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                /* SCSI eh reuses commands to verify us */
 511                sc->SCp.ptr = NULL;
 512                /*
 513                 * queue command may call this to free the task, so
 514                 * it will decide how to return sc to scsi-ml.
 515                 */
 516                if (oldstate != ISCSI_TASK_REQUEUE_SCSIQ)
 517                        sc->scsi_done(sc);
 518        }
 519}
 520
 521void __iscsi_get_task(struct iscsi_task *task)
 522{
 523        atomic_inc(&task->refcount);
 524}
 525EXPORT_SYMBOL_GPL(__iscsi_get_task);
 526
 527void __iscsi_put_task(struct iscsi_task *task)
 528{
 529        if (atomic_dec_and_test(&task->refcount))
 530                iscsi_free_task(task);
 531}
 532EXPORT_SYMBOL_GPL(__iscsi_put_task);
 533
 534void iscsi_put_task(struct iscsi_task *task)
 535{
 536        struct iscsi_session *session = task->conn->session;
 537
 538        spin_lock_bh(&session->lock);
 539        __iscsi_put_task(task);
 540        spin_unlock_bh(&session->lock);
 541}
 542EXPORT_SYMBOL_GPL(iscsi_put_task);
 543
 544/**
 545 * iscsi_complete_task - finish a task
 546 * @task: iscsi cmd task
 547 * @state: state to complete task with
 548 *
 549 * Must be called with session lock.
 550 */
 551static void iscsi_complete_task(struct iscsi_task *task, int state)
 552{
 553        struct iscsi_conn *conn = task->conn;
 554
 555        ISCSI_DBG_SESSION(conn->session,
 556                          "complete task itt 0x%x state %d sc %p\n",
 557                          task->itt, task->state, task->sc);
 558        if (task->state == ISCSI_TASK_COMPLETED ||
 559            task->state == ISCSI_TASK_ABRT_TMF ||
 560            task->state == ISCSI_TASK_ABRT_SESS_RECOV ||
 561            task->state == ISCSI_TASK_REQUEUE_SCSIQ)
 562                return;
 563        WARN_ON_ONCE(task->state == ISCSI_TASK_FREE);
 564        task->state = state;
 565
 566        if (!list_empty(&task->running))
 567                list_del_init(&task->running);
 568
 569        if (conn->task == task)
 570                conn->task = NULL;
 571
 572        if (conn->ping_task == task)
 573                conn->ping_task = NULL;
 574
 575        /* release get from queueing */
 576        __iscsi_put_task(task);
 577}
 578
 579/**
 580 * iscsi_complete_scsi_task - finish scsi task normally
 581 * @task: iscsi task for scsi cmd
 582 * @exp_cmdsn: expected cmd sn in cpu format
 583 * @max_cmdsn: max cmd sn in cpu format
 584 *
 585 * This is used when drivers do not need or cannot perform
 586 * lower level pdu processing.
 587 *
 588 * Called with session lock
 589 */
 590void iscsi_complete_scsi_task(struct iscsi_task *task,
 591                              uint32_t exp_cmdsn, uint32_t max_cmdsn)
 592{
 593        struct iscsi_conn *conn = task->conn;
 594
 595        ISCSI_DBG_SESSION(conn->session, "[itt 0x%x]\n", task->itt);
 596
 597        conn->last_recv = jiffies;
 598        __iscsi_update_cmdsn(conn->session, exp_cmdsn, max_cmdsn);
 599        iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
 600}
 601EXPORT_SYMBOL_GPL(iscsi_complete_scsi_task);
 602
 603
 604/*
 605 * session lock must be held and if not called for a task that is
 606 * still pending or from the xmit thread, then xmit thread must
 607 * be suspended.
 608 */
 609static void fail_scsi_task(struct iscsi_task *task, int err)
 610{
 611        struct iscsi_conn *conn = task->conn;
 612        struct scsi_cmnd *sc;
 613        int state;
 614
 615        /*
 616         * if a command completes and we get a successful tmf response
 617         * we will hit this because the scsi eh abort code does not take
 618         * a ref to the task.
 619         */
 620        sc = task->sc;
 621        if (!sc)
 622                return;
 623
 624        if (task->state == ISCSI_TASK_PENDING) {
 625                /*
 626                 * cmd never made it to the xmit thread, so we should not count
 627                 * the cmd in the sequencing
 628                 */
 629                conn->session->queued_cmdsn--;
 630                /* it was never sent so just complete like normal */
 631                state = ISCSI_TASK_COMPLETED;
 632        } else if (err == DID_TRANSPORT_DISRUPTED)
 633                state = ISCSI_TASK_ABRT_SESS_RECOV;
 634        else
 635                state = ISCSI_TASK_ABRT_TMF;
 636
 637        sc->result = err << 16;
 638        if (!scsi_bidi_cmnd(sc))
 639                scsi_set_resid(sc, scsi_bufflen(sc));
 640        else {
 641                scsi_out(sc)->resid = scsi_out(sc)->length;
 642                scsi_in(sc)->resid = scsi_in(sc)->length;
 643        }
 644
 645        iscsi_complete_task(task, state);
 646}
 647
 648static int iscsi_prep_mgmt_task(struct iscsi_conn *conn,
 649                                struct iscsi_task *task)
 650{
 651        struct iscsi_session *session = conn->session;
 652        struct iscsi_hdr *hdr = task->hdr;
 653        struct iscsi_nopout *nop = (struct iscsi_nopout *)hdr;
 654        uint8_t opcode = hdr->opcode & ISCSI_OPCODE_MASK;
 655
 656        if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
 657                return -ENOTCONN;
 658
 659        if (opcode != ISCSI_OP_LOGIN && opcode != ISCSI_OP_TEXT)
 660                nop->exp_statsn = cpu_to_be32(conn->exp_statsn);
 661        /*
 662         * pre-format CmdSN for outgoing PDU.
 663         */
 664        nop->cmdsn = cpu_to_be32(session->cmdsn);
 665        if (hdr->itt != RESERVED_ITT) {
 666                /*
 667                 * TODO: We always use immediate for normal session pdus.
 668                 * If we start to send tmfs or nops as non-immediate then
 669                 * we should start checking the cmdsn numbers for mgmt tasks.
 670                 *
 671                 * During discovery sessions iscsid sends TEXT as non immediate,
 672                 * but we always only send one PDU at a time.
 673                 */
 674                if (conn->c_stage == ISCSI_CONN_STARTED &&
 675                    !(hdr->opcode & ISCSI_OP_IMMEDIATE)) {
 676                        session->queued_cmdsn++;
 677                        session->cmdsn++;
 678                }
 679        }
 680
 681        if (session->tt->init_task && session->tt->init_task(task))
 682                return -EIO;
 683
 684        if ((hdr->opcode & ISCSI_OPCODE_MASK) == ISCSI_OP_LOGOUT)
 685                session->state = ISCSI_STATE_LOGGING_OUT;
 686
 687        task->state = ISCSI_TASK_RUNNING;
 688        ISCSI_DBG_SESSION(session, "mgmtpdu [op 0x%x hdr->itt 0x%x "
 689                          "datalen %d]\n", hdr->opcode & ISCSI_OPCODE_MASK,
 690                          hdr->itt, task->data_count);
 691        return 0;
 692}
 693
 694static struct iscsi_task *
 695__iscsi_conn_send_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 696                      char *data, uint32_t data_size)
 697{
 698        struct iscsi_session *session = conn->session;
 699        struct iscsi_host *ihost = shost_priv(session->host);
 700        uint8_t opcode = hdr->opcode & ISCSI_OPCODE_MASK;
 701        struct iscsi_task *task;
 702        itt_t itt;
 703
 704        if (session->state == ISCSI_STATE_TERMINATE)
 705                return NULL;
 706
 707        if (opcode == ISCSI_OP_LOGIN || opcode == ISCSI_OP_TEXT) {
 708                /*
 709                 * Login and Text are sent serially, in
 710                 * request-followed-by-response sequence.
 711                 * Same task can be used. Same ITT must be used.
 712                 * Note that login_task is preallocated at conn_create().
 713                 */
 714                if (conn->login_task->state != ISCSI_TASK_FREE) {
 715                        iscsi_conn_printk(KERN_ERR, conn, "Login/Text in "
 716                                          "progress. Cannot start new task.\n");
 717                        return NULL;
 718                }
 719
 720                task = conn->login_task;
 721        } else {
 722                if (session->state != ISCSI_STATE_LOGGED_IN)
 723                        return NULL;
 724
 725                BUG_ON(conn->c_stage == ISCSI_CONN_INITIAL_STAGE);
 726                BUG_ON(conn->c_stage == ISCSI_CONN_STOPPED);
 727
 728                if (!kfifo_out(&session->cmdpool.queue,
 729                                 (void*)&task, sizeof(void*)))
 730                        return NULL;
 731        }
 732        /*
 733         * released in complete pdu for task we expect a response for, and
 734         * released by the lld when it has transmitted the task for
 735         * pdus we do not expect a response for.
 736         */
 737        atomic_set(&task->refcount, 1);
 738        task->conn = conn;
 739        task->sc = NULL;
 740        INIT_LIST_HEAD(&task->running);
 741        task->state = ISCSI_TASK_PENDING;
 742
 743        if (data_size) {
 744                memcpy(task->data, data, data_size);
 745                task->data_count = data_size;
 746        } else
 747                task->data_count = 0;
 748
 749        if (conn->session->tt->alloc_pdu) {
 750                if (conn->session->tt->alloc_pdu(task, hdr->opcode)) {
 751                        iscsi_conn_printk(KERN_ERR, conn, "Could not allocate "
 752                                         "pdu for mgmt task.\n");
 753                        goto free_task;
 754                }
 755        }
 756
 757        itt = task->hdr->itt;
 758        task->hdr_len = sizeof(struct iscsi_hdr);
 759        memcpy(task->hdr, hdr, sizeof(struct iscsi_hdr));
 760
 761        if (hdr->itt != RESERVED_ITT) {
 762                if (session->tt->parse_pdu_itt)
 763                        task->hdr->itt = itt;
 764                else
 765                        task->hdr->itt = build_itt(task->itt,
 766                                                   task->conn->session->age);
 767        }
 768
 769        if (!ihost->workq) {
 770                if (iscsi_prep_mgmt_task(conn, task))
 771                        goto free_task;
 772
 773                if (session->tt->xmit_task(task))
 774                        goto free_task;
 775        } else {
 776                list_add_tail(&task->running, &conn->mgmtqueue);
 777                iscsi_conn_queue_work(conn);
 778        }
 779
 780        return task;
 781
 782free_task:
 783        __iscsi_put_task(task);
 784        return NULL;
 785}
 786
 787int iscsi_conn_send_pdu(struct iscsi_cls_conn *cls_conn, struct iscsi_hdr *hdr,
 788                        char *data, uint32_t data_size)
 789{
 790        struct iscsi_conn *conn = cls_conn->dd_data;
 791        struct iscsi_session *session = conn->session;
 792        int err = 0;
 793
 794        spin_lock_bh(&session->lock);
 795        if (!__iscsi_conn_send_pdu(conn, hdr, data, data_size))
 796                err = -EPERM;
 797        spin_unlock_bh(&session->lock);
 798        return err;
 799}
 800EXPORT_SYMBOL_GPL(iscsi_conn_send_pdu);
 801
 802/**
 803 * iscsi_cmd_rsp - SCSI Command Response processing
 804 * @conn: iscsi connection
 805 * @hdr: iscsi header
 806 * @task: scsi command task
 807 * @data: cmd data buffer
 808 * @datalen: len of buffer
 809 *
 810 * iscsi_cmd_rsp sets up the scsi_cmnd fields based on the PDU and
 811 * then completes the command and task.
 812 **/
 813static void iscsi_scsi_cmd_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 814                               struct iscsi_task *task, char *data,
 815                               int datalen)
 816{
 817        struct iscsi_scsi_rsp *rhdr = (struct iscsi_scsi_rsp *)hdr;
 818        struct iscsi_session *session = conn->session;
 819        struct scsi_cmnd *sc = task->sc;
 820
 821        iscsi_update_cmdsn(session, (struct iscsi_nopin*)rhdr);
 822        conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
 823
 824        sc->result = (DID_OK << 16) | rhdr->cmd_status;
 825
 826        if (rhdr->response != ISCSI_STATUS_CMD_COMPLETED) {
 827                sc->result = DID_ERROR << 16;
 828                goto out;
 829        }
 830
 831        if (rhdr->cmd_status == SAM_STAT_CHECK_CONDITION) {
 832                uint16_t senselen;
 833
 834                if (datalen < 2) {
 835invalid_datalen:
 836                        iscsi_conn_printk(KERN_ERR,  conn,
 837                                         "Got CHECK_CONDITION but invalid data "
 838                                         "buffer size of %d\n", datalen);
 839                        sc->result = DID_BAD_TARGET << 16;
 840                        goto out;
 841                }
 842
 843                senselen = get_unaligned_be16(data);
 844                if (datalen < senselen)
 845                        goto invalid_datalen;
 846
 847                memcpy(sc->sense_buffer, data + 2,
 848                       min_t(uint16_t, senselen, SCSI_SENSE_BUFFERSIZE));
 849                ISCSI_DBG_SESSION(session, "copied %d bytes of sense\n",
 850                                  min_t(uint16_t, senselen,
 851                                  SCSI_SENSE_BUFFERSIZE));
 852        }
 853
 854        if (rhdr->flags & (ISCSI_FLAG_CMD_BIDI_UNDERFLOW |
 855                           ISCSI_FLAG_CMD_BIDI_OVERFLOW)) {
 856                int res_count = be32_to_cpu(rhdr->bi_residual_count);
 857
 858                if (scsi_bidi_cmnd(sc) && res_count > 0 &&
 859                                (rhdr->flags & ISCSI_FLAG_CMD_BIDI_OVERFLOW ||
 860                                 res_count <= scsi_in(sc)->length))
 861                        scsi_in(sc)->resid = res_count;
 862                else
 863                        sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 864        }
 865
 866        if (rhdr->flags & (ISCSI_FLAG_CMD_UNDERFLOW |
 867                           ISCSI_FLAG_CMD_OVERFLOW)) {
 868                int res_count = be32_to_cpu(rhdr->residual_count);
 869
 870                if (res_count > 0 &&
 871                    (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
 872                     res_count <= scsi_bufflen(sc)))
 873                        /* write side for bidi or uni-io set_resid */
 874                        scsi_set_resid(sc, res_count);
 875                else
 876                        sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 877        }
 878out:
 879        ISCSI_DBG_SESSION(session, "cmd rsp done [sc %p res %d itt 0x%x]\n",
 880                          sc, sc->result, task->itt);
 881        conn->scsirsp_pdus_cnt++;
 882        iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
 883}
 884
 885/**
 886 * iscsi_data_in_rsp - SCSI Data-In Response processing
 887 * @conn: iscsi connection
 888 * @hdr:  iscsi pdu
 889 * @task: scsi command task
 890 **/
 891static void
 892iscsi_data_in_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 893                  struct iscsi_task *task)
 894{
 895        struct iscsi_data_rsp *rhdr = (struct iscsi_data_rsp *)hdr;
 896        struct scsi_cmnd *sc = task->sc;
 897
 898        if (!(rhdr->flags & ISCSI_FLAG_DATA_STATUS))
 899                return;
 900
 901        iscsi_update_cmdsn(conn->session, (struct iscsi_nopin *)hdr);
 902        sc->result = (DID_OK << 16) | rhdr->cmd_status;
 903        conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
 904        if (rhdr->flags & (ISCSI_FLAG_DATA_UNDERFLOW |
 905                           ISCSI_FLAG_DATA_OVERFLOW)) {
 906                int res_count = be32_to_cpu(rhdr->residual_count);
 907
 908                if (res_count > 0 &&
 909                    (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
 910                     res_count <= scsi_in(sc)->length))
 911                        scsi_in(sc)->resid = res_count;
 912                else
 913                        sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 914        }
 915
 916        ISCSI_DBG_SESSION(conn->session, "data in with status done "
 917                          "[sc %p res %d itt 0x%x]\n",
 918                          sc, sc->result, task->itt);
 919        conn->scsirsp_pdus_cnt++;
 920        iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
 921}
 922
 923static void iscsi_tmf_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr)
 924{
 925        struct iscsi_tm_rsp *tmf = (struct iscsi_tm_rsp *)hdr;
 926
 927        conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
 928        conn->tmfrsp_pdus_cnt++;
 929
 930        if (conn->tmf_state != TMF_QUEUED)
 931                return;
 932
 933        if (tmf->response == ISCSI_TMF_RSP_COMPLETE)
 934                conn->tmf_state = TMF_SUCCESS;
 935        else if (tmf->response == ISCSI_TMF_RSP_NO_TASK)
 936                conn->tmf_state = TMF_NOT_FOUND;
 937        else
 938                conn->tmf_state = TMF_FAILED;
 939        wake_up(&conn->ehwait);
 940}
 941
 942static void iscsi_send_nopout(struct iscsi_conn *conn, struct iscsi_nopin *rhdr)
 943{
 944        struct iscsi_nopout hdr;
 945        struct iscsi_task *task;
 946
 947        if (!rhdr && conn->ping_task)
 948                return;
 949
 950        memset(&hdr, 0, sizeof(struct iscsi_nopout));
 951        hdr.opcode = ISCSI_OP_NOOP_OUT | ISCSI_OP_IMMEDIATE;
 952        hdr.flags = ISCSI_FLAG_CMD_FINAL;
 953
 954        if (rhdr) {
 955                hdr.lun = rhdr->lun;
 956                hdr.ttt = rhdr->ttt;
 957                hdr.itt = RESERVED_ITT;
 958        } else
 959                hdr.ttt = RESERVED_ITT;
 960
 961        task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)&hdr, NULL, 0);
 962        if (!task)
 963                iscsi_conn_printk(KERN_ERR, conn, "Could not send nopout\n");
 964        else if (!rhdr) {
 965                /* only track our nops */
 966                conn->ping_task = task;
 967                conn->last_ping = jiffies;
 968        }
 969}
 970
 971static int iscsi_nop_out_rsp(struct iscsi_task *task,
 972                             struct iscsi_nopin *nop, char *data, int datalen)
 973{
 974        struct iscsi_conn *conn = task->conn;
 975        int rc = 0;
 976
 977        if (conn->ping_task != task) {
 978                /*
 979                 * If this is not in response to one of our
 980                 * nops then it must be from userspace.
 981                 */
 982                if (iscsi_recv_pdu(conn->cls_conn, (struct iscsi_hdr *)nop,
 983                                   data, datalen))
 984                        rc = ISCSI_ERR_CONN_FAILED;
 985        } else
 986                mod_timer(&conn->transport_timer, jiffies + conn->recv_timeout);
 987        iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
 988        return rc;
 989}
 990
 991static int iscsi_handle_reject(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 992                               char *data, int datalen)
 993{
 994        struct iscsi_reject *reject = (struct iscsi_reject *)hdr;
 995        struct iscsi_hdr rejected_pdu;
 996        int opcode, rc = 0;
 997
 998        conn->exp_statsn = be32_to_cpu(reject->statsn) + 1;
 999
1000        if (ntoh24(reject->dlength) > datalen ||
1001            ntoh24(reject->dlength) < sizeof(struct iscsi_hdr)) {
1002                iscsi_conn_printk(KERN_ERR, conn, "Cannot handle rejected "
1003                                  "pdu. Invalid data length (pdu dlength "
1004                                  "%u, datalen %d\n", ntoh24(reject->dlength),
1005                                  datalen);
1006                return ISCSI_ERR_PROTO;
1007        }
1008        memcpy(&rejected_pdu, data, sizeof(struct iscsi_hdr));
1009        opcode = rejected_pdu.opcode & ISCSI_OPCODE_MASK;
1010
1011        switch (reject->reason) {
1012        case ISCSI_REASON_DATA_DIGEST_ERROR:
1013                iscsi_conn_printk(KERN_ERR, conn,
1014                                  "pdu (op 0x%x itt 0x%x) rejected "
1015                                  "due to DataDigest error.\n",
1016                                  rejected_pdu.itt, opcode);
1017                break;
1018        case ISCSI_REASON_IMM_CMD_REJECT:
1019                iscsi_conn_printk(KERN_ERR, conn,
1020                                  "pdu (op 0x%x itt 0x%x) rejected. Too many "
1021                                  "immediate commands.\n",
1022                                  rejected_pdu.itt, opcode);
1023                /*
1024                 * We only send one TMF at a time so if the target could not
1025                 * handle it, then it should get fixed (RFC mandates that
1026                 * a target can handle one immediate TMF per conn).
1027                 *
1028                 * For nops-outs, we could have sent more than one if
1029                 * the target is sending us lots of nop-ins
1030                 */
1031                if (opcode != ISCSI_OP_NOOP_OUT)
1032                        return 0;
1033
1034                 if (rejected_pdu.itt == cpu_to_be32(ISCSI_RESERVED_TAG))
1035                        /*
1036                         * nop-out in response to target's nop-out rejected.
1037                         * Just resend.
1038                         */
1039                        iscsi_send_nopout(conn,
1040                                          (struct iscsi_nopin*)&rejected_pdu);
1041                else {
1042                        struct iscsi_task *task;
1043                        /*
1044                         * Our nop as ping got dropped. We know the target
1045                         * and transport are ok so just clean up
1046                         */
1047                        task = iscsi_itt_to_task(conn, rejected_pdu.itt);
1048                        if (!task) {
1049                                iscsi_conn_printk(KERN_ERR, conn,
1050                                                 "Invalid pdu reject. Could "
1051                                                 "not lookup rejected task.\n");
1052                                rc = ISCSI_ERR_BAD_ITT;
1053                        } else
1054                                rc = iscsi_nop_out_rsp(task,
1055                                        (struct iscsi_nopin*)&rejected_pdu,
1056                                        NULL, 0);
1057                }
1058                break;
1059        default:
1060                iscsi_conn_printk(KERN_ERR, conn,
1061                                  "pdu (op 0x%x itt 0x%x) rejected. Reason "
1062                                  "code 0x%x\n", rejected_pdu.itt,
1063                                  rejected_pdu.opcode, reject->reason);
1064                break;
1065        }
1066        return rc;
1067}
1068
1069/**
1070 * iscsi_itt_to_task - look up task by itt
1071 * @conn: iscsi connection
1072 * @itt: itt
1073 *
1074 * This should be used for mgmt tasks like login and nops, or if
1075 * the LDD's itt space does not include the session age.
1076 *
1077 * The session lock must be held.
1078 */
1079struct iscsi_task *iscsi_itt_to_task(struct iscsi_conn *conn, itt_t itt)
1080{
1081        struct iscsi_session *session = conn->session;
1082        int i;
1083
1084        if (itt == RESERVED_ITT)
1085                return NULL;
1086
1087        if (session->tt->parse_pdu_itt)
1088                session->tt->parse_pdu_itt(conn, itt, &i, NULL);
1089        else
1090                i = get_itt(itt);
1091        if (i >= session->cmds_max)
1092                return NULL;
1093
1094        return session->cmds[i];
1095}
1096EXPORT_SYMBOL_GPL(iscsi_itt_to_task);
1097
1098/**
1099 * __iscsi_complete_pdu - complete pdu
1100 * @conn: iscsi conn
1101 * @hdr: iscsi header
1102 * @data: data buffer
1103 * @datalen: len of data buffer
1104 *
1105 * Completes pdu processing by freeing any resources allocated at
1106 * queuecommand or send generic. session lock must be held and verify
1107 * itt must have been called.
1108 */
1109int __iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1110                         char *data, int datalen)
1111{
1112        struct iscsi_session *session = conn->session;
1113        int opcode = hdr->opcode & ISCSI_OPCODE_MASK, rc = 0;
1114        struct iscsi_task *task;
1115        uint32_t itt;
1116
1117        conn->last_recv = jiffies;
1118        rc = iscsi_verify_itt(conn, hdr->itt);
1119        if (rc)
1120                return rc;
1121
1122        if (hdr->itt != RESERVED_ITT)
1123                itt = get_itt(hdr->itt);
1124        else
1125                itt = ~0U;
1126
1127        ISCSI_DBG_SESSION(session, "[op 0x%x cid %d itt 0x%x len %d]\n",
1128                          opcode, conn->id, itt, datalen);
1129
1130        if (itt == ~0U) {
1131                iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1132
1133                switch(opcode) {
1134                case ISCSI_OP_NOOP_IN:
1135                        if (datalen) {
1136                                rc = ISCSI_ERR_PROTO;
1137                                break;
1138                        }
1139
1140                        if (hdr->ttt == cpu_to_be32(ISCSI_RESERVED_TAG))
1141                                break;
1142
1143                        iscsi_send_nopout(conn, (struct iscsi_nopin*)hdr);
1144                        break;
1145                case ISCSI_OP_REJECT:
1146                        rc = iscsi_handle_reject(conn, hdr, data, datalen);
1147                        break;
1148                case ISCSI_OP_ASYNC_EVENT:
1149                        conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1150                        if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
1151                                rc = ISCSI_ERR_CONN_FAILED;
1152                        break;
1153                default:
1154                        rc = ISCSI_ERR_BAD_OPCODE;
1155                        break;
1156                }
1157                goto out;
1158        }
1159
1160        switch(opcode) {
1161        case ISCSI_OP_SCSI_CMD_RSP:
1162        case ISCSI_OP_SCSI_DATA_IN:
1163                task = iscsi_itt_to_ctask(conn, hdr->itt);
1164                if (!task)
1165                        return ISCSI_ERR_BAD_ITT;
1166                task->last_xfer = jiffies;
1167                break;
1168        case ISCSI_OP_R2T:
1169                /*
1170                 * LLD handles R2Ts if they need to.
1171                 */
1172                return 0;
1173        case ISCSI_OP_LOGOUT_RSP:
1174        case ISCSI_OP_LOGIN_RSP:
1175        case ISCSI_OP_TEXT_RSP:
1176        case ISCSI_OP_SCSI_TMFUNC_RSP:
1177        case ISCSI_OP_NOOP_IN:
1178                task = iscsi_itt_to_task(conn, hdr->itt);
1179                if (!task)
1180                        return ISCSI_ERR_BAD_ITT;
1181                break;
1182        default:
1183                return ISCSI_ERR_BAD_OPCODE;
1184        }
1185
1186        switch(opcode) {
1187        case ISCSI_OP_SCSI_CMD_RSP:
1188                iscsi_scsi_cmd_rsp(conn, hdr, task, data, datalen);
1189                break;
1190        case ISCSI_OP_SCSI_DATA_IN:
1191                iscsi_data_in_rsp(conn, hdr, task);
1192                break;
1193        case ISCSI_OP_LOGOUT_RSP:
1194                iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1195                if (datalen) {
1196                        rc = ISCSI_ERR_PROTO;
1197                        break;
1198                }
1199                conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1200                goto recv_pdu;
1201        case ISCSI_OP_LOGIN_RSP:
1202        case ISCSI_OP_TEXT_RSP:
1203                iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1204                /*
1205                 * login related PDU's exp_statsn is handled in
1206                 * userspace
1207                 */
1208                goto recv_pdu;
1209        case ISCSI_OP_SCSI_TMFUNC_RSP:
1210                iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1211                if (datalen) {
1212                        rc = ISCSI_ERR_PROTO;
1213                        break;
1214                }
1215
1216                iscsi_tmf_rsp(conn, hdr);
1217                iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1218                break;
1219        case ISCSI_OP_NOOP_IN:
1220                iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1221                if (hdr->ttt != cpu_to_be32(ISCSI_RESERVED_TAG) || datalen) {
1222                        rc = ISCSI_ERR_PROTO;
1223                        break;
1224                }
1225                conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1226
1227                rc = iscsi_nop_out_rsp(task, (struct iscsi_nopin*)hdr,
1228                                       data, datalen);
1229                break;
1230        default:
1231                rc = ISCSI_ERR_BAD_OPCODE;
1232                break;
1233        }
1234
1235out:
1236        return rc;
1237recv_pdu:
1238        if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
1239                rc = ISCSI_ERR_CONN_FAILED;
1240        iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1241        return rc;
1242}
1243EXPORT_SYMBOL_GPL(__iscsi_complete_pdu);
1244
1245int iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1246                       char *data, int datalen)
1247{
1248        int rc;
1249
1250        spin_lock(&conn->session->lock);
1251        rc = __iscsi_complete_pdu(conn, hdr, data, datalen);
1252        spin_unlock(&conn->session->lock);
1253        return rc;
1254}
1255EXPORT_SYMBOL_GPL(iscsi_complete_pdu);
1256
1257int iscsi_verify_itt(struct iscsi_conn *conn, itt_t itt)
1258{
1259        struct iscsi_session *session = conn->session;
1260        int age = 0, i = 0;
1261
1262        if (itt == RESERVED_ITT)
1263                return 0;
1264
1265        if (session->tt->parse_pdu_itt)
1266                session->tt->parse_pdu_itt(conn, itt, &i, &age);
1267        else {
1268                i = get_itt(itt);
1269                age = ((__force u32)itt >> ISCSI_AGE_SHIFT) & ISCSI_AGE_MASK;
1270        }
1271
1272        if (age != session->age) {
1273                iscsi_conn_printk(KERN_ERR, conn,
1274                                  "received itt %x expected session age (%x)\n",
1275                                  (__force u32)itt, session->age);
1276                return ISCSI_ERR_BAD_ITT;
1277        }
1278
1279        if (i >= session->cmds_max) {
1280                iscsi_conn_printk(KERN_ERR, conn,
1281                                  "received invalid itt index %u (max cmds "
1282                                   "%u.\n", i, session->cmds_max);
1283                return ISCSI_ERR_BAD_ITT;
1284        }
1285        return 0;
1286}
1287EXPORT_SYMBOL_GPL(iscsi_verify_itt);
1288
1289/**
1290 * iscsi_itt_to_ctask - look up ctask by itt
1291 * @conn: iscsi connection
1292 * @itt: itt
1293 *
1294 * This should be used for cmd tasks.
1295 *
1296 * The session lock must be held.
1297 */
1298struct iscsi_task *iscsi_itt_to_ctask(struct iscsi_conn *conn, itt_t itt)
1299{
1300        struct iscsi_task *task;
1301
1302        if (iscsi_verify_itt(conn, itt))
1303                return NULL;
1304
1305        task = iscsi_itt_to_task(conn, itt);
1306        if (!task || !task->sc)
1307                return NULL;
1308
1309        if (task->sc->SCp.phase != conn->session->age) {
1310                iscsi_session_printk(KERN_ERR, conn->session,
1311                                  "task's session age %d, expected %d\n",
1312                                  task->sc->SCp.phase, conn->session->age);
1313                return NULL;
1314        }
1315
1316        return task;
1317}
1318EXPORT_SYMBOL_GPL(iscsi_itt_to_ctask);
1319
1320void iscsi_session_failure(struct iscsi_session *session,
1321                           enum iscsi_err err)
1322{
1323        struct iscsi_conn *conn;
1324        struct device *dev;
1325
1326        spin_lock_bh(&session->lock);
1327        conn = session->leadconn;
1328        if (session->state == ISCSI_STATE_TERMINATE || !conn) {
1329                spin_unlock_bh(&session->lock);
1330                return;
1331        }
1332
1333        dev = get_device(&conn->cls_conn->dev);
1334        spin_unlock_bh(&session->lock);
1335        if (!dev)
1336                return;
1337        /*
1338         * if the host is being removed bypass the connection
1339         * recovery initialization because we are going to kill
1340         * the session.
1341         */
1342        if (err == ISCSI_ERR_INVALID_HOST)
1343                iscsi_conn_error_event(conn->cls_conn, err);
1344        else
1345                iscsi_conn_failure(conn, err);
1346        put_device(dev);
1347}
1348EXPORT_SYMBOL_GPL(iscsi_session_failure);
1349
1350void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err)
1351{
1352        struct iscsi_session *session = conn->session;
1353
1354        spin_lock_bh(&session->lock);
1355        if (session->state == ISCSI_STATE_FAILED) {
1356                spin_unlock_bh(&session->lock);
1357                return;
1358        }
1359
1360        if (conn->stop_stage == 0)
1361                session->state = ISCSI_STATE_FAILED;
1362        spin_unlock_bh(&session->lock);
1363
1364        set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1365        set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
1366        iscsi_conn_error_event(conn->cls_conn, err);
1367}
1368EXPORT_SYMBOL_GPL(iscsi_conn_failure);
1369
1370static int iscsi_check_cmdsn_window_closed(struct iscsi_conn *conn)
1371{
1372        struct iscsi_session *session = conn->session;
1373
1374        /*
1375         * Check for iSCSI window and take care of CmdSN wrap-around
1376         */
1377        if (!iscsi_sna_lte(session->queued_cmdsn, session->max_cmdsn)) {
1378                ISCSI_DBG_SESSION(session, "iSCSI CmdSN closed. ExpCmdSn "
1379                                  "%u MaxCmdSN %u CmdSN %u/%u\n",
1380                                  session->exp_cmdsn, session->max_cmdsn,
1381                                  session->cmdsn, session->queued_cmdsn);
1382                return -ENOSPC;
1383        }
1384        return 0;
1385}
1386
1387static int iscsi_xmit_task(struct iscsi_conn *conn)
1388{
1389        struct iscsi_task *task = conn->task;
1390        int rc;
1391
1392        if (test_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx))
1393                return -ENODATA;
1394
1395        __iscsi_get_task(task);
1396        spin_unlock_bh(&conn->session->lock);
1397        rc = conn->session->tt->xmit_task(task);
1398        spin_lock_bh(&conn->session->lock);
1399        if (!rc) {
1400                /* done with this task */
1401                task->last_xfer = jiffies;
1402                conn->task = NULL;
1403        }
1404        __iscsi_put_task(task);
1405        return rc;
1406}
1407
1408/**
1409 * iscsi_requeue_task - requeue task to run from session workqueue
1410 * @task: task to requeue
1411 *
1412 * LLDs that need to run a task from the session workqueue should call
1413 * this. The session lock must be held. This should only be called
1414 * by software drivers.
1415 */
1416void iscsi_requeue_task(struct iscsi_task *task)
1417{
1418        struct iscsi_conn *conn = task->conn;
1419
1420        /*
1421         * this may be on the requeue list already if the xmit_task callout
1422         * is handling the r2ts while we are adding new ones
1423         */
1424        if (list_empty(&task->running))
1425                list_add_tail(&task->running, &conn->requeue);
1426        iscsi_conn_queue_work(conn);
1427}
1428EXPORT_SYMBOL_GPL(iscsi_requeue_task);
1429
1430/**
1431 * iscsi_data_xmit - xmit any command into the scheduled connection
1432 * @conn: iscsi connection
1433 *
1434 * Notes:
1435 *      The function can return -EAGAIN in which case the caller must
1436 *      re-schedule it again later or recover. '0' return code means
1437 *      successful xmit.
1438 **/
1439static int iscsi_data_xmit(struct iscsi_conn *conn)
1440{
1441        struct iscsi_task *task;
1442        int rc = 0;
1443
1444        spin_lock_bh(&conn->session->lock);
1445        if (test_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx)) {
1446                ISCSI_DBG_SESSION(conn->session, "Tx suspended!\n");
1447                spin_unlock_bh(&conn->session->lock);
1448                return -ENODATA;
1449        }
1450
1451        if (conn->task) {
1452                rc = iscsi_xmit_task(conn);
1453                if (rc)
1454                        goto done;
1455        }
1456
1457        /*
1458         * process mgmt pdus like nops before commands since we should
1459         * only have one nop-out as a ping from us and targets should not
1460         * overflow us with nop-ins
1461         */
1462check_mgmt:
1463        while (!list_empty(&conn->mgmtqueue)) {
1464                conn->task = list_entry(conn->mgmtqueue.next,
1465                                         struct iscsi_task, running);
1466                list_del_init(&conn->task->running);
1467                if (iscsi_prep_mgmt_task(conn, conn->task)) {
1468                        __iscsi_put_task(conn->task);
1469                        conn->task = NULL;
1470                        continue;
1471                }
1472                rc = iscsi_xmit_task(conn);
1473                if (rc)
1474                        goto done;
1475        }
1476
1477        /* process pending command queue */
1478        while (!list_empty(&conn->cmdqueue)) {
1479                conn->task = list_entry(conn->cmdqueue.next, struct iscsi_task,
1480                                        running);
1481                list_del_init(&conn->task->running);
1482                if (conn->session->state == ISCSI_STATE_LOGGING_OUT) {
1483                        fail_scsi_task(conn->task, DID_IMM_RETRY);
1484                        continue;
1485                }
1486                rc = iscsi_prep_scsi_cmd_pdu(conn->task);
1487                if (rc) {
1488                        if (rc == -ENOMEM || rc == -EACCES) {
1489                                list_add_tail(&conn->task->running,
1490                                              &conn->cmdqueue);
1491                                conn->task = NULL;
1492                                goto done;
1493                        } else
1494                                fail_scsi_task(conn->task, DID_ABORT);
1495                        continue;
1496                }
1497                rc = iscsi_xmit_task(conn);
1498                if (rc)
1499                        goto done;
1500                /*
1501                 * we could continuously get new task requests so
1502                 * we need to check the mgmt queue for nops that need to
1503                 * be sent to aviod starvation
1504                 */
1505                if (!list_empty(&conn->mgmtqueue))
1506                        goto check_mgmt;
1507        }
1508
1509        while (!list_empty(&conn->requeue)) {
1510                /*
1511                 * we always do fastlogout - conn stop code will clean up.
1512                 */
1513                if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
1514                        break;
1515
1516                task = list_entry(conn->requeue.next, struct iscsi_task,
1517                                  running);
1518                if (iscsi_check_tmf_restrictions(task, ISCSI_OP_SCSI_DATA_OUT))
1519                        break;
1520
1521                conn->task = task;
1522                list_del_init(&conn->task->running);
1523                conn->task->state = ISCSI_TASK_RUNNING;
1524                rc = iscsi_xmit_task(conn);
1525                if (rc)
1526                        goto done;
1527                if (!list_empty(&conn->mgmtqueue))
1528                        goto check_mgmt;
1529        }
1530        spin_unlock_bh(&conn->session->lock);
1531        return -ENODATA;
1532
1533done:
1534        spin_unlock_bh(&conn->session->lock);
1535        return rc;
1536}
1537
1538static void iscsi_xmitworker(struct work_struct *work)
1539{
1540        struct iscsi_conn *conn =
1541                container_of(work, struct iscsi_conn, xmitwork);
1542        int rc;
1543        /*
1544         * serialize Xmit worker on a per-connection basis.
1545         */
1546        do {
1547                rc = iscsi_data_xmit(conn);
1548        } while (rc >= 0 || rc == -EAGAIN);
1549}
1550
1551static inline struct iscsi_task *iscsi_alloc_task(struct iscsi_conn *conn,
1552                                                  struct scsi_cmnd *sc)
1553{
1554        struct iscsi_task *task;
1555
1556        if (!kfifo_out(&conn->session->cmdpool.queue,
1557                         (void *) &task, sizeof(void *)))
1558                return NULL;
1559
1560        sc->SCp.phase = conn->session->age;
1561        sc->SCp.ptr = (char *) task;
1562
1563        atomic_set(&task->refcount, 1);
1564        task->state = ISCSI_TASK_PENDING;
1565        task->conn = conn;
1566        task->sc = sc;
1567        task->have_checked_conn = false;
1568        task->last_timeout = jiffies;
1569        task->last_xfer = jiffies;
1570        INIT_LIST_HEAD(&task->running);
1571        return task;
1572}
1573
1574enum {
1575        FAILURE_BAD_HOST = 1,
1576        FAILURE_SESSION_FAILED,
1577        FAILURE_SESSION_FREED,
1578        FAILURE_WINDOW_CLOSED,
1579        FAILURE_OOM,
1580        FAILURE_SESSION_TERMINATE,
1581        FAILURE_SESSION_IN_RECOVERY,
1582        FAILURE_SESSION_RECOVERY_TIMEOUT,
1583        FAILURE_SESSION_LOGGING_OUT,
1584        FAILURE_SESSION_NOT_READY,
1585};
1586
1587int iscsi_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *sc)
1588{
1589        struct iscsi_cls_session *cls_session;
1590        struct iscsi_host *ihost;
1591        int reason = 0;
1592        struct iscsi_session *session;
1593        struct iscsi_conn *conn;
1594        struct iscsi_task *task = NULL;
1595
1596        sc->result = 0;
1597        sc->SCp.ptr = NULL;
1598
1599        ihost = shost_priv(host);
1600
1601        cls_session = starget_to_session(scsi_target(sc->device));
1602        session = cls_session->dd_data;
1603        spin_lock_bh(&session->lock);
1604
1605        reason = iscsi_session_chkready(cls_session);
1606        if (reason) {
1607                sc->result = reason;
1608                goto fault;
1609        }
1610
1611        if (session->state != ISCSI_STATE_LOGGED_IN) {
1612                /*
1613                 * to handle the race between when we set the recovery state
1614                 * and block the session we requeue here (commands could
1615                 * be entering our queuecommand while a block is starting
1616                 * up because the block code is not locked)
1617                 */
1618                switch (session->state) {
1619                case ISCSI_STATE_FAILED:
1620                case ISCSI_STATE_IN_RECOVERY:
1621                        reason = FAILURE_SESSION_IN_RECOVERY;
1622                        sc->result = DID_IMM_RETRY << 16;
1623                        break;
1624                case ISCSI_STATE_LOGGING_OUT:
1625                        reason = FAILURE_SESSION_LOGGING_OUT;
1626                        sc->result = DID_IMM_RETRY << 16;
1627                        break;
1628                case ISCSI_STATE_RECOVERY_FAILED:
1629                        reason = FAILURE_SESSION_RECOVERY_TIMEOUT;
1630                        sc->result = DID_TRANSPORT_FAILFAST << 16;
1631                        break;
1632                case ISCSI_STATE_TERMINATE:
1633                        reason = FAILURE_SESSION_TERMINATE;
1634                        sc->result = DID_NO_CONNECT << 16;
1635                        break;
1636                default:
1637                        reason = FAILURE_SESSION_FREED;
1638                        sc->result = DID_NO_CONNECT << 16;
1639                }
1640                goto fault;
1641        }
1642
1643        conn = session->leadconn;
1644        if (!conn) {
1645                reason = FAILURE_SESSION_FREED;
1646                sc->result = DID_NO_CONNECT << 16;
1647                goto fault;
1648        }
1649
1650        if (test_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx)) {
1651                reason = FAILURE_SESSION_IN_RECOVERY;
1652                sc->result = DID_REQUEUE;
1653                goto fault;
1654        }
1655
1656        if (iscsi_check_cmdsn_window_closed(conn)) {
1657                reason = FAILURE_WINDOW_CLOSED;
1658                goto reject;
1659        }
1660
1661        task = iscsi_alloc_task(conn, sc);
1662        if (!task) {
1663                reason = FAILURE_OOM;
1664                goto reject;
1665        }
1666
1667        if (!ihost->workq) {
1668                reason = iscsi_prep_scsi_cmd_pdu(task);
1669                if (reason) {
1670                        if (reason == -ENOMEM ||  reason == -EACCES) {
1671                                reason = FAILURE_OOM;
1672                                goto prepd_reject;
1673                        } else {
1674                                sc->result = DID_ABORT << 16;
1675                                goto prepd_fault;
1676                        }
1677                }
1678                if (session->tt->xmit_task(task)) {
1679                        session->cmdsn--;
1680                        reason = FAILURE_SESSION_NOT_READY;
1681                        goto prepd_reject;
1682                }
1683        } else {
1684                list_add_tail(&task->running, &conn->cmdqueue);
1685                iscsi_conn_queue_work(conn);
1686        }
1687
1688        session->queued_cmdsn++;
1689        spin_unlock_bh(&session->lock);
1690        return 0;
1691
1692prepd_reject:
1693        iscsi_complete_task(task, ISCSI_TASK_REQUEUE_SCSIQ);
1694reject:
1695        spin_unlock_bh(&session->lock);
1696        ISCSI_DBG_SESSION(session, "cmd 0x%x rejected (%d)\n",
1697                          sc->cmnd[0], reason);
1698        return SCSI_MLQUEUE_TARGET_BUSY;
1699
1700prepd_fault:
1701        iscsi_complete_task(task, ISCSI_TASK_REQUEUE_SCSIQ);
1702fault:
1703        spin_unlock_bh(&session->lock);
1704        ISCSI_DBG_SESSION(session, "iscsi: cmd 0x%x is not queued (%d)\n",
1705                          sc->cmnd[0], reason);
1706        if (!scsi_bidi_cmnd(sc))
1707                scsi_set_resid(sc, scsi_bufflen(sc));
1708        else {
1709                scsi_out(sc)->resid = scsi_out(sc)->length;
1710                scsi_in(sc)->resid = scsi_in(sc)->length;
1711        }
1712        sc->scsi_done(sc);
1713        return 0;
1714}
1715EXPORT_SYMBOL_GPL(iscsi_queuecommand);
1716
1717int iscsi_change_queue_depth(struct scsi_device *sdev, int depth, int reason)
1718{
1719        switch (reason) {
1720        case SCSI_QDEPTH_DEFAULT:
1721                scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
1722                break;
1723        case SCSI_QDEPTH_QFULL:
1724                scsi_track_queue_full(sdev, depth);
1725                break;
1726        case SCSI_QDEPTH_RAMP_UP:
1727                scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
1728                break;
1729        default:
1730                return -EOPNOTSUPP;
1731        }
1732        return sdev->queue_depth;
1733}
1734EXPORT_SYMBOL_GPL(iscsi_change_queue_depth);
1735
1736int iscsi_target_alloc(struct scsi_target *starget)
1737{
1738        struct iscsi_cls_session *cls_session = starget_to_session(starget);
1739        struct iscsi_session *session = cls_session->dd_data;
1740
1741        starget->can_queue = session->scsi_cmds_max;
1742        return 0;
1743}
1744EXPORT_SYMBOL_GPL(iscsi_target_alloc);
1745
1746static void iscsi_tmf_timedout(unsigned long data)
1747{
1748        struct iscsi_conn *conn = (struct iscsi_conn *)data;
1749        struct iscsi_session *session = conn->session;
1750
1751        spin_lock(&session->lock);
1752        if (conn->tmf_state == TMF_QUEUED) {
1753                conn->tmf_state = TMF_TIMEDOUT;
1754                ISCSI_DBG_EH(session, "tmf timedout\n");
1755                /* unblock eh_abort() */
1756                wake_up(&conn->ehwait);
1757        }
1758        spin_unlock(&session->lock);
1759}
1760
1761static int iscsi_exec_task_mgmt_fn(struct iscsi_conn *conn,
1762                                   struct iscsi_tm *hdr, int age,
1763                                   int timeout)
1764{
1765        struct iscsi_session *session = conn->session;
1766        struct iscsi_task *task;
1767
1768        task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)hdr,
1769                                      NULL, 0);
1770        if (!task) {
1771                spin_unlock_bh(&session->lock);
1772                iscsi_conn_printk(KERN_ERR, conn, "Could not send TMF.\n");
1773                iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1774                spin_lock_bh(&session->lock);
1775                return -EPERM;
1776        }
1777        conn->tmfcmd_pdus_cnt++;
1778        conn->tmf_timer.expires = timeout * HZ + jiffies;
1779        conn->tmf_timer.function = iscsi_tmf_timedout;
1780        conn->tmf_timer.data = (unsigned long)conn;
1781        add_timer(&conn->tmf_timer);
1782        ISCSI_DBG_EH(session, "tmf set timeout\n");
1783
1784        spin_unlock_bh(&session->lock);
1785        mutex_unlock(&session->eh_mutex);
1786
1787        /*
1788         * block eh thread until:
1789         *
1790         * 1) tmf response
1791         * 2) tmf timeout
1792         * 3) session is terminated or restarted or userspace has
1793         * given up on recovery
1794         */
1795        wait_event_interruptible(conn->ehwait, age != session->age ||
1796                                 session->state != ISCSI_STATE_LOGGED_IN ||
1797                                 conn->tmf_state != TMF_QUEUED);
1798        if (signal_pending(current))
1799                flush_signals(current);
1800        del_timer_sync(&conn->tmf_timer);
1801
1802        mutex_lock(&session->eh_mutex);
1803        spin_lock_bh(&session->lock);
1804        /* if the session drops it will clean up the task */
1805        if (age != session->age ||
1806            session->state != ISCSI_STATE_LOGGED_IN)
1807                return -ENOTCONN;
1808        return 0;
1809}
1810
1811/*
1812 * Fail commands. session lock held and recv side suspended and xmit
1813 * thread flushed
1814 */
1815static void fail_scsi_tasks(struct iscsi_conn *conn, unsigned lun,
1816                            int error)
1817{
1818        struct iscsi_task *task;
1819        int i;
1820
1821        for (i = 0; i < conn->session->cmds_max; i++) {
1822                task = conn->session->cmds[i];
1823                if (!task->sc || task->state == ISCSI_TASK_FREE)
1824                        continue;
1825
1826                if (lun != -1 && lun != task->sc->device->lun)
1827                        continue;
1828
1829                ISCSI_DBG_SESSION(conn->session,
1830                                  "failing sc %p itt 0x%x state %d\n",
1831                                  task->sc, task->itt, task->state);
1832                fail_scsi_task(task, error);
1833        }
1834}
1835
1836/**
1837 * iscsi_suspend_queue - suspend iscsi_queuecommand
1838 * @conn: iscsi conn to stop queueing IO on
1839 *
1840 * This grabs the session lock to make sure no one is in
1841 * xmit_task/queuecommand, and then sets suspend to prevent
1842 * new commands from being queued. This only needs to be called
1843 * by offload drivers that need to sync a path like ep disconnect
1844 * with the iscsi_queuecommand/xmit_task. To start IO again libiscsi
1845 * will call iscsi_start_tx and iscsi_unblock_session when in FFP.
1846 */
1847void iscsi_suspend_queue(struct iscsi_conn *conn)
1848{
1849        spin_lock_bh(&conn->session->lock);
1850        set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1851        spin_unlock_bh(&conn->session->lock);
1852}
1853EXPORT_SYMBOL_GPL(iscsi_suspend_queue);
1854
1855/**
1856 * iscsi_suspend_tx - suspend iscsi_data_xmit
1857 * @conn: iscsi conn tp stop processing IO on.
1858 *
1859 * This function sets the suspend bit to prevent iscsi_data_xmit
1860 * from sending new IO, and if work is queued on the xmit thread
1861 * it will wait for it to be completed.
1862 */
1863void iscsi_suspend_tx(struct iscsi_conn *conn)
1864{
1865        struct Scsi_Host *shost = conn->session->host;
1866        struct iscsi_host *ihost = shost_priv(shost);
1867
1868        set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1869        if (ihost->workq)
1870                flush_workqueue(ihost->workq);
1871}
1872EXPORT_SYMBOL_GPL(iscsi_suspend_tx);
1873
1874static void iscsi_start_tx(struct iscsi_conn *conn)
1875{
1876        clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1877        iscsi_conn_queue_work(conn);
1878}
1879
1880/*
1881 * We want to make sure a ping is in flight. It has timed out.
1882 * And we are not busy processing a pdu that is making
1883 * progress but got started before the ping and is taking a while
1884 * to complete so the ping is just stuck behind it in a queue.
1885 */
1886static int iscsi_has_ping_timed_out(struct iscsi_conn *conn)
1887{
1888        if (conn->ping_task &&
1889            time_before_eq(conn->last_recv + (conn->recv_timeout * HZ) +
1890                           (conn->ping_timeout * HZ), jiffies))
1891                return 1;
1892        else
1893                return 0;
1894}
1895
1896static enum blk_eh_timer_return iscsi_eh_cmd_timed_out(struct scsi_cmnd *sc)
1897{
1898        enum blk_eh_timer_return rc = BLK_EH_NOT_HANDLED;
1899        struct iscsi_task *task = NULL, *running_task;
1900        struct iscsi_cls_session *cls_session;
1901        struct iscsi_session *session;
1902        struct iscsi_conn *conn;
1903        int i;
1904
1905        cls_session = starget_to_session(scsi_target(sc->device));
1906        session = cls_session->dd_data;
1907
1908        ISCSI_DBG_EH(session, "scsi cmd %p timedout\n", sc);
1909
1910        spin_lock(&session->lock);
1911        task = (struct iscsi_task *)sc->SCp.ptr;
1912        if (!task) {
1913                /*
1914                 * Raced with completion. Blk layer has taken ownership
1915                 * so let timeout code complete it now.
1916                 */
1917                rc = BLK_EH_HANDLED;
1918                goto done;
1919        }
1920
1921        if (session->state != ISCSI_STATE_LOGGED_IN) {
1922                /*
1923                 * We are probably in the middle of iscsi recovery so let
1924                 * that complete and handle the error.
1925                 */
1926                rc = BLK_EH_RESET_TIMER;
1927                goto done;
1928        }
1929
1930        conn = session->leadconn;
1931        if (!conn) {
1932                /* In the middle of shuting down */
1933                rc = BLK_EH_RESET_TIMER;
1934                goto done;
1935        }
1936
1937        /*
1938         * If we have sent (at least queued to the network layer) a pdu or
1939         * recvd one for the task since the last timeout ask for
1940         * more time. If on the next timeout we have not made progress
1941         * we can check if it is the task or connection when we send the
1942         * nop as a ping.
1943         */
1944        if (time_after(task->last_xfer, task->last_timeout)) {
1945                ISCSI_DBG_EH(session, "Command making progress. Asking "
1946                             "scsi-ml for more time to complete. "
1947                             "Last data xfer at %lu. Last timeout was at "
1948                             "%lu\n.", task->last_xfer, task->last_timeout);
1949                task->have_checked_conn = false;
1950                rc = BLK_EH_RESET_TIMER;
1951                goto done;
1952        }
1953
1954        if (!conn->recv_timeout && !conn->ping_timeout)
1955                goto done;
1956        /*
1957         * if the ping timedout then we are in the middle of cleaning up
1958         * and can let the iscsi eh handle it
1959         */
1960        if (iscsi_has_ping_timed_out(conn)) {
1961                rc = BLK_EH_RESET_TIMER;
1962                goto done;
1963        }
1964
1965        for (i = 0; i < conn->session->cmds_max; i++) {
1966                running_task = conn->session->cmds[i];
1967                if (!running_task->sc || running_task == task ||
1968                     running_task->state != ISCSI_TASK_RUNNING)
1969                        continue;
1970
1971                /*
1972                 * Only check if cmds started before this one have made
1973                 * progress, or this could never fail
1974                 */
1975                if (time_after(running_task->sc->jiffies_at_alloc,
1976                               task->sc->jiffies_at_alloc))
1977                        continue;
1978
1979                if (time_after(running_task->last_xfer, task->last_timeout)) {
1980                        /*
1981                         * This task has not made progress, but a task
1982                         * started before us has transferred data since
1983                         * we started/last-checked. We could be queueing
1984                         * too many tasks or the LU is bad.
1985                         *
1986                         * If the device is bad the cmds ahead of us on
1987                         * other devs will complete, and this loop will
1988                         * eventually fail starting the scsi eh.
1989                         */
1990                        ISCSI_DBG_EH(session, "Command has not made progress "
1991                                     "but commands ahead of it have. "
1992                                     "Asking scsi-ml for more time to "
1993                                     "complete. Our last xfer vs running task "
1994                                     "last xfer %lu/%lu. Last check %lu.\n",
1995                                     task->last_xfer, running_task->last_xfer,
1996                                     task->last_timeout);
1997                        rc = BLK_EH_RESET_TIMER;
1998                        goto done;
1999                }
2000        }
2001
2002        /* Assumes nop timeout is shorter than scsi cmd timeout */
2003        if (task->have_checked_conn)
2004                goto done;
2005
2006        /*
2007         * Checking the transport already or nop from a cmd timeout still
2008         * running
2009         */
2010        if (conn->ping_task) {
2011                task->have_checked_conn = true;
2012                rc = BLK_EH_RESET_TIMER;
2013                goto done;
2014        }
2015
2016        /* Make sure there is a transport check done */
2017        iscsi_send_nopout(conn, NULL);
2018        task->have_checked_conn = true;
2019        rc = BLK_EH_RESET_TIMER;
2020
2021done:
2022        if (task)
2023                task->last_timeout = jiffies;
2024        spin_unlock(&session->lock);
2025        ISCSI_DBG_EH(session, "return %s\n", rc == BLK_EH_RESET_TIMER ?
2026                     "timer reset" : "nh");
2027        return rc;
2028}
2029
2030static void iscsi_check_transport_timeouts(unsigned long data)
2031{
2032        struct iscsi_conn *conn = (struct iscsi_conn *)data;
2033        struct iscsi_session *session = conn->session;
2034        unsigned long recv_timeout, next_timeout = 0, last_recv;
2035
2036        spin_lock(&session->lock);
2037        if (session->state != ISCSI_STATE_LOGGED_IN)
2038                goto done;
2039
2040        recv_timeout = conn->recv_timeout;
2041        if (!recv_timeout)
2042                goto done;
2043
2044        recv_timeout *= HZ;
2045        last_recv = conn->last_recv;
2046
2047        if (iscsi_has_ping_timed_out(conn)) {
2048                iscsi_conn_printk(KERN_ERR, conn, "ping timeout of %d secs "
2049                                  "expired, recv timeout %d, last rx %lu, "
2050                                  "last ping %lu, now %lu\n",
2051                                  conn->ping_timeout, conn->recv_timeout,
2052                                  last_recv, conn->last_ping, jiffies);
2053                spin_unlock(&session->lock);
2054                iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
2055                return;
2056        }
2057
2058        if (time_before_eq(last_recv + recv_timeout, jiffies)) {
2059                /* send a ping to try to provoke some traffic */
2060                ISCSI_DBG_CONN(conn, "Sending nopout as ping\n");
2061                iscsi_send_nopout(conn, NULL);
2062                next_timeout = conn->last_ping + (conn->ping_timeout * HZ);
2063        } else
2064                next_timeout = last_recv + recv_timeout;
2065
2066        ISCSI_DBG_CONN(conn, "Setting next tmo %lu\n", next_timeout);
2067        mod_timer(&conn->transport_timer, next_timeout);
2068done:
2069        spin_unlock(&session->lock);
2070}
2071
2072static void iscsi_prep_abort_task_pdu(struct iscsi_task *task,
2073                                      struct iscsi_tm *hdr)
2074{
2075        memset(hdr, 0, sizeof(*hdr));
2076        hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2077        hdr->flags = ISCSI_TM_FUNC_ABORT_TASK & ISCSI_FLAG_TM_FUNC_MASK;
2078        hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2079        hdr->lun = task->lun;
2080        hdr->rtt = task->hdr_itt;
2081        hdr->refcmdsn = task->cmdsn;
2082}
2083
2084int iscsi_eh_abort(struct scsi_cmnd *sc)
2085{
2086        struct iscsi_cls_session *cls_session;
2087        struct iscsi_session *session;
2088        struct iscsi_conn *conn;
2089        struct iscsi_task *task;
2090        struct iscsi_tm *hdr;
2091        int rc, age;
2092
2093        cls_session = starget_to_session(scsi_target(sc->device));
2094        session = cls_session->dd_data;
2095
2096        ISCSI_DBG_EH(session, "aborting sc %p\n", sc);
2097
2098        mutex_lock(&session->eh_mutex);
2099        spin_lock_bh(&session->lock);
2100        /*
2101         * if session was ISCSI_STATE_IN_RECOVERY then we may not have
2102         * got the command.
2103         */
2104        if (!sc->SCp.ptr) {
2105                ISCSI_DBG_EH(session, "sc never reached iscsi layer or "
2106                                      "it completed.\n");
2107                spin_unlock_bh(&session->lock);
2108                mutex_unlock(&session->eh_mutex);
2109                return SUCCESS;
2110        }
2111
2112        /*
2113         * If we are not logged in or we have started a new session
2114         * then let the host reset code handle this
2115         */
2116        if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN ||
2117            sc->SCp.phase != session->age) {
2118                spin_unlock_bh(&session->lock);
2119                mutex_unlock(&session->eh_mutex);
2120                ISCSI_DBG_EH(session, "failing abort due to dropped "
2121                                  "session.\n");
2122                return FAILED;
2123        }
2124
2125        conn = session->leadconn;
2126        conn->eh_abort_cnt++;
2127        age = session->age;
2128
2129        task = (struct iscsi_task *)sc->SCp.ptr;
2130        ISCSI_DBG_EH(session, "aborting [sc %p itt 0x%x]\n",
2131                     sc, task->itt);
2132
2133        /* task completed before time out */
2134        if (!task->sc) {
2135                ISCSI_DBG_EH(session, "sc completed while abort in progress\n");
2136                goto success;
2137        }
2138
2139        if (task->state == ISCSI_TASK_PENDING) {
2140                fail_scsi_task(task, DID_ABORT);
2141                goto success;
2142        }
2143
2144        /* only have one tmf outstanding at a time */
2145        if (conn->tmf_state != TMF_INITIAL)
2146                goto failed;
2147        conn->tmf_state = TMF_QUEUED;
2148
2149        hdr = &conn->tmhdr;
2150        iscsi_prep_abort_task_pdu(task, hdr);
2151
2152        if (iscsi_exec_task_mgmt_fn(conn, hdr, age, session->abort_timeout)) {
2153                rc = FAILED;
2154                goto failed;
2155        }
2156
2157        switch (conn->tmf_state) {
2158        case TMF_SUCCESS:
2159                spin_unlock_bh(&session->lock);
2160                /*
2161                 * stop tx side incase the target had sent a abort rsp but
2162                 * the initiator was still writing out data.
2163                 */
2164                iscsi_suspend_tx(conn);
2165                /*
2166                 * we do not stop the recv side because targets have been
2167                 * good and have never sent us a successful tmf response
2168                 * then sent more data for the cmd.
2169                 */
2170                spin_lock_bh(&session->lock);
2171                fail_scsi_task(task, DID_ABORT);
2172                conn->tmf_state = TMF_INITIAL;
2173                memset(hdr, 0, sizeof(*hdr));
2174                spin_unlock_bh(&session->lock);
2175                iscsi_start_tx(conn);
2176                goto success_unlocked;
2177        case TMF_TIMEDOUT:
2178                spin_unlock_bh(&session->lock);
2179                iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2180                goto failed_unlocked;
2181        case TMF_NOT_FOUND:
2182                if (!sc->SCp.ptr) {
2183                        conn->tmf_state = TMF_INITIAL;
2184                        memset(hdr, 0, sizeof(*hdr));
2185                        /* task completed before tmf abort response */
2186                        ISCSI_DBG_EH(session, "sc completed while abort in "
2187                                              "progress\n");
2188                        goto success;
2189                }
2190                /* fall through */
2191        default:
2192                conn->tmf_state = TMF_INITIAL;
2193                goto failed;
2194        }
2195
2196success:
2197        spin_unlock_bh(&session->lock);
2198success_unlocked:
2199        ISCSI_DBG_EH(session, "abort success [sc %p itt 0x%x]\n",
2200                     sc, task->itt);
2201        mutex_unlock(&session->eh_mutex);
2202        return SUCCESS;
2203
2204failed:
2205        spin_unlock_bh(&session->lock);
2206failed_unlocked:
2207        ISCSI_DBG_EH(session, "abort failed [sc %p itt 0x%x]\n", sc,
2208                     task ? task->itt : 0);
2209        mutex_unlock(&session->eh_mutex);
2210        return FAILED;
2211}
2212EXPORT_SYMBOL_GPL(iscsi_eh_abort);
2213
2214static void iscsi_prep_lun_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
2215{
2216        memset(hdr, 0, sizeof(*hdr));
2217        hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2218        hdr->flags = ISCSI_TM_FUNC_LOGICAL_UNIT_RESET & ISCSI_FLAG_TM_FUNC_MASK;
2219        hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2220        int_to_scsilun(sc->device->lun, &hdr->lun);
2221        hdr->rtt = RESERVED_ITT;
2222}
2223
2224int iscsi_eh_device_reset(struct scsi_cmnd *sc)
2225{
2226        struct iscsi_cls_session *cls_session;
2227        struct iscsi_session *session;
2228        struct iscsi_conn *conn;
2229        struct iscsi_tm *hdr;
2230        int rc = FAILED;
2231
2232        cls_session = starget_to_session(scsi_target(sc->device));
2233        session = cls_session->dd_data;
2234
2235        ISCSI_DBG_EH(session, "LU Reset [sc %p lun %u]\n", sc, sc->device->lun);
2236
2237        mutex_lock(&session->eh_mutex);
2238        spin_lock_bh(&session->lock);
2239        /*
2240         * Just check if we are not logged in. We cannot check for
2241         * the phase because the reset could come from a ioctl.
2242         */
2243        if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN)
2244                goto unlock;
2245        conn = session->leadconn;
2246
2247        /* only have one tmf outstanding at a time */
2248        if (conn->tmf_state != TMF_INITIAL)
2249                goto unlock;
2250        conn->tmf_state = TMF_QUEUED;
2251
2252        hdr = &conn->tmhdr;
2253        iscsi_prep_lun_reset_pdu(sc, hdr);
2254
2255        if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age,
2256                                    session->lu_reset_timeout)) {
2257                rc = FAILED;
2258                goto unlock;
2259        }
2260
2261        switch (conn->tmf_state) {
2262        case TMF_SUCCESS:
2263                break;
2264        case TMF_TIMEDOUT:
2265                spin_unlock_bh(&session->lock);
2266                iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2267                goto done;
2268        default:
2269                conn->tmf_state = TMF_INITIAL;
2270                goto unlock;
2271        }
2272
2273        rc = SUCCESS;
2274        spin_unlock_bh(&session->lock);
2275
2276        iscsi_suspend_tx(conn);
2277
2278        spin_lock_bh(&session->lock);
2279        memset(hdr, 0, sizeof(*hdr));
2280        fail_scsi_tasks(conn, sc->device->lun, DID_ERROR);
2281        conn->tmf_state = TMF_INITIAL;
2282        spin_unlock_bh(&session->lock);
2283
2284        iscsi_start_tx(conn);
2285        goto done;
2286
2287unlock:
2288        spin_unlock_bh(&session->lock);
2289done:
2290        ISCSI_DBG_EH(session, "dev reset result = %s\n",
2291                     rc == SUCCESS ? "SUCCESS" : "FAILED");
2292        mutex_unlock(&session->eh_mutex);
2293        return rc;
2294}
2295EXPORT_SYMBOL_GPL(iscsi_eh_device_reset);
2296
2297void iscsi_session_recovery_timedout(struct iscsi_cls_session *cls_session)
2298{
2299        struct iscsi_session *session = cls_session->dd_data;
2300
2301        spin_lock_bh(&session->lock);
2302        if (session->state != ISCSI_STATE_LOGGED_IN) {
2303                session->state = ISCSI_STATE_RECOVERY_FAILED;
2304                if (session->leadconn)
2305                        wake_up(&session->leadconn->ehwait);
2306        }
2307        spin_unlock_bh(&session->lock);
2308}
2309EXPORT_SYMBOL_GPL(iscsi_session_recovery_timedout);
2310
2311/**
2312 * iscsi_eh_session_reset - drop session and attempt relogin
2313 * @sc: scsi command
2314 *
2315 * This function will wait for a relogin, session termination from
2316 * userspace, or a recovery/replacement timeout.
2317 */
2318int iscsi_eh_session_reset(struct scsi_cmnd *sc)
2319{
2320        struct iscsi_cls_session *cls_session;
2321        struct iscsi_session *session;
2322        struct iscsi_conn *conn;
2323
2324        cls_session = starget_to_session(scsi_target(sc->device));
2325        session = cls_session->dd_data;
2326        conn = session->leadconn;
2327
2328        mutex_lock(&session->eh_mutex);
2329        spin_lock_bh(&session->lock);
2330        if (session->state == ISCSI_STATE_TERMINATE) {
2331failed:
2332                ISCSI_DBG_EH(session,
2333                             "failing session reset: Could not log back into "
2334                             "%s, %s [age %d]\n", session->targetname,
2335                             conn->persistent_address, session->age);
2336                spin_unlock_bh(&session->lock);
2337                mutex_unlock(&session->eh_mutex);
2338                return FAILED;
2339        }
2340
2341        spin_unlock_bh(&session->lock);
2342        mutex_unlock(&session->eh_mutex);
2343        /*
2344         * we drop the lock here but the leadconn cannot be destoyed while
2345         * we are in the scsi eh
2346         */
2347        iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2348
2349        ISCSI_DBG_EH(session, "wait for relogin\n");
2350        wait_event_interruptible(conn->ehwait,
2351                                 session->state == ISCSI_STATE_TERMINATE ||
2352                                 session->state == ISCSI_STATE_LOGGED_IN ||
2353                                 session->state == ISCSI_STATE_RECOVERY_FAILED);
2354        if (signal_pending(current))
2355                flush_signals(current);
2356
2357        mutex_lock(&session->eh_mutex);
2358        spin_lock_bh(&session->lock);
2359        if (session->state == ISCSI_STATE_LOGGED_IN) {
2360                ISCSI_DBG_EH(session,
2361                             "session reset succeeded for %s,%s\n",
2362                             session->targetname, conn->persistent_address);
2363        } else
2364                goto failed;
2365        spin_unlock_bh(&session->lock);
2366        mutex_unlock(&session->eh_mutex);
2367        return SUCCESS;
2368}
2369EXPORT_SYMBOL_GPL(iscsi_eh_session_reset);
2370
2371static void iscsi_prep_tgt_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
2372{
2373        memset(hdr, 0, sizeof(*hdr));
2374        hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2375        hdr->flags = ISCSI_TM_FUNC_TARGET_WARM_RESET & ISCSI_FLAG_TM_FUNC_MASK;
2376        hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2377        hdr->rtt = RESERVED_ITT;
2378}
2379
2380/**
2381 * iscsi_eh_target_reset - reset target
2382 * @sc: scsi command
2383 *
2384 * This will attempt to send a warm target reset.
2385 */
2386int iscsi_eh_target_reset(struct scsi_cmnd *sc)
2387{
2388        struct iscsi_cls_session *cls_session;
2389        struct iscsi_session *session;
2390        struct iscsi_conn *conn;
2391        struct iscsi_tm *hdr;
2392        int rc = FAILED;
2393
2394        cls_session = starget_to_session(scsi_target(sc->device));
2395        session = cls_session->dd_data;
2396
2397        ISCSI_DBG_EH(session, "tgt Reset [sc %p tgt %s]\n", sc,
2398                     session->targetname);
2399
2400        mutex_lock(&session->eh_mutex);
2401        spin_lock_bh(&session->lock);
2402        /*
2403         * Just check if we are not logged in. We cannot check for
2404         * the phase because the reset could come from a ioctl.
2405         */
2406        if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN)
2407                goto unlock;
2408        conn = session->leadconn;
2409
2410        /* only have one tmf outstanding at a time */
2411        if (conn->tmf_state != TMF_INITIAL)
2412                goto unlock;
2413        conn->tmf_state = TMF_QUEUED;
2414
2415        hdr = &conn->tmhdr;
2416        iscsi_prep_tgt_reset_pdu(sc, hdr);
2417
2418        if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age,
2419                                    session->tgt_reset_timeout)) {
2420                rc = FAILED;
2421                goto unlock;
2422        }
2423
2424        switch (conn->tmf_state) {
2425        case TMF_SUCCESS:
2426                break;
2427        case TMF_TIMEDOUT:
2428                spin_unlock_bh(&session->lock);
2429                iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2430                goto done;
2431        default:
2432                conn->tmf_state = TMF_INITIAL;
2433                goto unlock;
2434        }
2435
2436        rc = SUCCESS;
2437        spin_unlock_bh(&session->lock);
2438
2439        iscsi_suspend_tx(conn);
2440
2441        spin_lock_bh(&session->lock);
2442        memset(hdr, 0, sizeof(*hdr));
2443        fail_scsi_tasks(conn, -1, DID_ERROR);
2444        conn->tmf_state = TMF_INITIAL;
2445        spin_unlock_bh(&session->lock);
2446
2447        iscsi_start_tx(conn);
2448        goto done;
2449
2450unlock:
2451        spin_unlock_bh(&session->lock);
2452done:
2453        ISCSI_DBG_EH(session, "tgt %s reset result = %s\n", session->targetname,
2454                     rc == SUCCESS ? "SUCCESS" : "FAILED");
2455        mutex_unlock(&session->eh_mutex);
2456        return rc;
2457}
2458EXPORT_SYMBOL_GPL(iscsi_eh_target_reset);
2459
2460/**
2461 * iscsi_eh_recover_target - reset target and possibly the session
2462 * @sc: scsi command
2463 *
2464 * This will attempt to send a warm target reset. If that fails,
2465 * we will escalate to ERL0 session recovery.
2466 */
2467int iscsi_eh_recover_target(struct scsi_cmnd *sc)
2468{
2469        int rc;
2470
2471        rc = iscsi_eh_target_reset(sc);
2472        if (rc == FAILED)
2473                rc = iscsi_eh_session_reset(sc);
2474        return rc;
2475}
2476EXPORT_SYMBOL_GPL(iscsi_eh_recover_target);
2477
2478/*
2479 * Pre-allocate a pool of @max items of @item_size. By default, the pool
2480 * should be accessed via kfifo_{get,put} on q->queue.
2481 * Optionally, the caller can obtain the array of object pointers
2482 * by passing in a non-NULL @items pointer
2483 */
2484int
2485iscsi_pool_init(struct iscsi_pool *q, int max, void ***items, int item_size)
2486{
2487        int i, num_arrays = 1;
2488
2489        memset(q, 0, sizeof(*q));
2490
2491        q->max = max;
2492
2493        /* If the user passed an items pointer, he wants a copy of
2494         * the array. */
2495        if (items)
2496                num_arrays++;
2497        q->pool = kzalloc(num_arrays * max * sizeof(void*), GFP_KERNEL);
2498        if (q->pool == NULL)
2499                return -ENOMEM;
2500
2501        kfifo_init(&q->queue, (void*)q->pool, max * sizeof(void*));
2502
2503        for (i = 0; i < max; i++) {
2504                q->pool[i] = kzalloc(item_size, GFP_KERNEL);
2505                if (q->pool[i] == NULL) {
2506                        q->max = i;
2507                        goto enomem;
2508                }
2509                kfifo_in(&q->queue, (void*)&q->pool[i], sizeof(void*));
2510        }
2511
2512        if (items) {
2513                *items = q->pool + max;
2514                memcpy(*items, q->pool, max * sizeof(void *));
2515        }
2516
2517        return 0;
2518
2519enomem:
2520        iscsi_pool_free(q);
2521        return -ENOMEM;
2522}
2523EXPORT_SYMBOL_GPL(iscsi_pool_init);
2524
2525void iscsi_pool_free(struct iscsi_pool *q)
2526{
2527        int i;
2528
2529        for (i = 0; i < q->max; i++)
2530                kfree(q->pool[i]);
2531        kfree(q->pool);
2532}
2533EXPORT_SYMBOL_GPL(iscsi_pool_free);
2534
2535/**
2536 * iscsi_host_add - add host to system
2537 * @shost: scsi host
2538 * @pdev: parent device
2539 *
2540 * This should be called by partial offload and software iscsi drivers
2541 * to add a host to the system.
2542 */
2543int iscsi_host_add(struct Scsi_Host *shost, struct device *pdev)
2544{
2545        if (!shost->can_queue)
2546                shost->can_queue = ISCSI_DEF_XMIT_CMDS_MAX;
2547
2548        if (!shost->cmd_per_lun)
2549                shost->cmd_per_lun = ISCSI_DEF_CMD_PER_LUN;
2550
2551        if (!shost->transportt->eh_timed_out)
2552                shost->transportt->eh_timed_out = iscsi_eh_cmd_timed_out;
2553        return scsi_add_host(shost, pdev);
2554}
2555EXPORT_SYMBOL_GPL(iscsi_host_add);
2556
2557/**
2558 * iscsi_host_alloc - allocate a host and driver data
2559 * @sht: scsi host template
2560 * @dd_data_size: driver host data size
2561 * @xmit_can_sleep: bool indicating if LLD will queue IO from a work queue
2562 *
2563 * This should be called by partial offload and software iscsi drivers.
2564 * To access the driver specific memory use the iscsi_host_priv() macro.
2565 */
2566struct Scsi_Host *iscsi_host_alloc(struct scsi_host_template *sht,
2567                                   int dd_data_size, bool xmit_can_sleep)
2568{
2569        struct Scsi_Host *shost;
2570        struct iscsi_host *ihost;
2571
2572        shost = scsi_host_alloc(sht, sizeof(struct iscsi_host) + dd_data_size);
2573        if (!shost)
2574                return NULL;
2575        ihost = shost_priv(shost);
2576
2577        if (xmit_can_sleep) {
2578                snprintf(ihost->workq_name, sizeof(ihost->workq_name),
2579                        "iscsi_q_%d", shost->host_no);
2580                ihost->workq = create_singlethread_workqueue(ihost->workq_name);
2581                if (!ihost->workq)
2582                        goto free_host;
2583        }
2584
2585        spin_lock_init(&ihost->lock);
2586        ihost->state = ISCSI_HOST_SETUP;
2587        ihost->num_sessions = 0;
2588        init_waitqueue_head(&ihost->session_removal_wq);
2589        return shost;
2590
2591free_host:
2592        scsi_host_put(shost);
2593        return NULL;
2594}
2595EXPORT_SYMBOL_GPL(iscsi_host_alloc);
2596
2597static void iscsi_notify_host_removed(struct iscsi_cls_session *cls_session)
2598{
2599        iscsi_session_failure(cls_session->dd_data, ISCSI_ERR_INVALID_HOST);
2600}
2601
2602/**
2603 * iscsi_host_remove - remove host and sessions
2604 * @shost: scsi host
2605 *
2606 * If there are any sessions left, this will initiate the removal and wait
2607 * for the completion.
2608 */
2609void iscsi_host_remove(struct Scsi_Host *shost)
2610{
2611        struct iscsi_host *ihost = shost_priv(shost);
2612        unsigned long flags;
2613
2614        spin_lock_irqsave(&ihost->lock, flags);
2615        ihost->state = ISCSI_HOST_REMOVED;
2616        spin_unlock_irqrestore(&ihost->lock, flags);
2617
2618        iscsi_host_for_each_session(shost, iscsi_notify_host_removed);
2619        wait_event_interruptible(ihost->session_removal_wq,
2620                                 ihost->num_sessions == 0);
2621        if (signal_pending(current))
2622                flush_signals(current);
2623
2624        scsi_remove_host(shost);
2625        if (ihost->workq)
2626                destroy_workqueue(ihost->workq);
2627}
2628EXPORT_SYMBOL_GPL(iscsi_host_remove);
2629
2630void iscsi_host_free(struct Scsi_Host *shost)
2631{
2632        struct iscsi_host *ihost = shost_priv(shost);
2633
2634        kfree(ihost->netdev);
2635        kfree(ihost->hwaddress);
2636        kfree(ihost->initiatorname);
2637        scsi_host_put(shost);
2638}
2639EXPORT_SYMBOL_GPL(iscsi_host_free);
2640
2641static void iscsi_host_dec_session_cnt(struct Scsi_Host *shost)
2642{
2643        struct iscsi_host *ihost = shost_priv(shost);
2644        unsigned long flags;
2645
2646        shost = scsi_host_get(shost);
2647        if (!shost) {
2648                printk(KERN_ERR "Invalid state. Cannot notify host removal "
2649                      "of session teardown event because host already "
2650                      "removed.\n");
2651                return;
2652        }
2653
2654        spin_lock_irqsave(&ihost->lock, flags);
2655        ihost->num_sessions--;
2656        if (ihost->num_sessions == 0)
2657                wake_up(&ihost->session_removal_wq);
2658        spin_unlock_irqrestore(&ihost->lock, flags);
2659        scsi_host_put(shost);
2660}
2661
2662/**
2663 * iscsi_session_setup - create iscsi cls session and host and session
2664 * @iscsit: iscsi transport template
2665 * @shost: scsi host
2666 * @cmds_max: session can queue
2667 * @cmd_task_size: LLD task private data size
2668 * @initial_cmdsn: initial CmdSN
2669 *
2670 * This can be used by software iscsi_transports that allocate
2671 * a session per scsi host.
2672 *
2673 * Callers should set cmds_max to the largest total numer (mgmt + scsi) of
2674 * tasks they support. The iscsi layer reserves ISCSI_MGMT_CMDS_MAX tasks
2675 * for nop handling and login/logout requests.
2676 */
2677struct iscsi_cls_session *
2678iscsi_session_setup(struct iscsi_transport *iscsit, struct Scsi_Host *shost,
2679                    uint16_t cmds_max, int dd_size, int cmd_task_size,
2680                    uint32_t initial_cmdsn, unsigned int id)
2681{
2682        struct iscsi_host *ihost = shost_priv(shost);
2683        struct iscsi_session *session;
2684        struct iscsi_cls_session *cls_session;
2685        int cmd_i, scsi_cmds, total_cmds = cmds_max;
2686        unsigned long flags;
2687
2688        spin_lock_irqsave(&ihost->lock, flags);
2689        if (ihost->state == ISCSI_HOST_REMOVED) {
2690                spin_unlock_irqrestore(&ihost->lock, flags);
2691                return NULL;
2692        }
2693        ihost->num_sessions++;
2694        spin_unlock_irqrestore(&ihost->lock, flags);
2695
2696        if (!total_cmds)
2697                total_cmds = ISCSI_DEF_XMIT_CMDS_MAX;
2698        /*
2699         * The iscsi layer needs some tasks for nop handling and tmfs,
2700         * so the cmds_max must at least be greater than ISCSI_MGMT_CMDS_MAX
2701         * + 1 command for scsi IO.
2702         */
2703        if (total_cmds < ISCSI_TOTAL_CMDS_MIN) {
2704                printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2705                       "must be a power of two that is at least %d.\n",
2706                       total_cmds, ISCSI_TOTAL_CMDS_MIN);
2707                goto dec_session_count;
2708        }
2709
2710        if (total_cmds > ISCSI_TOTAL_CMDS_MAX) {
2711                printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2712                       "must be a power of 2 less than or equal to %d.\n",
2713                       cmds_max, ISCSI_TOTAL_CMDS_MAX);
2714                total_cmds = ISCSI_TOTAL_CMDS_MAX;
2715        }
2716
2717        if (!is_power_of_2(total_cmds)) {
2718                printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2719                       "must be a power of 2.\n", total_cmds);
2720                total_cmds = rounddown_pow_of_two(total_cmds);
2721                if (total_cmds < ISCSI_TOTAL_CMDS_MIN)
2722                        return NULL;
2723                printk(KERN_INFO "iscsi: Rounding can_queue to %d.\n",
2724                       total_cmds);
2725        }
2726        scsi_cmds = total_cmds - ISCSI_MGMT_CMDS_MAX;
2727
2728        cls_session = iscsi_alloc_session(shost, iscsit,
2729                                          sizeof(struct iscsi_session) +
2730                                          dd_size);
2731        if (!cls_session)
2732                goto dec_session_count;
2733        session = cls_session->dd_data;
2734        session->cls_session = cls_session;
2735        session->host = shost;
2736        session->state = ISCSI_STATE_FREE;
2737        session->fast_abort = 1;
2738        session->tgt_reset_timeout = 30;
2739        session->lu_reset_timeout = 15;
2740        session->abort_timeout = 10;
2741        session->scsi_cmds_max = scsi_cmds;
2742        session->cmds_max = total_cmds;
2743        session->queued_cmdsn = session->cmdsn = initial_cmdsn;
2744        session->exp_cmdsn = initial_cmdsn + 1;
2745        session->max_cmdsn = initial_cmdsn + 1;
2746        session->max_r2t = 1;
2747        session->tt = iscsit;
2748        session->dd_data = cls_session->dd_data + sizeof(*session);
2749        mutex_init(&session->eh_mutex);
2750        spin_lock_init(&session->lock);
2751
2752        /* initialize SCSI PDU commands pool */
2753        if (iscsi_pool_init(&session->cmdpool, session->cmds_max,
2754                            (void***)&session->cmds,
2755                            cmd_task_size + sizeof(struct iscsi_task)))
2756                goto cmdpool_alloc_fail;
2757
2758        /* pre-format cmds pool with ITT */
2759        for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
2760                struct iscsi_task *task = session->cmds[cmd_i];
2761
2762                if (cmd_task_size)
2763                        task->dd_data = &task[1];
2764                task->itt = cmd_i;
2765                task->state = ISCSI_TASK_FREE;
2766                INIT_LIST_HEAD(&task->running);
2767        }
2768
2769        if (!try_module_get(iscsit->owner))
2770                goto module_get_fail;
2771
2772        if (iscsi_add_session(cls_session, id))
2773                goto cls_session_fail;
2774
2775        return cls_session;
2776
2777cls_session_fail:
2778        module_put(iscsit->owner);
2779module_get_fail:
2780        iscsi_pool_free(&session->cmdpool);
2781cmdpool_alloc_fail:
2782        iscsi_free_session(cls_session);
2783dec_session_count:
2784        iscsi_host_dec_session_cnt(shost);
2785        return NULL;
2786}
2787EXPORT_SYMBOL_GPL(iscsi_session_setup);
2788
2789/**
2790 * iscsi_session_teardown - destroy session, host, and cls_session
2791 * @cls_session: iscsi session
2792 *
2793 * The driver must have called iscsi_remove_session before
2794 * calling this.
2795 */
2796void iscsi_session_teardown(struct iscsi_cls_session *cls_session)
2797{
2798        struct iscsi_session *session = cls_session->dd_data;
2799        struct module *owner = cls_session->transport->owner;
2800        struct Scsi_Host *shost = session->host;
2801
2802        iscsi_pool_free(&session->cmdpool);
2803
2804        kfree(session->password);
2805        kfree(session->password_in);
2806        kfree(session->username);
2807        kfree(session->username_in);
2808        kfree(session->targetname);
2809        kfree(session->targetalias);
2810        kfree(session->initiatorname);
2811        kfree(session->boot_root);
2812        kfree(session->boot_nic);
2813        kfree(session->boot_target);
2814        kfree(session->ifacename);
2815
2816        iscsi_destroy_session(cls_session);
2817        iscsi_host_dec_session_cnt(shost);
2818        module_put(owner);
2819}
2820EXPORT_SYMBOL_GPL(iscsi_session_teardown);
2821
2822/**
2823 * iscsi_conn_setup - create iscsi_cls_conn and iscsi_conn
2824 * @cls_session: iscsi_cls_session
2825 * @dd_size: private driver data size
2826 * @conn_idx: cid
2827 */
2828struct iscsi_cls_conn *
2829iscsi_conn_setup(struct iscsi_cls_session *cls_session, int dd_size,
2830                 uint32_t conn_idx)
2831{
2832        struct iscsi_session *session = cls_session->dd_data;
2833        struct iscsi_conn *conn;
2834        struct iscsi_cls_conn *cls_conn;
2835        char *data;
2836
2837        cls_conn = iscsi_create_conn(cls_session, sizeof(*conn) + dd_size,
2838                                     conn_idx);
2839        if (!cls_conn)
2840                return NULL;
2841        conn = cls_conn->dd_data;
2842        memset(conn, 0, sizeof(*conn) + dd_size);
2843
2844        conn->dd_data = cls_conn->dd_data + sizeof(*conn);
2845        conn->session = session;
2846        conn->cls_conn = cls_conn;
2847        conn->c_stage = ISCSI_CONN_INITIAL_STAGE;
2848        conn->id = conn_idx;
2849        conn->exp_statsn = 0;
2850        conn->tmf_state = TMF_INITIAL;
2851
2852        init_timer(&conn->transport_timer);
2853        conn->transport_timer.data = (unsigned long)conn;
2854        conn->transport_timer.function = iscsi_check_transport_timeouts;
2855
2856        INIT_LIST_HEAD(&conn->mgmtqueue);
2857        INIT_LIST_HEAD(&conn->cmdqueue);
2858        INIT_LIST_HEAD(&conn->requeue);
2859        INIT_WORK(&conn->xmitwork, iscsi_xmitworker);
2860
2861        /* allocate login_task used for the login/text sequences */
2862        spin_lock_bh(&session->lock);
2863        if (!kfifo_out(&session->cmdpool.queue,
2864                         (void*)&conn->login_task,
2865                         sizeof(void*))) {
2866                spin_unlock_bh(&session->lock);
2867                goto login_task_alloc_fail;
2868        }
2869        spin_unlock_bh(&session->lock);
2870
2871        data = (char *) __get_free_pages(GFP_KERNEL,
2872                                         get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
2873        if (!data)
2874                goto login_task_data_alloc_fail;
2875        conn->login_task->data = conn->data = data;
2876
2877        init_timer(&conn->tmf_timer);
2878        init_waitqueue_head(&conn->ehwait);
2879
2880        return cls_conn;
2881
2882login_task_data_alloc_fail:
2883        kfifo_in(&session->cmdpool.queue, (void*)&conn->login_task,
2884                    sizeof(void*));
2885login_task_alloc_fail:
2886        iscsi_destroy_conn(cls_conn);
2887        return NULL;
2888}
2889EXPORT_SYMBOL_GPL(iscsi_conn_setup);
2890
2891/**
2892 * iscsi_conn_teardown - teardown iscsi connection
2893 * cls_conn: iscsi class connection
2894 *
2895 * TODO: we may need to make this into a two step process
2896 * like scsi-mls remove + put host
2897 */
2898void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn)
2899{
2900        struct iscsi_conn *conn = cls_conn->dd_data;
2901        struct iscsi_session *session = conn->session;
2902        unsigned long flags;
2903
2904        del_timer_sync(&conn->transport_timer);
2905
2906        spin_lock_bh(&session->lock);
2907        conn->c_stage = ISCSI_CONN_CLEANUP_WAIT;
2908        if (session->leadconn == conn) {
2909                /*
2910                 * leading connection? then give up on recovery.
2911                 */
2912                session->state = ISCSI_STATE_TERMINATE;
2913                wake_up(&conn->ehwait);
2914        }
2915        spin_unlock_bh(&session->lock);
2916
2917        /*
2918         * Block until all in-progress commands for this connection
2919         * time out or fail.
2920         */
2921        for (;;) {
2922                spin_lock_irqsave(session->host->host_lock, flags);
2923                if (!session->host->host_busy) { /* OK for ERL == 0 */
2924                        spin_unlock_irqrestore(session->host->host_lock, flags);
2925                        break;
2926                }
2927                spin_unlock_irqrestore(session->host->host_lock, flags);
2928                msleep_interruptible(500);
2929                iscsi_conn_printk(KERN_INFO, conn, "iscsi conn_destroy(): "
2930                                  "host_busy %d host_failed %d\n",
2931                                  session->host->host_busy,
2932                                  session->host->host_failed);
2933                /*
2934                 * force eh_abort() to unblock
2935                 */
2936                wake_up(&conn->ehwait);
2937        }
2938
2939        /* flush queued up work because we free the connection below */
2940        iscsi_suspend_tx(conn);
2941
2942        spin_lock_bh(&session->lock);
2943        free_pages((unsigned long) conn->data,
2944                   get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
2945        kfree(conn->persistent_address);
2946        kfifo_in(&session->cmdpool.queue, (void*)&conn->login_task,
2947                    sizeof(void*));
2948        if (session->leadconn == conn)
2949                session->leadconn = NULL;
2950        spin_unlock_bh(&session->lock);
2951
2952        iscsi_destroy_conn(cls_conn);
2953}
2954EXPORT_SYMBOL_GPL(iscsi_conn_teardown);
2955
2956int iscsi_conn_start(struct iscsi_cls_conn *cls_conn)
2957{
2958        struct iscsi_conn *conn = cls_conn->dd_data;
2959        struct iscsi_session *session = conn->session;
2960
2961        if (!session) {
2962                iscsi_conn_printk(KERN_ERR, conn,
2963                                  "can't start unbound connection\n");
2964                return -EPERM;
2965        }
2966
2967        if ((session->imm_data_en || !session->initial_r2t_en) &&
2968             session->first_burst > session->max_burst) {
2969                iscsi_conn_printk(KERN_INFO, conn, "invalid burst lengths: "
2970                                  "first_burst %d max_burst %d\n",
2971                                  session->first_burst, session->max_burst);
2972                return -EINVAL;
2973        }
2974
2975        if (conn->ping_timeout && !conn->recv_timeout) {
2976                iscsi_conn_printk(KERN_ERR, conn, "invalid recv timeout of "
2977                                  "zero. Using 5 seconds\n.");
2978                conn->recv_timeout = 5;
2979        }
2980
2981        if (conn->recv_timeout && !conn->ping_timeout) {
2982                iscsi_conn_printk(KERN_ERR, conn, "invalid ping timeout of "
2983                                  "zero. Using 5 seconds.\n");
2984                conn->ping_timeout = 5;
2985        }
2986
2987        spin_lock_bh(&session->lock);
2988        conn->c_stage = ISCSI_CONN_STARTED;
2989        session->state = ISCSI_STATE_LOGGED_IN;
2990        session->queued_cmdsn = session->cmdsn;
2991
2992        conn->last_recv = jiffies;
2993        conn->last_ping = jiffies;
2994        if (conn->recv_timeout && conn->ping_timeout)
2995                mod_timer(&conn->transport_timer,
2996                          jiffies + (conn->recv_timeout * HZ));
2997
2998        switch(conn->stop_stage) {
2999        case STOP_CONN_RECOVER:
3000                /*
3001                 * unblock eh_abort() if it is blocked. re-try all
3002                 * commands after successful recovery
3003                 */
3004                conn->stop_stage = 0;
3005                conn->tmf_state = TMF_INITIAL;
3006                session->age++;
3007                if (session->age == 16)
3008                        session->age = 0;
3009                break;
3010        case STOP_CONN_TERM:
3011                conn->stop_stage = 0;
3012                break;
3013        default:
3014                break;
3015        }
3016        spin_unlock_bh(&session->lock);
3017
3018        iscsi_unblock_session(session->cls_session);
3019        wake_up(&conn->ehwait);
3020        return 0;
3021}
3022EXPORT_SYMBOL_GPL(iscsi_conn_start);
3023
3024static void
3025fail_mgmt_tasks(struct iscsi_session *session, struct iscsi_conn *conn)
3026{
3027        struct iscsi_task *task;
3028        int i, state;
3029
3030        for (i = 0; i < conn->session->cmds_max; i++) {
3031                task = conn->session->cmds[i];
3032                if (task->sc)
3033                        continue;
3034
3035                if (task->state == ISCSI_TASK_FREE)
3036                        continue;
3037
3038                ISCSI_DBG_SESSION(conn->session,
3039                                  "failing mgmt itt 0x%x state %d\n",
3040                                  task->itt, task->state);
3041                state = ISCSI_TASK_ABRT_SESS_RECOV;
3042                if (task->state == ISCSI_TASK_PENDING)
3043                        state = ISCSI_TASK_COMPLETED;
3044                iscsi_complete_task(task, state);
3045
3046        }
3047}
3048
3049static void iscsi_start_session_recovery(struct iscsi_session *session,
3050                                         struct iscsi_conn *conn, int flag)
3051{
3052        int old_stop_stage;
3053
3054        mutex_lock(&session->eh_mutex);
3055        spin_lock_bh(&session->lock);
3056        if (conn->stop_stage == STOP_CONN_TERM) {
3057                spin_unlock_bh(&session->lock);
3058                mutex_unlock(&session->eh_mutex);
3059                return;
3060        }
3061
3062        /*
3063         * When this is called for the in_login state, we only want to clean
3064         * up the login task and connection. We do not need to block and set
3065         * the recovery state again
3066         */
3067        if (flag == STOP_CONN_TERM)
3068                session->state = ISCSI_STATE_TERMINATE;
3069        else if (conn->stop_stage != STOP_CONN_RECOVER)
3070                session->state = ISCSI_STATE_IN_RECOVERY;
3071
3072        old_stop_stage = conn->stop_stage;
3073        conn->stop_stage = flag;
3074        spin_unlock_bh(&session->lock);
3075
3076        del_timer_sync(&conn->transport_timer);
3077        iscsi_suspend_tx(conn);
3078
3079        spin_lock_bh(&session->lock);
3080        conn->c_stage = ISCSI_CONN_STOPPED;
3081        spin_unlock_bh(&session->lock);
3082
3083        /*
3084         * for connection level recovery we should not calculate
3085         * header digest. conn->hdr_size used for optimization
3086         * in hdr_extract() and will be re-negotiated at
3087         * set_param() time.
3088         */
3089        if (flag == STOP_CONN_RECOVER) {
3090                conn->hdrdgst_en = 0;
3091                conn->datadgst_en = 0;
3092                if (session->state == ISCSI_STATE_IN_RECOVERY &&
3093                    old_stop_stage != STOP_CONN_RECOVER) {
3094                        ISCSI_DBG_SESSION(session, "blocking session\n");
3095                        iscsi_block_session(session->cls_session);
3096                }
3097        }
3098
3099        /*
3100         * flush queues.
3101         */
3102        spin_lock_bh(&session->lock);
3103        fail_scsi_tasks(conn, -1, DID_TRANSPORT_DISRUPTED);
3104        fail_mgmt_tasks(session, conn);
3105        memset(&conn->tmhdr, 0, sizeof(conn->tmhdr));
3106        spin_unlock_bh(&session->lock);
3107        mutex_unlock(&session->eh_mutex);
3108}
3109
3110void iscsi_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
3111{
3112        struct iscsi_conn *conn = cls_conn->dd_data;
3113        struct iscsi_session *session = conn->session;
3114
3115        switch (flag) {
3116        case STOP_CONN_RECOVER:
3117        case STOP_CONN_TERM:
3118                iscsi_start_session_recovery(session, conn, flag);
3119                break;
3120        default:
3121                iscsi_conn_printk(KERN_ERR, conn,
3122                                  "invalid stop flag %d\n", flag);
3123        }
3124}
3125EXPORT_SYMBOL_GPL(iscsi_conn_stop);
3126
3127int iscsi_conn_bind(struct iscsi_cls_session *cls_session,
3128                    struct iscsi_cls_conn *cls_conn, int is_leading)
3129{
3130        struct iscsi_session *session = cls_session->dd_data;
3131        struct iscsi_conn *conn = cls_conn->dd_data;
3132
3133        spin_lock_bh(&session->lock);
3134        if (is_leading)
3135                session->leadconn = conn;
3136        spin_unlock_bh(&session->lock);
3137
3138        /*
3139         * Unblock xmitworker(), Login Phase will pass through.
3140         */
3141        clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
3142        clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
3143        return 0;
3144}
3145EXPORT_SYMBOL_GPL(iscsi_conn_bind);
3146
3147int iscsi_switch_str_param(char **param, char *new_val_buf)
3148{
3149        char *new_val;
3150
3151        if (*param) {
3152                if (!strcmp(*param, new_val_buf))
3153                        return 0;
3154        }
3155
3156        new_val = kstrdup(new_val_buf, GFP_NOIO);
3157        if (!new_val)
3158                return -ENOMEM;
3159
3160        kfree(*param);
3161        *param = new_val;
3162        return 0;
3163}
3164EXPORT_SYMBOL_GPL(iscsi_switch_str_param);
3165
3166int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
3167                    enum iscsi_param param, char *buf, int buflen)
3168{
3169        struct iscsi_conn *conn = cls_conn->dd_data;
3170        struct iscsi_session *session = conn->session;
3171
3172        switch(param) {
3173        case ISCSI_PARAM_FAST_ABORT:
3174                sscanf(buf, "%d", &session->fast_abort);
3175                break;
3176        case ISCSI_PARAM_ABORT_TMO:
3177                sscanf(buf, "%d", &session->abort_timeout);
3178                break;
3179        case ISCSI_PARAM_LU_RESET_TMO:
3180                sscanf(buf, "%d", &session->lu_reset_timeout);
3181                break;
3182        case ISCSI_PARAM_TGT_RESET_TMO:
3183                sscanf(buf, "%d", &session->tgt_reset_timeout);
3184                break;
3185        case ISCSI_PARAM_PING_TMO:
3186                sscanf(buf, "%d", &conn->ping_timeout);
3187                break;
3188        case ISCSI_PARAM_RECV_TMO:
3189                sscanf(buf, "%d", &conn->recv_timeout);
3190                break;
3191        case ISCSI_PARAM_MAX_RECV_DLENGTH:
3192                sscanf(buf, "%d", &conn->max_recv_dlength);
3193                break;
3194        case ISCSI_PARAM_MAX_XMIT_DLENGTH:
3195                sscanf(buf, "%d", &conn->max_xmit_dlength);
3196                break;
3197        case ISCSI_PARAM_HDRDGST_EN:
3198                sscanf(buf, "%d", &conn->hdrdgst_en);
3199                break;
3200        case ISCSI_PARAM_DATADGST_EN:
3201                sscanf(buf, "%d", &conn->datadgst_en);
3202                break;
3203        case ISCSI_PARAM_INITIAL_R2T_EN:
3204                sscanf(buf, "%d", &session->initial_r2t_en);
3205                break;
3206        case ISCSI_PARAM_MAX_R2T:
3207                sscanf(buf, "%hu", &session->max_r2t);
3208                break;
3209        case ISCSI_PARAM_IMM_DATA_EN:
3210                sscanf(buf, "%d", &session->imm_data_en);
3211                break;
3212        case ISCSI_PARAM_FIRST_BURST:
3213                sscanf(buf, "%d", &session->first_burst);
3214                break;
3215        case ISCSI_PARAM_MAX_BURST:
3216                sscanf(buf, "%d", &session->max_burst);
3217                break;
3218        case ISCSI_PARAM_PDU_INORDER_EN:
3219                sscanf(buf, "%d", &session->pdu_inorder_en);
3220                break;
3221        case ISCSI_PARAM_DATASEQ_INORDER_EN:
3222                sscanf(buf, "%d", &session->dataseq_inorder_en);
3223                break;
3224        case ISCSI_PARAM_ERL:
3225                sscanf(buf, "%d", &session->erl);
3226                break;
3227        case ISCSI_PARAM_EXP_STATSN:
3228                sscanf(buf, "%u", &conn->exp_statsn);
3229                break;
3230        case ISCSI_PARAM_USERNAME:
3231                return iscsi_switch_str_param(&session->username, buf);
3232        case ISCSI_PARAM_USERNAME_IN:
3233                return iscsi_switch_str_param(&session->username_in, buf);
3234        case ISCSI_PARAM_PASSWORD:
3235                return iscsi_switch_str_param(&session->password, buf);
3236        case ISCSI_PARAM_PASSWORD_IN:
3237                return iscsi_switch_str_param(&session->password_in, buf);
3238        case ISCSI_PARAM_TARGET_NAME:
3239                return iscsi_switch_str_param(&session->targetname, buf);
3240        case ISCSI_PARAM_TARGET_ALIAS:
3241                return iscsi_switch_str_param(&session->targetalias, buf);
3242        case ISCSI_PARAM_TPGT:
3243                sscanf(buf, "%d", &session->tpgt);
3244                break;
3245        case ISCSI_PARAM_PERSISTENT_PORT:
3246                sscanf(buf, "%d", &conn->persistent_port);
3247                break;
3248        case ISCSI_PARAM_PERSISTENT_ADDRESS:
3249                return iscsi_switch_str_param(&conn->persistent_address, buf);
3250        case ISCSI_PARAM_IFACE_NAME:
3251                return iscsi_switch_str_param(&session->ifacename, buf);
3252        case ISCSI_PARAM_INITIATOR_NAME:
3253                return iscsi_switch_str_param(&session->initiatorname, buf);
3254        case ISCSI_PARAM_BOOT_ROOT:
3255                return iscsi_switch_str_param(&session->boot_root, buf);
3256        case ISCSI_PARAM_BOOT_NIC:
3257                return iscsi_switch_str_param(&session->boot_nic, buf);
3258        case ISCSI_PARAM_BOOT_TARGET:
3259                return iscsi_switch_str_param(&session->boot_target, buf);
3260        default:
3261                return -ENOSYS;
3262        }
3263
3264        return 0;
3265}
3266EXPORT_SYMBOL_GPL(iscsi_set_param);
3267
3268int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
3269                            enum iscsi_param param, char *buf)
3270{
3271        struct iscsi_session *session = cls_session->dd_data;
3272        int len;
3273
3274        switch(param) {
3275        case ISCSI_PARAM_FAST_ABORT:
3276                len = sprintf(buf, "%d\n", session->fast_abort);
3277                break;
3278        case ISCSI_PARAM_ABORT_TMO:
3279                len = sprintf(buf, "%d\n", session->abort_timeout);
3280                break;
3281        case ISCSI_PARAM_LU_RESET_TMO:
3282                len = sprintf(buf, "%d\n", session->lu_reset_timeout);
3283                break;
3284        case ISCSI_PARAM_TGT_RESET_TMO:
3285                len = sprintf(buf, "%d\n", session->tgt_reset_timeout);
3286                break;
3287        case ISCSI_PARAM_INITIAL_R2T_EN:
3288                len = sprintf(buf, "%d\n", session->initial_r2t_en);
3289                break;
3290        case ISCSI_PARAM_MAX_R2T:
3291                len = sprintf(buf, "%hu\n", session->max_r2t);
3292                break;
3293        case ISCSI_PARAM_IMM_DATA_EN:
3294                len = sprintf(buf, "%d\n", session->imm_data_en);
3295                break;
3296        case ISCSI_PARAM_FIRST_BURST:
3297                len = sprintf(buf, "%u\n", session->first_burst);
3298                break;
3299        case ISCSI_PARAM_MAX_BURST:
3300                len = sprintf(buf, "%u\n", session->max_burst);
3301                break;
3302        case ISCSI_PARAM_PDU_INORDER_EN:
3303                len = sprintf(buf, "%d\n", session->pdu_inorder_en);
3304                break;
3305        case ISCSI_PARAM_DATASEQ_INORDER_EN:
3306                len = sprintf(buf, "%d\n", session->dataseq_inorder_en);
3307                break;
3308        case ISCSI_PARAM_ERL:
3309                len = sprintf(buf, "%d\n", session->erl);
3310                break;
3311        case ISCSI_PARAM_TARGET_NAME:
3312                len = sprintf(buf, "%s\n", session->targetname);
3313                break;
3314        case ISCSI_PARAM_TARGET_ALIAS:
3315                len = sprintf(buf, "%s\n", session->targetalias);
3316                break;
3317        case ISCSI_PARAM_TPGT:
3318                len = sprintf(buf, "%d\n", session->tpgt);
3319                break;
3320        case ISCSI_PARAM_USERNAME:
3321                len = sprintf(buf, "%s\n", session->username);
3322                break;
3323        case ISCSI_PARAM_USERNAME_IN:
3324                len = sprintf(buf, "%s\n", session->username_in);
3325                break;
3326        case ISCSI_PARAM_PASSWORD:
3327                len = sprintf(buf, "%s\n", session->password);
3328                break;
3329        case ISCSI_PARAM_PASSWORD_IN:
3330                len = sprintf(buf, "%s\n", session->password_in);
3331                break;
3332        case ISCSI_PARAM_IFACE_NAME:
3333                len = sprintf(buf, "%s\n", session->ifacename);
3334                break;
3335        case ISCSI_PARAM_INITIATOR_NAME:
3336                len = sprintf(buf, "%s\n", session->initiatorname);
3337                break;
3338        case ISCSI_PARAM_BOOT_ROOT:
3339                len = sprintf(buf, "%s\n", session->boot_root);
3340                break;
3341        case ISCSI_PARAM_BOOT_NIC:
3342                len = sprintf(buf, "%s\n", session->boot_nic);
3343                break;
3344        case ISCSI_PARAM_BOOT_TARGET:
3345                len = sprintf(buf, "%s\n", session->boot_target);
3346                break;
3347        default:
3348                return -ENOSYS;
3349        }
3350
3351        return len;
3352}
3353EXPORT_SYMBOL_GPL(iscsi_session_get_param);
3354
3355int iscsi_conn_get_addr_param(struct sockaddr_storage *addr,
3356                              enum iscsi_param param, char *buf)
3357{
3358        struct sockaddr_in6 *sin6 = NULL;
3359        struct sockaddr_in *sin = NULL;
3360        int len;
3361
3362        switch (addr->ss_family) {
3363        case AF_INET:
3364                sin = (struct sockaddr_in *)addr;
3365                break;
3366        case AF_INET6:
3367                sin6 = (struct sockaddr_in6 *)addr;
3368                break;
3369        default:
3370                return -EINVAL;
3371        }
3372
3373        switch (param) {
3374        case ISCSI_PARAM_CONN_ADDRESS:
3375        case ISCSI_HOST_PARAM_IPADDRESS:
3376                if (sin)
3377                        len = sprintf(buf, "%pI4\n", &sin->sin_addr.s_addr);
3378                else
3379                        len = sprintf(buf, "%pI6\n", &sin6->sin6_addr);
3380                break;
3381        case ISCSI_PARAM_CONN_PORT:
3382                if (sin)
3383                        len = sprintf(buf, "%hu\n", be16_to_cpu(sin->sin_port));
3384                else
3385                        len = sprintf(buf, "%hu\n",
3386                                      be16_to_cpu(sin6->sin6_port));
3387                break;
3388        default:
3389                return -EINVAL;
3390        }
3391
3392        return len;
3393}
3394EXPORT_SYMBOL_GPL(iscsi_conn_get_addr_param);
3395
3396int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
3397                         enum iscsi_param param, char *buf)
3398{
3399        struct iscsi_conn *conn = cls_conn->dd_data;
3400        int len;
3401
3402        switch(param) {
3403        case ISCSI_PARAM_PING_TMO:
3404                len = sprintf(buf, "%u\n", conn->ping_timeout);
3405                break;
3406        case ISCSI_PARAM_RECV_TMO:
3407                len = sprintf(buf, "%u\n", conn->recv_timeout);
3408                break;
3409        case ISCSI_PARAM_MAX_RECV_DLENGTH:
3410                len = sprintf(buf, "%u\n", conn->max_recv_dlength);
3411                break;
3412        case ISCSI_PARAM_MAX_XMIT_DLENGTH:
3413                len = sprintf(buf, "%u\n", conn->max_xmit_dlength);
3414                break;
3415        case ISCSI_PARAM_HDRDGST_EN:
3416                len = sprintf(buf, "%d\n", conn->hdrdgst_en);
3417                break;
3418        case ISCSI_PARAM_DATADGST_EN:
3419                len = sprintf(buf, "%d\n", conn->datadgst_en);
3420                break;
3421        case ISCSI_PARAM_IFMARKER_EN:
3422                len = sprintf(buf, "%d\n", conn->ifmarker_en);
3423                break;
3424        case ISCSI_PARAM_OFMARKER_EN:
3425                len = sprintf(buf, "%d\n", conn->ofmarker_en);
3426                break;
3427        case ISCSI_PARAM_EXP_STATSN:
3428                len = sprintf(buf, "%u\n", conn->exp_statsn);
3429                break;
3430        case ISCSI_PARAM_PERSISTENT_PORT:
3431                len = sprintf(buf, "%d\n", conn->persistent_port);
3432                break;
3433        case ISCSI_PARAM_PERSISTENT_ADDRESS:
3434                len = sprintf(buf, "%s\n", conn->persistent_address);
3435                break;
3436        default:
3437                return -ENOSYS;
3438        }
3439
3440        return len;
3441}
3442EXPORT_SYMBOL_GPL(iscsi_conn_get_param);
3443
3444int iscsi_host_get_param(struct Scsi_Host *shost, enum iscsi_host_param param,
3445                         char *buf)
3446{
3447        struct iscsi_host *ihost = shost_priv(shost);
3448        int len;
3449
3450        switch (param) {
3451        case ISCSI_HOST_PARAM_NETDEV_NAME:
3452                len = sprintf(buf, "%s\n", ihost->netdev);
3453                break;
3454        case ISCSI_HOST_PARAM_HWADDRESS:
3455                len = sprintf(buf, "%s\n", ihost->hwaddress);
3456                break;
3457        case ISCSI_HOST_PARAM_INITIATOR_NAME:
3458                len = sprintf(buf, "%s\n", ihost->initiatorname);
3459                break;
3460        default:
3461                return -ENOSYS;
3462        }
3463
3464        return len;
3465}
3466EXPORT_SYMBOL_GPL(iscsi_host_get_param);
3467
3468int iscsi_host_set_param(struct Scsi_Host *shost, enum iscsi_host_param param,
3469                         char *buf, int buflen)
3470{
3471        struct iscsi_host *ihost = shost_priv(shost);
3472
3473        switch (param) {
3474        case ISCSI_HOST_PARAM_NETDEV_NAME:
3475                return iscsi_switch_str_param(&ihost->netdev, buf);
3476        case ISCSI_HOST_PARAM_HWADDRESS:
3477                return iscsi_switch_str_param(&ihost->hwaddress, buf);
3478        case ISCSI_HOST_PARAM_INITIATOR_NAME:
3479                return iscsi_switch_str_param(&ihost->initiatorname, buf);
3480        default:
3481                return -ENOSYS;
3482        }
3483
3484        return 0;
3485}
3486EXPORT_SYMBOL_GPL(iscsi_host_set_param);
3487
3488MODULE_AUTHOR("Mike Christie");
3489MODULE_DESCRIPTION("iSCSI library functions");
3490MODULE_LICENSE("GPL");
3491
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