This is a note to let you know that I've just added the patch titled
mptcp: drop the push_pending field
to the 6.6-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
mptcp-drop-the-push_pending-field.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From bdd70eb68913c960acb895b00a8c62eb64715b1f Mon Sep 17 00:00:00 2001
From: Paolo Abeni <pabeni@xxxxxxxxxx>
Date: Thu, 8 Feb 2024 19:03:49 +0100
Subject: mptcp: drop the push_pending field
From: Paolo Abeni <pabeni@xxxxxxxxxx>
commit bdd70eb68913c960acb895b00a8c62eb64715b1f upstream.
Such field is there to avoid acquiring the data lock in a few spots,
but it adds complexity to the already non trivial locking schema.
All the relevant call sites (mptcp-level re-injection, set socket
options), are slow-path, drop such field in favor of 'cb_flags', adding
the relevant locking.
This patch could be seen as an improvement, instead of a fix. But it
simplifies the next patch. The 'Fixes' tag has been added to help having
this series backported to stable.
Fixes: e9d09baca676 ("mptcp: avoid atomic bit manipulation when possible")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Paolo Abeni <pabeni@xxxxxxxxxx>
Reviewed-by: Mat Martineau <martineau@xxxxxxxxxx>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/mptcp/protocol.c | 12 ++++++------
net/mptcp/protocol.h | 1 -
2 files changed, 6 insertions(+), 7 deletions(-)
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -1522,8 +1522,11 @@ static void mptcp_update_post_push(struc
void mptcp_check_and_set_pending(struct sock *sk)
{
- if (mptcp_send_head(sk))
- mptcp_sk(sk)->push_pending |= BIT(MPTCP_PUSH_PENDING);
+ if (mptcp_send_head(sk)) {
+ mptcp_data_lock(sk);
+ mptcp_sk(sk)->cb_flags |= BIT(MPTCP_PUSH_PENDING);
+ mptcp_data_unlock(sk);
+ }
}
static int __subflow_push_pending(struct sock *sk, struct sock *ssk,
@@ -3134,7 +3137,6 @@ static int mptcp_disconnect(struct sock
mptcp_destroy_common(msk, MPTCP_CF_FASTCLOSE);
WRITE_ONCE(msk->flags, 0);
msk->cb_flags = 0;
- msk->push_pending = 0;
msk->recovery = false;
msk->can_ack = false;
msk->fully_established = false;
@@ -3359,8 +3361,7 @@ static void mptcp_release_cb(struct sock
struct mptcp_sock *msk = mptcp_sk(sk);
for (;;) {
- unsigned long flags = (msk->cb_flags & MPTCP_FLAGS_PROCESS_CTX_NEED) |
- msk->push_pending;
+ unsigned long flags = (msk->cb_flags & MPTCP_FLAGS_PROCESS_CTX_NEED);
struct list_head join_list;
if (!flags)
@@ -3376,7 +3377,6 @@ static void mptcp_release_cb(struct sock
* datapath acquires the msk socket spinlock while helding
* the subflow socket lock
*/
- msk->push_pending = 0;
msk->cb_flags &= ~flags;
spin_unlock_bh(&sk->sk_lock.slock);
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -283,7 +283,6 @@ struct mptcp_sock {
int rmem_released;
unsigned long flags;
unsigned long cb_flags;
- unsigned long push_pending;
bool recovery; /* closing subflow write queue reinjected */
bool can_ack;
bool fully_established;
Patches currently in stable-queue which might be from pabeni@xxxxxxxxxx are
queue-6.6/mptcp-really-cope-with-fastopen-race.patch
queue-6.6/mptcp-fix-rcv-space-initialization.patch
queue-6.6/mptcp-drop-the-push_pending-field.patch
queue-6.6/net-stmmac-do-not-clear-tbs-enable-bit-on-link-up-down.patch
queue-6.6/mptcp-fix-data-re-injection-from-stale-subflow.patch
queue-6.6/selftests-mptcp-increase-timeout-to-30-min.patch
queue-6.6/connector-cn_proc-revert-connector-fix-proc_event_num_listeners-count-not-cleared.patch
queue-6.6/selftests-net-fix-bridge-backup-port-test-flakiness.patch
