From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0701023CB for ; Sat, 30 Jul 2022 08:05:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1659168305; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=C9K/Bki4tqwadc02E6yhA68T2+vw/VGE/d5nDEgpjBY=; b=i6OEuZ8r6E2DItMp36fWcBex9gICa1NTXIF3p0U3vpvc2TXU17uOYcPdkapZM2oIBfprQb QFmHRXB/m4C/2DtoqHp200O/BLJvt0f2lGxP+Lf0ckzHXs8OxpQPFNPHP7kq1DrnjXUvm0 tiWjvGNGXGCwIiUnh1jM4D1KH4vzYvk= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-131-vvLJfRYBPYSgDDxTcEXczw-1; Sat, 30 Jul 2022 04:04:59 -0400 X-MC-Unique: vvLJfRYBPYSgDDxTcEXczw-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 3F00685A584 for ; Sat, 30 Jul 2022 08:04:59 +0000 (UTC) Received: from gerbillo.redhat.com (unknown [10.39.192.37]) by smtp.corp.redhat.com (Postfix) with ESMTP id C16092026D64 for ; Sat, 30 Jul 2022 08:04:58 +0000 (UTC) From: Paolo Abeni To: mptcp@lists.linux.dev Subject: [PATCH v3 mptcp-next 3/4] mptcp: move msk input path under full msk socket lock Date: Sat, 30 Jul 2022 10:04:41 +0200 Message-Id: <77525c9134c096a13ebc0dda30d8696d9f64eb9a.1659165378.git.pabeni@redhat.com> In-Reply-To: References: Precedence: bulk X-Mailing-List: mptcp@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.78 on 10.11.54.4 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=pabeni@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset="US-ASCII"; x-default=true After commit c2e6048fa1cf ("mptcp: fix race in release_cb") it's pretty straight forward move the whole MPTCP rx path under the socket lock leveraging the release_cb. We can drop a bunch of spin_lock pairs in the receive functions, use a single receive queue and invoke __mptcp_move_skbs only when subflows ask for it. This will allow more cleanup in the next patch. Signed-off-by: Paolo Abeni --- net/mptcp/protocol.c | 78 +++++++++++++++++++------------------------- net/mptcp/protocol.h | 2 +- 2 files changed, 35 insertions(+), 45 deletions(-) diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index 17e2dbe43639..a916637b687f 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -795,7 +795,7 @@ static bool move_skbs_to_msk(struct mptcp_sock *msk, struct sock *ssk) return moved > 0; } -void mptcp_data_ready(struct sock *sk, struct sock *ssk) +static void __mptcp_data_ready(struct sock *sk, struct sock *ssk) { struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); @@ -807,10 +807,17 @@ void mptcp_data_ready(struct sock *sk, struct sock *ssk) return; /* Wake-up the reader only for in-sequence data */ - mptcp_data_lock(sk); if (move_skbs_to_msk(mptcp_sk(sk), ssk)) sk->sk_data_ready(sk); +} +void mptcp_data_ready(struct sock *sk, struct sock *ssk) +{ + mptcp_data_lock(sk); + if (!sock_owned_by_user(sk)) + __mptcp_data_ready(sk, ssk); + else + __set_bit(MPTCP_DEQUEUE, &mptcp_sk(sk)->cb_flags); mptcp_data_unlock(sk); } @@ -1768,16 +1775,22 @@ static int mptcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) return copied ? : ret; } -static int __mptcp_recvmsg_mskq(struct mptcp_sock *msk, +static bool __mptcp_move_skbs(struct sock *sk); + +static int __mptcp_recvmsg_mskq(struct sock *sk, struct msghdr *msg, size_t len, int flags, struct scm_timestamping_internal *tss, int *cmsg_flags) { + struct mptcp_sock *msk = mptcp_sk(sk); struct sk_buff *skb, *tmp; int copied = 0; - skb_queue_walk_safe(&msk->receive_queue, skb, tmp) { + if (skb_queue_empty(&sk->sk_receive_queue) && !__mptcp_move_skbs(sk)) + return 0; + + skb_queue_walk_safe(&sk->sk_receive_queue, skb, tmp) { u32 offset = MPTCP_SKB_CB(skb)->offset; u32 data_len = skb->len - offset; u32 count = min_t(size_t, len - copied, data_len); @@ -1811,7 +1824,7 @@ static int __mptcp_recvmsg_mskq(struct mptcp_sock *msk, /* we will bulk release the skb memory later */ skb->destructor = NULL; WRITE_ONCE(msk->rmem_released, msk->rmem_released + skb->truesize); - __skb_unlink(skb, &msk->receive_queue); + __skb_unlink(skb, &sk->sk_receive_queue); __kfree_skb(skb); } @@ -1932,16 +1945,9 @@ static void __mptcp_update_rmem(struct sock *sk) WRITE_ONCE(msk->rmem_released, 0); } -static void __mptcp_splice_receive_queue(struct sock *sk) +static bool __mptcp_move_skbs(struct sock *sk) { struct mptcp_sock *msk = mptcp_sk(sk); - - skb_queue_splice_tail_init(&sk->sk_receive_queue, &msk->receive_queue); -} - -static bool __mptcp_move_skbs(struct mptcp_sock *msk) -{ - struct sock *sk = (struct sock *)msk; unsigned int moved = 0; bool ret, done; @@ -1949,37 +1955,29 @@ static bool __mptcp_move_skbs(struct mptcp_sock *msk) struct sock *ssk = mptcp_subflow_recv_lookup(msk); bool slowpath; - /* we can have data pending in the subflows only if the msk - * receive buffer was full at subflow_data_ready() time, - * that is an unlikely slow path. - */ - if (likely(!ssk)) + if (unlikely(!ssk)) break; slowpath = lock_sock_fast(ssk); - mptcp_data_lock(sk); __mptcp_update_rmem(sk); done = __mptcp_move_skbs_from_subflow(msk, ssk, &moved); - mptcp_data_unlock(sk); if (unlikely(ssk->sk_err)) __mptcp_error_report(sk); unlock_sock_fast(ssk, slowpath); } while (!done); - /* acquire the data lock only if some input data is pending */ ret = moved > 0; if (!RB_EMPTY_ROOT(&msk->out_of_order_queue) || - !skb_queue_empty_lockless(&sk->sk_receive_queue)) { - mptcp_data_lock(sk); + !skb_queue_empty(&sk->sk_receive_queue)) { __mptcp_update_rmem(sk); ret |= __mptcp_ofo_queue(msk); - __mptcp_splice_receive_queue(sk); - mptcp_data_unlock(sk); } - if (ret) + if (ret) { + mptcp_cleanup_rbuf(msk); mptcp_check_data_fin((struct sock *)msk); - return !skb_queue_empty(&msk->receive_queue); + } + return ret; } static unsigned int mptcp_inq_hint(const struct sock *sk) @@ -1987,7 +1985,7 @@ static unsigned int mptcp_inq_hint(const struct sock *sk) const struct mptcp_sock *msk = mptcp_sk(sk); const struct sk_buff *skb; - skb = skb_peek(&msk->receive_queue); + skb = skb_peek(&sk->sk_receive_queue); if (skb) { u64 hint_val = msk->ack_seq - MPTCP_SKB_CB(skb)->map_seq; @@ -2033,7 +2031,7 @@ static int mptcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, while (copied < len) { int bytes_read; - bytes_read = __mptcp_recvmsg_mskq(msk, msg, len - copied, flags, &tss, &cmsg_flags); + bytes_read = __mptcp_recvmsg_mskq(sk, msg, len - copied, flags, &tss, &cmsg_flags); if (unlikely(bytes_read < 0)) { if (!copied) copied = bytes_read; @@ -2045,9 +2043,6 @@ static int mptcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, /* be sure to advertise window change */ mptcp_cleanup_rbuf(msk); - if (skb_queue_empty(&msk->receive_queue) && __mptcp_move_skbs(msk)) - continue; - /* only the master socket status is relevant here. The exit * conditions mirror closely tcp_recvmsg() */ @@ -2074,7 +2069,7 @@ static int mptcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, /* race breaker: the shutdown could be after the * previous receive queue check */ - if (__mptcp_move_skbs(msk)) + if (__mptcp_move_skbs(sk)) continue; break; } @@ -2111,9 +2106,8 @@ static int mptcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, } } - pr_debug("msk=%p rx queue empty=%d:%d copied=%d", - msk, skb_queue_empty_lockless(&sk->sk_receive_queue), - skb_queue_empty(&msk->receive_queue), copied); + pr_debug("msk=%p rx queue empty=%d copied=%d", + msk, skb_queue_empty(&sk->sk_receive_queue), copied); if (!(flags & MSG_PEEK)) mptcp_rcv_space_adjust(msk, copied); @@ -2566,7 +2560,6 @@ static int __mptcp_init_sock(struct sock *sk) INIT_LIST_HEAD(&msk->join_list); INIT_LIST_HEAD(&msk->rtx_queue); INIT_WORK(&msk->work, mptcp_worker); - __skb_queue_head_init(&msk->receive_queue); msk->out_of_order_queue = RB_ROOT; msk->first_pending = NULL; msk->rmem_fwd_alloc = 0; @@ -3048,12 +3041,8 @@ void mptcp_destroy_common(struct mptcp_sock *msk, unsigned int flags) mptcp_for_each_subflow_safe(msk, subflow, tmp) __mptcp_close_ssk(sk, mptcp_subflow_tcp_sock(subflow), subflow, flags); - /* move to sk_receive_queue, sk_stream_kill_queues will purge it */ - mptcp_data_lock(sk); - skb_queue_splice_tail_init(&msk->receive_queue, &sk->sk_receive_queue); __skb_queue_purge(&sk->sk_receive_queue); skb_rbtree_purge(&msk->out_of_order_queue); - mptcp_data_unlock(sk); /* move all the rx fwd alloc into the sk_mem_reclaim_final in * inet_sock_destruct() will dispose it @@ -3135,6 +3124,8 @@ static void mptcp_release_cb(struct sock *sk) __mptcp_flush_join_list(sk); if (flags & BIT(MPTCP_PUSH_PENDING)) __mptcp_push_pending(sk, 0); + if ((flags & BIT(MPTCP_DEQUEUE)) && __mptcp_move_skbs(sk)) + sk->sk_data_ready(sk); if (flags & BIT(MPTCP_RETRANSMIT)) __mptcp_retrans(sk); @@ -3383,7 +3374,7 @@ static int mptcp_ioctl(struct sock *sk, int cmd, unsigned long arg) return -EINVAL; lock_sock(sk); - __mptcp_move_skbs(msk); + __mptcp_move_skbs(sk); answ = mptcp_inq_hint(sk); release_sock(sk); break; @@ -3619,8 +3610,7 @@ static __poll_t mptcp_check_readable(struct mptcp_sock *msk) /* Concurrent splices from sk_receive_queue into receive_queue will * always show at least one non-empty queue when checked in this order. */ - if (skb_queue_empty_lockless(&((struct sock *)msk)->sk_receive_queue) && - skb_queue_empty_lockless(&msk->receive_queue)) + if (skb_queue_empty_lockless(&((struct sock *)msk)->sk_receive_queue)) return 0; return EPOLLIN | EPOLLRDNORM; diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h index 1e603f28f1db..f12a6e80171d 100644 --- a/net/mptcp/protocol.h +++ b/net/mptcp/protocol.h @@ -125,6 +125,7 @@ #define MPTCP_FLUSH_JOIN_LIST 5 #define MPTCP_CONNECTED 6 #define MPTCP_RESET_SCHEDULER 7 +#define MPTCP_DEQUEUE 8 static inline bool before64(__u64 seq1, __u64 seq2) { @@ -288,7 +289,6 @@ struct mptcp_sock { struct work_struct work; struct sk_buff *ooo_last_skb; struct rb_root out_of_order_queue; - struct sk_buff_head receive_queue; struct list_head conn_list; struct list_head rtx_queue; struct mptcp_data_frag *first_pending; -- 2.35.3