From: Paolo Abeni <pab...@redhat.com>
If we receive a MPTCP_PUSH_PENDING even from a subflow when
mptcp_release_cb() is serving the previous one, the latter
will be delayed up to the next release_sock(msk).
Address the issue implementing a test/serve loop for such
event.
Additionally rename the push helper to __mptcp_push_pending()
to be more consistent with the existing code.
Fixes: 6e628cd3a8f7 ("mptcp: use mptcp release_cb for delayed tasks")
Signed-off-by: Paolo Abeni <pab...@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martin...@linux.intel.com>
---
net/mptcp/protocol.c | 33 +++++++++++++++++++++------------
1 file changed, 21 insertions(+), 12 deletions(-)
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index 67aaf7154dca..d2a2169e6d9e 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -1445,7 +1445,7 @@ static void mptcp_push_release(struct sock *sk, struct
sock *ssk,
release_sock(ssk);
}
-static void mptcp_push_pending(struct sock *sk, unsigned int flags)
+static void __mptcp_push_pending(struct sock *sk, unsigned int flags)
{
struct sock *prev_ssk = NULL, *ssk = NULL;
struct mptcp_sock *msk = mptcp_sk(sk);
@@ -1697,14 +1697,14 @@ static int mptcp_sendmsg(struct sock *sk, struct msghdr
*msg, size_t len)
wait_for_memory:
mptcp_set_nospace(sk);
- mptcp_push_pending(sk, msg->msg_flags);
+ __mptcp_push_pending(sk, msg->msg_flags);
ret = sk_stream_wait_memory(sk, &timeo);
if (ret)
goto out;
}
if (copied)
- mptcp_push_pending(sk, msg->msg_flags);
+ __mptcp_push_pending(sk, msg->msg_flags);
out:
release_sock(sk);
@@ -2959,13 +2959,14 @@ static void mptcp_release_cb(struct sock *sk)
{
unsigned long flags, nflags;
- /* push_pending may touch wmem_reserved, do it before the later
- * cleanup
- */
- if (test_and_clear_bit(MPTCP_CLEAN_UNA, &mptcp_sk(sk)->flags))
- __mptcp_clean_una(sk);
- if (test_and_clear_bit(MPTCP_PUSH_PENDING, &mptcp_sk(sk)->flags)) {
- /* mptcp_push_pending() acquires the subflow socket lock
+ for (;;) {
+ flags = 0;
+ if (test_and_clear_bit(MPTCP_PUSH_PENDING,
&mptcp_sk(sk)->flags))
+ flags |= MPTCP_PUSH_PENDING;
+ if (!flags)
+ break;
+
+ /* the following actions acquire the subflow socket lock
*
* 1) can't be invoked in atomic scope
* 2) must avoid ABBA deadlock with msk socket spinlock: the RX
@@ -2974,13 +2975,21 @@ static void mptcp_release_cb(struct sock *sk)
*/
spin_unlock_bh(&sk->sk_lock.slock);
- mptcp_push_pending(sk, 0);
+ if (flags & MPTCP_PUSH_PENDING)
+ __mptcp_push_pending(sk, 0);
+
+ cond_resched();
spin_lock_bh(&sk->sk_lock.slock);
}
+
+ if (test_and_clear_bit(MPTCP_CLEAN_UNA, &mptcp_sk(sk)->flags))
+ __mptcp_clean_una(sk);
if (test_and_clear_bit(MPTCP_ERROR_REPORT, &mptcp_sk(sk)->flags))
__mptcp_error_report(sk);
- /* clear any wmem reservation and errors */
+ /* push_pending may touch wmem_reserved, ensure we do the cleanup
+ * later
+ */
__mptcp_update_wmem(sk);
__mptcp_update_rmem(sk);
--
2.30.1
