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 {
  48         struct se_tmr_req *tmr;
  49
  50         tmr = kmem_cache_zalloc(se_tmr_req_cache, (in_interrupt()) ?
  51                                         GFP_ATOMIC : GFP_KERNEL);
  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
  70         if (!dev) {
  71                 kmem_cache_free(se_tmr_req_cache, tmr);
  72                 return;
  73         }
  74
  75         spin_lock_irq(&dev->se_tmr_lock);
  76         list_del(&tmr->tmr_list);
  77         spin_unlock_irq(&dev->se_tmr_lock);
  78
  79         kmem_cache_free(se_tmr_req_cache, tmr);
  80 }
  81
  82 static void core_tmr_handle_tas_abort(
  83         struct se_node_acl *tmr_nacl,
  84         struct se_cmd *cmd,
  85         int tas,
  86         int fe_count)
  87 {
  88         if (!fe_count) {
  89                 transport_cmd_finish_abort(cmd, 1);
  90                 return;
  91         }
  92         /*
  93          * TASK ABORTED status (TAS) bit support
  94         */
  95         if ((tmr_nacl &&
  96              (tmr_nacl == cmd->se_sess->se_node_acl)) || tas)
  97                 transport_send_task_abort(cmd);
  98
  99         transport_cmd_finish_abort(cmd, 0);
 100 }
 101
 102 int core_tmr_lun_reset(
 103         struct se_device *dev,
 104         struct se_tmr_req *tmr,
 105         struct list_head *preempt_and_abort_list,
 106         struct se_cmd *prout_cmd)
 107 {
 108         struct se_cmd *cmd, *tcmd;
 109         struct se_node_acl *tmr_nacl = NULL;
 110         struct se_portal_group *tmr_tpg = NULL;
 111         struct se_queue_obj *qobj = &dev->dev_queue_obj;
 112         struct se_tmr_req *tmr_p, *tmr_pp;
 113         struct se_task *task, *task_tmp;
 114         unsigned long flags;
 115         int fe_count, tas;
 116         /*
 117          * TASK_ABORTED status bit, this is configurable via ConfigFS
 118          * struct se_device attributes.  spc4r17 section 7.4.6 Control mode page
 119          *
 120          * A task aborted status (TAS) bit set to zero specifies that aborted
 121          * tasks shall be terminated by the device server without any response
 122          * to the application client. A TAS bit set to one specifies that tasks
 123          * aborted by the actions of an I_T nexus other than the I_T nexus on
 124          * which the command was received shall be completed with TASK ABORTED
 125          * status (see SAM-4).
 126          */
 127         tas = dev->se_sub_dev->se_dev_attrib.emulate_tas;
 128         /*
 129          * Determine if this se_tmr is coming from a $FABRIC_MOD
 130          * or struct se_device passthrough..
 131          */
 132         if (tmr && tmr->task_cmd && tmr->task_cmd->se_sess) {
 133                 tmr_nacl = tmr->task_cmd->se_sess->se_node_acl;
 134                 tmr_tpg = tmr->task_cmd->se_sess->se_tpg;
 135                 if (tmr_nacl && tmr_tpg) {
 136                         pr_debug("LUN_RESET: TMR caller fabric: %s"
 137                                 " initiator port %s\n",
 138                                 tmr_tpg->se_tpg_tfo->get_fabric_name(),
 139                                 tmr_nacl->initiatorname);
 140                 }
 141         }
 142         pr_debug("LUN_RESET: %s starting for [%s], tas: %d\n",
 143                 (preempt_and_abort_list) ? "Preempt" : "TMR",
 144                 dev->transport->name, tas);
 145         /*
 146          * Release all pending and outgoing TMRs aside from the received
 147          * LUN_RESET tmr..
 148          */
 149         spin_lock_irq(&dev->se_tmr_lock);
 150         list_for_each_entry_safe(tmr_p, tmr_pp, &dev->dev_tmr_list, tmr_list) {
 151                 /*
 152                  * Allow the received TMR to return with FUNCTION_COMPLETE.
 153                  */
 154                 if (tmr && (tmr_p == tmr))
 155                         continue;
 156
 157                 cmd = tmr_p->task_cmd;
 158                 if (!cmd) {
 159                         pr_err("Unable to locate struct se_cmd for TMR\n");
 160                         continue;
 161                 }
 162                 /*
 163                  * If this function was called with a valid pr_res_key
 164                  * parameter (eg: for PROUT PREEMPT_AND_ABORT service action
 165                  * skip non regisration key matching TMRs.
 166                  */
 167                 if (preempt_and_abort_list &&
 168                     (core_scsi3_check_cdb_abort_and_preempt(
 169                                         preempt_and_abort_list, cmd) != 0))
 170                         continue;
 171                 spin_unlock_irq(&dev->se_tmr_lock);
 172
 173                 spin_lock_irqsave(&cmd->t_state_lock, flags);
 174                 if (!atomic_read(&cmd->t_transport_active)) {
 175                         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 176                         spin_lock_irq(&dev->se_tmr_lock);
 177                         continue;
 178                 }
 179                 if (cmd->t_state == TRANSPORT_ISTATE_PROCESSING) {
 180                         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 181                         spin_lock_irq(&dev->se_tmr_lock);
 182                         continue;
 183                 }
 184                 pr_debug("LUN_RESET: %s releasing TMR %p Function: 0x%02x,"
 185                         " Response: 0x%02x, t_state: %d\n",
 186                         (preempt_and_abort_list) ? "Preempt" : "", tmr_p,
 187                         tmr_p->function, tmr_p->response, cmd->t_state);
 188                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 189
 190                 transport_cmd_finish_abort_tmr(cmd);
 191                 spin_lock_irq(&dev->se_tmr_lock);
 192         }
 193         spin_unlock_irq(&dev->se_tmr_lock);
 194         /*
 195          * Complete outstanding struct se_task CDBs with TASK_ABORTED SAM status.
 196          * This is following sam4r17, section 5.6 Aborting commands, Table 38
 197          * for TMR LUN_RESET:
 198          *
 199          * a) "Yes" indicates that each command that is aborted on an I_T nexus
 200          * other than the one that caused the SCSI device condition is
 201          * completed with TASK ABORTED status, if the TAS bit is set to one in
 202          * the Control mode page (see SPC-4). "No" indicates that no status is
 203          * returned for aborted commands.
 204          *
 205          * d) If the logical unit reset is caused by a particular I_T nexus
 206          * (e.g., by a LOGICAL UNIT RESET task management function), then "yes"
 207          * (TASK_ABORTED status) applies.
 208          *
 209          * Otherwise (e.g., if triggered by a hard reset), "no"
 210          * (no TASK_ABORTED SAM status) applies.
 211          *
 212          * Note that this seems to be independent of TAS (Task Aborted Status)
 213          * in the Control Mode Page.
 214          */
 215         spin_lock_irqsave(&dev->execute_task_lock, flags);
 216         list_for_each_entry_safe(task, task_tmp, &dev->state_task_list,
 217                                 t_state_list) {
 218                 if (!task->task_se_cmd) {
 219                         pr_err("task->task_se_cmd is NULL!\n");
 220                         continue;
 221                 }
 222                 cmd = task->task_se_cmd;
 223
 224                 /*
 225                  * For PREEMPT_AND_ABORT usage, only process commands
 226                  * with a matching reservation key.
 227                  */
 228                 if (preempt_and_abort_list &&
 229                     (core_scsi3_check_cdb_abort_and_preempt(
 230                                         preempt_and_abort_list, cmd) != 0))
 231                         continue;
 232                 /*
 233                  * Not aborting PROUT PREEMPT_AND_ABORT CDB..
 234                  */
 235                 if (prout_cmd == cmd)
 236                         continue;
 237
 238                 list_del(&task->t_state_list);
 239                 atomic_set(&task->task_state_active, 0);
 240                 spin_unlock_irqrestore(&dev->execute_task_lock, flags);
 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                 } else {
 278                         if (atomic_read(&task->task_execute_queue) != 0)
 279                                 transport_remove_task_from_execute_queue(task, dev);
 280                 }
 281                 __transport_stop_task_timer(task, &flags);
 282
 283                 if (!atomic_dec_and_test(&cmd->t_task_cdbs_ex_left)) {
 284                         spin_unlock_irqrestore(
 285                                         &cmd->t_state_lock, flags);
 286                         pr_debug("LUN_RESET: Skipping task: %p, dev: %p for"
 287                                 " t_task_cdbs_ex_left: %d\n", task, dev,
 288                                 atomic_read(&cmd->t_task_cdbs_ex_left));
 289
 290                         spin_lock_irqsave(&dev->execute_task_lock, flags);
 291                         continue;
 292                 }
 293                 fe_count = atomic_read(&cmd->t_fe_count);
 294
 295                 if (atomic_read(&cmd->t_transport_active)) {
 296                         pr_debug("LUN_RESET: got t_transport_active = 1 for"
 297                                 " task: %p, t_fe_count: %d dev: %p\n", task,
 298                                 fe_count, dev);
 299                         atomic_set(&cmd->t_transport_aborted, 1);
 300                         spin_unlock_irqrestore(&cmd->t_state_lock,
 301                                                 flags);
 302                         core_tmr_handle_tas_abort(tmr_nacl, cmd, tas, fe_count);
 303
 304                         spin_lock_irqsave(&dev->execute_task_lock, flags);
 305                         continue;
 306                 }
 307                 pr_debug("LUN_RESET: Got t_transport_active = 0 for task: %p,"
 308                         " t_fe_count: %d dev: %p\n", task, fe_count, dev);
 309                 atomic_set(&cmd->t_transport_aborted, 1);
 310                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 311                 core_tmr_handle_tas_abort(tmr_nacl, cmd, tas, fe_count);
 312
 313                 spin_lock_irqsave(&dev->execute_task_lock, flags);
 314         }
 315         spin_unlock_irqrestore(&dev->execute_task_lock, flags);
 316         /*
 317          * Release all commands remaining in the struct se_device cmd queue.
 318          *
 319          * This follows the same logic as above for the struct se_device
 320          * struct se_task state list, where commands are returned with
 321          * TASK_ABORTED status, if there is an outstanding $FABRIC_MOD
 322          * reference, otherwise the struct se_cmd is released.
 323          */
 324         spin_lock_irqsave(&qobj->cmd_queue_lock, flags);
 325         list_for_each_entry_safe(cmd, tcmd, &qobj->qobj_list, se_queue_node) {
 326                 /*
 327                  * For PREEMPT_AND_ABORT usage, only process commands
 328                  * with a matching reservation key.
 329                  */
 330                 if (preempt_and_abort_list &&
 331                     (core_scsi3_check_cdb_abort_and_preempt(
 332                                         preempt_and_abort_list, cmd) != 0))
 333                         continue;
 334                 /*
 335                  * Not aborting PROUT PREEMPT_AND_ABORT CDB..
 336                  */
 337                 if (prout_cmd == cmd)
 338                         continue;
 339
 340                 atomic_dec(&cmd->t_transport_queue_active);
 341                 atomic_dec(&qobj->queue_cnt);
 342                 list_del_init(&cmd->se_queue_node);
 343                 spin_unlock_irqrestore(&qobj->cmd_queue_lock, flags);
 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                  * Signal that the command has failed via cmd->se_cmd_flags,
 351                  */
 352                 transport_new_cmd_failure(cmd);
 353
 354                 core_tmr_handle_tas_abort(tmr_nacl, cmd, tas,
 355                                 atomic_read(&cmd->t_fe_count));
 356                 spin_lock_irqsave(&qobj->cmd_queue_lock, flags);
 357         }
 358         spin_unlock_irqrestore(&qobj->cmd_queue_lock, flags);
 359         /*
 360          * Clear any legacy SPC-2 reservation when called during
 361          * LOGICAL UNIT RESET
 362          */
 363         if (!preempt_and_abort_list &&
 364              (dev->dev_flags & DF_SPC2_RESERVATIONS)) {
 365                 spin_lock(&dev->dev_reservation_lock);
 366                 dev->dev_reserved_node_acl = NULL;
 367                 dev->dev_flags &= ~DF_SPC2_RESERVATIONS;
 368                 spin_unlock(&dev->dev_reservation_lock);
 369                 pr_debug("LUN_RESET: SCSI-2 Released reservation\n");
 370         }
 371
 372         spin_lock_irq(&dev->stats_lock);
 373         dev->num_resets++;
 374         spin_unlock_irq(&dev->stats_lock);
 375
 376         pr_debug("LUN_RESET: %s for [%s] Complete\n",
 377                         (preempt_and_abort_list) ? "Preempt" : "TMR",
 378                         dev->transport->name);
 379         return 0;
 380 }