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 se_mem *mem;
  63         struct se_transport_task *task;
  64
  65         if (!(ft_debug_logging & FT_DEBUG_IO))
  66                 return;
  67
  68         se_cmd = &cmd->se_cmd;
  69         printk(KERN_INFO "%s: cmd %p state %d sess %p seq %p se_cmd %p\n",
  70                 caller, cmd, cmd->state, cmd->sess, cmd->seq, se_cmd);
  71         printk(KERN_INFO "%s: cmd %p cdb %p\n",
  72                 caller, cmd, cmd->cdb);
  73         printk(KERN_INFO "%s: cmd %p lun %d\n", caller, cmd, cmd->lun);
  74
  75         task = T_TASK(se_cmd);
  76         printk(KERN_INFO "%s: cmd %p task %p se_num %u buf %p len %u se_cmd_flags <0x%x>\n",
  77                caller, cmd, task, task->t_tasks_se_num,
  78                task->t_task_buf, se_cmd->data_length, se_cmd->se_cmd_flags);
  79         if (task->t_mem_list)
  80                 list_for_each_entry(mem, task->t_mem_list, se_list)
  81                         printk(KERN_INFO "%s: cmd %p mem %p page %p "
  82                                "len 0x%x off 0x%x\n",
  83                                caller, cmd, mem,
  84                                mem->se_page, mem->se_len, mem->se_off);
  85         sp = cmd->seq;
  86         if (sp) {
  87                 ep = fc_seq_exch(sp);
  88                 printk(KERN_INFO "%s: cmd %p sid %x did %x "
  89                         "ox_id %x rx_id %x seq_id %x e_stat %x\n",
  90                         caller, cmd, ep->sid, ep->did, ep->oxid, ep->rxid,
  91                         sp->id, ep->esb_stat);
  92         }
  93         print_hex_dump(KERN_INFO, "ft_dump_cmd ", DUMP_PREFIX_NONE,
  94                 16, 4, cmd->cdb, MAX_COMMAND_SIZE, 0);
  95 }
  96
  97 static void ft_queue_cmd(struct ft_sess *sess, struct ft_cmd *cmd)
  98 {
  99         struct se_queue_obj *qobj;
 100         unsigned long flags;
 101
 102         qobj = &sess->tport->tpg->qobj;
 103         spin_lock_irqsave(&qobj->cmd_queue_lock, flags);
 104         list_add_tail(&cmd->se_req.qr_list, &qobj->qobj_list);
 105         spin_unlock_irqrestore(&qobj->cmd_queue_lock, flags);
 106         atomic_inc(&qobj->queue_cnt);
 107         wake_up_interruptible(&qobj->thread_wq);
 108 }
 109
 110 static struct ft_cmd *ft_dequeue_cmd(struct se_queue_obj *qobj)
 111 {
 112         unsigned long flags;
 113         struct se_queue_req *qr;
 114
 115         spin_lock_irqsave(&qobj->cmd_queue_lock, flags);
 116         if (list_empty(&qobj->qobj_list)) {
 117                 spin_unlock_irqrestore(&qobj->cmd_queue_lock, flags);
 118                 return NULL;
 119         }
 120         qr = list_first_entry(&qobj->qobj_list, struct se_queue_req, qr_list);
 121         list_del(&qr->qr_list);
 122         atomic_dec(&qobj->queue_cnt);
 123         spin_unlock_irqrestore(&qobj->cmd_queue_lock, flags);
 124         return container_of(qr, struct ft_cmd, se_req);
 125 }
 126
 127 static void ft_free_cmd(struct ft_cmd *cmd)
 128 {
 129         struct fc_frame *fp;
 130         struct fc_lport *lport;
 131
 132         if (!cmd)
 133                 return;
 134         fp = cmd->req_frame;
 135         lport = fr_dev(fp);
 136         if (fr_seq(fp))
 137                 lport->tt.seq_release(fr_seq(fp));
 138         fc_frame_free(fp);
 139         ft_sess_put(cmd->sess); /* undo get from lookup at recv */
 140         kfree(cmd);
 141 }
 142
 143 void ft_release_cmd(struct se_cmd *se_cmd)
 144 {
 145         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
 146
 147         ft_free_cmd(cmd);
 148 }
 149
 150 void ft_check_stop_free(struct se_cmd *se_cmd)
 151 {
 152         transport_generic_free_cmd(se_cmd, 0, 1, 0);
 153 }
 154
 155 /*
 156  * Send response.
 157  */
 158 int ft_queue_status(struct se_cmd *se_cmd)
 159 {
 160         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
 161         struct fc_frame *fp;
 162         struct fcp_resp_with_ext *fcp;
 163         struct fc_lport *lport;
 164         struct fc_exch *ep;
 165         size_t len;
 166
 167         ft_dump_cmd(cmd, __func__);
 168         ep = fc_seq_exch(cmd->seq);
 169         lport = ep->lp;
 170         len = sizeof(*fcp) + se_cmd->scsi_sense_length;
 171         fp = fc_frame_alloc(lport, len);
 172         if (!fp) {
 173                 /* XXX shouldn't just drop it - requeue and retry? */
 174                 return 0;
 175         }
 176         fcp = fc_frame_payload_get(fp, len);
 177         memset(fcp, 0, len);
 178         fcp->resp.fr_status = se_cmd->scsi_status;
 179
 180         len = se_cmd->scsi_sense_length;
 181         if (len) {
 182                 fcp->resp.fr_flags |= FCP_SNS_LEN_VAL;
 183                 fcp->ext.fr_sns_len = htonl(len);
 184                 memcpy((fcp + 1), se_cmd->sense_buffer, len);
 185         }
 186
 187         /*
 188          * Test underflow and overflow with one mask.  Usually both are off.
 189          * Bidirectional commands are not handled yet.
 190          */
 191         if (se_cmd->se_cmd_flags & (SCF_OVERFLOW_BIT | SCF_UNDERFLOW_BIT)) {
 192                 if (se_cmd->se_cmd_flags & SCF_OVERFLOW_BIT)
 193                         fcp->resp.fr_flags |= FCP_RESID_OVER;
 194                 else
 195                         fcp->resp.fr_flags |= FCP_RESID_UNDER;
 196                 fcp->ext.fr_resid = cpu_to_be32(se_cmd->residual_count);
 197         }
 198
 199         /*
 200          * Send response.
 201          */
 202         cmd->seq = lport->tt.seq_start_next(cmd->seq);
 203         fc_fill_fc_hdr(fp, FC_RCTL_DD_CMD_STATUS, ep->did, ep->sid, FC_TYPE_FCP,
 204                        FC_FC_EX_CTX | FC_FC_LAST_SEQ | FC_FC_END_SEQ, 0);
 205
 206         lport->tt.seq_send(lport, cmd->seq, fp);
 207         lport->tt.exch_done(cmd->seq);
 208         return 0;
 209 }
 210
 211 int ft_write_pending_status(struct se_cmd *se_cmd)
 212 {
 213         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
 214
 215         return cmd->write_data_len != se_cmd->data_length;
 216 }
 217
 218 /*
 219  * Send TX_RDY (transfer ready).
 220  */
 221 int ft_write_pending(struct se_cmd *se_cmd)
 222 {
 223         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
 224         struct fc_frame *fp;
 225         struct fcp_txrdy *txrdy;
 226         struct fc_lport *lport;
 227         struct fc_exch *ep;
 228         struct fc_frame_header *fh;
 229         u32 f_ctl;
 230
 231         ft_dump_cmd(cmd, __func__);
 232
 233         ep = fc_seq_exch(cmd->seq);
 234         lport = ep->lp;
 235         fp = fc_frame_alloc(lport, sizeof(*txrdy));
 236         if (!fp)
 237                 return PYX_TRANSPORT_OUT_OF_MEMORY_RESOURCES;
 238
 239         txrdy = fc_frame_payload_get(fp, sizeof(*txrdy));
 240         memset(txrdy, 0, sizeof(*txrdy));
 241         txrdy->ft_burst_len = htonl(se_cmd->data_length);
 242
 243         cmd->seq = lport->tt.seq_start_next(cmd->seq);
 244         fc_fill_fc_hdr(fp, FC_RCTL_DD_DATA_DESC, ep->did, ep->sid, FC_TYPE_FCP,
 245                        FC_FC_EX_CTX | FC_FC_END_SEQ | FC_FC_SEQ_INIT, 0);
 246
 247         fh = fc_frame_header_get(fp);
 248         f_ctl = ntoh24(fh->fh_f_ctl);
 249
 250         /* Only if it is 'Exchange Responder' */
 251         if (f_ctl & FC_FC_EX_CTX) {
 252                 /* Target is 'exchange responder' and sending XFER_READY
 253                  * to 'exchange initiator (initiator)'
 254                  */
 255                 if ((ep->xid <= lport->lro_xid) &&
 256                     (fh->fh_r_ctl == FC_RCTL_DD_DATA_DESC)) {
 257                         if (se_cmd->se_cmd_flags & SCF_SCSI_DATA_SG_IO_CDB) {
 258                                 /*
 259                                  * Map se_mem list to scatterlist, so that
 260                                  * DDP can be setup. DDP setup function require
 261                                  * scatterlist. se_mem_list is internal to
 262                                  * TCM/LIO target
 263                                  */
 264                                 transport_do_task_sg_chain(se_cmd);
 265                                 cmd->sg = T_TASK(se_cmd)->t_tasks_sg_chained;
 266                                 cmd->sg_cnt =
 267                                         T_TASK(se_cmd)->t_tasks_sg_chained_no;
 268                         }
 269                         if (cmd->sg && lport->tt.ddp_target(lport, ep->xid,
 270                                                             cmd->sg,
 271                                                             cmd->sg_cnt))
 272                                 cmd->was_ddp_setup = 1;
 273                 }
 274         }
 275         lport->tt.seq_send(lport, cmd->seq, fp);
 276         return 0;
 277 }
 278
 279 u32 ft_get_task_tag(struct se_cmd *se_cmd)
 280 {
 281         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
 282
 283         return fc_seq_exch(cmd->seq)->rxid;
 284 }
 285
 286 int ft_get_cmd_state(struct se_cmd *se_cmd)
 287 {
 288         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
 289
 290         return cmd->state;
 291 }
 292
 293 int ft_is_state_remove(struct se_cmd *se_cmd)
 294 {
 295         return 0;       /* XXX TBD */
 296 }
 297
 298 void ft_new_cmd_failure(struct se_cmd *se_cmd)
 299 {
 300         /* XXX TBD */
 301         printk(KERN_INFO "%s: se_cmd %p\n", __func__, se_cmd);
 302 }
 303
 304 /*
 305  * FC sequence response handler for follow-on sequences (data) and aborts.
 306  */
 307 static void ft_recv_seq(struct fc_seq *sp, struct fc_frame *fp, void *arg)
 308 {
 309         struct ft_cmd *cmd = arg;
 310         struct fc_frame_header *fh;
 311
 312         if (IS_ERR(fp)) {
 313                 /* XXX need to find cmd if queued */
 314                 cmd->se_cmd.t_state = TRANSPORT_REMOVE;
 315                 cmd->seq = NULL;
 316                 transport_generic_free_cmd(&cmd->se_cmd, 0, 1, 0);
 317                 return;
 318         }
 319
 320         fh = fc_frame_header_get(fp);
 321
 322         switch (fh->fh_r_ctl) {
 323         case FC_RCTL_DD_SOL_DATA:       /* write data */
 324                 ft_recv_write_data(cmd, fp);
 325                 break;
 326         case FC_RCTL_DD_UNSOL_CTL:      /* command */
 327         case FC_RCTL_DD_SOL_CTL:        /* transfer ready */
 328         case FC_RCTL_DD_DATA_DESC:      /* transfer ready */
 329         default:
 330                 printk(KERN_INFO "%s: unhandled frame r_ctl %x\n",
 331                        __func__, fh->fh_r_ctl);
 332                 fc_frame_free(fp);
 333                 transport_generic_free_cmd(&cmd->se_cmd, 0, 1, 0);
 334                 break;
 335         }
 336 }
 337
 338 /*
 339  * Send a FCP response including SCSI status and optional FCP rsp_code.
 340  * status is SAM_STAT_GOOD (zero) iff code is valid.
 341  * This is used in error cases, such as allocation failures.
 342  */
 343 static void ft_send_resp_status(struct fc_lport *lport,
 344                                 const struct fc_frame *rx_fp,
 345                                 u32 status, enum fcp_resp_rsp_codes code)
 346 {
 347         struct fc_frame *fp;
 348         struct fc_seq *sp;
 349         const struct fc_frame_header *fh;
 350         size_t len;
 351         struct fcp_resp_with_ext *fcp;
 352         struct fcp_resp_rsp_info *info;
 353
 354         fh = fc_frame_header_get(rx_fp);
 355         FT_IO_DBG("FCP error response: did %x oxid %x status %x code %x\n",
 356                   ntoh24(fh->fh_s_id), ntohs(fh->fh_ox_id), status, code);
 357         len = sizeof(*fcp);
 358         if (status == SAM_STAT_GOOD)
 359                 len += sizeof(*info);
 360         fp = fc_frame_alloc(lport, len);
 361         if (!fp)
 362                 return;
 363         fcp = fc_frame_payload_get(fp, len);
 364         memset(fcp, 0, len);
 365         fcp->resp.fr_status = status;
 366         if (status == SAM_STAT_GOOD) {
 367                 fcp->ext.fr_rsp_len = htonl(sizeof(*info));
 368                 fcp->resp.fr_flags |= FCP_RSP_LEN_VAL;
 369                 info = (struct fcp_resp_rsp_info *)(fcp + 1);
 370                 info->rsp_code = code;
 371         }
 372
 373         fc_fill_reply_hdr(fp, rx_fp, FC_RCTL_DD_CMD_STATUS, 0);
 374         sp = fr_seq(fp);
 375         if (sp)
 376                 lport->tt.seq_send(lport, sp, fp);
 377         else
 378                 lport->tt.frame_send(lport, fp);
 379 }
 380
 381 /*
 382  * Send error or task management response.
 383  */
 384 static void ft_send_resp_code(struct ft_cmd *cmd,
 385                               enum fcp_resp_rsp_codes code)
 386 {
 387         ft_send_resp_status(cmd->sess->tport->lport,
 388                             cmd->req_frame, SAM_STAT_GOOD, code);
 389 }
 390
 391
 392 /*
 393  * Send error or task management response.
 394  * Always frees the cmd and associated state.
 395  */
 396 static void ft_send_resp_code_and_free(struct ft_cmd *cmd,
 397                                       enum fcp_resp_rsp_codes code)
 398 {
 399         ft_send_resp_code(cmd, code);
 400         ft_free_cmd(cmd);
 401 }
 402
 403 /*
 404  * Handle Task Management Request.
 405  */
 406 static void ft_send_tm(struct ft_cmd *cmd)
 407 {
 408         struct se_tmr_req *tmr;
 409         struct fcp_cmnd *fcp;
 410         struct ft_sess *sess;
 411         u8 tm_func;
 412
 413         fcp = fc_frame_payload_get(cmd->req_frame, sizeof(*fcp));
 414
 415         switch (fcp->fc_tm_flags) {
 416         case FCP_TMF_LUN_RESET:
 417                 tm_func = TMR_LUN_RESET;
 418                 break;
 419         case FCP_TMF_TGT_RESET:
 420                 tm_func = TMR_TARGET_WARM_RESET;
 421                 break;
 422         case FCP_TMF_CLR_TASK_SET:
 423                 tm_func = TMR_CLEAR_TASK_SET;
 424                 break;
 425         case FCP_TMF_ABT_TASK_SET:
 426                 tm_func = TMR_ABORT_TASK_SET;
 427                 break;
 428         case FCP_TMF_CLR_ACA:
 429                 tm_func = TMR_CLEAR_ACA;
 430                 break;
 431         default:
 432                 /*
 433                  * FCP4r01 indicates having a combination of
 434                  * tm_flags set is invalid.
 435                  */
 436                 FT_TM_DBG("invalid FCP tm_flags %x\n", fcp->fc_tm_flags);
 437                 ft_send_resp_code_and_free(cmd, FCP_CMND_FIELDS_INVALID);
 438                 return;
 439         }
 440
 441         FT_TM_DBG("alloc tm cmd fn %d\n", tm_func);
 442         tmr = core_tmr_alloc_req(&cmd->se_cmd, cmd, tm_func);
 443         if (!tmr) {
 444                 FT_TM_DBG("alloc failed\n");
 445                 ft_send_resp_code_and_free(cmd, FCP_TMF_FAILED);
 446                 return;
 447         }
 448         cmd->se_cmd.se_tmr_req = tmr;
 449
 450         switch (fcp->fc_tm_flags) {
 451         case FCP_TMF_LUN_RESET:
 452                 cmd->lun = scsilun_to_int((struct scsi_lun *)fcp->fc_lun);
 453                 if (transport_get_lun_for_tmr(&cmd->se_cmd, cmd->lun) < 0) {
 454                         /*
 455                          * Make sure to clean up newly allocated TMR request
 456                          * since "unable to  handle TMR request because failed
 457                          * to get to LUN"
 458                          */
 459                         FT_TM_DBG("Failed to get LUN for TMR func %d, "
 460                                   "se_cmd %p, unpacked_lun %d\n",
 461                                   tm_func, &cmd->se_cmd, cmd->lun);
 462                         ft_dump_cmd(cmd, __func__);
 463                         sess = cmd->sess;
 464                         transport_send_check_condition_and_sense(&cmd->se_cmd,
 465                                 cmd->se_cmd.scsi_sense_reason, 0);
 466                         transport_generic_free_cmd(&cmd->se_cmd, 0, 1, 0);
 467                         ft_sess_put(sess);
 468                         return;
 469                 }
 470                 break;
 471         case FCP_TMF_TGT_RESET:
 472         case FCP_TMF_CLR_TASK_SET:
 473         case FCP_TMF_ABT_TASK_SET:
 474         case FCP_TMF_CLR_ACA:
 475                 break;
 476         default:
 477                 return;
 478         }
 479         transport_generic_handle_tmr(&cmd->se_cmd);
 480 }
 481
 482 /*
 483  * Send status from completed task management request.
 484  */
 485 int ft_queue_tm_resp(struct se_cmd *se_cmd)
 486 {
 487         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
 488         struct se_tmr_req *tmr = se_cmd->se_tmr_req;
 489         enum fcp_resp_rsp_codes code;
 490
 491         switch (tmr->response) {
 492         case TMR_FUNCTION_COMPLETE:
 493                 code = FCP_TMF_CMPL;
 494                 break;
 495         case TMR_LUN_DOES_NOT_EXIST:
 496                 code = FCP_TMF_INVALID_LUN;
 497                 break;
 498         case TMR_FUNCTION_REJECTED:
 499                 code = FCP_TMF_REJECTED;
 500                 break;
 501         case TMR_TASK_DOES_NOT_EXIST:
 502         case TMR_TASK_STILL_ALLEGIANT:
 503         case TMR_TASK_FAILOVER_NOT_SUPPORTED:
 504         case TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED:
 505         case TMR_FUNCTION_AUTHORIZATION_FAILED:
 506         default:
 507                 code = FCP_TMF_FAILED;
 508                 break;
 509         }
 510         FT_TM_DBG("tmr fn %d resp %d fcp code %d\n",
 511                   tmr->function, tmr->response, code);
 512         ft_send_resp_code(cmd, code);
 513         return 0;
 514 }
 515
 516 /*
 517  * Handle incoming FCP command.
 518  */
 519 static void ft_recv_cmd(struct ft_sess *sess, struct fc_frame *fp)
 520 {
 521         struct ft_cmd *cmd;
 522         struct fc_lport *lport = sess->tport->lport;
 523
 524         cmd = kzalloc(sizeof(*cmd), GFP_ATOMIC);
 525         if (!cmd)
 526                 goto busy;
 527         cmd->sess = sess;
 528         cmd->seq = lport->tt.seq_assign(lport, fp);
 529         if (!cmd->seq) {
 530                 kfree(cmd);
 531                 goto busy;
 532         }
 533         cmd->req_frame = fp;            /* hold frame during cmd */
 534         ft_queue_cmd(sess, cmd);
 535         return;
 536
 537 busy:
 538         FT_IO_DBG("cmd or seq allocation failure - sending BUSY\n");
 539         ft_send_resp_status(lport, fp, SAM_STAT_BUSY, 0);
 540         fc_frame_free(fp);
 541         ft_sess_put(sess);              /* undo get from lookup */
 542 }
 543
 544
 545 /*
 546  * Handle incoming FCP frame.
 547  * Caller has verified that the frame is type FCP.
 548  */
 549 void ft_recv_req(struct ft_sess *sess, struct fc_frame *fp)
 550 {
 551         struct fc_frame_header *fh = fc_frame_header_get(fp);
 552
 553         switch (fh->fh_r_ctl) {
 554         case FC_RCTL_DD_UNSOL_CMD:      /* command */
 555                 ft_recv_cmd(sess, fp);
 556                 break;
 557         case FC_RCTL_DD_SOL_DATA:       /* write data */
 558         case FC_RCTL_DD_UNSOL_CTL:
 559         case FC_RCTL_DD_SOL_CTL:
 560         case FC_RCTL_DD_DATA_DESC:      /* transfer ready */
 561         case FC_RCTL_ELS4_REQ:          /* SRR, perhaps */
 562         default:
 563                 printk(KERN_INFO "%s: unhandled frame r_ctl %x\n",
 564                        __func__, fh->fh_r_ctl);
 565                 fc_frame_free(fp);
 566                 ft_sess_put(sess);      /* undo get from lookup */
 567                 break;
 568         }
 569 }
 570
 571 /*
 572  * Send new command to target.
 573  */
 574 static void ft_send_cmd(struct ft_cmd *cmd)
 575 {
 576         struct fc_frame_header *fh = fc_frame_header_get(cmd->req_frame);
 577         struct se_cmd *se_cmd;
 578         struct fcp_cmnd *fcp;
 579         int data_dir;
 580         u32 data_len;
 581         int task_attr;
 582         int ret;
 583
 584         fcp = fc_frame_payload_get(cmd->req_frame, sizeof(*fcp));
 585         if (!fcp)
 586                 goto err;
 587
 588         if (fcp->fc_flags & FCP_CFL_LEN_MASK)
 589                 goto err;               /* not handling longer CDBs yet */
 590
 591         if (fcp->fc_tm_flags) {
 592                 task_attr = FCP_PTA_SIMPLE;
 593                 data_dir = DMA_NONE;
 594                 data_len = 0;
 595         } else {
 596                 switch (fcp->fc_flags & (FCP_CFL_RDDATA | FCP_CFL_WRDATA)) {
 597                 case 0:
 598                         data_dir = DMA_NONE;
 599                         break;
 600                 case FCP_CFL_RDDATA:
 601                         data_dir = DMA_FROM_DEVICE;
 602                         break;
 603                 case FCP_CFL_WRDATA:
 604                         data_dir = DMA_TO_DEVICE;
 605                         break;
 606                 case FCP_CFL_WRDATA | FCP_CFL_RDDATA:
 607                         goto err;       /* TBD not supported by tcm_fc yet */
 608                 }
 609                 /*
 610                  * Locate the SAM Task Attr from fc_pri_ta
 611                  */
 612                 switch (fcp->fc_pri_ta & FCP_PTA_MASK) {
 613                 case FCP_PTA_HEADQ:
 614                         task_attr = MSG_HEAD_TAG;
 615                         break;
 616                 case FCP_PTA_ORDERED:
 617                         task_attr = MSG_ORDERED_TAG;
 618                         break;
 619                 case FCP_PTA_ACA:
 620                         task_attr = MSG_ACA_TAG;
 621                         break;
 622                 case FCP_PTA_SIMPLE: /* Fallthrough */
 623                 default:
 624                         task_attr = MSG_SIMPLE_TAG;
 625                 }
 626
 627
 628                 task_attr = fcp->fc_pri_ta & FCP_PTA_MASK;
 629                 data_len = ntohl(fcp->fc_dl);
 630                 cmd->cdb = fcp->fc_cdb;
 631         }
 632
 633         se_cmd = &cmd->se_cmd;
 634         /*
 635          * Initialize struct se_cmd descriptor from target_core_mod
 636          * infrastructure
 637          */
 638         transport_init_se_cmd(se_cmd, &ft_configfs->tf_ops, cmd->sess->se_sess,
 639                               data_len, data_dir, task_attr,
 640                               &cmd->ft_sense_buffer[0]);
 641         /*
 642          * Check for FCP task management flags
 643          */
 644         if (fcp->fc_tm_flags) {
 645                 ft_send_tm(cmd);
 646                 return;
 647         }
 648
 649         fc_seq_exch(cmd->seq)->lp->tt.seq_set_resp(cmd->seq, ft_recv_seq, cmd);
 650
 651         cmd->lun = scsilun_to_int((struct scsi_lun *)fcp->fc_lun);
 652         ret = transport_get_lun_for_cmd(&cmd->se_cmd, NULL, cmd->lun);
 653         if (ret < 0) {
 654                 ft_dump_cmd(cmd, __func__);
 655                 transport_send_check_condition_and_sense(&cmd->se_cmd,
 656                         cmd->se_cmd.scsi_sense_reason, 0);
 657                 return;
 658         }
 659
 660         ret = transport_generic_allocate_tasks(se_cmd, cmd->cdb);
 661
 662         FT_IO_DBG("r_ctl %x alloc task ret %d\n", fh->fh_r_ctl, ret);
 663         ft_dump_cmd(cmd, __func__);
 664
 665         if (ret == -1) {
 666                 transport_send_check_condition_and_sense(se_cmd,
 667                                 TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE, 0);
 668                 transport_generic_free_cmd(se_cmd, 0, 1, 0);
 669                 return;
 670         }
 671         if (ret == -2) {
 672                 if (se_cmd->se_cmd_flags & SCF_SCSI_RESERVATION_CONFLICT)
 673                         ft_queue_status(se_cmd);
 674                 else
 675                         transport_send_check_condition_and_sense(se_cmd,
 676                                         se_cmd->scsi_sense_reason, 0);
 677                 transport_generic_free_cmd(se_cmd, 0, 1, 0);
 678                 return;
 679         }
 680         transport_generic_handle_cdb(se_cmd);
 681         return;
 682
 683 err:
 684         ft_send_resp_code_and_free(cmd, FCP_CMND_FIELDS_INVALID);
 685         return;
 686 }
 687
 688 /*
 689  * Handle request in the command thread.
 690  */
 691 static void ft_exec_req(struct ft_cmd *cmd)
 692 {
 693         FT_IO_DBG("cmd state %x\n", cmd->state);
 694         switch (cmd->state) {
 695         case FC_CMD_ST_NEW:
 696                 ft_send_cmd(cmd);
 697                 break;
 698         default:
 699                 break;
 700         }
 701 }
 702
 703 /*
 704  * Processing thread.
 705  * Currently one thread per tpg.
 706  */
 707 int ft_thread(void *arg)
 708 {
 709         struct ft_tpg *tpg = arg;
 710         struct se_queue_obj *qobj = &tpg->qobj;
 711         struct ft_cmd *cmd;
 712         int ret;
 713
 714         set_user_nice(current, -20);
 715
 716         while (!kthread_should_stop()) {
 717                 ret = wait_event_interruptible(qobj->thread_wq,
 718                         atomic_read(&qobj->queue_cnt) || kthread_should_stop());
 719                 if (ret < 0 || kthread_should_stop())
 720                         goto out;
 721                 cmd = ft_dequeue_cmd(qobj);
 722                 if (cmd)
 723                         ft_exec_req(cmd);
 724         }
 725
 726 out:
 727         return 0;
 728 }