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/version.h>
  28 #include <linux/slab.h>
  29 #include <linux/spinlock.h>
  30 #include <linux/list.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 {
  49         struct se_tmr_req *tmr;
  50
  51         tmr = kmem_cache_zalloc(se_tmr_req_cache, (in_interrupt()) ?
  52                                         GFP_ATOMIC : GFP_KERNEL);
  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
  71         if (!dev) {
  72                 kmem_cache_free(se_tmr_req_cache, tmr);
  73                 return;
  74         }
  75
  76         spin_lock_irq(&dev->se_tmr_lock);
  77         list_del(&tmr->tmr_list);
  78         spin_unlock_irq(&dev->se_tmr_lock);
  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 int core_tmr_lun_reset(
 104         struct se_device *dev,
 105         struct se_tmr_req *tmr,
 106         struct list_head *preempt_and_abort_list,
 107         struct se_cmd *prout_cmd)
 108 {
 109         struct se_cmd *cmd, *tcmd;
 110         struct se_node_acl *tmr_nacl = NULL;
 111         struct se_portal_group *tmr_tpg = NULL;
 112         struct se_queue_obj *qobj = &dev->dev_queue_obj;
 113         struct se_tmr_req *tmr_p, *tmr_pp;
 114         struct se_task *task, *task_tmp;
 115         unsigned long flags;
 116         int fe_count, tas;
 117         /*
 118          * TASK_ABORTED status bit, this is configurable via ConfigFS
 119          * struct se_device attributes.  spc4r17 section 7.4.6 Control mode page
 120          *
 121          * A task aborted status (TAS) bit set to zero specifies that aborted
 122          * tasks shall be terminated by the device server without any response
 123          * to the application client. A TAS bit set to one specifies that tasks
 124          * aborted by the actions of an I_T nexus other than the I_T nexus on
 125          * which the command was received shall be completed with TASK ABORTED
 126          * status (see SAM-4).
 127          */
 128         tas = dev->se_sub_dev->se_dev_attrib.emulate_tas;
 129         /*
 130          * Determine if this se_tmr is coming from a $FABRIC_MOD
 131          * or struct se_device passthrough..
 132          */
 133         if (tmr && tmr->task_cmd && tmr->task_cmd->se_sess) {
 134                 tmr_nacl = tmr->task_cmd->se_sess->se_node_acl;
 135                 tmr_tpg = tmr->task_cmd->se_sess->se_tpg;
 136                 if (tmr_nacl && tmr_tpg) {
 137                         pr_debug("LUN_RESET: TMR caller fabric: %s"
 138                                 " initiator port %s\n",
 139                                 tmr_tpg->se_tpg_tfo->get_fabric_name(),
 140                                 tmr_nacl->initiatorname);
 141                 }
 142         }
 143         pr_debug("LUN_RESET: %s starting for [%s], tas: %d\n",
 144                 (preempt_and_abort_list) ? "Preempt" : "TMR",
 145                 dev->transport->name, tas);
 146         /*
 147          * Release all pending and outgoing TMRs aside from the received
 148          * LUN_RESET tmr..
 149          */
 150         spin_lock_irq(&dev->se_tmr_lock);
 151         list_for_each_entry_safe(tmr_p, tmr_pp, &dev->dev_tmr_list, tmr_list) {
 152                 /*
 153                  * Allow the received TMR to return with FUNCTION_COMPLETE.
 154                  */
 155                 if (tmr && (tmr_p == tmr))
 156                         continue;
 157
 158                 cmd = tmr_p->task_cmd;
 159                 if (!cmd) {
 160                         pr_err("Unable to locate struct se_cmd for TMR\n");
 161                         continue;
 162                 }
 163                 /*
 164                  * If this function was called with a valid pr_res_key
 165                  * parameter (eg: for PROUT PREEMPT_AND_ABORT service action
 166                  * skip non regisration key matching TMRs.
 167                  */
 168                 if (preempt_and_abort_list &&
 169                     (core_scsi3_check_cdb_abort_and_preempt(
 170                                         preempt_and_abort_list, cmd) != 0))
 171                         continue;
 172                 spin_unlock_irq(&dev->se_tmr_lock);
 173
 174                 spin_lock_irqsave(&cmd->t_state_lock, flags);
 175                 if (!atomic_read(&cmd->t_transport_active)) {
 176                         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 177                         spin_lock_irq(&dev->se_tmr_lock);
 178                         continue;
 179                 }
 180                 if (cmd->t_state == TRANSPORT_ISTATE_PROCESSING) {
 181                         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 182                         spin_lock_irq(&dev->se_tmr_lock);
 183                         continue;
 184                 }
 185                 pr_debug("LUN_RESET: %s releasing TMR %p Function: 0x%02x,"
 186                         " Response: 0x%02x, t_state: %d\n",
 187                         (preempt_and_abort_list) ? "Preempt" : "", tmr_p,
 188                         tmr_p->function, tmr_p->response, cmd->t_state);
 189                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 190
 191                 transport_cmd_finish_abort_tmr(cmd);
 192                 spin_lock_irq(&dev->se_tmr_lock);
 193         }
 194         spin_unlock_irq(&dev->se_tmr_lock);
 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 (preempt_and_abort_list &&
 230                     (core_scsi3_check_cdb_abort_and_preempt(
 231                                         preempt_and_abort_list, cmd) != 0))
 232                         continue;
 233                 /*
 234                  * Not aborting PROUT PREEMPT_AND_ABORT CDB..
 235                  */
 236                 if (prout_cmd == cmd)
 237                         continue;
 238
 239                 list_del(&task->t_state_list);
 240                 atomic_set(&task->task_state_active, 0);
 241                 spin_unlock_irqrestore(&dev->execute_task_lock, flags);
 242
 243                 spin_lock_irqsave(&cmd->t_state_lock, flags);
 244                 pr_debug("LUN_RESET: %s cmd: %p task: %p"
 245                         " ITT/CmdSN: 0x%08x/0x%08x, i_state: %d, t_state/"
 246                         "def_t_state: %d/%d cdb: 0x%02x\n",
 247                         (preempt_and_abort_list) ? "Preempt" : "", cmd, task,
 248                         cmd->se_tfo->get_task_tag(cmd), 0,
 249                         cmd->se_tfo->get_cmd_state(cmd), cmd->t_state,
 250                         cmd->deferred_t_state, cmd->t_task_cdb[0]);
 251                 pr_debug("LUN_RESET: ITT[0x%08x] - pr_res_key: 0x%016Lx"
 252                         " t_task_cdbs: %d t_task_cdbs_left: %d"
 253                         " t_task_cdbs_sent: %d -- t_transport_active: %d"
 254                         " t_transport_stop: %d t_transport_sent: %d\n",
 255                         cmd->se_tfo->get_task_tag(cmd), cmd->pr_res_key,
 256                         cmd->t_task_list_num,
 257                         atomic_read(&cmd->t_task_cdbs_left),
 258                         atomic_read(&cmd->t_task_cdbs_sent),
 259                         atomic_read(&cmd->t_transport_active),
 260                         atomic_read(&cmd->t_transport_stop),
 261                         atomic_read(&cmd->t_transport_sent));
 262
 263                 if (atomic_read(&task->task_active)) {
 264                         atomic_set(&task->task_stop, 1);
 265                         spin_unlock_irqrestore(
 266                                 &cmd->t_state_lock, flags);
 267
 268                         pr_debug("LUN_RESET: Waiting for task: %p to shutdown"
 269                                 " for dev: %p\n", task, dev);
 270                         wait_for_completion(&task->task_stop_comp);
 271                         pr_debug("LUN_RESET Completed task: %p shutdown for"
 272                                 " dev: %p\n", task, dev);
 273                         spin_lock_irqsave(&cmd->t_state_lock, flags);
 274                         atomic_dec(&cmd->t_task_cdbs_left);
 275
 276                         atomic_set(&task->task_active, 0);
 277                         atomic_set(&task->task_stop, 0);
 278                 } else {
 279                         if (atomic_read(&task->task_execute_queue) != 0)
 280                                 transport_remove_task_from_execute_queue(task, dev);
 281                 }
 282                 __transport_stop_task_timer(task, &flags);
 283
 284                 if (!atomic_dec_and_test(&cmd->t_task_cdbs_ex_left)) {
 285                         spin_unlock_irqrestore(
 286                                         &cmd->t_state_lock, flags);
 287                         pr_debug("LUN_RESET: Skipping task: %p, dev: %p for"
 288                                 " t_task_cdbs_ex_left: %d\n", task, dev,
 289                                 atomic_read(&cmd->t_task_cdbs_ex_left));
 290
 291                         spin_lock_irqsave(&dev->execute_task_lock, flags);
 292                         continue;
 293                 }
 294                 fe_count = atomic_read(&cmd->t_fe_count);
 295
 296                 if (atomic_read(&cmd->t_transport_active)) {
 297                         pr_debug("LUN_RESET: got t_transport_active = 1 for"
 298                                 " task: %p, t_fe_count: %d dev: %p\n", task,
 299                                 fe_count, dev);
 300                         atomic_set(&cmd->t_transport_aborted, 1);
 301                         spin_unlock_irqrestore(&cmd->t_state_lock,
 302                                                 flags);
 303                         core_tmr_handle_tas_abort(tmr_nacl, cmd, tas, fe_count);
 304
 305                         spin_lock_irqsave(&dev->execute_task_lock, flags);
 306                         continue;
 307                 }
 308                 pr_debug("LUN_RESET: Got t_transport_active = 0 for task: %p,"
 309                         " t_fe_count: %d dev: %p\n", task, fe_count, dev);
 310                 atomic_set(&cmd->t_transport_aborted, 1);
 311                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 312                 core_tmr_handle_tas_abort(tmr_nacl, cmd, tas, fe_count);
 313
 314                 spin_lock_irqsave(&dev->execute_task_lock, flags);
 315         }
 316         spin_unlock_irqrestore(&dev->execute_task_lock, flags);
 317         /*
 318          * Release all commands remaining in the struct se_device cmd queue.
 319          *
 320          * This follows the same logic as above for the struct se_device
 321          * struct se_task state list, where commands are returned with
 322          * TASK_ABORTED status, if there is an outstanding $FABRIC_MOD
 323          * reference, otherwise the struct se_cmd is released.
 324          */
 325         spin_lock_irqsave(&qobj->cmd_queue_lock, flags);
 326         list_for_each_entry_safe(cmd, tcmd, &qobj->qobj_list, se_queue_node) {
 327                 /*
 328                  * For PREEMPT_AND_ABORT usage, only process commands
 329                  * with a matching reservation key.
 330                  */
 331                 if (preempt_and_abort_list &&
 332                     (core_scsi3_check_cdb_abort_and_preempt(
 333                                         preempt_and_abort_list, cmd) != 0))
 334                         continue;
 335                 /*
 336                  * Not aborting PROUT PREEMPT_AND_ABORT CDB..
 337                  */
 338                 if (prout_cmd == cmd)
 339                         continue;
 340
 341                 atomic_dec(&cmd->t_transport_queue_active);
 342                 atomic_dec(&qobj->queue_cnt);
 343                 list_del(&cmd->se_queue_node);
 344                 spin_unlock_irqrestore(&qobj->cmd_queue_lock, flags);
 345
 346                 pr_debug("LUN_RESET: %s from Device Queue: cmd: %p t_state:"
 347                         " %d t_fe_count: %d\n", (preempt_and_abort_list) ?
 348                         "Preempt" : "", cmd, cmd->t_state,
 349                         atomic_read(&cmd->t_fe_count));
 350                 /*
 351                  * Signal that the command has failed via cmd->se_cmd_flags,
 352                  */
 353                 transport_new_cmd_failure(cmd);
 354
 355                 core_tmr_handle_tas_abort(tmr_nacl, cmd, tas,
 356                                 atomic_read(&cmd->t_fe_count));
 357                 spin_lock_irqsave(&qobj->cmd_queue_lock, flags);
 358         }
 359         spin_unlock_irqrestore(&qobj->cmd_queue_lock, flags);
 360         /*
 361          * Clear any legacy SPC-2 reservation when called during
 362          * LOGICAL UNIT RESET
 363          */
 364         if (!preempt_and_abort_list &&
 365              (dev->dev_flags & DF_SPC2_RESERVATIONS)) {
 366                 spin_lock(&dev->dev_reservation_lock);
 367                 dev->dev_reserved_node_acl = NULL;
 368                 dev->dev_flags &= ~DF_SPC2_RESERVATIONS;
 369                 spin_unlock(&dev->dev_reservation_lock);
 370                 pr_debug("LUN_RESET: SCSI-2 Released reservation\n");
 371         }
 372
 373         spin_lock_irq(&dev->stats_lock);
 374         dev->num_resets++;
 375         spin_unlock_irq(&dev->stats_lock);
 376
 377         pr_debug("LUN_RESET: %s for [%s] Complete\n",
 378                         (preempt_and_abort_list) ? "Preempt" : "TMR",
 379                         dev->transport->name);
 380         return 0;
 381 }