6.1-stable review patch. If anyone has any objections, please let me know.
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From: Paolo Abeni pabeni@redhat.com
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@vger.kernel.org Signed-off-by: Paolo Abeni pabeni@redhat.com Reviewed-by: Mat Martineau martineau@kernel.org Signed-off-by: Matthieu Baerts (NGI0) matttbe@kernel.org Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- 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 @@ -1582,8 +1582,11 @@ 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); + } }
void __mptcp_push_pending(struct sock *sk, unsigned int flags) @@ -3140,7 +3143,6 @@ static int mptcp_disconnect(struct sock msk->last_snd = NULL; WRITE_ONCE(msk->flags, 0); msk->cb_flags = 0; - msk->push_pending = 0; msk->recovery = false; msk->can_ack = false; msk->fully_established = false; @@ -3384,8 +3386,7 @@ 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) @@ -3401,7 +3402,6 @@ 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 @@ -272,7 +272,6 @@ 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;