From de8474eb9d50fd47b8c73816f34739dec5e96754 Mon Sep 17 00:00:00 2001 From: Stefan Raspl Date: Wed, 23 May 2018 16:38:11 +0200 Subject: [PATCH] net/smc: urgent data support Add support for out of band data send and receive. Signed-off-by: Stefan Raspl Signed-off-by: Ursula Braun Signed-off-by: David S. Miller --- net/smc/af_smc.c | 24 ++++++++++- net/smc/smc.h | 15 +++++++ net/smc/smc_cdc.c | 44 ++++++++++++++++++-- net/smc/smc_cdc.h | 13 ++++++ net/smc/smc_core.c | 1 + net/smc/smc_rx.c | 120 +++++++++++++++++++++++++++++++++++++++++++++++------ net/smc/smc_tx.c | 55 ++++++++++++++++-------- net/smc/smc_tx.h | 2 +- 8 files changed, 238 insertions(+), 36 deletions(-) diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c index f2d9259..2c369d4 100644 --- a/net/smc/af_smc.c +++ b/net/smc/af_smc.c @@ -8,8 +8,6 @@ * * Initial restrictions: * - support for alternate links postponed - * - partial support for non-blocking sockets only - * - support for urgent data postponed * * Copyright IBM Corp. 2016, 2018 * @@ -1338,6 +1336,8 @@ static __poll_t smc_poll(struct file *file, struct socket *sock, if (sk->sk_state == SMC_APPCLOSEWAIT1) mask |= EPOLLIN; } + if (smc->conn.urg_state == SMC_URG_VALID) + mask |= EPOLLPRI; } release_sock(sk); @@ -1477,10 +1477,13 @@ static int smc_getsockopt(struct socket *sock, int level, int optname, static int smc_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg) { + union smc_host_cursor cons, urg; + struct smc_connection *conn; struct smc_sock *smc; int answ; smc = smc_sk(sock->sk); + conn = &smc->conn; if (smc->use_fallback) { if (!smc->clcsock) return -EBADF; @@ -1517,6 +1520,23 @@ static int smc_ioctl(struct socket *sock, unsigned int cmd, else answ = smc_tx_prepared_sends(&smc->conn); break; + case SIOCATMARK: + if (smc->sk.sk_state == SMC_LISTEN) + return -EINVAL; + if (smc->sk.sk_state == SMC_INIT || + smc->sk.sk_state == SMC_CLOSED) { + answ = 0; + } else { + smc_curs_write(&cons, + smc_curs_read(&conn->local_tx_ctrl.cons, conn), + conn); + smc_curs_write(&urg, + smc_curs_read(&conn->urg_curs, conn), + conn); + answ = smc_curs_diff(conn->rmb_desc->len, + &cons, &urg) == 1; + } + break; default: return -ENOIOCTLCMD; } diff --git a/net/smc/smc.h b/net/smc/smc.h index a1467e4..51ae1f1 100644 --- a/net/smc/smc.h +++ b/net/smc/smc.h @@ -114,6 +114,12 @@ struct smc_host_cdc_msg { /* Connection Data Control message */ u8 reserved[18]; } __aligned(8); +enum smc_urg_state { + SMC_URG_VALID, /* data present */ + SMC_URG_NOTYET, /* data pending */ + SMC_URG_READ /* data was already read */ +}; + struct smc_connection { struct rb_node alert_node; struct smc_link_group *lgr; /* link group of connection */ @@ -160,6 +166,15 @@ struct smc_connection { union smc_host_cursor rx_curs_confirmed; /* confirmed to peer * source of snd_una ? */ + union smc_host_cursor urg_curs; /* points at urgent byte */ + enum smc_urg_state urg_state; + bool urg_tx_pend; /* urgent data staged */ + bool urg_rx_skip_pend; + /* indicate urgent oob data + * read, but previous regular + * data still pending + */ + char urg_rx_byte; /* urgent byte */ atomic_t bytes_to_rcv; /* arrived data, * not yet received */ diff --git a/net/smc/smc_cdc.c b/net/smc/smc_cdc.c index 8d2c079..a7e8d63 100644 --- a/net/smc/smc_cdc.c +++ b/net/smc/smc_cdc.c @@ -164,6 +164,28 @@ static inline bool smc_cdc_before(u16 seq1, u16 seq2) return (s16)(seq1 - seq2) < 0; } +static void smc_cdc_handle_urg_data_arrival(struct smc_sock *smc, + int *diff_prod) +{ + struct smc_connection *conn = &smc->conn; + char *base; + + /* new data included urgent business */ + smc_curs_write(&conn->urg_curs, + smc_curs_read(&conn->local_rx_ctrl.prod, conn), + conn); + conn->urg_state = SMC_URG_VALID; + if (!sock_flag(&smc->sk, SOCK_URGINLINE)) + /* we'll skip the urgent byte, so don't account for it */ + (*diff_prod)--; + base = (char *)conn->rmb_desc->cpu_addr; + if (conn->urg_curs.count) + conn->urg_rx_byte = *(base + conn->urg_curs.count - 1); + else + conn->urg_rx_byte = *(base + conn->rmb_desc->len - 1); + sk_send_sigurg(&smc->sk); +} + static void smc_cdc_msg_recv_action(struct smc_sock *smc, struct smc_cdc_msg *cdc) { @@ -194,15 +216,25 @@ static void smc_cdc_msg_recv_action(struct smc_sock *smc, diff_prod = smc_curs_diff(conn->rmb_desc->len, &prod_old, &conn->local_rx_ctrl.prod); if (diff_prod) { + if (conn->local_rx_ctrl.prod_flags.urg_data_present) + smc_cdc_handle_urg_data_arrival(smc, &diff_prod); /* bytes_to_rcv is decreased in smc_recvmsg */ smp_mb__before_atomic(); atomic_add(diff_prod, &conn->bytes_to_rcv); /* guarantee 0 <= bytes_to_rcv <= rmb_desc->len */ smp_mb__after_atomic(); smc->sk.sk_data_ready(&smc->sk); - } else if ((conn->local_rx_ctrl.prod_flags.write_blocked) || - (conn->local_rx_ctrl.prod_flags.cons_curs_upd_req)) { - smc->sk.sk_data_ready(&smc->sk); + } else { + if (conn->local_rx_ctrl.prod_flags.write_blocked || + conn->local_rx_ctrl.prod_flags.cons_curs_upd_req || + conn->local_rx_ctrl.prod_flags.urg_data_pending) { + if (conn->local_rx_ctrl.prod_flags.urg_data_pending) + conn->urg_state = SMC_URG_NOTYET; + /* force immediate tx of current consumer cursor, but + * under send_lock to guarantee arrival in seqno-order + */ + smc_tx_sndbuf_nonempty(conn); + } } /* piggy backed tx info */ @@ -212,6 +244,12 @@ static void smc_cdc_msg_recv_action(struct smc_sock *smc, /* trigger socket release if connection closed */ smc_close_wake_tx_prepared(smc); } + if (diff_cons && conn->urg_tx_pend && + atomic_read(&conn->peer_rmbe_space) == conn->peer_rmbe_size) { + /* urg data confirmed by peer, indicate we're ready for more */ + conn->urg_tx_pend = false; + smc->sk.sk_write_space(&smc->sk); + } if (conn->local_rx_ctrl.conn_state_flags.peer_conn_abort) { smc->sk.sk_err = ECONNRESET; diff --git a/net/smc/smc_cdc.h b/net/smc/smc_cdc.h index d2012fd..f60082f 100644 --- a/net/smc/smc_cdc.h +++ b/net/smc/smc_cdc.h @@ -146,6 +146,19 @@ static inline int smc_curs_diff(unsigned int size, return max_t(int, 0, (new->count - old->count)); } +/* calculate cursor difference between old and new - returns negative + * value in case old > new + */ +static inline int smc_curs_comp(unsigned int size, + union smc_host_cursor *old, + union smc_host_cursor *new) +{ + if (old->wrap > new->wrap || + (old->wrap == new->wrap && old->count > new->count)) + return -smc_curs_diff(size, new, old); + return smc_curs_diff(size, old, new); +} + static inline void smc_host_cursor_to_cdc(union smc_cdc_cursor *peer, union smc_host_cursor *local, struct smc_connection *conn) diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c index 21c244f..2bf138e 100644 --- a/net/smc/smc_core.c +++ b/net/smc/smc_core.c @@ -544,6 +544,7 @@ create: } conn->local_tx_ctrl.common.type = SMC_CDC_MSG_TYPE; conn->local_tx_ctrl.len = SMC_WR_TX_SIZE; + conn->urg_state = SMC_URG_READ; #ifndef KERNEL_HAS_ATOMIC64 spin_lock_init(&conn->acurs_lock); #endif diff --git a/net/smc/smc_rx.c b/net/smc/smc_rx.c index 290a434..3d77b38 100644 --- a/net/smc/smc_rx.c +++ b/net/smc/smc_rx.c @@ -47,16 +47,59 @@ static void smc_rx_wake_up(struct sock *sk) * @conn connection to update * @cons consumer cursor * @len number of Bytes consumed + * Returns: + * 1 if we should end our receive, 0 otherwise */ -static void smc_rx_update_consumer(struct smc_connection *conn, - union smc_host_cursor cons, size_t len) +static int smc_rx_update_consumer(struct smc_sock *smc, + union smc_host_cursor cons, size_t len) { + struct smc_connection *conn = &smc->conn; + struct sock *sk = &smc->sk; + bool force = false; + int diff, rc = 0; + smc_curs_add(conn->rmb_desc->len, &cons, len); + + /* did we process urgent data? */ + if (conn->urg_state == SMC_URG_VALID || conn->urg_rx_skip_pend) { + diff = smc_curs_comp(conn->rmb_desc->len, &cons, + &conn->urg_curs); + if (sock_flag(sk, SOCK_URGINLINE)) { + if (diff == 0) { + force = true; + rc = 1; + conn->urg_state = SMC_URG_READ; + } + } else { + if (diff == 1) { + /* skip urgent byte */ + force = true; + smc_curs_add(conn->rmb_desc->len, &cons, 1); + conn->urg_rx_skip_pend = false; + } else if (diff < -1) + /* we read past urgent byte */ + conn->urg_state = SMC_URG_READ; + } + } + smc_curs_write(&conn->local_tx_ctrl.cons, smc_curs_read(&cons, conn), conn); + /* send consumer cursor update if required */ /* similar to advertising new TCP rcv_wnd if required */ - smc_tx_consumer_update(conn); + smc_tx_consumer_update(conn, force); + + return rc; +} + +static void smc_rx_update_cons(struct smc_sock *smc, size_t len) +{ + struct smc_connection *conn = &smc->conn; + union smc_host_cursor cons; + + smc_curs_write(&cons, smc_curs_read(&conn->local_tx_ctrl.cons, conn), + conn); + smc_rx_update_consumer(smc, cons, len); } struct smc_spd_priv { @@ -70,7 +113,6 @@ static void smc_rx_pipe_buf_release(struct pipe_inode_info *pipe, struct smc_spd_priv *priv = (struct smc_spd_priv *)buf->private; struct smc_sock *smc = priv->smc; struct smc_connection *conn; - union smc_host_cursor cons; struct sock *sk = &smc->sk; if (sk->sk_state == SMC_CLOSED || @@ -79,9 +121,7 @@ static void smc_rx_pipe_buf_release(struct pipe_inode_info *pipe, goto out; conn = &smc->conn; lock_sock(sk); - smc_curs_write(&cons, smc_curs_read(&conn->local_tx_ctrl.cons, conn), - conn); - smc_rx_update_consumer(conn, cons, priv->len); + smc_rx_update_cons(smc, priv->len); release_sock(sk); if (atomic_sub_and_test(priv->len, &conn->splice_pending)) smc_rx_wake_up(sk); @@ -184,6 +224,52 @@ int smc_rx_wait(struct smc_sock *smc, long *timeo, return rc; } +static int smc_rx_recv_urg(struct smc_sock *smc, struct msghdr *msg, int len, + int flags) +{ + struct smc_connection *conn = &smc->conn; + union smc_host_cursor cons; + struct sock *sk = &smc->sk; + int rc = 0; + + if (sock_flag(sk, SOCK_URGINLINE) || + !(conn->urg_state == SMC_URG_VALID) || + conn->urg_state == SMC_URG_READ) + return -EINVAL; + + if (conn->urg_state == SMC_URG_VALID) { + if (!(flags & MSG_PEEK)) + smc->conn.urg_state = SMC_URG_READ; + msg->msg_flags |= MSG_OOB; + if (len > 0) { + if (!(flags & MSG_TRUNC)) + rc = memcpy_to_msg(msg, &conn->urg_rx_byte, 1); + len = 1; + smc_curs_write(&cons, + smc_curs_read(&conn->local_tx_ctrl.cons, + conn), + conn); + if (smc_curs_diff(conn->rmb_desc->len, &cons, + &conn->urg_curs) > 1) + conn->urg_rx_skip_pend = true; + /* Urgent Byte was already accounted for, but trigger + * skipping the urgent byte in non-inline case + */ + if (!(flags & MSG_PEEK)) + smc_rx_update_consumer(smc, cons, 0); + } else { + msg->msg_flags |= MSG_TRUNC; + } + + return rc ? -EFAULT : len; + } + + if (sk->sk_state == SMC_CLOSED || sk->sk_shutdown & RCV_SHUTDOWN) + return 0; + + return -EAGAIN; +} + /* smc_rx_recvmsg - receive data from RMBE * @msg: copy data to receive buffer * @pipe: copy data to pipe if set - indicates splice() call @@ -209,12 +295,12 @@ int smc_rx_recvmsg(struct smc_sock *smc, struct msghdr *msg, if (unlikely(flags & MSG_ERRQUEUE)) return -EINVAL; /* future work for sk.sk_family == AF_SMC */ - if (flags & MSG_OOB) - return -EINVAL; /* future work */ sk = &smc->sk; if (sk->sk_state == SMC_LISTEN) return -ENOTCONN; + if (flags & MSG_OOB) + return smc_rx_recv_urg(smc, msg, len, flags); timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT); target = sock_rcvlowat(sk, flags & MSG_WAITALL, len); @@ -227,6 +313,9 @@ int smc_rx_recvmsg(struct smc_sock *smc, struct msghdr *msg, if (atomic_read(&conn->bytes_to_rcv)) goto copy; + else if (conn->urg_state == SMC_URG_VALID) + /* we received a single urgent Byte - skip */ + smc_rx_update_cons(smc, 0); if (sk->sk_shutdown & RCV_SHUTDOWN || smc_cdc_rxed_any_close_or_senddone(conn) || @@ -281,14 +370,18 @@ copy: continue; } - /* not more than what user space asked for */ - copylen = min_t(size_t, read_remaining, readable); smc_curs_write(&cons, smc_curs_read(&conn->local_tx_ctrl.cons, conn), conn); /* subsequent splice() calls pick up where previous left */ if (splbytes) smc_curs_add(conn->rmb_desc->len, &cons, splbytes); + if (conn->urg_state == SMC_URG_VALID && + sock_flag(&smc->sk, SOCK_URGINLINE) && + readable > 1) + readable--; /* always stop at urgent Byte */ + /* not more than what user space asked for */ + copylen = min_t(size_t, read_remaining, readable); /* determine chunks where to read from rcvbuf */ /* either unwrapped case, or 1st chunk of wrapped case */ chunk_len = min_t(size_t, copylen, conn->rmb_desc->len - @@ -333,8 +426,8 @@ copy: atomic_sub(copylen, &conn->bytes_to_rcv); /* guarantee 0 <= bytes_to_rcv <= rmb_desc->len */ smp_mb__after_atomic(); - if (msg) - smc_rx_update_consumer(conn, cons, copylen); + if (msg && smc_rx_update_consumer(smc, cons, copylen)) + goto out; } } while (read_remaining); out: @@ -346,4 +439,5 @@ void smc_rx_init(struct smc_sock *smc) { smc->sk.sk_data_ready = smc_rx_wake_up; atomic_set(&smc->conn.splice_pending, 0); + smc->conn.urg_state = SMC_URG_READ; } diff --git a/net/smc/smc_tx.c b/net/smc/smc_tx.c index 1f4a38b..cee6664 100644 --- a/net/smc/smc_tx.c +++ b/net/smc/smc_tx.c @@ -32,7 +32,7 @@ /***************************** sndbuf producer *******************************/ /* callback implementation for sk.sk_write_space() - * to wakeup sndbuf producers that blocked with smc_tx_wait_memory(). + * to wakeup sndbuf producers that blocked with smc_tx_wait(). * called under sk_socket lock. */ static void smc_tx_write_space(struct sock *sk) @@ -56,7 +56,7 @@ static void smc_tx_write_space(struct sock *sk) } } -/* Wakeup sndbuf producers that blocked with smc_tx_wait_memory(). +/* Wakeup sndbuf producers that blocked with smc_tx_wait(). * Cf. tcp_data_snd_check()=>tcp_check_space()=>tcp_new_space(). */ void smc_tx_sndbuf_nonfull(struct smc_sock *smc) @@ -66,8 +66,10 @@ void smc_tx_sndbuf_nonfull(struct smc_sock *smc) smc->sk.sk_write_space(&smc->sk); } -/* blocks sndbuf producer until at least one byte of free space available */ -static int smc_tx_wait_memory(struct smc_sock *smc, int flags) +/* blocks sndbuf producer until at least one byte of free space available + * or urgent Byte was consumed + */ +static int smc_tx_wait(struct smc_sock *smc, int flags) { DEFINE_WAIT_FUNC(wait, woken_wake_function); struct smc_connection *conn = &smc->conn; @@ -103,14 +105,15 @@ static int smc_tx_wait_memory(struct smc_sock *smc, int flags) break; } sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk); - if (atomic_read(&conn->sndbuf_space)) - break; /* at least 1 byte of free space available */ + if (atomic_read(&conn->sndbuf_space) && !conn->urg_tx_pend) + break; /* at least 1 byte of free & no urgent data */ set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); sk_wait_event(sk, &timeo, sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN) || smc_cdc_rxed_any_close(conn) || - atomic_read(&conn->sndbuf_space), + (atomic_read(&conn->sndbuf_space) && + !conn->urg_tx_pend), &wait); } remove_wait_queue(sk_sleep(sk), &wait); @@ -157,8 +160,11 @@ int smc_tx_sendmsg(struct smc_sock *smc, struct msghdr *msg, size_t len) if (smc_cdc_rxed_any_close(conn)) return send_done ?: -ECONNRESET; - if (!atomic_read(&conn->sndbuf_space)) { - rc = smc_tx_wait_memory(smc, msg->msg_flags); + if (msg->msg_flags & MSG_OOB) + conn->local_tx_ctrl.prod_flags.urg_data_pending = 1; + + if (!atomic_read(&conn->sndbuf_space) || conn->urg_tx_pend) { + rc = smc_tx_wait(smc, msg->msg_flags); if (rc) { if (send_done) return send_done; @@ -168,7 +174,7 @@ int smc_tx_sendmsg(struct smc_sock *smc, struct msghdr *msg, size_t len) } /* initialize variables for 1st iteration of subsequent loop */ - /* could be just 1 byte, even after smc_tx_wait_memory above */ + /* could be just 1 byte, even after smc_tx_wait above */ writespace = atomic_read(&conn->sndbuf_space); /* not more than what user space asked for */ copylen = min_t(size_t, send_remaining, writespace); @@ -218,6 +224,8 @@ int smc_tx_sendmsg(struct smc_sock *smc, struct msghdr *msg, size_t len) /* since we just produced more new data into sndbuf, * trigger sndbuf consumer: RDMA write into peer RMBE and CDC */ + if ((msg->msg_flags & MSG_OOB) && !send_remaining) + conn->urg_tx_pend = true; if ((msg->msg_flags & MSG_MORE || smc_tx_is_corked(smc)) && (atomic_read(&conn->sndbuf_space) > (conn->sndbuf_desc->len >> 1))) @@ -299,6 +307,7 @@ static int smc_tx_rdma_writes(struct smc_connection *conn) union smc_host_cursor sent, prep, prod, cons; struct ib_sge sges[SMC_IB_MAX_SEND_SGE]; struct smc_link_group *lgr = conn->lgr; + struct smc_cdc_producer_flags *pflags; int to_send, rmbespace; struct smc_link *link; dma_addr_t dma_addr; @@ -326,7 +335,8 @@ static int smc_tx_rdma_writes(struct smc_connection *conn) conn); /* if usable snd_wnd closes ask peer to advertise once it opens again */ - conn->local_tx_ctrl.prod_flags.write_blocked = (to_send >= rmbespace); + pflags = &conn->local_tx_ctrl.prod_flags; + pflags->write_blocked = (to_send >= rmbespace); /* cf. usable snd_wnd */ len = min(to_send, rmbespace); @@ -391,6 +401,8 @@ static int smc_tx_rdma_writes(struct smc_connection *conn) src_len_sum = src_len; } + if (conn->urg_tx_pend && len == to_send) + pflags->urg_data_present = 1; smc_tx_advance_cursors(conn, &prod, &sent, len); /* update connection's cursors with advanced local cursors */ smc_curs_write(&conn->local_tx_ctrl.prod, @@ -410,6 +422,7 @@ static int smc_tx_rdma_writes(struct smc_connection *conn) */ int smc_tx_sndbuf_nonempty(struct smc_connection *conn) { + struct smc_cdc_producer_flags *pflags; struct smc_cdc_tx_pend *pend; struct smc_wr_buf *wr_buf; int rc; @@ -433,14 +446,21 @@ int smc_tx_sndbuf_nonempty(struct smc_connection *conn) goto out_unlock; } - rc = smc_tx_rdma_writes(conn); - if (rc) { - smc_wr_tx_put_slot(&conn->lgr->lnk[SMC_SINGLE_LINK], - (struct smc_wr_tx_pend_priv *)pend); - goto out_unlock; + if (!conn->local_tx_ctrl.prod_flags.urg_data_present) { + rc = smc_tx_rdma_writes(conn); + if (rc) { + smc_wr_tx_put_slot(&conn->lgr->lnk[SMC_SINGLE_LINK], + (struct smc_wr_tx_pend_priv *)pend); + goto out_unlock; + } } rc = smc_cdc_msg_send(conn, wr_buf, pend); + pflags = &conn->local_tx_ctrl.prod_flags; + if (!rc && pflags->urg_data_present) { + pflags->urg_data_pending = 0; + pflags->urg_data_present = 0; + } out_unlock: spin_unlock_bh(&conn->send_lock); @@ -473,7 +493,7 @@ out: release_sock(&smc->sk); } -void smc_tx_consumer_update(struct smc_connection *conn) +void smc_tx_consumer_update(struct smc_connection *conn, bool force) { union smc_host_cursor cfed, cons; int to_confirm; @@ -487,6 +507,7 @@ void smc_tx_consumer_update(struct smc_connection *conn) to_confirm = smc_curs_diff(conn->rmb_desc->len, &cfed, &cons); if (conn->local_rx_ctrl.prod_flags.cons_curs_upd_req || + force || ((to_confirm > conn->rmbe_update_limit) && ((to_confirm > (conn->rmb_desc->len / 2)) || conn->local_rx_ctrl.prod_flags.write_blocked))) { diff --git a/net/smc/smc_tx.h b/net/smc/smc_tx.h index 44d0779..9d223890 100644 --- a/net/smc/smc_tx.h +++ b/net/smc/smc_tx.h @@ -32,6 +32,6 @@ void smc_tx_init(struct smc_sock *smc); int smc_tx_sendmsg(struct smc_sock *smc, struct msghdr *msg, size_t len); int smc_tx_sndbuf_nonempty(struct smc_connection *conn); void smc_tx_sndbuf_nonfull(struct smc_sock *smc); -void smc_tx_consumer_update(struct smc_connection *conn); +void smc_tx_consumer_update(struct smc_connection *conn, bool force); #endif /* SMC_TX_H */ -- 2.7.4