linux/drivers/scsi/libiscsi.c
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   1/*
   2 * iSCSI lib functions
   3 *
   4 * Copyright (C) 2006 Red Hat, Inc.  All rights reserved.
   5 * Copyright (C) 2004 - 2006 Mike Christie
   6 * Copyright (C) 2004 - 2005 Dmitry Yusupov
   7 * Copyright (C) 2004 - 2005 Alex Aizman
   8 * maintained by open-iscsi@googlegroups.com
   9 *
  10 * This program is free software; you can redistribute it and/or modify
  11 * it under the terms of the GNU General Public License as published by
  12 * the Free Software Foundation; either version 2 of the License, or
  13 * (at your option) any later version.
  14 *
  15 * This program is distributed in the hope that it will be useful,
  16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18 * GNU General Public License for more details.
  19 *
  20 * You should have received a copy of the GNU General Public License
  21 * along with this program; if not, write to the Free Software
  22 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  23 */
  24#include <linux/types.h>
  25#include <linux/kfifo.h>
  26#include <linux/delay.h>
  27#include <linux/log2.h>
  28#include <linux/slab.h>
  29#include <linux/module.h>
  30#include <asm/unaligned.h>
  31#include <net/tcp.h>
  32#include <scsi/scsi_cmnd.h>
  33#include <scsi/scsi_device.h>
  34#include <scsi/scsi_eh.h>
  35#include <scsi/scsi_tcq.h>
  36#include <scsi/scsi_host.h>
  37#include <scsi/scsi.h>
  38#include <scsi/iscsi_proto.h>
  39#include <scsi/scsi_transport.h>
  40#include <scsi/scsi_transport_iscsi.h>
  41#include <scsi/libiscsi.h>
  42
  43static int iscsi_dbg_lib_conn;
  44module_param_named(debug_libiscsi_conn, iscsi_dbg_lib_conn, int,
  45                   S_IRUGO | S_IWUSR);
  46MODULE_PARM_DESC(debug_libiscsi_conn,
  47                 "Turn on debugging for connections in libiscsi module. "
  48                 "Set to 1 to turn on, and zero to turn off. Default is off.");
  49
  50static int iscsi_dbg_lib_session;
  51module_param_named(debug_libiscsi_session, iscsi_dbg_lib_session, int,
  52                   S_IRUGO | S_IWUSR);
  53MODULE_PARM_DESC(debug_libiscsi_session,
  54                 "Turn on debugging for sessions in libiscsi module. "
  55                 "Set to 1 to turn on, and zero to turn off. Default is off.");
  56
  57static int iscsi_dbg_lib_eh;
  58module_param_named(debug_libiscsi_eh, iscsi_dbg_lib_eh, int,
  59                   S_IRUGO | S_IWUSR);
  60MODULE_PARM_DESC(debug_libiscsi_eh,
  61                 "Turn on debugging for error handling in libiscsi module. "
  62                 "Set to 1 to turn on, and zero to turn off. Default is off.");
  63
  64#define ISCSI_DBG_CONN(_conn, dbg_fmt, arg...)                  \
  65        do {                                                    \
  66                if (iscsi_dbg_lib_conn)                         \
  67                        iscsi_conn_printk(KERN_INFO, _conn,     \
  68                                             "%s " dbg_fmt,     \
  69                                             __func__, ##arg);  \
  70        } while (0);
  71
  72#define ISCSI_DBG_SESSION(_session, dbg_fmt, arg...)                    \
  73        do {                                                            \
  74                if (iscsi_dbg_lib_session)                              \
  75                        iscsi_session_printk(KERN_INFO, _session,       \
  76                                             "%s " dbg_fmt,             \
  77                                             __func__, ##arg);          \
  78        } while (0);
  79
  80#define ISCSI_DBG_EH(_session, dbg_fmt, arg...)                         \
  81        do {                                                            \
  82                if (iscsi_dbg_lib_eh)                                   \
  83                        iscsi_session_printk(KERN_INFO, _session,       \
  84                                             "%s " dbg_fmt,             \
  85                                             __func__, ##arg);          \
  86        } while (0);
  87
  88inline void iscsi_conn_queue_work(struct iscsi_conn *conn)
  89{
  90        struct Scsi_Host *shost = conn->session->host;
  91        struct iscsi_host *ihost = shost_priv(shost);
  92
  93        if (ihost->workq)
  94                queue_work(ihost->workq, &conn->xmitwork);
  95}
  96EXPORT_SYMBOL_GPL(iscsi_conn_queue_work);
  97
  98static void __iscsi_update_cmdsn(struct iscsi_session *session,
  99                                 uint32_t exp_cmdsn, uint32_t max_cmdsn)
 100{
 101        /*
 102         * standard specifies this check for when to update expected and
 103         * max sequence numbers
 104         */
 105        if (iscsi_sna_lt(max_cmdsn, exp_cmdsn - 1))
 106                return;
 107
 108        if (exp_cmdsn != session->exp_cmdsn &&
 109            !iscsi_sna_lt(exp_cmdsn, session->exp_cmdsn))
 110                session->exp_cmdsn = exp_cmdsn;
 111
 112        if (max_cmdsn != session->max_cmdsn &&
 113            !iscsi_sna_lt(max_cmdsn, session->max_cmdsn)) {
 114                session->max_cmdsn = max_cmdsn;
 115                /*
 116                 * if the window closed with IO queued, then kick the
 117                 * xmit thread
 118                 */
 119                if (!list_empty(&session->leadconn->cmdqueue) ||
 120                    !list_empty(&session->leadconn->mgmtqueue))
 121                        iscsi_conn_queue_work(session->leadconn);
 122        }
 123}
 124
 125void iscsi_update_cmdsn(struct iscsi_session *session, struct iscsi_nopin *hdr)
 126{
 127        __iscsi_update_cmdsn(session, be32_to_cpu(hdr->exp_cmdsn),
 128                             be32_to_cpu(hdr->max_cmdsn));
 129}
 130EXPORT_SYMBOL_GPL(iscsi_update_cmdsn);
 131
 132/**
 133 * iscsi_prep_data_out_pdu - initialize Data-Out
 134 * @task: scsi command task
 135 * @r2t: R2T info
 136 * @hdr: iscsi data in pdu
 137 *
 138 * Notes:
 139 *      Initialize Data-Out within this R2T sequence and finds
 140 *      proper data_offset within this SCSI command.
 141 *
 142 *      This function is called with connection lock taken.
 143 **/
 144void iscsi_prep_data_out_pdu(struct iscsi_task *task, struct iscsi_r2t_info *r2t,
 145                           struct iscsi_data *hdr)
 146{
 147        struct iscsi_conn *conn = task->conn;
 148        unsigned int left = r2t->data_length - r2t->sent;
 149
 150        task->hdr_len = sizeof(struct iscsi_data);
 151
 152        memset(hdr, 0, sizeof(struct iscsi_data));
 153        hdr->ttt = r2t->ttt;
 154        hdr->datasn = cpu_to_be32(r2t->datasn);
 155        r2t->datasn++;
 156        hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
 157        hdr->lun = task->lun;
 158        hdr->itt = task->hdr_itt;
 159        hdr->exp_statsn = r2t->exp_statsn;
 160        hdr->offset = cpu_to_be32(r2t->data_offset + r2t->sent);
 161        if (left > conn->max_xmit_dlength) {
 162                hton24(hdr->dlength, conn->max_xmit_dlength);
 163                r2t->data_count = conn->max_xmit_dlength;
 164                hdr->flags = 0;
 165        } else {
 166                hton24(hdr->dlength, left);
 167                r2t->data_count = left;
 168                hdr->flags = ISCSI_FLAG_CMD_FINAL;
 169        }
 170        conn->dataout_pdus_cnt++;
 171}
 172EXPORT_SYMBOL_GPL(iscsi_prep_data_out_pdu);
 173
 174static int iscsi_add_hdr(struct iscsi_task *task, unsigned len)
 175{
 176        unsigned exp_len = task->hdr_len + len;
 177
 178        if (exp_len > task->hdr_max) {
 179                WARN_ON(1);
 180                return -EINVAL;
 181        }
 182
 183        WARN_ON(len & (ISCSI_PAD_LEN - 1)); /* caller must pad the AHS */
 184        task->hdr_len = exp_len;
 185        return 0;
 186}
 187
 188/*
 189 * make an extended cdb AHS
 190 */
 191static int iscsi_prep_ecdb_ahs(struct iscsi_task *task)
 192{
 193        struct scsi_cmnd *cmd = task->sc;
 194        unsigned rlen, pad_len;
 195        unsigned short ahslength;
 196        struct iscsi_ecdb_ahdr *ecdb_ahdr;
 197        int rc;
 198
 199        ecdb_ahdr = iscsi_next_hdr(task);
 200        rlen = cmd->cmd_len - ISCSI_CDB_SIZE;
 201
 202        BUG_ON(rlen > sizeof(ecdb_ahdr->ecdb));
 203        ahslength = rlen + sizeof(ecdb_ahdr->reserved);
 204
 205        pad_len = iscsi_padding(rlen);
 206
 207        rc = iscsi_add_hdr(task, sizeof(ecdb_ahdr->ahslength) +
 208                           sizeof(ecdb_ahdr->ahstype) + ahslength + pad_len);
 209        if (rc)
 210                return rc;
 211
 212        if (pad_len)
 213                memset(&ecdb_ahdr->ecdb[rlen], 0, pad_len);
 214
 215        ecdb_ahdr->ahslength = cpu_to_be16(ahslength);
 216        ecdb_ahdr->ahstype = ISCSI_AHSTYPE_CDB;
 217        ecdb_ahdr->reserved = 0;
 218        memcpy(ecdb_ahdr->ecdb, cmd->cmnd + ISCSI_CDB_SIZE, rlen);
 219
 220        ISCSI_DBG_SESSION(task->conn->session,
 221                          "iscsi_prep_ecdb_ahs: varlen_cdb_len %d "
 222                          "rlen %d pad_len %d ahs_length %d iscsi_headers_size "
 223                          "%u\n", cmd->cmd_len, rlen, pad_len, ahslength,
 224                          task->hdr_len);
 225        return 0;
 226}
 227
 228static int iscsi_prep_bidi_ahs(struct iscsi_task *task)
 229{
 230        struct scsi_cmnd *sc = task->sc;
 231        struct iscsi_rlength_ahdr *rlen_ahdr;
 232        int rc;
 233
 234        rlen_ahdr = iscsi_next_hdr(task);
 235        rc = iscsi_add_hdr(task, sizeof(*rlen_ahdr));
 236        if (rc)
 237                return rc;
 238
 239        rlen_ahdr->ahslength =
 240                cpu_to_be16(sizeof(rlen_ahdr->read_length) +
 241                                                  sizeof(rlen_ahdr->reserved));
 242        rlen_ahdr->ahstype = ISCSI_AHSTYPE_RLENGTH;
 243        rlen_ahdr->reserved = 0;
 244        rlen_ahdr->read_length = cpu_to_be32(scsi_in(sc)->length);
 245
 246        ISCSI_DBG_SESSION(task->conn->session,
 247                          "bidi-in rlen_ahdr->read_length(%d) "
 248                          "rlen_ahdr->ahslength(%d)\n",
 249                          be32_to_cpu(rlen_ahdr->read_length),
 250                          be16_to_cpu(rlen_ahdr->ahslength));
 251        return 0;
 252}
 253
 254/**
 255 * iscsi_check_tmf_restrictions - check if a task is affected by TMF
 256 * @task: iscsi task
 257 * @opcode: opcode to check for
 258 *
 259 * During TMF a task has to be checked if it's affected.
 260 * All unrelated I/O can be passed through, but I/O to the
 261 * affected LUN should be restricted.
 262 * If 'fast_abort' is set we won't be sending any I/O to the
 263 * affected LUN.
 264 * Otherwise the target is waiting for all TTTs to be completed,
 265 * so we have to send all outstanding Data-Out PDUs to the target.
 266 */
 267static int iscsi_check_tmf_restrictions(struct iscsi_task *task, int opcode)
 268{
 269        struct iscsi_conn *conn = task->conn;
 270        struct iscsi_tm *tmf = &conn->tmhdr;
 271        unsigned int hdr_lun;
 272
 273        if (conn->tmf_state == TMF_INITIAL)
 274                return 0;
 275
 276        if ((tmf->opcode & ISCSI_OPCODE_MASK) != ISCSI_OP_SCSI_TMFUNC)
 277                return 0;
 278
 279        switch (ISCSI_TM_FUNC_VALUE(tmf)) {
 280        case ISCSI_TM_FUNC_LOGICAL_UNIT_RESET:
 281                /*
 282                 * Allow PDUs for unrelated LUNs
 283                 */
 284                hdr_lun = scsilun_to_int(&tmf->lun);
 285                if (hdr_lun != task->sc->device->lun)
 286                        return 0;
 287                /* fall through */
 288        case ISCSI_TM_FUNC_TARGET_WARM_RESET:
 289                /*
 290                 * Fail all SCSI cmd PDUs
 291                 */
 292                if (opcode != ISCSI_OP_SCSI_DATA_OUT) {
 293                        iscsi_conn_printk(KERN_INFO, conn,
 294                                          "task [op %x/%x itt "
 295                                          "0x%x/0x%x] "
 296                                          "rejected.\n",
 297                                          task->hdr->opcode, opcode,
 298                                          task->itt, task->hdr_itt);
 299                        return -EACCES;
 300                }
 301                /*
 302                 * And also all data-out PDUs in response to R2T
 303                 * if fast_abort is set.
 304                 */
 305                if (conn->session->fast_abort) {
 306                        iscsi_conn_printk(KERN_INFO, conn,
 307                                          "task [op %x/%x itt "
 308                                          "0x%x/0x%x] fast abort.\n",
 309                                          task->hdr->opcode, opcode,
 310                                          task->itt, task->hdr_itt);
 311                        return -EACCES;
 312                }
 313                break;
 314        case ISCSI_TM_FUNC_ABORT_TASK:
 315                /*
 316                 * the caller has already checked if the task
 317                 * they want to abort was in the pending queue so if
 318                 * we are here the cmd pdu has gone out already, and
 319                 * we will only hit this for data-outs
 320                 */
 321                if (opcode == ISCSI_OP_SCSI_DATA_OUT &&
 322                    task->hdr_itt == tmf->rtt) {
 323                        ISCSI_DBG_SESSION(conn->session,
 324                                          "Preventing task %x/%x from sending "
 325                                          "data-out due to abort task in "
 326                                          "progress\n", task->itt,
 327                                          task->hdr_itt);
 328                        return -EACCES;
 329                }
 330                break;
 331        }
 332
 333        return 0;
 334}
 335
 336/**
 337 * iscsi_prep_scsi_cmd_pdu - prep iscsi scsi cmd pdu
 338 * @task: iscsi task
 339 *
 340 * Prep basic iSCSI PDU fields for a scsi cmd pdu. The LLD should set
 341 * fields like dlength or final based on how much data it sends
 342 */
 343static int iscsi_prep_scsi_cmd_pdu(struct iscsi_task *task)
 344{
 345        struct iscsi_conn *conn = task->conn;
 346        struct iscsi_session *session = conn->session;
 347        struct scsi_cmnd *sc = task->sc;
 348        struct iscsi_scsi_req *hdr;
 349        unsigned hdrlength, cmd_len;
 350        itt_t itt;
 351        int rc;
 352
 353        rc = iscsi_check_tmf_restrictions(task, ISCSI_OP_SCSI_CMD);
 354        if (rc)
 355                return rc;
 356
 357        if (conn->session->tt->alloc_pdu) {
 358                rc = conn->session->tt->alloc_pdu(task, ISCSI_OP_SCSI_CMD);
 359                if (rc)
 360                        return rc;
 361        }
 362        hdr = (struct iscsi_scsi_req *)task->hdr;
 363        itt = hdr->itt;
 364        memset(hdr, 0, sizeof(*hdr));
 365
 366        if (session->tt->parse_pdu_itt)
 367                hdr->itt = task->hdr_itt = itt;
 368        else
 369                hdr->itt = task->hdr_itt = build_itt(task->itt,
 370                                                     task->conn->session->age);
 371        task->hdr_len = 0;
 372        rc = iscsi_add_hdr(task, sizeof(*hdr));
 373        if (rc)
 374                return rc;
 375        hdr->opcode = ISCSI_OP_SCSI_CMD;
 376        hdr->flags = ISCSI_ATTR_SIMPLE;
 377        int_to_scsilun(sc->device->lun, &hdr->lun);
 378        task->lun = hdr->lun;
 379        hdr->exp_statsn = cpu_to_be32(conn->exp_statsn);
 380        cmd_len = sc->cmd_len;
 381        if (cmd_len < ISCSI_CDB_SIZE)
 382                memset(&hdr->cdb[cmd_len], 0, ISCSI_CDB_SIZE - cmd_len);
 383        else if (cmd_len > ISCSI_CDB_SIZE) {
 384                rc = iscsi_prep_ecdb_ahs(task);
 385                if (rc)
 386                        return rc;
 387                cmd_len = ISCSI_CDB_SIZE;
 388        }
 389        memcpy(hdr->cdb, sc->cmnd, cmd_len);
 390
 391        task->imm_count = 0;
 392        if (scsi_bidi_cmnd(sc)) {
 393                hdr->flags |= ISCSI_FLAG_CMD_READ;
 394                rc = iscsi_prep_bidi_ahs(task);
 395                if (rc)
 396                        return rc;
 397        }
 398        if (sc->sc_data_direction == DMA_TO_DEVICE) {
 399                unsigned out_len = scsi_out(sc)->length;
 400                struct iscsi_r2t_info *r2t = &task->unsol_r2t;
 401
 402                hdr->data_length = cpu_to_be32(out_len);
 403                hdr->flags |= ISCSI_FLAG_CMD_WRITE;
 404                /*
 405                 * Write counters:
 406                 *
 407                 *      imm_count       bytes to be sent right after
 408                 *                      SCSI PDU Header
 409                 *
 410                 *      unsol_count     bytes(as Data-Out) to be sent
 411                 *                      without R2T ack right after
 412                 *                      immediate data
 413                 *
 414                 *      r2t data_length bytes to be sent via R2T ack's
 415                 *
 416                 *      pad_count       bytes to be sent as zero-padding
 417                 */
 418                memset(r2t, 0, sizeof(*r2t));
 419
 420                if (session->imm_data_en) {
 421                        if (out_len >= session->first_burst)
 422                                task->imm_count = min(session->first_burst,
 423                                                        conn->max_xmit_dlength);
 424                        else
 425                                task->imm_count = min(out_len,
 426                                                        conn->max_xmit_dlength);
 427                        hton24(hdr->dlength, task->imm_count);
 428                } else
 429                        zero_data(hdr->dlength);
 430
 431                if (!session->initial_r2t_en) {
 432                        r2t->data_length = min(session->first_burst, out_len) -
 433                                               task->imm_count;
 434                        r2t->data_offset = task->imm_count;
 435                        r2t->ttt = cpu_to_be32(ISCSI_RESERVED_TAG);
 436                        r2t->exp_statsn = cpu_to_be32(conn->exp_statsn);
 437                }
 438
 439                if (!task->unsol_r2t.data_length)
 440                        /* No unsolicit Data-Out's */
 441                        hdr->flags |= ISCSI_FLAG_CMD_FINAL;
 442        } else {
 443                hdr->flags |= ISCSI_FLAG_CMD_FINAL;
 444                zero_data(hdr->dlength);
 445                hdr->data_length = cpu_to_be32(scsi_in(sc)->length);
 446
 447                if (sc->sc_data_direction == DMA_FROM_DEVICE)
 448                        hdr->flags |= ISCSI_FLAG_CMD_READ;
 449        }
 450
 451        /* calculate size of additional header segments (AHSs) */
 452        hdrlength = task->hdr_len - sizeof(*hdr);
 453
 454        WARN_ON(hdrlength & (ISCSI_PAD_LEN-1));
 455        hdrlength /= ISCSI_PAD_LEN;
 456
 457        WARN_ON(hdrlength >= 256);
 458        hdr->hlength = hdrlength & 0xFF;
 459        hdr->cmdsn = task->cmdsn = cpu_to_be32(session->cmdsn);
 460
 461        if (session->tt->init_task && session->tt->init_task(task))
 462                return -EIO;
 463
 464        task->state = ISCSI_TASK_RUNNING;
 465        session->cmdsn++;
 466
 467        conn->scsicmd_pdus_cnt++;
 468        ISCSI_DBG_SESSION(session, "iscsi prep [%s cid %d sc %p cdb 0x%x "
 469                          "itt 0x%x len %d bidi_len %d cmdsn %d win %d]\n",
 470                          scsi_bidi_cmnd(sc) ? "bidirectional" :
 471                          sc->sc_data_direction == DMA_TO_DEVICE ?
 472                          "write" : "read", conn->id, sc, sc->cmnd[0],
 473                          task->itt, scsi_bufflen(sc),
 474                          scsi_bidi_cmnd(sc) ? scsi_in(sc)->length : 0,
 475                          session->cmdsn,
 476                          session->max_cmdsn - session->exp_cmdsn + 1);
 477        return 0;
 478}
 479
 480/**
 481 * iscsi_free_task - free a task
 482 * @task: iscsi cmd task
 483 *
 484 * Must be called with session lock.
 485 * This function returns the scsi command to scsi-ml or cleans
 486 * up mgmt tasks then returns the task to the pool.
 487 */
 488static void iscsi_free_task(struct iscsi_task *task)
 489{
 490        struct iscsi_conn *conn = task->conn;
 491        struct iscsi_session *session = conn->session;
 492        struct scsi_cmnd *sc = task->sc;
 493        int oldstate = task->state;
 494
 495        ISCSI_DBG_SESSION(session, "freeing task itt 0x%x state %d sc %p\n",
 496                          task->itt, task->state, task->sc);
 497
 498        session->tt->cleanup_task(task);
 499        task->state = ISCSI_TASK_FREE;
 500        task->sc = NULL;
 501        /*
 502         * login task is preallocated so do not free
 503         */
 504        if (conn->login_task == task)
 505                return;
 506
 507        kfifo_in(&session->cmdpool.queue, (void*)&task, sizeof(void*));
 508
 509        if (sc) {
 510                task->sc = NULL;
 511                /* SCSI eh reuses commands to verify us */
 512                sc->SCp.ptr = NULL;
 513                /*
 514                 * queue command may call this to free the task, so
 515                 * it will decide how to return sc to scsi-ml.
 516                 */
 517                if (oldstate != ISCSI_TASK_REQUEUE_SCSIQ)
 518                        sc->scsi_done(sc);
 519        }
 520}
 521
 522void __iscsi_get_task(struct iscsi_task *task)
 523{
 524        atomic_inc(&task->refcount);
 525}
 526EXPORT_SYMBOL_GPL(__iscsi_get_task);
 527
 528void __iscsi_put_task(struct iscsi_task *task)
 529{
 530        if (atomic_dec_and_test(&task->refcount))
 531                iscsi_free_task(task);
 532}
 533EXPORT_SYMBOL_GPL(__iscsi_put_task);
 534
 535void iscsi_put_task(struct iscsi_task *task)
 536{
 537        struct iscsi_session *session = task->conn->session;
 538
 539        spin_lock_bh(&session->lock);
 540        __iscsi_put_task(task);
 541        spin_unlock_bh(&session->lock);
 542}
 543EXPORT_SYMBOL_GPL(iscsi_put_task);
 544
 545/**
 546 * iscsi_complete_task - finish a task
 547 * @task: iscsi cmd task
 548 * @state: state to complete task with
 549 *
 550 * Must be called with session lock.
 551 */
 552static void iscsi_complete_task(struct iscsi_task *task, int state)
 553{
 554        struct iscsi_conn *conn = task->conn;
 555
 556        ISCSI_DBG_SESSION(conn->session,
 557                          "complete task itt 0x%x state %d sc %p\n",
 558                          task->itt, task->state, task->sc);
 559        if (task->state == ISCSI_TASK_COMPLETED ||
 560            task->state == ISCSI_TASK_ABRT_TMF ||
 561            task->state == ISCSI_TASK_ABRT_SESS_RECOV ||
 562            task->state == ISCSI_TASK_REQUEUE_SCSIQ)
 563                return;
 564        WARN_ON_ONCE(task->state == ISCSI_TASK_FREE);
 565        task->state = state;
 566
 567        if (!list_empty(&task->running))
 568                list_del_init(&task->running);
 569
 570        if (conn->task == task)
 571                conn->task = NULL;
 572
 573        if (conn->ping_task == task)
 574                conn->ping_task = NULL;
 575
 576        /* release get from queueing */
 577        __iscsi_put_task(task);
 578}
 579
 580/**
 581 * iscsi_complete_scsi_task - finish scsi task normally
 582 * @task: iscsi task for scsi cmd
 583 * @exp_cmdsn: expected cmd sn in cpu format
 584 * @max_cmdsn: max cmd sn in cpu format
 585 *
 586 * This is used when drivers do not need or cannot perform
 587 * lower level pdu processing.
 588 *
 589 * Called with session lock
 590 */
 591void iscsi_complete_scsi_task(struct iscsi_task *task,
 592                              uint32_t exp_cmdsn, uint32_t max_cmdsn)
 593{
 594        struct iscsi_conn *conn = task->conn;
 595
 596        ISCSI_DBG_SESSION(conn->session, "[itt 0x%x]\n", task->itt);
 597
 598        conn->last_recv = jiffies;
 599        __iscsi_update_cmdsn(conn->session, exp_cmdsn, max_cmdsn);
 600        iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
 601}
 602EXPORT_SYMBOL_GPL(iscsi_complete_scsi_task);
 603
 604
 605/*
 606 * session lock must be held and if not called for a task that is
 607 * still pending or from the xmit thread, then xmit thread must
 608 * be suspended.
 609 */
 610static void fail_scsi_task(struct iscsi_task *task, int err)
 611{
 612        struct iscsi_conn *conn = task->conn;
 613        struct scsi_cmnd *sc;
 614        int state;
 615
 616        /*
 617         * if a command completes and we get a successful tmf response
 618         * we will hit this because the scsi eh abort code does not take
 619         * a ref to the task.
 620         */
 621        sc = task->sc;
 622        if (!sc)
 623                return;
 624
 625        if (task->state == ISCSI_TASK_PENDING) {
 626                /*
 627                 * cmd never made it to the xmit thread, so we should not count
 628                 * the cmd in the sequencing
 629                 */
 630                conn->session->queued_cmdsn--;
 631                /* it was never sent so just complete like normal */
 632                state = ISCSI_TASK_COMPLETED;
 633        } else if (err == DID_TRANSPORT_DISRUPTED)
 634                state = ISCSI_TASK_ABRT_SESS_RECOV;
 635        else
 636                state = ISCSI_TASK_ABRT_TMF;
 637
 638        sc->result = err << 16;
 639        if (!scsi_bidi_cmnd(sc))
 640                scsi_set_resid(sc, scsi_bufflen(sc));
 641        else {
 642                scsi_out(sc)->resid = scsi_out(sc)->length;
 643                scsi_in(sc)->resid = scsi_in(sc)->length;
 644        }
 645
 646        iscsi_complete_task(task, state);
 647}
 648
 649static int iscsi_prep_mgmt_task(struct iscsi_conn *conn,
 650                                struct iscsi_task *task)
 651{
 652        struct iscsi_session *session = conn->session;
 653        struct iscsi_hdr *hdr = task->hdr;
 654        struct iscsi_nopout *nop = (struct iscsi_nopout *)hdr;
 655        uint8_t opcode = hdr->opcode & ISCSI_OPCODE_MASK;
 656
 657        if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
 658                return -ENOTCONN;
 659
 660        if (opcode != ISCSI_OP_LOGIN && opcode != ISCSI_OP_TEXT)
 661                nop->exp_statsn = cpu_to_be32(conn->exp_statsn);
 662        /*
 663         * pre-format CmdSN for outgoing PDU.
 664         */
 665        nop->cmdsn = cpu_to_be32(session->cmdsn);
 666        if (hdr->itt != RESERVED_ITT) {
 667                /*
 668                 * TODO: We always use immediate for normal session pdus.
 669                 * If we start to send tmfs or nops as non-immediate then
 670                 * we should start checking the cmdsn numbers for mgmt tasks.
 671                 *
 672                 * During discovery sessions iscsid sends TEXT as non immediate,
 673                 * but we always only send one PDU at a time.
 674                 */
 675                if (conn->c_stage == ISCSI_CONN_STARTED &&
 676                    !(hdr->opcode & ISCSI_OP_IMMEDIATE)) {
 677                        session->queued_cmdsn++;
 678                        session->cmdsn++;
 679                }
 680        }
 681
 682        if (session->tt->init_task && session->tt->init_task(task))
 683                return -EIO;
 684
 685        if ((hdr->opcode & ISCSI_OPCODE_MASK) == ISCSI_OP_LOGOUT)
 686                session->state = ISCSI_STATE_LOGGING_OUT;
 687
 688        task->state = ISCSI_TASK_RUNNING;
 689        ISCSI_DBG_SESSION(session, "mgmtpdu [op 0x%x hdr->itt 0x%x "
 690                          "datalen %d]\n", hdr->opcode & ISCSI_OPCODE_MASK,
 691                          hdr->itt, task->data_count);
 692        return 0;
 693}
 694
 695static struct iscsi_task *
 696__iscsi_conn_send_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 697                      char *data, uint32_t data_size)
 698{
 699        struct iscsi_session *session = conn->session;
 700        struct iscsi_host *ihost = shost_priv(session->host);
 701        uint8_t opcode = hdr->opcode & ISCSI_OPCODE_MASK;
 702        struct iscsi_task *task;
 703        itt_t itt;
 704
 705        if (session->state == ISCSI_STATE_TERMINATE)
 706                return NULL;
 707
 708        if (opcode == ISCSI_OP_LOGIN || opcode == ISCSI_OP_TEXT) {
 709                /*
 710                 * Login and Text are sent serially, in
 711                 * request-followed-by-response sequence.
 712                 * Same task can be used. Same ITT must be used.
 713                 * Note that login_task is preallocated at conn_create().
 714                 */
 715                if (conn->login_task->state != ISCSI_TASK_FREE) {
 716                        iscsi_conn_printk(KERN_ERR, conn, "Login/Text in "
 717                                          "progress. Cannot start new task.\n");
 718                        return NULL;
 719                }
 720
 721                task = conn->login_task;
 722        } else {
 723                if (session->state != ISCSI_STATE_LOGGED_IN)
 724                        return NULL;
 725
 726                BUG_ON(conn->c_stage == ISCSI_CONN_INITIAL_STAGE);
 727                BUG_ON(conn->c_stage == ISCSI_CONN_STOPPED);
 728
 729                if (!kfifo_out(&session->cmdpool.queue,
 730                                 (void*)&task, sizeof(void*)))
 731                        return NULL;
 732        }
 733        /*
 734         * released in complete pdu for task we expect a response for, and
 735         * released by the lld when it has transmitted the task for
 736         * pdus we do not expect a response for.
 737         */
 738        atomic_set(&task->refcount, 1);
 739        task->conn = conn;
 740        task->sc = NULL;
 741        INIT_LIST_HEAD(&task->running);
 742        task->state = ISCSI_TASK_PENDING;
 743
 744        if (data_size) {
 745                memcpy(task->data, data, data_size);
 746                task->data_count = data_size;
 747        } else
 748                task->data_count = 0;
 749
 750        if (conn->session->tt->alloc_pdu) {
 751                if (conn->session->tt->alloc_pdu(task, hdr->opcode)) {
 752                        iscsi_conn_printk(KERN_ERR, conn, "Could not allocate "
 753                                         "pdu for mgmt task.\n");
 754                        goto free_task;
 755                }
 756        }
 757
 758        itt = task->hdr->itt;
 759        task->hdr_len = sizeof(struct iscsi_hdr);
 760        memcpy(task->hdr, hdr, sizeof(struct iscsi_hdr));
 761
 762        if (hdr->itt != RESERVED_ITT) {
 763                if (session->tt->parse_pdu_itt)
 764                        task->hdr->itt = itt;
 765                else
 766                        task->hdr->itt = build_itt(task->itt,
 767                                                   task->conn->session->age);
 768        }
 769
 770        if (!ihost->workq) {
 771                if (iscsi_prep_mgmt_task(conn, task))
 772                        goto free_task;
 773
 774                if (session->tt->xmit_task(task))
 775                        goto free_task;
 776        } else {
 777                list_add_tail(&task->running, &conn->mgmtqueue);
 778                iscsi_conn_queue_work(conn);
 779        }
 780
 781        return task;
 782
 783free_task:
 784        __iscsi_put_task(task);
 785        return NULL;
 786}
 787
 788int iscsi_conn_send_pdu(struct iscsi_cls_conn *cls_conn, struct iscsi_hdr *hdr,
 789                        char *data, uint32_t data_size)
 790{
 791        struct iscsi_conn *conn = cls_conn->dd_data;
 792        struct iscsi_session *session = conn->session;
 793        int err = 0;
 794
 795        spin_lock_bh(&session->lock);
 796        if (!__iscsi_conn_send_pdu(conn, hdr, data, data_size))
 797                err = -EPERM;
 798        spin_unlock_bh(&session->lock);
 799        return err;
 800}
 801EXPORT_SYMBOL_GPL(iscsi_conn_send_pdu);
 802
 803/**
 804 * iscsi_cmd_rsp - SCSI Command Response processing
 805 * @conn: iscsi connection
 806 * @hdr: iscsi header
 807 * @task: scsi command task
 808 * @data: cmd data buffer
 809 * @datalen: len of buffer
 810 *
 811 * iscsi_cmd_rsp sets up the scsi_cmnd fields based on the PDU and
 812 * then completes the command and task.
 813 **/
 814static void iscsi_scsi_cmd_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 815                               struct iscsi_task *task, char *data,
 816                               int datalen)
 817{
 818        struct iscsi_scsi_rsp *rhdr = (struct iscsi_scsi_rsp *)hdr;
 819        struct iscsi_session *session = conn->session;
 820        struct scsi_cmnd *sc = task->sc;
 821
 822        iscsi_update_cmdsn(session, (struct iscsi_nopin*)rhdr);
 823        conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
 824
 825        sc->result = (DID_OK << 16) | rhdr->cmd_status;
 826
 827        if (rhdr->response != ISCSI_STATUS_CMD_COMPLETED) {
 828                sc->result = DID_ERROR << 16;
 829                goto out;
 830        }
 831
 832        if (rhdr->cmd_status == SAM_STAT_CHECK_CONDITION) {
 833                uint16_t senselen;
 834
 835                if (datalen < 2) {
 836invalid_datalen:
 837                        iscsi_conn_printk(KERN_ERR,  conn,
 838                                         "Got CHECK_CONDITION but invalid data "
 839                                         "buffer size of %d\n", datalen);
 840                        sc->result = DID_BAD_TARGET << 16;
 841                        goto out;
 842                }
 843
 844                senselen = get_unaligned_be16(data);
 845                if (datalen < senselen)
 846                        goto invalid_datalen;
 847
 848                memcpy(sc->sense_buffer, data + 2,
 849                       min_t(uint16_t, senselen, SCSI_SENSE_BUFFERSIZE));
 850                ISCSI_DBG_SESSION(session, "copied %d bytes of sense\n",
 851                                  min_t(uint16_t, senselen,
 852                                  SCSI_SENSE_BUFFERSIZE));
 853        }
 854
 855        if (rhdr->flags & (ISCSI_FLAG_CMD_BIDI_UNDERFLOW |
 856                           ISCSI_FLAG_CMD_BIDI_OVERFLOW)) {
 857                int res_count = be32_to_cpu(rhdr->bi_residual_count);
 858
 859                if (scsi_bidi_cmnd(sc) && res_count > 0 &&
 860                                (rhdr->flags & ISCSI_FLAG_CMD_BIDI_OVERFLOW ||
 861                                 res_count <= scsi_in(sc)->length))
 862                        scsi_in(sc)->resid = res_count;
 863                else
 864                        sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 865        }
 866
 867        if (rhdr->flags & (ISCSI_FLAG_CMD_UNDERFLOW |
 868                           ISCSI_FLAG_CMD_OVERFLOW)) {
 869                int res_count = be32_to_cpu(rhdr->residual_count);
 870
 871                if (res_count > 0 &&
 872                    (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
 873                     res_count <= scsi_bufflen(sc)))
 874                        /* write side for bidi or uni-io set_resid */
 875                        scsi_set_resid(sc, res_count);
 876                else
 877                        sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 878        }
 879out:
 880        ISCSI_DBG_SESSION(session, "cmd rsp done [sc %p res %d itt 0x%x]\n",
 881                          sc, sc->result, task->itt);
 882        conn->scsirsp_pdus_cnt++;
 883        iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
 884}
 885
 886/**
 887 * iscsi_data_in_rsp - SCSI Data-In Response processing
 888 * @conn: iscsi connection
 889 * @hdr:  iscsi pdu
 890 * @task: scsi command task
 891 **/
 892static void
 893iscsi_data_in_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 894                  struct iscsi_task *task)
 895{
 896        struct iscsi_data_rsp *rhdr = (struct iscsi_data_rsp *)hdr;
 897        struct scsi_cmnd *sc = task->sc;
 898
 899        if (!(rhdr->flags & ISCSI_FLAG_DATA_STATUS))
 900                return;
 901
 902        iscsi_update_cmdsn(conn->session, (struct iscsi_nopin *)hdr);
 903        sc->result = (DID_OK << 16) | rhdr->cmd_status;
 904        conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
 905        if (rhdr->flags & (ISCSI_FLAG_DATA_UNDERFLOW |
 906                           ISCSI_FLAG_DATA_OVERFLOW)) {
 907                int res_count = be32_to_cpu(rhdr->residual_count);
 908
 909                if (res_count > 0 &&
 910                    (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
 911                     res_count <= scsi_in(sc)->length))
 912                        scsi_in(sc)->resid = res_count;
 913                else
 914                        sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 915        }
 916
 917        ISCSI_DBG_SESSION(conn->session, "data in with status done "
 918                          "[sc %p res %d itt 0x%x]\n",
 919                          sc, sc->result, task->itt);
 920        conn->scsirsp_pdus_cnt++;
 921        iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
 922}
 923
 924static void iscsi_tmf_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr)
 925{
 926        struct iscsi_tm_rsp *tmf = (struct iscsi_tm_rsp *)hdr;
 927
 928        conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
 929        conn->tmfrsp_pdus_cnt++;
 930
 931        if (conn->tmf_state != TMF_QUEUED)
 932                return;
 933
 934        if (tmf->response == ISCSI_TMF_RSP_COMPLETE)
 935                conn->tmf_state = TMF_SUCCESS;
 936        else if (tmf->response == ISCSI_TMF_RSP_NO_TASK)
 937                conn->tmf_state = TMF_NOT_FOUND;
 938        else
 939                conn->tmf_state = TMF_FAILED;
 940        wake_up(&conn->ehwait);
 941}
 942
 943static void iscsi_send_nopout(struct iscsi_conn *conn, struct iscsi_nopin *rhdr)
 944{
 945        struct iscsi_nopout hdr;
 946        struct iscsi_task *task;
 947
 948        if (!rhdr && conn->ping_task)
 949                return;
 950
 951        memset(&hdr, 0, sizeof(struct iscsi_nopout));
 952        hdr.opcode = ISCSI_OP_NOOP_OUT | ISCSI_OP_IMMEDIATE;
 953        hdr.flags = ISCSI_FLAG_CMD_FINAL;
 954
 955        if (rhdr) {
 956                hdr.lun = rhdr->lun;
 957                hdr.ttt = rhdr->ttt;
 958                hdr.itt = RESERVED_ITT;
 959        } else
 960                hdr.ttt = RESERVED_ITT;
 961
 962        task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)&hdr, NULL, 0);
 963        if (!task)
 964                iscsi_conn_printk(KERN_ERR, conn, "Could not send nopout\n");
 965        else if (!rhdr) {
 966                /* only track our nops */
 967                conn->ping_task = task;
 968                conn->last_ping = jiffies;
 969        }
 970}
 971
 972static int iscsi_nop_out_rsp(struct iscsi_task *task,
 973                             struct iscsi_nopin *nop, char *data, int datalen)
 974{
 975        struct iscsi_conn *conn = task->conn;
 976        int rc = 0;
 977
 978        if (conn->ping_task != task) {
 979                /*
 980                 * If this is not in response to one of our
 981                 * nops then it must be from userspace.
 982                 */
 983                if (iscsi_recv_pdu(conn->cls_conn, (struct iscsi_hdr *)nop,
 984                                   data, datalen))
 985                        rc = ISCSI_ERR_CONN_FAILED;
 986        } else
 987                mod_timer(&conn->transport_timer, jiffies + conn->recv_timeout);
 988        iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
 989        return rc;
 990}
 991
 992static int iscsi_handle_reject(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 993                               char *data, int datalen)
 994{
 995        struct iscsi_reject *reject = (struct iscsi_reject *)hdr;
 996        struct iscsi_hdr rejected_pdu;
 997        int opcode, rc = 0;
 998
 999        conn->exp_statsn = be32_to_cpu(reject->statsn) + 1;
1000
1001        if (ntoh24(reject->dlength) > datalen ||
1002            ntoh24(reject->dlength) < sizeof(struct iscsi_hdr)) {
1003                iscsi_conn_printk(KERN_ERR, conn, "Cannot handle rejected "
1004                                  "pdu. Invalid data length (pdu dlength "
1005                                  "%u, datalen %d\n", ntoh24(reject->dlength),
1006                                  datalen);
1007                return ISCSI_ERR_PROTO;
1008        }
1009        memcpy(&rejected_pdu, data, sizeof(struct iscsi_hdr));
1010        opcode = rejected_pdu.opcode & ISCSI_OPCODE_MASK;
1011
1012        switch (reject->reason) {
1013        case ISCSI_REASON_DATA_DIGEST_ERROR:
1014                iscsi_conn_printk(KERN_ERR, conn,
1015                                  "pdu (op 0x%x itt 0x%x) rejected "
1016                                  "due to DataDigest error.\n",
1017                                  rejected_pdu.itt, opcode);
1018                break;
1019        case ISCSI_REASON_IMM_CMD_REJECT:
1020                iscsi_conn_printk(KERN_ERR, conn,
1021                                  "pdu (op 0x%x itt 0x%x) rejected. Too many "
1022                                  "immediate commands.\n",
1023                                  rejected_pdu.itt, opcode);
1024                /*
1025                 * We only send one TMF at a time so if the target could not
1026                 * handle it, then it should get fixed (RFC mandates that
1027                 * a target can handle one immediate TMF per conn).
1028                 *
1029                 * For nops-outs, we could have sent more than one if
1030                 * the target is sending us lots of nop-ins
1031                 */
1032                if (opcode != ISCSI_OP_NOOP_OUT)
1033                        return 0;
1034
1035                 if (rejected_pdu.itt == cpu_to_be32(ISCSI_RESERVED_TAG))
1036                        /*
1037                         * nop-out in response to target's nop-out rejected.
1038                         * Just resend.
1039                         */
1040                        iscsi_send_nopout(conn,
1041                                          (struct iscsi_nopin*)&rejected_pdu);
1042                else {
1043                        struct iscsi_task *task;
1044                        /*
1045                         * Our nop as ping got dropped. We know the target
1046                         * and transport are ok so just clean up
1047                         */
1048                        task = iscsi_itt_to_task(conn, rejected_pdu.itt);
1049                        if (!task) {
1050                                iscsi_conn_printk(KERN_ERR, conn,
1051                                                 "Invalid pdu reject. Could "
1052                                                 "not lookup rejected task.\n");
1053                                rc = ISCSI_ERR_BAD_ITT;
1054                        } else
1055                                rc = iscsi_nop_out_rsp(task,
1056                                        (struct iscsi_nopin*)&rejected_pdu,
1057                                        NULL, 0);
1058                }
1059                break;
1060        default:
1061                iscsi_conn_printk(KERN_ERR, conn,
1062                                  "pdu (op 0x%x itt 0x%x) rejected. Reason "
1063                                  "code 0x%x\n", rejected_pdu.itt,
1064                                  rejected_pdu.opcode, reject->reason);
1065                break;
1066        }
1067        return rc;
1068}
1069
1070/**
1071 * iscsi_itt_to_task - look up task by itt
1072 * @conn: iscsi connection
1073 * @itt: itt
1074 *
1075 * This should be used for mgmt tasks like login and nops, or if
1076 * the LDD's itt space does not include the session age.
1077 *
1078 * The session lock must be held.
1079 */
1080struct iscsi_task *iscsi_itt_to_task(struct iscsi_conn *conn, itt_t itt)
1081{
1082        struct iscsi_session *session = conn->session;
1083        int i;
1084
1085        if (itt == RESERVED_ITT)
1086                return NULL;
1087
1088        if (session->tt->parse_pdu_itt)
1089                session->tt->parse_pdu_itt(conn, itt, &i, NULL);
1090        else
1091                i = get_itt(itt);
1092        if (i >= session->cmds_max)
1093                return NULL;
1094
1095        return session->cmds[i];
1096}
1097EXPORT_SYMBOL_GPL(iscsi_itt_to_task);
1098
1099/**
1100 * __iscsi_complete_pdu - complete pdu
1101 * @conn: iscsi conn
1102 * @hdr: iscsi header
1103 * @data: data buffer
1104 * @datalen: len of data buffer
1105 *
1106 * Completes pdu processing by freeing any resources allocated at
1107 * queuecommand or send generic. session lock must be held and verify
1108 * itt must have been called.
1109 */
1110int __iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1111                         char *data, int datalen)
1112{
1113        struct iscsi_session *session = conn->session;
1114        int opcode = hdr->opcode & ISCSI_OPCODE_MASK, rc = 0;
1115        struct iscsi_task *task;
1116        uint32_t itt;
1117
1118        conn->last_recv = jiffies;
1119        rc = iscsi_verify_itt(conn, hdr->itt);
1120        if (rc)
1121                return rc;
1122
1123        if (hdr->itt != RESERVED_ITT)
1124                itt = get_itt(hdr->itt);
1125        else
1126                itt = ~0U;
1127
1128        ISCSI_DBG_SESSION(session, "[op 0x%x cid %d itt 0x%x len %d]\n",
1129                          opcode, conn->id, itt, datalen);
1130
1131        if (itt == ~0U) {
1132                iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1133
1134                switch(opcode) {
1135                case ISCSI_OP_NOOP_IN:
1136                        if (datalen) {
1137                                rc = ISCSI_ERR_PROTO;
1138                                break;
1139                        }
1140
1141                        if (hdr->ttt == cpu_to_be32(ISCSI_RESERVED_TAG))
1142                                break;
1143
1144                        iscsi_send_nopout(conn, (struct iscsi_nopin*)hdr);
1145                        break;
1146                case ISCSI_OP_REJECT:
1147                        rc = iscsi_handle_reject(conn, hdr, data, datalen);
1148                        break;
1149                case ISCSI_OP_ASYNC_EVENT:
1150                        conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1151                        if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
1152                                rc = ISCSI_ERR_CONN_FAILED;
1153                        break;
1154                default:
1155                        rc = ISCSI_ERR_BAD_OPCODE;
1156                        break;
1157                }
1158                goto out;
1159        }
1160
1161        switch(opcode) {
1162        case ISCSI_OP_SCSI_CMD_RSP:
1163        case ISCSI_OP_SCSI_DATA_IN:
1164                task = iscsi_itt_to_ctask(conn, hdr->itt);
1165                if (!task)
1166                        return ISCSI_ERR_BAD_ITT;
1167                task->last_xfer = jiffies;
1168                break;
1169        case ISCSI_OP_R2T:
1170                /*
1171                 * LLD handles R2Ts if they need to.
1172                 */
1173                return 0;
1174        case ISCSI_OP_LOGOUT_RSP:
1175        case ISCSI_OP_LOGIN_RSP:
1176        case ISCSI_OP_TEXT_RSP:
1177        case ISCSI_OP_SCSI_TMFUNC_RSP:
1178        case ISCSI_OP_NOOP_IN:
1179                task = iscsi_itt_to_task(conn, hdr->itt);
1180                if (!task)
1181                        return ISCSI_ERR_BAD_ITT;
1182                break;
1183        default:
1184                return ISCSI_ERR_BAD_OPCODE;
1185        }
1186
1187        switch(opcode) {
1188        case ISCSI_OP_SCSI_CMD_RSP:
1189                iscsi_scsi_cmd_rsp(conn, hdr, task, data, datalen);
1190                break;
1191        case ISCSI_OP_SCSI_DATA_IN:
1192                iscsi_data_in_rsp(conn, hdr, task);
1193                break;
1194        case ISCSI_OP_LOGOUT_RSP:
1195                iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1196                if (datalen) {
1197                        rc = ISCSI_ERR_PROTO;
1198                        break;
1199                }
1200                conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1201                goto recv_pdu;
1202        case ISCSI_OP_LOGIN_RSP:
1203        case ISCSI_OP_TEXT_RSP:
1204                iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1205                /*
1206                 * login related PDU's exp_statsn is handled in
1207                 * userspace
1208                 */
1209                goto recv_pdu;
1210        case ISCSI_OP_SCSI_TMFUNC_RSP:
1211                iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1212                if (datalen) {
1213                        rc = ISCSI_ERR_PROTO;
1214                        break;
1215                }
1216
1217                iscsi_tmf_rsp(conn, hdr);
1218                iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1219                break;
1220        case ISCSI_OP_NOOP_IN:
1221                iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1222                if (hdr->ttt != cpu_to_be32(ISCSI_RESERVED_TAG) || datalen) {
1223                        rc = ISCSI_ERR_PROTO;
1224                        break;
1225                }
1226                conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1227
1228                rc = iscsi_nop_out_rsp(task, (struct iscsi_nopin*)hdr,
1229                                       data, datalen);
1230                break;
1231        default:
1232                rc = ISCSI_ERR_BAD_OPCODE;
1233                break;
1234        }
1235
1236out:
1237        return rc;
1238recv_pdu:
1239        if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
1240                rc = ISCSI_ERR_CONN_FAILED;
1241        iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1242        return rc;
1243}
1244EXPORT_SYMBOL_GPL(__iscsi_complete_pdu);
1245
1246int iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1247                       char *data, int datalen)
1248{
1249        int rc;
1250
1251        spin_lock(&conn->session->lock);
1252        rc = __iscsi_complete_pdu(conn, hdr, data, datalen);
1253        spin_unlock(&conn->session->lock);
1254        return rc;
1255}
1256EXPORT_SYMBOL_GPL(iscsi_complete_pdu);
1257
1258int iscsi_verify_itt(struct iscsi_conn *conn, itt_t itt)
1259{
1260        struct iscsi_session *session = conn->session;
1261        int age = 0, i = 0;
1262
1263        if (itt == RESERVED_ITT)
1264                return 0;
1265
1266        if (session->tt->parse_pdu_itt)
1267                session->tt->parse_pdu_itt(conn, itt, &i, &age);
1268        else {
1269                i = get_itt(itt);
1270                age = ((__force u32)itt >> ISCSI_AGE_SHIFT) & ISCSI_AGE_MASK;
1271        }
1272
1273        if (age != session->age) {
1274                iscsi_conn_printk(KERN_ERR, conn,
1275                                  "received itt %x expected session age (%x)\n",
1276                                  (__force u32)itt, session->age);
1277                return ISCSI_ERR_BAD_ITT;
1278        }
1279
1280        if (i >= session->cmds_max) {
1281                iscsi_conn_printk(KERN_ERR, conn,
1282                                  "received invalid itt index %u (max cmds "
1283                                   "%u.\n", i, session->cmds_max);
1284                return ISCSI_ERR_BAD_ITT;
1285        }
1286        return 0;
1287}
1288EXPORT_SYMBOL_GPL(iscsi_verify_itt);
1289
1290/**
1291 * iscsi_itt_to_ctask - look up ctask by itt
1292 * @conn: iscsi connection
1293 * @itt: itt
1294 *
1295 * This should be used for cmd tasks.
1296 *
1297 * The session lock must be held.
1298 */
1299struct iscsi_task *iscsi_itt_to_ctask(struct iscsi_conn *conn, itt_t itt)
1300{
1301        struct iscsi_task *task;
1302
1303        if (iscsi_verify_itt(conn, itt))
1304                return NULL;
1305
1306        task = iscsi_itt_to_task(conn, itt);
1307        if (!task || !task->sc)
1308                return NULL;
1309
1310        if (task->sc->SCp.phase != conn->session->age) {
1311                iscsi_session_printk(KERN_ERR, conn->session,
1312                                  "task's session age %d, expected %d\n",
1313                                  task->sc->SCp.phase, conn->session->age);
1314                return NULL;
1315        }
1316
1317        return task;
1318}
1319EXPORT_SYMBOL_GPL(iscsi_itt_to_ctask);
1320
1321void iscsi_session_failure(struct iscsi_session *session,
1322                           enum iscsi_err err)
1323{
1324        struct iscsi_conn *conn;
1325        struct device *dev;
1326
1327        spin_lock_bh(&session->lock);
1328        conn = session->leadconn;
1329        if (session->state == ISCSI_STATE_TERMINATE || !conn) {
1330                spin_unlock_bh(&session->lock);
1331                return;
1332        }
1333
1334        dev = get_device(&conn->cls_conn->dev);
1335        spin_unlock_bh(&session->lock);
1336        if (!dev)
1337                return;
1338        /*
1339         * if the host is being removed bypass the connection
1340         * recovery initialization because we are going to kill
1341         * the session.
1342         */
1343        if (err == ISCSI_ERR_INVALID_HOST)
1344                iscsi_conn_error_event(conn->cls_conn, err);
1345        else
1346                iscsi_conn_failure(conn, err);
1347        put_device(dev);
1348}
1349EXPORT_SYMBOL_GPL(iscsi_session_failure);
1350
1351void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err)
1352{
1353        struct iscsi_session *session = conn->session;
1354
1355        spin_lock_bh(&session->lock);
1356        if (session->state == ISCSI_STATE_FAILED) {
1357                spin_unlock_bh(&session->lock);
1358                return;
1359        }
1360
1361        if (conn->stop_stage == 0)
1362                session->state = ISCSI_STATE_FAILED;
1363        spin_unlock_bh(&session->lock);
1364
1365        set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1366        set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
1367        iscsi_conn_error_event(conn->cls_conn, err);
1368}
1369EXPORT_SYMBOL_GPL(iscsi_conn_failure);
1370
1371static int iscsi_check_cmdsn_window_closed(struct iscsi_conn *conn)
1372{
1373        struct iscsi_session *session = conn->session;
1374
1375        /*
1376         * Check for iSCSI window and take care of CmdSN wrap-around
1377         */
1378        if (!iscsi_sna_lte(session->queued_cmdsn, session->max_cmdsn)) {
1379                ISCSI_DBG_SESSION(session, "iSCSI CmdSN closed. ExpCmdSn "
1380                                  "%u MaxCmdSN %u CmdSN %u/%u\n",
1381                                  session->exp_cmdsn, session->max_cmdsn,
1382                                  session->cmdsn, session->queued_cmdsn);
1383                return -ENOSPC;
1384        }
1385        return 0;
1386}
1387
1388static int iscsi_xmit_task(struct iscsi_conn *conn)
1389{
1390        struct iscsi_task *task = conn->task;
1391        int rc;
1392
1393        if (test_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx))
1394                return -ENODATA;
1395
1396        __iscsi_get_task(task);
1397        spin_unlock_bh(&conn->session->lock);
1398        rc = conn->session->tt->xmit_task(task);
1399        spin_lock_bh(&conn->session->lock);
1400        if (!rc) {
1401                /* done with this task */
1402                task->last_xfer = jiffies;
1403                conn->task = NULL;
1404        }
1405        __iscsi_put_task(task);
1406        return rc;
1407}
1408
1409/**
1410 * iscsi_requeue_task - requeue task to run from session workqueue
1411 * @task: task to requeue
1412 *
1413 * LLDs that need to run a task from the session workqueue should call
1414 * this. The session lock must be held. This should only be called
1415 * by software drivers.
1416 */
1417void iscsi_requeue_task(struct iscsi_task *task)
1418{
1419        struct iscsi_conn *conn = task->conn;
1420
1421        /*
1422         * this may be on the requeue list already if the xmit_task callout
1423         * is handling the r2ts while we are adding new ones
1424         */
1425        if (list_empty(&task->running))
1426                list_add_tail(&task->running, &conn->requeue);
1427        iscsi_conn_queue_work(conn);
1428}
1429EXPORT_SYMBOL_GPL(iscsi_requeue_task);
1430
1431/**
1432 * iscsi_data_xmit - xmit any command into the scheduled connection
1433 * @conn: iscsi connection
1434 *
1435 * Notes:
1436 *      The function can return -EAGAIN in which case the caller must
1437 *      re-schedule it again later or recover. '0' return code means
1438 *      successful xmit.
1439 **/
1440static int iscsi_data_xmit(struct iscsi_conn *conn)
1441{
1442        struct iscsi_task *task;
1443        int rc = 0;
1444
1445        spin_lock_bh(&conn->session->lock);
1446        if (test_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx)) {
1447                ISCSI_DBG_SESSION(conn->session, "Tx suspended!\n");
1448                spin_unlock_bh(&conn->session->lock);
1449                return -ENODATA;
1450        }
1451
1452        if (conn->task) {
1453                rc = iscsi_xmit_task(conn);
1454                if (rc)
1455                        goto done;
1456        }
1457
1458        /*
1459         * process mgmt pdus like nops before commands since we should
1460         * only have one nop-out as a ping from us and targets should not
1461         * overflow us with nop-ins
1462         */
1463check_mgmt:
1464        while (!list_empty(&conn->mgmtqueue)) {
1465                conn->task = list_entry(conn->mgmtqueue.next,
1466                                         struct iscsi_task, running);
1467                list_del_init(&conn->task->running);
1468                if (iscsi_prep_mgmt_task(conn, conn->task)) {
1469                        __iscsi_put_task(conn->task);
1470                        conn->task = NULL;
1471                        continue;
1472                }
1473                rc = iscsi_xmit_task(conn);
1474                if (rc)
1475                        goto done;
1476        }
1477
1478        /* process pending command queue */
1479        while (!list_empty(&conn->cmdqueue)) {
1480                conn->task = list_entry(conn->cmdqueue.next, struct iscsi_task,
1481                                        running);
1482                list_del_init(&conn->task->running);
1483                if (conn->session->state == ISCSI_STATE_LOGGING_OUT) {
1484                        fail_scsi_task(conn->task, DID_IMM_RETRY);
1485                        continue;
1486                }
1487                rc = iscsi_prep_scsi_cmd_pdu(conn->task);
1488                if (rc) {
1489                        if (rc == -ENOMEM || rc == -EACCES) {
1490                                list_add_tail(&conn->task->running,
1491                                              &conn->cmdqueue);
1492                                conn->task = NULL;
1493                                goto done;
1494                        } else
1495                                fail_scsi_task(conn->task, DID_ABORT);
1496                        continue;
1497                }
1498                rc = iscsi_xmit_task(conn);
1499                if (rc)
1500                        goto done;
1501                /*
1502                 * we could continuously get new task requests so
1503                 * we need to check the mgmt queue for nops that need to
1504                 * be sent to aviod starvation
1505                 */
1506                if (!list_empty(&conn->mgmtqueue))
1507                        goto check_mgmt;
1508        }
1509
1510        while (!list_empty(&conn->requeue)) {
1511                /*
1512                 * we always do fastlogout - conn stop code will clean up.
1513                 */
1514                if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
1515                        break;
1516
1517                task = list_entry(conn->requeue.next, struct iscsi_task,
1518                                  running);
1519                if (iscsi_check_tmf_restrictions(task, ISCSI_OP_SCSI_DATA_OUT))
1520                        break;
1521
1522                conn->task = task;
1523                list_del_init(&conn->task->running);
1524                conn->task->state = ISCSI_TASK_RUNNING;
1525                rc = iscsi_xmit_task(conn);
1526                if (rc)
1527                        goto done;
1528                if (!list_empty(&conn->mgmtqueue))
1529                        goto check_mgmt;
1530        }
1531        spin_unlock_bh(&conn->session->lock);
1532        return -ENODATA;
1533
1534done:
1535        spin_unlock_bh(&conn->session->lock);
1536        return rc;
1537}
1538
1539static void iscsi_xmitworker(struct work_struct *work)
1540{
1541        struct iscsi_conn *conn =
1542                container_of(work, struct iscsi_conn, xmitwork);
1543        int rc;
1544        /*
1545         * serialize Xmit worker on a per-connection basis.
1546         */
1547        do {
1548                rc = iscsi_data_xmit(conn);
1549        } while (rc >= 0 || rc == -EAGAIN);
1550}
1551
1552static inline struct iscsi_task *iscsi_alloc_task(struct iscsi_conn *conn,
1553                                                  struct scsi_cmnd *sc)
1554{
1555        struct iscsi_task *task;
1556
1557        if (!kfifo_out(&conn->session->cmdpool.queue,
1558                         (void *) &task, sizeof(void *)))
1559                return NULL;
1560
1561        sc->SCp.phase = conn->session->age;
1562        sc->SCp.ptr = (char *) task;
1563
1564        atomic_set(&task->refcount, 1);
1565        task->state = ISCSI_TASK_PENDING;
1566        task->conn = conn;
1567        task->sc = sc;
1568        task->have_checked_conn = false;
1569        task->last_timeout = jiffies;
1570        task->last_xfer = jiffies;
1571        INIT_LIST_HEAD(&task->running);
1572        return task;
1573}
1574
1575enum {
1576        FAILURE_BAD_HOST = 1,
1577        FAILURE_SESSION_FAILED,
1578        FAILURE_SESSION_FREED,
1579        FAILURE_WINDOW_CLOSED,
1580        FAILURE_OOM,
1581        FAILURE_SESSION_TERMINATE,
1582        FAILURE_SESSION_IN_RECOVERY,
1583        FAILURE_SESSION_RECOVERY_TIMEOUT,
1584        FAILURE_SESSION_LOGGING_OUT,
1585        FAILURE_SESSION_NOT_READY,
1586};
1587
1588int iscsi_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *sc)
1589{
1590        struct iscsi_cls_session *cls_session;
1591        struct iscsi_host *ihost;
1592        int reason = 0;
1593        struct iscsi_session *session;
1594        struct iscsi_conn *conn;
1595        struct iscsi_task *task = NULL;
1596
1597        sc->result = 0;
1598        sc->SCp.ptr = NULL;
1599
1600        ihost = shost_priv(host);
1601
1602        cls_session = starget_to_session(scsi_target(sc->device));
1603        session = cls_session->dd_data;
1604        spin_lock_bh(&session->lock);
1605
1606        reason = iscsi_session_chkready(cls_session);
1607        if (reason) {
1608                sc->result = reason;
1609                goto fault;
1610        }
1611
1612        if (session->state != ISCSI_STATE_LOGGED_IN) {
1613                /*
1614                 * to handle the race between when we set the recovery state
1615                 * and block the session we requeue here (commands could
1616                 * be entering our queuecommand while a block is starting
1617                 * up because the block code is not locked)
1618                 */
1619                switch (session->state) {
1620                case ISCSI_STATE_FAILED:
1621                case ISCSI_STATE_IN_RECOVERY:
1622                        reason = FAILURE_SESSION_IN_RECOVERY;
1623                        sc->result = DID_IMM_RETRY << 16;
1624                        break;
1625                case ISCSI_STATE_LOGGING_OUT:
1626                        reason = FAILURE_SESSION_LOGGING_OUT;
1627                        sc->result = DID_IMM_RETRY << 16;
1628                        break;
1629                case ISCSI_STATE_RECOVERY_FAILED:
1630                        reason = FAILURE_SESSION_RECOVERY_TIMEOUT;
1631                        sc->result = DID_TRANSPORT_FAILFAST << 16;
1632                        break;
1633                case ISCSI_STATE_TERMINATE:
1634                        reason = FAILURE_SESSION_TERMINATE;
1635                        sc->result = DID_NO_CONNECT << 16;
1636                        break;
1637                default:
1638                        reason = FAILURE_SESSION_FREED;
1639                        sc->result = DID_NO_CONNECT << 16;
1640                }
1641                goto fault;
1642        }
1643
1644        conn = session->leadconn;
1645        if (!conn) {
1646                reason = FAILURE_SESSION_FREED;
1647                sc->result = DID_NO_CONNECT << 16;
1648                goto fault;
1649        }
1650
1651        if (test_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx)) {
1652                reason = FAILURE_SESSION_IN_RECOVERY;
1653                sc->result = DID_REQUEUE;
1654                goto fault;
1655        }
1656
1657        if (iscsi_check_cmdsn_window_closed(conn)) {
1658                reason = FAILURE_WINDOW_CLOSED;
1659                goto reject;
1660        }
1661
1662        task = iscsi_alloc_task(conn, sc);
1663        if (!task) {
1664                reason = FAILURE_OOM;
1665                goto reject;
1666        }
1667
1668        if (!ihost->workq) {
1669                reason = iscsi_prep_scsi_cmd_pdu(task);
1670                if (reason) {
1671                        if (reason == -ENOMEM ||  reason == -EACCES) {
1672                                reason = FAILURE_OOM;
1673                                goto prepd_reject;
1674                        } else {
1675                                sc->result = DID_ABORT << 16;
1676                                goto prepd_fault;
1677                        }
1678                }
1679                if (session->tt->xmit_task(task)) {
1680                        session->cmdsn--;
1681                        reason = FAILURE_SESSION_NOT_READY;
1682                        goto prepd_reject;
1683                }
1684        } else {
1685                list_add_tail(&task->running, &conn->cmdqueue);
1686                iscsi_conn_queue_work(conn);
1687        }
1688
1689        session->queued_cmdsn++;
1690        spin_unlock_bh(&session->lock);
1691        return 0;
1692
1693prepd_reject:
1694        iscsi_complete_task(task, ISCSI_TASK_REQUEUE_SCSIQ);
1695reject:
1696        spin_unlock_bh(&session->lock);
1697        ISCSI_DBG_SESSION(session, "cmd 0x%x rejected (%d)\n",
1698                          sc->cmnd[0], reason);
1699        return SCSI_MLQUEUE_TARGET_BUSY;
1700
1701prepd_fault:
1702        iscsi_complete_task(task, ISCSI_TASK_REQUEUE_SCSIQ);
1703fault:
1704        spin_unlock_bh(&session->lock);
1705        ISCSI_DBG_SESSION(session, "iscsi: cmd 0x%x is not queued (%d)\n",
1706                          sc->cmnd[0], reason);
1707        if (!scsi_bidi_cmnd(sc))
1708                scsi_set_resid(sc, scsi_bufflen(sc));
1709        else {
1710                scsi_out(sc)->resid = scsi_out(sc)->length;
1711                scsi_in(sc)->resid = scsi_in(sc)->length;
1712        }
1713        sc->scsi_done(sc);
1714        return 0;
1715}
1716EXPORT_SYMBOL_GPL(iscsi_queuecommand);
1717
1718int iscsi_change_queue_depth(struct scsi_device *sdev, int depth, int reason)
1719{
1720        switch (reason) {
1721        case SCSI_QDEPTH_DEFAULT:
1722                scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
1723                break;
1724        case SCSI_QDEPTH_QFULL:
1725                scsi_track_queue_full(sdev, depth);
1726                break;
1727        case SCSI_QDEPTH_RAMP_UP:
1728                scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
1729                break;
1730        default:
1731                return -EOPNOTSUPP;
1732        }
1733        return sdev->queue_depth;
1734}
1735EXPORT_SYMBOL_GPL(iscsi_change_queue_depth);
1736
1737int iscsi_target_alloc(struct scsi_target *starget)
1738{
1739        struct iscsi_cls_session *cls_session = starget_to_session(starget);
1740        struct iscsi_session *session = cls_session->dd_data;
1741
1742        starget->can_queue = session->scsi_cmds_max;
1743        return 0;
1744}
1745EXPORT_SYMBOL_GPL(iscsi_target_alloc);
1746
1747static void iscsi_tmf_timedout(unsigned long data)
1748{
1749        struct iscsi_conn *conn = (struct iscsi_conn *)data;
1750        struct iscsi_session *session = conn->session;
1751
1752        spin_lock(&session->lock);
1753        if (conn->tmf_state == TMF_QUEUED) {
1754                conn->tmf_state = TMF_TIMEDOUT;
1755                ISCSI_DBG_EH(session, "tmf timedout\n");
1756                /* unblock eh_abort() */
1757                wake_up(&conn->ehwait);
1758        }
1759        spin_unlock(&session->lock);
1760}
1761
1762static int iscsi_exec_task_mgmt_fn(struct iscsi_conn *conn,
1763                                   struct iscsi_tm *hdr, int age,
1764                                   int timeout)
1765{
1766        struct iscsi_session *session = conn->session;
1767        struct iscsi_task *task;
1768
1769        task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)hdr,
1770                                      NULL, 0);
1771        if (!task) {
1772                spin_unlock_bh(&session->lock);
1773                iscsi_conn_printk(KERN_ERR, conn, "Could not send TMF.\n");
1774                iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1775                spin_lock_bh(&session->lock);
1776                return -EPERM;
1777        }
1778        conn->tmfcmd_pdus_cnt++;
1779        conn->tmf_timer.expires = timeout * HZ + jiffies;
1780        conn->tmf_timer.function = iscsi_tmf_timedout;
1781        conn->tmf_timer.data = (unsigned long)conn;
1782        add_timer(&conn->tmf_timer);
1783        ISCSI_DBG_EH(session, "tmf set timeout\n");
1784
1785        spin_unlock_bh(&session->lock);
1786        mutex_unlock(&session->eh_mutex);
1787
1788        /*
1789         * block eh thread until:
1790         *
1791         * 1) tmf response
1792         * 2) tmf timeout
1793         * 3) session is terminated or restarted or userspace has
1794         * given up on recovery
1795         */
1796        wait_event_interruptible(conn->ehwait, age != session->age ||
1797                                 session->state != ISCSI_STATE_LOGGED_IN ||
1798                                 conn->tmf_state != TMF_QUEUED);
1799        if (signal_pending(current))
1800                flush_signals(current);
1801        del_timer_sync(&conn->tmf_timer);
1802
1803        mutex_lock(&session->eh_mutex);
1804        spin_lock_bh(&session->lock);
1805        /* if the session drops it will clean up the task */
1806        if (age != session->age ||
1807            session->state != ISCSI_STATE_LOGGED_IN)
1808                return -ENOTCONN;
1809        return 0;
1810}
1811
1812/*
1813 * Fail commands. session lock held and recv side suspended and xmit
1814 * thread flushed
1815 */
1816static void fail_scsi_tasks(struct iscsi_conn *conn, unsigned lun,
1817                            int error)
1818{
1819        struct iscsi_task *task;
1820        int i;
1821
1822        for (i = 0; i < conn->session->cmds_max; i++) {
1823                task = conn->session->cmds[i];
1824                if (!task->sc || task->state == ISCSI_TASK_FREE)
1825                        continue;
1826
1827                if (lun != -1 && lun != task->sc->device->lun)
1828                        continue;
1829
1830                ISCSI_DBG_SESSION(conn->session,
1831                                  "failing sc %p itt 0x%x state %d\n",
1832                                  task->sc, task->itt, task->state);
1833                fail_scsi_task(task, error);
1834        }
1835}
1836
1837/**
1838 * iscsi_suspend_queue - suspend iscsi_queuecommand
1839 * @conn: iscsi conn to stop queueing IO on
1840 *
1841 * This grabs the session lock to make sure no one is in
1842 * xmit_task/queuecommand, and then sets suspend to prevent
1843 * new commands from being queued. This only needs to be called
1844 * by offload drivers that need to sync a path like ep disconnect
1845 * with the iscsi_queuecommand/xmit_task. To start IO again libiscsi
1846 * will call iscsi_start_tx and iscsi_unblock_session when in FFP.
1847 */
1848void iscsi_suspend_queue(struct iscsi_conn *conn)
1849{
1850        spin_lock_bh(&conn->session->lock);
1851        set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1852        spin_unlock_bh(&conn->session->lock);
1853}
1854EXPORT_SYMBOL_GPL(iscsi_suspend_queue);
1855
1856/**
1857 * iscsi_suspend_tx - suspend iscsi_data_xmit
1858 * @conn: iscsi conn tp stop processing IO on.
1859 *
1860 * This function sets the suspend bit to prevent iscsi_data_xmit
1861 * from sending new IO, and if work is queued on the xmit thread
1862 * it will wait for it to be completed.
1863 */
1864void iscsi_suspend_tx(struct iscsi_conn *conn)
1865{
1866        struct Scsi_Host *shost = conn->session->host;
1867        struct iscsi_host *ihost = shost_priv(shost);
1868
1869        set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1870        if (ihost->workq)
1871                flush_workqueue(ihost->workq);
1872}
1873EXPORT_SYMBOL_GPL(iscsi_suspend_tx);
1874
1875static void iscsi_start_tx(struct iscsi_conn *conn)
1876{
1877        clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1878        iscsi_conn_queue_work(conn);
1879}
1880
1881/*
1882 * We want to make sure a ping is in flight. It has timed out.
1883 * And we are not busy processing a pdu that is making
1884 * progress but got started before the ping and is taking a while
1885 * to complete so the ping is just stuck behind it in a queue.
1886 */
1887static int iscsi_has_ping_timed_out(struct iscsi_conn *conn)
1888{
1889        if (conn->ping_task &&
1890            time_before_eq(conn->last_recv + (conn->recv_timeout * HZ) +
1891                           (conn->ping_timeout * HZ), jiffies))
1892                return 1;
1893        else
1894                return 0;
1895}
1896
1897static enum blk_eh_timer_return iscsi_eh_cmd_timed_out(struct scsi_cmnd *sc)
1898{
1899        enum blk_eh_timer_return rc = BLK_EH_NOT_HANDLED;
1900        struct iscsi_task *task = NULL, *running_task;
1901        struct iscsi_cls_session *cls_session;
1902        struct iscsi_session *session;
1903        struct iscsi_conn *conn;
1904        int i;
1905
1906        cls_session = starget_to_session(scsi_target(sc->device));
1907        session = cls_session->dd_data;
1908
1909        ISCSI_DBG_EH(session, "scsi cmd %p timedout\n", sc);
1910
1911        spin_lock(&session->lock);
1912        task = (struct iscsi_task *)sc->SCp.ptr;
1913        if (!task) {
1914                /*
1915                 * Raced with completion. Blk layer has taken ownership
1916                 * so let timeout code complete it now.
1917                 */
1918                rc = BLK_EH_HANDLED;
1919                goto done;
1920        }
1921
1922        if (session->state != ISCSI_STATE_LOGGED_IN) {
1923                /*
1924                 * We are probably in the middle of iscsi recovery so let
1925                 * that complete and handle the error.
1926                 */
1927                rc = BLK_EH_RESET_TIMER;
1928                goto done;
1929        }
1930
1931        conn = session->leadconn;
1932        if (!conn) {
1933                /* In the middle of shuting down */
1934                rc = BLK_EH_RESET_TIMER;
1935                goto done;
1936        }
1937
1938        /*
1939         * If we have sent (at least queued to the network layer) a pdu or
1940         * recvd one for the task since the last timeout ask for
1941         * more time. If on the next timeout we have not made progress
1942         * we can check if it is the task or connection when we send the
1943         * nop as a ping.
1944         */
1945        if (time_after(task->last_xfer, task->last_timeout)) {
1946                ISCSI_DBG_EH(session, "Command making progress. Asking "
1947                             "scsi-ml for more time to complete. "
1948                             "Last data xfer at %lu. Last timeout was at "
1949                             "%lu\n.", task->last_xfer, task->last_timeout);
1950                task->have_checked_conn = false;
1951                rc = BLK_EH_RESET_TIMER;
1952                goto done;
1953        }
1954
1955        if (!conn->recv_timeout && !conn->ping_timeout)
1956                goto done;
1957        /*
1958         * if the ping timedout then we are in the middle of cleaning up
1959         * and can let the iscsi eh handle it
1960         */
1961        if (iscsi_has_ping_timed_out(conn)) {
1962                rc = BLK_EH_RESET_TIMER;
1963                goto done;
1964        }
1965
1966        for (i = 0; i < conn->session->cmds_max; i++) {
1967                running_task = conn->session->cmds[i];
1968                if (!running_task->sc || running_task == task ||
1969                     running_task->state != ISCSI_TASK_RUNNING)
1970                        continue;
1971
1972                /*
1973                 * Only check if cmds started before this one have made
1974                 * progress, or this could never fail
1975                 */
1976                if (time_after(running_task->sc->jiffies_at_alloc,
1977                               task->sc->jiffies_at_alloc))
1978                        continue;
1979
1980                if (time_after(running_task->last_xfer, task->last_timeout)) {
1981                        /*
1982                         * This task has not made progress, but a task
1983                         * started before us has transferred data since
1984                         * we started/last-checked. We could be queueing
1985                         * too many tasks or the LU is bad.
1986                         *
1987                         * If the device is bad the cmds ahead of us on
1988                         * other devs will complete, and this loop will
1989                         * eventually fail starting the scsi eh.
1990                         */
1991                        ISCSI_DBG_EH(session, "Command has not made progress "
1992                                     "but commands ahead of it have. "
1993                                     "Asking scsi-ml for more time to "
1994                                     "complete. Our last xfer vs running task "
1995                                     "last xfer %lu/%lu. Last check %lu.\n",
1996                                     task->last_xfer, running_task->last_xfer,
1997                                     task->last_timeout);
1998                        rc = BLK_EH_RESET_TIMER;
1999                        goto done;
2000                }
2001        }
2002
2003        /* Assumes nop timeout is shorter than scsi cmd timeout */
2004        if (task->have_checked_conn)
2005                goto done;
2006
2007        /*
2008         * Checking the transport already or nop from a cmd timeout still
2009         * running
2010         */
2011        if (conn->ping_task) {
2012                task->have_checked_conn = true;
2013                rc = BLK_EH_RESET_TIMER;
2014                goto done;
2015        }
2016
2017        /* Make sure there is a transport check done */
2018        iscsi_send_nopout(conn, NULL);
2019        task->have_checked_conn = true;
2020        rc = BLK_EH_RESET_TIMER;
2021
2022done:
2023        if (task)
2024                task->last_timeout = jiffies;
2025        spin_unlock(&session->lock);
2026        ISCSI_DBG_EH(session, "return %s\n", rc == BLK_EH_RESET_TIMER ?
2027                     "timer reset" : "nh");
2028        return rc;
2029}
2030
2031static void iscsi_check_transport_timeouts(unsigned long data)
2032{
2033        struct iscsi_conn *conn = (struct iscsi_conn *)data;
2034        struct iscsi_session *session = conn->session;
2035        unsigned long recv_timeout, next_timeout = 0, last_recv;
2036
2037        spin_lock(&session->lock);
2038        if (session->state != ISCSI_STATE_LOGGED_IN)
2039                goto done;
2040
2041        recv_timeout = conn->recv_timeout;
2042        if (!recv_timeout)
2043                goto done;
2044
2045        recv_timeout *= HZ;
2046        last_recv = conn->last_recv;
2047
2048        if (iscsi_has_ping_timed_out(conn)) {
2049                iscsi_conn_printk(KERN_ERR, conn, "ping timeout of %d secs "
2050                                  "expired, recv timeout %d, last rx %lu, "
2051                                  "last ping %lu, now %lu\n",
2052                                  conn->ping_timeout, conn->recv_timeout,
2053                                  last_recv, conn->last_ping, jiffies);
2054                spin_unlock(&session->lock);
2055                iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
2056                return;
2057        }
2058
2059        if (time_before_eq(last_recv + recv_timeout, jiffies)) {
2060                /* send a ping to try to provoke some traffic */
2061                ISCSI_DBG_CONN(conn, "Sending nopout as ping\n");
2062                iscsi_send_nopout(conn, NULL);
2063                next_timeout = conn->last_ping + (conn->ping_timeout * HZ);
2064        } else
2065                next_timeout = last_recv + recv_timeout;
2066
2067        ISCSI_DBG_CONN(conn, "Setting next tmo %lu\n", next_timeout);
2068        mod_timer(&conn->transport_timer, next_timeout);
2069done:
2070        spin_unlock(&session->lock);
2071}
2072
2073static void iscsi_prep_abort_task_pdu(struct iscsi_task *task,
2074                                      struct iscsi_tm *hdr)
2075{
2076        memset(hdr, 0, sizeof(*hdr));
2077        hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2078        hdr->flags = ISCSI_TM_FUNC_ABORT_TASK & ISCSI_FLAG_TM_FUNC_MASK;
2079        hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2080        hdr->lun = task->lun;
2081        hdr->rtt = task->hdr_itt;
2082        hdr->refcmdsn = task->cmdsn;
2083}
2084
2085int iscsi_eh_abort(struct scsi_cmnd *sc)
2086{
2087        struct iscsi_cls_session *cls_session;
2088        struct iscsi_session *session;
2089        struct iscsi_conn *conn;
2090        struct iscsi_task *task;
2091        struct iscsi_tm *hdr;
2092        int rc, age;
2093
2094        cls_session = starget_to_session(scsi_target(sc->device));
2095        session = cls_session->dd_data;
2096
2097        ISCSI_DBG_EH(session, "aborting sc %p\n", sc);
2098
2099        mutex_lock(&session->eh_mutex);
2100        spin_lock_bh(&session->lock);
2101        /*
2102         * if session was ISCSI_STATE_IN_RECOVERY then we may not have
2103         * got the command.
2104         */
2105        if (!sc->SCp.ptr) {
2106                ISCSI_DBG_EH(session, "sc never reached iscsi layer or "
2107                                      "it completed.\n");
2108                spin_unlock_bh(&session->lock);
2109                mutex_unlock(&session->eh_mutex);
2110                return SUCCESS;
2111        }
2112
2113        /*
2114         * If we are not logged in or we have started a new session
2115         * then let the host reset code handle this
2116         */
2117        if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN ||
2118            sc->SCp.phase != session->age) {
2119                spin_unlock_bh(&session->lock);
2120                mutex_unlock(&session->eh_mutex);
2121                ISCSI_DBG_EH(session, "failing abort due to dropped "
2122                                  "session.\n");
2123                return FAILED;
2124        }
2125
2126        conn = session->leadconn;
2127        conn->eh_abort_cnt++;
2128        age = session->age;
2129
2130        task = (struct iscsi_task *)sc->SCp.ptr;
2131        ISCSI_DBG_EH(session, "aborting [sc %p itt 0x%x]\n",
2132                     sc, task->itt);
2133
2134        /* task completed before time out */
2135        if (!task->sc) {
2136                ISCSI_DBG_EH(session, "sc completed while abort in progress\n");
2137                goto success;
2138        }
2139
2140        if (task->state == ISCSI_TASK_PENDING) {
2141                fail_scsi_task(task, DID_ABORT);
2142                goto success;
2143        }
2144
2145        /* only have one tmf outstanding at a time */
2146        if (conn->tmf_state != TMF_INITIAL)
2147                goto failed;
2148        conn->tmf_state = TMF_QUEUED;
2149
2150        hdr = &conn->tmhdr;
2151        iscsi_prep_abort_task_pdu(task, hdr);
2152
2153        if (iscsi_exec_task_mgmt_fn(conn, hdr, age, session->abort_timeout)) {
2154                rc = FAILED;
2155                goto failed;
2156        }
2157
2158        switch (conn->tmf_state) {
2159        case TMF_SUCCESS:
2160                spin_unlock_bh(&session->lock);
2161                /*
2162                 * stop tx side incase the target had sent a abort rsp but
2163                 * the initiator was still writing out data.
2164                 */
2165                iscsi_suspend_tx(conn);
2166                /*
2167                 * we do not stop the recv side because targets have been
2168                 * good and have never sent us a successful tmf response
2169                 * then sent more data for the cmd.
2170                 */
2171                spin_lock_bh(&session->lock);
2172                fail_scsi_task(task, DID_ABORT);
2173                conn->tmf_state = TMF_INITIAL;
2174                memset(hdr, 0, sizeof(*hdr));
2175                spin_unlock_bh(&session->lock);
2176                iscsi_start_tx(conn);
2177                goto success_unlocked;
2178        case TMF_TIMEDOUT:
2179                spin_unlock_bh(&session->lock);
2180                iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2181                goto failed_unlocked;
2182        case TMF_NOT_FOUND:
2183                if (!sc->SCp.ptr) {
2184                        conn->tmf_state = TMF_INITIAL;
2185                        memset(hdr, 0, sizeof(*hdr));
2186                        /* task completed before tmf abort response */
2187                        ISCSI_DBG_EH(session, "sc completed while abort in "
2188                                              "progress\n");
2189                        goto success;
2190                }
2191                /* fall through */
2192        default:
2193                conn->tmf_state = TMF_INITIAL;
2194                goto failed;
2195        }
2196
2197success:
2198        spin_unlock_bh(&session->lock);
2199success_unlocked:
2200        ISCSI_DBG_EH(session, "abort success [sc %p itt 0x%x]\n",
2201                     sc, task->itt);
2202        mutex_unlock(&session->eh_mutex);
2203        return SUCCESS;
2204
2205failed:
2206        spin_unlock_bh(&session->lock);
2207failed_unlocked:
2208        ISCSI_DBG_EH(session, "abort failed [sc %p itt 0x%x]\n", sc,
2209                     task ? task->itt : 0);
2210        mutex_unlock(&session->eh_mutex);
2211        return FAILED;
2212}
2213EXPORT_SYMBOL_GPL(iscsi_eh_abort);
2214
2215static void iscsi_prep_lun_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
2216{
2217        memset(hdr, 0, sizeof(*hdr));
2218        hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2219        hdr->flags = ISCSI_TM_FUNC_LOGICAL_UNIT_RESET & ISCSI_FLAG_TM_FUNC_MASK;
2220        hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2221        int_to_scsilun(sc->device->lun, &hdr->lun);
2222        hdr->rtt = RESERVED_ITT;
2223}
2224
2225int iscsi_eh_device_reset(struct scsi_cmnd *sc)
2226{
2227        struct iscsi_cls_session *cls_session;
2228        struct iscsi_session *session;
2229        struct iscsi_conn *conn;
2230        struct iscsi_tm *hdr;
2231        int rc = FAILED;
2232
2233        cls_session = starget_to_session(scsi_target(sc->device));
2234        session = cls_session->dd_data;
2235
2236        ISCSI_DBG_EH(session, "LU Reset [sc %p lun %u]\n", sc, sc->device->lun);
2237
2238        mutex_lock(&session->eh_mutex);
2239        spin_lock_bh(&session->lock);
2240        /*
2241         * Just check if we are not logged in. We cannot check for
2242         * the phase because the reset could come from a ioctl.
2243         */
2244        if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN)
2245                goto unlock;
2246        conn = session->leadconn;
2247
2248        /* only have one tmf outstanding at a time */
2249        if (conn->tmf_state != TMF_INITIAL)
2250                goto unlock;
2251        conn->tmf_state = TMF_QUEUED;
2252
2253        hdr = &conn->tmhdr;
2254        iscsi_prep_lun_reset_pdu(sc, hdr);
2255
2256        if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age,
2257                                    session->lu_reset_timeout)) {
2258                rc = FAILED;
2259                goto unlock;
2260        }
2261
2262        switch (conn->tmf_state) {
2263        case TMF_SUCCESS:
2264                break;
2265        case TMF_TIMEDOUT:
2266                spin_unlock_bh(&session->lock);
2267                iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2268                goto done;
2269        default:
2270                conn->tmf_state = TMF_INITIAL;
2271                goto unlock;
2272        }
2273
2274        rc = SUCCESS;
2275        spin_unlock_bh(&session->lock);
2276
2277        iscsi_suspend_tx(conn);
2278
2279        spin_lock_bh(&session->lock);
2280        memset(hdr, 0, sizeof(*hdr));
2281        fail_scsi_tasks(conn, sc->device->lun, DID_ERROR);
2282        conn->tmf_state = TMF_INITIAL;
2283        spin_unlock_bh(&session->lock);
2284
2285        iscsi_start_tx(conn);
2286        goto done;
2287
2288unlock:
2289        spin_unlock_bh(&session->lock);
2290done:
2291        ISCSI_DBG_EH(session, "dev reset result = %s\n",
2292                     rc == SUCCESS ? "SUCCESS" : "FAILED");
2293        mutex_unlock(&session->eh_mutex);
2294        return rc;
2295}
2296EXPORT_SYMBOL_GPL(iscsi_eh_device_reset);
2297
2298void iscsi_session_recovery_timedout(struct iscsi_cls_session *cls_session)
2299{
2300        struct iscsi_session *session = cls_session->dd_data;
2301
2302        spin_lock_bh(&session->lock);
2303        if (session->state != ISCSI_STATE_LOGGED_IN) {
2304                session->state = ISCSI_STATE_RECOVERY_FAILED;
2305                if (session->leadconn)
2306                        wake_up(&session->leadconn->ehwait);
2307        }
2308        spin_unlock_bh(&session->lock);
2309}
2310EXPORT_SYMBOL_GPL(iscsi_session_recovery_timedout);
2311
2312/**
2313 * iscsi_eh_session_reset - drop session and attempt relogin
2314 * @sc: scsi command
2315 *
2316 * This function will wait for a relogin, session termination from
2317 * userspace, or a recovery/replacement timeout.
2318 */
2319int iscsi_eh_session_reset(struct scsi_cmnd *sc)
2320{
2321        struct iscsi_cls_session *cls_session;
2322        struct iscsi_session *session;
2323        struct iscsi_conn *conn;
2324
2325        cls_session = starget_to_session(scsi_target(sc->device));
2326        session = cls_session->dd_data;
2327        conn = session->leadconn;
2328
2329        mutex_lock(&session->eh_mutex);
2330        spin_lock_bh(&session->lock);
2331        if (session->state == ISCSI_STATE_TERMINATE) {
2332failed:
2333                ISCSI_DBG_EH(session,
2334                             "failing session reset: Could not log back into "
2335                             "%s, %s [age %d]\n", session->targetname,
2336                             conn->persistent_address, session->age);
2337                spin_unlock_bh(&session->lock);
2338                mutex_unlock(&session->eh_mutex);
2339                return FAILED;
2340        }
2341
2342        spin_unlock_bh(&session->lock);
2343        mutex_unlock(&session->eh_mutex);
2344        /*
2345         * we drop the lock here but the leadconn cannot be destoyed while
2346         * we are in the scsi eh
2347         */
2348        iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2349
2350        ISCSI_DBG_EH(session, "wait for relogin\n");
2351        wait_event_interruptible(conn->ehwait,
2352                                 session->state == ISCSI_STATE_TERMINATE ||
2353                                 session->state == ISCSI_STATE_LOGGED_IN ||
2354                                 session->state == ISCSI_STATE_RECOVERY_FAILED);
2355        if (signal_pending(current))
2356                flush_signals(current);
2357
2358        mutex_lock(&session->eh_mutex);
2359        spin_lock_bh(&session->lock);
2360        if (session->state == ISCSI_STATE_LOGGED_IN) {
2361                ISCSI_DBG_EH(session,
2362                             "session reset succeeded for %s,%s\n",
2363                             session->targetname, conn->persistent_address);
2364        } else
2365                goto failed;
2366        spin_unlock_bh(&session->lock);
2367        mutex_unlock(&session->eh_mutex);
2368        return SUCCESS;
2369}
2370EXPORT_SYMBOL_GPL(iscsi_eh_session_reset);
2371
2372static void iscsi_prep_tgt_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
2373{
2374        memset(hdr, 0, sizeof(*hdr));
2375        hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2376        hdr->flags = ISCSI_TM_FUNC_TARGET_WARM_RESET & ISCSI_FLAG_TM_FUNC_MASK;
2377        hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2378        hdr->rtt = RESERVED_ITT;
2379}
2380
2381/**
2382 * iscsi_eh_target_reset - reset target
2383 * @sc: scsi command
2384 *
2385 * This will attempt to send a warm target reset.
2386 */
2387int iscsi_eh_target_reset(struct scsi_cmnd *sc)
2388{
2389        struct iscsi_cls_session *cls_session;
2390        struct iscsi_session *session;
2391        struct iscsi_conn *conn;
2392        struct iscsi_tm *hdr;
2393        int rc = FAILED;
2394
2395        cls_session = starget_to_session(scsi_target(sc->device));
2396        session = cls_session->dd_data;
2397
2398        ISCSI_DBG_EH(session, "tgt Reset [sc %p tgt %s]\n", sc,
2399                     session->targetname);
2400
2401        mutex_lock(&session->eh_mutex);
2402        spin_lock_bh(&session->lock);
2403        /*
2404         * Just check if we are not logged in. We cannot check for
2405         * the phase because the reset could come from a ioctl.
2406         */
2407        if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN)
2408                goto unlock;
2409        conn = session->leadconn;
2410
2411        /* only have one tmf outstanding at a time */
2412        if (conn->tmf_state != TMF_INITIAL)
2413                goto unlock;
2414        conn->tmf_state = TMF_QUEUED;
2415
2416        hdr = &conn->tmhdr;
2417        iscsi_prep_tgt_reset_pdu(sc, hdr);
2418
2419        if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age,
2420                                    session->tgt_reset_timeout)) {
2421                rc = FAILED;
2422                goto unlock;
2423        }
2424
2425        switch (conn->tmf_state) {
2426        case TMF_SUCCESS:
2427                break;
2428        case TMF_TIMEDOUT:
2429                spin_unlock_bh(&session->lock);
2430                iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2431                goto done;
2432        default:
2433                conn->tmf_state = TMF_INITIAL;
2434                goto unlock;
2435        }
2436
2437        rc = SUCCESS;
2438        spin_unlock_bh(&session->lock);
2439
2440        iscsi_suspend_tx(conn);
2441
2442        spin_lock_bh(&session->lock);
2443        memset(hdr, 0, sizeof(*hdr));
2444        fail_scsi_tasks(conn, -1, DID_ERROR);
2445        conn->tmf_state = TMF_INITIAL;
2446        spin_unlock_bh(&session->lock);
2447
2448        iscsi_start_tx(conn);
2449        goto done;
2450
2451unlock:
2452        spin_unlock_bh(&session->lock);
2453done:
2454        ISCSI_DBG_EH(session, "tgt %s reset result = %s\n", session->targetname,
2455                     rc == SUCCESS ? "SUCCESS" : "FAILED");
2456        mutex_unlock(&session->eh_mutex);
2457        return rc;
2458}
2459EXPORT_SYMBOL_GPL(iscsi_eh_target_reset);
2460
2461/**
2462 * iscsi_eh_recover_target - reset target and possibly the session
2463 * @sc: scsi command
2464 *
2465 * This will attempt to send a warm target reset. If that fails,
2466 * we will escalate to ERL0 session recovery.
2467 */
2468int iscsi_eh_recover_target(struct scsi_cmnd *sc)
2469{
2470        int rc;
2471
2472        rc = iscsi_eh_target_reset(sc);
2473        if (rc == FAILED)
2474                rc = iscsi_eh_session_reset(sc);
2475        return rc;
2476}
2477EXPORT_SYMBOL_GPL(iscsi_eh_recover_target);
2478
2479/*
2480 * Pre-allocate a pool of @max items of @item_size. By default, the pool
2481 * should be accessed via kfifo_{get,put} on q->queue.
2482 * Optionally, the caller can obtain the array of object pointers
2483 * by passing in a non-NULL @items pointer
2484 */
2485int
2486iscsi_pool_init(struct iscsi_pool *q, int max, void ***items, int item_size)
2487{
2488        int i, num_arrays = 1;
2489
2490        memset(q, 0, sizeof(*q));
2491
2492        q->max = max;
2493
2494        /* If the user passed an items pointer, he wants a copy of
2495         * the array. */
2496        if (items)
2497                num_arrays++;
2498        q->pool = kzalloc(num_arrays * max * sizeof(void*), GFP_KERNEL);
2499        if (q->pool == NULL)
2500                return -ENOMEM;
2501
2502        kfifo_init(&q->queue, (void*)q->pool, max * sizeof(void*));
2503
2504        for (i = 0; i < max; i++) {
2505                q->pool[i] = kzalloc(item_size, GFP_KERNEL);
2506                if (q->pool[i] == NULL) {
2507                        q->max = i;
2508                        goto enomem;
2509                }
2510                kfifo_in(&q->queue, (void*)&q->pool[i], sizeof(void*));
2511        }
2512
2513        if (items) {
2514                *items = q->pool + max;
2515                memcpy(*items, q->pool, max * sizeof(void *));
2516        }
2517
2518        return 0;
2519
2520enomem:
2521        iscsi_pool_free(q);
2522        return -ENOMEM;
2523}
2524EXPORT_SYMBOL_GPL(iscsi_pool_init);
2525
2526void iscsi_pool_free(struct iscsi_pool *q)
2527{
2528        int i;
2529
2530        for (i = 0; i < q->max; i++)
2531                kfree(q->pool[i]);
2532        kfree(q->pool);
2533}
2534EXPORT_SYMBOL_GPL(iscsi_pool_free);
2535
2536/**
2537 * iscsi_host_add - add host to system
2538 * @shost: scsi host
2539 * @pdev: parent device
2540 *
2541 * This should be called by partial offload and software iscsi drivers
2542 * to add a host to the system.
2543 */
2544int iscsi_host_add(struct Scsi_Host *shost, struct device *pdev)
2545{
2546        if (!shost->can_queue)
2547                shost->can_queue = ISCSI_DEF_XMIT_CMDS_MAX;
2548
2549        if (!shost->cmd_per_lun)
2550                shost->cmd_per_lun = ISCSI_DEF_CMD_PER_LUN;
2551
2552        if (!shost->transportt->eh_timed_out)
2553                shost->transportt->eh_timed_out = iscsi_eh_cmd_timed_out;
2554        return scsi_add_host(shost, pdev);
2555}
2556EXPORT_SYMBOL_GPL(iscsi_host_add);
2557
2558/**
2559 * iscsi_host_alloc - allocate a host and driver data
2560 * @sht: scsi host template
2561 * @dd_data_size: driver host data size
2562 * @xmit_can_sleep: bool indicating if LLD will queue IO from a work queue
2563 *
2564 * This should be called by partial offload and software iscsi drivers.
2565 * To access the driver specific memory use the iscsi_host_priv() macro.
2566 */
2567struct Scsi_Host *iscsi_host_alloc(struct scsi_host_template *sht,
2568                                   int dd_data_size, bool xmit_can_sleep)
2569{
2570        struct Scsi_Host *shost;
2571        struct iscsi_host *ihost;
2572
2573        shost = scsi_host_alloc(sht, sizeof(struct iscsi_host) + dd_data_size);
2574        if (!shost)
2575                return NULL;
2576        ihost = shost_priv(shost);
2577
2578        if (xmit_can_sleep) {
2579                snprintf(ihost->workq_name, sizeof(ihost->workq_name),
2580                        "iscsi_q_%d", shost->host_no);
2581                ihost->workq = create_singlethread_workqueue(ihost->workq_name);
2582                if (!ihost->workq)
2583                        goto free_host;
2584        }
2585
2586        spin_lock_init(&ihost->lock);
2587        ihost->state = ISCSI_HOST_SETUP;
2588        ihost->num_sessions = 0;
2589        init_waitqueue_head(&ihost->session_removal_wq);
2590        return shost;
2591
2592free_host:
2593        scsi_host_put(shost);
2594        return NULL;
2595}
2596EXPORT_SYMBOL_GPL(iscsi_host_alloc);
2597
2598static void iscsi_notify_host_removed(struct iscsi_cls_session *cls_session)
2599{
2600        iscsi_session_failure(cls_session->dd_data, ISCSI_ERR_INVALID_HOST);
2601}
2602
2603/**
2604 * iscsi_host_remove - remove host and sessions
2605 * @shost: scsi host
2606 *
2607 * If there are any sessions left, this will initiate the removal and wait
2608 * for the completion.
2609 */
2610void iscsi_host_remove(struct Scsi_Host *shost)
2611{
2612        struct iscsi_host *ihost = shost_priv(shost);
2613        unsigned long flags;
2614
2615        spin_lock_irqsave(&ihost->lock, flags);
2616        ihost->state = ISCSI_HOST_REMOVED;
2617        spin_unlock_irqrestore(&ihost->lock, flags);
2618
2619        iscsi_host_for_each_session(shost, iscsi_notify_host_removed);
2620        wait_event_interruptible(ihost->session_removal_wq,
2621                                 ihost->num_sessions == 0);
2622        if (signal_pending(current))
2623                flush_signals(current);
2624
2625        scsi_remove_host(shost);
2626        if (ihost->workq)
2627                destroy_workqueue(ihost->workq);
2628}
2629EXPORT_SYMBOL_GPL(iscsi_host_remove);
2630
2631void iscsi_host_free(struct Scsi_Host *shost)
2632{
2633        struct iscsi_host *ihost = shost_priv(shost);
2634
2635        kfree(ihost->netdev);
2636        kfree(ihost->hwaddress);
2637        kfree(ihost->initiatorname);
2638        scsi_host_put(shost);
2639}
2640EXPORT_SYMBOL_GPL(iscsi_host_free);
2641
2642static void iscsi_host_dec_session_cnt(struct Scsi_Host *shost)
2643{
2644        struct iscsi_host *ihost = shost_priv(shost);
2645        unsigned long flags;
2646
2647        shost = scsi_host_get(shost);
2648        if (!shost) {
2649                printk(KERN_ERR "Invalid state. Cannot notify host removal "
2650                      "of session teardown event because host already "
2651                      "removed.\n");
2652                return;
2653        }
2654
2655        spin_lock_irqsave(&ihost->lock, flags);
2656        ihost->num_sessions--;
2657        if (ihost->num_sessions == 0)
2658                wake_up(&ihost->session_removal_wq);
2659        spin_unlock_irqrestore(&ihost->lock, flags);
2660        scsi_host_put(shost);
2661}
2662
2663/**
2664 * iscsi_session_setup - create iscsi cls session and host and session
2665 * @iscsit: iscsi transport template
2666 * @shost: scsi host
2667 * @cmds_max: session can queue
2668 * @cmd_task_size: LLD task private data size
2669 * @initial_cmdsn: initial CmdSN
2670 *
2671 * This can be used by software iscsi_transports that allocate
2672 * a session per scsi host.
2673 *
2674 * Callers should set cmds_max to the largest total numer (mgmt + scsi) of
2675 * tasks they support. The iscsi layer reserves ISCSI_MGMT_CMDS_MAX tasks
2676 * for nop handling and login/logout requests.
2677 */
2678struct iscsi_cls_session *
2679iscsi_session_setup(struct iscsi_transport *iscsit, struct Scsi_Host *shost,
2680                    uint16_t cmds_max, int dd_size, int cmd_task_size,
2681                    uint32_t initial_cmdsn, unsigned int id)
2682{
2683        struct iscsi_host *ihost = shost_priv(shost);
2684        struct iscsi_session *session;
2685        struct iscsi_cls_session *cls_session;
2686        int cmd_i, scsi_cmds, total_cmds = cmds_max;
2687        unsigned long flags;
2688
2689        spin_lock_irqsave(&ihost->lock, flags);
2690        if (ihost->state == ISCSI_HOST_REMOVED) {
2691                spin_unlock_irqrestore(&ihost->lock, flags);
2692                return NULL;
2693        }
2694        ihost->num_sessions++;
2695        spin_unlock_irqrestore(&ihost->lock, flags);
2696
2697        if (!total_cmds)
2698                total_cmds = ISCSI_DEF_XMIT_CMDS_MAX;
2699        /*
2700         * The iscsi layer needs some tasks for nop handling and tmfs,
2701         * so the cmds_max must at least be greater than ISCSI_MGMT_CMDS_MAX
2702         * + 1 command for scsi IO.
2703         */
2704        if (total_cmds < ISCSI_TOTAL_CMDS_MIN) {
2705                printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2706                       "must be a power of two that is at least %d.\n",
2707                       total_cmds, ISCSI_TOTAL_CMDS_MIN);
2708                goto dec_session_count;
2709        }
2710
2711        if (total_cmds > ISCSI_TOTAL_CMDS_MAX) {
2712                printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2713                       "must be a power of 2 less than or equal to %d.\n",
2714                       cmds_max, ISCSI_TOTAL_CMDS_MAX);
2715                total_cmds = ISCSI_TOTAL_CMDS_MAX;
2716        }
2717
2718        if (!is_power_of_2(total_cmds)) {
2719                printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2720                       "must be a power of 2.\n", total_cmds);
2721                total_cmds = rounddown_pow_of_two(total_cmds);
2722                if (total_cmds < ISCSI_TOTAL_CMDS_MIN)
2723                        return NULL;
2724                printk(KERN_INFO "iscsi: Rounding can_queue to %d.\n",
2725                       total_cmds);
2726        }
2727        scsi_cmds = total_cmds - ISCSI_MGMT_CMDS_MAX;
2728
2729        cls_session = iscsi_alloc_session(shost, iscsit,
2730                                          sizeof(struct iscsi_session) +
2731                                          dd_size);
2732        if (!cls_session)
2733                goto dec_session_count;
2734        session = cls_session->dd_data;
2735        session->cls_session = cls_session;
2736        session->host = shost;
2737        session->state = ISCSI_STATE_FREE;
2738        session->fast_abort = 1;
2739        session->tgt_reset_timeout = 30;
2740        session->lu_reset_timeout = 15;
2741        session->abort_timeout = 10;
2742        session->scsi_cmds_max = scsi_cmds;
2743        session->cmds_max = total_cmds;
2744        session->queued_cmdsn = session->cmdsn = initial_cmdsn;
2745        session->exp_cmdsn = initial_cmdsn + 1;
2746        session->max_cmdsn = initial_cmdsn + 1;
2747        session->max_r2t = 1;
2748        session->tt = iscsit;
2749        session->dd_data = cls_session->dd_data + sizeof(*session);
2750        mutex_init(&session->eh_mutex);
2751        spin_lock_init(&session->lock);
2752
2753        /* initialize SCSI PDU commands pool */
2754        if (iscsi_pool_init(&session->cmdpool, session->cmds_max,
2755                            (void***)&session->cmds,
2756                            cmd_task_size + sizeof(struct iscsi_task)))
2757                goto cmdpool_alloc_fail;
2758
2759        /* pre-format cmds pool with ITT */
2760        for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
2761                struct iscsi_task *task = session->cmds[cmd_i];
2762
2763                if (cmd_task_size)
2764                        task->dd_data = &task[1];
2765                task->itt = cmd_i;
2766                task->state = ISCSI_TASK_FREE;
2767                INIT_LIST_HEAD(&task->running);
2768        }
2769
2770        if (!try_module_get(iscsit->owner))
2771                goto module_get_fail;
2772
2773        if (iscsi_add_session(cls_session, id))
2774                goto cls_session_fail;
2775
2776        return cls_session;
2777
2778cls_session_fail:
2779        module_put(iscsit->owner);
2780module_get_fail:
2781        iscsi_pool_free(&session->cmdpool);
2782cmdpool_alloc_fail:
2783        iscsi_free_session(cls_session);
2784dec_session_count:
2785        iscsi_host_dec_session_cnt(shost);
2786        return NULL;
2787}
2788EXPORT_SYMBOL_GPL(iscsi_session_setup);
2789
2790/**
2791 * iscsi_session_teardown - destroy session, host, and cls_session
2792 * @cls_session: iscsi session
2793 *
2794 * The driver must have called iscsi_remove_session before
2795 * calling this.
2796 */
2797void iscsi_session_teardown(struct iscsi_cls_session *cls_session)
2798{
2799        struct iscsi_session *session = cls_session->dd_data;
2800        struct module *owner = cls_session->transport->owner;
2801        struct Scsi_Host *shost = session->host;
2802
2803        iscsi_pool_free(&session->cmdpool);
2804
2805        kfree(session->password);
2806        kfree(session->password_in);
2807        kfree(session->username);
2808        kfree(session->username_in);
2809        kfree(session->targetname);
2810        kfree(session->targetalias);
2811        kfree(session->initiatorname);
2812        kfree(session->ifacename);
2813
2814        iscsi_destroy_session(cls_session);
2815        iscsi_host_dec_session_cnt(shost);
2816        module_put(owner);
2817}
2818EXPORT_SYMBOL_GPL(iscsi_session_teardown);
2819
2820/**
2821 * iscsi_conn_setup - create iscsi_cls_conn and iscsi_conn
2822 * @cls_session: iscsi_cls_session
2823 * @dd_size: private driver data size
2824 * @conn_idx: cid
2825 */
2826struct iscsi_cls_conn *
2827iscsi_conn_setup(struct iscsi_cls_session *cls_session, int dd_size,
2828                 uint32_t conn_idx)
2829{
2830        struct iscsi_session *session = cls_session->dd_data;
2831        struct iscsi_conn *conn;
2832        struct iscsi_cls_conn *cls_conn;
2833        char *data;
2834
2835        cls_conn = iscsi_create_conn(cls_session, sizeof(*conn) + dd_size,
2836                                     conn_idx);
2837        if (!cls_conn)
2838                return NULL;
2839        conn = cls_conn->dd_data;
2840        memset(conn, 0, sizeof(*conn) + dd_size);
2841
2842        conn->dd_data = cls_conn->dd_data + sizeof(*conn);
2843        conn->session = session;
2844        conn->cls_conn = cls_conn;
2845        conn->c_stage = ISCSI_CONN_INITIAL_STAGE;
2846        conn->id = conn_idx;
2847        conn->exp_statsn = 0;
2848        conn->tmf_state = TMF_INITIAL;
2849
2850        init_timer(&conn->transport_timer);
2851        conn->transport_timer.data = (unsigned long)conn;
2852        conn->transport_timer.function = iscsi_check_transport_timeouts;
2853
2854        INIT_LIST_HEAD(&conn->mgmtqueue);
2855        INIT_LIST_HEAD(&conn->cmdqueue);
2856        INIT_LIST_HEAD(&conn->requeue);
2857        INIT_WORK(&conn->xmitwork, iscsi_xmitworker);
2858
2859        /* allocate login_task used for the login/text sequences */
2860        spin_lock_bh(&session->lock);
2861        if (!kfifo_out(&session->cmdpool.queue,
2862                         (void*)&conn->login_task,
2863                         sizeof(void*))) {
2864                spin_unlock_bh(&session->lock);
2865                goto login_task_alloc_fail;
2866        }
2867        spin_unlock_bh(&session->lock);
2868
2869        data = (char *) __get_free_pages(GFP_KERNEL,
2870                                         get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
2871        if (!data)
2872                goto login_task_data_alloc_fail;
2873        conn->login_task->data = conn->data = data;
2874
2875        init_timer(&conn->tmf_timer);
2876        init_waitqueue_head(&conn->ehwait);
2877
2878        return cls_conn;
2879
2880login_task_data_alloc_fail:
2881        kfifo_in(&session->cmdpool.queue, (void*)&conn->login_task,
2882                    sizeof(void*));
2883login_task_alloc_fail:
2884        iscsi_destroy_conn(cls_conn);
2885        return NULL;
2886}
2887EXPORT_SYMBOL_GPL(iscsi_conn_setup);
2888
2889/**
2890 * iscsi_conn_teardown - teardown iscsi connection
2891 * cls_conn: iscsi class connection
2892 *
2893 * TODO: we may need to make this into a two step process
2894 * like scsi-mls remove + put host
2895 */
2896void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn)
2897{
2898        struct iscsi_conn *conn = cls_conn->dd_data;
2899        struct iscsi_session *session = conn->session;
2900        unsigned long flags;
2901
2902        del_timer_sync(&conn->transport_timer);
2903
2904        spin_lock_bh(&session->lock);
2905        conn->c_stage = ISCSI_CONN_CLEANUP_WAIT;
2906        if (session->leadconn == conn) {
2907                /*
2908                 * leading connection? then give up on recovery.
2909                 */
2910                session->state = ISCSI_STATE_TERMINATE;
2911                wake_up(&conn->ehwait);
2912        }
2913        spin_unlock_bh(&session->lock);
2914
2915        /*
2916         * Block until all in-progress commands for this connection
2917         * time out or fail.
2918         */
2919        for (;;) {
2920                spin_lock_irqsave(session->host->host_lock, flags);
2921                if (!session->host->host_busy) { /* OK for ERL == 0 */
2922                        spin_unlock_irqrestore(session->host->host_lock, flags);
2923                        break;
2924                }
2925                spin_unlock_irqrestore(session->host->host_lock, flags);
2926                msleep_interruptible(500);
2927                iscsi_conn_printk(KERN_INFO, conn, "iscsi conn_destroy(): "
2928                                  "host_busy %d host_failed %d\n",
2929                                  session->host->host_busy,
2930                                  session->host->host_failed);
2931                /*
2932                 * force eh_abort() to unblock
2933                 */
2934                wake_up(&conn->ehwait);
2935        }
2936
2937        /* flush queued up work because we free the connection below */
2938        iscsi_suspend_tx(conn);
2939
2940        spin_lock_bh(&session->lock);
2941        free_pages((unsigned long) conn->data,
2942                   get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
2943        kfree(conn->persistent_address);
2944        kfifo_in(&session->cmdpool.queue, (void*)&conn->login_task,
2945                    sizeof(void*));
2946        if (session->leadconn == conn)
2947                session->leadconn = NULL;
2948        spin_unlock_bh(&session->lock);
2949
2950        iscsi_destroy_conn(cls_conn);
2951}
2952EXPORT_SYMBOL_GPL(iscsi_conn_teardown);
2953
2954int iscsi_conn_start(struct iscsi_cls_conn *cls_conn)
2955{
2956        struct iscsi_conn *conn = cls_conn->dd_data;
2957        struct iscsi_session *session = conn->session;
2958
2959        if (!session) {
2960                iscsi_conn_printk(KERN_ERR, conn,
2961                                  "can't start unbound connection\n");
2962                return -EPERM;
2963        }
2964
2965        if ((session->imm_data_en || !session->initial_r2t_en) &&
2966             session->first_burst > session->max_burst) {
2967                iscsi_conn_printk(KERN_INFO, conn, "invalid burst lengths: "
2968                                  "first_burst %d max_burst %d\n",
2969                                  session->first_burst, session->max_burst);
2970                return -EINVAL;
2971        }
2972
2973        if (conn->ping_timeout && !conn->recv_timeout) {
2974                iscsi_conn_printk(KERN_ERR, conn, "invalid recv timeout of "
2975                                  "zero. Using 5 seconds\n.");
2976                conn->recv_timeout = 5;
2977        }
2978
2979        if (conn->recv_timeout && !conn->ping_timeout) {
2980                iscsi_conn_printk(KERN_ERR, conn, "invalid ping timeout of "
2981                                  "zero. Using 5 seconds.\n");
2982                conn->ping_timeout = 5;
2983        }
2984
2985        spin_lock_bh(&session->lock);
2986        conn->c_stage = ISCSI_CONN_STARTED;
2987        session->state = ISCSI_STATE_LOGGED_IN;
2988        session->queued_cmdsn = session->cmdsn;
2989
2990        conn->last_recv = jiffies;
2991        conn->last_ping = jiffies;
2992        if (conn->recv_timeout && conn->ping_timeout)
2993                mod_timer(&conn->transport_timer,
2994                          jiffies + (conn->recv_timeout * HZ));
2995
2996        switch(conn->stop_stage) {
2997        case STOP_CONN_RECOVER:
2998                /*
2999                 * unblock eh_abort() if it is blocked. re-try all
3000                 * commands after successful recovery
3001                 */
3002                conn->stop_stage = 0;
3003                conn->tmf_state = TMF_INITIAL;
3004                session->age++;
3005                if (session->age == 16)
3006                        session->age = 0;
3007                break;
3008        case STOP_CONN_TERM:
3009                conn->stop_stage = 0;
3010                break;
3011        default:
3012                break;
3013        }
3014        spin_unlock_bh(&session->lock);
3015
3016        iscsi_unblock_session(session->cls_session);
3017        wake_up(&conn->ehwait);
3018        return 0;
3019}
3020EXPORT_SYMBOL_GPL(iscsi_conn_start);
3021
3022static void
3023fail_mgmt_tasks(struct iscsi_session *session, struct iscsi_conn *conn)
3024{
3025        struct iscsi_task *task;
3026        int i, state;
3027
3028        for (i = 0; i < conn->session->cmds_max; i++) {
3029                task = conn->session->cmds[i];
3030                if (task->sc)
3031                        continue;
3032
3033                if (task->state == ISCSI_TASK_FREE)
3034                        continue;
3035
3036                ISCSI_DBG_SESSION(conn->session,
3037                                  "failing mgmt itt 0x%x state %d\n",
3038                                  task->itt, task->state);
3039                state = ISCSI_TASK_ABRT_SESS_RECOV;
3040                if (task->state == ISCSI_TASK_PENDING)
3041                        state = ISCSI_TASK_COMPLETED;
3042                iscsi_complete_task(task, state);
3043
3044        }
3045}
3046
3047static void iscsi_start_session_recovery(struct iscsi_session *session,
3048                                         struct iscsi_conn *conn, int flag)
3049{
3050        int old_stop_stage;
3051
3052        mutex_lock(&session->eh_mutex);
3053        spin_lock_bh(&session->lock);
3054        if (conn->stop_stage == STOP_CONN_TERM) {
3055                spin_unlock_bh(&session->lock);
3056                mutex_unlock(&session->eh_mutex);
3057                return;
3058        }
3059
3060        /*
3061         * When this is called for the in_login state, we only want to clean
3062         * up the login task and connection. We do not need to block and set
3063         * the recovery state again
3064         */
3065        if (flag == STOP_CONN_TERM)
3066                session->state = ISCSI_STATE_TERMINATE;
3067        else if (conn->stop_stage != STOP_CONN_RECOVER)
3068                session->state = ISCSI_STATE_IN_RECOVERY;
3069
3070        old_stop_stage = conn->stop_stage;
3071        conn->stop_stage = flag;
3072        spin_unlock_bh(&session->lock);
3073
3074        del_timer_sync(&conn->transport_timer);
3075        iscsi_suspend_tx(conn);
3076
3077        spin_lock_bh(&session->lock);
3078        conn->c_stage = ISCSI_CONN_STOPPED;
3079        spin_unlock_bh(&session->lock);
3080
3081        /*
3082         * for connection level recovery we should not calculate
3083         * header digest. conn->hdr_size used for optimization
3084         * in hdr_extract() and will be re-negotiated at
3085         * set_param() time.
3086         */
3087        if (flag == STOP_CONN_RECOVER) {
3088                conn->hdrdgst_en = 0;
3089                conn->datadgst_en = 0;
3090                if (session->state == ISCSI_STATE_IN_RECOVERY &&
3091                    old_stop_stage != STOP_CONN_RECOVER) {
3092                        ISCSI_DBG_SESSION(session, "blocking session\n");
3093                        iscsi_block_session(session->cls_session);
3094                }
3095        }
3096
3097        /*
3098         * flush queues.
3099         */
3100        spin_lock_bh(&session->lock);
3101        fail_scsi_tasks(conn, -1, DID_TRANSPORT_DISRUPTED);
3102        fail_mgmt_tasks(session, conn);
3103        memset(&conn->tmhdr, 0, sizeof(conn->tmhdr));
3104        spin_unlock_bh(&session->lock);
3105        mutex_unlock(&session->eh_mutex);
3106}
3107
3108void iscsi_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
3109{
3110        struct iscsi_conn *conn = cls_conn->dd_data;
3111        struct iscsi_session *session = conn->session;
3112
3113        switch (flag) {
3114        case STOP_CONN_RECOVER:
3115        case STOP_CONN_TERM:
3116                iscsi_start_session_recovery(session, conn, flag);
3117                break;
3118        default:
3119                iscsi_conn_printk(KERN_ERR, conn,
3120                                  "invalid stop flag %d\n", flag);
3121        }
3122}
3123EXPORT_SYMBOL_GPL(iscsi_conn_stop);
3124
3125int iscsi_conn_bind(struct iscsi_cls_session *cls_session,
3126                    struct iscsi_cls_conn *cls_conn, int is_leading)
3127{
3128        struct iscsi_session *session = cls_session->dd_data;
3129        struct iscsi_conn *conn = cls_conn->dd_data;
3130
3131        spin_lock_bh(&session->lock);
3132        if (is_leading)
3133                session->leadconn = conn;
3134        spin_unlock_bh(&session->lock);
3135
3136        /*
3137         * Unblock xmitworker(), Login Phase will pass through.
3138         */
3139        clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
3140        clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
3141        return 0;
3142}
3143EXPORT_SYMBOL_GPL(iscsi_conn_bind);
3144
3145static int iscsi_switch_str_param(char **param, char *new_val_buf)
3146{
3147        char *new_val;
3148
3149        if (*param) {
3150                if (!strcmp(*param, new_val_buf))
3151                        return 0;
3152        }
3153
3154        new_val = kstrdup(new_val_buf, GFP_NOIO);
3155        if (!new_val)
3156                return -ENOMEM;
3157
3158        kfree(*param);
3159        *param = new_val;
3160        return 0;
3161}
3162
3163int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
3164                    enum iscsi_param param, char *buf, int buflen)
3165{
3166        struct iscsi_conn *conn = cls_conn->dd_data;
3167        struct iscsi_session *session = conn->session;
3168
3169        switch(param) {
3170        case ISCSI_PARAM_FAST_ABORT:
3171                sscanf(buf, "%d", &session->fast_abort);
3172                break;
3173        case ISCSI_PARAM_ABORT_TMO:
3174                sscanf(buf, "%d", &session->abort_timeout);
3175                break;
3176        case ISCSI_PARAM_LU_RESET_TMO:
3177                sscanf(buf, "%d", &session->lu_reset_timeout);
3178                break;
3179        case ISCSI_PARAM_TGT_RESET_TMO:
3180                sscanf(buf, "%d", &session->tgt_reset_timeout);
3181                break;
3182        case ISCSI_PARAM_PING_TMO:
3183                sscanf(buf, "%d", &conn->ping_timeout);
3184                break;
3185        case ISCSI_PARAM_RECV_TMO:
3186                sscanf(buf, "%d", &conn->recv_timeout);
3187                break;
3188        case ISCSI_PARAM_MAX_RECV_DLENGTH:
3189                sscanf(buf, "%d", &conn->max_recv_dlength);
3190                break;
3191        case ISCSI_PARAM_MAX_XMIT_DLENGTH:
3192                sscanf(buf, "%d", &conn->max_xmit_dlength);
3193                break;
3194        case ISCSI_PARAM_HDRDGST_EN:
3195                sscanf(buf, "%d", &conn->hdrdgst_en);
3196                break;
3197        case ISCSI_PARAM_DATADGST_EN:
3198                sscanf(buf, "%d", &conn->datadgst_en);
3199                break;
3200        case ISCSI_PARAM_INITIAL_R2T_EN:
3201                sscanf(buf, "%d", &session->initial_r2t_en);
3202                break;
3203        case ISCSI_PARAM_MAX_R2T:
3204                sscanf(buf, "%hu", &session->max_r2t);
3205                break;
3206        case ISCSI_PARAM_IMM_DATA_EN:
3207                sscanf(buf, "%d", &session->imm_data_en);
3208                break;
3209        case ISCSI_PARAM_FIRST_BURST:
3210                sscanf(buf, "%d", &session->first_burst);
3211                break;
3212        case ISCSI_PARAM_MAX_BURST:
3213                sscanf(buf, "%d", &session->max_burst);
3214                break;
3215        case ISCSI_PARAM_PDU_INORDER_EN:
3216                sscanf(buf, "%d", &session->pdu_inorder_en);
3217                break;
3218        case ISCSI_PARAM_DATASEQ_INORDER_EN:
3219                sscanf(buf, "%d", &session->dataseq_inorder_en);
3220                break;
3221        case ISCSI_PARAM_ERL:
3222                sscanf(buf, "%d", &session->erl);
3223                break;
3224        case ISCSI_PARAM_EXP_STATSN:
3225                sscanf(buf, "%u", &conn->exp_statsn);
3226                break;
3227        case ISCSI_PARAM_USERNAME:
3228                return iscsi_switch_str_param(&session->username, buf);
3229        case ISCSI_PARAM_USERNAME_IN:
3230                return iscsi_switch_str_param(&session->username_in, buf);
3231        case ISCSI_PARAM_PASSWORD:
3232                return iscsi_switch_str_param(&session->password, buf);
3233        case ISCSI_PARAM_PASSWORD_IN:
3234                return iscsi_switch_str_param(&session->password_in, buf);
3235        case ISCSI_PARAM_TARGET_NAME:
3236                return iscsi_switch_str_param(&session->targetname, buf);
3237        case ISCSI_PARAM_TARGET_ALIAS:
3238                return iscsi_switch_str_param(&session->targetalias, buf);
3239        case ISCSI_PARAM_TPGT:
3240                sscanf(buf, "%d", &session->tpgt);
3241                break;
3242        case ISCSI_PARAM_PERSISTENT_PORT:
3243                sscanf(buf, "%d", &conn->persistent_port);
3244                break;
3245        case ISCSI_PARAM_PERSISTENT_ADDRESS:
3246                return iscsi_switch_str_param(&conn->persistent_address, buf);
3247        case ISCSI_PARAM_IFACE_NAME:
3248                return iscsi_switch_str_param(&session->ifacename, buf);
3249        case ISCSI_PARAM_INITIATOR_NAME:
3250                return iscsi_switch_str_param(&session->initiatorname, buf);
3251        default:
3252                return -ENOSYS;
3253        }
3254
3255        return 0;
3256}
3257EXPORT_SYMBOL_GPL(iscsi_set_param);
3258
3259int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
3260                            enum iscsi_param param, char *buf)
3261{
3262        struct iscsi_session *session = cls_session->dd_data;
3263        int len;
3264
3265        switch(param) {
3266        case ISCSI_PARAM_FAST_ABORT:
3267                len = sprintf(buf, "%d\n", session->fast_abort);
3268                break;
3269        case ISCSI_PARAM_ABORT_TMO:
3270                len = sprintf(buf, "%d\n", session->abort_timeout);
3271                break;
3272        case ISCSI_PARAM_LU_RESET_TMO:
3273                len = sprintf(buf, "%d\n", session->lu_reset_timeout);
3274                break;
3275        case ISCSI_PARAM_TGT_RESET_TMO:
3276                len = sprintf(buf, "%d\n", session->tgt_reset_timeout);
3277                break;
3278        case ISCSI_PARAM_INITIAL_R2T_EN:
3279                len = sprintf(buf, "%d\n", session->initial_r2t_en);
3280                break;
3281        case ISCSI_PARAM_MAX_R2T:
3282                len = sprintf(buf, "%hu\n", session->max_r2t);
3283                break;
3284        case ISCSI_PARAM_IMM_DATA_EN:
3285                len = sprintf(buf, "%d\n", session->imm_data_en);
3286                break;
3287        case ISCSI_PARAM_FIRST_BURST:
3288                len = sprintf(buf, "%u\n", session->first_burst);
3289                break;
3290        case ISCSI_PARAM_MAX_BURST:
3291                len = sprintf(buf, "%u\n", session->max_burst);
3292                break;
3293        case ISCSI_PARAM_PDU_INORDER_EN:
3294                len = sprintf(buf, "%d\n", session->pdu_inorder_en);
3295                break;
3296        case ISCSI_PARAM_DATASEQ_INORDER_EN:
3297                len = sprintf(buf, "%d\n", session->dataseq_inorder_en);
3298                break;
3299        case ISCSI_PARAM_ERL:
3300                len = sprintf(buf, "%d\n", session->erl);
3301                break;
3302        case ISCSI_PARAM_TARGET_NAME:
3303                len = sprintf(buf, "%s\n", session->targetname);
3304                break;
3305        case ISCSI_PARAM_TARGET_ALIAS:
3306                len = sprintf(buf, "%s\n", session->targetalias);
3307                break;
3308        case ISCSI_PARAM_TPGT:
3309                len = sprintf(buf, "%d\n", session->tpgt);
3310                break;
3311        case ISCSI_PARAM_USERNAME:
3312                len = sprintf(buf, "%s\n", session->username);
3313                break;
3314        case ISCSI_PARAM_USERNAME_IN:
3315                len = sprintf(buf, "%s\n", session->username_in);
3316                break;
3317        case ISCSI_PARAM_PASSWORD:
3318                len = sprintf(buf, "%s\n", session->password);
3319                break;
3320        case ISCSI_PARAM_PASSWORD_IN:
3321                len = sprintf(buf, "%s\n", session->password_in);
3322                break;
3323        case ISCSI_PARAM_IFACE_NAME:
3324                len = sprintf(buf, "%s\n", session->ifacename);
3325                break;
3326        case ISCSI_PARAM_INITIATOR_NAME:
3327                len = sprintf(buf, "%s\n", session->initiatorname);
3328                break;
3329        default:
3330                return -ENOSYS;
3331        }
3332
3333        return len;
3334}
3335EXPORT_SYMBOL_GPL(iscsi_session_get_param);
3336
3337int iscsi_conn_get_addr_param(struct sockaddr_storage *addr,
3338                              enum iscsi_param param, char *buf)
3339{
3340        struct sockaddr_in6 *sin6 = NULL;
3341        struct sockaddr_in *sin = NULL;
3342        int len;
3343
3344        switch (addr->ss_family) {
3345        case AF_INET:
3346                sin = (struct sockaddr_in *)addr;
3347                break;
3348        case AF_INET6:
3349                sin6 = (struct sockaddr_in6 *)addr;
3350                break;
3351        default:
3352                return -EINVAL;
3353        }
3354
3355        switch (param) {
3356        case ISCSI_PARAM_CONN_ADDRESS:
3357        case ISCSI_HOST_PARAM_IPADDRESS:
3358                if (sin)
3359                        len = sprintf(buf, "%pI4\n", &sin->sin_addr.s_addr);
3360                else
3361                        len = sprintf(buf, "%pI6\n", &sin6->sin6_addr);
3362                break;
3363        case ISCSI_PARAM_CONN_PORT:
3364                if (sin)
3365                        len = sprintf(buf, "%hu\n", be16_to_cpu(sin->sin_port));
3366                else
3367                        len = sprintf(buf, "%hu\n",
3368                                      be16_to_cpu(sin6->sin6_port));
3369                break;
3370        default:
3371                return -EINVAL;
3372        }
3373
3374        return len;
3375}
3376EXPORT_SYMBOL_GPL(iscsi_conn_get_addr_param);
3377
3378int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
3379                         enum iscsi_param param, char *buf)
3380{
3381        struct iscsi_conn *conn = cls_conn->dd_data;
3382        int len;
3383
3384        switch(param) {
3385        case ISCSI_PARAM_PING_TMO:
3386                len = sprintf(buf, "%u\n", conn->ping_timeout);
3387                break;
3388        case ISCSI_PARAM_RECV_TMO:
3389                len = sprintf(buf, "%u\n", conn->recv_timeout);
3390                break;
3391        case ISCSI_PARAM_MAX_RECV_DLENGTH:
3392                len = sprintf(buf, "%u\n", conn->max_recv_dlength);
3393                break;
3394        case ISCSI_PARAM_MAX_XMIT_DLENGTH:
3395                len = sprintf(buf, "%u\n", conn->max_xmit_dlength);
3396                break;
3397        case ISCSI_PARAM_HDRDGST_EN:
3398                len = sprintf(buf, "%d\n", conn->hdrdgst_en);
3399                break;
3400        case ISCSI_PARAM_DATADGST_EN:
3401                len = sprintf(buf, "%d\n", conn->datadgst_en);
3402                break;
3403        case ISCSI_PARAM_IFMARKER_EN:
3404                len = sprintf(buf, "%d\n", conn->ifmarker_en);
3405                break;
3406        case ISCSI_PARAM_OFMARKER_EN:
3407                len = sprintf(buf, "%d\n", conn->ofmarker_en);
3408                break;
3409        case ISCSI_PARAM_EXP_STATSN:
3410                len = sprintf(buf, "%u\n", conn->exp_statsn);
3411                break;
3412        case ISCSI_PARAM_PERSISTENT_PORT:
3413                len = sprintf(buf, "%d\n", conn->persistent_port);
3414                break;
3415        case ISCSI_PARAM_PERSISTENT_ADDRESS:
3416                len = sprintf(buf, "%s\n", conn->persistent_address);
3417                break;
3418        default:
3419                return -ENOSYS;
3420        }
3421
3422        return len;
3423}
3424EXPORT_SYMBOL_GPL(iscsi_conn_get_param);
3425
3426int iscsi_host_get_param(struct Scsi_Host *shost, enum iscsi_host_param param,
3427                         char *buf)
3428{
3429        struct iscsi_host *ihost = shost_priv(shost);
3430        int len;
3431
3432        switch (param) {
3433        case ISCSI_HOST_PARAM_NETDEV_NAME:
3434                len = sprintf(buf, "%s\n", ihost->netdev);
3435                break;
3436        case ISCSI_HOST_PARAM_HWADDRESS:
3437                len = sprintf(buf, "%s\n", ihost->hwaddress);
3438                break;
3439        case ISCSI_HOST_PARAM_INITIATOR_NAME:
3440                len = sprintf(buf, "%s\n", ihost->initiatorname);
3441                break;
3442        default:
3443                return -ENOSYS;
3444        }
3445
3446        return len;
3447}
3448EXPORT_SYMBOL_GPL(iscsi_host_get_param);
3449
3450int iscsi_host_set_param(struct Scsi_Host *shost, enum iscsi_host_param param,
3451                         char *buf, int buflen)
3452{
3453        struct iscsi_host *ihost = shost_priv(shost);
3454
3455        switch (param) {
3456        case ISCSI_HOST_PARAM_NETDEV_NAME:
3457                return iscsi_switch_str_param(&ihost->netdev, buf);
3458        case ISCSI_HOST_PARAM_HWADDRESS:
3459                return iscsi_switch_str_param(&ihost->hwaddress, buf);
3460        case ISCSI_HOST_PARAM_INITIATOR_NAME:
3461                return iscsi_switch_str_param(&ihost->initiatorname, buf);
3462        default:
3463                return -ENOSYS;
3464        }
3465
3466        return 0;
3467}
3468EXPORT_SYMBOL_GPL(iscsi_host_set_param);
3469
3470MODULE_AUTHOR("Mike Christie");
3471MODULE_DESCRIPTION("iSCSI library functions");
3472MODULE_LICENSE("GPL");
3473
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