/*
* Copyright (c) 2006 Oracle. 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);