file)
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -235,7 +235,7 @@ struct mptcp_pm_data {
        u8              add_addr_accepted;
        u8              local_addr_used;
        u8              pm_type;
-       u8              subflows;
+       u8              extra_subflows;
        u8              status;
 
        );
@@ -1188,7 +1188,7 @@ unsigned int mptcp_pm_get_local_addr_max(const struct mptcp_sock *msk);
 /* called under PM lock */
 static inline void __mptcp_pm_close_subflow(struct mptcp_sock *msk)
 {
-       if (--msk->pm.subflows < mptcp_pm_get_subflows_max(msk))
+       if (--msk->pm.extra_subflows < mptcp_pm_get_subflows_max(msk))
                WRITE_ONCE(msk->pm.accept_subflow, true);
 }
 
@@ -1204,7 +1204,7 @@ static inline bool mptcp_pm_add_addr_c_flag_case(struct mptcp_sock *msk)
        return READ_ONCE(msk->pm.remote_deny_join_id0) &&
               msk->pm.local_addr_used == 0 &&
               mptcp_pm_get_add_addr_accept_max(msk) == 0 &&
-              msk->pm.subflows < mptcp_pm_get_subflows_max(msk);
+              msk->pm.extra_subflows < mptcp_pm_get_subflows_max(msk);
 }
 
 void mptcp_sockopt_sync_locked(struct mptcp_sock *msk, struct sock *ssk);

diff --git a/net/mptcp/sockopt.c b/net/mptcp/sockopt.c
index 2abe6f1e99400498e915176c360be9281fd524f6..17966da80239d731de925f3e4211b3ee00f802e4 100644 (file)
--- a/net/mptcp/sockopt.c
+++ b/net/mptcp/sockopt.c
@@ -962,7 +962,7 @@ void mptcp_diag_fill_info(struct mptcp_sock *msk, struct mptcp_info *info)
 
        memset(info, 0, sizeof(*info));
 
-       info->mptcpi_subflows = READ_ONCE(msk->pm.subflows);
+       info->mptcpi_extra_subflows = READ_ONCE(msk->pm.extra_subflows);
        info->mptcpi_add_addr_signal = READ_ONCE(msk->pm.add_addr_signaled);
        info->mptcpi_add_addr_accepted = READ_ONCE(msk->pm.add_addr_accepted);
        info->mptcpi_local_addr_used = READ_ONCE(msk->pm.local_addr_used);
@@ -996,7 +996,7 @@ void mptcp_diag_fill_info(struct mptcp_sock *msk, struct mptcp_info *info)
        info->mptcpi_bytes_sent = msk->bytes_sent;
        info->mptcpi_bytes_received = msk->bytes_received;
        info->mptcpi_bytes_retrans = msk->bytes_retrans;
-       info->mptcpi_subflows_total = info->mptcpi_subflows +
+       info->mptcpi_subflows_total = info->mptcpi_extra_subflows +
                __mptcp_has_initial_subflow(msk);
        now = tcp_jiffies32;
        info->mptcpi_last_data_sent = jiffies_to_msecs(now - msk->last_data_sent);

diff --git a/tools/testing/selftests/bpf/progs/mptcp_subflow.c b/tools/testing/selftests/bpf/progs/mptcp_subflow.c
index 70302477e326eecaef6aad4ecf899aa3d6606f23..41389e579578b7d6c0d9ffff520c9f3e930abb51 100644 (file)
--- a/tools/testing/selftests/bpf/progs/mptcp_subflow.c
+++ b/tools/testing/selftests/bpf/progs/mptcp_subflow.c
@@ -117,7 +117,7 @@ int _getsockopt_subflow(struct bpf_sockopt *ctx)
                return 1;
 
        msk = bpf_core_cast(sk, struct mptcp_sock);
-       if (msk->pm.subflows != 1) {
+       if (msk->pm.extra_subflows != 1) {
                ctx->retval = -1;
                return 1;
        }