err.no Git - linux-2.6/blob - drivers/scsi/iscsi_tcp.c

   1 /*
   2  * iSCSI Initiator over TCP/IP Data-Path
   3  *
   4  * Copyright (C) 2004 Dmitry Yusupov
   5  * Copyright (C) 2004 Alex Aizman
   6  * Copyright (C) 2005 Mike Christie
   7  * maintained by open-iscsi@googlegroups.com
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published
  11  * by the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful, but
  15  * WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  17  * General Public License for more details.
  18  *
  19  * See the file COPYING included with this distribution for more details.
  20  *
  21  * Credits:
  22  *      Christoph Hellwig
  23  *      FUJITA Tomonori
  24  *      Arne Redlich
  25  *      Zhenyu Wang
  26  */
  27
  28 #include <linux/types.h>
  29 #include <linux/list.h>
  30 #include <linux/inet.h>
  31 #include <linux/blkdev.h>
  32 #include <linux/crypto.h>
  33 #include <linux/delay.h>
  34 #include <linux/kfifo.h>
  35 #include <linux/scatterlist.h>
  36 #include <net/tcp.h>
  37 #include <scsi/scsi_cmnd.h>
  38 #include <scsi/scsi_device.h>
  39 #include <scsi/scsi_eh.h>
  40 #include <scsi/scsi_request.h>
  41 #include <scsi/scsi_tcq.h>
  42 #include <scsi/scsi_host.h>
  43 #include <scsi/scsi.h>
  44 #include <scsi/scsi_transport_iscsi.h>
  45
  46 #include "iscsi_tcp.h"
  47
  48 MODULE_AUTHOR("Dmitry Yusupov <dmitry_yus@yahoo.com>, "
  49               "Alex Aizman <itn780@yahoo.com>");
  50 MODULE_DESCRIPTION("iSCSI/TCP data-path");
  51 MODULE_LICENSE("GPL");
  52 MODULE_VERSION("0:4.409");
  53 /* #define DEBUG_TCP */
  54 /* #define DEBUG_SCSI */
  55 #define DEBUG_ASSERT
  56
  57 #ifdef DEBUG_TCP
  58 #define debug_tcp(fmt...) printk(KERN_DEBUG "tcp: " fmt)
  59 #else
  60 #define debug_tcp(fmt...)
  61 #endif
  62
  63 #ifdef DEBUG_SCSI
  64 #define debug_scsi(fmt...) printk(KERN_DEBUG "scsi: " fmt)
  65 #else
  66 #define debug_scsi(fmt...)
  67 #endif
  68
  69 #ifndef DEBUG_ASSERT
  70 #ifdef BUG_ON
  71 #undef BUG_ON
  72 #endif
  73 #define BUG_ON(expr)
  74 #endif
  75
  76 #define INVALID_SN_DELTA        0xffff
  77
  78 static unsigned int iscsi_max_lun = 512;
  79 module_param_named(max_lun, iscsi_max_lun, uint, S_IRUGO);
  80
  81 /* global data */
  82 static kmem_cache_t *taskcache;
  83
  84 static inline void
  85 iscsi_buf_init_virt(struct iscsi_buf *ibuf, char *vbuf, int size)
  86 {
  87         sg_init_one(&ibuf->sg, (u8 *)vbuf, size);
  88         ibuf->sent = 0;
  89 }
  90
  91 static inline void
  92 iscsi_buf_init_iov(struct iscsi_buf *ibuf, char *vbuf, int size)
  93 {
  94         ibuf->sg.page = (void*)vbuf;
  95         ibuf->sg.offset = (unsigned int)-1;
  96         ibuf->sg.length = size;
  97         ibuf->sent = 0;
  98 }
  99
 100 static inline void*
 101 iscsi_buf_iov_base(struct iscsi_buf *ibuf)
 102 {
 103         return (char*)ibuf->sg.page + ibuf->sent;
 104 }
 105
 106 static inline void
 107 iscsi_buf_init_sg(struct iscsi_buf *ibuf, struct scatterlist *sg)
 108 {
 109         /*
 110          * Fastpath: sg element fits into single page
 111          */
 112         if (sg->length + sg->offset <= PAGE_SIZE && page_count(sg->page) >= 2) {
 113                 ibuf->sg.page = sg->page;
 114                 ibuf->sg.offset = sg->offset;
 115                 ibuf->sg.length = sg->length;
 116         } else
 117                 iscsi_buf_init_iov(ibuf, page_address(sg->page), sg->length);
 118         ibuf->sent = 0;
 119 }
 120
 121 static inline int
 122 iscsi_buf_left(struct iscsi_buf *ibuf)
 123 {
 124         int rc;
 125
 126         rc = ibuf->sg.length - ibuf->sent;
 127         BUG_ON(rc < 0);
 128         return rc;
 129 }
 130
 131 static inline void
 132 iscsi_hdr_digest(struct iscsi_conn *conn, struct iscsi_buf *buf,
 133                  u8* crc)
 134 {
 135         crypto_digest_digest(conn->tx_tfm, &buf->sg, 1, crc);
 136         buf->sg.length += sizeof(uint32_t);
 137 }
 138
 139 static void
 140 iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err)
 141 {
 142         struct iscsi_session *session = conn->session;
 143         unsigned long flags;
 144
 145         spin_lock_irqsave(&session->lock, flags);
 146         if (session->conn_cnt == 1 || session->leadconn == conn)
 147                 session->state = ISCSI_STATE_FAILED;
 148         spin_unlock_irqrestore(&session->lock, flags);
 149         set_bit(SUSPEND_BIT, &conn->suspend_tx);
 150         set_bit(SUSPEND_BIT, &conn->suspend_rx);
 151         iscsi_conn_error(iscsi_handle(conn), err);
 152 }
 153
 154 static inline int
 155 iscsi_check_assign_cmdsn(struct iscsi_session *session, struct iscsi_nopin *hdr)
 156 {
 157         uint32_t max_cmdsn = be32_to_cpu(hdr->max_cmdsn);
 158         uint32_t exp_cmdsn = be32_to_cpu(hdr->exp_cmdsn);
 159
 160         if (max_cmdsn < exp_cmdsn -1 &&
 161             max_cmdsn > exp_cmdsn - INVALID_SN_DELTA)
 162                 return ISCSI_ERR_MAX_CMDSN;
 163         if (max_cmdsn > session->max_cmdsn ||
 164             max_cmdsn < session->max_cmdsn - INVALID_SN_DELTA)
 165                 session->max_cmdsn = max_cmdsn;
 166         if (exp_cmdsn > session->exp_cmdsn ||
 167             exp_cmdsn < session->exp_cmdsn - INVALID_SN_DELTA)
 168                 session->exp_cmdsn = exp_cmdsn;
 169
 170         return 0;
 171 }
 172
 173 static inline int
 174 iscsi_hdr_extract(struct iscsi_conn *conn)
 175 {
 176         struct sk_buff *skb = conn->in.skb;
 177
 178         if (conn->in.copy >= conn->hdr_size &&
 179             conn->in_progress == IN_PROGRESS_WAIT_HEADER) {
 180                 /*
 181                  * Zero-copy PDU Header: using connection context
 182                  * to store header pointer.
 183                  */
 184                 if (skb_shinfo(skb)->frag_list == NULL &&
 185                     !skb_shinfo(skb)->nr_frags)
 186                         conn->in.hdr = (struct iscsi_hdr *)
 187                                 ((char*)skb->data + conn->in.offset);
 188                 else {
 189                         /* ignoring return code since we checked
 190                          * in.copy before */
 191                         skb_copy_bits(skb, conn->in.offset,
 192                                 &conn->hdr, conn->hdr_size);
 193                         conn->in.hdr = &conn->hdr;
 194                 }
 195                 conn->in.offset += conn->hdr_size;
 196                 conn->in.copy -= conn->hdr_size;
 197         } else {
 198                 int hdr_remains;
 199                 int copylen;
 200
 201                 /*
 202                  * PDU header scattered across SKB's,
 203                  * copying it... This'll happen quite rarely.
 204                  */
 205
 206                 if (conn->in_progress == IN_PROGRESS_WAIT_HEADER)
 207                         conn->in.hdr_offset = 0;
 208
 209                 hdr_remains = conn->hdr_size - conn->in.hdr_offset;
 210                 BUG_ON(hdr_remains <= 0);
 211
 212                 copylen = min(conn->in.copy, hdr_remains);
 213                 skb_copy_bits(skb, conn->in.offset,
 214                         (char*)&conn->hdr + conn->in.hdr_offset, copylen);
 215
 216                 debug_tcp("PDU gather offset %d bytes %d in.offset %d "
 217                        "in.copy %d\n", conn->in.hdr_offset, copylen,
 218                        conn->in.offset, conn->in.copy);
 219
 220                 conn->in.offset += copylen;
 221                 conn->in.copy -= copylen;
 222                 if (copylen < hdr_remains)  {
 223                         conn->in_progress = IN_PROGRESS_HEADER_GATHER;
 224                         conn->in.hdr_offset += copylen;
 225                         return -EAGAIN;
 226                 }
 227                 conn->in.hdr = &conn->hdr;
 228                 conn->discontiguous_hdr_cnt++;
 229                 conn->in_progress = IN_PROGRESS_WAIT_HEADER;
 230         }
 231
 232         return 0;
 233 }
 234
 235 static inline void
 236 iscsi_ctask_cleanup(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
 237 {
 238         struct scsi_cmnd *sc = ctask->sc;
 239         struct iscsi_session *session = conn->session;
 240
 241         spin_lock(&session->lock);
 242         if (unlikely(!sc)) {
 243                 spin_unlock(&session->lock);
 244                 return;
 245         }
 246         if (sc->sc_data_direction == DMA_TO_DEVICE) {
 247                 struct iscsi_data_task *dtask, *n;
 248                 /* WRITE: cleanup Data-Out's if any */
 249                 spin_lock(&conn->lock);
 250                 list_for_each_entry_safe(dtask, n, &ctask->dataqueue, item) {
 251                         list_del(&dtask->item);
 252                         mempool_free(dtask, ctask->datapool);
 253                 }
 254                 spin_unlock(&conn->lock);
 255         }
 256         ctask->xmstate = XMSTATE_IDLE;
 257         ctask->r2t = NULL;
 258         ctask->sc = NULL;
 259         __kfifo_put(session->cmdpool.queue, (void*)&ctask, sizeof(void*));
 260         spin_unlock(&session->lock);
 261 }
 262
 263 /**
 264  * iscsi_cmd_rsp - SCSI Command Response processing
 265  * @conn: iscsi connection
 266  * @ctask: scsi command task
 267  **/
 268 static int
 269 iscsi_cmd_rsp(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
 270 {
 271         int rc;
 272         struct iscsi_cmd_rsp *rhdr = (struct iscsi_cmd_rsp *)conn->in.hdr;
 273         struct iscsi_session *session = conn->session;
 274         struct scsi_cmnd *sc = ctask->sc;
 275
 276         rc = iscsi_check_assign_cmdsn(session, (struct iscsi_nopin*)rhdr);
 277         if (rc) {
 278                 sc->result = (DID_ERROR << 16);
 279                 goto out;
 280         }
 281
 282         conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
 283
 284         sc->result = (DID_OK << 16) | rhdr->cmd_status;
 285
 286         if (rhdr->response != ISCSI_STATUS_CMD_COMPLETED) {
 287                 sc->result = (DID_ERROR << 16);
 288                 goto out;
 289         }
 290
 291         if (rhdr->cmd_status == SAM_STAT_CHECK_CONDITION && conn->senselen) {
 292                 int sensecopy = min(conn->senselen, SCSI_SENSE_BUFFERSIZE);
 293
 294                 memcpy(sc->sense_buffer, conn->data + 2, sensecopy);
 295                 debug_scsi("copied %d bytes of sense\n", sensecopy);
 296         }
 297
 298         if (sc->sc_data_direction == DMA_TO_DEVICE)
 299                 goto out;
 300
 301         if (rhdr->flags & ISCSI_FLAG_CMD_UNDERFLOW) {
 302                 int res_count = be32_to_cpu(rhdr->residual_count);
 303
 304                 if (res_count > 0 && res_count <= sc->request_bufflen)
 305                         sc->resid = res_count;
 306                 else
 307                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 308         } else if (rhdr->flags & ISCSI_FLAG_CMD_BIDI_UNDERFLOW)
 309                 sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 310         else if (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW)
 311                 sc->resid = be32_to_cpu(rhdr->residual_count);
 312
 313 out:
 314         debug_scsi("done [sc %lx res %d itt 0x%x]\n",
 315                    (long)sc, sc->result, ctask->itt);
 316         conn->scsirsp_pdus_cnt++;
 317         iscsi_ctask_cleanup(conn, ctask);
 318         sc->scsi_done(sc);
 319         return rc;
 320 }
 321
 322 /**
 323  * iscsi_data_rsp - SCSI Data-In Response processing
 324  * @conn: iscsi connection
 325  * @ctask: scsi command task
 326  **/
 327 static int
 328 iscsi_data_rsp(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
 329 {
 330         int rc;
 331         struct iscsi_data_rsp *rhdr = (struct iscsi_data_rsp *)conn->in.hdr;
 332         struct iscsi_session *session = conn->session;
 333         int datasn = be32_to_cpu(rhdr->datasn);
 334
 335         rc = iscsi_check_assign_cmdsn(session, (struct iscsi_nopin*)rhdr);
 336         if (rc)
 337                 return rc;
 338         /*
 339          * setup Data-In byte counter (gets decremented..)
 340          */
 341         ctask->data_count = conn->in.datalen;
 342
 343         if (conn->in.datalen == 0)
 344                 return 0;
 345
 346         if (ctask->datasn != datasn)
 347                 return ISCSI_ERR_DATASN;
 348
 349         ctask->datasn++;
 350
 351         ctask->data_offset = be32_to_cpu(rhdr->offset);
 352         if (ctask->data_offset + conn->in.datalen > ctask->total_length)
 353                 return ISCSI_ERR_DATA_OFFSET;
 354
 355         if (rhdr->flags & ISCSI_FLAG_DATA_STATUS) {
 356                 struct scsi_cmnd *sc = ctask->sc;
 357
 358                 conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
 359                 if (rhdr->flags & ISCSI_FLAG_CMD_UNDERFLOW) {
 360                         int res_count = be32_to_cpu(rhdr->residual_count);
 361
 362                         if (res_count > 0 &&
 363                             res_count <= sc->request_bufflen) {
 364                                 sc->resid = res_count;
 365                                 sc->result = (DID_OK << 16) | rhdr->cmd_status;
 366                         } else
 367                                 sc->result = (DID_BAD_TARGET << 16) |
 368                                         rhdr->cmd_status;
 369                 } else if (rhdr->flags & ISCSI_FLAG_CMD_BIDI_UNDERFLOW)
 370                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 371                 else if (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW) {
 372                         sc->resid = be32_to_cpu(rhdr->residual_count);
 373                         sc->result = (DID_OK << 16) | rhdr->cmd_status;
 374                 } else
 375                         sc->result = (DID_OK << 16) | rhdr->cmd_status;
 376         }
 377
 378         conn->datain_pdus_cnt++;
 379         return 0;
 380 }
 381
 382 /**
 383  * iscsi_solicit_data_init - initialize first Data-Out
 384  * @conn: iscsi connection
 385  * @ctask: scsi command task
 386  * @r2t: R2T info
 387  *
 388  * Notes:
 389  *      Initialize first Data-Out within this R2T sequence and finds
 390  *      proper data_offset within this SCSI command.
 391  *
 392  *      This function is called with connection lock taken.
 393  **/
 394 static void
 395 iscsi_solicit_data_init(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
 396                         struct iscsi_r2t_info *r2t)
 397 {
 398         struct iscsi_data *hdr;
 399         struct iscsi_data_task *dtask;
 400         struct scsi_cmnd *sc = ctask->sc;
 401
 402         dtask = mempool_alloc(ctask->datapool, GFP_ATOMIC);
 403         BUG_ON(!dtask);
 404         hdr = &dtask->hdr;
 405         memset(hdr, 0, sizeof(struct iscsi_data));
 406         hdr->ttt = r2t->ttt;
 407         hdr->datasn = cpu_to_be32(r2t->solicit_datasn);
 408         r2t->solicit_datasn++;
 409         hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
 410         memcpy(hdr->lun, ctask->hdr.lun, sizeof(hdr->lun));
 411         hdr->itt = ctask->hdr.itt;
 412         hdr->exp_statsn = r2t->exp_statsn;
 413         hdr->offset = cpu_to_be32(r2t->data_offset);
 414         if (r2t->data_length > conn->max_xmit_dlength) {
 415                 hton24(hdr->dlength, conn->max_xmit_dlength);
 416                 r2t->data_count = conn->max_xmit_dlength;
 417                 hdr->flags = 0;
 418         } else {
 419                 hton24(hdr->dlength, r2t->data_length);
 420                 r2t->data_count = r2t->data_length;
 421                 hdr->flags = ISCSI_FLAG_CMD_FINAL;
 422         }
 423         conn->dataout_pdus_cnt++;
 424
 425         r2t->sent = 0;
 426
 427         iscsi_buf_init_virt(&r2t->headbuf, (char*)hdr,
 428                            sizeof(struct iscsi_hdr));
 429
 430         r2t->dtask = dtask;
 431
 432         if (sc->use_sg) {
 433                 int i, sg_count = 0;
 434                 struct scatterlist *sg = sc->request_buffer;
 435
 436                 r2t->sg = NULL;
 437                 for (i = 0; i < sc->use_sg; i++, sg += 1) {
 438                         /* FIXME: prefetch ? */
 439                         if (sg_count + sg->length > r2t->data_offset) {
 440                                 int page_offset;
 441
 442                                 /* sg page found! */
 443
 444                                 /* offset within this page */
 445                                 page_offset = r2t->data_offset - sg_count;
 446
 447                                 /* fill in this buffer */
 448                                 iscsi_buf_init_sg(&r2t->sendbuf, sg);
 449                                 r2t->sendbuf.sg.offset += page_offset;
 450                                 r2t->sendbuf.sg.length -= page_offset;
 451
 452                                 /* xmit logic will continue with next one */
 453                                 r2t->sg = sg + 1;
 454                                 break;
 455                         }
 456                         sg_count += sg->length;
 457                 }
 458                 BUG_ON(r2t->sg == NULL);
 459         } else
 460                 iscsi_buf_init_iov(&ctask->sendbuf,
 461                             (char*)sc->request_buffer + r2t->data_offset,
 462                             r2t->data_count);
 463
 464         list_add(&dtask->item, &ctask->dataqueue);
 465 }
 466
 467 /**
 468  * iscsi_r2t_rsp - iSCSI R2T Response processing
 469  * @conn: iscsi connection
 470  * @ctask: scsi command task
 471  **/
 472 static int
 473 iscsi_r2t_rsp(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
 474 {
 475         struct iscsi_r2t_info *r2t;
 476         struct iscsi_session *session = conn->session;
 477         struct iscsi_r2t_rsp *rhdr = (struct iscsi_r2t_rsp *)conn->in.hdr;
 478         int r2tsn = be32_to_cpu(rhdr->r2tsn);
 479         int rc;
 480
 481         if (conn->in.ahslen)
 482                 return ISCSI_ERR_AHSLEN;
 483
 484         if (conn->in.datalen)
 485                 return ISCSI_ERR_DATALEN;
 486
 487         if (ctask->exp_r2tsn && ctask->exp_r2tsn != r2tsn)
 488                 return ISCSI_ERR_R2TSN;
 489
 490         rc = iscsi_check_assign_cmdsn(session, (struct iscsi_nopin*)rhdr);
 491         if (rc)
 492                 return rc;
 493
 494         /* FIXME: use R2TSN to detect missing R2T */
 495
 496         /* fill-in new R2T associated with the task */
 497         spin_lock(&session->lock);
 498         if (!ctask->sc || ctask->mtask ||
 499              session->state != ISCSI_STATE_LOGGED_IN) {
 500                 printk(KERN_INFO "iscsi_tcp: dropping R2T itt %d in "
 501                        "recovery...\n", ctask->itt);
 502                 spin_unlock(&session->lock);
 503                 return 0;
 504         }
 505         rc = __kfifo_get(ctask->r2tpool.queue, (void*)&r2t, sizeof(void*));
 506         BUG_ON(!rc);
 507
 508         r2t->exp_statsn = rhdr->statsn;
 509         r2t->data_length = be32_to_cpu(rhdr->data_length);
 510         if (r2t->data_length == 0 ||
 511             r2t->data_length > session->max_burst) {
 512                 spin_unlock(&session->lock);
 513                 return ISCSI_ERR_DATALEN;
 514         }
 515
 516         r2t->data_offset = be32_to_cpu(rhdr->data_offset);
 517         if (r2t->data_offset + r2t->data_length > ctask->total_length) {
 518                 spin_unlock(&session->lock);
 519                 return ISCSI_ERR_DATALEN;
 520         }
 521
 522         r2t->ttt = rhdr->ttt; /* no flip */
 523         r2t->solicit_datasn = 0;
 524
 525         iscsi_solicit_data_init(conn, ctask, r2t);
 526
 527         ctask->exp_r2tsn = r2tsn + 1;
 528         ctask->xmstate |= XMSTATE_SOL_HDR;
 529         __kfifo_put(ctask->r2tqueue, (void*)&r2t, sizeof(void*));
 530         __kfifo_put(conn->writequeue, (void*)&ctask, sizeof(void*));
 531
 532         schedule_work(&conn->xmitwork);
 533         conn->r2t_pdus_cnt++;
 534         spin_unlock(&session->lock);
 535
 536         return 0;
 537 }
 538
 539 static int
 540 iscsi_hdr_recv(struct iscsi_conn *conn)
 541 {
 542         int rc = 0;
 543         struct iscsi_hdr *hdr;
 544         struct iscsi_cmd_task *ctask;
 545         struct iscsi_session *session = conn->session;
 546         uint32_t cdgst, rdgst = 0;
 547
 548         hdr = conn->in.hdr;
 549
 550         /* verify PDU length */
 551         conn->in.datalen = ntoh24(hdr->dlength);
 552         if (conn->in.datalen > conn->max_recv_dlength) {
 553                 printk(KERN_ERR "iscsi_tcp: datalen %d > %d\n",
 554                        conn->in.datalen, conn->max_recv_dlength);
 555                 return ISCSI_ERR_DATALEN;
 556         }
 557         conn->data_copied = 0;
 558
 559         /* read AHS */
 560         conn->in.ahslen = hdr->hlength * 4;
 561         conn->in.offset += conn->in.ahslen;
 562         conn->in.copy -= conn->in.ahslen;
 563         if (conn->in.copy < 0) {
 564                 printk(KERN_ERR "iscsi_tcp: can't handle AHS with length "
 565                        "%d bytes\n", conn->in.ahslen);
 566                 return ISCSI_ERR_AHSLEN;
 567         }
 568
 569         /* calculate read padding */
 570         conn->in.padding = conn->in.datalen & (ISCSI_PAD_LEN-1);
 571         if (conn->in.padding) {
 572                 conn->in.padding = ISCSI_PAD_LEN - conn->in.padding;
 573                 debug_scsi("read padding %d bytes\n", conn->in.padding);
 574         }
 575
 576         if (conn->hdrdgst_en) {
 577                 struct scatterlist sg;
 578
 579                 sg_init_one(&sg, (u8 *)hdr,
 580                             sizeof(struct iscsi_hdr) + conn->in.ahslen);
 581                 crypto_digest_digest(conn->rx_tfm, &sg, 1, (u8 *)&cdgst);
 582                 rdgst = *(uint32_t*)((char*)hdr + sizeof(struct iscsi_hdr) +
 583                                      conn->in.ahslen);
 584         }
 585
 586         /* save opcode for later */
 587         conn->in.opcode = hdr->opcode & ISCSI_OPCODE_MASK;
 588
 589         /* verify itt (itt encoding: age+cid+itt) */
 590         if (hdr->itt != cpu_to_be32(ISCSI_RESERVED_TAG)) {
 591                 if ((hdr->itt & AGE_MASK) !=
 592                                 (session->age << AGE_SHIFT)) {
 593                         printk(KERN_ERR "iscsi_tcp: received itt %x expected "
 594                                 "session age (%x)\n", hdr->itt,
 595                                 session->age & AGE_MASK);
 596                         return ISCSI_ERR_BAD_ITT;
 597                 }
 598
 599                 if ((hdr->itt & CID_MASK) != (conn->id << CID_SHIFT)) {
 600                         printk(KERN_ERR "iscsi_tcp: received itt %x, expected "
 601                                 "CID (%x)\n", hdr->itt, conn->id);
 602                         return ISCSI_ERR_BAD_ITT;
 603                 }
 604                 conn->in.itt = hdr->itt & ITT_MASK;
 605         } else
 606                 conn->in.itt = hdr->itt;
 607
 608         debug_tcp("opcode 0x%x offset %d copy %d ahslen %d datalen %d\n",
 609                   hdr->opcode, conn->in.offset, conn->in.copy,
 610                   conn->in.ahslen, conn->in.datalen);
 611
 612         if (conn->in.itt < session->cmds_max) {
 613                 if (conn->hdrdgst_en && cdgst != rdgst) {
 614                         printk(KERN_ERR "iscsi_tcp: itt %x: hdrdgst error "
 615                                "recv 0x%x calc 0x%x\n", conn->in.itt, rdgst,
 616                                cdgst);
 617                         return ISCSI_ERR_HDR_DGST;
 618                 }
 619
 620                 ctask = (struct iscsi_cmd_task *)session->cmds[conn->in.itt];
 621
 622                 if (!ctask->sc) {
 623                         printk(KERN_INFO "iscsi_tcp: dropping ctask with "
 624                                "itt 0x%x\n", ctask->itt);
 625                         conn->in.datalen = 0; /* force drop */
 626                         return 0;
 627                 }
 628
 629                 if (ctask->sc->SCp.phase != session->age) {
 630                         printk(KERN_ERR "iscsi_tcp: ctask's session age %d, "
 631                                 "expected %d\n", ctask->sc->SCp.phase,
 632                                 session->age);
 633                         return ISCSI_ERR_SESSION_FAILED;
 634                 }
 635
 636                 conn->in.ctask = ctask;
 637
 638                 debug_scsi("rsp [op 0x%x cid %d sc %lx itt 0x%x len %d]\n",
 639                            hdr->opcode, conn->id, (long)ctask->sc,
 640                            ctask->itt, conn->in.datalen);
 641
 642                 switch(conn->in.opcode) {
 643                 case ISCSI_OP_SCSI_CMD_RSP:
 644                         BUG_ON((void*)ctask != ctask->sc->SCp.ptr);
 645                         if (!conn->in.datalen)
 646                                 rc = iscsi_cmd_rsp(conn, ctask);
 647                         else
 648                                 /*
 649                                  * got sense or response data; copying PDU
 650                                  * Header to the connection's header
 651                                  * placeholder
 652                                  */
 653                                 memcpy(&conn->hdr, hdr,
 654                                        sizeof(struct iscsi_hdr));
 655                         break;
 656                 case ISCSI_OP_SCSI_DATA_IN:
 657                         BUG_ON((void*)ctask != ctask->sc->SCp.ptr);
 658                         /* save flags for non-exceptional status */
 659                         conn->in.flags = hdr->flags;
 660                         /* save cmd_status for sense data */
 661                         conn->in.cmd_status =
 662                                 ((struct iscsi_data_rsp*)hdr)->cmd_status;
 663                         rc = iscsi_data_rsp(conn, ctask);
 664                         break;
 665                 case ISCSI_OP_R2T:
 666                         BUG_ON((void*)ctask != ctask->sc->SCp.ptr);
 667                         if (ctask->sc->sc_data_direction == DMA_TO_DEVICE)
 668                                 rc = iscsi_r2t_rsp(conn, ctask);
 669                         else
 670                                 rc = ISCSI_ERR_PROTO;
 671                         break;
 672                 default:
 673                         rc = ISCSI_ERR_BAD_OPCODE;
 674                         break;
 675                 }
 676         } else if (conn->in.itt >= ISCSI_MGMT_ITT_OFFSET &&
 677                    conn->in.itt < ISCSI_MGMT_ITT_OFFSET +
 678                                         session->mgmtpool_max) {
 679                 struct iscsi_mgmt_task *mtask = (struct iscsi_mgmt_task *)
 680                                         session->mgmt_cmds[conn->in.itt -
 681                                                 ISCSI_MGMT_ITT_OFFSET];
 682
 683                 debug_scsi("immrsp [op 0x%x cid %d itt 0x%x len %d]\n",
 684                            conn->in.opcode, conn->id, mtask->itt,
 685                            conn->in.datalen);
 686
 687                 switch(conn->in.opcode) {
 688                 case ISCSI_OP_LOGIN_RSP:
 689                 case ISCSI_OP_TEXT_RSP:
 690                 case ISCSI_OP_LOGOUT_RSP:
 691                         rc = iscsi_check_assign_cmdsn(session,
 692                                                  (struct iscsi_nopin*)hdr);
 693                         if (rc)
 694                                 break;
 695
 696                         if (!conn->in.datalen) {
 697                                 rc = iscsi_recv_pdu(iscsi_handle(conn), hdr,
 698                                                     NULL, 0);
 699                                 if (conn->login_mtask != mtask) {
 700                                         spin_lock(&session->lock);
 701                                         __kfifo_put(session->mgmtpool.queue,
 702                                             (void*)&mtask, sizeof(void*));
 703                                         spin_unlock(&session->lock);
 704                                 }
 705                         }
 706                         break;
 707                 case ISCSI_OP_SCSI_TMFUNC_RSP:
 708                         rc = iscsi_check_assign_cmdsn(session,
 709                                                  (struct iscsi_nopin*)hdr);
 710                         if (rc)
 711                                 break;
 712
 713                         if (conn->in.datalen || conn->in.ahslen) {
 714                                 rc = ISCSI_ERR_PROTO;
 715                                 break;
 716                         }
 717                         conn->tmfrsp_pdus_cnt++;
 718                         spin_lock(&session->lock);
 719                         if (conn->tmabort_state == TMABORT_INITIAL) {
 720                                 __kfifo_put(session->mgmtpool.queue,
 721                                                 (void*)&mtask, sizeof(void*));
 722                                 conn->tmabort_state =
 723                                         ((struct iscsi_tm_rsp *)hdr)->
 724                                         response == ISCSI_TMF_RSP_COMPLETE ?
 725                                                 TMABORT_SUCCESS:TMABORT_FAILED;
 726                                 /* unblock eh_abort() */
 727                                 wake_up(&conn->ehwait);
 728                         }
 729                         spin_unlock(&session->lock);
 730                         break;
 731                 case ISCSI_OP_NOOP_IN:
 732                         if (hdr->ttt != ISCSI_RESERVED_TAG) {
 733                                 rc = ISCSI_ERR_PROTO;
 734                                 break;
 735                         }
 736                         rc = iscsi_check_assign_cmdsn(session,
 737                                                 (struct iscsi_nopin*)hdr);
 738                         if (rc)
 739                                 break;
 740                         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
 741
 742                         if (!conn->in.datalen) {
 743                                 struct iscsi_mgmt_task *mtask;
 744
 745                                 rc = iscsi_recv_pdu(iscsi_handle(conn), hdr,
 746                                                     NULL, 0);
 747                                 mtask = (struct iscsi_mgmt_task *)
 748                                         session->mgmt_cmds[conn->in.itt -
 749                                                         ISCSI_MGMT_ITT_OFFSET];
 750                                 if (conn->login_mtask != mtask) {
 751                                         spin_lock(&session->lock);
 752                                         __kfifo_put(session->mgmtpool.queue,
 753                                                   (void*)&mtask, sizeof(void*));
 754                                         spin_unlock(&session->lock);
 755                                 }
 756                         }
 757                         break;
 758                 default:
 759                         rc = ISCSI_ERR_BAD_OPCODE;
 760                         break;
 761                 }
 762         } else if (conn->in.itt == ISCSI_RESERVED_TAG) {
 763                 switch(conn->in.opcode) {
 764                 case ISCSI_OP_NOOP_IN:
 765                         if (!conn->in.datalen) {
 766                                 rc = iscsi_check_assign_cmdsn(session,
 767                                                  (struct iscsi_nopin*)hdr);
 768                                 if (!rc && hdr->ttt != ISCSI_RESERVED_TAG)
 769                                         rc = iscsi_recv_pdu(iscsi_handle(conn),
 770                                                             hdr, NULL, 0);
 771                         } else
 772                                 rc = ISCSI_ERR_PROTO;
 773                         break;
 774                 case ISCSI_OP_REJECT:
 775                         /* we need sth like iscsi_reject_rsp()*/
 776                 case ISCSI_OP_ASYNC_EVENT:
 777                         /* we need sth like iscsi_async_event_rsp() */
 778                         rc = ISCSI_ERR_BAD_OPCODE;
 779                         break;
 780                 default:
 781                         rc = ISCSI_ERR_BAD_OPCODE;
 782                         break;
 783                 }
 784         } else
 785                 rc = ISCSI_ERR_BAD_ITT;
 786
 787         return rc;
 788 }
 789
 790 /**
 791  * iscsi_ctask_copy - copy skb bits to the destanation cmd task
 792  * @conn: iscsi connection
 793  * @ctask: scsi command task
 794  * @buf: buffer to copy to
 795  * @buf_size: size of buffer
 796  * @offset: offset within the buffer
 797  *
 798  * Notes:
 799  *      The function calls skb_copy_bits() and updates per-connection and
 800  *      per-cmd byte counters.
 801  *
 802  *      Read counters (in bytes):
 803  *
 804  *      conn->in.offset         offset within in progress SKB
 805  *      conn->in.copy           left to copy from in progress SKB
 806  *                              including padding
 807  *      conn->in.copied         copied already from in progress SKB
 808  *      conn->data_copied       copied already from in progress buffer
 809  *      ctask->sent             total bytes sent up to the MidLayer
 810  *      ctask->data_count       left to copy from in progress Data-In
 811  *      buf_left                left to copy from in progress buffer
 812  **/
 813 static inline int
 814 iscsi_ctask_copy(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
 815                 void *buf, int buf_size, int offset)
 816 {
 817         int buf_left = buf_size - (conn->data_copied + offset);
 818         int size = min(conn->in.copy, buf_left);
 819         int rc;
 820
 821         size = min(size, ctask->data_count);
 822
 823         debug_tcp("ctask_copy %d bytes at offset %d copied %d\n",
 824                size, conn->in.offset, conn->in.copied);
 825
 826         BUG_ON(size <= 0);
 827         BUG_ON(ctask->sent + size > ctask->total_length);
 828
 829         rc = skb_copy_bits(conn->in.skb, conn->in.offset,
 830                            (char*)buf + (offset + conn->data_copied), size);
 831         /* must fit into skb->len */
 832         BUG_ON(rc);
 833
 834         conn->in.offset += size;
 835         conn->in.copy -= size;
 836         conn->in.copied += size;
 837         conn->data_copied += size;
 838         ctask->sent += size;
 839         ctask->data_count -= size;
 840
 841         BUG_ON(conn->in.copy < 0);
 842         BUG_ON(ctask->data_count < 0);
 843
 844         if (buf_size != (conn->data_copied + offset)) {
 845                 if (!ctask->data_count) {
 846                         BUG_ON(buf_size - conn->data_copied < 0);
 847                         /* done with this PDU */
 848                         return buf_size - conn->data_copied;
 849                 }
 850                 return -EAGAIN;
 851         }
 852
 853         /* done with this buffer or with both - PDU and buffer */
 854         conn->data_copied = 0;
 855         return 0;
 856 }
 857
 858 /**
 859  * iscsi_tcp_copy - copy skb bits to the destanation buffer
 860  * @conn: iscsi connection
 861  * @buf: buffer to copy to
 862  * @buf_size: number of bytes to copy
 863  *
 864  * Notes:
 865  *      The function calls skb_copy_bits() and updates per-connection
 866  *      byte counters.
 867  **/
 868 static inline int
 869 iscsi_tcp_copy(struct iscsi_conn *conn, void *buf, int buf_size)
 870 {
 871         int buf_left = buf_size - conn->data_copied;
 872         int size = min(conn->in.copy, buf_left);
 873         int rc;
 874
 875         debug_tcp("tcp_copy %d bytes at offset %d copied %d\n",
 876                size, conn->in.offset, conn->data_copied);
 877         BUG_ON(size <= 0);
 878
 879         rc = skb_copy_bits(conn->in.skb, conn->in.offset,
 880                            (char*)buf + conn->data_copied, size);
 881         BUG_ON(rc);
 882
 883         conn->in.offset += size;
 884         conn->in.copy -= size;
 885         conn->in.copied += size;
 886         conn->data_copied += size;
 887
 888         if (buf_size != conn->data_copied)
 889                 return -EAGAIN;
 890
 891         return 0;
 892 }
 893
 894 static inline void
 895 partial_sg_digest_update(struct iscsi_conn *conn, struct scatterlist *sg,
 896                          int offset, int length)
 897 {
 898         struct scatterlist temp;
 899
 900         memcpy(&temp, sg, sizeof(struct scatterlist));
 901         temp.offset = offset;
 902         temp.length = length;
 903         crypto_digest_update(conn->data_rx_tfm, &temp, 1);
 904 }
 905
 906 static int iscsi_scsi_data_in(struct iscsi_conn *conn)
 907 {
 908         struct iscsi_cmd_task *ctask = conn->in.ctask;
 909         struct scsi_cmnd *sc = ctask->sc;
 910         struct scatterlist tmp, *sg;
 911         int i, offset, rc = 0;
 912
 913         BUG_ON((void*)ctask != sc->SCp.ptr);
 914
 915         /*
 916          * copying Data-In into the Scsi_Cmnd
 917          */
 918         if (!sc->use_sg) {
 919                 i = ctask->data_count;
 920                 rc = iscsi_ctask_copy(conn, ctask, sc->request_buffer,
 921                                       sc->request_bufflen, ctask->data_offset);
 922                 if (rc == -EAGAIN)
 923                         return rc;
 924                 if (conn->datadgst_en) {
 925                         sg_init_one(&tmp, sc->request_buffer, i);
 926                         crypto_digest_update(conn->data_rx_tfm, &tmp, 1);
 927                 }
 928                 rc = 0;
 929                 goto done;
 930         }
 931
 932         offset = ctask->data_offset;
 933         sg = sc->request_buffer;
 934
 935         if (ctask->data_offset)
 936                 for (i = 0; i < ctask->sg_count; i++)
 937                         offset -= sg[i].length;
 938         /* we've passed through partial sg*/
 939         if (offset < 0)
 940                 offset = 0;
 941
 942         for (i = ctask->sg_count; i < sc->use_sg; i++) {
 943                 char *dest;
 944
 945                 dest = kmap_atomic(sg[i].page, KM_SOFTIRQ0);
 946                 rc = iscsi_ctask_copy(conn, ctask, dest + sg[i].offset,
 947                                       sg[i].length, offset);
 948                 kunmap_atomic(dest, KM_SOFTIRQ0);
 949                 if (rc == -EAGAIN)
 950                         /* continue with the next SKB/PDU */
 951                         return rc;
 952                 if (!rc) {
 953                         if (conn->datadgst_en) {
 954                                 if (!offset)
 955                                         crypto_digest_update(conn->data_rx_tfm,
 956                                                              &sg[i], 1);
 957                                 else
 958                                         partial_sg_digest_update(conn, &sg[i],
 959                                                         sg[i].offset + offset,
 960                                                         sg[i].length - offset);
 961                         }
 962                         offset = 0;
 963                         ctask->sg_count++;
 964                 }
 965
 966                 if (!ctask->data_count) {
 967                         if (rc && conn->datadgst_en)
 968                                 /*
 969                                  * data-in is complete, but buffer not...
 970                                  */
 971                                 partial_sg_digest_update(conn, &sg[i],
 972                                                 sg[i].offset, sg[i].length-rc);
 973                         rc = 0;
 974                         break;
 975                 }
 976
 977                 if (!conn->in.copy)
 978                         return -EAGAIN;
 979         }
 980         BUG_ON(ctask->data_count);
 981
 982 done:
 983         /* check for non-exceptional status */
 984         if (conn->in.flags & ISCSI_FLAG_DATA_STATUS) {
 985                 debug_scsi("done [sc %lx res %d itt 0x%x]\n",
 986                            (long)sc, sc->result, ctask->itt);
 987                 conn->scsirsp_pdus_cnt++;
 988                 iscsi_ctask_cleanup(conn, ctask);
 989                 sc->scsi_done(sc);
 990         }
 991
 992         return rc;
 993 }
 994
 995 static int
 996 iscsi_data_recv(struct iscsi_conn *conn)
 997 {
 998         struct iscsi_session *session = conn->session;
 999         int rc = 0;
1000
1001         switch(conn->in.opcode) {
1002         case ISCSI_OP_SCSI_DATA_IN:
1003                 rc = iscsi_scsi_data_in(conn);
1004                 break;
1005         case ISCSI_OP_SCSI_CMD_RSP: {
1006                 /*
1007                  * SCSI Sense Data:
1008                  * copying the entire Data Segment.
1009                  */
1010                 if (iscsi_tcp_copy(conn, conn->data, conn->in.datalen)) {
1011                         rc = -EAGAIN;
1012                         goto exit;
1013                 }
1014
1015                 /*
1016                  * check for sense
1017                  */
1018                 conn->in.hdr = &conn->hdr;
1019                 conn->senselen = (conn->data[0] << 8) | conn->data[1];
1020                 rc = iscsi_cmd_rsp(conn, conn->in.ctask);
1021         }
1022         break;
1023         case ISCSI_OP_TEXT_RSP:
1024         case ISCSI_OP_LOGIN_RSP:
1025         case ISCSI_OP_NOOP_IN: {
1026                 struct iscsi_mgmt_task *mtask = NULL;
1027
1028                 if (conn->in.itt != ISCSI_RESERVED_TAG)
1029                         mtask = (struct iscsi_mgmt_task *)
1030                                 session->mgmt_cmds[conn->in.itt -
1031                                         ISCSI_MGMT_ITT_OFFSET];
1032
1033                 /*
1034                  * Collect data segment to the connection's data
1035                  * placeholder
1036                  */
1037                 if (iscsi_tcp_copy(conn, conn->data, conn->in.datalen)) {
1038                         rc = -EAGAIN;
1039                         goto exit;
1040                 }
1041
1042                 rc = iscsi_recv_pdu(iscsi_handle(conn), conn->in.hdr,
1043                                     conn->data, conn->in.datalen);
1044
1045                 if (mtask && conn->login_mtask != mtask) {
1046                         spin_lock(&session->lock);
1047                         __kfifo_put(session->mgmtpool.queue, (void*)&mtask,
1048                                     sizeof(void*));
1049                         spin_unlock(&session->lock);
1050                 }
1051         }
1052         break;
1053         default:
1054                 BUG_ON(1);
1055         }
1056 exit:
1057         return rc;
1058 }
1059
1060 /**
1061  * iscsi_tcp_data_recv - TCP receive in sendfile fashion
1062  * @rd_desc: read descriptor
1063  * @skb: socket buffer
1064  * @offset: offset in skb
1065  * @len: skb->len - offset
1066  **/
1067 static int
1068 iscsi_tcp_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb,
1069                 unsigned int offset, size_t len)
1070 {
1071         int rc;
1072         struct iscsi_conn *conn = rd_desc->arg.data;
1073         int processed;
1074         char pad[ISCSI_PAD_LEN];
1075         struct scatterlist sg;
1076
1077         /*
1078          * Save current SKB and its offset in the corresponding
1079          * connection context.
1080          */
1081         conn->in.copy = skb->len - offset;
1082         conn->in.offset = offset;
1083         conn->in.skb = skb;
1084         conn->in.len = conn->in.copy;
1085         BUG_ON(conn->in.copy <= 0);
1086         debug_tcp("in %d bytes\n", conn->in.copy);
1087
1088 more:
1089         conn->in.copied = 0;
1090         rc = 0;
1091
1092         if (unlikely(conn->suspend_rx)) {
1093                 debug_tcp("conn %d Rx suspended!\n", conn->id);
1094                 return 0;
1095         }
1096
1097         if (conn->in_progress == IN_PROGRESS_WAIT_HEADER ||
1098             conn->in_progress == IN_PROGRESS_HEADER_GATHER) {
1099                 rc = iscsi_hdr_extract(conn);
1100                 if (rc) {
1101                        if (rc == -EAGAIN)
1102                                 goto nomore;
1103                        else {
1104                                 iscsi_conn_failure(conn, rc);
1105                                 return 0;
1106                        }
1107                 }
1108
1109                 /*
1110                  * Verify and process incoming PDU header.
1111                  */
1112                 rc = iscsi_hdr_recv(conn);
1113                 if (!rc && conn->in.datalen) {
1114                         if (conn->datadgst_en &&
1115                             conn->in.opcode == ISCSI_OP_SCSI_DATA_IN) {
1116                                 BUG_ON(!conn->data_rx_tfm);
1117                                 crypto_digest_init(conn->data_rx_tfm);
1118                         }
1119                         conn->in_progress = IN_PROGRESS_DATA_RECV;
1120                 } else if (rc) {
1121                         iscsi_conn_failure(conn, rc);
1122                         return 0;
1123                 }
1124         }
1125
1126         if (conn->in_progress == IN_PROGRESS_DDIGEST_RECV) {
1127                 debug_tcp("extra data_recv offset %d copy %d\n",
1128                           conn->in.offset, conn->in.copy);
1129                 if (conn->in.opcode == ISCSI_OP_SCSI_DATA_IN) {
1130                         uint32_t recv_digest;
1131                         skb_copy_bits(conn->in.skb, conn->in.offset,
1132                                       &recv_digest, 4);
1133                         conn->in.offset += 4;
1134                         conn->in.copy -= 4;
1135                         if (recv_digest != conn->in.datadgst) {
1136                                 debug_tcp("iscsi_tcp: data digest error!"
1137                                           "0x%x != 0x%x\n", recv_digest,
1138                                           conn->in.datadgst);
1139                                 iscsi_conn_failure(conn, ISCSI_ERR_DATA_DGST);
1140                                 return 0;
1141                         } else {
1142                                 debug_tcp("iscsi_tcp: data digest match!"
1143                                           "0x%x == 0x%x\n", recv_digest,
1144                                           conn->in.datadgst);
1145                                 conn->in_progress = IN_PROGRESS_WAIT_HEADER;
1146                         }
1147                 }
1148         }
1149
1150         if (conn->in_progress == IN_PROGRESS_DATA_RECV && conn->in.copy) {
1151
1152                 debug_tcp("data_recv offset %d copy %d\n",
1153                        conn->in.offset, conn->in.copy);
1154
1155                 rc = iscsi_data_recv(conn);
1156                 if (rc) {
1157                         if (rc == -EAGAIN) {
1158                                 rd_desc->count = conn->in.datalen -
1159                                                 conn->in.ctask->data_count;
1160                                 goto again;
1161                         }
1162                         iscsi_conn_failure(conn, rc);
1163                         return 0;
1164                 }
1165                 conn->in.copy -= conn->in.padding;
1166                 conn->in.offset += conn->in.padding;
1167                 if (conn->datadgst_en &&
1168                     conn->in.opcode == ISCSI_OP_SCSI_DATA_IN) {
1169                         if (conn->in.padding) {
1170                                 debug_tcp("padding -> %d\n", conn->in.padding);
1171                                 memset(pad, 0, conn->in.padding);
1172                                 sg_init_one(&sg, pad, conn->in.padding);
1173                                 crypto_digest_update(conn->data_rx_tfm, &sg, 1);
1174                         }
1175                         crypto_digest_final(conn->data_rx_tfm,
1176                                             (u8 *) & conn->in.datadgst);
1177                         debug_tcp("rx digest 0x%x\n", conn->in.datadgst);
1178                         conn->in_progress = IN_PROGRESS_DDIGEST_RECV;
1179                 } else
1180                         conn->in_progress = IN_PROGRESS_WAIT_HEADER;
1181         }
1182
1183         debug_tcp("f, processed %d from out of %d padding %d\n",
1184                conn->in.offset - offset, (int)len, conn->in.padding);
1185         BUG_ON(conn->in.offset - offset > len);
1186
1187         if (conn->in.offset - offset != len) {
1188                 debug_tcp("continue to process %d bytes\n",
1189                        (int)len - (conn->in.offset - offset));
1190                 goto more;
1191         }
1192
1193 nomore:
1194         processed = conn->in.offset - offset;
1195         BUG_ON(processed == 0);
1196         return processed;
1197
1198 again:
1199         processed = conn->in.offset - offset;
1200         debug_tcp("c, processed %d from out of %d rd_desc_cnt %d\n",
1201                   processed, (int)len, (int)rd_desc->count);
1202         BUG_ON(processed == 0);
1203         BUG_ON(processed > len);
1204
1205         conn->rxdata_octets += processed;
1206         return processed;
1207 }
1208
1209 static void
1210 iscsi_tcp_data_ready(struct sock *sk, int flag)
1211 {
1212         struct iscsi_conn *conn = sk->sk_user_data;
1213         read_descriptor_t rd_desc;
1214
1215         read_lock(&sk->sk_callback_lock);
1216
1217         /* use rd_desc to pass 'conn' to iscsi_tcp_data_recv */
1218         rd_desc.arg.data = conn;
1219         rd_desc.count = 0;
1220         tcp_read_sock(sk, &rd_desc, iscsi_tcp_data_recv);
1221
1222         read_unlock(&sk->sk_callback_lock);
1223 }
1224
1225 static void
1226 iscsi_tcp_state_change(struct sock *sk)
1227 {
1228         struct iscsi_conn *conn;
1229         struct iscsi_session *session;
1230         void (*old_state_change)(struct sock *);
1231
1232         read_lock(&sk->sk_callback_lock);
1233
1234         conn = (struct iscsi_conn*)sk->sk_user_data;
1235         session = conn->session;
1236
1237         if ((sk->sk_state == TCP_CLOSE_WAIT ||
1238              sk->sk_state == TCP_CLOSE) &&
1239             !atomic_read(&sk->sk_rmem_alloc)) {
1240                 debug_tcp("iscsi_tcp_state_change: TCP_CLOSE|TCP_CLOSE_WAIT\n");
1241                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1242         }
1243
1244         old_state_change = conn->old_state_change;
1245
1246         read_unlock(&sk->sk_callback_lock);
1247
1248         old_state_change(sk);
1249 }
1250
1251 /**
1252  * iscsi_write_space - Called when more output buffer space is available
1253  * @sk: socket space is available for
1254  **/
1255 static void
1256 iscsi_write_space(struct sock *sk)
1257 {
1258         struct iscsi_conn *conn = (struct iscsi_conn*)sk->sk_user_data;
1259         conn->old_write_space(sk);
1260         debug_tcp("iscsi_write_space: cid %d\n", conn->id);
1261         clear_bit(SUSPEND_BIT, &conn->suspend_tx);
1262         schedule_work(&conn->xmitwork);
1263 }
1264
1265 static void
1266 iscsi_conn_set_callbacks(struct iscsi_conn *conn)
1267 {
1268         struct sock *sk = conn->sock->sk;
1269
1270         /* assign new callbacks */
1271         write_lock_bh(&sk->sk_callback_lock);
1272         sk->sk_user_data = conn;
1273         conn->old_data_ready = sk->sk_data_ready;
1274         conn->old_state_change = sk->sk_state_change;
1275         conn->old_write_space = sk->sk_write_space;
1276         sk->sk_data_ready = iscsi_tcp_data_ready;
1277         sk->sk_state_change = iscsi_tcp_state_change;
1278         sk->sk_write_space = iscsi_write_space;
1279         write_unlock_bh(&sk->sk_callback_lock);
1280 }
1281
1282 static void
1283 iscsi_conn_restore_callbacks(struct iscsi_conn *conn)
1284 {
1285         struct sock *sk = conn->sock->sk;
1286
1287         /* restore socket callbacks, see also: iscsi_conn_set_callbacks() */
1288         write_lock_bh(&sk->sk_callback_lock);
1289         sk->sk_user_data    = NULL;
1290         sk->sk_data_ready   = conn->old_data_ready;
1291         sk->sk_state_change = conn->old_state_change;
1292         sk->sk_write_space  = conn->old_write_space;
1293         sk->sk_no_check  = 0;
1294         write_unlock_bh(&sk->sk_callback_lock);
1295 }
1296
1297 /**
1298  * iscsi_send - generic send routine
1299  * @sk: kernel's socket
1300  * @buf: buffer to write from
1301  * @size: actual size to write
1302  * @flags: socket's flags
1303  *
1304  * Notes:
1305  *      depending on buffer will use tcp_sendpage() or tcp_sendmsg().
1306  *      buf->sg.offset == -1 tells us that buffer is non S/G and forces
1307  *      to use tcp_sendmsg().
1308  */
1309 static inline int
1310 iscsi_send(struct socket *sk, struct iscsi_buf *buf, int size, int flags)
1311 {
1312         int res;
1313
1314         if ((int)buf->sg.offset >= 0) {
1315                 int offset = buf->sg.offset + buf->sent;
1316
1317                 /* tcp_sendpage */
1318                 res = sk->ops->sendpage(sk, buf->sg.page, offset, size, flags);
1319         } else {
1320                 struct msghdr msg;
1321
1322                 buf->iov.iov_base = iscsi_buf_iov_base(buf);
1323                 buf->iov.iov_len = size;
1324
1325                 memset(&msg, 0, sizeof(struct msghdr));
1326
1327                 /* tcp_sendmsg */
1328                 res = kernel_sendmsg(sk, &msg, &buf->iov, 1, size);
1329         }
1330
1331         return res;
1332 }
1333
1334 /**
1335  * iscsi_sendhdr - send PDU Header via tcp_sendpage()
1336  * @conn: iscsi connection
1337  * @buf: buffer to write from
1338  * @datalen: lenght of data to be sent after the header
1339  *
1340  * Notes:
1341  *      (Tx, Fast Path)
1342  **/
1343 static inline int
1344 iscsi_sendhdr(struct iscsi_conn *conn, struct iscsi_buf *buf, int datalen)
1345 {
1346         struct socket *sk = conn->sock;
1347         int flags = 0; /* MSG_DONTWAIT; */
1348         int res, size;
1349
1350         size = buf->sg.length - buf->sent;
1351         BUG_ON(buf->sent + size > buf->sg.length);
1352         if (buf->sent + size != buf->sg.length || datalen)
1353                 flags |= MSG_MORE;
1354
1355         res = iscsi_send(sk, buf, size, flags);
1356         debug_tcp("sendhdr %d bytes, sent %d res %d\n", size, buf->sent, res);
1357         if (res >= 0) {
1358                 conn->txdata_octets += res;
1359                 buf->sent += res;
1360                 if (size != res)
1361                         return -EAGAIN;
1362                 return 0;
1363         } else if (res == -EAGAIN) {
1364                 conn->sendpage_failures_cnt++;
1365                 set_bit(SUSPEND_BIT, &conn->suspend_tx);
1366         } else if (res == -EPIPE)
1367                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1368
1369         return res;
1370 }
1371
1372 /**
1373  * iscsi_sendpage - send one page of iSCSI Data-Out.
1374  * @conn: iscsi connection
1375  * @buf: buffer to write from
1376  * @count: remaining data
1377  * @sent: number of bytes sent
1378  *
1379  * Notes:
1380  *      (Tx, Fast Path)
1381  **/
1382 static inline int
1383 iscsi_sendpage(struct iscsi_conn *conn, struct iscsi_buf *buf,
1384                int *count, int *sent)
1385 {
1386         struct socket *sk = conn->sock;
1387         int flags = 0; /* MSG_DONTWAIT; */
1388         int res, size;
1389
1390         size = buf->sg.length - buf->sent;
1391         BUG_ON(buf->sent + size > buf->sg.length);
1392         if (size > *count)
1393                 size = *count;
1394         if (buf->sent + size != buf->sg.length || *count != size)
1395                 flags |= MSG_MORE;
1396
1397         res = iscsi_send(sk, buf, size, flags);
1398         debug_tcp("sendpage: %d bytes, sent %d left %d sent %d res %d\n",
1399                   size, buf->sent, *count, *sent, res);
1400         if (res >= 0) {
1401                 conn->txdata_octets += res;
1402                 buf->sent += res;
1403                 *count -= res;
1404                 *sent += res;
1405                 if (size != res)
1406                         return -EAGAIN;
1407                 return 0;
1408         } else if (res == -EAGAIN) {
1409                 conn->sendpage_failures_cnt++;
1410                 set_bit(SUSPEND_BIT, &conn->suspend_tx);
1411         } else if (res == -EPIPE)
1412                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1413
1414         return res;
1415 }
1416
1417 static inline void
1418 iscsi_data_digest_init(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1419 {
1420         BUG_ON(!conn->data_tx_tfm);
1421         crypto_digest_init(conn->data_tx_tfm);
1422         ctask->digest_count = 4;
1423 }
1424
1425 static inline void
1426 iscsi_buf_data_digest_update(struct iscsi_conn *conn, struct iscsi_buf *buf)
1427 {
1428         struct scatterlist sg;
1429
1430         if (buf->sg.offset != -1)
1431                 crypto_digest_update(conn->data_tx_tfm, &buf->sg, 1);
1432         else {
1433                 sg_init_one(&sg, (char *)buf->sg.page, buf->sg.length);
1434                 crypto_digest_update(conn->data_tx_tfm, &sg, 1);
1435         }
1436 }
1437
1438 static inline int
1439 iscsi_digest_final_send(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
1440                         struct iscsi_buf *buf, uint32_t *digest, int final)
1441 {
1442         int rc = 0;
1443         int sent = 0;
1444
1445         if (final)
1446                 crypto_digest_final(conn->data_tx_tfm, (u8*)digest);
1447
1448         iscsi_buf_init_virt(buf, (char*)digest, 4);
1449         rc = iscsi_sendpage(conn, buf, &ctask->digest_count, &sent);
1450         if (rc) {
1451                 ctask->datadigest = *digest;
1452                 ctask->xmstate |= XMSTATE_DATA_DIGEST;
1453         } else
1454                 ctask->digest_count = 4;
1455         return rc;
1456 }
1457
1458 /**
1459  * iscsi_solicit_data_cont - initialize next Data-Out
1460  * @conn: iscsi connection
1461  * @ctask: scsi command task
1462  * @r2t: R2T info
1463  * @left: bytes left to transfer
1464  *
1465  * Notes:
1466  *      Initialize next Data-Out within this R2T sequence and continue
1467  *      to process next Scatter-Gather element(if any) of this SCSI command.
1468  *
1469  *      Called under connection lock.
1470  **/
1471 static void
1472 iscsi_solicit_data_cont(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
1473                         struct iscsi_r2t_info *r2t, int left)
1474 {
1475         struct iscsi_data *hdr;
1476         struct iscsi_data_task *dtask;
1477         struct scsi_cmnd *sc = ctask->sc;
1478         int new_offset;
1479
1480         dtask = mempool_alloc(ctask->datapool, GFP_ATOMIC);
1481         BUG_ON(!dtask);
1482         hdr = &dtask->hdr;
1483         memset(hdr, 0, sizeof(struct iscsi_data));
1484         hdr->ttt = r2t->ttt;
1485         hdr->datasn = cpu_to_be32(r2t->solicit_datasn);
1486         r2t->solicit_datasn++;
1487         hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
1488         memcpy(hdr->lun, ctask->hdr.lun, sizeof(hdr->lun));
1489         hdr->itt = ctask->hdr.itt;
1490         hdr->exp_statsn = r2t->exp_statsn;
1491         new_offset = r2t->data_offset + r2t->sent;
1492         hdr->offset = cpu_to_be32(new_offset);
1493         if (left > conn->max_xmit_dlength) {
1494                 hton24(hdr->dlength, conn->max_xmit_dlength);
1495                 r2t->data_count = conn->max_xmit_dlength;
1496         } else {
1497                 hton24(hdr->dlength, left);
1498                 r2t->data_count = left;
1499                 hdr->flags = ISCSI_FLAG_CMD_FINAL;
1500         }
1501         conn->dataout_pdus_cnt++;
1502
1503         iscsi_buf_init_virt(&r2t->headbuf, (char*)hdr,
1504                            sizeof(struct iscsi_hdr));
1505
1506         r2t->dtask = dtask;
1507
1508         if (sc->use_sg && !iscsi_buf_left(&r2t->sendbuf)) {
1509                 BUG_ON(ctask->bad_sg == r2t->sg);
1510                 iscsi_buf_init_sg(&r2t->sendbuf, r2t->sg);
1511                 r2t->sg += 1;
1512         } else
1513                 iscsi_buf_init_iov(&ctask->sendbuf,
1514                             (char*)sc->request_buffer + new_offset,
1515                             r2t->data_count);
1516
1517         list_add(&dtask->item, &ctask->dataqueue);
1518 }
1519
1520 static void
1521 iscsi_unsolicit_data_init(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1522 {
1523         struct iscsi_data *hdr;
1524         struct iscsi_data_task *dtask;
1525
1526         dtask = mempool_alloc(ctask->datapool, GFP_ATOMIC);
1527         BUG_ON(!dtask);
1528         hdr = &dtask->hdr;
1529         memset(hdr, 0, sizeof(struct iscsi_data));
1530         hdr->ttt = cpu_to_be32(ISCSI_RESERVED_TAG);
1531         hdr->datasn = cpu_to_be32(ctask->unsol_datasn);
1532         ctask->unsol_datasn++;
1533         hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
1534         memcpy(hdr->lun, ctask->hdr.lun, sizeof(hdr->lun));
1535         hdr->itt = ctask->hdr.itt;
1536         hdr->exp_statsn = cpu_to_be32(conn->exp_statsn);
1537         hdr->offset = cpu_to_be32(ctask->total_length -
1538                                   ctask->r2t_data_count -
1539                                   ctask->unsol_count);
1540         if (ctask->unsol_count > conn->max_xmit_dlength) {
1541                 hton24(hdr->dlength, conn->max_xmit_dlength);
1542                 ctask->data_count = conn->max_xmit_dlength;
1543                 hdr->flags = 0;
1544         } else {
1545                 hton24(hdr->dlength, ctask->unsol_count);
1546                 ctask->data_count = ctask->unsol_count;
1547                 hdr->flags = ISCSI_FLAG_CMD_FINAL;
1548         }
1549
1550         iscsi_buf_init_virt(&ctask->headbuf, (char*)hdr,
1551                            sizeof(struct iscsi_hdr));
1552
1553         list_add(&dtask->item, &ctask->dataqueue);
1554
1555         ctask->dtask = dtask;
1556 }
1557
1558 /**
1559  * iscsi_cmd_init - Initialize iSCSI SCSI_READ or SCSI_WRITE commands
1560  * @conn: iscsi connection
1561  * @ctask: scsi command task
1562  * @sc: scsi command
1563  **/
1564 static void
1565 iscsi_cmd_init(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
1566                 struct scsi_cmnd *sc)
1567 {
1568         struct iscsi_session *session = conn->session;
1569
1570         BUG_ON(__kfifo_len(ctask->r2tqueue));
1571
1572         ctask->sc = sc;
1573         ctask->conn = conn;
1574         ctask->hdr.opcode = ISCSI_OP_SCSI_CMD;
1575         ctask->hdr.flags = ISCSI_ATTR_SIMPLE;
1576         int_to_scsilun(sc->device->lun, (struct scsi_lun *)ctask->hdr.lun);
1577         ctask->hdr.itt = ctask->itt | (conn->id << CID_SHIFT) |
1578                          (session->age << AGE_SHIFT);
1579         ctask->hdr.data_length = cpu_to_be32(sc->request_bufflen);
1580         ctask->hdr.cmdsn = cpu_to_be32(session->cmdsn); session->cmdsn++;
1581         ctask->hdr.exp_statsn = cpu_to_be32(conn->exp_statsn);
1582         memcpy(ctask->hdr.cdb, sc->cmnd, sc->cmd_len);
1583         memset(&ctask->hdr.cdb[sc->cmd_len], 0, MAX_COMMAND_SIZE - sc->cmd_len);
1584
1585         ctask->mtask = NULL;
1586         ctask->sent = 0;
1587         ctask->sg_count = 0;
1588
1589         ctask->total_length = sc->request_bufflen;
1590
1591         if (sc->sc_data_direction == DMA_TO_DEVICE) {
1592                 ctask->exp_r2tsn = 0;
1593                 ctask->hdr.flags |= ISCSI_FLAG_CMD_WRITE;
1594                 BUG_ON(ctask->total_length == 0);
1595                 if (sc->use_sg) {
1596                         struct scatterlist *sg = sc->request_buffer;
1597
1598                         iscsi_buf_init_sg(&ctask->sendbuf,
1599                                           &sg[ctask->sg_count++]);
1600                         ctask->sg = sg;
1601                         ctask->bad_sg = sg + sc->use_sg;
1602                 } else {
1603                         iscsi_buf_init_iov(&ctask->sendbuf, sc->request_buffer,
1604                                         sc->request_bufflen);
1605                 }
1606
1607                 /*
1608                  * Write counters:
1609                  *
1610                  *      imm_count       bytes to be sent right after
1611                  *                      SCSI PDU Header
1612                  *
1613                  *      unsol_count     bytes(as Data-Out) to be sent
1614                  *                      without R2T ack right after
1615                  *                      immediate data
1616                  *
1617                  *      r2t_data_count  bytes to be sent via R2T ack's
1618                  *
1619                  *      pad_count       bytes to be sent as zero-padding
1620                  */
1621                 ctask->imm_count = 0;
1622                 ctask->unsol_count = 0;
1623                 ctask->unsol_datasn = 0;
1624                 ctask->xmstate = XMSTATE_W_HDR;
1625                 /* calculate write padding */
1626                 ctask->pad_count = ctask->total_length & (ISCSI_PAD_LEN-1);
1627                 if (ctask->pad_count) {
1628                         ctask->pad_count = ISCSI_PAD_LEN - ctask->pad_count;
1629                         debug_scsi("write padding %d bytes\n",
1630                                 ctask->pad_count);
1631                         ctask->xmstate |= XMSTATE_W_PAD;
1632                 }
1633                 if (session->imm_data_en) {
1634                         if (ctask->total_length >= session->first_burst)
1635                                 ctask->imm_count = min(session->first_burst,
1636                                                         conn->max_xmit_dlength);
1637                         else
1638                                 ctask->imm_count = min(ctask->total_length,
1639                                                         conn->max_xmit_dlength);
1640                         hton24(ctask->hdr.dlength, ctask->imm_count);
1641                         ctask->xmstate |= XMSTATE_IMM_DATA;
1642                 } else
1643                         zero_data(ctask->hdr.dlength);
1644
1645                 if (!session->initial_r2t_en)
1646                         ctask->unsol_count = min(session->first_burst,
1647                                 ctask->total_length) - ctask->imm_count;
1648                 if (!ctask->unsol_count)
1649                         /* No unsolicit Data-Out's */
1650                         ctask->hdr.flags |= ISCSI_FLAG_CMD_FINAL;
1651                 else
1652                         ctask->xmstate |= XMSTATE_UNS_HDR | XMSTATE_UNS_INIT;
1653
1654                 ctask->r2t_data_count = ctask->total_length -
1655                                     ctask->imm_count -
1656                                     ctask->unsol_count;
1657
1658                 debug_scsi("cmd [itt %x total %d imm %d imm_data %d "
1659                            "r2t_data %d]\n",
1660                            ctask->itt, ctask->total_length, ctask->imm_count,
1661                            ctask->unsol_count, ctask->r2t_data_count);
1662         } else {
1663                 ctask->hdr.flags |= ISCSI_FLAG_CMD_FINAL;
1664                 if (sc->sc_data_direction == DMA_FROM_DEVICE)
1665                         ctask->hdr.flags |= ISCSI_FLAG_CMD_READ;
1666                 ctask->datasn = 0;
1667                 ctask->xmstate = XMSTATE_R_HDR;
1668                 zero_data(ctask->hdr.dlength);
1669         }
1670
1671         iscsi_buf_init_virt(&ctask->headbuf, (char*)&ctask->hdr,
1672                             sizeof(struct iscsi_hdr));
1673         conn->scsicmd_pdus_cnt++;
1674 }
1675
1676 /**
1677  * iscsi_mtask_xmit - xmit management(immediate) task
1678  * @conn: iscsi connection
1679  * @mtask: task management task
1680  *
1681  * Notes:
1682  *      The function can return -EAGAIN in which case caller must
1683  *      call it again later, or recover. '0' return code means successful
1684  *      xmit.
1685  *
1686  *      Management xmit state machine consists of two states:
1687  *              IN_PROGRESS_IMM_HEAD - PDU Header xmit in progress
1688  *              IN_PROGRESS_IMM_DATA - PDU Data xmit in progress
1689  **/
1690 static int
1691 iscsi_mtask_xmit(struct iscsi_conn *conn, struct iscsi_mgmt_task *mtask)
1692 {
1693
1694         debug_scsi("mtask deq [cid %d state %x itt 0x%x]\n",
1695                 conn->id, mtask->xmstate, mtask->itt);
1696
1697         if (mtask->xmstate & XMSTATE_IMM_HDR) {
1698                 mtask->xmstate &= ~XMSTATE_IMM_HDR;
1699                 if (mtask->data_count)
1700                         mtask->xmstate |= XMSTATE_IMM_DATA;
1701                 if (conn->c_stage != ISCSI_CONN_INITIAL_STAGE &&
1702                     conn->stop_stage != STOP_CONN_RECOVER &&
1703                     conn->hdrdgst_en)
1704                         iscsi_hdr_digest(conn, &mtask->headbuf,
1705                                         (u8*)mtask->hdrext);
1706                 if (iscsi_sendhdr(conn, &mtask->headbuf, mtask->data_count)) {
1707                         mtask->xmstate |= XMSTATE_IMM_HDR;
1708                         if (mtask->data_count)
1709                                 mtask->xmstate &= ~XMSTATE_IMM_DATA;
1710                         return -EAGAIN;
1711                 }
1712         }
1713
1714         if (mtask->xmstate & XMSTATE_IMM_DATA) {
1715                 BUG_ON(!mtask->data_count);
1716                 mtask->xmstate &= ~XMSTATE_IMM_DATA;
1717                 /* FIXME: implement.
1718                  * Virtual buffer could be spreaded across multiple pages...
1719                  */
1720                 do {
1721                         if (iscsi_sendpage(conn, &mtask->sendbuf,
1722                                    &mtask->data_count, &mtask->sent)) {
1723                                 mtask->xmstate |= XMSTATE_IMM_DATA;
1724                                 return -EAGAIN;
1725                         }
1726                 } while (mtask->data_count);
1727         }
1728
1729         BUG_ON(mtask->xmstate != XMSTATE_IDLE);
1730         return 0;
1731 }
1732
1733 static inline int
1734 handle_xmstate_r_hdr(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1735 {
1736         ctask->xmstate &= ~XMSTATE_R_HDR;
1737         if (conn->hdrdgst_en)
1738                 iscsi_hdr_digest(conn, &ctask->headbuf, (u8*)ctask->hdrext);
1739         if (!iscsi_sendhdr(conn, &ctask->headbuf, 0)) {
1740                 BUG_ON(ctask->xmstate != XMSTATE_IDLE);
1741                 return 0; /* wait for Data-In */
1742         }
1743         ctask->xmstate |= XMSTATE_R_HDR;
1744         return -EAGAIN;
1745 }
1746
1747 static inline int
1748 handle_xmstate_w_hdr(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1749 {
1750         ctask->xmstate &= ~XMSTATE_W_HDR;
1751         if (conn->hdrdgst_en)
1752                 iscsi_hdr_digest(conn, &ctask->headbuf, (u8*)ctask->hdrext);
1753         if (iscsi_sendhdr(conn, &ctask->headbuf, ctask->imm_count)) {
1754                 ctask->xmstate |= XMSTATE_W_HDR;
1755                 return -EAGAIN;
1756         }
1757         return 0;
1758 }
1759
1760 static inline int
1761 handle_xmstate_data_digest(struct iscsi_conn *conn,
1762                            struct iscsi_cmd_task *ctask)
1763 {
1764         ctask->xmstate &= ~XMSTATE_DATA_DIGEST;
1765         debug_tcp("resent data digest 0x%x\n", ctask->datadigest);
1766         if (iscsi_digest_final_send(conn, ctask, &ctask->immbuf,
1767                                     &ctask->datadigest, 0)) {
1768                 ctask->xmstate |= XMSTATE_DATA_DIGEST;
1769                 debug_tcp("resent data digest 0x%x fail!\n",
1770                           ctask->datadigest);
1771                 return -EAGAIN;
1772         }
1773         return 0;
1774 }
1775
1776 static inline int
1777 handle_xmstate_imm_data(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1778 {
1779         BUG_ON(!ctask->imm_count);
1780         ctask->xmstate &= ~XMSTATE_IMM_DATA;
1781
1782         if (conn->datadgst_en) {
1783                 iscsi_data_digest_init(conn, ctask);
1784                 ctask->immdigest = 0;
1785         }
1786
1787         for (;;) {
1788                 if (iscsi_sendpage(conn, &ctask->sendbuf, &ctask->imm_count,
1789                                    &ctask->sent)) {
1790                         ctask->xmstate |= XMSTATE_IMM_DATA;
1791                         if (conn->datadgst_en) {
1792                                 crypto_digest_final(conn->data_tx_tfm,
1793                                                 (u8*)&ctask->immdigest);
1794                                 debug_tcp("tx imm sendpage fail 0x%x\n",
1795                                           ctask->datadigest);
1796                         }
1797                         return -EAGAIN;
1798                 }
1799                 if (conn->datadgst_en)
1800                         iscsi_buf_data_digest_update(conn, &ctask->sendbuf);
1801
1802                 if (!ctask->imm_count)
1803                         break;
1804                 iscsi_buf_init_sg(&ctask->sendbuf,
1805                                   &ctask->sg[ctask->sg_count++]);
1806         }
1807
1808         if (conn->datadgst_en && !(ctask->xmstate & XMSTATE_W_PAD)) {
1809                 if (iscsi_digest_final_send(conn, ctask, &ctask->immbuf,
1810                                             &ctask->immdigest, 1)) {
1811                         debug_tcp("sending imm digest 0x%x fail!\n",
1812                                   ctask->immdigest);
1813                         return -EAGAIN;
1814                 }
1815                 debug_tcp("sending imm digest 0x%x\n", ctask->immdigest);
1816         }
1817
1818         return 0;
1819 }
1820
1821 static inline int
1822 handle_xmstate_uns_hdr(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1823 {
1824         struct iscsi_data_task *dtask;
1825
1826         ctask->xmstate |= XMSTATE_UNS_DATA;
1827         if (ctask->xmstate & XMSTATE_UNS_INIT) {
1828                 iscsi_unsolicit_data_init(conn, ctask);
1829                 BUG_ON(!ctask->dtask);
1830                 dtask = ctask->dtask;
1831                 if (conn->hdrdgst_en)
1832                         iscsi_hdr_digest(conn, &ctask->headbuf,
1833                                         (u8*)dtask->hdrext);
1834                 ctask->xmstate &= ~XMSTATE_UNS_INIT;
1835         }
1836         if (iscsi_sendhdr(conn, &ctask->headbuf, ctask->data_count)) {
1837                 ctask->xmstate &= ~XMSTATE_UNS_DATA;
1838                 ctask->xmstate |= XMSTATE_UNS_HDR;
1839                 return -EAGAIN;
1840         }
1841
1842         debug_scsi("uns dout [itt 0x%x dlen %d sent %d]\n",
1843                    ctask->itt, ctask->unsol_count, ctask->sent);
1844         return 0;
1845 }
1846
1847 static inline int
1848 handle_xmstate_uns_data(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1849 {
1850         struct iscsi_data_task *dtask = ctask->dtask;
1851
1852         BUG_ON(!ctask->data_count);
1853         ctask->xmstate &= ~XMSTATE_UNS_DATA;
1854
1855         if (conn->datadgst_en) {
1856                 iscsi_data_digest_init(conn, ctask);
1857                 dtask->digest = 0;
1858         }
1859
1860         for (;;) {
1861                 int start = ctask->sent;
1862
1863                 if (iscsi_sendpage(conn, &ctask->sendbuf, &ctask->data_count,
1864                                    &ctask->sent)) {
1865                         ctask->unsol_count -= ctask->sent - start;
1866                         ctask->xmstate |= XMSTATE_UNS_DATA;
1867                         /* will continue with this ctask later.. */
1868                         if (conn->datadgst_en) {
1869                                 crypto_digest_final(conn->data_tx_tfm,
1870                                                 (u8 *)&dtask->digest);
1871                                 debug_tcp("tx uns data fail 0x%x\n",
1872                                           dtask->digest);
1873                         }
1874                         return -EAGAIN;
1875                 }
1876
1877                 BUG_ON(ctask->sent > ctask->total_length);
1878                 ctask->unsol_count -= ctask->sent - start;
1879
1880                 /*
1881                  * XXX:we may run here with un-initial sendbuf.
1882                  * so pass it
1883                  */
1884                 if (conn->datadgst_en && ctask->sent - start > 0)
1885                         iscsi_buf_data_digest_update(conn, &ctask->sendbuf);
1886
1887                 if (!ctask->data_count)
1888                         break;
1889                 iscsi_buf_init_sg(&ctask->sendbuf,
1890                                   &ctask->sg[ctask->sg_count++]);
1891         }
1892         BUG_ON(ctask->unsol_count < 0);
1893
1894         /*
1895          * Done with the Data-Out. Next, check if we need
1896          * to send another unsolicited Data-Out.
1897          */
1898         if (ctask->unsol_count) {
1899                 if (conn->datadgst_en) {
1900                         if (iscsi_digest_final_send(conn, ctask,
1901                                                     &dtask->digestbuf,
1902                                                     &dtask->digest, 1)) {
1903                                 debug_tcp("send uns digest 0x%x fail\n",
1904                                           dtask->digest);
1905                                 return -EAGAIN;
1906                         }
1907                         debug_tcp("sending uns digest 0x%x, more uns\n",
1908                                   dtask->digest);
1909                 }
1910                 ctask->xmstate |= XMSTATE_UNS_INIT;
1911                 return 1;
1912         }
1913
1914         if (conn->datadgst_en && !(ctask->xmstate & XMSTATE_W_PAD)) {
1915                 if (iscsi_digest_final_send(conn, ctask,
1916                                             &dtask->digestbuf,
1917                                             &dtask->digest, 1)) {
1918                         debug_tcp("send last uns digest 0x%x fail\n",
1919                                    dtask->digest);
1920                         return -EAGAIN;
1921                 }
1922                 debug_tcp("sending uns digest 0x%x\n",dtask->digest);
1923         }
1924
1925         return 0;
1926 }
1927
1928 static inline int
1929 handle_xmstate_sol_data(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1930 {
1931         struct iscsi_session *session = conn->session;
1932         struct iscsi_r2t_info *r2t = ctask->r2t;
1933         struct iscsi_data_task *dtask = r2t->dtask;
1934         int left;
1935
1936         ctask->xmstate &= ~XMSTATE_SOL_DATA;
1937         ctask->dtask = dtask;
1938
1939         if (conn->datadgst_en) {
1940                 iscsi_data_digest_init(conn, ctask);
1941                 dtask->digest = 0;
1942         }
1943 solicit_again:
1944         /*
1945          * send Data-Out whitnin this R2T sequence.
1946          */
1947         if (!r2t->data_count)
1948                 goto data_out_done;
1949
1950         if (iscsi_sendpage(conn, &r2t->sendbuf, &r2t->data_count, &r2t->sent)) {
1951                 ctask->xmstate |= XMSTATE_SOL_DATA;
1952                 /* will continue with this ctask later.. */
1953                 if (conn->datadgst_en) {
1954                         crypto_digest_final(conn->data_tx_tfm,
1955                                           (u8 *)&dtask->digest);
1956                         debug_tcp("r2t data send fail 0x%x\n", dtask->digest);
1957                 }
1958                 return -EAGAIN;
1959         }
1960
1961         BUG_ON(r2t->data_count < 0);
1962         if (conn->datadgst_en)
1963                 iscsi_buf_data_digest_update(conn, &r2t->sendbuf);
1964
1965         if (r2t->data_count) {
1966                 BUG_ON(ctask->sc->use_sg == 0);
1967                 if (!iscsi_buf_left(&r2t->sendbuf)) {
1968                         BUG_ON(ctask->bad_sg == r2t->sg);
1969                         iscsi_buf_init_sg(&r2t->sendbuf, r2t->sg);
1970                         r2t->sg += 1;
1971                 }
1972                 goto solicit_again;
1973         }
1974
1975 data_out_done:
1976         /*
1977          * Done with this Data-Out. Next, check if we have
1978          * to send another Data-Out for this R2T.
1979          */
1980         BUG_ON(r2t->data_length - r2t->sent < 0);
1981         left = r2t->data_length - r2t->sent;
1982         if (left) {
1983                 if (conn->datadgst_en) {
1984                         if (iscsi_digest_final_send(conn, ctask,
1985                                                     &dtask->digestbuf,
1986                                                     &dtask->digest, 1)) {
1987                                 debug_tcp("send r2t data digest 0x%x"
1988                                           "fail\n", dtask->digest);
1989                                 return -EAGAIN;
1990                         }
1991                         debug_tcp("r2t data send digest 0x%x\n",
1992                                   dtask->digest);
1993                 }
1994                 iscsi_solicit_data_cont(conn, ctask, r2t, left);
1995                 ctask->xmstate |= XMSTATE_SOL_DATA;
1996                 ctask->xmstate &= ~XMSTATE_SOL_HDR;
1997                 return 1;
1998         }
1999
2000         /*
2001          * Done with this R2T. Check if there are more
2002          * outstanding R2Ts ready to be processed.
2003          */
2004         BUG_ON(ctask->r2t_data_count - r2t->data_length < 0);
2005         if (conn->datadgst_en) {
2006                 if (iscsi_digest_final_send(conn, ctask, &dtask->digestbuf,
2007                                             &dtask->digest, 1)) {
2008                         debug_tcp("send last r2t data digest 0x%x"
2009                                   "fail\n", dtask->digest);
2010                         return -EAGAIN;
2011                 }
2012                 debug_tcp("r2t done dout digest 0x%x\n", dtask->digest);
2013         }
2014
2015         ctask->r2t_data_count -= r2t->data_length;
2016         ctask->r2t = NULL;
2017         spin_lock_bh(&session->lock);
2018         __kfifo_put(ctask->r2tpool.queue, (void*)&r2t, sizeof(void*));
2019         spin_unlock_bh(&session->lock);
2020         if (__kfifo_get(ctask->r2tqueue, (void*)&r2t, sizeof(void*))) {
2021                 ctask->r2t = r2t;
2022                 ctask->xmstate |= XMSTATE_SOL_DATA;
2023                 ctask->xmstate &= ~XMSTATE_SOL_HDR;
2024                 return 1;
2025         }
2026
2027         return 0;
2028 }
2029
2030 static inline int
2031 handle_xmstate_w_pad(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
2032 {
2033         struct iscsi_data_task *dtask = ctask->dtask;
2034         int sent;
2035
2036         ctask->xmstate &= ~XMSTATE_W_PAD;
2037         iscsi_buf_init_virt(&ctask->sendbuf, (char*)&ctask->pad,
2038                             ctask->pad_count);
2039         if (iscsi_sendpage(conn, &ctask->sendbuf, &ctask->pad_count, &sent)) {
2040                 ctask->xmstate |= XMSTATE_W_PAD;
2041                 return -EAGAIN;
2042         }
2043
2044         if (conn->datadgst_en) {
2045                 iscsi_buf_data_digest_update(conn, &ctask->sendbuf);
2046                 /* imm data? */
2047                 if (!dtask) {
2048                         if (iscsi_digest_final_send(conn, ctask, &ctask->immbuf,
2049                                                     &ctask->immdigest, 1)) {
2050                                 debug_tcp("send padding digest 0x%x"
2051                                           "fail!\n", ctask->immdigest);
2052                                 return -EAGAIN;
2053                         }
2054                         debug_tcp("done with padding, digest 0x%x\n",
2055                                   ctask->datadigest);
2056                 } else {
2057                         if (iscsi_digest_final_send(conn, ctask,
2058                                                     &dtask->digestbuf,
2059                                                     &dtask->digest, 1)) {
2060                                 debug_tcp("send padding digest 0x%x"
2061                                           "fail\n", dtask->digest);
2062                                 return -EAGAIN;
2063                         }
2064                         debug_tcp("done with padding, digest 0x%x\n",
2065                                   dtask->digest);
2066                 }
2067         }
2068
2069         return 0;
2070 }
2071
2072 static int
2073 iscsi_ctask_xmit(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
2074 {
2075         int rc = 0;
2076
2077         debug_scsi("ctask deq [cid %d xmstate %x itt 0x%x]\n",
2078                 conn->id, ctask->xmstate, ctask->itt);
2079
2080         /*
2081          * serialize with TMF AbortTask
2082          */
2083         if (ctask->mtask)
2084                 return rc;
2085
2086         if (ctask->xmstate & XMSTATE_R_HDR) {
2087                 rc = handle_xmstate_r_hdr(conn, ctask);
2088                 return rc;
2089         }
2090
2091         if (ctask->xmstate & XMSTATE_W_HDR) {
2092                 rc = handle_xmstate_w_hdr(conn, ctask);
2093                 if (rc)
2094                         return rc;
2095         }
2096
2097         /* XXX: for data digest xmit recover */
2098         if (ctask->xmstate & XMSTATE_DATA_DIGEST) {
2099                 rc = handle_xmstate_data_digest(conn, ctask);
2100                 if (rc)
2101                         return rc;
2102         }
2103
2104         if (ctask->xmstate & XMSTATE_IMM_DATA) {
2105                 rc = handle_xmstate_imm_data(conn, ctask);
2106                 if (rc)
2107                         return rc;
2108         }
2109
2110         if (ctask->xmstate & XMSTATE_UNS_HDR) {
2111                 BUG_ON(!ctask->unsol_count);
2112                 ctask->xmstate &= ~XMSTATE_UNS_HDR;
2113 unsolicit_head_again:
2114                 rc = handle_xmstate_uns_hdr(conn, ctask);
2115                 if (rc)
2116                         return rc;
2117         }
2118
2119         if (ctask->xmstate & XMSTATE_UNS_DATA) {
2120                 rc = handle_xmstate_uns_data(conn, ctask);
2121                 if (rc == 1)
2122                         goto unsolicit_head_again;
2123                 else if (rc)
2124                         return rc;
2125                 goto done;
2126         }
2127
2128         if (ctask->xmstate & XMSTATE_SOL_HDR) {
2129                 struct iscsi_r2t_info *r2t;
2130
2131                 ctask->xmstate &= ~XMSTATE_SOL_HDR;
2132                 ctask->xmstate |= XMSTATE_SOL_DATA;
2133                 if (!ctask->r2t)
2134                         __kfifo_get(ctask->r2tqueue, (void*)&ctask->r2t,
2135                                     sizeof(void*));
2136 solicit_head_again:
2137                 r2t = ctask->r2t;
2138                 if (conn->hdrdgst_en)
2139                         iscsi_hdr_digest(conn, &r2t->headbuf,
2140                                         (u8*)r2t->dtask->hdrext);
2141                 if (iscsi_sendhdr(conn, &r2t->headbuf, r2t->data_count)) {
2142                         ctask->xmstate &= ~XMSTATE_SOL_DATA;
2143                         ctask->xmstate |= XMSTATE_SOL_HDR;
2144                         return -EAGAIN;
2145                 }
2146
2147                 debug_scsi("sol dout [dsn %d itt 0x%x dlen %d sent %d]\n",
2148                         r2t->solicit_datasn - 1, ctask->itt, r2t->data_count,
2149                         r2t->sent);
2150         }
2151
2152         if (ctask->xmstate & XMSTATE_SOL_DATA) {
2153                 rc = handle_xmstate_sol_data(conn, ctask);
2154                 if (rc == 1)
2155                         goto solicit_head_again;
2156                 if (rc)
2157                         return rc;
2158         }
2159
2160 done:
2161         /*
2162          * Last thing to check is whether we need to send write
2163          * padding. Note that we check for xmstate equality, not just the bit.
2164          */
2165         if (ctask->xmstate == XMSTATE_W_PAD)
2166                 rc = handle_xmstate_w_pad(conn, ctask);
2167
2168         return rc;
2169 }
2170
2171 /**
2172  * iscsi_data_xmit - xmit any command into the scheduled connection
2173  * @conn: iscsi connection
2174  *
2175  * Notes:
2176  *      The function can return -EAGAIN in which case the caller must
2177  *      re-schedule it again later or recover. '0' return code means
2178  *      successful xmit.
2179  **/
2180 static int
2181 iscsi_data_xmit(struct iscsi_conn *conn)
2182 {
2183         if (unlikely(conn->suspend_tx)) {
2184                 debug_tcp("conn %d Tx suspended!\n", conn->id);
2185                 return 0;
2186         }
2187
2188         /*
2189          * Transmit in the following order:
2190          *
2191          * 1) un-finished xmit (ctask or mtask)
2192          * 2) immediate control PDUs
2193          * 3) write data
2194          * 4) SCSI commands
2195          * 5) non-immediate control PDUs
2196          *
2197          * No need to lock around __kfifo_get as long as
2198          * there's one producer and one consumer.
2199          */
2200
2201         BUG_ON(conn->ctask && conn->mtask);
2202
2203         if (conn->ctask) {
2204                 if (iscsi_ctask_xmit(conn, conn->ctask))
2205                         goto again;
2206                 /* done with this in-progress ctask */
2207                 conn->ctask = NULL;
2208         }
2209         if (conn->mtask) {
2210                 if (iscsi_mtask_xmit(conn, conn->mtask))
2211                         goto again;
2212                 /* done with this in-progress mtask */
2213                 conn->mtask = NULL;
2214         }
2215
2216         /* process immediate first */
2217         if (unlikely(__kfifo_len(conn->immqueue))) {
2218                 struct iscsi_session *session = conn->session;
2219                 while (__kfifo_get(conn->immqueue, (void*)&conn->mtask,
2220                                    sizeof(void*))) {
2221                         if (iscsi_mtask_xmit(conn, conn->mtask))
2222                                 goto again;
2223
2224                         if (conn->mtask->hdr.itt ==
2225                                         cpu_to_be32(ISCSI_RESERVED_TAG)) {
2226                                 spin_lock_bh(&session->lock);
2227                                 __kfifo_put(session->mgmtpool.queue,
2228                                             (void*)&conn->mtask, sizeof(void*));
2229                                 spin_unlock_bh(&session->lock);
2230                         }
2231                 }
2232                 /* done with this mtask */
2233                 conn->mtask = NULL;
2234         }
2235
2236         /* process write queue */
2237         while (__kfifo_get(conn->writequeue, (void*)&conn->ctask,
2238                            sizeof(void*))) {
2239                 if (iscsi_ctask_xmit(conn, conn->ctask))
2240                         goto again;
2241         }
2242
2243         /* process command queue */
2244         while (__kfifo_get(conn->xmitqueue, (void*)&conn->ctask,
2245                            sizeof(void*))) {
2246                 if (iscsi_ctask_xmit(conn, conn->ctask))
2247                         goto again;
2248         }
2249         /* done with this ctask */
2250         conn->ctask = NULL;
2251
2252         /* process the rest control plane PDUs, if any */
2253         if (unlikely(__kfifo_len(conn->mgmtqueue))) {
2254                 struct iscsi_session *session = conn->session;
2255
2256                 while (__kfifo_get(conn->mgmtqueue, (void*)&conn->mtask,
2257                                    sizeof(void*))) {
2258                         if (iscsi_mtask_xmit(conn, conn->mtask))
2259                                 goto again;
2260
2261                         if (conn->mtask->hdr.itt ==
2262                                         cpu_to_be32(ISCSI_RESERVED_TAG)) {
2263                                 spin_lock_bh(&session->lock);
2264                                 __kfifo_put(session->mgmtpool.queue,
2265                                             (void*)&conn->mtask,
2266                                             sizeof(void*));
2267                                 spin_unlock_bh(&session->lock);
2268                         }
2269                 }
2270                 /* done with this mtask */
2271                 conn->mtask = NULL;
2272         }
2273
2274         return 0;
2275
2276 again:
2277         if (unlikely(conn->suspend_tx))
2278                 return 0;
2279
2280         return -EAGAIN;
2281 }
2282
2283 static void
2284 iscsi_xmitworker(void *data)
2285 {
2286         struct iscsi_conn *conn = data;
2287
2288         /*
2289          * serialize Xmit worker on a per-connection basis.
2290          */
2291         down(&conn->xmitsema);
2292         if (iscsi_data_xmit(conn))
2293                 schedule_work(&conn->xmitwork);
2294         up(&conn->xmitsema);
2295 }
2296
2297 #define FAILURE_BAD_HOST                1
2298 #define FAILURE_SESSION_FAILED          2
2299 #define FAILURE_SESSION_FREED           3
2300 #define FAILURE_WINDOW_CLOSED           4
2301 #define FAILURE_SESSION_TERMINATE       5
2302
2303 static int
2304 iscsi_queuecommand(struct scsi_cmnd *sc, void (*done)(struct scsi_cmnd *))
2305 {
2306         struct Scsi_Host *host;
2307         int reason = 0;
2308         struct iscsi_session *session;
2309         struct iscsi_conn *conn = NULL;
2310         struct iscsi_cmd_task *ctask = NULL;
2311
2312         sc->scsi_done = done;
2313         sc->result = 0;
2314
2315         host = sc->device->host;
2316         session = iscsi_hostdata(host->hostdata);
2317         BUG_ON(host != session->host);
2318
2319         spin_lock(&session->lock);
2320
2321         if (session->state != ISCSI_STATE_LOGGED_IN) {
2322                 if (session->state == ISCSI_STATE_FAILED) {
2323                         reason = FAILURE_SESSION_FAILED;
2324                         goto reject;
2325                 } else if (session->state == ISCSI_STATE_TERMINATE) {
2326                         reason = FAILURE_SESSION_TERMINATE;
2327                         goto fault;
2328                 }
2329                 reason = FAILURE_SESSION_FREED;
2330                 goto fault;
2331         }
2332
2333         /*
2334          * Check for iSCSI window and take care of CmdSN wrap-around
2335          */
2336         if ((int)(session->max_cmdsn - session->cmdsn) < 0) {
2337                 reason = FAILURE_WINDOW_CLOSED;
2338                 goto reject;
2339         }
2340
2341         conn = session->leadconn;
2342
2343         __kfifo_get(session->cmdpool.queue, (void*)&ctask, sizeof(void*));
2344         BUG_ON(ctask->sc);
2345
2346         sc->SCp.phase = session->age;
2347         sc->SCp.ptr = (char*)ctask;
2348         iscsi_cmd_init(conn, ctask, sc);
2349
2350         __kfifo_put(conn->xmitqueue, (void*)&ctask, sizeof(void*));
2351         debug_scsi(
2352                "ctask enq [%s cid %d sc %lx itt 0x%x len %d cmdsn %d win %d]\n",
2353                 sc->sc_data_direction == DMA_TO_DEVICE ? "write" : "read",
2354                 conn->id, (long)sc, ctask->itt, sc->request_bufflen,
2355                 session->cmdsn, session->max_cmdsn - session->exp_cmdsn + 1);
2356         spin_unlock(&session->lock);
2357
2358         if (!in_interrupt() && !down_trylock(&conn->xmitsema)) {
2359                 spin_unlock_irq(host->host_lock);
2360                 if (iscsi_data_xmit(conn))
2361                         schedule_work(&conn->xmitwork);
2362                 up(&conn->xmitsema);
2363                 spin_lock_irq(host->host_lock);
2364         } else
2365                 schedule_work(&conn->xmitwork);
2366
2367         return 0;
2368
2369 reject:
2370         spin_unlock(&session->lock);
2371         debug_scsi("cmd 0x%x rejected (%d)\n", sc->cmnd[0], reason);
2372         return SCSI_MLQUEUE_HOST_BUSY;
2373
2374 fault:
2375         spin_unlock(&session->lock);
2376         printk(KERN_ERR "iscsi_tcp: cmd 0x%x is not queued (%d)\n",
2377                sc->cmnd[0], reason);
2378         sc->sense_buffer[0] = 0x70;
2379         sc->sense_buffer[2] = NOT_READY;
2380         sc->sense_buffer[7] = 0x6;
2381         sc->sense_buffer[12] = 0x08;
2382         sc->sense_buffer[13] = 0x00;
2383         sc->result = (DID_NO_CONNECT << 16);
2384         sc->resid = sc->request_bufflen;
2385         sc->scsi_done(sc);
2386         return 0;
2387 }
2388
2389 static int
2390 iscsi_pool_init(struct iscsi_queue *q, int max, void ***items, int item_size)
2391 {
2392         int i;
2393
2394         *items = kmalloc(max * sizeof(void*), GFP_KERNEL);
2395         if (*items == NULL)
2396                 return -ENOMEM;
2397
2398         q->max = max;
2399         q->pool = kmalloc(max * sizeof(void*), GFP_KERNEL);
2400         if (q->pool == NULL) {
2401                 kfree(*items);
2402                 return -ENOMEM;
2403         }
2404
2405         q->queue = kfifo_init((void*)q->pool, max * sizeof(void*),
2406                               GFP_KERNEL, NULL);
2407         if (q->queue == ERR_PTR(-ENOMEM)) {
2408                 kfree(q->pool);
2409                 kfree(*items);
2410                 return -ENOMEM;
2411         }
2412
2413         for (i = 0; i < max; i++) {
2414                 q->pool[i] = kmalloc(item_size, GFP_KERNEL);
2415                 if (q->pool[i] == NULL) {
2416                         int j;
2417
2418                         for (j = 0; j < i; j++)
2419                                 kfree(q->pool[j]);
2420
2421                         kfifo_free(q->queue);
2422                         kfree(q->pool);
2423                         kfree(*items);
2424                         return -ENOMEM;
2425                 }
2426                 memset(q->pool[i], 0, item_size);
2427                 (*items)[i] = q->pool[i];
2428                 __kfifo_put(q->queue, (void*)&q->pool[i], sizeof(void*));
2429         }
2430         return 0;
2431 }
2432
2433 static void
2434 iscsi_pool_free(struct iscsi_queue *q, void **items)
2435 {
2436         int i;
2437
2438         for (i = 0; i < q->max; i++)
2439                 kfree(items[i]);
2440         kfree(q->pool);
2441         kfree(items);
2442 }
2443
2444 static iscsi_connh_t
2445 iscsi_conn_create(iscsi_sessionh_t sessionh, uint32_t conn_idx)
2446 {
2447         struct iscsi_session *session = iscsi_ptr(sessionh);
2448         struct iscsi_conn *conn = NULL;
2449
2450         conn = kmalloc(sizeof(struct iscsi_conn), GFP_KERNEL);
2451         if (conn == NULL)
2452                 goto conn_alloc_fail;
2453         memset(conn, 0, sizeof(struct iscsi_conn));
2454
2455         conn->c_stage = ISCSI_CONN_INITIAL_STAGE;
2456         conn->in_progress = IN_PROGRESS_WAIT_HEADER;
2457         conn->id = conn_idx;
2458         conn->exp_statsn = 0;
2459         conn->tmabort_state = TMABORT_INITIAL;
2460
2461         /* initial operational parameters */
2462         conn->hdr_size = sizeof(struct iscsi_hdr);
2463         conn->data_size = DEFAULT_MAX_RECV_DATA_SEGMENT_LENGTH;
2464         conn->max_recv_dlength = DEFAULT_MAX_RECV_DATA_SEGMENT_LENGTH;
2465
2466         spin_lock_init(&conn->lock);
2467
2468         /* initialize general xmit PDU commands queue */
2469         conn->xmitqueue = kfifo_alloc(session->cmds_max * sizeof(void*),
2470                                         GFP_KERNEL, NULL);
2471         if (conn->xmitqueue == ERR_PTR(-ENOMEM))
2472                 goto xmitqueue_alloc_fail;
2473
2474         /* initialize write response PDU commands queue */
2475         conn->writequeue = kfifo_alloc(session->cmds_max * sizeof(void*),
2476                                         GFP_KERNEL, NULL);
2477         if (conn->writequeue == ERR_PTR(-ENOMEM))
2478                 goto writequeue_alloc_fail;
2479
2480         /* initialize general immediate & non-immediate PDU commands queue */
2481         conn->immqueue = kfifo_alloc(session->mgmtpool_max * sizeof(void*),
2482                                         GFP_KERNEL, NULL);
2483         if (conn->immqueue == ERR_PTR(-ENOMEM))
2484                 goto immqueue_alloc_fail;
2485
2486         conn->mgmtqueue = kfifo_alloc(session->mgmtpool_max * sizeof(void*),
2487                                         GFP_KERNEL, NULL);
2488         if (conn->mgmtqueue == ERR_PTR(-ENOMEM))
2489                 goto mgmtqueue_alloc_fail;
2490
2491         INIT_WORK(&conn->xmitwork, iscsi_xmitworker, conn);
2492
2493         /* allocate login_mtask used for the login/text sequences */
2494         spin_lock_bh(&session->lock);
2495         if (!__kfifo_get(session->mgmtpool.queue,
2496                          (void*)&conn->login_mtask,
2497                          sizeof(void*))) {
2498                 spin_unlock_bh(&session->lock);
2499                 goto login_mtask_alloc_fail;
2500         }
2501         spin_unlock_bh(&session->lock);
2502
2503         /* allocate initial PDU receive place holder */
2504         if (conn->data_size <= PAGE_SIZE)
2505                 conn->data = kmalloc(conn->data_size, GFP_KERNEL);
2506         else
2507                 conn->data = (void*)__get_free_pages(GFP_KERNEL,
2508                                         get_order(conn->data_size));
2509         if (!conn->data)
2510                 goto max_recv_dlenght_alloc_fail;
2511
2512         init_timer(&conn->tmabort_timer);
2513         init_MUTEX(&conn->xmitsema);
2514         init_waitqueue_head(&conn->ehwait);
2515
2516         return iscsi_handle(conn);
2517
2518 max_recv_dlenght_alloc_fail:
2519         spin_lock_bh(&session->lock);
2520         __kfifo_put(session->mgmtpool.queue, (void*)&conn->login_mtask,
2521                     sizeof(void*));
2522         spin_unlock_bh(&session->lock);
2523 login_mtask_alloc_fail:
2524         kfifo_free(conn->mgmtqueue);
2525 mgmtqueue_alloc_fail:
2526         kfifo_free(conn->immqueue);
2527 immqueue_alloc_fail:
2528         kfifo_free(conn->writequeue);
2529 writequeue_alloc_fail:
2530         kfifo_free(conn->xmitqueue);
2531 xmitqueue_alloc_fail:
2532         kfree(conn);
2533 conn_alloc_fail:
2534         return iscsi_handle(NULL);
2535 }
2536
2537 static void
2538 iscsi_conn_destroy(iscsi_connh_t connh)
2539 {
2540         struct iscsi_conn *conn = iscsi_ptr(connh);
2541         struct iscsi_session *session = conn->session;
2542
2543         down(&conn->xmitsema);
2544         set_bit(SUSPEND_BIT, &conn->suspend_tx);
2545         if (conn->c_stage == ISCSI_CONN_INITIAL_STAGE && conn->sock) {
2546                 struct sock *sk = conn->sock->sk;
2547
2548                 /*
2549                  * conn_start() has never been called!
2550                  * need to cleanup the socket.
2551                  */
2552                 write_lock_bh(&sk->sk_callback_lock);
2553                 set_bit(SUSPEND_BIT, &conn->suspend_rx);
2554                 write_unlock_bh(&sk->sk_callback_lock);
2555
2556                 sock_hold(conn->sock->sk);
2557                 iscsi_conn_restore_callbacks(conn);
2558                 sock_put(conn->sock->sk);
2559                 sock_release(conn->sock);
2560                 conn->sock = NULL;
2561         }
2562
2563         spin_lock_bh(&session->lock);
2564         conn->c_stage = ISCSI_CONN_CLEANUP_WAIT;
2565         if (session->leadconn == conn) {
2566                 /*
2567                  * leading connection? then give up on recovery.
2568                  */
2569                 session->state = ISCSI_STATE_TERMINATE;
2570                 wake_up(&conn->ehwait);
2571         }
2572         spin_unlock_bh(&session->lock);
2573
2574         up(&conn->xmitsema);
2575
2576         /*
2577          * Block until all in-progress commands for this connection
2578          * time out or fail.
2579          */
2580         for (;;) {
2581                 spin_lock_bh(&conn->lock);
2582                 if (!session->host->host_busy) { /* OK for ERL == 0 */
2583                         spin_unlock_bh(&conn->lock);
2584                         break;
2585                 }
2586                 spin_unlock_bh(&conn->lock);
2587                 msleep_interruptible(500);
2588                 printk("conn_destroy(): host_busy %d host_failed %d\n",
2589                         session->host->host_busy, session->host->host_failed);
2590                 /*
2591                  * force eh_abort() to unblock
2592                  */
2593                 wake_up(&conn->ehwait);
2594         }
2595
2596         /* now free crypto */
2597         if (conn->hdrdgst_en || conn->datadgst_en) {
2598                 if (conn->tx_tfm)
2599                         crypto_free_tfm(conn->tx_tfm);
2600                 if (conn->rx_tfm)
2601                         crypto_free_tfm(conn->rx_tfm);
2602                 if (conn->data_tx_tfm)
2603                         crypto_free_tfm(conn->data_tx_tfm);
2604                 if (conn->data_rx_tfm)
2605                         crypto_free_tfm(conn->data_rx_tfm);
2606         }
2607
2608         /* free conn->data, size = MaxRecvDataSegmentLength */
2609         if (conn->data_size <= PAGE_SIZE)
2610                 kfree(conn->data);
2611         else
2612                 free_pages((unsigned long)conn->data,
2613                                         get_order(conn->data_size));
2614
2615         spin_lock_bh(&session->lock);
2616         __kfifo_put(session->mgmtpool.queue, (void*)&conn->login_mtask,
2617                     sizeof(void*));
2618         list_del(&conn->item);
2619         if (list_empty(&session->connections))
2620                 session->leadconn = NULL;
2621         if (session->leadconn && session->leadconn == conn)
2622                 session->leadconn = container_of(session->connections.next,
2623                         struct iscsi_conn, item);
2624
2625         if (session->leadconn == NULL)
2626                 /* none connections exits.. reset sequencing */
2627                 session->cmdsn = session->max_cmdsn = session->exp_cmdsn = 1;
2628         spin_unlock_bh(&session->lock);
2629
2630         kfifo_free(conn->xmitqueue);
2631         kfifo_free(conn->writequeue);
2632         kfifo_free(conn->immqueue);
2633         kfifo_free(conn->mgmtqueue);
2634         kfree(conn);
2635 }
2636
2637 static int
2638 iscsi_conn_bind(iscsi_sessionh_t sessionh, iscsi_connh_t connh,
2639                 uint32_t transport_fd, int is_leading)
2640 {
2641         struct iscsi_session *session = iscsi_ptr(sessionh);
2642         struct iscsi_conn *tmp = ERR_PTR(-EEXIST), *conn = iscsi_ptr(connh);
2643         struct sock *sk;
2644         struct socket *sock;
2645         int err;
2646
2647         /* lookup for existing socket */
2648         sock = sockfd_lookup(transport_fd, &err);
2649         if (!sock) {
2650                 printk(KERN_ERR "iscsi_tcp: sockfd_lookup failed %d\n", err);
2651                 return -EEXIST;
2652         }
2653
2654         /* lookup for existing connection */
2655         spin_lock_bh(&session->lock);
2656         list_for_each_entry(tmp, &session->connections, item) {
2657                 if (tmp == conn) {
2658                         if (conn->c_stage != ISCSI_CONN_STOPPED ||
2659                             conn->stop_stage == STOP_CONN_TERM) {
2660                                 printk(KERN_ERR "iscsi_tcp: can't bind "
2661                                        "non-stopped connection (%d:%d)\n",
2662                                        conn->c_stage, conn->stop_stage);
2663                                 spin_unlock_bh(&session->lock);
2664                                 return -EIO;
2665                         }
2666                         break;
2667                 }
2668         }
2669         if (tmp != conn) {
2670                 /* bind new iSCSI connection to session */
2671                 conn->session = session;
2672
2673                 list_add(&conn->item, &session->connections);
2674         }
2675         spin_unlock_bh(&session->lock);
2676
2677         if (conn->stop_stage != STOP_CONN_SUSPEND) {
2678                 /* bind iSCSI connection and socket */
2679                 conn->sock = sock;
2680
2681                 /* setup Socket parameters */
2682                 sk = sock->sk;
2683                 sk->sk_reuse = 1;
2684                 sk->sk_sndtimeo = 15 * HZ; /* FIXME: make it configurable */
2685                 sk->sk_allocation = GFP_ATOMIC;
2686
2687                 /* FIXME: disable Nagle's algorithm */
2688
2689                 /*
2690                  * Intercept TCP callbacks for sendfile like receive
2691                  * processing.
2692                  */
2693                 iscsi_conn_set_callbacks(conn);
2694
2695                 /*
2696                  * set receive state machine into initial state
2697                  */
2698                 conn->in_progress = IN_PROGRESS_WAIT_HEADER;
2699         }
2700
2701         if (is_leading)
2702                 session->leadconn = conn;
2703
2704         /*
2705          * Unblock xmitworker(), Login Phase will pass through.
2706          */
2707         clear_bit(SUSPEND_BIT, &conn->suspend_rx);
2708         clear_bit(SUSPEND_BIT, &conn->suspend_tx);
2709
2710         return 0;
2711 }
2712
2713 static int
2714 iscsi_conn_start(iscsi_connh_t connh)
2715 {
2716         struct iscsi_conn *conn = iscsi_ptr(connh);
2717         struct iscsi_session *session = conn->session;
2718         struct sock *sk;
2719
2720         /* FF phase warming up... */
2721
2722         if (session == NULL) {
2723                 printk(KERN_ERR "iscsi_tcp: can't start unbound connection\n");
2724                 return -EPERM;
2725         }
2726
2727         sk = conn->sock->sk;
2728
2729         write_lock_bh(&sk->sk_callback_lock);
2730         spin_lock_bh(&session->lock);
2731         conn->c_stage = ISCSI_CONN_STARTED;
2732         session->state = ISCSI_STATE_LOGGED_IN;
2733
2734         switch(conn->stop_stage) {
2735         case STOP_CONN_RECOVER:
2736                 /*
2737                  * unblock eh_abort() if it is blocked. re-try all
2738                  * commands after successful recovery
2739                  */
2740                 session->conn_cnt++;
2741                 conn->stop_stage = 0;
2742                 conn->tmabort_state = TMABORT_INITIAL;
2743                 session->age++;
2744                 wake_up(&conn->ehwait);
2745                 break;
2746         case STOP_CONN_TERM:
2747                 session->conn_cnt++;
2748                 conn->stop_stage = 0;
2749                 break;
2750         case STOP_CONN_SUSPEND:
2751                 conn->stop_stage = 0;
2752                 clear_bit(SUSPEND_BIT, &conn->suspend_rx);
2753                 clear_bit(SUSPEND_BIT, &conn->suspend_tx);
2754                 break;
2755         default:
2756                 break;
2757         }
2758         spin_unlock_bh(&session->lock);
2759         write_unlock_bh(&sk->sk_callback_lock);
2760
2761         return 0;
2762 }
2763
2764 static void
2765 iscsi_conn_stop(iscsi_connh_t connh, int flag)
2766 {
2767         struct iscsi_conn *conn = iscsi_ptr(connh);
2768         struct iscsi_session *session = conn->session;
2769         struct sock *sk;
2770         unsigned long flags;
2771
2772         BUG_ON(!conn->sock);
2773         sk = conn->sock->sk;
2774         write_lock_bh(&sk->sk_callback_lock);
2775         set_bit(SUSPEND_BIT, &conn->suspend_rx);
2776         write_unlock_bh(&sk->sk_callback_lock);
2777
2778         down(&conn->xmitsema);
2779
2780         spin_lock_irqsave(session->host->host_lock, flags);
2781         spin_lock(&session->lock);
2782         conn->stop_stage = flag;
2783         conn->c_stage = ISCSI_CONN_STOPPED;
2784         set_bit(SUSPEND_BIT, &conn->suspend_tx);
2785
2786         if (flag != STOP_CONN_SUSPEND)
2787                 session->conn_cnt--;
2788
2789         if (session->conn_cnt == 0 || session->leadconn == conn)
2790                 session->state = ISCSI_STATE_FAILED;
2791
2792         spin_unlock(&session->lock);
2793         spin_unlock_irqrestore(session->host->host_lock, flags);
2794
2795         if (flag == STOP_CONN_TERM || flag == STOP_CONN_RECOVER) {
2796                 struct iscsi_cmd_task *ctask;
2797                 struct iscsi_mgmt_task *mtask;
2798
2799                 /*
2800                  * Socket must go now.
2801                  */
2802                 sock_hold(conn->sock->sk);
2803                 iscsi_conn_restore_callbacks(conn);
2804                 sock_put(conn->sock->sk);
2805
2806                 /*
2807                  * flush xmit queues.
2808                  */
2809                 spin_lock_bh(&session->lock);
2810                 while (__kfifo_get(conn->writequeue, (void*)&ctask,
2811                             sizeof(void*)) ||
2812                         __kfifo_get(conn->xmitqueue, (void*)&ctask,
2813                             sizeof(void*))) {
2814                         struct iscsi_r2t_info *r2t;
2815
2816                         /*
2817                          * flush ctask's r2t queues
2818                          */
2819                         while (__kfifo_get(ctask->r2tqueue, (void*)&r2t,
2820                                 sizeof(void*)))
2821                                 __kfifo_put(ctask->r2tpool.queue, (void*)&r2t,
2822                                             sizeof(void*));
2823
2824                         spin_unlock_bh(&session->lock);
2825                         local_bh_disable();
2826                         iscsi_ctask_cleanup(conn, ctask);
2827                         local_bh_enable();
2828                         spin_lock_bh(&session->lock);
2829                 }
2830                 conn->ctask = NULL;
2831                 while (__kfifo_get(conn->immqueue, (void*)&mtask,
2832                            sizeof(void*)) ||
2833                         __kfifo_get(conn->mgmtqueue, (void*)&mtask,
2834                            sizeof(void*))) {
2835                         __kfifo_put(session->mgmtpool.queue,
2836                                     (void*)&mtask, sizeof(void*));
2837                 }
2838                 conn->mtask = NULL;
2839                 spin_unlock_bh(&session->lock);
2840
2841                 /*
2842                  * release socket only after we stopped data_xmit()
2843                  * activity and flushed all outstandings
2844                  */
2845                 sock_release(conn->sock);
2846                 conn->sock = NULL;
2847
2848                 /*
2849                  * for connection level recovery we should not calculate
2850                  * header digest. conn->hdr_size used for optimization
2851                  * in hdr_extract() and will be re-negotiated at
2852                  * set_param() time.
2853                  */
2854                 if (flag == STOP_CONN_RECOVER)
2855                         conn->hdr_size = sizeof(struct iscsi_hdr);
2856         }
2857         up(&conn->xmitsema);
2858 }
2859
2860 static int
2861 iscsi_conn_send_generic(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
2862                         char *data, uint32_t data_size)
2863 {
2864         struct iscsi_session *session = conn->session;
2865         struct iscsi_nopout *nop = (struct iscsi_nopout *)hdr;
2866         struct iscsi_mgmt_task *mtask;
2867
2868         spin_lock_bh(&session->lock);
2869         if (session->state == ISCSI_STATE_TERMINATE) {
2870                 spin_unlock_bh(&session->lock);
2871                 return -EPERM;
2872         }
2873         if (hdr->opcode == (ISCSI_OP_LOGIN | ISCSI_OP_IMMEDIATE) ||
2874             hdr->opcode == (ISCSI_OP_TEXT | ISCSI_OP_IMMEDIATE))
2875                 /*
2876                  * Login and Text are sent serially, in
2877                  * request-followed-by-response sequence.
2878                  * Same mtask can be used. Same ITT must be used.
2879                  * Note that login_mtask is preallocated at conn_create().
2880                  */
2881                 mtask = conn->login_mtask;
2882         else {
2883                 BUG_ON(conn->c_stage == ISCSI_CONN_INITIAL_STAGE);
2884                 BUG_ON(conn->c_stage == ISCSI_CONN_STOPPED);
2885
2886                 if (!__kfifo_get(session->mgmtpool.queue,
2887                                  (void*)&mtask, sizeof(void*))) {
2888                         spin_unlock_bh(&session->lock);
2889                         return -ENOSPC;
2890                 }
2891         }
2892
2893         /*
2894          * pre-format CmdSN and ExpStatSN for outgoing PDU.
2895          */
2896         if (hdr->itt != cpu_to_be32(ISCSI_RESERVED_TAG)) {
2897                 hdr->itt = mtask->itt | (conn->id << CID_SHIFT) |
2898                            (session->age << AGE_SHIFT);
2899                 nop->cmdsn = cpu_to_be32(session->cmdsn);
2900                 if (conn->c_stage == ISCSI_CONN_STARTED &&
2901                     !(hdr->opcode & ISCSI_OP_IMMEDIATE))
2902                         session->cmdsn++;
2903         } else
2904                 /* do not advance CmdSN */
2905                 nop->cmdsn = cpu_to_be32(session->cmdsn);
2906
2907         nop->exp_statsn = cpu_to_be32(conn->exp_statsn);
2908
2909         memcpy(&mtask->hdr, hdr, sizeof(struct iscsi_hdr));
2910
2911         iscsi_buf_init_virt(&mtask->headbuf, (char*)&mtask->hdr,
2912                                     sizeof(struct iscsi_hdr));
2913
2914         spin_unlock_bh(&session->lock);
2915
2916         if (data_size) {
2917                 memcpy(mtask->data, data, data_size);
2918                 mtask->data_count = data_size;
2919         } else
2920                 mtask->data_count = 0;
2921
2922         mtask->xmstate = XMSTATE_IMM_HDR;
2923
2924         if (mtask->data_count) {
2925                 iscsi_buf_init_iov(&mtask->sendbuf, (char*)mtask->data,
2926                                     mtask->data_count);
2927         }
2928
2929         debug_scsi("mgmtpdu [op 0x%x hdr->itt 0x%x datalen %d]\n",
2930                    hdr->opcode, hdr->itt, data_size);
2931
2932         /*
2933          * since send_pdu() could be called at least from two contexts,
2934          * we need to serialize __kfifo_put, so we don't have to take
2935          * additional lock on fast data-path
2936          */
2937         if (hdr->opcode & ISCSI_OP_IMMEDIATE)
2938                 __kfifo_put(conn->immqueue, (void*)&mtask, sizeof(void*));
2939         else
2940                 __kfifo_put(conn->mgmtqueue, (void*)&mtask, sizeof(void*));
2941
2942         schedule_work(&conn->xmitwork);
2943
2944         return 0;
2945 }
2946
2947 static int
2948 iscsi_eh_host_reset(struct scsi_cmnd *sc)
2949 {
2950         struct iscsi_cmd_task *ctask = (struct iscsi_cmd_task *)sc->SCp.ptr;
2951         struct iscsi_conn *conn = ctask->conn;
2952         struct iscsi_session *session = conn->session;
2953
2954         spin_lock_bh(&session->lock);
2955         if (session->state == ISCSI_STATE_TERMINATE) {
2956                 debug_scsi("failing host reset: session terminated "
2957                            "[CID %d age %d]", conn->id, session->age);
2958                 spin_unlock_bh(&session->lock);
2959                 return FAILED;
2960         }
2961         spin_unlock_bh(&session->lock);
2962
2963         debug_scsi("failing connection CID %d due to SCSI host reset "
2964                    "[itt 0x%x age %d]", conn->id, ctask->itt,
2965                    session->age);
2966         iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
2967
2968         return SUCCESS;
2969 }
2970
2971 static void
2972 iscsi_tmabort_timedout(unsigned long data)
2973 {
2974         struct iscsi_cmd_task *ctask = (struct iscsi_cmd_task *)data;
2975         struct iscsi_conn *conn = ctask->conn;
2976         struct iscsi_session *session = conn->session;
2977
2978         spin_lock(&session->lock);
2979         if (conn->tmabort_state == TMABORT_INITIAL) {
2980                 __kfifo_put(session->mgmtpool.queue,
2981                                 (void*)&ctask->mtask, sizeof(void*));
2982                 conn->tmabort_state = TMABORT_TIMEDOUT;
2983                 debug_scsi("tmabort timedout [sc %lx itt 0x%x]\n",
2984                         (long)ctask->sc, ctask->itt);
2985                 /* unblock eh_abort() */
2986                 wake_up(&conn->ehwait);
2987         }
2988         spin_unlock(&session->lock);
2989 }
2990
2991 static int
2992 iscsi_eh_abort(struct scsi_cmnd *sc)
2993 {
2994         int rc;
2995         struct iscsi_cmd_task *ctask = (struct iscsi_cmd_task *)sc->SCp.ptr;
2996         struct iscsi_conn *conn = ctask->conn;
2997         struct iscsi_session *session = conn->session;
2998
2999         conn->eh_abort_cnt++;
3000         debug_scsi("aborting [sc %lx itt 0x%x]\n", (long)sc, ctask->itt);
3001
3002         /*
3003          * two cases for ERL=0 here:
3004          *
3005          * 1) connection-level failure;
3006          * 2) recovery due protocol error;
3007          */
3008         down(&conn->xmitsema);
3009         spin_lock_bh(&session->lock);
3010         if (session->state != ISCSI_STATE_LOGGED_IN) {
3011                 if (session->state == ISCSI_STATE_TERMINATE) {
3012                         spin_unlock_bh(&session->lock);
3013                         up(&conn->xmitsema);
3014                         goto failed;
3015                 }
3016                 spin_unlock_bh(&session->lock);
3017         } else {
3018                 struct iscsi_tm *hdr = &conn->tmhdr;
3019
3020                 /*
3021                  * Still LOGGED_IN...
3022                  */
3023
3024                 if (!ctask->sc || sc->SCp.phase != session->age) {
3025                         /*
3026                          * 1) ctask completed before time out. But session
3027                          *    is still ok => Happy Retry.
3028                          * 2) session was re-open during time out of ctask.
3029                          */
3030                         spin_unlock_bh(&session->lock);
3031                         up(&conn->xmitsema);
3032                         goto success;
3033                 }
3034                 conn->tmabort_state = TMABORT_INITIAL;
3035                 spin_unlock_bh(&session->lock);
3036
3037                 /*
3038                  * ctask timed out but session is OK
3039                  * ERL=0 requires task mgmt abort to be issued on each
3040                  * failed command. requests must be serialized.
3041                  */
3042                 memset(hdr, 0, sizeof(struct iscsi_tm));
3043                 hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
3044                 hdr->flags = ISCSI_TM_FUNC_ABORT_TASK;
3045                 hdr->flags |= ISCSI_FLAG_CMD_FINAL;
3046                 memcpy(hdr->lun, ctask->hdr.lun, sizeof(hdr->lun));
3047                 hdr->rtt = ctask->hdr.itt;
3048                 hdr->refcmdsn = ctask->hdr.cmdsn;
3049
3050                 rc = iscsi_conn_send_generic(conn, (struct iscsi_hdr *)hdr,
3051                                              NULL, 0);
3052                 if (rc) {
3053                         iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
3054                         debug_scsi("abort sent failure [itt 0x%x]", ctask->itt);
3055                 } else {
3056                         struct iscsi_r2t_info *r2t;
3057
3058                         /*
3059                          * TMF abort vs. TMF response race logic
3060                          */
3061                         spin_lock_bh(&session->lock);
3062                         ctask->mtask = (struct iscsi_mgmt_task *)
3063                                 session->mgmt_cmds[(hdr->itt & ITT_MASK) -
3064                                                         ISCSI_MGMT_ITT_OFFSET];
3065                         /*
3066                          * have to flush r2tqueue to avoid r2t leaks
3067                          */
3068                         while (__kfifo_get(ctask->r2tqueue, (void*)&r2t,
3069                                 sizeof(void*))) {
3070                                 __kfifo_put(ctask->r2tpool.queue, (void*)&r2t,
3071                                         sizeof(void*));
3072                         }
3073                         if (conn->tmabort_state == TMABORT_INITIAL) {
3074                                 conn->tmfcmd_pdus_cnt++;
3075                                 conn->tmabort_timer.expires = 3*HZ + jiffies;
3076                                 conn->tmabort_timer.function =
3077                                                 iscsi_tmabort_timedout;
3078                                 conn->tmabort_timer.data = (unsigned long)ctask;
3079                                 add_timer(&conn->tmabort_timer);
3080                                 debug_scsi("abort sent [itt 0x%x]", ctask->itt);
3081                         } else {
3082                                 if (!ctask->sc ||
3083                                     conn->tmabort_state == TMABORT_SUCCESS) {
3084                                         conn->tmabort_state = TMABORT_INITIAL;
3085                                         spin_unlock_bh(&session->lock);
3086                                         up(&conn->xmitsema);
3087                                         goto success;
3088                                 }
3089                                 conn->tmabort_state = TMABORT_INITIAL;
3090                                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
3091                         }
3092                         spin_unlock_bh(&session->lock);
3093                 }
3094         }
3095         up(&conn->xmitsema);
3096
3097
3098         /*
3099          * block eh thread until:
3100          *
3101          * 1) abort response;
3102          * 2) abort timeout;
3103          * 3) session re-opened;
3104          * 4) session terminated;
3105          */
3106         for (;;) {
3107                 int p_state = session->state;
3108
3109                 rc = wait_event_interruptible(conn->ehwait,
3110                         (p_state == ISCSI_STATE_LOGGED_IN ?
3111                          (session->state == ISCSI_STATE_TERMINATE ||
3112                           conn->tmabort_state != TMABORT_INITIAL) :
3113                          (session->state == ISCSI_STATE_TERMINATE ||
3114                           session->state == ISCSI_STATE_LOGGED_IN)));
3115                 if (rc) {
3116                         /* shutdown.. */
3117                         session->state = ISCSI_STATE_TERMINATE;
3118                         goto failed;
3119                 }
3120
3121                 if (signal_pending(current))
3122                         flush_signals(current);
3123
3124                 if (session->state == ISCSI_STATE_TERMINATE)
3125                         goto failed;
3126
3127                 spin_lock_bh(&session->lock);
3128                 if (sc->SCp.phase == session->age &&
3129                    (conn->tmabort_state == TMABORT_TIMEDOUT ||
3130                     conn->tmabort_state == TMABORT_FAILED)) {
3131                         conn->tmabort_state = TMABORT_INITIAL;
3132                         if (!ctask->sc) {
3133                                 /*
3134                                  * ctask completed before tmf abort response or
3135                                  * time out.
3136                                  * But session is still ok => Happy Retry.
3137                                  */
3138                                 spin_unlock_bh(&session->lock);
3139                                 break;
3140                         }
3141                         spin_unlock_bh(&session->lock);
3142                         iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
3143                         continue;
3144                 }
3145                 spin_unlock_bh(&session->lock);
3146                 break;
3147         }
3148
3149 success:
3150         debug_scsi("abort success [sc %lx itt 0x%x]\n", (long)sc, ctask->itt);
3151         rc = SUCCESS;
3152         goto exit;
3153
3154 failed:
3155         debug_scsi("abort failed [sc %lx itt 0x%x]\n", (long)sc, ctask->itt);
3156         rc = FAILED;
3157
3158 exit:
3159         del_timer_sync(&conn->tmabort_timer);
3160
3161         down(&conn->xmitsema);
3162         if (conn->sock) {
3163                 struct sock *sk = conn->sock->sk;
3164
3165                 write_lock_bh(&sk->sk_callback_lock);
3166                 iscsi_ctask_cleanup(conn, ctask);
3167                 write_unlock_bh(&sk->sk_callback_lock);
3168         }
3169         up(&conn->xmitsema);
3170         return rc;
3171 }
3172
3173 static int
3174 iscsi_r2tpool_alloc(struct iscsi_session *session)
3175 {
3176         int i;
3177         int cmd_i;
3178
3179         /*
3180          * initialize per-task: R2T pool and xmit queue
3181          */
3182         for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
3183                 struct iscsi_cmd_task *ctask = session->cmds[cmd_i];
3184
3185                 /*
3186                  * pre-allocated x4 as much r2ts to handle race when
3187                  * target acks DataOut faster than we data_xmit() queues
3188                  * could replenish r2tqueue.
3189                  */
3190
3191                 /* R2T pool */
3192                 if (iscsi_pool_init(&ctask->r2tpool, session->max_r2t * 4,
3193                         (void***)&ctask->r2ts, sizeof(struct iscsi_r2t_info))) {
3194                         goto r2t_alloc_fail;
3195                 }
3196
3197                 /* R2T xmit queue */
3198                 ctask->r2tqueue = kfifo_alloc(
3199                       session->max_r2t * 4 * sizeof(void*), GFP_KERNEL, NULL);
3200                 if (ctask->r2tqueue == ERR_PTR(-ENOMEM)) {
3201                         iscsi_pool_free(&ctask->r2tpool, (void**)ctask->r2ts);
3202                         goto r2t_alloc_fail;
3203                 }
3204
3205                 /*
3206                  * number of
3207                  * Data-Out PDU's within R2T-sequence can be quite big;
3208                  * using mempool
3209                  */
3210                 ctask->datapool = mempool_create(ISCSI_DTASK_DEFAULT_MAX,
3211                          mempool_alloc_slab, mempool_free_slab, taskcache);
3212                 if (ctask->datapool == NULL) {
3213                         kfifo_free(ctask->r2tqueue);
3214                         iscsi_pool_free(&ctask->r2tpool, (void**)ctask->r2ts);
3215                         goto r2t_alloc_fail;
3216                 }
3217                 INIT_LIST_HEAD(&ctask->dataqueue);
3218         }
3219
3220         return 0;
3221
3222 r2t_alloc_fail:
3223         for (i = 0; i < cmd_i; i++) {
3224                 mempool_destroy(session->cmds[i]->datapool);
3225                 kfifo_free(session->cmds[i]->r2tqueue);
3226                 iscsi_pool_free(&session->cmds[i]->r2tpool,
3227                                 (void**)session->cmds[i]->r2ts);
3228         }
3229         return -ENOMEM;
3230 }
3231
3232 static void
3233 iscsi_r2tpool_free(struct iscsi_session *session)
3234 {
3235         int i;
3236
3237         for (i = 0; i < session->cmds_max; i++) {
3238                 mempool_destroy(session->cmds[i]->datapool);
3239                 kfifo_free(session->cmds[i]->r2tqueue);
3240                 iscsi_pool_free(&session->cmds[i]->r2tpool,
3241                                 (void**)session->cmds[i]->r2ts);
3242         }
3243 }
3244
3245 static struct scsi_host_template iscsi_sht = {
3246         .name                   = "iSCSI Initiator over TCP/IP, v."
3247                                   ISCSI_VERSION_STR,
3248         .queuecommand           = iscsi_queuecommand,
3249         .can_queue              = ISCSI_XMIT_CMDS_MAX - 1,
3250         .sg_tablesize           = ISCSI_SG_TABLESIZE,
3251         .cmd_per_lun            = ISCSI_CMD_PER_LUN,
3252         .eh_abort_handler       = iscsi_eh_abort,
3253         .eh_host_reset_handler  = iscsi_eh_host_reset,
3254         .use_clustering         = DISABLE_CLUSTERING,
3255         .proc_name              = "iscsi_tcp",
3256         .this_id                = -1,
3257 };
3258
3259 static iscsi_sessionh_t
3260 iscsi_session_create(uint32_t initial_cmdsn, struct Scsi_Host *host)
3261 {
3262         int cmd_i;
3263         struct iscsi_session *session;
3264
3265         session = iscsi_hostdata(host->hostdata);
3266         memset(session, 0, sizeof(struct iscsi_session));
3267
3268         session->host = host;
3269         session->id = host->host_no;
3270         session->state = ISCSI_STATE_LOGGED_IN;
3271         session->mgmtpool_max = ISCSI_MGMT_CMDS_MAX;
3272         session->cmds_max = ISCSI_XMIT_CMDS_MAX;
3273         session->cmdsn = initial_cmdsn;
3274         session->exp_cmdsn = initial_cmdsn + 1;
3275         session->max_cmdsn = initial_cmdsn + 1;
3276         session->max_r2t = 1;
3277
3278         /* initialize SCSI PDU commands pool */
3279         if (iscsi_pool_init(&session->cmdpool, session->cmds_max,
3280                 (void***)&session->cmds, sizeof(struct iscsi_cmd_task)))
3281                 goto cmdpool_alloc_fail;
3282
3283         /* pre-format cmds pool with ITT */
3284         for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++)
3285                 session->cmds[cmd_i]->itt = cmd_i;
3286
3287         spin_lock_init(&session->lock);
3288         INIT_LIST_HEAD(&session->connections);
3289
3290         /* initialize immediate command pool */
3291         if (iscsi_pool_init(&session->mgmtpool, session->mgmtpool_max,
3292                 (void***)&session->mgmt_cmds, sizeof(struct iscsi_mgmt_task)))
3293                 goto mgmtpool_alloc_fail;
3294
3295
3296         /* pre-format immediate cmds pool with ITT */
3297         for (cmd_i = 0; cmd_i < session->mgmtpool_max; cmd_i++) {
3298                 session->mgmt_cmds[cmd_i]->itt = ISCSI_MGMT_ITT_OFFSET + cmd_i;
3299                 session->mgmt_cmds[cmd_i]->data = kmalloc(
3300                         DEFAULT_MAX_RECV_DATA_SEGMENT_LENGTH, GFP_KERNEL);
3301                 if (!session->mgmt_cmds[cmd_i]->data) {
3302                         int j;
3303
3304                         for (j = 0; j < cmd_i; j++)
3305                                 kfree(session->mgmt_cmds[j]->data);
3306                         goto immdata_alloc_fail;
3307                 }
3308         }
3309
3310         if (iscsi_r2tpool_alloc(session))
3311                 goto r2tpool_alloc_fail;
3312
3313         return iscsi_handle(session);
3314
3315 r2tpool_alloc_fail:
3316         for (cmd_i = 0; cmd_i < session->mgmtpool_max; cmd_i++)
3317                 kfree(session->mgmt_cmds[cmd_i]->data);
3318         iscsi_pool_free(&session->mgmtpool, (void**)session->mgmt_cmds);
3319 immdata_alloc_fail:
3320 mgmtpool_alloc_fail:
3321         iscsi_pool_free(&session->cmdpool, (void**)session->cmds);
3322 cmdpool_alloc_fail:
3323         return iscsi_handle(NULL);
3324 }
3325
3326 static void
3327 iscsi_session_destroy(iscsi_sessionh_t sessionh)
3328 {
3329         int cmd_i;
3330         struct iscsi_data_task *dtask, *n;
3331         struct iscsi_session *session = iscsi_ptr(sessionh);
3332
3333         for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
3334                 struct iscsi_cmd_task *ctask = session->cmds[cmd_i];
3335                 list_for_each_entry_safe(dtask, n, &ctask->dataqueue, item) {
3336                         list_del(&dtask->item);
3337                         mempool_free(dtask, ctask->datapool);
3338                 }
3339         }
3340
3341         for (cmd_i = 0; cmd_i < session->mgmtpool_max; cmd_i++)
3342                 kfree(session->mgmt_cmds[cmd_i]->data);
3343
3344         iscsi_r2tpool_free(session);
3345         iscsi_pool_free(&session->mgmtpool, (void**)session->mgmt_cmds);
3346         iscsi_pool_free(&session->cmdpool, (void**)session->cmds);
3347 }
3348
3349 static int
3350 iscsi_conn_set_param(iscsi_connh_t connh, enum iscsi_param param,
3351                      uint32_t value)
3352 {
3353         struct iscsi_conn *conn = iscsi_ptr(connh);
3354         struct iscsi_session *session = conn->session;
3355
3356         spin_lock_bh(&session->lock);
3357         if (conn->c_stage != ISCSI_CONN_INITIAL_STAGE &&
3358             conn->stop_stage != STOP_CONN_RECOVER) {
3359                 printk(KERN_ERR "iscsi_tcp: can not change parameter [%d]\n",
3360                        param);
3361                 spin_unlock_bh(&session->lock);
3362                 return 0;
3363         }
3364         spin_unlock_bh(&session->lock);
3365
3366         switch(param) {
3367         case ISCSI_PARAM_MAX_RECV_DLENGTH: {
3368                 char *saveptr = conn->data;
3369                 int flags = GFP_KERNEL;
3370
3371                 if (conn->data_size >= value) {
3372                         conn->max_recv_dlength = value;
3373                         break;
3374                 }
3375
3376                 spin_lock_bh(&session->lock);
3377                 if (conn->stop_stage == STOP_CONN_RECOVER)
3378                         flags = GFP_ATOMIC;
3379                 spin_unlock_bh(&session->lock);
3380
3381                 if (value <= PAGE_SIZE)
3382                         conn->data = kmalloc(value, flags);
3383                 else
3384                         conn->data = (void*)__get_free_pages(flags,
3385                                                              get_order(value));
3386                 if (conn->data == NULL) {
3387                         conn->data = saveptr;
3388                         return -ENOMEM;
3389                 }
3390                 if (conn->data_size <= PAGE_SIZE)
3391                         kfree(saveptr);
3392                 else
3393                         free_pages((unsigned long)saveptr,
3394                                    get_order(conn->data_size));
3395                 conn->max_recv_dlength = value;
3396                 conn->data_size = value;
3397                 }
3398                 break;
3399         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
3400                 conn->max_xmit_dlength =  value;
3401                 break;
3402         case ISCSI_PARAM_HDRDGST_EN:
3403                 conn->hdrdgst_en = value;
3404                 conn->hdr_size = sizeof(struct iscsi_hdr);
3405                 if (conn->hdrdgst_en) {
3406                         conn->hdr_size += sizeof(__u32);
3407                         if (!conn->tx_tfm)
3408                                 conn->tx_tfm = crypto_alloc_tfm("crc32c", 0);
3409                         if (!conn->tx_tfm)
3410                                 return -ENOMEM;
3411                         if (!conn->rx_tfm)
3412                                 conn->rx_tfm = crypto_alloc_tfm("crc32c", 0);
3413                         if (!conn->rx_tfm) {
3414                                 crypto_free_tfm(conn->tx_tfm);
3415                                 return -ENOMEM;
3416                         }
3417                 } else {
3418                         if (conn->tx_tfm)
3419                                 crypto_free_tfm(conn->tx_tfm);
3420                         if (conn->rx_tfm)
3421                                 crypto_free_tfm(conn->rx_tfm);
3422                 }
3423                 break;
3424         case ISCSI_PARAM_DATADGST_EN:
3425                 conn->datadgst_en = value;
3426                 if (conn->datadgst_en) {
3427                         if (!conn->data_tx_tfm)
3428                                 conn->data_tx_tfm =
3429                                     crypto_alloc_tfm("crc32c", 0);
3430                         if (!conn->data_tx_tfm)
3431                                 return -ENOMEM;
3432                         if (!conn->data_rx_tfm)
3433                                 conn->data_rx_tfm =
3434                                     crypto_alloc_tfm("crc32c", 0);
3435                         if (!conn->data_rx_tfm) {
3436                                 crypto_free_tfm(conn->data_tx_tfm);
3437                                 return -ENOMEM;
3438                         }
3439                 } else {
3440                         if (conn->data_tx_tfm)
3441                                 crypto_free_tfm(conn->data_tx_tfm);
3442                         if (conn->data_rx_tfm)
3443                                 crypto_free_tfm(conn->data_rx_tfm);
3444                 }
3445                 break;
3446         case ISCSI_PARAM_INITIAL_R2T_EN:
3447                 session->initial_r2t_en = value;
3448                 break;
3449         case ISCSI_PARAM_MAX_R2T:
3450                 if (session->max_r2t == roundup_pow_of_two(value))
3451                         break;
3452                 iscsi_r2tpool_free(session);
3453                 session->max_r2t = value;
3454                 if (session->max_r2t & (session->max_r2t - 1))
3455                         session->max_r2t = roundup_pow_of_two(session->max_r2t);
3456                 if (iscsi_r2tpool_alloc(session))
3457                         return -ENOMEM;
3458                 break;
3459         case ISCSI_PARAM_IMM_DATA_EN:
3460                 session->imm_data_en = value;
3461                 break;
3462         case ISCSI_PARAM_FIRST_BURST:
3463                 session->first_burst = value;
3464                 break;
3465         case ISCSI_PARAM_MAX_BURST:
3466                 session->max_burst = value;
3467                 break;
3468         case ISCSI_PARAM_PDU_INORDER_EN:
3469                 session->pdu_inorder_en = value;
3470                 break;
3471         case ISCSI_PARAM_DATASEQ_INORDER_EN:
3472                 session->dataseq_inorder_en = value;
3473                 break;
3474         case ISCSI_PARAM_ERL:
3475                 session->erl = value;
3476                 break;
3477         case ISCSI_PARAM_IFMARKER_EN:
3478                 BUG_ON(value);
3479                 session->ifmarker_en = value;
3480                 break;
3481         case ISCSI_PARAM_OFMARKER_EN:
3482                 BUG_ON(value);
3483                 session->ofmarker_en = value;
3484                 break;
3485         default:
3486                 break;
3487         }
3488
3489         return 0;
3490 }
3491
3492 static int
3493 iscsi_conn_get_param(iscsi_connh_t connh, enum iscsi_param param,
3494                      uint32_t *value)
3495 {
3496         struct iscsi_conn *conn = iscsi_ptr(connh);
3497         struct iscsi_session *session = conn->session;
3498
3499         switch(param) {
3500         case ISCSI_PARAM_MAX_RECV_DLENGTH:
3501                 *value = conn->max_recv_dlength;
3502                 break;
3503         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
3504                 *value = conn->max_xmit_dlength;
3505                 break;
3506         case ISCSI_PARAM_HDRDGST_EN:
3507                 *value = conn->hdrdgst_en;
3508                 break;
3509         case ISCSI_PARAM_DATADGST_EN:
3510                 *value = conn->datadgst_en;
3511                 break;
3512         case ISCSI_PARAM_INITIAL_R2T_EN:
3513                 *value = session->initial_r2t_en;
3514                 break;
3515         case ISCSI_PARAM_MAX_R2T:
3516                 *value = session->max_r2t;
3517                 break;
3518         case ISCSI_PARAM_IMM_DATA_EN:
3519                 *value = session->imm_data_en;
3520                 break;
3521         case ISCSI_PARAM_FIRST_BURST:
3522                 *value = session->first_burst;
3523                 break;
3524         case ISCSI_PARAM_MAX_BURST:
3525                 *value = session->max_burst;
3526                 break;
3527         case ISCSI_PARAM_PDU_INORDER_EN:
3528                 *value = session->pdu_inorder_en;
3529                 break;
3530         case ISCSI_PARAM_DATASEQ_INORDER_EN:
3531                 *value = session->dataseq_inorder_en;
3532                 break;
3533         case ISCSI_PARAM_ERL:
3534                 *value = session->erl;
3535                 break;
3536         case ISCSI_PARAM_IFMARKER_EN:
3537                 *value = session->ifmarker_en;
3538                 break;
3539         case ISCSI_PARAM_OFMARKER_EN:
3540                 *value = session->ofmarker_en;
3541                 break;
3542         default:
3543                 return ISCSI_ERR_PARAM_NOT_FOUND;
3544         }
3545
3546         return 0;
3547 }
3548
3549 static void
3550 iscsi_conn_get_stats(iscsi_connh_t connh, struct iscsi_stats *stats)
3551 {
3552         struct iscsi_conn *conn = iscsi_ptr(connh);
3553
3554         stats->txdata_octets = conn->txdata_octets;
3555         stats->rxdata_octets = conn->rxdata_octets;
3556         stats->scsicmd_pdus = conn->scsicmd_pdus_cnt;
3557         stats->dataout_pdus = conn->dataout_pdus_cnt;
3558         stats->scsirsp_pdus = conn->scsirsp_pdus_cnt;
3559         stats->datain_pdus = conn->datain_pdus_cnt;
3560         stats->r2t_pdus = conn->r2t_pdus_cnt;
3561         stats->tmfcmd_pdus = conn->tmfcmd_pdus_cnt;
3562         stats->tmfrsp_pdus = conn->tmfrsp_pdus_cnt;
3563         stats->custom_length = 3;
3564         strcpy(stats->custom[0].desc, "tx_sendpage_failures");
3565         stats->custom[0].value = conn->sendpage_failures_cnt;
3566         strcpy(stats->custom[1].desc, "rx_discontiguous_hdr");
3567         stats->custom[1].value = conn->discontiguous_hdr_cnt;
3568         strcpy(stats->custom[2].desc, "eh_abort_cnt");
3569         stats->custom[2].value = conn->eh_abort_cnt;
3570 }
3571
3572 static int
3573 iscsi_conn_send_pdu(iscsi_connh_t connh, struct iscsi_hdr *hdr, char *data,
3574                     uint32_t data_size)
3575 {
3576         struct iscsi_conn *conn = iscsi_ptr(connh);
3577         int rc;
3578
3579         down(&conn->xmitsema);
3580         rc = iscsi_conn_send_generic(conn, hdr, data, data_size);
3581         up(&conn->xmitsema);
3582
3583         return rc;
3584 }
3585
3586 static struct iscsi_transport iscsi_tcp_transport = {
3587         .owner                  = THIS_MODULE,
3588         .name                   = "tcp",
3589         .caps                   = CAP_RECOVERY_L0 | CAP_MULTI_R2T | CAP_HDRDGST
3590                                   | CAP_DATADGST,
3591         .host_template          = &iscsi_sht,
3592         .hostdata_size          = sizeof(struct iscsi_session),
3593         .max_conn               = 1,
3594         .max_cmd_len            = ISCSI_TCP_MAX_CMD_LEN,
3595         .create_session         = iscsi_session_create,
3596         .destroy_session        = iscsi_session_destroy,
3597         .create_conn            = iscsi_conn_create,
3598         .bind_conn              = iscsi_conn_bind,
3599         .destroy_conn           = iscsi_conn_destroy,
3600         .set_param              = iscsi_conn_set_param,
3601         .get_param              = iscsi_conn_get_param,
3602         .start_conn             = iscsi_conn_start,
3603         .stop_conn              = iscsi_conn_stop,
3604         .send_pdu               = iscsi_conn_send_pdu,
3605         .get_stats              = iscsi_conn_get_stats,
3606 };
3607
3608 static int __init
3609 iscsi_tcp_init(void)
3610 {
3611         int error;
3612
3613         if (iscsi_max_lun < 1) {
3614                 printk(KERN_ERR "Invalid max_lun value of %u\n", iscsi_max_lun);
3615                 return -EINVAL;
3616         }
3617         iscsi_tcp_transport.max_lun = iscsi_max_lun;
3618
3619         taskcache = kmem_cache_create("iscsi_taskcache",
3620                         sizeof(struct iscsi_data_task), 0,
3621                         SLAB_HWCACHE_ALIGN | SLAB_NO_REAP, NULL, NULL);
3622         if (!taskcache)
3623                 return -ENOMEM;
3624
3625         error = iscsi_register_transport(&iscsi_tcp_transport);
3626         if (error)
3627                 kmem_cache_destroy(taskcache);
3628
3629         return error;
3630 }
3631
3632 static void __exit
3633 iscsi_tcp_exit(void)
3634 {
3635         iscsi_unregister_transport(&iscsi_tcp_transport);
3636         kmem_cache_destroy(taskcache);
3637 }
3638
3639 module_init(iscsi_tcp_init);
3640 module_exit(iscsi_tcp_exit);