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   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
  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*sizeof(__u16));
 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                 case ISCSI_OP_NOOP_IN:
 676                 case ISCSI_OP_TEXT_RSP:
 677                 case ISCSI_OP_LOGOUT_RSP:
 678                 case ISCSI_OP_ASYNC_EVENT:
 679                 case ISCSI_OP_REJECT:
 680                         rc = iscsi_check_assign_cmdsn(session,
 681                                                  (struct iscsi_nopin*)hdr);
 682                         if (rc)
 683                                 break;
 684
 685                         /* update ExpStatSN */
 686                         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
 687                         if (!conn->in.datalen) {
 688                                 struct iscsi_mgmt_task *mtask;
 689
 690                                 rc = iscsi_recv_pdu(iscsi_handle(conn), hdr,
 691                                                     NULL, 0);
 692                                 mtask = (struct iscsi_mgmt_task *)
 693                                         session->mgmt_cmds[conn->in.itt -
 694                                                 ISCSI_MGMT_ITT_OFFSET];
 695                                 if (conn->login_mtask != mtask) {
 696                                         spin_lock(&session->lock);
 697                                         __kfifo_put(session->mgmtpool.queue,
 698                                             (void*)&mtask, sizeof(void*));
 699                                         spin_unlock(&session->lock);
 700                                 }
 701                         }
 702                         break;
 703                 default:
 704                         rc = ISCSI_ERR_BAD_OPCODE;
 705                         break;
 706                 }
 707         } else if (conn->in.itt >= ISCSI_MGMT_ITT_OFFSET &&
 708                    conn->in.itt < ISCSI_MGMT_ITT_OFFSET +
 709                                         session->mgmtpool_max) {
 710                 struct iscsi_mgmt_task *mtask = (struct iscsi_mgmt_task *)
 711                                         session->mgmt_cmds[conn->in.itt -
 712                                                 ISCSI_MGMT_ITT_OFFSET];
 713
 714                 debug_scsi("immrsp [op 0x%x cid %d itt 0x%x len %d]\n",
 715                            conn->in.opcode, conn->id, mtask->itt,
 716                            conn->in.datalen);
 717
 718                 switch(conn->in.opcode) {
 719                 case ISCSI_OP_LOGIN_RSP:
 720                 case ISCSI_OP_TEXT_RSP:
 721                         rc = iscsi_check_assign_cmdsn(session,
 722                                                  (struct iscsi_nopin*)hdr);
 723                         if (rc)
 724                                 break;
 725
 726                         if (!conn->in.datalen) {
 727                                 rc = iscsi_recv_pdu(iscsi_handle(conn), hdr,
 728                                                     NULL, 0);
 729                                 if (conn->login_mtask != mtask) {
 730                                         spin_lock(&session->lock);
 731                                         __kfifo_put(session->mgmtpool.queue,
 732                                             (void*)&mtask, sizeof(void*));
 733                                         spin_unlock(&session->lock);
 734                                 }
 735                         }
 736                         break;
 737                 case ISCSI_OP_SCSI_TMFUNC_RSP:
 738                         rc = iscsi_check_assign_cmdsn(session,
 739                                                  (struct iscsi_nopin*)hdr);
 740                         if (rc)
 741                                 break;
 742
 743                         if (conn->in.datalen || conn->in.ahslen) {
 744                                 rc = ISCSI_ERR_PROTO;
 745                                 break;
 746                         }
 747                         conn->tmfrsp_pdus_cnt++;
 748                         spin_lock(&session->lock);
 749                         if (conn->tmabort_state == TMABORT_INITIAL) {
 750                                 __kfifo_put(session->mgmtpool.queue,
 751                                                 (void*)&mtask, sizeof(void*));
 752                                 conn->tmabort_state =
 753                                         ((struct iscsi_tm_rsp *)hdr)->
 754                                         response == SCSI_TCP_TM_RESP_COMPLETE ?
 755                                                 TMABORT_SUCCESS:TMABORT_FAILED;
 756                                 /* unblock eh_abort() */
 757                                 wake_up(&conn->ehwait);
 758                         }
 759                         spin_unlock(&session->lock);
 760                         break;
 761                 default:
 762                         rc = ISCSI_ERR_BAD_OPCODE;
 763                         break;
 764                 }
 765         } else if (conn->in.itt == ISCSI_RESERVED_TAG) {
 766                 if (conn->in.opcode == ISCSI_OP_NOOP_IN && !conn->in.datalen) {
 767                         rc = iscsi_check_assign_cmdsn(session,
 768                                                  (struct iscsi_nopin*)hdr);
 769                         if (!rc)
 770                                 rc = iscsi_recv_pdu(iscsi_handle(conn),
 771                                                     hdr, NULL, 0);
 772                 }
 773                 else
 774                         rc = ISCSI_ERR_BAD_OPCODE;
 775         } else
 776                 rc = ISCSI_ERR_BAD_ITT;
 777
 778         return rc;
 779 }
 780
 781 /**
 782  * iscsi_ctask_copy - copy skb bits to the destanation cmd task
 783  * @conn: iscsi connection
 784  * @ctask: scsi command task
 785  * @buf: buffer to copy to
 786  * @buf_size: size of buffer
 787  * @offset: offset within the buffer
 788  *
 789  * Notes:
 790  *      The function calls skb_copy_bits() and updates per-connection and
 791  *      per-cmd byte counters.
 792  *
 793  *      Read counters (in bytes):
 794  *
 795  *      conn->in.offset         offset within in progress SKB
 796  *      conn->in.copy           left to copy from in progress SKB
 797  *                              including padding
 798  *      conn->in.copied         copied already from in progress SKB
 799  *      conn->data_copied       copied already from in progress buffer
 800  *      ctask->sent             total bytes sent up to the MidLayer
 801  *      ctask->data_count       left to copy from in progress Data-In
 802  *      buf_left                left to copy from in progress buffer
 803  **/
 804 static inline int
 805 iscsi_ctask_copy(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
 806                 void *buf, int buf_size, int offset)
 807 {
 808         int buf_left = buf_size - (conn->data_copied + offset);
 809         int size = min(conn->in.copy, buf_left);
 810         int rc;
 811
 812         size = min(size, ctask->data_count);
 813
 814         debug_tcp("ctask_copy %d bytes at offset %d copied %d\n",
 815                size, conn->in.offset, conn->in.copied);
 816
 817         BUG_ON(size <= 0);
 818         BUG_ON(ctask->sent + size > ctask->total_length);
 819
 820         rc = skb_copy_bits(conn->in.skb, conn->in.offset,
 821                            (char*)buf + (offset + conn->data_copied), size);
 822         /* must fit into skb->len */
 823         BUG_ON(rc);
 824
 825         conn->in.offset += size;
 826         conn->in.copy -= size;
 827         conn->in.copied += size;
 828         conn->data_copied += size;
 829         ctask->sent += size;
 830         ctask->data_count -= size;
 831
 832         BUG_ON(conn->in.copy < 0);
 833         BUG_ON(ctask->data_count < 0);
 834
 835         if (buf_size != (conn->data_copied + offset)) {
 836                 if (!ctask->data_count) {
 837                         BUG_ON(buf_size - conn->data_copied < 0);
 838                         /* done with this PDU */
 839                         return buf_size - conn->data_copied;
 840                 }
 841                 return -EAGAIN;
 842         }
 843
 844         /* done with this buffer or with both - PDU and buffer */
 845         conn->data_copied = 0;
 846         return 0;
 847 }
 848
 849 /**
 850  * iscsi_tcp_copy - copy skb bits to the destanation buffer
 851  * @conn: iscsi connection
 852  * @buf: buffer to copy to
 853  * @buf_size: number of bytes to copy
 854  *
 855  * Notes:
 856  *      The function calls skb_copy_bits() and updates per-connection
 857  *      byte counters.
 858  **/
 859 static inline int
 860 iscsi_tcp_copy(struct iscsi_conn *conn, void *buf, int buf_size)
 861 {
 862         int buf_left = buf_size - conn->data_copied;
 863         int size = min(conn->in.copy, buf_left);
 864         int rc;
 865
 866         debug_tcp("tcp_copy %d bytes at offset %d copied %d\n",
 867                size, conn->in.offset, conn->data_copied);
 868         BUG_ON(size <= 0);
 869
 870         rc = skb_copy_bits(conn->in.skb, conn->in.offset,
 871                            (char*)buf + conn->data_copied, size);
 872         BUG_ON(rc);
 873
 874         conn->in.offset += size;
 875         conn->in.copy -= size;
 876         conn->in.copied += size;
 877         conn->data_copied += size;
 878
 879         if (buf_size != conn->data_copied)
 880                 return -EAGAIN;
 881
 882         return 0;
 883 }
 884
 885 static inline void
 886 partial_sg_digest_update(struct iscsi_conn *conn, struct scatterlist *sg,
 887                          int offset, int length)
 888 {
 889         struct scatterlist temp;
 890
 891         memcpy(&temp, sg, sizeof(struct scatterlist));
 892         temp.offset = offset;
 893         temp.length = length;
 894         crypto_digest_update(conn->data_rx_tfm, &temp, 1);
 895 }
 896
 897 static int iscsi_scsi_data_in(struct iscsi_conn *conn)
 898 {
 899         struct iscsi_cmd_task *ctask = conn->in.ctask;
 900         struct scsi_cmnd *sc = ctask->sc;
 901         struct scatterlist tmp, *sg;
 902         int i, offset, rc = 0;
 903
 904         BUG_ON((void*)ctask != sc->SCp.ptr);
 905
 906         /*
 907          * copying Data-In into the Scsi_Cmnd
 908          */
 909         if (!sc->use_sg) {
 910                 i = ctask->data_count;
 911                 rc = iscsi_ctask_copy(conn, ctask, sc->request_buffer,
 912                                       sc->request_bufflen, ctask->data_offset);
 913                 if (rc == -EAGAIN)
 914                         return rc;
 915                 if (conn->datadgst_en) {
 916                         sg_init_one(&tmp, sc->request_buffer, i);
 917                         crypto_digest_update(conn->data_rx_tfm, &tmp, 1);
 918                 }
 919                 rc = 0;
 920                 goto done;
 921         }
 922
 923         offset = ctask->data_offset;
 924         sg = sc->request_buffer;
 925
 926         if (ctask->data_offset)
 927                 for (i = 0; i < ctask->sg_count; i++)
 928                         offset -= sg[i].length;
 929         /* we've passed through partial sg*/
 930         if (offset < 0)
 931                 offset = 0;
 932
 933         for (i = ctask->sg_count; i < sc->use_sg; i++) {
 934                 char *dest;
 935
 936                 dest = kmap_atomic(sg[i].page, KM_SOFTIRQ0);
 937                 rc = iscsi_ctask_copy(conn, ctask, dest + sg[i].offset,
 938                                       sg[i].length, offset);
 939                 kunmap_atomic(dest, KM_SOFTIRQ0);
 940                 if (rc == -EAGAIN)
 941                         /* continue with the next SKB/PDU */
 942                         return rc;
 943                 if (!rc) {
 944                         if (conn->datadgst_en) {
 945                                 if (!offset)
 946                                         crypto_digest_update(conn->data_rx_tfm,
 947                                                              &sg[i], 1);
 948                                 else
 949                                         partial_sg_digest_update(conn, &sg[i],
 950                                                         sg[i].offset + offset,
 951                                                         sg[i].length - offset);
 952                         }
 953                         offset = 0;
 954                         ctask->sg_count++;
 955                 }
 956
 957                 if (!ctask->data_count) {
 958                         if (rc && conn->datadgst_en)
 959                                 /*
 960                                  * data-in is complete, but buffer not...
 961                                  */
 962                                 partial_sg_digest_update(conn, &sg[i],
 963                                                 sg[i].offset, sg[i].length-rc);
 964                         rc = 0;
 965                         break;
 966                 }
 967
 968                 if (!conn->in.copy)
 969                         return -EAGAIN;
 970         }
 971         BUG_ON(ctask->data_count);
 972
 973 done:
 974         /* check for non-exceptional status */
 975         if (conn->in.flags & ISCSI_FLAG_DATA_STATUS) {
 976                 debug_scsi("done [sc %lx res %d itt 0x%x]\n",
 977                            (long)sc, sc->result, ctask->itt);
 978                 conn->scsirsp_pdus_cnt++;
 979                 iscsi_ctask_cleanup(conn, ctask);
 980                 sc->scsi_done(sc);
 981         }
 982
 983         return rc;
 984 }
 985
 986 static int
 987 iscsi_data_recv(struct iscsi_conn *conn)
 988 {
 989         struct iscsi_session *session = conn->session;
 990         int rc = 0;
 991
 992         switch(conn->in.opcode) {
 993         case ISCSI_OP_SCSI_DATA_IN:
 994                 rc = iscsi_scsi_data_in(conn);
 995                 break;
 996         case ISCSI_OP_SCSI_CMD_RSP: {
 997                 /*
 998                  * SCSI Sense Data:
 999                  * copying the entire Data Segment.
1000                  */
1001                 if (iscsi_tcp_copy(conn, conn->data, conn->in.datalen)) {
1002                         rc = -EAGAIN;
1003                         goto exit;
1004                 }
1005
1006                 /*
1007                  * check for sense
1008                  */
1009                 conn->in.hdr = &conn->hdr;
1010                 conn->senselen = (conn->data[0] << 8) | conn->data[1];
1011                 rc = iscsi_cmd_rsp(conn, conn->in.ctask);
1012         }
1013         break;
1014         case ISCSI_OP_TEXT_RSP:
1015         case ISCSI_OP_LOGIN_RSP:
1016         case ISCSI_OP_NOOP_IN: {
1017                 struct iscsi_mgmt_task *mtask = NULL;
1018
1019                 if (conn->in.itt != ISCSI_RESERVED_TAG)
1020                         mtask = (struct iscsi_mgmt_task *)
1021                                 session->mgmt_cmds[conn->in.itt -
1022                                         ISCSI_MGMT_ITT_OFFSET];
1023
1024                 /*
1025                  * Collect data segment to the connection's data
1026                  * placeholder
1027                  */
1028                 if (iscsi_tcp_copy(conn, conn->data, conn->in.datalen)) {
1029                         rc = -EAGAIN;
1030                         goto exit;
1031                 }
1032
1033                 rc = iscsi_recv_pdu(iscsi_handle(conn), conn->in.hdr,
1034                                     conn->data, conn->in.datalen);
1035
1036                 if (mtask && conn->login_mtask != mtask) {
1037                         spin_lock(&session->lock);
1038                         __kfifo_put(session->mgmtpool.queue, (void*)&mtask,
1039                                     sizeof(void*));
1040                         spin_unlock(&session->lock);
1041                 }
1042         }
1043         break;
1044         default:
1045                 BUG_ON(1);
1046         }
1047 exit:
1048         return rc;
1049 }
1050
1051 /**
1052  * iscsi_tcp_data_recv - TCP receive in sendfile fashion
1053  * @rd_desc: read descriptor
1054  * @skb: socket buffer
1055  * @offset: offset in skb
1056  * @len: skb->len - offset
1057  **/
1058 static int
1059 iscsi_tcp_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb,
1060                 unsigned int offset, size_t len)
1061 {
1062         int rc;
1063         struct iscsi_conn *conn = rd_desc->arg.data;
1064         int processed;
1065         char pad[ISCSI_PAD_LEN];
1066         struct scatterlist sg;
1067
1068         /*
1069          * Save current SKB and its offset in the corresponding
1070          * connection context.
1071          */
1072         conn->in.copy = skb->len - offset;
1073         conn->in.offset = offset;
1074         conn->in.skb = skb;
1075         conn->in.len = conn->in.copy;
1076         BUG_ON(conn->in.copy <= 0);
1077         debug_tcp("in %d bytes\n", conn->in.copy);
1078
1079 more:
1080         conn->in.copied = 0;
1081         rc = 0;
1082
1083         if (unlikely(conn->suspend_rx)) {
1084                 debug_tcp("conn %d Rx suspended!\n", conn->id);
1085                 return 0;
1086         }
1087
1088         if (conn->in_progress == IN_PROGRESS_WAIT_HEADER ||
1089             conn->in_progress == IN_PROGRESS_HEADER_GATHER) {
1090                 rc = iscsi_hdr_extract(conn);
1091                 if (rc) {
1092                        if (rc == -EAGAIN)
1093                                 goto nomore;
1094                        else {
1095                                 iscsi_conn_failure(conn, rc);
1096                                 return 0;
1097                        }
1098                 }
1099
1100                 /*
1101                  * Verify and process incoming PDU header.
1102                  */
1103                 rc = iscsi_hdr_recv(conn);
1104                 if (!rc && conn->in.datalen) {
1105                         if (conn->datadgst_en &&
1106                             conn->in.opcode == ISCSI_OP_SCSI_DATA_IN) {
1107                                 BUG_ON(!conn->data_rx_tfm);
1108                                 crypto_digest_init(conn->data_rx_tfm);
1109                         }
1110                         conn->in_progress = IN_PROGRESS_DATA_RECV;
1111                 } else if (rc) {
1112                         iscsi_conn_failure(conn, rc);
1113                         return 0;
1114                 }
1115         }
1116
1117         if (conn->in_progress == IN_PROGRESS_DDIGEST_RECV) {
1118                 debug_tcp("extra data_recv offset %d copy %d\n",
1119                           conn->in.offset, conn->in.copy);
1120                 if (conn->in.opcode == ISCSI_OP_SCSI_DATA_IN) {
1121                         uint32_t recv_digest;
1122                         skb_copy_bits(conn->in.skb, conn->in.offset,
1123                                       &recv_digest, 4);
1124                         conn->in.offset += 4;
1125                         conn->in.copy -= 4;
1126                         if (recv_digest != conn->in.datadgst) {
1127                                 debug_tcp("iscsi_tcp: data digest error!"
1128                                           "0x%x != 0x%x\n", recv_digest,
1129                                           conn->in.datadgst);
1130                                 iscsi_conn_failure(conn, ISCSI_ERR_DATA_DGST);
1131                                 return 0;
1132                         } else {
1133                                 debug_tcp("iscsi_tcp: data digest match!"
1134                                           "0x%x == 0x%x\n", recv_digest,
1135                                           conn->in.datadgst);
1136                                 conn->in_progress = IN_PROGRESS_WAIT_HEADER;
1137                         }
1138                 }
1139         }
1140
1141         if (conn->in_progress == IN_PROGRESS_DATA_RECV && conn->in.copy) {
1142
1143                 debug_tcp("data_recv offset %d copy %d\n",
1144                        conn->in.offset, conn->in.copy);
1145
1146                 rc = iscsi_data_recv(conn);
1147                 if (rc) {
1148                         if (rc == -EAGAIN) {
1149                                 rd_desc->count = conn->in.datalen -
1150                                                 conn->in.ctask->data_count;
1151                                 goto again;
1152                         }
1153                         iscsi_conn_failure(conn, rc);
1154                         return 0;
1155                 }
1156                 conn->in.copy -= conn->in.padding;
1157                 conn->in.offset += conn->in.padding;
1158                 if (conn->datadgst_en &&
1159                     conn->in.opcode == ISCSI_OP_SCSI_DATA_IN) {
1160                         if (conn->in.padding) {
1161                                 debug_tcp("padding -> %d\n", conn->in.padding);
1162                                 memset(pad, 0, conn->in.padding);
1163                                 sg_init_one(&sg, pad, conn->in.padding);
1164                                 crypto_digest_update(conn->data_rx_tfm, &sg, 1);
1165                         }
1166                         crypto_digest_final(conn->data_rx_tfm,
1167                                             (u8 *) & conn->in.datadgst);
1168                         debug_tcp("rx digest 0x%x\n", conn->in.datadgst);
1169                         conn->in_progress = IN_PROGRESS_DDIGEST_RECV;
1170                 } else
1171                         conn->in_progress = IN_PROGRESS_WAIT_HEADER;
1172         }
1173
1174         debug_tcp("f, processed %d from out of %d padding %d\n",
1175                conn->in.offset - offset, (int)len, conn->in.padding);
1176         BUG_ON(conn->in.offset - offset > len);
1177
1178         if (conn->in.offset - offset != len) {
1179                 debug_tcp("continue to process %d bytes\n",
1180                        (int)len - (conn->in.offset - offset));
1181                 goto more;
1182         }
1183
1184 nomore:
1185         processed = conn->in.offset - offset;
1186         BUG_ON(processed == 0);
1187         return processed;
1188
1189 again:
1190         processed = conn->in.offset - offset;
1191         debug_tcp("c, processed %d from out of %d rd_desc_cnt %d\n",
1192                   processed, (int)len, (int)rd_desc->count);
1193         BUG_ON(processed == 0);
1194         BUG_ON(processed > len);
1195
1196         conn->rxdata_octets += processed;
1197         return processed;
1198 }
1199
1200 static void
1201 iscsi_tcp_data_ready(struct sock *sk, int flag)
1202 {
1203         struct iscsi_conn *conn = sk->sk_user_data;
1204         read_descriptor_t rd_desc;
1205
1206         read_lock(&sk->sk_callback_lock);
1207
1208         /* use rd_desc to pass 'conn' to iscsi_tcp_data_recv */
1209         rd_desc.arg.data = conn;
1210         rd_desc.count = 0;
1211         tcp_read_sock(sk, &rd_desc, iscsi_tcp_data_recv);
1212
1213         read_unlock(&sk->sk_callback_lock);
1214 }
1215
1216 static void
1217 iscsi_tcp_state_change(struct sock *sk)
1218 {
1219         struct iscsi_conn *conn;
1220         struct iscsi_session *session;
1221         void (*old_state_change)(struct sock *);
1222
1223         read_lock(&sk->sk_callback_lock);
1224
1225         conn = (struct iscsi_conn*)sk->sk_user_data;
1226         session = conn->session;
1227
1228         if (sk->sk_state == TCP_CLOSE_WAIT ||
1229             sk->sk_state == TCP_CLOSE) {
1230                 debug_tcp("iscsi_tcp_state_change: TCP_CLOSE|TCP_CLOSE_WAIT\n");
1231                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1232         }
1233
1234         old_state_change = conn->old_state_change;
1235
1236         read_unlock(&sk->sk_callback_lock);
1237
1238         old_state_change(sk);
1239 }
1240
1241 /**
1242  * iscsi_write_space - Called when more output buffer space is available
1243  * @sk: socket space is available for
1244  **/
1245 static void
1246 iscsi_write_space(struct sock *sk)
1247 {
1248         struct iscsi_conn *conn = (struct iscsi_conn*)sk->sk_user_data;
1249         conn->old_write_space(sk);
1250         debug_tcp("iscsi_write_space: cid %d\n", conn->id);
1251         clear_bit(SUSPEND_BIT, &conn->suspend_tx);
1252         schedule_work(&conn->xmitwork);
1253 }
1254
1255 static void
1256 iscsi_conn_set_callbacks(struct iscsi_conn *conn)
1257 {
1258         struct sock *sk = conn->sock->sk;
1259
1260         /* assign new callbacks */
1261         write_lock_bh(&sk->sk_callback_lock);
1262         sk->sk_user_data = conn;
1263         conn->old_data_ready = sk->sk_data_ready;
1264         conn->old_state_change = sk->sk_state_change;
1265         conn->old_write_space = sk->sk_write_space;
1266         sk->sk_data_ready = iscsi_tcp_data_ready;
1267         sk->sk_state_change = iscsi_tcp_state_change;
1268         sk->sk_write_space = iscsi_write_space;
1269         write_unlock_bh(&sk->sk_callback_lock);
1270 }
1271
1272 static void
1273 iscsi_conn_restore_callbacks(struct iscsi_conn *conn)
1274 {
1275         struct sock *sk = conn->sock->sk;
1276
1277         /* restore socket callbacks, see also: iscsi_conn_set_callbacks() */
1278         write_lock_bh(&sk->sk_callback_lock);
1279         sk->sk_user_data    = NULL;
1280         sk->sk_data_ready   = conn->old_data_ready;
1281         sk->sk_state_change = conn->old_state_change;
1282         sk->sk_write_space  = conn->old_write_space;
1283         sk->sk_no_check  = 0;
1284         write_unlock_bh(&sk->sk_callback_lock);
1285 }
1286
1287 /**
1288  * iscsi_send - generic send routine
1289  * @sk: kernel's socket
1290  * @buf: buffer to write from
1291  * @size: actual size to write
1292  * @flags: socket's flags
1293  *
1294  * Notes:
1295  *      depending on buffer will use tcp_sendpage() or tcp_sendmsg().
1296  *      buf->sg.offset == -1 tells us that buffer is non S/G and forces
1297  *      to use tcp_sendmsg().
1298  */
1299 static inline int
1300 iscsi_send(struct socket *sk, struct iscsi_buf *buf, int size, int flags)
1301 {
1302         int res;
1303
1304         if ((int)buf->sg.offset >= 0) {
1305                 int offset = buf->sg.offset + buf->sent;
1306
1307                 /* tcp_sendpage */
1308                 res = sk->ops->sendpage(sk, buf->sg.page, offset, size, flags);
1309         } else {
1310                 struct msghdr msg;
1311
1312                 buf->iov.iov_base = iscsi_buf_iov_base(buf);
1313                 buf->iov.iov_len = size;
1314
1315                 memset(&msg, 0, sizeof(struct msghdr));
1316
1317                 /* tcp_sendmsg */
1318                 res = kernel_sendmsg(sk, &msg, &buf->iov, 1, size);
1319         }
1320
1321         return res;
1322 }
1323
1324 /**
1325  * iscsi_sendhdr - send PDU Header via tcp_sendpage()
1326  * @conn: iscsi connection
1327  * @buf: buffer to write from
1328  * @datalen: lenght of data to be sent after the header
1329  *
1330  * Notes:
1331  *      (Tx, Fast Path)
1332  **/
1333 static inline int
1334 iscsi_sendhdr(struct iscsi_conn *conn, struct iscsi_buf *buf, int datalen)
1335 {
1336         struct socket *sk = conn->sock;
1337         int flags = 0; /* MSG_DONTWAIT; */
1338         int res, size;
1339
1340         size = buf->sg.length - buf->sent;
1341         BUG_ON(buf->sent + size > buf->sg.length);
1342         if (buf->sent + size != buf->sg.length || datalen)
1343                 flags |= MSG_MORE;
1344
1345         res = iscsi_send(sk, buf, size, flags);
1346         debug_tcp("sendhdr %d bytes, sent %d res %d\n", size, buf->sent, res);
1347         if (res >= 0) {
1348                 conn->txdata_octets += res;
1349                 buf->sent += res;
1350                 if (size != res)
1351                         return -EAGAIN;
1352                 return 0;
1353         } else if (res == -EAGAIN) {
1354                 conn->sendpage_failures_cnt++;
1355                 set_bit(SUSPEND_BIT, &conn->suspend_tx);
1356         } else if (res == -EPIPE)
1357                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1358
1359         return res;
1360 }
1361
1362 /**
1363  * iscsi_sendpage - send one page of iSCSI Data-Out.
1364  * @conn: iscsi connection
1365  * @buf: buffer to write from
1366  * @count: remaining data
1367  * @sent: number of bytes sent
1368  *
1369  * Notes:
1370  *      (Tx, Fast Path)
1371  **/
1372 static inline int
1373 iscsi_sendpage(struct iscsi_conn *conn, struct iscsi_buf *buf,
1374                int *count, int *sent)
1375 {
1376         struct socket *sk = conn->sock;
1377         int flags = 0; /* MSG_DONTWAIT; */
1378         int res, size;
1379
1380         size = buf->sg.length - buf->sent;
1381         BUG_ON(buf->sent + size > buf->sg.length);
1382         if (size > *count)
1383                 size = *count;
1384         if (buf->sent + size != buf->sg.length || *count != size)
1385                 flags |= MSG_MORE;
1386
1387         res = iscsi_send(sk, buf, size, flags);
1388         debug_tcp("sendpage: %d bytes, sent %d left %d sent %d res %d\n",
1389                   size, buf->sent, *count, *sent, res);
1390         if (res >= 0) {
1391                 conn->txdata_octets += res;
1392                 buf->sent += res;
1393                 *count -= res;
1394                 *sent += res;
1395                 if (size != res)
1396                         return -EAGAIN;
1397                 return 0;
1398         } else if (res == -EAGAIN) {
1399                 conn->sendpage_failures_cnt++;
1400                 set_bit(SUSPEND_BIT, &conn->suspend_tx);
1401         } else if (res == -EPIPE)
1402                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1403
1404         return res;
1405 }
1406
1407 static inline void
1408 iscsi_data_digest_init(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1409 {
1410         BUG_ON(!conn->data_tx_tfm);
1411         crypto_digest_init(conn->data_tx_tfm);
1412         ctask->digest_count = 4;
1413 }
1414
1415 static inline void
1416 iscsi_buf_data_digest_update(struct iscsi_conn *conn, struct iscsi_buf *buf)
1417 {
1418         struct scatterlist sg;
1419
1420         if (buf->sg.offset != -1)
1421                 crypto_digest_update(conn->data_tx_tfm, &buf->sg, 1);
1422         else {
1423                 sg_init_one(&sg, (char *)buf->sg.page, buf->sg.length);
1424                 crypto_digest_update(conn->data_tx_tfm, &sg, 1);
1425         }
1426 }
1427
1428 static inline int
1429 iscsi_digest_final_send(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
1430                         struct iscsi_buf *buf, uint32_t *digest, int final)
1431 {
1432         int rc = 0;
1433         int sent = 0;
1434
1435         if (final)
1436                 crypto_digest_final(conn->data_tx_tfm, (u8*)digest);
1437
1438         iscsi_buf_init_virt(buf, (char*)digest, 4);
1439         rc = iscsi_sendpage(conn, buf, &ctask->digest_count, &sent);
1440         if (rc) {
1441                 ctask->datadigest = *digest;
1442                 ctask->xmstate |= XMSTATE_DATA_DIGEST;
1443         } else
1444                 ctask->digest_count = 4;
1445         return rc;
1446 }
1447
1448 /**
1449  * iscsi_solicit_data_cont - initialize next Data-Out
1450  * @conn: iscsi connection
1451  * @ctask: scsi command task
1452  * @r2t: R2T info
1453  * @left: bytes left to transfer
1454  *
1455  * Notes:
1456  *      Initialize next Data-Out within this R2T sequence and continue
1457  *      to process next Scatter-Gather element(if any) of this SCSI command.
1458  *
1459  *      Called under connection lock.
1460  **/
1461 static void
1462 iscsi_solicit_data_cont(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
1463                         struct iscsi_r2t_info *r2t, int left)
1464 {
1465         struct iscsi_data *hdr;
1466         struct iscsi_data_task *dtask;
1467         struct scsi_cmnd *sc = ctask->sc;
1468         int new_offset;
1469
1470         dtask = mempool_alloc(ctask->datapool, GFP_ATOMIC);
1471         BUG_ON(!dtask);
1472         hdr = &dtask->hdr;
1473         memset(hdr, 0, sizeof(struct iscsi_data));
1474         hdr->ttt = r2t->ttt;
1475         hdr->datasn = cpu_to_be32(r2t->solicit_datasn);
1476         r2t->solicit_datasn++;
1477         hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
1478         memcpy(hdr->lun, ctask->hdr.lun, sizeof(hdr->lun));
1479         hdr->itt = ctask->hdr.itt;
1480         hdr->exp_statsn = r2t->exp_statsn;
1481         new_offset = r2t->data_offset + r2t->sent;
1482         hdr->offset = cpu_to_be32(new_offset);
1483         if (left > conn->max_xmit_dlength) {
1484                 hton24(hdr->dlength, conn->max_xmit_dlength);
1485                 r2t->data_count = conn->max_xmit_dlength;
1486         } else {
1487                 hton24(hdr->dlength, left);
1488                 r2t->data_count = left;
1489                 hdr->flags = ISCSI_FLAG_CMD_FINAL;
1490         }
1491         conn->dataout_pdus_cnt++;
1492
1493         iscsi_buf_init_virt(&r2t->headbuf, (char*)hdr,
1494                            sizeof(struct iscsi_hdr));
1495
1496         r2t->dtask = dtask;
1497
1498         if (sc->use_sg && !iscsi_buf_left(&r2t->sendbuf)) {
1499                 BUG_ON(ctask->bad_sg == r2t->sg);
1500                 iscsi_buf_init_sg(&r2t->sendbuf, r2t->sg);
1501                 r2t->sg += 1;
1502         } else
1503                 iscsi_buf_init_iov(&ctask->sendbuf,
1504                             (char*)sc->request_buffer + new_offset,
1505                             r2t->data_count);
1506
1507         list_add(&dtask->item, &ctask->dataqueue);
1508 }
1509
1510 static void
1511 iscsi_unsolicit_data_init(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1512 {
1513         struct iscsi_data *hdr;
1514         struct iscsi_data_task *dtask;
1515
1516         dtask = mempool_alloc(ctask->datapool, GFP_ATOMIC);
1517         BUG_ON(!dtask);
1518         hdr = &dtask->hdr;
1519         memset(hdr, 0, sizeof(struct iscsi_data));
1520         hdr->ttt = cpu_to_be32(ISCSI_RESERVED_TAG);
1521         hdr->datasn = cpu_to_be32(ctask->unsol_datasn);
1522         ctask->unsol_datasn++;
1523         hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
1524         memcpy(hdr->lun, ctask->hdr.lun, sizeof(hdr->lun));
1525         hdr->itt = ctask->hdr.itt;
1526         hdr->exp_statsn = cpu_to_be32(conn->exp_statsn);
1527         hdr->offset = cpu_to_be32(ctask->total_length -
1528                                   ctask->r2t_data_count -
1529                                   ctask->unsol_count);
1530         if (ctask->unsol_count > conn->max_xmit_dlength) {
1531                 hton24(hdr->dlength, conn->max_xmit_dlength);
1532                 ctask->data_count = conn->max_xmit_dlength;
1533                 hdr->flags = 0;
1534         } else {
1535                 hton24(hdr->dlength, ctask->unsol_count);
1536                 ctask->data_count = ctask->unsol_count;
1537                 hdr->flags = ISCSI_FLAG_CMD_FINAL;
1538         }
1539
1540         iscsi_buf_init_virt(&ctask->headbuf, (char*)hdr,
1541                            sizeof(struct iscsi_hdr));
1542
1543         list_add(&dtask->item, &ctask->dataqueue);
1544
1545         ctask->dtask = dtask;
1546 }
1547
1548 /**
1549  * iscsi_cmd_init - Initialize iSCSI SCSI_READ or SCSI_WRITE commands
1550  * @conn: iscsi connection
1551  * @ctask: scsi command task
1552  * @sc: scsi command
1553  **/
1554 static void
1555 iscsi_cmd_init(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
1556                 struct scsi_cmnd *sc)
1557 {
1558         struct iscsi_session *session = conn->session;
1559
1560         BUG_ON(__kfifo_len(ctask->r2tqueue));
1561
1562         ctask->sc = sc;
1563         ctask->conn = conn;
1564         ctask->hdr.opcode = ISCSI_OP_SCSI_CMD;
1565         ctask->hdr.flags = ISCSI_ATTR_SIMPLE;
1566         int_to_scsilun(sc->device->lun, (struct scsi_lun *)ctask->hdr.lun);
1567         ctask->hdr.itt = ctask->itt | (conn->id << CID_SHIFT) |
1568                          (session->age << AGE_SHIFT);
1569         ctask->hdr.data_length = cpu_to_be32(sc->request_bufflen);
1570         ctask->hdr.cmdsn = cpu_to_be32(session->cmdsn); session->cmdsn++;
1571         ctask->hdr.exp_statsn = cpu_to_be32(conn->exp_statsn);
1572         memcpy(ctask->hdr.cdb, sc->cmnd, sc->cmd_len);
1573         memset(&ctask->hdr.cdb[sc->cmd_len], 0, MAX_COMMAND_SIZE - sc->cmd_len);
1574
1575         ctask->mtask = NULL;
1576         ctask->sent = 0;
1577         ctask->sg_count = 0;
1578
1579         ctask->total_length = sc->request_bufflen;
1580
1581         if (sc->sc_data_direction == DMA_TO_DEVICE) {
1582                 ctask->exp_r2tsn = 0;
1583                 ctask->hdr.flags |= ISCSI_FLAG_CMD_WRITE;
1584                 BUG_ON(ctask->total_length == 0);
1585                 if (sc->use_sg) {
1586                         struct scatterlist *sg = sc->request_buffer;
1587
1588                         iscsi_buf_init_sg(&ctask->sendbuf,
1589                                           &sg[ctask->sg_count++]);
1590                         ctask->sg = sg;
1591                         ctask->bad_sg = sg + sc->use_sg;
1592                 } else {
1593                         iscsi_buf_init_iov(&ctask->sendbuf, sc->request_buffer,
1594                                         sc->request_bufflen);
1595                 }
1596
1597                 /*
1598                  * Write counters:
1599                  *
1600                  *      imm_count       bytes to be sent right after
1601                  *                      SCSI PDU Header
1602                  *
1603                  *      unsol_count     bytes(as Data-Out) to be sent
1604                  *                      without R2T ack right after
1605                  *                      immediate data
1606                  *
1607                  *      r2t_data_count  bytes to be sent via R2T ack's
1608                  *
1609                  *      pad_count       bytes to be sent as zero-padding
1610                  */
1611                 ctask->imm_count = 0;
1612                 ctask->unsol_count = 0;
1613                 ctask->unsol_datasn = 0;
1614                 ctask->xmstate = XMSTATE_W_HDR;
1615                 /* calculate write padding */
1616                 ctask->pad_count = ctask->total_length & (ISCSI_PAD_LEN-1);
1617                 if (ctask->pad_count) {
1618                         ctask->pad_count = ISCSI_PAD_LEN - ctask->pad_count;
1619                         debug_scsi("write padding %d bytes\n",
1620                                 ctask->pad_count);
1621                         ctask->xmstate |= XMSTATE_W_PAD;
1622                 }
1623                 if (session->imm_data_en) {
1624                         if (ctask->total_length >= session->first_burst)
1625                                 ctask->imm_count = min(session->first_burst,
1626                                                         conn->max_xmit_dlength);
1627                         else
1628                                 ctask->imm_count = min(ctask->total_length,
1629                                                         conn->max_xmit_dlength);
1630                         hton24(ctask->hdr.dlength, ctask->imm_count);
1631                         ctask->xmstate |= XMSTATE_IMM_DATA;
1632                 } else
1633                         zero_data(ctask->hdr.dlength);
1634
1635                 if (!session->initial_r2t_en)
1636                         ctask->unsol_count = min(session->first_burst,
1637                                 ctask->total_length) - ctask->imm_count;
1638                 if (!ctask->unsol_count)
1639                         /* No unsolicit Data-Out's */
1640                         ctask->hdr.flags |= ISCSI_FLAG_CMD_FINAL;
1641                 else
1642                         ctask->xmstate |= XMSTATE_UNS_HDR | XMSTATE_UNS_INIT;
1643
1644                 ctask->r2t_data_count = ctask->total_length -
1645                                     ctask->imm_count -
1646                                     ctask->unsol_count;
1647
1648                 debug_scsi("cmd [itt %x total %d imm %d imm_data %d "
1649                            "r2t_data %d]\n",
1650                            ctask->itt, ctask->total_length, ctask->imm_count,
1651                            ctask->unsol_count, ctask->r2t_data_count);
1652         } else {
1653                 ctask->hdr.flags |= ISCSI_FLAG_CMD_FINAL;
1654                 if (sc->sc_data_direction == DMA_FROM_DEVICE)
1655                         ctask->hdr.flags |= ISCSI_FLAG_CMD_READ;
1656                 ctask->datasn = 0;
1657                 ctask->xmstate = XMSTATE_R_HDR;
1658                 zero_data(ctask->hdr.dlength);
1659         }
1660
1661         iscsi_buf_init_virt(&ctask->headbuf, (char*)&ctask->hdr,
1662                             sizeof(struct iscsi_hdr));
1663         conn->scsicmd_pdus_cnt++;
1664 }
1665
1666 /**
1667  * iscsi_mtask_xmit - xmit management(immediate) task
1668  * @conn: iscsi connection
1669  * @mtask: task management task
1670  *
1671  * Notes:
1672  *      The function can return -EAGAIN in which case caller must
1673  *      call it again later, or recover. '0' return code means successful
1674  *      xmit.
1675  *
1676  *      Management xmit state machine consists of two states:
1677  *              IN_PROGRESS_IMM_HEAD - PDU Header xmit in progress
1678  *              IN_PROGRESS_IMM_DATA - PDU Data xmit in progress
1679  **/
1680 static int
1681 iscsi_mtask_xmit(struct iscsi_conn *conn, struct iscsi_mgmt_task *mtask)
1682 {
1683
1684         debug_scsi("mtask deq [cid %d state %x itt 0x%x]\n",
1685                 conn->id, mtask->xmstate, mtask->itt);
1686
1687         if (mtask->xmstate & XMSTATE_IMM_HDR) {
1688                 mtask->xmstate &= ~XMSTATE_IMM_HDR;
1689                 if (mtask->data_count)
1690                         mtask->xmstate |= XMSTATE_IMM_DATA;
1691                 if (conn->c_stage != ISCSI_CONN_INITIAL_STAGE &&
1692                     conn->stop_stage != STOP_CONN_RECOVER &&
1693                     conn->hdrdgst_en)
1694                         iscsi_hdr_digest(conn, &mtask->headbuf,
1695                                         (u8*)mtask->hdrext);
1696                 if (iscsi_sendhdr(conn, &mtask->headbuf, mtask->data_count)) {
1697                         mtask->xmstate |= XMSTATE_IMM_HDR;
1698                         if (mtask->data_count)
1699                                 mtask->xmstate &= ~XMSTATE_IMM_DATA;
1700                         return -EAGAIN;
1701                 }
1702         }
1703
1704         if (mtask->xmstate & XMSTATE_IMM_DATA) {
1705                 BUG_ON(!mtask->data_count);
1706                 mtask->xmstate &= ~XMSTATE_IMM_DATA;
1707                 /* FIXME: implement.
1708                  * Virtual buffer could be spreaded across multiple pages...
1709                  */
1710                 do {
1711                         if (iscsi_sendpage(conn, &mtask->sendbuf,
1712                                    &mtask->data_count, &mtask->sent)) {
1713                                 mtask->xmstate |= XMSTATE_IMM_DATA;
1714                                 return -EAGAIN;
1715                         }
1716                 } while (mtask->data_count);
1717         }
1718
1719         BUG_ON(mtask->xmstate != XMSTATE_IDLE);
1720         return 0;
1721 }
1722
1723 static inline int
1724 handle_xmstate_r_hdr(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1725 {
1726         ctask->xmstate &= ~XMSTATE_R_HDR;
1727         if (conn->hdrdgst_en)
1728                 iscsi_hdr_digest(conn, &ctask->headbuf, (u8*)ctask->hdrext);
1729         if (!iscsi_sendhdr(conn, &ctask->headbuf, 0)) {
1730                 BUG_ON(ctask->xmstate != XMSTATE_IDLE);
1731                 return 0; /* wait for Data-In */
1732         }
1733         ctask->xmstate |= XMSTATE_R_HDR;
1734         return -EAGAIN;
1735 }
1736
1737 static inline int
1738 handle_xmstate_w_hdr(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1739 {
1740         ctask->xmstate &= ~XMSTATE_W_HDR;
1741         if (conn->hdrdgst_en)
1742                 iscsi_hdr_digest(conn, &ctask->headbuf, (u8*)ctask->hdrext);
1743         if (iscsi_sendhdr(conn, &ctask->headbuf, ctask->imm_count)) {
1744                 ctask->xmstate |= XMSTATE_W_HDR;
1745                 return -EAGAIN;
1746         }
1747         return 0;
1748 }
1749
1750 static inline int
1751 handle_xmstate_data_digest(struct iscsi_conn *conn,
1752                            struct iscsi_cmd_task *ctask)
1753 {
1754         ctask->xmstate &= ~XMSTATE_DATA_DIGEST;
1755         debug_tcp("resent data digest 0x%x\n", ctask->datadigest);
1756         if (iscsi_digest_final_send(conn, ctask, &ctask->immbuf,
1757                                     &ctask->datadigest, 0)) {
1758                 ctask->xmstate |= XMSTATE_DATA_DIGEST;
1759                 debug_tcp("resent data digest 0x%x fail!\n",
1760                           ctask->datadigest);
1761                 return -EAGAIN;
1762         }
1763         return 0;
1764 }
1765
1766 static inline int
1767 handle_xmstate_imm_data(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1768 {
1769         BUG_ON(!ctask->imm_count);
1770         ctask->xmstate &= ~XMSTATE_IMM_DATA;
1771
1772         if (conn->datadgst_en) {
1773                 iscsi_data_digest_init(conn, ctask);
1774                 ctask->immdigest = 0;
1775         }
1776
1777         for (;;) {
1778                 if (iscsi_sendpage(conn, &ctask->sendbuf, &ctask->imm_count,
1779                                    &ctask->sent)) {
1780                         ctask->xmstate |= XMSTATE_IMM_DATA;
1781                         if (conn->datadgst_en) {
1782                                 crypto_digest_final(conn->data_tx_tfm,
1783                                                 (u8*)&ctask->immdigest);
1784                                 debug_tcp("tx imm sendpage fail 0x%x\n",
1785                                           ctask->datadigest);
1786                         }
1787                         return -EAGAIN;
1788                 }
1789                 if (conn->datadgst_en)
1790                         iscsi_buf_data_digest_update(conn, &ctask->sendbuf);
1791
1792                 if (!ctask->imm_count)
1793                         break;
1794                 iscsi_buf_init_sg(&ctask->sendbuf,
1795                                   &ctask->sg[ctask->sg_count++]);
1796         }
1797
1798         if (conn->datadgst_en && !(ctask->xmstate & XMSTATE_W_PAD)) {
1799                 if (iscsi_digest_final_send(conn, ctask, &ctask->immbuf,
1800                                             &ctask->immdigest, 1)) {
1801                         debug_tcp("sending imm digest 0x%x fail!\n",
1802                                   ctask->immdigest);
1803                         return -EAGAIN;
1804                 }
1805                 debug_tcp("sending imm digest 0x%x\n", ctask->immdigest);
1806         }
1807
1808         return 0;
1809 }
1810
1811 static inline int
1812 handle_xmstate_uns_hdr(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1813 {
1814         struct iscsi_data_task *dtask;
1815
1816         ctask->xmstate |= XMSTATE_UNS_DATA;
1817         if (ctask->xmstate & XMSTATE_UNS_INIT) {
1818                 iscsi_unsolicit_data_init(conn, ctask);
1819                 BUG_ON(!ctask->dtask);
1820                 dtask = ctask->dtask;
1821                 if (conn->hdrdgst_en)
1822                         iscsi_hdr_digest(conn, &ctask->headbuf,
1823                                         (u8*)dtask->hdrext);
1824                 ctask->xmstate &= ~XMSTATE_UNS_INIT;
1825         }
1826         if (iscsi_sendhdr(conn, &ctask->headbuf, ctask->data_count)) {
1827                 ctask->xmstate &= ~XMSTATE_UNS_DATA;
1828                 ctask->xmstate |= XMSTATE_UNS_HDR;
1829                 return -EAGAIN;
1830         }
1831
1832         debug_scsi("uns dout [itt 0x%x dlen %d sent %d]\n",
1833                    ctask->itt, ctask->unsol_count, ctask->sent);
1834         return 0;
1835 }
1836
1837 static inline int
1838 handle_xmstate_uns_data(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1839 {
1840         struct iscsi_data_task *dtask = ctask->dtask;
1841
1842         BUG_ON(!ctask->data_count);
1843         ctask->xmstate &= ~XMSTATE_UNS_DATA;
1844
1845         if (conn->datadgst_en) {
1846                 iscsi_data_digest_init(conn, ctask);
1847                 dtask->digest = 0;
1848         }
1849
1850         for (;;) {
1851                 int start = ctask->sent;
1852
1853                 if (iscsi_sendpage(conn, &ctask->sendbuf, &ctask->data_count,
1854                                    &ctask->sent)) {
1855                         ctask->unsol_count -= ctask->sent - start;
1856                         ctask->xmstate |= XMSTATE_UNS_DATA;
1857                         /* will continue with this ctask later.. */
1858                         if (conn->datadgst_en) {
1859                                 crypto_digest_final(conn->data_tx_tfm,
1860                                                 (u8 *)&dtask->digest);
1861                                 debug_tcp("tx uns data fail 0x%x\n",
1862                                           dtask->digest);
1863                         }
1864                         return -EAGAIN;
1865                 }
1866
1867                 BUG_ON(ctask->sent > ctask->total_length);
1868                 ctask->unsol_count -= ctask->sent - start;
1869
1870                 /*
1871                  * XXX:we may run here with un-initial sendbuf.
1872                  * so pass it
1873                  */
1874                 if (conn->datadgst_en && ctask->sent - start > 0)
1875                         iscsi_buf_data_digest_update(conn, &ctask->sendbuf);
1876
1877                 if (!ctask->data_count)
1878                         break;
1879                 iscsi_buf_init_sg(&ctask->sendbuf,
1880                                   &ctask->sg[ctask->sg_count++]);
1881         }
1882         BUG_ON(ctask->unsol_count < 0);
1883
1884         /*
1885          * Done with the Data-Out. Next, check if we need
1886          * to send another unsolicited Data-Out.
1887          */
1888         if (ctask->unsol_count) {
1889                 if (conn->datadgst_en) {
1890                         if (iscsi_digest_final_send(conn, ctask,
1891                                                     &dtask->digestbuf,
1892                                                     &dtask->digest, 1)) {
1893                                 debug_tcp("send uns digest 0x%x fail\n",
1894                                           dtask->digest);
1895                                 return -EAGAIN;
1896                         }
1897                         debug_tcp("sending uns digest 0x%x, more uns\n",
1898                                   dtask->digest);
1899                 }
1900                 ctask->xmstate |= XMSTATE_UNS_INIT;
1901                 return 1;
1902         }
1903
1904         if (conn->datadgst_en && !(ctask->xmstate & XMSTATE_W_PAD)) {
1905                 if (iscsi_digest_final_send(conn, ctask,
1906                                             &dtask->digestbuf,
1907                                             &dtask->digest, 1)) {
1908                         debug_tcp("send last uns digest 0x%x fail\n",
1909                                    dtask->digest);
1910                         return -EAGAIN;
1911                 }
1912                 debug_tcp("sending uns digest 0x%x\n",dtask->digest);
1913         }
1914
1915         return 0;
1916 }
1917
1918 static inline int
1919 handle_xmstate_sol_data(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1920 {
1921         struct iscsi_session *session = conn->session;
1922         struct iscsi_r2t_info *r2t = ctask->r2t;
1923         struct iscsi_data_task *dtask = r2t->dtask;
1924         int left;
1925
1926         ctask->xmstate &= ~XMSTATE_SOL_DATA;
1927         ctask->dtask = dtask;
1928
1929         if (conn->datadgst_en) {
1930                 iscsi_data_digest_init(conn, ctask);
1931                 dtask->digest = 0;
1932         }
1933 solicit_again:
1934         /*
1935          * send Data-Out whitnin this R2T sequence.
1936          */
1937         if (!r2t->data_count)
1938                 goto data_out_done;
1939
1940         if (iscsi_sendpage(conn, &r2t->sendbuf, &r2t->data_count, &r2t->sent)) {
1941                 ctask->xmstate |= XMSTATE_SOL_DATA;
1942                 /* will continue with this ctask later.. */
1943                 if (conn->datadgst_en) {
1944                         crypto_digest_final(conn->data_tx_tfm,
1945                                           (u8 *)&dtask->digest);
1946                         debug_tcp("r2t data send fail 0x%x\n", dtask->digest);
1947                 }
1948                 return -EAGAIN;
1949         }
1950
1951         BUG_ON(r2t->data_count < 0);
1952         if (conn->datadgst_en)
1953                 iscsi_buf_data_digest_update(conn, &r2t->sendbuf);
1954
1955         if (r2t->data_count) {
1956                 BUG_ON(ctask->sc->use_sg == 0);
1957                 if (!iscsi_buf_left(&r2t->sendbuf)) {
1958                         BUG_ON(ctask->bad_sg == r2t->sg);
1959                         iscsi_buf_init_sg(&r2t->sendbuf, r2t->sg);
1960                         r2t->sg += 1;
1961                 }
1962                 goto solicit_again;
1963         }
1964
1965 data_out_done:
1966         /*
1967          * Done with this Data-Out. Next, check if we have
1968          * to send another Data-Out for this R2T.
1969          */
1970         BUG_ON(r2t->data_length - r2t->sent < 0);
1971         left = r2t->data_length - r2t->sent;
1972         if (left) {
1973                 if (conn->datadgst_en) {
1974                         if (iscsi_digest_final_send(conn, ctask,
1975                                                     &dtask->digestbuf,
1976                                                     &dtask->digest, 1)) {
1977                                 debug_tcp("send r2t data digest 0x%x"
1978                                           "fail\n", dtask->digest);
1979                                 return -EAGAIN;
1980                         }
1981                         debug_tcp("r2t data send digest 0x%x\n",
1982                                   dtask->digest);
1983                 }
1984                 iscsi_solicit_data_cont(conn, ctask, r2t, left);
1985                 ctask->xmstate |= XMSTATE_SOL_DATA;
1986                 ctask->xmstate &= ~XMSTATE_SOL_HDR;
1987                 return 1;
1988         }
1989
1990         /*
1991          * Done with this R2T. Check if there are more
1992          * outstanding R2Ts ready to be processed.
1993          */
1994         BUG_ON(ctask->r2t_data_count - r2t->data_length < 0);
1995         if (conn->datadgst_en) {
1996                 if (iscsi_digest_final_send(conn, ctask, &dtask->digestbuf,
1997                                             &dtask->digest, 1)) {
1998                         debug_tcp("send last r2t data digest 0x%x"
1999                                   "fail\n", dtask->digest);
2000                         return -EAGAIN;
2001                 }
2002                 debug_tcp("r2t done dout digest 0x%x\n", dtask->digest);
2003         }
2004
2005         ctask->r2t_data_count -= r2t->data_length;
2006         ctask->r2t = NULL;
2007         spin_lock_bh(&session->lock);
2008         __kfifo_put(ctask->r2tpool.queue, (void*)&r2t, sizeof(void*));
2009         spin_unlock_bh(&session->lock);
2010         if (__kfifo_get(ctask->r2tqueue, (void*)&r2t, sizeof(void*))) {
2011                 ctask->r2t = r2t;
2012                 ctask->xmstate |= XMSTATE_SOL_DATA;
2013                 ctask->xmstate &= ~XMSTATE_SOL_HDR;
2014                 return 1;
2015         }
2016
2017         return 0;
2018 }
2019
2020 static inline int
2021 handle_xmstate_w_pad(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
2022 {
2023         struct iscsi_data_task *dtask = ctask->dtask;
2024         int sent;
2025
2026         ctask->xmstate &= ~XMSTATE_W_PAD;
2027         iscsi_buf_init_virt(&ctask->sendbuf, (char*)&ctask->pad,
2028                             ctask->pad_count);
2029         if (iscsi_sendpage(conn, &ctask->sendbuf, &ctask->pad_count, &sent)) {
2030                 ctask->xmstate |= XMSTATE_W_PAD;
2031                 return -EAGAIN;
2032         }
2033
2034         if (conn->datadgst_en) {
2035                 iscsi_buf_data_digest_update(conn, &ctask->sendbuf);
2036                 /* imm data? */
2037                 if (!dtask) {
2038                         if (iscsi_digest_final_send(conn, ctask, &ctask->immbuf,
2039                                                     &ctask->immdigest, 1)) {
2040                                 debug_tcp("send padding digest 0x%x"
2041                                           "fail!\n", ctask->immdigest);
2042                                 return -EAGAIN;
2043                         }
2044                         debug_tcp("done with padding, digest 0x%x\n",
2045                                   ctask->datadigest);
2046                 } else {
2047                         if (iscsi_digest_final_send(conn, ctask,
2048                                                     &dtask->digestbuf,
2049                                                     &dtask->digest, 1)) {
2050                                 debug_tcp("send padding digest 0x%x"
2051                                           "fail\n", dtask->digest);
2052                                 return -EAGAIN;
2053                         }
2054                         debug_tcp("done with padding, digest 0x%x\n",
2055                                   dtask->digest);
2056                 }
2057         }
2058
2059         return 0;
2060 }
2061
2062 static int
2063 iscsi_ctask_xmit(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
2064 {
2065         int rc = 0;
2066
2067         debug_scsi("ctask deq [cid %d xmstate %x itt 0x%x]\n",
2068                 conn->id, ctask->xmstate, ctask->itt);
2069
2070         /*
2071          * serialize with TMF AbortTask
2072          */
2073         if (ctask->mtask)
2074                 return rc;
2075
2076         if (ctask->xmstate & XMSTATE_R_HDR) {
2077                 rc = handle_xmstate_r_hdr(conn, ctask);
2078                 return rc;
2079         }
2080
2081         if (ctask->xmstate & XMSTATE_W_HDR) {
2082                 rc = handle_xmstate_w_hdr(conn, ctask);
2083                 if (rc)
2084                         return rc;
2085         }
2086
2087         /* XXX: for data digest xmit recover */
2088         if (ctask->xmstate & XMSTATE_DATA_DIGEST) {
2089                 rc = handle_xmstate_data_digest(conn, ctask);
2090                 if (rc)
2091                         return rc;
2092         }
2093
2094         if (ctask->xmstate & XMSTATE_IMM_DATA) {
2095                 rc = handle_xmstate_imm_data(conn, ctask);
2096                 if (rc)
2097                         return rc;
2098         }
2099
2100         if (ctask->xmstate & XMSTATE_UNS_HDR) {
2101                 BUG_ON(!ctask->unsol_count);
2102                 ctask->xmstate &= ~XMSTATE_UNS_HDR;
2103 unsolicit_head_again:
2104                 rc = handle_xmstate_uns_hdr(conn, ctask);
2105                 if (rc)
2106                         return rc;
2107         }
2108
2109         if (ctask->xmstate & XMSTATE_UNS_DATA) {
2110                 rc = handle_xmstate_uns_data(conn, ctask);
2111                 if (rc == 1)
2112                         goto unsolicit_head_again;
2113                 else if (rc)
2114                         return rc;
2115                 goto done;
2116         }
2117
2118         if (ctask->xmstate & XMSTATE_SOL_HDR) {
2119                 struct iscsi_r2t_info *r2t;
2120
2121                 ctask->xmstate &= ~XMSTATE_SOL_HDR;
2122                 ctask->xmstate |= XMSTATE_SOL_DATA;
2123                 if (!ctask->r2t)
2124                         __kfifo_get(ctask->r2tqueue, (void*)&ctask->r2t,
2125                                     sizeof(void*));
2126 solicit_head_again:
2127                 r2t = ctask->r2t;
2128                 if (conn->hdrdgst_en)
2129                         iscsi_hdr_digest(conn, &r2t->headbuf,
2130                                         (u8*)r2t->dtask->hdrext);
2131                 if (iscsi_sendhdr(conn, &r2t->headbuf, r2t->data_count)) {
2132                         ctask->xmstate &= ~XMSTATE_SOL_DATA;
2133                         ctask->xmstate |= XMSTATE_SOL_HDR;
2134                         return -EAGAIN;
2135                 }
2136
2137                 debug_scsi("sol dout [dsn %d itt 0x%x dlen %d sent %d]\n",
2138                         r2t->solicit_datasn - 1, ctask->itt, r2t->data_count,
2139                         r2t->sent);
2140         }
2141
2142         if (ctask->xmstate & XMSTATE_SOL_DATA) {
2143                 rc = handle_xmstate_sol_data(conn, ctask);
2144                 if (rc == 1)
2145                         goto solicit_head_again;
2146                 if (rc)
2147                         return rc;
2148         }
2149
2150 done:
2151         /*
2152          * Last thing to check is whether we need to send write
2153          * padding. Note that we check for xmstate equality, not just the bit.
2154          */
2155         if (ctask->xmstate == XMSTATE_W_PAD)
2156                 rc = handle_xmstate_w_pad(conn, ctask);
2157
2158         return rc;
2159 }
2160
2161 /**
2162  * iscsi_data_xmit - xmit any command into the scheduled connection
2163  * @conn: iscsi connection
2164  *
2165  * Notes:
2166  *      The function can return -EAGAIN in which case the caller must
2167  *      re-schedule it again later or recover. '0' return code means
2168  *      successful xmit.
2169  **/
2170 static int
2171 iscsi_data_xmit(struct iscsi_conn *conn)
2172 {
2173         if (unlikely(conn->suspend_tx)) {
2174                 debug_tcp("conn %d Tx suspended!\n", conn->id);
2175                 return 0;
2176         }
2177
2178         /*
2179          * Transmit in the following order:
2180          *
2181          * 1) un-finished xmit (ctask or mtask)
2182          * 2) immediate control PDUs
2183          * 3) write data
2184          * 4) SCSI commands
2185          * 5) non-immediate control PDUs
2186          *
2187          * No need to lock around __kfifo_get as long as
2188          * there's one producer and one consumer.
2189          */
2190
2191         BUG_ON(conn->ctask && conn->mtask);
2192
2193         if (conn->ctask) {
2194                 if (iscsi_ctask_xmit(conn, conn->ctask))
2195                         goto again;
2196                 /* done with this in-progress ctask */
2197                 conn->ctask = NULL;
2198         }
2199         if (conn->mtask) {
2200                 if (iscsi_mtask_xmit(conn, conn->mtask))
2201                         goto again;
2202                 /* done with this in-progress mtask */
2203                 conn->mtask = NULL;
2204         }
2205
2206         /* process immediate first */
2207         if (unlikely(__kfifo_len(conn->immqueue))) {
2208                 struct iscsi_session *session = conn->session;
2209                 while (__kfifo_get(conn->immqueue, (void*)&conn->mtask,
2210                                    sizeof(void*))) {
2211                         if (iscsi_mtask_xmit(conn, conn->mtask))
2212                                 goto again;
2213
2214                         if (conn->mtask->hdr.itt ==
2215                                         cpu_to_be32(ISCSI_RESERVED_TAG)) {
2216                                 spin_lock_bh(&session->lock);
2217                                 __kfifo_put(session->mgmtpool.queue,
2218                                             (void*)&conn->mtask, sizeof(void*));
2219                                 spin_unlock_bh(&session->lock);
2220                         }
2221                 }
2222                 /* done with this mtask */
2223                 conn->mtask = NULL;
2224         }
2225
2226         /* process write queue */
2227         while (__kfifo_get(conn->writequeue, (void*)&conn->ctask,
2228                            sizeof(void*))) {
2229                 if (iscsi_ctask_xmit(conn, conn->ctask))
2230                         goto again;
2231         }
2232
2233         /* process command queue */
2234         while (__kfifo_get(conn->xmitqueue, (void*)&conn->ctask,
2235                            sizeof(void*))) {
2236                 if (iscsi_ctask_xmit(conn, conn->ctask))
2237                         goto again;
2238         }
2239         /* done with this ctask */
2240         conn->ctask = NULL;
2241
2242         /* process the rest control plane PDUs, if any */
2243         if (unlikely(__kfifo_len(conn->mgmtqueue))) {
2244                 struct iscsi_session *session = conn->session;
2245
2246                 while (__kfifo_get(conn->mgmtqueue, (void*)&conn->mtask,
2247                                    sizeof(void*))) {
2248                         if (iscsi_mtask_xmit(conn, conn->mtask))
2249                                 goto again;
2250
2251                         if (conn->mtask->hdr.itt ==
2252                                         cpu_to_be32(ISCSI_RESERVED_TAG)) {
2253                                 spin_lock_bh(&session->lock);
2254                                 __kfifo_put(session->mgmtpool.queue,
2255                                             (void*)&conn->mtask,
2256                                             sizeof(void*));
2257                                 spin_unlock_bh(&session->lock);
2258                         }
2259                 }
2260                 /* done with this mtask */
2261                 conn->mtask = NULL;
2262         }
2263
2264         return 0;
2265
2266 again:
2267         if (unlikely(conn->suspend_tx))
2268                 return 0;
2269
2270         return -EAGAIN;
2271 }
2272
2273 static void
2274 iscsi_xmitworker(void *data)
2275 {
2276         struct iscsi_conn *conn = data;
2277
2278         /*
2279          * serialize Xmit worker on a per-connection basis.
2280          */
2281         down(&conn->xmitsema);
2282         if (iscsi_data_xmit(conn))
2283                 schedule_work(&conn->xmitwork);
2284         up(&conn->xmitsema);
2285 }
2286
2287 #define FAILURE_BAD_HOST                1
2288 #define FAILURE_SESSION_FAILED          2
2289 #define FAILURE_SESSION_FREED           3
2290 #define FAILURE_WINDOW_CLOSED           4
2291 #define FAILURE_SESSION_TERMINATE       5
2292
2293 static int
2294 iscsi_queuecommand(struct scsi_cmnd *sc, void (*done)(struct scsi_cmnd *))
2295 {
2296         struct Scsi_Host *host;
2297         int reason = 0;
2298         struct iscsi_session *session;
2299         struct iscsi_conn *conn = NULL;
2300         struct iscsi_cmd_task *ctask = NULL;
2301
2302         sc->scsi_done = done;
2303         sc->result = 0;
2304
2305         host = sc->device->host;
2306         session = iscsi_hostdata(host->hostdata);
2307         BUG_ON(host != session->host);
2308
2309         spin_lock(&session->lock);
2310
2311         if (session->state != ISCSI_STATE_LOGGED_IN) {
2312                 if (session->state == ISCSI_STATE_FAILED) {
2313                         reason = FAILURE_SESSION_FAILED;
2314                         goto reject;
2315                 } else if (session->state == ISCSI_STATE_TERMINATE) {
2316                         reason = FAILURE_SESSION_TERMINATE;
2317                         goto fault;
2318                 }
2319                 reason = FAILURE_SESSION_FREED;
2320                 goto fault;
2321         }
2322
2323         /*
2324          * Check for iSCSI window and take care of CmdSN wrap-around
2325          */
2326         if ((int)(session->max_cmdsn - session->cmdsn) < 0) {
2327                 reason = FAILURE_WINDOW_CLOSED;
2328                 goto reject;
2329         }
2330
2331         conn = session->leadconn;
2332
2333         __kfifo_get(session->cmdpool.queue, (void*)&ctask, sizeof(void*));
2334         BUG_ON(ctask->sc);
2335
2336         sc->SCp.phase = session->age;
2337         sc->SCp.ptr = (char*)ctask;
2338         iscsi_cmd_init(conn, ctask, sc);
2339
2340         __kfifo_put(conn->xmitqueue, (void*)&ctask, sizeof(void*));
2341         debug_scsi(
2342                "ctask enq [%s cid %d sc %lx itt 0x%x len %d cmdsn %d win %d]\n",
2343                 sc->sc_data_direction == DMA_TO_DEVICE ? "write" : "read",
2344                 conn->id, (long)sc, ctask->itt, sc->request_bufflen,
2345                 session->cmdsn, session->max_cmdsn - session->exp_cmdsn + 1);
2346         spin_unlock(&session->lock);
2347
2348         if (!in_interrupt() && !down_trylock(&conn->xmitsema)) {
2349                 spin_unlock_irq(host->host_lock);
2350                 if (iscsi_data_xmit(conn))
2351                         schedule_work(&conn->xmitwork);
2352                 up(&conn->xmitsema);
2353                 spin_lock_irq(host->host_lock);
2354         } else
2355                 schedule_work(&conn->xmitwork);
2356
2357         return 0;
2358
2359 reject:
2360         spin_unlock(&session->lock);
2361         debug_scsi("cmd 0x%x rejected (%d)\n", sc->cmnd[0], reason);
2362         return SCSI_MLQUEUE_HOST_BUSY;
2363
2364 fault:
2365         spin_unlock(&session->lock);
2366         printk(KERN_ERR "iscsi_tcp: cmd 0x%x is not queued (%d)\n",
2367                sc->cmnd[0], reason);
2368         sc->sense_buffer[0] = 0x70;
2369         sc->sense_buffer[2] = NOT_READY;
2370         sc->sense_buffer[7] = 0x6;
2371         sc->sense_buffer[12] = 0x08;
2372         sc->sense_buffer[13] = 0x00;
2373         sc->result = (DID_NO_CONNECT << 16);
2374         sc->resid = sc->request_bufflen;
2375         sc->scsi_done(sc);
2376         return 0;
2377 }
2378
2379 static int
2380 iscsi_pool_init(struct iscsi_queue *q, int max, void ***items, int item_size)
2381 {
2382         int i;
2383
2384         *items = kmalloc(max * sizeof(void*), GFP_KERNEL);
2385         if (*items == NULL)
2386                 return -ENOMEM;
2387
2388         q->max = max;
2389         q->pool = kmalloc(max * sizeof(void*), GFP_KERNEL);
2390         if (q->pool == NULL) {
2391                 kfree(*items);
2392                 return -ENOMEM;
2393         }
2394
2395         q->queue = kfifo_init((void*)q->pool, max * sizeof(void*),
2396                               GFP_KERNEL, NULL);
2397         if (q->queue == ERR_PTR(-ENOMEM)) {
2398                 kfree(q->pool);
2399                 kfree(*items);
2400                 return -ENOMEM;
2401         }
2402
2403         for (i = 0; i < max; i++) {
2404                 q->pool[i] = kmalloc(item_size, GFP_KERNEL);
2405                 if (q->pool[i] == NULL) {
2406                         int j;
2407
2408                         for (j = 0; j < i; j++)
2409                                 kfree(q->pool[j]);
2410
2411                         kfifo_free(q->queue);
2412                         kfree(q->pool);
2413                         kfree(*items);
2414                         return -ENOMEM;
2415                 }
2416                 memset(q->pool[i], 0, item_size);
2417                 (*items)[i] = q->pool[i];
2418                 __kfifo_put(q->queue, (void*)&q->pool[i], sizeof(void*));
2419         }
2420         return 0;
2421 }
2422
2423 static void
2424 iscsi_pool_free(struct iscsi_queue *q, void **items)
2425 {
2426         int i;
2427
2428         for (i = 0; i < q->max; i++)
2429                 kfree(items[i]);
2430         kfree(q->pool);
2431         kfree(items);
2432 }
2433
2434 static iscsi_connh_t
2435 iscsi_conn_create(iscsi_sessionh_t sessionh, uint32_t conn_idx)
2436 {
2437         struct iscsi_session *session = iscsi_ptr(sessionh);
2438         struct iscsi_conn *conn = NULL;
2439
2440         conn = kmalloc(sizeof(struct iscsi_conn), GFP_KERNEL);
2441         if (conn == NULL)
2442                 goto conn_alloc_fail;
2443         memset(conn, 0, sizeof(struct iscsi_conn));
2444
2445         conn->c_stage = ISCSI_CONN_INITIAL_STAGE;
2446         conn->in_progress = IN_PROGRESS_WAIT_HEADER;
2447         conn->id = conn_idx;
2448         conn->exp_statsn = 0;
2449         conn->tmabort_state = TMABORT_INITIAL;
2450
2451         /* initial operational parameters */
2452         conn->hdr_size = sizeof(struct iscsi_hdr);
2453         conn->data_size = DEFAULT_MAX_RECV_DATA_SEGMENT_LENGTH;
2454         conn->max_recv_dlength = DEFAULT_MAX_RECV_DATA_SEGMENT_LENGTH;
2455
2456         spin_lock_init(&conn->lock);
2457
2458         /* initialize general xmit PDU commands queue */
2459         conn->xmitqueue = kfifo_alloc(session->cmds_max * sizeof(void*),
2460                                         GFP_KERNEL, NULL);
2461         if (conn->xmitqueue == ERR_PTR(-ENOMEM))
2462                 goto xmitqueue_alloc_fail;
2463
2464         /* initialize write response PDU commands queue */
2465         conn->writequeue = kfifo_alloc(session->cmds_max * sizeof(void*),
2466                                         GFP_KERNEL, NULL);
2467         if (conn->writequeue == ERR_PTR(-ENOMEM))
2468                 goto writequeue_alloc_fail;
2469
2470         /* initialize general immediate & non-immediate PDU commands queue */
2471         conn->immqueue = kfifo_alloc(session->mgmtpool_max * sizeof(void*),
2472                                         GFP_KERNEL, NULL);
2473         if (conn->immqueue == ERR_PTR(-ENOMEM))
2474                 goto immqueue_alloc_fail;
2475
2476         conn->mgmtqueue = kfifo_alloc(session->mgmtpool_max * sizeof(void*),
2477                                         GFP_KERNEL, NULL);
2478         if (conn->mgmtqueue == ERR_PTR(-ENOMEM))
2479                 goto mgmtqueue_alloc_fail;
2480
2481         INIT_WORK(&conn->xmitwork, iscsi_xmitworker, conn);
2482
2483         /* allocate login_mtask used for the login/text sequences */
2484         spin_lock_bh(&session->lock);
2485         if (!__kfifo_get(session->mgmtpool.queue,
2486                          (void*)&conn->login_mtask,
2487                          sizeof(void*))) {
2488                 spin_unlock_bh(&session->lock);
2489                 goto login_mtask_alloc_fail;
2490         }
2491         spin_unlock_bh(&session->lock);
2492
2493         /* allocate initial PDU receive place holder */
2494         if (conn->data_size <= PAGE_SIZE)
2495                 conn->data = kmalloc(conn->data_size, GFP_KERNEL);
2496         else
2497                 conn->data = (void*)__get_free_pages(GFP_KERNEL,
2498                                         get_order(conn->data_size));
2499         if (!conn->data)
2500                 goto max_recv_dlenght_alloc_fail;
2501
2502         init_timer(&conn->tmabort_timer);
2503         init_MUTEX(&conn->xmitsema);
2504         init_waitqueue_head(&conn->ehwait);
2505
2506         return iscsi_handle(conn);
2507
2508 max_recv_dlenght_alloc_fail:
2509         spin_lock_bh(&session->lock);
2510         __kfifo_put(session->mgmtpool.queue, (void*)&conn->login_mtask,
2511                     sizeof(void*));
2512         spin_unlock_bh(&session->lock);
2513 login_mtask_alloc_fail:
2514         kfifo_free(conn->mgmtqueue);
2515 mgmtqueue_alloc_fail:
2516         kfifo_free(conn->immqueue);
2517 immqueue_alloc_fail:
2518         kfifo_free(conn->writequeue);
2519 writequeue_alloc_fail:
2520         kfifo_free(conn->xmitqueue);
2521 xmitqueue_alloc_fail:
2522         kfree(conn);
2523 conn_alloc_fail:
2524         return iscsi_handle(NULL);
2525 }
2526
2527 static void
2528 iscsi_conn_destroy(iscsi_connh_t connh)
2529 {
2530         struct iscsi_conn *conn = iscsi_ptr(connh);
2531         struct iscsi_session *session = conn->session;
2532
2533         down(&conn->xmitsema);
2534         set_bit(SUSPEND_BIT, &conn->suspend_tx);
2535         if (conn->c_stage == ISCSI_CONN_INITIAL_STAGE && conn->sock) {
2536                 struct sock *sk = conn->sock->sk;
2537
2538                 /*
2539                  * conn_start() has never been called!
2540                  * need to cleanup the socket.
2541                  */
2542                 write_lock_bh(&sk->sk_callback_lock);
2543                 set_bit(SUSPEND_BIT, &conn->suspend_rx);
2544                 write_unlock_bh(&sk->sk_callback_lock);
2545
2546                 sock_hold(conn->sock->sk);
2547                 iscsi_conn_restore_callbacks(conn);
2548                 sock_put(conn->sock->sk);
2549                 sock_release(conn->sock);
2550                 conn->sock = NULL;
2551         }
2552
2553         spin_lock_bh(&session->lock);
2554         conn->c_stage = ISCSI_CONN_CLEANUP_WAIT;
2555         if (session->leadconn == conn) {
2556                 /*
2557                  * leading connection? then give up on recovery.
2558                  */
2559                 session->state = ISCSI_STATE_TERMINATE;
2560                 wake_up(&conn->ehwait);
2561         }
2562         spin_unlock_bh(&session->lock);
2563
2564         up(&conn->xmitsema);
2565
2566         /*
2567          * Block until all in-progress commands for this connection
2568          * time out or fail.
2569          */
2570         for (;;) {
2571                 spin_lock_bh(&conn->lock);
2572                 if (!session->host->host_busy) { /* OK for ERL == 0 */
2573                         spin_unlock_bh(&conn->lock);
2574                         break;
2575                 }
2576                 spin_unlock_bh(&conn->lock);
2577                 msleep_interruptible(500);
2578                 printk("conn_destroy(): host_busy %d host_failed %d\n",
2579                         session->host->host_busy, session->host->host_failed);
2580                 /*
2581                  * force eh_abort() to unblock
2582                  */
2583                 wake_up(&conn->ehwait);
2584         }
2585
2586         /* now free crypto */
2587         if (conn->hdrdgst_en || conn->datadgst_en) {
2588                 if (conn->tx_tfm)
2589                         crypto_free_tfm(conn->tx_tfm);
2590                 if (conn->rx_tfm)
2591                         crypto_free_tfm(conn->rx_tfm);
2592                 if (conn->data_tx_tfm)
2593                         crypto_free_tfm(conn->data_tx_tfm);
2594                 if (conn->data_rx_tfm)
2595                         crypto_free_tfm(conn->data_rx_tfm);
2596         }
2597
2598         /* free conn->data, size = MaxRecvDataSegmentLength */
2599         if (conn->data_size <= PAGE_SIZE)
2600                 kfree(conn->data);
2601         else
2602                 free_pages((unsigned long)conn->data,
2603                                         get_order(conn->data_size));
2604
2605         spin_lock_bh(&session->lock);
2606         __kfifo_put(session->mgmtpool.queue, (void*)&conn->login_mtask,
2607                     sizeof(void*));
2608         list_del(&conn->item);
2609         if (list_empty(&session->connections))
2610                 session->leadconn = NULL;
2611         if (session->leadconn && session->leadconn == conn)
2612                 session->leadconn = container_of(session->connections.next,
2613                         struct iscsi_conn, item);
2614
2615         if (session->leadconn == NULL)
2616                 /* none connections exits.. reset sequencing */
2617                 session->cmdsn = session->max_cmdsn = session->exp_cmdsn = 1;
2618         spin_unlock_bh(&session->lock);
2619
2620         kfifo_free(conn->xmitqueue);
2621         kfifo_free(conn->writequeue);
2622         kfifo_free(conn->immqueue);
2623         kfifo_free(conn->mgmtqueue);
2624         kfree(conn);
2625 }
2626
2627 static int
2628 iscsi_conn_bind(iscsi_sessionh_t sessionh, iscsi_connh_t connh,
2629                 uint32_t transport_fd, int is_leading)
2630 {
2631         struct iscsi_session *session = iscsi_ptr(sessionh);
2632         struct iscsi_conn *tmp = ERR_PTR(-EEXIST), *conn = iscsi_ptr(connh);
2633         struct sock *sk;
2634         struct socket *sock;
2635         int err;
2636
2637         /* lookup for existing socket */
2638         sock = sockfd_lookup(transport_fd, &err);
2639         if (!sock) {
2640                 printk(KERN_ERR "iscsi_tcp: sockfd_lookup failed %d\n", err);
2641                 return -EEXIST;
2642         }
2643
2644         /* lookup for existing connection */
2645         spin_lock_bh(&session->lock);
2646         list_for_each_entry(tmp, &session->connections, item) {
2647                 if (tmp == conn) {
2648                         if (conn->c_stage != ISCSI_CONN_STOPPED ||
2649                             conn->stop_stage == STOP_CONN_TERM) {
2650                                 printk(KERN_ERR "iscsi_tcp: can't bind "
2651                                        "non-stopped connection (%d:%d)\n",
2652                                        conn->c_stage, conn->stop_stage);
2653                                 spin_unlock_bh(&session->lock);
2654                                 return -EIO;
2655                         }
2656                         break;
2657                 }
2658         }
2659         if (tmp != conn) {
2660                 /* bind new iSCSI connection to session */
2661                 conn->session = session;
2662
2663                 list_add(&conn->item, &session->connections);
2664         }
2665         spin_unlock_bh(&session->lock);
2666
2667         if (conn->stop_stage != STOP_CONN_SUSPEND) {
2668                 /* bind iSCSI connection and socket */
2669                 conn->sock = sock;
2670
2671                 /* setup Socket parameters */
2672                 sk = sock->sk;
2673                 sk->sk_reuse = 1;
2674                 sk->sk_sndtimeo = 15 * HZ; /* FIXME: make it configurable */
2675                 sk->sk_allocation = GFP_ATOMIC;
2676
2677                 /* FIXME: disable Nagle's algorithm */
2678
2679                 /*
2680                  * Intercept TCP callbacks for sendfile like receive
2681                  * processing.
2682                  */
2683                 iscsi_conn_set_callbacks(conn);
2684
2685                 /*
2686                  * set receive state machine into initial state
2687                  */
2688                 conn->in_progress = IN_PROGRESS_WAIT_HEADER;
2689         }
2690
2691         if (is_leading)
2692                 session->leadconn = conn;
2693
2694         /*
2695          * Unblock xmitworker(), Login Phase will pass through.
2696          */
2697         clear_bit(SUSPEND_BIT, &conn->suspend_rx);
2698         clear_bit(SUSPEND_BIT, &conn->suspend_tx);
2699
2700         return 0;
2701 }
2702
2703 static int
2704 iscsi_conn_start(iscsi_connh_t connh)
2705 {
2706         struct iscsi_conn *conn = iscsi_ptr(connh);
2707         struct iscsi_session *session = conn->session;
2708         struct sock *sk;
2709
2710         /* FF phase warming up... */
2711
2712         if (session == NULL) {
2713                 printk(KERN_ERR "iscsi_tcp: can't start unbound connection\n");
2714                 return -EPERM;
2715         }
2716
2717         sk = conn->sock->sk;
2718
2719         write_lock_bh(&sk->sk_callback_lock);
2720         spin_lock_bh(&session->lock);
2721         conn->c_stage = ISCSI_CONN_STARTED;
2722         session->state = ISCSI_STATE_LOGGED_IN;
2723
2724         switch(conn->stop_stage) {
2725         case STOP_CONN_RECOVER:
2726                 /*
2727                  * unblock eh_abort() if it is blocked. re-try all
2728                  * commands after successful recovery
2729                  */
2730                 session->conn_cnt++;
2731                 conn->stop_stage = 0;
2732                 conn->tmabort_state = TMABORT_INITIAL;
2733                 session->age++;
2734                 wake_up(&conn->ehwait);
2735                 break;
2736         case STOP_CONN_TERM:
2737                 session->conn_cnt++;
2738                 conn->stop_stage = 0;
2739                 break;
2740         case STOP_CONN_SUSPEND:
2741                 conn->stop_stage = 0;
2742                 clear_bit(SUSPEND_BIT, &conn->suspend_rx);
2743                 clear_bit(SUSPEND_BIT, &conn->suspend_tx);
2744                 break;
2745         default:
2746                 break;
2747         }
2748         spin_unlock_bh(&session->lock);
2749         write_unlock_bh(&sk->sk_callback_lock);
2750
2751         return 0;
2752 }
2753
2754 static void
2755 iscsi_conn_stop(iscsi_connh_t connh, int flag)
2756 {
2757         struct iscsi_conn *conn = iscsi_ptr(connh);
2758         struct iscsi_session *session = conn->session;
2759         struct sock *sk;
2760         unsigned long flags;
2761
2762         BUG_ON(!conn->sock);
2763         sk = conn->sock->sk;
2764         write_lock_bh(&sk->sk_callback_lock);
2765         set_bit(SUSPEND_BIT, &conn->suspend_rx);
2766         write_unlock_bh(&sk->sk_callback_lock);
2767
2768         down(&conn->xmitsema);
2769
2770         spin_lock_irqsave(session->host->host_lock, flags);
2771         spin_lock(&session->lock);
2772         conn->stop_stage = flag;
2773         conn->c_stage = ISCSI_CONN_STOPPED;
2774         set_bit(SUSPEND_BIT, &conn->suspend_tx);
2775
2776         if (flag != STOP_CONN_SUSPEND)
2777                 session->conn_cnt--;
2778
2779         if (session->conn_cnt == 0 || session->leadconn == conn)
2780                 session->state = ISCSI_STATE_FAILED;
2781
2782         spin_unlock(&session->lock);
2783         spin_unlock_irqrestore(session->host->host_lock, flags);
2784
2785         if (flag == STOP_CONN_TERM || flag == STOP_CONN_RECOVER) {
2786                 struct iscsi_cmd_task *ctask;
2787                 struct iscsi_mgmt_task *mtask;
2788
2789                 /*
2790                  * Socket must go now.
2791                  */
2792                 sock_hold(conn->sock->sk);
2793                 iscsi_conn_restore_callbacks(conn);
2794                 sock_put(conn->sock->sk);
2795
2796                 /*
2797                  * flush xmit queues.
2798                  */
2799                 spin_lock_bh(&session->lock);
2800                 while (__kfifo_get(conn->writequeue, (void*)&ctask,
2801                             sizeof(void*)) ||
2802                         __kfifo_get(conn->xmitqueue, (void*)&ctask,
2803                             sizeof(void*))) {
2804                         struct iscsi_r2t_info *r2t;
2805
2806                         /*
2807                          * flush ctask's r2t queues
2808                          */
2809                         while (__kfifo_get(ctask->r2tqueue, (void*)&r2t,
2810                                 sizeof(void*)))
2811                                 __kfifo_put(ctask->r2tpool.queue, (void*)&r2t,
2812                                             sizeof(void*));
2813
2814                         spin_unlock_bh(&session->lock);
2815                         local_bh_disable();
2816                         iscsi_ctask_cleanup(conn, ctask);
2817                         local_bh_enable();
2818                         spin_lock_bh(&session->lock);
2819                 }
2820                 conn->ctask = NULL;
2821                 while (__kfifo_get(conn->immqueue, (void*)&mtask,
2822                            sizeof(void*)) ||
2823                         __kfifo_get(conn->mgmtqueue, (void*)&mtask,
2824                            sizeof(void*))) {
2825                         __kfifo_put(session->mgmtpool.queue,
2826                                     (void*)&mtask, sizeof(void*));
2827                 }
2828                 conn->mtask = NULL;
2829                 spin_unlock_bh(&session->lock);
2830
2831                 /*
2832                  * release socket only after we stopped data_xmit()
2833                  * activity and flushed all outstandings
2834                  */
2835                 sock_release(conn->sock);
2836                 conn->sock = NULL;
2837
2838                 /*
2839                  * for connection level recovery we should not calculate
2840                  * header digest. conn->hdr_size used for optimization
2841                  * in hdr_extract() and will be re-negotiated at
2842                  * set_param() time.
2843                  */
2844                 if (flag == STOP_CONN_RECOVER)
2845                         conn->hdr_size = sizeof(struct iscsi_hdr);
2846         }
2847         up(&conn->xmitsema);
2848 }
2849
2850 static int
2851 iscsi_conn_send_generic(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
2852                         char *data, uint32_t data_size)
2853 {
2854         struct iscsi_session *session = conn->session;
2855         struct iscsi_nopout *nop = (struct iscsi_nopout *)hdr;
2856         struct iscsi_mgmt_task *mtask;
2857
2858         spin_lock_bh(&session->lock);
2859         if (session->state == ISCSI_STATE_TERMINATE) {
2860                 spin_unlock_bh(&session->lock);
2861                 return -EPERM;
2862         }
2863         if (hdr->opcode == (ISCSI_OP_LOGIN | ISCSI_OP_IMMEDIATE) ||
2864             hdr->opcode == (ISCSI_OP_TEXT | ISCSI_OP_IMMEDIATE))
2865                 /*
2866                  * Login and Text are sent serially, in
2867                  * request-followed-by-response sequence.
2868                  * Same mtask can be used. Same ITT must be used.
2869                  * Note that login_mtask is preallocated at conn_create().
2870                  */
2871                 mtask = conn->login_mtask;
2872         else {
2873                 BUG_ON(conn->c_stage == ISCSI_CONN_INITIAL_STAGE);
2874                 BUG_ON(conn->c_stage == ISCSI_CONN_STOPPED);
2875
2876                 if (!__kfifo_get(session->mgmtpool.queue,
2877                                  (void*)&mtask, sizeof(void*))) {
2878                         spin_unlock_bh(&session->lock);
2879                         return -ENOSPC;
2880                 }
2881         }
2882
2883         /*
2884          * pre-format CmdSN and ExpStatSN for outgoing PDU.
2885          */
2886         if (hdr->itt != cpu_to_be32(ISCSI_RESERVED_TAG)) {
2887                 hdr->itt = mtask->itt | (conn->id << CID_SHIFT) |
2888                            (session->age << AGE_SHIFT);
2889                 nop->cmdsn = cpu_to_be32(session->cmdsn);
2890                 if (conn->c_stage == ISCSI_CONN_STARTED &&
2891                     !(hdr->opcode & ISCSI_OP_IMMEDIATE))
2892                         session->cmdsn++;
2893         } else
2894                 /* do not advance CmdSN */
2895                 nop->cmdsn = cpu_to_be32(session->cmdsn);
2896
2897         nop->exp_statsn = cpu_to_be32(conn->exp_statsn);
2898
2899         memcpy(&mtask->hdr, hdr, sizeof(struct iscsi_hdr));
2900
2901         iscsi_buf_init_virt(&mtask->headbuf, (char*)&mtask->hdr,
2902                                     sizeof(struct iscsi_hdr));
2903
2904         spin_unlock_bh(&session->lock);
2905
2906         if (data_size) {
2907                 memcpy(mtask->data, data, data_size);
2908                 mtask->data_count = data_size;
2909         } else
2910                 mtask->data_count = 0;
2911
2912         mtask->xmstate = XMSTATE_IMM_HDR;
2913
2914         if (mtask->data_count) {
2915                 iscsi_buf_init_iov(&mtask->sendbuf, (char*)mtask->data,
2916                                     mtask->data_count);
2917         }
2918
2919         debug_scsi("mgmtpdu [op 0x%x hdr->itt 0x%x datalen %d]\n",
2920                    hdr->opcode, hdr->itt, data_size);
2921
2922         /*
2923          * since send_pdu() could be called at least from two contexts,
2924          * we need to serialize __kfifo_put, so we don't have to take
2925          * additional lock on fast data-path
2926          */
2927         if (hdr->opcode & ISCSI_OP_IMMEDIATE)
2928                 __kfifo_put(conn->immqueue, (void*)&mtask, sizeof(void*));
2929         else
2930                 __kfifo_put(conn->mgmtqueue, (void*)&mtask, sizeof(void*));
2931
2932         schedule_work(&conn->xmitwork);
2933
2934         return 0;
2935 }
2936
2937 static int
2938 iscsi_eh_host_reset(struct scsi_cmnd *sc)
2939 {
2940         struct iscsi_cmd_task *ctask = (struct iscsi_cmd_task *)sc->SCp.ptr;
2941         struct iscsi_conn *conn = ctask->conn;
2942         struct iscsi_session *session = conn->session;
2943
2944         spin_lock_bh(&session->lock);
2945         if (session->state == ISCSI_STATE_TERMINATE) {
2946                 debug_scsi("failing host reset: session terminated "
2947                            "[CID %d age %d]", conn->id, session->age);
2948                 spin_unlock_bh(&session->lock);
2949                 return FAILED;
2950         }
2951         spin_unlock_bh(&session->lock);
2952
2953         debug_scsi("failing connection CID %d due to SCSI host reset "
2954                    "[itt 0x%x age %d]", conn->id, ctask->itt,
2955                    session->age);
2956         iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
2957
2958         return SUCCESS;
2959 }
2960
2961 static void
2962 iscsi_tmabort_timedout(unsigned long data)
2963 {
2964         struct iscsi_cmd_task *ctask = (struct iscsi_cmd_task *)data;
2965         struct iscsi_conn *conn = ctask->conn;
2966         struct iscsi_session *session = conn->session;
2967
2968         spin_lock(&session->lock);
2969         if (conn->tmabort_state == TMABORT_INITIAL) {
2970                 __kfifo_put(session->mgmtpool.queue,
2971                                 (void*)&ctask->mtask, sizeof(void*));
2972                 conn->tmabort_state = TMABORT_TIMEDOUT;
2973                 debug_scsi("tmabort timedout [sc %lx itt 0x%x]\n",
2974                         (long)ctask->sc, ctask->itt);
2975                 /* unblock eh_abort() */
2976                 wake_up(&conn->ehwait);
2977         }
2978         spin_unlock(&session->lock);
2979 }
2980
2981 static int
2982 iscsi_eh_abort(struct scsi_cmnd *sc)
2983 {
2984         int rc;
2985         struct iscsi_cmd_task *ctask = (struct iscsi_cmd_task *)sc->SCp.ptr;
2986         struct iscsi_conn *conn = ctask->conn;
2987         struct iscsi_session *session = conn->session;
2988
2989         conn->eh_abort_cnt++;
2990         debug_scsi("aborting [sc %lx itt 0x%x]\n", (long)sc, ctask->itt);
2991
2992         /*
2993          * two cases for ERL=0 here:
2994          *
2995          * 1) connection-level failure;
2996          * 2) recovery due protocol error;
2997          */
2998         down(&conn->xmitsema);
2999         spin_lock_bh(&session->lock);
3000         if (session->state != ISCSI_STATE_LOGGED_IN) {
3001                 if (session->state == ISCSI_STATE_TERMINATE) {
3002                         spin_unlock_bh(&session->lock);
3003                         up(&conn->xmitsema);
3004                         goto failed;
3005                 }
3006                 spin_unlock_bh(&session->lock);
3007         } else {
3008                 struct iscsi_tm *hdr = &conn->tmhdr;
3009
3010                 /*
3011                  * Still LOGGED_IN...
3012                  */
3013
3014                 if (!ctask->sc || sc->SCp.phase != session->age) {
3015                         /*
3016                          * 1) ctask completed before time out. But session
3017                          *    is still ok => Happy Retry.
3018                          * 2) session was re-open during time out of ctask.
3019                          */
3020                         spin_unlock_bh(&session->lock);
3021                         up(&conn->xmitsema);
3022                         goto success;
3023                 }
3024                 conn->tmabort_state = TMABORT_INITIAL;
3025                 spin_unlock_bh(&session->lock);
3026
3027                 /*
3028                  * ctask timed out but session is OK
3029                  * ERL=0 requires task mgmt abort to be issued on each
3030                  * failed command. requests must be serialized.
3031                  */
3032                 memset(hdr, 0, sizeof(struct iscsi_tm));
3033                 hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
3034                 hdr->flags = ISCSI_TM_FUNC_ABORT_TASK;
3035                 hdr->flags |= ISCSI_FLAG_CMD_FINAL;
3036                 memcpy(hdr->lun, ctask->hdr.lun, sizeof(hdr->lun));
3037                 hdr->rtt = ctask->hdr.itt;
3038                 hdr->refcmdsn = ctask->hdr.cmdsn;
3039
3040                 rc = iscsi_conn_send_generic(conn, (struct iscsi_hdr *)hdr,
3041                                              NULL, 0);
3042                 if (rc) {
3043                         iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
3044                         debug_scsi("abort sent failure [itt 0x%x]", ctask->itt);
3045                 } else {
3046                         struct iscsi_r2t_info *r2t;
3047
3048                         /*
3049                          * TMF abort vs. TMF response race logic
3050                          */
3051                         spin_lock_bh(&session->lock);
3052                         ctask->mtask = (struct iscsi_mgmt_task *)
3053                                 session->mgmt_cmds[(hdr->itt & ITT_MASK) -
3054                                                         ISCSI_MGMT_ITT_OFFSET];
3055                         /*
3056                          * have to flush r2tqueue to avoid r2t leaks
3057                          */
3058                         while (__kfifo_get(ctask->r2tqueue, (void*)&r2t,
3059                                 sizeof(void*))) {
3060                                 __kfifo_put(ctask->r2tpool.queue, (void*)&r2t,
3061                                         sizeof(void*));
3062                         }
3063                         if (conn->tmabort_state == TMABORT_INITIAL) {
3064                                 conn->tmfcmd_pdus_cnt++;
3065                                 conn->tmabort_timer.expires = 3*HZ + jiffies;
3066                                 conn->tmabort_timer.function =
3067                                                 iscsi_tmabort_timedout;
3068                                 conn->tmabort_timer.data = (unsigned long)ctask;
3069                                 add_timer(&conn->tmabort_timer);
3070                                 debug_scsi("abort sent [itt 0x%x]", ctask->itt);
3071                         } else {
3072                                 if (!ctask->sc ||
3073                                     conn->tmabort_state == TMABORT_SUCCESS) {
3074                                         conn->tmabort_state = TMABORT_INITIAL;
3075                                         spin_unlock_bh(&session->lock);
3076                                         up(&conn->xmitsema);
3077                                         goto success;
3078                                 }
3079                                 conn->tmabort_state = TMABORT_INITIAL;
3080                                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
3081                         }
3082                         spin_unlock_bh(&session->lock);
3083                 }
3084         }
3085         up(&conn->xmitsema);
3086
3087
3088         /*
3089          * block eh thread until:
3090          *
3091          * 1) abort response;
3092          * 2) abort timeout;
3093          * 3) session re-opened;
3094          * 4) session terminated;
3095          */
3096         for (;;) {
3097                 int p_state = session->state;
3098
3099                 rc = wait_event_interruptible(conn->ehwait,
3100                         (p_state == ISCSI_STATE_LOGGED_IN ?
3101                          (session->state == ISCSI_STATE_TERMINATE ||
3102                           conn->tmabort_state != TMABORT_INITIAL) :
3103                          (session->state == ISCSI_STATE_TERMINATE ||
3104                           session->state == ISCSI_STATE_LOGGED_IN)));
3105                 if (rc) {
3106                         /* shutdown.. */
3107                         session->state = ISCSI_STATE_TERMINATE;
3108                         goto failed;
3109                 }
3110
3111                 if (signal_pending(current))
3112                         flush_signals(current);
3113
3114                 if (session->state == ISCSI_STATE_TERMINATE)
3115                         goto failed;
3116
3117                 spin_lock_bh(&session->lock);
3118                 if (sc->SCp.phase == session->age &&
3119                    (conn->tmabort_state == TMABORT_TIMEDOUT ||
3120                     conn->tmabort_state == TMABORT_FAILED)) {
3121                         conn->tmabort_state = TMABORT_INITIAL;
3122                         if (!ctask->sc) {
3123                                 /*
3124                                  * ctask completed before tmf abort response or
3125                                  * time out.
3126                                  * But session is still ok => Happy Retry.
3127                                  */
3128                                 spin_unlock_bh(&session->lock);
3129                                 break;
3130                         }
3131                         spin_unlock_bh(&session->lock);
3132                         iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
3133                         continue;
3134                 }
3135                 spin_unlock_bh(&session->lock);
3136                 break;
3137         }
3138
3139 success:
3140         debug_scsi("abort success [sc %lx itt 0x%x]\n", (long)sc, ctask->itt);
3141         rc = SUCCESS;
3142         goto exit;
3143
3144 failed:
3145         debug_scsi("abort failed [sc %lx itt 0x%x]\n", (long)sc, ctask->itt);
3146         rc = FAILED;
3147
3148 exit:
3149         del_timer_sync(&conn->tmabort_timer);
3150
3151         down(&conn->xmitsema);
3152         if (conn->sock) {
3153                 struct sock *sk = conn->sock->sk;
3154
3155                 write_lock_bh(&sk->sk_callback_lock);
3156                 iscsi_ctask_cleanup(conn, ctask);
3157                 write_unlock_bh(&sk->sk_callback_lock);
3158         }
3159         up(&conn->xmitsema);
3160         return rc;
3161 }
3162
3163 static int
3164 iscsi_r2tpool_alloc(struct iscsi_session *session)
3165 {
3166         int i;
3167         int cmd_i;
3168
3169         /*
3170          * initialize per-task: R2T pool and xmit queue
3171          */
3172         for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
3173                 struct iscsi_cmd_task *ctask = session->cmds[cmd_i];
3174
3175                 /*
3176                  * pre-allocated x4 as much r2ts to handle race when
3177                  * target acks DataOut faster than we data_xmit() queues
3178                  * could replenish r2tqueue.
3179                  */
3180
3181                 /* R2T pool */
3182                 if (iscsi_pool_init(&ctask->r2tpool, session->max_r2t * 4,
3183                         (void***)&ctask->r2ts, sizeof(struct iscsi_r2t_info))) {
3184                         goto r2t_alloc_fail;
3185                 }
3186
3187                 /* R2T xmit queue */
3188                 ctask->r2tqueue = kfifo_alloc(
3189                       session->max_r2t * 4 * sizeof(void*), GFP_KERNEL, NULL);
3190                 if (ctask->r2tqueue == ERR_PTR(-ENOMEM)) {
3191                         iscsi_pool_free(&ctask->r2tpool, (void**)ctask->r2ts);
3192                         goto r2t_alloc_fail;
3193                 }
3194
3195                 /*
3196                  * number of
3197                  * Data-Out PDU's within R2T-sequence can be quite big;
3198                  * using mempool
3199                  */
3200                 ctask->datapool = mempool_create(ISCSI_DTASK_DEFAULT_MAX,
3201                          mempool_alloc_slab, mempool_free_slab, taskcache);
3202                 if (ctask->datapool == NULL) {
3203                         kfifo_free(ctask->r2tqueue);
3204                         iscsi_pool_free(&ctask->r2tpool, (void**)ctask->r2ts);
3205                         goto r2t_alloc_fail;
3206                 }
3207                 INIT_LIST_HEAD(&ctask->dataqueue);
3208         }
3209
3210         return 0;
3211
3212 r2t_alloc_fail:
3213         for (i = 0; i < cmd_i; i++) {
3214                 mempool_destroy(session->cmds[i]->datapool);
3215                 kfifo_free(session->cmds[i]->r2tqueue);
3216                 iscsi_pool_free(&session->cmds[i]->r2tpool,
3217                                 (void**)session->cmds[i]->r2ts);
3218         }
3219         return -ENOMEM;
3220 }
3221
3222 static void
3223 iscsi_r2tpool_free(struct iscsi_session *session)
3224 {
3225         int i;
3226
3227         for (i = 0; i < session->cmds_max; i++) {
3228                 mempool_destroy(session->cmds[i]->datapool);
3229                 kfifo_free(session->cmds[i]->r2tqueue);
3230                 iscsi_pool_free(&session->cmds[i]->r2tpool,
3231                                 (void**)session->cmds[i]->r2ts);
3232         }
3233 }
3234
3235 static struct scsi_host_template iscsi_sht = {
3236         .name                   = "iSCSI Initiator over TCP/IP, v."
3237                                   ISCSI_VERSION_STR,
3238         .queuecommand           = iscsi_queuecommand,
3239         .can_queue              = ISCSI_XMIT_CMDS_MAX - 1,
3240         .sg_tablesize           = ISCSI_SG_TABLESIZE,
3241         .cmd_per_lun            = ISCSI_CMD_PER_LUN,
3242         .eh_abort_handler       = iscsi_eh_abort,
3243         .eh_host_reset_handler  = iscsi_eh_host_reset,
3244         .use_clustering         = DISABLE_CLUSTERING,
3245         .proc_name              = "iscsi_tcp",
3246         .this_id                = -1,
3247 };
3248
3249 static iscsi_sessionh_t
3250 iscsi_session_create(uint32_t initial_cmdsn, struct Scsi_Host *host)
3251 {
3252         int cmd_i;
3253         struct iscsi_session *session;
3254
3255         session = iscsi_hostdata(host->hostdata);
3256         memset(session, 0, sizeof(struct iscsi_session));
3257
3258         session->host = host;
3259         session->id = host->host_no;
3260         session->state = ISCSI_STATE_LOGGED_IN;
3261         session->mgmtpool_max = ISCSI_MGMT_CMDS_MAX;
3262         session->cmds_max = ISCSI_XMIT_CMDS_MAX;
3263         session->cmdsn = initial_cmdsn;
3264         session->exp_cmdsn = initial_cmdsn + 1;
3265         session->max_cmdsn = initial_cmdsn + 1;
3266         session->max_r2t = 1;
3267
3268         /* initialize SCSI PDU commands pool */
3269         if (iscsi_pool_init(&session->cmdpool, session->cmds_max,
3270                 (void***)&session->cmds, sizeof(struct iscsi_cmd_task)))
3271                 goto cmdpool_alloc_fail;
3272
3273         /* pre-format cmds pool with ITT */
3274         for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++)
3275                 session->cmds[cmd_i]->itt = cmd_i;
3276
3277         spin_lock_init(&session->lock);
3278         INIT_LIST_HEAD(&session->connections);
3279
3280         /* initialize immediate command pool */
3281         if (iscsi_pool_init(&session->mgmtpool, session->mgmtpool_max,
3282                 (void***)&session->mgmt_cmds, sizeof(struct iscsi_mgmt_task)))
3283                 goto mgmtpool_alloc_fail;
3284
3285
3286         /* pre-format immediate cmds pool with ITT */
3287         for (cmd_i = 0; cmd_i < session->mgmtpool_max; cmd_i++) {
3288                 session->mgmt_cmds[cmd_i]->itt = ISCSI_MGMT_ITT_OFFSET + cmd_i;
3289                 session->mgmt_cmds[cmd_i]->data = kmalloc(
3290                         DEFAULT_MAX_RECV_DATA_SEGMENT_LENGTH, GFP_KERNEL);
3291                 if (!session->mgmt_cmds[cmd_i]->data) {
3292                         int j;
3293
3294                         for (j = 0; j < cmd_i; j++)
3295                                 kfree(session->mgmt_cmds[j]->data);
3296                         goto immdata_alloc_fail;
3297                 }
3298         }
3299
3300         if (iscsi_r2tpool_alloc(session))
3301                 goto r2tpool_alloc_fail;
3302
3303         return iscsi_handle(session);
3304
3305 r2tpool_alloc_fail:
3306         for (cmd_i = 0; cmd_i < session->mgmtpool_max; cmd_i++)
3307                 kfree(session->mgmt_cmds[cmd_i]->data);
3308         iscsi_pool_free(&session->mgmtpool, (void**)session->mgmt_cmds);
3309 immdata_alloc_fail:
3310 mgmtpool_alloc_fail:
3311         iscsi_pool_free(&session->cmdpool, (void**)session->cmds);
3312 cmdpool_alloc_fail:
3313         return iscsi_handle(NULL);
3314 }
3315
3316 static void
3317 iscsi_session_destroy(iscsi_sessionh_t sessionh)
3318 {
3319         int cmd_i;
3320         struct iscsi_data_task *dtask, *n;
3321         struct iscsi_session *session = iscsi_ptr(sessionh);
3322
3323         for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
3324                 struct iscsi_cmd_task *ctask = session->cmds[cmd_i];
3325                 list_for_each_entry_safe(dtask, n, &ctask->dataqueue, item) {
3326                         list_del(&dtask->item);
3327                         mempool_free(dtask, ctask->datapool);
3328                 }
3329         }
3330
3331         for (cmd_i = 0; cmd_i < session->mgmtpool_max; cmd_i++)
3332                 kfree(session->mgmt_cmds[cmd_i]->data);
3333
3334         iscsi_r2tpool_free(session);
3335         iscsi_pool_free(&session->mgmtpool, (void**)session->mgmt_cmds);
3336         iscsi_pool_free(&session->cmdpool, (void**)session->cmds);
3337 }
3338
3339 static int
3340 iscsi_conn_set_param(iscsi_connh_t connh, enum iscsi_param param,
3341                      uint32_t value)
3342 {
3343         struct iscsi_conn *conn = iscsi_ptr(connh);
3344         struct iscsi_session *session = conn->session;
3345
3346         spin_lock_bh(&session->lock);
3347         if (conn->c_stage != ISCSI_CONN_INITIAL_STAGE &&
3348             conn->stop_stage != STOP_CONN_RECOVER) {
3349                 printk(KERN_ERR "iscsi_tcp: can not change parameter [%d]\n",
3350                        param);
3351                 spin_unlock_bh(&session->lock);
3352                 return 0;
3353         }
3354         spin_unlock_bh(&session->lock);
3355
3356         switch(param) {
3357         case ISCSI_PARAM_MAX_RECV_DLENGTH: {
3358                 char *saveptr = conn->data;
3359                 int flags = GFP_KERNEL;
3360
3361                 if (conn->data_size >= value) {
3362                         conn->max_recv_dlength = value;
3363                         break;
3364                 }
3365
3366                 spin_lock_bh(&session->lock);
3367                 if (conn->stop_stage == STOP_CONN_RECOVER)
3368                         flags = GFP_ATOMIC;
3369                 spin_unlock_bh(&session->lock);
3370
3371                 if (value <= PAGE_SIZE)
3372                         conn->data = kmalloc(value, flags);
3373                 else
3374                         conn->data = (void*)__get_free_pages(flags,
3375                                                              get_order(value));
3376                 if (conn->data == NULL) {
3377                         conn->data = saveptr;
3378                         return -ENOMEM;
3379                 }
3380                 if (conn->data_size <= PAGE_SIZE)
3381                         kfree(saveptr);
3382                 else
3383                         free_pages((unsigned long)saveptr,
3384                                    get_order(conn->data_size));
3385                 conn->max_recv_dlength = value;
3386                 conn->data_size = value;
3387                 }
3388                 break;
3389         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
3390                 conn->max_xmit_dlength =  value;
3391                 break;
3392         case ISCSI_PARAM_HDRDGST_EN:
3393                 conn->hdrdgst_en = value;
3394                 conn->hdr_size = sizeof(struct iscsi_hdr);
3395                 if (conn->hdrdgst_en) {
3396                         conn->hdr_size += sizeof(__u32);
3397                         if (!conn->tx_tfm)
3398                                 conn->tx_tfm = crypto_alloc_tfm("crc32c", 0);
3399                         if (!conn->tx_tfm)
3400                                 return -ENOMEM;
3401                         if (!conn->rx_tfm)
3402                                 conn->rx_tfm = crypto_alloc_tfm("crc32c", 0);
3403                         if (!conn->rx_tfm) {
3404                                 crypto_free_tfm(conn->tx_tfm);
3405                                 return -ENOMEM;
3406                         }
3407                 } else {
3408                         if (conn->tx_tfm)
3409                                 crypto_free_tfm(conn->tx_tfm);
3410                         if (conn->rx_tfm)
3411                                 crypto_free_tfm(conn->rx_tfm);
3412                 }
3413                 break;
3414         case ISCSI_PARAM_DATADGST_EN:
3415                 conn->datadgst_en = value;
3416                 if (conn->datadgst_en) {
3417                         if (!conn->data_tx_tfm)
3418                                 conn->data_tx_tfm =
3419                                     crypto_alloc_tfm("crc32c", 0);
3420                         if (!conn->data_tx_tfm)
3421                                 return -ENOMEM;
3422                         if (!conn->data_rx_tfm)
3423                                 conn->data_rx_tfm =
3424                                     crypto_alloc_tfm("crc32c", 0);
3425                         if (!conn->data_rx_tfm) {
3426                                 crypto_free_tfm(conn->data_tx_tfm);
3427                                 return -ENOMEM;
3428                         }
3429                 } else {
3430                         if (conn->data_tx_tfm)
3431                                 crypto_free_tfm(conn->data_tx_tfm);
3432                         if (conn->data_rx_tfm)
3433                                 crypto_free_tfm(conn->data_rx_tfm);
3434                 }
3435                 break;
3436         case ISCSI_PARAM_INITIAL_R2T_EN:
3437                 session->initial_r2t_en = value;
3438                 break;
3439         case ISCSI_PARAM_MAX_R2T:
3440                 if (session->max_r2t == roundup_pow_of_two(value))
3441                         break;
3442                 iscsi_r2tpool_free(session);
3443                 session->max_r2t = value;
3444                 if (session->max_r2t & (session->max_r2t - 1))
3445                         session->max_r2t = roundup_pow_of_two(session->max_r2t);
3446                 if (iscsi_r2tpool_alloc(session))
3447                         return -ENOMEM;
3448                 break;
3449         case ISCSI_PARAM_IMM_DATA_EN:
3450                 session->imm_data_en = value;
3451                 break;
3452         case ISCSI_PARAM_FIRST_BURST:
3453                 session->first_burst = value;
3454                 break;
3455         case ISCSI_PARAM_MAX_BURST:
3456                 session->max_burst = value;
3457                 break;
3458         case ISCSI_PARAM_PDU_INORDER_EN:
3459                 session->pdu_inorder_en = value;
3460                 break;
3461         case ISCSI_PARAM_DATASEQ_INORDER_EN:
3462                 session->dataseq_inorder_en = value;
3463                 break;
3464         case ISCSI_PARAM_ERL:
3465                 session->erl = value;
3466                 break;
3467         case ISCSI_PARAM_IFMARKER_EN:
3468                 BUG_ON(value);
3469                 session->ifmarker_en = value;
3470                 break;
3471         case ISCSI_PARAM_OFMARKER_EN:
3472                 BUG_ON(value);
3473                 session->ofmarker_en = value;
3474                 break;
3475         default:
3476                 break;
3477         }
3478
3479         return 0;
3480 }
3481
3482 static int
3483 iscsi_conn_get_param(iscsi_connh_t connh, enum iscsi_param param,
3484                      uint32_t *value)
3485 {
3486         struct iscsi_conn *conn = iscsi_ptr(connh);
3487         struct iscsi_session *session = conn->session;
3488
3489         switch(param) {
3490         case ISCSI_PARAM_MAX_RECV_DLENGTH:
3491                 *value = conn->max_recv_dlength;
3492                 break;
3493         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
3494                 *value = conn->max_xmit_dlength;
3495                 break;
3496         case ISCSI_PARAM_HDRDGST_EN:
3497                 *value = conn->hdrdgst_en;
3498                 break;
3499         case ISCSI_PARAM_DATADGST_EN:
3500                 *value = conn->datadgst_en;
3501                 break;
3502         case ISCSI_PARAM_INITIAL_R2T_EN:
3503                 *value = session->initial_r2t_en;
3504                 break;
3505         case ISCSI_PARAM_MAX_R2T:
3506                 *value = session->max_r2t;
3507                 break;
3508         case ISCSI_PARAM_IMM_DATA_EN:
3509                 *value = session->imm_data_en;
3510                 break;
3511         case ISCSI_PARAM_FIRST_BURST:
3512                 *value = session->first_burst;
3513                 break;
3514         case ISCSI_PARAM_MAX_BURST:
3515                 *value = session->max_burst;
3516                 break;
3517         case ISCSI_PARAM_PDU_INORDER_EN:
3518                 *value = session->pdu_inorder_en;
3519                 break;
3520         case ISCSI_PARAM_DATASEQ_INORDER_EN:
3521                 *value = session->dataseq_inorder_en;
3522                 break;
3523         case ISCSI_PARAM_ERL:
3524                 *value = session->erl;
3525                 break;
3526         case ISCSI_PARAM_IFMARKER_EN:
3527                 *value = session->ifmarker_en;
3528                 break;
3529         case ISCSI_PARAM_OFMARKER_EN:
3530                 *value = session->ofmarker_en;
3531                 break;
3532         default:
3533                 return ISCSI_ERR_PARAM_NOT_FOUND;
3534         }
3535
3536         return 0;
3537 }
3538
3539 static void
3540 iscsi_conn_get_stats(iscsi_connh_t connh, struct iscsi_stats *stats)
3541 {
3542         struct iscsi_conn *conn = iscsi_ptr(connh);
3543
3544         stats->txdata_octets = conn->txdata_octets;
3545         stats->rxdata_octets = conn->rxdata_octets;
3546         stats->scsicmd_pdus = conn->scsicmd_pdus_cnt;
3547         stats->dataout_pdus = conn->dataout_pdus_cnt;
3548         stats->scsirsp_pdus = conn->scsirsp_pdus_cnt;
3549         stats->datain_pdus = conn->datain_pdus_cnt;
3550         stats->r2t_pdus = conn->r2t_pdus_cnt;
3551         stats->tmfcmd_pdus = conn->tmfcmd_pdus_cnt;
3552         stats->tmfrsp_pdus = conn->tmfrsp_pdus_cnt;
3553         stats->custom_length = 3;
3554         strcpy(stats->custom[0].desc, "tx_sendpage_failures");
3555         stats->custom[0].value = conn->sendpage_failures_cnt;
3556         strcpy(stats->custom[1].desc, "rx_discontiguous_hdr");
3557         stats->custom[1].value = conn->discontiguous_hdr_cnt;
3558         strcpy(stats->custom[2].desc, "eh_abort_cnt");
3559         stats->custom[2].value = conn->eh_abort_cnt;
3560 }
3561
3562 static int
3563 iscsi_conn_send_pdu(iscsi_connh_t connh, struct iscsi_hdr *hdr, char *data,
3564                     uint32_t data_size)
3565 {
3566         struct iscsi_conn *conn = iscsi_ptr(connh);
3567         int rc;
3568
3569         down(&conn->xmitsema);
3570         rc = iscsi_conn_send_generic(conn, hdr, data, data_size);
3571         up(&conn->xmitsema);
3572
3573         return rc;
3574 }
3575
3576 static struct iscsi_transport iscsi_tcp_transport = {
3577         .owner                  = THIS_MODULE,
3578         .name                   = "tcp",
3579         .caps                   = CAP_RECOVERY_L0 | CAP_MULTI_R2T | CAP_HDRDGST
3580                                   | CAP_DATADGST,
3581         .host_template          = &iscsi_sht,
3582         .hostdata_size          = sizeof(struct iscsi_session),
3583         .max_conn               = 1,
3584         .max_cmd_len            = ISCSI_TCP_MAX_CMD_LEN,
3585         .create_session         = iscsi_session_create,
3586         .destroy_session        = iscsi_session_destroy,
3587         .create_conn            = iscsi_conn_create,
3588         .bind_conn              = iscsi_conn_bind,
3589         .destroy_conn           = iscsi_conn_destroy,
3590         .set_param              = iscsi_conn_set_param,
3591         .get_param              = iscsi_conn_get_param,
3592         .start_conn             = iscsi_conn_start,
3593         .stop_conn              = iscsi_conn_stop,
3594         .send_pdu               = iscsi_conn_send_pdu,
3595         .get_stats              = iscsi_conn_get_stats,
3596 };
3597
3598 static int __init
3599 iscsi_tcp_init(void)
3600 {
3601         int error;
3602
3603         if (iscsi_max_lun < 1) {
3604                 printk(KERN_ERR "Invalid max_lun value of %u\n", iscsi_max_lun);
3605                 return -EINVAL;
3606         }
3607         iscsi_tcp_transport.max_lun = iscsi_max_lun;
3608
3609         taskcache = kmem_cache_create("iscsi_taskcache",
3610                         sizeof(struct iscsi_data_task), 0,
3611                         SLAB_HWCACHE_ALIGN | SLAB_NO_REAP, NULL, NULL);
3612         if (!taskcache)
3613                 return -ENOMEM;
3614
3615         error = iscsi_register_transport(&iscsi_tcp_transport);
3616         if (error)
3617                 kmem_cache_destroy(taskcache);
3618
3619         return error;
3620 }
3621
3622 static void __exit
3623 iscsi_tcp_exit(void)
3624 {
3625         iscsi_unregister_transport(&iscsi_tcp_transport);
3626         kmem_cache_destroy(taskcache);
3627 }
3628
3629 module_init(iscsi_tcp_init);
3630 module_exit(iscsi_tcp_exit);