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_device.h>
  36 #include <target/target_core_tmr.h>
  37 #include <target/target_core_transport.h>
  38 #include <target/target_core_fabric_ops.h>
  39 #include <target/target_core_configfs.h>
  40
  41 #include "target_core_internal.h"
  42 #include "target_core_alua.h"
  43 #include "target_core_pr.h"
  44
  45 struct se_tmr_req *core_tmr_alloc_req(
  46         struct se_cmd *se_cmd,
  47         void *fabric_tmr_ptr,
  48         u8 function,
  49         gfp_t gfp_flags)
  50 {
  51         struct se_tmr_req *tmr;
  52
  53         tmr = kmem_cache_zalloc(se_tmr_req_cache, gfp_flags);
  54         if (!tmr) {
  55                 pr_err("Unable to allocate struct se_tmr_req\n");
  56                 return ERR_PTR(-ENOMEM);
  57         }
  58         tmr->task_cmd = se_cmd;
  59         tmr->fabric_tmr_ptr = fabric_tmr_ptr;
  60         tmr->function = function;
  61         INIT_LIST_HEAD(&tmr->tmr_list);
  62
  63         return tmr;
  64 }
  65 EXPORT_SYMBOL(core_tmr_alloc_req);
  66
  67 void core_tmr_release_req(
  68         struct se_tmr_req *tmr)
  69 {
  70         struct se_device *dev = tmr->tmr_dev;
  71         unsigned long flags;
  72
  73         if (!dev) {
  74                 kmem_cache_free(se_tmr_req_cache, tmr);
  75                 return;
  76         }
  77
  78         spin_lock_irqsave(&dev->se_tmr_lock, flags);
  79         list_del(&tmr->tmr_list);
  80         spin_unlock_irqrestore(&dev->se_tmr_lock, flags);
  81
  82         kmem_cache_free(se_tmr_req_cache, tmr);
  83 }
  84
  85 static void core_tmr_handle_tas_abort(
  86         struct se_node_acl *tmr_nacl,
  87         struct se_cmd *cmd,
  88         int tas,
  89         int fe_count)
  90 {
  91         if (!fe_count) {
  92                 transport_cmd_finish_abort(cmd, 1);
  93                 return;
  94         }
  95         /*
  96          * TASK ABORTED status (TAS) bit support
  97         */
  98         if ((tmr_nacl &&
  99              (tmr_nacl == cmd->se_sess->se_node_acl)) || tas)
 100                 transport_send_task_abort(cmd);
 101
 102         transport_cmd_finish_abort(cmd, 0);
 103 }
 104
 105 static void core_tmr_drain_tmr_list(
 106         struct se_device *dev,
 107         struct se_tmr_req *tmr,
 108         struct list_head *preempt_and_abort_list)
 109 {
 110         LIST_HEAD(drain_tmr_list);
 111         struct se_tmr_req *tmr_p, *tmr_pp;
 112         struct se_cmd *cmd;
 113         unsigned long flags;
 114         /*
 115          * Release all pending and outgoing TMRs aside from the received
 116          * LUN_RESET tmr..
 117          */
 118         spin_lock_irqsave(&dev->se_tmr_lock, flags);
 119         list_for_each_entry_safe(tmr_p, tmr_pp, &dev->dev_tmr_list, tmr_list) {
 120                 /*
 121                  * Allow the received TMR to return with FUNCTION_COMPLETE.
 122                  */
 123                 if (tmr_p == tmr)
 124                         continue;
 125
 126                 cmd = tmr_p->task_cmd;
 127                 if (!cmd) {
 128                         pr_err("Unable to locate struct se_cmd for TMR\n");
 129                         continue;
 130                 }
 131                 /*
 132                  * If this function was called with a valid pr_res_key
 133                  * parameter (eg: for PROUT PREEMPT_AND_ABORT service action
 134                  * skip non regisration key matching TMRs.
 135                  */
 136                 if (preempt_and_abort_list &&
 137                     (core_scsi3_check_cdb_abort_and_preempt(
 138                                         preempt_and_abort_list, cmd) != 0))
 139                         continue;
 140
 141                 spin_lock(&cmd->t_state_lock);
 142                 if (!atomic_read(&cmd->t_transport_active)) {
 143                         spin_unlock(&cmd->t_state_lock);
 144                         continue;
 145                 }
 146                 if (cmd->t_state == TRANSPORT_ISTATE_PROCESSING) {
 147                         spin_unlock(&cmd->t_state_lock);
 148                         continue;
 149                 }
 150                 spin_unlock(&cmd->t_state_lock);
 151
 152                 list_move_tail(&tmr_p->tmr_list, &drain_tmr_list);
 153         }
 154         spin_unlock_irqrestore(&dev->se_tmr_lock, flags);
 155
 156         list_for_each_entry_safe(tmr_p, tmr_pp, &drain_tmr_list, tmr_list) {
 157                 list_del_init(&tmr_p->tmr_list);
 158                 cmd = tmr_p->task_cmd;
 159
 160                 pr_debug("LUN_RESET: %s releasing TMR %p Function: 0x%02x,"
 161                         " Response: 0x%02x, t_state: %d\n",
 162                         (preempt_and_abort_list) ? "Preempt" : "", tmr_p,
 163                         tmr_p->function, tmr_p->response, cmd->t_state);
 164
 165                 transport_cmd_finish_abort(cmd, 1);
 166         }
 167 }
 168
 169 static void core_tmr_drain_task_list(
 170         struct se_device *dev,
 171         struct se_cmd *prout_cmd,
 172         struct se_node_acl *tmr_nacl,
 173         int tas,
 174         struct list_head *preempt_and_abort_list)
 175 {
 176         LIST_HEAD(drain_task_list);
 177         struct se_cmd *cmd;
 178         struct se_task *task, *task_tmp;
 179         unsigned long flags;
 180         int fe_count;
 181         /*
 182          * Complete outstanding struct se_task CDBs with TASK_ABORTED SAM status.
 183          * This is following sam4r17, section 5.6 Aborting commands, Table 38
 184          * for TMR LUN_RESET:
 185          *
 186          * a) "Yes" indicates that each command that is aborted on an I_T nexus
 187          * other than the one that caused the SCSI device condition is
 188          * completed with TASK ABORTED status, if the TAS bit is set to one in
 189          * the Control mode page (see SPC-4). "No" indicates that no status is
 190          * returned for aborted commands.
 191          *
 192          * d) If the logical unit reset is caused by a particular I_T nexus
 193          * (e.g., by a LOGICAL UNIT RESET task management function), then "yes"
 194          * (TASK_ABORTED status) applies.
 195          *
 196          * Otherwise (e.g., if triggered by a hard reset), "no"
 197          * (no TASK_ABORTED SAM status) applies.
 198          *
 199          * Note that this seems to be independent of TAS (Task Aborted Status)
 200          * in the Control Mode Page.
 201          */
 202         spin_lock_irqsave(&dev->execute_task_lock, flags);
 203         list_for_each_entry_safe(task, task_tmp, &dev->state_task_list,
 204                                 t_state_list) {
 205                 if (!task->task_se_cmd) {
 206                         pr_err("task->task_se_cmd is NULL!\n");
 207                         continue;
 208                 }
 209                 cmd = task->task_se_cmd;
 210
 211                 /*
 212                  * For PREEMPT_AND_ABORT usage, only process commands
 213                  * with a matching reservation key.
 214                  */
 215                 if (preempt_and_abort_list &&
 216                     (core_scsi3_check_cdb_abort_and_preempt(
 217                                         preempt_and_abort_list, cmd) != 0))
 218                         continue;
 219                 /*
 220                  * Not aborting PROUT PREEMPT_AND_ABORT CDB..
 221                  */
 222                 if (prout_cmd == cmd)
 223                         continue;
 224
 225                 list_move_tail(&task->t_state_list, &drain_task_list);
 226                 atomic_set(&task->task_state_active, 0);
 227                 /*
 228                  * Remove from task execute list before processing drain_task_list
 229                  */
 230                 if (!list_empty(&task->t_execute_list))
 231                         __transport_remove_task_from_execute_queue(task, dev);
 232         }
 233         spin_unlock_irqrestore(&dev->execute_task_lock, flags);
 234
 235         while (!list_empty(&drain_task_list)) {
 236                 task = list_entry(drain_task_list.next, struct se_task, t_state_list);
 237                 list_del(&task->t_state_list);
 238                 cmd = task->task_se_cmd;
 239
 240                 pr_debug("LUN_RESET: %s cmd: %p task: %p"
 241                         " ITT/CmdSN: 0x%08x/0x%08x, i_state: %d, t_state: %d"
 242                         "cdb: 0x%02x\n",
 243                         (preempt_and_abort_list) ? "Preempt" : "", cmd, task,
 244                         cmd->se_tfo->get_task_tag(cmd), 0,
 245                         cmd->se_tfo->get_cmd_state(cmd), cmd->t_state,
 246                         cmd->t_task_cdb[0]);
 247                 pr_debug("LUN_RESET: ITT[0x%08x] - pr_res_key: 0x%016Lx"
 248                         " t_task_cdbs: %d t_task_cdbs_left: %d"
 249                         " t_task_cdbs_sent: %d -- t_transport_active: %d"
 250                         " t_transport_stop: %d t_transport_sent: %d\n",
 251                         cmd->se_tfo->get_task_tag(cmd), cmd->pr_res_key,
 252                         cmd->t_task_list_num,
 253                         atomic_read(&cmd->t_task_cdbs_left),
 254                         atomic_read(&cmd->t_task_cdbs_sent),
 255                         atomic_read(&cmd->t_transport_active),
 256                         atomic_read(&cmd->t_transport_stop),
 257                         atomic_read(&cmd->t_transport_sent));
 258
 259                 /*
 260                  * If the command may be queued onto a workqueue cancel it now.
 261                  *
 262                  * This is equivalent to removal from the execute queue in the
 263                  * loop above, but we do it down here given that
 264                  * cancel_work_sync may block.
 265                  */
 266                 if (cmd->t_state == TRANSPORT_COMPLETE)
 267                         cancel_work_sync(&cmd->work);
 268
 269                 spin_lock_irqsave(&cmd->t_state_lock, flags);
 270                 target_stop_task(task, &flags);
 271
 272                 if (!atomic_dec_and_test(&cmd->t_task_cdbs_ex_left)) {
 273                         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 274                         pr_debug("LUN_RESET: Skipping task: %p, dev: %p for"
 275                                 " t_task_cdbs_ex_left: %d\n", task, dev,
 276                                 atomic_read(&cmd->t_task_cdbs_ex_left));
 277                         continue;
 278                 }
 279                 fe_count = atomic_read(&cmd->t_fe_count);
 280
 281                 if (atomic_read(&cmd->t_transport_active)) {
 282                         pr_debug("LUN_RESET: got t_transport_active = 1 for"
 283                                 " task: %p, t_fe_count: %d dev: %p\n", task,
 284                                 fe_count, dev);
 285                         atomic_set(&cmd->t_transport_aborted, 1);
 286                         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 287
 288                         core_tmr_handle_tas_abort(tmr_nacl, cmd, tas, fe_count);
 289                         continue;
 290                 }
 291                 pr_debug("LUN_RESET: Got t_transport_active = 0 for task: %p,"
 292                         " t_fe_count: %d dev: %p\n", task, fe_count, dev);
 293                 atomic_set(&cmd->t_transport_aborted, 1);
 294                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 295
 296                 core_tmr_handle_tas_abort(tmr_nacl, cmd, tas, fe_count);
 297         }
 298 }
 299
 300 static void core_tmr_drain_cmd_list(
 301         struct se_device *dev,
 302         struct se_cmd *prout_cmd,
 303         struct se_node_acl *tmr_nacl,
 304         int tas,
 305         struct list_head *preempt_and_abort_list)
 306 {
 307         LIST_HEAD(drain_cmd_list);
 308         struct se_queue_obj *qobj = &dev->dev_queue_obj;
 309         struct se_cmd *cmd, *tcmd;
 310         unsigned long flags;
 311         /*
 312          * Release all commands remaining in the struct se_device cmd queue.
 313          *
 314          * This follows the same logic as above for the struct se_device
 315          * struct se_task state list, where commands are returned with
 316          * TASK_ABORTED status, if there is an outstanding $FABRIC_MOD
 317          * reference, otherwise the struct se_cmd is released.
 318          */
 319         spin_lock_irqsave(&qobj->cmd_queue_lock, flags);
 320         list_for_each_entry_safe(cmd, tcmd, &qobj->qobj_list, se_queue_node) {
 321                 /*
 322                  * For PREEMPT_AND_ABORT usage, only process commands
 323                  * with a matching reservation key.
 324                  */
 325                 if (preempt_and_abort_list &&
 326                     (core_scsi3_check_cdb_abort_and_preempt(
 327                                         preempt_and_abort_list, cmd) != 0))
 328                         continue;
 329                 /*
 330                  * Not aborting PROUT PREEMPT_AND_ABORT CDB..
 331                  */
 332                 if (prout_cmd == cmd)
 333                         continue;
 334
 335                 atomic_set(&cmd->t_transport_queue_active, 0);
 336                 atomic_dec(&qobj->queue_cnt);
 337                 list_move_tail(&cmd->se_queue_node, &drain_cmd_list);
 338         }
 339         spin_unlock_irqrestore(&qobj->cmd_queue_lock, flags);
 340
 341         while (!list_empty(&drain_cmd_list)) {
 342                 cmd = list_entry(drain_cmd_list.next, struct se_cmd, se_queue_node);
 343                 list_del_init(&cmd->se_queue_node);
 344
 345                 pr_debug("LUN_RESET: %s from Device Queue: cmd: %p t_state:"
 346                         " %d t_fe_count: %d\n", (preempt_and_abort_list) ?
 347                         "Preempt" : "", cmd, cmd->t_state,
 348                         atomic_read(&cmd->t_fe_count));
 349
 350                 core_tmr_handle_tas_abort(tmr_nacl, cmd, tas,
 351                                 atomic_read(&cmd->t_fe_count));
 352         }
 353 }
 354
 355 int core_tmr_lun_reset(
 356         struct se_device *dev,
 357         struct se_tmr_req *tmr,
 358         struct list_head *preempt_and_abort_list,
 359         struct se_cmd *prout_cmd)
 360 {
 361         struct se_node_acl *tmr_nacl = NULL;
 362         struct se_portal_group *tmr_tpg = NULL;
 363         int tas;
 364         /*
 365          * TASK_ABORTED status bit, this is configurable via ConfigFS
 366          * struct se_device attributes.  spc4r17 section 7.4.6 Control mode page
 367          *
 368          * A task aborted status (TAS) bit set to zero specifies that aborted
 369          * tasks shall be terminated by the device server without any response
 370          * to the application client. A TAS bit set to one specifies that tasks
 371          * aborted by the actions of an I_T nexus other than the I_T nexus on
 372          * which the command was received shall be completed with TASK ABORTED
 373          * status (see SAM-4).
 374          */
 375         tas = dev->se_sub_dev->se_dev_attrib.emulate_tas;
 376         /*
 377          * Determine if this se_tmr is coming from a $FABRIC_MOD
 378          * or struct se_device passthrough..
 379          */
 380         if (tmr && tmr->task_cmd && tmr->task_cmd->se_sess) {
 381                 tmr_nacl = tmr->task_cmd->se_sess->se_node_acl;
 382                 tmr_tpg = tmr->task_cmd->se_sess->se_tpg;
 383                 if (tmr_nacl && tmr_tpg) {
 384                         pr_debug("LUN_RESET: TMR caller fabric: %s"
 385                                 " initiator port %s\n",
 386                                 tmr_tpg->se_tpg_tfo->get_fabric_name(),
 387                                 tmr_nacl->initiatorname);
 388                 }
 389         }
 390         pr_debug("LUN_RESET: %s starting for [%s], tas: %d\n",
 391                 (preempt_and_abort_list) ? "Preempt" : "TMR",
 392                 dev->transport->name, tas);
 393
 394         core_tmr_drain_tmr_list(dev, tmr, preempt_and_abort_list);
 395         core_tmr_drain_task_list(dev, prout_cmd, tmr_nacl, tas,
 396                                 preempt_and_abort_list);
 397         core_tmr_drain_cmd_list(dev, prout_cmd, tmr_nacl, tas,
 398                                 preempt_and_abort_list);
 399         /*
 400          * Clear any legacy SPC-2 reservation when called during
 401          * LOGICAL UNIT RESET
 402          */
 403         if (!preempt_and_abort_list &&
 404              (dev->dev_flags & DF_SPC2_RESERVATIONS)) {
 405                 spin_lock(&dev->dev_reservation_lock);
 406                 dev->dev_reserved_node_acl = NULL;
 407                 dev->dev_flags &= ~DF_SPC2_RESERVATIONS;
 408                 spin_unlock(&dev->dev_reservation_lock);
 409                 pr_debug("LUN_RESET: SCSI-2 Released reservation\n");
 410         }
 411
 412         spin_lock_irq(&dev->stats_lock);
 413         dev->num_resets++;
 414         spin_unlock_irq(&dev->stats_lock);
 415
 416         pr_debug("LUN_RESET: %s for [%s] Complete\n",
 417                         (preempt_and_abort_list) ? "Preempt" : "TMR",
 418                         dev->transport->name);
 419         return 0;
 420 }
 421