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_tmr.h>
  49 #include <target/configfs_macros.h>
  50
  51 #include "tcm_fc.h"
  52
  53 /*
  54  * Dump cmd state for debugging.
  55  */
  56 void ft_dump_cmd(struct ft_cmd *cmd, const char *caller)
  57 {
  58         struct fc_exch *ep;
  59         struct fc_seq *sp;
  60         struct se_cmd *se_cmd;
  61         struct se_mem *mem;
  62         struct se_transport_task *task;
  63
  64         if (!(ft_debug_logging & FT_DEBUG_IO))
  65                 return;
  66
  67         se_cmd = &cmd->se_cmd;
  68         printk(KERN_INFO "%s: cmd %p state %d sess %p seq %p se_cmd %p\n",
  69                 caller, cmd, cmd->state, cmd->sess, cmd->seq, se_cmd);
  70         printk(KERN_INFO "%s: cmd %p cdb %p\n",
  71                 caller, cmd, cmd->cdb);
  72         printk(KERN_INFO "%s: cmd %p lun %d\n", caller, cmd, cmd->lun);
  73
  74         task = T_TASK(se_cmd);
  75         printk(KERN_INFO "%s: cmd %p task %p se_num %u buf %p len %u se_cmd_flags <0x%x>\n",
  76                caller, cmd, task, task->t_tasks_se_num,
  77                task->t_task_buf, se_cmd->data_length, se_cmd->se_cmd_flags);
  78         if (task->t_mem_list)
  79                 list_for_each_entry(mem, task->t_mem_list, se_list)
  80                         printk(KERN_INFO "%s: cmd %p mem %p page %p "
  81                                "len 0x%x off 0x%x\n",
  82                                caller, cmd, mem,
  83                                mem->se_page, mem->se_len, mem->se_off);
  84         sp = cmd->seq;
  85         if (sp) {
  86                 ep = fc_seq_exch(sp);
  87                 printk(KERN_INFO "%s: cmd %p sid %x did %x "
  88                         "ox_id %x rx_id %x seq_id %x e_stat %x\n",
  89                         caller, cmd, ep->sid, ep->did, ep->oxid, ep->rxid,
  90                         sp->id, ep->esb_stat);
  91         }
  92         print_hex_dump(KERN_INFO, "ft_dump_cmd ", DUMP_PREFIX_NONE,
  93                 16, 4, cmd->cdb, MAX_COMMAND_SIZE, 0);
  94 }
  95
  96 /*
  97  * Get LUN from CDB.
  98  */
  99 static int ft_get_lun_for_cmd(struct ft_cmd *cmd, u8 *lunp)
 100 {
 101         u64 lun;
 102
 103         lun = lunp[1];
 104         switch (lunp[0] >> 6) {
 105         case 0:
 106                 break;
 107         case 1:
 108                 lun |= (lunp[0] & 0x3f) << 8;
 109                 break;
 110         default:
 111                 return -1;
 112         }
 113         if (lun >= TRANSPORT_MAX_LUNS_PER_TPG)
 114                 return -1;
 115         cmd->lun = lun;
 116         return transport_get_lun_for_cmd(&cmd->se_cmd, NULL, lun);
 117 }
 118
 119 static void ft_queue_cmd(struct ft_sess *sess, struct ft_cmd *cmd)
 120 {
 121         struct se_queue_obj *qobj;
 122         unsigned long flags;
 123
 124         qobj = &sess->tport->tpg->qobj;
 125         spin_lock_irqsave(&qobj->cmd_queue_lock, flags);
 126         list_add_tail(&cmd->se_req.qr_list, &qobj->qobj_list);
 127         spin_unlock_irqrestore(&qobj->cmd_queue_lock, flags);
 128         atomic_inc(&qobj->queue_cnt);
 129         wake_up_interruptible(&qobj->thread_wq);
 130 }
 131
 132 static struct ft_cmd *ft_dequeue_cmd(struct se_queue_obj *qobj)
 133 {
 134         unsigned long flags;
 135         struct se_queue_req *qr;
 136
 137         spin_lock_irqsave(&qobj->cmd_queue_lock, flags);
 138         if (list_empty(&qobj->qobj_list)) {
 139                 spin_unlock_irqrestore(&qobj->cmd_queue_lock, flags);
 140                 return NULL;
 141         }
 142         qr = list_first_entry(&qobj->qobj_list, struct se_queue_req, qr_list);
 143         list_del(&qr->qr_list);
 144         atomic_dec(&qobj->queue_cnt);
 145         spin_unlock_irqrestore(&qobj->cmd_queue_lock, flags);
 146         return container_of(qr, struct ft_cmd, se_req);
 147 }
 148
 149 static void ft_free_cmd(struct ft_cmd *cmd)
 150 {
 151         struct fc_frame *fp;
 152         struct fc_lport *lport;
 153
 154         if (!cmd)
 155                 return;
 156         fp = cmd->req_frame;
 157         lport = fr_dev(fp);
 158         if (fr_seq(fp))
 159                 lport->tt.seq_release(fr_seq(fp));
 160         fc_frame_free(fp);
 161         ft_sess_put(cmd->sess); /* undo get from lookup at recv */
 162         kfree(cmd);
 163 }
 164
 165 void ft_release_cmd(struct se_cmd *se_cmd)
 166 {
 167         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
 168
 169         ft_free_cmd(cmd);
 170 }
 171
 172 void ft_check_stop_free(struct se_cmd *se_cmd)
 173 {
 174         transport_generic_free_cmd(se_cmd, 0, 1, 0);
 175 }
 176
 177 /*
 178  * Send response.
 179  */
 180 int ft_queue_status(struct se_cmd *se_cmd)
 181 {
 182         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
 183         struct fc_frame *fp;
 184         struct fcp_resp_with_ext *fcp;
 185         struct fc_lport *lport;
 186         struct fc_exch *ep;
 187         size_t len;
 188
 189         ft_dump_cmd(cmd, __func__);
 190         ep = fc_seq_exch(cmd->seq);
 191         lport = ep->lp;
 192         len = sizeof(*fcp) + se_cmd->scsi_sense_length;
 193         fp = fc_frame_alloc(lport, len);
 194         if (!fp) {
 195                 /* XXX shouldn't just drop it - requeue and retry? */
 196                 return 0;
 197         }
 198         fcp = fc_frame_payload_get(fp, len);
 199         memset(fcp, 0, len);
 200         fcp->resp.fr_status = se_cmd->scsi_status;
 201
 202         len = se_cmd->scsi_sense_length;
 203         if (len) {
 204                 fcp->resp.fr_flags |= FCP_SNS_LEN_VAL;
 205                 fcp->ext.fr_sns_len = htonl(len);
 206                 memcpy((fcp + 1), se_cmd->sense_buffer, len);
 207         }
 208
 209         /*
 210          * Test underflow and overflow with one mask.  Usually both are off.
 211          * Bidirectional commands are not handled yet.
 212          */
 213         if (se_cmd->se_cmd_flags & (SCF_OVERFLOW_BIT | SCF_UNDERFLOW_BIT)) {
 214                 if (se_cmd->se_cmd_flags & SCF_OVERFLOW_BIT)
 215                         fcp->resp.fr_flags |= FCP_RESID_OVER;
 216                 else
 217                         fcp->resp.fr_flags |= FCP_RESID_UNDER;
 218                 fcp->ext.fr_resid = cpu_to_be32(se_cmd->residual_count);
 219         }
 220
 221         /*
 222          * Send response.
 223          */
 224         cmd->seq = lport->tt.seq_start_next(cmd->seq);
 225         fc_fill_fc_hdr(fp, FC_RCTL_DD_CMD_STATUS, ep->did, ep->sid, FC_TYPE_FCP,
 226                        FC_FC_EX_CTX | FC_FC_LAST_SEQ | FC_FC_END_SEQ, 0);
 227
 228         lport->tt.seq_send(lport, cmd->seq, fp);
 229         lport->tt.exch_done(cmd->seq);
 230         return 0;
 231 }
 232
 233 int ft_write_pending_status(struct se_cmd *se_cmd)
 234 {
 235         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
 236
 237         return cmd->write_data_len != se_cmd->data_length;
 238 }
 239
 240 /*
 241  * Send TX_RDY (transfer ready).
 242  */
 243 int ft_write_pending(struct se_cmd *se_cmd)
 244 {
 245         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
 246         struct fc_frame *fp;
 247         struct fcp_txrdy *txrdy;
 248         struct fc_lport *lport;
 249         struct fc_exch *ep;
 250         struct fc_frame_header *fh;
 251         u32 f_ctl;
 252
 253         ft_dump_cmd(cmd, __func__);
 254
 255         ep = fc_seq_exch(cmd->seq);
 256         lport = ep->lp;
 257         fp = fc_frame_alloc(lport, sizeof(*txrdy));
 258         if (!fp)
 259                 return PYX_TRANSPORT_OUT_OF_MEMORY_RESOURCES;
 260
 261         txrdy = fc_frame_payload_get(fp, sizeof(*txrdy));
 262         memset(txrdy, 0, sizeof(*txrdy));
 263         txrdy->ft_burst_len = htonl(se_cmd->data_length);
 264
 265         cmd->seq = lport->tt.seq_start_next(cmd->seq);
 266         fc_fill_fc_hdr(fp, FC_RCTL_DD_DATA_DESC, ep->did, ep->sid, FC_TYPE_FCP,
 267                        FC_FC_EX_CTX | FC_FC_END_SEQ | FC_FC_SEQ_INIT, 0);
 268
 269         fh = fc_frame_header_get(fp);
 270         f_ctl = ntoh24(fh->fh_f_ctl);
 271
 272         /* Only if it is 'Exchange Responder' */
 273         if (f_ctl & FC_FC_EX_CTX) {
 274                 /* Target is 'exchange responder' and sending XFER_READY
 275                  * to 'exchange initiator (initiator)'
 276                  */
 277                 if ((ep->xid <= lport->lro_xid) &&
 278                     (fh->fh_r_ctl == FC_RCTL_DD_DATA_DESC)) {
 279                         if (se_cmd->se_cmd_flags & SCF_SCSI_DATA_SG_IO_CDB) {
 280                                 /*
 281                                  * Map se_mem list to scatterlist, so that
 282                                  * DDP can be setup. DDP setup function require
 283                                  * scatterlist. se_mem_list is internal to
 284                                  * TCM/LIO target
 285                                  */
 286                                 transport_do_task_sg_chain(se_cmd);
 287                                 cmd->sg = T_TASK(se_cmd)->t_tasks_sg_chained;
 288                                 cmd->sg_cnt =
 289                                         T_TASK(se_cmd)->t_tasks_sg_chained_no;
 290                         }
 291                         if (cmd->sg && lport->tt.ddp_setup(lport, ep->xid,
 292                                                     cmd->sg, cmd->sg_cnt))
 293                                 cmd->was_ddp_setup = 1;
 294                 }
 295         }
 296         lport->tt.seq_send(lport, cmd->seq, fp);
 297         return 0;
 298 }
 299
 300 u32 ft_get_task_tag(struct se_cmd *se_cmd)
 301 {
 302         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
 303
 304         return fc_seq_exch(cmd->seq)->rxid;
 305 }
 306
 307 int ft_get_cmd_state(struct se_cmd *se_cmd)
 308 {
 309         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
 310
 311         return cmd->state;
 312 }
 313
 314 int ft_is_state_remove(struct se_cmd *se_cmd)
 315 {
 316         return 0;       /* XXX TBD */
 317 }
 318
 319 void ft_new_cmd_failure(struct se_cmd *se_cmd)
 320 {
 321         /* XXX TBD */
 322         printk(KERN_INFO "%s: se_cmd %p\n", __func__, se_cmd);
 323 }
 324
 325 /*
 326  * FC sequence response handler for follow-on sequences (data) and aborts.
 327  */
 328 static void ft_recv_seq(struct fc_seq *sp, struct fc_frame *fp, void *arg)
 329 {
 330         struct ft_cmd *cmd = arg;
 331         struct fc_frame_header *fh;
 332
 333         if (IS_ERR(fp)) {
 334                 /* XXX need to find cmd if queued */
 335                 cmd->se_cmd.t_state = TRANSPORT_REMOVE;
 336                 cmd->seq = NULL;
 337                 transport_generic_free_cmd(&cmd->se_cmd, 0, 1, 0);
 338                 return;
 339         }
 340
 341         fh = fc_frame_header_get(fp);
 342
 343         switch (fh->fh_r_ctl) {
 344         case FC_RCTL_DD_SOL_DATA:       /* write data */
 345                 ft_recv_write_data(cmd, fp);
 346                 break;
 347         case FC_RCTL_DD_UNSOL_CTL:      /* command */
 348         case FC_RCTL_DD_SOL_CTL:        /* transfer ready */
 349         case FC_RCTL_DD_DATA_DESC:      /* transfer ready */
 350         default:
 351                 printk(KERN_INFO "%s: unhandled frame r_ctl %x\n",
 352                        __func__, fh->fh_r_ctl);
 353                 fc_frame_free(fp);
 354                 transport_generic_free_cmd(&cmd->se_cmd, 0, 1, 0);
 355                 break;
 356         }
 357 }
 358
 359 /*
 360  * Send a FCP response including SCSI status and optional FCP rsp_code.
 361  * status is SAM_STAT_GOOD (zero) iff code is valid.
 362  * This is used in error cases, such as allocation failures.
 363  */
 364 static void ft_send_resp_status(struct fc_lport *lport,
 365                                 const struct fc_frame *rx_fp,
 366                                 u32 status, enum fcp_resp_rsp_codes code)
 367 {
 368         struct fc_frame *fp;
 369         struct fc_seq *sp;
 370         const struct fc_frame_header *fh;
 371         size_t len;
 372         struct fcp_resp_with_ext *fcp;
 373         struct fcp_resp_rsp_info *info;
 374
 375         fh = fc_frame_header_get(rx_fp);
 376         FT_IO_DBG("FCP error response: did %x oxid %x status %x code %x\n",
 377                   ntoh24(fh->fh_s_id), ntohs(fh->fh_ox_id), status, code);
 378         len = sizeof(*fcp);
 379         if (status == SAM_STAT_GOOD)
 380                 len += sizeof(*info);
 381         fp = fc_frame_alloc(lport, len);
 382         if (!fp)
 383                 return;
 384         fcp = fc_frame_payload_get(fp, len);
 385         memset(fcp, 0, len);
 386         fcp->resp.fr_status = status;
 387         if (status == SAM_STAT_GOOD) {
 388                 fcp->ext.fr_rsp_len = htonl(sizeof(*info));
 389                 fcp->resp.fr_flags |= FCP_RSP_LEN_VAL;
 390                 info = (struct fcp_resp_rsp_info *)(fcp + 1);
 391                 info->rsp_code = code;
 392         }
 393
 394         fc_fill_reply_hdr(fp, rx_fp, FC_RCTL_DD_CMD_STATUS, 0);
 395         sp = fr_seq(fp);
 396         if (sp)
 397                 lport->tt.seq_send(lport, sp, fp);
 398         else
 399                 lport->tt.frame_send(lport, fp);
 400 }
 401
 402 /*
 403  * Send error or task management response.
 404  * Always frees the cmd and associated state.
 405  */
 406 static void ft_send_resp_code(struct ft_cmd *cmd, enum fcp_resp_rsp_codes code)
 407 {
 408         ft_send_resp_status(cmd->sess->tport->lport,
 409                             cmd->req_frame, SAM_STAT_GOOD, code);
 410         ft_free_cmd(cmd);
 411 }
 412
 413 /*
 414  * Handle Task Management Request.
 415  */
 416 static void ft_send_tm(struct ft_cmd *cmd)
 417 {
 418         struct se_tmr_req *tmr;
 419         struct fcp_cmnd *fcp;
 420         u8 tm_func;
 421
 422         fcp = fc_frame_payload_get(cmd->req_frame, sizeof(*fcp));
 423
 424         switch (fcp->fc_tm_flags) {
 425         case FCP_TMF_LUN_RESET:
 426                 tm_func = TMR_LUN_RESET;
 427                 if (ft_get_lun_for_cmd(cmd, fcp->fc_lun) < 0) {
 428                         ft_dump_cmd(cmd, __func__);
 429                         transport_send_check_condition_and_sense(&cmd->se_cmd,
 430                                 cmd->se_cmd.scsi_sense_reason, 0);
 431                         ft_sess_put(cmd->sess);
 432                         return;
 433                 }
 434                 break;
 435         case FCP_TMF_TGT_RESET:
 436                 tm_func = TMR_TARGET_WARM_RESET;
 437                 break;
 438         case FCP_TMF_CLR_TASK_SET:
 439                 tm_func = TMR_CLEAR_TASK_SET;
 440                 break;
 441         case FCP_TMF_ABT_TASK_SET:
 442                 tm_func = TMR_ABORT_TASK_SET;
 443                 break;
 444         case FCP_TMF_CLR_ACA:
 445                 tm_func = TMR_CLEAR_ACA;
 446                 break;
 447         default:
 448                 /*
 449                  * FCP4r01 indicates having a combination of
 450                  * tm_flags set is invalid.
 451                  */
 452                 FT_TM_DBG("invalid FCP tm_flags %x\n", fcp->fc_tm_flags);
 453                 ft_send_resp_code(cmd, FCP_CMND_FIELDS_INVALID);
 454                 return;
 455         }
 456
 457         FT_TM_DBG("alloc tm cmd fn %d\n", tm_func);
 458         tmr = core_tmr_alloc_req(&cmd->se_cmd, cmd, tm_func);
 459         if (!tmr) {
 460                 FT_TM_DBG("alloc failed\n");
 461                 ft_send_resp_code(cmd, FCP_TMF_FAILED);
 462                 return;
 463         }
 464         cmd->se_cmd.se_tmr_req = tmr;
 465         transport_generic_handle_tmr(&cmd->se_cmd);
 466 }
 467
 468 /*
 469  * Send status from completed task management request.
 470  */
 471 int ft_queue_tm_resp(struct se_cmd *se_cmd)
 472 {
 473         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
 474         struct se_tmr_req *tmr = se_cmd->se_tmr_req;
 475         enum fcp_resp_rsp_codes code;
 476
 477         switch (tmr->response) {
 478         case TMR_FUNCTION_COMPLETE:
 479                 code = FCP_TMF_CMPL;
 480                 break;
 481         case TMR_LUN_DOES_NOT_EXIST:
 482                 code = FCP_TMF_INVALID_LUN;
 483                 break;
 484         case TMR_FUNCTION_REJECTED:
 485                 code = FCP_TMF_REJECTED;
 486                 break;
 487         case TMR_TASK_DOES_NOT_EXIST:
 488         case TMR_TASK_STILL_ALLEGIANT:
 489         case TMR_TASK_FAILOVER_NOT_SUPPORTED:
 490         case TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED:
 491         case TMR_FUNCTION_AUTHORIZATION_FAILED:
 492         default:
 493                 code = FCP_TMF_FAILED;
 494                 break;
 495         }
 496         FT_TM_DBG("tmr fn %d resp %d fcp code %d\n",
 497                   tmr->function, tmr->response, code);
 498         ft_send_resp_code(cmd, code);
 499         return 0;
 500 }
 501
 502 /*
 503  * Handle incoming FCP command.
 504  */
 505 static void ft_recv_cmd(struct ft_sess *sess, struct fc_frame *fp)
 506 {
 507         struct ft_cmd *cmd;
 508         struct fc_lport *lport = sess->tport->lport;
 509
 510         cmd = kzalloc(sizeof(*cmd), GFP_ATOMIC);
 511         if (!cmd)
 512                 goto busy;
 513         cmd->sess = sess;
 514         cmd->seq = lport->tt.seq_assign(lport, fp);
 515         if (!cmd->seq) {
 516                 kfree(cmd);
 517                 goto busy;
 518         }
 519         cmd->req_frame = fp;            /* hold frame during cmd */
 520         ft_queue_cmd(sess, cmd);
 521         return;
 522
 523 busy:
 524         FT_IO_DBG("cmd or seq allocation failure - sending BUSY\n");
 525         ft_send_resp_status(lport, fp, SAM_STAT_BUSY, 0);
 526         fc_frame_free(fp);
 527         ft_sess_put(sess);              /* undo get from lookup */
 528 }
 529
 530
 531 /*
 532  * Handle incoming FCP frame.
 533  * Caller has verified that the frame is type FCP.
 534  */
 535 void ft_recv_req(struct ft_sess *sess, struct fc_frame *fp)
 536 {
 537         struct fc_frame_header *fh = fc_frame_header_get(fp);
 538
 539         switch (fh->fh_r_ctl) {
 540         case FC_RCTL_DD_UNSOL_CMD:      /* command */
 541                 ft_recv_cmd(sess, fp);
 542                 break;
 543         case FC_RCTL_DD_SOL_DATA:       /* write data */
 544         case FC_RCTL_DD_UNSOL_CTL:
 545         case FC_RCTL_DD_SOL_CTL:
 546         case FC_RCTL_DD_DATA_DESC:      /* transfer ready */
 547         case FC_RCTL_ELS4_REQ:          /* SRR, perhaps */
 548         default:
 549                 printk(KERN_INFO "%s: unhandled frame r_ctl %x\n",
 550                        __func__, fh->fh_r_ctl);
 551                 fc_frame_free(fp);
 552                 ft_sess_put(sess);      /* undo get from lookup */
 553                 break;
 554         }
 555 }
 556
 557 /*
 558  * Send new command to target.
 559  */
 560 static void ft_send_cmd(struct ft_cmd *cmd)
 561 {
 562         struct fc_frame_header *fh = fc_frame_header_get(cmd->req_frame);
 563         struct se_cmd *se_cmd;
 564         struct fcp_cmnd *fcp;
 565         int data_dir;
 566         u32 data_len;
 567         int task_attr;
 568         int ret;
 569
 570         fcp = fc_frame_payload_get(cmd->req_frame, sizeof(*fcp));
 571         if (!fcp)
 572                 goto err;
 573
 574         if (fcp->fc_flags & FCP_CFL_LEN_MASK)
 575                 goto err;               /* not handling longer CDBs yet */
 576
 577         if (fcp->fc_tm_flags) {
 578                 task_attr = FCP_PTA_SIMPLE;
 579                 data_dir = DMA_NONE;
 580                 data_len = 0;
 581         } else {
 582                 switch (fcp->fc_flags & (FCP_CFL_RDDATA | FCP_CFL_WRDATA)) {
 583                 case 0:
 584                         data_dir = DMA_NONE;
 585                         break;
 586                 case FCP_CFL_RDDATA:
 587                         data_dir = DMA_FROM_DEVICE;
 588                         break;
 589                 case FCP_CFL_WRDATA:
 590                         data_dir = DMA_TO_DEVICE;
 591                         break;
 592                 case FCP_CFL_WRDATA | FCP_CFL_RDDATA:
 593                         goto err;       /* TBD not supported by tcm_fc yet */
 594                 }
 595                 /*
 596                  * Locate the SAM Task Attr from fc_pri_ta
 597                  */
 598                 switch (fcp->fc_pri_ta & FCP_PTA_MASK) {
 599                 case FCP_PTA_HEADQ:
 600                         task_attr = MSG_HEAD_TAG;
 601                         break;
 602                 case FCP_PTA_ORDERED:
 603                         task_attr = MSG_ORDERED_TAG;
 604                         break;
 605                 case FCP_PTA_ACA:
 606                         task_attr = MSG_ACA_TAG;
 607                         break;
 608                 case FCP_PTA_SIMPLE: /* Fallthrough */
 609                 default:
 610                         task_attr = MSG_SIMPLE_TAG;
 611                 }
 612
 613
 614                 task_attr = fcp->fc_pri_ta & FCP_PTA_MASK;
 615                 data_len = ntohl(fcp->fc_dl);
 616                 cmd->cdb = fcp->fc_cdb;
 617         }
 618
 619         se_cmd = &cmd->se_cmd;
 620         /*
 621          * Initialize struct se_cmd descriptor from target_core_mod
 622          * infrastructure
 623          */
 624         transport_init_se_cmd(se_cmd, &ft_configfs->tf_ops, cmd->sess->se_sess,
 625                               data_len, data_dir, task_attr,
 626                               &cmd->ft_sense_buffer[0]);
 627         /*
 628          * Check for FCP task management flags
 629          */
 630         if (fcp->fc_tm_flags) {
 631                 ft_send_tm(cmd);
 632                 return;
 633         }
 634
 635         fc_seq_exch(cmd->seq)->lp->tt.seq_set_resp(cmd->seq, ft_recv_seq, cmd);
 636
 637         ret = ft_get_lun_for_cmd(cmd, fcp->fc_lun);
 638         if (ret < 0) {
 639                 ft_dump_cmd(cmd, __func__);
 640                 transport_send_check_condition_and_sense(&cmd->se_cmd,
 641                         cmd->se_cmd.scsi_sense_reason, 0);
 642                 return;
 643         }
 644
 645         ret = transport_generic_allocate_tasks(se_cmd, cmd->cdb);
 646
 647         FT_IO_DBG("r_ctl %x alloc task ret %d\n", fh->fh_r_ctl, ret);
 648         ft_dump_cmd(cmd, __func__);
 649
 650         if (ret == -1) {
 651                 transport_send_check_condition_and_sense(se_cmd,
 652                                 TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE, 0);
 653                 transport_generic_free_cmd(se_cmd, 0, 1, 0);
 654                 return;
 655         }
 656         if (ret == -2) {
 657                 if (se_cmd->se_cmd_flags & SCF_SCSI_RESERVATION_CONFLICT)
 658                         ft_queue_status(se_cmd);
 659                 else
 660                         transport_send_check_condition_and_sense(se_cmd,
 661                                         se_cmd->scsi_sense_reason, 0);
 662                 transport_generic_free_cmd(se_cmd, 0, 1, 0);
 663                 return;
 664         }
 665         transport_generic_handle_cdb(se_cmd);
 666         return;
 667
 668 err:
 669         ft_send_resp_code(cmd, FCP_CMND_FIELDS_INVALID);
 670         return;
 671 }
 672
 673 /*
 674  * Handle request in the command thread.
 675  */
 676 static void ft_exec_req(struct ft_cmd *cmd)
 677 {
 678         FT_IO_DBG("cmd state %x\n", cmd->state);
 679         switch (cmd->state) {
 680         case FC_CMD_ST_NEW:
 681                 ft_send_cmd(cmd);
 682                 break;
 683         default:
 684                 break;
 685         }
 686 }
 687
 688 /*
 689  * Processing thread.
 690  * Currently one thread per tpg.
 691  */
 692 int ft_thread(void *arg)
 693 {
 694         struct ft_tpg *tpg = arg;
 695         struct se_queue_obj *qobj = &tpg->qobj;
 696         struct ft_cmd *cmd;
 697         int ret;
 698
 699         set_user_nice(current, -20);
 700
 701         while (!kthread_should_stop()) {
 702                 ret = wait_event_interruptible(qobj->thread_wq,
 703                         atomic_read(&qobj->queue_cnt) || kthread_should_stop());
 704                 if (ret < 0 || kthread_should_stop())
 705                         goto out;
 706                 cmd = ft_dequeue_cmd(qobj);
 707                 if (cmd)
 708                         ft_exec_req(cmd);
 709         }
 710
 711 out:
 712         return 0;
 713 }