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         spin_lock(&dev->se_tmr_lock);
  79         list_del(&tmr->tmr_list);
  80         kmem_cache_free(se_tmr_req_cache, tmr);
  81         spin_unlock(&dev->se_tmr_lock);
  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 != NULL) &&
  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 int core_tmr_lun_reset(
 105         struct se_device *dev,
 106         struct se_tmr_req *tmr,
 107         struct list_head *preempt_and_abort_list,
 108         struct se_cmd *prout_cmd)
 109 {
 110         struct se_cmd *cmd;
 111         struct se_queue_req *qr, *qr_tmp;
 112         struct se_node_acl *tmr_nacl = NULL;
 113         struct se_portal_group *tmr_tpg = NULL;
 114         struct se_queue_obj *qobj = dev->dev_queue_obj;
 115         struct se_tmr_req *tmr_p, *tmr_pp;
 116         struct se_task *task, *task_tmp;
 117         unsigned long flags;
 118         int fe_count, state, tas;
 119         /*
 120          * TASK_ABORTED status bit, this is configurable via ConfigFS
 121          * struct se_device attributes.  spc4r17 section 7.4.6 Control mode page
 122          *
 123          * A task aborted status (TAS) bit set to zero specifies that aborted
 124          * tasks shall be terminated by the device server without any response
 125          * to the application client. A TAS bit set to one specifies that tasks
 126          * aborted by the actions of an I_T nexus other than the I_T nexus on
 127          * which the command was received shall be completed with TASK ABORTED
 128          * status (see SAM-4).
 129          */
 130         tas = DEV_ATTRIB(dev)->emulate_tas;
 131         /*
 132          * Determine if this se_tmr is coming from a $FABRIC_MOD
 133          * or struct se_device passthrough..
 134          */
 135         if (tmr && tmr->task_cmd && tmr->task_cmd->se_sess) {
 136                 tmr_nacl = tmr->task_cmd->se_sess->se_node_acl;
 137                 tmr_tpg = tmr->task_cmd->se_sess->se_tpg;
 138                 if (tmr_nacl && tmr_tpg) {
 139                         DEBUG_LR("LUN_RESET: TMR caller fabric: %s"
 140                                 " initiator port %s\n",
 141                                 TPG_TFO(tmr_tpg)->get_fabric_name(),
 142                                 tmr_nacl->initiatorname);
 143                 }
 144         }
 145         DEBUG_LR("LUN_RESET: %s starting for [%s], tas: %d\n",
 146                 (preempt_and_abort_list) ? "Preempt" : "TMR",
 147                 TRANSPORT(dev)->name, tas);
 148         /*
 149          * Release all pending and outgoing TMRs aside from the received
 150          * LUN_RESET tmr..
 151          */
 152         spin_lock(&dev->se_tmr_lock);
 153         list_for_each_entry_safe(tmr_p, tmr_pp, &dev->dev_tmr_list, tmr_list) {
 154                 /*
 155                  * Allow the received TMR to return with FUNCTION_COMPLETE.
 156                  */
 157                 if (tmr && (tmr_p == tmr))
 158                         continue;
 159
 160                 cmd = tmr_p->task_cmd;
 161                 if (!(cmd)) {
 162                         printk(KERN_ERR "Unable to locate struct se_cmd for TMR\n");
 163                         continue;
 164                 }
 165                 /*
 166                  * If this function was called with a valid pr_res_key
 167                  * parameter (eg: for PROUT PREEMPT_AND_ABORT service action
 168                  * skip non regisration key matching TMRs.
 169                  */
 170                 if ((preempt_and_abort_list != NULL) &&
 171                     (core_scsi3_check_cdb_abort_and_preempt(
 172                                         preempt_and_abort_list, cmd) != 0))
 173                         continue;
 174                 spin_unlock(&dev->se_tmr_lock);
 175
 176                 spin_lock_irqsave(&T_TASK(cmd)->t_state_lock, flags);
 177                 if (!(atomic_read(&T_TASK(cmd)->t_transport_active))) {
 178                         spin_unlock_irqrestore(&T_TASK(cmd)->t_state_lock, flags);
 179                         spin_lock(&dev->se_tmr_lock);
 180                         continue;
 181                 }
 182                 if (cmd->t_state == TRANSPORT_ISTATE_PROCESSING) {
 183                         spin_unlock_irqrestore(&T_TASK(cmd)->t_state_lock, flags);
 184                         spin_lock(&dev->se_tmr_lock);
 185                         continue;
 186                 }
 187                 DEBUG_LR("LUN_RESET: %s releasing TMR %p Function: 0x%02x,"
 188                         " Response: 0x%02x, t_state: %d\n",
 189                         (preempt_and_abort_list) ? "Preempt" : "", tmr_p,
 190                         tmr_p->function, tmr_p->response, cmd->t_state);
 191                 spin_unlock_irqrestore(&T_TASK(cmd)->t_state_lock, flags);
 192
 193                 transport_cmd_finish_abort_tmr(cmd);
 194                 spin_lock(&dev->se_tmr_lock);
 195         }
 196         spin_unlock(&dev->se_tmr_lock);
 197         /*
 198          * Complete outstanding struct se_task CDBs with TASK_ABORTED SAM status.
 199          * This is following sam4r17, section 5.6 Aborting commands, Table 38
 200          * for TMR LUN_RESET:
 201          *
 202          * a) "Yes" indicates that each command that is aborted on an I_T nexus
 203          * other than the one that caused the SCSI device condition is
 204          * completed with TASK ABORTED status, if the TAS bit is set to one in
 205          * the Control mode page (see SPC-4). "No" indicates that no status is
 206          * returned for aborted commands.
 207          *
 208          * d) If the logical unit reset is caused by a particular I_T nexus
 209          * (e.g., by a LOGICAL UNIT RESET task management function), then "yes"
 210          * (TASK_ABORTED status) applies.
 211          *
 212          * Otherwise (e.g., if triggered by a hard reset), "no"
 213          * (no TASK_ABORTED SAM status) applies.
 214          *
 215          * Note that this seems to be independent of TAS (Task Aborted Status)
 216          * in the Control Mode Page.
 217          */
 218         spin_lock_irqsave(&dev->execute_task_lock, flags);
 219         list_for_each_entry_safe(task, task_tmp, &dev->state_task_list,
 220                                 t_state_list) {
 221                 if (!(TASK_CMD(task))) {
 222                         printk(KERN_ERR "TASK_CMD(task) is NULL!\n");
 223                         continue;
 224                 }
 225                 cmd = TASK_CMD(task);
 226
 227                 if (!T_TASK(cmd)) {
 228                         printk(KERN_ERR "T_TASK(cmd) is NULL for task: %p cmd:"
 229                                 " %p ITT: 0x%08x\n", task, cmd,
 230                                 CMD_TFO(cmd)->get_task_tag(cmd));
 231                         continue;
 232                 }
 233                 /*
 234                  * For PREEMPT_AND_ABORT usage, only process commands
 235                  * with a matching reservation key.
 236                  */
 237                 if ((preempt_and_abort_list != NULL) &&
 238                     (core_scsi3_check_cdb_abort_and_preempt(
 239                                         preempt_and_abort_list, cmd) != 0))
 240                         continue;
 241                 /*
 242                  * Not aborting PROUT PREEMPT_AND_ABORT CDB..
 243                  */
 244                 if (prout_cmd == cmd)
 245                         continue;
 246
 247                 list_del(&task->t_state_list);
 248                 atomic_set(&task->task_state_active, 0);
 249                 spin_unlock_irqrestore(&dev->execute_task_lock, flags);
 250
 251                 spin_lock_irqsave(&T_TASK(cmd)->t_state_lock, flags);
 252                 DEBUG_LR("LUN_RESET: %s cmd: %p task: %p"
 253                         " ITT/CmdSN: 0x%08x/0x%08x, i_state: %d, t_state/"
 254                         "def_t_state: %d/%d cdb: 0x%02x\n",
 255                         (preempt_and_abort_list) ? "Preempt" : "", cmd, task,
 256                         CMD_TFO(cmd)->get_task_tag(cmd), 0,
 257                         CMD_TFO(cmd)->get_cmd_state(cmd), cmd->t_state,
 258                         cmd->deferred_t_state, T_TASK(cmd)->t_task_cdb[0]);
 259                 DEBUG_LR("LUN_RESET: ITT[0x%08x] - pr_res_key: 0x%016Lx"
 260                         " t_task_cdbs: %d t_task_cdbs_left: %d"
 261                         " t_task_cdbs_sent: %d -- t_transport_active: %d"
 262                         " t_transport_stop: %d t_transport_sent: %d\n",
 263                         CMD_TFO(cmd)->get_task_tag(cmd), cmd->pr_res_key,
 264                         T_TASK(cmd)->t_task_cdbs,
 265                         atomic_read(&T_TASK(cmd)->t_task_cdbs_left),
 266                         atomic_read(&T_TASK(cmd)->t_task_cdbs_sent),
 267                         atomic_read(&T_TASK(cmd)->t_transport_active),
 268                         atomic_read(&T_TASK(cmd)->t_transport_stop),
 269                         atomic_read(&T_TASK(cmd)->t_transport_sent));
 270
 271                 if (atomic_read(&task->task_active)) {
 272                         atomic_set(&task->task_stop, 1);
 273                         spin_unlock_irqrestore(
 274                                 &T_TASK(cmd)->t_state_lock, flags);
 275
 276                         DEBUG_LR("LUN_RESET: Waiting for task: %p to shutdown"
 277                                 " for dev: %p\n", task, dev);
 278                         wait_for_completion(&task->task_stop_comp);
 279                         DEBUG_LR("LUN_RESET Completed task: %p shutdown for"
 280                                 " dev: %p\n", task, dev);
 281                         spin_lock_irqsave(&T_TASK(cmd)->t_state_lock, flags);
 282                         atomic_dec(&T_TASK(cmd)->t_task_cdbs_left);
 283
 284                         atomic_set(&task->task_active, 0);
 285                         atomic_set(&task->task_stop, 0);
 286                 } else {
 287                         if (atomic_read(&task->task_execute_queue) != 0)
 288                                 transport_remove_task_from_execute_queue(task, dev);
 289                 }
 290                 __transport_stop_task_timer(task, &flags);
 291
 292                 if (!(atomic_dec_and_test(&T_TASK(cmd)->t_task_cdbs_ex_left))) {
 293                         spin_unlock_irqrestore(
 294                                         &T_TASK(cmd)->t_state_lock, flags);
 295                         DEBUG_LR("LUN_RESET: Skipping task: %p, dev: %p for"
 296                                 " t_task_cdbs_ex_left: %d\n", task, dev,
 297                                 atomic_read(&T_TASK(cmd)->t_task_cdbs_ex_left));
 298
 299                         spin_lock_irqsave(&dev->execute_task_lock, flags);
 300                         continue;
 301                 }
 302                 fe_count = atomic_read(&T_TASK(cmd)->t_fe_count);
 303
 304                 if (atomic_read(&T_TASK(cmd)->t_transport_active)) {
 305                         DEBUG_LR("LUN_RESET: got t_transport_active = 1 for"
 306                                 " task: %p, t_fe_count: %d dev: %p\n", task,
 307                                 fe_count, dev);
 308                         atomic_set(&T_TASK(cmd)->t_transport_aborted, 1);
 309                         spin_unlock_irqrestore(&T_TASK(cmd)->t_state_lock,
 310                                                 flags);
 311                         core_tmr_handle_tas_abort(tmr_nacl, cmd, tas, fe_count);
 312
 313                         spin_lock_irqsave(&dev->execute_task_lock, flags);
 314                         continue;
 315                 }
 316                 DEBUG_LR("LUN_RESET: Got t_transport_active = 0 for task: %p,"
 317                         " t_fe_count: %d dev: %p\n", task, fe_count, dev);
 318                 atomic_set(&T_TASK(cmd)->t_transport_aborted, 1);
 319                 spin_unlock_irqrestore(&T_TASK(cmd)->t_state_lock, flags);
 320                 core_tmr_handle_tas_abort(tmr_nacl, cmd, tas, fe_count);
 321
 322                 spin_lock_irqsave(&dev->execute_task_lock, flags);
 323         }
 324         spin_unlock_irqrestore(&dev->execute_task_lock, flags);
 325         /*
 326          * Release all commands remaining in the struct se_device cmd queue.
 327          *
 328          * This follows the same logic as above for the struct se_device
 329          * struct se_task state list, where commands are returned with
 330          * TASK_ABORTED status, if there is an outstanding $FABRIC_MOD
 331          * reference, otherwise the struct se_cmd is released.
 332          */
 333         spin_lock_irqsave(&qobj->cmd_queue_lock, flags);
 334         list_for_each_entry_safe(qr, qr_tmp, &qobj->qobj_list, qr_list) {
 335                 cmd = (struct se_cmd *)qr->cmd;
 336                 if (!(cmd)) {
 337                         /*
 338                          * Skip these for non PREEMPT_AND_ABORT usage..
 339                          */
 340                         if (preempt_and_abort_list != NULL)
 341                                 continue;
 342
 343                         atomic_dec(&qobj->queue_cnt);
 344                         list_del(&qr->qr_list);
 345                         kfree(qr);
 346                         continue;
 347                 }
 348                 /*
 349                  * For PREEMPT_AND_ABORT usage, only process commands
 350                  * with a matching reservation key.
 351                  */
 352                 if ((preempt_and_abort_list != NULL) &&
 353                     (core_scsi3_check_cdb_abort_and_preempt(
 354                                         preempt_and_abort_list, cmd) != 0))
 355                         continue;
 356                 /*
 357                  * Not aborting PROUT PREEMPT_AND_ABORT CDB..
 358                  */
 359                 if (prout_cmd == cmd)
 360                         continue;
 361
 362                 atomic_dec(&T_TASK(cmd)->t_transport_queue_active);
 363                 atomic_dec(&qobj->queue_cnt);
 364                 list_del(&qr->qr_list);
 365                 spin_unlock_irqrestore(&qobj->cmd_queue_lock, flags);
 366
 367                 state = qr->state;
 368                 kfree(qr);
 369
 370                 DEBUG_LR("LUN_RESET: %s from Device Queue: cmd: %p t_state:"
 371                         " %d t_fe_count: %d\n", (preempt_and_abort_list) ?
 372                         "Preempt" : "", cmd, state,
 373                         atomic_read(&T_TASK(cmd)->t_fe_count));
 374                 /*
 375                  * Signal that the command has failed via cmd->se_cmd_flags,
 376                  * and call TFO->new_cmd_failure() to wakeup any fabric
 377                  * dependent code used to wait for unsolicited data out
 378                  * allocation to complete.  The fabric module is expected
 379                  * to dump any remaining unsolicited data out for the aborted
 380                  * command at this point.
 381                  */
 382                 transport_new_cmd_failure(cmd);
 383
 384                 core_tmr_handle_tas_abort(tmr_nacl, cmd, tas,
 385                                 atomic_read(&T_TASK(cmd)->t_fe_count));
 386                 spin_lock_irqsave(&qobj->cmd_queue_lock, flags);
 387         }
 388         spin_unlock_irqrestore(&qobj->cmd_queue_lock, flags);
 389         /*
 390          * Clear any legacy SPC-2 reservation when called during
 391          * LOGICAL UNIT RESET
 392          */
 393         if (!(preempt_and_abort_list) &&
 394              (dev->dev_flags & DF_SPC2_RESERVATIONS)) {
 395                 spin_lock(&dev->dev_reservation_lock);
 396                 dev->dev_reserved_node_acl = NULL;
 397                 dev->dev_flags &= ~DF_SPC2_RESERVATIONS;
 398                 spin_unlock(&dev->dev_reservation_lock);
 399                 printk(KERN_INFO "LUN_RESET: SCSI-2 Released reservation\n");
 400         }
 401
 402         spin_lock_irq(&dev->stats_lock);
 403         dev->num_resets++;
 404         spin_unlock_irq(&dev->stats_lock);
 405
 406         DEBUG_LR("LUN_RESET: %s for [%s] Complete\n",
 407                         (preempt_and_abort_list) ? "Preempt" : "TMR",
 408                         TRANSPORT(dev)->name);
 409         return 0;
 410 }