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;
 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 (ctask->hdr.flags & ISCSI_FLAG_CMD_WRITE)
 646                                 rc = iscsi_cmd_rsp(conn, ctask);
 647                         else if (!conn->in.datalen)
 648                                 rc = iscsi_cmd_rsp(conn, ctask);
 649                         else
 650                                 /*
 651                                  * got sense or response data; copying PDU
 652                                  * Header to the connection's header
 653                                  * placeholder
 654                                  */
 655                                 memcpy(&conn->hdr, hdr,
 656                                        sizeof(struct iscsi_hdr));
 657                         break;
 658                 case ISCSI_OP_SCSI_DATA_IN:
 659                         BUG_ON((void*)ctask != ctask->sc->SCp.ptr);
 660                         /* save flags for non-exceptional status */
 661                         conn->in.flags = hdr->flags;
 662                         /* save cmd_status for sense data */
 663                         conn->in.cmd_status =
 664                                 ((struct iscsi_data_rsp*)hdr)->cmd_status;
 665                         rc = iscsi_data_rsp(conn, ctask);
 666                         break;
 667                 case ISCSI_OP_R2T:
 668                         BUG_ON((void*)ctask != ctask->sc->SCp.ptr);
 669                         if (ctask->hdr.flags & ISCSI_FLAG_CMD_WRITE &&
 670                             ctask->sc->sc_data_direction == DMA_TO_DEVICE)
 671                                 rc = iscsi_r2t_rsp(conn, ctask);
 672                         else
 673                                 rc = ISCSI_ERR_PROTO;
 674                         break;
 675                 default:
 676                         rc = ISCSI_ERR_BAD_OPCODE;
 677                         break;
 678                 }
 679         } else if (conn->in.itt >= ISCSI_MGMT_ITT_OFFSET &&
 680                    conn->in.itt < ISCSI_MGMT_ITT_OFFSET +
 681                                         session->mgmtpool_max) {
 682                 struct iscsi_mgmt_task *mtask = (struct iscsi_mgmt_task *)
 683                                         session->mgmt_cmds[conn->in.itt -
 684                                                 ISCSI_MGMT_ITT_OFFSET];
 685
 686                 debug_scsi("immrsp [op 0x%x cid %d itt 0x%x len %d]\n",
 687                            conn->in.opcode, conn->id, mtask->itt,
 688                            conn->in.datalen);
 689
 690                 switch(conn->in.opcode) {
 691                 case ISCSI_OP_LOGIN_RSP:
 692                 case ISCSI_OP_TEXT_RSP:
 693                 case ISCSI_OP_LOGOUT_RSP:
 694                         rc = iscsi_check_assign_cmdsn(session,
 695                                                  (struct iscsi_nopin*)hdr);
 696                         if (rc)
 697                                 break;
 698
 699                         if (!conn->in.datalen) {
 700                                 rc = iscsi_recv_pdu(iscsi_handle(conn), hdr,
 701                                                     NULL, 0);
 702                                 if (conn->login_mtask != mtask) {
 703                                         spin_lock(&session->lock);
 704                                         __kfifo_put(session->mgmtpool.queue,
 705                                             (void*)&mtask, sizeof(void*));
 706                                         spin_unlock(&session->lock);
 707                                 }
 708                         }
 709                         break;
 710                 case ISCSI_OP_SCSI_TMFUNC_RSP:
 711                         rc = iscsi_check_assign_cmdsn(session,
 712                                                  (struct iscsi_nopin*)hdr);
 713                         if (rc)
 714                                 break;
 715
 716                         if (conn->in.datalen || conn->in.ahslen) {
 717                                 rc = ISCSI_ERR_PROTO;
 718                                 break;
 719                         }
 720                         conn->tmfrsp_pdus_cnt++;
 721                         spin_lock(&session->lock);
 722                         if (conn->tmabort_state == TMABORT_INITIAL) {
 723                                 __kfifo_put(session->mgmtpool.queue,
 724                                                 (void*)&mtask, sizeof(void*));
 725                                 conn->tmabort_state =
 726                                         ((struct iscsi_tm_rsp *)hdr)->
 727                                         response == ISCSI_TMF_RSP_COMPLETE ?
 728                                                 TMABORT_SUCCESS:TMABORT_FAILED;
 729                                 /* unblock eh_abort() */
 730                                 wake_up(&conn->ehwait);
 731                         }
 732                         spin_unlock(&session->lock);
 733                         break;
 734                 case ISCSI_OP_NOOP_IN:
 735                         if (hdr->ttt != ISCSI_RESERVED_TAG) {
 736                                 rc = ISCSI_ERR_PROTO;
 737                                 break;
 738                         }
 739                         rc = iscsi_check_assign_cmdsn(session,
 740                                                 (struct iscsi_nopin*)hdr);
 741                         if (rc)
 742                                 break;
 743                         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
 744
 745                         if (!conn->in.datalen) {
 746                                 struct iscsi_mgmt_task *mtask;
 747
 748                                 rc = iscsi_recv_pdu(iscsi_handle(conn), hdr,
 749                                                     NULL, 0);
 750                                 mtask = (struct iscsi_mgmt_task *)
 751                                         session->mgmt_cmds[conn->in.itt -
 752                                                         ISCSI_MGMT_ITT_OFFSET];
 753                                 if (conn->login_mtask != mtask) {
 754                                         spin_lock(&session->lock);
 755                                         __kfifo_put(session->mgmtpool.queue,
 756                                                   (void*)&mtask, sizeof(void*));
 757                                         spin_unlock(&session->lock);
 758                                 }
 759                         }
 760                         break;
 761                 default:
 762                         rc = ISCSI_ERR_BAD_OPCODE;
 763                         break;
 764                 }
 765         } else if (conn->in.itt == ISCSI_RESERVED_TAG) {
 766                 switch(conn->in.opcode) {
 767                 case ISCSI_OP_NOOP_IN:
 768                         if (!conn->in.datalen) {
 769                                 rc = iscsi_check_assign_cmdsn(session,
 770                                                  (struct iscsi_nopin*)hdr);
 771                                 if (!rc && hdr->ttt != ISCSI_RESERVED_TAG)
 772                                         rc = iscsi_recv_pdu(iscsi_handle(conn),
 773                                                             hdr, NULL, 0);
 774                         } else
 775                                 rc = ISCSI_ERR_PROTO;
 776                         break;
 777                 case ISCSI_OP_REJECT:
 778                         /* we need sth like iscsi_reject_rsp()*/
 779                 case ISCSI_OP_ASYNC_EVENT:
 780                         /* we need sth like iscsi_async_event_rsp() */
 781                         rc = ISCSI_ERR_BAD_OPCODE;
 782                         break;
 783                 default:
 784                         rc = ISCSI_ERR_BAD_OPCODE;
 785                         break;
 786                 }
 787         } else
 788                 rc = ISCSI_ERR_BAD_ITT;
 789
 790         return rc;
 791 }
 792
 793 /**
 794  * iscsi_ctask_copy - copy skb bits to the destanation cmd task
 795  * @conn: iscsi connection
 796  * @ctask: scsi command task
 797  * @buf: buffer to copy to
 798  * @buf_size: size of buffer
 799  * @offset: offset within the buffer
 800  *
 801  * Notes:
 802  *      The function calls skb_copy_bits() and updates per-connection and
 803  *      per-cmd byte counters.
 804  *
 805  *      Read counters (in bytes):
 806  *
 807  *      conn->in.offset         offset within in progress SKB
 808  *      conn->in.copy           left to copy from in progress SKB
 809  *                              including padding
 810  *      conn->in.copied         copied already from in progress SKB
 811  *      conn->data_copied       copied already from in progress buffer
 812  *      ctask->sent             total bytes sent up to the MidLayer
 813  *      ctask->data_count       left to copy from in progress Data-In
 814  *      buf_left                left to copy from in progress buffer
 815  **/
 816 static inline int
 817 iscsi_ctask_copy(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
 818                 void *buf, int buf_size, int offset)
 819 {
 820         int buf_left = buf_size - (conn->data_copied + offset);
 821         int size = min(conn->in.copy, buf_left);
 822         int rc;
 823
 824         size = min(size, ctask->data_count);
 825
 826         debug_tcp("ctask_copy %d bytes at offset %d copied %d\n",
 827                size, conn->in.offset, conn->in.copied);
 828
 829         BUG_ON(size <= 0);
 830         BUG_ON(ctask->sent + size > ctask->total_length);
 831
 832         rc = skb_copy_bits(conn->in.skb, conn->in.offset,
 833                            (char*)buf + (offset + conn->data_copied), size);
 834         /* must fit into skb->len */
 835         BUG_ON(rc);
 836
 837         conn->in.offset += size;
 838         conn->in.copy -= size;
 839         conn->in.copied += size;
 840         conn->data_copied += size;
 841         ctask->sent += size;
 842         ctask->data_count -= size;
 843
 844         BUG_ON(conn->in.copy < 0);
 845         BUG_ON(ctask->data_count < 0);
 846
 847         if (buf_size != (conn->data_copied + offset)) {
 848                 if (!ctask->data_count) {
 849                         BUG_ON(buf_size - conn->data_copied < 0);
 850                         /* done with this PDU */
 851                         return buf_size - conn->data_copied;
 852                 }
 853                 return -EAGAIN;
 854         }
 855
 856         /* done with this buffer or with both - PDU and buffer */
 857         conn->data_copied = 0;
 858         return 0;
 859 }
 860
 861 /**
 862  * iscsi_tcp_copy - copy skb bits to the destanation buffer
 863  * @conn: iscsi connection
 864  * @buf: buffer to copy to
 865  * @buf_size: number of bytes to copy
 866  *
 867  * Notes:
 868  *      The function calls skb_copy_bits() and updates per-connection
 869  *      byte counters.
 870  **/
 871 static inline int
 872 iscsi_tcp_copy(struct iscsi_conn *conn, void *buf, int buf_size)
 873 {
 874         int buf_left = buf_size - conn->data_copied;
 875         int size = min(conn->in.copy, buf_left);
 876         int rc;
 877
 878         debug_tcp("tcp_copy %d bytes at offset %d copied %d\n",
 879                size, conn->in.offset, conn->data_copied);
 880         BUG_ON(size <= 0);
 881
 882         rc = skb_copy_bits(conn->in.skb, conn->in.offset,
 883                            (char*)buf + conn->data_copied, size);
 884         BUG_ON(rc);
 885
 886         conn->in.offset += size;
 887         conn->in.copy -= size;
 888         conn->in.copied += size;
 889         conn->data_copied += size;
 890
 891         if (buf_size != conn->data_copied)
 892                 return -EAGAIN;
 893
 894         return 0;
 895 }
 896
 897 static inline void
 898 partial_sg_digest_update(struct iscsi_conn *conn, struct scatterlist *sg,
 899                          int offset, int length)
 900 {
 901         struct scatterlist temp;
 902
 903         memcpy(&temp, sg, sizeof(struct scatterlist));
 904         temp.offset = offset;
 905         temp.length = length;
 906         crypto_digest_update(conn->data_rx_tfm, &temp, 1);
 907 }
 908
 909 static int iscsi_scsi_data_in(struct iscsi_conn *conn)
 910 {
 911         struct iscsi_cmd_task *ctask = conn->in.ctask;
 912         struct scsi_cmnd *sc = ctask->sc;
 913         struct scatterlist tmp, *sg;
 914         int i, offset, rc = 0;
 915
 916         BUG_ON((void*)ctask != sc->SCp.ptr);
 917
 918         /*
 919          * copying Data-In into the Scsi_Cmnd
 920          */
 921         if (!sc->use_sg) {
 922                 i = ctask->data_count;
 923                 rc = iscsi_ctask_copy(conn, ctask, sc->request_buffer,
 924                                       sc->request_bufflen, ctask->data_offset);
 925                 if (rc == -EAGAIN)
 926                         return rc;
 927                 if (conn->datadgst_en) {
 928                         sg_init_one(&tmp, sc->request_buffer, i);
 929                         crypto_digest_update(conn->data_rx_tfm, &tmp, 1);
 930                 }
 931                 rc = 0;
 932                 goto done;
 933         }
 934
 935         offset = ctask->data_offset;
 936         sg = sc->request_buffer;
 937
 938         if (ctask->data_offset)
 939                 for (i = 0; i < ctask->sg_count; i++)
 940                         offset -= sg[i].length;
 941         /* we've passed through partial sg*/
 942         if (offset < 0)
 943                 offset = 0;
 944
 945         for (i = ctask->sg_count; i < sc->use_sg; i++) {
 946                 char *dest;
 947
 948                 dest = kmap_atomic(sg[i].page, KM_SOFTIRQ0);
 949                 rc = iscsi_ctask_copy(conn, ctask, dest + sg[i].offset,
 950                                       sg[i].length, offset);
 951                 kunmap_atomic(dest, KM_SOFTIRQ0);
 952                 if (rc == -EAGAIN)
 953                         /* continue with the next SKB/PDU */
 954                         return rc;
 955                 if (!rc) {
 956                         if (conn->datadgst_en) {
 957                                 if (!offset)
 958                                         crypto_digest_update(conn->data_rx_tfm,
 959                                                              &sg[i], 1);
 960                                 else
 961                                         partial_sg_digest_update(conn, &sg[i],
 962                                                         sg[i].offset + offset,
 963                                                         sg[i].length - offset);
 964                         }
 965                         offset = 0;
 966                         ctask->sg_count++;
 967                 }
 968
 969                 if (!ctask->data_count) {
 970                         if (rc && conn->datadgst_en)
 971                                 /*
 972                                  * data-in is complete, but buffer not...
 973                                  */
 974                                 partial_sg_digest_update(conn, &sg[i],
 975                                                 sg[i].offset, sg[i].length-rc);
 976                         rc = 0;
 977                         break;
 978                 }
 979
 980                 if (!conn->in.copy)
 981                         return -EAGAIN;
 982         }
 983         BUG_ON(ctask->data_count);
 984
 985 done:
 986         /* check for non-exceptional status */
 987         if (conn->in.flags & ISCSI_FLAG_DATA_STATUS) {
 988                 debug_scsi("done [sc %lx res %d itt 0x%x]\n",
 989                            (long)sc, sc->result, ctask->itt);
 990                 conn->scsirsp_pdus_cnt++;
 991                 iscsi_ctask_cleanup(conn, ctask);
 992                 sc->scsi_done(sc);
 993         }
 994
 995         return rc;
 996 }
 997
 998 static int
 999 iscsi_data_recv(struct iscsi_conn *conn)
1000 {
1001         struct iscsi_session *session = conn->session;
1002         int rc = 0;
1003
1004         switch(conn->in.opcode) {
1005         case ISCSI_OP_SCSI_DATA_IN:
1006                 rc = iscsi_scsi_data_in(conn);
1007                 break;
1008         case ISCSI_OP_SCSI_CMD_RSP: {
1009                 /*
1010                  * SCSI Sense Data:
1011                  * copying the entire Data Segment.
1012                  */
1013                 if (iscsi_tcp_copy(conn, conn->data, conn->in.datalen)) {
1014                         rc = -EAGAIN;
1015                         goto exit;
1016                 }
1017
1018                 /*
1019                  * check for sense
1020                  */
1021                 conn->in.hdr = &conn->hdr;
1022                 conn->senselen = (conn->data[0] << 8) | conn->data[1];
1023                 rc = iscsi_cmd_rsp(conn, conn->in.ctask);
1024         }
1025         break;
1026         case ISCSI_OP_TEXT_RSP:
1027         case ISCSI_OP_LOGIN_RSP:
1028         case ISCSI_OP_NOOP_IN: {
1029                 struct iscsi_mgmt_task *mtask = NULL;
1030
1031                 if (conn->in.itt != ISCSI_RESERVED_TAG)
1032                         mtask = (struct iscsi_mgmt_task *)
1033                                 session->mgmt_cmds[conn->in.itt -
1034                                         ISCSI_MGMT_ITT_OFFSET];
1035
1036                 /*
1037                  * Collect data segment to the connection's data
1038                  * placeholder
1039                  */
1040                 if (iscsi_tcp_copy(conn, conn->data, conn->in.datalen)) {
1041                         rc = -EAGAIN;
1042                         goto exit;
1043                 }
1044
1045                 rc = iscsi_recv_pdu(iscsi_handle(conn), conn->in.hdr,
1046                                     conn->data, conn->in.datalen);
1047
1048                 if (mtask && conn->login_mtask != mtask) {
1049                         spin_lock(&session->lock);
1050                         __kfifo_put(session->mgmtpool.queue, (void*)&mtask,
1051                                     sizeof(void*));
1052                         spin_unlock(&session->lock);
1053                 }
1054         }
1055         break;
1056         default:
1057                 BUG_ON(1);
1058         }
1059 exit:
1060         return rc;
1061 }
1062
1063 /**
1064  * iscsi_tcp_data_recv - TCP receive in sendfile fashion
1065  * @rd_desc: read descriptor
1066  * @skb: socket buffer
1067  * @offset: offset in skb
1068  * @len: skb->len - offset
1069  **/
1070 static int
1071 iscsi_tcp_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb,
1072                 unsigned int offset, size_t len)
1073 {
1074         int rc;
1075         struct iscsi_conn *conn = rd_desc->arg.data;
1076         int processed;
1077         char pad[ISCSI_PAD_LEN];
1078         struct scatterlist sg;
1079
1080         /*
1081          * Save current SKB and its offset in the corresponding
1082          * connection context.
1083          */
1084         conn->in.copy = skb->len - offset;
1085         conn->in.offset = offset;
1086         conn->in.skb = skb;
1087         conn->in.len = conn->in.copy;
1088         BUG_ON(conn->in.copy <= 0);
1089         debug_tcp("in %d bytes\n", conn->in.copy);
1090
1091 more:
1092         conn->in.copied = 0;
1093         rc = 0;
1094
1095         if (unlikely(conn->suspend_rx)) {
1096                 debug_tcp("conn %d Rx suspended!\n", conn->id);
1097                 return 0;
1098         }
1099
1100         if (conn->in_progress == IN_PROGRESS_WAIT_HEADER ||
1101             conn->in_progress == IN_PROGRESS_HEADER_GATHER) {
1102                 rc = iscsi_hdr_extract(conn);
1103                 if (rc) {
1104                        if (rc == -EAGAIN)
1105                                 goto nomore;
1106                        else {
1107                                 iscsi_conn_failure(conn, rc);
1108                                 return 0;
1109                        }
1110                 }
1111
1112                 /*
1113                  * Verify and process incoming PDU header.
1114                  */
1115                 rc = iscsi_hdr_recv(conn);
1116                 if (!rc && conn->in.datalen) {
1117                         if (conn->datadgst_en &&
1118                             conn->in.opcode == ISCSI_OP_SCSI_DATA_IN) {
1119                                 BUG_ON(!conn->data_rx_tfm);
1120                                 crypto_digest_init(conn->data_rx_tfm);
1121                         }
1122                         conn->in_progress = IN_PROGRESS_DATA_RECV;
1123                 } else if (rc) {
1124                         iscsi_conn_failure(conn, rc);
1125                         return 0;
1126                 }
1127         }
1128
1129         if (conn->in_progress == IN_PROGRESS_DDIGEST_RECV) {
1130                 debug_tcp("extra data_recv offset %d copy %d\n",
1131                           conn->in.offset, conn->in.copy);
1132                 if (conn->in.opcode == ISCSI_OP_SCSI_DATA_IN) {
1133                         uint32_t recv_digest;
1134                         skb_copy_bits(conn->in.skb, conn->in.offset,
1135                                       &recv_digest, 4);
1136                         conn->in.offset += 4;
1137                         conn->in.copy -= 4;
1138                         if (recv_digest != conn->in.datadgst) {
1139                                 debug_tcp("iscsi_tcp: data digest error!"
1140                                           "0x%x != 0x%x\n", recv_digest,
1141                                           conn->in.datadgst);
1142                                 iscsi_conn_failure(conn, ISCSI_ERR_DATA_DGST);
1143                                 return 0;
1144                         } else {
1145                                 debug_tcp("iscsi_tcp: data digest match!"
1146                                           "0x%x == 0x%x\n", recv_digest,
1147                                           conn->in.datadgst);
1148                                 conn->in_progress = IN_PROGRESS_WAIT_HEADER;
1149                         }
1150                 }
1151         }
1152
1153         if (conn->in_progress == IN_PROGRESS_DATA_RECV && conn->in.copy) {
1154
1155                 debug_tcp("data_recv offset %d copy %d\n",
1156                        conn->in.offset, conn->in.copy);
1157
1158                 rc = iscsi_data_recv(conn);
1159                 if (rc) {
1160                         if (rc == -EAGAIN) {
1161                                 rd_desc->count = conn->in.datalen -
1162                                                 conn->in.ctask->data_count;
1163                                 goto again;
1164                         }
1165                         iscsi_conn_failure(conn, rc);
1166                         return 0;
1167                 }
1168                 conn->in.copy -= conn->in.padding;
1169                 conn->in.offset += conn->in.padding;
1170                 if (conn->datadgst_en &&
1171                     conn->in.opcode == ISCSI_OP_SCSI_DATA_IN) {
1172                         if (conn->in.padding) {
1173                                 debug_tcp("padding -> %d\n", conn->in.padding);
1174                                 memset(pad, 0, conn->in.padding);
1175                                 sg_init_one(&sg, pad, conn->in.padding);
1176                                 crypto_digest_update(conn->data_rx_tfm, &sg, 1);
1177                         }
1178                         crypto_digest_final(conn->data_rx_tfm,
1179                                             (u8 *) & conn->in.datadgst);
1180                         debug_tcp("rx digest 0x%x\n", conn->in.datadgst);
1181                         conn->in_progress = IN_PROGRESS_DDIGEST_RECV;
1182                 } else
1183                         conn->in_progress = IN_PROGRESS_WAIT_HEADER;
1184         }
1185
1186         debug_tcp("f, processed %d from out of %d padding %d\n",
1187                conn->in.offset - offset, (int)len, conn->in.padding);
1188         BUG_ON(conn->in.offset - offset > len);
1189
1190         if (conn->in.offset - offset != len) {
1191                 debug_tcp("continue to process %d bytes\n",
1192                        (int)len - (conn->in.offset - offset));
1193                 goto more;
1194         }
1195
1196 nomore:
1197         processed = conn->in.offset - offset;
1198         BUG_ON(processed == 0);
1199         return processed;
1200
1201 again:
1202         processed = conn->in.offset - offset;
1203         debug_tcp("c, processed %d from out of %d rd_desc_cnt %d\n",
1204                   processed, (int)len, (int)rd_desc->count);
1205         BUG_ON(processed == 0);
1206         BUG_ON(processed > len);
1207
1208         conn->rxdata_octets += processed;
1209         return processed;
1210 }
1211
1212 static void
1213 iscsi_tcp_data_ready(struct sock *sk, int flag)
1214 {
1215         struct iscsi_conn *conn = sk->sk_user_data;
1216         read_descriptor_t rd_desc;
1217
1218         read_lock(&sk->sk_callback_lock);
1219
1220         /* use rd_desc to pass 'conn' to iscsi_tcp_data_recv */
1221         rd_desc.arg.data = conn;
1222         rd_desc.count = 0;
1223         tcp_read_sock(sk, &rd_desc, iscsi_tcp_data_recv);
1224
1225         read_unlock(&sk->sk_callback_lock);
1226 }
1227
1228 static void
1229 iscsi_tcp_state_change(struct sock *sk)
1230 {
1231         struct iscsi_conn *conn;
1232         struct iscsi_session *session;
1233         void (*old_state_change)(struct sock *);
1234
1235         read_lock(&sk->sk_callback_lock);
1236
1237         conn = (struct iscsi_conn*)sk->sk_user_data;
1238         session = conn->session;
1239
1240         if (sk->sk_state == TCP_CLOSE_WAIT ||
1241             sk->sk_state == TCP_CLOSE) {
1242                 debug_tcp("iscsi_tcp_state_change: TCP_CLOSE|TCP_CLOSE_WAIT\n");
1243                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1244         }
1245
1246         old_state_change = conn->old_state_change;
1247
1248         read_unlock(&sk->sk_callback_lock);
1249
1250         old_state_change(sk);
1251 }
1252
1253 /**
1254  * iscsi_write_space - Called when more output buffer space is available
1255  * @sk: socket space is available for
1256  **/
1257 static void
1258 iscsi_write_space(struct sock *sk)
1259 {
1260         struct iscsi_conn *conn = (struct iscsi_conn*)sk->sk_user_data;
1261         conn->old_write_space(sk);
1262         debug_tcp("iscsi_write_space: cid %d\n", conn->id);
1263         clear_bit(SUSPEND_BIT, &conn->suspend_tx);
1264         schedule_work(&conn->xmitwork);
1265 }
1266
1267 static void
1268 iscsi_conn_set_callbacks(struct iscsi_conn *conn)
1269 {
1270         struct sock *sk = conn->sock->sk;
1271
1272         /* assign new callbacks */
1273         write_lock_bh(&sk->sk_callback_lock);
1274         sk->sk_user_data = conn;
1275         conn->old_data_ready = sk->sk_data_ready;
1276         conn->old_state_change = sk->sk_state_change;
1277         conn->old_write_space = sk->sk_write_space;
1278         sk->sk_data_ready = iscsi_tcp_data_ready;
1279         sk->sk_state_change = iscsi_tcp_state_change;
1280         sk->sk_write_space = iscsi_write_space;
1281         write_unlock_bh(&sk->sk_callback_lock);
1282 }
1283
1284 static void
1285 iscsi_conn_restore_callbacks(struct iscsi_conn *conn)
1286 {
1287         struct sock *sk = conn->sock->sk;
1288
1289         /* restore socket callbacks, see also: iscsi_conn_set_callbacks() */
1290         write_lock_bh(&sk->sk_callback_lock);
1291         sk->sk_user_data    = NULL;
1292         sk->sk_data_ready   = conn->old_data_ready;
1293         sk->sk_state_change = conn->old_state_change;
1294         sk->sk_write_space  = conn->old_write_space;
1295         sk->sk_no_check  = 0;
1296         write_unlock_bh(&sk->sk_callback_lock);
1297 }
1298
1299 /**
1300  * iscsi_send - generic send routine
1301  * @sk: kernel's socket
1302  * @buf: buffer to write from
1303  * @size: actual size to write
1304  * @flags: socket's flags
1305  *
1306  * Notes:
1307  *      depending on buffer will use tcp_sendpage() or tcp_sendmsg().
1308  *      buf->sg.offset == -1 tells us that buffer is non S/G and forces
1309  *      to use tcp_sendmsg().
1310  */
1311 static inline int
1312 iscsi_send(struct socket *sk, struct iscsi_buf *buf, int size, int flags)
1313 {
1314         int res;
1315
1316         if ((int)buf->sg.offset >= 0) {
1317                 int offset = buf->sg.offset + buf->sent;
1318
1319                 /* tcp_sendpage */
1320                 res = sk->ops->sendpage(sk, buf->sg.page, offset, size, flags);
1321         } else {
1322                 struct msghdr msg;
1323
1324                 buf->iov.iov_base = iscsi_buf_iov_base(buf);
1325                 buf->iov.iov_len = size;
1326
1327                 memset(&msg, 0, sizeof(struct msghdr));
1328
1329                 /* tcp_sendmsg */
1330                 res = kernel_sendmsg(sk, &msg, &buf->iov, 1, size);
1331         }
1332
1333         return res;
1334 }
1335
1336 /**
1337  * iscsi_sendhdr - send PDU Header via tcp_sendpage()
1338  * @conn: iscsi connection
1339  * @buf: buffer to write from
1340  * @datalen: lenght of data to be sent after the header
1341  *
1342  * Notes:
1343  *      (Tx, Fast Path)
1344  **/
1345 static inline int
1346 iscsi_sendhdr(struct iscsi_conn *conn, struct iscsi_buf *buf, int datalen)
1347 {
1348         struct socket *sk = conn->sock;
1349         int flags = 0; /* MSG_DONTWAIT; */
1350         int res, size;
1351
1352         size = buf->sg.length - buf->sent;
1353         BUG_ON(buf->sent + size > buf->sg.length);
1354         if (buf->sent + size != buf->sg.length || datalen)
1355                 flags |= MSG_MORE;
1356
1357         res = iscsi_send(sk, buf, size, flags);
1358         debug_tcp("sendhdr %d bytes, sent %d res %d\n", size, buf->sent, res);
1359         if (res >= 0) {
1360                 conn->txdata_octets += res;
1361                 buf->sent += res;
1362                 if (size != res)
1363                         return -EAGAIN;
1364                 return 0;
1365         } else if (res == -EAGAIN) {
1366                 conn->sendpage_failures_cnt++;
1367                 set_bit(SUSPEND_BIT, &conn->suspend_tx);
1368         } else if (res == -EPIPE)
1369                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1370
1371         return res;
1372 }
1373
1374 /**
1375  * iscsi_sendpage - send one page of iSCSI Data-Out.
1376  * @conn: iscsi connection
1377  * @buf: buffer to write from
1378  * @count: remaining data
1379  * @sent: number of bytes sent
1380  *
1381  * Notes:
1382  *      (Tx, Fast Path)
1383  **/
1384 static inline int
1385 iscsi_sendpage(struct iscsi_conn *conn, struct iscsi_buf *buf,
1386                int *count, int *sent)
1387 {
1388         struct socket *sk = conn->sock;
1389         int flags = 0; /* MSG_DONTWAIT; */
1390         int res, size;
1391
1392         size = buf->sg.length - buf->sent;
1393         BUG_ON(buf->sent + size > buf->sg.length);
1394         if (size > *count)
1395                 size = *count;
1396         if (buf->sent + size != buf->sg.length || *count != size)
1397                 flags |= MSG_MORE;
1398
1399         res = iscsi_send(sk, buf, size, flags);
1400         debug_tcp("sendpage: %d bytes, sent %d left %d sent %d res %d\n",
1401                   size, buf->sent, *count, *sent, res);
1402         if (res >= 0) {
1403                 conn->txdata_octets += res;
1404                 buf->sent += res;
1405                 *count -= res;
1406                 *sent += res;
1407                 if (size != res)
1408                         return -EAGAIN;
1409                 return 0;
1410         } else if (res == -EAGAIN) {
1411                 conn->sendpage_failures_cnt++;
1412                 set_bit(SUSPEND_BIT, &conn->suspend_tx);
1413         } else if (res == -EPIPE)
1414                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1415
1416         return res;
1417 }
1418
1419 static inline void
1420 iscsi_data_digest_init(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1421 {
1422         BUG_ON(!conn->data_tx_tfm);
1423         crypto_digest_init(conn->data_tx_tfm);
1424         ctask->digest_count = 4;
1425 }
1426
1427 static inline void
1428 iscsi_buf_data_digest_update(struct iscsi_conn *conn, struct iscsi_buf *buf)
1429 {
1430         struct scatterlist sg;
1431
1432         if (buf->sg.offset != -1)
1433                 crypto_digest_update(conn->data_tx_tfm, &buf->sg, 1);
1434         else {
1435                 sg_init_one(&sg, (char *)buf->sg.page, buf->sg.length);
1436                 crypto_digest_update(conn->data_tx_tfm, &sg, 1);
1437         }
1438 }
1439
1440 static inline int
1441 iscsi_digest_final_send(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
1442                         struct iscsi_buf *buf, uint32_t *digest, int final)
1443 {
1444         int rc = 0;
1445         int sent = 0;
1446
1447         if (final)
1448                 crypto_digest_final(conn->data_tx_tfm, (u8*)digest);
1449
1450         iscsi_buf_init_virt(buf, (char*)digest, 4);
1451         rc = iscsi_sendpage(conn, buf, &ctask->digest_count, &sent);
1452         if (rc) {
1453                 ctask->datadigest = *digest;
1454                 ctask->xmstate |= XMSTATE_DATA_DIGEST;
1455         } else
1456                 ctask->digest_count = 4;
1457         return rc;
1458 }
1459
1460 /**
1461  * iscsi_solicit_data_cont - initialize next Data-Out
1462  * @conn: iscsi connection
1463  * @ctask: scsi command task
1464  * @r2t: R2T info
1465  * @left: bytes left to transfer
1466  *
1467  * Notes:
1468  *      Initialize next Data-Out within this R2T sequence and continue
1469  *      to process next Scatter-Gather element(if any) of this SCSI command.
1470  *
1471  *      Called under connection lock.
1472  **/
1473 static void
1474 iscsi_solicit_data_cont(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
1475                         struct iscsi_r2t_info *r2t, int left)
1476 {
1477         struct iscsi_data *hdr;
1478         struct iscsi_data_task *dtask;
1479         struct scsi_cmnd *sc = ctask->sc;
1480         int new_offset;
1481
1482         dtask = mempool_alloc(ctask->datapool, GFP_ATOMIC);
1483         BUG_ON(!dtask);
1484         hdr = &dtask->hdr;
1485         memset(hdr, 0, sizeof(struct iscsi_data));
1486         hdr->ttt = r2t->ttt;
1487         hdr->datasn = cpu_to_be32(r2t->solicit_datasn);
1488         r2t->solicit_datasn++;
1489         hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
1490         memcpy(hdr->lun, ctask->hdr.lun, sizeof(hdr->lun));
1491         hdr->itt = ctask->hdr.itt;
1492         hdr->exp_statsn = r2t->exp_statsn;
1493         new_offset = r2t->data_offset + r2t->sent;
1494         hdr->offset = cpu_to_be32(new_offset);
1495         if (left > conn->max_xmit_dlength) {
1496                 hton24(hdr->dlength, conn->max_xmit_dlength);
1497                 r2t->data_count = conn->max_xmit_dlength;
1498         } else {
1499                 hton24(hdr->dlength, left);
1500                 r2t->data_count = left;
1501                 hdr->flags = ISCSI_FLAG_CMD_FINAL;
1502         }
1503         conn->dataout_pdus_cnt++;
1504
1505         iscsi_buf_init_virt(&r2t->headbuf, (char*)hdr,
1506                            sizeof(struct iscsi_hdr));
1507
1508         r2t->dtask = dtask;
1509
1510         if (sc->use_sg && !iscsi_buf_left(&r2t->sendbuf)) {
1511                 BUG_ON(ctask->bad_sg == r2t->sg);
1512                 iscsi_buf_init_sg(&r2t->sendbuf, r2t->sg);
1513                 r2t->sg += 1;
1514         } else
1515                 iscsi_buf_init_iov(&ctask->sendbuf,
1516                             (char*)sc->request_buffer + new_offset,
1517                             r2t->data_count);
1518
1519         list_add(&dtask->item, &ctask->dataqueue);
1520 }
1521
1522 static void
1523 iscsi_unsolicit_data_init(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1524 {
1525         struct iscsi_data *hdr;
1526         struct iscsi_data_task *dtask;
1527
1528         dtask = mempool_alloc(ctask->datapool, GFP_ATOMIC);
1529         BUG_ON(!dtask);
1530         hdr = &dtask->hdr;
1531         memset(hdr, 0, sizeof(struct iscsi_data));
1532         hdr->ttt = cpu_to_be32(ISCSI_RESERVED_TAG);
1533         hdr->datasn = cpu_to_be32(ctask->unsol_datasn);
1534         ctask->unsol_datasn++;
1535         hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
1536         memcpy(hdr->lun, ctask->hdr.lun, sizeof(hdr->lun));
1537         hdr->itt = ctask->hdr.itt;
1538         hdr->exp_statsn = cpu_to_be32(conn->exp_statsn);
1539         hdr->offset = cpu_to_be32(ctask->total_length -
1540                                   ctask->r2t_data_count -
1541                                   ctask->unsol_count);
1542         if (ctask->unsol_count > conn->max_xmit_dlength) {
1543                 hton24(hdr->dlength, conn->max_xmit_dlength);
1544                 ctask->data_count = conn->max_xmit_dlength;
1545                 hdr->flags = 0;
1546         } else {
1547                 hton24(hdr->dlength, ctask->unsol_count);
1548                 ctask->data_count = ctask->unsol_count;
1549                 hdr->flags = ISCSI_FLAG_CMD_FINAL;
1550         }
1551
1552         iscsi_buf_init_virt(&ctask->headbuf, (char*)hdr,
1553                            sizeof(struct iscsi_hdr));
1554
1555         list_add(&dtask->item, &ctask->dataqueue);
1556
1557         ctask->dtask = dtask;
1558 }
1559
1560 /**
1561  * iscsi_cmd_init - Initialize iSCSI SCSI_READ or SCSI_WRITE commands
1562  * @conn: iscsi connection
1563  * @ctask: scsi command task
1564  * @sc: scsi command
1565  **/
1566 static void
1567 iscsi_cmd_init(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
1568                 struct scsi_cmnd *sc)
1569 {
1570         struct iscsi_session *session = conn->session;
1571
1572         BUG_ON(__kfifo_len(ctask->r2tqueue));
1573
1574         ctask->sc = sc;
1575         ctask->conn = conn;
1576         ctask->hdr.opcode = ISCSI_OP_SCSI_CMD;
1577         ctask->hdr.flags = ISCSI_ATTR_SIMPLE;
1578         int_to_scsilun(sc->device->lun, (struct scsi_lun *)ctask->hdr.lun);
1579         ctask->hdr.itt = ctask->itt | (conn->id << CID_SHIFT) |
1580                          (session->age << AGE_SHIFT);
1581         ctask->hdr.data_length = cpu_to_be32(sc->request_bufflen);
1582         ctask->hdr.cmdsn = cpu_to_be32(session->cmdsn); session->cmdsn++;
1583         ctask->hdr.exp_statsn = cpu_to_be32(conn->exp_statsn);
1584         memcpy(ctask->hdr.cdb, sc->cmnd, sc->cmd_len);
1585         memset(&ctask->hdr.cdb[sc->cmd_len], 0, MAX_COMMAND_SIZE - sc->cmd_len);
1586
1587         ctask->mtask = NULL;
1588         ctask->sent = 0;
1589         ctask->sg_count = 0;
1590
1591         ctask->total_length = sc->request_bufflen;
1592
1593         if (sc->sc_data_direction == DMA_TO_DEVICE) {
1594                 ctask->exp_r2tsn = 0;
1595                 ctask->hdr.flags |= ISCSI_FLAG_CMD_WRITE;
1596                 BUG_ON(ctask->total_length == 0);
1597                 if (sc->use_sg) {
1598                         struct scatterlist *sg = sc->request_buffer;
1599
1600                         iscsi_buf_init_sg(&ctask->sendbuf,
1601                                           &sg[ctask->sg_count++]);
1602                         ctask->sg = sg;
1603                         ctask->bad_sg = sg + sc->use_sg;
1604                 } else {
1605                         iscsi_buf_init_iov(&ctask->sendbuf, sc->request_buffer,
1606                                         sc->request_bufflen);
1607                 }
1608
1609                 /*
1610                  * Write counters:
1611                  *
1612                  *      imm_count       bytes to be sent right after
1613                  *                      SCSI PDU Header
1614                  *
1615                  *      unsol_count     bytes(as Data-Out) to be sent
1616                  *                      without R2T ack right after
1617                  *                      immediate data
1618                  *
1619                  *      r2t_data_count  bytes to be sent via R2T ack's
1620                  *
1621                  *      pad_count       bytes to be sent as zero-padding
1622                  */
1623                 ctask->imm_count = 0;
1624                 ctask->unsol_count = 0;
1625                 ctask->unsol_datasn = 0;
1626                 ctask->xmstate = XMSTATE_W_HDR;
1627                 /* calculate write padding */
1628                 ctask->pad_count = ctask->total_length & (ISCSI_PAD_LEN-1);
1629                 if (ctask->pad_count) {
1630                         ctask->pad_count = ISCSI_PAD_LEN - ctask->pad_count;
1631                         debug_scsi("write padding %d bytes\n",
1632                                 ctask->pad_count);
1633                         ctask->xmstate |= XMSTATE_W_PAD;
1634                 }
1635                 if (session->imm_data_en) {
1636                         if (ctask->total_length >= session->first_burst)
1637                                 ctask->imm_count = min(session->first_burst,
1638                                                         conn->max_xmit_dlength);
1639                         else
1640                                 ctask->imm_count = min(ctask->total_length,
1641                                                         conn->max_xmit_dlength);
1642                         hton24(ctask->hdr.dlength, ctask->imm_count);
1643                         ctask->xmstate |= XMSTATE_IMM_DATA;
1644                 } else
1645                         zero_data(ctask->hdr.dlength);
1646
1647                 if (!session->initial_r2t_en)
1648                         ctask->unsol_count = min(session->first_burst,
1649                                 ctask->total_length) - ctask->imm_count;
1650                 if (!ctask->unsol_count)
1651                         /* No unsolicit Data-Out's */
1652                         ctask->hdr.flags |= ISCSI_FLAG_CMD_FINAL;
1653                 else
1654                         ctask->xmstate |= XMSTATE_UNS_HDR | XMSTATE_UNS_INIT;
1655
1656                 ctask->r2t_data_count = ctask->total_length -
1657                                     ctask->imm_count -
1658                                     ctask->unsol_count;
1659
1660                 debug_scsi("cmd [itt %x total %d imm %d imm_data %d "
1661                            "r2t_data %d]\n",
1662                            ctask->itt, ctask->total_length, ctask->imm_count,
1663                            ctask->unsol_count, ctask->r2t_data_count);
1664         } else {
1665                 ctask->hdr.flags |= ISCSI_FLAG_CMD_FINAL;
1666                 if (sc->sc_data_direction == DMA_FROM_DEVICE)
1667                         ctask->hdr.flags |= ISCSI_FLAG_CMD_READ;
1668                 ctask->datasn = 0;
1669                 ctask->xmstate = XMSTATE_R_HDR;
1670                 zero_data(ctask->hdr.dlength);
1671         }
1672
1673         iscsi_buf_init_virt(&ctask->headbuf, (char*)&ctask->hdr,
1674                             sizeof(struct iscsi_hdr));
1675         conn->scsicmd_pdus_cnt++;
1676 }
1677
1678 /**
1679  * iscsi_mtask_xmit - xmit management(immediate) task
1680  * @conn: iscsi connection
1681  * @mtask: task management task
1682  *
1683  * Notes:
1684  *      The function can return -EAGAIN in which case caller must
1685  *      call it again later, or recover. '0' return code means successful
1686  *      xmit.
1687  *
1688  *      Management xmit state machine consists of two states:
1689  *              IN_PROGRESS_IMM_HEAD - PDU Header xmit in progress
1690  *              IN_PROGRESS_IMM_DATA - PDU Data xmit in progress
1691  **/
1692 static int
1693 iscsi_mtask_xmit(struct iscsi_conn *conn, struct iscsi_mgmt_task *mtask)
1694 {
1695
1696         debug_scsi("mtask deq [cid %d state %x itt 0x%x]\n",
1697                 conn->id, mtask->xmstate, mtask->itt);
1698
1699         if (mtask->xmstate & XMSTATE_IMM_HDR) {
1700                 mtask->xmstate &= ~XMSTATE_IMM_HDR;
1701                 if (mtask->data_count)
1702                         mtask->xmstate |= XMSTATE_IMM_DATA;
1703                 if (conn->c_stage != ISCSI_CONN_INITIAL_STAGE &&
1704                     conn->stop_stage != STOP_CONN_RECOVER &&
1705                     conn->hdrdgst_en)
1706                         iscsi_hdr_digest(conn, &mtask->headbuf,
1707                                         (u8*)mtask->hdrext);
1708                 if (iscsi_sendhdr(conn, &mtask->headbuf, mtask->data_count)) {
1709                         mtask->xmstate |= XMSTATE_IMM_HDR;
1710                         if (mtask->data_count)
1711                                 mtask->xmstate &= ~XMSTATE_IMM_DATA;
1712                         return -EAGAIN;
1713                 }
1714         }
1715
1716         if (mtask->xmstate & XMSTATE_IMM_DATA) {
1717                 BUG_ON(!mtask->data_count);
1718                 mtask->xmstate &= ~XMSTATE_IMM_DATA;
1719                 /* FIXME: implement.
1720                  * Virtual buffer could be spreaded across multiple pages...
1721                  */
1722                 do {
1723                         if (iscsi_sendpage(conn, &mtask->sendbuf,
1724                                    &mtask->data_count, &mtask->sent)) {
1725                                 mtask->xmstate |= XMSTATE_IMM_DATA;
1726                                 return -EAGAIN;
1727                         }
1728                 } while (mtask->data_count);
1729         }
1730
1731         BUG_ON(mtask->xmstate != XMSTATE_IDLE);
1732         return 0;
1733 }
1734
1735 static inline int
1736 handle_xmstate_r_hdr(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1737 {
1738         ctask->xmstate &= ~XMSTATE_R_HDR;
1739         if (conn->hdrdgst_en)
1740                 iscsi_hdr_digest(conn, &ctask->headbuf, (u8*)ctask->hdrext);
1741         if (!iscsi_sendhdr(conn, &ctask->headbuf, 0)) {
1742                 BUG_ON(ctask->xmstate != XMSTATE_IDLE);
1743                 return 0; /* wait for Data-In */
1744         }
1745         ctask->xmstate |= XMSTATE_R_HDR;
1746         return -EAGAIN;
1747 }
1748
1749 static inline int
1750 handle_xmstate_w_hdr(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1751 {
1752         ctask->xmstate &= ~XMSTATE_W_HDR;
1753         if (conn->hdrdgst_en)
1754                 iscsi_hdr_digest(conn, &ctask->headbuf, (u8*)ctask->hdrext);
1755         if (iscsi_sendhdr(conn, &ctask->headbuf, ctask->imm_count)) {
1756                 ctask->xmstate |= XMSTATE_W_HDR;
1757                 return -EAGAIN;
1758         }
1759         return 0;
1760 }
1761
1762 static inline int
1763 handle_xmstate_data_digest(struct iscsi_conn *conn,
1764                            struct iscsi_cmd_task *ctask)
1765 {
1766         ctask->xmstate &= ~XMSTATE_DATA_DIGEST;
1767         debug_tcp("resent data digest 0x%x\n", ctask->datadigest);
1768         if (iscsi_digest_final_send(conn, ctask, &ctask->immbuf,
1769                                     &ctask->datadigest, 0)) {
1770                 ctask->xmstate |= XMSTATE_DATA_DIGEST;
1771                 debug_tcp("resent data digest 0x%x fail!\n",
1772                           ctask->datadigest);
1773                 return -EAGAIN;
1774         }
1775         return 0;
1776 }
1777
1778 static inline int
1779 handle_xmstate_imm_data(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1780 {
1781         BUG_ON(!ctask->imm_count);
1782         ctask->xmstate &= ~XMSTATE_IMM_DATA;
1783
1784         if (conn->datadgst_en) {
1785                 iscsi_data_digest_init(conn, ctask);
1786                 ctask->immdigest = 0;
1787         }
1788
1789         for (;;) {
1790                 if (iscsi_sendpage(conn, &ctask->sendbuf, &ctask->imm_count,
1791                                    &ctask->sent)) {
1792                         ctask->xmstate |= XMSTATE_IMM_DATA;
1793                         if (conn->datadgst_en) {
1794                                 crypto_digest_final(conn->data_tx_tfm,
1795                                                 (u8*)&ctask->immdigest);
1796                                 debug_tcp("tx imm sendpage fail 0x%x\n",
1797                                           ctask->datadigest);
1798                         }
1799                         return -EAGAIN;
1800                 }
1801                 if (conn->datadgst_en)
1802                         iscsi_buf_data_digest_update(conn, &ctask->sendbuf);
1803
1804                 if (!ctask->imm_count)
1805                         break;
1806                 iscsi_buf_init_sg(&ctask->sendbuf,
1807                                   &ctask->sg[ctask->sg_count++]);
1808         }
1809
1810         if (conn->datadgst_en && !(ctask->xmstate & XMSTATE_W_PAD)) {
1811                 if (iscsi_digest_final_send(conn, ctask, &ctask->immbuf,
1812                                             &ctask->immdigest, 1)) {
1813                         debug_tcp("sending imm digest 0x%x fail!\n",
1814                                   ctask->immdigest);
1815                         return -EAGAIN;
1816                 }
1817                 debug_tcp("sending imm digest 0x%x\n", ctask->immdigest);
1818         }
1819
1820         return 0;
1821 }
1822
1823 static inline int
1824 handle_xmstate_uns_hdr(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1825 {
1826         struct iscsi_data_task *dtask;
1827
1828         ctask->xmstate |= XMSTATE_UNS_DATA;
1829         if (ctask->xmstate & XMSTATE_UNS_INIT) {
1830                 iscsi_unsolicit_data_init(conn, ctask);
1831                 BUG_ON(!ctask->dtask);
1832                 dtask = ctask->dtask;
1833                 if (conn->hdrdgst_en)
1834                         iscsi_hdr_digest(conn, &ctask->headbuf,
1835                                         (u8*)dtask->hdrext);
1836                 ctask->xmstate &= ~XMSTATE_UNS_INIT;
1837         }
1838         if (iscsi_sendhdr(conn, &ctask->headbuf, ctask->data_count)) {
1839                 ctask->xmstate &= ~XMSTATE_UNS_DATA;
1840                 ctask->xmstate |= XMSTATE_UNS_HDR;
1841                 return -EAGAIN;
1842         }
1843
1844         debug_scsi("uns dout [itt 0x%x dlen %d sent %d]\n",
1845                    ctask->itt, ctask->unsol_count, ctask->sent);
1846         return 0;
1847 }
1848
1849 static inline int
1850 handle_xmstate_uns_data(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1851 {
1852         struct iscsi_data_task *dtask = ctask->dtask;
1853
1854         BUG_ON(!ctask->data_count);
1855         ctask->xmstate &= ~XMSTATE_UNS_DATA;
1856
1857         if (conn->datadgst_en) {
1858                 iscsi_data_digest_init(conn, ctask);
1859                 dtask->digest = 0;
1860         }
1861
1862         for (;;) {
1863                 int start = ctask->sent;
1864
1865                 if (iscsi_sendpage(conn, &ctask->sendbuf, &ctask->data_count,
1866                                    &ctask->sent)) {
1867                         ctask->unsol_count -= ctask->sent - start;
1868                         ctask->xmstate |= XMSTATE_UNS_DATA;
1869                         /* will continue with this ctask later.. */
1870                         if (conn->datadgst_en) {
1871                                 crypto_digest_final(conn->data_tx_tfm,
1872                                                 (u8 *)&dtask->digest);
1873                                 debug_tcp("tx uns data fail 0x%x\n",
1874                                           dtask->digest);
1875                         }
1876                         return -EAGAIN;
1877                 }
1878
1879                 BUG_ON(ctask->sent > ctask->total_length);
1880                 ctask->unsol_count -= ctask->sent - start;
1881
1882                 /*
1883                  * XXX:we may run here with un-initial sendbuf.
1884                  * so pass it
1885                  */
1886                 if (conn->datadgst_en && ctask->sent - start > 0)
1887                         iscsi_buf_data_digest_update(conn, &ctask->sendbuf);
1888
1889                 if (!ctask->data_count)
1890                         break;
1891                 iscsi_buf_init_sg(&ctask->sendbuf,
1892                                   &ctask->sg[ctask->sg_count++]);
1893         }
1894         BUG_ON(ctask->unsol_count < 0);
1895
1896         /*
1897          * Done with the Data-Out. Next, check if we need
1898          * to send another unsolicited Data-Out.
1899          */
1900         if (ctask->unsol_count) {
1901                 if (conn->datadgst_en) {
1902                         if (iscsi_digest_final_send(conn, ctask,
1903                                                     &dtask->digestbuf,
1904                                                     &dtask->digest, 1)) {
1905                                 debug_tcp("send uns digest 0x%x fail\n",
1906                                           dtask->digest);
1907                                 return -EAGAIN;
1908                         }
1909                         debug_tcp("sending uns digest 0x%x, more uns\n",
1910                                   dtask->digest);
1911                 }
1912                 ctask->xmstate |= XMSTATE_UNS_INIT;
1913                 return 1;
1914         }
1915
1916         if (conn->datadgst_en && !(ctask->xmstate & XMSTATE_W_PAD)) {
1917                 if (iscsi_digest_final_send(conn, ctask,
1918                                             &dtask->digestbuf,
1919                                             &dtask->digest, 1)) {
1920                         debug_tcp("send last uns digest 0x%x fail\n",
1921                                    dtask->digest);
1922                         return -EAGAIN;
1923                 }
1924                 debug_tcp("sending uns digest 0x%x\n",dtask->digest);
1925         }
1926
1927         return 0;
1928 }
1929
1930 static inline int
1931 handle_xmstate_sol_data(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1932 {
1933         struct iscsi_session *session = conn->session;
1934         struct iscsi_r2t_info *r2t = ctask->r2t;
1935         struct iscsi_data_task *dtask = r2t->dtask;
1936         int left;
1937
1938         ctask->xmstate &= ~XMSTATE_SOL_DATA;
1939         ctask->dtask = dtask;
1940
1941         if (conn->datadgst_en) {
1942                 iscsi_data_digest_init(conn, ctask);
1943                 dtask->digest = 0;
1944         }
1945 solicit_again:
1946         /*
1947          * send Data-Out whitnin this R2T sequence.
1948          */
1949         if (!r2t->data_count)
1950                 goto data_out_done;
1951
1952         if (iscsi_sendpage(conn, &r2t->sendbuf, &r2t->data_count, &r2t->sent)) {
1953                 ctask->xmstate |= XMSTATE_SOL_DATA;
1954                 /* will continue with this ctask later.. */
1955                 if (conn->datadgst_en) {
1956                         crypto_digest_final(conn->data_tx_tfm,
1957                                           (u8 *)&dtask->digest);
1958                         debug_tcp("r2t data send fail 0x%x\n", dtask->digest);
1959                 }
1960                 return -EAGAIN;
1961         }
1962
1963         BUG_ON(r2t->data_count < 0);
1964         if (conn->datadgst_en)
1965                 iscsi_buf_data_digest_update(conn, &r2t->sendbuf);
1966
1967         if (r2t->data_count) {
1968                 BUG_ON(ctask->sc->use_sg == 0);
1969                 if (!iscsi_buf_left(&r2t->sendbuf)) {
1970                         BUG_ON(ctask->bad_sg == r2t->sg);
1971                         iscsi_buf_init_sg(&r2t->sendbuf, r2t->sg);
1972                         r2t->sg += 1;
1973                 }
1974                 goto solicit_again;
1975         }
1976
1977 data_out_done:
1978         /*
1979          * Done with this Data-Out. Next, check if we have
1980          * to send another Data-Out for this R2T.
1981          */
1982         BUG_ON(r2t->data_length - r2t->sent < 0);
1983         left = r2t->data_length - r2t->sent;
1984         if (left) {
1985                 if (conn->datadgst_en) {
1986                         if (iscsi_digest_final_send(conn, ctask,
1987                                                     &dtask->digestbuf,
1988                                                     &dtask->digest, 1)) {
1989                                 debug_tcp("send r2t data digest 0x%x"
1990                                           "fail\n", dtask->digest);
1991                                 return -EAGAIN;
1992                         }
1993                         debug_tcp("r2t data send digest 0x%x\n",
1994                                   dtask->digest);
1995                 }
1996                 iscsi_solicit_data_cont(conn, ctask, r2t, left);
1997                 ctask->xmstate |= XMSTATE_SOL_DATA;
1998                 ctask->xmstate &= ~XMSTATE_SOL_HDR;
1999                 return 1;
2000         }
2001
2002         /*
2003          * Done with this R2T. Check if there are more
2004          * outstanding R2Ts ready to be processed.
2005          */
2006         BUG_ON(ctask->r2t_data_count - r2t->data_length < 0);
2007         if (conn->datadgst_en) {
2008                 if (iscsi_digest_final_send(conn, ctask, &dtask->digestbuf,
2009                                             &dtask->digest, 1)) {
2010                         debug_tcp("send last r2t data digest 0x%x"
2011                                   "fail\n", dtask->digest);
2012                         return -EAGAIN;
2013                 }
2014                 debug_tcp("r2t done dout digest 0x%x\n", dtask->digest);
2015         }
2016
2017         ctask->r2t_data_count -= r2t->data_length;
2018         ctask->r2t = NULL;
2019         spin_lock_bh(&session->lock);
2020         __kfifo_put(ctask->r2tpool.queue, (void*)&r2t, sizeof(void*));
2021         spin_unlock_bh(&session->lock);
2022         if (__kfifo_get(ctask->r2tqueue, (void*)&r2t, sizeof(void*))) {
2023                 ctask->r2t = r2t;
2024                 ctask->xmstate |= XMSTATE_SOL_DATA;
2025                 ctask->xmstate &= ~XMSTATE_SOL_HDR;
2026                 return 1;
2027         }
2028
2029         return 0;
2030 }
2031
2032 static inline int
2033 handle_xmstate_w_pad(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
2034 {
2035         struct iscsi_data_task *dtask = ctask->dtask;
2036         int sent;
2037
2038         ctask->xmstate &= ~XMSTATE_W_PAD;
2039         iscsi_buf_init_virt(&ctask->sendbuf, (char*)&ctask->pad,
2040                             ctask->pad_count);
2041         if (iscsi_sendpage(conn, &ctask->sendbuf, &ctask->pad_count, &sent)) {
2042                 ctask->xmstate |= XMSTATE_W_PAD;
2043                 return -EAGAIN;
2044         }
2045
2046         if (conn->datadgst_en) {
2047                 iscsi_buf_data_digest_update(conn, &ctask->sendbuf);
2048                 /* imm data? */
2049                 if (!dtask) {
2050                         if (iscsi_digest_final_send(conn, ctask, &ctask->immbuf,
2051                                                     &ctask->immdigest, 1)) {
2052                                 debug_tcp("send padding digest 0x%x"
2053                                           "fail!\n", ctask->immdigest);
2054                                 return -EAGAIN;
2055                         }
2056                         debug_tcp("done with padding, digest 0x%x\n",
2057                                   ctask->datadigest);
2058                 } else {
2059                         if (iscsi_digest_final_send(conn, ctask,
2060                                                     &dtask->digestbuf,
2061                                                     &dtask->digest, 1)) {
2062                                 debug_tcp("send padding digest 0x%x"
2063                                           "fail\n", dtask->digest);
2064                                 return -EAGAIN;
2065                         }
2066                         debug_tcp("done with padding, digest 0x%x\n",
2067                                   dtask->digest);
2068                 }
2069         }
2070
2071         return 0;
2072 }
2073
2074 static int
2075 iscsi_ctask_xmit(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
2076 {
2077         int rc = 0;
2078
2079         debug_scsi("ctask deq [cid %d xmstate %x itt 0x%x]\n",
2080                 conn->id, ctask->xmstate, ctask->itt);
2081
2082         /*
2083          * serialize with TMF AbortTask
2084          */
2085         if (ctask->mtask)
2086                 return rc;
2087
2088         if (ctask->xmstate & XMSTATE_R_HDR) {
2089                 rc = handle_xmstate_r_hdr(conn, ctask);
2090                 return rc;
2091         }
2092
2093         if (ctask->xmstate & XMSTATE_W_HDR) {
2094                 rc = handle_xmstate_w_hdr(conn, ctask);
2095                 if (rc)
2096                         return rc;
2097         }
2098
2099         /* XXX: for data digest xmit recover */
2100         if (ctask->xmstate & XMSTATE_DATA_DIGEST) {
2101                 rc = handle_xmstate_data_digest(conn, ctask);
2102                 if (rc)
2103                         return rc;
2104         }
2105
2106         if (ctask->xmstate & XMSTATE_IMM_DATA) {
2107                 rc = handle_xmstate_imm_data(conn, ctask);
2108                 if (rc)
2109                         return rc;
2110         }
2111
2112         if (ctask->xmstate & XMSTATE_UNS_HDR) {
2113                 BUG_ON(!ctask->unsol_count);
2114                 ctask->xmstate &= ~XMSTATE_UNS_HDR;
2115 unsolicit_head_again:
2116                 rc = handle_xmstate_uns_hdr(conn, ctask);
2117                 if (rc)
2118                         return rc;
2119         }
2120
2121         if (ctask->xmstate & XMSTATE_UNS_DATA) {
2122                 rc = handle_xmstate_uns_data(conn, ctask);
2123                 if (rc == 1)
2124                         goto unsolicit_head_again;
2125                 else if (rc)
2126                         return rc;
2127                 goto done;
2128         }
2129
2130         if (ctask->xmstate & XMSTATE_SOL_HDR) {
2131                 struct iscsi_r2t_info *r2t;
2132
2133                 ctask->xmstate &= ~XMSTATE_SOL_HDR;
2134                 ctask->xmstate |= XMSTATE_SOL_DATA;
2135                 if (!ctask->r2t)
2136                         __kfifo_get(ctask->r2tqueue, (void*)&ctask->r2t,
2137                                     sizeof(void*));
2138 solicit_head_again:
2139                 r2t = ctask->r2t;
2140                 if (conn->hdrdgst_en)
2141                         iscsi_hdr_digest(conn, &r2t->headbuf,
2142                                         (u8*)r2t->dtask->hdrext);
2143                 if (iscsi_sendhdr(conn, &r2t->headbuf, r2t->data_count)) {
2144                         ctask->xmstate &= ~XMSTATE_SOL_DATA;
2145                         ctask->xmstate |= XMSTATE_SOL_HDR;
2146                         return -EAGAIN;
2147                 }
2148
2149                 debug_scsi("sol dout [dsn %d itt 0x%x dlen %d sent %d]\n",
2150                         r2t->solicit_datasn - 1, ctask->itt, r2t->data_count,
2151                         r2t->sent);
2152         }
2153
2154         if (ctask->xmstate & XMSTATE_SOL_DATA) {
2155                 rc = handle_xmstate_sol_data(conn, ctask);
2156                 if (rc == 1)
2157                         goto solicit_head_again;
2158                 if (rc)
2159                         return rc;
2160         }
2161
2162 done:
2163         /*
2164          * Last thing to check is whether we need to send write
2165          * padding. Note that we check for xmstate equality, not just the bit.
2166          */
2167         if (ctask->xmstate == XMSTATE_W_PAD)
2168                 rc = handle_xmstate_w_pad(conn, ctask);
2169
2170         return rc;
2171 }
2172
2173 /**
2174  * iscsi_data_xmit - xmit any command into the scheduled connection
2175  * @conn: iscsi connection
2176  *
2177  * Notes:
2178  *      The function can return -EAGAIN in which case the caller must
2179  *      re-schedule it again later or recover. '0' return code means
2180  *      successful xmit.
2181  **/
2182 static int
2183 iscsi_data_xmit(struct iscsi_conn *conn)
2184 {
2185         if (unlikely(conn->suspend_tx)) {
2186                 debug_tcp("conn %d Tx suspended!\n", conn->id);
2187                 return 0;
2188         }
2189
2190         /*
2191          * Transmit in the following order:
2192          *
2193          * 1) un-finished xmit (ctask or mtask)
2194          * 2) immediate control PDUs
2195          * 3) write data
2196          * 4) SCSI commands
2197          * 5) non-immediate control PDUs
2198          *
2199          * No need to lock around __kfifo_get as long as
2200          * there's one producer and one consumer.
2201          */
2202
2203         BUG_ON(conn->ctask && conn->mtask);
2204
2205         if (conn->ctask) {
2206                 if (iscsi_ctask_xmit(conn, conn->ctask))
2207                         goto again;
2208                 /* done with this in-progress ctask */
2209                 conn->ctask = NULL;
2210         }
2211         if (conn->mtask) {
2212                 if (iscsi_mtask_xmit(conn, conn->mtask))
2213                         goto again;
2214                 /* done with this in-progress mtask */
2215                 conn->mtask = NULL;
2216         }
2217
2218         /* process immediate first */
2219         if (unlikely(__kfifo_len(conn->immqueue))) {
2220                 struct iscsi_session *session = conn->session;
2221                 while (__kfifo_get(conn->immqueue, (void*)&conn->mtask,
2222                                    sizeof(void*))) {
2223                         if (iscsi_mtask_xmit(conn, conn->mtask))
2224                                 goto again;
2225
2226                         if (conn->mtask->hdr.itt ==
2227                                         cpu_to_be32(ISCSI_RESERVED_TAG)) {
2228                                 spin_lock_bh(&session->lock);
2229                                 __kfifo_put(session->mgmtpool.queue,
2230                                             (void*)&conn->mtask, sizeof(void*));
2231                                 spin_unlock_bh(&session->lock);
2232                         }
2233                 }
2234                 /* done with this mtask */
2235                 conn->mtask = NULL;
2236         }
2237
2238         /* process write queue */
2239         while (__kfifo_get(conn->writequeue, (void*)&conn->ctask,
2240                            sizeof(void*))) {
2241                 if (iscsi_ctask_xmit(conn, conn->ctask))
2242                         goto again;
2243         }
2244
2245         /* process command queue */
2246         while (__kfifo_get(conn->xmitqueue, (void*)&conn->ctask,
2247                            sizeof(void*))) {
2248                 if (iscsi_ctask_xmit(conn, conn->ctask))
2249                         goto again;
2250         }
2251         /* done with this ctask */
2252         conn->ctask = NULL;
2253
2254         /* process the rest control plane PDUs, if any */
2255         if (unlikely(__kfifo_len(conn->mgmtqueue))) {
2256                 struct iscsi_session *session = conn->session;
2257
2258                 while (__kfifo_get(conn->mgmtqueue, (void*)&conn->mtask,
2259                                    sizeof(void*))) {
2260                         if (iscsi_mtask_xmit(conn, conn->mtask))
2261                                 goto again;
2262
2263                         if (conn->mtask->hdr.itt ==
2264                                         cpu_to_be32(ISCSI_RESERVED_TAG)) {
2265                                 spin_lock_bh(&session->lock);
2266                                 __kfifo_put(session->mgmtpool.queue,
2267                                             (void*)&conn->mtask,
2268                                             sizeof(void*));
2269                                 spin_unlock_bh(&session->lock);
2270                         }
2271                 }
2272                 /* done with this mtask */
2273                 conn->mtask = NULL;
2274         }
2275
2276         return 0;
2277
2278 again:
2279         if (unlikely(conn->suspend_tx))
2280                 return 0;
2281
2282         return -EAGAIN;
2283 }
2284
2285 static void
2286 iscsi_xmitworker(void *data)
2287 {
2288         struct iscsi_conn *conn = data;
2289
2290         /*
2291          * serialize Xmit worker on a per-connection basis.
2292          */
2293         down(&conn->xmitsema);
2294         if (iscsi_data_xmit(conn))
2295                 schedule_work(&conn->xmitwork);
2296         up(&conn->xmitsema);
2297 }
2298
2299 #define FAILURE_BAD_HOST                1
2300 #define FAILURE_SESSION_FAILED          2
2301 #define FAILURE_SESSION_FREED           3
2302 #define FAILURE_WINDOW_CLOSED           4
2303 #define FAILURE_SESSION_TERMINATE       5
2304
2305 static int
2306 iscsi_queuecommand(struct scsi_cmnd *sc, void (*done)(struct scsi_cmnd *))
2307 {
2308         struct Scsi_Host *host;
2309         int reason = 0;
2310         struct iscsi_session *session;
2311         struct iscsi_conn *conn = NULL;
2312         struct iscsi_cmd_task *ctask = NULL;
2313
2314         sc->scsi_done = done;
2315         sc->result = 0;
2316
2317         host = sc->device->host;
2318         session = iscsi_hostdata(host->hostdata);
2319         BUG_ON(host != session->host);
2320
2321         spin_lock(&session->lock);
2322
2323         if (session->state != ISCSI_STATE_LOGGED_IN) {
2324                 if (session->state == ISCSI_STATE_FAILED) {
2325                         reason = FAILURE_SESSION_FAILED;
2326                         goto reject;
2327                 } else if (session->state == ISCSI_STATE_TERMINATE) {
2328                         reason = FAILURE_SESSION_TERMINATE;
2329                         goto fault;
2330                 }
2331                 reason = FAILURE_SESSION_FREED;
2332                 goto fault;
2333         }
2334
2335         /*
2336          * Check for iSCSI window and take care of CmdSN wrap-around
2337          */
2338         if ((int)(session->max_cmdsn - session->cmdsn) < 0) {
2339                 reason = FAILURE_WINDOW_CLOSED;
2340                 goto reject;
2341         }
2342
2343         conn = session->leadconn;
2344
2345         __kfifo_get(session->cmdpool.queue, (void*)&ctask, sizeof(void*));
2346         BUG_ON(ctask->sc);
2347
2348         sc->SCp.phase = session->age;
2349         sc->SCp.ptr = (char*)ctask;
2350         iscsi_cmd_init(conn, ctask, sc);
2351
2352         __kfifo_put(conn->xmitqueue, (void*)&ctask, sizeof(void*));
2353         debug_scsi(
2354                "ctask enq [%s cid %d sc %lx itt 0x%x len %d cmdsn %d win %d]\n",
2355                 sc->sc_data_direction == DMA_TO_DEVICE ? "write" : "read",
2356                 conn->id, (long)sc, ctask->itt, sc->request_bufflen,
2357                 session->cmdsn, session->max_cmdsn - session->exp_cmdsn + 1);
2358         spin_unlock(&session->lock);
2359
2360         if (!in_interrupt() && !down_trylock(&conn->xmitsema)) {
2361                 spin_unlock_irq(host->host_lock);
2362                 if (iscsi_data_xmit(conn))
2363                         schedule_work(&conn->xmitwork);
2364                 up(&conn->xmitsema);
2365                 spin_lock_irq(host->host_lock);
2366         } else
2367                 schedule_work(&conn->xmitwork);
2368
2369         return 0;
2370
2371 reject:
2372         spin_unlock(&session->lock);
2373         debug_scsi("cmd 0x%x rejected (%d)\n", sc->cmnd[0], reason);
2374         return SCSI_MLQUEUE_HOST_BUSY;
2375
2376 fault:
2377         spin_unlock(&session->lock);
2378         printk(KERN_ERR "iscsi_tcp: cmd 0x%x is not queued (%d)\n",
2379                sc->cmnd[0], reason);
2380         sc->sense_buffer[0] = 0x70;
2381         sc->sense_buffer[2] = NOT_READY;
2382         sc->sense_buffer[7] = 0x6;
2383         sc->sense_buffer[12] = 0x08;
2384         sc->sense_buffer[13] = 0x00;
2385         sc->result = (DID_NO_CONNECT << 16);
2386         sc->resid = sc->request_bufflen;
2387         sc->scsi_done(sc);
2388         return 0;
2389 }
2390
2391 static int
2392 iscsi_pool_init(struct iscsi_queue *q, int max, void ***items, int item_size)
2393 {
2394         int i;
2395
2396         *items = kmalloc(max * sizeof(void*), GFP_KERNEL);
2397         if (*items == NULL)
2398                 return -ENOMEM;
2399
2400         q->max = max;
2401         q->pool = kmalloc(max * sizeof(void*), GFP_KERNEL);
2402         if (q->pool == NULL) {
2403                 kfree(*items);
2404                 return -ENOMEM;
2405         }
2406
2407         q->queue = kfifo_init((void*)q->pool, max * sizeof(void*),
2408                               GFP_KERNEL, NULL);
2409         if (q->queue == ERR_PTR(-ENOMEM)) {
2410                 kfree(q->pool);
2411                 kfree(*items);
2412                 return -ENOMEM;
2413         }
2414
2415         for (i = 0; i < max; i++) {
2416                 q->pool[i] = kmalloc(item_size, GFP_KERNEL);
2417                 if (q->pool[i] == NULL) {
2418                         int j;
2419
2420                         for (j = 0; j < i; j++)
2421                                 kfree(q->pool[j]);
2422
2423                         kfifo_free(q->queue);
2424                         kfree(q->pool);
2425                         kfree(*items);
2426                         return -ENOMEM;
2427                 }
2428                 memset(q->pool[i], 0, item_size);
2429                 (*items)[i] = q->pool[i];
2430                 __kfifo_put(q->queue, (void*)&q->pool[i], sizeof(void*));
2431         }
2432         return 0;
2433 }
2434
2435 static void
2436 iscsi_pool_free(struct iscsi_queue *q, void **items)
2437 {
2438         int i;
2439
2440         for (i = 0; i < q->max; i++)
2441                 kfree(items[i]);
2442         kfree(q->pool);
2443         kfree(items);
2444 }
2445
2446 static iscsi_connh_t
2447 iscsi_conn_create(iscsi_sessionh_t sessionh, uint32_t conn_idx)
2448 {
2449         struct iscsi_session *session = iscsi_ptr(sessionh);
2450         struct iscsi_conn *conn = NULL;
2451
2452         conn = kmalloc(sizeof(struct iscsi_conn), GFP_KERNEL);
2453         if (conn == NULL)
2454                 goto conn_alloc_fail;
2455         memset(conn, 0, sizeof(struct iscsi_conn));
2456
2457         conn->c_stage = ISCSI_CONN_INITIAL_STAGE;
2458         conn->in_progress = IN_PROGRESS_WAIT_HEADER;
2459         conn->id = conn_idx;
2460         conn->exp_statsn = 0;
2461         conn->tmabort_state = TMABORT_INITIAL;
2462
2463         /* initial operational parameters */
2464         conn->hdr_size = sizeof(struct iscsi_hdr);
2465         conn->data_size = DEFAULT_MAX_RECV_DATA_SEGMENT_LENGTH;
2466         conn->max_recv_dlength = DEFAULT_MAX_RECV_DATA_SEGMENT_LENGTH;
2467
2468         spin_lock_init(&conn->lock);
2469
2470         /* initialize general xmit PDU commands queue */
2471         conn->xmitqueue = kfifo_alloc(session->cmds_max * sizeof(void*),
2472                                         GFP_KERNEL, NULL);
2473         if (conn->xmitqueue == ERR_PTR(-ENOMEM))
2474                 goto xmitqueue_alloc_fail;
2475
2476         /* initialize write response PDU commands queue */
2477         conn->writequeue = kfifo_alloc(session->cmds_max * sizeof(void*),
2478                                         GFP_KERNEL, NULL);
2479         if (conn->writequeue == ERR_PTR(-ENOMEM))
2480                 goto writequeue_alloc_fail;
2481
2482         /* initialize general immediate & non-immediate PDU commands queue */
2483         conn->immqueue = kfifo_alloc(session->mgmtpool_max * sizeof(void*),
2484                                         GFP_KERNEL, NULL);
2485         if (conn->immqueue == ERR_PTR(-ENOMEM))
2486                 goto immqueue_alloc_fail;
2487
2488         conn->mgmtqueue = kfifo_alloc(session->mgmtpool_max * sizeof(void*),
2489                                         GFP_KERNEL, NULL);
2490         if (conn->mgmtqueue == ERR_PTR(-ENOMEM))
2491                 goto mgmtqueue_alloc_fail;
2492
2493         INIT_WORK(&conn->xmitwork, iscsi_xmitworker, conn);
2494
2495         /* allocate login_mtask used for the login/text sequences */
2496         spin_lock_bh(&session->lock);
2497         if (!__kfifo_get(session->mgmtpool.queue,
2498                          (void*)&conn->login_mtask,
2499                          sizeof(void*))) {
2500                 spin_unlock_bh(&session->lock);
2501                 goto login_mtask_alloc_fail;
2502         }
2503         spin_unlock_bh(&session->lock);
2504
2505         /* allocate initial PDU receive place holder */
2506         if (conn->data_size <= PAGE_SIZE)
2507                 conn->data = kmalloc(conn->data_size, GFP_KERNEL);
2508         else
2509                 conn->data = (void*)__get_free_pages(GFP_KERNEL,
2510                                         get_order(conn->data_size));
2511         if (!conn->data)
2512                 goto max_recv_dlenght_alloc_fail;
2513
2514         init_timer(&conn->tmabort_timer);
2515         init_MUTEX(&conn->xmitsema);
2516         init_waitqueue_head(&conn->ehwait);
2517
2518         return iscsi_handle(conn);
2519
2520 max_recv_dlenght_alloc_fail:
2521         spin_lock_bh(&session->lock);
2522         __kfifo_put(session->mgmtpool.queue, (void*)&conn->login_mtask,
2523                     sizeof(void*));
2524         spin_unlock_bh(&session->lock);
2525 login_mtask_alloc_fail:
2526         kfifo_free(conn->mgmtqueue);
2527 mgmtqueue_alloc_fail:
2528         kfifo_free(conn->immqueue);
2529 immqueue_alloc_fail:
2530         kfifo_free(conn->writequeue);
2531 writequeue_alloc_fail:
2532         kfifo_free(conn->xmitqueue);
2533 xmitqueue_alloc_fail:
2534         kfree(conn);
2535 conn_alloc_fail:
2536         return iscsi_handle(NULL);
2537 }
2538
2539 static void
2540 iscsi_conn_destroy(iscsi_connh_t connh)
2541 {
2542         struct iscsi_conn *conn = iscsi_ptr(connh);
2543         struct iscsi_session *session = conn->session;
2544
2545         down(&conn->xmitsema);
2546         set_bit(SUSPEND_BIT, &conn->suspend_tx);
2547         if (conn->c_stage == ISCSI_CONN_INITIAL_STAGE && conn->sock) {
2548                 struct sock *sk = conn->sock->sk;
2549
2550                 /*
2551                  * conn_start() has never been called!
2552                  * need to cleanup the socket.
2553                  */
2554                 write_lock_bh(&sk->sk_callback_lock);
2555                 set_bit(SUSPEND_BIT, &conn->suspend_rx);
2556                 write_unlock_bh(&sk->sk_callback_lock);
2557
2558                 sock_hold(conn->sock->sk);
2559                 iscsi_conn_restore_callbacks(conn);
2560                 sock_put(conn->sock->sk);
2561                 sock_release(conn->sock);
2562                 conn->sock = NULL;
2563         }
2564
2565         spin_lock_bh(&session->lock);
2566         conn->c_stage = ISCSI_CONN_CLEANUP_WAIT;
2567         if (session->leadconn == conn) {
2568                 /*
2569                  * leading connection? then give up on recovery.
2570                  */
2571                 session->state = ISCSI_STATE_TERMINATE;
2572                 wake_up(&conn->ehwait);
2573         }
2574         spin_unlock_bh(&session->lock);
2575
2576         up(&conn->xmitsema);
2577
2578         /*
2579          * Block until all in-progress commands for this connection
2580          * time out or fail.
2581          */
2582         for (;;) {
2583                 spin_lock_bh(&conn->lock);
2584                 if (!session->host->host_busy) { /* OK for ERL == 0 */
2585                         spin_unlock_bh(&conn->lock);
2586                         break;
2587                 }
2588                 spin_unlock_bh(&conn->lock);
2589                 msleep_interruptible(500);
2590                 printk("conn_destroy(): host_busy %d host_failed %d\n",
2591                         session->host->host_busy, session->host->host_failed);
2592                 /*
2593                  * force eh_abort() to unblock
2594                  */
2595                 wake_up(&conn->ehwait);
2596         }
2597
2598         /* now free crypto */
2599         if (conn->hdrdgst_en || conn->datadgst_en) {
2600                 if (conn->tx_tfm)
2601                         crypto_free_tfm(conn->tx_tfm);
2602                 if (conn->rx_tfm)
2603                         crypto_free_tfm(conn->rx_tfm);
2604                 if (conn->data_tx_tfm)
2605                         crypto_free_tfm(conn->data_tx_tfm);
2606                 if (conn->data_rx_tfm)
2607                         crypto_free_tfm(conn->data_rx_tfm);
2608         }
2609
2610         /* free conn->data, size = MaxRecvDataSegmentLength */
2611         if (conn->data_size <= PAGE_SIZE)
2612                 kfree(conn->data);
2613         else
2614                 free_pages((unsigned long)conn->data,
2615                                         get_order(conn->data_size));
2616
2617         spin_lock_bh(&session->lock);
2618         __kfifo_put(session->mgmtpool.queue, (void*)&conn->login_mtask,
2619                     sizeof(void*));
2620         list_del(&conn->item);
2621         if (list_empty(&session->connections))
2622                 session->leadconn = NULL;
2623         if (session->leadconn && session->leadconn == conn)
2624                 session->leadconn = container_of(session->connections.next,
2625                         struct iscsi_conn, item);
2626
2627         if (session->leadconn == NULL)
2628                 /* none connections exits.. reset sequencing */
2629                 session->cmdsn = session->max_cmdsn = session->exp_cmdsn = 1;
2630         spin_unlock_bh(&session->lock);
2631
2632         kfifo_free(conn->xmitqueue);
2633         kfifo_free(conn->writequeue);
2634         kfifo_free(conn->immqueue);
2635         kfifo_free(conn->mgmtqueue);
2636         kfree(conn);
2637 }
2638
2639 static int
2640 iscsi_conn_bind(iscsi_sessionh_t sessionh, iscsi_connh_t connh,
2641                 uint32_t transport_fd, int is_leading)
2642 {
2643         struct iscsi_session *session = iscsi_ptr(sessionh);
2644         struct iscsi_conn *tmp = ERR_PTR(-EEXIST), *conn = iscsi_ptr(connh);
2645         struct sock *sk;
2646         struct socket *sock;
2647         int err;
2648
2649         /* lookup for existing socket */
2650         sock = sockfd_lookup(transport_fd, &err);
2651         if (!sock) {
2652                 printk(KERN_ERR "iscsi_tcp: sockfd_lookup failed %d\n", err);
2653                 return -EEXIST;
2654         }
2655
2656         /* lookup for existing connection */
2657         spin_lock_bh(&session->lock);
2658         list_for_each_entry(tmp, &session->connections, item) {
2659                 if (tmp == conn) {
2660                         if (conn->c_stage != ISCSI_CONN_STOPPED ||
2661                             conn->stop_stage == STOP_CONN_TERM) {
2662                                 printk(KERN_ERR "iscsi_tcp: can't bind "
2663                                        "non-stopped connection (%d:%d)\n",
2664                                        conn->c_stage, conn->stop_stage);
2665                                 spin_unlock_bh(&session->lock);
2666                                 return -EIO;
2667                         }
2668                         break;
2669                 }
2670         }
2671         if (tmp != conn) {
2672                 /* bind new iSCSI connection to session */
2673                 conn->session = session;
2674
2675                 list_add(&conn->item, &session->connections);
2676         }
2677         spin_unlock_bh(&session->lock);
2678
2679         if (conn->stop_stage != STOP_CONN_SUSPEND) {
2680                 /* bind iSCSI connection and socket */
2681                 conn->sock = sock;
2682
2683                 /* setup Socket parameters */
2684                 sk = sock->sk;
2685                 sk->sk_reuse = 1;
2686                 sk->sk_sndtimeo = 15 * HZ; /* FIXME: make it configurable */
2687                 sk->sk_allocation = GFP_ATOMIC;
2688
2689                 /* FIXME: disable Nagle's algorithm */
2690
2691                 /*
2692                  * Intercept TCP callbacks for sendfile like receive
2693                  * processing.
2694                  */
2695                 iscsi_conn_set_callbacks(conn);
2696
2697                 /*
2698                  * set receive state machine into initial state
2699                  */
2700                 conn->in_progress = IN_PROGRESS_WAIT_HEADER;
2701         }
2702
2703         if (is_leading)
2704                 session->leadconn = conn;
2705
2706         /*
2707          * Unblock xmitworker(), Login Phase will pass through.
2708          */
2709         clear_bit(SUSPEND_BIT, &conn->suspend_rx);
2710         clear_bit(SUSPEND_BIT, &conn->suspend_tx);
2711
2712         return 0;
2713 }
2714
2715 static int
2716 iscsi_conn_start(iscsi_connh_t connh)
2717 {
2718         struct iscsi_conn *conn = iscsi_ptr(connh);
2719         struct iscsi_session *session = conn->session;
2720         struct sock *sk;
2721
2722         /* FF phase warming up... */
2723
2724         if (session == NULL) {
2725                 printk(KERN_ERR "iscsi_tcp: can't start unbound connection\n");
2726                 return -EPERM;
2727         }
2728
2729         sk = conn->sock->sk;
2730
2731         write_lock_bh(&sk->sk_callback_lock);
2732         spin_lock_bh(&session->lock);
2733         conn->c_stage = ISCSI_CONN_STARTED;
2734         session->state = ISCSI_STATE_LOGGED_IN;
2735
2736         switch(conn->stop_stage) {
2737         case STOP_CONN_RECOVER:
2738                 /*
2739                  * unblock eh_abort() if it is blocked. re-try all
2740                  * commands after successful recovery
2741                  */
2742                 session->conn_cnt++;
2743                 conn->stop_stage = 0;
2744                 conn->tmabort_state = TMABORT_INITIAL;
2745                 session->age++;
2746                 wake_up(&conn->ehwait);
2747                 break;
2748         case STOP_CONN_TERM:
2749                 session->conn_cnt++;
2750                 conn->stop_stage = 0;
2751                 break;
2752         case STOP_CONN_SUSPEND:
2753                 conn->stop_stage = 0;
2754                 clear_bit(SUSPEND_BIT, &conn->suspend_rx);
2755                 clear_bit(SUSPEND_BIT, &conn->suspend_tx);
2756                 break;
2757         default:
2758                 break;
2759         }
2760         spin_unlock_bh(&session->lock);
2761         write_unlock_bh(&sk->sk_callback_lock);
2762
2763         return 0;
2764 }
2765
2766 static void
2767 iscsi_conn_stop(iscsi_connh_t connh, int flag)
2768 {
2769         struct iscsi_conn *conn = iscsi_ptr(connh);
2770         struct iscsi_session *session = conn->session;
2771         struct sock *sk;
2772         unsigned long flags;
2773
2774         BUG_ON(!conn->sock);
2775         sk = conn->sock->sk;
2776         write_lock_bh(&sk->sk_callback_lock);
2777         set_bit(SUSPEND_BIT, &conn->suspend_rx);
2778         write_unlock_bh(&sk->sk_callback_lock);
2779
2780         down(&conn->xmitsema);
2781
2782         spin_lock_irqsave(session->host->host_lock, flags);
2783         spin_lock(&session->lock);
2784         conn->stop_stage = flag;
2785         conn->c_stage = ISCSI_CONN_STOPPED;
2786         set_bit(SUSPEND_BIT, &conn->suspend_tx);
2787
2788         if (flag != STOP_CONN_SUSPEND)
2789                 session->conn_cnt--;
2790
2791         if (session->conn_cnt == 0 || session->leadconn == conn)
2792                 session->state = ISCSI_STATE_FAILED;
2793
2794         spin_unlock(&session->lock);
2795         spin_unlock_irqrestore(session->host->host_lock, flags);
2796
2797         if (flag == STOP_CONN_TERM || flag == STOP_CONN_RECOVER) {
2798                 struct iscsi_cmd_task *ctask;
2799                 struct iscsi_mgmt_task *mtask;
2800
2801                 /*
2802                  * Socket must go now.
2803                  */
2804                 sock_hold(conn->sock->sk);
2805                 iscsi_conn_restore_callbacks(conn);
2806                 sock_put(conn->sock->sk);
2807
2808                 /*
2809                  * flush xmit queues.
2810                  */
2811                 spin_lock_bh(&session->lock);
2812                 while (__kfifo_get(conn->writequeue, (void*)&ctask,
2813                             sizeof(void*)) ||
2814                         __kfifo_get(conn->xmitqueue, (void*)&ctask,
2815                             sizeof(void*))) {
2816                         struct iscsi_r2t_info *r2t;
2817
2818                         /*
2819                          * flush ctask's r2t queues
2820                          */
2821                         while (__kfifo_get(ctask->r2tqueue, (void*)&r2t,
2822                                 sizeof(void*)))
2823                                 __kfifo_put(ctask->r2tpool.queue, (void*)&r2t,
2824                                             sizeof(void*));
2825
2826                         spin_unlock_bh(&session->lock);
2827                         local_bh_disable();
2828                         iscsi_ctask_cleanup(conn, ctask);
2829                         local_bh_enable();
2830                         spin_lock_bh(&session->lock);
2831                 }
2832                 conn->ctask = NULL;
2833                 while (__kfifo_get(conn->immqueue, (void*)&mtask,
2834                            sizeof(void*)) ||
2835                         __kfifo_get(conn->mgmtqueue, (void*)&mtask,
2836                            sizeof(void*))) {
2837                         __kfifo_put(session->mgmtpool.queue,
2838                                     (void*)&mtask, sizeof(void*));
2839                 }
2840                 conn->mtask = NULL;
2841                 spin_unlock_bh(&session->lock);
2842
2843                 /*
2844                  * release socket only after we stopped data_xmit()
2845                  * activity and flushed all outstandings
2846                  */
2847                 sock_release(conn->sock);
2848                 conn->sock = NULL;
2849
2850                 /*
2851                  * for connection level recovery we should not calculate
2852                  * header digest. conn->hdr_size used for optimization
2853                  * in hdr_extract() and will be re-negotiated at
2854                  * set_param() time.
2855                  */
2856                 if (flag == STOP_CONN_RECOVER)
2857                         conn->hdr_size = sizeof(struct iscsi_hdr);
2858         }
2859         up(&conn->xmitsema);
2860 }
2861
2862 static int
2863 iscsi_conn_send_generic(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
2864                         char *data, uint32_t data_size)
2865 {
2866         struct iscsi_session *session = conn->session;
2867         struct iscsi_nopout *nop = (struct iscsi_nopout *)hdr;
2868         struct iscsi_mgmt_task *mtask;
2869
2870         spin_lock_bh(&session->lock);
2871         if (session->state == ISCSI_STATE_TERMINATE) {
2872                 spin_unlock_bh(&session->lock);
2873                 return -EPERM;
2874         }
2875         if (hdr->opcode == (ISCSI_OP_LOGIN | ISCSI_OP_IMMEDIATE) ||
2876             hdr->opcode == (ISCSI_OP_TEXT | ISCSI_OP_IMMEDIATE))
2877                 /*
2878                  * Login and Text are sent serially, in
2879                  * request-followed-by-response sequence.
2880                  * Same mtask can be used. Same ITT must be used.
2881                  * Note that login_mtask is preallocated at conn_create().
2882                  */
2883                 mtask = conn->login_mtask;
2884         else {
2885                 BUG_ON(conn->c_stage == ISCSI_CONN_INITIAL_STAGE);
2886                 BUG_ON(conn->c_stage == ISCSI_CONN_STOPPED);
2887
2888                 if (!__kfifo_get(session->mgmtpool.queue,
2889                                  (void*)&mtask, sizeof(void*))) {
2890                         spin_unlock_bh(&session->lock);
2891                         return -ENOSPC;
2892                 }
2893         }
2894
2895         /*
2896          * pre-format CmdSN and ExpStatSN for outgoing PDU.
2897          */
2898         if (hdr->itt != cpu_to_be32(ISCSI_RESERVED_TAG)) {
2899                 hdr->itt = mtask->itt | (conn->id << CID_SHIFT) |
2900                            (session->age << AGE_SHIFT);
2901                 nop->cmdsn = cpu_to_be32(session->cmdsn);
2902                 if (conn->c_stage == ISCSI_CONN_STARTED &&
2903                     !(hdr->opcode & ISCSI_OP_IMMEDIATE))
2904                         session->cmdsn++;
2905         } else
2906                 /* do not advance CmdSN */
2907                 nop->cmdsn = cpu_to_be32(session->cmdsn);
2908
2909         nop->exp_statsn = cpu_to_be32(conn->exp_statsn);
2910
2911         memcpy(&mtask->hdr, hdr, sizeof(struct iscsi_hdr));
2912
2913         iscsi_buf_init_virt(&mtask->headbuf, (char*)&mtask->hdr,
2914                                     sizeof(struct iscsi_hdr));
2915
2916         spin_unlock_bh(&session->lock);
2917
2918         if (data_size) {
2919                 memcpy(mtask->data, data, data_size);
2920                 mtask->data_count = data_size;
2921         } else
2922                 mtask->data_count = 0;
2923
2924         mtask->xmstate = XMSTATE_IMM_HDR;
2925
2926         if (mtask->data_count) {
2927                 iscsi_buf_init_iov(&mtask->sendbuf, (char*)mtask->data,
2928                                     mtask->data_count);
2929         }
2930
2931         debug_scsi("mgmtpdu [op 0x%x hdr->itt 0x%x datalen %d]\n",
2932                    hdr->opcode, hdr->itt, data_size);
2933
2934         /*
2935          * since send_pdu() could be called at least from two contexts,
2936          * we need to serialize __kfifo_put, so we don't have to take
2937          * additional lock on fast data-path
2938          */
2939         if (hdr->opcode & ISCSI_OP_IMMEDIATE)
2940                 __kfifo_put(conn->immqueue, (void*)&mtask, sizeof(void*));
2941         else
2942                 __kfifo_put(conn->mgmtqueue, (void*)&mtask, sizeof(void*));
2943
2944         schedule_work(&conn->xmitwork);
2945
2946         return 0;
2947 }
2948
2949 static int
2950 iscsi_eh_host_reset(struct scsi_cmnd *sc)
2951 {
2952         struct iscsi_cmd_task *ctask = (struct iscsi_cmd_task *)sc->SCp.ptr;
2953         struct iscsi_conn *conn = ctask->conn;
2954         struct iscsi_session *session = conn->session;
2955
2956         spin_lock_bh(&session->lock);
2957         if (session->state == ISCSI_STATE_TERMINATE) {
2958                 debug_scsi("failing host reset: session terminated "
2959                            "[CID %d age %d]", conn->id, session->age);
2960                 spin_unlock_bh(&session->lock);
2961                 return FAILED;
2962         }
2963         spin_unlock_bh(&session->lock);
2964
2965         debug_scsi("failing connection CID %d due to SCSI host reset "
2966                    "[itt 0x%x age %d]", conn->id, ctask->itt,
2967                    session->age);
2968         iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
2969
2970         return SUCCESS;
2971 }
2972
2973 static void
2974 iscsi_tmabort_timedout(unsigned long data)
2975 {
2976         struct iscsi_cmd_task *ctask = (struct iscsi_cmd_task *)data;
2977         struct iscsi_conn *conn = ctask->conn;
2978         struct iscsi_session *session = conn->session;
2979
2980         spin_lock(&session->lock);
2981         if (conn->tmabort_state == TMABORT_INITIAL) {
2982                 __kfifo_put(session->mgmtpool.queue,
2983                                 (void*)&ctask->mtask, sizeof(void*));
2984                 conn->tmabort_state = TMABORT_TIMEDOUT;
2985                 debug_scsi("tmabort timedout [sc %lx itt 0x%x]\n",
2986                         (long)ctask->sc, ctask->itt);
2987                 /* unblock eh_abort() */
2988                 wake_up(&conn->ehwait);
2989         }
2990         spin_unlock(&session->lock);
2991 }
2992
2993 static int
2994 iscsi_eh_abort(struct scsi_cmnd *sc)
2995 {
2996         int rc;
2997         struct iscsi_cmd_task *ctask = (struct iscsi_cmd_task *)sc->SCp.ptr;
2998         struct iscsi_conn *conn = ctask->conn;
2999         struct iscsi_session *session = conn->session;
3000
3001         conn->eh_abort_cnt++;
3002         debug_scsi("aborting [sc %lx itt 0x%x]\n", (long)sc, ctask->itt);
3003
3004         /*
3005          * two cases for ERL=0 here:
3006          *
3007          * 1) connection-level failure;
3008          * 2) recovery due protocol error;
3009          */
3010         down(&conn->xmitsema);
3011         spin_lock_bh(&session->lock);
3012         if (session->state != ISCSI_STATE_LOGGED_IN) {
3013                 if (session->state == ISCSI_STATE_TERMINATE) {
3014                         spin_unlock_bh(&session->lock);
3015                         up(&conn->xmitsema);
3016                         goto failed;
3017                 }
3018                 spin_unlock_bh(&session->lock);
3019         } else {
3020                 struct iscsi_tm *hdr = &conn->tmhdr;
3021
3022                 /*
3023                  * Still LOGGED_IN...
3024                  */
3025
3026                 if (!ctask->sc || sc->SCp.phase != session->age) {
3027                         /*
3028                          * 1) ctask completed before time out. But session
3029                          *    is still ok => Happy Retry.
3030                          * 2) session was re-open during time out of ctask.
3031                          */
3032                         spin_unlock_bh(&session->lock);
3033                         up(&conn->xmitsema);
3034                         goto success;
3035                 }
3036                 conn->tmabort_state = TMABORT_INITIAL;
3037                 spin_unlock_bh(&session->lock);
3038
3039                 /*
3040                  * ctask timed out but session is OK
3041                  * ERL=0 requires task mgmt abort to be issued on each
3042                  * failed command. requests must be serialized.
3043                  */
3044                 memset(hdr, 0, sizeof(struct iscsi_tm));
3045                 hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
3046                 hdr->flags = ISCSI_TM_FUNC_ABORT_TASK;
3047                 hdr->flags |= ISCSI_FLAG_CMD_FINAL;
3048                 memcpy(hdr->lun, ctask->hdr.lun, sizeof(hdr->lun));
3049                 hdr->rtt = ctask->hdr.itt;
3050                 hdr->refcmdsn = ctask->hdr.cmdsn;
3051
3052                 rc = iscsi_conn_send_generic(conn, (struct iscsi_hdr *)hdr,
3053                                              NULL, 0);
3054                 if (rc) {
3055                         iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
3056                         debug_scsi("abort sent failure [itt 0x%x]", ctask->itt);
3057                 } else {
3058                         struct iscsi_r2t_info *r2t;
3059
3060                         /*
3061                          * TMF abort vs. TMF response race logic
3062                          */
3063                         spin_lock_bh(&session->lock);
3064                         ctask->mtask = (struct iscsi_mgmt_task *)
3065                                 session->mgmt_cmds[(hdr->itt & ITT_MASK) -
3066                                                         ISCSI_MGMT_ITT_OFFSET];
3067                         /*
3068                          * have to flush r2tqueue to avoid r2t leaks
3069                          */
3070                         while (__kfifo_get(ctask->r2tqueue, (void*)&r2t,
3071                                 sizeof(void*))) {
3072                                 __kfifo_put(ctask->r2tpool.queue, (void*)&r2t,
3073                                         sizeof(void*));
3074                         }
3075                         if (conn->tmabort_state == TMABORT_INITIAL) {
3076                                 conn->tmfcmd_pdus_cnt++;
3077                                 conn->tmabort_timer.expires = 3*HZ + jiffies;
3078                                 conn->tmabort_timer.function =
3079                                                 iscsi_tmabort_timedout;
3080                                 conn->tmabort_timer.data = (unsigned long)ctask;
3081                                 add_timer(&conn->tmabort_timer);
3082                                 debug_scsi("abort sent [itt 0x%x]", ctask->itt);
3083                         } else {
3084                                 if (!ctask->sc ||
3085                                     conn->tmabort_state == TMABORT_SUCCESS) {
3086                                         conn->tmabort_state = TMABORT_INITIAL;
3087                                         spin_unlock_bh(&session->lock);
3088                                         up(&conn->xmitsema);
3089                                         goto success;
3090                                 }
3091                                 conn->tmabort_state = TMABORT_INITIAL;
3092                                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
3093                         }
3094                         spin_unlock_bh(&session->lock);
3095                 }
3096         }
3097         up(&conn->xmitsema);
3098
3099
3100         /*
3101          * block eh thread until:
3102          *
3103          * 1) abort response;
3104          * 2) abort timeout;
3105          * 3) session re-opened;
3106          * 4) session terminated;
3107          */
3108         for (;;) {
3109                 int p_state = session->state;
3110
3111                 rc = wait_event_interruptible(conn->ehwait,
3112                         (p_state == ISCSI_STATE_LOGGED_IN ?
3113                          (session->state == ISCSI_STATE_TERMINATE ||
3114                           conn->tmabort_state != TMABORT_INITIAL) :
3115                          (session->state == ISCSI_STATE_TERMINATE ||
3116                           session->state == ISCSI_STATE_LOGGED_IN)));
3117                 if (rc) {
3118                         /* shutdown.. */
3119                         session->state = ISCSI_STATE_TERMINATE;
3120                         goto failed;
3121                 }
3122
3123                 if (signal_pending(current))
3124                         flush_signals(current);
3125
3126                 if (session->state == ISCSI_STATE_TERMINATE)
3127                         goto failed;
3128
3129                 spin_lock_bh(&session->lock);
3130                 if (sc->SCp.phase == session->age &&
3131                    (conn->tmabort_state == TMABORT_TIMEDOUT ||
3132                     conn->tmabort_state == TMABORT_FAILED)) {
3133                         conn->tmabort_state = TMABORT_INITIAL;
3134                         if (!ctask->sc) {
3135                                 /*
3136                                  * ctask completed before tmf abort response or
3137                                  * time out.
3138                                  * But session is still ok => Happy Retry.
3139                                  */
3140                                 spin_unlock_bh(&session->lock);
3141                                 break;
3142                         }
3143                         spin_unlock_bh(&session->lock);
3144                         iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
3145                         continue;
3146                 }
3147                 spin_unlock_bh(&session->lock);
3148                 break;
3149         }
3150
3151 success:
3152         debug_scsi("abort success [sc %lx itt 0x%x]\n", (long)sc, ctask->itt);
3153         rc = SUCCESS;
3154         goto exit;
3155
3156 failed:
3157         debug_scsi("abort failed [sc %lx itt 0x%x]\n", (long)sc, ctask->itt);
3158         rc = FAILED;
3159
3160 exit:
3161         del_timer_sync(&conn->tmabort_timer);
3162
3163         down(&conn->xmitsema);
3164         if (conn->sock) {
3165                 struct sock *sk = conn->sock->sk;
3166
3167                 write_lock_bh(&sk->sk_callback_lock);
3168                 iscsi_ctask_cleanup(conn, ctask);
3169                 write_unlock_bh(&sk->sk_callback_lock);
3170         }
3171         up(&conn->xmitsema);
3172         return rc;
3173 }
3174
3175 static int
3176 iscsi_r2tpool_alloc(struct iscsi_session *session)
3177 {
3178         int i;
3179         int cmd_i;
3180
3181         /*
3182          * initialize per-task: R2T pool and xmit queue
3183          */
3184         for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
3185                 struct iscsi_cmd_task *ctask = session->cmds[cmd_i];
3186
3187                 /*
3188                  * pre-allocated x4 as much r2ts to handle race when
3189                  * target acks DataOut faster than we data_xmit() queues
3190                  * could replenish r2tqueue.
3191                  */
3192
3193                 /* R2T pool */
3194                 if (iscsi_pool_init(&ctask->r2tpool, session->max_r2t * 4,
3195                         (void***)&ctask->r2ts, sizeof(struct iscsi_r2t_info))) {
3196                         goto r2t_alloc_fail;
3197                 }
3198
3199                 /* R2T xmit queue */
3200                 ctask->r2tqueue = kfifo_alloc(
3201                       session->max_r2t * 4 * sizeof(void*), GFP_KERNEL, NULL);
3202                 if (ctask->r2tqueue == ERR_PTR(-ENOMEM)) {
3203                         iscsi_pool_free(&ctask->r2tpool, (void**)ctask->r2ts);
3204                         goto r2t_alloc_fail;
3205                 }
3206
3207                 /*
3208                  * number of
3209                  * Data-Out PDU's within R2T-sequence can be quite big;
3210                  * using mempool
3211                  */
3212                 ctask->datapool = mempool_create(ISCSI_DTASK_DEFAULT_MAX,
3213                          mempool_alloc_slab, mempool_free_slab, taskcache);
3214                 if (ctask->datapool == NULL) {
3215                         kfifo_free(ctask->r2tqueue);
3216                         iscsi_pool_free(&ctask->r2tpool, (void**)ctask->r2ts);
3217                         goto r2t_alloc_fail;
3218                 }
3219                 INIT_LIST_HEAD(&ctask->dataqueue);
3220         }
3221
3222         return 0;
3223
3224 r2t_alloc_fail:
3225         for (i = 0; i < cmd_i; i++) {
3226                 mempool_destroy(session->cmds[i]->datapool);
3227                 kfifo_free(session->cmds[i]->r2tqueue);
3228                 iscsi_pool_free(&session->cmds[i]->r2tpool,
3229                                 (void**)session->cmds[i]->r2ts);
3230         }
3231         return -ENOMEM;
3232 }
3233
3234 static void
3235 iscsi_r2tpool_free(struct iscsi_session *session)
3236 {
3237         int i;
3238
3239         for (i = 0; i < session->cmds_max; i++) {
3240                 mempool_destroy(session->cmds[i]->datapool);
3241                 kfifo_free(session->cmds[i]->r2tqueue);
3242                 iscsi_pool_free(&session->cmds[i]->r2tpool,
3243                                 (void**)session->cmds[i]->r2ts);
3244         }
3245 }
3246
3247 static struct scsi_host_template iscsi_sht = {
3248         .name                   = "iSCSI Initiator over TCP/IP, v."
3249                                   ISCSI_VERSION_STR,
3250         .queuecommand           = iscsi_queuecommand,
3251         .can_queue              = ISCSI_XMIT_CMDS_MAX - 1,
3252         .sg_tablesize           = ISCSI_SG_TABLESIZE,
3253         .cmd_per_lun            = ISCSI_CMD_PER_LUN,
3254         .eh_abort_handler       = iscsi_eh_abort,
3255         .eh_host_reset_handler  = iscsi_eh_host_reset,
3256         .use_clustering         = DISABLE_CLUSTERING,
3257         .proc_name              = "iscsi_tcp",
3258         .this_id                = -1,
3259 };
3260
3261 static iscsi_sessionh_t
3262 iscsi_session_create(uint32_t initial_cmdsn, struct Scsi_Host *host)
3263 {
3264         int cmd_i;
3265         struct iscsi_session *session;
3266
3267         session = iscsi_hostdata(host->hostdata);
3268         memset(session, 0, sizeof(struct iscsi_session));
3269
3270         session->host = host;
3271         session->id = host->host_no;
3272         session->state = ISCSI_STATE_LOGGED_IN;
3273         session->mgmtpool_max = ISCSI_MGMT_CMDS_MAX;
3274         session->cmds_max = ISCSI_XMIT_CMDS_MAX;
3275         session->cmdsn = initial_cmdsn;
3276         session->exp_cmdsn = initial_cmdsn + 1;
3277         session->max_cmdsn = initial_cmdsn + 1;
3278         session->max_r2t = 1;
3279
3280         /* initialize SCSI PDU commands pool */
3281         if (iscsi_pool_init(&session->cmdpool, session->cmds_max,
3282                 (void***)&session->cmds, sizeof(struct iscsi_cmd_task)))
3283                 goto cmdpool_alloc_fail;
3284
3285         /* pre-format cmds pool with ITT */
3286         for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++)
3287                 session->cmds[cmd_i]->itt = cmd_i;
3288
3289         spin_lock_init(&session->lock);
3290         INIT_LIST_HEAD(&session->connections);
3291
3292         /* initialize immediate command pool */
3293         if (iscsi_pool_init(&session->mgmtpool, session->mgmtpool_max,
3294                 (void***)&session->mgmt_cmds, sizeof(struct iscsi_mgmt_task)))
3295                 goto mgmtpool_alloc_fail;
3296
3297
3298         /* pre-format immediate cmds pool with ITT */
3299         for (cmd_i = 0; cmd_i < session->mgmtpool_max; cmd_i++) {
3300                 session->mgmt_cmds[cmd_i]->itt = ISCSI_MGMT_ITT_OFFSET + cmd_i;
3301                 session->mgmt_cmds[cmd_i]->data = kmalloc(
3302                         DEFAULT_MAX_RECV_DATA_SEGMENT_LENGTH, GFP_KERNEL);
3303                 if (!session->mgmt_cmds[cmd_i]->data) {
3304                         int j;
3305
3306                         for (j = 0; j < cmd_i; j++)
3307                                 kfree(session->mgmt_cmds[j]->data);
3308                         goto immdata_alloc_fail;
3309                 }
3310         }
3311
3312         if (iscsi_r2tpool_alloc(session))
3313                 goto r2tpool_alloc_fail;
3314
3315         return iscsi_handle(session);
3316
3317 r2tpool_alloc_fail:
3318         for (cmd_i = 0; cmd_i < session->mgmtpool_max; cmd_i++)
3319                 kfree(session->mgmt_cmds[cmd_i]->data);
3320         iscsi_pool_free(&session->mgmtpool, (void**)session->mgmt_cmds);
3321 immdata_alloc_fail:
3322 mgmtpool_alloc_fail:
3323         iscsi_pool_free(&session->cmdpool, (void**)session->cmds);
3324 cmdpool_alloc_fail:
3325         return iscsi_handle(NULL);
3326 }
3327
3328 static void
3329 iscsi_session_destroy(iscsi_sessionh_t sessionh)
3330 {
3331         int cmd_i;
3332         struct iscsi_data_task *dtask, *n;
3333         struct iscsi_session *session = iscsi_ptr(sessionh);
3334
3335         for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
3336                 struct iscsi_cmd_task *ctask = session->cmds[cmd_i];
3337                 list_for_each_entry_safe(dtask, n, &ctask->dataqueue, item) {
3338                         list_del(&dtask->item);
3339                         mempool_free(dtask, ctask->datapool);
3340                 }
3341         }
3342
3343         for (cmd_i = 0; cmd_i < session->mgmtpool_max; cmd_i++)
3344                 kfree(session->mgmt_cmds[cmd_i]->data);
3345
3346         iscsi_r2tpool_free(session);
3347         iscsi_pool_free(&session->mgmtpool, (void**)session->mgmt_cmds);
3348         iscsi_pool_free(&session->cmdpool, (void**)session->cmds);
3349 }
3350
3351 static int
3352 iscsi_conn_set_param(iscsi_connh_t connh, enum iscsi_param param,
3353                      uint32_t value)
3354 {
3355         struct iscsi_conn *conn = iscsi_ptr(connh);
3356         struct iscsi_session *session = conn->session;
3357
3358         spin_lock_bh(&session->lock);
3359         if (conn->c_stage != ISCSI_CONN_INITIAL_STAGE &&
3360             conn->stop_stage != STOP_CONN_RECOVER) {
3361                 printk(KERN_ERR "iscsi_tcp: can not change parameter [%d]\n",
3362                        param);
3363                 spin_unlock_bh(&session->lock);
3364                 return 0;
3365         }
3366         spin_unlock_bh(&session->lock);
3367
3368         switch(param) {
3369         case ISCSI_PARAM_MAX_RECV_DLENGTH: {
3370                 char *saveptr = conn->data;
3371                 int flags = GFP_KERNEL;
3372
3373                 if (conn->data_size >= value) {
3374                         conn->max_recv_dlength = value;
3375                         break;
3376                 }
3377
3378                 spin_lock_bh(&session->lock);
3379                 if (conn->stop_stage == STOP_CONN_RECOVER)
3380                         flags = GFP_ATOMIC;
3381                 spin_unlock_bh(&session->lock);
3382
3383                 if (value <= PAGE_SIZE)
3384                         conn->data = kmalloc(value, flags);
3385                 else
3386                         conn->data = (void*)__get_free_pages(flags,
3387                                                              get_order(value));
3388                 if (conn->data == NULL) {
3389                         conn->data = saveptr;
3390                         return -ENOMEM;
3391                 }
3392                 if (conn->data_size <= PAGE_SIZE)
3393                         kfree(saveptr);
3394                 else
3395                         free_pages((unsigned long)saveptr,
3396                                    get_order(conn->data_size));
3397                 conn->max_recv_dlength = value;
3398                 conn->data_size = value;
3399                 }
3400                 break;
3401         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
3402                 conn->max_xmit_dlength =  value;
3403                 break;
3404         case ISCSI_PARAM_HDRDGST_EN:
3405                 conn->hdrdgst_en = value;
3406                 conn->hdr_size = sizeof(struct iscsi_hdr);
3407                 if (conn->hdrdgst_en) {
3408                         conn->hdr_size += sizeof(__u32);
3409                         if (!conn->tx_tfm)
3410                                 conn->tx_tfm = crypto_alloc_tfm("crc32c", 0);
3411                         if (!conn->tx_tfm)
3412                                 return -ENOMEM;
3413                         if (!conn->rx_tfm)
3414                                 conn->rx_tfm = crypto_alloc_tfm("crc32c", 0);
3415                         if (!conn->rx_tfm) {
3416                                 crypto_free_tfm(conn->tx_tfm);
3417                                 return -ENOMEM;
3418                         }
3419                 } else {
3420                         if (conn->tx_tfm)
3421                                 crypto_free_tfm(conn->tx_tfm);
3422                         if (conn->rx_tfm)
3423                                 crypto_free_tfm(conn->rx_tfm);
3424                 }
3425                 break;
3426         case ISCSI_PARAM_DATADGST_EN:
3427                 conn->datadgst_en = value;
3428                 if (conn->datadgst_en) {
3429                         if (!conn->data_tx_tfm)
3430                                 conn->data_tx_tfm =
3431                                     crypto_alloc_tfm("crc32c", 0);
3432                         if (!conn->data_tx_tfm)
3433                                 return -ENOMEM;
3434                         if (!conn->data_rx_tfm)
3435                                 conn->data_rx_tfm =
3436                                     crypto_alloc_tfm("crc32c", 0);
3437                         if (!conn->data_rx_tfm) {
3438                                 crypto_free_tfm(conn->data_tx_tfm);
3439                                 return -ENOMEM;
3440                         }
3441                 } else {
3442                         if (conn->data_tx_tfm)
3443                                 crypto_free_tfm(conn->data_tx_tfm);
3444                         if (conn->data_rx_tfm)
3445                                 crypto_free_tfm(conn->data_rx_tfm);
3446                 }
3447                 break;
3448         case ISCSI_PARAM_INITIAL_R2T_EN:
3449                 session->initial_r2t_en = value;
3450                 break;
3451         case ISCSI_PARAM_MAX_R2T:
3452                 if (session->max_r2t == roundup_pow_of_two(value))
3453                         break;
3454                 iscsi_r2tpool_free(session);
3455                 session->max_r2t = value;
3456                 if (session->max_r2t & (session->max_r2t - 1))
3457                         session->max_r2t = roundup_pow_of_two(session->max_r2t);
3458                 if (iscsi_r2tpool_alloc(session))
3459                         return -ENOMEM;
3460                 break;
3461         case ISCSI_PARAM_IMM_DATA_EN:
3462                 session->imm_data_en = value;
3463                 break;
3464         case ISCSI_PARAM_FIRST_BURST:
3465                 session->first_burst = value;
3466                 break;
3467         case ISCSI_PARAM_MAX_BURST:
3468                 session->max_burst = value;
3469                 break;
3470         case ISCSI_PARAM_PDU_INORDER_EN:
3471                 session->pdu_inorder_en = value;
3472                 break;
3473         case ISCSI_PARAM_DATASEQ_INORDER_EN:
3474                 session->dataseq_inorder_en = value;
3475                 break;
3476         case ISCSI_PARAM_ERL:
3477                 session->erl = value;
3478                 break;
3479         case ISCSI_PARAM_IFMARKER_EN:
3480                 BUG_ON(value);
3481                 session->ifmarker_en = value;
3482                 break;
3483         case ISCSI_PARAM_OFMARKER_EN:
3484                 BUG_ON(value);
3485                 session->ofmarker_en = value;
3486                 break;
3487         default:
3488                 break;
3489         }
3490
3491         return 0;
3492 }
3493
3494 static int
3495 iscsi_conn_get_param(iscsi_connh_t connh, enum iscsi_param param,
3496                      uint32_t *value)
3497 {
3498         struct iscsi_conn *conn = iscsi_ptr(connh);
3499         struct iscsi_session *session = conn->session;
3500
3501         switch(param) {
3502         case ISCSI_PARAM_MAX_RECV_DLENGTH:
3503                 *value = conn->max_recv_dlength;
3504                 break;
3505         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
3506                 *value = conn->max_xmit_dlength;
3507                 break;
3508         case ISCSI_PARAM_HDRDGST_EN:
3509                 *value = conn->hdrdgst_en;
3510                 break;
3511         case ISCSI_PARAM_DATADGST_EN:
3512                 *value = conn->datadgst_en;
3513                 break;
3514         case ISCSI_PARAM_INITIAL_R2T_EN:
3515                 *value = session->initial_r2t_en;
3516                 break;
3517         case ISCSI_PARAM_MAX_R2T:
3518                 *value = session->max_r2t;
3519                 break;
3520         case ISCSI_PARAM_IMM_DATA_EN:
3521                 *value = session->imm_data_en;
3522                 break;
3523         case ISCSI_PARAM_FIRST_BURST:
3524                 *value = session->first_burst;
3525                 break;
3526         case ISCSI_PARAM_MAX_BURST:
3527                 *value = session->max_burst;
3528                 break;
3529         case ISCSI_PARAM_PDU_INORDER_EN:
3530                 *value = session->pdu_inorder_en;
3531                 break;
3532         case ISCSI_PARAM_DATASEQ_INORDER_EN:
3533                 *value = session->dataseq_inorder_en;
3534                 break;
3535         case ISCSI_PARAM_ERL:
3536                 *value = session->erl;
3537                 break;
3538         case ISCSI_PARAM_IFMARKER_EN:
3539                 *value = session->ifmarker_en;
3540                 break;
3541         case ISCSI_PARAM_OFMARKER_EN:
3542                 *value = session->ofmarker_en;
3543                 break;
3544         default:
3545                 return ISCSI_ERR_PARAM_NOT_FOUND;
3546         }
3547
3548         return 0;
3549 }
3550
3551 static void
3552 iscsi_conn_get_stats(iscsi_connh_t connh, struct iscsi_stats *stats)
3553 {
3554         struct iscsi_conn *conn = iscsi_ptr(connh);
3555
3556         stats->txdata_octets = conn->txdata_octets;
3557         stats->rxdata_octets = conn->rxdata_octets;
3558         stats->scsicmd_pdus = conn->scsicmd_pdus_cnt;
3559         stats->dataout_pdus = conn->dataout_pdus_cnt;
3560         stats->scsirsp_pdus = conn->scsirsp_pdus_cnt;
3561         stats->datain_pdus = conn->datain_pdus_cnt;
3562         stats->r2t_pdus = conn->r2t_pdus_cnt;
3563         stats->tmfcmd_pdus = conn->tmfcmd_pdus_cnt;
3564         stats->tmfrsp_pdus = conn->tmfrsp_pdus_cnt;
3565         stats->custom_length = 3;
3566         strcpy(stats->custom[0].desc, "tx_sendpage_failures");
3567         stats->custom[0].value = conn->sendpage_failures_cnt;
3568         strcpy(stats->custom[1].desc, "rx_discontiguous_hdr");
3569         stats->custom[1].value = conn->discontiguous_hdr_cnt;
3570         strcpy(stats->custom[2].desc, "eh_abort_cnt");
3571         stats->custom[2].value = conn->eh_abort_cnt;
3572 }
3573
3574 static int
3575 iscsi_conn_send_pdu(iscsi_connh_t connh, struct iscsi_hdr *hdr, char *data,
3576                     uint32_t data_size)
3577 {
3578         struct iscsi_conn *conn = iscsi_ptr(connh);
3579         int rc;
3580
3581         down(&conn->xmitsema);
3582         rc = iscsi_conn_send_generic(conn, hdr, data, data_size);
3583         up(&conn->xmitsema);
3584
3585         return rc;
3586 }
3587
3588 static struct iscsi_transport iscsi_tcp_transport = {
3589         .owner                  = THIS_MODULE,
3590         .name                   = "tcp",
3591         .caps                   = CAP_RECOVERY_L0 | CAP_MULTI_R2T | CAP_HDRDGST
3592                                   | CAP_DATADGST,
3593         .host_template          = &iscsi_sht,
3594         .hostdata_size          = sizeof(struct iscsi_session),
3595         .max_conn               = 1,
3596         .max_cmd_len            = ISCSI_TCP_MAX_CMD_LEN,
3597         .create_session         = iscsi_session_create,
3598         .destroy_session        = iscsi_session_destroy,
3599         .create_conn            = iscsi_conn_create,
3600         .bind_conn              = iscsi_conn_bind,
3601         .destroy_conn           = iscsi_conn_destroy,
3602         .set_param              = iscsi_conn_set_param,
3603         .get_param              = iscsi_conn_get_param,
3604         .start_conn             = iscsi_conn_start,
3605         .stop_conn              = iscsi_conn_stop,
3606         .send_pdu               = iscsi_conn_send_pdu,
3607         .get_stats              = iscsi_conn_get_stats,
3608 };
3609
3610 static int __init
3611 iscsi_tcp_init(void)
3612 {
3613         int error;
3614
3615         if (iscsi_max_lun < 1) {
3616                 printk(KERN_ERR "Invalid max_lun value of %u\n", iscsi_max_lun);
3617                 return -EINVAL;
3618         }
3619         iscsi_tcp_transport.max_lun = iscsi_max_lun;
3620
3621         taskcache = kmem_cache_create("iscsi_taskcache",
3622                         sizeof(struct iscsi_data_task), 0,
3623                         SLAB_HWCACHE_ALIGN | SLAB_NO_REAP, NULL, NULL);
3624         if (!taskcache)
3625                 return -ENOMEM;
3626
3627         error = iscsi_register_transport(&iscsi_tcp_transport);
3628         if (error)
3629                 kmem_cache_destroy(taskcache);
3630
3631         return error;
3632 }
3633
3634 static void __exit
3635 iscsi_tcp_exit(void)
3636 {
3637         iscsi_unregister_transport(&iscsi_tcp_transport);
3638         kmem_cache_destroy(taskcache);
3639 }
3640
3641 module_init(iscsi_tcp_init);
3642 module_exit(iscsi_tcp_exit);