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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 01:02:30 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 01:02:30 +0000 |
commit | 76cb841cb886eef6b3bee341a2266c76578724ad (patch) | |
tree | f5892e5ba6cc11949952a6ce4ecbe6d516d6ce58 /net/rds/tcp_send.c | |
parent | Initial commit. (diff) | |
download | linux-76cb841cb886eef6b3bee341a2266c76578724ad.tar.xz linux-76cb841cb886eef6b3bee341a2266c76578724ad.zip |
Adding upstream version 4.19.249.upstream/4.19.249upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | net/rds/tcp_send.c | 230 |
1 files changed, 230 insertions, 0 deletions
diff --git a/net/rds/tcp_send.c b/net/rds/tcp_send.c new file mode 100644 index 000000000..78a2554a4 --- /dev/null +++ b/net/rds/tcp_send.c @@ -0,0 +1,230 @@ +/* + * Copyright (c) 2006, 2017 Oracle and/or its affiliates. All rights reserved. + * + * This software is available to you under a choice of one of two + * licenses. You may choose to be licensed under the terms of the GNU + * General Public License (GPL) Version 2, available from the file + * COPYING in the main directory of this source tree, or the + * OpenIB.org BSD license below: + * + * Redistribution and use in source and binary forms, with or + * without modification, are permitted provided that the following + * conditions are met: + * + * - Redistributions of source code must retain the above + * copyright notice, this list of conditions and the following + * disclaimer. + * + * - Redistributions in binary form must reproduce the above + * copyright notice, this list of conditions and the following + * disclaimer in the documentation and/or other materials + * provided with the distribution. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS + * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN + * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + * + */ +#include <linux/kernel.h> +#include <linux/in.h> +#include <net/tcp.h> + +#include "rds_single_path.h" +#include "rds.h" +#include "tcp.h" + +static void rds_tcp_cork(struct socket *sock, int val) +{ + kernel_setsockopt(sock, SOL_TCP, TCP_CORK, (void *)&val, sizeof(val)); +} + +void rds_tcp_xmit_path_prepare(struct rds_conn_path *cp) +{ + struct rds_tcp_connection *tc = cp->cp_transport_data; + + rds_tcp_cork(tc->t_sock, 1); +} + +void rds_tcp_xmit_path_complete(struct rds_conn_path *cp) +{ + struct rds_tcp_connection *tc = cp->cp_transport_data; + + rds_tcp_cork(tc->t_sock, 0); +} + +/* the core send_sem serializes this with other xmit and shutdown */ +static int rds_tcp_sendmsg(struct socket *sock, void *data, unsigned int len) +{ + struct kvec vec = { + .iov_base = data, + .iov_len = len, + }; + struct msghdr msg = { + .msg_flags = MSG_DONTWAIT | MSG_NOSIGNAL, + }; + + return kernel_sendmsg(sock, &msg, &vec, 1, vec.iov_len); +} + +/* the core send_sem serializes this with other xmit and shutdown */ +int rds_tcp_xmit(struct rds_connection *conn, struct rds_message *rm, + unsigned int hdr_off, unsigned int sg, unsigned int off) +{ + struct rds_conn_path *cp = rm->m_inc.i_conn_path; + struct rds_tcp_connection *tc = cp->cp_transport_data; + int done = 0; + int ret = 0; + int more; + + if (hdr_off == 0) { + /* + * m_ack_seq is set to the sequence number of the last byte of + * header and data. see rds_tcp_is_acked(). + */ + tc->t_last_sent_nxt = rds_tcp_write_seq(tc); + rm->m_ack_seq = tc->t_last_sent_nxt + + sizeof(struct rds_header) + + be32_to_cpu(rm->m_inc.i_hdr.h_len) - 1; + smp_mb__before_atomic(); + set_bit(RDS_MSG_HAS_ACK_SEQ, &rm->m_flags); + tc->t_last_expected_una = rm->m_ack_seq + 1; + + if (test_bit(RDS_MSG_RETRANSMITTED, &rm->m_flags)) + rm->m_inc.i_hdr.h_flags |= RDS_FLAG_RETRANSMITTED; + + rdsdebug("rm %p tcp nxt %u ack_seq %llu\n", + rm, rds_tcp_write_seq(tc), + (unsigned long long)rm->m_ack_seq); + } + + if (hdr_off < sizeof(struct rds_header)) { + /* see rds_tcp_write_space() */ + set_bit(SOCK_NOSPACE, &tc->t_sock->sk->sk_socket->flags); + + ret = rds_tcp_sendmsg(tc->t_sock, + (void *)&rm->m_inc.i_hdr + hdr_off, + sizeof(rm->m_inc.i_hdr) - hdr_off); + if (ret < 0) + goto out; + done += ret; + if (hdr_off + done != sizeof(struct rds_header)) + goto out; + } + + more = rm->data.op_nents > 1 ? (MSG_MORE | MSG_SENDPAGE_NOTLAST) : 0; + while (sg < rm->data.op_nents) { + int flags = MSG_DONTWAIT | MSG_NOSIGNAL | more; + + ret = tc->t_sock->ops->sendpage(tc->t_sock, + sg_page(&rm->data.op_sg[sg]), + rm->data.op_sg[sg].offset + off, + rm->data.op_sg[sg].length - off, + flags); + rdsdebug("tcp sendpage %p:%u:%u ret %d\n", (void *)sg_page(&rm->data.op_sg[sg]), + rm->data.op_sg[sg].offset + off, rm->data.op_sg[sg].length - off, + ret); + if (ret <= 0) + break; + + off += ret; + done += ret; + if (off == rm->data.op_sg[sg].length) { + off = 0; + sg++; + } + if (sg == rm->data.op_nents - 1) + more = 0; + } + +out: + if (ret <= 0) { + /* write_space will hit after EAGAIN, all else fatal */ + if (ret == -EAGAIN) { + rds_tcp_stats_inc(s_tcp_sndbuf_full); + ret = 0; + } else { + /* No need to disconnect/reconnect if path_drop + * has already been triggered, because, e.g., of + * an incoming RST. + */ + if (rds_conn_path_up(cp)) { + pr_warn("RDS/tcp: send to %pI6c on cp [%d]" + "returned %d, " + "disconnecting and reconnecting\n", + &conn->c_faddr, cp->cp_index, ret); + rds_conn_path_drop(cp, false); + } + } + } + if (done == 0) + done = ret; + return done; +} + +/* + * rm->m_ack_seq is set to the tcp sequence number that corresponds to the + * last byte of the message, including the header. This means that the + * entire message has been received if rm->m_ack_seq is "before" the next + * unacked byte of the TCP sequence space. We have to do very careful + * wrapping 32bit comparisons here. + */ +static int rds_tcp_is_acked(struct rds_message *rm, uint64_t ack) +{ + if (!test_bit(RDS_MSG_HAS_ACK_SEQ, &rm->m_flags)) + return 0; + return (__s32)((u32)rm->m_ack_seq - (u32)ack) < 0; +} + +void rds_tcp_write_space(struct sock *sk) +{ + void (*write_space)(struct sock *sk); + struct rds_conn_path *cp; + struct rds_tcp_connection *tc; + + read_lock_bh(&sk->sk_callback_lock); + cp = sk->sk_user_data; + if (!cp) { + write_space = sk->sk_write_space; + goto out; + } + + tc = cp->cp_transport_data; + rdsdebug("write_space for tc %p\n", tc); + write_space = tc->t_orig_write_space; + rds_tcp_stats_inc(s_tcp_write_space_calls); + + rdsdebug("tcp una %u\n", rds_tcp_snd_una(tc)); + tc->t_last_seen_una = rds_tcp_snd_una(tc); + rds_send_path_drop_acked(cp, rds_tcp_snd_una(tc), rds_tcp_is_acked); + + rcu_read_lock(); + if ((refcount_read(&sk->sk_wmem_alloc) << 1) <= sk->sk_sndbuf && + !rds_destroy_pending(cp->cp_conn)) + queue_delayed_work(rds_wq, &cp->cp_send_w, 0); + rcu_read_unlock(); + +out: + read_unlock_bh(&sk->sk_callback_lock); + + /* + * write_space is only called when data leaves tcp's send queue if + * SOCK_NOSPACE is set. We set SOCK_NOSPACE every time we put + * data in tcp's send queue because we use write_space to parse the + * sequence numbers and notice that rds messages have been fully + * received. + * + * tcp's write_space clears SOCK_NOSPACE if the send queue has more + * than a certain amount of space. So we need to set it again *after* + * we call tcp's write_space or else we might only get called on the + * first of a series of incoming tcp acks. + */ + write_space(sk); + + if (sk->sk_socket) + set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); +} |