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