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![Andy Grover](/assets/img/avatar_default.png)
Now that rdma and tcp transports will be modularized, we need to export a number of functions so they can call them. Signed-off-by: Andy Grover <andy.grover@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
1006 lines
28 KiB
C
1006 lines
28 KiB
C
/*
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* Copyright (c) 2006 Oracle. All rights reserved.
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*
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* This software is available to you under a choice of one of two
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* licenses. You may choose to be licensed under the terms of the GNU
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* General Public License (GPL) Version 2, available from the file
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* COPYING in the main directory of this source tree, or the
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* OpenIB.org BSD license below:
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*
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* Redistribution and use in source and binary forms, with or
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* without modification, are permitted provided that the following
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* conditions are met:
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*
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* - Redistributions of source code must retain the above
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* copyright notice, this list of conditions and the following
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* disclaimer.
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*
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* - Redistributions in binary form must reproduce the above
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* copyright notice, this list of conditions and the following
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* disclaimer in the documentation and/or other materials
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* provided with the distribution.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
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* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
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* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
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* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
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* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
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* SOFTWARE.
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*
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*/
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#include <linux/kernel.h>
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#include <net/sock.h>
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#include <linux/in.h>
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#include <linux/list.h>
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#include "rds.h"
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#include "rdma.h"
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/* When transmitting messages in rds_send_xmit, we need to emerge from
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* time to time and briefly release the CPU. Otherwise the softlock watchdog
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* will kick our shin.
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* Also, it seems fairer to not let one busy connection stall all the
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* others.
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*
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* send_batch_count is the number of times we'll loop in send_xmit. Setting
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* it to 0 will restore the old behavior (where we looped until we had
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* drained the queue).
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*/
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static int send_batch_count = 64;
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module_param(send_batch_count, int, 0444);
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MODULE_PARM_DESC(send_batch_count, " batch factor when working the send queue");
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/*
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* Reset the send state. Caller must hold c_send_lock when calling here.
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*/
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void rds_send_reset(struct rds_connection *conn)
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{
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struct rds_message *rm, *tmp;
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unsigned long flags;
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if (conn->c_xmit_rm) {
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/* Tell the user the RDMA op is no longer mapped by the
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* transport. This isn't entirely true (it's flushed out
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* independently) but as the connection is down, there's
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* no ongoing RDMA to/from that memory */
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rds_message_unmapped(conn->c_xmit_rm);
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rds_message_put(conn->c_xmit_rm);
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conn->c_xmit_rm = NULL;
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}
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conn->c_xmit_sg = 0;
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conn->c_xmit_hdr_off = 0;
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conn->c_xmit_data_off = 0;
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conn->c_xmit_rdma_sent = 0;
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conn->c_map_queued = 0;
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conn->c_unacked_packets = rds_sysctl_max_unacked_packets;
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conn->c_unacked_bytes = rds_sysctl_max_unacked_bytes;
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/* Mark messages as retransmissions, and move them to the send q */
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spin_lock_irqsave(&conn->c_lock, flags);
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list_for_each_entry_safe(rm, tmp, &conn->c_retrans, m_conn_item) {
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set_bit(RDS_MSG_ACK_REQUIRED, &rm->m_flags);
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set_bit(RDS_MSG_RETRANSMITTED, &rm->m_flags);
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}
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list_splice_init(&conn->c_retrans, &conn->c_send_queue);
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spin_unlock_irqrestore(&conn->c_lock, flags);
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}
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/*
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* We're making the concious trade-off here to only send one message
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* down the connection at a time.
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* Pro:
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* - tx queueing is a simple fifo list
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* - reassembly is optional and easily done by transports per conn
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* - no per flow rx lookup at all, straight to the socket
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* - less per-frag memory and wire overhead
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* Con:
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* - queued acks can be delayed behind large messages
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* Depends:
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* - small message latency is higher behind queued large messages
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* - large message latency isn't starved by intervening small sends
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*/
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int rds_send_xmit(struct rds_connection *conn)
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{
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struct rds_message *rm;
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unsigned long flags;
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unsigned int tmp;
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unsigned int send_quota = send_batch_count;
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struct scatterlist *sg;
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int ret = 0;
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int was_empty = 0;
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LIST_HEAD(to_be_dropped);
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/*
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* sendmsg calls here after having queued its message on the send
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* queue. We only have one task feeding the connection at a time. If
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* another thread is already feeding the queue then we back off. This
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* avoids blocking the caller and trading per-connection data between
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* caches per message.
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*
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* The sem holder will issue a retry if they notice that someone queued
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* a message after they stopped walking the send queue but before they
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* dropped the sem.
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*/
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if (!mutex_trylock(&conn->c_send_lock)) {
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rds_stats_inc(s_send_sem_contention);
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ret = -ENOMEM;
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goto out;
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}
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if (conn->c_trans->xmit_prepare)
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conn->c_trans->xmit_prepare(conn);
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/*
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* spin trying to push headers and data down the connection until
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* the connection doens't make forward progress.
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*/
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while (--send_quota) {
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/*
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* See if need to send a congestion map update if we're
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* between sending messages. The send_sem protects our sole
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* use of c_map_offset and _bytes.
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* Note this is used only by transports that define a special
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* xmit_cong_map function. For all others, we create allocate
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* a cong_map message and treat it just like any other send.
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*/
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if (conn->c_map_bytes) {
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ret = conn->c_trans->xmit_cong_map(conn, conn->c_lcong,
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conn->c_map_offset);
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if (ret <= 0)
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break;
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conn->c_map_offset += ret;
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conn->c_map_bytes -= ret;
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if (conn->c_map_bytes)
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continue;
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}
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/* If we're done sending the current message, clear the
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* offset and S/G temporaries.
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*/
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rm = conn->c_xmit_rm;
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if (rm != NULL &&
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conn->c_xmit_hdr_off == sizeof(struct rds_header) &&
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conn->c_xmit_sg == rm->m_nents) {
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conn->c_xmit_rm = NULL;
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conn->c_xmit_sg = 0;
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conn->c_xmit_hdr_off = 0;
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conn->c_xmit_data_off = 0;
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conn->c_xmit_rdma_sent = 0;
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/* Release the reference to the previous message. */
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rds_message_put(rm);
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rm = NULL;
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}
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/* If we're asked to send a cong map update, do so.
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*/
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if (rm == NULL && test_and_clear_bit(0, &conn->c_map_queued)) {
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if (conn->c_trans->xmit_cong_map != NULL) {
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conn->c_map_offset = 0;
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conn->c_map_bytes = sizeof(struct rds_header) +
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RDS_CONG_MAP_BYTES;
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continue;
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}
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rm = rds_cong_update_alloc(conn);
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if (IS_ERR(rm)) {
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ret = PTR_ERR(rm);
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break;
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}
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conn->c_xmit_rm = rm;
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}
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/*
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* Grab the next message from the send queue, if there is one.
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*
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* c_xmit_rm holds a ref while we're sending this message down
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* the connction. We can use this ref while holding the
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* send_sem.. rds_send_reset() is serialized with it.
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*/
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if (rm == NULL) {
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unsigned int len;
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spin_lock_irqsave(&conn->c_lock, flags);
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if (!list_empty(&conn->c_send_queue)) {
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rm = list_entry(conn->c_send_queue.next,
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struct rds_message,
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m_conn_item);
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rds_message_addref(rm);
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/*
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* Move the message from the send queue to the retransmit
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* list right away.
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*/
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list_move_tail(&rm->m_conn_item, &conn->c_retrans);
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}
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spin_unlock_irqrestore(&conn->c_lock, flags);
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if (rm == NULL) {
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was_empty = 1;
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break;
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}
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/* Unfortunately, the way Infiniband deals with
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* RDMA to a bad MR key is by moving the entire
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* queue pair to error state. We cold possibly
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* recover from that, but right now we drop the
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* connection.
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* Therefore, we never retransmit messages with RDMA ops.
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*/
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if (rm->m_rdma_op
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&& test_bit(RDS_MSG_RETRANSMITTED, &rm->m_flags)) {
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spin_lock_irqsave(&conn->c_lock, flags);
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if (test_and_clear_bit(RDS_MSG_ON_CONN, &rm->m_flags))
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list_move(&rm->m_conn_item, &to_be_dropped);
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spin_unlock_irqrestore(&conn->c_lock, flags);
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rds_message_put(rm);
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continue;
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}
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/* Require an ACK every once in a while */
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len = ntohl(rm->m_inc.i_hdr.h_len);
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if (conn->c_unacked_packets == 0
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|| conn->c_unacked_bytes < len) {
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__set_bit(RDS_MSG_ACK_REQUIRED, &rm->m_flags);
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conn->c_unacked_packets = rds_sysctl_max_unacked_packets;
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conn->c_unacked_bytes = rds_sysctl_max_unacked_bytes;
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rds_stats_inc(s_send_ack_required);
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} else {
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conn->c_unacked_bytes -= len;
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conn->c_unacked_packets--;
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}
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conn->c_xmit_rm = rm;
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}
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/*
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* Try and send an rdma message. Let's see if we can
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* keep this simple and require that the transport either
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* send the whole rdma or none of it.
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*/
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if (rm->m_rdma_op && !conn->c_xmit_rdma_sent) {
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ret = conn->c_trans->xmit_rdma(conn, rm->m_rdma_op);
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if (ret)
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break;
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conn->c_xmit_rdma_sent = 1;
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/* The transport owns the mapped memory for now.
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* You can't unmap it while it's on the send queue */
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set_bit(RDS_MSG_MAPPED, &rm->m_flags);
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}
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if (conn->c_xmit_hdr_off < sizeof(struct rds_header) ||
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conn->c_xmit_sg < rm->m_nents) {
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ret = conn->c_trans->xmit(conn, rm,
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conn->c_xmit_hdr_off,
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conn->c_xmit_sg,
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conn->c_xmit_data_off);
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if (ret <= 0)
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break;
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if (conn->c_xmit_hdr_off < sizeof(struct rds_header)) {
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tmp = min_t(int, ret,
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sizeof(struct rds_header) -
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conn->c_xmit_hdr_off);
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conn->c_xmit_hdr_off += tmp;
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ret -= tmp;
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}
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sg = &rm->m_sg[conn->c_xmit_sg];
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while (ret) {
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tmp = min_t(int, ret, sg->length -
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conn->c_xmit_data_off);
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conn->c_xmit_data_off += tmp;
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ret -= tmp;
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if (conn->c_xmit_data_off == sg->length) {
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conn->c_xmit_data_off = 0;
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sg++;
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conn->c_xmit_sg++;
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BUG_ON(ret != 0 &&
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conn->c_xmit_sg == rm->m_nents);
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}
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}
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}
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}
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/* Nuke any messages we decided not to retransmit. */
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if (!list_empty(&to_be_dropped))
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rds_send_remove_from_sock(&to_be_dropped, RDS_RDMA_DROPPED);
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if (conn->c_trans->xmit_complete)
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conn->c_trans->xmit_complete(conn);
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/*
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* We might be racing with another sender who queued a message but
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* backed off on noticing that we held the c_send_lock. If we check
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* for queued messages after dropping the sem then either we'll
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* see the queued message or the queuer will get the sem. If we
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* notice the queued message then we trigger an immediate retry.
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*
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* We need to be careful only to do this when we stopped processing
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* the send queue because it was empty. It's the only way we
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* stop processing the loop when the transport hasn't taken
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* responsibility for forward progress.
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*/
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mutex_unlock(&conn->c_send_lock);
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if (conn->c_map_bytes || (send_quota == 0 && !was_empty)) {
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/* We exhausted the send quota, but there's work left to
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* do. Return and (re-)schedule the send worker.
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*/
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ret = -EAGAIN;
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}
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if (ret == 0 && was_empty) {
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/* A simple bit test would be way faster than taking the
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* spin lock */
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spin_lock_irqsave(&conn->c_lock, flags);
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if (!list_empty(&conn->c_send_queue)) {
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rds_stats_inc(s_send_sem_queue_raced);
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ret = -EAGAIN;
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}
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spin_unlock_irqrestore(&conn->c_lock, flags);
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}
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out:
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return ret;
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}
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static void rds_send_sndbuf_remove(struct rds_sock *rs, struct rds_message *rm)
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{
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u32 len = be32_to_cpu(rm->m_inc.i_hdr.h_len);
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assert_spin_locked(&rs->rs_lock);
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BUG_ON(rs->rs_snd_bytes < len);
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rs->rs_snd_bytes -= len;
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if (rs->rs_snd_bytes == 0)
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rds_stats_inc(s_send_queue_empty);
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}
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static inline int rds_send_is_acked(struct rds_message *rm, u64 ack,
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is_acked_func is_acked)
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{
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if (is_acked)
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return is_acked(rm, ack);
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return be64_to_cpu(rm->m_inc.i_hdr.h_sequence) <= ack;
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}
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/*
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* Returns true if there are no messages on the send and retransmit queues
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* which have a sequence number greater than or equal to the given sequence
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* number.
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*/
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int rds_send_acked_before(struct rds_connection *conn, u64 seq)
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{
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struct rds_message *rm, *tmp;
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int ret = 1;
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spin_lock(&conn->c_lock);
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list_for_each_entry_safe(rm, tmp, &conn->c_retrans, m_conn_item) {
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if (be64_to_cpu(rm->m_inc.i_hdr.h_sequence) < seq)
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ret = 0;
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break;
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}
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list_for_each_entry_safe(rm, tmp, &conn->c_send_queue, m_conn_item) {
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if (be64_to_cpu(rm->m_inc.i_hdr.h_sequence) < seq)
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ret = 0;
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break;
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}
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spin_unlock(&conn->c_lock);
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return ret;
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}
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/*
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* This is pretty similar to what happens below in the ACK
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* handling code - except that we call here as soon as we get
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* the IB send completion on the RDMA op and the accompanying
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* message.
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*/
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void rds_rdma_send_complete(struct rds_message *rm, int status)
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{
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struct rds_sock *rs = NULL;
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struct rds_rdma_op *ro;
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struct rds_notifier *notifier;
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spin_lock(&rm->m_rs_lock);
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ro = rm->m_rdma_op;
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if (test_bit(RDS_MSG_ON_SOCK, &rm->m_flags)
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&& ro && ro->r_notify && ro->r_notifier) {
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notifier = ro->r_notifier;
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rs = rm->m_rs;
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sock_hold(rds_rs_to_sk(rs));
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notifier->n_status = status;
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spin_lock(&rs->rs_lock);
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list_add_tail(¬ifier->n_list, &rs->rs_notify_queue);
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spin_unlock(&rs->rs_lock);
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ro->r_notifier = NULL;
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}
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spin_unlock(&rm->m_rs_lock);
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if (rs) {
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rds_wake_sk_sleep(rs);
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sock_put(rds_rs_to_sk(rs));
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}
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}
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EXPORT_SYMBOL_GPL(rds_rdma_send_complete);
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/*
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* This is the same as rds_rdma_send_complete except we
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* don't do any locking - we have all the ingredients (message,
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* socket, socket lock) and can just move the notifier.
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*/
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static inline void
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__rds_rdma_send_complete(struct rds_sock *rs, struct rds_message *rm, int status)
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{
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struct rds_rdma_op *ro;
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ro = rm->m_rdma_op;
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if (ro && ro->r_notify && ro->r_notifier) {
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ro->r_notifier->n_status = status;
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list_add_tail(&ro->r_notifier->n_list, &rs->rs_notify_queue);
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ro->r_notifier = NULL;
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}
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/* No need to wake the app - caller does this */
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}
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/*
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* This is called from the IB send completion when we detect
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* a RDMA operation that failed with remote access error.
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* So speed is not an issue here.
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*/
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struct rds_message *rds_send_get_message(struct rds_connection *conn,
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struct rds_rdma_op *op)
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{
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struct rds_message *rm, *tmp, *found = NULL;
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unsigned long flags;
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spin_lock_irqsave(&conn->c_lock, flags);
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list_for_each_entry_safe(rm, tmp, &conn->c_retrans, m_conn_item) {
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if (rm->m_rdma_op == op) {
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atomic_inc(&rm->m_refcount);
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found = rm;
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goto out;
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}
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}
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|
|
list_for_each_entry_safe(rm, tmp, &conn->c_send_queue, m_conn_item) {
|
|
if (rm->m_rdma_op == op) {
|
|
atomic_inc(&rm->m_refcount);
|
|
found = rm;
|
|
break;
|
|
}
|
|
}
|
|
|
|
out:
|
|
spin_unlock_irqrestore(&conn->c_lock, flags);
|
|
|
|
return found;
|
|
}
|
|
EXPORT_SYMBOL_GPL(rds_send_get_message);
|
|
|
|
/*
|
|
* 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.
|
|
*/
|
|
void rds_send_remove_from_sock(struct list_head *messages, int status)
|
|
{
|
|
unsigned long flags = 0; /* silence gcc :P */
|
|
struct rds_sock *rs = NULL;
|
|
struct rds_message *rm;
|
|
|
|
local_irq_save(flags);
|
|
while (!list_empty(messages)) {
|
|
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(&rm->m_rs_lock);
|
|
if (!test_bit(RDS_MSG_ON_SOCK, &rm->m_flags))
|
|
goto unlock_and_drop;
|
|
|
|
if (rs != rm->m_rs) {
|
|
if (rs) {
|
|
spin_unlock(&rs->rs_lock);
|
|
rds_wake_sk_sleep(rs);
|
|
sock_put(rds_rs_to_sk(rs));
|
|
}
|
|
rs = rm->m_rs;
|
|
spin_lock(&rs->rs_lock);
|
|
sock_hold(rds_rs_to_sk(rs));
|
|
}
|
|
|
|
if (test_and_clear_bit(RDS_MSG_ON_SOCK, &rm->m_flags)) {
|
|
struct rds_rdma_op *ro = rm->m_rdma_op;
|
|
struct rds_notifier *notifier;
|
|
|
|
list_del_init(&rm->m_sock_item);
|
|
rds_send_sndbuf_remove(rs, rm);
|
|
|
|
if (ro && ro->r_notifier
|
|
&& (status || ro->r_notify)) {
|
|
notifier = ro->r_notifier;
|
|
list_add_tail(¬ifier->n_list,
|
|
&rs->rs_notify_queue);
|
|
if (!notifier->n_status)
|
|
notifier->n_status = status;
|
|
rm->m_rdma_op->r_notifier = NULL;
|
|
}
|
|
rds_message_put(rm);
|
|
rm->m_rs = NULL;
|
|
}
|
|
|
|
unlock_and_drop:
|
|
spin_unlock(&rm->m_rs_lock);
|
|
rds_message_put(rm);
|
|
}
|
|
|
|
if (rs) {
|
|
spin_unlock(&rs->rs_lock);
|
|
rds_wake_sk_sleep(rs);
|
|
sock_put(rds_rs_to_sk(rs));
|
|
}
|
|
local_irq_restore(flags);
|
|
}
|
|
|
|
/*
|
|
* 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.
|
|
*
|
|
* XXX It's not clear to me how this is safely serialized with socket
|
|
* destruction. Maybe it should bail if it sees SOCK_DEAD.
|
|
*/
|
|
void rds_send_drop_acked(struct rds_connection *conn, u64 ack,
|
|
is_acked_func is_acked)
|
|
{
|
|
struct rds_message *rm, *tmp;
|
|
unsigned long flags;
|
|
LIST_HEAD(list);
|
|
|
|
spin_lock_irqsave(&conn->c_lock, flags);
|
|
|
|
list_for_each_entry_safe(rm, tmp, &conn->c_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_clear_bit();
|
|
|
|
spin_unlock_irqrestore(&conn->c_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_drop_acked);
|
|
|
|
void rds_send_drop_to(struct rds_sock *rs, struct sockaddr_in *dest)
|
|
{
|
|
struct rds_message *rm, *tmp;
|
|
struct rds_connection *conn;
|
|
unsigned long flags, flags2;
|
|
LIST_HEAD(list);
|
|
int wake = 0;
|
|
|
|
/* 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 && (dest->sin_addr.s_addr != rm->m_daddr ||
|
|
dest->sin_port != rm->m_inc.i_hdr.h_dport))
|
|
continue;
|
|
|
|
wake = 1;
|
|
list_move(&rm->m_sock_item, &list);
|
|
rds_send_sndbuf_remove(rs, rm);
|
|
clear_bit(RDS_MSG_ON_SOCK, &rm->m_flags);
|
|
|
|
/* If this is a RDMA operation, notify the app. */
|
|
__rds_rdma_send_complete(rs, rm, RDS_RDMA_CANCELED);
|
|
}
|
|
|
|
/* order flag updates with the rs lock */
|
|
if (wake)
|
|
smp_mb__after_clear_bit();
|
|
|
|
spin_unlock_irqrestore(&rs->rs_lock, flags);
|
|
|
|
if (wake)
|
|
rds_wake_sk_sleep(rs);
|
|
|
|
conn = NULL;
|
|
|
|
/* now remove the messages from the conn list as needed */
|
|
list_for_each_entry(rm, &list, m_sock_item) {
|
|
/* We do this here rather than in the loop above, so that
|
|
* we don't have to nest m_rs_lock under rs->rs_lock */
|
|
spin_lock_irqsave(&rm->m_rs_lock, flags2);
|
|
rm->m_rs = NULL;
|
|
spin_unlock_irqrestore(&rm->m_rs_lock, flags2);
|
|
|
|
/*
|
|
* If we see this flag cleared then we're *sure* that someone
|
|
* else beat us to removing it 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_bit(RDS_MSG_ON_CONN, &rm->m_flags))
|
|
continue;
|
|
|
|
if (conn != rm->m_inc.i_conn) {
|
|
if (conn)
|
|
spin_unlock_irqrestore(&conn->c_lock, flags);
|
|
conn = rm->m_inc.i_conn;
|
|
spin_lock_irqsave(&conn->c_lock, flags);
|
|
}
|
|
|
|
if (test_and_clear_bit(RDS_MSG_ON_CONN, &rm->m_flags)) {
|
|
list_del_init(&rm->m_conn_item);
|
|
rds_message_put(rm);
|
|
}
|
|
}
|
|
|
|
if (conn)
|
|
spin_unlock_irqrestore(&conn->c_lock, flags);
|
|
|
|
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);
|
|
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_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);
|
|
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;
|
|
rds_message_addref(rm);
|
|
|
|
spin_lock(&conn->c_lock);
|
|
rm->m_inc.i_hdr.h_sequence = cpu_to_be64(conn->c_next_tx_seq++);
|
|
list_add_tail(&rm->m_conn_item, &conn->c_send_queue);
|
|
set_bit(RDS_MSG_ON_CONN, &rm->m_flags);
|
|
spin_unlock(&conn->c_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;
|
|
}
|
|
|
|
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 (cmsg = CMSG_FIRSTHDR(msg); cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) {
|
|
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->m_rdma_cookie and rm->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;
|
|
break;
|
|
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (ret)
|
|
break;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
int rds_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
|
|
size_t payload_len)
|
|
{
|
|
struct sock *sk = sock->sk;
|
|
struct rds_sock *rs = rds_sk_to_rs(sk);
|
|
struct sockaddr_in *usin = (struct sockaddr_in *)msg->msg_name;
|
|
__be32 daddr;
|
|
__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_rcvtimeo(sk, nonblock);
|
|
|
|
/* Mirror Linux UDP mirror of BSD error message compatibility */
|
|
/* XXX: Perhaps MSG_MORE someday */
|
|
if (msg->msg_flags & ~(MSG_DONTWAIT | MSG_CMSG_COMPAT)) {
|
|
printk(KERN_INFO "msg_flags 0x%08X\n", msg->msg_flags);
|
|
ret = -EOPNOTSUPP;
|
|
goto out;
|
|
}
|
|
|
|
if (msg->msg_namelen) {
|
|
/* XXX fail non-unicast destination IPs? */
|
|
if (msg->msg_namelen < sizeof(*usin) || usin->sin_family != AF_INET) {
|
|
ret = -EINVAL;
|
|
goto out;
|
|
}
|
|
daddr = usin->sin_addr.s_addr;
|
|
dport = usin->sin_port;
|
|
} else {
|
|
/* We only care about consistency with ->connect() */
|
|
lock_sock(sk);
|
|
daddr = rs->rs_conn_addr;
|
|
dport = rs->rs_conn_port;
|
|
release_sock(sk);
|
|
}
|
|
|
|
/* racing with another thread binding seems ok here */
|
|
if (daddr == 0 || rs->rs_bound_addr == 0) {
|
|
ret = -ENOTCONN; /* XXX not a great errno */
|
|
goto out;
|
|
}
|
|
|
|
rm = rds_message_copy_from_user(msg->msg_iov, payload_len);
|
|
if (IS_ERR(rm)) {
|
|
ret = PTR_ERR(rm);
|
|
rm = NULL;
|
|
goto out;
|
|
}
|
|
|
|
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 && rs->rs_conn->c_faddr == daddr)
|
|
conn = rs->rs_conn;
|
|
else {
|
|
conn = rds_conn_create_outgoing(rs->rs_bound_addr, daddr,
|
|
rs->rs_transport,
|
|
sock->sk->sk_allocation);
|
|
if (IS_ERR(conn)) {
|
|
ret = PTR_ERR(conn);
|
|
goto out;
|
|
}
|
|
rs->rs_conn = conn;
|
|
}
|
|
|
|
/* Parse any control messages the user may have included. */
|
|
ret = rds_cmsg_send(rs, rm, msg, &allocated_mr);
|
|
if (ret)
|
|
goto out;
|
|
|
|
if ((rm->m_rdma_cookie || rm->m_rdma_op)
|
|
&& conn->c_trans->xmit_rdma == NULL) {
|
|
if (printk_ratelimit())
|
|
printk(KERN_NOTICE "rdma_op %p conn xmit_rdma %p\n",
|
|
rm->m_rdma_op, conn->c_trans->xmit_rdma);
|
|
ret = -EOPNOTSUPP;
|
|
goto out;
|
|
}
|
|
|
|
/* If the connection is down, trigger a connect. We may
|
|
* have scheduled a delayed reconnect however - in this case
|
|
* we should not interfere.
|
|
*/
|
|
if (rds_conn_state(conn) == RDS_CONN_DOWN
|
|
&& !test_and_set_bit(RDS_RECONNECT_PENDING, &conn->c_flags))
|
|
queue_delayed_work(rds_wq, &conn->c_conn_w, 0);
|
|
|
|
ret = rds_cong_wait(conn->c_fcong, dport, nonblock, rs);
|
|
if (ret)
|
|
goto out;
|
|
|
|
while (!rds_send_queue_rm(rs, conn, rm, rs->rs_bound_port,
|
|
dport, &queued)) {
|
|
rds_stats_inc(s_send_queue_full);
|
|
/* XXX make sure this is reasonable */
|
|
if (payload_len > rds_sk_sndbuf(rs)) {
|
|
ret = -EMSGSIZE;
|
|
goto out;
|
|
}
|
|
if (nonblock) {
|
|
ret = -EAGAIN;
|
|
goto out;
|
|
}
|
|
|
|
timeo = wait_event_interruptible_timeout(*sk->sk_sleep,
|
|
rds_send_queue_rm(rs, conn, 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);
|
|
|
|
if (!test_bit(RDS_LL_SEND_FULL, &conn->c_flags))
|
|
rds_send_worker(&conn->c_send_w.work);
|
|
|
|
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;
|
|
}
|
|
|
|
/*
|
|
* Reply to a ping packet.
|
|
*/
|
|
int
|
|
rds_send_pong(struct rds_connection *conn, __be16 dport)
|
|
{
|
|
struct rds_message *rm;
|
|
unsigned long flags;
|
|
int ret = 0;
|
|
|
|
rm = rds_message_alloc(0, GFP_ATOMIC);
|
|
if (rm == NULL) {
|
|
ret = -ENOMEM;
|
|
goto out;
|
|
}
|
|
|
|
rm->m_daddr = conn->c_faddr;
|
|
|
|
/* If the connection is down, trigger a connect. We may
|
|
* have scheduled a delayed reconnect however - in this case
|
|
* we should not interfere.
|
|
*/
|
|
if (rds_conn_state(conn) == RDS_CONN_DOWN
|
|
&& !test_and_set_bit(RDS_RECONNECT_PENDING, &conn->c_flags))
|
|
queue_delayed_work(rds_wq, &conn->c_conn_w, 0);
|
|
|
|
ret = rds_cong_wait(conn->c_fcong, dport, 1, NULL);
|
|
if (ret)
|
|
goto out;
|
|
|
|
spin_lock_irqsave(&conn->c_lock, flags);
|
|
list_add_tail(&rm->m_conn_item, &conn->c_send_queue);
|
|
set_bit(RDS_MSG_ON_CONN, &rm->m_flags);
|
|
rds_message_addref(rm);
|
|
rm->m_inc.i_conn = conn;
|
|
|
|
rds_message_populate_header(&rm->m_inc.i_hdr, 0, dport,
|
|
conn->c_next_tx_seq);
|
|
conn->c_next_tx_seq++;
|
|
spin_unlock_irqrestore(&conn->c_lock, flags);
|
|
|
|
rds_stats_inc(s_send_queued);
|
|
rds_stats_inc(s_send_pong);
|
|
|
|
queue_delayed_work(rds_wq, &conn->c_send_w, 0);
|
|
rds_message_put(rm);
|
|
return 0;
|
|
|
|
out:
|
|
if (rm)
|
|
rds_message_put(rm);
|
|
return ret;
|
|
}
|