drivers/scsi/iscsi_tcp.c

   1 /*
   2  * iSCSI Initiator over TCP/IP Data-Path
   3  *
   4  * Copyright (C) 2004 Dmitry Yusupov
   5  * Copyright (C) 2004 Alex Aizman
   6  * Copyright (C) 2005 Mike Christie
   7  * maintained by open-iscsi@googlegroups.com
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published
  11  * by the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful, but
  15  * WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  17  * General Public License for more details.
  18  *
  19  * See the file COPYING included with this distribution for more details.
  20  *
  21  * Credits:
  22  *      Christoph Hellwig
  23  *      FUJITA Tomonori
  24  *      Arne Redlich
  25  *      Zhenyu Wang
  26  */
  27
  28 #include <linux/types.h>
  29 #include <linux/list.h>
  30 #include <linux/inet.h>
  31 #include <linux/blkdev.h>
  32 #include <linux/crypto.h>
  33 #include <linux/delay.h>
  34 #include <linux/kfifo.h>
  35 #include <linux/scatterlist.h>
  36 #include <net/tcp.h>
  37 #include <scsi/scsi_cmnd.h>
  38 #include <scsi/scsi_device.h>
  39 #include <scsi/scsi_eh.h>
  40 #include <scsi/scsi_request.h>
  41 #include <scsi/scsi_tcq.h>
  42 #include <scsi/scsi_host.h>
  43 #include <scsi/scsi.h>
  44 #include <scsi/scsi_transport_iscsi.h>
  45
  46 #include "iscsi_tcp.h"
  47
  48 MODULE_AUTHOR("Dmitry Yusupov <dmitry_yus@yahoo.com>, "
  49               "Alex Aizman <itn780@yahoo.com>");
  50 MODULE_DESCRIPTION("iSCSI/TCP data-path");
  51 MODULE_LICENSE("GPL");
  52 MODULE_VERSION("0:4.445");
  53 /* #define DEBUG_TCP */
  54 /* #define DEBUG_SCSI */
  55 #define DEBUG_ASSERT
  56
  57 #ifdef DEBUG_TCP
  58 #define debug_tcp(fmt...) printk(KERN_DEBUG "tcp: " fmt)
  59 #else
  60 #define debug_tcp(fmt...)
  61 #endif
  62
  63 #ifdef DEBUG_SCSI
  64 #define debug_scsi(fmt...) printk(KERN_DEBUG "scsi: " fmt)
  65 #else
  66 #define debug_scsi(fmt...)
  67 #endif
  68
  69 #ifndef DEBUG_ASSERT
  70 #ifdef BUG_ON
  71 #undef BUG_ON
  72 #endif
  73 #define BUG_ON(expr)
  74 #endif
  75
  76 #define INVALID_SN_DELTA        0xffff
  77
  78 static unsigned int iscsi_max_lun = 512;
  79 module_param_named(max_lun, iscsi_max_lun, uint, S_IRUGO);
  80
  81 /* global data */
  82 static kmem_cache_t *taskcache;
  83
  84 static inline void
  85 iscsi_buf_init_virt(struct iscsi_buf *ibuf, char *vbuf, int size)
  86 {
  87         sg_init_one(&ibuf->sg, (u8 *)vbuf, size);
  88         ibuf->sent = 0;
  89 }
  90
  91 static inline void
  92 iscsi_buf_init_iov(struct iscsi_buf *ibuf, char *vbuf, int size)
  93 {
  94         ibuf->sg.page = (void*)vbuf;
  95         ibuf->sg.offset = (unsigned int)-1;
  96         ibuf->sg.length = size;
  97         ibuf->sent = 0;
  98 }
  99
 100 static inline void*
 101 iscsi_buf_iov_base(struct iscsi_buf *ibuf)
 102 {
 103         return (char*)ibuf->sg.page + ibuf->sent;
 104 }
 105
 106 static inline void
 107 iscsi_buf_init_sg(struct iscsi_buf *ibuf, struct scatterlist *sg)
 108 {
 109         /*
 110          * Fastpath: sg element fits into single page
 111          */
 112         if (sg->length + sg->offset <= PAGE_SIZE && page_count(sg->page) >= 2) {
 113                 ibuf->sg.page = sg->page;
 114                 ibuf->sg.offset = sg->offset;
 115                 ibuf->sg.length = sg->length;
 116         } else
 117                 iscsi_buf_init_iov(ibuf, page_address(sg->page), sg->length);
 118         ibuf->sent = 0;
 119 }
 120
 121 static inline int
 122 iscsi_buf_left(struct iscsi_buf *ibuf)
 123 {
 124         int rc;
 125
 126         rc = ibuf->sg.length - ibuf->sent;
 127         BUG_ON(rc < 0);
 128         return rc;
 129 }
 130
 131 static inline void
 132 iscsi_hdr_digest(struct iscsi_conn *conn, struct iscsi_buf *buf,
 133                  u8* crc)
 134 {
 135         crypto_digest_digest(conn->tx_tfm, &buf->sg, 1, crc);
 136         buf->sg.length += sizeof(uint32_t);
 137 }
 138
 139 static void
 140 iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err)
 141 {
 142         struct iscsi_session *session = conn->session;
 143         unsigned long flags;
 144
 145         spin_lock_irqsave(&session->lock, flags);
 146         if (session->conn_cnt == 1 || session->leadconn == conn)
 147                 session->state = ISCSI_STATE_FAILED;
 148         spin_unlock_irqrestore(&session->lock, flags);
 149         set_bit(SUSPEND_BIT, &conn->suspend_tx);
 150         set_bit(SUSPEND_BIT, &conn->suspend_rx);
 151         iscsi_conn_error(iscsi_handle(conn), err);
 152 }
 153
 154 static inline int
 155 iscsi_check_assign_cmdsn(struct iscsi_session *session, struct iscsi_nopin *hdr)
 156 {
 157         uint32_t max_cmdsn = be32_to_cpu(hdr->max_cmdsn);
 158         uint32_t exp_cmdsn = be32_to_cpu(hdr->exp_cmdsn);
 159
 160         if (max_cmdsn < exp_cmdsn -1 &&
 161             max_cmdsn > exp_cmdsn - INVALID_SN_DELTA)
 162                 return ISCSI_ERR_MAX_CMDSN;
 163         if (max_cmdsn > session->max_cmdsn ||
 164             max_cmdsn < session->max_cmdsn - INVALID_SN_DELTA)
 165                 session->max_cmdsn = max_cmdsn;
 166         if (exp_cmdsn > session->exp_cmdsn ||
 167             exp_cmdsn < session->exp_cmdsn - INVALID_SN_DELTA)
 168                 session->exp_cmdsn = exp_cmdsn;
 169
 170         return 0;
 171 }
 172
 173 static inline int
 174 iscsi_hdr_extract(struct iscsi_conn *conn)
 175 {
 176         struct sk_buff *skb = conn->in.skb;
 177
 178         if (conn->in.copy >= conn->hdr_size &&
 179             conn->in_progress == IN_PROGRESS_WAIT_HEADER) {
 180                 /*
 181                  * Zero-copy PDU Header: using connection context
 182                  * to store header pointer.
 183                  */
 184                 if (skb_shinfo(skb)->frag_list == NULL &&
 185                     !skb_shinfo(skb)->nr_frags)
 186                         conn->in.hdr = (struct iscsi_hdr *)
 187                                 ((char*)skb->data + conn->in.offset);
 188                 else {
 189                         /* ignoring return code since we checked
 190                          * in.copy before */
 191                         skb_copy_bits(skb, conn->in.offset,
 192                                 &conn->hdr, conn->hdr_size);
 193                         conn->in.hdr = &conn->hdr;
 194                 }
 195                 conn->in.offset += conn->hdr_size;
 196                 conn->in.copy -= conn->hdr_size;
 197         } else {
 198                 int hdr_remains;
 199                 int copylen;
 200
 201                 /*
 202                  * PDU header scattered across SKB's,
 203                  * copying it... This'll happen quite rarely.
 204                  */
 205
 206                 if (conn->in_progress == IN_PROGRESS_WAIT_HEADER)
 207                         conn->in.hdr_offset = 0;
 208
 209                 hdr_remains = conn->hdr_size - conn->in.hdr_offset;
 210                 BUG_ON(hdr_remains <= 0);
 211
 212                 copylen = min(conn->in.copy, hdr_remains);
 213                 skb_copy_bits(skb, conn->in.offset,
 214                         (char*)&conn->hdr + conn->in.hdr_offset, copylen);
 215
 216                 debug_tcp("PDU gather offset %d bytes %d in.offset %d "
 217                        "in.copy %d\n", conn->in.hdr_offset, copylen,
 218                        conn->in.offset, conn->in.copy);
 219
 220                 conn->in.offset += copylen;
 221                 conn->in.copy -= copylen;
 222                 if (copylen < hdr_remains)  {
 223                         conn->in_progress = IN_PROGRESS_HEADER_GATHER;
 224                         conn->in.hdr_offset += copylen;
 225                         return -EAGAIN;
 226                 }
 227                 conn->in.hdr = &conn->hdr;
 228                 conn->discontiguous_hdr_cnt++;
 229                 conn->in_progress = IN_PROGRESS_WAIT_HEADER;
 230         }
 231
 232         return 0;
 233 }
 234
 235 static inline void
 236 iscsi_ctask_cleanup(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
 237 {
 238         struct scsi_cmnd *sc = ctask->sc;
 239         struct iscsi_session *session = conn->session;
 240
 241         spin_lock(&session->lock);
 242         if (unlikely(!sc)) {
 243                 spin_unlock(&session->lock);
 244                 return;
 245         }
 246         if (sc->sc_data_direction == DMA_TO_DEVICE) {
 247                 struct iscsi_data_task *dtask, *n;
 248                 /* WRITE: cleanup Data-Out's if any */
 249                 spin_lock(&conn->lock);
 250                 list_for_each_entry_safe(dtask, n, &ctask->dataqueue, item) {
 251                         list_del(&dtask->item);
 252                         mempool_free(dtask, ctask->datapool);
 253                 }
 254                 spin_unlock(&conn->lock);
 255         }
 256         ctask->xmstate = XMSTATE_IDLE;
 257         ctask->r2t = NULL;
 258         ctask->sc = NULL;
 259         __kfifo_put(session->cmdpool.queue, (void*)&ctask, sizeof(void*));
 260         spin_unlock(&session->lock);
 261 }
 262
 263 /**
 264  * iscsi_cmd_rsp - SCSI Command Response processing
 265  * @conn: iscsi connection
 266  * @ctask: scsi command task
 267  **/
 268 static int
 269 iscsi_cmd_rsp(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
 270 {
 271         int rc;
 272         struct iscsi_cmd_rsp *rhdr = (struct iscsi_cmd_rsp *)conn->in.hdr;
 273         struct iscsi_session *session = conn->session;
 274         struct scsi_cmnd *sc = ctask->sc;
 275
 276         rc = iscsi_check_assign_cmdsn(session, (struct iscsi_nopin*)rhdr);
 277         if (rc) {
 278                 sc->result = (DID_ERROR << 16);
 279                 goto out;
 280         }
 281
 282         conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
 283
 284         sc->result = (DID_OK << 16) | rhdr->cmd_status;
 285
 286         if (rhdr->response != ISCSI_STATUS_CMD_COMPLETED) {
 287                 sc->result = (DID_ERROR << 16);
 288                 goto out;
 289         }
 290
 291         if (rhdr->cmd_status == SAM_STAT_CHECK_CONDITION && conn->senselen) {
 292                 int sensecopy = min(conn->senselen, SCSI_SENSE_BUFFERSIZE);
 293
 294                 memcpy(sc->sense_buffer, conn->data + 2, sensecopy);
 295                 debug_scsi("copied %d bytes of sense\n", sensecopy);
 296         }
 297
 298         if (sc->sc_data_direction == DMA_TO_DEVICE)
 299                 goto out;
 300
 301         if (rhdr->flags & ISCSI_FLAG_CMD_UNDERFLOW) {
 302                 int res_count = be32_to_cpu(rhdr->residual_count);
 303
 304                 if (res_count > 0 && res_count <= sc->request_bufflen)
 305                         sc->resid = res_count;
 306                 else
 307                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 308         } else if (rhdr->flags & ISCSI_FLAG_CMD_BIDI_UNDERFLOW)
 309                 sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 310         else if (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW)
 311                 sc->resid = be32_to_cpu(rhdr->residual_count);
 312
 313 out:
 314         debug_scsi("done [sc %lx res %d itt 0x%x]\n",
 315                    (long)sc, sc->result, ctask->itt);
 316         conn->scsirsp_pdus_cnt++;
 317         iscsi_ctask_cleanup(conn, ctask);
 318         sc->scsi_done(sc);
 319         return rc;
 320 }
 321
 322 /**
 323  * iscsi_data_rsp - SCSI Data-In Response processing
 324  * @conn: iscsi connection
 325  * @ctask: scsi command task
 326  **/
 327 static int
 328 iscsi_data_rsp(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
 329 {
 330         int rc;
 331         struct iscsi_data_rsp *rhdr = (struct iscsi_data_rsp *)conn->in.hdr;
 332         struct iscsi_session *session = conn->session;
 333         int datasn = be32_to_cpu(rhdr->datasn);
 334
 335         rc = iscsi_check_assign_cmdsn(session, (struct iscsi_nopin*)rhdr);
 336         if (rc)
 337                 return rc;
 338         /*
 339          * setup Data-In byte counter (gets decremented..)
 340          */
 341         ctask->data_count = conn->in.datalen;
 342
 343         if (conn->in.datalen == 0)
 344                 return 0;
 345
 346         if (ctask->datasn != datasn)
 347                 return ISCSI_ERR_DATASN;
 348
 349         ctask->datasn++;
 350
 351         ctask->data_offset = be32_to_cpu(rhdr->offset);
 352         if (ctask->data_offset + conn->in.datalen > ctask->total_length)
 353                 return ISCSI_ERR_DATA_OFFSET;
 354
 355         if (rhdr->flags & ISCSI_FLAG_DATA_STATUS) {
 356                 struct scsi_cmnd *sc = ctask->sc;
 357
 358                 conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
 359                 if (rhdr->flags & ISCSI_FLAG_CMD_UNDERFLOW) {
 360                         int res_count = be32_to_cpu(rhdr->residual_count);
 361
 362                         if (res_count > 0 &&
 363                             res_count <= sc->request_bufflen) {
 364                                 sc->resid = res_count;
 365                                 sc->result = (DID_OK << 16) | rhdr->cmd_status;
 366                         } else
 367                                 sc->result = (DID_BAD_TARGET << 16) |
 368                                         rhdr->cmd_status;
 369                 } else if (rhdr->flags & ISCSI_FLAG_CMD_BIDI_UNDERFLOW)
 370                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 371                 else if (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW) {
 372                         sc->resid = be32_to_cpu(rhdr->residual_count);
 373                         sc->result = (DID_OK << 16) | rhdr->cmd_status;
 374                 } else
 375                         sc->result = (DID_OK << 16) | rhdr->cmd_status;
 376         }
 377
 378         conn->datain_pdus_cnt++;
 379         return 0;
 380 }
 381
 382 /**
 383  * iscsi_solicit_data_init - initialize first Data-Out
 384  * @conn: iscsi connection
 385  * @ctask: scsi command task
 386  * @r2t: R2T info
 387  *
 388  * Notes:
 389  *      Initialize first Data-Out within this R2T sequence and finds
 390  *      proper data_offset within this SCSI command.
 391  *
 392  *      This function is called with connection lock taken.
 393  **/
 394 static void
 395 iscsi_solicit_data_init(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
 396                         struct iscsi_r2t_info *r2t)
 397 {
 398         struct iscsi_data *hdr;
 399         struct iscsi_data_task *dtask;
 400         struct scsi_cmnd *sc = ctask->sc;
 401
 402         dtask = mempool_alloc(ctask->datapool, GFP_ATOMIC);
 403         BUG_ON(!dtask);
 404         hdr = &dtask->hdr;
 405         memset(hdr, 0, sizeof(struct iscsi_data));
 406         hdr->ttt = r2t->ttt;
 407         hdr->datasn = cpu_to_be32(r2t->solicit_datasn);
 408         r2t->solicit_datasn++;
 409         hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
 410         memcpy(hdr->lun, ctask->hdr.lun, sizeof(hdr->lun));
 411         hdr->itt = ctask->hdr.itt;
 412         hdr->exp_statsn = r2t->exp_statsn;
 413         hdr->offset = cpu_to_be32(r2t->data_offset);
 414         if (r2t->data_length > conn->max_xmit_dlength) {
 415                 hton24(hdr->dlength, conn->max_xmit_dlength);
 416                 r2t->data_count = conn->max_xmit_dlength;
 417                 hdr->flags = 0;
 418         } else {
 419                 hton24(hdr->dlength, r2t->data_length);
 420                 r2t->data_count = r2t->data_length;
 421                 hdr->flags = ISCSI_FLAG_CMD_FINAL;
 422         }
 423         conn->dataout_pdus_cnt++;
 424
 425         r2t->sent = 0;
 426
 427         iscsi_buf_init_virt(&r2t->headbuf, (char*)hdr,
 428                            sizeof(struct iscsi_hdr));
 429
 430         r2t->dtask = dtask;
 431
 432         if (sc->use_sg) {
 433                 int i, sg_count = 0;
 434                 struct scatterlist *sg = sc->request_buffer;
 435
 436                 r2t->sg = NULL;
 437                 for (i = 0; i < sc->use_sg; i++, sg += 1) {
 438                         /* FIXME: prefetch ? */
 439                         if (sg_count + sg->length > r2t->data_offset) {
 440                                 int page_offset;
 441
 442                                 /* sg page found! */
 443
 444                                 /* offset within this page */
 445                                 page_offset = r2t->data_offset - sg_count;
 446
 447                                 /* fill in this buffer */
 448                                 iscsi_buf_init_sg(&r2t->sendbuf, sg);
 449                                 r2t->sendbuf.sg.offset += page_offset;
 450                                 r2t->sendbuf.sg.length -= page_offset;
 451
 452                                 /* xmit logic will continue with next one */
 453                                 r2t->sg = sg + 1;
 454                                 break;
 455                         }
 456                         sg_count += sg->length;
 457                 }
 458                 BUG_ON(r2t->sg == NULL);
 459         } else
 460                 iscsi_buf_init_iov(&ctask->sendbuf,
 461                             (char*)sc->request_buffer + r2t->data_offset,
 462                             r2t->data_count);
 463
 464         list_add(&dtask->item, &ctask->dataqueue);
 465 }
 466
 467 /**
 468  * iscsi_r2t_rsp - iSCSI R2T Response processing
 469  * @conn: iscsi connection
 470  * @ctask: scsi command task
 471  **/
 472 static int
 473 iscsi_r2t_rsp(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
 474 {
 475         struct iscsi_r2t_info *r2t;
 476         struct iscsi_session *session = conn->session;
 477         struct iscsi_r2t_rsp *rhdr = (struct iscsi_r2t_rsp *)conn->in.hdr;
 478         int r2tsn = be32_to_cpu(rhdr->r2tsn);
 479         int rc;
 480
 481         if (conn->in.ahslen)
 482                 return ISCSI_ERR_AHSLEN;
 483
 484         if (conn->in.datalen)
 485                 return ISCSI_ERR_DATALEN;
 486
 487         if (ctask->exp_r2tsn && ctask->exp_r2tsn != r2tsn)
 488                 return ISCSI_ERR_R2TSN;
 489
 490         rc = iscsi_check_assign_cmdsn(session, (struct iscsi_nopin*)rhdr);
 491         if (rc)
 492                 return rc;
 493
 494         /* FIXME: use R2TSN to detect missing R2T */
 495
 496         /* fill-in new R2T associated with the task */
 497         spin_lock(&session->lock);
 498         if (!ctask->sc || ctask->mtask ||
 499              session->state != ISCSI_STATE_LOGGED_IN) {
 500                 printk(KERN_INFO "iscsi_tcp: dropping R2T itt %d in "
 501                        "recovery...\n", ctask->itt);
 502                 spin_unlock(&session->lock);
 503                 return 0;
 504         }
 505         rc = __kfifo_get(ctask->r2tpool.queue, (void*)&r2t, sizeof(void*));
 506         BUG_ON(!rc);
 507
 508         r2t->exp_statsn = rhdr->statsn;
 509         r2t->data_length = be32_to_cpu(rhdr->data_length);
 510         if (r2t->data_length == 0 ||
 511             r2t->data_length > session->max_burst) {
 512                 spin_unlock(&session->lock);
 513                 return ISCSI_ERR_DATALEN;
 514         }
 515
 516         r2t->data_offset = be32_to_cpu(rhdr->data_offset);
 517         if (r2t->data_offset + r2t->data_length > ctask->total_length) {
 518                 spin_unlock(&session->lock);
 519                 return ISCSI_ERR_DATALEN;
 520         }
 521
 522         r2t->ttt = rhdr->ttt; /* no flip */
 523         r2t->solicit_datasn = 0;
 524
 525         iscsi_solicit_data_init(conn, ctask, r2t);
 526
 527         ctask->exp_r2tsn = r2tsn + 1;
 528         ctask->xmstate |= XMSTATE_SOL_HDR;
 529         __kfifo_put(ctask->r2tqueue, (void*)&r2t, sizeof(void*));
 530         __kfifo_put(conn->writequeue, (void*)&ctask, sizeof(void*));
 531
 532         schedule_work(&conn->xmitwork);
 533         conn->r2t_pdus_cnt++;
 534         spin_unlock(&session->lock);
 535
 536         return 0;
 537 }
 538
 539 static int
 540 iscsi_hdr_recv(struct iscsi_conn *conn)
 541 {
 542         int rc = 0;
 543         struct iscsi_hdr *hdr;
 544         struct iscsi_cmd_task *ctask;
 545         struct iscsi_session *session = conn->session;
 546         uint32_t cdgst, rdgst = 0;
 547
 548         hdr = conn->in.hdr;
 549
 550         /* verify PDU length */
 551         conn->in.datalen = ntoh24(hdr->dlength);
 552         if (conn->in.datalen > conn->max_recv_dlength) {
 553                 printk(KERN_ERR "iscsi_tcp: datalen %d > %d\n",
 554                        conn->in.datalen, conn->max_recv_dlength);
 555                 return ISCSI_ERR_DATALEN;
 556         }
 557         conn->data_copied = 0;
 558
 559         /* read AHS */
 560         conn->in.ahslen = hdr->hlength * 4;
 561         conn->in.offset += conn->in.ahslen;
 562         conn->in.copy -= conn->in.ahslen;
 563         if (conn->in.copy < 0) {
 564                 printk(KERN_ERR "iscsi_tcp: can't handle AHS with length "
 565                        "%d bytes\n", conn->in.ahslen);
 566                 return ISCSI_ERR_AHSLEN;
 567         }
 568
 569         /* calculate read padding */
 570         conn->in.padding = conn->in.datalen & (ISCSI_PAD_LEN-1);
 571         if (conn->in.padding) {
 572                 conn->in.padding = ISCSI_PAD_LEN - conn->in.padding;
 573                 debug_scsi("read padding %d bytes\n", conn->in.padding);
 574         }
 575
 576         if (conn->hdrdgst_en) {
 577                 struct scatterlist sg;
 578
 579                 sg_init_one(&sg, (u8 *)hdr,
 580                             sizeof(struct iscsi_hdr) + conn->in.ahslen);
 581                 crypto_digest_digest(conn->rx_tfm, &sg, 1, (u8 *)&cdgst);
 582                 rdgst = *(uint32_t*)((char*)hdr + sizeof(struct iscsi_hdr) +
 583                                      conn->in.ahslen);
 584         }
 585
 586         /* save opcode for later */
 587         conn->in.opcode = hdr->opcode & ISCSI_OPCODE_MASK;
 588
 589         /* verify itt (itt encoding: age+cid+itt) */
 590         if (hdr->itt != cpu_to_be32(ISCSI_RESERVED_TAG)) {
 591                 if ((hdr->itt & AGE_MASK) !=
 592                                 (session->age << AGE_SHIFT)) {
 593                         printk(KERN_ERR "iscsi_tcp: received itt %x expected "
 594                                 "session age (%x)\n", hdr->itt,
 595                                 session->age & AGE_MASK);
 596                         return ISCSI_ERR_BAD_ITT;
 597                 }
 598
 599                 if ((hdr->itt & CID_MASK) != (conn->id << CID_SHIFT)) {
 600                         printk(KERN_ERR "iscsi_tcp: received itt %x, expected "
 601                                 "CID (%x)\n", hdr->itt, conn->id);
 602                         return ISCSI_ERR_BAD_ITT;
 603                 }
 604                 conn->in.itt = hdr->itt & ITT_MASK;
 605         } else
 606                 conn->in.itt = hdr->itt;
 607
 608         debug_tcp("opcode 0x%x offset %d copy %d ahslen %d datalen %d\n",
 609                   hdr->opcode, conn->in.offset, conn->in.copy,
 610                   conn->in.ahslen, conn->in.datalen);
 611
 612         if (conn->in.itt < session->cmds_max) {
 613                 if (conn->hdrdgst_en && cdgst != rdgst) {
 614                         printk(KERN_ERR "iscsi_tcp: itt %x: hdrdgst error "
 615                                "recv 0x%x calc 0x%x\n", conn->in.itt, rdgst,
 616                                cdgst);
 617                         return ISCSI_ERR_HDR_DGST;
 618                 }
 619
 620                 ctask = (struct iscsi_cmd_task *)session->cmds[conn->in.itt];
 621
 622                 if (!ctask->sc) {
 623                         printk(KERN_INFO "iscsi_tcp: dropping ctask with "
 624                                "itt 0x%x\n", ctask->itt);
 625                         conn->in.datalen = 0; /* force drop */
 626                         return 0;
 627                 }
 628
 629                 if (ctask->sc->SCp.phase != session->age) {
 630                         printk(KERN_ERR "iscsi_tcp: ctask's session age %d, "
 631                                 "expected %d\n", ctask->sc->SCp.phase,
 632                                 session->age);
 633                         return ISCSI_ERR_SESSION_FAILED;
 634                 }
 635
 636                 conn->in.ctask = ctask;
 637
 638                 debug_scsi("rsp [op 0x%x cid %d sc %lx itt 0x%x len %d]\n",
 639                            hdr->opcode, conn->id, (long)ctask->sc,
 640                            ctask->itt, conn->in.datalen);
 641
 642                 switch(conn->in.opcode) {
 643                 case ISCSI_OP_SCSI_CMD_RSP:
 644                         BUG_ON((void*)ctask != ctask->sc->SCp.ptr);
 645                         if (!conn->in.datalen)
 646                                 rc = iscsi_cmd_rsp(conn, ctask);
 647                         else
 648                                 /*
 649                                  * got sense or response data; copying PDU
 650                                  * Header to the connection's header
 651                                  * placeholder
 652                                  */
 653                                 memcpy(&conn->hdr, hdr,
 654                                        sizeof(struct iscsi_hdr));
 655                         break;
 656                 case ISCSI_OP_SCSI_DATA_IN:
 657                         BUG_ON((void*)ctask != ctask->sc->SCp.ptr);
 658                         /* save flags for non-exceptional status */
 659                         conn->in.flags = hdr->flags;
 660                         /* save cmd_status for sense data */
 661                         conn->in.cmd_status =
 662                                 ((struct iscsi_data_rsp*)hdr)->cmd_status;
 663                         rc = iscsi_data_rsp(conn, ctask);
 664                         break;
 665                 case ISCSI_OP_R2T:
 666                         BUG_ON((void*)ctask != ctask->sc->SCp.ptr);
 667                         if (ctask->sc->sc_data_direction == DMA_TO_DEVICE)
 668                                 rc = iscsi_r2t_rsp(conn, ctask);
 669                         else
 670                                 rc = ISCSI_ERR_PROTO;
 671                         break;
 672                 default:
 673                         rc = ISCSI_ERR_BAD_OPCODE;
 674                         break;
 675                 }
 676         } else if (conn->in.itt >= ISCSI_MGMT_ITT_OFFSET &&
 677                    conn->in.itt < ISCSI_MGMT_ITT_OFFSET +
 678                                         session->mgmtpool_max) {
 679                 struct iscsi_mgmt_task *mtask = (struct iscsi_mgmt_task *)
 680                                         session->mgmt_cmds[conn->in.itt -
 681                                                 ISCSI_MGMT_ITT_OFFSET];
 682
 683                 debug_scsi("immrsp [op 0x%x cid %d itt 0x%x len %d]\n",
 684                            conn->in.opcode, conn->id, mtask->itt,
 685                            conn->in.datalen);
 686
 687                 switch(conn->in.opcode) {
 688                 case ISCSI_OP_LOGIN_RSP:
 689                 case ISCSI_OP_TEXT_RSP:
 690                 case ISCSI_OP_LOGOUT_RSP:
 691                         rc = iscsi_check_assign_cmdsn(session,
 692                                                  (struct iscsi_nopin*)hdr);
 693                         if (rc)
 694                                 break;
 695
 696                         if (!conn->in.datalen) {
 697                                 rc = iscsi_recv_pdu(iscsi_handle(conn), hdr,
 698                                                     NULL, 0);
 699                                 if (conn->login_mtask != mtask) {
 700                                         spin_lock(&session->lock);
 701                                         __kfifo_put(session->mgmtpool.queue,
 702                                             (void*)&mtask, sizeof(void*));
 703                                         spin_unlock(&session->lock);
 704                                 }
 705                         }
 706                         break;
 707                 case ISCSI_OP_SCSI_TMFUNC_RSP:
 708                         rc = iscsi_check_assign_cmdsn(session,
 709                                                  (struct iscsi_nopin*)hdr);
 710                         if (rc)
 711                                 break;
 712
 713                         if (conn->in.datalen || conn->in.ahslen) {
 714                                 rc = ISCSI_ERR_PROTO;
 715                                 break;
 716                         }
 717                         conn->tmfrsp_pdus_cnt++;
 718                         spin_lock(&session->lock);
 719                         if (conn->tmabort_state == TMABORT_INITIAL) {
 720                                 __kfifo_put(session->mgmtpool.queue,
 721                                                 (void*)&mtask, sizeof(void*));
 722                                 conn->tmabort_state =
 723                                         ((struct iscsi_tm_rsp *)hdr)->
 724                                         response == ISCSI_TMF_RSP_COMPLETE ?
 725                                                 TMABORT_SUCCESS:TMABORT_FAILED;
 726                                 /* unblock eh_abort() */
 727                                 wake_up(&conn->ehwait);
 728                         }
 729                         spin_unlock(&session->lock);
 730                         break;
 731                 case ISCSI_OP_NOOP_IN:
 732                         if (hdr->ttt != ISCSI_RESERVED_TAG) {
 733                                 rc = ISCSI_ERR_PROTO;
 734                                 break;
 735                         }
 736                         rc = iscsi_check_assign_cmdsn(session,
 737                                                 (struct iscsi_nopin*)hdr);
 738                         if (rc)
 739                                 break;
 740                         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
 741
 742                         if (!conn->in.datalen) {
 743                                 struct iscsi_mgmt_task *mtask;
 744
 745                                 rc = iscsi_recv_pdu(iscsi_handle(conn), hdr,
 746                                                     NULL, 0);
 747                                 mtask = (struct iscsi_mgmt_task *)
 748                                         session->mgmt_cmds[conn->in.itt -
 749                                                         ISCSI_MGMT_ITT_OFFSET];
 750                                 if (conn->login_mtask != mtask) {
 751                                         spin_lock(&session->lock);
 752                                         __kfifo_put(session->mgmtpool.queue,
 753                                                   (void*)&mtask, sizeof(void*));
 754                                         spin_unlock(&session->lock);
 755                                 }
 756                         }
 757                         break;
 758                 default:
 759                         rc = ISCSI_ERR_BAD_OPCODE;
 760                         break;
 761                 }
 762         } else if (conn->in.itt == ISCSI_RESERVED_TAG) {
 763                 switch(conn->in.opcode) {
 764                 case ISCSI_OP_NOOP_IN:
 765                         if (!conn->in.datalen) {
 766                                 rc = iscsi_check_assign_cmdsn(session,
 767                                                  (struct iscsi_nopin*)hdr);
 768                                 if (!rc && hdr->ttt != ISCSI_RESERVED_TAG)
 769                                         rc = iscsi_recv_pdu(iscsi_handle(conn),
 770                                                             hdr, NULL, 0);
 771                         } else
 772                                 rc = ISCSI_ERR_PROTO;
 773                         break;
 774                 case ISCSI_OP_REJECT:
 775                         /* we need sth like iscsi_reject_rsp()*/
 776                 case ISCSI_OP_ASYNC_EVENT:
 777                         /* we need sth like iscsi_async_event_rsp() */
 778                         rc = ISCSI_ERR_BAD_OPCODE;
 779                         break;
 780                 default:
 781                         rc = ISCSI_ERR_BAD_OPCODE;
 782                         break;
 783                 }
 784         } else
 785                 rc = ISCSI_ERR_BAD_ITT;
 786
 787         return rc;
 788 }
 789
 790 /**
 791  * iscsi_ctask_copy - copy skb bits to the destanation cmd task
 792  * @conn: iscsi connection
 793  * @ctask: scsi command task
 794  * @buf: buffer to copy to
 795  * @buf_size: size of buffer
 796  * @offset: offset within the buffer
 797  *
 798  * Notes:
 799  *      The function calls skb_copy_bits() and updates per-connection and
 800  *      per-cmd byte counters.
 801  *
 802  *      Read counters (in bytes):
 803  *
 804  *      conn->in.offset         offset within in progress SKB
 805  *      conn->in.copy           left to copy from in progress SKB
 806  *                              including padding
 807  *      conn->in.copied         copied already from in progress SKB
 808  *      conn->data_copied       copied already from in progress buffer
 809  *      ctask->sent             total bytes sent up to the MidLayer
 810  *      ctask->data_count       left to copy from in progress Data-In
 811  *      buf_left                left to copy from in progress buffer
 812  **/
 813 static inline int
 814 iscsi_ctask_copy(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
 815                 void *buf, int buf_size, int offset)
 816 {
 817         int buf_left = buf_size - (conn->data_copied + offset);
 818         int size = min(conn->in.copy, buf_left);
 819         int rc;
 820
 821         size = min(size, ctask->data_count);
 822
 823         debug_tcp("ctask_copy %d bytes at offset %d copied %d\n",
 824                size, conn->in.offset, conn->in.copied);
 825
 826         BUG_ON(size <= 0);
 827         BUG_ON(ctask->sent + size > ctask->total_length);
 828
 829         rc = skb_copy_bits(conn->in.skb, conn->in.offset,
 830                            (char*)buf + (offset + conn->data_copied), size);
 831         /* must fit into skb->len */
 832         BUG_ON(rc);
 833
 834         conn->in.offset += size;
 835         conn->in.copy -= size;
 836         conn->in.copied += size;
 837         conn->data_copied += size;
 838         ctask->sent += size;
 839         ctask->data_count -= size;
 840
 841         BUG_ON(conn->in.copy < 0);
 842         BUG_ON(ctask->data_count < 0);
 843
 844         if (buf_size != (conn->data_copied + offset)) {
 845                 if (!ctask->data_count) {
 846                         BUG_ON(buf_size - conn->data_copied < 0);
 847                         /* done with this PDU */
 848                         return buf_size - conn->data_copied;
 849                 }
 850                 return -EAGAIN;
 851         }
 852
 853         /* done with this buffer or with both - PDU and buffer */
 854         conn->data_copied = 0;
 855         return 0;
 856 }
 857
 858 /**
 859  * iscsi_tcp_copy - copy skb bits to the destanation buffer
 860  * @conn: iscsi connection
 861  * @buf: buffer to copy to
 862  * @buf_size: number of bytes to copy
 863  *
 864  * Notes:
 865  *      The function calls skb_copy_bits() and updates per-connection
 866  *      byte counters.
 867  **/
 868 static inline int
 869 iscsi_tcp_copy(struct iscsi_conn *conn, void *buf, int buf_size)
 870 {
 871         int buf_left = buf_size - conn->data_copied;
 872         int size = min(conn->in.copy, buf_left);
 873         int rc;
 874
 875         debug_tcp("tcp_copy %d bytes at offset %d copied %d\n",
 876                size, conn->in.offset, conn->data_copied);
 877         BUG_ON(size <= 0);
 878
 879         rc = skb_copy_bits(conn->in.skb, conn->in.offset,
 880                            (char*)buf + conn->data_copied, size);
 881         BUG_ON(rc);
 882
 883         conn->in.offset += size;
 884         conn->in.copy -= size;
 885         conn->in.copied += size;
 886         conn->data_copied += size;
 887
 888         if (buf_size != conn->data_copied)
 889                 return -EAGAIN;
 890
 891         return 0;
 892 }
 893
 894 static inline void
 895 partial_sg_digest_update(struct iscsi_conn *conn, struct scatterlist *sg,
 896                          int offset, int length)
 897 {
 898         struct scatterlist temp;
 899
 900         memcpy(&temp, sg, sizeof(struct scatterlist));
 901         temp.offset = offset;
 902         temp.length = length;
 903         crypto_digest_update(conn->data_rx_tfm, &temp, 1);
 904 }
 905
 906 static void
 907 iscsi_recv_digest_update(struct iscsi_conn *conn, char* buf, int len)
 908 {
 909         struct scatterlist tmp;
 910
 911         sg_init_one(&tmp, buf, len);
 912         crypto_digest_update(conn->data_rx_tfm, &tmp, 1);
 913 }
 914
 915 static int iscsi_scsi_data_in(struct iscsi_conn *conn)
 916 {
 917         struct iscsi_cmd_task *ctask = conn->in.ctask;
 918         struct scsi_cmnd *sc = ctask->sc;
 919         struct scatterlist *sg;
 920         int i, offset, rc = 0;
 921
 922         BUG_ON((void*)ctask != sc->SCp.ptr);
 923
 924         /*
 925          * copying Data-In into the Scsi_Cmnd
 926          */
 927         if (!sc->use_sg) {
 928                 i = ctask->data_count;
 929                 rc = iscsi_ctask_copy(conn, ctask, sc->request_buffer,
 930                                       sc->request_bufflen, ctask->data_offset);
 931                 if (rc == -EAGAIN)
 932                         return rc;
 933                 if (conn->datadgst_en)
 934                         iscsi_recv_digest_update(conn, sc->request_buffer, i);
 935                 rc = 0;
 936                 goto done;
 937         }
 938
 939         offset = ctask->data_offset;
 940         sg = sc->request_buffer;
 941
 942         if (ctask->data_offset)
 943                 for (i = 0; i < ctask->sg_count; i++)
 944                         offset -= sg[i].length;
 945         /* we've passed through partial sg*/
 946         if (offset < 0)
 947                 offset = 0;
 948
 949         for (i = ctask->sg_count; i < sc->use_sg; i++) {
 950                 char *dest;
 951
 952                 dest = kmap_atomic(sg[i].page, KM_SOFTIRQ0);
 953                 rc = iscsi_ctask_copy(conn, ctask, dest + sg[i].offset,
 954                                       sg[i].length, offset);
 955                 kunmap_atomic(dest, KM_SOFTIRQ0);
 956                 if (rc == -EAGAIN)
 957                         /* continue with the next SKB/PDU */
 958                         return rc;
 959                 if (!rc) {
 960                         if (conn->datadgst_en) {
 961                                 if (!offset)
 962                                         crypto_digest_update(conn->data_rx_tfm,
 963                                                              &sg[i], 1);
 964                                 else
 965                                         partial_sg_digest_update(conn, &sg[i],
 966                                                         sg[i].offset + offset,
 967                                                         sg[i].length - offset);
 968                         }
 969                         offset = 0;
 970                         ctask->sg_count++;
 971                 }
 972
 973                 if (!ctask->data_count) {
 974                         if (rc && conn->datadgst_en)
 975                                 /*
 976                                  * data-in is complete, but buffer not...
 977                                  */
 978                                 partial_sg_digest_update(conn, &sg[i],
 979                                                 sg[i].offset, sg[i].length-rc);
 980                         rc = 0;
 981                         break;
 982                 }
 983
 984                 if (!conn->in.copy)
 985                         return -EAGAIN;
 986         }
 987         BUG_ON(ctask->data_count);
 988
 989 done:
 990         /* check for non-exceptional status */
 991         if (conn->in.flags & ISCSI_FLAG_DATA_STATUS) {
 992                 debug_scsi("done [sc %lx res %d itt 0x%x]\n",
 993                            (long)sc, sc->result, ctask->itt);
 994                 conn->scsirsp_pdus_cnt++;
 995                 iscsi_ctask_cleanup(conn, ctask);
 996                 sc->scsi_done(sc);
 997         }
 998
 999         return rc;
1000 }
1001
1002 static int
1003 iscsi_data_recv(struct iscsi_conn *conn)
1004 {
1005         struct iscsi_session *session = conn->session;
1006         int rc = 0;
1007
1008         switch(conn->in.opcode) {
1009         case ISCSI_OP_SCSI_DATA_IN:
1010                 rc = iscsi_scsi_data_in(conn);
1011                 break;
1012         case ISCSI_OP_SCSI_CMD_RSP: {
1013                 /*
1014                  * SCSI Sense Data:
1015                  * copying the entire Data Segment.
1016                  */
1017                 if (iscsi_tcp_copy(conn, conn->data, conn->in.datalen)) {
1018                         rc = -EAGAIN;
1019                         goto exit;
1020                 }
1021
1022                 /*
1023                  * check for sense
1024                  */
1025                 conn->in.hdr = &conn->hdr;
1026                 conn->senselen = (conn->data[0] << 8) | conn->data[1];
1027                 rc = iscsi_cmd_rsp(conn, conn->in.ctask);
1028                 if (!rc && conn->datadgst_en)
1029                         iscsi_recv_digest_update(conn, conn->data,
1030                                                  conn->in.datalen);
1031         }
1032         break;
1033         case ISCSI_OP_TEXT_RSP:
1034         case ISCSI_OP_LOGIN_RSP:
1035         case ISCSI_OP_NOOP_IN: {
1036                 struct iscsi_mgmt_task *mtask = NULL;
1037
1038                 if (conn->in.itt != ISCSI_RESERVED_TAG)
1039                         mtask = (struct iscsi_mgmt_task *)
1040                                 session->mgmt_cmds[conn->in.itt -
1041                                         ISCSI_MGMT_ITT_OFFSET];
1042
1043                 /*
1044                  * Collect data segment to the connection's data
1045                  * placeholder
1046                  */
1047                 if (iscsi_tcp_copy(conn, conn->data, conn->in.datalen)) {
1048                         rc = -EAGAIN;
1049                         goto exit;
1050                 }
1051
1052                 rc = iscsi_recv_pdu(iscsi_handle(conn), conn->in.hdr,
1053                                     conn->data, conn->in.datalen);
1054
1055                 if (!rc && conn->datadgst_en &&
1056                         conn->in.opcode != ISCSI_OP_LOGIN_RSP)
1057                         iscsi_recv_digest_update(conn, conn->data,
1058                                                 conn->in.datalen);
1059
1060                 if (mtask && conn->login_mtask != mtask) {
1061                         spin_lock(&session->lock);
1062                         __kfifo_put(session->mgmtpool.queue, (void*)&mtask,
1063                                     sizeof(void*));
1064                         spin_unlock(&session->lock);
1065                 }
1066         }
1067         break;
1068         case ISCSI_OP_ASYNC_EVENT:
1069         case ISCSI_OP_REJECT:
1070         default:
1071                 BUG_ON(1);
1072         }
1073 exit:
1074         return rc;
1075 }
1076
1077 /**
1078  * iscsi_tcp_data_recv - TCP receive in sendfile fashion
1079  * @rd_desc: read descriptor
1080  * @skb: socket buffer
1081  * @offset: offset in skb
1082  * @len: skb->len - offset
1083  **/
1084 static int
1085 iscsi_tcp_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb,
1086                 unsigned int offset, size_t len)
1087 {
1088         int rc;
1089         struct iscsi_conn *conn = rd_desc->arg.data;
1090         int processed;
1091         char pad[ISCSI_PAD_LEN];
1092         struct scatterlist sg;
1093
1094         /*
1095          * Save current SKB and its offset in the corresponding
1096          * connection context.
1097          */
1098         conn->in.copy = skb->len - offset;
1099         conn->in.offset = offset;
1100         conn->in.skb = skb;
1101         conn->in.len = conn->in.copy;
1102         BUG_ON(conn->in.copy <= 0);
1103         debug_tcp("in %d bytes\n", conn->in.copy);
1104
1105 more:
1106         conn->in.copied = 0;
1107         rc = 0;
1108
1109         if (unlikely(conn->suspend_rx)) {
1110                 debug_tcp("conn %d Rx suspended!\n", conn->id);
1111                 return 0;
1112         }
1113
1114         if (conn->in_progress == IN_PROGRESS_WAIT_HEADER ||
1115             conn->in_progress == IN_PROGRESS_HEADER_GATHER) {
1116                 rc = iscsi_hdr_extract(conn);
1117                 if (rc) {
1118                        if (rc == -EAGAIN)
1119                                 goto nomore;
1120                        else {
1121                                 iscsi_conn_failure(conn, rc);
1122                                 return 0;
1123                        }
1124                 }
1125
1126                 /*
1127                  * Verify and process incoming PDU header.
1128                  */
1129                 rc = iscsi_hdr_recv(conn);
1130                 if (!rc && conn->in.datalen) {
1131                         if (conn->datadgst_en &&
1132                                 conn->in.opcode != ISCSI_OP_LOGIN_RSP) {
1133                                 BUG_ON(!conn->data_rx_tfm);
1134                                 crypto_digest_init(conn->data_rx_tfm);
1135                         }
1136                         conn->in_progress = IN_PROGRESS_DATA_RECV;
1137                 } else if (rc) {
1138                         iscsi_conn_failure(conn, rc);
1139                         return 0;
1140                 }
1141         }
1142
1143         if (conn->in_progress == IN_PROGRESS_DDIGEST_RECV) {
1144                 uint32_t recv_digest;
1145                 debug_tcp("extra data_recv offset %d copy %d\n",
1146                           conn->in.offset, conn->in.copy);
1147                 skb_copy_bits(conn->in.skb, conn->in.offset,
1148                                 &recv_digest, 4);
1149                 conn->in.offset += 4;
1150                 conn->in.copy -= 4;
1151                 if (recv_digest != conn->in.datadgst) {
1152                         debug_tcp("iscsi_tcp: data digest error!"
1153                                   "0x%x != 0x%x\n", recv_digest,
1154                                   conn->in.datadgst);
1155                         iscsi_conn_failure(conn, ISCSI_ERR_DATA_DGST);
1156                         return 0;
1157                 } else {
1158                         debug_tcp("iscsi_tcp: data digest match!"
1159                                   "0x%x == 0x%x\n", recv_digest,
1160                                   conn->in.datadgst);
1161                         conn->in_progress = IN_PROGRESS_WAIT_HEADER;
1162                 }
1163         }
1164
1165         if (conn->in_progress == IN_PROGRESS_DATA_RECV && conn->in.copy) {
1166
1167                 debug_tcp("data_recv offset %d copy %d\n",
1168                        conn->in.offset, conn->in.copy);
1169
1170                 rc = iscsi_data_recv(conn);
1171                 if (rc) {
1172                         if (rc == -EAGAIN) {
1173                                 rd_desc->count = conn->in.datalen -
1174                                                 conn->in.ctask->data_count;
1175                                 goto again;
1176                         }
1177                         iscsi_conn_failure(conn, rc);
1178                         return 0;
1179                 }
1180                 conn->in.copy -= conn->in.padding;
1181                 conn->in.offset += conn->in.padding;
1182                 if (conn->datadgst_en &&
1183                         conn->in.opcode != ISCSI_OP_LOGIN_RSP) {
1184                         if (conn->in.padding) {
1185                                 debug_tcp("padding -> %d\n", conn->in.padding);
1186                                 memset(pad, 0, conn->in.padding);
1187                                 sg_init_one(&sg, pad, conn->in.padding);
1188                                 crypto_digest_update(conn->data_rx_tfm, &sg, 1);
1189                         }
1190                         crypto_digest_final(conn->data_rx_tfm,
1191                                             (u8 *) & conn->in.datadgst);
1192                         debug_tcp("rx digest 0x%x\n", conn->in.datadgst);
1193                         conn->in_progress = IN_PROGRESS_DDIGEST_RECV;
1194                 } else
1195                         conn->in_progress = IN_PROGRESS_WAIT_HEADER;
1196         }
1197
1198         debug_tcp("f, processed %d from out of %d padding %d\n",
1199                conn->in.offset - offset, (int)len, conn->in.padding);
1200         BUG_ON(conn->in.offset - offset > len);
1201
1202         if (conn->in.offset - offset != len) {
1203                 debug_tcp("continue to process %d bytes\n",
1204                        (int)len - (conn->in.offset - offset));
1205                 goto more;
1206         }
1207
1208 nomore:
1209         processed = conn->in.offset - offset;
1210         BUG_ON(processed == 0);
1211         return processed;
1212
1213 again:
1214         processed = conn->in.offset - offset;
1215         debug_tcp("c, processed %d from out of %d rd_desc_cnt %d\n",
1216                   processed, (int)len, (int)rd_desc->count);
1217         BUG_ON(processed == 0);
1218         BUG_ON(processed > len);
1219
1220         conn->rxdata_octets += processed;
1221         return processed;
1222 }
1223
1224 static void
1225 iscsi_tcp_data_ready(struct sock *sk, int flag)
1226 {
1227         struct iscsi_conn *conn = sk->sk_user_data;
1228         read_descriptor_t rd_desc;
1229
1230         read_lock(&sk->sk_callback_lock);
1231
1232         /* use rd_desc to pass 'conn' to iscsi_tcp_data_recv */
1233         rd_desc.arg.data = conn;
1234         rd_desc.count = 0;
1235         tcp_read_sock(sk, &rd_desc, iscsi_tcp_data_recv);
1236
1237         read_unlock(&sk->sk_callback_lock);
1238 }
1239
1240 static void
1241 iscsi_tcp_state_change(struct sock *sk)
1242 {
1243         struct iscsi_conn *conn;
1244         struct iscsi_session *session;
1245         void (*old_state_change)(struct sock *);
1246
1247         read_lock(&sk->sk_callback_lock);
1248
1249         conn = (struct iscsi_conn*)sk->sk_user_data;
1250         session = conn->session;
1251
1252         if ((sk->sk_state == TCP_CLOSE_WAIT ||
1253              sk->sk_state == TCP_CLOSE) &&
1254             !atomic_read(&sk->sk_rmem_alloc)) {
1255                 debug_tcp("iscsi_tcp_state_change: TCP_CLOSE|TCP_CLOSE_WAIT\n");
1256                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1257         }
1258
1259         old_state_change = conn->old_state_change;
1260
1261         read_unlock(&sk->sk_callback_lock);
1262
1263         old_state_change(sk);
1264 }
1265
1266 /**
1267  * iscsi_write_space - Called when more output buffer space is available
1268  * @sk: socket space is available for
1269  **/
1270 static void
1271 iscsi_write_space(struct sock *sk)
1272 {
1273         struct iscsi_conn *conn = (struct iscsi_conn*)sk->sk_user_data;
1274         conn->old_write_space(sk);
1275         debug_tcp("iscsi_write_space: cid %d\n", conn->id);
1276         clear_bit(SUSPEND_BIT, &conn->suspend_tx);
1277         schedule_work(&conn->xmitwork);
1278 }
1279
1280 static void
1281 iscsi_conn_set_callbacks(struct iscsi_conn *conn)
1282 {
1283         struct sock *sk = conn->sock->sk;
1284
1285         /* assign new callbacks */
1286         write_lock_bh(&sk->sk_callback_lock);
1287         sk->sk_user_data = conn;
1288         conn->old_data_ready = sk->sk_data_ready;
1289         conn->old_state_change = sk->sk_state_change;
1290         conn->old_write_space = sk->sk_write_space;
1291         sk->sk_data_ready = iscsi_tcp_data_ready;
1292         sk->sk_state_change = iscsi_tcp_state_change;
1293         sk->sk_write_space = iscsi_write_space;
1294         write_unlock_bh(&sk->sk_callback_lock);
1295 }
1296
1297 static void
1298 iscsi_conn_restore_callbacks(struct iscsi_conn *conn)
1299 {
1300         struct sock *sk = conn->sock->sk;
1301
1302         /* restore socket callbacks, see also: iscsi_conn_set_callbacks() */
1303         write_lock_bh(&sk->sk_callback_lock);
1304         sk->sk_user_data    = NULL;
1305         sk->sk_data_ready   = conn->old_data_ready;
1306         sk->sk_state_change = conn->old_state_change;
1307         sk->sk_write_space  = conn->old_write_space;
1308         sk->sk_no_check  = 0;
1309         write_unlock_bh(&sk->sk_callback_lock);
1310 }
1311
1312 /**
1313  * iscsi_send - generic send routine
1314  * @sk: kernel's socket
1315  * @buf: buffer to write from
1316  * @size: actual size to write
1317  * @flags: socket's flags
1318  *
1319  * Notes:
1320  *      depending on buffer will use tcp_sendpage() or tcp_sendmsg().
1321  *      buf->sg.offset == -1 tells us that buffer is non S/G and forces
1322  *      to use tcp_sendmsg().
1323  */
1324 static inline int
1325 iscsi_send(struct socket *sk, struct iscsi_buf *buf, int size, int flags)
1326 {
1327         int res;
1328
1329         if ((int)buf->sg.offset >= 0) {
1330                 int offset = buf->sg.offset + buf->sent;
1331
1332                 /* tcp_sendpage */
1333                 res = sk->ops->sendpage(sk, buf->sg.page, offset, size, flags);
1334         } else {
1335                 struct msghdr msg;
1336
1337                 buf->iov.iov_base = iscsi_buf_iov_base(buf);
1338                 buf->iov.iov_len = size;
1339
1340                 memset(&msg, 0, sizeof(struct msghdr));
1341
1342                 /* tcp_sendmsg */
1343                 res = kernel_sendmsg(sk, &msg, &buf->iov, 1, size);
1344         }
1345
1346         return res;
1347 }
1348
1349 /**
1350  * iscsi_sendhdr - send PDU Header via tcp_sendpage()
1351  * @conn: iscsi connection
1352  * @buf: buffer to write from
1353  * @datalen: lenght of data to be sent after the header
1354  *
1355  * Notes:
1356  *      (Tx, Fast Path)
1357  **/
1358 static inline int
1359 iscsi_sendhdr(struct iscsi_conn *conn, struct iscsi_buf *buf, int datalen)
1360 {
1361         struct socket *sk = conn->sock;
1362         int flags = 0; /* MSG_DONTWAIT; */
1363         int res, size;
1364
1365         size = buf->sg.length - buf->sent;
1366         BUG_ON(buf->sent + size > buf->sg.length);
1367         if (buf->sent + size != buf->sg.length || datalen)
1368                 flags |= MSG_MORE;
1369
1370         res = iscsi_send(sk, buf, size, flags);
1371         debug_tcp("sendhdr %d bytes, sent %d res %d\n", size, buf->sent, res);
1372         if (res >= 0) {
1373                 conn->txdata_octets += res;
1374                 buf->sent += res;
1375                 if (size != res)
1376                         return -EAGAIN;
1377                 return 0;
1378         } else if (res == -EAGAIN) {
1379                 conn->sendpage_failures_cnt++;
1380                 set_bit(SUSPEND_BIT, &conn->suspend_tx);
1381         } else if (res == -EPIPE)
1382                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1383
1384         return res;
1385 }
1386
1387 /**
1388  * iscsi_sendpage - send one page of iSCSI Data-Out.
1389  * @conn: iscsi connection
1390  * @buf: buffer to write from
1391  * @count: remaining data
1392  * @sent: number of bytes sent
1393  *
1394  * Notes:
1395  *      (Tx, Fast Path)
1396  **/
1397 static inline int
1398 iscsi_sendpage(struct iscsi_conn *conn, struct iscsi_buf *buf,
1399                int *count, int *sent)
1400 {
1401         struct socket *sk = conn->sock;
1402         int flags = 0; /* MSG_DONTWAIT; */
1403         int res, size;
1404
1405         size = buf->sg.length - buf->sent;
1406         BUG_ON(buf->sent + size > buf->sg.length);
1407         if (size > *count)
1408                 size = *count;
1409         if (buf->sent + size != buf->sg.length || *count != size)
1410                 flags |= MSG_MORE;
1411
1412         res = iscsi_send(sk, buf, size, flags);
1413         debug_tcp("sendpage: %d bytes, sent %d left %d sent %d res %d\n",
1414                   size, buf->sent, *count, *sent, res);
1415         if (res >= 0) {
1416                 conn->txdata_octets += res;
1417                 buf->sent += res;
1418                 *count -= res;
1419                 *sent += res;
1420                 if (size != res)
1421                         return -EAGAIN;
1422                 return 0;
1423         } else if (res == -EAGAIN) {
1424                 conn->sendpage_failures_cnt++;
1425                 set_bit(SUSPEND_BIT, &conn->suspend_tx);
1426         } else if (res == -EPIPE)
1427                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1428
1429         return res;
1430 }
1431
1432 static inline void
1433 iscsi_data_digest_init(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1434 {
1435         BUG_ON(!conn->data_tx_tfm);
1436         crypto_digest_init(conn->data_tx_tfm);
1437         ctask->digest_count = 4;
1438 }
1439
1440 static inline void
1441 iscsi_buf_data_digest_update(struct iscsi_conn *conn, struct iscsi_buf *buf)
1442 {
1443         struct scatterlist sg;
1444
1445         if (buf->sg.offset != -1)
1446                 crypto_digest_update(conn->data_tx_tfm, &buf->sg, 1);
1447         else {
1448                 sg_init_one(&sg, (char *)buf->sg.page, buf->sg.length);
1449                 crypto_digest_update(conn->data_tx_tfm, &sg, 1);
1450         }
1451 }
1452
1453 static inline int
1454 iscsi_digest_final_send(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
1455                         struct iscsi_buf *buf, uint32_t *digest, int final)
1456 {
1457         int rc = 0;
1458         int sent = 0;
1459
1460         if (final)
1461                 crypto_digest_final(conn->data_tx_tfm, (u8*)digest);
1462
1463         iscsi_buf_init_virt(buf, (char*)digest, 4);
1464         rc = iscsi_sendpage(conn, buf, &ctask->digest_count, &sent);
1465         if (rc) {
1466                 ctask->datadigest = *digest;
1467                 ctask->xmstate |= XMSTATE_DATA_DIGEST;
1468         } else
1469                 ctask->digest_count = 4;
1470         return rc;
1471 }
1472
1473 /**
1474  * iscsi_solicit_data_cont - initialize next Data-Out
1475  * @conn: iscsi connection
1476  * @ctask: scsi command task
1477  * @r2t: R2T info
1478  * @left: bytes left to transfer
1479  *
1480  * Notes:
1481  *      Initialize next Data-Out within this R2T sequence and continue
1482  *      to process next Scatter-Gather element(if any) of this SCSI command.
1483  *
1484  *      Called under connection lock.
1485  **/
1486 static void
1487 iscsi_solicit_data_cont(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
1488                         struct iscsi_r2t_info *r2t, int left)
1489 {
1490         struct iscsi_data *hdr;
1491         struct iscsi_data_task *dtask;
1492         struct scsi_cmnd *sc = ctask->sc;
1493         int new_offset;
1494
1495         dtask = mempool_alloc(ctask->datapool, GFP_ATOMIC);
1496         BUG_ON(!dtask);
1497         hdr = &dtask->hdr;
1498         memset(hdr, 0, sizeof(struct iscsi_data));
1499         hdr->ttt = r2t->ttt;
1500         hdr->datasn = cpu_to_be32(r2t->solicit_datasn);
1501         r2t->solicit_datasn++;
1502         hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
1503         memcpy(hdr->lun, ctask->hdr.lun, sizeof(hdr->lun));
1504         hdr->itt = ctask->hdr.itt;
1505         hdr->exp_statsn = r2t->exp_statsn;
1506         new_offset = r2t->data_offset + r2t->sent;
1507         hdr->offset = cpu_to_be32(new_offset);
1508         if (left > conn->max_xmit_dlength) {
1509                 hton24(hdr->dlength, conn->max_xmit_dlength);
1510                 r2t->data_count = conn->max_xmit_dlength;
1511         } else {
1512                 hton24(hdr->dlength, left);
1513                 r2t->data_count = left;
1514                 hdr->flags = ISCSI_FLAG_CMD_FINAL;
1515         }
1516         conn->dataout_pdus_cnt++;
1517
1518         iscsi_buf_init_virt(&r2t->headbuf, (char*)hdr,
1519                            sizeof(struct iscsi_hdr));
1520
1521         r2t->dtask = dtask;
1522
1523         if (sc->use_sg && !iscsi_buf_left(&r2t->sendbuf)) {
1524                 BUG_ON(ctask->bad_sg == r2t->sg);
1525                 iscsi_buf_init_sg(&r2t->sendbuf, r2t->sg);
1526                 r2t->sg += 1;
1527         } else
1528                 iscsi_buf_init_iov(&ctask->sendbuf,
1529                             (char*)sc->request_buffer + new_offset,
1530                             r2t->data_count);
1531
1532         list_add(&dtask->item, &ctask->dataqueue);
1533 }
1534
1535 static void
1536 iscsi_unsolicit_data_init(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1537 {
1538         struct iscsi_data *hdr;
1539         struct iscsi_data_task *dtask;
1540
1541         dtask = mempool_alloc(ctask->datapool, GFP_ATOMIC);
1542         BUG_ON(!dtask);
1543         hdr = &dtask->hdr;
1544         memset(hdr, 0, sizeof(struct iscsi_data));
1545         hdr->ttt = cpu_to_be32(ISCSI_RESERVED_TAG);
1546         hdr->datasn = cpu_to_be32(ctask->unsol_datasn);
1547         ctask->unsol_datasn++;
1548         hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
1549         memcpy(hdr->lun, ctask->hdr.lun, sizeof(hdr->lun));
1550         hdr->itt = ctask->hdr.itt;
1551         hdr->exp_statsn = cpu_to_be32(conn->exp_statsn);
1552         hdr->offset = cpu_to_be32(ctask->total_length -
1553                                   ctask->r2t_data_count -
1554                                   ctask->unsol_count);
1555         if (ctask->unsol_count > conn->max_xmit_dlength) {
1556                 hton24(hdr->dlength, conn->max_xmit_dlength);
1557                 ctask->data_count = conn->max_xmit_dlength;
1558                 hdr->flags = 0;
1559         } else {
1560                 hton24(hdr->dlength, ctask->unsol_count);
1561                 ctask->data_count = ctask->unsol_count;
1562                 hdr->flags = ISCSI_FLAG_CMD_FINAL;
1563         }
1564
1565         iscsi_buf_init_virt(&ctask->headbuf, (char*)hdr,
1566                            sizeof(struct iscsi_hdr));
1567
1568         list_add(&dtask->item, &ctask->dataqueue);
1569
1570         ctask->dtask = dtask;
1571 }
1572
1573 /**
1574  * iscsi_cmd_init - Initialize iSCSI SCSI_READ or SCSI_WRITE commands
1575  * @conn: iscsi connection
1576  * @ctask: scsi command task
1577  * @sc: scsi command
1578  **/
1579 static void
1580 iscsi_cmd_init(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
1581                 struct scsi_cmnd *sc)
1582 {
1583         struct iscsi_session *session = conn->session;
1584
1585         BUG_ON(__kfifo_len(ctask->r2tqueue));
1586
1587         ctask->sc = sc;
1588         ctask->conn = conn;
1589         ctask->hdr.opcode = ISCSI_OP_SCSI_CMD;
1590         ctask->hdr.flags = ISCSI_ATTR_SIMPLE;
1591         int_to_scsilun(sc->device->lun, (struct scsi_lun *)ctask->hdr.lun);
1592         ctask->hdr.itt = ctask->itt | (conn->id << CID_SHIFT) |
1593                          (session->age << AGE_SHIFT);
1594         ctask->hdr.data_length = cpu_to_be32(sc->request_bufflen);
1595         ctask->hdr.cmdsn = cpu_to_be32(session->cmdsn); session->cmdsn++;
1596         ctask->hdr.exp_statsn = cpu_to_be32(conn->exp_statsn);
1597         memcpy(ctask->hdr.cdb, sc->cmnd, sc->cmd_len);
1598         memset(&ctask->hdr.cdb[sc->cmd_len], 0, MAX_COMMAND_SIZE - sc->cmd_len);
1599
1600         ctask->mtask = NULL;
1601         ctask->sent = 0;
1602         ctask->sg_count = 0;
1603
1604         ctask->total_length = sc->request_bufflen;
1605
1606         if (sc->sc_data_direction == DMA_TO_DEVICE) {
1607                 ctask->exp_r2tsn = 0;
1608                 ctask->hdr.flags |= ISCSI_FLAG_CMD_WRITE;
1609                 BUG_ON(ctask->total_length == 0);
1610                 if (sc->use_sg) {
1611                         struct scatterlist *sg = sc->request_buffer;
1612
1613                         iscsi_buf_init_sg(&ctask->sendbuf,
1614                                           &sg[ctask->sg_count++]);
1615                         ctask->sg = sg;
1616                         ctask->bad_sg = sg + sc->use_sg;
1617                 } else {
1618                         iscsi_buf_init_iov(&ctask->sendbuf, sc->request_buffer,
1619                                         sc->request_bufflen);
1620                 }
1621
1622                 /*
1623                  * Write counters:
1624                  *
1625                  *      imm_count       bytes to be sent right after
1626                  *                      SCSI PDU Header
1627                  *
1628                  *      unsol_count     bytes(as Data-Out) to be sent
1629                  *                      without R2T ack right after
1630                  *                      immediate data
1631                  *
1632                  *      r2t_data_count  bytes to be sent via R2T ack's
1633                  *
1634                  *      pad_count       bytes to be sent as zero-padding
1635                  */
1636                 ctask->imm_count = 0;
1637                 ctask->unsol_count = 0;
1638                 ctask->unsol_datasn = 0;
1639                 ctask->xmstate = XMSTATE_W_HDR;
1640                 /* calculate write padding */
1641                 ctask->pad_count = ctask->total_length & (ISCSI_PAD_LEN-1);
1642                 if (ctask->pad_count) {
1643                         ctask->pad_count = ISCSI_PAD_LEN - ctask->pad_count;
1644                         debug_scsi("write padding %d bytes\n",
1645                                 ctask->pad_count);
1646                         ctask->xmstate |= XMSTATE_W_PAD;
1647                 }
1648                 if (session->imm_data_en) {
1649                         if (ctask->total_length >= session->first_burst)
1650                                 ctask->imm_count = min(session->first_burst,
1651                                                         conn->max_xmit_dlength);
1652                         else
1653                                 ctask->imm_count = min(ctask->total_length,
1654                                                         conn->max_xmit_dlength);
1655                         hton24(ctask->hdr.dlength, ctask->imm_count);
1656                         ctask->xmstate |= XMSTATE_IMM_DATA;
1657                 } else
1658                         zero_data(ctask->hdr.dlength);
1659
1660                 if (!session->initial_r2t_en)
1661                         ctask->unsol_count = min(session->first_burst,
1662                                 ctask->total_length) - ctask->imm_count;
1663                 if (!ctask->unsol_count)
1664                         /* No unsolicit Data-Out's */
1665                         ctask->hdr.flags |= ISCSI_FLAG_CMD_FINAL;
1666                 else
1667                         ctask->xmstate |= XMSTATE_UNS_HDR | XMSTATE_UNS_INIT;
1668
1669                 ctask->r2t_data_count = ctask->total_length -
1670                                     ctask->imm_count -
1671                                     ctask->unsol_count;
1672
1673                 debug_scsi("cmd [itt %x total %d imm %d imm_data %d "
1674                            "r2t_data %d]\n",
1675                            ctask->itt, ctask->total_length, ctask->imm_count,
1676                            ctask->unsol_count, ctask->r2t_data_count);
1677         } else {
1678                 ctask->hdr.flags |= ISCSI_FLAG_CMD_FINAL;
1679                 if (sc->sc_data_direction == DMA_FROM_DEVICE)
1680                         ctask->hdr.flags |= ISCSI_FLAG_CMD_READ;
1681                 ctask->datasn = 0;
1682                 ctask->xmstate = XMSTATE_R_HDR;
1683                 zero_data(ctask->hdr.dlength);
1684         }
1685
1686         iscsi_buf_init_virt(&ctask->headbuf, (char*)&ctask->hdr,
1687                             sizeof(struct iscsi_hdr));
1688         conn->scsicmd_pdus_cnt++;
1689 }
1690
1691 /**
1692  * iscsi_mtask_xmit - xmit management(immediate) task
1693  * @conn: iscsi connection
1694  * @mtask: task management task
1695  *
1696  * Notes:
1697  *      The function can return -EAGAIN in which case caller must
1698  *      call it again later, or recover. '0' return code means successful
1699  *      xmit.
1700  *
1701  *      Management xmit state machine consists of two states:
1702  *              IN_PROGRESS_IMM_HEAD - PDU Header xmit in progress
1703  *              IN_PROGRESS_IMM_DATA - PDU Data xmit in progress
1704  **/
1705 static int
1706 iscsi_mtask_xmit(struct iscsi_conn *conn, struct iscsi_mgmt_task *mtask)
1707 {
1708
1709         debug_scsi("mtask deq [cid %d state %x itt 0x%x]\n",
1710                 conn->id, mtask->xmstate, mtask->itt);
1711
1712         if (mtask->xmstate & XMSTATE_IMM_HDR) {
1713                 mtask->xmstate &= ~XMSTATE_IMM_HDR;
1714                 if (mtask->data_count)
1715                         mtask->xmstate |= XMSTATE_IMM_DATA;
1716                 if (conn->c_stage != ISCSI_CONN_INITIAL_STAGE &&
1717                     conn->stop_stage != STOP_CONN_RECOVER &&
1718                     conn->hdrdgst_en)
1719                         iscsi_hdr_digest(conn, &mtask->headbuf,
1720                                         (u8*)mtask->hdrext);
1721                 if (iscsi_sendhdr(conn, &mtask->headbuf, mtask->data_count)) {
1722                         mtask->xmstate |= XMSTATE_IMM_HDR;
1723                         if (mtask->data_count)
1724                                 mtask->xmstate &= ~XMSTATE_IMM_DATA;
1725                         return -EAGAIN;
1726                 }
1727         }
1728
1729         if (mtask->xmstate & XMSTATE_IMM_DATA) {
1730                 BUG_ON(!mtask->data_count);
1731                 mtask->xmstate &= ~XMSTATE_IMM_DATA;
1732                 /* FIXME: implement.
1733                  * Virtual buffer could be spreaded across multiple pages...
1734                  */
1735                 do {
1736                         if (iscsi_sendpage(conn, &mtask->sendbuf,
1737                                    &mtask->data_count, &mtask->sent)) {
1738                                 mtask->xmstate |= XMSTATE_IMM_DATA;
1739                                 return -EAGAIN;
1740                         }
1741                 } while (mtask->data_count);
1742         }
1743
1744         BUG_ON(mtask->xmstate != XMSTATE_IDLE);
1745         return 0;
1746 }
1747
1748 static inline int
1749 handle_xmstate_r_hdr(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1750 {
1751         ctask->xmstate &= ~XMSTATE_R_HDR;
1752         if (conn->hdrdgst_en)
1753                 iscsi_hdr_digest(conn, &ctask->headbuf, (u8*)ctask->hdrext);
1754         if (!iscsi_sendhdr(conn, &ctask->headbuf, 0)) {
1755                 BUG_ON(ctask->xmstate != XMSTATE_IDLE);
1756                 return 0; /* wait for Data-In */
1757         }
1758         ctask->xmstate |= XMSTATE_R_HDR;
1759         return -EAGAIN;
1760 }
1761
1762 static inline int
1763 handle_xmstate_w_hdr(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1764 {
1765         ctask->xmstate &= ~XMSTATE_W_HDR;
1766         if (conn->hdrdgst_en)
1767                 iscsi_hdr_digest(conn, &ctask->headbuf, (u8*)ctask->hdrext);
1768         if (iscsi_sendhdr(conn, &ctask->headbuf, ctask->imm_count)) {
1769                 ctask->xmstate |= XMSTATE_W_HDR;
1770                 return -EAGAIN;
1771         }
1772         return 0;
1773 }
1774
1775 static inline int
1776 handle_xmstate_data_digest(struct iscsi_conn *conn,
1777                            struct iscsi_cmd_task *ctask)
1778 {
1779         ctask->xmstate &= ~XMSTATE_DATA_DIGEST;
1780         debug_tcp("resent data digest 0x%x\n", ctask->datadigest);
1781         if (iscsi_digest_final_send(conn, ctask, &ctask->immbuf,
1782                                     &ctask->datadigest, 0)) {
1783                 ctask->xmstate |= XMSTATE_DATA_DIGEST;
1784                 debug_tcp("resent data digest 0x%x fail!\n",
1785                           ctask->datadigest);
1786                 return -EAGAIN;
1787         }
1788         return 0;
1789 }
1790
1791 static inline int
1792 handle_xmstate_imm_data(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1793 {
1794         BUG_ON(!ctask->imm_count);
1795         ctask->xmstate &= ~XMSTATE_IMM_DATA;
1796
1797         if (conn->datadgst_en) {
1798                 iscsi_data_digest_init(conn, ctask);
1799                 ctask->immdigest = 0;
1800         }
1801
1802         for (;;) {
1803                 if (iscsi_sendpage(conn, &ctask->sendbuf, &ctask->imm_count,
1804                                    &ctask->sent)) {
1805                         ctask->xmstate |= XMSTATE_IMM_DATA;
1806                         if (conn->datadgst_en) {
1807                                 crypto_digest_final(conn->data_tx_tfm,
1808                                                 (u8*)&ctask->immdigest);
1809                                 debug_tcp("tx imm sendpage fail 0x%x\n",
1810                                           ctask->datadigest);
1811                         }
1812                         return -EAGAIN;
1813                 }
1814                 if (conn->datadgst_en)
1815                         iscsi_buf_data_digest_update(conn, &ctask->sendbuf);
1816
1817                 if (!ctask->imm_count)
1818                         break;
1819                 iscsi_buf_init_sg(&ctask->sendbuf,
1820                                   &ctask->sg[ctask->sg_count++]);
1821         }
1822
1823         if (conn->datadgst_en && !(ctask->xmstate & XMSTATE_W_PAD)) {
1824                 if (iscsi_digest_final_send(conn, ctask, &ctask->immbuf,
1825                                             &ctask->immdigest, 1)) {
1826                         debug_tcp("sending imm digest 0x%x fail!\n",
1827                                   ctask->immdigest);
1828                         return -EAGAIN;
1829                 }
1830                 debug_tcp("sending imm digest 0x%x\n", ctask->immdigest);
1831         }
1832
1833         return 0;
1834 }
1835
1836 static inline int
1837 handle_xmstate_uns_hdr(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1838 {
1839         struct iscsi_data_task *dtask;
1840
1841         ctask->xmstate |= XMSTATE_UNS_DATA;
1842         if (ctask->xmstate & XMSTATE_UNS_INIT) {
1843                 iscsi_unsolicit_data_init(conn, ctask);
1844                 BUG_ON(!ctask->dtask);
1845                 dtask = ctask->dtask;
1846                 if (conn->hdrdgst_en)
1847                         iscsi_hdr_digest(conn, &ctask->headbuf,
1848                                         (u8*)dtask->hdrext);
1849                 ctask->xmstate &= ~XMSTATE_UNS_INIT;
1850         }
1851         if (iscsi_sendhdr(conn, &ctask->headbuf, ctask->data_count)) {
1852                 ctask->xmstate &= ~XMSTATE_UNS_DATA;
1853                 ctask->xmstate |= XMSTATE_UNS_HDR;
1854                 return -EAGAIN;
1855         }
1856
1857         debug_scsi("uns dout [itt 0x%x dlen %d sent %d]\n",
1858                    ctask->itt, ctask->unsol_count, ctask->sent);
1859         return 0;
1860 }
1861
1862 static inline int
1863 handle_xmstate_uns_data(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1864 {
1865         struct iscsi_data_task *dtask = ctask->dtask;
1866
1867         BUG_ON(!ctask->data_count);
1868         ctask->xmstate &= ~XMSTATE_UNS_DATA;
1869
1870         if (conn->datadgst_en) {
1871                 iscsi_data_digest_init(conn, ctask);
1872                 dtask->digest = 0;
1873         }
1874
1875         for (;;) {
1876                 int start = ctask->sent;
1877
1878                 if (iscsi_sendpage(conn, &ctask->sendbuf, &ctask->data_count,
1879                                    &ctask->sent)) {
1880                         ctask->unsol_count -= ctask->sent - start;
1881                         ctask->xmstate |= XMSTATE_UNS_DATA;
1882                         /* will continue with this ctask later.. */
1883                         if (conn->datadgst_en) {
1884                                 crypto_digest_final(conn->data_tx_tfm,
1885                                                 (u8 *)&dtask->digest);
1886                                 debug_tcp("tx uns data fail 0x%x\n",
1887                                           dtask->digest);
1888                         }
1889                         return -EAGAIN;
1890                 }
1891
1892                 BUG_ON(ctask->sent > ctask->total_length);
1893                 ctask->unsol_count -= ctask->sent - start;
1894
1895                 /*
1896                  * XXX:we may run here with un-initial sendbuf.
1897                  * so pass it
1898                  */
1899                 if (conn->datadgst_en && ctask->sent - start > 0)
1900                         iscsi_buf_data_digest_update(conn, &ctask->sendbuf);
1901
1902                 if (!ctask->data_count)
1903                         break;
1904                 iscsi_buf_init_sg(&ctask->sendbuf,
1905                                   &ctask->sg[ctask->sg_count++]);
1906         }
1907         BUG_ON(ctask->unsol_count < 0);
1908
1909         /*
1910          * Done with the Data-Out. Next, check if we need
1911          * to send another unsolicited Data-Out.
1912          */
1913         if (ctask->unsol_count) {
1914                 if (conn->datadgst_en) {
1915                         if (iscsi_digest_final_send(conn, ctask,
1916                                                     &dtask->digestbuf,
1917                                                     &dtask->digest, 1)) {
1918                                 debug_tcp("send uns digest 0x%x fail\n",
1919                                           dtask->digest);
1920                                 return -EAGAIN;
1921                         }
1922                         debug_tcp("sending uns digest 0x%x, more uns\n",
1923                                   dtask->digest);
1924                 }
1925                 ctask->xmstate |= XMSTATE_UNS_INIT;
1926                 return 1;
1927         }
1928
1929         if (conn->datadgst_en && !(ctask->xmstate & XMSTATE_W_PAD)) {
1930                 if (iscsi_digest_final_send(conn, ctask,
1931                                             &dtask->digestbuf,
1932                                             &dtask->digest, 1)) {
1933                         debug_tcp("send last uns digest 0x%x fail\n",
1934                                    dtask->digest);
1935                         return -EAGAIN;
1936                 }
1937                 debug_tcp("sending uns digest 0x%x\n",dtask->digest);
1938         }
1939
1940         return 0;
1941 }
1942
1943 static inline int
1944 handle_xmstate_sol_data(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1945 {
1946         struct iscsi_session *session = conn->session;
1947         struct iscsi_r2t_info *r2t = ctask->r2t;
1948         struct iscsi_data_task *dtask = r2t->dtask;
1949         int left;
1950
1951         ctask->xmstate &= ~XMSTATE_SOL_DATA;
1952         ctask->dtask = dtask;
1953
1954         if (conn->datadgst_en) {
1955                 iscsi_data_digest_init(conn, ctask);
1956                 dtask->digest = 0;
1957         }
1958 solicit_again:
1959         /*
1960          * send Data-Out whitnin this R2T sequence.
1961          */
1962         if (!r2t->data_count)
1963                 goto data_out_done;
1964
1965         if (iscsi_sendpage(conn, &r2t->sendbuf, &r2t->data_count, &r2t->sent)) {
1966                 ctask->xmstate |= XMSTATE_SOL_DATA;
1967                 /* will continue with this ctask later.. */
1968                 if (conn->datadgst_en) {
1969                         crypto_digest_final(conn->data_tx_tfm,
1970                                           (u8 *)&dtask->digest);
1971                         debug_tcp("r2t data send fail 0x%x\n", dtask->digest);
1972                 }
1973                 return -EAGAIN;
1974         }
1975
1976         BUG_ON(r2t->data_count < 0);
1977         if (conn->datadgst_en)
1978                 iscsi_buf_data_digest_update(conn, &r2t->sendbuf);
1979
1980         if (r2t->data_count) {
1981                 BUG_ON(ctask->sc->use_sg == 0);
1982                 if (!iscsi_buf_left(&r2t->sendbuf)) {
1983                         BUG_ON(ctask->bad_sg == r2t->sg);
1984                         iscsi_buf_init_sg(&r2t->sendbuf, r2t->sg);
1985                         r2t->sg += 1;
1986                 }
1987                 goto solicit_again;
1988         }
1989
1990 data_out_done:
1991         /*
1992          * Done with this Data-Out. Next, check if we have
1993          * to send another Data-Out for this R2T.
1994          */
1995         BUG_ON(r2t->data_length - r2t->sent < 0);
1996         left = r2t->data_length - r2t->sent;
1997         if (left) {
1998                 if (conn->datadgst_en) {
1999                         if (iscsi_digest_final_send(conn, ctask,
2000                                                     &dtask->digestbuf,
2001                                                     &dtask->digest, 1)) {
2002                                 debug_tcp("send r2t data digest 0x%x"
2003                                           "fail\n", dtask->digest);
2004                                 return -EAGAIN;
2005                         }
2006                         debug_tcp("r2t data send digest 0x%x\n",
2007                                   dtask->digest);
2008                 }
2009                 iscsi_solicit_data_cont(conn, ctask, r2t, left);
2010                 ctask->xmstate |= XMSTATE_SOL_DATA;
2011                 ctask->xmstate &= ~XMSTATE_SOL_HDR;
2012                 return 1;
2013         }
2014
2015         /*
2016          * Done with this R2T. Check if there are more
2017          * outstanding R2Ts ready to be processed.
2018          */
2019         BUG_ON(ctask->r2t_data_count - r2t->data_length < 0);
2020         if (conn->datadgst_en) {
2021                 if (iscsi_digest_final_send(conn, ctask, &dtask->digestbuf,
2022                                             &dtask->digest, 1)) {
2023                         debug_tcp("send last r2t data digest 0x%x"
2024                                   "fail\n", dtask->digest);
2025                         return -EAGAIN;
2026                 }
2027                 debug_tcp("r2t done dout digest 0x%x\n", dtask->digest);
2028         }
2029
2030         ctask->r2t_data_count -= r2t->data_length;
2031         ctask->r2t = NULL;
2032         spin_lock_bh(&session->lock);
2033         __kfifo_put(ctask->r2tpool.queue, (void*)&r2t, sizeof(void*));
2034         spin_unlock_bh(&session->lock);
2035         if (__kfifo_get(ctask->r2tqueue, (void*)&r2t, sizeof(void*))) {
2036                 ctask->r2t = r2t;
2037                 ctask->xmstate |= XMSTATE_SOL_DATA;
2038                 ctask->xmstate &= ~XMSTATE_SOL_HDR;
2039                 return 1;
2040         }
2041
2042         return 0;
2043 }
2044
2045 static inline int
2046 handle_xmstate_w_pad(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
2047 {
2048         struct iscsi_data_task *dtask = ctask->dtask;
2049         int sent;
2050
2051         ctask->xmstate &= ~XMSTATE_W_PAD;
2052         iscsi_buf_init_virt(&ctask->sendbuf, (char*)&ctask->pad,
2053                             ctask->pad_count);
2054         if (iscsi_sendpage(conn, &ctask->sendbuf, &ctask->pad_count, &sent)) {
2055                 ctask->xmstate |= XMSTATE_W_PAD;
2056                 return -EAGAIN;
2057         }
2058
2059         if (conn->datadgst_en) {
2060                 iscsi_buf_data_digest_update(conn, &ctask->sendbuf);
2061                 /* imm data? */
2062                 if (!dtask) {
2063                         if (iscsi_digest_final_send(conn, ctask, &ctask->immbuf,
2064                                                     &ctask->immdigest, 1)) {
2065                                 debug_tcp("send padding digest 0x%x"
2066                                           "fail!\n", ctask->immdigest);
2067                                 return -EAGAIN;
2068                         }
2069                         debug_tcp("done with padding, digest 0x%x\n",
2070                                   ctask->datadigest);
2071                 } else {
2072                         if (iscsi_digest_final_send(conn, ctask,
2073                                                     &dtask->digestbuf,
2074                                                     &dtask->digest, 1)) {
2075                                 debug_tcp("send padding digest 0x%x"
2076                                           "fail\n", dtask->digest);
2077                                 return -EAGAIN;
2078                         }
2079                         debug_tcp("done with padding, digest 0x%x\n",
2080                                   dtask->digest);
2081                 }
2082         }
2083
2084         return 0;
2085 }
2086
2087 static int
2088 iscsi_ctask_xmit(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
2089 {
2090         int rc = 0;
2091
2092         debug_scsi("ctask deq [cid %d xmstate %x itt 0x%x]\n",
2093                 conn->id, ctask->xmstate, ctask->itt);
2094
2095         /*
2096          * serialize with TMF AbortTask
2097          */
2098         if (ctask->mtask)
2099                 return rc;
2100
2101         if (ctask->xmstate & XMSTATE_R_HDR) {
2102                 rc = handle_xmstate_r_hdr(conn, ctask);
2103                 return rc;
2104         }
2105
2106         if (ctask->xmstate & XMSTATE_W_HDR) {
2107                 rc = handle_xmstate_w_hdr(conn, ctask);
2108                 if (rc)
2109                         return rc;
2110         }
2111
2112         /* XXX: for data digest xmit recover */
2113         if (ctask->xmstate & XMSTATE_DATA_DIGEST) {
2114                 rc = handle_xmstate_data_digest(conn, ctask);
2115                 if (rc)
2116                         return rc;
2117         }
2118
2119         if (ctask->xmstate & XMSTATE_IMM_DATA) {
2120                 rc = handle_xmstate_imm_data(conn, ctask);
2121                 if (rc)
2122                         return rc;
2123         }
2124
2125         if (ctask->xmstate & XMSTATE_UNS_HDR) {
2126                 BUG_ON(!ctask->unsol_count);
2127                 ctask->xmstate &= ~XMSTATE_UNS_HDR;
2128 unsolicit_head_again:
2129                 rc = handle_xmstate_uns_hdr(conn, ctask);
2130                 if (rc)
2131                         return rc;
2132         }
2133
2134         if (ctask->xmstate & XMSTATE_UNS_DATA) {
2135                 rc = handle_xmstate_uns_data(conn, ctask);
2136                 if (rc == 1)
2137                         goto unsolicit_head_again;
2138                 else if (rc)
2139                         return rc;
2140                 goto done;
2141         }
2142
2143         if (ctask->xmstate & XMSTATE_SOL_HDR) {
2144                 struct iscsi_r2t_info *r2t;
2145
2146                 ctask->xmstate &= ~XMSTATE_SOL_HDR;
2147                 ctask->xmstate |= XMSTATE_SOL_DATA;
2148                 if (!ctask->r2t)
2149                         __kfifo_get(ctask->r2tqueue, (void*)&ctask->r2t,
2150                                     sizeof(void*));
2151 solicit_head_again:
2152                 r2t = ctask->r2t;
2153                 if (conn->hdrdgst_en)
2154                         iscsi_hdr_digest(conn, &r2t->headbuf,
2155                                         (u8*)r2t->dtask->hdrext);
2156                 if (iscsi_sendhdr(conn, &r2t->headbuf, r2t->data_count)) {
2157                         ctask->xmstate &= ~XMSTATE_SOL_DATA;
2158                         ctask->xmstate |= XMSTATE_SOL_HDR;
2159                         return -EAGAIN;
2160                 }
2161
2162                 debug_scsi("sol dout [dsn %d itt 0x%x dlen %d sent %d]\n",
2163                         r2t->solicit_datasn - 1, ctask->itt, r2t->data_count,
2164                         r2t->sent);
2165         }
2166
2167         if (ctask->xmstate & XMSTATE_SOL_DATA) {
2168                 rc = handle_xmstate_sol_data(conn, ctask);
2169                 if (rc == 1)
2170                         goto solicit_head_again;
2171                 if (rc)
2172                         return rc;
2173         }
2174
2175 done:
2176         /*
2177          * Last thing to check is whether we need to send write
2178          * padding. Note that we check for xmstate equality, not just the bit.
2179          */
2180         if (ctask->xmstate == XMSTATE_W_PAD)
2181                 rc = handle_xmstate_w_pad(conn, ctask);
2182
2183         return rc;
2184 }
2185
2186 /**
2187  * iscsi_data_xmit - xmit any command into the scheduled connection
2188  * @conn: iscsi connection
2189  *
2190  * Notes:
2191  *      The function can return -EAGAIN in which case the caller must
2192  *      re-schedule it again later or recover. '0' return code means
2193  *      successful xmit.
2194  **/
2195 static int
2196 iscsi_data_xmit(struct iscsi_conn *conn)
2197 {
2198         if (unlikely(conn->suspend_tx)) {
2199                 debug_tcp("conn %d Tx suspended!\n", conn->id);
2200                 return 0;
2201         }
2202
2203         /*
2204          * Transmit in the following order:
2205          *
2206          * 1) un-finished xmit (ctask or mtask)
2207          * 2) immediate control PDUs
2208          * 3) write data
2209          * 4) SCSI commands
2210          * 5) non-immediate control PDUs
2211          *
2212          * No need to lock around __kfifo_get as long as
2213          * there's one producer and one consumer.
2214          */
2215
2216         BUG_ON(conn->ctask && conn->mtask);
2217
2218         if (conn->ctask) {
2219                 if (iscsi_ctask_xmit(conn, conn->ctask))
2220                         goto again;
2221                 /* done with this in-progress ctask */
2222                 conn->ctask = NULL;
2223         }
2224         if (conn->mtask) {
2225                 if (iscsi_mtask_xmit(conn, conn->mtask))
2226                         goto again;
2227                 /* done with this in-progress mtask */
2228                 conn->mtask = NULL;
2229         }
2230
2231         /* process immediate first */
2232         if (unlikely(__kfifo_len(conn->immqueue))) {
2233                 struct iscsi_session *session = conn->session;
2234                 while (__kfifo_get(conn->immqueue, (void*)&conn->mtask,
2235                                    sizeof(void*))) {
2236                         if (iscsi_mtask_xmit(conn, conn->mtask))
2237                                 goto again;
2238
2239                         if (conn->mtask->hdr.itt ==
2240                                         cpu_to_be32(ISCSI_RESERVED_TAG)) {
2241                                 spin_lock_bh(&session->lock);
2242                                 __kfifo_put(session->mgmtpool.queue,
2243                                             (void*)&conn->mtask, sizeof(void*));
2244                                 spin_unlock_bh(&session->lock);
2245                         }
2246                 }
2247                 /* done with this mtask */
2248                 conn->mtask = NULL;
2249         }
2250
2251         /* process write queue */
2252         while (__kfifo_get(conn->writequeue, (void*)&conn->ctask,
2253                            sizeof(void*))) {
2254                 if (iscsi_ctask_xmit(conn, conn->ctask))
2255                         goto again;
2256         }
2257
2258         /* process command queue */
2259         while (__kfifo_get(conn->xmitqueue, (void*)&conn->ctask,
2260                            sizeof(void*))) {
2261                 if (iscsi_ctask_xmit(conn, conn->ctask))
2262                         goto again;
2263         }
2264         /* done with this ctask */
2265         conn->ctask = NULL;
2266
2267         /* process the rest control plane PDUs, if any */
2268         if (unlikely(__kfifo_len(conn->mgmtqueue))) {
2269                 struct iscsi_session *session = conn->session;
2270
2271                 while (__kfifo_get(conn->mgmtqueue, (void*)&conn->mtask,
2272                                    sizeof(void*))) {
2273                         if (iscsi_mtask_xmit(conn, conn->mtask))
2274                                 goto again;
2275
2276                         if (conn->mtask->hdr.itt ==
2277                                         cpu_to_be32(ISCSI_RESERVED_TAG)) {
2278                                 spin_lock_bh(&session->lock);
2279                                 __kfifo_put(session->mgmtpool.queue,
2280                                             (void*)&conn->mtask,
2281                                             sizeof(void*));
2282                                 spin_unlock_bh(&session->lock);
2283                         }
2284                 }
2285                 /* done with this mtask */
2286                 conn->mtask = NULL;
2287         }
2288
2289         return 0;
2290
2291 again:
2292         if (unlikely(conn->suspend_tx))
2293                 return 0;
2294
2295         return -EAGAIN;
2296 }
2297
2298 static void
2299 iscsi_xmitworker(void *data)
2300 {
2301         struct iscsi_conn *conn = data;
2302
2303         /*
2304          * serialize Xmit worker on a per-connection basis.
2305          */
2306         down(&conn->xmitsema);
2307         if (iscsi_data_xmit(conn))
2308                 schedule_work(&conn->xmitwork);
2309         up(&conn->xmitsema);
2310 }
2311
2312 #define FAILURE_BAD_HOST                1
2313 #define FAILURE_SESSION_FAILED          2
2314 #define FAILURE_SESSION_FREED           3
2315 #define FAILURE_WINDOW_CLOSED           4
2316 #define FAILURE_SESSION_TERMINATE       5
2317
2318 static int
2319 iscsi_queuecommand(struct scsi_cmnd *sc, void (*done)(struct scsi_cmnd *))
2320 {
2321         struct Scsi_Host *host;
2322         int reason = 0;
2323         struct iscsi_session *session;
2324         struct iscsi_conn *conn = NULL;
2325         struct iscsi_cmd_task *ctask = NULL;
2326
2327         sc->scsi_done = done;
2328         sc->result = 0;
2329
2330         host = sc->device->host;
2331         session = iscsi_hostdata(host->hostdata);
2332         BUG_ON(host != session->host);
2333
2334         spin_lock(&session->lock);
2335
2336         if (session->state != ISCSI_STATE_LOGGED_IN) {
2337                 if (session->state == ISCSI_STATE_FAILED) {
2338                         reason = FAILURE_SESSION_FAILED;
2339                         goto reject;
2340                 } else if (session->state == ISCSI_STATE_TERMINATE) {
2341                         reason = FAILURE_SESSION_TERMINATE;
2342                         goto fault;
2343                 }
2344                 reason = FAILURE_SESSION_FREED;
2345                 goto fault;
2346         }
2347
2348         /*
2349          * Check for iSCSI window and take care of CmdSN wrap-around
2350          */
2351         if ((int)(session->max_cmdsn - session->cmdsn) < 0) {
2352                 reason = FAILURE_WINDOW_CLOSED;
2353                 goto reject;
2354         }
2355
2356         conn = session->leadconn;
2357
2358         __kfifo_get(session->cmdpool.queue, (void*)&ctask, sizeof(void*));
2359         BUG_ON(ctask->sc);
2360
2361         sc->SCp.phase = session->age;
2362         sc->SCp.ptr = (char*)ctask;
2363         iscsi_cmd_init(conn, ctask, sc);
2364
2365         __kfifo_put(conn->xmitqueue, (void*)&ctask, sizeof(void*));
2366         debug_scsi(
2367                "ctask enq [%s cid %d sc %lx itt 0x%x len %d cmdsn %d win %d]\n",
2368                 sc->sc_data_direction == DMA_TO_DEVICE ? "write" : "read",
2369                 conn->id, (long)sc, ctask->itt, sc->request_bufflen,
2370                 session->cmdsn, session->max_cmdsn - session->exp_cmdsn + 1);
2371         spin_unlock(&session->lock);
2372
2373         if (!in_interrupt() && !down_trylock(&conn->xmitsema)) {
2374                 spin_unlock_irq(host->host_lock);
2375                 if (iscsi_data_xmit(conn))
2376                         schedule_work(&conn->xmitwork);
2377                 up(&conn->xmitsema);
2378                 spin_lock_irq(host->host_lock);
2379         } else
2380                 schedule_work(&conn->xmitwork);
2381
2382         return 0;
2383
2384 reject:
2385         spin_unlock(&session->lock);
2386         debug_scsi("cmd 0x%x rejected (%d)\n", sc->cmnd[0], reason);
2387         return SCSI_MLQUEUE_HOST_BUSY;
2388
2389 fault:
2390         spin_unlock(&session->lock);
2391         printk(KERN_ERR "iscsi_tcp: cmd 0x%x is not queued (%d)\n",
2392                sc->cmnd[0], reason);
2393         sc->sense_buffer[0] = 0x70;
2394         sc->sense_buffer[2] = NOT_READY;
2395         sc->sense_buffer[7] = 0x6;
2396         sc->sense_buffer[12] = 0x08;
2397         sc->sense_buffer[13] = 0x00;
2398         sc->result = (DID_NO_CONNECT << 16);
2399         sc->resid = sc->request_bufflen;
2400         sc->scsi_done(sc);
2401         return 0;
2402 }
2403
2404 static int
2405 iscsi_change_queue_depth(struct scsi_device *sdev, int depth)
2406 {
2407         if (depth > ISCSI_MAX_CMD_PER_LUN)
2408                 depth = ISCSI_MAX_CMD_PER_LUN;
2409         scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
2410         return sdev->queue_depth;
2411 }
2412
2413 static int
2414 iscsi_pool_init(struct iscsi_queue *q, int max, void ***items, int item_size)
2415 {
2416         int i;
2417
2418         *items = kmalloc(max * sizeof(void*), GFP_KERNEL);
2419         if (*items == NULL)
2420                 return -ENOMEM;
2421
2422         q->max = max;
2423         q->pool = kmalloc(max * sizeof(void*), GFP_KERNEL);
2424         if (q->pool == NULL) {
2425                 kfree(*items);
2426                 return -ENOMEM;
2427         }
2428
2429         q->queue = kfifo_init((void*)q->pool, max * sizeof(void*),
2430                               GFP_KERNEL, NULL);
2431         if (q->queue == ERR_PTR(-ENOMEM)) {
2432                 kfree(q->pool);
2433                 kfree(*items);
2434                 return -ENOMEM;
2435         }
2436
2437         for (i = 0; i < max; i++) {
2438                 q->pool[i] = kmalloc(item_size, GFP_KERNEL);
2439                 if (q->pool[i] == NULL) {
2440                         int j;
2441
2442                         for (j = 0; j < i; j++)
2443                                 kfree(q->pool[j]);
2444
2445                         kfifo_free(q->queue);
2446                         kfree(q->pool);
2447                         kfree(*items);
2448                         return -ENOMEM;
2449                 }
2450                 memset(q->pool[i], 0, item_size);
2451                 (*items)[i] = q->pool[i];
2452                 __kfifo_put(q->queue, (void*)&q->pool[i], sizeof(void*));
2453         }
2454         return 0;
2455 }
2456
2457 static void
2458 iscsi_pool_free(struct iscsi_queue *q, void **items)
2459 {
2460         int i;
2461
2462         for (i = 0; i < q->max; i++)
2463                 kfree(items[i]);
2464         kfree(q->pool);
2465         kfree(items);
2466 }
2467
2468 static iscsi_connh_t
2469 iscsi_conn_create(iscsi_sessionh_t sessionh, uint32_t conn_idx)
2470 {
2471         struct iscsi_session *session = iscsi_ptr(sessionh);
2472         struct iscsi_conn *conn = NULL;
2473
2474         conn = kmalloc(sizeof(struct iscsi_conn), GFP_KERNEL);
2475         if (conn == NULL)
2476                 goto conn_alloc_fail;
2477         memset(conn, 0, sizeof(struct iscsi_conn));
2478
2479         conn->c_stage = ISCSI_CONN_INITIAL_STAGE;
2480         conn->in_progress = IN_PROGRESS_WAIT_HEADER;
2481         conn->id = conn_idx;
2482         conn->exp_statsn = 0;
2483         conn->tmabort_state = TMABORT_INITIAL;
2484
2485         /* initial operational parameters */
2486         conn->hdr_size = sizeof(struct iscsi_hdr);
2487         conn->data_size = DEFAULT_MAX_RECV_DATA_SEGMENT_LENGTH;
2488         conn->max_recv_dlength = DEFAULT_MAX_RECV_DATA_SEGMENT_LENGTH;
2489
2490         spin_lock_init(&conn->lock);
2491
2492         /* initialize general xmit PDU commands queue */
2493         conn->xmitqueue = kfifo_alloc(session->cmds_max * sizeof(void*),
2494                                         GFP_KERNEL, NULL);
2495         if (conn->xmitqueue == ERR_PTR(-ENOMEM))
2496                 goto xmitqueue_alloc_fail;
2497
2498         /* initialize write response PDU commands queue */
2499         conn->writequeue = kfifo_alloc(session->cmds_max * sizeof(void*),
2500                                         GFP_KERNEL, NULL);
2501         if (conn->writequeue == ERR_PTR(-ENOMEM))
2502                 goto writequeue_alloc_fail;
2503
2504         /* initialize general immediate & non-immediate PDU commands queue */
2505         conn->immqueue = kfifo_alloc(session->mgmtpool_max * sizeof(void*),
2506                                         GFP_KERNEL, NULL);
2507         if (conn->immqueue == ERR_PTR(-ENOMEM))
2508                 goto immqueue_alloc_fail;
2509
2510         conn->mgmtqueue = kfifo_alloc(session->mgmtpool_max * sizeof(void*),
2511                                         GFP_KERNEL, NULL);
2512         if (conn->mgmtqueue == ERR_PTR(-ENOMEM))
2513                 goto mgmtqueue_alloc_fail;
2514
2515         INIT_WORK(&conn->xmitwork, iscsi_xmitworker, conn);
2516
2517         /* allocate login_mtask used for the login/text sequences */
2518         spin_lock_bh(&session->lock);
2519         if (!__kfifo_get(session->mgmtpool.queue,
2520                          (void*)&conn->login_mtask,
2521                          sizeof(void*))) {
2522                 spin_unlock_bh(&session->lock);
2523                 goto login_mtask_alloc_fail;
2524         }
2525         spin_unlock_bh(&session->lock);
2526
2527         /* allocate initial PDU receive place holder */
2528         if (conn->data_size <= PAGE_SIZE)
2529                 conn->data = kmalloc(conn->data_size, GFP_KERNEL);
2530         else
2531                 conn->data = (void*)__get_free_pages(GFP_KERNEL,
2532                                         get_order(conn->data_size));
2533         if (!conn->data)
2534                 goto max_recv_dlenght_alloc_fail;
2535
2536         init_timer(&conn->tmabort_timer);
2537         init_MUTEX(&conn->xmitsema);
2538         init_waitqueue_head(&conn->ehwait);
2539
2540         return iscsi_handle(conn);
2541
2542 max_recv_dlenght_alloc_fail:
2543         spin_lock_bh(&session->lock);
2544         __kfifo_put(session->mgmtpool.queue, (void*)&conn->login_mtask,
2545                     sizeof(void*));
2546         spin_unlock_bh(&session->lock);
2547 login_mtask_alloc_fail:
2548         kfifo_free(conn->mgmtqueue);
2549 mgmtqueue_alloc_fail:
2550         kfifo_free(conn->immqueue);
2551 immqueue_alloc_fail:
2552         kfifo_free(conn->writequeue);
2553 writequeue_alloc_fail:
2554         kfifo_free(conn->xmitqueue);
2555 xmitqueue_alloc_fail:
2556         kfree(conn);
2557 conn_alloc_fail:
2558         return iscsi_handle(NULL);
2559 }
2560
2561 static void
2562 iscsi_conn_destroy(iscsi_connh_t connh)
2563 {
2564         struct iscsi_conn *conn = iscsi_ptr(connh);
2565         struct iscsi_session *session = conn->session;
2566
2567         down(&conn->xmitsema);
2568         set_bit(SUSPEND_BIT, &conn->suspend_tx);
2569         if (conn->c_stage == ISCSI_CONN_INITIAL_STAGE && conn->sock) {
2570                 struct sock *sk = conn->sock->sk;
2571
2572                 /*
2573                  * conn_start() has never been called!
2574                  * need to cleanup the socket.
2575                  */
2576                 write_lock_bh(&sk->sk_callback_lock);
2577                 set_bit(SUSPEND_BIT, &conn->suspend_rx);
2578                 write_unlock_bh(&sk->sk_callback_lock);
2579
2580                 sock_hold(conn->sock->sk);
2581                 iscsi_conn_restore_callbacks(conn);
2582                 sock_put(conn->sock->sk);
2583                 sock_release(conn->sock);
2584                 conn->sock = NULL;
2585         }
2586
2587         spin_lock_bh(&session->lock);
2588         conn->c_stage = ISCSI_CONN_CLEANUP_WAIT;
2589         if (session->leadconn == conn) {
2590                 /*
2591                  * leading connection? then give up on recovery.
2592                  */
2593                 session->state = ISCSI_STATE_TERMINATE;
2594                 wake_up(&conn->ehwait);
2595         }
2596         spin_unlock_bh(&session->lock);
2597
2598         up(&conn->xmitsema);
2599
2600         /*
2601          * Block until all in-progress commands for this connection
2602          * time out or fail.
2603          */
2604         for (;;) {
2605                 spin_lock_bh(&conn->lock);
2606                 if (!session->host->host_busy) { /* OK for ERL == 0 */
2607                         spin_unlock_bh(&conn->lock);
2608                         break;
2609                 }
2610                 spin_unlock_bh(&conn->lock);
2611                 msleep_interruptible(500);
2612                 printk("conn_destroy(): host_busy %d host_failed %d\n",
2613                         session->host->host_busy, session->host->host_failed);
2614                 /*
2615                  * force eh_abort() to unblock
2616                  */
2617                 wake_up(&conn->ehwait);
2618         }
2619
2620         /* now free crypto */
2621         if (conn->hdrdgst_en || conn->datadgst_en) {
2622                 if (conn->tx_tfm)
2623                         crypto_free_tfm(conn->tx_tfm);
2624                 if (conn->rx_tfm)
2625                         crypto_free_tfm(conn->rx_tfm);
2626                 if (conn->data_tx_tfm)
2627                         crypto_free_tfm(conn->data_tx_tfm);
2628                 if (conn->data_rx_tfm)
2629                         crypto_free_tfm(conn->data_rx_tfm);
2630         }
2631
2632         /* free conn->data, size = MaxRecvDataSegmentLength */
2633         if (conn->data_size <= PAGE_SIZE)
2634                 kfree(conn->data);
2635         else
2636                 free_pages((unsigned long)conn->data,
2637                                         get_order(conn->data_size));
2638
2639         spin_lock_bh(&session->lock);
2640         __kfifo_put(session->mgmtpool.queue, (void*)&conn->login_mtask,
2641                     sizeof(void*));
2642         list_del(&conn->item);
2643         if (list_empty(&session->connections))
2644                 session->leadconn = NULL;
2645         if (session->leadconn && session->leadconn == conn)
2646                 session->leadconn = container_of(session->connections.next,
2647                         struct iscsi_conn, item);
2648
2649         if (session->leadconn == NULL)
2650                 /* none connections exits.. reset sequencing */
2651                 session->cmdsn = session->max_cmdsn = session->exp_cmdsn = 1;
2652         spin_unlock_bh(&session->lock);
2653
2654         kfifo_free(conn->xmitqueue);
2655         kfifo_free(conn->writequeue);
2656         kfifo_free(conn->immqueue);
2657         kfifo_free(conn->mgmtqueue);
2658         kfree(conn);
2659 }
2660
2661 static int
2662 iscsi_conn_bind(iscsi_sessionh_t sessionh, iscsi_connh_t connh,
2663                 uint32_t transport_fd, int is_leading)
2664 {
2665         struct iscsi_session *session = iscsi_ptr(sessionh);
2666         struct iscsi_conn *tmp = ERR_PTR(-EEXIST), *conn = iscsi_ptr(connh);
2667         struct sock *sk;
2668         struct socket *sock;
2669         int err;
2670
2671         /* lookup for existing socket */
2672         sock = sockfd_lookup(transport_fd, &err);
2673         if (!sock) {
2674                 printk(KERN_ERR "iscsi_tcp: sockfd_lookup failed %d\n", err);
2675                 return -EEXIST;
2676         }
2677
2678         /* lookup for existing connection */
2679         spin_lock_bh(&session->lock);
2680         list_for_each_entry(tmp, &session->connections, item) {
2681                 if (tmp == conn) {
2682                         if (conn->c_stage != ISCSI_CONN_STOPPED ||
2683                             conn->stop_stage == STOP_CONN_TERM) {
2684                                 printk(KERN_ERR "iscsi_tcp: can't bind "
2685                                        "non-stopped connection (%d:%d)\n",
2686                                        conn->c_stage, conn->stop_stage);
2687                                 spin_unlock_bh(&session->lock);
2688                                 return -EIO;
2689                         }
2690                         break;
2691                 }
2692         }
2693         if (tmp != conn) {
2694                 /* bind new iSCSI connection to session */
2695                 conn->session = session;
2696
2697                 list_add(&conn->item, &session->connections);
2698         }
2699         spin_unlock_bh(&session->lock);
2700
2701         if (conn->stop_stage != STOP_CONN_SUSPEND) {
2702                 /* bind iSCSI connection and socket */
2703                 conn->sock = sock;
2704
2705                 /* setup Socket parameters */
2706                 sk = sock->sk;
2707                 sk->sk_reuse = 1;
2708                 sk->sk_sndtimeo = 15 * HZ; /* FIXME: make it configurable */
2709                 sk->sk_allocation = GFP_ATOMIC;
2710
2711                 /* FIXME: disable Nagle's algorithm */
2712
2713                 /*
2714                  * Intercept TCP callbacks for sendfile like receive
2715                  * processing.
2716                  */
2717                 iscsi_conn_set_callbacks(conn);
2718
2719                 /*
2720                  * set receive state machine into initial state
2721                  */
2722                 conn->in_progress = IN_PROGRESS_WAIT_HEADER;
2723         }
2724
2725         if (is_leading)
2726                 session->leadconn = conn;
2727
2728         /*
2729          * Unblock xmitworker(), Login Phase will pass through.
2730          */
2731         clear_bit(SUSPEND_BIT, &conn->suspend_rx);
2732         clear_bit(SUSPEND_BIT, &conn->suspend_tx);
2733
2734         return 0;
2735 }
2736
2737 static int
2738 iscsi_conn_start(iscsi_connh_t connh)
2739 {
2740         struct iscsi_conn *conn = iscsi_ptr(connh);
2741         struct iscsi_session *session = conn->session;
2742         struct sock *sk;
2743
2744         /* FF phase warming up... */
2745
2746         if (session == NULL) {
2747                 printk(KERN_ERR "iscsi_tcp: can't start unbound connection\n");
2748                 return -EPERM;
2749         }
2750
2751         sk = conn->sock->sk;
2752
2753         write_lock_bh(&sk->sk_callback_lock);
2754         spin_lock_bh(&session->lock);
2755         conn->c_stage = ISCSI_CONN_STARTED;
2756         session->state = ISCSI_STATE_LOGGED_IN;
2757
2758         switch(conn->stop_stage) {
2759         case STOP_CONN_RECOVER:
2760                 /*
2761                  * unblock eh_abort() if it is blocked. re-try all
2762                  * commands after successful recovery
2763                  */
2764                 session->conn_cnt++;
2765                 conn->stop_stage = 0;
2766                 conn->tmabort_state = TMABORT_INITIAL;
2767                 session->age++;
2768                 wake_up(&conn->ehwait);
2769                 break;
2770         case STOP_CONN_TERM:
2771                 session->conn_cnt++;
2772                 conn->stop_stage = 0;
2773                 break;
2774         case STOP_CONN_SUSPEND:
2775                 conn->stop_stage = 0;
2776                 clear_bit(SUSPEND_BIT, &conn->suspend_rx);
2777                 clear_bit(SUSPEND_BIT, &conn->suspend_tx);
2778                 break;
2779         default:
2780                 break;
2781         }
2782         spin_unlock_bh(&session->lock);
2783         write_unlock_bh(&sk->sk_callback_lock);
2784
2785         return 0;
2786 }
2787
2788 static void
2789 iscsi_conn_stop(iscsi_connh_t connh, int flag)
2790 {
2791         struct iscsi_conn *conn = iscsi_ptr(connh);
2792         struct iscsi_session *session = conn->session;
2793         struct sock *sk;
2794         unsigned long flags;
2795
2796         BUG_ON(!conn->sock);
2797         sk = conn->sock->sk;
2798         write_lock_bh(&sk->sk_callback_lock);
2799         set_bit(SUSPEND_BIT, &conn->suspend_rx);
2800         write_unlock_bh(&sk->sk_callback_lock);
2801
2802         down(&conn->xmitsema);
2803
2804         spin_lock_irqsave(session->host->host_lock, flags);
2805         spin_lock(&session->lock);
2806         conn->stop_stage = flag;
2807         conn->c_stage = ISCSI_CONN_STOPPED;
2808         set_bit(SUSPEND_BIT, &conn->suspend_tx);
2809
2810         if (flag != STOP_CONN_SUSPEND)
2811                 session->conn_cnt--;
2812
2813         if (session->conn_cnt == 0 || session->leadconn == conn)
2814                 session->state = ISCSI_STATE_FAILED;
2815
2816         spin_unlock(&session->lock);
2817         spin_unlock_irqrestore(session->host->host_lock, flags);
2818
2819         if (flag == STOP_CONN_TERM || flag == STOP_CONN_RECOVER) {
2820                 struct iscsi_cmd_task *ctask;
2821                 struct iscsi_mgmt_task *mtask;
2822
2823                 /*
2824                  * Socket must go now.
2825                  */
2826                 sock_hold(conn->sock->sk);
2827                 iscsi_conn_restore_callbacks(conn);
2828                 sock_put(conn->sock->sk);
2829
2830                 /*
2831                  * flush xmit queues.
2832                  */
2833                 spin_lock_bh(&session->lock);
2834                 while (__kfifo_get(conn->writequeue, (void*)&ctask,
2835                             sizeof(void*)) ||
2836                         __kfifo_get(conn->xmitqueue, (void*)&ctask,
2837                             sizeof(void*))) {
2838                         struct iscsi_r2t_info *r2t;
2839
2840                         /*
2841                          * flush ctask's r2t queues
2842                          */
2843                         while (__kfifo_get(ctask->r2tqueue, (void*)&r2t,
2844                                 sizeof(void*)))
2845                                 __kfifo_put(ctask->r2tpool.queue, (void*)&r2t,
2846                                             sizeof(void*));
2847
2848                         spin_unlock_bh(&session->lock);
2849                         local_bh_disable();
2850                         iscsi_ctask_cleanup(conn, ctask);
2851                         local_bh_enable();
2852                         spin_lock_bh(&session->lock);
2853                 }
2854                 conn->ctask = NULL;
2855                 while (__kfifo_get(conn->immqueue, (void*)&mtask,
2856                            sizeof(void*)) ||
2857                         __kfifo_get(conn->mgmtqueue, (void*)&mtask,
2858                            sizeof(void*))) {
2859                         __kfifo_put(session->mgmtpool.queue,
2860                                     (void*)&mtask, sizeof(void*));
2861                 }
2862                 conn->mtask = NULL;
2863                 spin_unlock_bh(&session->lock);
2864
2865                 /*
2866                  * release socket only after we stopped data_xmit()
2867                  * activity and flushed all outstandings
2868                  */
2869                 sock_release(conn->sock);
2870                 conn->sock = NULL;
2871
2872                 /*
2873                  * for connection level recovery we should not calculate
2874                  * header digest. conn->hdr_size used for optimization
2875                  * in hdr_extract() and will be re-negotiated at
2876                  * set_param() time.
2877                  */
2878                 if (flag == STOP_CONN_RECOVER)
2879                         conn->hdr_size = sizeof(struct iscsi_hdr);
2880         }
2881         up(&conn->xmitsema);
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         down(&conn->xmitsema);
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                         up(&conn->xmitsema);
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                         up(&conn->xmitsema);
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                                         up(&conn->xmitsema);
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         up(&conn->xmitsema);
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         down(&conn->xmitsema);
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         up(&conn->xmitsema);
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                 int 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         down(&conn->xmitsema);
3605         rc = iscsi_conn_send_generic(conn, hdr, data, data_size);
3606         up(&conn->xmitsema);
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);