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 <scsi/scsi.h>
  31 #include <scsi/scsi_cmnd.h>
  32
  33 #include <target/target_core_base.h>
  34 #include <target/target_core_device.h>
  35 #include <target/target_core_tmr.h>
  36 #include <target/target_core_transport.h>
  37 #include <target/target_core_fabric_ops.h>
  38 #include <target/target_core_configfs.h>
  39
  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 void core_tmr_drain_tmr_list(
 104         struct se_device *dev,
 105         struct se_tmr_req *tmr,
 106         struct list_head *preempt_and_abort_list)
 107 {
 108         LIST_HEAD(drain_tmr_list);
 109         struct se_tmr_req *tmr_p, *tmr_pp;
 110         struct se_cmd *cmd;
 111         unsigned long flags;
 112         /*
 113          * Release all pending and outgoing TMRs aside from the received
 114          * LUN_RESET tmr..
 115          */
 116         spin_lock_irqsave(&dev->se_tmr_lock, flags);
 117         list_for_each_entry_safe(tmr_p, tmr_pp, &dev->dev_tmr_list, tmr_list) {
 118                 /*
 119                  * Allow the received TMR to return with FUNCTION_COMPLETE.
 120                  */
 121                 if (tmr && (tmr_p == tmr))
 122                         continue;
 123
 124                 cmd = tmr_p->task_cmd;
 125                 if (!cmd) {
 126                         pr_err("Unable to locate struct se_cmd for TMR\n");
 127                         continue;
 128                 }
 129                 /*
 130                  * If this function was called with a valid pr_res_key
 131                  * parameter (eg: for PROUT PREEMPT_AND_ABORT service action
 132                  * skip non regisration key matching TMRs.
 133                  */
 134                 if (preempt_and_abort_list &&
 135                     (core_scsi3_check_cdb_abort_and_preempt(
 136                                         preempt_and_abort_list, cmd) != 0))
 137                         continue;
 138
 139                 spin_lock(&cmd->t_state_lock);
 140                 if (!atomic_read(&cmd->t_transport_active)) {
 141                         spin_unlock(&cmd->t_state_lock);
 142                         continue;
 143                 }
 144                 if (cmd->t_state == TRANSPORT_ISTATE_PROCESSING) {
 145                         spin_unlock(&cmd->t_state_lock);
 146                         continue;
 147                 }
 148                 spin_unlock(&cmd->t_state_lock);
 149
 150                 list_move_tail(&tmr->tmr_list, &drain_tmr_list);
 151         }
 152         spin_unlock_irqrestore(&dev->se_tmr_lock, flags);
 153
 154         while (!list_empty(&drain_tmr_list)) {
 155                 tmr = list_entry(drain_tmr_list.next, struct se_tmr_req, tmr_list);
 156                 list_del(&tmr->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,
 162                         tmr->function, tmr->response, cmd->t_state);
 163
 164                 transport_cmd_finish_abort_tmr(cmd);
 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 (atomic_read(&task->task_execute_queue) != 0) {
 230                         list_del(&task->t_execute_list);
 231                         atomic_set(&task->task_execute_queue, 0);
 232                         atomic_dec(&dev->execute_tasks);
 233                 }
 234         }
 235         spin_unlock_irqrestore(&dev->execute_task_lock, flags);
 236
 237         while (!list_empty(&drain_task_list)) {
 238                 task = list_entry(drain_task_list.next, struct se_task, t_state_list);
 239                 list_del(&task->t_state_list);
 240                 cmd = task->task_se_cmd;
 241
 242                 spin_lock_irqsave(&cmd->t_state_lock, flags);
 243                 pr_debug("LUN_RESET: %s cmd: %p task: %p"
 244                         " ITT/CmdSN: 0x%08x/0x%08x, i_state: %d, t_state/"
 245                         "def_t_state: %d/%d cdb: 0x%02x\n",
 246                         (preempt_and_abort_list) ? "Preempt" : "", cmd, task,
 247                         cmd->se_tfo->get_task_tag(cmd), 0,
 248                         cmd->se_tfo->get_cmd_state(cmd), cmd->t_state,
 249                         cmd->deferred_t_state, cmd->t_task_cdb[0]);
 250                 pr_debug("LUN_RESET: ITT[0x%08x] - pr_res_key: 0x%016Lx"
 251                         " t_task_cdbs: %d t_task_cdbs_left: %d"
 252                         " t_task_cdbs_sent: %d -- t_transport_active: %d"
 253                         " t_transport_stop: %d t_transport_sent: %d\n",
 254                         cmd->se_tfo->get_task_tag(cmd), cmd->pr_res_key,
 255                         cmd->t_task_list_num,
 256                         atomic_read(&cmd->t_task_cdbs_left),
 257                         atomic_read(&cmd->t_task_cdbs_sent),
 258                         atomic_read(&cmd->t_transport_active),
 259                         atomic_read(&cmd->t_transport_stop),
 260                         atomic_read(&cmd->t_transport_sent));
 261
 262                 if (atomic_read(&task->task_active)) {
 263                         atomic_set(&task->task_stop, 1);
 264                         spin_unlock_irqrestore(
 265                                 &cmd->t_state_lock, flags);
 266
 267                         pr_debug("LUN_RESET: Waiting for task: %p to shutdown"
 268                                 " for dev: %p\n", task, dev);
 269                         wait_for_completion(&task->task_stop_comp);
 270                         pr_debug("LUN_RESET Completed task: %p shutdown for"
 271                                 " dev: %p\n", task, dev);
 272                         spin_lock_irqsave(&cmd->t_state_lock, flags);
 273                         atomic_dec(&cmd->t_task_cdbs_left);
 274
 275                         atomic_set(&task->task_active, 0);
 276                         atomic_set(&task->task_stop, 0);
 277                 }
 278                 __transport_stop_task_timer(task, &flags);
 279
 280                 if (!atomic_dec_and_test(&cmd->t_task_cdbs_ex_left)) {
 281                         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 282                         pr_debug("LUN_RESET: Skipping task: %p, dev: %p for"
 283                                 " t_task_cdbs_ex_left: %d\n", task, dev,
 284                                 atomic_read(&cmd->t_task_cdbs_ex_left));
 285                         continue;
 286                 }
 287                 fe_count = atomic_read(&cmd->t_fe_count);
 288
 289                 if (atomic_read(&cmd->t_transport_active)) {
 290                         pr_debug("LUN_RESET: got t_transport_active = 1 for"
 291                                 " task: %p, t_fe_count: %d dev: %p\n", task,
 292                                 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                         continue;
 298                 }
 299                 pr_debug("LUN_RESET: Got t_transport_active = 0 for task: %p,"
 300                         " t_fe_count: %d dev: %p\n", task, fe_count, dev);
 301                 atomic_set(&cmd->t_transport_aborted, 1);
 302                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 303
 304                 core_tmr_handle_tas_abort(tmr_nacl, cmd, tas, fe_count);
 305         }
 306 }
 307
 308 static void core_tmr_drain_cmd_list(
 309         struct se_device *dev,
 310         struct se_cmd *prout_cmd,
 311         struct se_node_acl *tmr_nacl,
 312         int tas,
 313         struct list_head *preempt_and_abort_list)
 314 {
 315         LIST_HEAD(drain_cmd_list);
 316         struct se_queue_obj *qobj = &dev->dev_queue_obj;
 317         struct se_cmd *cmd, *tcmd;
 318         unsigned long flags;
 319         /*
 320          * Release all commands remaining in the struct se_device cmd queue.
 321          *
 322          * This follows the same logic as above for the struct se_device
 323          * struct se_task state list, where commands are returned with
 324          * TASK_ABORTED status, if there is an outstanding $FABRIC_MOD
 325          * reference, otherwise the struct se_cmd is released.
 326          */
 327         spin_lock_irqsave(&qobj->cmd_queue_lock, flags);
 328         list_for_each_entry_safe(cmd, tcmd, &qobj->qobj_list, se_queue_node) {
 329                 /*
 330                  * For PREEMPT_AND_ABORT usage, only process commands
 331                  * with a matching reservation key.
 332                  */
 333                 if (preempt_and_abort_list &&
 334                     (core_scsi3_check_cdb_abort_and_preempt(
 335                                         preempt_and_abort_list, cmd) != 0))
 336                         continue;
 337                 /*
 338                  * Not aborting PROUT PREEMPT_AND_ABORT CDB..
 339                  */
 340                 if (prout_cmd == cmd)
 341                         continue;
 342                 /*
 343                  * Skip direct processing of TRANSPORT_FREE_CMD_INTR for
 344                  * HW target mode fabrics.
 345                  */
 346                 spin_lock(&cmd->t_state_lock);
 347                 if (cmd->t_state == TRANSPORT_FREE_CMD_INTR) {
 348                         spin_unlock(&cmd->t_state_lock);
 349                         continue;
 350                 }
 351                 spin_unlock(&cmd->t_state_lock);
 352
 353                 atomic_set(&cmd->t_transport_queue_active, 0);
 354                 atomic_dec(&qobj->queue_cnt);
 355                 list_move_tail(&cmd->se_queue_node, &drain_cmd_list);
 356         }
 357         spin_unlock_irqrestore(&qobj->cmd_queue_lock, flags);
 358
 359         while (!list_empty(&drain_cmd_list)) {
 360                 cmd = list_entry(drain_cmd_list.next, struct se_cmd, se_queue_node);
 361                 list_del_init(&cmd->se_queue_node);
 362
 363                 pr_debug("LUN_RESET: %s from Device Queue: cmd: %p t_state:"
 364                         " %d t_fe_count: %d\n", (preempt_and_abort_list) ?
 365                         "Preempt" : "", cmd, cmd->t_state,
 366                         atomic_read(&cmd->t_fe_count));
 367                 /*
 368                  * Signal that the command has failed via cmd->se_cmd_flags,
 369                  */
 370                 transport_new_cmd_failure(cmd);
 371
 372                 core_tmr_handle_tas_abort(tmr_nacl, cmd, tas,
 373                                 atomic_read(&cmd->t_fe_count));
 374         }
 375 }
 376
 377 int core_tmr_lun_reset(
 378         struct se_device *dev,
 379         struct se_tmr_req *tmr,
 380         struct list_head *preempt_and_abort_list,
 381         struct se_cmd *prout_cmd)
 382 {
 383         struct se_node_acl *tmr_nacl = NULL;
 384         struct se_portal_group *tmr_tpg = NULL;
 385         int tas;
 386         /*
 387          * TASK_ABORTED status bit, this is configurable via ConfigFS
 388          * struct se_device attributes.  spc4r17 section 7.4.6 Control mode page
 389          *
 390          * A task aborted status (TAS) bit set to zero specifies that aborted
 391          * tasks shall be terminated by the device server without any response
 392          * to the application client. A TAS bit set to one specifies that tasks
 393          * aborted by the actions of an I_T nexus other than the I_T nexus on
 394          * which the command was received shall be completed with TASK ABORTED
 395          * status (see SAM-4).
 396          */
 397         tas = dev->se_sub_dev->se_dev_attrib.emulate_tas;
 398         /*
 399          * Determine if this se_tmr is coming from a $FABRIC_MOD
 400          * or struct se_device passthrough..
 401          */
 402         if (tmr && tmr->task_cmd && tmr->task_cmd->se_sess) {
 403                 tmr_nacl = tmr->task_cmd->se_sess->se_node_acl;
 404                 tmr_tpg = tmr->task_cmd->se_sess->se_tpg;
 405                 if (tmr_nacl && tmr_tpg) {
 406                         pr_debug("LUN_RESET: TMR caller fabric: %s"
 407                                 " initiator port %s\n",
 408                                 tmr_tpg->se_tpg_tfo->get_fabric_name(),
 409                                 tmr_nacl->initiatorname);
 410                 }
 411         }
 412         pr_debug("LUN_RESET: %s starting for [%s], tas: %d\n",
 413                 (preempt_and_abort_list) ? "Preempt" : "TMR",
 414                 dev->transport->name, tas);
 415
 416         core_tmr_drain_tmr_list(dev, tmr, preempt_and_abort_list);
 417         core_tmr_drain_task_list(dev, prout_cmd, tmr_nacl, tas,
 418                                 preempt_and_abort_list);
 419         core_tmr_drain_cmd_list(dev, prout_cmd, tmr_nacl, tas,
 420                                 preempt_and_abort_list);
 421         /*
 422          * Clear any legacy SPC-2 reservation when called during
 423          * LOGICAL UNIT RESET
 424          */
 425         if (!preempt_and_abort_list &&
 426              (dev->dev_flags & DF_SPC2_RESERVATIONS)) {
 427                 spin_lock(&dev->dev_reservation_lock);
 428                 dev->dev_reserved_node_acl = NULL;
 429                 dev->dev_flags &= ~DF_SPC2_RESERVATIONS;
 430                 spin_unlock(&dev->dev_reservation_lock);
 431                 pr_debug("LUN_RESET: SCSI-2 Released reservation\n");
 432         }
 433
 434         spin_lock_irq(&dev->stats_lock);
 435         dev->num_resets++;
 436         spin_unlock_irq(&dev->stats_lock);
 437
 438         pr_debug("LUN_RESET: %s for [%s] Complete\n",
 439                         (preempt_and_abort_list) ? "Preempt" : "TMR",
 440                         dev->transport->name);
 441         return 0;
 442 }
 443