drivers/target/loopback/tcm_loop.c

   1 /*******************************************************************************
   2  *
   3  * This file contains the Linux/SCSI LLD virtual SCSI initiator driver
   4  * for emulated SAS initiator ports
   5  *
   6  * © Copyright 2011-2013 Datera, Inc.
   7  *
   8  * Licensed to the Linux Foundation under the General Public License (GPL) version 2.
   9  *
  10  * Author: Nicholas A. Bellinger <nab@risingtidesystems.com>
  11  *
  12  * This program is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU General Public License as published by
  14  * the Free Software Foundation; either version 2 of the License, or
  15  * (at your option) any later version.
  16  *
  17  * This program is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  * GNU General Public License for more details.
  21  ****************************************************************************/
  22
  23 #include <linux/module.h>
  24 #include <linux/moduleparam.h>
  25 #include <linux/init.h>
  26 #include <linux/slab.h>
  27 #include <linux/types.h>
  28 #include <linux/configfs.h>
  29 #include <scsi/scsi.h>
  30 #include <scsi/scsi_tcq.h>
  31 #include <scsi/scsi_host.h>
  32 #include <scsi/scsi_device.h>
  33 #include <scsi/scsi_cmnd.h>
  34
  35 #include <target/target_core_base.h>
  36 #include <target/target_core_fabric.h>
  37
  38 #include "tcm_loop.h"
  39
  40 #define to_tcm_loop_hba(hba)    container_of(hba, struct tcm_loop_hba, dev)
  41
  42 static struct kmem_cache *tcm_loop_cmd_cache;
  43
  44 static int tcm_loop_hba_no_cnt;
  45
  46 static int tcm_loop_queue_status(struct se_cmd *se_cmd);
  47
  48 static unsigned int tcm_loop_nr_hw_queues = 1;
  49 module_param_named(nr_hw_queues, tcm_loop_nr_hw_queues, uint, 0644);
  50
  51 static unsigned int tcm_loop_can_queue = 1024;
  52 module_param_named(can_queue, tcm_loop_can_queue, uint, 0644);
  53
  54 static unsigned int tcm_loop_cmd_per_lun = 1024;
  55 module_param_named(cmd_per_lun, tcm_loop_cmd_per_lun, uint, 0644);
  56
  57 /*
  58  * Called from struct target_core_fabric_ops->check_stop_free()
  59  */
  60 static int tcm_loop_check_stop_free(struct se_cmd *se_cmd)
  61 {
  62         return transport_generic_free_cmd(se_cmd, 0);
  63 }
  64
  65 static void tcm_loop_release_cmd(struct se_cmd *se_cmd)
  66 {
  67         struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
  68                                 struct tcm_loop_cmd, tl_se_cmd);
  69         struct scsi_cmnd *sc = tl_cmd->sc;
  70
  71         if (se_cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
  72                 kmem_cache_free(tcm_loop_cmd_cache, tl_cmd);
  73         else
  74                 sc->scsi_done(sc);
  75 }
  76
  77 static int tcm_loop_show_info(struct seq_file *m, struct Scsi_Host *host)
  78 {
  79         seq_puts(m, "tcm_loop_proc_info()\n");
  80         return 0;
  81 }
  82
  83 static int tcm_loop_driver_probe(struct device *);
  84 static void tcm_loop_driver_remove(struct device *);
  85
  86 static int pseudo_lld_bus_match(struct device *dev,
  87                                 struct device_driver *dev_driver)
  88 {
  89         return 1;
  90 }
  91
  92 static struct bus_type tcm_loop_lld_bus = {
  93         .name                   = "tcm_loop_bus",
  94         .match                  = pseudo_lld_bus_match,
  95         .probe                  = tcm_loop_driver_probe,
  96         .remove                 = tcm_loop_driver_remove,
  97 };
  98
  99 static struct device_driver tcm_loop_driverfs = {
 100         .name                   = "tcm_loop",
 101         .bus                    = &tcm_loop_lld_bus,
 102 };
 103 /*
 104  * Used with root_device_register() in tcm_loop_alloc_core_bus() below
 105  */
 106 static struct device *tcm_loop_primary;
 107
 108 static void tcm_loop_target_queue_cmd(struct tcm_loop_cmd *tl_cmd)
 109 {
 110         struct se_cmd *se_cmd = &tl_cmd->tl_se_cmd;
 111         struct scsi_cmnd *sc = tl_cmd->sc;
 112         struct tcm_loop_nexus *tl_nexus;
 113         struct tcm_loop_hba *tl_hba;
 114         struct tcm_loop_tpg *tl_tpg;
 115         struct scatterlist *sgl_bidi = NULL;
 116         u32 sgl_bidi_count = 0, transfer_length;
 117
 118         tl_hba = *(struct tcm_loop_hba **)shost_priv(sc->device->host);
 119         tl_tpg = &tl_hba->tl_hba_tpgs[sc->device->id];
 120
 121         /*
 122          * Ensure that this tl_tpg reference from the incoming sc->device->id
 123          * has already been configured via tcm_loop_make_naa_tpg().
 124          */
 125         if (!tl_tpg->tl_hba) {
 126                 set_host_byte(sc, DID_NO_CONNECT);
 127                 goto out_done;
 128         }
 129         if (tl_tpg->tl_transport_status == TCM_TRANSPORT_OFFLINE) {
 130                 set_host_byte(sc, DID_TRANSPORT_DISRUPTED);
 131                 goto out_done;
 132         }
 133         tl_nexus = tl_tpg->tl_nexus;
 134         if (!tl_nexus) {
 135                 scmd_printk(KERN_ERR, sc,
 136                             "TCM_Loop I_T Nexus does not exist\n");
 137                 set_host_byte(sc, DID_ERROR);
 138                 goto out_done;
 139         }
 140
 141         transfer_length = scsi_transfer_length(sc);
 142         if (!scsi_prot_sg_count(sc) &&
 143             scsi_get_prot_op(sc) != SCSI_PROT_NORMAL) {
 144                 se_cmd->prot_pto = true;
 145                 /*
 146                  * loopback transport doesn't support
 147                  * WRITE_GENERATE, READ_STRIP protection
 148                  * information operations, go ahead unprotected.
 149                  */
 150                 transfer_length = scsi_bufflen(sc);
 151         }
 152
 153         se_cmd->tag = tl_cmd->sc_cmd_tag;
 154         target_init_cmd(se_cmd, tl_nexus->se_sess, &tl_cmd->tl_sense_buf[0],
 155                         tl_cmd->sc->device->lun, transfer_length,
 156                         TCM_SIMPLE_TAG, sc->sc_data_direction, 0);
 157
 158         if (target_submit_prep(se_cmd, sc->cmnd, scsi_sglist(sc),
 159                                scsi_sg_count(sc), sgl_bidi, sgl_bidi_count,
 160                                scsi_prot_sglist(sc), scsi_prot_sg_count(sc),
 161                                GFP_ATOMIC))
 162                 return;
 163
 164         target_queue_submission(se_cmd);
 165         return;
 166
 167 out_done:
 168         sc->scsi_done(sc);
 169 }
 170
 171 /*
 172  * ->queuecommand can be and usually is called from interrupt context, so
 173  * defer the actual submission to a workqueue.
 174  */
 175 static int tcm_loop_queuecommand(struct Scsi_Host *sh, struct scsi_cmnd *sc)
 176 {
 177         struct tcm_loop_cmd *tl_cmd = scsi_cmd_priv(sc);
 178
 179         pr_debug("%s() %d:%d:%d:%llu got CDB: 0x%02x scsi_buf_len: %u\n",
 180                  __func__, sc->device->host->host_no, sc->device->id,
 181                  sc->device->channel, sc->device->lun, sc->cmnd[0],
 182                  scsi_bufflen(sc));
 183
 184         memset(tl_cmd, 0, sizeof(*tl_cmd));
 185         tl_cmd->sc = sc;
 186         tl_cmd->sc_cmd_tag = scsi_cmd_to_rq(sc)->tag;
 187
 188         tcm_loop_target_queue_cmd(tl_cmd);
 189         return 0;
 190 }
 191
 192 /*
 193  * Called from SCSI EH process context to issue a LUN_RESET TMR
 194  * to struct scsi_device
 195  */
 196 static int tcm_loop_issue_tmr(struct tcm_loop_tpg *tl_tpg,
 197                               u64 lun, int task, enum tcm_tmreq_table tmr)
 198 {
 199         struct se_cmd *se_cmd;
 200         struct se_session *se_sess;
 201         struct tcm_loop_nexus *tl_nexus;
 202         struct tcm_loop_cmd *tl_cmd;
 203         int ret = TMR_FUNCTION_FAILED, rc;
 204
 205         /*
 206          * Locate the tl_nexus and se_sess pointers
 207          */
 208         tl_nexus = tl_tpg->tl_nexus;
 209         if (!tl_nexus) {
 210                 pr_err("Unable to perform device reset without active I_T Nexus\n");
 211                 return ret;
 212         }
 213
 214         tl_cmd = kmem_cache_zalloc(tcm_loop_cmd_cache, GFP_KERNEL);
 215         if (!tl_cmd)
 216                 return ret;
 217
 218         init_completion(&tl_cmd->tmr_done);
 219
 220         se_cmd = &tl_cmd->tl_se_cmd;
 221         se_sess = tl_tpg->tl_nexus->se_sess;
 222
 223         rc = target_submit_tmr(se_cmd, se_sess, tl_cmd->tl_sense_buf, lun,
 224                                NULL, tmr, GFP_KERNEL, task,
 225                                TARGET_SCF_ACK_KREF);
 226         if (rc < 0)
 227                 goto release;
 228         wait_for_completion(&tl_cmd->tmr_done);
 229         ret = se_cmd->se_tmr_req->response;
 230         target_put_sess_cmd(se_cmd);
 231
 232 out:
 233         return ret;
 234
 235 release:
 236         kmem_cache_free(tcm_loop_cmd_cache, tl_cmd);
 237         goto out;
 238 }
 239
 240 static int tcm_loop_abort_task(struct scsi_cmnd *sc)
 241 {
 242         struct tcm_loop_hba *tl_hba;
 243         struct tcm_loop_tpg *tl_tpg;
 244         int ret;
 245
 246         /*
 247          * Locate the tcm_loop_hba_t pointer
 248          */
 249         tl_hba = *(struct tcm_loop_hba **)shost_priv(sc->device->host);
 250         tl_tpg = &tl_hba->tl_hba_tpgs[sc->device->id];
 251         ret = tcm_loop_issue_tmr(tl_tpg, sc->device->lun,
 252                                  scsi_cmd_to_rq(sc)->tag, TMR_ABORT_TASK);
 253         return (ret == TMR_FUNCTION_COMPLETE) ? SUCCESS : FAILED;
 254 }
 255
 256 /*
 257  * Called from SCSI EH process context to issue a LUN_RESET TMR
 258  * to struct scsi_device
 259  */
 260 static int tcm_loop_device_reset(struct scsi_cmnd *sc)
 261 {
 262         struct tcm_loop_hba *tl_hba;
 263         struct tcm_loop_tpg *tl_tpg;
 264         int ret;
 265
 266         /*
 267          * Locate the tcm_loop_hba_t pointer
 268          */
 269         tl_hba = *(struct tcm_loop_hba **)shost_priv(sc->device->host);
 270         tl_tpg = &tl_hba->tl_hba_tpgs[sc->device->id];
 271
 272         ret = tcm_loop_issue_tmr(tl_tpg, sc->device->lun,
 273                                  0, TMR_LUN_RESET);
 274         return (ret == TMR_FUNCTION_COMPLETE) ? SUCCESS : FAILED;
 275 }
 276
 277 static int tcm_loop_target_reset(struct scsi_cmnd *sc)
 278 {
 279         struct tcm_loop_hba *tl_hba;
 280         struct tcm_loop_tpg *tl_tpg;
 281
 282         /*
 283          * Locate the tcm_loop_hba_t pointer
 284          */
 285         tl_hba = *(struct tcm_loop_hba **)shost_priv(sc->device->host);
 286         if (!tl_hba) {
 287                 pr_err("Unable to perform device reset without active I_T Nexus\n");
 288                 return FAILED;
 289         }
 290         /*
 291          * Locate the tl_tpg pointer from TargetID in sc->device->id
 292          */
 293         tl_tpg = &tl_hba->tl_hba_tpgs[sc->device->id];
 294         if (tl_tpg) {
 295                 tl_tpg->tl_transport_status = TCM_TRANSPORT_ONLINE;
 296                 return SUCCESS;
 297         }
 298         return FAILED;
 299 }
 300
 301 static struct scsi_host_template tcm_loop_driver_template = {
 302         .show_info              = tcm_loop_show_info,
 303         .proc_name              = "tcm_loopback",
 304         .name                   = "TCM_Loopback",
 305         .queuecommand           = tcm_loop_queuecommand,
 306         .change_queue_depth     = scsi_change_queue_depth,
 307         .eh_abort_handler = tcm_loop_abort_task,
 308         .eh_device_reset_handler = tcm_loop_device_reset,
 309         .eh_target_reset_handler = tcm_loop_target_reset,
 310         .this_id                = -1,
 311         .sg_tablesize           = 256,
 312         .max_sectors            = 0xFFFF,
 313         .dma_boundary           = PAGE_SIZE - 1,
 314         .module                 = THIS_MODULE,
 315         .track_queue_depth      = 1,
 316         .cmd_size               = sizeof(struct tcm_loop_cmd),
 317 };
 318
 319 static int tcm_loop_driver_probe(struct device *dev)
 320 {
 321         struct tcm_loop_hba *tl_hba;
 322         struct Scsi_Host *sh;
 323         int error, host_prot;
 324
 325         tl_hba = to_tcm_loop_hba(dev);
 326
 327         sh = scsi_host_alloc(&tcm_loop_driver_template,
 328                         sizeof(struct tcm_loop_hba));
 329         if (!sh) {
 330                 pr_err("Unable to allocate struct scsi_host\n");
 331                 return -ENODEV;
 332         }
 333         tl_hba->sh = sh;
 334
 335         /*
 336          * Assign the struct tcm_loop_hba pointer to struct Scsi_Host->hostdata
 337          */
 338         *((struct tcm_loop_hba **)sh->hostdata) = tl_hba;
 339         /*
 340          * Setup single ID, Channel and LUN for now..
 341          */
 342         sh->max_id = 2;
 343         sh->max_lun = 0;
 344         sh->max_channel = 0;
 345         sh->max_cmd_len = SCSI_MAX_VARLEN_CDB_SIZE;
 346         sh->nr_hw_queues = tcm_loop_nr_hw_queues;
 347         sh->can_queue = tcm_loop_can_queue;
 348         sh->cmd_per_lun = tcm_loop_cmd_per_lun;
 349
 350         host_prot = SHOST_DIF_TYPE1_PROTECTION | SHOST_DIF_TYPE2_PROTECTION |
 351                     SHOST_DIF_TYPE3_PROTECTION | SHOST_DIX_TYPE1_PROTECTION |
 352                     SHOST_DIX_TYPE2_PROTECTION | SHOST_DIX_TYPE3_PROTECTION;
 353
 354         scsi_host_set_prot(sh, host_prot);
 355         scsi_host_set_guard(sh, SHOST_DIX_GUARD_CRC);
 356
 357         error = scsi_add_host(sh, &tl_hba->dev);
 358         if (error) {
 359                 pr_err("%s: scsi_add_host failed\n", __func__);
 360                 scsi_host_put(sh);
 361                 return -ENODEV;
 362         }
 363         return 0;
 364 }
 365
 366 static void tcm_loop_driver_remove(struct device *dev)
 367 {
 368         struct tcm_loop_hba *tl_hba;
 369         struct Scsi_Host *sh;
 370
 371         tl_hba = to_tcm_loop_hba(dev);
 372         sh = tl_hba->sh;
 373
 374         scsi_remove_host(sh);
 375         scsi_host_put(sh);
 376 }
 377
 378 static void tcm_loop_release_adapter(struct device *dev)
 379 {
 380         struct tcm_loop_hba *tl_hba = to_tcm_loop_hba(dev);
 381
 382         kfree(tl_hba);
 383 }
 384
 385 /*
 386  * Called from tcm_loop_make_scsi_hba() in tcm_loop_configfs.c
 387  */
 388 static int tcm_loop_setup_hba_bus(struct tcm_loop_hba *tl_hba, int tcm_loop_host_id)
 389 {
 390         int ret;
 391
 392         tl_hba->dev.bus = &tcm_loop_lld_bus;
 393         tl_hba->dev.parent = tcm_loop_primary;
 394         tl_hba->dev.release = &tcm_loop_release_adapter;
 395         dev_set_name(&tl_hba->dev, "tcm_loop_adapter_%d", tcm_loop_host_id);
 396
 397         ret = device_register(&tl_hba->dev);
 398         if (ret) {
 399                 pr_err("device_register() failed for tl_hba->dev: %d\n", ret);
 400                 return -ENODEV;
 401         }
 402
 403         return 0;
 404 }
 405
 406 /*
 407  * Called from tcm_loop_fabric_init() in tcl_loop_fabric.c to load the emulated
 408  * tcm_loop SCSI bus.
 409  */
 410 static int tcm_loop_alloc_core_bus(void)
 411 {
 412         int ret;
 413
 414         tcm_loop_primary = root_device_register("tcm_loop_0");
 415         if (IS_ERR(tcm_loop_primary)) {
 416                 pr_err("Unable to allocate tcm_loop_primary\n");
 417                 return PTR_ERR(tcm_loop_primary);
 418         }
 419
 420         ret = bus_register(&tcm_loop_lld_bus);
 421         if (ret) {
 422                 pr_err("bus_register() failed for tcm_loop_lld_bus\n");
 423                 goto dev_unreg;
 424         }
 425
 426         ret = driver_register(&tcm_loop_driverfs);
 427         if (ret) {
 428                 pr_err("driver_register() failed for tcm_loop_driverfs\n");
 429                 goto bus_unreg;
 430         }
 431
 432         pr_debug("Initialized TCM Loop Core Bus\n");
 433         return ret;
 434
 435 bus_unreg:
 436         bus_unregister(&tcm_loop_lld_bus);
 437 dev_unreg:
 438         root_device_unregister(tcm_loop_primary);
 439         return ret;
 440 }
 441
 442 static void tcm_loop_release_core_bus(void)
 443 {
 444         driver_unregister(&tcm_loop_driverfs);
 445         bus_unregister(&tcm_loop_lld_bus);
 446         root_device_unregister(tcm_loop_primary);
 447
 448         pr_debug("Releasing TCM Loop Core BUS\n");
 449 }
 450
 451 static inline struct tcm_loop_tpg *tl_tpg(struct se_portal_group *se_tpg)
 452 {
 453         return container_of(se_tpg, struct tcm_loop_tpg, tl_se_tpg);
 454 }
 455
 456 static char *tcm_loop_get_endpoint_wwn(struct se_portal_group *se_tpg)
 457 {
 458         /*
 459          * Return the passed NAA identifier for the Target Port
 460          */
 461         return &tl_tpg(se_tpg)->tl_hba->tl_wwn_address[0];
 462 }
 463
 464 static u16 tcm_loop_get_tag(struct se_portal_group *se_tpg)
 465 {
 466         /*
 467          * This Tag is used when forming SCSI Name identifier in EVPD=1 0x83
 468          * to represent the SCSI Target Port.
 469          */
 470         return tl_tpg(se_tpg)->tl_tpgt;
 471 }
 472
 473 /*
 474  * Returning (1) here allows for target_core_mod struct se_node_acl to be generated
 475  * based upon the incoming fabric dependent SCSI Initiator Port
 476  */
 477 static int tcm_loop_check_demo_mode(struct se_portal_group *se_tpg)
 478 {
 479         return 1;
 480 }
 481
 482 static int tcm_loop_check_demo_mode_cache(struct se_portal_group *se_tpg)
 483 {
 484         return 0;
 485 }
 486
 487 /*
 488  * Allow I_T Nexus full READ-WRITE access without explict Initiator Node ACLs for
 489  * local virtual Linux/SCSI LLD passthrough into VM hypervisor guest
 490  */
 491 static int tcm_loop_check_demo_mode_write_protect(struct se_portal_group *se_tpg)
 492 {
 493         return 0;
 494 }
 495
 496 /*
 497  * Because TCM_Loop does not use explict ACLs and MappedLUNs, this will
 498  * never be called for TCM_Loop by target_core_fabric_configfs.c code.
 499  * It has been added here as a nop for target_fabric_tf_ops_check()
 500  */
 501 static int tcm_loop_check_prod_mode_write_protect(struct se_portal_group *se_tpg)
 502 {
 503         return 0;
 504 }
 505
 506 static int tcm_loop_check_prot_fabric_only(struct se_portal_group *se_tpg)
 507 {
 508         struct tcm_loop_tpg *tl_tpg = container_of(se_tpg, struct tcm_loop_tpg,
 509                                                    tl_se_tpg);
 510         return tl_tpg->tl_fabric_prot_type;
 511 }
 512
 513 static u32 tcm_loop_get_inst_index(struct se_portal_group *se_tpg)
 514 {
 515         return 1;
 516 }
 517
 518 static u32 tcm_loop_sess_get_index(struct se_session *se_sess)
 519 {
 520         return 1;
 521 }
 522
 523 static void tcm_loop_set_default_node_attributes(struct se_node_acl *se_acl)
 524 {
 525         return;
 526 }
 527
 528 static int tcm_loop_get_cmd_state(struct se_cmd *se_cmd)
 529 {
 530         struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
 531                         struct tcm_loop_cmd, tl_se_cmd);
 532
 533         return tl_cmd->sc_cmd_state;
 534 }
 535
 536 static int tcm_loop_write_pending(struct se_cmd *se_cmd)
 537 {
 538         /*
 539          * Since Linux/SCSI has already sent down a struct scsi_cmnd
 540          * sc->sc_data_direction of DMA_TO_DEVICE with struct scatterlist array
 541          * memory, and memory has already been mapped to struct se_cmd->t_mem_list
 542          * format with transport_generic_map_mem_to_cmd().
 543          *
 544          * We now tell TCM to add this WRITE CDB directly into the TCM storage
 545          * object execution queue.
 546          */
 547         target_execute_cmd(se_cmd);
 548         return 0;
 549 }
 550
 551 static int tcm_loop_queue_data_or_status(const char *func,
 552                 struct se_cmd *se_cmd, u8 scsi_status)
 553 {
 554         struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
 555                                 struct tcm_loop_cmd, tl_se_cmd);
 556         struct scsi_cmnd *sc = tl_cmd->sc;
 557
 558         pr_debug("%s() called for scsi_cmnd: %p cdb: 0x%02x\n",
 559                  func, sc, sc->cmnd[0]);
 560
 561         if (se_cmd->sense_buffer &&
 562            ((se_cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) ||
 563             (se_cmd->se_cmd_flags & SCF_EMULATED_TASK_SENSE))) {
 564
 565                 memcpy(sc->sense_buffer, se_cmd->sense_buffer,
 566                                 SCSI_SENSE_BUFFERSIZE);
 567                 sc->result = SAM_STAT_CHECK_CONDITION;
 568         } else
 569                 sc->result = scsi_status;
 570
 571         set_host_byte(sc, DID_OK);
 572         if ((se_cmd->se_cmd_flags & SCF_OVERFLOW_BIT) ||
 573             (se_cmd->se_cmd_flags & SCF_UNDERFLOW_BIT))
 574                 scsi_set_resid(sc, se_cmd->residual_count);
 575         return 0;
 576 }
 577
 578 static int tcm_loop_queue_data_in(struct se_cmd *se_cmd)
 579 {
 580         return tcm_loop_queue_data_or_status(__func__, se_cmd, SAM_STAT_GOOD);
 581 }
 582
 583 static int tcm_loop_queue_status(struct se_cmd *se_cmd)
 584 {
 585         return tcm_loop_queue_data_or_status(__func__,
 586                                              se_cmd, se_cmd->scsi_status);
 587 }
 588
 589 static void tcm_loop_queue_tm_rsp(struct se_cmd *se_cmd)
 590 {
 591         struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
 592                                 struct tcm_loop_cmd, tl_se_cmd);
 593
 594         /* Wake up tcm_loop_issue_tmr(). */
 595         complete(&tl_cmd->tmr_done);
 596 }
 597
 598 static void tcm_loop_aborted_task(struct se_cmd *se_cmd)
 599 {
 600         return;
 601 }
 602
 603 static char *tcm_loop_dump_proto_id(struct tcm_loop_hba *tl_hba)
 604 {
 605         switch (tl_hba->tl_proto_id) {
 606         case SCSI_PROTOCOL_SAS:
 607                 return "SAS";
 608         case SCSI_PROTOCOL_FCP:
 609                 return "FCP";
 610         case SCSI_PROTOCOL_ISCSI:
 611                 return "iSCSI";
 612         default:
 613                 break;
 614         }
 615
 616         return "Unknown";
 617 }
 618
 619 /* Start items for tcm_loop_port_cit */
 620
 621 static int tcm_loop_port_link(
 622         struct se_portal_group *se_tpg,
 623         struct se_lun *lun)
 624 {
 625         struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
 626                                 struct tcm_loop_tpg, tl_se_tpg);
 627         struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
 628
 629         atomic_inc_mb(&tl_tpg->tl_tpg_port_count);
 630         /*
 631          * Add Linux/SCSI struct scsi_device by HCTL
 632          */
 633         scsi_add_device(tl_hba->sh, 0, tl_tpg->tl_tpgt, lun->unpacked_lun);
 634
 635         pr_debug("TCM_Loop_ConfigFS: Port Link Successful\n");
 636         return 0;
 637 }
 638
 639 static void tcm_loop_port_unlink(
 640         struct se_portal_group *se_tpg,
 641         struct se_lun *se_lun)
 642 {
 643         struct scsi_device *sd;
 644         struct tcm_loop_hba *tl_hba;
 645         struct tcm_loop_tpg *tl_tpg;
 646
 647         tl_tpg = container_of(se_tpg, struct tcm_loop_tpg, tl_se_tpg);
 648         tl_hba = tl_tpg->tl_hba;
 649
 650         sd = scsi_device_lookup(tl_hba->sh, 0, tl_tpg->tl_tpgt,
 651                                 se_lun->unpacked_lun);
 652         if (!sd) {
 653                 pr_err("Unable to locate struct scsi_device for %d:%d:%llu\n",
 654                        0, tl_tpg->tl_tpgt, se_lun->unpacked_lun);
 655                 return;
 656         }
 657         /*
 658          * Remove Linux/SCSI struct scsi_device by HCTL
 659          */
 660         scsi_remove_device(sd);
 661         scsi_device_put(sd);
 662
 663         atomic_dec_mb(&tl_tpg->tl_tpg_port_count);
 664
 665         pr_debug("TCM_Loop_ConfigFS: Port Unlink Successful\n");
 666 }
 667
 668 /* End items for tcm_loop_port_cit */
 669
 670 static ssize_t tcm_loop_tpg_attrib_fabric_prot_type_show(
 671                 struct config_item *item, char *page)
 672 {
 673         struct se_portal_group *se_tpg = attrib_to_tpg(item);
 674         struct tcm_loop_tpg *tl_tpg = container_of(se_tpg, struct tcm_loop_tpg,
 675                                                    tl_se_tpg);
 676
 677         return sprintf(page, "%d\n", tl_tpg->tl_fabric_prot_type);
 678 }
 679
 680 static ssize_t tcm_loop_tpg_attrib_fabric_prot_type_store(
 681                 struct config_item *item, const char *page, size_t count)
 682 {
 683         struct se_portal_group *se_tpg = attrib_to_tpg(item);
 684         struct tcm_loop_tpg *tl_tpg = container_of(se_tpg, struct tcm_loop_tpg,
 685                                                    tl_se_tpg);
 686         unsigned long val;
 687         int ret = kstrtoul(page, 0, &val);
 688
 689         if (ret) {
 690                 pr_err("kstrtoul() returned %d for fabric_prot_type\n", ret);
 691                 return ret;
 692         }
 693         if (val != 0 && val != 1 && val != 3) {
 694                 pr_err("Invalid qla2xxx fabric_prot_type: %lu\n", val);
 695                 return -EINVAL;
 696         }
 697         tl_tpg->tl_fabric_prot_type = val;
 698
 699         return count;
 700 }
 701
 702 CONFIGFS_ATTR(tcm_loop_tpg_attrib_, fabric_prot_type);
 703
 704 static struct configfs_attribute *tcm_loop_tpg_attrib_attrs[] = {
 705         &tcm_loop_tpg_attrib_attr_fabric_prot_type,
 706         NULL,
 707 };
 708
 709 /* Start items for tcm_loop_nexus_cit */
 710
 711 static int tcm_loop_alloc_sess_cb(struct se_portal_group *se_tpg,
 712                                   struct se_session *se_sess, void *p)
 713 {
 714         struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
 715                                         struct tcm_loop_tpg, tl_se_tpg);
 716
 717         tl_tpg->tl_nexus = p;
 718         return 0;
 719 }
 720
 721 static int tcm_loop_make_nexus(
 722         struct tcm_loop_tpg *tl_tpg,
 723         const char *name)
 724 {
 725         struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
 726         struct tcm_loop_nexus *tl_nexus;
 727         int ret;
 728
 729         if (tl_tpg->tl_nexus) {
 730                 pr_debug("tl_tpg->tl_nexus already exists\n");
 731                 return -EEXIST;
 732         }
 733
 734         tl_nexus = kzalloc(sizeof(*tl_nexus), GFP_KERNEL);
 735         if (!tl_nexus)
 736                 return -ENOMEM;
 737
 738         tl_nexus->se_sess = target_setup_session(&tl_tpg->tl_se_tpg, 0, 0,
 739                                         TARGET_PROT_DIN_PASS | TARGET_PROT_DOUT_PASS,
 740                                         name, tl_nexus, tcm_loop_alloc_sess_cb);
 741         if (IS_ERR(tl_nexus->se_sess)) {
 742                 ret = PTR_ERR(tl_nexus->se_sess);
 743                 kfree(tl_nexus);
 744                 return ret;
 745         }
 746
 747         pr_debug("TCM_Loop_ConfigFS: Established I_T Nexus to emulated %s Initiator Port: %s\n",
 748                  tcm_loop_dump_proto_id(tl_hba), name);
 749         return 0;
 750 }
 751
 752 static int tcm_loop_drop_nexus(
 753         struct tcm_loop_tpg *tpg)
 754 {
 755         struct se_session *se_sess;
 756         struct tcm_loop_nexus *tl_nexus;
 757
 758         tl_nexus = tpg->tl_nexus;
 759         if (!tl_nexus)
 760                 return -ENODEV;
 761
 762         se_sess = tl_nexus->se_sess;
 763         if (!se_sess)
 764                 return -ENODEV;
 765
 766         if (atomic_read(&tpg->tl_tpg_port_count)) {
 767                 pr_err("Unable to remove TCM_Loop I_T Nexus with active TPG port count: %d\n",
 768                        atomic_read(&tpg->tl_tpg_port_count));
 769                 return -EPERM;
 770         }
 771
 772         pr_debug("TCM_Loop_ConfigFS: Removing I_T Nexus to emulated %s Initiator Port: %s\n",
 773                  tcm_loop_dump_proto_id(tpg->tl_hba),
 774                  tl_nexus->se_sess->se_node_acl->initiatorname);
 775         /*
 776          * Release the SCSI I_T Nexus to the emulated Target Port
 777          */
 778         target_remove_session(se_sess);
 779         tpg->tl_nexus = NULL;
 780         kfree(tl_nexus);
 781         return 0;
 782 }
 783
 784 /* End items for tcm_loop_nexus_cit */
 785
 786 static ssize_t tcm_loop_tpg_nexus_show(struct config_item *item, char *page)
 787 {
 788         struct se_portal_group *se_tpg = to_tpg(item);
 789         struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
 790                         struct tcm_loop_tpg, tl_se_tpg);
 791         struct tcm_loop_nexus *tl_nexus;
 792         ssize_t ret;
 793
 794         tl_nexus = tl_tpg->tl_nexus;
 795         if (!tl_nexus)
 796                 return -ENODEV;
 797
 798         ret = snprintf(page, PAGE_SIZE, "%s\n",
 799                 tl_nexus->se_sess->se_node_acl->initiatorname);
 800
 801         return ret;
 802 }
 803
 804 static ssize_t tcm_loop_tpg_nexus_store(struct config_item *item,
 805                 const char *page, size_t count)
 806 {
 807         struct se_portal_group *se_tpg = to_tpg(item);
 808         struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
 809                         struct tcm_loop_tpg, tl_se_tpg);
 810         struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
 811         unsigned char i_port[TL_WWN_ADDR_LEN], *ptr, *port_ptr;
 812         int ret;
 813         /*
 814          * Shutdown the active I_T nexus if 'NULL' is passed..
 815          */
 816         if (!strncmp(page, "NULL", 4)) {
 817                 ret = tcm_loop_drop_nexus(tl_tpg);
 818                 return (!ret) ? count : ret;
 819         }
 820         /*
 821          * Otherwise make sure the passed virtual Initiator port WWN matches
 822          * the fabric protocol_id set in tcm_loop_make_scsi_hba(), and call
 823          * tcm_loop_make_nexus()
 824          */
 825         if (strlen(page) >= TL_WWN_ADDR_LEN) {
 826                 pr_err("Emulated NAA Sas Address: %s, exceeds max: %d\n",
 827                        page, TL_WWN_ADDR_LEN);
 828                 return -EINVAL;
 829         }
 830         snprintf(&i_port[0], TL_WWN_ADDR_LEN, "%s", page);
 831
 832         ptr = strstr(i_port, "naa.");
 833         if (ptr) {
 834                 if (tl_hba->tl_proto_id != SCSI_PROTOCOL_SAS) {
 835                         pr_err("Passed SAS Initiator Port %s does not match target port protoid: %s\n",
 836                                i_port, tcm_loop_dump_proto_id(tl_hba));
 837                         return -EINVAL;
 838                 }
 839                 port_ptr = &i_port[0];
 840                 goto check_newline;
 841         }
 842         ptr = strstr(i_port, "fc.");
 843         if (ptr) {
 844                 if (tl_hba->tl_proto_id != SCSI_PROTOCOL_FCP) {
 845                         pr_err("Passed FCP Initiator Port %s does not match target port protoid: %s\n",
 846                                i_port, tcm_loop_dump_proto_id(tl_hba));
 847                         return -EINVAL;
 848                 }
 849                 port_ptr = &i_port[3]; /* Skip over "fc." */
 850                 goto check_newline;
 851         }
 852         ptr = strstr(i_port, "iqn.");
 853         if (ptr) {
 854                 if (tl_hba->tl_proto_id != SCSI_PROTOCOL_ISCSI) {
 855                         pr_err("Passed iSCSI Initiator Port %s does not match target port protoid: %s\n",
 856                                i_port, tcm_loop_dump_proto_id(tl_hba));
 857                         return -EINVAL;
 858                 }
 859                 port_ptr = &i_port[0];
 860                 goto check_newline;
 861         }
 862         pr_err("Unable to locate prefix for emulated Initiator Port: %s\n",
 863                i_port);
 864         return -EINVAL;
 865         /*
 866          * Clear any trailing newline for the NAA WWN
 867          */
 868 check_newline:
 869         if (i_port[strlen(i_port)-1] == '\n')
 870                 i_port[strlen(i_port)-1] = '\0';
 871
 872         ret = tcm_loop_make_nexus(tl_tpg, port_ptr);
 873         if (ret < 0)
 874                 return ret;
 875
 876         return count;
 877 }
 878
 879 static ssize_t tcm_loop_tpg_transport_status_show(struct config_item *item,
 880                 char *page)
 881 {
 882         struct se_portal_group *se_tpg = to_tpg(item);
 883         struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
 884                         struct tcm_loop_tpg, tl_se_tpg);
 885         const char *status = NULL;
 886         ssize_t ret = -EINVAL;
 887
 888         switch (tl_tpg->tl_transport_status) {
 889         case TCM_TRANSPORT_ONLINE:
 890                 status = "online";
 891                 break;
 892         case TCM_TRANSPORT_OFFLINE:
 893                 status = "offline";
 894                 break;
 895         default:
 896                 break;
 897         }
 898
 899         if (status)
 900                 ret = snprintf(page, PAGE_SIZE, "%s\n", status);
 901
 902         return ret;
 903 }
 904
 905 static ssize_t tcm_loop_tpg_transport_status_store(struct config_item *item,
 906                 const char *page, size_t count)
 907 {
 908         struct se_portal_group *se_tpg = to_tpg(item);
 909         struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
 910                         struct tcm_loop_tpg, tl_se_tpg);
 911
 912         if (!strncmp(page, "online", 6)) {
 913                 tl_tpg->tl_transport_status = TCM_TRANSPORT_ONLINE;
 914                 return count;
 915         }
 916         if (!strncmp(page, "offline", 7)) {
 917                 tl_tpg->tl_transport_status = TCM_TRANSPORT_OFFLINE;
 918                 if (tl_tpg->tl_nexus) {
 919                         struct se_session *tl_sess = tl_tpg->tl_nexus->se_sess;
 920
 921                         core_allocate_nexus_loss_ua(tl_sess->se_node_acl);
 922                 }
 923                 return count;
 924         }
 925         return -EINVAL;
 926 }
 927
 928 static ssize_t tcm_loop_tpg_address_show(struct config_item *item,
 929                                          char *page)
 930 {
 931         struct se_portal_group *se_tpg = to_tpg(item);
 932         struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
 933                         struct tcm_loop_tpg, tl_se_tpg);
 934         struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
 935
 936         return snprintf(page, PAGE_SIZE, "%d:0:%d\n",
 937                         tl_hba->sh->host_no, tl_tpg->tl_tpgt);
 938 }
 939
 940 CONFIGFS_ATTR(tcm_loop_tpg_, nexus);
 941 CONFIGFS_ATTR(tcm_loop_tpg_, transport_status);
 942 CONFIGFS_ATTR_RO(tcm_loop_tpg_, address);
 943
 944 static struct configfs_attribute *tcm_loop_tpg_attrs[] = {
 945         &tcm_loop_tpg_attr_nexus,
 946         &tcm_loop_tpg_attr_transport_status,
 947         &tcm_loop_tpg_attr_address,
 948         NULL,
 949 };
 950
 951 /* Start items for tcm_loop_naa_cit */
 952
 953 static struct se_portal_group *tcm_loop_make_naa_tpg(struct se_wwn *wwn,
 954                                                      const char *name)
 955 {
 956         struct tcm_loop_hba *tl_hba = container_of(wwn,
 957                         struct tcm_loop_hba, tl_hba_wwn);
 958         struct tcm_loop_tpg *tl_tpg;
 959         int ret;
 960         unsigned long tpgt;
 961
 962         if (strstr(name, "tpgt_") != name) {
 963                 pr_err("Unable to locate \"tpgt_#\" directory group\n");
 964                 return ERR_PTR(-EINVAL);
 965         }
 966         if (kstrtoul(name+5, 10, &tpgt))
 967                 return ERR_PTR(-EINVAL);
 968
 969         if (tpgt >= TL_TPGS_PER_HBA) {
 970                 pr_err("Passed tpgt: %lu exceeds TL_TPGS_PER_HBA: %u\n",
 971                        tpgt, TL_TPGS_PER_HBA);
 972                 return ERR_PTR(-EINVAL);
 973         }
 974         tl_tpg = &tl_hba->tl_hba_tpgs[tpgt];
 975         tl_tpg->tl_hba = tl_hba;
 976         tl_tpg->tl_tpgt = tpgt;
 977         /*
 978          * Register the tl_tpg as a emulated TCM Target Endpoint
 979          */
 980         ret = core_tpg_register(wwn, &tl_tpg->tl_se_tpg, tl_hba->tl_proto_id);
 981         if (ret < 0)
 982                 return ERR_PTR(-ENOMEM);
 983
 984         pr_debug("TCM_Loop_ConfigFS: Allocated Emulated %s Target Port %s,t,0x%04lx\n",
 985                  tcm_loop_dump_proto_id(tl_hba),
 986                  config_item_name(&wwn->wwn_group.cg_item), tpgt);
 987         return &tl_tpg->tl_se_tpg;
 988 }
 989
 990 static void tcm_loop_drop_naa_tpg(
 991         struct se_portal_group *se_tpg)
 992 {
 993         struct se_wwn *wwn = se_tpg->se_tpg_wwn;
 994         struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
 995                                 struct tcm_loop_tpg, tl_se_tpg);
 996         struct tcm_loop_hba *tl_hba;
 997         unsigned short tpgt;
 998
 999         tl_hba = tl_tpg->tl_hba;
1000         tpgt = tl_tpg->tl_tpgt;
1001         /*
1002          * Release the I_T Nexus for the Virtual target link if present
1003          */
1004         tcm_loop_drop_nexus(tl_tpg);
1005         /*
1006          * Deregister the tl_tpg as a emulated TCM Target Endpoint
1007          */
1008         core_tpg_deregister(se_tpg);
1009
1010         tl_tpg->tl_hba = NULL;
1011         tl_tpg->tl_tpgt = 0;
1012
1013         pr_debug("TCM_Loop_ConfigFS: Deallocated Emulated %s Target Port %s,t,0x%04x\n",
1014                  tcm_loop_dump_proto_id(tl_hba),
1015                  config_item_name(&wwn->wwn_group.cg_item), tpgt);
1016 }
1017
1018 /* End items for tcm_loop_naa_cit */
1019
1020 /* Start items for tcm_loop_cit */
1021
1022 static struct se_wwn *tcm_loop_make_scsi_hba(
1023         struct target_fabric_configfs *tf,
1024         struct config_group *group,
1025         const char *name)
1026 {
1027         struct tcm_loop_hba *tl_hba;
1028         struct Scsi_Host *sh;
1029         char *ptr;
1030         int ret, off = 0;
1031
1032         tl_hba = kzalloc(sizeof(*tl_hba), GFP_KERNEL);
1033         if (!tl_hba)
1034                 return ERR_PTR(-ENOMEM);
1035
1036         /*
1037          * Determine the emulated Protocol Identifier and Target Port Name
1038          * based on the incoming configfs directory name.
1039          */
1040         ptr = strstr(name, "naa.");
1041         if (ptr) {
1042                 tl_hba->tl_proto_id = SCSI_PROTOCOL_SAS;
1043                 goto check_len;
1044         }
1045         ptr = strstr(name, "fc.");
1046         if (ptr) {
1047                 tl_hba->tl_proto_id = SCSI_PROTOCOL_FCP;
1048                 off = 3; /* Skip over "fc." */
1049                 goto check_len;
1050         }
1051         ptr = strstr(name, "iqn.");
1052         if (!ptr) {
1053                 pr_err("Unable to locate prefix for emulated Target Port: %s\n",
1054                        name);
1055                 ret = -EINVAL;
1056                 goto out;
1057         }
1058         tl_hba->tl_proto_id = SCSI_PROTOCOL_ISCSI;
1059
1060 check_len:
1061         if (strlen(name) >= TL_WWN_ADDR_LEN) {
1062                 pr_err("Emulated NAA %s Address: %s, exceeds max: %d\n",
1063                        name, tcm_loop_dump_proto_id(tl_hba), TL_WWN_ADDR_LEN);
1064                 ret = -EINVAL;
1065                 goto out;
1066         }
1067         snprintf(&tl_hba->tl_wwn_address[0], TL_WWN_ADDR_LEN, "%s", &name[off]);
1068
1069         /*
1070          * Call device_register(tl_hba->dev) to register the emulated
1071          * Linux/SCSI LLD of type struct Scsi_Host at tl_hba->sh after
1072          * device_register() callbacks in tcm_loop_driver_probe()
1073          */
1074         ret = tcm_loop_setup_hba_bus(tl_hba, tcm_loop_hba_no_cnt);
1075         if (ret)
1076                 goto out;
1077
1078         sh = tl_hba->sh;
1079         tcm_loop_hba_no_cnt++;
1080         pr_debug("TCM_Loop_ConfigFS: Allocated emulated Target %s Address: %s at Linux/SCSI Host ID: %d\n",
1081                  tcm_loop_dump_proto_id(tl_hba), name, sh->host_no);
1082         return &tl_hba->tl_hba_wwn;
1083 out:
1084         kfree(tl_hba);
1085         return ERR_PTR(ret);
1086 }
1087
1088 static void tcm_loop_drop_scsi_hba(
1089         struct se_wwn *wwn)
1090 {
1091         struct tcm_loop_hba *tl_hba = container_of(wwn,
1092                                 struct tcm_loop_hba, tl_hba_wwn);
1093
1094         pr_debug("TCM_Loop_ConfigFS: Deallocating emulated Target %s Address: %s at Linux/SCSI Host ID: %d\n",
1095                  tcm_loop_dump_proto_id(tl_hba), tl_hba->tl_wwn_address,
1096                  tl_hba->sh->host_no);
1097         /*
1098          * Call device_unregister() on the original tl_hba->dev.
1099          * tcm_loop_fabric_scsi.c:tcm_loop_release_adapter() will
1100          * release *tl_hba;
1101          */
1102         device_unregister(&tl_hba->dev);
1103 }
1104
1105 /* Start items for tcm_loop_cit */
1106 static ssize_t tcm_loop_wwn_version_show(struct config_item *item, char *page)
1107 {
1108         return sprintf(page, "TCM Loopback Fabric module %s\n", TCM_LOOP_VERSION);
1109 }
1110
1111 CONFIGFS_ATTR_RO(tcm_loop_wwn_, version);
1112
1113 static struct configfs_attribute *tcm_loop_wwn_attrs[] = {
1114         &tcm_loop_wwn_attr_version,
1115         NULL,
1116 };
1117
1118 /* End items for tcm_loop_cit */
1119
1120 static const struct target_core_fabric_ops loop_ops = {
1121         .module                         = THIS_MODULE,
1122         .fabric_name                    = "loopback",
1123         .tpg_get_wwn                    = tcm_loop_get_endpoint_wwn,
1124         .tpg_get_tag                    = tcm_loop_get_tag,
1125         .tpg_check_demo_mode            = tcm_loop_check_demo_mode,
1126         .tpg_check_demo_mode_cache      = tcm_loop_check_demo_mode_cache,
1127         .tpg_check_demo_mode_write_protect =
1128                                 tcm_loop_check_demo_mode_write_protect,
1129         .tpg_check_prod_mode_write_protect =
1130                                 tcm_loop_check_prod_mode_write_protect,
1131         .tpg_check_prot_fabric_only     = tcm_loop_check_prot_fabric_only,
1132         .tpg_get_inst_index             = tcm_loop_get_inst_index,
1133         .check_stop_free                = tcm_loop_check_stop_free,
1134         .release_cmd                    = tcm_loop_release_cmd,
1135         .sess_get_index                 = tcm_loop_sess_get_index,
1136         .write_pending                  = tcm_loop_write_pending,
1137         .set_default_node_attributes    = tcm_loop_set_default_node_attributes,
1138         .get_cmd_state                  = tcm_loop_get_cmd_state,
1139         .queue_data_in                  = tcm_loop_queue_data_in,
1140         .queue_status                   = tcm_loop_queue_status,
1141         .queue_tm_rsp                   = tcm_loop_queue_tm_rsp,
1142         .aborted_task                   = tcm_loop_aborted_task,
1143         .fabric_make_wwn                = tcm_loop_make_scsi_hba,
1144         .fabric_drop_wwn                = tcm_loop_drop_scsi_hba,
1145         .fabric_make_tpg                = tcm_loop_make_naa_tpg,
1146         .fabric_drop_tpg                = tcm_loop_drop_naa_tpg,
1147         .fabric_post_link               = tcm_loop_port_link,
1148         .fabric_pre_unlink              = tcm_loop_port_unlink,
1149         .tfc_wwn_attrs                  = tcm_loop_wwn_attrs,
1150         .tfc_tpg_base_attrs             = tcm_loop_tpg_attrs,
1151         .tfc_tpg_attrib_attrs           = tcm_loop_tpg_attrib_attrs,
1152 };
1153
1154 static int __init tcm_loop_fabric_init(void)
1155 {
1156         int ret = -ENOMEM;
1157
1158         tcm_loop_cmd_cache = kmem_cache_create("tcm_loop_cmd_cache",
1159                                 sizeof(struct tcm_loop_cmd),
1160                                 __alignof__(struct tcm_loop_cmd),
1161                                 0, NULL);
1162         if (!tcm_loop_cmd_cache) {
1163                 pr_debug("kmem_cache_create() for tcm_loop_cmd_cache failed\n");
1164                 goto out;
1165         }
1166
1167         ret = tcm_loop_alloc_core_bus();
1168         if (ret)
1169                 goto out_destroy_cache;
1170
1171         ret = target_register_template(&loop_ops);
1172         if (ret)
1173                 goto out_release_core_bus;
1174
1175         return 0;
1176
1177 out_release_core_bus:
1178         tcm_loop_release_core_bus();
1179 out_destroy_cache:
1180         kmem_cache_destroy(tcm_loop_cmd_cache);
1181 out:
1182         return ret;
1183 }
1184
1185 static void __exit tcm_loop_fabric_exit(void)
1186 {
1187         target_unregister_template(&loop_ops);
1188         tcm_loop_release_core_bus();
1189         kmem_cache_destroy(tcm_loop_cmd_cache);
1190 }
1191
1192 MODULE_DESCRIPTION("TCM loopback virtual Linux/SCSI fabric module");
1193 MODULE_AUTHOR("Nicholas A. Bellinger <nab@risingtidesystems.com>");
1194 MODULE_LICENSE("GPL");
1195 module_init(tcm_loop_fabric_init);
1196 module_exit(tcm_loop_fabric_exit);