path: root/fs/cifs/transport.c

/*
 *   fs/cifs/transport.c
 *
 *   Copyright (C) International Business Machines  Corp., 2002,2008
 *   Author(s): Steve French (sfrench@us.ibm.com)
 *   Jeremy Allison (jra@samba.org) 2006.
 *
 *   This library is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU Lesser General Public License as published
 *   by the Free Software Foundation; either version 2.1 of the License, or
 *   (at your option) any later version.
 *
 *   This library is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
 *   the GNU Lesser General Public License for more details.
 *
 *   You should have received a copy of the GNU Lesser General Public License
 *   along with this library; if not, write to the Free Software
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

#include <linux/fs.h>
#include <linux/list.h>
#include <linux/gfp.h>
#include <linux/wait.h>
#include <linux/net.h>
#include <linux/delay.h>
#include <linux/freezer.h>
#include <asm/uaccess.h>
#include <asm/processor.h>
#include <linux/mempool.h>
#include "cifspdu.h"
#include "cifsglob.h"
#include "cifsproto.h"
#include "cifs_debug.h"

extern mempool_t *cifs_mid_poolp;

static void
wake_up_task(struct mid_q_entry *mid)
{
	wake_up_process(mid->callback_data);
}

struct mid_q_entry *
AllocMidQEntry(const struct smb_hdr *smb_buffer, struct TCP_Server_Info *server)
{
	struct mid_q_entry *temp;

	if (server == NULL) {
		cERROR(1, "Null TCP session in AllocMidQEntry");
		return NULL;
	}

	temp = mempool_alloc(cifs_mid_poolp, GFP_NOFS);
	if (temp == NULL)
		return temp;
	else {
		memset(temp, 0, sizeof(struct mid_q_entry));
		temp->mid = smb_buffer->Mid;	/* always LE */
		temp->pid = current->pid;
		temp->command = cpu_to_le16(smb_buffer->Command);
		cFYI(1, "For smb_command %d", smb_buffer->Command);
	/*	do_gettimeofday(&temp->when_sent);*/ /* easier to use jiffies */
		/* when mid allocated can be before when sent */
		temp->when_alloc = jiffies;

		/*
		 * The default is for the mid to be synchronous, so the
		 * default callback just wakes up the current task.
		 */
		temp->callback = wake_up_task;
		temp->callback_data = current;
	}

	atomic_inc(&midCount);
	temp->mid_state = MID_REQUEST_ALLOCATED;
	return temp;
}

void
DeleteMidQEntry(struct mid_q_entry *midEntry)
{
#ifdef CONFIG_CIFS_STATS2
	unsigned long now;
#endif
	midEntry->mid_state = MID_FREE;
	atomic_dec(&midCount);
	if (midEntry->large_buf)
		cifs_buf_release(midEntry->resp_buf);
	else
		cifs_small_buf_release(midEntry->resp_buf);
#ifdef CONFIG_CIFS_STATS2
	now = jiffies;
	/* commands taking longer than one second are indications that
	   something is wrong, unless it is quite a slow link or server */
	if ((now - midEntry->when_alloc) > HZ) {
		if ((cifsFYI & CIFS_TIMER) &&
		    (midEntry->command != cpu_to_le16(SMB_COM_LOCKING_ANDX))) {
			printk(KERN_DEBUG " CIFS slow rsp: cmd %d mid %llu",
			       midEntry->command, midEntry->mid);
			printk(" A: 0x%lx S: 0x%lx R: 0x%lx\n",
			       now - midEntry->when_alloc,
			       now - midEntry->when_sent,
			       now - midEntry->when_received);
		}
	}
#endif
	mempool_free(midEntry, cifs_mid_poolp);
}

static void
delete_mid(struct mid_q_entry *mid)
{
	spin_lock(&GlobalMid_Lock);
	list_del(&mid->qhead);
	spin_unlock(&GlobalMid_Lock);

	DeleteMidQEntry(mid);
}

static int
smb_sendv(struct TCP_Server_Info *server, struct kvec *iov, int n_vec)
{
	int rc = 0;
	int i = 0;
	struct msghdr smb_msg;
	__be32 *buf_len = (__be32 *)(iov[0].iov_base);
	unsigned int len = iov[0].iov_len;
	unsigned int total_len;
	int first_vec = 0;
	unsigned int smb_buf_length = get_rfc1002_length(iov[0].iov_base);
	struct socket *ssocket = server->ssocket;

	if (ssocket == NULL)
		return -ENOTSOCK; /* BB eventually add reconnect code here */

	smb_msg.msg_name = (struct sockaddr *) &server->dstaddr;
	smb_msg.msg_namelen = sizeof(struct sockaddr);
	smb_msg.msg_control = NULL;
	smb_msg.msg_controllen = 0;
	if (server->noblocksnd)
		smb_msg.msg_flags = MSG_DONTWAIT + MSG_NOSIGNAL;
	else
		smb_msg.msg_flags = MSG_NOSIGNAL;

	total_len = 0;
	for (i = 0; i < n_vec; i++)
		total_len += iov[i].iov_len;

	cFYI(1, "Sending smb:  total_len %d", total_len);
	dump_smb(iov[0].iov_base, len);

	i = 0;
	while (total_len) {
		rc = kernel_sendmsg(ssocket, &smb_msg, &iov[first_vec],
				    n_vec - first_vec, total_len);
		if ((rc == -ENOSPC) || (rc == -EAGAIN)) {
			i++;
			/*
			 * If blocking send we try 3 times, since each can block