Release 4.11 drivers/scsi/iscsi_tcp.c

Directory: drivers/scsi
/*
 * iSCSI Initiator over TCP/IP Data-Path
 *
 * Copyright (C) 2004 Dmitry Yusupov
 * Copyright (C) 2004 Alex Aizman
 * Copyright (C) 2005 - 2006 Mike Christie
 * Copyright (C) 2006 Red Hat, Inc.  All rights reserved.
 * maintained by open-iscsi@googlegroups.com
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published
 * by the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program 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
 * General Public License for more details.
 *
 * See the file COPYING included with this distribution for more details.
 *
 * Credits:
 *      Christoph Hellwig
 *      FUJITA Tomonori
 *      Arne Redlich
 *      Zhenyu Wang
 */

#include <crypto/hash.h>
#include <linux/types.h>
#include <linux/inet.h>
#include <linux/slab.h>
#include <linux/file.h>
#include <linux/blkdev.h>
#include <linux/delay.h>
#include <linux/kfifo.h>
#include <linux/scatterlist.h>
#include <linux/module.h>
#include <net/tcp.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi.h>
#include <scsi/scsi_transport_iscsi.h>

#include "iscsi_tcp.h"

MODULE_AUTHOR("Mike Christie <michaelc@cs.wisc.edu>, "
	      "Dmitry Yusupov <dmitry_yus@yahoo.com>, "
	      "Alex Aizman <itn780@yahoo.com>");
MODULE_DESCRIPTION("iSCSI/TCP data-path");
MODULE_LICENSE("GPL");


static struct scsi_transport_template *iscsi_sw_tcp_scsi_transport;

static struct scsi_host_template iscsi_sw_tcp_sht;

static struct iscsi_transport iscsi_sw_tcp_transport;


static unsigned int iscsi_max_lun = ~0;
module_param_named(max_lun, iscsi_max_lun, uint, S_IRUGO);


static int iscsi_sw_tcp_dbg;
module_param_named(debug_iscsi_tcp, iscsi_sw_tcp_dbg, int,
		   S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(debug_iscsi_tcp, "Turn on debugging for iscsi_tcp module "
		 "Set to 1 to turn on, and zero to turn off. Default is off.");


#define ISCSI_SW_TCP_DBG(_conn, dbg_fmt, arg...)		\
	do {                                                    \
                if (iscsi_sw_tcp_dbg)                           \
                        iscsi_conn_printk(KERN_INFO, _conn,     \
                                             "%s " dbg_fmt,     \
                                             __func__, ##arg);  \
        } while (0);


/**
 * iscsi_sw_tcp_recv - TCP receive in sendfile fashion
 * @rd_desc: read descriptor
 * @skb: socket buffer
 * @offset: offset in skb
 * @len: skb->len - offset
 */


static int iscsi_sw_tcp_recv(read_descriptor_t *rd_desc, struct sk_buff *skb,
			     unsigned int offset, size_t len)
{
	struct iscsi_conn *conn = rd_desc->arg.data;
	unsigned int consumed, total_consumed = 0;
	int status;

	ISCSI_SW_TCP_DBG(conn, "in %d bytes\n", skb->len - offset);

	do {
		status = 0;
		consumed = iscsi_tcp_recv_skb(conn, skb, offset, 0, &status);
		offset += consumed;
		total_consumed += consumed;
	} while (consumed != 0 && status != ISCSI_TCP_SKB_DONE);

	ISCSI_SW_TCP_DBG(conn, "read %d bytes status %d\n",
			 skb->len - offset, status);
	return total_consumed;
}

Contributors
Person Tokens Prop Commits CommitProp
Mike Christie 91 77.78% 2 40.00%
Olaf Kirch 14 11.97% 2 40.00%
Alex Aizman 12 10.26% 1 20.00%
Total 117 100.00% 5 100.00%

/**
 * iscsi_sw_sk_state_check - check socket state
 * @sk: socket
 *
 * If the socket is in CLOSE or CLOSE_WAIT we should
 * not close the connection if there is still some
 * data pending.
 *
 * Must be called with sk_callback_lock.
 */


static inline int iscsi_sw_sk_state_check(struct sock *sk)
{
	struct iscsi_conn *conn = sk->sk_user_data;

	if ((sk->sk_state == TCP_CLOSE_WAIT || sk->sk_state == TCP_CLOSE) &&
	    (conn->session->state != ISCSI_STATE_LOGGING_OUT) &&
	    !atomic_read(&sk->sk_rmem_alloc)) {
		ISCSI_SW_TCP_DBG(conn, "TCP_CLOSE|TCP_CLOSE_WAIT\n");
		iscsi_conn_failure(conn, ISCSI_ERR_TCP_CONN_CLOSE);
		return -ECONNRESET;
	}
	return 0;
}

Contributors
Person Tokens Prop Commits CommitProp
Hannes Reinecke 44 55.70% 1 33.33%
Mike Christie 25 31.65% 1 33.33%
Christopher Leech 10 12.66% 1 33.33%
Total 79 100.00% 3 100.00%



static void iscsi_sw_tcp_data_ready(struct sock *sk)
{
	struct iscsi_conn *conn;
	struct iscsi_tcp_conn *tcp_conn;
	read_descriptor_t rd_desc;

	read_lock_bh(&sk->sk_callback_lock);
	conn = sk->sk_user_data;
	if (!conn) {
		read_unlock_bh(&sk->sk_callback_lock);
		return;
	}
	tcp_conn = conn->dd_data;

	/*
         * Use rd_desc to pass 'conn' to iscsi_tcp_recv.
         * We set count to 1 because we want the network layer to
         * hand us all the skbs that are available. iscsi_tcp_recv
         * handled pdus that cross buffers or pdus that still need data.
         */
	rd_desc.arg.data = conn;
	rd_desc.count = 1;
	tcp_read_sock(sk, &rd_desc, iscsi_sw_tcp_recv);

	iscsi_sw_sk_state_check(sk);

	/* If we had to (atomically) map a highmem page,
         * unmap it now. */
	iscsi_tcp_segment_unmap(&tcp_conn->in.segment);
	read_unlock_bh(&sk->sk_callback_lock);
}

Contributors
Person Tokens Prop Commits CommitProp
Mike Christie 78 71.56% 3 37.50%
Alex Aizman 13 11.93% 1 12.50%
Olaf Kirch 10 9.17% 2 25.00%
Hannes Reinecke 5 4.59% 1 12.50%
Eric Dumazet 3 2.75% 1 12.50%
Total 109 100.00% 8 100.00%



static void iscsi_sw_tcp_state_change(struct sock *sk)
{
	struct iscsi_tcp_conn *tcp_conn;
	struct iscsi_sw_tcp_conn *tcp_sw_conn;
	struct iscsi_conn *conn;
	struct iscsi_session *session;
	void (*old_state_change)(struct sock *);

	read_lock_bh(&sk->sk_callback_lock);
	conn = sk->sk_user_data;
	if (!conn) {
		read_unlock_bh(&sk->sk_callback_lock);
		return;
	}
	session = conn->session;

	iscsi_sw_sk_state_check(sk);

	tcp_conn = conn->dd_data;
	tcp_sw_conn = tcp_conn->dd_data;
	old_state_change = tcp_sw_conn->old_state_change;

	read_unlock_bh(&sk->sk_callback_lock);

	old_state_change(sk);
}

Contributors
Person Tokens Prop Commits CommitProp
Mike Christie 93 81.58% 2 33.33%
Olaf Kirch 9 7.89% 1 16.67%
Alex Aizman 8 7.02% 1 16.67%
Eric Dumazet 3 2.63% 1 16.67%
Hannes Reinecke 1 0.88% 1 16.67%
Total 114 100.00% 6 100.00%

/**
 * iscsi_write_space - Called when more output buffer space is available
 * @sk: socket space is available for
 **/


static void iscsi_sw_tcp_write_space(struct sock *sk)
{
	struct iscsi_conn *conn;
	struct iscsi_tcp_conn *tcp_conn;
	struct iscsi_sw_tcp_conn *tcp_sw_conn;
	void (*old_write_space)(struct sock *);

	read_lock_bh(&sk->sk_callback_lock);
	conn = sk->sk_user_data;
	if (!conn) {
		read_unlock_bh(&sk->sk_callback_lock);
		return;
	}

	tcp_conn = conn->dd_data;
	tcp_sw_conn = tcp_conn->dd_data;
	old_write_space = tcp_sw_conn->old_write_space;
	read_unlock_bh(&sk->sk_callback_lock);

	old_write_space(sk);

	ISCSI_SW_TCP_DBG(conn, "iscsi_write_space\n");
	iscsi_conn_queue_work(conn);
}

Contributors
Person Tokens Prop Commits CommitProp
Mike Christie 97 88.18% 4 57.14%
Alex Aizman 11 10.00% 1 14.29%
Olaf Kirch 1 0.91% 1 14.29%
Herbert Xu 1 0.91% 1 14.29%
Total 110 100.00% 7 100.00%



static void iscsi_sw_tcp_conn_set_callbacks(struct iscsi_conn *conn)
{
	struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
	struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
	struct sock *sk = tcp_sw_conn->sock->sk;

	/* assign new callbacks */
	write_lock_bh(&sk->sk_callback_lock);
	sk->sk_user_data = conn;
	tcp_sw_conn->old_data_ready = sk->sk_data_ready;
	tcp_sw_conn->old_state_change = sk->sk_state_change;
	tcp_sw_conn->old_write_space = sk->sk_write_space;
	sk->sk_data_ready = iscsi_sw_tcp_data_ready;
	sk->sk_state_change = iscsi_sw_tcp_state_change;
	sk->sk_write_space = iscsi_sw_tcp_write_space;
	write_unlock_bh(&sk->sk_callback_lock);
}

Contributors
Person Tokens Prop Commits CommitProp
Mike Christie 75 71.43% 2 66.67%
Alex Aizman 30 28.57% 1 33.33%
Total 105 100.00% 3 100.00%


static void

iscsi_sw_tcp_conn_restore_callbacks(struct iscsi_conn *conn)
{
	struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
	struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
	struct sock *sk = tcp_sw_conn->sock->sk;

	/* restore socket callbacks, see also: iscsi_conn_set_callbacks() */
	write_lock_bh(&sk->sk_callback_lock);
	sk->sk_user_data    = NULL;
	sk->sk_data_ready   = tcp_sw_conn->old_data_ready;
	sk->sk_state_change = tcp_sw_conn->old_state_change;
	sk->sk_write_space  = tcp_sw_conn->old_write_space;
	sk->sk_no_check_tx = 0;
	write_unlock_bh(&sk->sk_callback_lock);
}

Contributors
Person Tokens Prop Commits CommitProp
Mike Christie 58 62.37% 3 50.00%
Avi Kaplan 20 21.51% 1 16.67%
Alex Aizman 14 15.05% 1 16.67%
Tom Herbert 1 1.08% 1 16.67%
Total 93 100.00% 6 100.00%

/**
 * iscsi_sw_tcp_xmit_segment - transmit segment
 * @tcp_conn: the iSCSI TCP connection
 * @segment: the buffer to transmnit
 *
 * This function transmits as much of the buffer as
 * the network layer will accept, and returns the number of
 * bytes transmitted.
 *
 * If CRC hashing is enabled, the function will compute the
 * hash as it goes. When the entire segment has been transmitted,
 * it will retrieve the hash value and send it as well.
 */


static int iscsi_sw_tcp_xmit_segment(struct iscsi_tcp_conn *tcp_conn,
				     struct iscsi_segment *segment)
{
	struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
	struct socket *sk = tcp_sw_conn->sock;
	unsigned int copied = 0;
	int r = 0;

	while (!iscsi_tcp_segment_done(tcp_conn, segment, 0, r)) {
		struct scatterlist *sg;
		unsigned int offset, copy;
		int flags = 0;

		r = 0;
		offset = segment->copied;
		copy = segment->size - offset;

		if (segment->total_copied + segment->size < segment->total_size)
			flags |= MSG_MORE;

		/* Use sendpage if we can; else fall back to sendmsg */
		if (!segment->data) {
			sg = segment->sg;
			offset += segment->sg_offset + sg->offset;
			r = tcp_sw_conn->sendpage(sk, sg_page(sg), offset,
						  copy, flags);
		} else {
			struct msghdr msg = { .msg_flags = flags };
			struct kvec iov = {
				.iov_base = segment->data + offset,
				.iov_len = copy
			};

			r = kernel_sendmsg(sk, &msg, &iov, 1, copy);
		}

		if (r < 0) {
			iscsi_tcp_segment_unmap(segment);
			return r;
		}
		copied += r;
	}
	return copied;
}

Contributors
Person Tokens Prop Commits CommitProp
Mike Christie 189 81.12% 7 77.78%
Olaf Kirch 37 15.88% 1 11.11%
Alex Aizman 7 3.00% 1 11.11%
Total 233 100.00% 9 100.00%

/**
 * iscsi_sw_tcp_xmit - TCP transmit
 **/


static int iscsi_sw_tcp_xmit(struct iscsi_conn *conn)
{
	struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
	struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
	struct iscsi_segment *segment = &tcp_sw_conn->out.segment;
	unsigned int consumed = 0;
	int rc = 0;

	while (1) {
		rc = iscsi_sw_tcp_xmit_segment(tcp_conn, segment);
		/*
                 * We may not have been able to send data because the conn
                 * is getting stopped. libiscsi will know so propagate err
                 * for it to do the right thing.
                 */
		if (rc == -EAGAIN)
			return rc;
		else if (rc < 0) {
			rc = ISCSI_ERR_XMIT_FAILED;
			goto error;
		} else if (rc == 0)
			break;

		consumed += rc;

		if (segment->total_copied >= segment->total_size) {
			if (segment->done != NULL) {
				rc = segment->done(tcp_conn, segment);
				if (rc != 0)
					goto error;
			}
		}
	}

	ISCSI_SW_TCP_DBG(conn, "xmit %d bytes\n", consumed);

	conn->txdata_octets += consumed;
	return consumed;

error:
	/* Transmit error. We could initiate error recovery
         * here. */
	ISCSI_SW_TCP_DBG(conn, "Error sending PDU, errno=%d\n", rc);
	iscsi_conn_failure(conn, rc);
	return -EIO;
}

Contributors
Person Tokens Prop Commits CommitProp
Mike Christie 138 73.02% 9 75.00%
Olaf Kirch 38 20.11% 1 8.33%
Alex Aizman 12 6.35% 1 8.33%
Lucas De Marchi 1 0.53% 1 8.33%
Total 189 100.00% 12 100.00%

/**
 * iscsi_tcp_xmit_qlen - return the number of bytes queued for xmit
 */


static inline int iscsi_sw_tcp_xmit_qlen(struct iscsi_conn *conn)
{
	struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
	struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
	struct iscsi_segment *segment = &tcp_sw_conn->out.segment;

	return segment->total_copied - segment->total_size;
}

Contributors
Person Tokens Prop Commits CommitProp
Mike Christie 38 74.51% 4 66.67%
Olaf Kirch 11 21.57% 1 16.67%
Alex Aizman 2 3.92% 1 16.67%
Total 51 100.00% 6 100.00%



static int iscsi_sw_tcp_pdu_xmit(struct iscsi_task *task)
{
	struct iscsi_conn *conn = task->conn;
	unsigned long pflags = current->flags;
	int rc = 0;

	current->flags |= PF_MEMALLOC;

	while (iscsi_sw_tcp_xmit_qlen(conn)) {
		rc = iscsi_sw_tcp_xmit(conn);
		if (rc == 0) {
			rc = -EAGAIN;
			break;
		}
		if (rc < 0)
			break;
		rc = 0;
	}

	tsk_restore_flags(current, pflags, PF_MEMALLOC);
	return rc;
}

Contributors
Person Tokens Prop Commits CommitProp
Mike Christie 79 85.87% 6 75.00%
Alex Aizman 9 9.78% 1 12.50%
Olaf Kirch 4 4.35% 1 12.50%
Total 92 100.00% 8 100.00%

/*
 * This is called when we're done sending the header.
 * Simply copy the data_segment to the send segment, and return.
 */


static int iscsi_sw_tcp_send_hdr_done(struct iscsi_tcp_conn *tcp_conn,
				      struct iscsi_segment *segment)
{
	struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;

	tcp_sw_conn->out.segment = tcp_sw_conn->out.data_segment;
	ISCSI_SW_TCP_DBG(tcp_conn->iscsi_conn,
			 "Header done. Next segment size %u total_size %u\n",
			 tcp_sw_conn->out.segment.size,
			 tcp_sw_conn->out.segment.total_size);
	return 0;
}

Contributors
Person Tokens Prop Commits CommitProp
Mike Christie 55 84.62% 4 66.67%
Olaf Kirch 7 10.77% 1 16.67%
Alex Aizman 3 4.62% 1 16.67%
Total 65 100.00% 6 100.00%



static void iscsi_sw_tcp_send_hdr_prep(struct iscsi_conn *conn, void *hdr,
				       size_t hdrlen)
{
	struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
	struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;

	ISCSI_SW_TCP_DBG(conn, "%s\n", conn->hdrdgst_en ?
			 "digest enabled" : "digest disabled");

	/* Clear the data segment - needs to be filled in by the
         * caller using iscsi_tcp_send_data_prep() */
	memset(&tcp_sw_conn->out.data_segment, 0,
	       sizeof(struct iscsi_segment));

	/* If header digest is enabled, compute the CRC and
         * place the digest into the same buffer. We make
         * sure that both iscsi_tcp_task and mtask have
         * sufficient room.
         */
	if (conn->hdrdgst_en) {
		iscsi_tcp_dgst_header(tcp_sw_conn->tx_hash, hdr, hdrlen,
				      hdr + hdrlen);
		hdrlen += ISCSI_DIGEST_SIZE;
	}

	/* Remember header pointer for later, when we need
         * to decide whether there's a payload to go along
         * with the header. */
	tcp_sw_conn->out.hdr = hdr;

	iscsi_segment_init_linear(&tcp_sw_conn->out.segment, hdr, hdrlen,
				  iscsi_sw_tcp_send_hdr_done, NULL);
}

Contributors
Person Tokens Prop Commits CommitProp
Mike Christie 107 85.60% 7 70.00%
Olaf Kirch 10 8.00% 1 10.00%
Alex Aizman 6 4.80% 1 10.00%
Boaz Harrosh 2 1.60% 1 10.00%
Total 125 100.00% 10 100.00%

/*
 * Prepare the send buffer for the payload data.
 * Padding and checksumming will all be taken care
 * of by the iscsi_segment routines.
 */

static int

iscsi_sw_tcp_send_data_prep(struct iscsi_conn *conn, struct scatterlist *sg,
			    unsigned int count, unsigned int offset,
			    unsigned int len)
{
	struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
	struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
	struct ahash_request *tx_hash = NULL;
	unsigned int hdr_spec_len;

	ISCSI_SW_TCP_DBG(conn, "offset=%d, datalen=%d %s\n", offset, len,
			 conn->datadgst_en ?
			 "digest enabled" : "digest disabled");

	/* Make sure the datalen matches what the caller
           said he would send. */
	hdr_spec_len = ntoh24(tcp_sw_conn->out.hdr->dlength);
	WARN_ON(iscsi_padded(len) != iscsi_padded(hdr_spec_len));

	if (conn->datadgst_en)
		tx_hash = tcp_sw_conn->tx_hash;

	return iscsi_segment_seek_sg(&tcp_sw_conn->out.data_segment,
				     sg, count, offset, len,
				     NULL, tx_hash);
}

Contributors
Person Tokens Prop Commits CommitProp
Mike Christie 124 89.86% 8 80.00%
Olaf Kirch 13 9.42% 1 10.00%
Herbert Xu 1 0.72% 1 10.00%
Total 138 100.00% 10 100.00%


static void

iscsi_sw_tcp_send_linear_data_prep(struct iscsi_conn *conn, void *data,
				   size_t len)
{
	struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
	struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
	struct ahash_request *tx_hash = NULL;
	unsigned int hdr_spec_len;

	ISCSI_SW_TCP_DBG(conn, "datalen=%zd %s\n", len, conn->datadgst_en ?
			 "digest enabled" : "digest disabled");

	/* Make sure the datalen matches what the caller
           said he would send. */
	hdr_spec_len = ntoh24(tcp_sw_conn->out.hdr->dlength);
	WARN_ON(iscsi_padded(len) != iscsi_padded(hdr_spec_len));

	if (conn->datadgst_en)
		tx_hash = tcp_sw_conn->tx_hash;

	iscsi_segment_init_linear(&tcp_sw_conn->out.data_segment,
				data, len, NULL, tx_hash);
}

Contributors
Person Tokens Prop Commits CommitProp
Mike Christie 108 89.26% 5 71.43%
Olaf Kirch 12 9.92% 1 14.29%
Herbert Xu 1 0.83% 1 14.29%
Total 121 100.00% 7 100.00%



static int iscsi_sw_tcp_pdu_init(struct iscsi_task *task,
				 unsigned int offset, unsigned int count)
{
	struct iscsi_conn *conn = task->conn;
	int err = 0;

	iscsi_sw_tcp_send_hdr_prep(conn, task->hdr, task->hdr_len);

	if (!count)
		return 0;

	if (!task->sc)
		iscsi_sw_tcp_send_linear_data_prep(conn, task->data, count);
	else {
		struct scsi_data_buffer *sdb = scsi_out(task->sc);

		err = iscsi_sw_tcp_send_data_prep(conn, sdb->table.sgl,
						  sdb->table.nents, offset,
						  count);
	}

	if (err) {
		/* got invalid offset/len */
		return -EIO;
	}
	return 0;
}

Contributors
Person Tokens Prop Commits CommitProp
Mike Christie 118 95.16% 5 83.33%
Olaf Kirch 6 4.84% 1 16.67%
Total 124 100.00% 6 100.00%



static int iscsi_sw_tcp_pdu_alloc(struct iscsi_task *task, uint8_t opcode)
{
	struct iscsi_tcp_task *tcp_task = task->dd_data;

	task->hdr = task->dd_data + sizeof(*tcp_task);
	task->hdr_max = sizeof(struct iscsi_sw_tcp_hdrbuf) - ISCSI_DIGEST_SIZE;
	return 0;
}

Contributors
Person Tokens Prop Commits CommitProp
Mike Christie 47 90.38% 6 75.00%
Alex Aizman 3 5.77% 1 12.50%
Olaf Kirch 2 3.85% 1 12.50%
Total 52 100.00% 8 100.00%


static struct iscsi_cls_conn *

iscsi_sw_tcp_conn_create(struct iscsi_cls_session *cls_session,
			 uint32_t conn_idx)
{
	struct iscsi_conn *conn;
	struct iscsi_cls_conn *cls_conn;
	struct iscsi_tcp_conn *tcp_conn;
	struct iscsi_sw_tcp_conn *tcp_sw_conn;
	struct crypto_ahash *tfm;

	cls_conn = iscsi_tcp_conn_setup(cls_session, sizeof(*tcp_sw_conn),
					conn_idx);
	if (!cls_conn)
		return NULL;
	conn = cls_conn->dd_data;
	tcp_conn = conn->dd_data;
	tcp_sw_conn = tcp_conn->dd_data;

	tfm = crypto_alloc_ahash("crc32c", 0, CRYPTO_ALG_ASYNC);
	if (IS_ERR(tfm))
		goto free_conn;

	tcp_sw_conn->tx_hash = ahash_request_alloc(tfm, GFP_KERNEL);
	if (!tcp_sw_conn->tx_hash)
		goto free_tfm;
	ahash_request_set_callback(tcp_sw_conn->tx_hash, 0, NULL, NULL);

	tcp_sw_conn->rx_hash = ahash_request_alloc(tfm, GFP_KERNEL);
	if (!tcp_sw_conn->rx_hash)
		goto free_tx_hash;
	ahash_request_set_callback(tcp_sw_conn->rx_hash, 0, NULL, NULL);

	tcp_conn->rx_hash = tcp_sw_conn->rx_hash;

	return cls_conn;

free_tx_hash:
	ahash_request_free(tcp_sw_conn->tx_hash);
free_tfm:
	crypto_free_ahash(tfm);
free_conn:
	iscsi_conn_printk(KERN_ERR, conn,
			  "Could not create connection due to crc32c "
			  "loading error. Make sure the crc32c "
			  "module is built as a module or into the "
			  "kernel\n");
	iscsi_tcp_conn_teardown(cls_conn);
	return NULL;
}

Contributors
Person Tokens Prop Commits CommitProp
Mike Christie 138 62.73% 6 66.67%
Herbert Xu 59 26.82% 1 11.11%
James Bottomley 16 7.27% 1 11.11%
Alex Aizman 7 3.18% 1 11.11%
Total 220 100.00% 9 100.00%



static void iscsi_sw_tcp_release_conn(struct iscsi_conn *conn)
{
	struct iscsi_session *session = conn->session;
	struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
	struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
	struct socket *sock = tcp_sw_conn->sock;

	if (!sock)
		return;

	sock_hold(sock->sk);
	iscsi_sw_tcp_conn_restore_callbacks(conn);
	sock_put(sock->sk);

	spin_lock_bh(&session->frwd_lock);
	tcp_sw_conn->sock = NULL;
	spin_unlock_bh(&session->frwd_lock);
	sockfd_put(sock);
}

Contributors
Person Tokens Prop Commits CommitProp
Mike Christie 96 96.97% 4 66.67%
Shlomo Pongratz 2 2.02% 1 16.67%
Avi Kaplan 1 1.01% 1 16.67%
Total 99 100.00% 6 100.00%



static void iscsi_sw_tcp_conn_destroy(struct iscsi_cls_conn *cls_conn)
{
	struct iscsi_conn *conn = cls_conn->dd_data;
	struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
	struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;

	iscsi_sw_tcp_release_conn(conn);

	ahash_request_free(tcp_sw_conn->rx_hash);
	if (tcp_sw_conn->tx_hash) {
		struct crypto_ahash *tfm;

		tfm = crypto_ahash_reqtfm(tcp_sw_conn->tx_hash);
		ahash_request_free(tcp_sw_conn->tx_hash);
		crypto_free_ahash(tfm);
	}

	iscsi_tcp_conn_teardown(cls_conn);
}

Contributors
Person Tokens Prop Commits CommitProp
Mike Christie 53 59.55% 4 50.00%
Herbert Xu 24 26.97% 2 25.00%
Alex Aizman 10 11.24% 1 12.50%
James Bottomley 2 2.25% 1 12.50%
Total 89 100.00% 8 100.00%



static void iscsi_sw_tcp_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
{
	struct iscsi_conn *conn = cls_conn->dd_data;
	struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
	struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
	struct socket *sock = tcp_sw_conn->sock;

	/* userspace may have goofed up and not bound us */
	if (!sock)
		return;

	sock->sk->sk_err = EIO;
	wake_up_interruptible(sk_sleep(sock->sk));

	/* stop xmit side */
	iscsi_suspend_tx(conn);

	/* stop recv side and release socket */
	iscsi_sw_tcp_release_conn(conn);

	iscsi_conn_stop(cls_conn, flag);
}

Contributors
Person Tokens Prop Commits CommitProp
Mike Christie 91 96.81% 6 85.71%
Eric Dumazet 3 3.19% 1 14.29%
Total 94 100.00% 7 100.00%


static int

iscsi_sw_tcp_conn_bind(struct iscsi_cls_session *cls_session,
		       struct iscsi_cls_conn *cls_conn, uint64_t transport_eph,
		       int is_leading)
{
	struct iscsi_session *session = cls_session->dd_data;
	struct iscsi_conn *conn = cls_conn->dd_data;
	struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
	struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
	struct sock *sk;
	struct socket *sock;
	int err;

	/* lookup for existing socket */
	sock = sockfd_lookup((int)transport_eph, &err);
	if (!sock) {
		iscsi_conn_printk(KERN_ERR, conn,
				  "sockfd_lookup failed %d\n", err);
		return -EEXIST;
	}

	err = iscsi_conn_bind(cls_session, cls_conn, is_leading);
	if (err)
		goto free_socket;

	spin_lock_bh(&session->frwd_lock);
	/* bind iSCSI connection and socket */
	tcp_sw_conn->sock = sock;
	spin_unlock_bh(&session->frwd_lock);

	/* setup Socket parameters */
	sk = sock->sk;
	sk->sk_reuse = SK_CAN_REUSE;
	sk->sk_sndtimeo = 15 * HZ; /* FIXME: make it configurable */
	sk->sk_allocation = GFP_ATOMIC;
	sk_set_memalloc(sk);

	iscsi_sw_tcp_conn_set_callbacks(conn);
	tcp_sw_conn->sendpage = tcp_sw_conn->sock->ops->sendpage;
	/*
         * set receive state machine into initial state
         */
	iscsi_tcp_hdr_recv_prep(tcp_conn);
	return 0;

free_socket:
	sockfd_put(sock);
	return err;
}

Contributors
Person Tokens Prop Commits CommitProp
Mike Christie 181 83.41% 11 73.33%
Alex Aizman 27 12.44% 1 6.67%
Or Gerlitz 6 2.76% 1 6.67%
Shlomo Pongratz 2 0.92% 1 6.67%
Pavel Emelyanov 1 0.46% 1 6.67%
Total 217 100.00% 15 100.00%



static int iscsi_sw_tcp_conn_set_param(struct iscsi_cls_conn *cls_conn,
				       enum iscsi_param param, char *buf,
				       int buflen)
{
	struct iscsi_conn *conn = cls_conn->dd_data;
	struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
	struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;

	switch(param) {
	case ISCSI_PARAM_HDRDGST_EN:
		iscsi_set_param(cls_conn, param, buf, buflen);
		break;
	case ISCSI_PARAM_DATADGST_EN:
		iscsi_set_param(cls_conn, param, buf, buflen);
		tcp_sw_conn->sendpage = conn->datadgst_en ?
			sock_no_sendpage : tcp_sw_conn->sock->ops->sendpage;
		break;
	case ISCSI_PARAM_MAX_R2T:
		return iscsi_tcp_set_max_r2t(conn, buf);
	default:
		return iscsi_set_param(cls_conn, param, buf, buflen);
	}

	return 0;
}

Contributors
<Person Tokens Prop Commits CommitProp
Mike Christie 80 61.54% 6 75.00%
Alex Aizman 34 26.15% 1 12.50%
FUJITA Tomonori 16 12.31% 1 12.50%
Total 130 100.00% 8
Person	Tokens	Prop	Commits	CommitProp
Mike Christie	91	77.78%	2	40.00%
Olaf Kirch	14	11.97%	2	40.00%
Alex Aizman	12	10.26%	1	20.00%
Total	117	100.00%	5	100.00%
cregit-Linux how code gets into the kernel

Release 4.11 drivers/scsi/iscsi_tcp.c

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