drivers/target/target_core_tmr.c

   1 /*******************************************************************************
   2  * Filename:  target_core_tmr.c
   3  *
   4  * This file contains SPC-3 task management infrastructure
   5  *
   6  * Copyright (c) 2009,2010 Rising Tide Systems
   7  * Copyright (c) 2009,2010 Linux-iSCSI.org
   8  *
   9  * Nicholas A. Bellinger <nab@kernel.org>
  10  *
  11  * This program is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License as published by
  13  * the Free Software Foundation; either version 2 of the License, or
  14  * (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  * GNU General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with this program; if not, write to the Free Software
  23  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  24  *
  25  ******************************************************************************/
  26
  27 #include <linux/slab.h>
  28 #include <linux/spinlock.h>
  29 #include <linux/list.h>
  30 #include <linux/export.h>
  31 #include <scsi/scsi.h>
  32 #include <scsi/scsi_cmnd.h>
  33
  34 #include <target/target_core_base.h>
  35 #include <target/target_core_backend.h>
  36 #include <target/target_core_fabric.h>
  37 #include <target/target_core_configfs.h>
  38
  39 #include "target_core_internal.h"
  40 #include "target_core_alua.h"
  41 #include "target_core_pr.h"
  42
  43 int core_tmr_alloc_req(
  44         struct se_cmd *se_cmd,
  45         void *fabric_tmr_ptr,
  46         u8 function,
  47         gfp_t gfp_flags)
  48 {
  49         struct se_tmr_req *tmr;
  50
  51         tmr = kzalloc(sizeof(struct se_tmr_req), gfp_flags);
  52         if (!tmr) {
  53                 pr_err("Unable to allocate struct se_tmr_req\n");
  54                 return -ENOMEM;
  55         }
  56
  57         se_cmd->se_cmd_flags |= SCF_SCSI_TMR_CDB;
  58         se_cmd->se_tmr_req = tmr;
  59         tmr->task_cmd = se_cmd;
  60         tmr->fabric_tmr_ptr = fabric_tmr_ptr;
  61         tmr->function = function;
  62         INIT_LIST_HEAD(&tmr->tmr_list);
  63
  64         return 0;
  65 }
  66 EXPORT_SYMBOL(core_tmr_alloc_req);
  67
  68 void core_tmr_release_req(
  69         struct se_tmr_req *tmr)
  70 {
  71         struct se_device *dev = tmr->tmr_dev;
  72         unsigned long flags;
  73
  74         if (!dev) {
  75                 kfree(tmr);
  76                 return;
  77         }
  78
  79         spin_lock_irqsave(&dev->se_tmr_lock, flags);
  80         list_del(&tmr->tmr_list);
  81         spin_unlock_irqrestore(&dev->se_tmr_lock, flags);
  82
  83         kfree(tmr);
  84 }
  85
  86 static void core_tmr_handle_tas_abort(
  87         struct se_node_acl *tmr_nacl,
  88         struct se_cmd *cmd,
  89         int tas,
  90         int fe_count)
  91 {
  92         if (!fe_count) {
  93                 transport_cmd_finish_abort(cmd, 1);
  94                 return;
  95         }
  96         /*
  97          * TASK ABORTED status (TAS) bit support
  98         */
  99         if ((tmr_nacl &&
 100              (tmr_nacl == cmd->se_sess->se_node_acl)) || tas)
 101                 transport_send_task_abort(cmd);
 102
 103         transport_cmd_finish_abort(cmd, 0);
 104 }
 105
 106 static int target_check_cdb_and_preempt(struct list_head *list,
 107                 struct se_cmd *cmd)
 108 {
 109         struct t10_pr_registration *reg;
 110
 111         if (!list)
 112                 return 0;
 113         list_for_each_entry(reg, list, pr_reg_abort_list) {
 114                 if (reg->pr_res_key == cmd->pr_res_key)
 115                         return 0;
 116         }
 117
 118         return 1;
 119 }
 120
 121 void core_tmr_abort_task(
 122         struct se_device *dev,
 123         struct se_tmr_req *tmr,
 124         struct se_session *se_sess)
 125 {
 126         struct se_cmd *se_cmd, *tmp_cmd;
 127         unsigned long flags;
 128         int ref_tag;
 129
 130         spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
 131         list_for_each_entry_safe(se_cmd, tmp_cmd,
 132                         &se_sess->sess_cmd_list, se_cmd_list) {
 133
 134                 if (dev != se_cmd->se_dev)
 135                         continue;
 136                 ref_tag = se_cmd->se_tfo->get_task_tag(se_cmd);
 137                 if (tmr->ref_task_tag != ref_tag)
 138                         continue;
 139
 140                 printk("ABORT_TASK: Found referenced %s task_tag: %u\n",
 141                         se_cmd->se_tfo->get_fabric_name(), ref_tag);
 142
 143                 spin_lock_irq(&se_cmd->t_state_lock);
 144                 if (se_cmd->transport_state & CMD_T_COMPLETE) {
 145                         printk("ABORT_TASK: ref_tag: %u already complete, skipping\n", ref_tag);
 146                         spin_unlock_irq(&se_cmd->t_state_lock);
 147                         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
 148                         goto out;
 149                 }
 150                 se_cmd->transport_state |= CMD_T_ABORTED;
 151                 spin_unlock_irq(&se_cmd->t_state_lock);
 152
 153                 list_del_init(&se_cmd->se_cmd_list);
 154                 kref_get(&se_cmd->cmd_kref);
 155                 spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
 156
 157                 cancel_work_sync(&se_cmd->work);
 158                 transport_wait_for_tasks(se_cmd);
 159                 /*
 160                  * Now send SAM_STAT_TASK_ABORTED status for the referenced
 161                  * se_cmd descriptor..
 162                  */
 163                 transport_send_task_abort(se_cmd);
 164                 /*
 165                  * Also deal with possible extra acknowledge reference..
 166                  */
 167                 if (se_cmd->se_cmd_flags & SCF_ACK_KREF)
 168                         target_put_sess_cmd(se_sess, se_cmd);
 169
 170                 target_put_sess_cmd(se_sess, se_cmd);
 171
 172                 printk("ABORT_TASK: Sending TMR_FUNCTION_COMPLETE for"
 173                                 " ref_tag: %d\n", ref_tag);
 174                 tmr->response = TMR_FUNCTION_COMPLETE;
 175                 return;
 176         }
 177         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
 178
 179 out:
 180         printk("ABORT_TASK: Sending TMR_TASK_DOES_NOT_EXIST for ref_tag: %d\n",
 181                         tmr->ref_task_tag);
 182         tmr->response = TMR_TASK_DOES_NOT_EXIST;
 183 }
 184
 185 static void core_tmr_drain_tmr_list(
 186         struct se_device *dev,
 187         struct se_tmr_req *tmr,
 188         struct list_head *preempt_and_abort_list)
 189 {
 190         LIST_HEAD(drain_tmr_list);
 191         struct se_tmr_req *tmr_p, *tmr_pp;
 192         struct se_cmd *cmd;
 193         unsigned long flags;
 194         /*
 195          * Release all pending and outgoing TMRs aside from the received
 196          * LUN_RESET tmr..
 197          */
 198         spin_lock_irqsave(&dev->se_tmr_lock, flags);
 199         list_for_each_entry_safe(tmr_p, tmr_pp, &dev->dev_tmr_list, tmr_list) {
 200                 /*
 201                  * Allow the received TMR to return with FUNCTION_COMPLETE.
 202                  */
 203                 if (tmr_p == tmr)
 204                         continue;
 205
 206                 cmd = tmr_p->task_cmd;
 207                 if (!cmd) {
 208                         pr_err("Unable to locate struct se_cmd for TMR\n");
 209                         continue;
 210                 }
 211                 /*
 212                  * If this function was called with a valid pr_res_key
 213                  * parameter (eg: for PROUT PREEMPT_AND_ABORT service action
 214                  * skip non regisration key matching TMRs.
 215                  */
 216                 if (target_check_cdb_and_preempt(preempt_and_abort_list, cmd))
 217                         continue;
 218
 219                 spin_lock(&cmd->t_state_lock);
 220                 if (!(cmd->transport_state & CMD_T_ACTIVE)) {
 221                         spin_unlock(&cmd->t_state_lock);
 222                         continue;
 223                 }
 224                 if (cmd->t_state == TRANSPORT_ISTATE_PROCESSING) {
 225                         spin_unlock(&cmd->t_state_lock);
 226                         continue;
 227                 }
 228                 spin_unlock(&cmd->t_state_lock);
 229
 230                 list_move_tail(&tmr_p->tmr_list, &drain_tmr_list);
 231         }
 232         spin_unlock_irqrestore(&dev->se_tmr_lock, flags);
 233
 234         list_for_each_entry_safe(tmr_p, tmr_pp, &drain_tmr_list, tmr_list) {
 235                 list_del_init(&tmr_p->tmr_list);
 236                 cmd = tmr_p->task_cmd;
 237
 238                 pr_debug("LUN_RESET: %s releasing TMR %p Function: 0x%02x,"
 239                         " Response: 0x%02x, t_state: %d\n",
 240                         (preempt_and_abort_list) ? "Preempt" : "", tmr_p,
 241                         tmr_p->function, tmr_p->response, cmd->t_state);
 242
 243                 transport_cmd_finish_abort(cmd, 1);
 244         }
 245 }
 246
 247 static void core_tmr_drain_task_list(
 248         struct se_device *dev,
 249         struct se_cmd *prout_cmd,
 250         struct se_node_acl *tmr_nacl,
 251         int tas,
 252         struct list_head *preempt_and_abort_list)
 253 {
 254         LIST_HEAD(drain_task_list);
 255         struct se_cmd *cmd;
 256         struct se_task *task, *task_tmp;
 257         unsigned long flags;
 258         int fe_count;
 259         /*
 260          * Complete outstanding struct se_task CDBs with TASK_ABORTED SAM status.
 261          * This is following sam4r17, section 5.6 Aborting commands, Table 38
 262          * for TMR LUN_RESET:
 263          *
 264          * a) "Yes" indicates that each command that is aborted on an I_T nexus
 265          * other than the one that caused the SCSI device condition is
 266          * completed with TASK ABORTED status, if the TAS bit is set to one in
 267          * the Control mode page (see SPC-4). "No" indicates that no status is
 268          * returned for aborted commands.
 269          *
 270          * d) If the logical unit reset is caused by a particular I_T nexus
 271          * (e.g., by a LOGICAL UNIT RESET task management function), then "yes"
 272          * (TASK_ABORTED status) applies.
 273          *
 274          * Otherwise (e.g., if triggered by a hard reset), "no"
 275          * (no TASK_ABORTED SAM status) applies.
 276          *
 277          * Note that this seems to be independent of TAS (Task Aborted Status)
 278          * in the Control Mode Page.
 279          */
 280         spin_lock_irqsave(&dev->execute_task_lock, flags);
 281         list_for_each_entry_safe(task, task_tmp, &dev->state_task_list,
 282                                 t_state_list) {
 283                 if (!task->task_se_cmd) {
 284                         pr_err("task->task_se_cmd is NULL!\n");
 285                         continue;
 286                 }
 287                 cmd = task->task_se_cmd;
 288
 289                 /*
 290                  * For PREEMPT_AND_ABORT usage, only process commands
 291                  * with a matching reservation key.
 292                  */
 293                 if (target_check_cdb_and_preempt(preempt_and_abort_list, cmd))
 294                         continue;
 295                 /*
 296                  * Not aborting PROUT PREEMPT_AND_ABORT CDB..
 297                  */
 298                 if (prout_cmd == cmd)
 299                         continue;
 300
 301                 list_move_tail(&task->t_state_list, &drain_task_list);
 302                 task->t_state_active = false;
 303                 /*
 304                  * Remove from task execute list before processing drain_task_list
 305                  */
 306                 if (!list_empty(&task->t_execute_list))
 307                         __transport_remove_task_from_execute_queue(task, dev);
 308         }
 309         spin_unlock_irqrestore(&dev->execute_task_lock, flags);
 310
 311         while (!list_empty(&drain_task_list)) {
 312                 task = list_entry(drain_task_list.next, struct se_task, t_state_list);
 313                 list_del(&task->t_state_list);
 314                 cmd = task->task_se_cmd;
 315
 316                 pr_debug("LUN_RESET: %s cmd: %p task: %p"
 317                         " ITT/CmdSN: 0x%08x/0x%08x, i_state: %d, t_state: %d"
 318                         "cdb: 0x%02x\n",
 319                         (preempt_and_abort_list) ? "Preempt" : "", cmd, task,
 320                         cmd->se_tfo->get_task_tag(cmd), 0,
 321                         cmd->se_tfo->get_cmd_state(cmd), cmd->t_state,
 322                         cmd->t_task_cdb[0]);
 323                 pr_debug("LUN_RESET: ITT[0x%08x] - pr_res_key: 0x%016Lx"
 324                         " t_task_cdbs: %d t_task_cdbs_left: %d"
 325                         " t_task_cdbs_sent: %d -- CMD_T_ACTIVE: %d"
 326                         " CMD_T_STOP: %d CMD_T_SENT: %d\n",
 327                         cmd->se_tfo->get_task_tag(cmd), cmd->pr_res_key,
 328                         cmd->t_task_list_num,
 329                         atomic_read(&cmd->t_task_cdbs_left),
 330                         atomic_read(&cmd->t_task_cdbs_sent),
 331                         (cmd->transport_state & CMD_T_ACTIVE) != 0,
 332                         (cmd->transport_state & CMD_T_STOP) != 0,
 333                         (cmd->transport_state & CMD_T_SENT) != 0);
 334
 335                 /*
 336                  * If the command may be queued onto a workqueue cancel it now.
 337                  *
 338                  * This is equivalent to removal from the execute queue in the
 339                  * loop above, but we do it down here given that
 340                  * cancel_work_sync may block.
 341                  */
 342                 if (cmd->t_state == TRANSPORT_COMPLETE)
 343                         cancel_work_sync(&cmd->work);
 344
 345                 spin_lock_irqsave(&cmd->t_state_lock, flags);
 346                 target_stop_task(task, &flags);
 347
 348                 if (!atomic_dec_and_test(&cmd->t_task_cdbs_ex_left)) {
 349                         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 350                         pr_debug("LUN_RESET: Skipping task: %p, dev: %p for"
 351                                 " t_task_cdbs_ex_left: %d\n", task, dev,
 352                                 atomic_read(&cmd->t_task_cdbs_ex_left));
 353                         continue;
 354                 }
 355                 fe_count = atomic_read(&cmd->t_fe_count);
 356
 357                 if (!(cmd->transport_state & CMD_T_ACTIVE)) {
 358                         pr_debug("LUN_RESET: got CMD_T_ACTIVE for"
 359                                 " task: %p, t_fe_count: %d dev: %p\n", task,
 360                                 fe_count, dev);
 361                         cmd->transport_state |= CMD_T_ABORTED;
 362                         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 363
 364                         core_tmr_handle_tas_abort(tmr_nacl, cmd, tas, fe_count);
 365                         continue;
 366                 }
 367                 pr_debug("LUN_RESET: Got !CMD_T_ACTIVE for task: %p,"
 368                         " t_fe_count: %d dev: %p\n", task, fe_count, dev);
 369                 cmd->transport_state |= CMD_T_ABORTED;
 370                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 371
 372                 core_tmr_handle_tas_abort(tmr_nacl, cmd, tas, fe_count);
 373         }
 374 }
 375
 376 static void core_tmr_drain_cmd_list(
 377         struct se_device *dev,
 378         struct se_cmd *prout_cmd,
 379         struct se_node_acl *tmr_nacl,
 380         int tas,
 381         struct list_head *preempt_and_abort_list)
 382 {
 383         LIST_HEAD(drain_cmd_list);
 384         struct se_queue_obj *qobj = &dev->dev_queue_obj;
 385         struct se_cmd *cmd, *tcmd;
 386         unsigned long flags;
 387         /*
 388          * Release all commands remaining in the struct se_device cmd queue.
 389          *
 390          * This follows the same logic as above for the struct se_device
 391          * struct se_task state list, where commands are returned with
 392          * TASK_ABORTED status, if there is an outstanding $FABRIC_MOD
 393          * reference, otherwise the struct se_cmd is released.
 394          */
 395         spin_lock_irqsave(&qobj->cmd_queue_lock, flags);
 396         list_for_each_entry_safe(cmd, tcmd, &qobj->qobj_list, se_queue_node) {
 397                 /*
 398                  * For PREEMPT_AND_ABORT usage, only process commands
 399                  * with a matching reservation key.
 400                  */
 401                 if (target_check_cdb_and_preempt(preempt_and_abort_list, cmd))
 402                         continue;
 403                 /*
 404                  * Not aborting PROUT PREEMPT_AND_ABORT CDB..
 405                  */
 406                 if (prout_cmd == cmd)
 407                         continue;
 408
 409                 cmd->transport_state &= ~CMD_T_QUEUED;
 410                 atomic_dec(&qobj->queue_cnt);
 411                 list_move_tail(&cmd->se_queue_node, &drain_cmd_list);
 412         }
 413         spin_unlock_irqrestore(&qobj->cmd_queue_lock, flags);
 414
 415         while (!list_empty(&drain_cmd_list)) {
 416                 cmd = list_entry(drain_cmd_list.next, struct se_cmd, se_queue_node);
 417                 list_del_init(&cmd->se_queue_node);
 418
 419                 pr_debug("LUN_RESET: %s from Device Queue: cmd: %p t_state:"
 420                         " %d t_fe_count: %d\n", (preempt_and_abort_list) ?
 421                         "Preempt" : "", cmd, cmd->t_state,
 422                         atomic_read(&cmd->t_fe_count));
 423
 424                 core_tmr_handle_tas_abort(tmr_nacl, cmd, tas,
 425                                 atomic_read(&cmd->t_fe_count));
 426         }
 427 }
 428
 429 int core_tmr_lun_reset(
 430         struct se_device *dev,
 431         struct se_tmr_req *tmr,
 432         struct list_head *preempt_and_abort_list,
 433         struct se_cmd *prout_cmd)
 434 {
 435         struct se_node_acl *tmr_nacl = NULL;
 436         struct se_portal_group *tmr_tpg = NULL;
 437         int tas;
 438         /*
 439          * TASK_ABORTED status bit, this is configurable via ConfigFS
 440          * struct se_device attributes.  spc4r17 section 7.4.6 Control mode page
 441          *
 442          * A task aborted status (TAS) bit set to zero specifies that aborted
 443          * tasks shall be terminated by the device server without any response
 444          * to the application client. A TAS bit set to one specifies that tasks
 445          * aborted by the actions of an I_T nexus other than the I_T nexus on
 446          * which the command was received shall be completed with TASK ABORTED
 447          * status (see SAM-4).
 448          */
 449         tas = dev->se_sub_dev->se_dev_attrib.emulate_tas;
 450         /*
 451          * Determine if this se_tmr is coming from a $FABRIC_MOD
 452          * or struct se_device passthrough..
 453          */
 454         if (tmr && tmr->task_cmd && tmr->task_cmd->se_sess) {
 455                 tmr_nacl = tmr->task_cmd->se_sess->se_node_acl;
 456                 tmr_tpg = tmr->task_cmd->se_sess->se_tpg;
 457                 if (tmr_nacl && tmr_tpg) {
 458                         pr_debug("LUN_RESET: TMR caller fabric: %s"
 459                                 " initiator port %s\n",
 460                                 tmr_tpg->se_tpg_tfo->get_fabric_name(),
 461                                 tmr_nacl->initiatorname);
 462                 }
 463         }
 464         pr_debug("LUN_RESET: %s starting for [%s], tas: %d\n",
 465                 (preempt_and_abort_list) ? "Preempt" : "TMR",
 466                 dev->transport->name, tas);
 467
 468         core_tmr_drain_tmr_list(dev, tmr, preempt_and_abort_list);
 469         core_tmr_drain_task_list(dev, prout_cmd, tmr_nacl, tas,
 470                                 preempt_and_abort_list);
 471         core_tmr_drain_cmd_list(dev, prout_cmd, tmr_nacl, tas,
 472                                 preempt_and_abort_list);
 473         /*
 474          * Clear any legacy SPC-2 reservation when called during
 475          * LOGICAL UNIT RESET
 476          */
 477         if (!preempt_and_abort_list &&
 478              (dev->dev_flags & DF_SPC2_RESERVATIONS)) {
 479                 spin_lock(&dev->dev_reservation_lock);
 480                 dev->dev_reserved_node_acl = NULL;
 481                 dev->dev_flags &= ~DF_SPC2_RESERVATIONS;
 482                 spin_unlock(&dev->dev_reservation_lock);
 483                 pr_debug("LUN_RESET: SCSI-2 Released reservation\n");
 484         }
 485
 486         spin_lock_irq(&dev->stats_lock);
 487         dev->num_resets++;
 488         spin_unlock_irq(&dev->stats_lock);
 489
 490         pr_debug("LUN_RESET: %s for [%s] Complete\n",
 491                         (preempt_and_abort_list) ? "Preempt" : "TMR",
 492                         dev->transport->name);
 493         return 0;
 494 }
 495