diff options
| author | Geliang Tang <geliangtang@gmail.com> | 2020-09-24 08:29:53 +0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2020-09-24 19:58:33 -0700 |
| commit | f58f065aa10683a4e2d975c71e0238cfe2c41024 (patch) | |
| tree | 557ae8d2086063dbbec76c4817bcb4dc1cc1005d | |
| parent | be61316003d962cece23cca867aafd8e67e48a90 (diff) | |
mptcp: add accept_subflow re-check
The re-check of pm->accept_subflow with pm->lock held was missing, this
patch fixed it.
Suggested-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | net/mptcp/pm.c | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c index 39a76620d0a5..be4157279e15 100644 --- a/net/mptcp/pm.c +++ b/net/mptcp/pm.c @@ -48,7 +48,7 @@ void mptcp_pm_new_connection(struct mptcp_sock *msk, int server_side) bool mptcp_pm_allow_new_subflow(struct mptcp_sock *msk) { struct mptcp_pm_data *pm = &msk->pm; - int ret; + int ret = 0; pr_debug("msk=%p subflows=%d max=%d allow=%d", msk, pm->subflows, pm->subflows_max, READ_ONCE(pm->accept_subflow)); @@ -58,9 +58,11 @@ bool mptcp_pm_allow_new_subflow(struct mptcp_sock *msk) return false; spin_lock_bh(&pm->lock); - ret = pm->subflows < pm->subflows_max; - if (ret && ++pm->subflows == pm->subflows_max) - WRITE_ONCE(pm->accept_subflow, false); + if (READ_ONCE(pm->accept_subflow)) { + ret = pm->subflows < pm->subflows_max; + if (ret && ++pm->subflows == pm->subflows_max) + WRITE_ONCE(pm->accept_subflow, false); + } spin_unlock_bh(&pm->lock); return ret; |