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	mptcp: drop the push_pending field
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: e9d09baca6 ("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>
			
			
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					 2 changed files with 6 additions and 7 deletions
				
			
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					@ -1505,8 +1505,11 @@ static void mptcp_update_post_push(struct mptcp_sock *msk,
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void mptcp_check_and_set_pending(struct sock *sk)
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					void mptcp_check_and_set_pending(struct sock *sk)
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{
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					{
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	if (mptcp_send_head(sk))
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						if (mptcp_send_head(sk)) {
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		mptcp_sk(sk)->push_pending |= BIT(MPTCP_PUSH_PENDING);
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							mptcp_data_lock(sk);
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							mptcp_sk(sk)->cb_flags |= BIT(MPTCP_PUSH_PENDING);
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							mptcp_data_unlock(sk);
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						}
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}
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					}
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static int __subflow_push_pending(struct sock *sk, struct sock *ssk,
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					static int __subflow_push_pending(struct sock *sk, struct sock *ssk,
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					@ -3142,7 +3145,6 @@ static int mptcp_disconnect(struct sock *sk, int flags)
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	mptcp_destroy_common(msk, MPTCP_CF_FASTCLOSE);
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						mptcp_destroy_common(msk, MPTCP_CF_FASTCLOSE);
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	WRITE_ONCE(msk->flags, 0);
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						WRITE_ONCE(msk->flags, 0);
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	msk->cb_flags = 0;
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						msk->cb_flags = 0;
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	msk->push_pending = 0;
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	msk->recovery = false;
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						msk->recovery = false;
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	msk->can_ack = false;
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						msk->can_ack = false;
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	msk->fully_established = false;
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						msk->fully_established = false;
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					@ -3330,8 +3332,7 @@ static void mptcp_release_cb(struct sock *sk)
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	struct mptcp_sock *msk = mptcp_sk(sk);
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						struct mptcp_sock *msk = mptcp_sk(sk);
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	for (;;) {
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						for (;;) {
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		unsigned long flags = (msk->cb_flags & MPTCP_FLAGS_PROCESS_CTX_NEED) |
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							unsigned long flags = (msk->cb_flags & MPTCP_FLAGS_PROCESS_CTX_NEED);
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				      msk->push_pending;
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		struct list_head join_list;
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							struct list_head join_list;
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		if (!flags)
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							if (!flags)
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					@ -3347,7 +3348,6 @@ static void mptcp_release_cb(struct sock *sk)
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		 *    datapath acquires the msk socket spinlock while helding
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							 *    datapath acquires the msk socket spinlock while helding
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		 *    the subflow socket lock
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							 *    the subflow socket lock
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		 */
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							 */
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		msk->push_pending = 0;
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		msk->cb_flags &= ~flags;
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							msk->cb_flags &= ~flags;
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		spin_unlock_bh(&sk->sk_lock.slock);
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							spin_unlock_bh(&sk->sk_lock.slock);
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					@ -286,7 +286,6 @@ struct mptcp_sock {
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	int		rmem_released;
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						int		rmem_released;
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	unsigned long	flags;
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						unsigned long	flags;
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	unsigned long	cb_flags;
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						unsigned long	cb_flags;
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	unsigned long	push_pending;
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	bool		recovery;		/* closing subflow write queue reinjected */
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						bool		recovery;		/* closing subflow write queue reinjected */
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	bool		can_ack;
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						bool		can_ack;
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	bool		fully_established;
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						bool		fully_established;
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