drivers/scsi/iscsi_tcp.c

   1 /*
   2  * iSCSI Initiator over TCP/IP Data-Path
   3  *
   4  * Copyright (C) 2004 Dmitry Yusupov
   5  * Copyright (C) 2004 Alex Aizman
   6  * Copyright (C) 2005 Mike Christie
   7  * maintained by open-iscsi@googlegroups.com
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published
  11  * by the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful, but
  15  * WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  17  * General Public License for more details.
  18  *
  19  * See the file COPYING included with this distribution for more details.
  20  *
  21  * Credits:
  22  *      Christoph Hellwig
  23  *      FUJITA Tomonori
  24  *      Arne Redlich
  25  *      Zhenyu Wang
  26  */
  27
  28 #include <linux/types.h>
  29 #include <linux/list.h>
  30 #include <linux/inet.h>
  31 #include <linux/blkdev.h>
  32 #include <linux/crypto.h>
  33 #include <linux/delay.h>
  34 #include <linux/kfifo.h>
  35 #include <linux/scatterlist.h>
  36 #include <linux/mutex.h>
  37 #include <net/tcp.h>
  38 #include <scsi/scsi_cmnd.h>
  39 #include <scsi/scsi_device.h>
  40 #include <scsi/scsi_eh.h>
  41 #include <scsi/scsi_request.h>
  42 #include <scsi/scsi_tcq.h>
  43 #include <scsi/scsi_host.h>
  44 #include <scsi/scsi.h>
  45 #include <scsi/scsi_transport_iscsi.h>
  46
  47 #include "iscsi_tcp.h"
  48
  49 MODULE_AUTHOR("Dmitry Yusupov <dmitry_yus@yahoo.com>, "
  50               "Alex Aizman <itn780@yahoo.com>");
  51 MODULE_DESCRIPTION("iSCSI/TCP data-path");
  52 MODULE_LICENSE("GPL");
  53 MODULE_VERSION("0:4.445");
  54 /* #define DEBUG_TCP */
  55 /* #define DEBUG_SCSI */
  56 #define DEBUG_ASSERT
  57
  58 #ifdef DEBUG_TCP
  59 #define debug_tcp(fmt...) printk(KERN_DEBUG "tcp: " fmt)
  60 #else
  61 #define debug_tcp(fmt...)
  62 #endif
  63
  64 #ifdef DEBUG_SCSI
  65 #define debug_scsi(fmt...) printk(KERN_DEBUG "scsi: " fmt)
  66 #else
  67 #define debug_scsi(fmt...)
  68 #endif
  69
  70 #ifndef DEBUG_ASSERT
  71 #ifdef BUG_ON
  72 #undef BUG_ON
  73 #endif
  74 #define BUG_ON(expr)
  75 #endif
  76
  77 #define INVALID_SN_DELTA        0xffff
  78
  79 static unsigned int iscsi_max_lun = 512;
  80 module_param_named(max_lun, iscsi_max_lun, uint, S_IRUGO);
  81
  82 /* global data */
  83 static kmem_cache_t *taskcache;
  84
  85 static inline void
  86 iscsi_buf_init_virt(struct iscsi_buf *ibuf, char *vbuf, int size)
  87 {
  88         sg_init_one(&ibuf->sg, (u8 *)vbuf, size);
  89         ibuf->sent = 0;
  90 }
  91
  92 static inline void
  93 iscsi_buf_init_iov(struct iscsi_buf *ibuf, char *vbuf, int size)
  94 {
  95         ibuf->sg.page = (void*)vbuf;
  96         ibuf->sg.offset = (unsigned int)-1;
  97         ibuf->sg.length = size;
  98         ibuf->sent = 0;
  99 }
 100
 101 static inline void*
 102 iscsi_buf_iov_base(struct iscsi_buf *ibuf)
 103 {
 104         return (char*)ibuf->sg.page + ibuf->sent;
 105 }
 106
 107 static inline void
 108 iscsi_buf_init_sg(struct iscsi_buf *ibuf, struct scatterlist *sg)
 109 {
 110         /*
 111          * Fastpath: sg element fits into single page
 112          */
 113         if (sg->length + sg->offset <= PAGE_SIZE && page_count(sg->page) >= 2) {
 114                 ibuf->sg.page = sg->page;
 115                 ibuf->sg.offset = sg->offset;
 116                 ibuf->sg.length = sg->length;
 117         } else
 118                 iscsi_buf_init_iov(ibuf, page_address(sg->page), sg->length);
 119         ibuf->sent = 0;
 120 }
 121
 122 static inline int
 123 iscsi_buf_left(struct iscsi_buf *ibuf)
 124 {
 125         int rc;
 126
 127         rc = ibuf->sg.length - ibuf->sent;
 128         BUG_ON(rc < 0);
 129         return rc;
 130 }
 131
 132 static inline void
 133 iscsi_hdr_digest(struct iscsi_conn *conn, struct iscsi_buf *buf,
 134                  u8* crc)
 135 {
 136         crypto_digest_digest(conn->tx_tfm, &buf->sg, 1, crc);
 137         buf->sg.length += sizeof(uint32_t);
 138 }
 139
 140 static void
 141 iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err)
 142 {
 143         struct iscsi_session *session = conn->session;
 144         unsigned long flags;
 145
 146         spin_lock_irqsave(&session->lock, flags);
 147         if (session->conn_cnt == 1 || session->leadconn == conn)
 148                 session->state = ISCSI_STATE_FAILED;
 149         spin_unlock_irqrestore(&session->lock, flags);
 150         set_bit(SUSPEND_BIT, &conn->suspend_tx);
 151         set_bit(SUSPEND_BIT, &conn->suspend_rx);
 152         iscsi_conn_error(iscsi_handle(conn), err);
 153 }
 154
 155 static inline int
 156 iscsi_check_assign_cmdsn(struct iscsi_session *session, struct iscsi_nopin *hdr)
 157 {
 158         uint32_t max_cmdsn = be32_to_cpu(hdr->max_cmdsn);
 159         uint32_t exp_cmdsn = be32_to_cpu(hdr->exp_cmdsn);
 160
 161         if (max_cmdsn < exp_cmdsn -1 &&
 162             max_cmdsn > exp_cmdsn - INVALID_SN_DELTA)
 163                 return ISCSI_ERR_MAX_CMDSN;
 164         if (max_cmdsn > session->max_cmdsn ||
 165             max_cmdsn < session->max_cmdsn - INVALID_SN_DELTA)
 166                 session->max_cmdsn = max_cmdsn;
 167         if (exp_cmdsn > session->exp_cmdsn ||
 168             exp_cmdsn < session->exp_cmdsn - INVALID_SN_DELTA)
 169                 session->exp_cmdsn = exp_cmdsn;
 170
 171         return 0;
 172 }
 173
 174 static inline int
 175 iscsi_hdr_extract(struct iscsi_conn *conn)
 176 {
 177         struct sk_buff *skb = conn->in.skb;
 178
 179         if (conn->in.copy >= conn->hdr_size &&
 180             conn->in_progress == IN_PROGRESS_WAIT_HEADER) {
 181                 /*
 182                  * Zero-copy PDU Header: using connection context
 183                  * to store header pointer.
 184                  */
 185                 if (skb_shinfo(skb)->frag_list == NULL &&
 186                     !skb_shinfo(skb)->nr_frags)
 187                         conn->in.hdr = (struct iscsi_hdr *)
 188                                 ((char*)skb->data + conn->in.offset);
 189                 else {
 190                         /* ignoring return code since we checked
 191                          * in.copy before */
 192                         skb_copy_bits(skb, conn->in.offset,
 193                                 &conn->hdr, conn->hdr_size);
 194                         conn->in.hdr = &conn->hdr;
 195                 }
 196                 conn->in.offset += conn->hdr_size;
 197                 conn->in.copy -= conn->hdr_size;
 198         } else {
 199                 int hdr_remains;
 200                 int copylen;
 201
 202                 /*
 203                  * PDU header scattered across SKB's,
 204                  * copying it... This'll happen quite rarely.
 205                  */
 206
 207                 if (conn->in_progress == IN_PROGRESS_WAIT_HEADER)
 208                         conn->in.hdr_offset = 0;
 209
 210                 hdr_remains = conn->hdr_size - conn->in.hdr_offset;
 211                 BUG_ON(hdr_remains <= 0);
 212
 213                 copylen = min(conn->in.copy, hdr_remains);
 214                 skb_copy_bits(skb, conn->in.offset,
 215                         (char*)&conn->hdr + conn->in.hdr_offset, copylen);
 216
 217                 debug_tcp("PDU gather offset %d bytes %d in.offset %d "
 218                        "in.copy %d\n", conn->in.hdr_offset, copylen,
 219                        conn->in.offset, conn->in.copy);
 220
 221                 conn->in.offset += copylen;
 222                 conn->in.copy -= copylen;
 223                 if (copylen < hdr_remains)  {
 224                         conn->in_progress = IN_PROGRESS_HEADER_GATHER;
 225                         conn->in.hdr_offset += copylen;
 226                         return -EAGAIN;
 227                 }
 228                 conn->in.hdr = &conn->hdr;
 229                 conn->discontiguous_hdr_cnt++;
 230                 conn->in_progress = IN_PROGRESS_WAIT_HEADER;
 231         }
 232
 233         return 0;
 234 }
 235
 236 static inline void
 237 iscsi_ctask_cleanup(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
 238 {
 239         struct scsi_cmnd *sc = ctask->sc;
 240         struct iscsi_session *session = conn->session;
 241
 242         spin_lock(&session->lock);
 243         if (unlikely(!sc)) {
 244                 spin_unlock(&session->lock);
 245                 return;
 246         }
 247         if (sc->sc_data_direction == DMA_TO_DEVICE) {
 248                 struct iscsi_data_task *dtask, *n;
 249                 /* WRITE: cleanup Data-Out's if any */
 250                 spin_lock(&conn->lock);
 251                 list_for_each_entry_safe(dtask, n, &ctask->dataqueue, item) {
 252                         list_del(&dtask->item);
 253                         mempool_free(dtask, ctask->datapool);
 254                 }
 255                 spin_unlock(&conn->lock);
 256         }
 257         ctask->xmstate = XMSTATE_IDLE;
 258         ctask->r2t = NULL;
 259         ctask->sc = NULL;
 260         __kfifo_put(session->cmdpool.queue, (void*)&ctask, sizeof(void*));
 261         spin_unlock(&session->lock);
 262 }
 263
 264 /**
 265  * iscsi_cmd_rsp - SCSI Command Response processing
 266  * @conn: iscsi connection
 267  * @ctask: scsi command task
 268  **/
 269 static int
 270 iscsi_cmd_rsp(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
 271 {
 272         int rc;
 273         struct iscsi_cmd_rsp *rhdr = (struct iscsi_cmd_rsp *)conn->in.hdr;
 274         struct iscsi_session *session = conn->session;
 275         struct scsi_cmnd *sc = ctask->sc;
 276
 277         rc = iscsi_check_assign_cmdsn(session, (struct iscsi_nopin*)rhdr);
 278         if (rc) {
 279                 sc->result = (DID_ERROR << 16);
 280                 goto out;
 281         }
 282
 283         conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
 284
 285         sc->result = (DID_OK << 16) | rhdr->cmd_status;
 286
 287         if (rhdr->response != ISCSI_STATUS_CMD_COMPLETED) {
 288                 sc->result = (DID_ERROR << 16);
 289                 goto out;
 290         }
 291
 292         if (rhdr->cmd_status == SAM_STAT_CHECK_CONDITION && conn->senselen) {
 293                 int sensecopy = min(conn->senselen, SCSI_SENSE_BUFFERSIZE);
 294
 295                 memcpy(sc->sense_buffer, conn->data + 2, sensecopy);
 296                 debug_scsi("copied %d bytes of sense\n", sensecopy);
 297         }
 298
 299         if (sc->sc_data_direction == DMA_TO_DEVICE)
 300                 goto out;
 301
 302         if (rhdr->flags & ISCSI_FLAG_CMD_UNDERFLOW) {
 303                 int res_count = be32_to_cpu(rhdr->residual_count);
 304
 305                 if (res_count > 0 && res_count <= sc->request_bufflen)
 306                         sc->resid = res_count;
 307                 else
 308                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 309         } else if (rhdr->flags & ISCSI_FLAG_CMD_BIDI_UNDERFLOW)
 310                 sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 311         else if (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW)
 312                 sc->resid = be32_to_cpu(rhdr->residual_count);
 313
 314 out:
 315         debug_scsi("done [sc %lx res %d itt 0x%x]\n",
 316                    (long)sc, sc->result, ctask->itt);
 317         conn->scsirsp_pdus_cnt++;
 318         iscsi_ctask_cleanup(conn, ctask);
 319         sc->scsi_done(sc);
 320         return rc;
 321 }
 322
 323 /**
 324  * iscsi_data_rsp - SCSI Data-In Response processing
 325  * @conn: iscsi connection
 326  * @ctask: scsi command task
 327  **/
 328 static int
 329 iscsi_data_rsp(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
 330 {
 331         int rc;
 332         struct iscsi_data_rsp *rhdr = (struct iscsi_data_rsp *)conn->in.hdr;
 333         struct iscsi_session *session = conn->session;
 334         int datasn = be32_to_cpu(rhdr->datasn);
 335
 336         rc = iscsi_check_assign_cmdsn(session, (struct iscsi_nopin*)rhdr);
 337         if (rc)
 338                 return rc;
 339         /*
 340          * setup Data-In byte counter (gets decremented..)
 341          */
 342         ctask->data_count = conn->in.datalen;
 343
 344         if (conn->in.datalen == 0)
 345                 return 0;
 346
 347         if (ctask->datasn != datasn)
 348                 return ISCSI_ERR_DATASN;
 349
 350         ctask->datasn++;
 351
 352         ctask->data_offset = be32_to_cpu(rhdr->offset);
 353         if (ctask->data_offset + conn->in.datalen > ctask->total_length)
 354                 return ISCSI_ERR_DATA_OFFSET;
 355
 356         if (rhdr->flags & ISCSI_FLAG_DATA_STATUS) {
 357                 struct scsi_cmnd *sc = ctask->sc;
 358
 359                 conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
 360                 if (rhdr->flags & ISCSI_FLAG_DATA_UNDERFLOW) {
 361                         int res_count = be32_to_cpu(rhdr->residual_count);
 362
 363                         if (res_count > 0 &&
 364                             res_count <= sc->request_bufflen) {
 365                                 sc->resid = res_count;
 366                                 sc->result = (DID_OK << 16) | rhdr->cmd_status;
 367                         } else
 368                                 sc->result = (DID_BAD_TARGET << 16) |
 369                                         rhdr->cmd_status;
 370                 } else if (rhdr->flags & ISCSI_FLAG_DATA_OVERFLOW) {
 371                         sc->resid = be32_to_cpu(rhdr->residual_count);
 372                         sc->result = (DID_OK << 16) | rhdr->cmd_status;
 373                 } else
 374                         sc->result = (DID_OK << 16) | rhdr->cmd_status;
 375         }
 376
 377         conn->datain_pdus_cnt++;
 378         return 0;
 379 }
 380
 381 /**
 382  * iscsi_solicit_data_init - initialize first Data-Out
 383  * @conn: iscsi connection
 384  * @ctask: scsi command task
 385  * @r2t: R2T info
 386  *
 387  * Notes:
 388  *      Initialize first Data-Out within this R2T sequence and finds
 389  *      proper data_offset within this SCSI command.
 390  *
 391  *      This function is called with connection lock taken.
 392  **/
 393 static void
 394 iscsi_solicit_data_init(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
 395                         struct iscsi_r2t_info *r2t)
 396 {
 397         struct iscsi_data *hdr;
 398         struct iscsi_data_task *dtask;
 399         struct scsi_cmnd *sc = ctask->sc;
 400
 401         dtask = mempool_alloc(ctask->datapool, GFP_ATOMIC);
 402         BUG_ON(!dtask);
 403         hdr = &dtask->hdr;
 404         memset(hdr, 0, sizeof(struct iscsi_data));
 405         hdr->ttt = r2t->ttt;
 406         hdr->datasn = cpu_to_be32(r2t->solicit_datasn);
 407         r2t->solicit_datasn++;
 408         hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
 409         memcpy(hdr->lun, ctask->hdr.lun, sizeof(hdr->lun));
 410         hdr->itt = ctask->hdr.itt;
 411         hdr->exp_statsn = r2t->exp_statsn;
 412         hdr->offset = cpu_to_be32(r2t->data_offset);
 413         if (r2t->data_length > conn->max_xmit_dlength) {
 414                 hton24(hdr->dlength, conn->max_xmit_dlength);
 415                 r2t->data_count = conn->max_xmit_dlength;
 416                 hdr->flags = 0;
 417         } else {
 418                 hton24(hdr->dlength, r2t->data_length);
 419                 r2t->data_count = r2t->data_length;
 420                 hdr->flags = ISCSI_FLAG_CMD_FINAL;
 421         }
 422         conn->dataout_pdus_cnt++;
 423
 424         r2t->sent = 0;
 425
 426         iscsi_buf_init_virt(&r2t->headbuf, (char*)hdr,
 427                            sizeof(struct iscsi_hdr));
 428
 429         r2t->dtask = dtask;
 430
 431         if (sc->use_sg) {
 432                 int i, sg_count = 0;
 433                 struct scatterlist *sg = sc->request_buffer;
 434
 435                 r2t->sg = NULL;
 436                 for (i = 0; i < sc->use_sg; i++, sg += 1) {
 437                         /* FIXME: prefetch ? */
 438                         if (sg_count + sg->length > r2t->data_offset) {
 439                                 int page_offset;
 440
 441                                 /* sg page found! */
 442
 443                                 /* offset within this page */
 444                                 page_offset = r2t->data_offset - sg_count;
 445
 446                                 /* fill in this buffer */
 447                                 iscsi_buf_init_sg(&r2t->sendbuf, sg);
 448                                 r2t->sendbuf.sg.offset += page_offset;
 449                                 r2t->sendbuf.sg.length -= page_offset;
 450
 451                                 /* xmit logic will continue with next one */
 452                                 r2t->sg = sg + 1;
 453                                 break;
 454                         }
 455                         sg_count += sg->length;
 456                 }
 457                 BUG_ON(r2t->sg == NULL);
 458         } else
 459                 iscsi_buf_init_iov(&ctask->sendbuf,
 460                             (char*)sc->request_buffer + r2t->data_offset,
 461                             r2t->data_count);
 462
 463         list_add(&dtask->item, &ctask->dataqueue);
 464 }
 465
 466 /**
 467  * iscsi_r2t_rsp - iSCSI R2T Response processing
 468  * @conn: iscsi connection
 469  * @ctask: scsi command task
 470  **/
 471 static int
 472 iscsi_r2t_rsp(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
 473 {
 474         struct iscsi_r2t_info *r2t;
 475         struct iscsi_session *session = conn->session;
 476         struct iscsi_r2t_rsp *rhdr = (struct iscsi_r2t_rsp *)conn->in.hdr;
 477         int r2tsn = be32_to_cpu(rhdr->r2tsn);
 478         int rc;
 479
 480         if (conn->in.ahslen)
 481                 return ISCSI_ERR_AHSLEN;
 482
 483         if (conn->in.datalen)
 484                 return ISCSI_ERR_DATALEN;
 485
 486         if (ctask->exp_r2tsn && ctask->exp_r2tsn != r2tsn)
 487                 return ISCSI_ERR_R2TSN;
 488
 489         rc = iscsi_check_assign_cmdsn(session, (struct iscsi_nopin*)rhdr);
 490         if (rc)
 491                 return rc;
 492
 493         /* FIXME: use R2TSN to detect missing R2T */
 494
 495         /* fill-in new R2T associated with the task */
 496         spin_lock(&session->lock);
 497         if (!ctask->sc || ctask->mtask ||
 498              session->state != ISCSI_STATE_LOGGED_IN) {
 499                 printk(KERN_INFO "iscsi_tcp: dropping R2T itt %d in "
 500                        "recovery...\n", ctask->itt);
 501                 spin_unlock(&session->lock);
 502                 return 0;
 503         }
 504         rc = __kfifo_get(ctask->r2tpool.queue, (void*)&r2t, sizeof(void*));
 505         BUG_ON(!rc);
 506
 507         r2t->exp_statsn = rhdr->statsn;
 508         r2t->data_length = be32_to_cpu(rhdr->data_length);
 509         if (r2t->data_length == 0 ||
 510             r2t->data_length > session->max_burst) {
 511                 spin_unlock(&session->lock);
 512                 return ISCSI_ERR_DATALEN;
 513         }
 514
 515         r2t->data_offset = be32_to_cpu(rhdr->data_offset);
 516         if (r2t->data_offset + r2t->data_length > ctask->total_length) {
 517                 spin_unlock(&session->lock);
 518                 return ISCSI_ERR_DATALEN;
 519         }
 520
 521         r2t->ttt = rhdr->ttt; /* no flip */
 522         r2t->solicit_datasn = 0;
 523
 524         iscsi_solicit_data_init(conn, ctask, r2t);
 525
 526         ctask->exp_r2tsn = r2tsn + 1;
 527         ctask->xmstate |= XMSTATE_SOL_HDR;
 528         __kfifo_put(ctask->r2tqueue, (void*)&r2t, sizeof(void*));
 529         __kfifo_put(conn->writequeue, (void*)&ctask, sizeof(void*));
 530
 531         schedule_work(&conn->xmitwork);
 532         conn->r2t_pdus_cnt++;
 533         spin_unlock(&session->lock);
 534
 535         return 0;
 536 }
 537
 538 static int
 539 iscsi_hdr_recv(struct iscsi_conn *conn)
 540 {
 541         int rc = 0;
 542         struct iscsi_hdr *hdr;
 543         struct iscsi_cmd_task *ctask;
 544         struct iscsi_session *session = conn->session;
 545         uint32_t cdgst, rdgst = 0;
 546
 547         hdr = conn->in.hdr;
 548
 549         /* verify PDU length */
 550         conn->in.datalen = ntoh24(hdr->dlength);
 551         if (conn->in.datalen > conn->max_recv_dlength) {
 552                 printk(KERN_ERR "iscsi_tcp: datalen %d > %d\n",
 553                        conn->in.datalen, conn->max_recv_dlength);
 554                 return ISCSI_ERR_DATALEN;
 555         }
 556         conn->data_copied = 0;
 557
 558         /* read AHS */
 559         conn->in.ahslen = hdr->hlength * 4;
 560         conn->in.offset += conn->in.ahslen;
 561         conn->in.copy -= conn->in.ahslen;
 562         if (conn->in.copy < 0) {
 563                 printk(KERN_ERR "iscsi_tcp: can't handle AHS with length "
 564                        "%d bytes\n", conn->in.ahslen);
 565                 return ISCSI_ERR_AHSLEN;
 566         }
 567
 568         /* calculate read padding */
 569         conn->in.padding = conn->in.datalen & (ISCSI_PAD_LEN-1);
 570         if (conn->in.padding) {
 571                 conn->in.padding = ISCSI_PAD_LEN - conn->in.padding;
 572                 debug_scsi("read padding %d bytes\n", conn->in.padding);
 573         }
 574
 575         if (conn->hdrdgst_en) {
 576                 struct scatterlist sg;
 577
 578                 sg_init_one(&sg, (u8 *)hdr,
 579                             sizeof(struct iscsi_hdr) + conn->in.ahslen);
 580                 crypto_digest_digest(conn->rx_tfm, &sg, 1, (u8 *)&cdgst);
 581                 rdgst = *(uint32_t*)((char*)hdr + sizeof(struct iscsi_hdr) +
 582                                      conn->in.ahslen);
 583                 if (cdgst != rdgst) {
 584                         printk(KERN_ERR "iscsi_tcp: itt %x: hdrdgst error "
 585                                "recv 0x%x calc 0x%x\n", conn->in.itt, rdgst,
 586                                cdgst);
 587                         return ISCSI_ERR_HDR_DGST;
 588                 }
 589         }
 590
 591         /* save opcode for later */
 592         conn->in.opcode = hdr->opcode & ISCSI_OPCODE_MASK;
 593
 594         /* verify itt (itt encoding: age+cid+itt) */
 595         if (hdr->itt != cpu_to_be32(ISCSI_RESERVED_TAG)) {
 596                 if ((hdr->itt & AGE_MASK) !=
 597                                 (session->age << AGE_SHIFT)) {
 598                         printk(KERN_ERR "iscsi_tcp: received itt %x expected "
 599                                 "session age (%x)\n", hdr->itt,
 600                                 session->age & AGE_MASK);
 601                         return ISCSI_ERR_BAD_ITT;
 602                 }
 603
 604                 if ((hdr->itt & CID_MASK) != (conn->id << CID_SHIFT)) {
 605                         printk(KERN_ERR "iscsi_tcp: received itt %x, expected "
 606                                 "CID (%x)\n", hdr->itt, conn->id);
 607                         return ISCSI_ERR_BAD_ITT;
 608                 }
 609                 conn->in.itt = hdr->itt & ITT_MASK;
 610         } else
 611                 conn->in.itt = hdr->itt;
 612
 613         debug_tcp("opcode 0x%x offset %d copy %d ahslen %d datalen %d\n",
 614                   hdr->opcode, conn->in.offset, conn->in.copy,
 615                   conn->in.ahslen, conn->in.datalen);
 616
 617         if (conn->in.itt < session->cmds_max) {
 618                 ctask = (struct iscsi_cmd_task *)session->cmds[conn->in.itt];
 619
 620                 if (!ctask->sc) {
 621                         printk(KERN_INFO "iscsi_tcp: dropping ctask with "
 622                                "itt 0x%x\n", ctask->itt);
 623                         conn->in.datalen = 0; /* force drop */
 624                         return 0;
 625                 }
 626
 627                 if (ctask->sc->SCp.phase != session->age) {
 628                         printk(KERN_ERR "iscsi_tcp: ctask's session age %d, "
 629                                 "expected %d\n", ctask->sc->SCp.phase,
 630                                 session->age);
 631                         return ISCSI_ERR_SESSION_FAILED;
 632                 }
 633
 634                 conn->in.ctask = ctask;
 635
 636                 debug_scsi("rsp [op 0x%x cid %d sc %lx itt 0x%x len %d]\n",
 637                            hdr->opcode, conn->id, (long)ctask->sc,
 638                            ctask->itt, conn->in.datalen);
 639
 640                 switch(conn->in.opcode) {
 641                 case ISCSI_OP_SCSI_CMD_RSP:
 642                         BUG_ON((void*)ctask != ctask->sc->SCp.ptr);
 643                         if (!conn->in.datalen)
 644                                 rc = iscsi_cmd_rsp(conn, ctask);
 645                         else
 646                                 /*
 647                                  * got sense or response data; copying PDU
 648                                  * Header to the connection's header
 649                                  * placeholder
 650                                  */
 651                                 memcpy(&conn->hdr, hdr,
 652                                        sizeof(struct iscsi_hdr));
 653                         break;
 654                 case ISCSI_OP_SCSI_DATA_IN:
 655                         BUG_ON((void*)ctask != ctask->sc->SCp.ptr);
 656                         /* save flags for non-exceptional status */
 657                         conn->in.flags = hdr->flags;
 658                         /* save cmd_status for sense data */
 659                         conn->in.cmd_status =
 660                                 ((struct iscsi_data_rsp*)hdr)->cmd_status;
 661                         rc = iscsi_data_rsp(conn, ctask);
 662                         break;
 663                 case ISCSI_OP_R2T:
 664                         BUG_ON((void*)ctask != ctask->sc->SCp.ptr);
 665                         if (ctask->sc->sc_data_direction == DMA_TO_DEVICE)
 666                                 rc = iscsi_r2t_rsp(conn, ctask);
 667                         else
 668                                 rc = ISCSI_ERR_PROTO;
 669                         break;
 670                 default:
 671                         rc = ISCSI_ERR_BAD_OPCODE;
 672                         break;
 673                 }
 674         } else if (conn->in.itt >= ISCSI_MGMT_ITT_OFFSET &&
 675                    conn->in.itt < ISCSI_MGMT_ITT_OFFSET +
 676                                         session->mgmtpool_max) {
 677                 struct iscsi_mgmt_task *mtask = (struct iscsi_mgmt_task *)
 678                                         session->mgmt_cmds[conn->in.itt -
 679                                                 ISCSI_MGMT_ITT_OFFSET];
 680
 681                 debug_scsi("immrsp [op 0x%x cid %d itt 0x%x len %d]\n",
 682                            conn->in.opcode, conn->id, mtask->itt,
 683                            conn->in.datalen);
 684
 685                 switch(conn->in.opcode) {
 686                 case ISCSI_OP_LOGIN_RSP:
 687                 case ISCSI_OP_TEXT_RSP:
 688                 case ISCSI_OP_LOGOUT_RSP:
 689                         rc = iscsi_check_assign_cmdsn(session,
 690                                                  (struct iscsi_nopin*)hdr);
 691                         if (rc)
 692                                 break;
 693
 694                         if (!conn->in.datalen) {
 695                                 rc = iscsi_recv_pdu(iscsi_handle(conn), hdr,
 696                                                     NULL, 0);
 697                                 if (conn->login_mtask != mtask) {
 698                                         spin_lock(&session->lock);
 699                                         __kfifo_put(session->mgmtpool.queue,
 700                                             (void*)&mtask, sizeof(void*));
 701                                         spin_unlock(&session->lock);
 702                                 }
 703                         }
 704                         break;
 705                 case ISCSI_OP_SCSI_TMFUNC_RSP:
 706                         rc = iscsi_check_assign_cmdsn(session,
 707                                                  (struct iscsi_nopin*)hdr);
 708                         if (rc)
 709                                 break;
 710
 711                         if (conn->in.datalen || conn->in.ahslen) {
 712                                 rc = ISCSI_ERR_PROTO;
 713                                 break;
 714                         }
 715                         conn->tmfrsp_pdus_cnt++;
 716                         spin_lock(&session->lock);
 717                         if (conn->tmabort_state == TMABORT_INITIAL) {
 718                                 __kfifo_put(session->mgmtpool.queue,
 719                                                 (void*)&mtask, sizeof(void*));
 720                                 conn->tmabort_state =
 721                                         ((struct iscsi_tm_rsp *)hdr)->
 722                                         response == ISCSI_TMF_RSP_COMPLETE ?
 723                                                 TMABORT_SUCCESS:TMABORT_FAILED;
 724                                 /* unblock eh_abort() */
 725                                 wake_up(&conn->ehwait);
 726                         }
 727                         spin_unlock(&session->lock);
 728                         break;
 729                 case ISCSI_OP_NOOP_IN:
 730                         if (hdr->ttt != ISCSI_RESERVED_TAG) {
 731                                 rc = ISCSI_ERR_PROTO;
 732                                 break;
 733                         }
 734                         rc = iscsi_check_assign_cmdsn(session,
 735                                                 (struct iscsi_nopin*)hdr);
 736                         if (rc)
 737                                 break;
 738                         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
 739
 740                         if (!conn->in.datalen) {
 741                                 struct iscsi_mgmt_task *mtask;
 742
 743                                 rc = iscsi_recv_pdu(iscsi_handle(conn), hdr,
 744                                                     NULL, 0);
 745                                 mtask = (struct iscsi_mgmt_task *)
 746                                         session->mgmt_cmds[conn->in.itt -
 747                                                         ISCSI_MGMT_ITT_OFFSET];
 748                                 if (conn->login_mtask != mtask) {
 749                                         spin_lock(&session->lock);
 750                                         __kfifo_put(session->mgmtpool.queue,
 751                                                   (void*)&mtask, sizeof(void*));
 752                                         spin_unlock(&session->lock);
 753                                 }
 754                         }
 755                         break;
 756                 default:
 757                         rc = ISCSI_ERR_BAD_OPCODE;
 758                         break;
 759                 }
 760         } else if (conn->in.itt == ISCSI_RESERVED_TAG) {
 761                 switch(conn->in.opcode) {
 762                 case ISCSI_OP_NOOP_IN:
 763                         if (!conn->in.datalen) {
 764                                 rc = iscsi_check_assign_cmdsn(session,
 765                                                  (struct iscsi_nopin*)hdr);
 766                                 if (!rc && hdr->ttt != ISCSI_RESERVED_TAG)
 767                                         rc = iscsi_recv_pdu(iscsi_handle(conn),
 768                                                             hdr, NULL, 0);
 769                         } else
 770                                 rc = ISCSI_ERR_PROTO;
 771                         break;
 772                 case ISCSI_OP_REJECT:
 773                         /* we need sth like iscsi_reject_rsp()*/
 774                 case ISCSI_OP_ASYNC_EVENT:
 775                         /* we need sth like iscsi_async_event_rsp() */
 776                         rc = ISCSI_ERR_BAD_OPCODE;
 777                         break;
 778                 default:
 779                         rc = ISCSI_ERR_BAD_OPCODE;
 780                         break;
 781                 }
 782         } else
 783                 rc = ISCSI_ERR_BAD_ITT;
 784
 785         return rc;
 786 }
 787
 788 /**
 789  * iscsi_ctask_copy - copy skb bits to the destanation cmd task
 790  * @conn: iscsi connection
 791  * @ctask: scsi command task
 792  * @buf: buffer to copy to
 793  * @buf_size: size of buffer
 794  * @offset: offset within the buffer
 795  *
 796  * Notes:
 797  *      The function calls skb_copy_bits() and updates per-connection and
 798  *      per-cmd byte counters.
 799  *
 800  *      Read counters (in bytes):
 801  *
 802  *      conn->in.offset         offset within in progress SKB
 803  *      conn->in.copy           left to copy from in progress SKB
 804  *                              including padding
 805  *      conn->in.copied         copied already from in progress SKB
 806  *      conn->data_copied       copied already from in progress buffer
 807  *      ctask->sent             total bytes sent up to the MidLayer
 808  *      ctask->data_count       left to copy from in progress Data-In
 809  *      buf_left                left to copy from in progress buffer
 810  **/
 811 static inline int
 812 iscsi_ctask_copy(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
 813                 void *buf, int buf_size, int offset)
 814 {
 815         int buf_left = buf_size - (conn->data_copied + offset);
 816         int size = min(conn->in.copy, buf_left);
 817         int rc;
 818
 819         size = min(size, ctask->data_count);
 820
 821         debug_tcp("ctask_copy %d bytes at offset %d copied %d\n",
 822                size, conn->in.offset, conn->in.copied);
 823
 824         BUG_ON(size <= 0);
 825         BUG_ON(ctask->sent + size > ctask->total_length);
 826
 827         rc = skb_copy_bits(conn->in.skb, conn->in.offset,
 828                            (char*)buf + (offset + conn->data_copied), size);
 829         /* must fit into skb->len */
 830         BUG_ON(rc);
 831
 832         conn->in.offset += size;
 833         conn->in.copy -= size;
 834         conn->in.copied += size;
 835         conn->data_copied += size;
 836         ctask->sent += size;
 837         ctask->data_count -= size;
 838
 839         BUG_ON(conn->in.copy < 0);
 840         BUG_ON(ctask->data_count < 0);
 841
 842         if (buf_size != (conn->data_copied + offset)) {
 843                 if (!ctask->data_count) {
 844                         BUG_ON(buf_size - conn->data_copied < 0);
 845                         /* done with this PDU */
 846                         return buf_size - conn->data_copied;
 847                 }
 848                 return -EAGAIN;
 849         }
 850
 851         /* done with this buffer or with both - PDU and buffer */
 852         conn->data_copied = 0;
 853         return 0;
 854 }
 855
 856 /**
 857  * iscsi_tcp_copy - copy skb bits to the destanation buffer
 858  * @conn: iscsi connection
 859  * @buf: buffer to copy to
 860  * @buf_size: number of bytes to copy
 861  *
 862  * Notes:
 863  *      The function calls skb_copy_bits() and updates per-connection
 864  *      byte counters.
 865  **/
 866 static inline int
 867 iscsi_tcp_copy(struct iscsi_conn *conn, void *buf, int buf_size)
 868 {
 869         int buf_left = buf_size - conn->data_copied;
 870         int size = min(conn->in.copy, buf_left);
 871         int rc;
 872
 873         debug_tcp("tcp_copy %d bytes at offset %d copied %d\n",
 874                size, conn->in.offset, conn->data_copied);
 875         BUG_ON(size <= 0);
 876
 877         rc = skb_copy_bits(conn->in.skb, conn->in.offset,
 878                            (char*)buf + conn->data_copied, size);
 879         BUG_ON(rc);
 880
 881         conn->in.offset += size;
 882         conn->in.copy -= size;
 883         conn->in.copied += size;
 884         conn->data_copied += size;
 885
 886         if (buf_size != conn->data_copied)
 887                 return -EAGAIN;
 888
 889         return 0;
 890 }
 891
 892 static inline void
 893 partial_sg_digest_update(struct iscsi_conn *conn, struct scatterlist *sg,
 894                          int offset, int length)
 895 {
 896         struct scatterlist temp;
 897
 898         memcpy(&temp, sg, sizeof(struct scatterlist));
 899         temp.offset = offset;
 900         temp.length = length;
 901         crypto_digest_update(conn->data_rx_tfm, &temp, 1);
 902 }
 903
 904 static void
 905 iscsi_recv_digest_update(struct iscsi_conn *conn, char* buf, int len)
 906 {
 907         struct scatterlist tmp;
 908
 909         sg_init_one(&tmp, buf, len);
 910         crypto_digest_update(conn->data_rx_tfm, &tmp, 1);
 911 }
 912
 913 static int iscsi_scsi_data_in(struct iscsi_conn *conn)
 914 {
 915         struct iscsi_cmd_task *ctask = conn->in.ctask;
 916         struct scsi_cmnd *sc = ctask->sc;
 917         struct scatterlist *sg;
 918         int i, offset, rc = 0;
 919
 920         BUG_ON((void*)ctask != sc->SCp.ptr);
 921
 922         /*
 923          * copying Data-In into the Scsi_Cmnd
 924          */
 925         if (!sc->use_sg) {
 926                 i = ctask->data_count;
 927                 rc = iscsi_ctask_copy(conn, ctask, sc->request_buffer,
 928                                       sc->request_bufflen, ctask->data_offset);
 929                 if (rc == -EAGAIN)
 930                         return rc;
 931                 if (conn->datadgst_en)
 932                         iscsi_recv_digest_update(conn, sc->request_buffer, i);
 933                 rc = 0;
 934                 goto done;
 935         }
 936
 937         offset = ctask->data_offset;
 938         sg = sc->request_buffer;
 939
 940         if (ctask->data_offset)
 941                 for (i = 0; i < ctask->sg_count; i++)
 942                         offset -= sg[i].length;
 943         /* we've passed through partial sg*/
 944         if (offset < 0)
 945                 offset = 0;
 946
 947         for (i = ctask->sg_count; i < sc->use_sg; i++) {
 948                 char *dest;
 949
 950                 dest = kmap_atomic(sg[i].page, KM_SOFTIRQ0);
 951                 rc = iscsi_ctask_copy(conn, ctask, dest + sg[i].offset,
 952                                       sg[i].length, offset);
 953                 kunmap_atomic(dest, KM_SOFTIRQ0);
 954                 if (rc == -EAGAIN)
 955                         /* continue with the next SKB/PDU */
 956                         return rc;
 957                 if (!rc) {
 958                         if (conn->datadgst_en) {
 959                                 if (!offset)
 960                                         crypto_digest_update(conn->data_rx_tfm,
 961                                                              &sg[i], 1);
 962                                 else
 963                                         partial_sg_digest_update(conn, &sg[i],
 964                                                         sg[i].offset + offset,
 965                                                         sg[i].length - offset);
 966                         }
 967                         offset = 0;
 968                         ctask->sg_count++;
 969                 }
 970
 971                 if (!ctask->data_count) {
 972                         if (rc && conn->datadgst_en)
 973                                 /*
 974                                  * data-in is complete, but buffer not...
 975                                  */
 976                                 partial_sg_digest_update(conn, &sg[i],
 977                                                 sg[i].offset, sg[i].length-rc);
 978                         rc = 0;
 979                         break;
 980                 }
 981
 982                 if (!conn->in.copy)
 983                         return -EAGAIN;
 984         }
 985         BUG_ON(ctask->data_count);
 986
 987 done:
 988         /* check for non-exceptional status */
 989         if (conn->in.flags & ISCSI_FLAG_DATA_STATUS) {
 990                 debug_scsi("done [sc %lx res %d itt 0x%x]\n",
 991                            (long)sc, sc->result, ctask->itt);
 992                 conn->scsirsp_pdus_cnt++;
 993                 iscsi_ctask_cleanup(conn, ctask);
 994                 sc->scsi_done(sc);
 995         }
 996
 997         return rc;
 998 }
 999
1000 static int
1001 iscsi_data_recv(struct iscsi_conn *conn)
1002 {
1003         struct iscsi_session *session = conn->session;
1004         int rc = 0;
1005
1006         switch(conn->in.opcode) {
1007         case ISCSI_OP_SCSI_DATA_IN:
1008                 rc = iscsi_scsi_data_in(conn);
1009                 break;
1010         case ISCSI_OP_SCSI_CMD_RSP: {
1011                 /*
1012                  * SCSI Sense Data:
1013                  * copying the entire Data Segment.
1014                  */
1015                 if (iscsi_tcp_copy(conn, conn->data, conn->in.datalen)) {
1016                         rc = -EAGAIN;
1017                         goto exit;
1018                 }
1019
1020                 /*
1021                  * check for sense
1022                  */
1023                 conn->in.hdr = &conn->hdr;
1024                 conn->senselen = (conn->data[0] << 8) | conn->data[1];
1025                 rc = iscsi_cmd_rsp(conn, conn->in.ctask);
1026                 if (!rc && conn->datadgst_en)
1027                         iscsi_recv_digest_update(conn, conn->data,
1028                                                  conn->in.datalen);
1029         }
1030         break;
1031         case ISCSI_OP_TEXT_RSP:
1032         case ISCSI_OP_LOGIN_RSP:
1033         case ISCSI_OP_NOOP_IN: {
1034                 struct iscsi_mgmt_task *mtask = NULL;
1035
1036                 if (conn->in.itt != ISCSI_RESERVED_TAG)
1037                         mtask = (struct iscsi_mgmt_task *)
1038                                 session->mgmt_cmds[conn->in.itt -
1039                                         ISCSI_MGMT_ITT_OFFSET];
1040
1041                 /*
1042                  * Collect data segment to the connection's data
1043                  * placeholder
1044                  */
1045                 if (iscsi_tcp_copy(conn, conn->data, conn->in.datalen)) {
1046                         rc = -EAGAIN;
1047                         goto exit;
1048                 }
1049
1050                 rc = iscsi_recv_pdu(iscsi_handle(conn), conn->in.hdr,
1051                                     conn->data, conn->in.datalen);
1052
1053                 if (!rc && conn->datadgst_en &&
1054                         conn->in.opcode != ISCSI_OP_LOGIN_RSP)
1055                         iscsi_recv_digest_update(conn, conn->data,
1056                                                 conn->in.datalen);
1057
1058                 if (mtask && conn->login_mtask != mtask) {
1059                         spin_lock(&session->lock);
1060                         __kfifo_put(session->mgmtpool.queue, (void*)&mtask,
1061                                     sizeof(void*));
1062                         spin_unlock(&session->lock);
1063                 }
1064         }
1065         break;
1066         case ISCSI_OP_ASYNC_EVENT:
1067         case ISCSI_OP_REJECT:
1068         default:
1069                 BUG_ON(1);
1070         }
1071 exit:
1072         return rc;
1073 }
1074
1075 /**
1076  * iscsi_tcp_data_recv - TCP receive in sendfile fashion
1077  * @rd_desc: read descriptor
1078  * @skb: socket buffer
1079  * @offset: offset in skb
1080  * @len: skb->len - offset
1081  **/
1082 static int
1083 iscsi_tcp_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb,
1084                 unsigned int offset, size_t len)
1085 {
1086         int rc;
1087         struct iscsi_conn *conn = rd_desc->arg.data;
1088         int processed;
1089         char pad[ISCSI_PAD_LEN];
1090         struct scatterlist sg;
1091
1092         /*
1093          * Save current SKB and its offset in the corresponding
1094          * connection context.
1095          */
1096         conn->in.copy = skb->len - offset;
1097         conn->in.offset = offset;
1098         conn->in.skb = skb;
1099         conn->in.len = conn->in.copy;
1100         BUG_ON(conn->in.copy <= 0);
1101         debug_tcp("in %d bytes\n", conn->in.copy);
1102
1103 more:
1104         conn->in.copied = 0;
1105         rc = 0;
1106
1107         if (unlikely(conn->suspend_rx)) {
1108                 debug_tcp("conn %d Rx suspended!\n", conn->id);
1109                 return 0;
1110         }
1111
1112         if (conn->in_progress == IN_PROGRESS_WAIT_HEADER ||
1113             conn->in_progress == IN_PROGRESS_HEADER_GATHER) {
1114                 rc = iscsi_hdr_extract(conn);
1115                 if (rc) {
1116                        if (rc == -EAGAIN)
1117                                 goto nomore;
1118                        else {
1119                                 iscsi_conn_failure(conn, rc);
1120                                 return 0;
1121                        }
1122                 }
1123
1124                 /*
1125                  * Verify and process incoming PDU header.
1126                  */
1127                 rc = iscsi_hdr_recv(conn);
1128                 if (!rc && conn->in.datalen) {
1129                         if (conn->datadgst_en) {
1130                                 BUG_ON(!conn->data_rx_tfm);
1131                                 crypto_digest_init(conn->data_rx_tfm);
1132                         }
1133                         conn->in_progress = IN_PROGRESS_DATA_RECV;
1134                 } else if (rc) {
1135                         iscsi_conn_failure(conn, rc);
1136                         return 0;
1137                 }
1138         }
1139
1140         if (conn->in_progress == IN_PROGRESS_DDIGEST_RECV) {
1141                 uint32_t recv_digest;
1142                 debug_tcp("extra data_recv offset %d copy %d\n",
1143                           conn->in.offset, conn->in.copy);
1144                 skb_copy_bits(conn->in.skb, conn->in.offset,
1145                                 &recv_digest, 4);
1146                 conn->in.offset += 4;
1147                 conn->in.copy -= 4;
1148                 if (recv_digest != conn->in.datadgst) {
1149                         debug_tcp("iscsi_tcp: data digest error!"
1150                                   "0x%x != 0x%x\n", recv_digest,
1151                                   conn->in.datadgst);
1152                         iscsi_conn_failure(conn, ISCSI_ERR_DATA_DGST);
1153                         return 0;
1154                 } else {
1155                         debug_tcp("iscsi_tcp: data digest match!"
1156                                   "0x%x == 0x%x\n", recv_digest,
1157                                   conn->in.datadgst);
1158                         conn->in_progress = IN_PROGRESS_WAIT_HEADER;
1159                 }
1160         }
1161
1162         if (conn->in_progress == IN_PROGRESS_DATA_RECV && conn->in.copy) {
1163
1164                 debug_tcp("data_recv offset %d copy %d\n",
1165                        conn->in.offset, conn->in.copy);
1166
1167                 rc = iscsi_data_recv(conn);
1168                 if (rc) {
1169                         if (rc == -EAGAIN) {
1170                                 rd_desc->count = conn->in.datalen -
1171                                                 conn->in.ctask->data_count;
1172                                 goto again;
1173                         }
1174                         iscsi_conn_failure(conn, rc);
1175                         return 0;
1176                 }
1177                 conn->in.copy -= conn->in.padding;
1178                 conn->in.offset += conn->in.padding;
1179                 if (conn->datadgst_en) {
1180                         if (conn->in.padding) {
1181                                 debug_tcp("padding -> %d\n", conn->in.padding);
1182                                 memset(pad, 0, conn->in.padding);
1183                                 sg_init_one(&sg, pad, conn->in.padding);
1184                                 crypto_digest_update(conn->data_rx_tfm, &sg, 1);
1185                         }
1186                         crypto_digest_final(conn->data_rx_tfm,
1187                                             (u8 *) & conn->in.datadgst);
1188                         debug_tcp("rx digest 0x%x\n", conn->in.datadgst);
1189                         conn->in_progress = IN_PROGRESS_DDIGEST_RECV;
1190                 } else
1191                         conn->in_progress = IN_PROGRESS_WAIT_HEADER;
1192         }
1193
1194         debug_tcp("f, processed %d from out of %d padding %d\n",
1195                conn->in.offset - offset, (int)len, conn->in.padding);
1196         BUG_ON(conn->in.offset - offset > len);
1197
1198         if (conn->in.offset - offset != len) {
1199                 debug_tcp("continue to process %d bytes\n",
1200                        (int)len - (conn->in.offset - offset));
1201                 goto more;
1202         }
1203
1204 nomore:
1205         processed = conn->in.offset - offset;
1206         BUG_ON(processed == 0);
1207         return processed;
1208
1209 again:
1210         processed = conn->in.offset - offset;
1211         debug_tcp("c, processed %d from out of %d rd_desc_cnt %d\n",
1212                   processed, (int)len, (int)rd_desc->count);
1213         BUG_ON(processed == 0);
1214         BUG_ON(processed > len);
1215
1216         conn->rxdata_octets += processed;
1217         return processed;
1218 }
1219
1220 static void
1221 iscsi_tcp_data_ready(struct sock *sk, int flag)
1222 {
1223         struct iscsi_conn *conn = sk->sk_user_data;
1224         read_descriptor_t rd_desc;
1225
1226         read_lock(&sk->sk_callback_lock);
1227
1228         /* use rd_desc to pass 'conn' to iscsi_tcp_data_recv */
1229         rd_desc.arg.data = conn;
1230         rd_desc.count = 0;
1231         tcp_read_sock(sk, &rd_desc, iscsi_tcp_data_recv);
1232
1233         read_unlock(&sk->sk_callback_lock);
1234 }
1235
1236 static void
1237 iscsi_tcp_state_change(struct sock *sk)
1238 {
1239         struct iscsi_conn *conn;
1240         struct iscsi_session *session;
1241         void (*old_state_change)(struct sock *);
1242
1243         read_lock(&sk->sk_callback_lock);
1244
1245         conn = (struct iscsi_conn*)sk->sk_user_data;
1246         session = conn->session;
1247
1248         if ((sk->sk_state == TCP_CLOSE_WAIT ||
1249              sk->sk_state == TCP_CLOSE) &&
1250             !atomic_read(&sk->sk_rmem_alloc)) {
1251                 debug_tcp("iscsi_tcp_state_change: TCP_CLOSE|TCP_CLOSE_WAIT\n");
1252                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1253         }
1254
1255         old_state_change = conn->old_state_change;
1256
1257         read_unlock(&sk->sk_callback_lock);
1258
1259         old_state_change(sk);
1260 }
1261
1262 /**
1263  * iscsi_write_space - Called when more output buffer space is available
1264  * @sk: socket space is available for
1265  **/
1266 static void
1267 iscsi_write_space(struct sock *sk)
1268 {
1269         struct iscsi_conn *conn = (struct iscsi_conn*)sk->sk_user_data;
1270         conn->old_write_space(sk);
1271         debug_tcp("iscsi_write_space: cid %d\n", conn->id);
1272         clear_bit(SUSPEND_BIT, &conn->suspend_tx);
1273         schedule_work(&conn->xmitwork);
1274 }
1275
1276 static void
1277 iscsi_conn_set_callbacks(struct iscsi_conn *conn)
1278 {
1279         struct sock *sk = conn->sock->sk;
1280
1281         /* assign new callbacks */
1282         write_lock_bh(&sk->sk_callback_lock);
1283         sk->sk_user_data = conn;
1284         conn->old_data_ready = sk->sk_data_ready;
1285         conn->old_state_change = sk->sk_state_change;
1286         conn->old_write_space = sk->sk_write_space;
1287         sk->sk_data_ready = iscsi_tcp_data_ready;
1288         sk->sk_state_change = iscsi_tcp_state_change;
1289         sk->sk_write_space = iscsi_write_space;
1290         write_unlock_bh(&sk->sk_callback_lock);
1291 }
1292
1293 static void
1294 iscsi_conn_restore_callbacks(struct iscsi_conn *conn)
1295 {
1296         struct sock *sk = conn->sock->sk;
1297
1298         /* restore socket callbacks, see also: iscsi_conn_set_callbacks() */
1299         write_lock_bh(&sk->sk_callback_lock);
1300         sk->sk_user_data    = NULL;
1301         sk->sk_data_ready   = conn->old_data_ready;
1302         sk->sk_state_change = conn->old_state_change;
1303         sk->sk_write_space  = conn->old_write_space;
1304         sk->sk_no_check  = 0;
1305         write_unlock_bh(&sk->sk_callback_lock);
1306 }
1307
1308 /**
1309  * iscsi_send - generic send routine
1310  * @sk: kernel's socket
1311  * @buf: buffer to write from
1312  * @size: actual size to write
1313  * @flags: socket's flags
1314  *
1315  * Notes:
1316  *      depending on buffer will use tcp_sendpage() or tcp_sendmsg().
1317  *      buf->sg.offset == -1 tells us that buffer is non S/G and forces
1318  *      to use tcp_sendmsg().
1319  */
1320 static inline int
1321 iscsi_send(struct socket *sk, struct iscsi_buf *buf, int size, int flags)
1322 {
1323         int res;
1324
1325         if ((int)buf->sg.offset >= 0) {
1326                 int offset = buf->sg.offset + buf->sent;
1327
1328                 /* tcp_sendpage */
1329                 res = sk->ops->sendpage(sk, buf->sg.page, offset, size, flags);
1330         } else {
1331                 struct msghdr msg;
1332
1333                 buf->iov.iov_base = iscsi_buf_iov_base(buf);
1334                 buf->iov.iov_len = size;
1335
1336                 memset(&msg, 0, sizeof(struct msghdr));
1337
1338                 /* tcp_sendmsg */
1339                 res = kernel_sendmsg(sk, &msg, &buf->iov, 1, size);
1340         }
1341
1342         return res;
1343 }
1344
1345 /**
1346  * iscsi_sendhdr - send PDU Header via tcp_sendpage()
1347  * @conn: iscsi connection
1348  * @buf: buffer to write from
1349  * @datalen: lenght of data to be sent after the header
1350  *
1351  * Notes:
1352  *      (Tx, Fast Path)
1353  **/
1354 static inline int
1355 iscsi_sendhdr(struct iscsi_conn *conn, struct iscsi_buf *buf, int datalen)
1356 {
1357         struct socket *sk = conn->sock;
1358         int flags = 0; /* MSG_DONTWAIT; */
1359         int res, size;
1360
1361         size = buf->sg.length - buf->sent;
1362         BUG_ON(buf->sent + size > buf->sg.length);
1363         if (buf->sent + size != buf->sg.length || datalen)
1364                 flags |= MSG_MORE;
1365
1366         res = iscsi_send(sk, buf, size, flags);
1367         debug_tcp("sendhdr %d bytes, sent %d res %d\n", size, buf->sent, res);
1368         if (res >= 0) {
1369                 conn->txdata_octets += res;
1370                 buf->sent += res;
1371                 if (size != res)
1372                         return -EAGAIN;
1373                 return 0;
1374         } else if (res == -EAGAIN) {
1375                 conn->sendpage_failures_cnt++;
1376                 set_bit(SUSPEND_BIT, &conn->suspend_tx);
1377         } else if (res == -EPIPE)
1378                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1379
1380         return res;
1381 }
1382
1383 /**
1384  * iscsi_sendpage - send one page of iSCSI Data-Out.
1385  * @conn: iscsi connection
1386  * @buf: buffer to write from
1387  * @count: remaining data
1388  * @sent: number of bytes sent
1389  *
1390  * Notes:
1391  *      (Tx, Fast Path)
1392  **/
1393 static inline int
1394 iscsi_sendpage(struct iscsi_conn *conn, struct iscsi_buf *buf,
1395                int *count, int *sent)
1396 {
1397         struct socket *sk = conn->sock;
1398         int flags = 0; /* MSG_DONTWAIT; */
1399         int res, size;
1400
1401         size = buf->sg.length - buf->sent;
1402         BUG_ON(buf->sent + size > buf->sg.length);
1403         if (size > *count)
1404                 size = *count;
1405         if (buf->sent + size != buf->sg.length || *count != size)
1406                 flags |= MSG_MORE;
1407
1408         res = iscsi_send(sk, buf, size, flags);
1409         debug_tcp("sendpage: %d bytes, sent %d left %d sent %d res %d\n",
1410                   size, buf->sent, *count, *sent, res);
1411         if (res >= 0) {
1412                 conn->txdata_octets += res;
1413                 buf->sent += res;
1414                 *count -= res;
1415                 *sent += res;
1416                 if (size != res)
1417                         return -EAGAIN;
1418                 return 0;
1419         } else if (res == -EAGAIN) {
1420                 conn->sendpage_failures_cnt++;
1421                 set_bit(SUSPEND_BIT, &conn->suspend_tx);
1422         } else if (res == -EPIPE)
1423                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1424
1425         return res;
1426 }
1427
1428 static inline void
1429 iscsi_data_digest_init(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1430 {
1431         BUG_ON(!conn->data_tx_tfm);
1432         crypto_digest_init(conn->data_tx_tfm);
1433         ctask->digest_count = 4;
1434 }
1435
1436 static inline void
1437 iscsi_buf_data_digest_update(struct iscsi_conn *conn, struct iscsi_buf *buf)
1438 {
1439         struct scatterlist sg;
1440
1441         if (buf->sg.offset != -1)
1442                 crypto_digest_update(conn->data_tx_tfm, &buf->sg, 1);
1443         else {
1444                 sg_init_one(&sg, (char *)buf->sg.page, buf->sg.length);
1445                 crypto_digest_update(conn->data_tx_tfm, &sg, 1);
1446         }
1447 }
1448
1449 static inline int
1450 iscsi_digest_final_send(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
1451                         struct iscsi_buf *buf, uint32_t *digest, int final)
1452 {
1453         int rc = 0;
1454         int sent = 0;
1455
1456         if (final)
1457                 crypto_digest_final(conn->data_tx_tfm, (u8*)digest);
1458
1459         iscsi_buf_init_virt(buf, (char*)digest, 4);
1460         rc = iscsi_sendpage(conn, buf, &ctask->digest_count, &sent);
1461         if (rc) {
1462                 ctask->datadigest = *digest;
1463                 ctask->xmstate |= XMSTATE_DATA_DIGEST;
1464         } else
1465                 ctask->digest_count = 4;
1466         return rc;
1467 }
1468
1469 /**
1470  * iscsi_solicit_data_cont - initialize next Data-Out
1471  * @conn: iscsi connection
1472  * @ctask: scsi command task
1473  * @r2t: R2T info
1474  * @left: bytes left to transfer
1475  *
1476  * Notes:
1477  *      Initialize next Data-Out within this R2T sequence and continue
1478  *      to process next Scatter-Gather element(if any) of this SCSI command.
1479  *
1480  *      Called under connection lock.
1481  **/
1482 static void
1483 iscsi_solicit_data_cont(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
1484                         struct iscsi_r2t_info *r2t, int left)
1485 {
1486         struct iscsi_data *hdr;
1487         struct iscsi_data_task *dtask;
1488         struct scsi_cmnd *sc = ctask->sc;
1489         int new_offset;
1490
1491         dtask = mempool_alloc(ctask->datapool, GFP_ATOMIC);
1492         BUG_ON(!dtask);
1493         hdr = &dtask->hdr;
1494         memset(hdr, 0, sizeof(struct iscsi_data));
1495         hdr->ttt = r2t->ttt;
1496         hdr->datasn = cpu_to_be32(r2t->solicit_datasn);
1497         r2t->solicit_datasn++;
1498         hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
1499         memcpy(hdr->lun, ctask->hdr.lun, sizeof(hdr->lun));
1500         hdr->itt = ctask->hdr.itt;
1501         hdr->exp_statsn = r2t->exp_statsn;
1502         new_offset = r2t->data_offset + r2t->sent;
1503         hdr->offset = cpu_to_be32(new_offset);
1504         if (left > conn->max_xmit_dlength) {
1505                 hton24(hdr->dlength, conn->max_xmit_dlength);
1506                 r2t->data_count = conn->max_xmit_dlength;
1507         } else {
1508                 hton24(hdr->dlength, left);
1509                 r2t->data_count = left;
1510                 hdr->flags = ISCSI_FLAG_CMD_FINAL;
1511         }
1512         conn->dataout_pdus_cnt++;
1513
1514         iscsi_buf_init_virt(&r2t->headbuf, (char*)hdr,
1515                            sizeof(struct iscsi_hdr));
1516
1517         r2t->dtask = dtask;
1518
1519         if (sc->use_sg && !iscsi_buf_left(&r2t->sendbuf)) {
1520                 BUG_ON(ctask->bad_sg == r2t->sg);
1521                 iscsi_buf_init_sg(&r2t->sendbuf, r2t->sg);
1522                 r2t->sg += 1;
1523         } else
1524                 iscsi_buf_init_iov(&ctask->sendbuf,
1525                             (char*)sc->request_buffer + new_offset,
1526                             r2t->data_count);
1527
1528         list_add(&dtask->item, &ctask->dataqueue);
1529 }
1530
1531 static void
1532 iscsi_unsolicit_data_init(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1533 {
1534         struct iscsi_data *hdr;
1535         struct iscsi_data_task *dtask;
1536
1537         dtask = mempool_alloc(ctask->datapool, GFP_ATOMIC);
1538         BUG_ON(!dtask);
1539         hdr = &dtask->hdr;
1540         memset(hdr, 0, sizeof(struct iscsi_data));
1541         hdr->ttt = cpu_to_be32(ISCSI_RESERVED_TAG);
1542         hdr->datasn = cpu_to_be32(ctask->unsol_datasn);
1543         ctask->unsol_datasn++;
1544         hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
1545         memcpy(hdr->lun, ctask->hdr.lun, sizeof(hdr->lun));
1546         hdr->itt = ctask->hdr.itt;
1547         hdr->exp_statsn = cpu_to_be32(conn->exp_statsn);
1548         hdr->offset = cpu_to_be32(ctask->total_length -
1549                                   ctask->r2t_data_count -
1550                                   ctask->unsol_count);
1551         if (ctask->unsol_count > conn->max_xmit_dlength) {
1552                 hton24(hdr->dlength, conn->max_xmit_dlength);
1553                 ctask->data_count = conn->max_xmit_dlength;
1554                 hdr->flags = 0;
1555         } else {
1556                 hton24(hdr->dlength, ctask->unsol_count);
1557                 ctask->data_count = ctask->unsol_count;
1558                 hdr->flags = ISCSI_FLAG_CMD_FINAL;
1559         }
1560
1561         iscsi_buf_init_virt(&ctask->headbuf, (char*)hdr,
1562                            sizeof(struct iscsi_hdr));
1563
1564         list_add(&dtask->item, &ctask->dataqueue);
1565
1566         ctask->dtask = dtask;
1567 }
1568
1569 /**
1570  * iscsi_cmd_init - Initialize iSCSI SCSI_READ or SCSI_WRITE commands
1571  * @conn: iscsi connection
1572  * @ctask: scsi command task
1573  * @sc: scsi command
1574  **/
1575 static void
1576 iscsi_cmd_init(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
1577                 struct scsi_cmnd *sc)
1578 {
1579         struct iscsi_session *session = conn->session;
1580
1581         BUG_ON(__kfifo_len(ctask->r2tqueue));
1582
1583         ctask->sc = sc;
1584         ctask->conn = conn;
1585         ctask->hdr.opcode = ISCSI_OP_SCSI_CMD;
1586         ctask->hdr.flags = ISCSI_ATTR_SIMPLE;
1587         int_to_scsilun(sc->device->lun, (struct scsi_lun *)ctask->hdr.lun);
1588         ctask->hdr.itt = ctask->itt | (conn->id << CID_SHIFT) |
1589                          (session->age << AGE_SHIFT);
1590         ctask->hdr.data_length = cpu_to_be32(sc->request_bufflen);
1591         ctask->hdr.cmdsn = cpu_to_be32(session->cmdsn); session->cmdsn++;
1592         ctask->hdr.exp_statsn = cpu_to_be32(conn->exp_statsn);
1593         memcpy(ctask->hdr.cdb, sc->cmnd, sc->cmd_len);
1594         memset(&ctask->hdr.cdb[sc->cmd_len], 0, MAX_COMMAND_SIZE - sc->cmd_len);
1595
1596         ctask->mtask = NULL;
1597         ctask->sent = 0;
1598         ctask->sg_count = 0;
1599
1600         ctask->total_length = sc->request_bufflen;
1601
1602         if (sc->sc_data_direction == DMA_TO_DEVICE) {
1603                 ctask->exp_r2tsn = 0;
1604                 ctask->hdr.flags |= ISCSI_FLAG_CMD_WRITE;
1605                 BUG_ON(ctask->total_length == 0);
1606                 if (sc->use_sg) {
1607                         struct scatterlist *sg = sc->request_buffer;
1608
1609                         iscsi_buf_init_sg(&ctask->sendbuf,
1610                                           &sg[ctask->sg_count++]);
1611                         ctask->sg = sg;
1612                         ctask->bad_sg = sg + sc->use_sg;
1613                 } else {
1614                         iscsi_buf_init_iov(&ctask->sendbuf, sc->request_buffer,
1615                                         sc->request_bufflen);
1616                 }
1617
1618                 /*
1619                  * Write counters:
1620                  *
1621                  *      imm_count       bytes to be sent right after
1622                  *                      SCSI PDU Header
1623                  *
1624                  *      unsol_count     bytes(as Data-Out) to be sent
1625                  *                      without R2T ack right after
1626                  *                      immediate data
1627                  *
1628                  *      r2t_data_count  bytes to be sent via R2T ack's
1629                  *
1630                  *      pad_count       bytes to be sent as zero-padding
1631                  */
1632                 ctask->imm_count = 0;
1633                 ctask->unsol_count = 0;
1634                 ctask->unsol_datasn = 0;
1635                 ctask->xmstate = XMSTATE_W_HDR;
1636                 /* calculate write padding */
1637                 ctask->pad_count = ctask->total_length & (ISCSI_PAD_LEN-1);
1638                 if (ctask->pad_count) {
1639                         ctask->pad_count = ISCSI_PAD_LEN - ctask->pad_count;
1640                         debug_scsi("write padding %d bytes\n",
1641                                 ctask->pad_count);
1642                         ctask->xmstate |= XMSTATE_W_PAD;
1643                 }
1644                 if (session->imm_data_en) {
1645                         if (ctask->total_length >= session->first_burst)
1646                                 ctask->imm_count = min(session->first_burst,
1647                                                         conn->max_xmit_dlength);
1648                         else
1649                                 ctask->imm_count = min(ctask->total_length,
1650                                                         conn->max_xmit_dlength);
1651                         hton24(ctask->hdr.dlength, ctask->imm_count);
1652                         ctask->xmstate |= XMSTATE_IMM_DATA;
1653                 } else
1654                         zero_data(ctask->hdr.dlength);
1655
1656                 if (!session->initial_r2t_en)
1657                         ctask->unsol_count = min(session->first_burst,
1658                                 ctask->total_length) - ctask->imm_count;
1659                 if (!ctask->unsol_count)
1660                         /* No unsolicit Data-Out's */
1661                         ctask->hdr.flags |= ISCSI_FLAG_CMD_FINAL;
1662                 else
1663                         ctask->xmstate |= XMSTATE_UNS_HDR | XMSTATE_UNS_INIT;
1664
1665                 ctask->r2t_data_count = ctask->total_length -
1666                                     ctask->imm_count -
1667                                     ctask->unsol_count;
1668
1669                 debug_scsi("cmd [itt %x total %d imm %d imm_data %d "
1670                            "r2t_data %d]\n",
1671                            ctask->itt, ctask->total_length, ctask->imm_count,
1672                            ctask->unsol_count, ctask->r2t_data_count);
1673         } else {
1674                 ctask->hdr.flags |= ISCSI_FLAG_CMD_FINAL;
1675                 if (sc->sc_data_direction == DMA_FROM_DEVICE)
1676                         ctask->hdr.flags |= ISCSI_FLAG_CMD_READ;
1677                 ctask->datasn = 0;
1678                 ctask->xmstate = XMSTATE_R_HDR;
1679                 zero_data(ctask->hdr.dlength);
1680         }
1681
1682         iscsi_buf_init_virt(&ctask->headbuf, (char*)&ctask->hdr,
1683                             sizeof(struct iscsi_hdr));
1684         conn->scsicmd_pdus_cnt++;
1685 }
1686
1687 /**
1688  * iscsi_mtask_xmit - xmit management(immediate) task
1689  * @conn: iscsi connection
1690  * @mtask: task management task
1691  *
1692  * Notes:
1693  *      The function can return -EAGAIN in which case caller must
1694  *      call it again later, or recover. '0' return code means successful
1695  *      xmit.
1696  *
1697  *      Management xmit state machine consists of two states:
1698  *              IN_PROGRESS_IMM_HEAD - PDU Header xmit in progress
1699  *              IN_PROGRESS_IMM_DATA - PDU Data xmit in progress
1700  **/
1701 static int
1702 iscsi_mtask_xmit(struct iscsi_conn *conn, struct iscsi_mgmt_task *mtask)
1703 {
1704
1705         debug_scsi("mtask deq [cid %d state %x itt 0x%x]\n",
1706                 conn->id, mtask->xmstate, mtask->itt);
1707
1708         if (mtask->xmstate & XMSTATE_IMM_HDR) {
1709                 mtask->xmstate &= ~XMSTATE_IMM_HDR;
1710                 if (mtask->data_count)
1711                         mtask->xmstate |= XMSTATE_IMM_DATA;
1712                 if (conn->c_stage != ISCSI_CONN_INITIAL_STAGE &&
1713                     conn->stop_stage != STOP_CONN_RECOVER &&
1714                     conn->hdrdgst_en)
1715                         iscsi_hdr_digest(conn, &mtask->headbuf,
1716                                         (u8*)mtask->hdrext);
1717                 if (iscsi_sendhdr(conn, &mtask->headbuf, mtask->data_count)) {
1718                         mtask->xmstate |= XMSTATE_IMM_HDR;
1719                         if (mtask->data_count)
1720                                 mtask->xmstate &= ~XMSTATE_IMM_DATA;
1721                         return -EAGAIN;
1722                 }
1723         }
1724
1725         if (mtask->xmstate & XMSTATE_IMM_DATA) {
1726                 BUG_ON(!mtask->data_count);
1727                 mtask->xmstate &= ~XMSTATE_IMM_DATA;
1728                 /* FIXME: implement.
1729                  * Virtual buffer could be spreaded across multiple pages...
1730                  */
1731                 do {
1732                         if (iscsi_sendpage(conn, &mtask->sendbuf,
1733                                    &mtask->data_count, &mtask->sent)) {
1734                                 mtask->xmstate |= XMSTATE_IMM_DATA;
1735                                 return -EAGAIN;
1736                         }
1737                 } while (mtask->data_count);
1738         }
1739
1740         BUG_ON(mtask->xmstate != XMSTATE_IDLE);
1741         return 0;
1742 }
1743
1744 static inline int
1745 handle_xmstate_r_hdr(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1746 {
1747         ctask->xmstate &= ~XMSTATE_R_HDR;
1748         if (conn->hdrdgst_en)
1749                 iscsi_hdr_digest(conn, &ctask->headbuf, (u8*)ctask->hdrext);
1750         if (!iscsi_sendhdr(conn, &ctask->headbuf, 0)) {
1751                 BUG_ON(ctask->xmstate != XMSTATE_IDLE);
1752                 return 0; /* wait for Data-In */
1753         }
1754         ctask->xmstate |= XMSTATE_R_HDR;
1755         return -EAGAIN;
1756 }
1757
1758 static inline int
1759 handle_xmstate_w_hdr(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1760 {
1761         ctask->xmstate &= ~XMSTATE_W_HDR;
1762         if (conn->hdrdgst_en)
1763                 iscsi_hdr_digest(conn, &ctask->headbuf, (u8*)ctask->hdrext);
1764         if (iscsi_sendhdr(conn, &ctask->headbuf, ctask->imm_count)) {
1765                 ctask->xmstate |= XMSTATE_W_HDR;
1766                 return -EAGAIN;
1767         }
1768         return 0;
1769 }
1770
1771 static inline int
1772 handle_xmstate_data_digest(struct iscsi_conn *conn,
1773                            struct iscsi_cmd_task *ctask)
1774 {
1775         ctask->xmstate &= ~XMSTATE_DATA_DIGEST;
1776         debug_tcp("resent data digest 0x%x\n", ctask->datadigest);
1777         if (iscsi_digest_final_send(conn, ctask, &ctask->immbuf,
1778                                     &ctask->datadigest, 0)) {
1779                 ctask->xmstate |= XMSTATE_DATA_DIGEST;
1780                 debug_tcp("resent data digest 0x%x fail!\n",
1781                           ctask->datadigest);
1782                 return -EAGAIN;
1783         }
1784         return 0;
1785 }
1786
1787 static inline int
1788 handle_xmstate_imm_data(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1789 {
1790         BUG_ON(!ctask->imm_count);
1791         ctask->xmstate &= ~XMSTATE_IMM_DATA;
1792
1793         if (conn->datadgst_en) {
1794                 iscsi_data_digest_init(conn, ctask);
1795                 ctask->immdigest = 0;
1796         }
1797
1798         for (;;) {
1799                 if (iscsi_sendpage(conn, &ctask->sendbuf, &ctask->imm_count,
1800                                    &ctask->sent)) {
1801                         ctask->xmstate |= XMSTATE_IMM_DATA;
1802                         if (conn->datadgst_en) {
1803                                 crypto_digest_final(conn->data_tx_tfm,
1804                                                 (u8*)&ctask->immdigest);
1805                                 debug_tcp("tx imm sendpage fail 0x%x\n",
1806                                           ctask->datadigest);
1807                         }
1808                         return -EAGAIN;
1809                 }
1810                 if (conn->datadgst_en)
1811                         iscsi_buf_data_digest_update(conn, &ctask->sendbuf);
1812
1813                 if (!ctask->imm_count)
1814                         break;
1815                 iscsi_buf_init_sg(&ctask->sendbuf,
1816                                   &ctask->sg[ctask->sg_count++]);
1817         }
1818
1819         if (conn->datadgst_en && !(ctask->xmstate & XMSTATE_W_PAD)) {
1820                 if (iscsi_digest_final_send(conn, ctask, &ctask->immbuf,
1821                                             &ctask->immdigest, 1)) {
1822                         debug_tcp("sending imm digest 0x%x fail!\n",
1823                                   ctask->immdigest);
1824                         return -EAGAIN;
1825                 }
1826                 debug_tcp("sending imm digest 0x%x\n", ctask->immdigest);
1827         }
1828
1829         return 0;
1830 }
1831
1832 static inline int
1833 handle_xmstate_uns_hdr(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1834 {
1835         struct iscsi_data_task *dtask;
1836
1837         ctask->xmstate |= XMSTATE_UNS_DATA;
1838         if (ctask->xmstate & XMSTATE_UNS_INIT) {
1839                 iscsi_unsolicit_data_init(conn, ctask);
1840                 BUG_ON(!ctask->dtask);
1841                 dtask = ctask->dtask;
1842                 if (conn->hdrdgst_en)
1843                         iscsi_hdr_digest(conn, &ctask->headbuf,
1844                                         (u8*)dtask->hdrext);
1845                 ctask->xmstate &= ~XMSTATE_UNS_INIT;
1846         }
1847         if (iscsi_sendhdr(conn, &ctask->headbuf, ctask->data_count)) {
1848                 ctask->xmstate &= ~XMSTATE_UNS_DATA;
1849                 ctask->xmstate |= XMSTATE_UNS_HDR;
1850                 return -EAGAIN;
1851         }
1852
1853         debug_scsi("uns dout [itt 0x%x dlen %d sent %d]\n",
1854                    ctask->itt, ctask->unsol_count, ctask->sent);
1855         return 0;
1856 }
1857
1858 static inline int
1859 handle_xmstate_uns_data(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1860 {
1861         struct iscsi_data_task *dtask = ctask->dtask;
1862
1863         BUG_ON(!ctask->data_count);
1864         ctask->xmstate &= ~XMSTATE_UNS_DATA;
1865
1866         if (conn->datadgst_en) {
1867                 iscsi_data_digest_init(conn, ctask);
1868                 dtask->digest = 0;
1869         }
1870
1871         for (;;) {
1872                 int start = ctask->sent;
1873
1874                 if (iscsi_sendpage(conn, &ctask->sendbuf, &ctask->data_count,
1875                                    &ctask->sent)) {
1876                         ctask->unsol_count -= ctask->sent - start;
1877                         ctask->xmstate |= XMSTATE_UNS_DATA;
1878                         /* will continue with this ctask later.. */
1879                         if (conn->datadgst_en) {
1880                                 crypto_digest_final(conn->data_tx_tfm,
1881                                                 (u8 *)&dtask->digest);
1882                                 debug_tcp("tx uns data fail 0x%x\n",
1883                                           dtask->digest);
1884                         }
1885                         return -EAGAIN;
1886                 }
1887
1888                 BUG_ON(ctask->sent > ctask->total_length);
1889                 ctask->unsol_count -= ctask->sent - start;
1890
1891                 /*
1892                  * XXX:we may run here with un-initial sendbuf.
1893                  * so pass it
1894                  */
1895                 if (conn->datadgst_en && ctask->sent - start > 0)
1896                         iscsi_buf_data_digest_update(conn, &ctask->sendbuf);
1897
1898                 if (!ctask->data_count)
1899                         break;
1900                 iscsi_buf_init_sg(&ctask->sendbuf,
1901                                   &ctask->sg[ctask->sg_count++]);
1902         }
1903         BUG_ON(ctask->unsol_count < 0);
1904
1905         /*
1906          * Done with the Data-Out. Next, check if we need
1907          * to send another unsolicited Data-Out.
1908          */
1909         if (ctask->unsol_count) {
1910                 if (conn->datadgst_en) {
1911                         if (iscsi_digest_final_send(conn, ctask,
1912                                                     &dtask->digestbuf,
1913                                                     &dtask->digest, 1)) {
1914                                 debug_tcp("send uns digest 0x%x fail\n",
1915                                           dtask->digest);
1916                                 return -EAGAIN;
1917                         }
1918                         debug_tcp("sending uns digest 0x%x, more uns\n",
1919                                   dtask->digest);
1920                 }
1921                 ctask->xmstate |= XMSTATE_UNS_INIT;
1922                 return 1;
1923         }
1924
1925         if (conn->datadgst_en && !(ctask->xmstate & XMSTATE_W_PAD)) {
1926                 if (iscsi_digest_final_send(conn, ctask,
1927                                             &dtask->digestbuf,
1928                                             &dtask->digest, 1)) {
1929                         debug_tcp("send last uns digest 0x%x fail\n",
1930                                    dtask->digest);
1931                         return -EAGAIN;
1932                 }
1933                 debug_tcp("sending uns digest 0x%x\n",dtask->digest);
1934         }
1935
1936         return 0;
1937 }
1938
1939 static inline int
1940 handle_xmstate_sol_data(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1941 {
1942         struct iscsi_session *session = conn->session;
1943         struct iscsi_r2t_info *r2t = ctask->r2t;
1944         struct iscsi_data_task *dtask = r2t->dtask;
1945         int left;
1946
1947         ctask->xmstate &= ~XMSTATE_SOL_DATA;
1948         ctask->dtask = dtask;
1949
1950         if (conn->datadgst_en) {
1951                 iscsi_data_digest_init(conn, ctask);
1952                 dtask->digest = 0;
1953         }
1954 solicit_again:
1955         /*
1956          * send Data-Out whitnin this R2T sequence.
1957          */
1958         if (!r2t->data_count)
1959                 goto data_out_done;
1960
1961         if (iscsi_sendpage(conn, &r2t->sendbuf, &r2t->data_count, &r2t->sent)) {
1962                 ctask->xmstate |= XMSTATE_SOL_DATA;
1963                 /* will continue with this ctask later.. */
1964                 if (conn->datadgst_en) {
1965                         crypto_digest_final(conn->data_tx_tfm,
1966                                           (u8 *)&dtask->digest);
1967                         debug_tcp("r2t data send fail 0x%x\n", dtask->digest);
1968                 }
1969                 return -EAGAIN;
1970         }
1971
1972         BUG_ON(r2t->data_count < 0);
1973         if (conn->datadgst_en)
1974                 iscsi_buf_data_digest_update(conn, &r2t->sendbuf);
1975
1976         if (r2t->data_count) {
1977                 BUG_ON(ctask->sc->use_sg == 0);
1978                 if (!iscsi_buf_left(&r2t->sendbuf)) {
1979                         BUG_ON(ctask->bad_sg == r2t->sg);
1980                         iscsi_buf_init_sg(&r2t->sendbuf, r2t->sg);
1981                         r2t->sg += 1;
1982                 }
1983                 goto solicit_again;
1984         }
1985
1986 data_out_done:
1987         /*
1988          * Done with this Data-Out. Next, check if we have
1989          * to send another Data-Out for this R2T.
1990          */
1991         BUG_ON(r2t->data_length - r2t->sent < 0);
1992         left = r2t->data_length - r2t->sent;
1993         if (left) {
1994                 if (conn->datadgst_en) {
1995                         if (iscsi_digest_final_send(conn, ctask,
1996                                                     &dtask->digestbuf,
1997                                                     &dtask->digest, 1)) {
1998                                 debug_tcp("send r2t data digest 0x%x"
1999                                           "fail\n", dtask->digest);
2000                                 return -EAGAIN;
2001                         }
2002                         debug_tcp("r2t data send digest 0x%x\n",
2003                                   dtask->digest);
2004                 }
2005                 iscsi_solicit_data_cont(conn, ctask, r2t, left);
2006                 ctask->xmstate |= XMSTATE_SOL_DATA;
2007                 ctask->xmstate &= ~XMSTATE_SOL_HDR;
2008                 return 1;
2009         }
2010
2011         /*
2012          * Done with this R2T. Check if there are more
2013          * outstanding R2Ts ready to be processed.
2014          */
2015         BUG_ON(ctask->r2t_data_count - r2t->data_length < 0);
2016         if (conn->datadgst_en) {
2017                 if (iscsi_digest_final_send(conn, ctask, &dtask->digestbuf,
2018                                             &dtask->digest, 1)) {
2019                         debug_tcp("send last r2t data digest 0x%x"
2020                                   "fail\n", dtask->digest);
2021                         return -EAGAIN;
2022                 }
2023                 debug_tcp("r2t done dout digest 0x%x\n", dtask->digest);
2024         }
2025
2026         ctask->r2t_data_count -= r2t->data_length;
2027         ctask->r2t = NULL;
2028         spin_lock_bh(&session->lock);
2029         __kfifo_put(ctask->r2tpool.queue, (void*)&r2t, sizeof(void*));
2030         spin_unlock_bh(&session->lock);
2031         if (__kfifo_get(ctask->r2tqueue, (void*)&r2t, sizeof(void*))) {
2032                 ctask->r2t = r2t;
2033                 ctask->xmstate |= XMSTATE_SOL_DATA;
2034                 ctask->xmstate &= ~XMSTATE_SOL_HDR;
2035                 return 1;
2036         }
2037
2038         return 0;
2039 }
2040
2041 static inline int
2042 handle_xmstate_w_pad(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
2043 {
2044         struct iscsi_data_task *dtask = ctask->dtask;
2045         int sent;
2046
2047         ctask->xmstate &= ~XMSTATE_W_PAD;
2048         iscsi_buf_init_virt(&ctask->sendbuf, (char*)&ctask->pad,
2049                             ctask->pad_count);
2050         if (iscsi_sendpage(conn, &ctask->sendbuf, &ctask->pad_count, &sent)) {
2051                 ctask->xmstate |= XMSTATE_W_PAD;
2052                 return -EAGAIN;
2053         }
2054
2055         if (conn->datadgst_en) {
2056                 iscsi_buf_data_digest_update(conn, &ctask->sendbuf);
2057                 /* imm data? */
2058                 if (!dtask) {
2059                         if (iscsi_digest_final_send(conn, ctask, &ctask->immbuf,
2060                                                     &ctask->immdigest, 1)) {
2061                                 debug_tcp("send padding digest 0x%x"
2062                                           "fail!\n", ctask->immdigest);
2063                                 return -EAGAIN;
2064                         }
2065                         debug_tcp("done with padding, digest 0x%x\n",
2066                                   ctask->datadigest);
2067                 } else {
2068                         if (iscsi_digest_final_send(conn, ctask,
2069                                                     &dtask->digestbuf,
2070                                                     &dtask->digest, 1)) {
2071                                 debug_tcp("send padding digest 0x%x"
2072                                           "fail\n", dtask->digest);
2073                                 return -EAGAIN;
2074                         }
2075                         debug_tcp("done with padding, digest 0x%x\n",
2076                                   dtask->digest);
2077                 }
2078         }
2079
2080         return 0;
2081 }
2082
2083 static int
2084 iscsi_ctask_xmit(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
2085 {
2086         int rc = 0;
2087
2088         debug_scsi("ctask deq [cid %d xmstate %x itt 0x%x]\n",
2089                 conn->id, ctask->xmstate, ctask->itt);
2090
2091         /*
2092          * serialize with TMF AbortTask
2093          */
2094         if (ctask->mtask)
2095                 return rc;
2096
2097         if (ctask->xmstate & XMSTATE_R_HDR) {
2098                 rc = handle_xmstate_r_hdr(conn, ctask);
2099                 return rc;
2100         }
2101
2102         if (ctask->xmstate & XMSTATE_W_HDR) {
2103                 rc = handle_xmstate_w_hdr(conn, ctask);
2104                 if (rc)
2105                         return rc;
2106         }
2107
2108         /* XXX: for data digest xmit recover */
2109         if (ctask->xmstate & XMSTATE_DATA_DIGEST) {
2110                 rc = handle_xmstate_data_digest(conn, ctask);
2111                 if (rc)
2112                         return rc;
2113         }
2114
2115         if (ctask->xmstate & XMSTATE_IMM_DATA) {
2116                 rc = handle_xmstate_imm_data(conn, ctask);
2117                 if (rc)
2118                         return rc;
2119         }
2120
2121         if (ctask->xmstate & XMSTATE_UNS_HDR) {
2122                 BUG_ON(!ctask->unsol_count);
2123                 ctask->xmstate &= ~XMSTATE_UNS_HDR;
2124 unsolicit_head_again:
2125                 rc = handle_xmstate_uns_hdr(conn, ctask);
2126                 if (rc)
2127                         return rc;
2128         }
2129
2130         if (ctask->xmstate & XMSTATE_UNS_DATA) {
2131                 rc = handle_xmstate_uns_data(conn, ctask);
2132                 if (rc == 1)
2133                         goto unsolicit_head_again;
2134                 else if (rc)
2135                         return rc;
2136                 goto done;
2137         }
2138
2139         if (ctask->xmstate & XMSTATE_SOL_HDR) {
2140                 struct iscsi_r2t_info *r2t;
2141
2142                 ctask->xmstate &= ~XMSTATE_SOL_HDR;
2143                 ctask->xmstate |= XMSTATE_SOL_DATA;
2144                 if (!ctask->r2t)
2145                         __kfifo_get(ctask->r2tqueue, (void*)&ctask->r2t,
2146                                     sizeof(void*));
2147 solicit_head_again:
2148                 r2t = ctask->r2t;
2149                 if (conn->hdrdgst_en)
2150                         iscsi_hdr_digest(conn, &r2t->headbuf,
2151                                         (u8*)r2t->dtask->hdrext);
2152                 if (iscsi_sendhdr(conn, &r2t->headbuf, r2t->data_count)) {
2153                         ctask->xmstate &= ~XMSTATE_SOL_DATA;
2154                         ctask->xmstate |= XMSTATE_SOL_HDR;
2155                         return -EAGAIN;
2156                 }
2157
2158                 debug_scsi("sol dout [dsn %d itt 0x%x dlen %d sent %d]\n",
2159                         r2t->solicit_datasn - 1, ctask->itt, r2t->data_count,
2160                         r2t->sent);
2161         }
2162
2163         if (ctask->xmstate & XMSTATE_SOL_DATA) {
2164                 rc = handle_xmstate_sol_data(conn, ctask);
2165                 if (rc == 1)
2166                         goto solicit_head_again;
2167                 if (rc)
2168                         return rc;
2169         }
2170
2171 done:
2172         /*
2173          * Last thing to check is whether we need to send write
2174          * padding. Note that we check for xmstate equality, not just the bit.
2175          */
2176         if (ctask->xmstate == XMSTATE_W_PAD)
2177                 rc = handle_xmstate_w_pad(conn, ctask);
2178
2179         return rc;
2180 }
2181
2182 /**
2183  * iscsi_data_xmit - xmit any command into the scheduled connection
2184  * @conn: iscsi connection
2185  *
2186  * Notes:
2187  *      The function can return -EAGAIN in which case the caller must
2188  *      re-schedule it again later or recover. '0' return code means
2189  *      successful xmit.
2190  **/
2191 static int
2192 iscsi_data_xmit(struct iscsi_conn *conn)
2193 {
2194         if (unlikely(conn->suspend_tx)) {
2195                 debug_tcp("conn %d Tx suspended!\n", conn->id);
2196                 return 0;
2197         }
2198
2199         /*
2200          * Transmit in the following order:
2201          *
2202          * 1) un-finished xmit (ctask or mtask)
2203          * 2) immediate control PDUs
2204          * 3) write data
2205          * 4) SCSI commands
2206          * 5) non-immediate control PDUs
2207          *
2208          * No need to lock around __kfifo_get as long as
2209          * there's one producer and one consumer.
2210          */
2211
2212         BUG_ON(conn->ctask && conn->mtask);
2213
2214         if (conn->ctask) {
2215                 if (iscsi_ctask_xmit(conn, conn->ctask))
2216                         goto again;
2217                 /* done with this in-progress ctask */
2218                 conn->ctask = NULL;
2219         }
2220         if (conn->mtask) {
2221                 if (iscsi_mtask_xmit(conn, conn->mtask))
2222                         goto again;
2223                 /* done with this in-progress mtask */
2224                 conn->mtask = NULL;
2225         }
2226
2227         /* process immediate first */
2228         if (unlikely(__kfifo_len(conn->immqueue))) {
2229                 struct iscsi_session *session = conn->session;
2230                 while (__kfifo_get(conn->immqueue, (void*)&conn->mtask,
2231                                    sizeof(void*))) {
2232                         if (iscsi_mtask_xmit(conn, conn->mtask))
2233                                 goto again;
2234
2235                         if (conn->mtask->hdr.itt ==
2236                                         cpu_to_be32(ISCSI_RESERVED_TAG)) {
2237                                 spin_lock_bh(&session->lock);
2238                                 __kfifo_put(session->mgmtpool.queue,
2239                                             (void*)&conn->mtask, sizeof(void*));
2240                                 spin_unlock_bh(&session->lock);
2241                         }
2242                 }
2243                 /* done with this mtask */
2244                 conn->mtask = NULL;
2245         }
2246
2247         /* process write queue */
2248         while (__kfifo_get(conn->writequeue, (void*)&conn->ctask,
2249                            sizeof(void*))) {
2250                 if (iscsi_ctask_xmit(conn, conn->ctask))
2251                         goto again;
2252         }
2253
2254         /* process command queue */
2255         while (__kfifo_get(conn->xmitqueue, (void*)&conn->ctask,
2256                            sizeof(void*))) {
2257                 if (iscsi_ctask_xmit(conn, conn->ctask))
2258                         goto again;
2259         }
2260         /* done with this ctask */
2261         conn->ctask = NULL;
2262
2263         /* process the rest control plane PDUs, if any */
2264         if (unlikely(__kfifo_len(conn->mgmtqueue))) {
2265                 struct iscsi_session *session = conn->session;
2266
2267                 while (__kfifo_get(conn->mgmtqueue, (void*)&conn->mtask,
2268                                    sizeof(void*))) {
2269                         if (iscsi_mtask_xmit(conn, conn->mtask))
2270                                 goto again;
2271
2272                         if (conn->mtask->hdr.itt ==
2273                                         cpu_to_be32(ISCSI_RESERVED_TAG)) {
2274                                 spin_lock_bh(&session->lock);
2275                                 __kfifo_put(session->mgmtpool.queue,
2276                                             (void*)&conn->mtask,
2277                                             sizeof(void*));
2278                                 spin_unlock_bh(&session->lock);
2279                         }
2280                 }
2281                 /* done with this mtask */
2282                 conn->mtask = NULL;
2283         }
2284
2285         return 0;
2286
2287 again:
2288         if (unlikely(conn->suspend_tx))
2289                 return 0;
2290
2291         return -EAGAIN;
2292 }
2293
2294 static void
2295 iscsi_xmitworker(void *data)
2296 {
2297         struct iscsi_conn *conn = data;
2298
2299         /*
2300          * serialize Xmit worker on a per-connection basis.
2301          */
2302         mutex_lock(&conn->xmitmutex);
2303         if (iscsi_data_xmit(conn))
2304                 schedule_work(&conn->xmitwork);
2305         mutex_unlock(&conn->xmitmutex);
2306 }
2307
2308 #define FAILURE_BAD_HOST                1
2309 #define FAILURE_SESSION_FAILED          2
2310 #define FAILURE_SESSION_FREED           3
2311 #define FAILURE_WINDOW_CLOSED           4
2312 #define FAILURE_SESSION_TERMINATE       5
2313
2314 static int
2315 iscsi_queuecommand(struct scsi_cmnd *sc, void (*done)(struct scsi_cmnd *))
2316 {
2317         struct Scsi_Host *host;
2318         int reason = 0;
2319         struct iscsi_session *session;
2320         struct iscsi_conn *conn = NULL;
2321         struct iscsi_cmd_task *ctask = NULL;
2322
2323         sc->scsi_done = done;
2324         sc->result = 0;
2325
2326         host = sc->device->host;
2327         session = iscsi_hostdata(host->hostdata);
2328         BUG_ON(host != session->host);
2329
2330         spin_lock(&session->lock);
2331
2332         if (session->state != ISCSI_STATE_LOGGED_IN) {
2333                 if (session->state == ISCSI_STATE_FAILED) {
2334                         reason = FAILURE_SESSION_FAILED;
2335                         goto reject;
2336                 } else if (session->state == ISCSI_STATE_TERMINATE) {
2337                         reason = FAILURE_SESSION_TERMINATE;
2338                         goto fault;
2339                 }
2340                 reason = FAILURE_SESSION_FREED;
2341                 goto fault;
2342         }
2343
2344         /*
2345          * Check for iSCSI window and take care of CmdSN wrap-around
2346          */
2347         if ((int)(session->max_cmdsn - session->cmdsn) < 0) {
2348                 reason = FAILURE_WINDOW_CLOSED;
2349                 goto reject;
2350         }
2351
2352         conn = session->leadconn;
2353
2354         __kfifo_get(session->cmdpool.queue, (void*)&ctask, sizeof(void*));
2355         BUG_ON(ctask->sc);
2356
2357         sc->SCp.phase = session->age;
2358         sc->SCp.ptr = (char*)ctask;
2359         iscsi_cmd_init(conn, ctask, sc);
2360
2361         __kfifo_put(conn->xmitqueue, (void*)&ctask, sizeof(void*));
2362         debug_scsi(
2363                "ctask enq [%s cid %d sc %lx itt 0x%x len %d cmdsn %d win %d]\n",
2364                 sc->sc_data_direction == DMA_TO_DEVICE ? "write" : "read",
2365                 conn->id, (long)sc, ctask->itt, sc->request_bufflen,
2366                 session->cmdsn, session->max_cmdsn - session->exp_cmdsn + 1);
2367         spin_unlock(&session->lock);
2368
2369         if (!in_interrupt() && mutex_trylock(&conn->xmitmutex)) {
2370                 spin_unlock_irq(host->host_lock);
2371                 if (iscsi_data_xmit(conn))
2372                         schedule_work(&conn->xmitwork);
2373                 mutex_unlock(&conn->xmitmutex);
2374                 spin_lock_irq(host->host_lock);
2375         } else
2376                 schedule_work(&conn->xmitwork);
2377
2378         return 0;
2379
2380 reject:
2381         spin_unlock(&session->lock);
2382         debug_scsi("cmd 0x%x rejected (%d)\n", sc->cmnd[0], reason);
2383         return SCSI_MLQUEUE_HOST_BUSY;
2384
2385 fault:
2386         spin_unlock(&session->lock);
2387         printk(KERN_ERR "iscsi_tcp: cmd 0x%x is not queued (%d)\n",
2388                sc->cmnd[0], reason);
2389         sc->sense_buffer[0] = 0x70;
2390         sc->sense_buffer[2] = NOT_READY;
2391         sc->sense_buffer[7] = 0x6;
2392         sc->sense_buffer[12] = 0x08;
2393         sc->sense_buffer[13] = 0x00;
2394         sc->result = (DID_NO_CONNECT << 16);
2395         sc->resid = sc->request_bufflen;
2396         sc->scsi_done(sc);
2397         return 0;
2398 }
2399
2400 static int
2401 iscsi_change_queue_depth(struct scsi_device *sdev, int depth)
2402 {
2403         if (depth > ISCSI_MAX_CMD_PER_LUN)
2404                 depth = ISCSI_MAX_CMD_PER_LUN;
2405         scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
2406         return sdev->queue_depth;
2407 }
2408
2409 static int
2410 iscsi_pool_init(struct iscsi_queue *q, int max, void ***items, int item_size)
2411 {
2412         int i;
2413
2414         *items = kmalloc(max * sizeof(void*), GFP_KERNEL);
2415         if (*items == NULL)
2416                 return -ENOMEM;
2417
2418         q->max = max;
2419         q->pool = kmalloc(max * sizeof(void*), GFP_KERNEL);
2420         if (q->pool == NULL) {
2421                 kfree(*items);
2422                 return -ENOMEM;
2423         }
2424
2425         q->queue = kfifo_init((void*)q->pool, max * sizeof(void*),
2426                               GFP_KERNEL, NULL);
2427         if (q->queue == ERR_PTR(-ENOMEM)) {
2428                 kfree(q->pool);
2429                 kfree(*items);
2430                 return -ENOMEM;
2431         }
2432
2433         for (i = 0; i < max; i++) {
2434                 q->pool[i] = kmalloc(item_size, GFP_KERNEL);
2435                 if (q->pool[i] == NULL) {
2436                         int j;
2437
2438                         for (j = 0; j < i; j++)
2439                                 kfree(q->pool[j]);
2440
2441                         kfifo_free(q->queue);
2442                         kfree(q->pool);
2443                         kfree(*items);
2444                         return -ENOMEM;
2445                 }
2446                 memset(q->pool[i], 0, item_size);
2447                 (*items)[i] = q->pool[i];
2448                 __kfifo_put(q->queue, (void*)&q->pool[i], sizeof(void*));
2449         }
2450         return 0;
2451 }
2452
2453 static void
2454 iscsi_pool_free(struct iscsi_queue *q, void **items)
2455 {
2456         int i;
2457
2458         for (i = 0; i < q->max; i++)
2459                 kfree(items[i]);
2460         kfree(q->pool);
2461         kfree(items);
2462 }
2463
2464 static iscsi_connh_t
2465 iscsi_conn_create(iscsi_sessionh_t sessionh, uint32_t conn_idx)
2466 {
2467         struct iscsi_session *session = iscsi_ptr(sessionh);
2468         struct iscsi_conn *conn = NULL;
2469
2470         conn = kmalloc(sizeof(struct iscsi_conn), GFP_KERNEL);
2471         if (conn == NULL)
2472                 goto conn_alloc_fail;
2473         memset(conn, 0, sizeof(struct iscsi_conn));
2474
2475         conn->c_stage = ISCSI_CONN_INITIAL_STAGE;
2476         conn->in_progress = IN_PROGRESS_WAIT_HEADER;
2477         conn->id = conn_idx;
2478         conn->exp_statsn = 0;
2479         conn->tmabort_state = TMABORT_INITIAL;
2480
2481         /* initial operational parameters */
2482         conn->hdr_size = sizeof(struct iscsi_hdr);
2483         conn->data_size = DEFAULT_MAX_RECV_DATA_SEGMENT_LENGTH;
2484         conn->max_recv_dlength = DEFAULT_MAX_RECV_DATA_SEGMENT_LENGTH;
2485
2486         spin_lock_init(&conn->lock);
2487
2488         /* initialize general xmit PDU commands queue */
2489         conn->xmitqueue = kfifo_alloc(session->cmds_max * sizeof(void*),
2490                                         GFP_KERNEL, NULL);
2491         if (conn->xmitqueue == ERR_PTR(-ENOMEM))
2492                 goto xmitqueue_alloc_fail;
2493
2494         /* initialize write response PDU commands queue */
2495         conn->writequeue = kfifo_alloc(session->cmds_max * sizeof(void*),
2496                                         GFP_KERNEL, NULL);
2497         if (conn->writequeue == ERR_PTR(-ENOMEM))
2498                 goto writequeue_alloc_fail;
2499
2500         /* initialize general immediate & non-immediate PDU commands queue */
2501         conn->immqueue = kfifo_alloc(session->mgmtpool_max * sizeof(void*),
2502                                         GFP_KERNEL, NULL);
2503         if (conn->immqueue == ERR_PTR(-ENOMEM))
2504                 goto immqueue_alloc_fail;
2505
2506         conn->mgmtqueue = kfifo_alloc(session->mgmtpool_max * sizeof(void*),
2507                                         GFP_KERNEL, NULL);
2508         if (conn->mgmtqueue == ERR_PTR(-ENOMEM))
2509                 goto mgmtqueue_alloc_fail;
2510
2511         INIT_WORK(&conn->xmitwork, iscsi_xmitworker, conn);
2512
2513         /* allocate login_mtask used for the login/text sequences */
2514         spin_lock_bh(&session->lock);
2515         if (!__kfifo_get(session->mgmtpool.queue,
2516                          (void*)&conn->login_mtask,
2517                          sizeof(void*))) {
2518                 spin_unlock_bh(&session->lock);
2519                 goto login_mtask_alloc_fail;
2520         }
2521         spin_unlock_bh(&session->lock);
2522
2523         /* allocate initial PDU receive place holder */
2524         if (conn->data_size <= PAGE_SIZE)
2525                 conn->data = kmalloc(conn->data_size, GFP_KERNEL);
2526         else
2527                 conn->data = (void*)__get_free_pages(GFP_KERNEL,
2528                                         get_order(conn->data_size));
2529         if (!conn->data)
2530                 goto max_recv_dlenght_alloc_fail;
2531
2532         init_timer(&conn->tmabort_timer);
2533         mutex_init(&conn->xmitmutex);
2534         init_waitqueue_head(&conn->ehwait);
2535
2536         return iscsi_handle(conn);
2537
2538 max_recv_dlenght_alloc_fail:
2539         spin_lock_bh(&session->lock);
2540         __kfifo_put(session->mgmtpool.queue, (void*)&conn->login_mtask,
2541                     sizeof(void*));
2542         spin_unlock_bh(&session->lock);
2543 login_mtask_alloc_fail:
2544         kfifo_free(conn->mgmtqueue);
2545 mgmtqueue_alloc_fail:
2546         kfifo_free(conn->immqueue);
2547 immqueue_alloc_fail:
2548         kfifo_free(conn->writequeue);
2549 writequeue_alloc_fail:
2550         kfifo_free(conn->xmitqueue);
2551 xmitqueue_alloc_fail:
2552         kfree(conn);
2553 conn_alloc_fail:
2554         return iscsi_handle(NULL);
2555 }
2556
2557 static void
2558 iscsi_conn_destroy(iscsi_connh_t connh)
2559 {
2560         struct iscsi_conn *conn = iscsi_ptr(connh);
2561         struct iscsi_session *session = conn->session;
2562         unsigned long flags;
2563
2564         mutex_lock(&conn->xmitmutex);
2565         set_bit(SUSPEND_BIT, &conn->suspend_tx);
2566         if (conn->c_stage == ISCSI_CONN_INITIAL_STAGE && conn->sock) {
2567                 struct sock *sk = conn->sock->sk;
2568
2569                 /*
2570                  * conn_start() has never been called!
2571                  * need to cleanup the socket.
2572                  */
2573                 write_lock_bh(&sk->sk_callback_lock);
2574                 set_bit(SUSPEND_BIT, &conn->suspend_rx);
2575                 write_unlock_bh(&sk->sk_callback_lock);
2576
2577                 sock_hold(conn->sock->sk);
2578                 iscsi_conn_restore_callbacks(conn);
2579                 sock_put(conn->sock->sk);
2580                 sock_release(conn->sock);
2581                 conn->sock = NULL;
2582         }
2583
2584         spin_lock_bh(&session->lock);
2585         conn->c_stage = ISCSI_CONN_CLEANUP_WAIT;
2586         if (session->leadconn == conn) {
2587                 /*
2588                  * leading connection? then give up on recovery.
2589                  */
2590                 session->state = ISCSI_STATE_TERMINATE;
2591                 wake_up(&conn->ehwait);
2592         }
2593         spin_unlock_bh(&session->lock);
2594
2595         mutex_unlock(&conn->xmitmutex);
2596
2597         /*
2598          * Block until all in-progress commands for this connection
2599          * time out or fail.
2600          */
2601         for (;;) {
2602                 spin_lock_irqsave(session->host->host_lock, flags);
2603                 if (!session->host->host_busy) { /* OK for ERL == 0 */
2604                         spin_unlock_irqrestore(session->host->host_lock, flags);
2605                         break;
2606                 }
2607                 spin_unlock_irqrestore(session->host->host_lock, flags);
2608                 msleep_interruptible(500);
2609                 printk("conn_destroy(): host_busy %d host_failed %d\n",
2610                         session->host->host_busy, session->host->host_failed);
2611                 /*
2612                  * force eh_abort() to unblock
2613                  */
2614                 wake_up(&conn->ehwait);
2615         }
2616
2617         /* now free crypto */
2618         if (conn->hdrdgst_en || conn->datadgst_en) {
2619                 if (conn->tx_tfm)
2620                         crypto_free_tfm(conn->tx_tfm);
2621                 if (conn->rx_tfm)
2622                         crypto_free_tfm(conn->rx_tfm);
2623                 if (conn->data_tx_tfm)
2624                         crypto_free_tfm(conn->data_tx_tfm);
2625                 if (conn->data_rx_tfm)
2626                         crypto_free_tfm(conn->data_rx_tfm);
2627         }
2628
2629         /* free conn->data, size = MaxRecvDataSegmentLength */
2630         if (conn->data_size <= PAGE_SIZE)
2631                 kfree(conn->data);
2632         else
2633                 free_pages((unsigned long)conn->data,
2634                                         get_order(conn->data_size));
2635
2636         spin_lock_bh(&session->lock);
2637         __kfifo_put(session->mgmtpool.queue, (void*)&conn->login_mtask,
2638                     sizeof(void*));
2639         list_del(&conn->item);
2640         if (list_empty(&session->connections))
2641                 session->leadconn = NULL;
2642         if (session->leadconn && session->leadconn == conn)
2643                 session->leadconn = container_of(session->connections.next,
2644                         struct iscsi_conn, item);
2645
2646         if (session->leadconn == NULL)
2647                 /* none connections exits.. reset sequencing */
2648                 session->cmdsn = session->max_cmdsn = session->exp_cmdsn = 1;
2649         spin_unlock_bh(&session->lock);
2650
2651         kfifo_free(conn->xmitqueue);
2652         kfifo_free(conn->writequeue);
2653         kfifo_free(conn->immqueue);
2654         kfifo_free(conn->mgmtqueue);
2655         kfree(conn);
2656 }
2657
2658 static int
2659 iscsi_conn_bind(iscsi_sessionh_t sessionh, iscsi_connh_t connh,
2660                 uint32_t transport_fd, int is_leading)
2661 {
2662         struct iscsi_session *session = iscsi_ptr(sessionh);
2663         struct iscsi_conn *tmp = ERR_PTR(-EEXIST), *conn = iscsi_ptr(connh);
2664         struct sock *sk;
2665         struct socket *sock;
2666         int err;
2667
2668         /* lookup for existing socket */
2669         sock = sockfd_lookup(transport_fd, &err);
2670         if (!sock) {
2671                 printk(KERN_ERR "iscsi_tcp: sockfd_lookup failed %d\n", err);
2672                 return -EEXIST;
2673         }
2674
2675         /* lookup for existing connection */
2676         spin_lock_bh(&session->lock);
2677         list_for_each_entry(tmp, &session->connections, item) {
2678                 if (tmp == conn) {
2679                         if (conn->c_stage != ISCSI_CONN_STOPPED ||
2680                             conn->stop_stage == STOP_CONN_TERM) {
2681                                 printk(KERN_ERR "iscsi_tcp: can't bind "
2682                                        "non-stopped connection (%d:%d)\n",
2683                                        conn->c_stage, conn->stop_stage);
2684                                 spin_unlock_bh(&session->lock);
2685                                 return -EIO;
2686                         }
2687                         break;
2688                 }
2689         }
2690         if (tmp != conn) {
2691                 /* bind new iSCSI connection to session */
2692                 conn->session = session;
2693
2694                 list_add(&conn->item, &session->connections);
2695         }
2696         spin_unlock_bh(&session->lock);
2697
2698         if (conn->stop_stage != STOP_CONN_SUSPEND) {
2699                 /* bind iSCSI connection and socket */
2700                 conn->sock = sock;
2701
2702                 /* setup Socket parameters */
2703                 sk = sock->sk;
2704                 sk->sk_reuse = 1;
2705                 sk->sk_sndtimeo = 15 * HZ; /* FIXME: make it configurable */
2706                 sk->sk_allocation = GFP_ATOMIC;
2707
2708                 /* FIXME: disable Nagle's algorithm */
2709
2710                 /*
2711                  * Intercept TCP callbacks for sendfile like receive
2712                  * processing.
2713                  */
2714                 iscsi_conn_set_callbacks(conn);
2715
2716                 /*
2717                  * set receive state machine into initial state
2718                  */
2719                 conn->in_progress = IN_PROGRESS_WAIT_HEADER;
2720         }
2721
2722         if (is_leading)
2723                 session->leadconn = conn;
2724
2725         /*
2726          * Unblock xmitworker(), Login Phase will pass through.
2727          */
2728         clear_bit(SUSPEND_BIT, &conn->suspend_rx);
2729         clear_bit(SUSPEND_BIT, &conn->suspend_tx);
2730
2731         return 0;
2732 }
2733
2734 static int
2735 iscsi_conn_start(iscsi_connh_t connh)
2736 {
2737         struct iscsi_conn *conn = iscsi_ptr(connh);
2738         struct iscsi_session *session = conn->session;
2739         struct sock *sk;
2740
2741         /* FF phase warming up... */
2742
2743         if (session == NULL) {
2744                 printk(KERN_ERR "iscsi_tcp: can't start unbound connection\n");
2745                 return -EPERM;
2746         }
2747
2748         sk = conn->sock->sk;
2749
2750         write_lock_bh(&sk->sk_callback_lock);
2751         spin_lock_bh(&session->lock);
2752         conn->c_stage = ISCSI_CONN_STARTED;
2753         session->state = ISCSI_STATE_LOGGED_IN;
2754
2755         switch(conn->stop_stage) {
2756         case STOP_CONN_RECOVER:
2757                 /*
2758                  * unblock eh_abort() if it is blocked. re-try all
2759                  * commands after successful recovery
2760                  */
2761                 session->conn_cnt++;
2762                 conn->stop_stage = 0;
2763                 conn->tmabort_state = TMABORT_INITIAL;
2764                 session->age++;
2765                 wake_up(&conn->ehwait);
2766                 break;
2767         case STOP_CONN_TERM:
2768                 session->conn_cnt++;
2769                 conn->stop_stage = 0;
2770                 break;
2771         case STOP_CONN_SUSPEND:
2772                 conn->stop_stage = 0;
2773                 clear_bit(SUSPEND_BIT, &conn->suspend_rx);
2774                 clear_bit(SUSPEND_BIT, &conn->suspend_tx);
2775                 break;
2776         default:
2777                 break;
2778         }
2779         spin_unlock_bh(&session->lock);
2780         write_unlock_bh(&sk->sk_callback_lock);
2781
2782         return 0;
2783 }
2784
2785 static void
2786 iscsi_conn_stop(iscsi_connh_t connh, int flag)
2787 {
2788         struct iscsi_conn *conn = iscsi_ptr(connh);
2789         struct iscsi_session *session = conn->session;
2790         struct sock *sk;
2791         unsigned long flags;
2792
2793         BUG_ON(!conn->sock);
2794         sk = conn->sock->sk;
2795         write_lock_bh(&sk->sk_callback_lock);
2796         set_bit(SUSPEND_BIT, &conn->suspend_rx);
2797         write_unlock_bh(&sk->sk_callback_lock);
2798
2799         mutex_lock(&conn->xmitmutex);
2800
2801         spin_lock_irqsave(session->host->host_lock, flags);
2802         spin_lock(&session->lock);
2803         conn->stop_stage = flag;
2804         conn->c_stage = ISCSI_CONN_STOPPED;
2805         set_bit(SUSPEND_BIT, &conn->suspend_tx);
2806
2807         if (flag != STOP_CONN_SUSPEND)
2808                 session->conn_cnt--;
2809
2810         if (session->conn_cnt == 0 || session->leadconn == conn)
2811                 session->state = ISCSI_STATE_FAILED;
2812
2813         spin_unlock(&session->lock);
2814         spin_unlock_irqrestore(session->host->host_lock, flags);
2815
2816         if (flag == STOP_CONN_TERM || flag == STOP_CONN_RECOVER) {
2817                 struct iscsi_cmd_task *ctask;
2818                 struct iscsi_mgmt_task *mtask;
2819
2820                 /*
2821                  * Socket must go now.
2822                  */
2823                 sock_hold(conn->sock->sk);
2824                 iscsi_conn_restore_callbacks(conn);
2825                 sock_put(conn->sock->sk);
2826
2827                 /*
2828                  * flush xmit queues.
2829                  */
2830                 spin_lock_bh(&session->lock);
2831                 while (__kfifo_get(conn->writequeue, (void*)&ctask,
2832                             sizeof(void*)) ||
2833                         __kfifo_get(conn->xmitqueue, (void*)&ctask,
2834                             sizeof(void*))) {
2835                         struct iscsi_r2t_info *r2t;
2836
2837                         /*
2838                          * flush ctask's r2t queues
2839                          */
2840                         while (__kfifo_get(ctask->r2tqueue, (void*)&r2t,
2841                                 sizeof(void*)))
2842                                 __kfifo_put(ctask->r2tpool.queue, (void*)&r2t,
2843                                             sizeof(void*));
2844
2845                         spin_unlock_bh(&session->lock);
2846                         local_bh_disable();
2847                         iscsi_ctask_cleanup(conn, ctask);
2848                         local_bh_enable();
2849                         spin_lock_bh(&session->lock);
2850                 }
2851                 conn->ctask = NULL;
2852                 while (__kfifo_get(conn->immqueue, (void*)&mtask,
2853                            sizeof(void*)) ||
2854                         __kfifo_get(conn->mgmtqueue, (void*)&mtask,
2855                            sizeof(void*))) {
2856                         __kfifo_put(session->mgmtpool.queue,
2857                                     (void*)&mtask, sizeof(void*));
2858                 }
2859                 conn->mtask = NULL;
2860                 spin_unlock_bh(&session->lock);
2861
2862                 /*
2863                  * release socket only after we stopped data_xmit()
2864                  * activity and flushed all outstandings
2865                  */
2866                 sock_release(conn->sock);
2867                 conn->sock = NULL;
2868
2869                 /*
2870                  * for connection level recovery we should not calculate
2871                  * header digest. conn->hdr_size used for optimization
2872                  * in hdr_extract() and will be re-negotiated at
2873                  * set_param() time.
2874                  */
2875                 if (flag == STOP_CONN_RECOVER) {
2876                         conn->hdr_size = sizeof(struct iscsi_hdr);
2877                         conn->hdrdgst_en = 0;
2878                         conn->datadgst_en = 0;
2879                 }
2880         }
2881         mutex_unlock(&conn->xmitmutex);
2882 }
2883
2884 static int
2885 iscsi_conn_send_generic(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
2886                         char *data, uint32_t data_size)
2887 {
2888         struct iscsi_session *session = conn->session;
2889         struct iscsi_nopout *nop = (struct iscsi_nopout *)hdr;
2890         struct iscsi_mgmt_task *mtask;
2891
2892         spin_lock_bh(&session->lock);
2893         if (session->state == ISCSI_STATE_TERMINATE) {
2894                 spin_unlock_bh(&session->lock);
2895                 return -EPERM;
2896         }
2897         if (hdr->opcode == (ISCSI_OP_LOGIN | ISCSI_OP_IMMEDIATE) ||
2898             hdr->opcode == (ISCSI_OP_TEXT | ISCSI_OP_IMMEDIATE))
2899                 /*
2900                  * Login and Text are sent serially, in
2901                  * request-followed-by-response sequence.
2902                  * Same mtask can be used. Same ITT must be used.
2903                  * Note that login_mtask is preallocated at conn_create().
2904                  */
2905                 mtask = conn->login_mtask;
2906         else {
2907                 BUG_ON(conn->c_stage == ISCSI_CONN_INITIAL_STAGE);
2908                 BUG_ON(conn->c_stage == ISCSI_CONN_STOPPED);
2909
2910                 if (!__kfifo_get(session->mgmtpool.queue,
2911                                  (void*)&mtask, sizeof(void*))) {
2912                         spin_unlock_bh(&session->lock);
2913                         return -ENOSPC;
2914                 }
2915         }
2916
2917         /*
2918          * pre-format CmdSN and ExpStatSN for outgoing PDU.
2919          */
2920         if (hdr->itt != cpu_to_be32(ISCSI_RESERVED_TAG)) {
2921                 hdr->itt = mtask->itt | (conn->id << CID_SHIFT) |
2922                            (session->age << AGE_SHIFT);
2923                 nop->cmdsn = cpu_to_be32(session->cmdsn);
2924                 if (conn->c_stage == ISCSI_CONN_STARTED &&
2925                     !(hdr->opcode & ISCSI_OP_IMMEDIATE))
2926                         session->cmdsn++;
2927         } else
2928                 /* do not advance CmdSN */
2929                 nop->cmdsn = cpu_to_be32(session->cmdsn);
2930
2931         nop->exp_statsn = cpu_to_be32(conn->exp_statsn);
2932
2933         memcpy(&mtask->hdr, hdr, sizeof(struct iscsi_hdr));
2934
2935         iscsi_buf_init_virt(&mtask->headbuf, (char*)&mtask->hdr,
2936                                     sizeof(struct iscsi_hdr));
2937
2938         spin_unlock_bh(&session->lock);
2939
2940         if (data_size) {
2941                 memcpy(mtask->data, data, data_size);
2942                 mtask->data_count = data_size;
2943         } else
2944                 mtask->data_count = 0;
2945
2946         mtask->xmstate = XMSTATE_IMM_HDR;
2947
2948         if (mtask->data_count) {
2949                 iscsi_buf_init_iov(&mtask->sendbuf, (char*)mtask->data,
2950                                     mtask->data_count);
2951         }
2952
2953         debug_scsi("mgmtpdu [op 0x%x hdr->itt 0x%x datalen %d]\n",
2954                    hdr->opcode, hdr->itt, data_size);
2955
2956         /*
2957          * since send_pdu() could be called at least from two contexts,
2958          * we need to serialize __kfifo_put, so we don't have to take
2959          * additional lock on fast data-path
2960          */
2961         if (hdr->opcode & ISCSI_OP_IMMEDIATE)
2962                 __kfifo_put(conn->immqueue, (void*)&mtask, sizeof(void*));
2963         else
2964                 __kfifo_put(conn->mgmtqueue, (void*)&mtask, sizeof(void*));
2965
2966         schedule_work(&conn->xmitwork);
2967
2968         return 0;
2969 }
2970
2971 static int
2972 iscsi_eh_host_reset(struct scsi_cmnd *sc)
2973 {
2974         struct iscsi_cmd_task *ctask = (struct iscsi_cmd_task *)sc->SCp.ptr;
2975         struct iscsi_conn *conn = ctask->conn;
2976         struct iscsi_session *session = conn->session;
2977
2978         spin_lock_bh(&session->lock);
2979         if (session->state == ISCSI_STATE_TERMINATE) {
2980                 debug_scsi("failing host reset: session terminated "
2981                            "[CID %d age %d]", conn->id, session->age);
2982                 spin_unlock_bh(&session->lock);
2983                 return FAILED;
2984         }
2985         spin_unlock_bh(&session->lock);
2986
2987         debug_scsi("failing connection CID %d due to SCSI host reset "
2988                    "[itt 0x%x age %d]", conn->id, ctask->itt,
2989                    session->age);
2990         iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
2991
2992         return SUCCESS;
2993 }
2994
2995 static void
2996 iscsi_tmabort_timedout(unsigned long data)
2997 {
2998         struct iscsi_cmd_task *ctask = (struct iscsi_cmd_task *)data;
2999         struct iscsi_conn *conn = ctask->conn;
3000         struct iscsi_session *session = conn->session;
3001
3002         spin_lock(&session->lock);
3003         if (conn->tmabort_state == TMABORT_INITIAL) {
3004                 __kfifo_put(session->mgmtpool.queue,
3005                                 (void*)&ctask->mtask, sizeof(void*));
3006                 conn->tmabort_state = TMABORT_TIMEDOUT;
3007                 debug_scsi("tmabort timedout [sc %lx itt 0x%x]\n",
3008                         (long)ctask->sc, ctask->itt);
3009                 /* unblock eh_abort() */
3010                 wake_up(&conn->ehwait);
3011         }
3012         spin_unlock(&session->lock);
3013 }
3014
3015 static int
3016 iscsi_eh_abort(struct scsi_cmnd *sc)
3017 {
3018         int rc;
3019         struct iscsi_cmd_task *ctask = (struct iscsi_cmd_task *)sc->SCp.ptr;
3020         struct iscsi_conn *conn = ctask->conn;
3021         struct iscsi_session *session = conn->session;
3022
3023         conn->eh_abort_cnt++;
3024         debug_scsi("aborting [sc %lx itt 0x%x]\n", (long)sc, ctask->itt);
3025
3026         /*
3027          * two cases for ERL=0 here:
3028          *
3029          * 1) connection-level failure;
3030          * 2) recovery due protocol error;
3031          */
3032         mutex_lock(&conn->xmitmutex);
3033         spin_lock_bh(&session->lock);
3034         if (session->state != ISCSI_STATE_LOGGED_IN) {
3035                 if (session->state == ISCSI_STATE_TERMINATE) {
3036                         spin_unlock_bh(&session->lock);
3037                         mutex_unlock(&conn->xmitmutex);
3038                         goto failed;
3039                 }
3040                 spin_unlock_bh(&session->lock);
3041         } else {
3042                 struct iscsi_tm *hdr = &conn->tmhdr;
3043
3044                 /*
3045                  * Still LOGGED_IN...
3046                  */
3047
3048                 if (!ctask->sc || sc->SCp.phase != session->age) {
3049                         /*
3050                          * 1) ctask completed before time out. But session
3051                          *    is still ok => Happy Retry.
3052                          * 2) session was re-open during time out of ctask.
3053                          */
3054                         spin_unlock_bh(&session->lock);
3055                         mutex_unlock(&conn->xmitmutex);
3056                         goto success;
3057                 }
3058                 conn->tmabort_state = TMABORT_INITIAL;
3059                 spin_unlock_bh(&session->lock);
3060
3061                 /*
3062                  * ctask timed out but session is OK
3063                  * ERL=0 requires task mgmt abort to be issued on each
3064                  * failed command. requests must be serialized.
3065                  */
3066                 memset(hdr, 0, sizeof(struct iscsi_tm));
3067                 hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
3068                 hdr->flags = ISCSI_TM_FUNC_ABORT_TASK;
3069                 hdr->flags |= ISCSI_FLAG_CMD_FINAL;
3070                 memcpy(hdr->lun, ctask->hdr.lun, sizeof(hdr->lun));
3071                 hdr->rtt = ctask->hdr.itt;
3072                 hdr->refcmdsn = ctask->hdr.cmdsn;
3073
3074                 rc = iscsi_conn_send_generic(conn, (struct iscsi_hdr *)hdr,
3075                                              NULL, 0);
3076                 if (rc) {
3077                         iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
3078                         debug_scsi("abort sent failure [itt 0x%x]", ctask->itt);
3079                 } else {
3080                         struct iscsi_r2t_info *r2t;
3081
3082                         /*
3083                          * TMF abort vs. TMF response race logic
3084                          */
3085                         spin_lock_bh(&session->lock);
3086                         ctask->mtask = (struct iscsi_mgmt_task *)
3087                                 session->mgmt_cmds[(hdr->itt & ITT_MASK) -
3088                                                         ISCSI_MGMT_ITT_OFFSET];
3089                         /*
3090                          * have to flush r2tqueue to avoid r2t leaks
3091                          */
3092                         while (__kfifo_get(ctask->r2tqueue, (void*)&r2t,
3093                                 sizeof(void*))) {
3094                                 __kfifo_put(ctask->r2tpool.queue, (void*)&r2t,
3095                                         sizeof(void*));
3096                         }
3097                         if (conn->tmabort_state == TMABORT_INITIAL) {
3098                                 conn->tmfcmd_pdus_cnt++;
3099                                 conn->tmabort_timer.expires = 3*HZ + jiffies;
3100                                 conn->tmabort_timer.function =
3101                                                 iscsi_tmabort_timedout;
3102                                 conn->tmabort_timer.data = (unsigned long)ctask;
3103                                 add_timer(&conn->tmabort_timer);
3104                                 debug_scsi("abort sent [itt 0x%x]", ctask->itt);
3105                         } else {
3106                                 if (!ctask->sc ||
3107                                     conn->tmabort_state == TMABORT_SUCCESS) {
3108                                         conn->tmabort_state = TMABORT_INITIAL;
3109                                         spin_unlock_bh(&session->lock);
3110                                         mutex_unlock(&conn->xmitmutex);
3111                                         goto success;
3112                                 }
3113                                 conn->tmabort_state = TMABORT_INITIAL;
3114                                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
3115                         }
3116                         spin_unlock_bh(&session->lock);
3117                 }
3118         }
3119         mutex_unlock(&conn->xmitmutex);
3120
3121
3122         /*
3123          * block eh thread until:
3124          *
3125          * 1) abort response;
3126          * 2) abort timeout;
3127          * 3) session re-opened;
3128          * 4) session terminated;
3129          */
3130         for (;;) {
3131                 int p_state = session->state;
3132
3133                 rc = wait_event_interruptible(conn->ehwait,
3134                         (p_state == ISCSI_STATE_LOGGED_IN ?
3135                          (session->state == ISCSI_STATE_TERMINATE ||
3136                           conn->tmabort_state != TMABORT_INITIAL) :
3137                          (session->state == ISCSI_STATE_TERMINATE ||
3138                           session->state == ISCSI_STATE_LOGGED_IN)));
3139                 if (rc) {
3140                         /* shutdown.. */
3141                         session->state = ISCSI_STATE_TERMINATE;
3142                         goto failed;
3143                 }
3144
3145                 if (signal_pending(current))
3146                         flush_signals(current);
3147
3148                 if (session->state == ISCSI_STATE_TERMINATE)
3149                         goto failed;
3150
3151                 spin_lock_bh(&session->lock);
3152                 if (sc->SCp.phase == session->age &&
3153                    (conn->tmabort_state == TMABORT_TIMEDOUT ||
3154                     conn->tmabort_state == TMABORT_FAILED)) {
3155                         conn->tmabort_state = TMABORT_INITIAL;
3156                         if (!ctask->sc) {
3157                                 /*
3158                                  * ctask completed before tmf abort response or
3159                                  * time out.
3160                                  * But session is still ok => Happy Retry.
3161                                  */
3162                                 spin_unlock_bh(&session->lock);
3163                                 break;
3164                         }
3165                         spin_unlock_bh(&session->lock);
3166                         iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
3167                         continue;
3168                 }
3169                 spin_unlock_bh(&session->lock);
3170                 break;
3171         }
3172
3173 success:
3174         debug_scsi("abort success [sc %lx itt 0x%x]\n", (long)sc, ctask->itt);
3175         rc = SUCCESS;
3176         goto exit;
3177
3178 failed:
3179         debug_scsi("abort failed [sc %lx itt 0x%x]\n", (long)sc, ctask->itt);
3180         rc = FAILED;
3181
3182 exit:
3183         del_timer_sync(&conn->tmabort_timer);
3184
3185         mutex_lock(&conn->xmitmutex);
3186         if (conn->sock) {
3187                 struct sock *sk = conn->sock->sk;
3188
3189                 write_lock_bh(&sk->sk_callback_lock);
3190                 iscsi_ctask_cleanup(conn, ctask);
3191                 write_unlock_bh(&sk->sk_callback_lock);
3192         }
3193         mutex_unlock(&conn->xmitmutex);
3194         return rc;
3195 }
3196
3197 static int
3198 iscsi_r2tpool_alloc(struct iscsi_session *session)
3199 {
3200         int i;
3201         int cmd_i;
3202
3203         /*
3204          * initialize per-task: R2T pool and xmit queue
3205          */
3206         for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
3207                 struct iscsi_cmd_task *ctask = session->cmds[cmd_i];
3208
3209                 /*
3210                  * pre-allocated x4 as much r2ts to handle race when
3211                  * target acks DataOut faster than we data_xmit() queues
3212                  * could replenish r2tqueue.
3213                  */
3214
3215                 /* R2T pool */
3216                 if (iscsi_pool_init(&ctask->r2tpool, session->max_r2t * 4,
3217                         (void***)&ctask->r2ts, sizeof(struct iscsi_r2t_info))) {
3218                         goto r2t_alloc_fail;
3219                 }
3220
3221                 /* R2T xmit queue */
3222                 ctask->r2tqueue = kfifo_alloc(
3223                       session->max_r2t * 4 * sizeof(void*), GFP_KERNEL, NULL);
3224                 if (ctask->r2tqueue == ERR_PTR(-ENOMEM)) {
3225                         iscsi_pool_free(&ctask->r2tpool, (void**)ctask->r2ts);
3226                         goto r2t_alloc_fail;
3227                 }
3228
3229                 /*
3230                  * number of
3231                  * Data-Out PDU's within R2T-sequence can be quite big;
3232                  * using mempool
3233                  */
3234                 ctask->datapool = mempool_create(ISCSI_DTASK_DEFAULT_MAX,
3235                          mempool_alloc_slab, mempool_free_slab, taskcache);
3236                 if (ctask->datapool == NULL) {
3237                         kfifo_free(ctask->r2tqueue);
3238                         iscsi_pool_free(&ctask->r2tpool, (void**)ctask->r2ts);
3239                         goto r2t_alloc_fail;
3240                 }
3241                 INIT_LIST_HEAD(&ctask->dataqueue);
3242         }
3243
3244         return 0;
3245
3246 r2t_alloc_fail:
3247         for (i = 0; i < cmd_i; i++) {
3248                 mempool_destroy(session->cmds[i]->datapool);
3249                 kfifo_free(session->cmds[i]->r2tqueue);
3250                 iscsi_pool_free(&session->cmds[i]->r2tpool,
3251                                 (void**)session->cmds[i]->r2ts);
3252         }
3253         return -ENOMEM;
3254 }
3255
3256 static void
3257 iscsi_r2tpool_free(struct iscsi_session *session)
3258 {
3259         int i;
3260
3261         for (i = 0; i < session->cmds_max; i++) {
3262                 mempool_destroy(session->cmds[i]->datapool);
3263                 kfifo_free(session->cmds[i]->r2tqueue);
3264                 iscsi_pool_free(&session->cmds[i]->r2tpool,
3265                                 (void**)session->cmds[i]->r2ts);
3266         }
3267 }
3268
3269 static struct scsi_host_template iscsi_sht = {
3270         .name                   = "iSCSI Initiator over TCP/IP, v."
3271                                   ISCSI_VERSION_STR,
3272         .queuecommand           = iscsi_queuecommand,
3273         .change_queue_depth     = iscsi_change_queue_depth,
3274         .can_queue              = ISCSI_XMIT_CMDS_MAX - 1,
3275         .sg_tablesize           = ISCSI_SG_TABLESIZE,
3276         .cmd_per_lun            = ISCSI_DEF_CMD_PER_LUN,
3277         .eh_abort_handler       = iscsi_eh_abort,
3278         .eh_host_reset_handler  = iscsi_eh_host_reset,
3279         .use_clustering         = DISABLE_CLUSTERING,
3280         .proc_name              = "iscsi_tcp",
3281         .this_id                = -1,
3282 };
3283
3284 static iscsi_sessionh_t
3285 iscsi_session_create(uint32_t initial_cmdsn, struct Scsi_Host *host)
3286 {
3287         int cmd_i;
3288         struct iscsi_session *session;
3289
3290         session = iscsi_hostdata(host->hostdata);
3291         memset(session, 0, sizeof(struct iscsi_session));
3292
3293         session->host = host;
3294         session->id = host->host_no;
3295         session->state = ISCSI_STATE_LOGGED_IN;
3296         session->mgmtpool_max = ISCSI_MGMT_CMDS_MAX;
3297         session->cmds_max = ISCSI_XMIT_CMDS_MAX;
3298         session->cmdsn = initial_cmdsn;
3299         session->exp_cmdsn = initial_cmdsn + 1;
3300         session->max_cmdsn = initial_cmdsn + 1;
3301         session->max_r2t = 1;
3302
3303         /* initialize SCSI PDU commands pool */
3304         if (iscsi_pool_init(&session->cmdpool, session->cmds_max,
3305                 (void***)&session->cmds, sizeof(struct iscsi_cmd_task)))
3306                 goto cmdpool_alloc_fail;
3307
3308         /* pre-format cmds pool with ITT */
3309         for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++)
3310                 session->cmds[cmd_i]->itt = cmd_i;
3311
3312         spin_lock_init(&session->lock);
3313         INIT_LIST_HEAD(&session->connections);
3314
3315         /* initialize immediate command pool */
3316         if (iscsi_pool_init(&session->mgmtpool, session->mgmtpool_max,
3317                 (void***)&session->mgmt_cmds, sizeof(struct iscsi_mgmt_task)))
3318                 goto mgmtpool_alloc_fail;
3319
3320
3321         /* pre-format immediate cmds pool with ITT */
3322         for (cmd_i = 0; cmd_i < session->mgmtpool_max; cmd_i++) {
3323                 session->mgmt_cmds[cmd_i]->itt = ISCSI_MGMT_ITT_OFFSET + cmd_i;
3324                 session->mgmt_cmds[cmd_i]->data = kmalloc(
3325                         DEFAULT_MAX_RECV_DATA_SEGMENT_LENGTH, GFP_KERNEL);
3326                 if (!session->mgmt_cmds[cmd_i]->data) {
3327                         int j;
3328
3329                         for (j = 0; j < cmd_i; j++)
3330                                 kfree(session->mgmt_cmds[j]->data);
3331                         goto immdata_alloc_fail;
3332                 }
3333         }
3334
3335         if (iscsi_r2tpool_alloc(session))
3336                 goto r2tpool_alloc_fail;
3337
3338         return iscsi_handle(session);
3339
3340 r2tpool_alloc_fail:
3341         for (cmd_i = 0; cmd_i < session->mgmtpool_max; cmd_i++)
3342                 kfree(session->mgmt_cmds[cmd_i]->data);
3343         iscsi_pool_free(&session->mgmtpool, (void**)session->mgmt_cmds);
3344 immdata_alloc_fail:
3345 mgmtpool_alloc_fail:
3346         iscsi_pool_free(&session->cmdpool, (void**)session->cmds);
3347 cmdpool_alloc_fail:
3348         return iscsi_handle(NULL);
3349 }
3350
3351 static void
3352 iscsi_session_destroy(iscsi_sessionh_t sessionh)
3353 {
3354         int cmd_i;
3355         struct iscsi_data_task *dtask, *n;
3356         struct iscsi_session *session = iscsi_ptr(sessionh);
3357
3358         for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
3359                 struct iscsi_cmd_task *ctask = session->cmds[cmd_i];
3360                 list_for_each_entry_safe(dtask, n, &ctask->dataqueue, item) {
3361                         list_del(&dtask->item);
3362                         mempool_free(dtask, ctask->datapool);
3363                 }
3364         }
3365
3366         for (cmd_i = 0; cmd_i < session->mgmtpool_max; cmd_i++)
3367                 kfree(session->mgmt_cmds[cmd_i]->data);
3368
3369         iscsi_r2tpool_free(session);
3370         iscsi_pool_free(&session->mgmtpool, (void**)session->mgmt_cmds);
3371         iscsi_pool_free(&session->cmdpool, (void**)session->cmds);
3372 }
3373
3374 static int
3375 iscsi_conn_set_param(iscsi_connh_t connh, enum iscsi_param param,
3376                      uint32_t value)
3377 {
3378         struct iscsi_conn *conn = iscsi_ptr(connh);
3379         struct iscsi_session *session = conn->session;
3380
3381         spin_lock_bh(&session->lock);
3382         if (conn->c_stage != ISCSI_CONN_INITIAL_STAGE &&
3383             conn->stop_stage != STOP_CONN_RECOVER) {
3384                 printk(KERN_ERR "iscsi_tcp: can not change parameter [%d]\n",
3385                        param);
3386                 spin_unlock_bh(&session->lock);
3387                 return 0;
3388         }
3389         spin_unlock_bh(&session->lock);
3390
3391         switch(param) {
3392         case ISCSI_PARAM_MAX_RECV_DLENGTH: {
3393                 char *saveptr = conn->data;
3394                 gfp_t flags = GFP_KERNEL;
3395
3396                 if (conn->data_size >= value) {
3397                         conn->max_recv_dlength = value;
3398                         break;
3399                 }
3400
3401                 spin_lock_bh(&session->lock);
3402                 if (conn->stop_stage == STOP_CONN_RECOVER)
3403                         flags = GFP_ATOMIC;
3404                 spin_unlock_bh(&session->lock);
3405
3406                 if (value <= PAGE_SIZE)
3407                         conn->data = kmalloc(value, flags);
3408                 else
3409                         conn->data = (void*)__get_free_pages(flags,
3410                                                              get_order(value));
3411                 if (conn->data == NULL) {
3412                         conn->data = saveptr;
3413                         return -ENOMEM;
3414                 }
3415                 if (conn->data_size <= PAGE_SIZE)
3416                         kfree(saveptr);
3417                 else
3418                         free_pages((unsigned long)saveptr,
3419                                    get_order(conn->data_size));
3420                 conn->max_recv_dlength = value;
3421                 conn->data_size = value;
3422                 }
3423                 break;
3424         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
3425                 conn->max_xmit_dlength =  value;
3426                 break;
3427         case ISCSI_PARAM_HDRDGST_EN:
3428                 conn->hdrdgst_en = value;
3429                 conn->hdr_size = sizeof(struct iscsi_hdr);
3430                 if (conn->hdrdgst_en) {
3431                         conn->hdr_size += sizeof(__u32);
3432                         if (!conn->tx_tfm)
3433                                 conn->tx_tfm = crypto_alloc_tfm("crc32c", 0);
3434                         if (!conn->tx_tfm)
3435                                 return -ENOMEM;
3436                         if (!conn->rx_tfm)
3437                                 conn->rx_tfm = crypto_alloc_tfm("crc32c", 0);
3438                         if (!conn->rx_tfm) {
3439                                 crypto_free_tfm(conn->tx_tfm);
3440                                 return -ENOMEM;
3441                         }
3442                 } else {
3443                         if (conn->tx_tfm)
3444                                 crypto_free_tfm(conn->tx_tfm);
3445                         if (conn->rx_tfm)
3446                                 crypto_free_tfm(conn->rx_tfm);
3447                 }
3448                 break;
3449         case ISCSI_PARAM_DATADGST_EN:
3450                 conn->datadgst_en = value;
3451                 if (conn->datadgst_en) {
3452                         if (!conn->data_tx_tfm)
3453                                 conn->data_tx_tfm =
3454                                     crypto_alloc_tfm("crc32c", 0);
3455                         if (!conn->data_tx_tfm)
3456                                 return -ENOMEM;
3457                         if (!conn->data_rx_tfm)
3458                                 conn->data_rx_tfm =
3459                                     crypto_alloc_tfm("crc32c", 0);
3460                         if (!conn->data_rx_tfm) {
3461                                 crypto_free_tfm(conn->data_tx_tfm);
3462                                 return -ENOMEM;
3463                         }
3464                 } else {
3465                         if (conn->data_tx_tfm)
3466                                 crypto_free_tfm(conn->data_tx_tfm);
3467                         if (conn->data_rx_tfm)
3468                                 crypto_free_tfm(conn->data_rx_tfm);
3469                 }
3470                 break;
3471         case ISCSI_PARAM_INITIAL_R2T_EN:
3472                 session->initial_r2t_en = value;
3473                 break;
3474         case ISCSI_PARAM_MAX_R2T:
3475                 if (session->max_r2t == roundup_pow_of_two(value))
3476                         break;
3477                 iscsi_r2tpool_free(session);
3478                 session->max_r2t = value;
3479                 if (session->max_r2t & (session->max_r2t - 1))
3480                         session->max_r2t = roundup_pow_of_two(session->max_r2t);
3481                 if (iscsi_r2tpool_alloc(session))
3482                         return -ENOMEM;
3483                 break;
3484         case ISCSI_PARAM_IMM_DATA_EN:
3485                 session->imm_data_en = value;
3486                 break;
3487         case ISCSI_PARAM_FIRST_BURST:
3488                 session->first_burst = value;
3489                 break;
3490         case ISCSI_PARAM_MAX_BURST:
3491                 session->max_burst = value;
3492                 break;
3493         case ISCSI_PARAM_PDU_INORDER_EN:
3494                 session->pdu_inorder_en = value;
3495                 break;
3496         case ISCSI_PARAM_DATASEQ_INORDER_EN:
3497                 session->dataseq_inorder_en = value;
3498                 break;
3499         case ISCSI_PARAM_ERL:
3500                 session->erl = value;
3501                 break;
3502         case ISCSI_PARAM_IFMARKER_EN:
3503                 BUG_ON(value);
3504                 session->ifmarker_en = value;
3505                 break;
3506         case ISCSI_PARAM_OFMARKER_EN:
3507                 BUG_ON(value);
3508                 session->ofmarker_en = value;
3509                 break;
3510         default:
3511                 break;
3512         }
3513
3514         return 0;
3515 }
3516
3517 static int
3518 iscsi_conn_get_param(iscsi_connh_t connh, enum iscsi_param param,
3519                      uint32_t *value)
3520 {
3521         struct iscsi_conn *conn = iscsi_ptr(connh);
3522         struct iscsi_session *session = conn->session;
3523
3524         switch(param) {
3525         case ISCSI_PARAM_MAX_RECV_DLENGTH:
3526                 *value = conn->max_recv_dlength;
3527                 break;
3528         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
3529                 *value = conn->max_xmit_dlength;
3530                 break;
3531         case ISCSI_PARAM_HDRDGST_EN:
3532                 *value = conn->hdrdgst_en;
3533                 break;
3534         case ISCSI_PARAM_DATADGST_EN:
3535                 *value = conn->datadgst_en;
3536                 break;
3537         case ISCSI_PARAM_INITIAL_R2T_EN:
3538                 *value = session->initial_r2t_en;
3539                 break;
3540         case ISCSI_PARAM_MAX_R2T:
3541                 *value = session->max_r2t;
3542                 break;
3543         case ISCSI_PARAM_IMM_DATA_EN:
3544                 *value = session->imm_data_en;
3545                 break;
3546         case ISCSI_PARAM_FIRST_BURST:
3547                 *value = session->first_burst;
3548                 break;
3549         case ISCSI_PARAM_MAX_BURST:
3550                 *value = session->max_burst;
3551                 break;
3552         case ISCSI_PARAM_PDU_INORDER_EN:
3553                 *value = session->pdu_inorder_en;
3554                 break;
3555         case ISCSI_PARAM_DATASEQ_INORDER_EN:
3556                 *value = session->dataseq_inorder_en;
3557                 break;
3558         case ISCSI_PARAM_ERL:
3559                 *value = session->erl;
3560                 break;
3561         case ISCSI_PARAM_IFMARKER_EN:
3562                 *value = session->ifmarker_en;
3563                 break;
3564         case ISCSI_PARAM_OFMARKER_EN:
3565                 *value = session->ofmarker_en;
3566                 break;
3567         default:
3568                 return ISCSI_ERR_PARAM_NOT_FOUND;
3569         }
3570
3571         return 0;
3572 }
3573
3574 static void
3575 iscsi_conn_get_stats(iscsi_connh_t connh, struct iscsi_stats *stats)
3576 {
3577         struct iscsi_conn *conn = iscsi_ptr(connh);
3578
3579         stats->txdata_octets = conn->txdata_octets;
3580         stats->rxdata_octets = conn->rxdata_octets;
3581         stats->scsicmd_pdus = conn->scsicmd_pdus_cnt;
3582         stats->dataout_pdus = conn->dataout_pdus_cnt;
3583         stats->scsirsp_pdus = conn->scsirsp_pdus_cnt;
3584         stats->datain_pdus = conn->datain_pdus_cnt;
3585         stats->r2t_pdus = conn->r2t_pdus_cnt;
3586         stats->tmfcmd_pdus = conn->tmfcmd_pdus_cnt;
3587         stats->tmfrsp_pdus = conn->tmfrsp_pdus_cnt;
3588         stats->custom_length = 3;
3589         strcpy(stats->custom[0].desc, "tx_sendpage_failures");
3590         stats->custom[0].value = conn->sendpage_failures_cnt;
3591         strcpy(stats->custom[1].desc, "rx_discontiguous_hdr");
3592         stats->custom[1].value = conn->discontiguous_hdr_cnt;
3593         strcpy(stats->custom[2].desc, "eh_abort_cnt");
3594         stats->custom[2].value = conn->eh_abort_cnt;
3595 }
3596
3597 static int
3598 iscsi_conn_send_pdu(iscsi_connh_t connh, struct iscsi_hdr *hdr, char *data,
3599                     uint32_t data_size)
3600 {
3601         struct iscsi_conn *conn = iscsi_ptr(connh);
3602         int rc;
3603
3604         mutex_lock(&conn->xmitmutex);
3605         rc = iscsi_conn_send_generic(conn, hdr, data, data_size);
3606         mutex_unlock(&conn->xmitmutex);
3607
3608         return rc;
3609 }
3610
3611 static struct iscsi_transport iscsi_tcp_transport = {
3612         .owner                  = THIS_MODULE,
3613         .name                   = "tcp",
3614         .caps                   = CAP_RECOVERY_L0 | CAP_MULTI_R2T | CAP_HDRDGST
3615                                   | CAP_DATADGST,
3616         .host_template          = &iscsi_sht,
3617         .hostdata_size          = sizeof(struct iscsi_session),
3618         .max_conn               = 1,
3619         .max_cmd_len            = ISCSI_TCP_MAX_CMD_LEN,
3620         .create_session         = iscsi_session_create,
3621         .destroy_session        = iscsi_session_destroy,
3622         .create_conn            = iscsi_conn_create,
3623         .bind_conn              = iscsi_conn_bind,
3624         .destroy_conn           = iscsi_conn_destroy,
3625         .set_param              = iscsi_conn_set_param,
3626         .get_param              = iscsi_conn_get_param,
3627         .start_conn             = iscsi_conn_start,
3628         .stop_conn              = iscsi_conn_stop,
3629         .send_pdu               = iscsi_conn_send_pdu,
3630         .get_stats              = iscsi_conn_get_stats,
3631 };
3632
3633 static int __init
3634 iscsi_tcp_init(void)
3635 {
3636         int error;
3637
3638         if (iscsi_max_lun < 1) {
3639                 printk(KERN_ERR "Invalid max_lun value of %u\n", iscsi_max_lun);
3640                 return -EINVAL;
3641         }
3642         iscsi_tcp_transport.max_lun = iscsi_max_lun;
3643
3644         taskcache = kmem_cache_create("iscsi_taskcache",
3645                         sizeof(struct iscsi_data_task), 0,
3646                         SLAB_HWCACHE_ALIGN | SLAB_NO_REAP, NULL, NULL);
3647         if (!taskcache)
3648                 return -ENOMEM;
3649
3650         error = iscsi_register_transport(&iscsi_tcp_transport);
3651         if (error)
3652                 kmem_cache_destroy(taskcache);
3653
3654         return error;
3655 }
3656
3657 static void __exit
3658 iscsi_tcp_exit(void)
3659 {
3660         iscsi_unregister_transport(&iscsi_tcp_transport);
3661         kmem_cache_destroy(taskcache);
3662 }
3663
3664 module_init(iscsi_tcp_init);
3665 module_exit(iscsi_tcp_exit);