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