drivers/target/tcm_fc/tfc_cmd.c

   1 /*
   2  * Copyright (c) 2010 Cisco Systems, Inc.
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms and conditions of the GNU General Public License,
   6  * version 2, as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  11  * more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along with
  14  * this program; if not, write to the Free Software Foundation, Inc.,
  15  * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
  16  */
  17
  18 /* XXX TBD some includes may be extraneous */
  19
  20 #include <linux/module.h>
  21 #include <linux/moduleparam.h>
  22 #include <linux/version.h>
  23 #include <generated/utsrelease.h>
  24 #include <linux/utsname.h>
  25 #include <linux/init.h>
  26 #include <linux/slab.h>
  27 #include <linux/kthread.h>
  28 #include <linux/types.h>
  29 #include <linux/string.h>
  30 #include <linux/configfs.h>
  31 #include <linux/ctype.h>
  32 #include <linux/hash.h>
  33 #include <asm/unaligned.h>
  34 #include <scsi/scsi.h>
  35 #include <scsi/scsi_host.h>
  36 #include <scsi/scsi_device.h>
  37 #include <scsi/scsi_cmnd.h>
  38 #include <scsi/scsi_tcq.h>
  39 #include <scsi/libfc.h>
  40 #include <scsi/fc_encode.h>
  41
  42 #include <target/target_core_base.h>
  43 #include <target/target_core_transport.h>
  44 #include <target/target_core_fabric_ops.h>
  45 #include <target/target_core_device.h>
  46 #include <target/target_core_tpg.h>
  47 #include <target/target_core_configfs.h>
  48 #include <target/target_core_base.h>
  49 #include <target/target_core_tmr.h>
  50 #include <target/configfs_macros.h>
  51
  52 #include "tcm_fc.h"
  53
  54 /*
  55  * Dump cmd state for debugging.
  56  */
  57 void ft_dump_cmd(struct ft_cmd *cmd, const char *caller)
  58 {
  59         struct fc_exch *ep;
  60         struct fc_seq *sp;
  61         struct se_cmd *se_cmd;
  62         struct scatterlist *sg;
  63         int count;
  64
  65         se_cmd = &cmd->se_cmd;
  66         pr_debug("%s: cmd %p state %d sess %p seq %p se_cmd %p\n",
  67                 caller, cmd, cmd->state, cmd->sess, cmd->seq, se_cmd);
  68         pr_debug("%s: cmd %p cdb %p\n",
  69                 caller, cmd, cmd->cdb);
  70         pr_debug("%s: cmd %p lun %d\n", caller, cmd, cmd->lun);
  71
  72         pr_debug("%s: cmd %p data_nents %u len %u se_cmd_flags <0x%x>\n",
  73                 caller, cmd, se_cmd->t_data_nents,
  74                se_cmd->data_length, se_cmd->se_cmd_flags);
  75
  76         for_each_sg(se_cmd->t_data_sg, sg, se_cmd->t_data_nents, count)
  77                 pr_debug("%s: cmd %p sg %p page %p "
  78                         "len 0x%x off 0x%x\n",
  79                         caller, cmd, sg,
  80                         sg_page(sg), sg->length, sg->offset);
  81
  82         sp = cmd->seq;
  83         if (sp) {
  84                 ep = fc_seq_exch(sp);
  85                 pr_debug("%s: cmd %p sid %x did %x "
  86                         "ox_id %x rx_id %x seq_id %x e_stat %x\n",
  87                         caller, cmd, ep->sid, ep->did, ep->oxid, ep->rxid,
  88                         sp->id, ep->esb_stat);
  89         }
  90         print_hex_dump(KERN_INFO, "ft_dump_cmd ", DUMP_PREFIX_NONE,
  91                 16, 4, cmd->cdb, MAX_COMMAND_SIZE, 0);
  92 }
  93
  94 static void ft_queue_cmd(struct ft_sess *sess, struct ft_cmd *cmd)
  95 {
  96         struct ft_tpg *tpg = sess->tport->tpg;
  97         struct se_queue_obj *qobj = &tpg->qobj;
  98         unsigned long flags;
  99
 100         qobj = &sess->tport->tpg->qobj;
 101         spin_lock_irqsave(&qobj->cmd_queue_lock, flags);
 102         list_add_tail(&cmd->se_req.qr_list, &qobj->qobj_list);
 103         atomic_inc(&qobj->queue_cnt);
 104         spin_unlock_irqrestore(&qobj->cmd_queue_lock, flags);
 105
 106         wake_up_process(tpg->thread);
 107 }
 108
 109 static struct ft_cmd *ft_dequeue_cmd(struct se_queue_obj *qobj)
 110 {
 111         unsigned long flags;
 112         struct se_queue_req *qr;
 113
 114         spin_lock_irqsave(&qobj->cmd_queue_lock, flags);
 115         if (list_empty(&qobj->qobj_list)) {
 116                 spin_unlock_irqrestore(&qobj->cmd_queue_lock, flags);
 117                 return NULL;
 118         }
 119         qr = list_first_entry(&qobj->qobj_list, struct se_queue_req, qr_list);
 120         list_del(&qr->qr_list);
 121         atomic_dec(&qobj->queue_cnt);
 122         spin_unlock_irqrestore(&qobj->cmd_queue_lock, flags);
 123         return container_of(qr, struct ft_cmd, se_req);
 124 }
 125
 126 static void ft_free_cmd(struct ft_cmd *cmd)
 127 {
 128         struct fc_frame *fp;
 129         struct fc_lport *lport;
 130
 131         if (!cmd)
 132                 return;
 133         fp = cmd->req_frame;
 134         lport = fr_dev(fp);
 135         if (fr_seq(fp))
 136                 lport->tt.seq_release(fr_seq(fp));
 137         fc_frame_free(fp);
 138         ft_sess_put(cmd->sess); /* undo get from lookup at recv */
 139         kfree(cmd);
 140 }
 141
 142 void ft_release_cmd(struct se_cmd *se_cmd)
 143 {
 144         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
 145
 146         ft_free_cmd(cmd);
 147 }
 148
 149 void ft_check_stop_free(struct se_cmd *se_cmd)
 150 {
 151         transport_generic_free_cmd(se_cmd, 0, 0);
 152 }
 153
 154 /*
 155  * Send response.
 156  */
 157 int ft_queue_status(struct se_cmd *se_cmd)
 158 {
 159         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
 160         struct fc_frame *fp;
 161         struct fcp_resp_with_ext *fcp;
 162         struct fc_lport *lport;
 163         struct fc_exch *ep;
 164         size_t len;
 165
 166         ft_dump_cmd(cmd, __func__);
 167         ep = fc_seq_exch(cmd->seq);
 168         lport = ep->lp;
 169         len = sizeof(*fcp) + se_cmd->scsi_sense_length;
 170         fp = fc_frame_alloc(lport, len);
 171         if (!fp) {
 172                 /* XXX shouldn't just drop it - requeue and retry? */
 173                 return 0;
 174         }
 175         fcp = fc_frame_payload_get(fp, len);
 176         memset(fcp, 0, len);
 177         fcp->resp.fr_status = se_cmd->scsi_status;
 178
 179         len = se_cmd->scsi_sense_length;
 180         if (len) {
 181                 fcp->resp.fr_flags |= FCP_SNS_LEN_VAL;
 182                 fcp->ext.fr_sns_len = htonl(len);
 183                 memcpy((fcp + 1), se_cmd->sense_buffer, len);
 184         }
 185
 186         /*
 187          * Test underflow and overflow with one mask.  Usually both are off.
 188          * Bidirectional commands are not handled yet.
 189          */
 190         if (se_cmd->se_cmd_flags & (SCF_OVERFLOW_BIT | SCF_UNDERFLOW_BIT)) {
 191                 if (se_cmd->se_cmd_flags & SCF_OVERFLOW_BIT)
 192                         fcp->resp.fr_flags |= FCP_RESID_OVER;
 193                 else
 194                         fcp->resp.fr_flags |= FCP_RESID_UNDER;
 195                 fcp->ext.fr_resid = cpu_to_be32(se_cmd->residual_count);
 196         }
 197
 198         /*
 199          * Send response.
 200          */
 201         cmd->seq = lport->tt.seq_start_next(cmd->seq);
 202         fc_fill_fc_hdr(fp, FC_RCTL_DD_CMD_STATUS, ep->did, ep->sid, FC_TYPE_FCP,
 203                        FC_FC_EX_CTX | FC_FC_LAST_SEQ | FC_FC_END_SEQ, 0);
 204
 205         lport->tt.seq_send(lport, cmd->seq, fp);
 206         lport->tt.exch_done(cmd->seq);
 207         return 0;
 208 }
 209
 210 int ft_write_pending_status(struct se_cmd *se_cmd)
 211 {
 212         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
 213
 214         return cmd->write_data_len != se_cmd->data_length;
 215 }
 216
 217 /*
 218  * Send TX_RDY (transfer ready).
 219  */
 220 int ft_write_pending(struct se_cmd *se_cmd)
 221 {
 222         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
 223         struct fc_frame *fp;
 224         struct fcp_txrdy *txrdy;
 225         struct fc_lport *lport;
 226         struct fc_exch *ep;
 227         struct fc_frame_header *fh;
 228         u32 f_ctl;
 229
 230         ft_dump_cmd(cmd, __func__);
 231
 232         ep = fc_seq_exch(cmd->seq);
 233         lport = ep->lp;
 234         fp = fc_frame_alloc(lport, sizeof(*txrdy));
 235         if (!fp)
 236                 return PYX_TRANSPORT_OUT_OF_MEMORY_RESOURCES;
 237
 238         txrdy = fc_frame_payload_get(fp, sizeof(*txrdy));
 239         memset(txrdy, 0, sizeof(*txrdy));
 240         txrdy->ft_burst_len = htonl(se_cmd->data_length);
 241
 242         cmd->seq = lport->tt.seq_start_next(cmd->seq);
 243         fc_fill_fc_hdr(fp, FC_RCTL_DD_DATA_DESC, ep->did, ep->sid, FC_TYPE_FCP,
 244                        FC_FC_EX_CTX | FC_FC_END_SEQ | FC_FC_SEQ_INIT, 0);
 245
 246         fh = fc_frame_header_get(fp);
 247         f_ctl = ntoh24(fh->fh_f_ctl);
 248
 249         /* Only if it is 'Exchange Responder' */
 250         if (f_ctl & FC_FC_EX_CTX) {
 251                 /* Target is 'exchange responder' and sending XFER_READY
 252                  * to 'exchange initiator (initiator)'
 253                  */
 254                 if ((ep->xid <= lport->lro_xid) &&
 255                     (fh->fh_r_ctl == FC_RCTL_DD_DATA_DESC)) {
 256                         if (se_cmd->se_cmd_flags & SCF_SCSI_DATA_SG_IO_CDB) {
 257                                 /*
 258                                  * cmd may have been broken up into multiple
 259                                  * tasks. Link their sgs together so we can
 260                                  * operate on them all at once.
 261                                  */
 262                                 transport_do_task_sg_chain(se_cmd);
 263                                 cmd->sg = se_cmd->t_tasks_sg_chained;
 264                                 cmd->sg_cnt =
 265                                         se_cmd->t_tasks_sg_chained_no;
 266                         }
 267                         if (cmd->sg && lport->tt.ddp_target(lport, ep->xid,
 268                                                             cmd->sg,
 269                                                             cmd->sg_cnt))
 270                                 cmd->was_ddp_setup = 1;
 271                 }
 272         }
 273         lport->tt.seq_send(lport, cmd->seq, fp);
 274         return 0;
 275 }
 276
 277 u32 ft_get_task_tag(struct se_cmd *se_cmd)
 278 {
 279         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
 280
 281         return fc_seq_exch(cmd->seq)->rxid;
 282 }
 283
 284 int ft_get_cmd_state(struct se_cmd *se_cmd)
 285 {
 286         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
 287
 288         return cmd->state;
 289 }
 290
 291 int ft_is_state_remove(struct se_cmd *se_cmd)
 292 {
 293         return 0;       /* XXX TBD */
 294 }
 295
 296 /*
 297  * FC sequence response handler for follow-on sequences (data) and aborts.
 298  */
 299 static void ft_recv_seq(struct fc_seq *sp, struct fc_frame *fp, void *arg)
 300 {
 301         struct ft_cmd *cmd = arg;
 302         struct fc_frame_header *fh;
 303
 304         if (IS_ERR(fp)) {
 305                 /* XXX need to find cmd if queued */
 306                 cmd->se_cmd.t_state = TRANSPORT_REMOVE;
 307                 cmd->seq = NULL;
 308                 transport_generic_free_cmd(&cmd->se_cmd, 0, 0);
 309                 return;
 310         }
 311
 312         fh = fc_frame_header_get(fp);
 313
 314         switch (fh->fh_r_ctl) {
 315         case FC_RCTL_DD_SOL_DATA:       /* write data */
 316                 ft_recv_write_data(cmd, fp);
 317                 break;
 318         case FC_RCTL_DD_UNSOL_CTL:      /* command */
 319         case FC_RCTL_DD_SOL_CTL:        /* transfer ready */
 320         case FC_RCTL_DD_DATA_DESC:      /* transfer ready */
 321         default:
 322                 pr_debug("%s: unhandled frame r_ctl %x\n",
 323                        __func__, fh->fh_r_ctl);
 324                 fc_frame_free(fp);
 325                 transport_generic_free_cmd(&cmd->se_cmd, 0, 0);
 326                 break;
 327         }
 328 }
 329
 330 /*
 331  * Send a FCP response including SCSI status and optional FCP rsp_code.
 332  * status is SAM_STAT_GOOD (zero) iff code is valid.
 333  * This is used in error cases, such as allocation failures.
 334  */
 335 static void ft_send_resp_status(struct fc_lport *lport,
 336                                 const struct fc_frame *rx_fp,
 337                                 u32 status, enum fcp_resp_rsp_codes code)
 338 {
 339         struct fc_frame *fp;
 340         struct fc_seq *sp;
 341         const struct fc_frame_header *fh;
 342         size_t len;
 343         struct fcp_resp_with_ext *fcp;
 344         struct fcp_resp_rsp_info *info;
 345
 346         fh = fc_frame_header_get(rx_fp);
 347         pr_debug("FCP error response: did %x oxid %x status %x code %x\n",
 348                   ntoh24(fh->fh_s_id), ntohs(fh->fh_ox_id), status, code);
 349         len = sizeof(*fcp);
 350         if (status == SAM_STAT_GOOD)
 351                 len += sizeof(*info);
 352         fp = fc_frame_alloc(lport, len);
 353         if (!fp)
 354                 return;
 355         fcp = fc_frame_payload_get(fp, len);
 356         memset(fcp, 0, len);
 357         fcp->resp.fr_status = status;
 358         if (status == SAM_STAT_GOOD) {
 359                 fcp->ext.fr_rsp_len = htonl(sizeof(*info));
 360                 fcp->resp.fr_flags |= FCP_RSP_LEN_VAL;
 361                 info = (struct fcp_resp_rsp_info *)(fcp + 1);
 362                 info->rsp_code = code;
 363         }
 364
 365         fc_fill_reply_hdr(fp, rx_fp, FC_RCTL_DD_CMD_STATUS, 0);
 366         sp = fr_seq(fp);
 367         if (sp)
 368                 lport->tt.seq_send(lport, sp, fp);
 369         else
 370                 lport->tt.frame_send(lport, fp);
 371 }
 372
 373 /*
 374  * Send error or task management response.
 375  */
 376 static void ft_send_resp_code(struct ft_cmd *cmd,
 377                               enum fcp_resp_rsp_codes code)
 378 {
 379         ft_send_resp_status(cmd->sess->tport->lport,
 380                             cmd->req_frame, SAM_STAT_GOOD, code);
 381 }
 382
 383
 384 /*
 385  * Send error or task management response.
 386  * Always frees the cmd and associated state.
 387  */
 388 static void ft_send_resp_code_and_free(struct ft_cmd *cmd,
 389                                       enum fcp_resp_rsp_codes code)
 390 {
 391         ft_send_resp_code(cmd, code);
 392         ft_free_cmd(cmd);
 393 }
 394
 395 /*
 396  * Handle Task Management Request.
 397  */
 398 static void ft_send_tm(struct ft_cmd *cmd)
 399 {
 400         struct se_tmr_req *tmr;
 401         struct fcp_cmnd *fcp;
 402         struct ft_sess *sess;
 403         u8 tm_func;
 404
 405         fcp = fc_frame_payload_get(cmd->req_frame, sizeof(*fcp));
 406
 407         switch (fcp->fc_tm_flags) {
 408         case FCP_TMF_LUN_RESET:
 409                 tm_func = TMR_LUN_RESET;
 410                 break;
 411         case FCP_TMF_TGT_RESET:
 412                 tm_func = TMR_TARGET_WARM_RESET;
 413                 break;
 414         case FCP_TMF_CLR_TASK_SET:
 415                 tm_func = TMR_CLEAR_TASK_SET;
 416                 break;
 417         case FCP_TMF_ABT_TASK_SET:
 418                 tm_func = TMR_ABORT_TASK_SET;
 419                 break;
 420         case FCP_TMF_CLR_ACA:
 421                 tm_func = TMR_CLEAR_ACA;
 422                 break;
 423         default:
 424                 /*
 425                  * FCP4r01 indicates having a combination of
 426                  * tm_flags set is invalid.
 427                  */
 428                 pr_debug("invalid FCP tm_flags %x\n", fcp->fc_tm_flags);
 429                 ft_send_resp_code_and_free(cmd, FCP_CMND_FIELDS_INVALID);
 430                 return;
 431         }
 432
 433         pr_debug("alloc tm cmd fn %d\n", tm_func);
 434         tmr = core_tmr_alloc_req(&cmd->se_cmd, cmd, tm_func);
 435         if (!tmr) {
 436                 pr_debug("alloc failed\n");
 437                 ft_send_resp_code_and_free(cmd, FCP_TMF_FAILED);
 438                 return;
 439         }
 440         cmd->se_cmd.se_tmr_req = tmr;
 441
 442         switch (fcp->fc_tm_flags) {
 443         case FCP_TMF_LUN_RESET:
 444                 cmd->lun = scsilun_to_int((struct scsi_lun *)fcp->fc_lun);
 445                 if (transport_lookup_tmr_lun(&cmd->se_cmd, cmd->lun) < 0) {
 446                         /*
 447                          * Make sure to clean up newly allocated TMR request
 448                          * since "unable to  handle TMR request because failed
 449                          * to get to LUN"
 450                          */
 451                         pr_debug("Failed to get LUN for TMR func %d, "
 452                                   "se_cmd %p, unpacked_lun %d\n",
 453                                   tm_func, &cmd->se_cmd, cmd->lun);
 454                         ft_dump_cmd(cmd, __func__);
 455                         sess = cmd->sess;
 456                         transport_send_check_condition_and_sense(&cmd->se_cmd,
 457                                 cmd->se_cmd.scsi_sense_reason, 0);
 458                         transport_generic_free_cmd(&cmd->se_cmd, 0, 0);
 459                         ft_sess_put(sess);
 460                         return;
 461                 }
 462                 break;
 463         case FCP_TMF_TGT_RESET:
 464         case FCP_TMF_CLR_TASK_SET:
 465         case FCP_TMF_ABT_TASK_SET:
 466         case FCP_TMF_CLR_ACA:
 467                 break;
 468         default:
 469                 return;
 470         }
 471         transport_generic_handle_tmr(&cmd->se_cmd);
 472 }
 473
 474 /*
 475  * Send status from completed task management request.
 476  */
 477 int ft_queue_tm_resp(struct se_cmd *se_cmd)
 478 {
 479         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
 480         struct se_tmr_req *tmr = se_cmd->se_tmr_req;
 481         enum fcp_resp_rsp_codes code;
 482
 483         switch (tmr->response) {
 484         case TMR_FUNCTION_COMPLETE:
 485                 code = FCP_TMF_CMPL;
 486                 break;
 487         case TMR_LUN_DOES_NOT_EXIST:
 488                 code = FCP_TMF_INVALID_LUN;
 489                 break;
 490         case TMR_FUNCTION_REJECTED:
 491                 code = FCP_TMF_REJECTED;
 492                 break;
 493         case TMR_TASK_DOES_NOT_EXIST:
 494         case TMR_TASK_STILL_ALLEGIANT:
 495         case TMR_TASK_FAILOVER_NOT_SUPPORTED:
 496         case TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED:
 497         case TMR_FUNCTION_AUTHORIZATION_FAILED:
 498         default:
 499                 code = FCP_TMF_FAILED;
 500                 break;
 501         }
 502         pr_debug("tmr fn %d resp %d fcp code %d\n",
 503                   tmr->function, tmr->response, code);
 504         ft_send_resp_code(cmd, code);
 505         return 0;
 506 }
 507
 508 /*
 509  * Handle incoming FCP command.
 510  */
 511 static void ft_recv_cmd(struct ft_sess *sess, struct fc_frame *fp)
 512 {
 513         struct ft_cmd *cmd;
 514         struct fc_lport *lport = sess->tport->lport;
 515
 516         cmd = kzalloc(sizeof(*cmd), GFP_ATOMIC);
 517         if (!cmd)
 518                 goto busy;
 519         cmd->sess = sess;
 520         cmd->seq = lport->tt.seq_assign(lport, fp);
 521         if (!cmd->seq) {
 522                 kfree(cmd);
 523                 goto busy;
 524         }
 525         cmd->req_frame = fp;            /* hold frame during cmd */
 526         ft_queue_cmd(sess, cmd);
 527         return;
 528
 529 busy:
 530         pr_debug("cmd or seq allocation failure - sending BUSY\n");
 531         ft_send_resp_status(lport, fp, SAM_STAT_BUSY, 0);
 532         fc_frame_free(fp);
 533         ft_sess_put(sess);              /* undo get from lookup */
 534 }
 535
 536
 537 /*
 538  * Handle incoming FCP frame.
 539  * Caller has verified that the frame is type FCP.
 540  */
 541 void ft_recv_req(struct ft_sess *sess, struct fc_frame *fp)
 542 {
 543         struct fc_frame_header *fh = fc_frame_header_get(fp);
 544
 545         switch (fh->fh_r_ctl) {
 546         case FC_RCTL_DD_UNSOL_CMD:      /* command */
 547                 ft_recv_cmd(sess, fp);
 548                 break;
 549         case FC_RCTL_DD_SOL_DATA:       /* write data */
 550         case FC_RCTL_DD_UNSOL_CTL:
 551         case FC_RCTL_DD_SOL_CTL:
 552         case FC_RCTL_DD_DATA_DESC:      /* transfer ready */
 553         case FC_RCTL_ELS4_REQ:          /* SRR, perhaps */
 554         default:
 555                 pr_debug("%s: unhandled frame r_ctl %x\n",
 556                        __func__, fh->fh_r_ctl);
 557                 fc_frame_free(fp);
 558                 ft_sess_put(sess);      /* undo get from lookup */
 559                 break;
 560         }
 561 }
 562
 563 /*
 564  * Send new command to target.
 565  */
 566 static void ft_send_cmd(struct ft_cmd *cmd)
 567 {
 568         struct fc_frame_header *fh = fc_frame_header_get(cmd->req_frame);
 569         struct se_cmd *se_cmd;
 570         struct fcp_cmnd *fcp;
 571         int data_dir;
 572         u32 data_len;
 573         int task_attr;
 574         int ret;
 575
 576         fcp = fc_frame_payload_get(cmd->req_frame, sizeof(*fcp));
 577         if (!fcp)
 578                 goto err;
 579
 580         if (fcp->fc_flags & FCP_CFL_LEN_MASK)
 581                 goto err;               /* not handling longer CDBs yet */
 582
 583         if (fcp->fc_tm_flags) {
 584                 task_attr = FCP_PTA_SIMPLE;
 585                 data_dir = DMA_NONE;
 586                 data_len = 0;
 587         } else {
 588                 switch (fcp->fc_flags & (FCP_CFL_RDDATA | FCP_CFL_WRDATA)) {
 589                 case 0:
 590                         data_dir = DMA_NONE;
 591                         break;
 592                 case FCP_CFL_RDDATA:
 593                         data_dir = DMA_FROM_DEVICE;
 594                         break;
 595                 case FCP_CFL_WRDATA:
 596                         data_dir = DMA_TO_DEVICE;
 597                         break;
 598                 case FCP_CFL_WRDATA | FCP_CFL_RDDATA:
 599                         goto err;       /* TBD not supported by tcm_fc yet */
 600                 }
 601                 /*
 602                  * Locate the SAM Task Attr from fc_pri_ta
 603                  */
 604                 switch (fcp->fc_pri_ta & FCP_PTA_MASK) {
 605                 case FCP_PTA_HEADQ:
 606                         task_attr = MSG_HEAD_TAG;
 607                         break;
 608                 case FCP_PTA_ORDERED:
 609                         task_attr = MSG_ORDERED_TAG;
 610                         break;
 611                 case FCP_PTA_ACA:
 612                         task_attr = MSG_ACA_TAG;
 613                         break;
 614                 case FCP_PTA_SIMPLE: /* Fallthrough */
 615                 default:
 616                         task_attr = MSG_SIMPLE_TAG;
 617                 }
 618
 619
 620                 task_attr = fcp->fc_pri_ta & FCP_PTA_MASK;
 621                 data_len = ntohl(fcp->fc_dl);
 622                 cmd->cdb = fcp->fc_cdb;
 623         }
 624
 625         se_cmd = &cmd->se_cmd;
 626         /*
 627          * Initialize struct se_cmd descriptor from target_core_mod
 628          * infrastructure
 629          */
 630         transport_init_se_cmd(se_cmd, &ft_configfs->tf_ops, cmd->sess->se_sess,
 631                               data_len, data_dir, task_attr,
 632                               &cmd->ft_sense_buffer[0]);
 633         /*
 634          * Check for FCP task management flags
 635          */
 636         if (fcp->fc_tm_flags) {
 637                 ft_send_tm(cmd);
 638                 return;
 639         }
 640
 641         fc_seq_exch(cmd->seq)->lp->tt.seq_set_resp(cmd->seq, ft_recv_seq, cmd);
 642
 643         cmd->lun = scsilun_to_int((struct scsi_lun *)fcp->fc_lun);
 644         ret = transport_lookup_cmd_lun(&cmd->se_cmd, cmd->lun);
 645         if (ret < 0) {
 646                 ft_dump_cmd(cmd, __func__);
 647                 transport_send_check_condition_and_sense(&cmd->se_cmd,
 648                         cmd->se_cmd.scsi_sense_reason, 0);
 649                 return;
 650         }
 651
 652         ret = transport_generic_allocate_tasks(se_cmd, cmd->cdb);
 653
 654         pr_debug("r_ctl %x alloc task ret %d\n", fh->fh_r_ctl, ret);
 655         ft_dump_cmd(cmd, __func__);
 656
 657         if (ret == -ENOMEM) {
 658                 transport_send_check_condition_and_sense(se_cmd,
 659                                 TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE, 0);
 660                 transport_generic_free_cmd(se_cmd, 0, 0);
 661                 return;
 662         }
 663         if (ret == -EINVAL) {
 664                 if (se_cmd->se_cmd_flags & SCF_SCSI_RESERVATION_CONFLICT)
 665                         ft_queue_status(se_cmd);
 666                 else
 667                         transport_send_check_condition_and_sense(se_cmd,
 668                                         se_cmd->scsi_sense_reason, 0);
 669                 transport_generic_free_cmd(se_cmd, 0, 0);
 670                 return;
 671         }
 672         transport_generic_handle_cdb(se_cmd);
 673         return;
 674
 675 err:
 676         ft_send_resp_code_and_free(cmd, FCP_CMND_FIELDS_INVALID);
 677 }
 678
 679 /*
 680  * Handle request in the command thread.
 681  */
 682 static void ft_exec_req(struct ft_cmd *cmd)
 683 {
 684         pr_debug("cmd state %x\n", cmd->state);
 685         switch (cmd->state) {
 686         case FC_CMD_ST_NEW:
 687                 ft_send_cmd(cmd);
 688                 break;
 689         default:
 690                 break;
 691         }
 692 }
 693
 694 /*
 695  * Processing thread.
 696  * Currently one thread per tpg.
 697  */
 698 int ft_thread(void *arg)
 699 {
 700         struct ft_tpg *tpg = arg;
 701         struct se_queue_obj *qobj = &tpg->qobj;
 702         struct ft_cmd *cmd;
 703
 704         while (!kthread_should_stop()) {
 705                 schedule_timeout_interruptible(MAX_SCHEDULE_TIMEOUT);
 706                 if (kthread_should_stop())
 707                         goto out;
 708
 709                 cmd = ft_dequeue_cmd(qobj);
 710                 if (cmd)
 711                         ft_exec_req(cmd);
 712         }
 713
 714 out:
 715         return 0;
 716 }