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, GFP_KERNEL);
  59         if (!(tmr)) {
  60                 printk(KERN_ERR "Unable to allocate struct se_tmr_req\n");
  61                 return ERR_PTR(-ENOMEM);
  62         }
  63         tmr->task_cmd = se_cmd;
  64         tmr->fabric_tmr_ptr = fabric_tmr_ptr;
  65         tmr->function = function;
  66         INIT_LIST_HEAD(&tmr->tmr_list);
  67
  68         return tmr;
  69 }
  70 EXPORT_SYMBOL(core_tmr_alloc_req);
  71
  72 void core_tmr_release_req(
  73         struct se_tmr_req *tmr)
  74 {
  75         struct se_device *dev = tmr->tmr_dev;
  76
  77         spin_lock(&dev->se_tmr_lock);
  78         list_del(&tmr->tmr_list);
  79         kmem_cache_free(se_tmr_req_cache, tmr);
  80         spin_unlock(&dev->se_tmr_lock);
  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 != NULL) &&
  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;
 110         struct se_queue_req *qr, *qr_tmp;
 111         struct se_node_acl *tmr_nacl = NULL;
 112         struct se_portal_group *tmr_tpg = NULL;
 113         struct se_queue_obj *qobj = dev->dev_queue_obj;
 114         struct se_tmr_req *tmr_p, *tmr_pp;
 115         struct se_task *task, *task_tmp;
 116         unsigned long flags;
 117         int fe_count, state, tas;
 118         /*
 119          * TASK_ABORTED status bit, this is configurable via ConfigFS
 120          * struct se_device attributes.  spc4r17 section 7.4.6 Control mode page
 121          *
 122          * A task aborted status (TAS) bit set to zero specifies that aborted
 123          * tasks shall be terminated by the device server without any response
 124          * to the application client. A TAS bit set to one specifies that tasks
 125          * aborted by the actions of an I_T nexus other than the I_T nexus on
 126          * which the command was received shall be completed with TASK ABORTED
 127          * status (see SAM-4).
 128          */
 129         tas = DEV_ATTRIB(dev)->emulate_tas;
 130         /*
 131          * Determine if this se_tmr is coming from a $FABRIC_MOD
 132          * or struct se_device passthrough..
 133          */
 134         if (tmr && tmr->task_cmd && tmr->task_cmd->se_sess) {
 135                 tmr_nacl = tmr->task_cmd->se_sess->se_node_acl;
 136                 tmr_tpg = tmr->task_cmd->se_sess->se_tpg;
 137                 if (tmr_nacl && tmr_tpg) {
 138                         DEBUG_LR("LUN_RESET: TMR caller fabric: %s"
 139                                 " initiator port %s\n",
 140                                 TPG_TFO(tmr_tpg)->get_fabric_name(),
 141                                 tmr_nacl->initiatorname);
 142                 }
 143         }
 144         DEBUG_LR("LUN_RESET: %s starting for [%s], tas: %d\n",
 145                 (preempt_and_abort_list) ? "Preempt" : "TMR",
 146                 TRANSPORT(dev)->name, tas);
 147         /*
 148          * Release all pending and outgoing TMRs aside from the received
 149          * LUN_RESET tmr..
 150          */
 151         spin_lock(&dev->se_tmr_lock);
 152         list_for_each_entry_safe(tmr_p, tmr_pp, &dev->dev_tmr_list, tmr_list) {
 153                 /*
 154                  * Allow the received TMR to return with FUNCTION_COMPLETE.
 155                  */
 156                 if (tmr && (tmr_p == tmr))
 157                         continue;
 158
 159                 cmd = tmr_p->task_cmd;
 160                 if (!(cmd)) {
 161                         printk(KERN_ERR "Unable to locate struct se_cmd for TMR\n");
 162                         continue;
 163                 }
 164                 /*
 165                  * If this function was called with a valid pr_res_key
 166                  * parameter (eg: for PROUT PREEMPT_AND_ABORT service action
 167                  * skip non regisration key matching TMRs.
 168                  */
 169                 if ((preempt_and_abort_list != NULL) &&
 170                     (core_scsi3_check_cdb_abort_and_preempt(
 171                                         preempt_and_abort_list, cmd) != 0))
 172                         continue;
 173                 spin_unlock(&dev->se_tmr_lock);
 174
 175                 spin_lock_irqsave(&T_TASK(cmd)->t_state_lock, flags);
 176                 if (!(atomic_read(&T_TASK(cmd)->t_transport_active))) {
 177                         spin_unlock_irqrestore(&T_TASK(cmd)->t_state_lock, flags);
 178                         spin_lock(&dev->se_tmr_lock);
 179                         continue;
 180                 }
 181                 if (cmd->t_state == TRANSPORT_ISTATE_PROCESSING) {
 182                         spin_unlock_irqrestore(&T_TASK(cmd)->t_state_lock, flags);
 183                         spin_lock(&dev->se_tmr_lock);
 184                         continue;
 185                 }
 186                 DEBUG_LR("LUN_RESET: %s releasing TMR %p Function: 0x%02x,"
 187                         " Response: 0x%02x, t_state: %d\n",
 188                         (preempt_and_abort_list) ? "Preempt" : "", tmr_p,
 189                         tmr_p->function, tmr_p->response, cmd->t_state);
 190                 spin_unlock_irqrestore(&T_TASK(cmd)->t_state_lock, flags);
 191
 192                 transport_cmd_finish_abort_tmr(cmd);
 193                 spin_lock(&dev->se_tmr_lock);
 194         }
 195         spin_unlock(&dev->se_tmr_lock);
 196         /*
 197          * Complete outstanding struct se_task CDBs with TASK_ABORTED SAM status.
 198          * This is following sam4r17, section 5.6 Aborting commands, Table 38
 199          * for TMR LUN_RESET:
 200          *
 201          * a) "Yes" indicates that each command that is aborted on an I_T nexus
 202          * other than the one that caused the SCSI device condition is
 203          * completed with TASK ABORTED status, if the TAS bit is set to one in
 204          * the Control mode page (see SPC-4). "No" indicates that no status is
 205          * returned for aborted commands.
 206          *
 207          * d) If the logical unit reset is caused by a particular I_T nexus
 208          * (e.g., by a LOGICAL UNIT RESET task management function), then "yes"
 209          * (TASK_ABORTED status) applies.
 210          *
 211          * Otherwise (e.g., if triggered by a hard reset), "no"
 212          * (no TASK_ABORTED SAM status) applies.
 213          *
 214          * Note that this seems to be independent of TAS (Task Aborted Status)
 215          * in the Control Mode Page.
 216          */
 217         spin_lock_irqsave(&dev->execute_task_lock, flags);
 218         list_for_each_entry_safe(task, task_tmp, &dev->state_task_list,
 219                                 t_state_list) {
 220                 if (!(TASK_CMD(task))) {
 221                         printk(KERN_ERR "TASK_CMD(task) is NULL!\n");
 222                         continue;
 223                 }
 224                 cmd = TASK_CMD(task);
 225
 226                 if (!T_TASK(cmd)) {
 227                         printk(KERN_ERR "T_TASK(cmd) is NULL for task: %p cmd:"
 228                                 " %p ITT: 0x%08x\n", task, cmd,
 229                                 CMD_TFO(cmd)->get_task_tag(cmd));
 230                         continue;
 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(&T_TASK(cmd)->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_TFO(cmd)->get_task_tag(cmd), 0,
 256                         CMD_TFO(cmd)->get_cmd_state(cmd), cmd->t_state,
 257                         cmd->deferred_t_state, T_TASK(cmd)->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_TFO(cmd)->get_task_tag(cmd), cmd->pr_res_key,
 263                         T_TASK(cmd)->t_task_cdbs,
 264                         atomic_read(&T_TASK(cmd)->t_task_cdbs_left),
 265                         atomic_read(&T_TASK(cmd)->t_task_cdbs_sent),
 266                         atomic_read(&T_TASK(cmd)->t_transport_active),
 267                         atomic_read(&T_TASK(cmd)->t_transport_stop),
 268                         atomic_read(&T_TASK(cmd)->t_transport_sent));
 269
 270                 if (atomic_read(&task->task_active)) {
 271                         atomic_set(&task->task_stop, 1);
 272                         spin_unlock_irqrestore(
 273                                 &T_TASK(cmd)->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(&T_TASK(cmd)->t_state_lock, flags);
 281                         atomic_dec(&T_TASK(cmd)->t_task_cdbs_left);
 282
 283                         atomic_set(&task->task_active, 0);
 284                         atomic_set(&task->task_stop, 0);
 285                 }
 286                 __transport_stop_task_timer(task, &flags);
 287
 288                 if (!(atomic_dec_and_test(&T_TASK(cmd)->t_task_cdbs_ex_left))) {
 289                         spin_unlock_irqrestore(
 290                                         &T_TASK(cmd)->t_state_lock, flags);
 291                         DEBUG_LR("LUN_RESET: Skipping task: %p, dev: %p for"
 292                                 " t_task_cdbs_ex_left: %d\n", task, dev,
 293                                 atomic_read(&T_TASK(cmd)->t_task_cdbs_ex_left));
 294
 295                         spin_lock_irqsave(&dev->execute_task_lock, flags);
 296                         continue;
 297                 }
 298                 fe_count = atomic_read(&T_TASK(cmd)->t_fe_count);
 299
 300                 if (atomic_read(&T_TASK(cmd)->t_transport_active)) {
 301                         DEBUG_LR("LUN_RESET: got t_transport_active = 1 for"
 302                                 " task: %p, t_fe_count: %d dev: %p\n", task,
 303                                 fe_count, dev);
 304                         spin_unlock_irqrestore(&T_TASK(cmd)->t_state_lock,
 305                                                 flags);
 306                         core_tmr_handle_tas_abort(tmr_nacl, cmd, tas, fe_count);
 307
 308                         spin_lock_irqsave(&dev->execute_task_lock, flags);
 309                         continue;
 310                 }
 311                 DEBUG_LR("LUN_RESET: Got t_transport_active = 0 for task: %p,"
 312                         " t_fe_count: %d dev: %p\n", task, fe_count, dev);
 313                 spin_unlock_irqrestore(&T_TASK(cmd)->t_state_lock, flags);
 314                 core_tmr_handle_tas_abort(tmr_nacl, cmd, tas, fe_count);
 315
 316                 spin_lock_irqsave(&dev->execute_task_lock, flags);
 317         }
 318         spin_unlock_irqrestore(&dev->execute_task_lock, 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(qr, qr_tmp, &qobj->qobj_list, qr_list) {
 329                 cmd = (struct se_cmd *)qr->cmd;
 330                 if (!(cmd)) {
 331                         /*
 332                          * Skip these for non PREEMPT_AND_ABORT usage..
 333                          */
 334                         if (preempt_and_abort_list != NULL)
 335                                 continue;
 336
 337                         atomic_dec(&qobj->queue_cnt);
 338                         list_del(&qr->qr_list);
 339                         kfree(qr);
 340                         continue;
 341                 }
 342                 /*
 343                  * For PREEMPT_AND_ABORT usage, only process commands
 344                  * with a matching reservation key.
 345                  */
 346                 if ((preempt_and_abort_list != NULL) &&
 347                     (core_scsi3_check_cdb_abort_and_preempt(
 348                                         preempt_and_abort_list, cmd) != 0))
 349                         continue;
 350                 /*
 351                  * Not aborting PROUT PREEMPT_AND_ABORT CDB..
 352                  */
 353                 if (prout_cmd == cmd)
 354                         continue;
 355
 356                 atomic_dec(&T_TASK(cmd)->t_transport_queue_active);
 357                 atomic_dec(&qobj->queue_cnt);
 358                 list_del(&qr->qr_list);
 359                 spin_unlock_irqrestore(&qobj->cmd_queue_lock, flags);
 360
 361                 state = qr->state;
 362                 kfree(qr);
 363
 364                 DEBUG_LR("LUN_RESET: %s from Device Queue: cmd: %p t_state:"
 365                         " %d t_fe_count: %d\n", (preempt_and_abort_list) ?
 366                         "Preempt" : "", cmd, state,
 367                         atomic_read(&T_TASK(cmd)->t_fe_count));
 368                 /*
 369                  * Signal that the command has failed via cmd->se_cmd_flags,
 370                  * and call TFO->new_cmd_failure() to wakeup any fabric
 371                  * dependent code used to wait for unsolicited data out
 372                  * allocation to complete.  The fabric module is expected
 373                  * to dump any remaining unsolicited data out for the aborted
 374                  * command at this point.
 375                  */
 376                 transport_new_cmd_failure(cmd);
 377
 378                 core_tmr_handle_tas_abort(tmr_nacl, cmd, tas,
 379                                 atomic_read(&T_TASK(cmd)->t_fe_count));
 380                 spin_lock_irqsave(&qobj->cmd_queue_lock, flags);
 381         }
 382         spin_unlock_irqrestore(&qobj->cmd_queue_lock, flags);
 383         /*
 384          * Clear any legacy SPC-2 reservation when called during
 385          * LOGICAL UNIT RESET
 386          */
 387         if (!(preempt_and_abort_list) &&
 388              (dev->dev_flags & DF_SPC2_RESERVATIONS)) {
 389                 spin_lock(&dev->dev_reservation_lock);
 390                 dev->dev_reserved_node_acl = NULL;
 391                 dev->dev_flags &= ~DF_SPC2_RESERVATIONS;
 392                 spin_unlock(&dev->dev_reservation_lock);
 393                 printk(KERN_INFO "LUN_RESET: SCSI-2 Released reservation\n");
 394         }
 395
 396         spin_lock(&dev->stats_lock);
 397         dev->num_resets++;
 398         spin_unlock(&dev->stats_lock);
 399
 400         DEBUG_LR("LUN_RESET: %s for [%s] Complete\n",
 401                         (preempt_and_abort_list) ? "Preempt" : "TMR",
 402                         TRANSPORT(dev)->name);
 403         return 0;
 404 }