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 static void core_tmr_drain_tmr_list(
 122         struct se_device *dev,
 123         struct se_tmr_req *tmr,
 124         struct list_head *preempt_and_abort_list)
 125 {
 126         LIST_HEAD(drain_tmr_list);
 127         struct se_tmr_req *tmr_p, *tmr_pp;
 128         struct se_cmd *cmd;
 129         unsigned long flags;
 130         /*
 131          * Release all pending and outgoing TMRs aside from the received
 132          * LUN_RESET tmr..
 133          */
 134         spin_lock_irqsave(&dev->se_tmr_lock, flags);
 135         list_for_each_entry_safe(tmr_p, tmr_pp, &dev->dev_tmr_list, tmr_list) {
 136                 /*
 137                  * Allow the received TMR to return with FUNCTION_COMPLETE.
 138                  */
 139                 if (tmr_p == tmr)
 140                         continue;
 141
 142                 cmd = tmr_p->task_cmd;
 143                 if (!cmd) {
 144                         pr_err("Unable to locate struct se_cmd for TMR\n");
 145                         continue;
 146                 }
 147                 /*
 148                  * If this function was called with a valid pr_res_key
 149                  * parameter (eg: for PROUT PREEMPT_AND_ABORT service action
 150                  * skip non regisration key matching TMRs.
 151                  */
 152                 if (target_check_cdb_and_preempt(preempt_and_abort_list, cmd))
 153                         continue;
 154
 155                 spin_lock(&cmd->t_state_lock);
 156                 if (!(cmd->transport_state & CMD_T_ACTIVE)) {
 157                         spin_unlock(&cmd->t_state_lock);
 158                         continue;
 159                 }
 160                 if (cmd->t_state == TRANSPORT_ISTATE_PROCESSING) {
 161                         spin_unlock(&cmd->t_state_lock);
 162                         continue;
 163                 }
 164                 spin_unlock(&cmd->t_state_lock);
 165
 166                 list_move_tail(&tmr_p->tmr_list, &drain_tmr_list);
 167         }
 168         spin_unlock_irqrestore(&dev->se_tmr_lock, flags);
 169
 170         list_for_each_entry_safe(tmr_p, tmr_pp, &drain_tmr_list, tmr_list) {
 171                 list_del_init(&tmr_p->tmr_list);
 172                 cmd = tmr_p->task_cmd;
 173
 174                 pr_debug("LUN_RESET: %s releasing TMR %p Function: 0x%02x,"
 175                         " Response: 0x%02x, t_state: %d\n",
 176                         (preempt_and_abort_list) ? "Preempt" : "", tmr_p,
 177                         tmr_p->function, tmr_p->response, cmd->t_state);
 178
 179                 transport_cmd_finish_abort(cmd, 1);
 180         }
 181 }
 182
 183 static void core_tmr_drain_task_list(
 184         struct se_device *dev,
 185         struct se_cmd *prout_cmd,
 186         struct se_node_acl *tmr_nacl,
 187         int tas,
 188         struct list_head *preempt_and_abort_list)
 189 {
 190         LIST_HEAD(drain_task_list);
 191         struct se_cmd *cmd;
 192         struct se_task *task, *task_tmp;
 193         unsigned long flags;
 194         int fe_count;
 195         /*
 196          * Complete outstanding struct se_task CDBs with TASK_ABORTED SAM status.
 197          * This is following sam4r17, section 5.6 Aborting commands, Table 38
 198          * for TMR LUN_RESET:
 199          *
 200          * a) "Yes" indicates that each command that is aborted on an I_T nexus
 201          * other than the one that caused the SCSI device condition is
 202          * completed with TASK ABORTED status, if the TAS bit is set to one in
 203          * the Control mode page (see SPC-4). "No" indicates that no status is
 204          * returned for aborted commands.
 205          *
 206          * d) If the logical unit reset is caused by a particular I_T nexus
 207          * (e.g., by a LOGICAL UNIT RESET task management function), then "yes"
 208          * (TASK_ABORTED status) applies.
 209          *
 210          * Otherwise (e.g., if triggered by a hard reset), "no"
 211          * (no TASK_ABORTED SAM status) applies.
 212          *
 213          * Note that this seems to be independent of TAS (Task Aborted Status)
 214          * in the Control Mode Page.
 215          */
 216         spin_lock_irqsave(&dev->execute_task_lock, flags);
 217         list_for_each_entry_safe(task, task_tmp, &dev->state_task_list,
 218                                 t_state_list) {
 219                 if (!task->task_se_cmd) {
 220                         pr_err("task->task_se_cmd is NULL!\n");
 221                         continue;
 222                 }
 223                 cmd = task->task_se_cmd;
 224
 225                 /*
 226                  * For PREEMPT_AND_ABORT usage, only process commands
 227                  * with a matching reservation key.
 228                  */
 229                 if (target_check_cdb_and_preempt(preempt_and_abort_list, cmd))
 230                         continue;
 231                 /*
 232                  * Not aborting PROUT PREEMPT_AND_ABORT CDB..
 233                  */
 234                 if (prout_cmd == cmd)
 235                         continue;
 236
 237                 list_move_tail(&task->t_state_list, &drain_task_list);
 238                 task->t_state_active = false;
 239                 /*
 240                  * Remove from task execute list before processing drain_task_list
 241                  */
 242                 if (!list_empty(&task->t_execute_list))
 243                         __transport_remove_task_from_execute_queue(task, dev);
 244         }
 245         spin_unlock_irqrestore(&dev->execute_task_lock, flags);
 246
 247         while (!list_empty(&drain_task_list)) {
 248                 task = list_entry(drain_task_list.next, struct se_task, t_state_list);
 249                 list_del(&task->t_state_list);
 250                 cmd = task->task_se_cmd;
 251
 252                 pr_debug("LUN_RESET: %s cmd: %p task: %p"
 253                         " ITT/CmdSN: 0x%08x/0x%08x, i_state: %d, t_state: %d"
 254                         "cdb: 0x%02x\n",
 255                         (preempt_and_abort_list) ? "Preempt" : "", cmd, task,
 256                         cmd->se_tfo->get_task_tag(cmd), 0,
 257                         cmd->se_tfo->get_cmd_state(cmd), cmd->t_state,
 258                         cmd->t_task_cdb[0]);
 259                 pr_debug("LUN_RESET: ITT[0x%08x] - pr_res_key: 0x%016Lx"
 260                         " t_task_cdbs: %d t_task_cdbs_left: %d"
 261                         " t_task_cdbs_sent: %d -- CMD_T_ACTIVE: %d"
 262                         " CMD_T_STOP: %d CMD_T_SENT: %d\n",
 263                         cmd->se_tfo->get_task_tag(cmd), cmd->pr_res_key,
 264                         cmd->t_task_list_num,
 265                         atomic_read(&cmd->t_task_cdbs_left),
 266                         atomic_read(&cmd->t_task_cdbs_sent),
 267                         (cmd->transport_state & CMD_T_ACTIVE) != 0,
 268                         (cmd->transport_state & CMD_T_STOP) != 0,
 269                         (cmd->transport_state & CMD_T_SENT) != 0);
 270
 271                 /*
 272                  * If the command may be queued onto a workqueue cancel it now.
 273                  *
 274                  * This is equivalent to removal from the execute queue in the
 275                  * loop above, but we do it down here given that
 276                  * cancel_work_sync may block.
 277                  */
 278                 if (cmd->t_state == TRANSPORT_COMPLETE)
 279                         cancel_work_sync(&cmd->work);
 280
 281                 spin_lock_irqsave(&cmd->t_state_lock, flags);
 282                 target_stop_task(task, &flags);
 283
 284                 if (!atomic_dec_and_test(&cmd->t_task_cdbs_ex_left)) {
 285                         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 286                         pr_debug("LUN_RESET: Skipping task: %p, dev: %p for"
 287                                 " t_task_cdbs_ex_left: %d\n", task, dev,
 288                                 atomic_read(&cmd->t_task_cdbs_ex_left));
 289                         continue;
 290                 }
 291                 fe_count = atomic_read(&cmd->t_fe_count);
 292
 293                 if (!(cmd->transport_state & CMD_T_ACTIVE)) {
 294                         pr_debug("LUN_RESET: got CMD_T_ACTIVE for"
 295                                 " task: %p, t_fe_count: %d dev: %p\n", task,
 296                                 fe_count, dev);
 297                         cmd->transport_state |= CMD_T_ABORTED;
 298                         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 299
 300                         core_tmr_handle_tas_abort(tmr_nacl, cmd, tas, fe_count);
 301                         continue;
 302                 }
 303                 pr_debug("LUN_RESET: Got !CMD_T_ACTIVE for task: %p,"
 304                         " t_fe_count: %d dev: %p\n", task, fe_count, dev);
 305                 cmd->transport_state |= CMD_T_ABORTED;
 306                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 307
 308                 core_tmr_handle_tas_abort(tmr_nacl, cmd, tas, fe_count);
 309         }
 310 }
 311
 312 static void core_tmr_drain_cmd_list(
 313         struct se_device *dev,
 314         struct se_cmd *prout_cmd,
 315         struct se_node_acl *tmr_nacl,
 316         int tas,
 317         struct list_head *preempt_and_abort_list)
 318 {
 319         LIST_HEAD(drain_cmd_list);
 320         struct se_queue_obj *qobj = &dev->dev_queue_obj;
 321         struct se_cmd *cmd, *tcmd;
 322         unsigned long flags;
 323         /*
 324          * Release all commands remaining in the struct se_device cmd queue.
 325          *
 326          * This follows the same logic as above for the struct se_device
 327          * struct se_task state list, where commands are returned with
 328          * TASK_ABORTED status, if there is an outstanding $FABRIC_MOD
 329          * reference, otherwise the struct se_cmd is released.
 330          */
 331         spin_lock_irqsave(&qobj->cmd_queue_lock, flags);
 332         list_for_each_entry_safe(cmd, tcmd, &qobj->qobj_list, se_queue_node) {
 333                 /*
 334                  * For PREEMPT_AND_ABORT usage, only process commands
 335                  * with a matching reservation key.
 336                  */
 337                 if (target_check_cdb_and_preempt(preempt_and_abort_list, cmd))
 338                         continue;
 339                 /*
 340                  * Not aborting PROUT PREEMPT_AND_ABORT CDB..
 341                  */
 342                 if (prout_cmd == cmd)
 343                         continue;
 344
 345                 cmd->transport_state &= ~CMD_T_QUEUED;
 346                 atomic_dec(&qobj->queue_cnt);
 347                 list_move_tail(&cmd->se_queue_node, &drain_cmd_list);
 348         }
 349         spin_unlock_irqrestore(&qobj->cmd_queue_lock, flags);
 350
 351         while (!list_empty(&drain_cmd_list)) {
 352                 cmd = list_entry(drain_cmd_list.next, struct se_cmd, se_queue_node);
 353                 list_del_init(&cmd->se_queue_node);
 354
 355                 pr_debug("LUN_RESET: %s from Device Queue: cmd: %p t_state:"
 356                         " %d t_fe_count: %d\n", (preempt_and_abort_list) ?
 357                         "Preempt" : "", cmd, cmd->t_state,
 358                         atomic_read(&cmd->t_fe_count));
 359
 360                 core_tmr_handle_tas_abort(tmr_nacl, cmd, tas,
 361                                 atomic_read(&cmd->t_fe_count));
 362         }
 363 }
 364
 365 int core_tmr_lun_reset(
 366         struct se_device *dev,
 367         struct se_tmr_req *tmr,
 368         struct list_head *preempt_and_abort_list,
 369         struct se_cmd *prout_cmd)
 370 {
 371         struct se_node_acl *tmr_nacl = NULL;
 372         struct se_portal_group *tmr_tpg = NULL;
 373         int tas;
 374         /*
 375          * TASK_ABORTED status bit, this is configurable via ConfigFS
 376          * struct se_device attributes.  spc4r17 section 7.4.6 Control mode page
 377          *
 378          * A task aborted status (TAS) bit set to zero specifies that aborted
 379          * tasks shall be terminated by the device server without any response
 380          * to the application client. A TAS bit set to one specifies that tasks
 381          * aborted by the actions of an I_T nexus other than the I_T nexus on
 382          * which the command was received shall be completed with TASK ABORTED
 383          * status (see SAM-4).
 384          */
 385         tas = dev->se_sub_dev->se_dev_attrib.emulate_tas;
 386         /*
 387          * Determine if this se_tmr is coming from a $FABRIC_MOD
 388          * or struct se_device passthrough..
 389          */
 390         if (tmr && tmr->task_cmd && tmr->task_cmd->se_sess) {
 391                 tmr_nacl = tmr->task_cmd->se_sess->se_node_acl;
 392                 tmr_tpg = tmr->task_cmd->se_sess->se_tpg;
 393                 if (tmr_nacl && tmr_tpg) {
 394                         pr_debug("LUN_RESET: TMR caller fabric: %s"
 395                                 " initiator port %s\n",
 396                                 tmr_tpg->se_tpg_tfo->get_fabric_name(),
 397                                 tmr_nacl->initiatorname);
 398                 }
 399         }
 400         pr_debug("LUN_RESET: %s starting for [%s], tas: %d\n",
 401                 (preempt_and_abort_list) ? "Preempt" : "TMR",
 402                 dev->transport->name, tas);
 403
 404         core_tmr_drain_tmr_list(dev, tmr, preempt_and_abort_list);
 405         core_tmr_drain_task_list(dev, prout_cmd, tmr_nacl, tas,
 406                                 preempt_and_abort_list);
 407         core_tmr_drain_cmd_list(dev, prout_cmd, tmr_nacl, tas,
 408                                 preempt_and_abort_list);
 409         /*
 410          * Clear any legacy SPC-2 reservation when called during
 411          * LOGICAL UNIT RESET
 412          */
 413         if (!preempt_and_abort_list &&
 414              (dev->dev_flags & DF_SPC2_RESERVATIONS)) {
 415                 spin_lock(&dev->dev_reservation_lock);
 416                 dev->dev_reserved_node_acl = NULL;
 417                 dev->dev_flags &= ~DF_SPC2_RESERVATIONS;
 418                 spin_unlock(&dev->dev_reservation_lock);
 419                 pr_debug("LUN_RESET: SCSI-2 Released reservation\n");
 420         }
 421
 422         spin_lock_irq(&dev->stats_lock);
 423         dev->num_resets++;
 424         spin_unlock_irq(&dev->stats_lock);
 425
 426         pr_debug("LUN_RESET: %s for [%s] Complete\n",
 427                         (preempt_and_abort_list) ? "Preempt" : "TMR",
 428                         dev->transport->name);
 429         return 0;
 430 }
 431