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56851698c2
kernel_optimize_test/drivers/scsi/iscsi_tcp.c
FUJITA Tomonori 56851698c2 [SCSI] iscsi: data digest page cache usage fix 
Users can write to a page while we are sending it and making
digest calculations. This ends up causing us to retry the command
when a digest error is later reported. By using sock_no_sendpage
when data digests are calculated we can avoid a lot of (not all but it
helps) the retries becuase sock_no_sendpage is not zero copy.

Signed-off-by: Alex Aizman <itn780@yahoo.com>
Signed-off-by: Dmitry Yusupov <dmitry_yus@yahoo.com>
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
2006-01-14 10:55:17 -06:00

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/*
* iSCSI Initiator over TCP/IP Data-Path
*
* Copyright (C) 2004 Dmitry Yusupov
* Copyright (C) 2004 Alex Aizman
* Copyright (C) 2005 Mike Christie
* 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 <linux/types.h>
#include <linux/list.h>
#include <linux/inet.h>
#include <linux/blkdev.h>
#include <linux/crypto.h>
#include <linux/delay.h>
#include <linux/kfifo.h>
#include <linux/scatterlist.h>
#include <linux/mutex.h>
#include <net/tcp.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_eh.h>
#include <scsi/scsi_request.h>
#include <scsi/scsi_tcq.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi.h>
#include <scsi/scsi_transport_iscsi.h>
#include "iscsi_tcp.h"
MODULE_AUTHOR("Dmitry Yusupov <dmitry_yus@yahoo.com>, "
"Alex Aizman <itn780@yahoo.com>");
MODULE_DESCRIPTION("iSCSI/TCP data-path");
MODULE_LICENSE("GPL");
MODULE_VERSION("0:4.445");
/* #define DEBUG_TCP */
/* #define DEBUG_SCSI */
#define DEBUG_ASSERT
#ifdef DEBUG_TCP
#define debug_tcp(fmt...) printk(KERN_DEBUG "tcp: " fmt)
#else
#define debug_tcp(fmt...)
#endif
#ifdef DEBUG_SCSI
#define debug_scsi(fmt...) printk(KERN_DEBUG "scsi: " fmt)
#else
#define debug_scsi(fmt...)
#endif
#ifndef DEBUG_ASSERT
#ifdef BUG_ON
#undef BUG_ON
#endif
#define BUG_ON(expr)
#endif
#define INVALID_SN_DELTA 0xffff
static unsigned int iscsi_max_lun = 512;
module_param_named(max_lun, iscsi_max_lun, uint, S_IRUGO);
/* global data */
static kmem_cache_t *taskcache;
static inline void
iscsi_buf_init_virt(struct iscsi_buf *ibuf, char *vbuf, int size)
{
sg_init_one(&ibuf->sg, (u8 *)vbuf, size);
ibuf->sent = 0;
}
static inline void
iscsi_buf_init_iov(struct iscsi_buf *ibuf, char *vbuf, int size)
{
ibuf->sg.page = (void*)vbuf;
ibuf->sg.offset = (unsigned int)-1;
ibuf->sg.length = size;
ibuf->sent = 0;
}
static inline void*
iscsi_buf_iov_base(struct iscsi_buf *ibuf)
{
return (char*)ibuf->sg.page + ibuf->sent;
}
static inline void
iscsi_buf_init_sg(struct iscsi_buf *ibuf, struct scatterlist *sg)
{
/*
* Fastpath: sg element fits into single page
*/
if (sg->length + sg->offset <= PAGE_SIZE && page_count(sg->page) >= 2) {
ibuf->sg.page = sg->page;
ibuf->sg.offset = sg->offset;
ibuf->sg.length = sg->length;
} else
iscsi_buf_init_iov(ibuf, page_address(sg->page), sg->length);
ibuf->sent = 0;
}
static inline int
iscsi_buf_left(struct iscsi_buf *ibuf)
{
int rc;
rc = ibuf->sg.length - ibuf->sent;
BUG_ON(rc < 0);
return rc;
}
static inline void
iscsi_hdr_digest(struct iscsi_conn *conn, struct iscsi_buf *buf,
u8* crc)
{
crypto_digest_digest(conn->tx_tfm, &buf->sg, 1, crc);
buf->sg.length += sizeof(uint32_t);
}
static void
iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err)
{
struct iscsi_session *session = conn->session;
unsigned long flags;
spin_lock_irqsave(&session->lock, flags);
if (session->conn_cnt == 1 || session->leadconn == conn)
session->state = ISCSI_STATE_FAILED;
spin_unlock_irqrestore(&session->lock, flags);
set_bit(SUSPEND_BIT, &conn->suspend_tx);
set_bit(SUSPEND_BIT, &conn->suspend_rx);
iscsi_conn_error(iscsi_handle(conn), err);
}
static inline int
iscsi_check_assign_cmdsn(struct iscsi_session *session, struct iscsi_nopin *hdr)
{
uint32_t max_cmdsn = be32_to_cpu(hdr->max_cmdsn);
uint32_t exp_cmdsn = be32_to_cpu(hdr->exp_cmdsn);
if (max_cmdsn < exp_cmdsn -1 &&
max_cmdsn > exp_cmdsn - INVALID_SN_DELTA)
return ISCSI_ERR_MAX_CMDSN;
if (max_cmdsn > session->max_cmdsn ||
max_cmdsn < session->max_cmdsn - INVALID_SN_DELTA)
session->max_cmdsn = max_cmdsn;
if (exp_cmdsn > session->exp_cmdsn ||
exp_cmdsn < session->exp_cmdsn - INVALID_SN_DELTA)
session->exp_cmdsn = exp_cmdsn;
return 0;
}
static inline int
iscsi_hdr_extract(struct iscsi_conn *conn)
{
struct sk_buff *skb = conn->in.skb;
if (conn->in.copy >= conn->hdr_size &&
conn->in_progress == IN_PROGRESS_WAIT_HEADER) {
/*
* Zero-copy PDU Header: using connection context
* to store header pointer.
*/
if (skb_shinfo(skb)->frag_list == NULL &&
!skb_shinfo(skb)->nr_frags)
conn->in.hdr = (struct iscsi_hdr *)
((char*)skb->data + conn->in.offset);
else {
/* ignoring return code since we checked
* in.copy before */
skb_copy_bits(skb, conn->in.offset,
&conn->hdr, conn->hdr_size);
conn->in.hdr = &conn->hdr;
}
conn->in.offset += conn->hdr_size;
conn->in.copy -= conn->hdr_size;
} else {
int hdr_remains;
int copylen;
/*
* PDU header scattered across SKB's,
* copying it... This'll happen quite rarely.
*/
if (conn->in_progress == IN_PROGRESS_WAIT_HEADER)
conn->in.hdr_offset = 0;
hdr_remains = conn->hdr_size - conn->in.hdr_offset;
BUG_ON(hdr_remains <= 0);
copylen = min(conn->in.copy, hdr_remains);
skb_copy_bits(skb, conn->in.offset,
(char*)&conn->hdr + conn->in.hdr_offset, copylen);
debug_tcp("PDU gather offset %d bytes %d in.offset %d "
"in.copy %d\n", conn->in.hdr_offset, copylen,
conn->in.offset, conn->in.copy);
conn->in.offset += copylen;
conn->in.copy -= copylen;
if (copylen < hdr_remains) {
conn->in_progress = IN_PROGRESS_HEADER_GATHER;
conn->in.hdr_offset += copylen;
return -EAGAIN;
}
conn->in.hdr = &conn->hdr;
conn->discontiguous_hdr_cnt++;
conn->in_progress = IN_PROGRESS_WAIT_HEADER;
}
return 0;
}
static inline void
iscsi_ctask_cleanup(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
{
struct scsi_cmnd *sc = ctask->sc;
struct iscsi_session *session = conn->session;
spin_lock(&session->lock);
if (unlikely(!sc)) {
spin_unlock(&session->lock);
return;
}
if (sc->sc_data_direction == DMA_TO_DEVICE) {
struct iscsi_data_task *dtask, *n;
/* WRITE: cleanup Data-Out's if any */
spin_lock(&conn->lock);
list_for_each_entry_safe(dtask, n, &ctask->dataqueue, item) {
list_del(&dtask->item);
mempool_free(dtask, ctask->datapool);
}
spin_unlock(&conn->lock);
}
ctask->xmstate = XMSTATE_IDLE;
ctask->r2t = NULL;
ctask->sc = NULL;
__kfifo_put(session->cmdpool.queue, (void*)&ctask, sizeof(void*));
spin_unlock(&session->lock);
}
/**
* iscsi_cmd_rsp - SCSI Command Response processing
* @conn: iscsi connection
* @ctask: scsi command task
**/
static int
iscsi_cmd_rsp(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
{
int rc;
struct iscsi_cmd_rsp *rhdr = (struct iscsi_cmd_rsp *)conn->in.hdr;
struct iscsi_session *session = conn->session;
struct scsi_cmnd *sc = ctask->sc;
rc = iscsi_check_assign_cmdsn(session, (struct iscsi_nopin*)rhdr);
if (rc) {
sc->result = (DID_ERROR << 16);
goto out;
}
conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
sc->result = (DID_OK << 16) | rhdr->cmd_status;
if (rhdr->response != ISCSI_STATUS_CMD_COMPLETED) {
sc->result = (DID_ERROR << 16);
goto out;
}
if (rhdr->cmd_status == SAM_STAT_CHECK_CONDITION && conn->senselen) {
int sensecopy = min(conn->senselen, SCSI_SENSE_BUFFERSIZE);
memcpy(sc->sense_buffer, conn->data + 2, sensecopy);
debug_scsi("copied %d bytes of sense\n", sensecopy);
}
if (sc->sc_data_direction == DMA_TO_DEVICE)
goto out;
if (rhdr->flags & ISCSI_FLAG_CMD_UNDERFLOW) {
int res_count = be32_to_cpu(rhdr->residual_count);
if (res_count > 0 && res_count <= sc->request_bufflen)
sc->resid = res_count;
else
sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
} else if (rhdr->flags & ISCSI_FLAG_CMD_BIDI_UNDERFLOW)
sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
else if (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW)
sc->resid = be32_to_cpu(rhdr->residual_count);
out:
debug_scsi("done [sc %lx res %d itt 0x%x]\n",
(long)sc, sc->result, ctask->itt);
conn->scsirsp_pdus_cnt++;
iscsi_ctask_cleanup(conn, ctask);
sc->scsi_done(sc);
return rc;
}
/**
* iscsi_data_rsp - SCSI Data-In Response processing
* @conn: iscsi connection
* @ctask: scsi command task
**/
static int
iscsi_data_rsp(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
{
int rc;
struct iscsi_data_rsp *rhdr = (struct iscsi_data_rsp *)conn->in.hdr;
struct iscsi_session *session = conn->session;
int datasn = be32_to_cpu(rhdr->datasn);
rc = iscsi_check_assign_cmdsn(session, (struct iscsi_nopin*)rhdr);
if (rc)
return rc;
/*
* setup Data-In byte counter (gets decremented..)
*/
ctask->data_count = conn->in.datalen;
if (conn->in.datalen == 0)
return 0;
if (ctask->datasn != datasn)
return ISCSI_ERR_DATASN;
ctask->datasn++;
ctask->data_offset = be32_to_cpu(rhdr->offset);
if (ctask->data_offset + conn->in.datalen > ctask->total_length)
return ISCSI_ERR_DATA_OFFSET;
if (rhdr->flags & ISCSI_FLAG_DATA_STATUS) {
struct scsi_cmnd *sc = ctask->sc;
conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
if (rhdr->flags & ISCSI_FLAG_DATA_UNDERFLOW) {
int res_count = be32_to_cpu(rhdr->residual_count);
if (res_count > 0 &&
res_count <= sc->request_bufflen) {
sc->resid = res_count;
sc->result = (DID_OK << 16) | rhdr->cmd_status;
} else
sc->result = (DID_BAD_TARGET << 16) |
rhdr->cmd_status;
} else if (rhdr->flags & ISCSI_FLAG_DATA_OVERFLOW) {
sc->resid = be32_to_cpu(rhdr->residual_count);
sc->result = (DID_OK << 16) | rhdr->cmd_status;
} else
sc->result = (DID_OK << 16) | rhdr->cmd_status;
}
conn->datain_pdus_cnt++;
return 0;
}
/**
* iscsi_solicit_data_init - initialize first Data-Out
* @conn: iscsi connection
* @ctask: scsi command task
* @r2t: R2T info
*
* Notes:
* Initialize first Data-Out within this R2T sequence and finds
* proper data_offset within this SCSI command.
*
* This function is called with connection lock taken.
**/
static void
iscsi_solicit_data_init(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
struct iscsi_r2t_info *r2t)
{
struct iscsi_data *hdr;
struct iscsi_data_task *dtask;
struct scsi_cmnd *sc = ctask->sc;
dtask = mempool_alloc(ctask->datapool, GFP_ATOMIC);
BUG_ON(!dtask);
hdr = &dtask->hdr;
memset(hdr, 0, sizeof(struct iscsi_data));
hdr->ttt = r2t->ttt;
hdr->datasn = cpu_to_be32(r2t->solicit_datasn);
r2t->solicit_datasn++;
hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
memcpy(hdr->lun, ctask->hdr.lun, sizeof(hdr->lun));
hdr->itt = ctask->hdr.itt;
hdr->exp_statsn = r2t->exp_statsn;
hdr->offset = cpu_to_be32(r2t->data_offset);
if (r2t->data_length > conn->max_xmit_dlength) {
hton24(hdr->dlength, conn->max_xmit_dlength);
r2t->data_count = conn->max_xmit_dlength;
hdr->flags = 0;
} else {
hton24(hdr->dlength, r2t->data_length);
r2t->data_count = r2t->data_length;
hdr->flags = ISCSI_FLAG_CMD_FINAL;
}
conn->dataout_pdus_cnt++;
r2t->sent = 0;
iscsi_buf_init_virt(&r2t->headbuf, (char*)hdr,
sizeof(struct iscsi_hdr));
r2t->dtask = dtask;
if (sc->use_sg) {
int i, sg_count = 0;
struct scatterlist *sg = sc->request_buffer;
r2t->sg = NULL;
for (i = 0; i < sc->use_sg; i++, sg += 1) {
/* FIXME: prefetch ? */
if (sg_count + sg->length > r2t->data_offset) {
int page_offset;
/* sg page found! */
/* offset within this page */
page_offset = r2t->data_offset - sg_count;
/* fill in this buffer */
iscsi_buf_init_sg(&r2t->sendbuf, sg);
r2t->sendbuf.sg.offset += page_offset;
r2t->sendbuf.sg.length -= page_offset;
/* xmit logic will continue with next one */
r2t->sg = sg + 1;
break;
}
sg_count += sg->length;
}
BUG_ON(r2t->sg == NULL);
} else
iscsi_buf_init_iov(&ctask->sendbuf,
(char*)sc->request_buffer + r2t->data_offset,
r2t->data_count);
list_add(&dtask->item, &ctask->dataqueue);
}
/**
* iscsi_r2t_rsp - iSCSI R2T Response processing
* @conn: iscsi connection
* @ctask: scsi command task
**/
static int
iscsi_r2t_rsp(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
{
struct iscsi_r2t_info *r2t;
struct iscsi_session *session = conn->session;
struct iscsi_r2t_rsp *rhdr = (struct iscsi_r2t_rsp *)conn->in.hdr;
int r2tsn = be32_to_cpu(rhdr->r2tsn);
int rc;
if (conn->in.ahslen)
return ISCSI_ERR_AHSLEN;
if (conn->in.datalen)
return ISCSI_ERR_DATALEN;
if (ctask->exp_r2tsn && ctask->exp_r2tsn != r2tsn)
return ISCSI_ERR_R2TSN;
rc = iscsi_check_assign_cmdsn(session, (struct iscsi_nopin*)rhdr);
if (rc)
return rc;
/* FIXME: use R2TSN to detect missing R2T */
/* fill-in new R2T associated with the task */
spin_lock(&session->lock);
if (!ctask->sc || ctask->mtask ||
session->state != ISCSI_STATE_LOGGED_IN) {
printk(KERN_INFO "iscsi_tcp: dropping R2T itt %d in "
"recovery...\n", ctask->itt);
spin_unlock(&session->lock);
return 0;
}
rc = __kfifo_get(ctask->r2tpool.queue, (void*)&r2t, sizeof(void*));
BUG_ON(!rc);
r2t->exp_statsn = rhdr->statsn;
r2t->data_length = be32_to_cpu(rhdr->data_length);
if (r2t->data_length == 0 ||
r2t->data_length > session->max_burst) {
spin_unlock(&session->lock);
return ISCSI_ERR_DATALEN;
}
r2t->data_offset = be32_to_cpu(rhdr->data_offset);
if (r2t->data_offset + r2t->data_length > ctask->total_length) {
spin_unlock(&session->lock);
return ISCSI_ERR_DATALEN;
}
r2t->ttt = rhdr->ttt; /* no flip */
r2t->solicit_datasn = 0;
iscsi_solicit_data_init(conn, ctask, r2t);
ctask->exp_r2tsn = r2tsn + 1;
ctask->xmstate |= XMSTATE_SOL_HDR;
__kfifo_put(ctask->r2tqueue, (void*)&r2t, sizeof(void*));
__kfifo_put(conn->writequeue, (void*)&ctask, sizeof(void*));
schedule_work(&conn->xmitwork);
conn->r2t_pdus_cnt++;
spin_unlock(&session->lock);
return 0;
}
static int
iscsi_hdr_recv(struct iscsi_conn *conn)
{
int rc = 0;
struct iscsi_hdr *hdr;
struct iscsi_cmd_task *ctask;
struct iscsi_session *session = conn->session;
uint32_t cdgst, rdgst = 0;
hdr = conn->in.hdr;
/* verify PDU length */
conn->in.datalen = ntoh24(hdr->dlength);
if (conn->in.datalen > conn->max_recv_dlength) {
printk(KERN_ERR "iscsi_tcp: datalen %d > %d\n",
conn->in.datalen, conn->max_recv_dlength);
return ISCSI_ERR_DATALEN;
}
conn->data_copied = 0;
/* read AHS */
conn->in.ahslen = hdr->hlength * 4;
conn->in.offset += conn->in.ahslen;
conn->in.copy -= conn->in.ahslen;
if (conn->in.copy < 0) {
printk(KERN_ERR "iscsi_tcp: can't handle AHS with length "
"%d bytes\n", conn->in.ahslen);
return ISCSI_ERR_AHSLEN;
}
/* calculate read padding */
conn->in.padding = conn->in.datalen & (ISCSI_PAD_LEN-1);
if (conn->in.padding) {
conn->in.padding = ISCSI_PAD_LEN - conn->in.padding;
debug_scsi("read padding %d bytes\n", conn->in.padding);
}
if (conn->hdrdgst_en) {
struct scatterlist sg;
sg_init_one(&sg, (u8 *)hdr,
sizeof(struct iscsi_hdr) + conn->in.ahslen);
crypto_digest_digest(conn->rx_tfm, &sg, 1, (u8 *)&cdgst);
rdgst = *(uint32_t*)((char*)hdr + sizeof(struct iscsi_hdr) +
conn->in.ahslen);
if (cdgst != rdgst) {
printk(KERN_ERR "iscsi_tcp: itt %x: hdrdgst error "
"recv 0x%x calc 0x%x\n", conn->in.itt, rdgst,
cdgst);
return ISCSI_ERR_HDR_DGST;
}
}
/* save opcode for later */
conn->in.opcode = hdr->opcode & ISCSI_OPCODE_MASK;
/* verify itt (itt encoding: age+cid+itt) */
if (hdr->itt != cpu_to_be32(ISCSI_RESERVED_TAG)) {
if ((hdr->itt & AGE_MASK) !=
(session->age << AGE_SHIFT)) {
printk(KERN_ERR "iscsi_tcp: received itt %x expected "
"session age (%x)\n", hdr->itt,
session->age & AGE_MASK);
return ISCSI_ERR_BAD_ITT;
}
if ((hdr->itt & CID_MASK) != (conn->id << CID_SHIFT)) {
printk(KERN_ERR "iscsi_tcp: received itt %x, expected "
"CID (%x)\n", hdr->itt, conn->id);
return ISCSI_ERR_BAD_ITT;
}
conn->in.itt = hdr->itt & ITT_MASK;
} else
conn->in.itt = hdr->itt;
debug_tcp("opcode 0x%x offset %d copy %d ahslen %d datalen %d\n",
hdr->opcode, conn->in.offset, conn->in.copy,
conn->in.ahslen, conn->in.datalen);
if (conn->in.itt < session->cmds_max) {
ctask = (struct iscsi_cmd_task *)session->cmds[conn->in.itt];
if (!ctask->sc) {
printk(KERN_INFO "iscsi_tcp: dropping ctask with "
"itt 0x%x\n", ctask->itt);
conn->in.datalen = 0; /* force drop */
return 0;
}
if (ctask->sc->SCp.phase != session->age) {
printk(KERN_ERR "iscsi_tcp: ctask's session age %d, "
"expected %d\n", ctask->sc->SCp.phase,
session->age);
return ISCSI_ERR_SESSION_FAILED;
}
conn->in.ctask = ctask;
debug_scsi("rsp [op 0x%x cid %d sc %lx itt 0x%x len %d]\n",
hdr->opcode, conn->id, (long)ctask->sc,
ctask->itt, conn->in.datalen);
switch(conn->in.opcode) {
case ISCSI_OP_SCSI_CMD_RSP:
BUG_ON((void*)ctask != ctask->sc->SCp.ptr);
if (!conn->in.datalen)
rc = iscsi_cmd_rsp(conn, ctask);
else
/*
* got sense or response data; copying PDU
* Header to the connection's header
* placeholder
*/
memcpy(&conn->hdr, hdr,
sizeof(struct iscsi_hdr));
break;
case ISCSI_OP_SCSI_DATA_IN:
BUG_ON((void*)ctask != ctask->sc->SCp.ptr);
/* save flags for non-exceptional status */
conn->in.flags = hdr->flags;
/* save cmd_status for sense data */
conn->in.cmd_status =
((struct iscsi_data_rsp*)hdr)->cmd_status;
rc = iscsi_data_rsp(conn, ctask);
break;
case ISCSI_OP_R2T:
BUG_ON((void*)ctask != ctask->sc->SCp.ptr);
if (ctask->sc->sc_data_direction == DMA_TO_DEVICE)
rc = iscsi_r2t_rsp(conn, ctask);
else
rc = ISCSI_ERR_PROTO;
break;
default:
rc = ISCSI_ERR_BAD_OPCODE;
break;
}
} else if (conn->in.itt >= ISCSI_MGMT_ITT_OFFSET &&
conn->in.itt < ISCSI_MGMT_ITT_OFFSET +
session->mgmtpool_max) {
struct iscsi_mgmt_task *mtask = (struct iscsi_mgmt_task *)
session->mgmt_cmds[conn->in.itt -
ISCSI_MGMT_ITT_OFFSET];
debug_scsi("immrsp [op 0x%x cid %d itt 0x%x len %d]\n",
conn->in.opcode, conn->id, mtask->itt,
conn->in.datalen);
switch(conn->in.opcode) {
case ISCSI_OP_LOGIN_RSP:
case ISCSI_OP_TEXT_RSP:
case ISCSI_OP_LOGOUT_RSP:
rc = iscsi_check_assign_cmdsn(session,
(struct iscsi_nopin*)hdr);
if (rc)
break;
if (!conn->in.datalen) {
rc = iscsi_recv_pdu(iscsi_handle(conn), hdr,
NULL, 0);
if (conn->login_mtask != mtask) {
spin_lock(&session->lock);
__kfifo_put(session->mgmtpool.queue,
(void*)&mtask, sizeof(void*));
spin_unlock(&session->lock);
}
}
break;
case ISCSI_OP_SCSI_TMFUNC_RSP:
rc = iscsi_check_assign_cmdsn(session,
(struct iscsi_nopin*)hdr);
if (rc)
break;
if (conn->in.datalen || conn->in.ahslen) {
rc = ISCSI_ERR_PROTO;
break;
}
conn->tmfrsp_pdus_cnt++;
spin_lock(&session->lock);
if (conn->tmabort_state == TMABORT_INITIAL) {
__kfifo_put(session->mgmtpool.queue,
(void*)&mtask, sizeof(void*));
conn->tmabort_state =
((struct iscsi_tm_rsp *)hdr)->
response == ISCSI_TMF_RSP_COMPLETE ?
TMABORT_SUCCESS:TMABORT_FAILED;
/* unblock eh_abort() */
wake_up(&conn->ehwait);
}
spin_unlock(&session->lock);
break;
case ISCSI_OP_NOOP_IN:
if (hdr->ttt != ISCSI_RESERVED_TAG) {
rc = ISCSI_ERR_PROTO;
break;
}
rc = iscsi_check_assign_cmdsn(session,
(struct iscsi_nopin*)hdr);
if (rc)
break;
conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
if (!conn->in.datalen) {
struct iscsi_mgmt_task *mtask;
rc = iscsi_recv_pdu(iscsi_handle(conn), hdr,
NULL, 0);
mtask = (struct iscsi_mgmt_task *)
session->mgmt_cmds[conn->in.itt -
ISCSI_MGMT_ITT_OFFSET];
if (conn->login_mtask != mtask) {
spin_lock(&session->lock);
__kfifo_put(session->mgmtpool.queue,
(void*)&mtask, sizeof(void*));
spin_unlock(&session->lock);
}
}
break;
default:
rc = ISCSI_ERR_BAD_OPCODE;
break;
}
} else if (conn->in.itt == ISCSI_RESERVED_TAG) {
switch(conn->in.opcode) {
case ISCSI_OP_NOOP_IN:
if (!conn->in.datalen) {
rc = iscsi_check_assign_cmdsn(session,
(struct iscsi_nopin*)hdr);
if (!rc && hdr->ttt != ISCSI_RESERVED_TAG)
rc = iscsi_recv_pdu(iscsi_handle(conn),
hdr, NULL, 0);
} else
rc = ISCSI_ERR_PROTO;
break;
case ISCSI_OP_REJECT:
/* we need sth like iscsi_reject_rsp()*/
case ISCSI_OP_ASYNC_EVENT:
/* we need sth like iscsi_async_event_rsp() */
rc = ISCSI_ERR_BAD_OPCODE;
break;
default:
rc = ISCSI_ERR_BAD_OPCODE;
break;
}
} else
rc = ISCSI_ERR_BAD_ITT;
return rc;
}
/**
* iscsi_ctask_copy - copy skb bits to the destanation cmd task
* @conn: iscsi connection
* @ctask: scsi command task
* @buf: buffer to copy to
* @buf_size: size of buffer
* @offset: offset within the buffer
*
* Notes:
* The function calls skb_copy_bits() and updates per-connection and
* per-cmd byte counters.
*
* Read counters (in bytes):
*
* conn->in.offset offset within in progress SKB
* conn->in.copy left to copy from in progress SKB
* including padding
* conn->in.copied copied already from in progress SKB
* conn->data_copied copied already from in progress buffer
* ctask->sent total bytes sent up to the MidLayer
* ctask->data_count left to copy from in progress Data-In
* buf_left left to copy from in progress buffer
**/
static inline int
iscsi_ctask_copy(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
void *buf, int buf_size, int offset)
{
int buf_left = buf_size - (conn->data_copied + offset);
int size = min(conn->in.copy, buf_left);
int rc;
size = min(size, ctask->data_count);
debug_tcp("ctask_copy %d bytes at offset %d copied %d\n",
size, conn->in.offset, conn->in.copied);
BUG_ON(size <= 0);
BUG_ON(ctask->sent + size > ctask->total_length);
rc = skb_copy_bits(conn->in.skb, conn->in.offset,
(char*)buf + (offset + conn->data_copied), size);
/* must fit into skb->len */
BUG_ON(rc);
conn->in.offset += size;
conn->in.copy -= size;
conn->in.copied += size;
conn->data_copied += size;
ctask->sent += size;
ctask->data_count -= size;
BUG_ON(conn->in.copy < 0);
BUG_ON(ctask->data_count < 0);
if (buf_size != (conn->data_copied + offset)) {
if (!ctask->data_count) {
BUG_ON(buf_size - conn->data_copied < 0);
/* done with this PDU */
return buf_size - conn->data_copied;
}
return -EAGAIN;
}
/* done with this buffer or with both - PDU and buffer */
conn->data_copied = 0;
return 0;
}
/**
* iscsi_tcp_copy - copy skb bits to the destanation buffer
* @conn: iscsi connection
* @buf: buffer to copy to
* @buf_size: number of bytes to copy
*
* Notes:
* The function calls skb_copy_bits() and updates per-connection
* byte counters.
**/
static inline int
iscsi_tcp_copy(struct iscsi_conn *conn, void *buf, int buf_size)
{
int buf_left = buf_size - conn->data_copied;
int size = min(conn->in.copy, buf_left);
int rc;
debug_tcp("tcp_copy %d bytes at offset %d copied %d\n",
size, conn->in.offset, conn->data_copied);
BUG_ON(size <= 0);
rc = skb_copy_bits(conn->in.skb, conn->in.offset,
(char*)buf + conn->data_copied, size);
BUG_ON(rc);
conn->in.offset += size;
conn->in.copy -= size;
conn->in.copied += size;
conn->data_copied += size;
if (buf_size != conn->data_copied)
return -EAGAIN;
return 0;
}
static inline void
partial_sg_digest_update(struct iscsi_conn *conn, struct scatterlist *sg,
int offset, int length)
{
struct scatterlist temp;
memcpy(&temp, sg, sizeof(struct scatterlist));
temp.offset = offset;
temp.length = length;
crypto_digest_update(conn->data_rx_tfm, &temp, 1);
}
static void
iscsi_recv_digest_update(struct iscsi_conn *conn, char* buf, int len)
{
struct scatterlist tmp;
sg_init_one(&tmp, buf, len);
crypto_digest_update(conn->data_rx_tfm, &tmp, 1);
}
static int iscsi_scsi_data_in(struct iscsi_conn *conn)
{
struct iscsi_cmd_task *ctask = conn->in.ctask;
struct scsi_cmnd *sc = ctask->sc;
struct scatterlist *sg;
int i, offset, rc = 0;
BUG_ON((void*)ctask != sc->SCp.ptr);
/*
* copying Data-In into the Scsi_Cmnd
*/
if (!sc->use_sg) {
i = ctask->data_count;
rc = iscsi_ctask_copy(conn, ctask, sc->request_buffer,
sc->request_bufflen, ctask->data_offset);
if (rc == -EAGAIN)
return rc;
if (conn->datadgst_en)
iscsi_recv_digest_update(conn, sc->request_buffer, i);
rc = 0;
goto done;
}
offset = ctask->data_offset;
sg = sc->request_buffer;
if (ctask->data_offset)
for (i = 0; i < ctask->sg_count; i++)
offset -= sg[i].length;
/* we've passed through partial sg*/
if (offset < 0)
offset = 0;
for (i = ctask->sg_count; i < sc->use_sg; i++) {
char *dest;
dest = kmap_atomic(sg[i].page, KM_SOFTIRQ0);
rc = iscsi_ctask_copy(conn, ctask, dest + sg[i].offset,
sg[i].length, offset);
kunmap_atomic(dest, KM_SOFTIRQ0);
if (rc == -EAGAIN)
/* continue with the next SKB/PDU */
return rc;
if (!rc) {
if (conn->datadgst_en) {
if (!offset)
crypto_digest_update(conn->data_rx_tfm,
&sg[i], 1);
else
partial_sg_digest_update(conn, &sg[i],
sg[i].offset + offset,
sg[i].length - offset);
}
offset = 0;
ctask->sg_count++;
}
if (!ctask->data_count) {
if (rc && conn->datadgst_en)
/*
* data-in is complete, but buffer not...
*/
partial_sg_digest_update(conn, &sg[i],
sg[i].offset, sg[i].length-rc);
rc = 0;
break;
}
if (!conn->in.copy)
return -EAGAIN;
}
BUG_ON(ctask->data_count);
done:
/* check for non-exceptional status */
if (conn->in.flags & ISCSI_FLAG_DATA_STATUS) {
debug_scsi("done [sc %lx res %d itt 0x%x]\n",
(long)sc, sc->result, ctask->itt);
conn->scsirsp_pdus_cnt++;
iscsi_ctask_cleanup(conn, ctask);
sc->scsi_done(sc);
}
return rc;
}
static int
iscsi_data_recv(struct iscsi_conn *conn)
{
struct iscsi_session *session = conn->session;
int rc = 0;
switch(conn->in.opcode) {
case ISCSI_OP_SCSI_DATA_IN:
rc = iscsi_scsi_data_in(conn);
break;
case ISCSI_OP_SCSI_CMD_RSP: {
/*
* SCSI Sense Data:
* copying the entire Data Segment.
*/
if (iscsi_tcp_copy(conn, conn->data, conn->in.datalen)) {
rc = -EAGAIN;
goto exit;
}
/*
* check for sense
*/
conn->in.hdr = &conn->hdr;
conn->senselen = (conn->data[0] << 8) | conn->data[1];
rc = iscsi_cmd_rsp(conn, conn->in.ctask);
if (!rc && conn->datadgst_en)
iscsi_recv_digest_update(conn, conn->data,
conn->in.datalen);
}
break;
case ISCSI_OP_TEXT_RSP:
case ISCSI_OP_LOGIN_RSP:
case ISCSI_OP_NOOP_IN: {
struct iscsi_mgmt_task *mtask = NULL;
if (conn->in.itt != ISCSI_RESERVED_TAG)
mtask = (struct iscsi_mgmt_task *)
session->mgmt_cmds[conn->in.itt -
ISCSI_MGMT_ITT_OFFSET];
/*
* Collect data segment to the connection's data
* placeholder
*/
if (iscsi_tcp_copy(conn, conn->data, conn->in.datalen)) {
rc = -EAGAIN;
goto exit;
}
rc = iscsi_recv_pdu(iscsi_handle(conn), conn->in.hdr,
conn->data, conn->in.datalen);
if (!rc && conn->datadgst_en &&
conn->in.opcode != ISCSI_OP_LOGIN_RSP)
iscsi_recv_digest_update(conn, conn->data,
conn->in.datalen);
if (mtask && conn->login_mtask != mtask) {
spin_lock(&session->lock);
__kfifo_put(session->mgmtpool.queue, (void*)&mtask,
sizeof(void*));
spin_unlock(&session->lock);
}
}
break;
case ISCSI_OP_ASYNC_EVENT:
case ISCSI_OP_REJECT:
default:
BUG_ON(1);
}
exit:
return rc;
}
/**
* iscsi_tcp_data_recv - TCP receive in sendfile fashion
* @rd_desc: read descriptor
* @skb: socket buffer
* @offset: offset in skb
* @len: skb->len - offset
**/
static int
iscsi_tcp_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb,
unsigned int offset, size_t len)
{
int rc;
struct iscsi_conn *conn = rd_desc->arg.data;
int processed;
char pad[ISCSI_PAD_LEN];
struct scatterlist sg;
/*
* Save current SKB and its offset in the corresponding
* connection context.
*/
conn->in.copy = skb->len - offset;
conn->in.offset = offset;
conn->in.skb = skb;
conn->in.len = conn->in.copy;
BUG_ON(conn->in.copy <= 0);
debug_tcp("in %d bytes\n", conn->in.copy);
more:
conn->in.copied = 0;
rc = 0;
if (unlikely(conn->suspend_rx)) {
debug_tcp("conn %d Rx suspended!\n", conn->id);
return 0;
}
if (conn->in_progress == IN_PROGRESS_WAIT_HEADER ||
conn->in_progress == IN_PROGRESS_HEADER_GATHER) {
rc = iscsi_hdr_extract(conn);
if (rc) {
if (rc == -EAGAIN)
goto nomore;
else {
iscsi_conn_failure(conn, rc);
return 0;
}
}
/*
* Verify and process incoming PDU header.
*/
rc = iscsi_hdr_recv(conn);
if (!rc && conn->in.datalen) {
if (conn->datadgst_en) {
BUG_ON(!conn->data_rx_tfm);
crypto_digest_init(conn->data_rx_tfm);
}
conn->in_progress = IN_PROGRESS_DATA_RECV;
} else if (rc) {
iscsi_conn_failure(conn, rc);
return 0;
}
}
if (conn->in_progress == IN_PROGRESS_DDIGEST_RECV) {
uint32_t recv_digest;
debug_tcp("extra data_recv offset %d copy %d\n",
conn->in.offset, conn->in.copy);
skb_copy_bits(conn->in.skb, conn->in.offset,
&recv_digest, 4);
conn->in.offset += 4;
conn->in.copy -= 4;
if (recv_digest != conn->in.datadgst) {
debug_tcp("iscsi_tcp: data digest error!"
"0x%x != 0x%x\n", recv_digest,
conn->in.datadgst);
iscsi_conn_failure(conn, ISCSI_ERR_DATA_DGST);
return 0;
} else {
debug_tcp("iscsi_tcp: data digest match!"
"0x%x == 0x%x\n", recv_digest,
conn->in.datadgst);
conn->in_progress = IN_PROGRESS_WAIT_HEADER;
}
}
if (conn->in_progress == IN_PROGRESS_DATA_RECV && conn->in.copy) {
debug_tcp("data_recv offset %d copy %d\n",
conn->in.offset, conn->in.copy);
rc = iscsi_data_recv(conn);
if (rc) {
if (rc == -EAGAIN) {
rd_desc->count = conn->in.datalen -
conn->in.ctask->data_count;
goto again;
}
iscsi_conn_failure(conn, rc);
return 0;
}
conn->in.copy -= conn->in.padding;
conn->in.offset += conn->in.padding;
if (conn->datadgst_en) {
if (conn->in.padding) {
debug_tcp("padding -> %d\n", conn->in.padding);
memset(pad, 0, conn->in.padding);
sg_init_one(&sg, pad, conn->in.padding);
crypto_digest_update(conn->data_rx_tfm, &sg, 1);
}
crypto_digest_final(conn->data_rx_tfm,
(u8 *) & conn->in.datadgst);
debug_tcp("rx digest 0x%x\n", conn->in.datadgst);
conn->in_progress = IN_PROGRESS_DDIGEST_RECV;
} else
conn->in_progress = IN_PROGRESS_WAIT_HEADER;
}
debug_tcp("f, processed %d from out of %d padding %d\n",
conn->in.offset - offset, (int)len, conn->in.padding);
BUG_ON(conn->in.offset - offset > len);
if (conn->in.offset - offset != len) {
debug_tcp("continue to process %d bytes\n",
(int)len - (conn->in.offset - offset));
goto more;
}
nomore:
processed = conn->in.offset - offset;
BUG_ON(processed == 0);
return processed;
again:
processed = conn->in.offset - offset;
debug_tcp("c, processed %d from out of %d rd_desc_cnt %d\n",
processed, (int)len, (int)rd_desc->count);
BUG_ON(processed == 0);
BUG_ON(processed > len);
conn->rxdata_octets += processed;
return processed;
}
static void
iscsi_tcp_data_ready(struct sock *sk, int flag)
{
struct iscsi_conn *conn = sk->sk_user_data;
read_descriptor_t rd_desc;
read_lock(&sk->sk_callback_lock);
/* use rd_desc to pass 'conn' to iscsi_tcp_data_recv */
rd_desc.arg.data = conn;
rd_desc.count = 0;
tcp_read_sock(sk, &rd_desc, iscsi_tcp_data_recv);
read_unlock(&sk->sk_callback_lock);
}
static void
iscsi_tcp_state_change(struct sock *sk)
{
struct iscsi_conn *conn;
struct iscsi_session *session;
void (*old_state_change)(struct sock *);
read_lock(&sk->sk_callback_lock);
conn = (struct iscsi_conn*)sk->sk_user_data;
session = conn->session;
if ((sk->sk_state == TCP_CLOSE_WAIT ||
sk->sk_state == TCP_CLOSE) &&
!atomic_read(&sk->sk_rmem_alloc)) {
debug_tcp("iscsi_tcp_state_change: TCP_CLOSE|TCP_CLOSE_WAIT\n");
iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
}
old_state_change = conn->old_state_change;
read_unlock(&sk->sk_callback_lock);
old_state_change(sk);
}
/**
* iscsi_write_space - Called when more output buffer space is available
* @sk: socket space is available for
**/
static void
iscsi_write_space(struct sock *sk)
{
struct iscsi_conn *conn = (struct iscsi_conn*)sk->sk_user_data;
conn->old_write_space(sk);
debug_tcp("iscsi_write_space: cid %d\n", conn->id);
clear_bit(SUSPEND_BIT, &conn->suspend_tx);
schedule_work(&conn->xmitwork);
}
static void
iscsi_conn_set_callbacks(struct iscsi_conn *conn)
{
struct sock *sk = conn->sock->sk;
/* assign new callbacks */
write_lock_bh(&sk->sk_callback_lock);
sk->sk_user_data = conn;
conn->old_data_ready = sk->sk_data_ready;
conn->old_state_change = sk->sk_state_change;
conn->old_write_space = sk->sk_write_space;
sk->sk_data_ready = iscsi_tcp_data_ready;
sk->sk_state_change = iscsi_tcp_state_change;
sk->sk_write_space = iscsi_write_space;
write_unlock_bh(&sk->sk_callback_lock);
}
static void
iscsi_conn_restore_callbacks(struct iscsi_conn *conn)
{
struct sock *sk = 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 = conn->old_data_ready;
sk->sk_state_change = conn->old_state_change;
sk->sk_write_space = conn->old_write_space;
sk->sk_no_check = 0;
write_unlock_bh(&sk->sk_callback_lock);
}
/**
* iscsi_send - generic send routine
* @sk: kernel's socket
* @buf: buffer to write from
* @size: actual size to write
* @flags: socket's flags
*
* Notes:
* depending on buffer will use tcp_sendpage() or tcp_sendmsg().
* buf->sg.offset == -1 tells us that buffer is non S/G and forces
* to use tcp_sendmsg().
*/
static inline int
iscsi_send(struct iscsi_conn *conn, struct iscsi_buf *buf, int size, int flags)
{
struct socket *sk = conn->sock;
int res;
if ((int)buf->sg.offset >= 0) {
int offset = buf->sg.offset + buf->sent;
res = conn->sendpage(sk, buf->sg.page, offset, size, flags);
} else {
struct msghdr msg;
buf->iov.iov_base = iscsi_buf_iov_base(buf);
buf->iov.iov_len = size;
memset(&msg, 0, sizeof(struct msghdr));
/* tcp_sendmsg */
res = kernel_sendmsg(sk, &msg, &buf->iov, 1, size);
}
return res;
}
/**
* iscsi_sendhdr - send PDU Header via tcp_sendpage()
* @conn: iscsi connection
* @buf: buffer to write from
* @datalen: lenght of data to be sent after the header
*
* Notes:
* (Tx, Fast Path)
**/
static inline int
iscsi_sendhdr(struct iscsi_conn *conn, struct iscsi_buf *buf, int datalen)
{
int flags = 0; /* MSG_DONTWAIT; */
int res, size;
size = buf->sg.length - buf->sent;
BUG_ON(buf->sent + size > buf->sg.length);
if (buf->sent + size != buf->sg.length || datalen)
flags |= MSG_MORE;
res = iscsi_send(conn, buf, size, flags);
debug_tcp("sendhdr %d bytes, sent %d res %d\n", size, buf->sent, res);
if (res >= 0) {
conn->txdata_octets += res;
buf->sent += res;
if (size != res)
return -EAGAIN;
return 0;
} else if (res == -EAGAIN) {
conn->sendpage_failures_cnt++;
set_bit(SUSPEND_BIT, &conn->suspend_tx);
} else if (res == -EPIPE)
iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
return res;
}
/**
* iscsi_sendpage - send one page of iSCSI Data-Out.
* @conn: iscsi connection
* @buf: buffer to write from
* @count: remaining data
* @sent: number of bytes sent
*
* Notes:
* (Tx, Fast Path)
**/
static inline int
iscsi_sendpage(struct iscsi_conn *conn, struct iscsi_buf *buf,
int *count, int *sent)
{
int flags = 0; /* MSG_DONTWAIT; */
int res, size;
size = buf->sg.length - buf->sent;
BUG_ON(buf->sent + size > buf->sg.length);
if (size > *count)
size = *count;
if (buf->sent + size != buf->sg.length || *count != size)
flags |= MSG_MORE;
res = iscsi_send(conn, buf, size, flags);
debug_tcp("sendpage: %d bytes, sent %d left %d sent %d res %d\n",
size, buf->sent, *count, *sent, res);
if (res >= 0) {
conn->txdata_octets += res;
buf->sent += res;
*count -= res;
*sent += res;
if (size != res)
return -EAGAIN;
return 0;
} else if (res == -EAGAIN) {
conn->sendpage_failures_cnt++;
set_bit(SUSPEND_BIT, &conn->suspend_tx);
} else if (res == -EPIPE)
iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
return res;
}
static inline void
iscsi_data_digest_init(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
{
BUG_ON(!conn->data_tx_tfm);
crypto_digest_init(conn->data_tx_tfm);
ctask->digest_count = 4;
}
static inline void
iscsi_buf_data_digest_update(struct iscsi_conn *conn, struct iscsi_buf *buf)
{
struct scatterlist sg;
if (buf->sg.offset != -1)
crypto_digest_update(conn->data_tx_tfm, &buf->sg, 1);
else {
sg_init_one(&sg, (char *)buf->sg.page, buf->sg.length);
crypto_digest_update(conn->data_tx_tfm, &sg, 1);
}
}
static inline int
iscsi_digest_final_send(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
struct iscsi_buf *buf, uint32_t *digest, int final)
{
int rc = 0;
int sent = 0;
if (final)
crypto_digest_final(conn->data_tx_tfm, (u8*)digest);
iscsi_buf_init_virt(buf, (char*)digest, 4);
rc = iscsi_sendpage(conn, buf, &ctask->digest_count, &sent);
if (rc) {
ctask->datadigest = *digest;
ctask->xmstate |= XMSTATE_DATA_DIGEST;
} else
ctask->digest_count = 4;
return rc;
}
/**
* iscsi_solicit_data_cont - initialize next Data-Out
* @conn: iscsi connection
* @ctask: scsi command task
* @r2t: R2T info
* @left: bytes left to transfer
*
* Notes:
* Initialize next Data-Out within this R2T sequence and continue
* to process next Scatter-Gather element(if any) of this SCSI command.
*
* Called under connection lock.
**/
static void
iscsi_solicit_data_cont(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
struct iscsi_r2t_info *r2t, int left)
{
struct iscsi_data *hdr;
struct iscsi_data_task *dtask;
struct scsi_cmnd *sc = ctask->sc;
int new_offset;
dtask = mempool_alloc(ctask->datapool, GFP_ATOMIC);
BUG_ON(!dtask);
hdr = &dtask->hdr;
memset(hdr, 0, sizeof(struct iscsi_data));
hdr->ttt = r2t->ttt;
hdr->datasn = cpu_to_be32(r2t->solicit_datasn);
r2t->solicit_datasn++;
hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
memcpy(hdr->lun, ctask->hdr.lun, sizeof(hdr->lun));
hdr->itt = ctask->hdr.itt;
hdr->exp_statsn = r2t->exp_statsn;
new_offset = r2t->data_offset + r2t->sent;
hdr->offset = cpu_to_be32(new_offset);
if (left > conn->max_xmit_dlength) {
hton24(hdr->dlength, conn->max_xmit_dlength);
r2t->data_count = conn->max_xmit_dlength;
} else {
hton24(hdr->dlength, left);
r2t->data_count = left;
hdr->flags = ISCSI_FLAG_CMD_FINAL;
}
conn->dataout_pdus_cnt++;
iscsi_buf_init_virt(&r2t->headbuf, (char*)hdr,
sizeof(struct iscsi_hdr));
r2t->dtask = dtask;
if (sc->use_sg && !iscsi_buf_left(&r2t->sendbuf)) {
BUG_ON(ctask->bad_sg == r2t->sg);
iscsi_buf_init_sg(&r2t->sendbuf, r2t->sg);
r2t->sg += 1;
} else
iscsi_buf_init_iov(&ctask->sendbuf,
(char*)sc->request_buffer + new_offset,
r2t->data_count);
list_add(&dtask->item, &ctask->dataqueue);
}
static void
iscsi_unsolicit_data_init(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
{
struct iscsi_data *hdr;
struct iscsi_data_task *dtask;
dtask = mempool_alloc(ctask->datapool, GFP_ATOMIC);
BUG_ON(!dtask);
hdr = &dtask->hdr;
memset(hdr, 0, sizeof(struct iscsi_data));
hdr->ttt = cpu_to_be32(ISCSI_RESERVED_TAG);
hdr->datasn = cpu_to_be32(ctask->unsol_datasn);
ctask->unsol_datasn++;
hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
memcpy(hdr->lun, ctask->hdr.lun, sizeof(hdr->lun));
hdr->itt = ctask->hdr.itt;
hdr->exp_statsn = cpu_to_be32(conn->exp_statsn);
hdr->offset = cpu_to_be32(ctask->total_length -
ctask->r2t_data_count -
ctask->unsol_count);
if (ctask->unsol_count > conn->max_xmit_dlength) {
hton24(hdr->dlength, conn->max_xmit_dlength);
ctask->data_count = conn->max_xmit_dlength;
hdr->flags = 0;
} else {
hton24(hdr->dlength, ctask->unsol_count);
ctask->data_count = ctask->unsol_count;
hdr->flags = ISCSI_FLAG_CMD_FINAL;
}
iscsi_buf_init_virt(&ctask->headbuf, (char*)hdr,
sizeof(struct iscsi_hdr));
list_add(&dtask->item, &ctask->dataqueue);
ctask->dtask = dtask;
}
/**
* iscsi_cmd_init - Initialize iSCSI SCSI_READ or SCSI_WRITE commands
* @conn: iscsi connection
* @ctask: scsi command task
* @sc: scsi command
**/
static void
iscsi_cmd_init(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
struct scsi_cmnd *sc)
{
struct iscsi_session *session = conn->session;
BUG_ON(__kfifo_len(ctask->r2tqueue));
ctask->sc = sc;
ctask->conn = conn;
ctask->hdr.opcode = ISCSI_OP_SCSI_CMD;
ctask->hdr.flags = ISCSI_ATTR_SIMPLE;
int_to_scsilun(sc->device->lun, (struct scsi_lun *)ctask->hdr.lun);
ctask->hdr.itt = ctask->itt | (conn->id << CID_SHIFT) |
(session->age << AGE_SHIFT);
ctask->hdr.data_length = cpu_to_be32(sc->request_bufflen);
ctask->hdr.cmdsn = cpu_to_be32(session->cmdsn); session->cmdsn++;
ctask->hdr.exp_statsn = cpu_to_be32(conn->exp_statsn);
memcpy(ctask->hdr.cdb, sc->cmnd, sc->cmd_len);
memset(&ctask->hdr.cdb[sc->cmd_len], 0, MAX_COMMAND_SIZE - sc->cmd_len);
ctask->mtask = NULL;
ctask->sent = 0;
ctask->sg_count = 0;
ctask->total_length = sc->request_bufflen;
if (sc->sc_data_direction == DMA_TO_DEVICE) {
ctask->exp_r2tsn = 0;
ctask->hdr.flags |= ISCSI_FLAG_CMD_WRITE;
BUG_ON(ctask->total_length == 0);
if (sc->use_sg) {
struct scatterlist *sg = sc->request_buffer;
iscsi_buf_init_sg(&ctask->sendbuf,
&sg[ctask->sg_count++]);
ctask->sg = sg;
ctask->bad_sg = sg + sc->use_sg;
} else {
iscsi_buf_init_iov(&ctask->sendbuf, sc->request_buffer,
sc->request_bufflen);
}
/*
* Write counters:
*
* imm_count bytes to be sent right after
* SCSI PDU Header
*
* unsol_count bytes(as Data-Out) to be sent
* without R2T ack right after
* immediate data
*
* r2t_data_count bytes to be sent via R2T ack's
*
* pad_count bytes to be sent as zero-padding
*/
ctask->imm_count = 0;
ctask->unsol_count = 0;
ctask->unsol_datasn = 0;
ctask->xmstate = XMSTATE_W_HDR;
/* calculate write padding */
ctask->pad_count = ctask->total_length & (ISCSI_PAD_LEN-1);
if (ctask->pad_count) {
ctask->pad_count = ISCSI_PAD_LEN - ctask->pad_count;
debug_scsi("write padding %d bytes\n",
ctask->pad_count);
ctask->xmstate |= XMSTATE_W_PAD;
}
if (session->imm_data_en) {
if (ctask->total_length >= session->first_burst)
ctask->imm_count = min(session->first_burst,
conn->max_xmit_dlength);
else
ctask->imm_count = min(ctask->total_length,
conn->max_xmit_dlength);
hton24(ctask->hdr.dlength, ctask->imm_count);
ctask->xmstate |= XMSTATE_IMM_DATA;
} else
zero_data(ctask->hdr.dlength);
if (!session->initial_r2t_en)
ctask->unsol_count = min(session->first_burst,
ctask->total_length) - ctask->imm_count;
if (!ctask->unsol_count)
/* No unsolicit Data-Out's */
ctask->hdr.flags |= ISCSI_FLAG_CMD_FINAL;
else
ctask->xmstate |= XMSTATE_UNS_HDR | XMSTATE_UNS_INIT;
ctask->r2t_data_count = ctask->total_length -
ctask->imm_count -
ctask->unsol_count;
debug_scsi("cmd [itt %x total %d imm %d imm_data %d "
"r2t_data %d]\n",
ctask->itt, ctask->total_length, ctask->imm_count,
ctask->unsol_count, ctask->r2t_data_count);
} else {
ctask->hdr.flags |= ISCSI_FLAG_CMD_FINAL;
if (sc->sc_data_direction == DMA_FROM_DEVICE)
ctask->hdr.flags |= ISCSI_FLAG_CMD_READ;
ctask->datasn = 0;
ctask->xmstate = XMSTATE_R_HDR;
zero_data(ctask->hdr.dlength);
}
iscsi_buf_init_virt(&ctask->headbuf, (char*)&ctask->hdr,
sizeof(struct iscsi_hdr));
conn->scsicmd_pdus_cnt++;
}
/**
* iscsi_mtask_xmit - xmit management(immediate) task
* @conn: iscsi connection
* @mtask: task management task
*
* Notes:
* The function can return -EAGAIN in which case caller must
* call it again later, or recover. '0' return code means successful
* xmit.
*
* Management xmit state machine consists of two states:
* IN_PROGRESS_IMM_HEAD - PDU Header xmit in progress
* IN_PROGRESS_IMM_DATA - PDU Data xmit in progress
**/
static int
iscsi_mtask_xmit(struct iscsi_conn *conn, struct iscsi_mgmt_task *mtask)
{
debug_scsi("mtask deq [cid %d state %x itt 0x%x]\n",
conn->id, mtask->xmstate, mtask->itt);
if (mtask->xmstate & XMSTATE_IMM_HDR) {
mtask->xmstate &= ~XMSTATE_IMM_HDR;
if (mtask->data_count)
mtask->xmstate |= XMSTATE_IMM_DATA;
if (conn->c_stage != ISCSI_CONN_INITIAL_STAGE &&
conn->stop_stage != STOP_CONN_RECOVER &&
conn->hdrdgst_en)
iscsi_hdr_digest(conn, &mtask->headbuf,
(u8*)mtask->hdrext);
if (iscsi_sendhdr(conn, &mtask->headbuf, mtask->data_count)) {
mtask->xmstate |= XMSTATE_IMM_HDR;
if (mtask->data_count)
mtask->xmstate &= ~XMSTATE_IMM_DATA;
return -EAGAIN;
}
}
if (mtask->xmstate & XMSTATE_IMM_DATA) {
BUG_ON(!mtask->data_count);
mtask->xmstate &= ~XMSTATE_IMM_DATA;
/* FIXME: implement.
* Virtual buffer could be spreaded across multiple pages...
*/
do {
if (iscsi_sendpage(conn, &mtask->sendbuf,
&mtask->data_count, &mtask->sent)) {
mtask->xmstate |= XMSTATE_IMM_DATA;
return -EAGAIN;
}
} while (mtask->data_count);
}
BUG_ON(mtask->xmstate != XMSTATE_IDLE);
return 0;
}
static inline int
handle_xmstate_r_hdr(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
{
ctask->xmstate &= ~XMSTATE_R_HDR;
if (conn->hdrdgst_en)
iscsi_hdr_digest(conn, &ctask->headbuf, (u8*)ctask->hdrext);
if (!iscsi_sendhdr(conn, &ctask->headbuf, 0)) {
BUG_ON(ctask->xmstate != XMSTATE_IDLE);
return 0; /* wait for Data-In */
}
ctask->xmstate |= XMSTATE_R_HDR;
return -EAGAIN;
}
static inline int
handle_xmstate_w_hdr(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
{
ctask->xmstate &= ~XMSTATE_W_HDR;
if (conn->hdrdgst_en)
iscsi_hdr_digest(conn, &ctask->headbuf, (u8*)ctask->hdrext);
if (iscsi_sendhdr(conn, &ctask->headbuf, ctask->imm_count)) {
ctask->xmstate |= XMSTATE_W_HDR;
return -EAGAIN;
}
return 0;
}
static inline int
handle_xmstate_data_digest(struct iscsi_conn *conn,
struct iscsi_cmd_task *ctask)
{
ctask->xmstate &= ~XMSTATE_DATA_DIGEST;
debug_tcp("resent data digest 0x%x\n", ctask->datadigest);
if (iscsi_digest_final_send(conn, ctask, &ctask->immbuf,
&ctask->datadigest, 0)) {
ctask->xmstate |= XMSTATE_DATA_DIGEST;
debug_tcp("resent data digest 0x%x fail!\n",
ctask->datadigest);
return -EAGAIN;
}
return 0;
}
static inline int
handle_xmstate_imm_data(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
{
BUG_ON(!ctask->imm_count);
ctask->xmstate &= ~XMSTATE_IMM_DATA;
if (conn->datadgst_en) {
iscsi_data_digest_init(conn, ctask);
ctask->immdigest = 0;
}
for (;;) {
if (iscsi_sendpage(conn, &ctask->sendbuf, &ctask->imm_count,
&ctask->sent)) {
ctask->xmstate |= XMSTATE_IMM_DATA;
if (conn->datadgst_en) {
crypto_digest_final(conn->data_tx_tfm,
(u8*)&ctask->immdigest);
debug_tcp("tx imm sendpage fail 0x%x\n",
ctask->datadigest);
}
return -EAGAIN;
}
if (conn->datadgst_en)
iscsi_buf_data_digest_update(conn, &ctask->sendbuf);
if (!ctask->imm_count)
break;
iscsi_buf_init_sg(&ctask->sendbuf,
&ctask->sg[ctask->sg_count++]);
}
if (conn->datadgst_en && !(ctask->xmstate & XMSTATE_W_PAD)) {
if (iscsi_digest_final_send(conn, ctask, &ctask->immbuf,
&ctask->immdigest, 1)) {
debug_tcp("sending imm digest 0x%x fail!\n",
ctask->immdigest);
return -EAGAIN;
}
debug_tcp("sending imm digest 0x%x\n", ctask->immdigest);
}
return 0;
}
static inline int
handle_xmstate_uns_hdr(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
{
struct iscsi_data_task *dtask;
ctask->xmstate |= XMSTATE_UNS_DATA;
if (ctask->xmstate & XMSTATE_UNS_INIT) {
iscsi_unsolicit_data_init(conn, ctask);
BUG_ON(!ctask->dtask);
dtask = ctask->dtask;
if (conn->hdrdgst_en)
iscsi_hdr_digest(conn, &ctask->headbuf,
(u8*)dtask->hdrext);
ctask->xmstate &= ~XMSTATE_UNS_INIT;
}
if (iscsi_sendhdr(conn, &ctask->headbuf, ctask->data_count)) {
ctask->xmstate &= ~XMSTATE_UNS_DATA;
ctask->xmstate |= XMSTATE_UNS_HDR;
return -EAGAIN;
}
debug_scsi("uns dout [itt 0x%x dlen %d sent %d]\n",
ctask->itt, ctask->unsol_count, ctask->sent);
return 0;
}
static inline int
handle_xmstate_uns_data(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
{
struct iscsi_data_task *dtask = ctask->dtask;
BUG_ON(!ctask->data_count);
ctask->xmstate &= ~XMSTATE_UNS_DATA;
if (conn->datadgst_en) {
iscsi_data_digest_init(conn, ctask);
dtask->digest = 0;
}
for (;;) {
int start = ctask->sent;
if (iscsi_sendpage(conn, &ctask->sendbuf, &ctask->data_count,
&ctask->sent)) {
ctask->unsol_count -= ctask->sent - start;
ctask->xmstate |= XMSTATE_UNS_DATA;
/* will continue with this ctask later.. */
if (conn->datadgst_en) {
crypto_digest_final(conn->data_tx_tfm,
(u8 *)&dtask->digest);
debug_tcp("tx uns data fail 0x%x\n",
dtask->digest);
}
return -EAGAIN;
}
BUG_ON(ctask->sent > ctask->total_length);
ctask->unsol_count -= ctask->sent - start;
/*
* XXX:we may run here with un-initial sendbuf.
* so pass it
*/
if (conn->datadgst_en && ctask->sent - start > 0)
iscsi_buf_data_digest_update(conn, &ctask->sendbuf);
if (!ctask->data_count)
break;
iscsi_buf_init_sg(&ctask->sendbuf,
&ctask->sg[ctask->sg_count++]);
}
BUG_ON(ctask->unsol_count < 0);
/*
* Done with the Data-Out. Next, check if we need
* to send another unsolicited Data-Out.
*/
if (ctask->unsol_count) {
if (conn->datadgst_en) {
if (iscsi_digest_final_send(conn, ctask,
&dtask->digestbuf,
&dtask->digest, 1)) {
debug_tcp("send uns digest 0x%x fail\n",
dtask->digest);
return -EAGAIN;
}
debug_tcp("sending uns digest 0x%x, more uns\n",
dtask->digest);
}
ctask->xmstate |= XMSTATE_UNS_INIT;
return 1;
}
if (conn->datadgst_en && !(ctask->xmstate & XMSTATE_W_PAD)) {
if (iscsi_digest_final_send(conn, ctask,
&dtask->digestbuf,
&dtask->digest, 1)) {
debug_tcp("send last uns digest 0x%x fail\n",
dtask->digest);
return -EAGAIN;
}
debug_tcp("sending uns digest 0x%x\n",dtask->digest);
}
return 0;
}
static inline int
handle_xmstate_sol_data(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
{
struct iscsi_session *session = conn->session;
struct iscsi_r2t_info *r2t = ctask->r2t;
struct iscsi_data_task *dtask = r2t->dtask;
int left;
ctask->xmstate &= ~XMSTATE_SOL_DATA;
ctask->dtask = dtask;
if (conn->datadgst_en) {
iscsi_data_digest_init(conn, ctask);
dtask->digest = 0;
}
solicit_again:
/*
* send Data-Out whitnin this R2T sequence.
*/
if (!r2t->data_count)
goto data_out_done;
if (iscsi_sendpage(conn, &r2t->sendbuf, &r2t->data_count, &r2t->sent)) {
ctask->xmstate |= XMSTATE_SOL_DATA;
/* will continue with this ctask later.. */
if (conn->datadgst_en) {
crypto_digest_final(conn->data_tx_tfm,
(u8 *)&dtask->digest);
debug_tcp("r2t data send fail 0x%x\n", dtask->digest);
}
return -EAGAIN;
}
BUG_ON(r2t->data_count < 0);
if (conn->datadgst_en)
iscsi_buf_data_digest_update(conn, &r2t->sendbuf);
if (r2t->data_count) {
BUG_ON(ctask->sc->use_sg == 0);
if (!iscsi_buf_left(&r2t->sendbuf)) {
BUG_ON(ctask->bad_sg == r2t->sg);
iscsi_buf_init_sg(&r2t->sendbuf, r2t->sg);
r2t->sg += 1;
}
goto solicit_again;
}
data_out_done:
/*
* Done with this Data-Out. Next, check if we have
* to send another Data-Out for this R2T.
*/
BUG_ON(r2t->data_length - r2t->sent < 0);
left = r2t->data_length - r2t->sent;
if (left) {
if (conn->datadgst_en) {
if (iscsi_digest_final_send(conn, ctask,
&dtask->digestbuf,
&dtask->digest, 1)) {
debug_tcp("send r2t data digest 0x%x"
"fail\n", dtask->digest);
return -EAGAIN;
}
debug_tcp("r2t data send digest 0x%x\n",
dtask->digest);
}
iscsi_solicit_data_cont(conn, ctask, r2t, left);
ctask->xmstate |= XMSTATE_SOL_DATA;
ctask->xmstate &= ~XMSTATE_SOL_HDR;
return 1;
}
/*
* Done with this R2T. Check if there are more
* outstanding R2Ts ready to be processed.
*/
BUG_ON(ctask->r2t_data_count - r2t->data_length < 0);
if (conn->datadgst_en) {
if (iscsi_digest_final_send(conn, ctask, &dtask->digestbuf,
&dtask->digest, 1)) {
debug_tcp("send last r2t data digest 0x%x"
"fail\n", dtask->digest);
return -EAGAIN;
}
debug_tcp("r2t done dout digest 0x%x\n", dtask->digest);
}
ctask->r2t_data_count -= r2t->data_length;
ctask->r2t = NULL;
spin_lock_bh(&session->lock);
__kfifo_put(ctask->r2tpool.queue, (void*)&r2t, sizeof(void*));
spin_unlock_bh(&session->lock);
if (__kfifo_get(ctask->r2tqueue, (void*)&r2t, sizeof(void*))) {
ctask->r2t = r2t;
ctask->xmstate |= XMSTATE_SOL_DATA;
ctask->xmstate &= ~XMSTATE_SOL_HDR;
return 1;
}
return 0;
}
static inline int
handle_xmstate_w_pad(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
{
struct iscsi_data_task *dtask = ctask->dtask;
int sent;
ctask->xmstate &= ~XMSTATE_W_PAD;
iscsi_buf_init_virt(&ctask->sendbuf, (char*)&ctask->pad,
ctask->pad_count);
if (iscsi_sendpage(conn, &ctask->sendbuf, &ctask->pad_count, &sent)) {
ctask->xmstate |= XMSTATE_W_PAD;
return -EAGAIN;
}
if (conn->datadgst_en) {
iscsi_buf_data_digest_update(conn, &ctask->sendbuf);
/* imm data? */
if (!dtask) {
if (iscsi_digest_final_send(conn, ctask, &ctask->immbuf,
&ctask->immdigest, 1)) {
debug_tcp("send padding digest 0x%x"
"fail!\n", ctask->immdigest);
return -EAGAIN;
}
debug_tcp("done with padding, digest 0x%x\n",
ctask->datadigest);
} else {
if (iscsi_digest_final_send(conn, ctask,
&dtask->digestbuf,
&dtask->digest, 1)) {
debug_tcp("send padding digest 0x%x"
"fail\n", dtask->digest);
return -EAGAIN;
}
debug_tcp("done with padding, digest 0x%x\n",
dtask->digest);
}
}
return 0;
}
static int
iscsi_ctask_xmit(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
{
int rc = 0;
debug_scsi("ctask deq [cid %d xmstate %x itt 0x%x]\n",
conn->id, ctask->xmstate, ctask->itt);
/*
* serialize with TMF AbortTask
*/
if (ctask->mtask)
return rc;
if (ctask->xmstate & XMSTATE_R_HDR) {
rc = handle_xmstate_r_hdr(conn, ctask);
return rc;
}
if (ctask->xmstate & XMSTATE_W_HDR) {
rc = handle_xmstate_w_hdr(conn, ctask);
if (rc)
return rc;
}
/* XXX: for data digest xmit recover */
if (ctask->xmstate & XMSTATE_DATA_DIGEST) {
rc = handle_xmstate_data_digest(conn, ctask);
if (rc)
return rc;
}
if (ctask->xmstate & XMSTATE_IMM_DATA) {
rc = handle_xmstate_imm_data(conn, ctask);
if (rc)
return rc;
}
if (ctask->xmstate & XMSTATE_UNS_HDR) {
BUG_ON(!ctask->unsol_count);
ctask->xmstate &= ~XMSTATE_UNS_HDR;
unsolicit_head_again:
rc = handle_xmstate_uns_hdr(conn, ctask);
if (rc)
return rc;
}
if (ctask->xmstate & XMSTATE_UNS_DATA) {
rc = handle_xmstate_uns_data(conn, ctask);
if (rc == 1)
goto unsolicit_head_again;
else if (rc)
return rc;
goto done;
}
if (ctask->xmstate & XMSTATE_SOL_HDR) {
struct iscsi_r2t_info *r2t;
ctask->xmstate &= ~XMSTATE_SOL_HDR;
ctask->xmstate |= XMSTATE_SOL_DATA;
if (!ctask->r2t)
__kfifo_get(ctask->r2tqueue, (void*)&ctask->r2t,
sizeof(void*));
solicit_head_again:
r2t = ctask->r2t;
if (conn->hdrdgst_en)
iscsi_hdr_digest(conn, &r2t->headbuf,
(u8*)r2t->dtask->hdrext);
if (iscsi_sendhdr(conn, &r2t->headbuf, r2t->data_count)) {
ctask->xmstate &= ~XMSTATE_SOL_DATA;
ctask->xmstate |= XMSTATE_SOL_HDR;
return -EAGAIN;
}
debug_scsi("sol dout [dsn %d itt 0x%x dlen %d sent %d]\n",
r2t->solicit_datasn - 1, ctask->itt, r2t->data_count,
r2t->sent);
}
if (ctask->xmstate & XMSTATE_SOL_DATA) {
rc = handle_xmstate_sol_data(conn, ctask);
if (rc == 1)
goto solicit_head_again;
if (rc)
return rc;
}
done:
/*
* Last thing to check is whether we need to send write
* padding. Note that we check for xmstate equality, not just the bit.
*/
if (ctask->xmstate == XMSTATE_W_PAD)
rc = handle_xmstate_w_pad(conn, ctask);
return rc;
}
/**
* iscsi_data_xmit - xmit any command into the scheduled connection
* @conn: iscsi connection
*
* Notes:
* The function can return -EAGAIN in which case the caller must
* re-schedule it again later or recover. '0' return code means
* successful xmit.
**/
static int
iscsi_data_xmit(struct iscsi_conn *conn)
{
if (unlikely(conn->suspend_tx)) {
debug_tcp("conn %d Tx suspended!\n", conn->id);
return 0;
}
/*
* Transmit in the following order:
*
* 1) un-finished xmit (ctask or mtask)
* 2) immediate control PDUs
* 3) write data
* 4) SCSI commands
* 5) non-immediate control PDUs
*
* No need to lock around __kfifo_get as long as
* there's one producer and one consumer.
*/
BUG_ON(conn->ctask && conn->mtask);
if (conn->ctask) {
if (iscsi_ctask_xmit(conn, conn->ctask))
goto again;
/* done with this in-progress ctask */
conn->ctask = NULL;
}
if (conn->mtask) {
if (iscsi_mtask_xmit(conn, conn->mtask))
goto again;
/* done with this in-progress mtask */
conn->mtask = NULL;
}
/* process immediate first */
if (unlikely(__kfifo_len(conn->immqueue))) {
struct iscsi_session *session = conn->session;
while (__kfifo_get(conn->immqueue, (void*)&conn->mtask,
sizeof(void*))) {
if (iscsi_mtask_xmit(conn, conn->mtask))
goto again;
if (conn->mtask->hdr.itt ==
cpu_to_be32(ISCSI_RESERVED_TAG)) {
spin_lock_bh(&session->lock);
__kfifo_put(session->mgmtpool.queue,
(void*)&conn->mtask, sizeof(void*));
spin_unlock_bh(&session->lock);
}
}
/* done with this mtask */
conn->mtask = NULL;
}
/* process write queue */
while (__kfifo_get(conn->writequeue, (void*)&conn->ctask,
sizeof(void*))) {
if (iscsi_ctask_xmit(conn, conn->ctask))
goto again;
}
/* process command queue */
while (__kfifo_get(conn->xmitqueue, (void*)&conn->ctask,
sizeof(void*))) {
if (iscsi_ctask_xmit(conn, conn->ctask))
goto again;
}
/* done with this ctask */
conn->ctask = NULL;
/* process the rest control plane PDUs, if any */
if (unlikely(__kfifo_len(conn->mgmtqueue))) {
struct iscsi_session *session = conn->session;
while (__kfifo_get(conn->mgmtqueue, (void*)&conn->mtask,
sizeof(void*))) {
if (iscsi_mtask_xmit(conn, conn->mtask))
goto again;
if (conn->mtask->hdr.itt ==
cpu_to_be32(ISCSI_RESERVED_TAG)) {
spin_lock_bh(&session->lock);
__kfifo_put(session->mgmtpool.queue,
(void*)&conn->mtask,
sizeof(void*));
spin_unlock_bh(&session->lock);
}
}
/* done with this mtask */
conn->mtask = NULL;
}
return 0;
again:
if (unlikely(conn->suspend_tx))
return 0;
return -EAGAIN;
}
static void
iscsi_xmitworker(void *data)
{
struct iscsi_conn *conn = data;
/*
* serialize Xmit worker on a per-connection basis.
*/
mutex_lock(&conn->xmitmutex);
if (iscsi_data_xmit(conn))
schedule_work(&conn->xmitwork);
mutex_unlock(&conn->xmitmutex);
}
#define FAILURE_BAD_HOST 1
#define FAILURE_SESSION_FAILED 2
#define FAILURE_SESSION_FREED 3
#define FAILURE_WINDOW_CLOSED 4
#define FAILURE_SESSION_TERMINATE 5
static int
iscsi_queuecommand(struct scsi_cmnd *sc, void (*done)(struct scsi_cmnd *))
{
struct Scsi_Host *host;
int reason = 0;
struct iscsi_session *session;
struct iscsi_conn *conn = NULL;
struct iscsi_cmd_task *ctask = NULL;
sc->scsi_done = done;
sc->result = 0;
host = sc->device->host;
session = iscsi_hostdata(host->hostdata);
BUG_ON(host != session->host);
spin_lock(&session->lock);
if (session->state != ISCSI_STATE_LOGGED_IN) {
if (session->state == ISCSI_STATE_FAILED) {
reason = FAILURE_SESSION_FAILED;
goto reject;
} else if (session->state == ISCSI_STATE_TERMINATE) {
reason = FAILURE_SESSION_TERMINATE;
goto fault;
}
reason = FAILURE_SESSION_FREED;
goto fault;
}
/*
* Check for iSCSI window and take care of CmdSN wrap-around
*/
if ((int)(session->max_cmdsn - session->cmdsn) < 0) {
reason = FAILURE_WINDOW_CLOSED;
goto reject;
}
conn = session->leadconn;
__kfifo_get(session->cmdpool.queue, (void*)&ctask, sizeof(void*));
BUG_ON(ctask->sc);
sc->SCp.phase = session->age;
sc->SCp.ptr = (char*)ctask;
iscsi_cmd_init(conn, ctask, sc);
__kfifo_put(conn->xmitqueue, (void*)&ctask, sizeof(void*));
debug_scsi(
"ctask enq [%s cid %d sc %lx itt 0x%x len %d cmdsn %d win %d]\n",
sc->sc_data_direction == DMA_TO_DEVICE ? "write" : "read",
conn->id, (long)sc, ctask->itt, sc->request_bufflen,
session->cmdsn, session->max_cmdsn - session->exp_cmdsn + 1);
spin_unlock(&session->lock);
if (!in_interrupt() && mutex_trylock(&conn->xmitmutex)) {
spin_unlock_irq(host->host_lock);
if (iscsi_data_xmit(conn))
schedule_work(&conn->xmitwork);
mutex_unlock(&conn->xmitmutex);
spin_lock_irq(host->host_lock);
} else
schedule_work(&conn->xmitwork);
return 0;
reject:
spin_unlock(&session->lock);
debug_scsi("cmd 0x%x rejected (%d)\n", sc->cmnd[0], reason);
return SCSI_MLQUEUE_HOST_BUSY;
fault:
spin_unlock(&session->lock);
printk(KERN_ERR "iscsi_tcp: cmd 0x%x is not queued (%d)\n",
sc->cmnd[0], reason);
sc->sense_buffer[0] = 0x70;
sc->sense_buffer[2] = NOT_READY;
sc->sense_buffer[7] = 0x6;
sc->sense_buffer[12] = 0x08;
sc->sense_buffer[13] = 0x00;
sc->result = (DID_NO_CONNECT << 16);
sc->resid = sc->request_bufflen;
sc->scsi_done(sc);
return 0;
}
static int
iscsi_change_queue_depth(struct scsi_device *sdev, int depth)
{
if (depth > ISCSI_MAX_CMD_PER_LUN)
depth = ISCSI_MAX_CMD_PER_LUN;
scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
return sdev->queue_depth;
}
static int
iscsi_pool_init(struct iscsi_queue *q, int max, void ***items, int item_size)
{
int i;
*items = kmalloc(max * sizeof(void*), GFP_KERNEL);
if (*items == NULL)
return -ENOMEM;
q->max = max;
q->pool = kmalloc(max * sizeof(void*), GFP_KERNEL);
if (q->pool == NULL) {
kfree(*items);
return -ENOMEM;
}
q->queue = kfifo_init((void*)q->pool, max * sizeof(void*),
GFP_KERNEL, NULL);
if (q->queue == ERR_PTR(-ENOMEM)) {
kfree(q->pool);
kfree(*items);
return -ENOMEM;
}
for (i = 0; i < max; i++) {
q->pool[i] = kmalloc(item_size, GFP_KERNEL);
if (q->pool[i] == NULL) {
int j;
for (j = 0; j < i; j++)
kfree(q->pool[j]);
kfifo_free(q->queue);
kfree(q->pool);
kfree(*items);
return -ENOMEM;
}
memset(q->pool[i], 0, item_size);
(*items)[i] = q->pool[i];
__kfifo_put(q->queue, (void*)&q->pool[i], sizeof(void*));
}
return 0;
}
static void
iscsi_pool_free(struct iscsi_queue *q, void **items)
{
int i;
for (i = 0; i < q->max; i++)
kfree(items[i]);
kfree(q->pool);
kfree(items);
}
static iscsi_connh_t
iscsi_conn_create(iscsi_sessionh_t sessionh, uint32_t conn_idx)
{
struct iscsi_session *session = iscsi_ptr(sessionh);
struct iscsi_conn *conn = NULL;
conn = kmalloc(sizeof(struct iscsi_conn), GFP_KERNEL);
if (conn == NULL)
goto conn_alloc_fail;
memset(conn, 0, sizeof(struct iscsi_conn));
conn->c_stage = ISCSI_CONN_INITIAL_STAGE;
conn->in_progress = IN_PROGRESS_WAIT_HEADER;
conn->id = conn_idx;
conn->exp_statsn = 0;
conn->tmabort_state = TMABORT_INITIAL;
/* initial operational parameters */
conn->hdr_size = sizeof(struct iscsi_hdr);
conn->data_size = DEFAULT_MAX_RECV_DATA_SEGMENT_LENGTH;
conn->max_recv_dlength = DEFAULT_MAX_RECV_DATA_SEGMENT_LENGTH;
spin_lock_init(&conn->lock);
/* initialize general xmit PDU commands queue */
conn->xmitqueue = kfifo_alloc(session->cmds_max * sizeof(void*),
GFP_KERNEL, NULL);
if (conn->xmitqueue == ERR_PTR(-ENOMEM))
goto xmitqueue_alloc_fail;
/* initialize write response PDU commands queue */
conn->writequeue = kfifo_alloc(session->cmds_max * sizeof(void*),
GFP_KERNEL, NULL);
if (conn->writequeue == ERR_PTR(-ENOMEM))
goto writequeue_alloc_fail;
/* initialize general immediate & non-immediate PDU commands queue */
conn->immqueue = kfifo_alloc(session->mgmtpool_max * sizeof(void*),
GFP_KERNEL, NULL);
if (conn->immqueue == ERR_PTR(-ENOMEM))
goto immqueue_alloc_fail;
conn->mgmtqueue = kfifo_alloc(session->mgmtpool_max * sizeof(void*),
GFP_KERNEL, NULL);
if (conn->mgmtqueue == ERR_PTR(-ENOMEM))
goto mgmtqueue_alloc_fail;
INIT_WORK(&conn->xmitwork, iscsi_xmitworker, conn);
/* allocate login_mtask used for the login/text sequences */
spin_lock_bh(&session->lock);
if (!__kfifo_get(session->mgmtpool.queue,
(void*)&conn->login_mtask,
sizeof(void*))) {
spin_unlock_bh(&session->lock);
goto login_mtask_alloc_fail;
}
spin_unlock_bh(&session->lock);
/* allocate initial PDU receive place holder */
if (conn->data_size <= PAGE_SIZE)
conn->data = kmalloc(conn->data_size, GFP_KERNEL);
else
conn->data = (void*)__get_free_pages(GFP_KERNEL,
get_order(conn->data_size));
if (!conn->data)
goto max_recv_dlenght_alloc_fail;
init_timer(&conn->tmabort_timer);
mutex_init(&conn->xmitmutex);
init_waitqueue_head(&conn->ehwait);
return iscsi_handle(conn);
max_recv_dlenght_alloc_fail:
spin_lock_bh(&session->lock);
__kfifo_put(session->mgmtpool.queue, (void*)&conn->login_mtask,
sizeof(void*));
spin_unlock_bh(&session->lock);
login_mtask_alloc_fail:
kfifo_free(conn->mgmtqueue);
mgmtqueue_alloc_fail:
kfifo_free(conn->immqueue);
immqueue_alloc_fail:
kfifo_free(conn->writequeue);
writequeue_alloc_fail:
kfifo_free(conn->xmitqueue);
xmitqueue_alloc_fail:
kfree(conn);
conn_alloc_fail:
return iscsi_handle(NULL);
}
static void
iscsi_conn_destroy(iscsi_connh_t connh)
{
struct iscsi_conn *conn = iscsi_ptr(connh);
struct iscsi_session *session = conn->session;
unsigned long flags;
mutex_lock(&conn->xmitmutex);
set_bit(SUSPEND_BIT, &conn->suspend_tx);
if (conn->c_stage == ISCSI_CONN_INITIAL_STAGE && conn->sock) {
struct sock *sk = conn->sock->sk;
/*
* conn_start() has never been called!
* need to cleanup the socket.
*/
write_lock_bh(&sk->sk_callback_lock);
set_bit(SUSPEND_BIT, &conn->suspend_rx);
write_unlock_bh(&sk->sk_callback_lock);
sock_hold(conn->sock->sk);
iscsi_conn_restore_callbacks(conn);
sock_put(conn->sock->sk);
sock_release(conn->sock);
conn->sock = NULL;
}
spin_lock_bh(&session->lock);
conn->c_stage = ISCSI_CONN_CLEANUP_WAIT;
if (session->leadconn == conn) {
/*
* leading connection? then give up on recovery.
*/
session->state = ISCSI_STATE_TERMINATE;
wake_up(&conn->ehwait);
}
spin_unlock_bh(&session->lock);
mutex_unlock(&conn->xmitmutex);
/*
* Block until all in-progress commands for this connection
* time out or fail.
*/
for (;;) {
spin_lock_irqsave(session->host->host_lock, flags);
if (!session->host->host_busy) { /* OK for ERL == 0 */
spin_unlock_irqrestore(session->host->host_lock, flags);
break;
}
spin_unlock_irqrestore(session->host->host_lock, flags);
msleep_interruptible(500);
printk("conn_destroy(): host_busy %d host_failed %d\n",
session->host->host_busy, session->host->host_failed);
/*
* force eh_abort() to unblock
*/
wake_up(&conn->ehwait);
}
/* now free crypto */
if (conn->hdrdgst_en || conn->datadgst_en) {
if (conn->tx_tfm)
crypto_free_tfm(conn->tx_tfm);
if (conn->rx_tfm)
crypto_free_tfm(conn->rx_tfm);
if (conn->data_tx_tfm)
crypto_free_tfm(conn->data_tx_tfm);
if (conn->data_rx_tfm)
crypto_free_tfm(conn->data_rx_tfm);
}
/* free conn->data, size = MaxRecvDataSegmentLength */
if (conn->data_size <= PAGE_SIZE)
kfree(conn->data);
else
free_pages((unsigned long)conn->data,
get_order(conn->data_size));
spin_lock_bh(&session->lock);
__kfifo_put(session->mgmtpool.queue, (void*)&conn->login_mtask,
sizeof(void*));
list_del(&conn->item);
if (list_empty(&session->connections))
session->leadconn = NULL;
if (session->leadconn && session->leadconn == conn)
session->leadconn = container_of(session->connections.next,
struct iscsi_conn, item);
if (session->leadconn == NULL)
/* none connections exits.. reset sequencing */
session->cmdsn = session->max_cmdsn = session->exp_cmdsn = 1;
spin_unlock_bh(&session->lock);
kfifo_free(conn->xmitqueue);
kfifo_free(conn->writequeue);
kfifo_free(conn->immqueue);
kfifo_free(conn->mgmtqueue);
kfree(conn);
}
static int
iscsi_conn_bind(iscsi_sessionh_t sessionh, iscsi_connh_t connh,
uint32_t transport_fd, int is_leading)
{
struct iscsi_session *session = iscsi_ptr(sessionh);
struct iscsi_conn *tmp = ERR_PTR(-EEXIST), *conn = iscsi_ptr(connh);
struct sock *sk;
struct socket *sock;
int err;
/* lookup for existing socket */
sock = sockfd_lookup(transport_fd, &err);
if (!sock) {
printk(KERN_ERR "iscsi_tcp: sockfd_lookup failed %d\n", err);
return -EEXIST;
}
/* lookup for existing connection */
spin_lock_bh(&session->lock);
list_for_each_entry(tmp, &session->connections, item) {
if (tmp == conn) {
if (conn->c_stage != ISCSI_CONN_STOPPED ||
conn->stop_stage == STOP_CONN_TERM) {
printk(KERN_ERR "iscsi_tcp: can't bind "
"non-stopped connection (%d:%d)\n",
conn->c_stage, conn->stop_stage);
spin_unlock_bh(&session->lock);
return -EIO;
}
break;
}
}
if (tmp != conn) {
/* bind new iSCSI connection to session */
conn->session = session;
list_add(&conn->item, &session->connections);
}
spin_unlock_bh(&session->lock);
if (conn->stop_stage != STOP_CONN_SUSPEND) {
/* bind iSCSI connection and socket */
conn->sock = sock;
/* setup Socket parameters */
sk = sock->sk;
sk->sk_reuse = 1;
sk->sk_sndtimeo = 15 * HZ; /* FIXME: make it configurable */
sk->sk_allocation = GFP_ATOMIC;
/* FIXME: disable Nagle's algorithm */
/*
* Intercept TCP callbacks for sendfile like receive
* processing.
*/
iscsi_conn_set_callbacks(conn);
conn->sendpage = conn->sock->ops->sendpage;
/*
* set receive state machine into initial state
*/
conn->in_progress = IN_PROGRESS_WAIT_HEADER;
}
if (is_leading)
session->leadconn = conn;
/*
* Unblock xmitworker(), Login Phase will pass through.
*/
clear_bit(SUSPEND_BIT, &conn->suspend_rx);
clear_bit(SUSPEND_BIT, &conn->suspend_tx);
return 0;
}
static int
iscsi_conn_start(iscsi_connh_t connh)
{
struct iscsi_conn *conn = iscsi_ptr(connh);
struct iscsi_session *session = conn->session;
struct sock *sk;
/* FF phase warming up... */
if (session == NULL) {
printk(KERN_ERR "iscsi_tcp: can't start unbound connection\n");
return -EPERM;
}
sk = conn->sock->sk;
write_lock_bh(&sk->sk_callback_lock);
spin_lock_bh(&session->lock);
conn->c_stage = ISCSI_CONN_STARTED;
session->state = ISCSI_STATE_LOGGED_IN;
switch(conn->stop_stage) {
case STOP_CONN_RECOVER:
/*
* unblock eh_abort() if it is blocked. re-try all
* commands after successful recovery
*/
session->conn_cnt++;
conn->stop_stage = 0;
conn->tmabort_state = TMABORT_INITIAL;
session->age++;
wake_up(&conn->ehwait);
break;
case STOP_CONN_TERM:
session->conn_cnt++;
conn->stop_stage = 0;
break;
case STOP_CONN_SUSPEND:
conn->stop_stage = 0;
clear_bit(SUSPEND_BIT, &conn->suspend_rx);
clear_bit(SUSPEND_BIT, &conn->suspend_tx);
break;
default:
break;
}
spin_unlock_bh(&session->lock);
write_unlock_bh(&sk->sk_callback_lock);
return 0;
}
static void
iscsi_conn_stop(iscsi_connh_t connh, int flag)
{
struct iscsi_conn *conn = iscsi_ptr(connh);
struct iscsi_session *session = conn->session;
struct sock *sk;
unsigned long flags;
BUG_ON(!conn->sock);
sk = conn->sock->sk;
write_lock_bh(&sk->sk_callback_lock);
set_bit(SUSPEND_BIT, &conn->suspend_rx);
write_unlock_bh(&sk->sk_callback_lock);
mutex_lock(&conn->xmitmutex);
spin_lock_irqsave(session->host->host_lock, flags);
spin_lock(&session->lock);
conn->stop_stage = flag;
conn->c_stage = ISCSI_CONN_STOPPED;
set_bit(SUSPEND_BIT, &conn->suspend_tx);
if (flag != STOP_CONN_SUSPEND)
session->conn_cnt--;
if (session->conn_cnt == 0 || session->leadconn == conn)
session->state = ISCSI_STATE_FAILED;
spin_unlock(&session->lock);
spin_unlock_irqrestore(session->host->host_lock, flags);
if (flag == STOP_CONN_TERM || flag == STOP_CONN_RECOVER) {
struct iscsi_cmd_task *ctask;
struct iscsi_mgmt_task *mtask;
/*
* Socket must go now.
*/
sock_hold(conn->sock->sk);
iscsi_conn_restore_callbacks(conn);
sock_put(conn->sock->sk);
/*
* flush xmit queues.
*/
spin_lock_bh(&session->lock);
while (__kfifo_get(conn->writequeue, (void*)&ctask,
sizeof(void*)) ||
__kfifo_get(conn->xmitqueue, (void*)&ctask,
sizeof(void*))) {
struct iscsi_r2t_info *r2t;
/*
* flush ctask's r2t queues
*/
while (__kfifo_get(ctask->r2tqueue, (void*)&r2t,
sizeof(void*)))
__kfifo_put(ctask->r2tpool.queue, (void*)&r2t,
sizeof(void*));
spin_unlock_bh(&session->lock);
local_bh_disable();
iscsi_ctask_cleanup(conn, ctask);
local_bh_enable();
spin_lock_bh(&session->lock);
}
conn->ctask = NULL;
while (__kfifo_get(conn->immqueue, (void*)&mtask,
sizeof(void*)) ||
__kfifo_get(conn->mgmtqueue, (void*)&mtask,
sizeof(void*))) {
__kfifo_put(session->mgmtpool.queue,
(void*)&mtask, sizeof(void*));
}
conn->mtask = NULL;
spin_unlock_bh(&session->lock);
/*
* release socket only after we stopped data_xmit()
* activity and flushed all outstandings
*/
sock_release(conn->sock);
conn->sock = NULL;
/*
* for connection level recovery we should not calculate
* header digest. conn->hdr_size used for optimization
* in hdr_extract() and will be re-negotiated at
* set_param() time.
*/
if (flag == STOP_CONN_RECOVER) {
conn->hdr_size = sizeof(struct iscsi_hdr);
conn->hdrdgst_en = 0;
conn->datadgst_en = 0;
}
}
mutex_unlock(&conn->xmitmutex);
}
static int
iscsi_conn_send_generic(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
char *data, uint32_t data_size)
{
struct iscsi_session *session = conn->session;
struct iscsi_nopout *nop = (struct iscsi_nopout *)hdr;
struct iscsi_mgmt_task *mtask;
spin_lock_bh(&session->lock);
if (session->state == ISCSI_STATE_TERMINATE) {
spin_unlock_bh(&session->lock);
return -EPERM;
}
if (hdr->opcode == (ISCSI_OP_LOGIN | ISCSI_OP_IMMEDIATE) ||
hdr->opcode == (ISCSI_OP_TEXT | ISCSI_OP_IMMEDIATE))
/*
* Login and Text are sent serially, in
* request-followed-by-response sequence.
* Same mtask can be used. Same ITT must be used.
* Note that login_mtask is preallocated at conn_create().
*/
mtask = conn->login_mtask;
else {
BUG_ON(conn->c_stage == ISCSI_CONN_INITIAL_STAGE);
BUG_ON(conn->c_stage == ISCSI_CONN_STOPPED);
if (!__kfifo_get(session->mgmtpool.queue,
(void*)&mtask, sizeof(void*))) {
spin_unlock_bh(&session->lock);
return -ENOSPC;
}
}
/*
* pre-format CmdSN and ExpStatSN for outgoing PDU.
*/
if (hdr->itt != cpu_to_be32(ISCSI_RESERVED_TAG)) {
hdr->itt = mtask->itt | (conn->id << CID_SHIFT) |
(session->age << AGE_SHIFT);
nop->cmdsn = cpu_to_be32(session->cmdsn);
if (conn->c_stage == ISCSI_CONN_STARTED &&
!(hdr->opcode & ISCSI_OP_IMMEDIATE))
session->cmdsn++;
} else
/* do not advance CmdSN */
nop->cmdsn = cpu_to_be32(session->cmdsn);
nop->exp_statsn = cpu_to_be32(conn->exp_statsn);
memcpy(&mtask->hdr, hdr, sizeof(struct iscsi_hdr));
iscsi_buf_init_virt(&mtask->headbuf, (char*)&mtask->hdr,
sizeof(struct iscsi_hdr));
spin_unlock_bh(&session->lock);
if (data_size) {
memcpy(mtask->data, data, data_size);
mtask->data_count = data_size;
} else
mtask->data_count = 0;
mtask->xmstate = XMSTATE_IMM_HDR;
if (mtask->data_count) {
iscsi_buf_init_iov(&mtask->sendbuf, (char*)mtask->data,
mtask->data_count);
}
debug_scsi("mgmtpdu [op 0x%x hdr->itt 0x%x datalen %d]\n",
hdr->opcode, hdr->itt, data_size);
/*
* since send_pdu() could be called at least from two contexts,
* we need to serialize __kfifo_put, so we don't have to take
* additional lock on fast data-path
*/
if (hdr->opcode & ISCSI_OP_IMMEDIATE)
__kfifo_put(conn->immqueue, (void*)&mtask, sizeof(void*));
else
__kfifo_put(conn->mgmtqueue, (void*)&mtask, sizeof(void*));
schedule_work(&conn->xmitwork);
return 0;
}
static int
iscsi_eh_host_reset(struct scsi_cmnd *sc)
{
struct iscsi_cmd_task *ctask = (struct iscsi_cmd_task *)sc->SCp.ptr;
struct iscsi_conn *conn = ctask->conn;
struct iscsi_session *session = conn->session;
spin_lock_bh(&session->lock);
if (session->state == ISCSI_STATE_TERMINATE) {
debug_scsi("failing host reset: session terminated "
"[CID %d age %d]", conn->id, session->age);
spin_unlock_bh(&session->lock);
return FAILED;
}
spin_unlock_bh(&session->lock);
debug_scsi("failing connection CID %d due to SCSI host reset "
"[itt 0x%x age %d]", conn->id, ctask->itt,
session->age);
iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
return SUCCESS;
}
static void
iscsi_tmabort_timedout(unsigned long data)
{
struct iscsi_cmd_task *ctask = (struct iscsi_cmd_task *)data;
struct iscsi_conn *conn = ctask->conn;
struct iscsi_session *session = conn->session;
spin_lock(&session->lock);
if (conn->tmabort_state == TMABORT_INITIAL) {
__kfifo_put(session->mgmtpool.queue,
(void*)&ctask->mtask, sizeof(void*));
conn->tmabort_state = TMABORT_TIMEDOUT;
debug_scsi("tmabort timedout [sc %lx itt 0x%x]\n",
(long)ctask->sc, ctask->itt);
/* unblock eh_abort() */
wake_up(&conn->ehwait);
}
spin_unlock(&session->lock);
}
static int
iscsi_eh_abort(struct scsi_cmnd *sc)
{
int rc;
struct iscsi_cmd_task *ctask = (struct iscsi_cmd_task *)sc->SCp.ptr;
struct iscsi_conn *conn = ctask->conn;
struct iscsi_session *session = conn->session;
conn->eh_abort_cnt++;
debug_scsi("aborting [sc %lx itt 0x%x]\n", (long)sc, ctask->itt);
/*
* two cases for ERL=0 here:
*
* 1) connection-level failure;
* 2) recovery due protocol error;
*/
mutex_lock(&conn->xmitmutex);
spin_lock_bh(&session->lock);
if (session->state != ISCSI_STATE_LOGGED_IN) {
if (session->state == ISCSI_STATE_TERMINATE) {
spin_unlock_bh(&session->lock);
mutex_unlock(&conn->xmitmutex);
goto failed;
}
spin_unlock_bh(&session->lock);
} else {
struct iscsi_tm *hdr = &conn->tmhdr;
/*
* Still LOGGED_IN...
*/
if (!ctask->sc || sc->SCp.phase != session->age) {
/*
* 1) ctask completed before time out. But session
* is still ok => Happy Retry.
* 2) session was re-open during time out of ctask.
*/
spin_unlock_bh(&session->lock);
mutex_unlock(&conn->xmitmutex);
goto success;
}
conn->tmabort_state = TMABORT_INITIAL;
spin_unlock_bh(&session->lock);
/*
* ctask timed out but session is OK
* ERL=0 requires task mgmt abort to be issued on each
* failed command. requests must be serialized.
*/
memset(hdr, 0, sizeof(struct iscsi_tm));
hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
hdr->flags = ISCSI_TM_FUNC_ABORT_TASK;
hdr->flags |= ISCSI_FLAG_CMD_FINAL;
memcpy(hdr->lun, ctask->hdr.lun, sizeof(hdr->lun));
hdr->rtt = ctask->hdr.itt;
hdr->refcmdsn = ctask->hdr.cmdsn;
rc = iscsi_conn_send_generic(conn, (struct iscsi_hdr *)hdr,
NULL, 0);
if (rc) {
iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
debug_scsi("abort sent failure [itt 0x%x]", ctask->itt);
} else {
struct iscsi_r2t_info *r2t;
/*
* TMF abort vs. TMF response race logic
*/
spin_lock_bh(&session->lock);
ctask->mtask = (struct iscsi_mgmt_task *)
session->mgmt_cmds[(hdr->itt & ITT_MASK) -
ISCSI_MGMT_ITT_OFFSET];
/*
* have to flush r2tqueue to avoid r2t leaks
*/
while (__kfifo_get(ctask->r2tqueue, (void*)&r2t,
sizeof(void*))) {
__kfifo_put(ctask->r2tpool.queue, (void*)&r2t,
sizeof(void*));
}
if (conn->tmabort_state == TMABORT_INITIAL) {
conn->tmfcmd_pdus_cnt++;
conn->tmabort_timer.expires = 3*HZ + jiffies;
conn->tmabort_timer.function =
iscsi_tmabort_timedout;
conn->tmabort_timer.data = (unsigned long)ctask;
add_timer(&conn->tmabort_timer);
debug_scsi("abort sent [itt 0x%x]", ctask->itt);
} else {
if (!ctask->sc ||
conn->tmabort_state == TMABORT_SUCCESS) {
conn->tmabort_state = TMABORT_INITIAL;
spin_unlock_bh(&session->lock);
mutex_unlock(&conn->xmitmutex);
goto success;
}
conn->tmabort_state = TMABORT_INITIAL;
iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
}
spin_unlock_bh(&session->lock);
}
}
mutex_unlock(&conn->xmitmutex);
/*
* block eh thread until:
*
* 1) abort response;
* 2) abort timeout;
* 3) session re-opened;
* 4) session terminated;
*/
for (;;) {
int p_state = session->state;
rc = wait_event_interruptible(conn->ehwait,
(p_state == ISCSI_STATE_LOGGED_IN ?
(session->state == ISCSI_STATE_TERMINATE ||
conn->tmabort_state != TMABORT_INITIAL) :
(session->state == ISCSI_STATE_TERMINATE ||
session->state == ISCSI_STATE_LOGGED_IN)));
if (rc) {
/* shutdown.. */
session->state = ISCSI_STATE_TERMINATE;
goto failed;
}
if (signal_pending(current))
flush_signals(current);
if (session->state == ISCSI_STATE_TERMINATE)
goto failed;
spin_lock_bh(&session->lock);
if (sc->SCp.phase == session->age &&
(conn->tmabort_state == TMABORT_TIMEDOUT ||
conn->tmabort_state == TMABORT_FAILED)) {
conn->tmabort_state = TMABORT_INITIAL;
if (!ctask->sc) {
/*
* ctask completed before tmf abort response or
* time out.
* But session is still ok => Happy Retry.
*/
spin_unlock_bh(&session->lock);
break;
}
spin_unlock_bh(&session->lock);
iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
continue;
}
spin_unlock_bh(&session->lock);
break;
}
success:
debug_scsi("abort success [sc %lx itt 0x%x]\n", (long)sc, ctask->itt);
rc = SUCCESS;
goto exit;
failed:
debug_scsi("abort failed [sc %lx itt 0x%x]\n", (long)sc, ctask->itt);
rc = FAILED;
exit:
del_timer_sync(&conn->tmabort_timer);
mutex_lock(&conn->xmitmutex);
if (conn->sock) {
struct sock *sk = conn->sock->sk;
write_lock_bh(&sk->sk_callback_lock);
iscsi_ctask_cleanup(conn, ctask);
write_unlock_bh(&sk->sk_callback_lock);
}
mutex_unlock(&conn->xmitmutex);
return rc;
}
static int
iscsi_r2tpool_alloc(struct iscsi_session *session)
{
int i;
int cmd_i;
/*
* initialize per-task: R2T pool and xmit queue
*/
for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
struct iscsi_cmd_task *ctask = session->cmds[cmd_i];
/*
* pre-allocated x4 as much r2ts to handle race when
* target acks DataOut faster than we data_xmit() queues
* could replenish r2tqueue.
*/
/* R2T pool */
if (iscsi_pool_init(&ctask->r2tpool, session->max_r2t * 4,
(void***)&ctask->r2ts, sizeof(struct iscsi_r2t_info))) {
goto r2t_alloc_fail;
}
/* R2T xmit queue */
ctask->r2tqueue = kfifo_alloc(
session->max_r2t * 4 * sizeof(void*), GFP_KERNEL, NULL);
if (ctask->r2tqueue == ERR_PTR(-ENOMEM)) {
iscsi_pool_free(&ctask->r2tpool, (void**)ctask->r2ts);
goto r2t_alloc_fail;
}
/*
* number of
* Data-Out PDU's within R2T-sequence can be quite big;
* using mempool
*/
ctask->datapool = mempool_create(ISCSI_DTASK_DEFAULT_MAX,
mempool_alloc_slab, mempool_free_slab, taskcache);
if (ctask->datapool == NULL) {
kfifo_free(ctask->r2tqueue);
iscsi_pool_free(&ctask->r2tpool, (void**)ctask->r2ts);
goto r2t_alloc_fail;
}
INIT_LIST_HEAD(&ctask->dataqueue);
}
return 0;
r2t_alloc_fail:
for (i = 0; i < cmd_i; i++) {
mempool_destroy(session->cmds[i]->datapool);
kfifo_free(session->cmds[i]->r2tqueue);
iscsi_pool_free(&session->cmds[i]->r2tpool,
(void**)session->cmds[i]->r2ts);
}
return -ENOMEM;
}
static void
iscsi_r2tpool_free(struct iscsi_session *session)
{
int i;
for (i = 0; i < session->cmds_max; i++) {
mempool_destroy(session->cmds[i]->datapool);
kfifo_free(session->cmds[i]->r2tqueue);
iscsi_pool_free(&session->cmds[i]->r2tpool,
(void**)session->cmds[i]->r2ts);
}
}
static struct scsi_host_template iscsi_sht = {
.name = "iSCSI Initiator over TCP/IP, v."
ISCSI_VERSION_STR,
.queuecommand = iscsi_queuecommand,
.change_queue_depth = iscsi_change_queue_depth,
.can_queue = ISCSI_XMIT_CMDS_MAX - 1,
.sg_tablesize = ISCSI_SG_TABLESIZE,
.cmd_per_lun = ISCSI_DEF_CMD_PER_LUN,
.eh_abort_handler = iscsi_eh_abort,
.eh_host_reset_handler = iscsi_eh_host_reset,
.use_clustering = DISABLE_CLUSTERING,
.proc_name = "iscsi_tcp",
.this_id = -1,
};
static iscsi_sessionh_t
iscsi_session_create(uint32_t initial_cmdsn, struct Scsi_Host *host)
{
int cmd_i;
struct iscsi_session *session;
session = iscsi_hostdata(host->hostdata);
memset(session, 0, sizeof(struct iscsi_session));
session->host = host;
session->id = host->host_no;
session->state = ISCSI_STATE_LOGGED_IN;
session->mgmtpool_max = ISCSI_MGMT_CMDS_MAX;
session->cmds_max = ISCSI_XMIT_CMDS_MAX;
session->cmdsn = initial_cmdsn;
session->exp_cmdsn = initial_cmdsn + 1;
session->max_cmdsn = initial_cmdsn + 1;
session->max_r2t = 1;
/* initialize SCSI PDU commands pool */
if (iscsi_pool_init(&session->cmdpool, session->cmds_max,
(void***)&session->cmds, sizeof(struct iscsi_cmd_task)))
goto cmdpool_alloc_fail;
/* pre-format cmds pool with ITT */
for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++)
session->cmds[cmd_i]->itt = cmd_i;
spin_lock_init(&session->lock);
INIT_LIST_HEAD(&session->connections);
/* initialize immediate command pool */
if (iscsi_pool_init(&session->mgmtpool, session->mgmtpool_max,
(void***)&session->mgmt_cmds, sizeof(struct iscsi_mgmt_task)))
goto mgmtpool_alloc_fail;
/* pre-format immediate cmds pool with ITT */
for (cmd_i = 0; cmd_i < session->mgmtpool_max; cmd_i++) {
session->mgmt_cmds[cmd_i]->itt = ISCSI_MGMT_ITT_OFFSET + cmd_i;
session->mgmt_cmds[cmd_i]->data = kmalloc(
DEFAULT_MAX_RECV_DATA_SEGMENT_LENGTH, GFP_KERNEL);
if (!session->mgmt_cmds[cmd_i]->data) {
int j;
for (j = 0; j < cmd_i; j++)
kfree(session->mgmt_cmds[j]->data);
goto immdata_alloc_fail;
}
}
if (iscsi_r2tpool_alloc(session))
goto r2tpool_alloc_fail;
return iscsi_handle(session);
r2tpool_alloc_fail:
for (cmd_i = 0; cmd_i < session->mgmtpool_max; cmd_i++)
kfree(session->mgmt_cmds[cmd_i]->data);
iscsi_pool_free(&session->mgmtpool, (void**)session->mgmt_cmds);
immdata_alloc_fail:
mgmtpool_alloc_fail:
iscsi_pool_free(&session->cmdpool, (void**)session->cmds);
cmdpool_alloc_fail:
return iscsi_handle(NULL);
}
static void
iscsi_session_destroy(iscsi_sessionh_t sessionh)
{
int cmd_i;
struct iscsi_data_task *dtask, *n;
struct iscsi_session *session = iscsi_ptr(sessionh);
for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
struct iscsi_cmd_task *ctask = session->cmds[cmd_i];
list_for_each_entry_safe(dtask, n, &ctask->dataqueue, item) {
list_del(&dtask->item);
mempool_free(dtask, ctask->datapool);
}
}
for (cmd_i = 0; cmd_i < session->mgmtpool_max; cmd_i++)
kfree(session->mgmt_cmds[cmd_i]->data);
iscsi_r2tpool_free(session);
iscsi_pool_free(&session->mgmtpool, (void**)session->mgmt_cmds);
iscsi_pool_free(&session->cmdpool, (void**)session->cmds);
}
static int
iscsi_conn_set_param(iscsi_connh_t connh, enum iscsi_param param,
uint32_t value)
{
struct iscsi_conn *conn = iscsi_ptr(connh);
struct iscsi_session *session = conn->session;
spin_lock_bh(&session->lock);
if (conn->c_stage != ISCSI_CONN_INITIAL_STAGE &&
conn->stop_stage != STOP_CONN_RECOVER) {
printk(KERN_ERR "iscsi_tcp: can not change parameter [%d]\n",
param);
spin_unlock_bh(&session->lock);
return 0;
}
spin_unlock_bh(&session->lock);
switch(param) {
case ISCSI_PARAM_MAX_RECV_DLENGTH: {
char *saveptr = conn->data;
gfp_t flags = GFP_KERNEL;
if (conn->data_size >= value) {
conn->max_recv_dlength = value;
break;
}
spin_lock_bh(&session->lock);
if (conn->stop_stage == STOP_CONN_RECOVER)
flags = GFP_ATOMIC;
spin_unlock_bh(&session->lock);
if (value <= PAGE_SIZE)
conn->data = kmalloc(value, flags);
else
conn->data = (void*)__get_free_pages(flags,
get_order(value));
if (conn->data == NULL) {
conn->data = saveptr;
return -ENOMEM;
}
if (conn->data_size <= PAGE_SIZE)
kfree(saveptr);
else
free_pages((unsigned long)saveptr,
get_order(conn->data_size));
conn->max_recv_dlength = value;
conn->data_size = value;
}
break;
case ISCSI_PARAM_MAX_XMIT_DLENGTH:
conn->max_xmit_dlength = value;
break;
case ISCSI_PARAM_HDRDGST_EN:
conn->hdrdgst_en = value;
conn->hdr_size = sizeof(struct iscsi_hdr);
if (conn->hdrdgst_en) {
conn->hdr_size += sizeof(__u32);
if (!conn->tx_tfm)
conn->tx_tfm = crypto_alloc_tfm("crc32c", 0);
if (!conn->tx_tfm)
return -ENOMEM;
if (!conn->rx_tfm)
conn->rx_tfm = crypto_alloc_tfm("crc32c", 0);
if (!conn->rx_tfm) {
crypto_free_tfm(conn->tx_tfm);
return -ENOMEM;
}
} else {
if (conn->tx_tfm)
crypto_free_tfm(conn->tx_tfm);
if (conn->rx_tfm)
crypto_free_tfm(conn->rx_tfm);
}
break;
case ISCSI_PARAM_DATADGST_EN:
conn->datadgst_en = value;
if (conn->datadgst_en) {
if (!conn->data_tx_tfm)
conn->data_tx_tfm =
crypto_alloc_tfm("crc32c", 0);
if (!conn->data_tx_tfm)
return -ENOMEM;
if (!conn->data_rx_tfm)
conn->data_rx_tfm =
crypto_alloc_tfm("crc32c", 0);
if (!conn->data_rx_tfm) {
crypto_free_tfm(conn->data_tx_tfm);
return -ENOMEM;
}
} else {
if (conn->data_tx_tfm)
crypto_free_tfm(conn->data_tx_tfm);
if (conn->data_rx_tfm)
crypto_free_tfm(conn->data_rx_tfm);
}
conn->sendpage = conn->datadgst_en ?
sock_no_sendpage : conn->sock->ops->sendpage;
break;
case ISCSI_PARAM_INITIAL_R2T_EN:
session->initial_r2t_en = value;
break;
case ISCSI_PARAM_MAX_R2T:
if (session->max_r2t == roundup_pow_of_two(value))
break;
iscsi_r2tpool_free(session);
session->max_r2t = value;
if (session->max_r2t & (session->max_r2t - 1))
session->max_r2t = roundup_pow_of_two(session->max_r2t);
if (iscsi_r2tpool_alloc(session))
return -ENOMEM;
break;
case ISCSI_PARAM_IMM_DATA_EN:
session->imm_data_en = value;
break;
case ISCSI_PARAM_FIRST_BURST:
session->first_burst = value;
break;
case ISCSI_PARAM_MAX_BURST:
session->max_burst = value;
break;
case ISCSI_PARAM_PDU_INORDER_EN:
session->pdu_inorder_en = value;
break;
case ISCSI_PARAM_DATASEQ_INORDER_EN:
session->dataseq_inorder_en = value;
break;
case ISCSI_PARAM_ERL:
session->erl = value;
break;
case ISCSI_PARAM_IFMARKER_EN:
BUG_ON(value);
session->ifmarker_en = value;
break;
case ISCSI_PARAM_OFMARKER_EN:
BUG_ON(value);
session->ofmarker_en = value;
break;
default:
break;
}
return 0;
}
static int
iscsi_conn_get_param(iscsi_connh_t connh, enum iscsi_param param,
uint32_t *value)
{
struct iscsi_conn *conn = iscsi_ptr(connh);
struct iscsi_session *session = conn->session;
switch(param) {
case ISCSI_PARAM_MAX_RECV_DLENGTH:
*value = conn->max_recv_dlength;
break;
case ISCSI_PARAM_MAX_XMIT_DLENGTH:
*value = conn->max_xmit_dlength;
break;
case ISCSI_PARAM_HDRDGST_EN:
*value = conn->hdrdgst_en;
break;
case ISCSI_PARAM_DATADGST_EN:
*value = conn->datadgst_en;
break;
case ISCSI_PARAM_INITIAL_R2T_EN:
*value = session->initial_r2t_en;
break;
case ISCSI_PARAM_MAX_R2T:
*value = session->max_r2t;
break;
case ISCSI_PARAM_IMM_DATA_EN:
*value = session->imm_data_en;
break;
case ISCSI_PARAM_FIRST_BURST:
*value = session->first_burst;
break;
case ISCSI_PARAM_MAX_BURST:
*value = session->max_burst;
break;
case ISCSI_PARAM_PDU_INORDER_EN:
*value = session->pdu_inorder_en;
break;
case ISCSI_PARAM_DATASEQ_INORDER_EN:
*value = session->dataseq_inorder_en;
break;
case ISCSI_PARAM_ERL:
*value = session->erl;
break;
case ISCSI_PARAM_IFMARKER_EN:
*value = session->ifmarker_en;
break;
case ISCSI_PARAM_OFMARKER_EN:
*value = session->ofmarker_en;
break;
default:
return ISCSI_ERR_PARAM_NOT_FOUND;
}
return 0;
}
static void
iscsi_conn_get_stats(iscsi_connh_t connh, struct iscsi_stats *stats)
{
struct iscsi_conn *conn = iscsi_ptr(connh);
stats->txdata_octets = conn->txdata_octets;
stats->rxdata_octets = conn->rxdata_octets;
stats->scsicmd_pdus = conn->scsicmd_pdus_cnt;
stats->dataout_pdus = conn->dataout_pdus_cnt;
stats->scsirsp_pdus = conn->scsirsp_pdus_cnt;
stats->datain_pdus = conn->datain_pdus_cnt;
stats->r2t_pdus = conn->r2t_pdus_cnt;
stats->tmfcmd_pdus = conn->tmfcmd_pdus_cnt;
stats->tmfrsp_pdus = conn->tmfrsp_pdus_cnt;
stats->custom_length = 3;
strcpy(stats->custom[0].desc, "tx_sendpage_failures");
stats->custom[0].value = conn->sendpage_failures_cnt;
strcpy(stats->custom[1].desc, "rx_discontiguous_hdr");
stats->custom[1].value = conn->discontiguous_hdr_cnt;
strcpy(stats->custom[2].desc, "eh_abort_cnt");
stats->custom[2].value = conn->eh_abort_cnt;
}
static int
iscsi_conn_send_pdu(iscsi_connh_t connh, struct iscsi_hdr *hdr, char *data,
uint32_t data_size)
{
struct iscsi_conn *conn = iscsi_ptr(connh);
int rc;
mutex_lock(&conn->xmitmutex);
rc = iscsi_conn_send_generic(conn, hdr, data, data_size);
mutex_unlock(&conn->xmitmutex);
return rc;
}
static struct iscsi_transport iscsi_tcp_transport = {
.owner = THIS_MODULE,
.name = "tcp",
.caps = CAP_RECOVERY_L0 | CAP_MULTI_R2T | CAP_HDRDGST
| CAP_DATADGST,
.host_template = &iscsi_sht,
.hostdata_size = sizeof(struct iscsi_session),
.max_conn = 1,
.max_cmd_len = ISCSI_TCP_MAX_CMD_LEN,
.create_session = iscsi_session_create,
.destroy_session = iscsi_session_destroy,
.create_conn = iscsi_conn_create,
.bind_conn = iscsi_conn_bind,
.destroy_conn = iscsi_conn_destroy,
.set_param = iscsi_conn_set_param,
.get_param = iscsi_conn_get_param,
.start_conn = iscsi_conn_start,
.stop_conn = iscsi_conn_stop,
.send_pdu = iscsi_conn_send_pdu,
.get_stats = iscsi_conn_get_stats,
};
static int __init
iscsi_tcp_init(void)
{
int error;
if (iscsi_max_lun < 1) {
printk(KERN_ERR "Invalid max_lun value of %u\n", iscsi_max_lun);
return -EINVAL;
}
iscsi_tcp_transport.max_lun = iscsi_max_lun;
taskcache = kmem_cache_create("iscsi_taskcache",
sizeof(struct iscsi_data_task), 0,
SLAB_HWCACHE_ALIGN | SLAB_NO_REAP, NULL, NULL);
if (!taskcache)
return -ENOMEM;
error = iscsi_register_transport(&iscsi_tcp_transport);
if (error)
kmem_cache_destroy(taskcache);
return error;
}
static void __exit
iscsi_tcp_exit(void)
{
iscsi_unregister_transport(&iscsi_tcp_transport);
kmem_cache_destroy(taskcache);
}
module_init(iscsi_tcp_init);
module_exit(iscsi_tcp_exit);
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