v4.19.13 snapshot.
diff --git a/net/rds/send.c b/net/rds/send.c
new file mode 100644
index 0000000..fe785ee
--- /dev/null
+++ b/net/rds/send.c
@@ -0,0 +1,1462 @@
+/*
+ * Copyright (c) 2006, 2018 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/moduleparam.h>
+#include <linux/gfp.h>
+#include <net/sock.h>
+#include <linux/in.h>
+#include <linux/list.h>
+#include <linux/ratelimit.h>
+#include <linux/export.h>
+#include <linux/sizes.h>
+
+#include "rds.h"
+
+/* When transmitting messages in rds_send_xmit, we need to emerge from
+ * time to time and briefly release the CPU. Otherwise the softlock watchdog
+ * will kick our shin.
+ * Also, it seems fairer to not let one busy connection stall all the
+ * others.
+ *
+ * send_batch_count is the number of times we'll loop in send_xmit. Setting
+ * it to 0 will restore the old behavior (where we looped until we had
+ * drained the queue).
+ */
+static int send_batch_count = SZ_1K;
+module_param(send_batch_count, int, 0444);
+MODULE_PARM_DESC(send_batch_count, " batch factor when working the send queue");
+
+static void rds_send_remove_from_sock(struct list_head *messages, int status);
+
+/*
+ * Reset the send state. Callers must ensure that this doesn't race with
+ * rds_send_xmit().
+ */
+void rds_send_path_reset(struct rds_conn_path *cp)
+{
+ struct rds_message *rm, *tmp;
+ unsigned long flags;
+
+ if (cp->cp_xmit_rm) {
+ rm = cp->cp_xmit_rm;
+ cp->cp_xmit_rm = NULL;
+ /* Tell the user the RDMA op is no longer mapped by the
+ * transport. This isn't entirely true (it's flushed out
+ * independently) but as the connection is down, there's
+ * no ongoing RDMA to/from that memory */
+ rds_message_unmapped(rm);
+ rds_message_put(rm);
+ }
+
+ cp->cp_xmit_sg = 0;
+ cp->cp_xmit_hdr_off = 0;
+ cp->cp_xmit_data_off = 0;
+ cp->cp_xmit_atomic_sent = 0;
+ cp->cp_xmit_rdma_sent = 0;
+ cp->cp_xmit_data_sent = 0;
+
+ cp->cp_conn->c_map_queued = 0;
+
+ cp->cp_unacked_packets = rds_sysctl_max_unacked_packets;
+ cp->cp_unacked_bytes = rds_sysctl_max_unacked_bytes;
+
+ /* Mark messages as retransmissions, and move them to the send q */
+ spin_lock_irqsave(&cp->cp_lock, flags);
+ list_for_each_entry_safe(rm, tmp, &cp->cp_retrans, m_conn_item) {
+ set_bit(RDS_MSG_ACK_REQUIRED, &rm->m_flags);
+ set_bit(RDS_MSG_RETRANSMITTED, &rm->m_flags);
+ }
+ list_splice_init(&cp->cp_retrans, &cp->cp_send_queue);
+ spin_unlock_irqrestore(&cp->cp_lock, flags);
+}
+EXPORT_SYMBOL_GPL(rds_send_path_reset);
+
+static int acquire_in_xmit(struct rds_conn_path *cp)
+{
+ return test_and_set_bit(RDS_IN_XMIT, &cp->cp_flags) == 0;
+}
+
+static void release_in_xmit(struct rds_conn_path *cp)
+{
+ clear_bit(RDS_IN_XMIT, &cp->cp_flags);
+ smp_mb__after_atomic();
+ /*
+ * We don't use wait_on_bit()/wake_up_bit() because our waking is in a
+ * hot path and finding waiters is very rare. We don't want to walk
+ * the system-wide hashed waitqueue buckets in the fast path only to
+ * almost never find waiters.
+ */
+ if (waitqueue_active(&cp->cp_waitq))
+ wake_up_all(&cp->cp_waitq);
+}
+
+/*
+ * We're making the conscious trade-off here to only send one message
+ * down the connection at a time.
+ * Pro:
+ * - tx queueing is a simple fifo list
+ * - reassembly is optional and easily done by transports per conn
+ * - no per flow rx lookup at all, straight to the socket
+ * - less per-frag memory and wire overhead
+ * Con:
+ * - queued acks can be delayed behind large messages
+ * Depends:
+ * - small message latency is higher behind queued large messages
+ * - large message latency isn't starved by intervening small sends
+ */
+int rds_send_xmit(struct rds_conn_path *cp)
+{
+ struct rds_connection *conn = cp->cp_conn;
+ struct rds_message *rm;
+ unsigned long flags;
+ unsigned int tmp;
+ struct scatterlist *sg;
+ int ret = 0;
+ LIST_HEAD(to_be_dropped);
+ int batch_count;
+ unsigned long send_gen = 0;
+
+restart:
+ batch_count = 0;
+
+ /*
+ * sendmsg calls here after having queued its message on the send
+ * queue. We only have one task feeding the connection at a time. If
+ * another thread is already feeding the queue then we back off. This
+ * avoids blocking the caller and trading per-connection data between
+ * caches per message.
+ */
+ if (!acquire_in_xmit(cp)) {
+ rds_stats_inc(s_send_lock_contention);
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ if (rds_destroy_pending(cp->cp_conn)) {
+ release_in_xmit(cp);
+ ret = -ENETUNREACH; /* dont requeue send work */
+ goto out;
+ }
+
+ /*
+ * we record the send generation after doing the xmit acquire.
+ * if someone else manages to jump in and do some work, we'll use
+ * this to avoid a goto restart farther down.
+ *
+ * The acquire_in_xmit() check above ensures that only one
+ * caller can increment c_send_gen at any time.
+ */
+ send_gen = READ_ONCE(cp->cp_send_gen) + 1;
+ WRITE_ONCE(cp->cp_send_gen, send_gen);
+
+ /*
+ * rds_conn_shutdown() sets the conn state and then tests RDS_IN_XMIT,
+ * we do the opposite to avoid races.
+ */
+ if (!rds_conn_path_up(cp)) {
+ release_in_xmit(cp);
+ ret = 0;
+ goto out;
+ }
+
+ if (conn->c_trans->xmit_path_prepare)
+ conn->c_trans->xmit_path_prepare(cp);
+
+ /*
+ * spin trying to push headers and data down the connection until
+ * the connection doesn't make forward progress.
+ */
+ while (1) {
+
+ rm = cp->cp_xmit_rm;
+
+ /*
+ * If between sending messages, we can send a pending congestion
+ * map update.
+ */
+ if (!rm && test_and_clear_bit(0, &conn->c_map_queued)) {
+ rm = rds_cong_update_alloc(conn);
+ if (IS_ERR(rm)) {
+ ret = PTR_ERR(rm);
+ break;
+ }
+ rm->data.op_active = 1;
+ rm->m_inc.i_conn_path = cp;
+ rm->m_inc.i_conn = cp->cp_conn;
+
+ cp->cp_xmit_rm = rm;
+ }
+
+ /*
+ * If not already working on one, grab the next message.
+ *
+ * cp_xmit_rm holds a ref while we're sending this message down
+ * the connction. We can use this ref while holding the
+ * send_sem.. rds_send_reset() is serialized with it.
+ */
+ if (!rm) {
+ unsigned int len;
+
+ batch_count++;
+
+ /* we want to process as big a batch as we can, but
+ * we also want to avoid softlockups. If we've been
+ * through a lot of messages, lets back off and see
+ * if anyone else jumps in
+ */
+ if (batch_count >= send_batch_count)
+ goto over_batch;
+
+ spin_lock_irqsave(&cp->cp_lock, flags);
+
+ if (!list_empty(&cp->cp_send_queue)) {
+ rm = list_entry(cp->cp_send_queue.next,
+ struct rds_message,
+ m_conn_item);
+ rds_message_addref(rm);
+
+ /*
+ * Move the message from the send queue to the retransmit
+ * list right away.
+ */
+ list_move_tail(&rm->m_conn_item,
+ &cp->cp_retrans);
+ }
+
+ spin_unlock_irqrestore(&cp->cp_lock, flags);
+
+ if (!rm)
+ break;
+
+ /* Unfortunately, the way Infiniband deals with
+ * RDMA to a bad MR key is by moving the entire
+ * queue pair to error state. We cold possibly
+ * recover from that, but right now we drop the
+ * connection.
+ * Therefore, we never retransmit messages with RDMA ops.
+ */
+ if (test_bit(RDS_MSG_FLUSH, &rm->m_flags) ||
+ (rm->rdma.op_active &&
+ test_bit(RDS_MSG_RETRANSMITTED, &rm->m_flags))) {
+ spin_lock_irqsave(&cp->cp_lock, flags);
+ if (test_and_clear_bit(RDS_MSG_ON_CONN, &rm->m_flags))
+ list_move(&rm->m_conn_item, &to_be_dropped);
+ spin_unlock_irqrestore(&cp->cp_lock, flags);
+ continue;
+ }
+
+ /* Require an ACK every once in a while */
+ len = ntohl(rm->m_inc.i_hdr.h_len);
+ if (cp->cp_unacked_packets == 0 ||
+ cp->cp_unacked_bytes < len) {
+ set_bit(RDS_MSG_ACK_REQUIRED, &rm->m_flags);
+
+ cp->cp_unacked_packets =
+ rds_sysctl_max_unacked_packets;
+ cp->cp_unacked_bytes =
+ rds_sysctl_max_unacked_bytes;
+ rds_stats_inc(s_send_ack_required);
+ } else {
+ cp->cp_unacked_bytes -= len;
+ cp->cp_unacked_packets--;
+ }
+
+ cp->cp_xmit_rm = rm;
+ }
+
+ /* The transport either sends the whole rdma or none of it */
+ if (rm->rdma.op_active && !cp->cp_xmit_rdma_sent) {
+ rm->m_final_op = &rm->rdma;
+ /* The transport owns the mapped memory for now.
+ * You can't unmap it while it's on the send queue
+ */
+ set_bit(RDS_MSG_MAPPED, &rm->m_flags);
+ ret = conn->c_trans->xmit_rdma(conn, &rm->rdma);
+ if (ret) {
+ clear_bit(RDS_MSG_MAPPED, &rm->m_flags);
+ wake_up_interruptible(&rm->m_flush_wait);
+ break;
+ }
+ cp->cp_xmit_rdma_sent = 1;
+
+ }
+
+ if (rm->atomic.op_active && !cp->cp_xmit_atomic_sent) {
+ rm->m_final_op = &rm->atomic;
+ /* The transport owns the mapped memory for now.
+ * You can't unmap it while it's on the send queue
+ */
+ set_bit(RDS_MSG_MAPPED, &rm->m_flags);
+ ret = conn->c_trans->xmit_atomic(conn, &rm->atomic);
+ if (ret) {
+ clear_bit(RDS_MSG_MAPPED, &rm->m_flags);
+ wake_up_interruptible(&rm->m_flush_wait);
+ break;
+ }
+ cp->cp_xmit_atomic_sent = 1;
+
+ }
+
+ /*
+ * A number of cases require an RDS header to be sent
+ * even if there is no data.
+ * We permit 0-byte sends; rds-ping depends on this.
+ * However, if there are exclusively attached silent ops,
+ * we skip the hdr/data send, to enable silent operation.
+ */
+ if (rm->data.op_nents == 0) {
+ int ops_present;
+ int all_ops_are_silent = 1;
+
+ ops_present = (rm->atomic.op_active || rm->rdma.op_active);
+ if (rm->atomic.op_active && !rm->atomic.op_silent)
+ all_ops_are_silent = 0;
+ if (rm->rdma.op_active && !rm->rdma.op_silent)
+ all_ops_are_silent = 0;
+
+ if (ops_present && all_ops_are_silent
+ && !rm->m_rdma_cookie)
+ rm->data.op_active = 0;
+ }
+
+ if (rm->data.op_active && !cp->cp_xmit_data_sent) {
+ rm->m_final_op = &rm->data;
+
+ ret = conn->c_trans->xmit(conn, rm,
+ cp->cp_xmit_hdr_off,
+ cp->cp_xmit_sg,
+ cp->cp_xmit_data_off);
+ if (ret <= 0)
+ break;
+
+ if (cp->cp_xmit_hdr_off < sizeof(struct rds_header)) {
+ tmp = min_t(int, ret,
+ sizeof(struct rds_header) -
+ cp->cp_xmit_hdr_off);
+ cp->cp_xmit_hdr_off += tmp;
+ ret -= tmp;
+ }
+
+ sg = &rm->data.op_sg[cp->cp_xmit_sg];
+ while (ret) {
+ tmp = min_t(int, ret, sg->length -
+ cp->cp_xmit_data_off);
+ cp->cp_xmit_data_off += tmp;
+ ret -= tmp;
+ if (cp->cp_xmit_data_off == sg->length) {
+ cp->cp_xmit_data_off = 0;
+ sg++;
+ cp->cp_xmit_sg++;
+ BUG_ON(ret != 0 && cp->cp_xmit_sg ==
+ rm->data.op_nents);
+ }
+ }
+
+ if (cp->cp_xmit_hdr_off == sizeof(struct rds_header) &&
+ (cp->cp_xmit_sg == rm->data.op_nents))
+ cp->cp_xmit_data_sent = 1;
+ }
+
+ /*
+ * A rm will only take multiple times through this loop
+ * if there is a data op. Thus, if the data is sent (or there was
+ * none), then we're done with the rm.
+ */
+ if (!rm->data.op_active || cp->cp_xmit_data_sent) {
+ cp->cp_xmit_rm = NULL;
+ cp->cp_xmit_sg = 0;
+ cp->cp_xmit_hdr_off = 0;
+ cp->cp_xmit_data_off = 0;
+ cp->cp_xmit_rdma_sent = 0;
+ cp->cp_xmit_atomic_sent = 0;
+ cp->cp_xmit_data_sent = 0;
+
+ rds_message_put(rm);
+ }
+ }
+
+over_batch:
+ if (conn->c_trans->xmit_path_complete)
+ conn->c_trans->xmit_path_complete(cp);
+ release_in_xmit(cp);
+
+ /* Nuke any messages we decided not to retransmit. */
+ if (!list_empty(&to_be_dropped)) {
+ /* irqs on here, so we can put(), unlike above */
+ list_for_each_entry(rm, &to_be_dropped, m_conn_item)
+ rds_message_put(rm);
+ rds_send_remove_from_sock(&to_be_dropped, RDS_RDMA_DROPPED);
+ }
+
+ /*
+ * Other senders can queue a message after we last test the send queue
+ * but before we clear RDS_IN_XMIT. In that case they'd back off and
+ * not try and send their newly queued message. We need to check the
+ * send queue after having cleared RDS_IN_XMIT so that their message
+ * doesn't get stuck on the send queue.
+ *
+ * If the transport cannot continue (i.e ret != 0), then it must
+ * call us when more room is available, such as from the tx
+ * completion handler.
+ *
+ * We have an extra generation check here so that if someone manages
+ * to jump in after our release_in_xmit, we'll see that they have done
+ * some work and we will skip our goto
+ */
+ if (ret == 0) {
+ bool raced;
+
+ smp_mb();
+ raced = send_gen != READ_ONCE(cp->cp_send_gen);
+
+ if ((test_bit(0, &conn->c_map_queued) ||
+ !list_empty(&cp->cp_send_queue)) && !raced) {
+ if (batch_count < send_batch_count)
+ goto restart;
+ rcu_read_lock();
+ if (rds_destroy_pending(cp->cp_conn))
+ ret = -ENETUNREACH;
+ else
+ queue_delayed_work(rds_wq, &cp->cp_send_w, 1);
+ rcu_read_unlock();
+ } else if (raced) {
+ rds_stats_inc(s_send_lock_queue_raced);
+ }
+ }
+out:
+ return ret;
+}
+EXPORT_SYMBOL_GPL(rds_send_xmit);
+
+static void rds_send_sndbuf_remove(struct rds_sock *rs, struct rds_message *rm)
+{
+ u32 len = be32_to_cpu(rm->m_inc.i_hdr.h_len);
+
+ assert_spin_locked(&rs->rs_lock);
+
+ BUG_ON(rs->rs_snd_bytes < len);
+ rs->rs_snd_bytes -= len;
+
+ if (rs->rs_snd_bytes == 0)
+ rds_stats_inc(s_send_queue_empty);
+}
+
+static inline int rds_send_is_acked(struct rds_message *rm, u64 ack,
+ is_acked_func is_acked)
+{
+ if (is_acked)
+ return is_acked(rm, ack);
+ return be64_to_cpu(rm->m_inc.i_hdr.h_sequence) <= ack;
+}
+
+/*
+ * This is pretty similar to what happens below in the ACK
+ * handling code - except that we call here as soon as we get
+ * the IB send completion on the RDMA op and the accompanying
+ * message.
+ */
+void rds_rdma_send_complete(struct rds_message *rm, int status)
+{
+ struct rds_sock *rs = NULL;
+ struct rm_rdma_op *ro;
+ struct rds_notifier *notifier;
+ unsigned long flags;
+ unsigned int notify = 0;
+
+ spin_lock_irqsave(&rm->m_rs_lock, flags);
+
+ notify = rm->rdma.op_notify | rm->data.op_notify;
+ ro = &rm->rdma;
+ if (test_bit(RDS_MSG_ON_SOCK, &rm->m_flags) &&
+ ro->op_active && notify && ro->op_notifier) {
+ notifier = ro->op_notifier;
+ rs = rm->m_rs;
+ sock_hold(rds_rs_to_sk(rs));
+
+ notifier->n_status = status;
+ spin_lock(&rs->rs_lock);
+ list_add_tail(¬ifier->n_list, &rs->rs_notify_queue);
+ spin_unlock(&rs->rs_lock);
+
+ ro->op_notifier = NULL;
+ }
+
+ spin_unlock_irqrestore(&rm->m_rs_lock, flags);
+
+ if (rs) {
+ rds_wake_sk_sleep(rs);
+ sock_put(rds_rs_to_sk(rs));
+ }
+}
+EXPORT_SYMBOL_GPL(rds_rdma_send_complete);
+
+/*
+ * Just like above, except looks at atomic op
+ */
+void rds_atomic_send_complete(struct rds_message *rm, int status)
+{
+ struct rds_sock *rs = NULL;
+ struct rm_atomic_op *ao;
+ struct rds_notifier *notifier;
+ unsigned long flags;
+
+ spin_lock_irqsave(&rm->m_rs_lock, flags);
+
+ ao = &rm->atomic;
+ if (test_bit(RDS_MSG_ON_SOCK, &rm->m_flags)
+ && ao->op_active && ao->op_notify && ao->op_notifier) {
+ notifier = ao->op_notifier;
+ rs = rm->m_rs;
+ sock_hold(rds_rs_to_sk(rs));
+
+ notifier->n_status = status;
+ spin_lock(&rs->rs_lock);
+ list_add_tail(¬ifier->n_list, &rs->rs_notify_queue);
+ spin_unlock(&rs->rs_lock);
+
+ ao->op_notifier = NULL;
+ }
+
+ spin_unlock_irqrestore(&rm->m_rs_lock, flags);
+
+ if (rs) {
+ rds_wake_sk_sleep(rs);
+ sock_put(rds_rs_to_sk(rs));
+ }
+}
+EXPORT_SYMBOL_GPL(rds_atomic_send_complete);
+
+/*
+ * This is the same as rds_rdma_send_complete except we
+ * don't do any locking - we have all the ingredients (message,
+ * socket, socket lock) and can just move the notifier.
+ */
+static inline void
+__rds_send_complete(struct rds_sock *rs, struct rds_message *rm, int status)
+{
+ struct rm_rdma_op *ro;
+ struct rm_atomic_op *ao;
+
+ ro = &rm->rdma;
+ if (ro->op_active && ro->op_notify && ro->op_notifier) {
+ ro->op_notifier->n_status = status;
+ list_add_tail(&ro->op_notifier->n_list, &rs->rs_notify_queue);
+ ro->op_notifier = NULL;
+ }
+
+ ao = &rm->atomic;
+ if (ao->op_active && ao->op_notify && ao->op_notifier) {
+ ao->op_notifier->n_status = status;
+ list_add_tail(&ao->op_notifier->n_list, &rs->rs_notify_queue);
+ ao->op_notifier = NULL;
+ }
+
+ /* No need to wake the app - caller does this */
+}
+
+/*
+ * This removes messages from the socket's list if they're on it. The list
+ * argument must be private to the caller, we must be able to modify it
+ * without locks. The messages must have a reference held for their
+ * position on the list. This function will drop that reference after
+ * removing the messages from the 'messages' list regardless of if it found
+ * the messages on the socket list or not.
+ */
+static void rds_send_remove_from_sock(struct list_head *messages, int status)
+{
+ unsigned long flags;
+ struct rds_sock *rs = NULL;
+ struct rds_message *rm;
+
+ while (!list_empty(messages)) {
+ int was_on_sock = 0;
+
+ rm = list_entry(messages->next, struct rds_message,
+ m_conn_item);
+ list_del_init(&rm->m_conn_item);
+
+ /*
+ * If we see this flag cleared then we're *sure* that someone
+ * else beat us to removing it from the sock. If we race
+ * with their flag update we'll get the lock and then really
+ * see that the flag has been cleared.
+ *
+ * The message spinlock makes sure nobody clears rm->m_rs
+ * while we're messing with it. It does not prevent the
+ * message from being removed from the socket, though.
+ */
+ spin_lock_irqsave(&rm->m_rs_lock, flags);
+ if (!test_bit(RDS_MSG_ON_SOCK, &rm->m_flags))
+ goto unlock_and_drop;
+
+ if (rs != rm->m_rs) {
+ if (rs) {
+ rds_wake_sk_sleep(rs);
+ sock_put(rds_rs_to_sk(rs));
+ }
+ rs = rm->m_rs;
+ if (rs)
+ sock_hold(rds_rs_to_sk(rs));
+ }
+ if (!rs)
+ goto unlock_and_drop;
+ spin_lock(&rs->rs_lock);
+
+ if (test_and_clear_bit(RDS_MSG_ON_SOCK, &rm->m_flags)) {
+ struct rm_rdma_op *ro = &rm->rdma;
+ struct rds_notifier *notifier;
+
+ list_del_init(&rm->m_sock_item);
+ rds_send_sndbuf_remove(rs, rm);
+
+ if (ro->op_active && ro->op_notifier &&
+ (ro->op_notify || (ro->op_recverr && status))) {
+ notifier = ro->op_notifier;
+ list_add_tail(¬ifier->n_list,
+ &rs->rs_notify_queue);
+ if (!notifier->n_status)
+ notifier->n_status = status;
+ rm->rdma.op_notifier = NULL;
+ }
+ was_on_sock = 1;
+ }
+ spin_unlock(&rs->rs_lock);
+
+unlock_and_drop:
+ spin_unlock_irqrestore(&rm->m_rs_lock, flags);
+ rds_message_put(rm);
+ if (was_on_sock)
+ rds_message_put(rm);
+ }
+
+ if (rs) {
+ rds_wake_sk_sleep(rs);
+ sock_put(rds_rs_to_sk(rs));
+ }
+}
+
+/*
+ * Transports call here when they've determined that the receiver queued
+ * messages up to, and including, the given sequence number. Messages are
+ * moved to the retrans queue when rds_send_xmit picks them off the send
+ * queue. This means that in the TCP case, the message may not have been
+ * assigned the m_ack_seq yet - but that's fine as long as tcp_is_acked
+ * checks the RDS_MSG_HAS_ACK_SEQ bit.
+ */
+void rds_send_path_drop_acked(struct rds_conn_path *cp, u64 ack,
+ is_acked_func is_acked)
+{
+ struct rds_message *rm, *tmp;
+ unsigned long flags;
+ LIST_HEAD(list);
+
+ spin_lock_irqsave(&cp->cp_lock, flags);
+
+ list_for_each_entry_safe(rm, tmp, &cp->cp_retrans, m_conn_item) {
+ if (!rds_send_is_acked(rm, ack, is_acked))
+ break;
+
+ list_move(&rm->m_conn_item, &list);
+ clear_bit(RDS_MSG_ON_CONN, &rm->m_flags);
+ }
+
+ /* order flag updates with spin locks */
+ if (!list_empty(&list))
+ smp_mb__after_atomic();
+
+ spin_unlock_irqrestore(&cp->cp_lock, flags);
+
+ /* now remove the messages from the sock list as needed */
+ rds_send_remove_from_sock(&list, RDS_RDMA_SUCCESS);
+}
+EXPORT_SYMBOL_GPL(rds_send_path_drop_acked);
+
+void rds_send_drop_acked(struct rds_connection *conn, u64 ack,
+ is_acked_func is_acked)
+{
+ WARN_ON(conn->c_trans->t_mp_capable);
+ rds_send_path_drop_acked(&conn->c_path[0], ack, is_acked);
+}
+EXPORT_SYMBOL_GPL(rds_send_drop_acked);
+
+void rds_send_drop_to(struct rds_sock *rs, struct sockaddr_in6 *dest)
+{
+ struct rds_message *rm, *tmp;
+ struct rds_connection *conn;
+ struct rds_conn_path *cp;
+ unsigned long flags;
+ LIST_HEAD(list);
+
+ /* get all the messages we're dropping under the rs lock */
+ spin_lock_irqsave(&rs->rs_lock, flags);
+
+ list_for_each_entry_safe(rm, tmp, &rs->rs_send_queue, m_sock_item) {
+ if (dest &&
+ (!ipv6_addr_equal(&dest->sin6_addr, &rm->m_daddr) ||
+ dest->sin6_port != rm->m_inc.i_hdr.h_dport))
+ continue;
+
+ list_move(&rm->m_sock_item, &list);
+ rds_send_sndbuf_remove(rs, rm);
+ clear_bit(RDS_MSG_ON_SOCK, &rm->m_flags);
+ }
+
+ /* order flag updates with the rs lock */
+ smp_mb__after_atomic();
+
+ spin_unlock_irqrestore(&rs->rs_lock, flags);
+
+ if (list_empty(&list))
+ return;
+
+ /* Remove the messages from the conn */
+ list_for_each_entry(rm, &list, m_sock_item) {
+
+ conn = rm->m_inc.i_conn;
+ if (conn->c_trans->t_mp_capable)
+ cp = rm->m_inc.i_conn_path;
+ else
+ cp = &conn->c_path[0];
+
+ spin_lock_irqsave(&cp->cp_lock, flags);
+ /*
+ * Maybe someone else beat us to removing rm from the conn.
+ * If we race with their flag update we'll get the lock and
+ * then really see that the flag has been cleared.
+ */
+ if (!test_and_clear_bit(RDS_MSG_ON_CONN, &rm->m_flags)) {
+ spin_unlock_irqrestore(&cp->cp_lock, flags);
+ continue;
+ }
+ list_del_init(&rm->m_conn_item);
+ spin_unlock_irqrestore(&cp->cp_lock, flags);
+
+ /*
+ * Couldn't grab m_rs_lock in top loop (lock ordering),
+ * but we can now.
+ */
+ spin_lock_irqsave(&rm->m_rs_lock, flags);
+
+ spin_lock(&rs->rs_lock);
+ __rds_send_complete(rs, rm, RDS_RDMA_CANCELED);
+ spin_unlock(&rs->rs_lock);
+
+ spin_unlock_irqrestore(&rm->m_rs_lock, flags);
+
+ rds_message_put(rm);
+ }
+
+ rds_wake_sk_sleep(rs);
+
+ while (!list_empty(&list)) {
+ rm = list_entry(list.next, struct rds_message, m_sock_item);
+ list_del_init(&rm->m_sock_item);
+ rds_message_wait(rm);
+
+ /* just in case the code above skipped this message
+ * because RDS_MSG_ON_CONN wasn't set, run it again here
+ * taking m_rs_lock is the only thing that keeps us
+ * from racing with ack processing.
+ */
+ spin_lock_irqsave(&rm->m_rs_lock, flags);
+
+ spin_lock(&rs->rs_lock);
+ __rds_send_complete(rs, rm, RDS_RDMA_CANCELED);
+ spin_unlock(&rs->rs_lock);
+
+ spin_unlock_irqrestore(&rm->m_rs_lock, flags);
+
+ rds_message_put(rm);
+ }
+}
+
+/*
+ * we only want this to fire once so we use the callers 'queued'. It's
+ * possible that another thread can race with us and remove the
+ * message from the flow with RDS_CANCEL_SENT_TO.
+ */
+static int rds_send_queue_rm(struct rds_sock *rs, struct rds_connection *conn,
+ struct rds_conn_path *cp,
+ struct rds_message *rm, __be16 sport,
+ __be16 dport, int *queued)
+{
+ unsigned long flags;
+ u32 len;
+
+ if (*queued)
+ goto out;
+
+ len = be32_to_cpu(rm->m_inc.i_hdr.h_len);
+
+ /* this is the only place which holds both the socket's rs_lock
+ * and the connection's c_lock */
+ spin_lock_irqsave(&rs->rs_lock, flags);
+
+ /*
+ * If there is a little space in sndbuf, we don't queue anything,
+ * and userspace gets -EAGAIN. But poll() indicates there's send
+ * room. This can lead to bad behavior (spinning) if snd_bytes isn't
+ * freed up by incoming acks. So we check the *old* value of
+ * rs_snd_bytes here to allow the last msg to exceed the buffer,
+ * and poll() now knows no more data can be sent.
+ */
+ if (rs->rs_snd_bytes < rds_sk_sndbuf(rs)) {
+ rs->rs_snd_bytes += len;
+
+ /* let recv side know we are close to send space exhaustion.
+ * This is probably not the optimal way to do it, as this
+ * means we set the flag on *all* messages as soon as our
+ * throughput hits a certain threshold.
+ */
+ if (rs->rs_snd_bytes >= rds_sk_sndbuf(rs) / 2)
+ set_bit(RDS_MSG_ACK_REQUIRED, &rm->m_flags);
+
+ list_add_tail(&rm->m_sock_item, &rs->rs_send_queue);
+ set_bit(RDS_MSG_ON_SOCK, &rm->m_flags);
+ rds_message_addref(rm);
+ sock_hold(rds_rs_to_sk(rs));
+ rm->m_rs = rs;
+
+ /* The code ordering is a little weird, but we're
+ trying to minimize the time we hold c_lock */
+ rds_message_populate_header(&rm->m_inc.i_hdr, sport, dport, 0);
+ rm->m_inc.i_conn = conn;
+ rm->m_inc.i_conn_path = cp;
+ rds_message_addref(rm);
+
+ spin_lock(&cp->cp_lock);
+ rm->m_inc.i_hdr.h_sequence = cpu_to_be64(cp->cp_next_tx_seq++);
+ list_add_tail(&rm->m_conn_item, &cp->cp_send_queue);
+ set_bit(RDS_MSG_ON_CONN, &rm->m_flags);
+ spin_unlock(&cp->cp_lock);
+
+ rdsdebug("queued msg %p len %d, rs %p bytes %d seq %llu\n",
+ rm, len, rs, rs->rs_snd_bytes,
+ (unsigned long long)be64_to_cpu(rm->m_inc.i_hdr.h_sequence));
+
+ *queued = 1;
+ }
+
+ spin_unlock_irqrestore(&rs->rs_lock, flags);
+out:
+ return *queued;
+}
+
+/*
+ * rds_message is getting to be quite complicated, and we'd like to allocate
+ * it all in one go. This figures out how big it needs to be up front.
+ */
+static int rds_rm_size(struct msghdr *msg, int num_sgs)
+{
+ struct cmsghdr *cmsg;
+ int size = 0;
+ int cmsg_groups = 0;
+ int retval;
+ bool zcopy_cookie = false;
+
+ for_each_cmsghdr(cmsg, msg) {
+ if (!CMSG_OK(msg, cmsg))
+ return -EINVAL;
+
+ if (cmsg->cmsg_level != SOL_RDS)
+ continue;
+
+ switch (cmsg->cmsg_type) {
+ case RDS_CMSG_RDMA_ARGS:
+ cmsg_groups |= 1;
+ retval = rds_rdma_extra_size(CMSG_DATA(cmsg));
+ if (retval < 0)
+ return retval;
+ size += retval;
+
+ break;
+
+ case RDS_CMSG_ZCOPY_COOKIE:
+ zcopy_cookie = true;
+ /* fall through */
+
+ case RDS_CMSG_RDMA_DEST:
+ case RDS_CMSG_RDMA_MAP:
+ cmsg_groups |= 2;
+ /* these are valid but do no add any size */
+ break;
+
+ case RDS_CMSG_ATOMIC_CSWP:
+ case RDS_CMSG_ATOMIC_FADD:
+ case RDS_CMSG_MASKED_ATOMIC_CSWP:
+ case RDS_CMSG_MASKED_ATOMIC_FADD:
+ cmsg_groups |= 1;
+ size += sizeof(struct scatterlist);
+ break;
+
+ default:
+ return -EINVAL;
+ }
+
+ }
+
+ if ((msg->msg_flags & MSG_ZEROCOPY) && !zcopy_cookie)
+ return -EINVAL;
+
+ size += num_sgs * sizeof(struct scatterlist);
+
+ /* Ensure (DEST, MAP) are never used with (ARGS, ATOMIC) */
+ if (cmsg_groups == 3)
+ return -EINVAL;
+
+ return size;
+}
+
+static int rds_cmsg_zcopy(struct rds_sock *rs, struct rds_message *rm,
+ struct cmsghdr *cmsg)
+{
+ u32 *cookie;
+
+ if (cmsg->cmsg_len < CMSG_LEN(sizeof(*cookie)) ||
+ !rm->data.op_mmp_znotifier)
+ return -EINVAL;
+ cookie = CMSG_DATA(cmsg);
+ rm->data.op_mmp_znotifier->z_cookie = *cookie;
+ return 0;
+}
+
+static int rds_cmsg_send(struct rds_sock *rs, struct rds_message *rm,
+ struct msghdr *msg, int *allocated_mr)
+{
+ struct cmsghdr *cmsg;
+ int ret = 0;
+
+ for_each_cmsghdr(cmsg, msg) {
+ if (!CMSG_OK(msg, cmsg))
+ return -EINVAL;
+
+ if (cmsg->cmsg_level != SOL_RDS)
+ continue;
+
+ /* As a side effect, RDMA_DEST and RDMA_MAP will set
+ * rm->rdma.m_rdma_cookie and rm->rdma.m_rdma_mr.
+ */
+ switch (cmsg->cmsg_type) {
+ case RDS_CMSG_RDMA_ARGS:
+ ret = rds_cmsg_rdma_args(rs, rm, cmsg);
+ break;
+
+ case RDS_CMSG_RDMA_DEST:
+ ret = rds_cmsg_rdma_dest(rs, rm, cmsg);
+ break;
+
+ case RDS_CMSG_RDMA_MAP:
+ ret = rds_cmsg_rdma_map(rs, rm, cmsg);
+ if (!ret)
+ *allocated_mr = 1;
+ else if (ret == -ENODEV)
+ /* Accommodate the get_mr() case which can fail
+ * if connection isn't established yet.
+ */
+ ret = -EAGAIN;
+ break;
+ case RDS_CMSG_ATOMIC_CSWP:
+ case RDS_CMSG_ATOMIC_FADD:
+ case RDS_CMSG_MASKED_ATOMIC_CSWP:
+ case RDS_CMSG_MASKED_ATOMIC_FADD:
+ ret = rds_cmsg_atomic(rs, rm, cmsg);
+ break;
+
+ case RDS_CMSG_ZCOPY_COOKIE:
+ ret = rds_cmsg_zcopy(rs, rm, cmsg);
+ break;
+
+ default:
+ return -EINVAL;
+ }
+
+ if (ret)
+ break;
+ }
+
+ return ret;
+}
+
+static int rds_send_mprds_hash(struct rds_sock *rs,
+ struct rds_connection *conn, int nonblock)
+{
+ int hash;
+
+ if (conn->c_npaths == 0)
+ hash = RDS_MPATH_HASH(rs, RDS_MPATH_WORKERS);
+ else
+ hash = RDS_MPATH_HASH(rs, conn->c_npaths);
+ if (conn->c_npaths == 0 && hash != 0) {
+ rds_send_ping(conn, 0);
+
+ /* The underlying connection is not up yet. Need to wait
+ * until it is up to be sure that the non-zero c_path can be
+ * used. But if we are interrupted, we have to use the zero
+ * c_path in case the connection ends up being non-MP capable.
+ */
+ if (conn->c_npaths == 0) {
+ /* Cannot wait for the connection be made, so just use
+ * the base c_path.
+ */
+ if (nonblock)
+ return 0;
+ if (wait_event_interruptible(conn->c_hs_waitq,
+ conn->c_npaths != 0))
+ hash = 0;
+ }
+ if (conn->c_npaths == 1)
+ hash = 0;
+ }
+ return hash;
+}
+
+static int rds_rdma_bytes(struct msghdr *msg, size_t *rdma_bytes)
+{
+ struct rds_rdma_args *args;
+ struct cmsghdr *cmsg;
+
+ for_each_cmsghdr(cmsg, msg) {
+ if (!CMSG_OK(msg, cmsg))
+ return -EINVAL;
+
+ if (cmsg->cmsg_level != SOL_RDS)
+ continue;
+
+ if (cmsg->cmsg_type == RDS_CMSG_RDMA_ARGS) {
+ if (cmsg->cmsg_len <
+ CMSG_LEN(sizeof(struct rds_rdma_args)))
+ return -EINVAL;
+ args = CMSG_DATA(cmsg);
+ *rdma_bytes += args->remote_vec.bytes;
+ }
+ }
+ return 0;
+}
+
+int rds_sendmsg(struct socket *sock, struct msghdr *msg, size_t payload_len)
+{
+ struct sock *sk = sock->sk;
+ struct rds_sock *rs = rds_sk_to_rs(sk);
+ DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name);
+ DECLARE_SOCKADDR(struct sockaddr_in *, usin, msg->msg_name);
+ __be16 dport;
+ struct rds_message *rm = NULL;
+ struct rds_connection *conn;
+ int ret = 0;
+ int queued = 0, allocated_mr = 0;
+ int nonblock = msg->msg_flags & MSG_DONTWAIT;
+ long timeo = sock_sndtimeo(sk, nonblock);
+ struct rds_conn_path *cpath;
+ struct in6_addr daddr;
+ __u32 scope_id = 0;
+ size_t total_payload_len = payload_len, rdma_payload_len = 0;
+ bool zcopy = ((msg->msg_flags & MSG_ZEROCOPY) &&
+ sock_flag(rds_rs_to_sk(rs), SOCK_ZEROCOPY));
+ int num_sgs = ceil(payload_len, PAGE_SIZE);
+ int namelen;
+
+ /* Mirror Linux UDP mirror of BSD error message compatibility */
+ /* XXX: Perhaps MSG_MORE someday */
+ if (msg->msg_flags & ~(MSG_DONTWAIT | MSG_CMSG_COMPAT | MSG_ZEROCOPY)) {
+ ret = -EOPNOTSUPP;
+ goto out;
+ }
+
+ namelen = msg->msg_namelen;
+ if (namelen != 0) {
+ if (namelen < sizeof(*usin)) {
+ ret = -EINVAL;
+ goto out;
+ }
+ switch (usin->sin_family) {
+ case AF_INET:
+ if (usin->sin_addr.s_addr == htonl(INADDR_ANY) ||
+ usin->sin_addr.s_addr == htonl(INADDR_BROADCAST) ||
+ IN_MULTICAST(ntohl(usin->sin_addr.s_addr))) {
+ ret = -EINVAL;
+ goto out;
+ }
+ ipv6_addr_set_v4mapped(usin->sin_addr.s_addr, &daddr);
+ dport = usin->sin_port;
+ break;
+
+#if IS_ENABLED(CONFIG_IPV6)
+ case AF_INET6: {
+ int addr_type;
+
+ if (namelen < sizeof(*sin6)) {
+ ret = -EINVAL;
+ goto out;
+ }
+ addr_type = ipv6_addr_type(&sin6->sin6_addr);
+ if (!(addr_type & IPV6_ADDR_UNICAST)) {
+ __be32 addr4;
+
+ if (!(addr_type & IPV6_ADDR_MAPPED)) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ /* It is a mapped address. Need to do some
+ * sanity checks.
+ */
+ addr4 = sin6->sin6_addr.s6_addr32[3];
+ if (addr4 == htonl(INADDR_ANY) ||
+ addr4 == htonl(INADDR_BROADCAST) ||
+ IN_MULTICAST(ntohl(addr4))) {
+ ret = -EINVAL;
+ goto out;
+ }
+ }
+ if (addr_type & IPV6_ADDR_LINKLOCAL) {
+ if (sin6->sin6_scope_id == 0) {
+ ret = -EINVAL;
+ goto out;
+ }
+ scope_id = sin6->sin6_scope_id;
+ }
+
+ daddr = sin6->sin6_addr;
+ dport = sin6->sin6_port;
+ break;
+ }
+#endif
+
+ default:
+ ret = -EINVAL;
+ goto out;
+ }
+ } else {
+ /* We only care about consistency with ->connect() */
+ lock_sock(sk);
+ daddr = rs->rs_conn_addr;
+ dport = rs->rs_conn_port;
+ scope_id = rs->rs_bound_scope_id;
+ release_sock(sk);
+ }
+
+ lock_sock(sk);
+ if (ipv6_addr_any(&rs->rs_bound_addr) || ipv6_addr_any(&daddr)) {
+ release_sock(sk);
+ ret = -ENOTCONN;
+ goto out;
+ } else if (namelen != 0) {
+ /* Cannot send to an IPv4 address using an IPv6 source
+ * address and cannot send to an IPv6 address using an
+ * IPv4 source address.
+ */
+ if (ipv6_addr_v4mapped(&daddr) ^
+ ipv6_addr_v4mapped(&rs->rs_bound_addr)) {
+ release_sock(sk);
+ ret = -EOPNOTSUPP;
+ goto out;
+ }
+ /* If the socket is already bound to a link local address,
+ * it can only send to peers on the same link. But allow
+ * communicating beween link local and non-link local address.
+ */
+ if (scope_id != rs->rs_bound_scope_id) {
+ if (!scope_id) {
+ scope_id = rs->rs_bound_scope_id;
+ } else if (rs->rs_bound_scope_id) {
+ release_sock(sk);
+ ret = -EINVAL;
+ goto out;
+ }
+ }
+ }
+ release_sock(sk);
+
+ ret = rds_rdma_bytes(msg, &rdma_payload_len);
+ if (ret)
+ goto out;
+
+ total_payload_len += rdma_payload_len;
+ if (max_t(size_t, payload_len, rdma_payload_len) > RDS_MAX_MSG_SIZE) {
+ ret = -EMSGSIZE;
+ goto out;
+ }
+
+ if (payload_len > rds_sk_sndbuf(rs)) {
+ ret = -EMSGSIZE;
+ goto out;
+ }
+
+ if (zcopy) {
+ if (rs->rs_transport->t_type != RDS_TRANS_TCP) {
+ ret = -EOPNOTSUPP;
+ goto out;
+ }
+ num_sgs = iov_iter_npages(&msg->msg_iter, INT_MAX);
+ }
+ /* size of rm including all sgs */
+ ret = rds_rm_size(msg, num_sgs);
+ if (ret < 0)
+ goto out;
+
+ rm = rds_message_alloc(ret, GFP_KERNEL);
+ if (!rm) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ /* Attach data to the rm */
+ if (payload_len) {
+ rm->data.op_sg = rds_message_alloc_sgs(rm, num_sgs);
+ if (!rm->data.op_sg) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ ret = rds_message_copy_from_user(rm, &msg->msg_iter, zcopy);
+ if (ret)
+ goto out;
+ }
+ rm->data.op_active = 1;
+
+ rm->m_daddr = daddr;
+
+ /* rds_conn_create has a spinlock that runs with IRQ off.
+ * Caching the conn in the socket helps a lot. */
+ if (rs->rs_conn && ipv6_addr_equal(&rs->rs_conn->c_faddr, &daddr))
+ conn = rs->rs_conn;
+ else {
+ conn = rds_conn_create_outgoing(sock_net(sock->sk),
+ &rs->rs_bound_addr, &daddr,
+ rs->rs_transport,
+ sock->sk->sk_allocation,
+ scope_id);
+ if (IS_ERR(conn)) {
+ ret = PTR_ERR(conn);
+ goto out;
+ }
+ rs->rs_conn = conn;
+ }
+
+ if (conn->c_trans->t_mp_capable)
+ cpath = &conn->c_path[rds_send_mprds_hash(rs, conn, nonblock)];
+ else
+ cpath = &conn->c_path[0];
+
+ rm->m_conn_path = cpath;
+
+ /* Parse any control messages the user may have included. */
+ ret = rds_cmsg_send(rs, rm, msg, &allocated_mr);
+ if (ret) {
+ /* Trigger connection so that its ready for the next retry */
+ if (ret == -EAGAIN)
+ rds_conn_connect_if_down(conn);
+ goto out;
+ }
+
+ if (rm->rdma.op_active && !conn->c_trans->xmit_rdma) {
+ printk_ratelimited(KERN_NOTICE "rdma_op %p conn xmit_rdma %p\n",
+ &rm->rdma, conn->c_trans->xmit_rdma);
+ ret = -EOPNOTSUPP;
+ goto out;
+ }
+
+ if (rm->atomic.op_active && !conn->c_trans->xmit_atomic) {
+ printk_ratelimited(KERN_NOTICE "atomic_op %p conn xmit_atomic %p\n",
+ &rm->atomic, conn->c_trans->xmit_atomic);
+ ret = -EOPNOTSUPP;
+ goto out;
+ }
+
+ if (rds_destroy_pending(conn)) {
+ ret = -EAGAIN;
+ goto out;
+ }
+
+ rds_conn_path_connect_if_down(cpath);
+
+ ret = rds_cong_wait(conn->c_fcong, dport, nonblock, rs);
+ if (ret) {
+ rs->rs_seen_congestion = 1;
+ goto out;
+ }
+ while (!rds_send_queue_rm(rs, conn, cpath, rm, rs->rs_bound_port,
+ dport, &queued)) {
+ rds_stats_inc(s_send_queue_full);
+
+ if (nonblock) {
+ ret = -EAGAIN;
+ goto out;
+ }
+
+ timeo = wait_event_interruptible_timeout(*sk_sleep(sk),
+ rds_send_queue_rm(rs, conn, cpath, rm,
+ rs->rs_bound_port,
+ dport,
+ &queued),
+ timeo);
+ rdsdebug("sendmsg woke queued %d timeo %ld\n", queued, timeo);
+ if (timeo > 0 || timeo == MAX_SCHEDULE_TIMEOUT)
+ continue;
+
+ ret = timeo;
+ if (ret == 0)
+ ret = -ETIMEDOUT;
+ goto out;
+ }
+
+ /*
+ * By now we've committed to the send. We reuse rds_send_worker()
+ * to retry sends in the rds thread if the transport asks us to.
+ */
+ rds_stats_inc(s_send_queued);
+
+ ret = rds_send_xmit(cpath);
+ if (ret == -ENOMEM || ret == -EAGAIN) {
+ ret = 0;
+ rcu_read_lock();
+ if (rds_destroy_pending(cpath->cp_conn))
+ ret = -ENETUNREACH;
+ else
+ queue_delayed_work(rds_wq, &cpath->cp_send_w, 1);
+ rcu_read_unlock();
+ }
+ if (ret)
+ goto out;
+ rds_message_put(rm);
+ return payload_len;
+
+out:
+ /* If the user included a RDMA_MAP cmsg, we allocated a MR on the fly.
+ * If the sendmsg goes through, we keep the MR. If it fails with EAGAIN
+ * or in any other way, we need to destroy the MR again */
+ if (allocated_mr)
+ rds_rdma_unuse(rs, rds_rdma_cookie_key(rm->m_rdma_cookie), 1);
+
+ if (rm)
+ rds_message_put(rm);
+ return ret;
+}
+
+/*
+ * send out a probe. Can be shared by rds_send_ping,
+ * rds_send_pong, rds_send_hb.
+ * rds_send_hb should use h_flags
+ * RDS_FLAG_HB_PING|RDS_FLAG_ACK_REQUIRED
+ * or
+ * RDS_FLAG_HB_PONG|RDS_FLAG_ACK_REQUIRED
+ */
+static int
+rds_send_probe(struct rds_conn_path *cp, __be16 sport,
+ __be16 dport, u8 h_flags)
+{
+ struct rds_message *rm;
+ unsigned long flags;
+ int ret = 0;
+
+ rm = rds_message_alloc(0, GFP_ATOMIC);
+ if (!rm) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ rm->m_daddr = cp->cp_conn->c_faddr;
+ rm->data.op_active = 1;
+
+ rds_conn_path_connect_if_down(cp);
+
+ ret = rds_cong_wait(cp->cp_conn->c_fcong, dport, 1, NULL);
+ if (ret)
+ goto out;
+
+ spin_lock_irqsave(&cp->cp_lock, flags);
+ list_add_tail(&rm->m_conn_item, &cp->cp_send_queue);
+ set_bit(RDS_MSG_ON_CONN, &rm->m_flags);
+ rds_message_addref(rm);
+ rm->m_inc.i_conn = cp->cp_conn;
+ rm->m_inc.i_conn_path = cp;
+
+ rds_message_populate_header(&rm->m_inc.i_hdr, sport, dport,
+ cp->cp_next_tx_seq);
+ rm->m_inc.i_hdr.h_flags |= h_flags;
+ cp->cp_next_tx_seq++;
+
+ if (RDS_HS_PROBE(be16_to_cpu(sport), be16_to_cpu(dport)) &&
+ cp->cp_conn->c_trans->t_mp_capable) {
+ u16 npaths = cpu_to_be16(RDS_MPATH_WORKERS);
+ u32 my_gen_num = cpu_to_be32(cp->cp_conn->c_my_gen_num);
+
+ rds_message_add_extension(&rm->m_inc.i_hdr,
+ RDS_EXTHDR_NPATHS, &npaths,
+ sizeof(npaths));
+ rds_message_add_extension(&rm->m_inc.i_hdr,
+ RDS_EXTHDR_GEN_NUM,
+ &my_gen_num,
+ sizeof(u32));
+ }
+ spin_unlock_irqrestore(&cp->cp_lock, flags);
+
+ rds_stats_inc(s_send_queued);
+ rds_stats_inc(s_send_pong);
+
+ /* schedule the send work on rds_wq */
+ rcu_read_lock();
+ if (!rds_destroy_pending(cp->cp_conn))
+ queue_delayed_work(rds_wq, &cp->cp_send_w, 1);
+ rcu_read_unlock();
+
+ rds_message_put(rm);
+ return 0;
+
+out:
+ if (rm)
+ rds_message_put(rm);
+ return ret;
+}
+
+int
+rds_send_pong(struct rds_conn_path *cp, __be16 dport)
+{
+ return rds_send_probe(cp, 0, dport, 0);
+}
+
+void
+rds_send_ping(struct rds_connection *conn, int cp_index)
+{
+ unsigned long flags;
+ struct rds_conn_path *cp = &conn->c_path[cp_index];
+
+ spin_lock_irqsave(&cp->cp_lock, flags);
+ if (conn->c_ping_triggered) {
+ spin_unlock_irqrestore(&cp->cp_lock, flags);
+ return;
+ }
+ conn->c_ping_triggered = 1;
+ spin_unlock_irqrestore(&cp->cp_lock, flags);
+ rds_send_probe(cp, cpu_to_be16(RDS_FLAG_PROBE_PORT), 0, 0);
+}
+EXPORT_SYMBOL_GPL(rds_send_ping);