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 /*
  98  * Get LUN from CDB.
  99  */
 100 static int ft_get_lun_for_cmd(struct ft_cmd *cmd, u8 *lunp)
 101 {
 102         u64 lun;
 103
 104         lun = lunp[1];
 105         switch (lunp[0] >> 6) {
 106         case 0:
 107                 break;
 108         case 1:
 109                 lun |= (lunp[0] & 0x3f) << 8;
 110                 break;
 111         default:
 112                 return -1;
 113         }
 114         if (lun >= TRANSPORT_MAX_LUNS_PER_TPG)
 115                 return -1;
 116         cmd->lun = lun;
 117         return transport_get_lun_for_cmd(&cmd->se_cmd, NULL, lun);
 118 }
 119
 120 static void ft_queue_cmd(struct ft_sess *sess, struct ft_cmd *cmd)
 121 {
 122         struct se_queue_obj *qobj;
 123         unsigned long flags;
 124
 125         qobj = &sess->tport->tpg->qobj;
 126         spin_lock_irqsave(&qobj->cmd_queue_lock, flags);
 127         list_add_tail(&cmd->se_req.qr_list, &qobj->qobj_list);
 128         spin_unlock_irqrestore(&qobj->cmd_queue_lock, flags);
 129         atomic_inc(&qobj->queue_cnt);
 130         wake_up_interruptible(&qobj->thread_wq);
 131 }
 132
 133 static struct ft_cmd *ft_dequeue_cmd(struct se_queue_obj *qobj)
 134 {
 135         unsigned long flags;
 136         struct se_queue_req *qr;
 137
 138         spin_lock_irqsave(&qobj->cmd_queue_lock, flags);
 139         if (list_empty(&qobj->qobj_list)) {
 140                 spin_unlock_irqrestore(&qobj->cmd_queue_lock, flags);
 141                 return NULL;
 142         }
 143         qr = list_first_entry(&qobj->qobj_list, struct se_queue_req, qr_list);
 144         list_del(&qr->qr_list);
 145         atomic_dec(&qobj->queue_cnt);
 146         spin_unlock_irqrestore(&qobj->cmd_queue_lock, flags);
 147         return container_of(qr, struct ft_cmd, se_req);
 148 }
 149
 150 static void ft_free_cmd(struct ft_cmd *cmd)
 151 {
 152         struct fc_frame *fp;
 153         struct fc_lport *lport;
 154
 155         if (!cmd)
 156                 return;
 157         fp = cmd->req_frame;
 158         lport = fr_dev(fp);
 159         if (fr_seq(fp))
 160                 lport->tt.seq_release(fr_seq(fp));
 161         fc_frame_free(fp);
 162         ft_sess_put(cmd->sess); /* undo get from lookup at recv */
 163         kfree(cmd);
 164 }
 165
 166 void ft_release_cmd(struct se_cmd *se_cmd)
 167 {
 168         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
 169
 170         ft_free_cmd(cmd);
 171 }
 172
 173 void ft_check_stop_free(struct se_cmd *se_cmd)
 174 {
 175         transport_generic_free_cmd(se_cmd, 0, 1, 0);
 176 }
 177
 178 /*
 179  * Send response.
 180  */
 181 int ft_queue_status(struct se_cmd *se_cmd)
 182 {
 183         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
 184         struct fc_frame *fp;
 185         struct fcp_resp_with_ext *fcp;
 186         struct fc_lport *lport;
 187         struct fc_exch *ep;
 188         size_t len;
 189
 190         ft_dump_cmd(cmd, __func__);
 191         ep = fc_seq_exch(cmd->seq);
 192         lport = ep->lp;
 193         len = sizeof(*fcp) + se_cmd->scsi_sense_length;
 194         fp = fc_frame_alloc(lport, len);
 195         if (!fp) {
 196                 /* XXX shouldn't just drop it - requeue and retry? */
 197                 return 0;
 198         }
 199         fcp = fc_frame_payload_get(fp, len);
 200         memset(fcp, 0, len);
 201         fcp->resp.fr_status = se_cmd->scsi_status;
 202
 203         len = se_cmd->scsi_sense_length;
 204         if (len) {
 205                 fcp->resp.fr_flags |= FCP_SNS_LEN_VAL;
 206                 fcp->ext.fr_sns_len = htonl(len);
 207                 memcpy((fcp + 1), se_cmd->sense_buffer, len);
 208         }
 209
 210         /*
 211          * Test underflow and overflow with one mask.  Usually both are off.
 212          * Bidirectional commands are not handled yet.
 213          */
 214         if (se_cmd->se_cmd_flags & (SCF_OVERFLOW_BIT | SCF_UNDERFLOW_BIT)) {
 215                 if (se_cmd->se_cmd_flags & SCF_OVERFLOW_BIT)
 216                         fcp->resp.fr_flags |= FCP_RESID_OVER;
 217                 else
 218                         fcp->resp.fr_flags |= FCP_RESID_UNDER;
 219                 fcp->ext.fr_resid = cpu_to_be32(se_cmd->residual_count);
 220         }
 221
 222         /*
 223          * Send response.
 224          */
 225         cmd->seq = lport->tt.seq_start_next(cmd->seq);
 226         fc_fill_fc_hdr(fp, FC_RCTL_DD_CMD_STATUS, ep->did, ep->sid, FC_TYPE_FCP,
 227                        FC_FC_EX_CTX | FC_FC_LAST_SEQ | FC_FC_END_SEQ, 0);
 228
 229         lport->tt.seq_send(lport, cmd->seq, fp);
 230         lport->tt.exch_done(cmd->seq);
 231         return 0;
 232 }
 233
 234 int ft_write_pending_status(struct se_cmd *se_cmd)
 235 {
 236         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
 237
 238         return cmd->write_data_len != se_cmd->data_length;
 239 }
 240
 241 /*
 242  * Send TX_RDY (transfer ready).
 243  */
 244 int ft_write_pending(struct se_cmd *se_cmd)
 245 {
 246         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
 247         struct fc_frame *fp;
 248         struct fcp_txrdy *txrdy;
 249         struct fc_lport *lport;
 250         struct fc_exch *ep;
 251         struct fc_frame_header *fh;
 252         u32 f_ctl;
 253
 254         ft_dump_cmd(cmd, __func__);
 255
 256         ep = fc_seq_exch(cmd->seq);
 257         lport = ep->lp;
 258         fp = fc_frame_alloc(lport, sizeof(*txrdy));
 259         if (!fp)
 260                 return PYX_TRANSPORT_OUT_OF_MEMORY_RESOURCES;
 261
 262         txrdy = fc_frame_payload_get(fp, sizeof(*txrdy));
 263         memset(txrdy, 0, sizeof(*txrdy));
 264         txrdy->ft_burst_len = htonl(se_cmd->data_length);
 265
 266         cmd->seq = lport->tt.seq_start_next(cmd->seq);
 267         fc_fill_fc_hdr(fp, FC_RCTL_DD_DATA_DESC, ep->did, ep->sid, FC_TYPE_FCP,
 268                        FC_FC_EX_CTX | FC_FC_END_SEQ | FC_FC_SEQ_INIT, 0);
 269
 270         fh = fc_frame_header_get(fp);
 271         f_ctl = ntoh24(fh->fh_f_ctl);
 272
 273         /* Only if it is 'Exchange Responder' */
 274         if (f_ctl & FC_FC_EX_CTX) {
 275                 /* Target is 'exchange responder' and sending XFER_READY
 276                  * to 'exchange initiator (initiator)'
 277                  */
 278                 if ((ep->xid <= lport->lro_xid) &&
 279                     (fh->fh_r_ctl == FC_RCTL_DD_DATA_DESC)) {
 280                         if (se_cmd->se_cmd_flags & SCF_SCSI_DATA_SG_IO_CDB) {
 281                                 /*
 282                                  * Map se_mem list to scatterlist, so that
 283                                  * DDP can be setup. DDP setup function require
 284                                  * scatterlist. se_mem_list is internal to
 285                                  * TCM/LIO target
 286                                  */
 287                                 transport_do_task_sg_chain(se_cmd);
 288                                 cmd->sg = T_TASK(se_cmd)->t_tasks_sg_chained;
 289                                 cmd->sg_cnt =
 290                                         T_TASK(se_cmd)->t_tasks_sg_chained_no;
 291                         }
 292                         if (cmd->sg && lport->tt.ddp_setup(lport, ep->xid,
 293                                                     cmd->sg, cmd->sg_cnt))
 294                                 cmd->was_ddp_setup = 1;
 295                 }
 296         }
 297         lport->tt.seq_send(lport, cmd->seq, fp);
 298         return 0;
 299 }
 300
 301 u32 ft_get_task_tag(struct se_cmd *se_cmd)
 302 {
 303         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
 304
 305         return fc_seq_exch(cmd->seq)->rxid;
 306 }
 307
 308 int ft_get_cmd_state(struct se_cmd *se_cmd)
 309 {
 310         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
 311
 312         return cmd->state;
 313 }
 314
 315 int ft_is_state_remove(struct se_cmd *se_cmd)
 316 {
 317         return 0;       /* XXX TBD */
 318 }
 319
 320 void ft_new_cmd_failure(struct se_cmd *se_cmd)
 321 {
 322         /* XXX TBD */
 323         printk(KERN_INFO "%s: se_cmd %p\n", __func__, se_cmd);
 324 }
 325
 326 /*
 327  * FC sequence response handler for follow-on sequences (data) and aborts.
 328  */
 329 static void ft_recv_seq(struct fc_seq *sp, struct fc_frame *fp, void *arg)
 330 {
 331         struct ft_cmd *cmd = arg;
 332         struct fc_frame_header *fh;
 333
 334         if (IS_ERR(fp)) {
 335                 /* XXX need to find cmd if queued */
 336                 cmd->se_cmd.t_state = TRANSPORT_REMOVE;
 337                 cmd->seq = NULL;
 338                 transport_generic_free_cmd(&cmd->se_cmd, 0, 1, 0);
 339                 return;
 340         }
 341
 342         fh = fc_frame_header_get(fp);
 343
 344         switch (fh->fh_r_ctl) {
 345         case FC_RCTL_DD_SOL_DATA:       /* write data */
 346                 ft_recv_write_data(cmd, fp);
 347                 break;
 348         case FC_RCTL_DD_UNSOL_CTL:      /* command */
 349         case FC_RCTL_DD_SOL_CTL:        /* transfer ready */
 350         case FC_RCTL_DD_DATA_DESC:      /* transfer ready */
 351         default:
 352                 printk(KERN_INFO "%s: unhandled frame r_ctl %x\n",
 353                        __func__, fh->fh_r_ctl);
 354                 fc_frame_free(fp);
 355                 transport_generic_free_cmd(&cmd->se_cmd, 0, 1, 0);
 356                 break;
 357         }
 358 }
 359
 360 /*
 361  * Send a FCP response including SCSI status and optional FCP rsp_code.
 362  * status is SAM_STAT_GOOD (zero) iff code is valid.
 363  * This is used in error cases, such as allocation failures.
 364  */
 365 static void ft_send_resp_status(struct fc_lport *lport,
 366                                 const struct fc_frame *rx_fp,
 367                                 u32 status, enum fcp_resp_rsp_codes code)
 368 {
 369         struct fc_frame *fp;
 370         struct fc_seq *sp;
 371         const struct fc_frame_header *fh;
 372         size_t len;
 373         struct fcp_resp_with_ext *fcp;
 374         struct fcp_resp_rsp_info *info;
 375
 376         fh = fc_frame_header_get(rx_fp);
 377         FT_IO_DBG("FCP error response: did %x oxid %x status %x code %x\n",
 378                   ntoh24(fh->fh_s_id), ntohs(fh->fh_ox_id), status, code);
 379         len = sizeof(*fcp);
 380         if (status == SAM_STAT_GOOD)
 381                 len += sizeof(*info);
 382         fp = fc_frame_alloc(lport, len);
 383         if (!fp)
 384                 return;
 385         fcp = fc_frame_payload_get(fp, len);
 386         memset(fcp, 0, len);
 387         fcp->resp.fr_status = status;
 388         if (status == SAM_STAT_GOOD) {
 389                 fcp->ext.fr_rsp_len = htonl(sizeof(*info));
 390                 fcp->resp.fr_flags |= FCP_RSP_LEN_VAL;
 391                 info = (struct fcp_resp_rsp_info *)(fcp + 1);
 392                 info->rsp_code = code;
 393         }
 394
 395         fc_fill_reply_hdr(fp, rx_fp, FC_RCTL_DD_CMD_STATUS, 0);
 396         sp = fr_seq(fp);
 397         if (sp)
 398                 lport->tt.seq_send(lport, sp, fp);
 399         else
 400                 lport->tt.frame_send(lport, fp);
 401 }
 402
 403 /*
 404  * Send error or task management response.
 405  * Always frees the cmd and associated state.
 406  */
 407 static void ft_send_resp_code(struct ft_cmd *cmd, enum fcp_resp_rsp_codes code)
 408 {
 409         ft_send_resp_status(cmd->sess->tport->lport,
 410                             cmd->req_frame, SAM_STAT_GOOD, code);
 411         ft_free_cmd(cmd);
 412 }
 413
 414 /*
 415  * Handle Task Management Request.
 416  */
 417 static void ft_send_tm(struct ft_cmd *cmd)
 418 {
 419         struct se_tmr_req *tmr;
 420         struct fcp_cmnd *fcp;
 421         u8 tm_func;
 422
 423         fcp = fc_frame_payload_get(cmd->req_frame, sizeof(*fcp));
 424
 425         switch (fcp->fc_tm_flags) {
 426         case FCP_TMF_LUN_RESET:
 427                 tm_func = TMR_LUN_RESET;
 428                 if (ft_get_lun_for_cmd(cmd, fcp->fc_lun) < 0) {
 429                         ft_dump_cmd(cmd, __func__);
 430                         transport_send_check_condition_and_sense(&cmd->se_cmd,
 431                                 cmd->se_cmd.scsi_sense_reason, 0);
 432                         ft_sess_put(cmd->sess);
 433                         return;
 434                 }
 435                 break;
 436         case FCP_TMF_TGT_RESET:
 437                 tm_func = TMR_TARGET_WARM_RESET;
 438                 break;
 439         case FCP_TMF_CLR_TASK_SET:
 440                 tm_func = TMR_CLEAR_TASK_SET;
 441                 break;
 442         case FCP_TMF_ABT_TASK_SET:
 443                 tm_func = TMR_ABORT_TASK_SET;
 444                 break;
 445         case FCP_TMF_CLR_ACA:
 446                 tm_func = TMR_CLEAR_ACA;
 447                 break;
 448         default:
 449                 /*
 450                  * FCP4r01 indicates having a combination of
 451                  * tm_flags set is invalid.
 452                  */
 453                 FT_TM_DBG("invalid FCP tm_flags %x\n", fcp->fc_tm_flags);
 454                 ft_send_resp_code(cmd, FCP_CMND_FIELDS_INVALID);
 455                 return;
 456         }
 457
 458         FT_TM_DBG("alloc tm cmd fn %d\n", tm_func);
 459         tmr = core_tmr_alloc_req(&cmd->se_cmd, cmd, tm_func);
 460         if (!tmr) {
 461                 FT_TM_DBG("alloc failed\n");
 462                 ft_send_resp_code(cmd, FCP_TMF_FAILED);
 463                 return;
 464         }
 465         cmd->se_cmd.se_tmr_req = tmr;
 466         transport_generic_handle_tmr(&cmd->se_cmd);
 467 }
 468
 469 /*
 470  * Send status from completed task management request.
 471  */
 472 int ft_queue_tm_resp(struct se_cmd *se_cmd)
 473 {
 474         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
 475         struct se_tmr_req *tmr = se_cmd->se_tmr_req;
 476         enum fcp_resp_rsp_codes code;
 477
 478         switch (tmr->response) {
 479         case TMR_FUNCTION_COMPLETE:
 480                 code = FCP_TMF_CMPL;
 481                 break;
 482         case TMR_LUN_DOES_NOT_EXIST:
 483                 code = FCP_TMF_INVALID_LUN;
 484                 break;
 485         case TMR_FUNCTION_REJECTED:
 486                 code = FCP_TMF_REJECTED;
 487                 break;
 488         case TMR_TASK_DOES_NOT_EXIST:
 489         case TMR_TASK_STILL_ALLEGIANT:
 490         case TMR_TASK_FAILOVER_NOT_SUPPORTED:
 491         case TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED:
 492         case TMR_FUNCTION_AUTHORIZATION_FAILED:
 493         default:
 494                 code = FCP_TMF_FAILED;
 495                 break;
 496         }
 497         FT_TM_DBG("tmr fn %d resp %d fcp code %d\n",
 498                   tmr->function, tmr->response, code);
 499         ft_send_resp_code(cmd, code);
 500         return 0;
 501 }
 502
 503 /*
 504  * Handle incoming FCP command.
 505  */
 506 static void ft_recv_cmd(struct ft_sess *sess, struct fc_frame *fp)
 507 {
 508         struct ft_cmd *cmd;
 509         struct fc_lport *lport = sess->tport->lport;
 510
 511         cmd = kzalloc(sizeof(*cmd), GFP_ATOMIC);
 512         if (!cmd)
 513                 goto busy;
 514         cmd->sess = sess;
 515         cmd->seq = lport->tt.seq_assign(lport, fp);
 516         if (!cmd->seq) {
 517                 kfree(cmd);
 518                 goto busy;
 519         }
 520         cmd->req_frame = fp;            /* hold frame during cmd */
 521         ft_queue_cmd(sess, cmd);
 522         return;
 523
 524 busy:
 525         FT_IO_DBG("cmd or seq allocation failure - sending BUSY\n");
 526         ft_send_resp_status(lport, fp, SAM_STAT_BUSY, 0);
 527         fc_frame_free(fp);
 528         ft_sess_put(sess);              /* undo get from lookup */
 529 }
 530
 531
 532 /*
 533  * Handle incoming FCP frame.
 534  * Caller has verified that the frame is type FCP.
 535  */
 536 void ft_recv_req(struct ft_sess *sess, struct fc_frame *fp)
 537 {
 538         struct fc_frame_header *fh = fc_frame_header_get(fp);
 539
 540         switch (fh->fh_r_ctl) {
 541         case FC_RCTL_DD_UNSOL_CMD:      /* command */
 542                 ft_recv_cmd(sess, fp);
 543                 break;
 544         case FC_RCTL_DD_SOL_DATA:       /* write data */
 545         case FC_RCTL_DD_UNSOL_CTL:
 546         case FC_RCTL_DD_SOL_CTL:
 547         case FC_RCTL_DD_DATA_DESC:      /* transfer ready */
 548         case FC_RCTL_ELS4_REQ:          /* SRR, perhaps */
 549         default:
 550                 printk(KERN_INFO "%s: unhandled frame r_ctl %x\n",
 551                        __func__, fh->fh_r_ctl);
 552                 fc_frame_free(fp);
 553                 ft_sess_put(sess);      /* undo get from lookup */
 554                 break;
 555         }
 556 }
 557
 558 /*
 559  * Send new command to target.
 560  */
 561 static void ft_send_cmd(struct ft_cmd *cmd)
 562 {
 563         struct fc_frame_header *fh = fc_frame_header_get(cmd->req_frame);
 564         struct se_cmd *se_cmd;
 565         struct fcp_cmnd *fcp;
 566         int data_dir;
 567         u32 data_len;
 568         int task_attr;
 569         int ret;
 570
 571         fcp = fc_frame_payload_get(cmd->req_frame, sizeof(*fcp));
 572         if (!fcp)
 573                 goto err;
 574
 575         if (fcp->fc_flags & FCP_CFL_LEN_MASK)
 576                 goto err;               /* not handling longer CDBs yet */
 577
 578         if (fcp->fc_tm_flags) {
 579                 task_attr = FCP_PTA_SIMPLE;
 580                 data_dir = DMA_NONE;
 581                 data_len = 0;
 582         } else {
 583                 switch (fcp->fc_flags & (FCP_CFL_RDDATA | FCP_CFL_WRDATA)) {
 584                 case 0:
 585                         data_dir = DMA_NONE;
 586                         break;
 587                 case FCP_CFL_RDDATA:
 588                         data_dir = DMA_FROM_DEVICE;
 589                         break;
 590                 case FCP_CFL_WRDATA:
 591                         data_dir = DMA_TO_DEVICE;
 592                         break;
 593                 case FCP_CFL_WRDATA | FCP_CFL_RDDATA:
 594                         goto err;       /* TBD not supported by tcm_fc yet */
 595                 }
 596                 /*
 597                  * Locate the SAM Task Attr from fc_pri_ta
 598                  */
 599                 switch (fcp->fc_pri_ta & FCP_PTA_MASK) {
 600                 case FCP_PTA_HEADQ:
 601                         task_attr = MSG_HEAD_TAG;
 602                         break;
 603                 case FCP_PTA_ORDERED:
 604                         task_attr = MSG_ORDERED_TAG;
 605                         break;
 606                 case FCP_PTA_ACA:
 607                         task_attr = MSG_ACA_TAG;
 608                         break;
 609                 case FCP_PTA_SIMPLE: /* Fallthrough */
 610                 default:
 611                         task_attr = MSG_SIMPLE_TAG;
 612                 }
 613
 614
 615                 task_attr = fcp->fc_pri_ta & FCP_PTA_MASK;
 616                 data_len = ntohl(fcp->fc_dl);
 617                 cmd->cdb = fcp->fc_cdb;
 618         }
 619
 620         se_cmd = &cmd->se_cmd;
 621         /*
 622          * Initialize struct se_cmd descriptor from target_core_mod
 623          * infrastructure
 624          */
 625         transport_init_se_cmd(se_cmd, &ft_configfs->tf_ops, cmd->sess->se_sess,
 626                               data_len, data_dir, task_attr,
 627                               &cmd->ft_sense_buffer[0]);
 628         /*
 629          * Check for FCP task management flags
 630          */
 631         if (fcp->fc_tm_flags) {
 632                 ft_send_tm(cmd);
 633                 return;
 634         }
 635
 636         fc_seq_exch(cmd->seq)->lp->tt.seq_set_resp(cmd->seq, ft_recv_seq, cmd);
 637
 638         ret = ft_get_lun_for_cmd(cmd, fcp->fc_lun);
 639         if (ret < 0) {
 640                 ft_dump_cmd(cmd, __func__);
 641                 transport_send_check_condition_and_sense(&cmd->se_cmd,
 642                         cmd->se_cmd.scsi_sense_reason, 0);
 643                 return;
 644         }
 645
 646         ret = transport_generic_allocate_tasks(se_cmd, cmd->cdb);
 647
 648         FT_IO_DBG("r_ctl %x alloc task ret %d\n", fh->fh_r_ctl, ret);
 649         ft_dump_cmd(cmd, __func__);
 650
 651         if (ret == -1) {
 652                 transport_send_check_condition_and_sense(se_cmd,
 653                                 TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE, 0);
 654                 transport_generic_free_cmd(se_cmd, 0, 1, 0);
 655                 return;
 656         }
 657         if (ret == -2) {
 658                 if (se_cmd->se_cmd_flags & SCF_SCSI_RESERVATION_CONFLICT)
 659                         ft_queue_status(se_cmd);
 660                 else
 661                         transport_send_check_condition_and_sense(se_cmd,
 662                                         se_cmd->scsi_sense_reason, 0);
 663                 transport_generic_free_cmd(se_cmd, 0, 1, 0);
 664                 return;
 665         }
 666         transport_generic_handle_cdb(se_cmd);
 667         return;
 668
 669 err:
 670         ft_send_resp_code(cmd, FCP_CMND_FIELDS_INVALID);
 671         return;
 672 }
 673
 674 /*
 675  * Handle request in the command thread.
 676  */
 677 static void ft_exec_req(struct ft_cmd *cmd)
 678 {
 679         FT_IO_DBG("cmd state %x\n", cmd->state);
 680         switch (cmd->state) {
 681         case FC_CMD_ST_NEW:
 682                 ft_send_cmd(cmd);
 683                 break;
 684         default:
 685                 break;
 686         }
 687 }
 688
 689 /*
 690  * Processing thread.
 691  * Currently one thread per tpg.
 692  */
 693 int ft_thread(void *arg)
 694 {
 695         struct ft_tpg *tpg = arg;
 696         struct se_queue_obj *qobj = &tpg->qobj;
 697         struct ft_cmd *cmd;
 698         int ret;
 699
 700         set_user_nice(current, -20);
 701
 702         while (!kthread_should_stop()) {
 703                 ret = wait_event_interruptible(qobj->thread_wq,
 704                         atomic_read(&qobj->queue_cnt) || kthread_should_stop());
 705                 if (ret < 0 || kthread_should_stop())
 706                         goto out;
 707                 cmd = ft_dequeue_cmd(qobj);
 708                 if (cmd)
 709                         ft_exec_req(cmd);
 710         }
 711
 712 out:
 713         return 0;
 714 }