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 struct se_tmr_req *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 = kmem_cache_zalloc(se_tmr_req_cache, gfp_flags);
  52         if (!tmr) {
  53                 pr_err("Unable to allocate struct se_tmr_req\n");
  54                 return ERR_PTR(-ENOMEM);
  55         }
  56         tmr->task_cmd = se_cmd;
  57         tmr->fabric_tmr_ptr = fabric_tmr_ptr;
  58         tmr->function = function;
  59         INIT_LIST_HEAD(&tmr->tmr_list);
  60
  61         return tmr;
  62 }
  63 EXPORT_SYMBOL(core_tmr_alloc_req);
  64
  65 void core_tmr_release_req(
  66         struct se_tmr_req *tmr)
  67 {
  68         struct se_device *dev = tmr->tmr_dev;
  69         unsigned long flags;
  70
  71         if (!dev) {
  72                 kmem_cache_free(se_tmr_req_cache, tmr);
  73                 return;
  74         }
  75
  76         spin_lock_irqsave(&dev->se_tmr_lock, flags);
  77         list_del(&tmr->tmr_list);
  78         spin_unlock_irqrestore(&dev->se_tmr_lock, flags);
  79
  80         kmem_cache_free(se_tmr_req_cache, tmr);
  81 }
  82
  83 static void core_tmr_handle_tas_abort(
  84         struct se_node_acl *tmr_nacl,
  85         struct se_cmd *cmd,
  86         int tas,
  87         int fe_count)
  88 {
  89         if (!fe_count) {
  90                 transport_cmd_finish_abort(cmd, 1);
  91                 return;
  92         }
  93         /*
  94          * TASK ABORTED status (TAS) bit support
  95         */
  96         if ((tmr_nacl &&
  97              (tmr_nacl == cmd->se_sess->se_node_acl)) || tas)
  98                 transport_send_task_abort(cmd);
  99
 100         transport_cmd_finish_abort(cmd, 0);
 101 }
 102
 103 static int target_check_cdb_and_preempt(struct list_head *list,
 104                 struct se_cmd *cmd)
 105 {
 106         struct t10_pr_registration *reg;
 107
 108         if (!list)
 109                 return 0;
 110         list_for_each_entry(reg, list, pr_reg_abort_list) {
 111                 if (reg->pr_res_key == cmd->pr_res_key)
 112                         return 0;
 113         }
 114
 115         return 1;
 116 }
 117
 118 static void core_tmr_drain_tmr_list(
 119         struct se_device *dev,
 120         struct se_tmr_req *tmr,
 121         struct list_head *preempt_and_abort_list)
 122 {
 123         LIST_HEAD(drain_tmr_list);
 124         struct se_tmr_req *tmr_p, *tmr_pp;
 125         struct se_cmd *cmd;
 126         unsigned long flags;
 127         /*
 128          * Release all pending and outgoing TMRs aside from the received
 129          * LUN_RESET tmr..
 130          */
 131         spin_lock_irqsave(&dev->se_tmr_lock, flags);
 132         list_for_each_entry_safe(tmr_p, tmr_pp, &dev->dev_tmr_list, tmr_list) {
 133                 /*
 134                  * Allow the received TMR to return with FUNCTION_COMPLETE.
 135                  */
 136                 if (tmr_p == tmr)
 137                         continue;
 138
 139                 cmd = tmr_p->task_cmd;
 140                 if (!cmd) {
 141                         pr_err("Unable to locate struct se_cmd for TMR\n");
 142                         continue;
 143                 }
 144                 /*
 145                  * If this function was called with a valid pr_res_key
 146                  * parameter (eg: for PROUT PREEMPT_AND_ABORT service action
 147                  * skip non regisration key matching TMRs.
 148                  */
 149                 if (target_check_cdb_and_preempt(preempt_and_abort_list, cmd))
 150                         continue;
 151
 152                 spin_lock(&cmd->t_state_lock);
 153                 if (!atomic_read(&cmd->t_transport_active)) {
 154                         spin_unlock(&cmd->t_state_lock);
 155                         continue;
 156                 }
 157                 if (cmd->t_state == TRANSPORT_ISTATE_PROCESSING) {
 158                         spin_unlock(&cmd->t_state_lock);
 159                         continue;
 160                 }
 161                 spin_unlock(&cmd->t_state_lock);
 162
 163                 list_move_tail(&tmr_p->tmr_list, &drain_tmr_list);
 164         }
 165         spin_unlock_irqrestore(&dev->se_tmr_lock, flags);
 166
 167         list_for_each_entry_safe(tmr_p, tmr_pp, &drain_tmr_list, tmr_list) {
 168                 list_del_init(&tmr_p->tmr_list);
 169                 cmd = tmr_p->task_cmd;
 170
 171                 pr_debug("LUN_RESET: %s releasing TMR %p Function: 0x%02x,"
 172                         " Response: 0x%02x, t_state: %d\n",
 173                         (preempt_and_abort_list) ? "Preempt" : "", tmr_p,
 174                         tmr_p->function, tmr_p->response, cmd->t_state);
 175
 176                 transport_cmd_finish_abort(cmd, 1);
 177         }
 178 }
 179
 180 static void core_tmr_drain_task_list(
 181         struct se_device *dev,
 182         struct se_cmd *prout_cmd,
 183         struct se_node_acl *tmr_nacl,
 184         int tas,
 185         struct list_head *preempt_and_abort_list)
 186 {
 187         LIST_HEAD(drain_task_list);
 188         struct se_cmd *cmd;
 189         struct se_task *task, *task_tmp;
 190         unsigned long flags;
 191         int fe_count;
 192         /*
 193          * Complete outstanding struct se_task CDBs with TASK_ABORTED SAM status.
 194          * This is following sam4r17, section 5.6 Aborting commands, Table 38
 195          * for TMR LUN_RESET:
 196          *
 197          * a) "Yes" indicates that each command that is aborted on an I_T nexus
 198          * other than the one that caused the SCSI device condition is
 199          * completed with TASK ABORTED status, if the TAS bit is set to one in
 200          * the Control mode page (see SPC-4). "No" indicates that no status is
 201          * returned for aborted commands.
 202          *
 203          * d) If the logical unit reset is caused by a particular I_T nexus
 204          * (e.g., by a LOGICAL UNIT RESET task management function), then "yes"
 205          * (TASK_ABORTED status) applies.
 206          *
 207          * Otherwise (e.g., if triggered by a hard reset), "no"
 208          * (no TASK_ABORTED SAM status) applies.
 209          *
 210          * Note that this seems to be independent of TAS (Task Aborted Status)
 211          * in the Control Mode Page.
 212          */
 213         spin_lock_irqsave(&dev->execute_task_lock, flags);
 214         list_for_each_entry_safe(task, task_tmp, &dev->state_task_list,
 215                                 t_state_list) {
 216                 if (!task->task_se_cmd) {
 217                         pr_err("task->task_se_cmd is NULL!\n");
 218                         continue;
 219                 }
 220                 cmd = task->task_se_cmd;
 221
 222                 /*
 223                  * For PREEMPT_AND_ABORT usage, only process commands
 224                  * with a matching reservation key.
 225                  */
 226                 if (target_check_cdb_and_preempt(preempt_and_abort_list, cmd))
 227                         continue;
 228                 /*
 229                  * Not aborting PROUT PREEMPT_AND_ABORT CDB..
 230                  */
 231                 if (prout_cmd == cmd)
 232                         continue;
 233
 234                 list_move_tail(&task->t_state_list, &drain_task_list);
 235                 task->t_state_active = false;
 236                 /*
 237                  * Remove from task execute list before processing drain_task_list
 238                  */
 239                 if (!list_empty(&task->t_execute_list))
 240                         __transport_remove_task_from_execute_queue(task, dev);
 241         }
 242         spin_unlock_irqrestore(&dev->execute_task_lock, flags);
 243
 244         while (!list_empty(&drain_task_list)) {
 245                 task = list_entry(drain_task_list.next, struct se_task, t_state_list);
 246                 list_del(&task->t_state_list);
 247                 cmd = task->task_se_cmd;
 248
 249                 pr_debug("LUN_RESET: %s cmd: %p task: %p"
 250                         " ITT/CmdSN: 0x%08x/0x%08x, i_state: %d, t_state: %d"
 251                         "cdb: 0x%02x\n",
 252                         (preempt_and_abort_list) ? "Preempt" : "", cmd, task,
 253                         cmd->se_tfo->get_task_tag(cmd), 0,
 254                         cmd->se_tfo->get_cmd_state(cmd), cmd->t_state,
 255                         cmd->t_task_cdb[0]);
 256                 pr_debug("LUN_RESET: ITT[0x%08x] - pr_res_key: 0x%016Lx"
 257                         " t_task_cdbs: %d t_task_cdbs_left: %d"
 258                         " t_task_cdbs_sent: %d -- t_transport_active: %d"
 259                         " t_transport_stop: %d t_transport_sent: %d\n",
 260                         cmd->se_tfo->get_task_tag(cmd), cmd->pr_res_key,
 261                         cmd->t_task_list_num,
 262                         atomic_read(&cmd->t_task_cdbs_left),
 263                         atomic_read(&cmd->t_task_cdbs_sent),
 264                         atomic_read(&cmd->t_transport_active),
 265                         atomic_read(&cmd->t_transport_stop),
 266                         atomic_read(&cmd->t_transport_sent));
 267
 268                 /*
 269                  * If the command may be queued onto a workqueue cancel it now.
 270                  *
 271                  * This is equivalent to removal from the execute queue in the
 272                  * loop above, but we do it down here given that
 273                  * cancel_work_sync may block.
 274                  */
 275                 if (cmd->t_state == TRANSPORT_COMPLETE)
 276                         cancel_work_sync(&cmd->work);
 277
 278                 spin_lock_irqsave(&cmd->t_state_lock, flags);
 279                 target_stop_task(task, &flags);
 280
 281                 if (!atomic_dec_and_test(&cmd->t_task_cdbs_ex_left)) {
 282                         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 283                         pr_debug("LUN_RESET: Skipping task: %p, dev: %p for"
 284                                 " t_task_cdbs_ex_left: %d\n", task, dev,
 285                                 atomic_read(&cmd->t_task_cdbs_ex_left));
 286                         continue;
 287                 }
 288                 fe_count = atomic_read(&cmd->t_fe_count);
 289
 290                 if (atomic_read(&cmd->t_transport_active)) {
 291                         pr_debug("LUN_RESET: got t_transport_active = 1 for"
 292                                 " task: %p, t_fe_count: %d dev: %p\n", task,
 293                                 fe_count, dev);
 294                         atomic_set(&cmd->t_transport_aborted, 1);
 295                         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 296
 297                         core_tmr_handle_tas_abort(tmr_nacl, cmd, tas, fe_count);
 298                         continue;
 299                 }
 300                 pr_debug("LUN_RESET: Got t_transport_active = 0 for task: %p,"
 301                         " t_fe_count: %d dev: %p\n", task, fe_count, dev);
 302                 atomic_set(&cmd->t_transport_aborted, 1);
 303                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 304
 305                 core_tmr_handle_tas_abort(tmr_nacl, cmd, tas, fe_count);
 306         }
 307 }
 308
 309 static void core_tmr_drain_cmd_list(
 310         struct se_device *dev,
 311         struct se_cmd *prout_cmd,
 312         struct se_node_acl *tmr_nacl,
 313         int tas,
 314         struct list_head *preempt_and_abort_list)
 315 {
 316         LIST_HEAD(drain_cmd_list);
 317         struct se_queue_obj *qobj = &dev->dev_queue_obj;
 318         struct se_cmd *cmd, *tcmd;
 319         unsigned long flags;
 320         /*
 321          * Release all commands remaining in the struct se_device cmd queue.
 322          *
 323          * This follows the same logic as above for the struct se_device
 324          * struct se_task state list, where commands are returned with
 325          * TASK_ABORTED status, if there is an outstanding $FABRIC_MOD
 326          * reference, otherwise the struct se_cmd is released.
 327          */
 328         spin_lock_irqsave(&qobj->cmd_queue_lock, flags);
 329         list_for_each_entry_safe(cmd, tcmd, &qobj->qobj_list, se_queue_node) {
 330                 /*
 331                  * For PREEMPT_AND_ABORT usage, only process commands
 332                  * with a matching reservation key.
 333                  */
 334                 if (target_check_cdb_and_preempt(preempt_and_abort_list, cmd))
 335                         continue;
 336                 /*
 337                  * Not aborting PROUT PREEMPT_AND_ABORT CDB..
 338                  */
 339                 if (prout_cmd == cmd)
 340                         continue;
 341
 342                 atomic_set(&cmd->t_transport_queue_active, 0);
 343                 atomic_dec(&qobj->queue_cnt);
 344                 list_move_tail(&cmd->se_queue_node, &drain_cmd_list);
 345         }
 346         spin_unlock_irqrestore(&qobj->cmd_queue_lock, flags);
 347
 348         while (!list_empty(&drain_cmd_list)) {
 349                 cmd = list_entry(drain_cmd_list.next, struct se_cmd, se_queue_node);
 350                 list_del_init(&cmd->se_queue_node);
 351
 352                 pr_debug("LUN_RESET: %s from Device Queue: cmd: %p t_state:"
 353                         " %d t_fe_count: %d\n", (preempt_and_abort_list) ?
 354                         "Preempt" : "", cmd, cmd->t_state,
 355                         atomic_read(&cmd->t_fe_count));
 356
 357                 core_tmr_handle_tas_abort(tmr_nacl, cmd, tas,
 358                                 atomic_read(&cmd->t_fe_count));
 359         }
 360 }
 361
 362 int core_tmr_lun_reset(
 363         struct se_device *dev,
 364         struct se_tmr_req *tmr,
 365         struct list_head *preempt_and_abort_list,
 366         struct se_cmd *prout_cmd)
 367 {
 368         struct se_node_acl *tmr_nacl = NULL;
 369         struct se_portal_group *tmr_tpg = NULL;
 370         int tas;
 371         /*
 372          * TASK_ABORTED status bit, this is configurable via ConfigFS
 373          * struct se_device attributes.  spc4r17 section 7.4.6 Control mode page
 374          *
 375          * A task aborted status (TAS) bit set to zero specifies that aborted
 376          * tasks shall be terminated by the device server without any response
 377          * to the application client. A TAS bit set to one specifies that tasks
 378          * aborted by the actions of an I_T nexus other than the I_T nexus on
 379          * which the command was received shall be completed with TASK ABORTED
 380          * status (see SAM-4).
 381          */
 382         tas = dev->se_sub_dev->se_dev_attrib.emulate_tas;
 383         /*
 384          * Determine if this se_tmr is coming from a $FABRIC_MOD
 385          * or struct se_device passthrough..
 386          */
 387         if (tmr && tmr->task_cmd && tmr->task_cmd->se_sess) {
 388                 tmr_nacl = tmr->task_cmd->se_sess->se_node_acl;
 389                 tmr_tpg = tmr->task_cmd->se_sess->se_tpg;
 390                 if (tmr_nacl && tmr_tpg) {
 391                         pr_debug("LUN_RESET: TMR caller fabric: %s"
 392                                 " initiator port %s\n",
 393                                 tmr_tpg->se_tpg_tfo->get_fabric_name(),
 394                                 tmr_nacl->initiatorname);
 395                 }
 396         }
 397         pr_debug("LUN_RESET: %s starting for [%s], tas: %d\n",
 398                 (preempt_and_abort_list) ? "Preempt" : "TMR",
 399                 dev->transport->name, tas);
 400
 401         core_tmr_drain_tmr_list(dev, tmr, preempt_and_abort_list);
 402         core_tmr_drain_task_list(dev, prout_cmd, tmr_nacl, tas,
 403                                 preempt_and_abort_list);
 404         core_tmr_drain_cmd_list(dev, prout_cmd, tmr_nacl, tas,
 405                                 preempt_and_abort_list);
 406         /*
 407          * Clear any legacy SPC-2 reservation when called during
 408          * LOGICAL UNIT RESET
 409          */
 410         if (!preempt_and_abort_list &&
 411              (dev->dev_flags & DF_SPC2_RESERVATIONS)) {
 412                 spin_lock(&dev->dev_reservation_lock);
 413                 dev->dev_reserved_node_acl = NULL;
 414                 dev->dev_flags &= ~DF_SPC2_RESERVATIONS;
 415                 spin_unlock(&dev->dev_reservation_lock);
 416                 pr_debug("LUN_RESET: SCSI-2 Released reservation\n");
 417         }
 418
 419         spin_lock_irq(&dev->stats_lock);
 420         dev->num_resets++;
 421         spin_unlock_irq(&dev->stats_lock);
 422
 423         pr_debug("LUN_RESET: %s for [%s] Complete\n",
 424                         (preempt_and_abort_list) ? "Preempt" : "TMR",
 425                         dev->transport->name);
 426         return 0;
 427 }
 428