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 = se_cmd->t_task;
  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 = se_cmd->t_task->t_tasks_sg_chained;
 266                                 cmd->sg_cnt =
 267                                         se_cmd->t_task->t_tasks_sg_chained_no;
 268                         }
 269                         if (cmd->sg && lport->tt.ddp_setup(lport, ep->xid,
 270                                                     cmd->sg, cmd->sg_cnt))
 271                                 cmd->was_ddp_setup = 1;
 272                 }
 273         }
 274         lport->tt.seq_send(lport, cmd->seq, fp);
 275         return 0;
 276 }
 277
 278 u32 ft_get_task_tag(struct se_cmd *se_cmd)
 279 {
 280         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
 281
 282         return fc_seq_exch(cmd->seq)->rxid;
 283 }
 284
 285 int ft_get_cmd_state(struct se_cmd *se_cmd)
 286 {
 287         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
 288
 289         return cmd->state;
 290 }
 291
 292 int ft_is_state_remove(struct se_cmd *se_cmd)
 293 {
 294         return 0;       /* XXX TBD */
 295 }
 296
 297 void ft_new_cmd_failure(struct se_cmd *se_cmd)
 298 {
 299         /* XXX TBD */
 300         printk(KERN_INFO "%s: se_cmd %p\n", __func__, se_cmd);
 301 }
 302
 303 /*
 304  * FC sequence response handler for follow-on sequences (data) and aborts.
 305  */
 306 static void ft_recv_seq(struct fc_seq *sp, struct fc_frame *fp, void *arg)
 307 {
 308         struct ft_cmd *cmd = arg;
 309         struct fc_frame_header *fh;
 310
 311         if (IS_ERR(fp)) {
 312                 /* XXX need to find cmd if queued */
 313                 cmd->se_cmd.t_state = TRANSPORT_REMOVE;
 314                 cmd->seq = NULL;
 315                 transport_generic_free_cmd(&cmd->se_cmd, 0, 1, 0);
 316                 return;
 317         }
 318
 319         fh = fc_frame_header_get(fp);
 320
 321         switch (fh->fh_r_ctl) {
 322         case FC_RCTL_DD_SOL_DATA:       /* write data */
 323                 ft_recv_write_data(cmd, fp);
 324                 break;
 325         case FC_RCTL_DD_UNSOL_CTL:      /* command */
 326         case FC_RCTL_DD_SOL_CTL:        /* transfer ready */
 327         case FC_RCTL_DD_DATA_DESC:      /* transfer ready */
 328         default:
 329                 printk(KERN_INFO "%s: unhandled frame r_ctl %x\n",
 330                        __func__, fh->fh_r_ctl);
 331                 fc_frame_free(fp);
 332                 transport_generic_free_cmd(&cmd->se_cmd, 0, 1, 0);
 333                 break;
 334         }
 335 }
 336
 337 /*
 338  * Send a FCP response including SCSI status and optional FCP rsp_code.
 339  * status is SAM_STAT_GOOD (zero) iff code is valid.
 340  * This is used in error cases, such as allocation failures.
 341  */
 342 static void ft_send_resp_status(struct fc_lport *lport,
 343                                 const struct fc_frame *rx_fp,
 344                                 u32 status, enum fcp_resp_rsp_codes code)
 345 {
 346         struct fc_frame *fp;
 347         struct fc_seq *sp;
 348         const struct fc_frame_header *fh;
 349         size_t len;
 350         struct fcp_resp_with_ext *fcp;
 351         struct fcp_resp_rsp_info *info;
 352
 353         fh = fc_frame_header_get(rx_fp);
 354         FT_IO_DBG("FCP error response: did %x oxid %x status %x code %x\n",
 355                   ntoh24(fh->fh_s_id), ntohs(fh->fh_ox_id), status, code);
 356         len = sizeof(*fcp);
 357         if (status == SAM_STAT_GOOD)
 358                 len += sizeof(*info);
 359         fp = fc_frame_alloc(lport, len);
 360         if (!fp)
 361                 return;
 362         fcp = fc_frame_payload_get(fp, len);
 363         memset(fcp, 0, len);
 364         fcp->resp.fr_status = status;
 365         if (status == SAM_STAT_GOOD) {
 366                 fcp->ext.fr_rsp_len = htonl(sizeof(*info));
 367                 fcp->resp.fr_flags |= FCP_RSP_LEN_VAL;
 368                 info = (struct fcp_resp_rsp_info *)(fcp + 1);
 369                 info->rsp_code = code;
 370         }
 371
 372         fc_fill_reply_hdr(fp, rx_fp, FC_RCTL_DD_CMD_STATUS, 0);
 373         sp = fr_seq(fp);
 374         if (sp)
 375                 lport->tt.seq_send(lport, sp, fp);
 376         else
 377                 lport->tt.frame_send(lport, fp);
 378 }
 379
 380 /*
 381  * Send error or task management response.
 382  * Always frees the cmd and associated state.
 383  */
 384 static void ft_send_resp_code(struct ft_cmd *cmd, enum fcp_resp_rsp_codes code)
 385 {
 386         ft_send_resp_status(cmd->sess->tport->lport,
 387                             cmd->req_frame, SAM_STAT_GOOD, code);
 388         ft_free_cmd(cmd);
 389 }
 390
 391 /*
 392  * Handle Task Management Request.
 393  */
 394 static void ft_send_tm(struct ft_cmd *cmd)
 395 {
 396         struct se_tmr_req *tmr;
 397         struct fcp_cmnd *fcp;
 398         struct ft_sess *sess;
 399         u8 tm_func;
 400
 401         fcp = fc_frame_payload_get(cmd->req_frame, sizeof(*fcp));
 402
 403         switch (fcp->fc_tm_flags) {
 404         case FCP_TMF_LUN_RESET:
 405                 tm_func = TMR_LUN_RESET;
 406                 break;
 407         case FCP_TMF_TGT_RESET:
 408                 tm_func = TMR_TARGET_WARM_RESET;
 409                 break;
 410         case FCP_TMF_CLR_TASK_SET:
 411                 tm_func = TMR_CLEAR_TASK_SET;
 412                 break;
 413         case FCP_TMF_ABT_TASK_SET:
 414                 tm_func = TMR_ABORT_TASK_SET;
 415                 break;
 416         case FCP_TMF_CLR_ACA:
 417                 tm_func = TMR_CLEAR_ACA;
 418                 break;
 419         default:
 420                 /*
 421                  * FCP4r01 indicates having a combination of
 422                  * tm_flags set is invalid.
 423                  */
 424                 FT_TM_DBG("invalid FCP tm_flags %x\n", fcp->fc_tm_flags);
 425                 ft_send_resp_code(cmd, FCP_CMND_FIELDS_INVALID);
 426                 return;
 427         }
 428
 429         FT_TM_DBG("alloc tm cmd fn %d\n", tm_func);
 430         tmr = core_tmr_alloc_req(&cmd->se_cmd, cmd, tm_func);
 431         if (!tmr) {
 432                 FT_TM_DBG("alloc failed\n");
 433                 ft_send_resp_code(cmd, FCP_TMF_FAILED);
 434                 return;
 435         }
 436         cmd->se_cmd.se_tmr_req = tmr;
 437
 438         switch (fcp->fc_tm_flags) {
 439         case FCP_TMF_LUN_RESET:
 440                 cmd->lun = scsilun_to_int((struct scsi_lun *)fcp->fc_lun);
 441                 if (transport_get_lun_for_tmr(&cmd->se_cmd, cmd->lun) < 0) {
 442                         /*
 443                          * Make sure to clean up newly allocated TMR request
 444                          * since "unable to  handle TMR request because failed
 445                          * to get to LUN"
 446                          */
 447                         FT_TM_DBG("Failed to get LUN for TMR func %d, "
 448                                   "se_cmd %p, unpacked_lun %d\n",
 449                                   tm_func, &cmd->se_cmd, cmd->lun);
 450                         ft_dump_cmd(cmd, __func__);
 451                         sess = cmd->sess;
 452                         transport_send_check_condition_and_sense(&cmd->se_cmd,
 453                                 cmd->se_cmd.scsi_sense_reason, 0);
 454                         transport_generic_free_cmd(&cmd->se_cmd, 0, 1, 0);
 455                         ft_sess_put(sess);
 456                         return;
 457                 }
 458                 break;
 459         case FCP_TMF_TGT_RESET:
 460         case FCP_TMF_CLR_TASK_SET:
 461         case FCP_TMF_ABT_TASK_SET:
 462         case FCP_TMF_CLR_ACA:
 463                 break;
 464         default:
 465                 return;
 466         }
 467         transport_generic_handle_tmr(&cmd->se_cmd);
 468 }
 469
 470 /*
 471  * Send status from completed task management request.
 472  */
 473 int ft_queue_tm_resp(struct se_cmd *se_cmd)
 474 {
 475         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
 476         struct se_tmr_req *tmr = se_cmd->se_tmr_req;
 477         enum fcp_resp_rsp_codes code;
 478
 479         switch (tmr->response) {
 480         case TMR_FUNCTION_COMPLETE:
 481                 code = FCP_TMF_CMPL;
 482                 break;
 483         case TMR_LUN_DOES_NOT_EXIST:
 484                 code = FCP_TMF_INVALID_LUN;
 485                 break;
 486         case TMR_FUNCTION_REJECTED:
 487                 code = FCP_TMF_REJECTED;
 488                 break;
 489         case TMR_TASK_DOES_NOT_EXIST:
 490         case TMR_TASK_STILL_ALLEGIANT:
 491         case TMR_TASK_FAILOVER_NOT_SUPPORTED:
 492         case TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED:
 493         case TMR_FUNCTION_AUTHORIZATION_FAILED:
 494         default:
 495                 code = FCP_TMF_FAILED;
 496                 break;
 497         }
 498         FT_TM_DBG("tmr fn %d resp %d fcp code %d\n",
 499                   tmr->function, tmr->response, code);
 500         ft_send_resp_code(cmd, code);
 501         return 0;
 502 }
 503
 504 /*
 505  * Handle incoming FCP command.
 506  */
 507 static void ft_recv_cmd(struct ft_sess *sess, struct fc_frame *fp)
 508 {
 509         struct ft_cmd *cmd;
 510         struct fc_lport *lport = sess->tport->lport;
 511
 512         cmd = kzalloc(sizeof(*cmd), GFP_ATOMIC);
 513         if (!cmd)
 514                 goto busy;
 515         cmd->sess = sess;
 516         cmd->seq = lport->tt.seq_assign(lport, fp);
 517         if (!cmd->seq) {
 518                 kfree(cmd);
 519                 goto busy;
 520         }
 521         cmd->req_frame = fp;            /* hold frame during cmd */
 522         ft_queue_cmd(sess, cmd);
 523         return;
 524
 525 busy:
 526         FT_IO_DBG("cmd or seq allocation failure - sending BUSY\n");
 527         ft_send_resp_status(lport, fp, SAM_STAT_BUSY, 0);
 528         fc_frame_free(fp);
 529         ft_sess_put(sess);              /* undo get from lookup */
 530 }
 531
 532
 533 /*
 534  * Handle incoming FCP frame.
 535  * Caller has verified that the frame is type FCP.
 536  */
 537 void ft_recv_req(struct ft_sess *sess, struct fc_frame *fp)
 538 {
 539         struct fc_frame_header *fh = fc_frame_header_get(fp);
 540
 541         switch (fh->fh_r_ctl) {
 542         case FC_RCTL_DD_UNSOL_CMD:      /* command */
 543                 ft_recv_cmd(sess, fp);
 544                 break;
 545         case FC_RCTL_DD_SOL_DATA:       /* write data */
 546         case FC_RCTL_DD_UNSOL_CTL:
 547         case FC_RCTL_DD_SOL_CTL:
 548         case FC_RCTL_DD_DATA_DESC:      /* transfer ready */
 549         case FC_RCTL_ELS4_REQ:          /* SRR, perhaps */
 550         default:
 551                 printk(KERN_INFO "%s: unhandled frame r_ctl %x\n",
 552                        __func__, fh->fh_r_ctl);
 553                 fc_frame_free(fp);
 554                 ft_sess_put(sess);      /* undo get from lookup */
 555                 break;
 556         }
 557 }
 558
 559 /*
 560  * Send new command to target.
 561  */
 562 static void ft_send_cmd(struct ft_cmd *cmd)
 563 {
 564         struct fc_frame_header *fh = fc_frame_header_get(cmd->req_frame);
 565         struct se_cmd *se_cmd;
 566         struct fcp_cmnd *fcp;
 567         int data_dir;
 568         u32 data_len;
 569         int task_attr;
 570         int ret;
 571
 572         fcp = fc_frame_payload_get(cmd->req_frame, sizeof(*fcp));
 573         if (!fcp)
 574                 goto err;
 575
 576         if (fcp->fc_flags & FCP_CFL_LEN_MASK)
 577                 goto err;               /* not handling longer CDBs yet */
 578
 579         if (fcp->fc_tm_flags) {
 580                 task_attr = FCP_PTA_SIMPLE;
 581                 data_dir = DMA_NONE;
 582                 data_len = 0;
 583         } else {
 584                 switch (fcp->fc_flags & (FCP_CFL_RDDATA | FCP_CFL_WRDATA)) {
 585                 case 0:
 586                         data_dir = DMA_NONE;
 587                         break;
 588                 case FCP_CFL_RDDATA:
 589                         data_dir = DMA_FROM_DEVICE;
 590                         break;
 591                 case FCP_CFL_WRDATA:
 592                         data_dir = DMA_TO_DEVICE;
 593                         break;
 594                 case FCP_CFL_WRDATA | FCP_CFL_RDDATA:
 595                         goto err;       /* TBD not supported by tcm_fc yet */
 596                 }
 597                 /*
 598                  * Locate the SAM Task Attr from fc_pri_ta
 599                  */
 600                 switch (fcp->fc_pri_ta & FCP_PTA_MASK) {
 601                 case FCP_PTA_HEADQ:
 602                         task_attr = MSG_HEAD_TAG;
 603                         break;
 604                 case FCP_PTA_ORDERED:
 605                         task_attr = MSG_ORDERED_TAG;
 606                         break;
 607                 case FCP_PTA_ACA:
 608                         task_attr = MSG_ACA_TAG;
 609                         break;
 610                 case FCP_PTA_SIMPLE: /* Fallthrough */
 611                 default:
 612                         task_attr = MSG_SIMPLE_TAG;
 613                 }
 614
 615
 616                 task_attr = fcp->fc_pri_ta & FCP_PTA_MASK;
 617                 data_len = ntohl(fcp->fc_dl);
 618                 cmd->cdb = fcp->fc_cdb;
 619         }
 620
 621         se_cmd = &cmd->se_cmd;
 622         /*
 623          * Initialize struct se_cmd descriptor from target_core_mod
 624          * infrastructure
 625          */
 626         transport_init_se_cmd(se_cmd, &ft_configfs->tf_ops, cmd->sess->se_sess,
 627                               data_len, data_dir, task_attr,
 628                               &cmd->ft_sense_buffer[0]);
 629         /*
 630          * Check for FCP task management flags
 631          */
 632         if (fcp->fc_tm_flags) {
 633                 ft_send_tm(cmd);
 634                 return;
 635         }
 636
 637         fc_seq_exch(cmd->seq)->lp->tt.seq_set_resp(cmd->seq, ft_recv_seq, cmd);
 638
 639         cmd->lun = scsilun_to_int((struct scsi_lun *)fcp->fc_lun);
 640         ret = transport_get_lun_for_cmd(&cmd->se_cmd, cmd->lun);
 641         if (ret < 0) {
 642                 ft_dump_cmd(cmd, __func__);
 643                 transport_send_check_condition_and_sense(&cmd->se_cmd,
 644                         cmd->se_cmd.scsi_sense_reason, 0);
 645                 return;
 646         }
 647
 648         ret = transport_generic_allocate_tasks(se_cmd, cmd->cdb);
 649
 650         FT_IO_DBG("r_ctl %x alloc task ret %d\n", fh->fh_r_ctl, ret);
 651         ft_dump_cmd(cmd, __func__);
 652
 653         if (ret == -1) {
 654                 transport_send_check_condition_and_sense(se_cmd,
 655                                 TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE, 0);
 656                 transport_generic_free_cmd(se_cmd, 0, 1, 0);
 657                 return;
 658         }
 659         if (ret == -2) {
 660                 if (se_cmd->se_cmd_flags & SCF_SCSI_RESERVATION_CONFLICT)
 661                         ft_queue_status(se_cmd);
 662                 else
 663                         transport_send_check_condition_and_sense(se_cmd,
 664                                         se_cmd->scsi_sense_reason, 0);
 665                 transport_generic_free_cmd(se_cmd, 0, 1, 0);
 666                 return;
 667         }
 668         transport_generic_handle_cdb(se_cmd);
 669         return;
 670
 671 err:
 672         ft_send_resp_code(cmd, FCP_CMND_FIELDS_INVALID);
 673 }
 674
 675 /*
 676  * Handle request in the command thread.
 677  */
 678 static void ft_exec_req(struct ft_cmd *cmd)
 679 {
 680         FT_IO_DBG("cmd state %x\n", cmd->state);
 681         switch (cmd->state) {
 682         case FC_CMD_ST_NEW:
 683                 ft_send_cmd(cmd);
 684                 break;
 685         default:
 686                 break;
 687         }
 688 }
 689
 690 /*
 691  * Processing thread.
 692  * Currently one thread per tpg.
 693  */
 694 int ft_thread(void *arg)
 695 {
 696         struct ft_tpg *tpg = arg;
 697         struct se_queue_obj *qobj = &tpg->qobj;
 698         struct ft_cmd *cmd;
 699         int ret;
 700
 701         set_user_nice(current, -20);
 702
 703         while (!kthread_should_stop()) {
 704                 ret = wait_event_interruptible(qobj->thread_wq,
 705                         atomic_read(&qobj->queue_cnt) || kthread_should_stop());
 706                 if (ret < 0 || kthread_should_stop())
 707                         goto out;
 708                 cmd = ft_dequeue_cmd(qobj);
 709                 if (cmd)
 710                         ft_exec_req(cmd);
 711         }
 712
 713 out:
 714         return 0;
 715 }