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;
 117         struct se_queue_req *qr, *qr_tmp;
 118         struct se_node_acl *tmr_nacl = NULL;
 119         struct se_portal_group *tmr_tpg = NULL;
 120         struct se_queue_obj *qobj = dev->dev_queue_obj;
 121         struct se_tmr_req *tmr_p, *tmr_pp;
 122         struct se_task *task, *task_tmp;
 123         unsigned long flags;
 124         int fe_count, state, tas;
 125         /*
 126          * TASK_ABORTED status bit, this is configurable via ConfigFS
 127          * struct se_device attributes.  spc4r17 section 7.4.6 Control mode page
 128          *
 129          * A task aborted status (TAS) bit set to zero specifies that aborted
 130          * tasks shall be terminated by the device server without any response
 131          * to the application client. A TAS bit set to one specifies that tasks
 132          * aborted by the actions of an I_T nexus other than the I_T nexus on
 133          * which the command was received shall be completed with TASK ABORTED
 134          * status (see SAM-4).
 135          */
 136         tas = DEV_ATTRIB(dev)->emulate_tas;
 137         /*
 138          * Determine if this se_tmr is coming from a $FABRIC_MOD
 139          * or struct se_device passthrough..
 140          */
 141         if (tmr && tmr->task_cmd && tmr->task_cmd->se_sess) {
 142                 tmr_nacl = tmr->task_cmd->se_sess->se_node_acl;
 143                 tmr_tpg = tmr->task_cmd->se_sess->se_tpg;
 144                 if (tmr_nacl && tmr_tpg) {
 145                         DEBUG_LR("LUN_RESET: TMR caller fabric: %s"
 146                                 " initiator port %s\n",
 147                                 TPG_TFO(tmr_tpg)->get_fabric_name(),
 148                                 tmr_nacl->initiatorname);
 149                 }
 150         }
 151         DEBUG_LR("LUN_RESET: %s starting for [%s], tas: %d\n",
 152                 (preempt_and_abort_list) ? "Preempt" : "TMR",
 153                 TRANSPORT(dev)->name, tas);
 154         /*
 155          * Release all pending and outgoing TMRs aside from the received
 156          * LUN_RESET tmr..
 157          */
 158         spin_lock(&dev->se_tmr_lock);
 159         list_for_each_entry_safe(tmr_p, tmr_pp, &dev->dev_tmr_list, tmr_list) {
 160                 /*
 161                  * Allow the received TMR to return with FUNCTION_COMPLETE.
 162                  */
 163                 if (tmr && (tmr_p == tmr))
 164                         continue;
 165
 166                 cmd = tmr_p->task_cmd;
 167                 if (!(cmd)) {
 168                         printk(KERN_ERR "Unable to locate struct se_cmd for TMR\n");
 169                         continue;
 170                 }
 171                 /*
 172                  * If this function was called with a valid pr_res_key
 173                  * parameter (eg: for PROUT PREEMPT_AND_ABORT service action
 174                  * skip non regisration key matching TMRs.
 175                  */
 176                 if ((preempt_and_abort_list != NULL) &&
 177                     (core_scsi3_check_cdb_abort_and_preempt(
 178                                         preempt_and_abort_list, cmd) != 0))
 179                         continue;
 180                 spin_unlock(&dev->se_tmr_lock);
 181
 182                 spin_lock_irqsave(&T_TASK(cmd)->t_state_lock, flags);
 183                 if (!(atomic_read(&T_TASK(cmd)->t_transport_active))) {
 184                         spin_unlock_irqrestore(&T_TASK(cmd)->t_state_lock, flags);
 185                         spin_lock(&dev->se_tmr_lock);
 186                         continue;
 187                 }
 188                 if (cmd->t_state == TRANSPORT_ISTATE_PROCESSING) {
 189                         spin_unlock_irqrestore(&T_TASK(cmd)->t_state_lock, flags);
 190                         spin_lock(&dev->se_tmr_lock);
 191                         continue;
 192                 }
 193                 DEBUG_LR("LUN_RESET: %s releasing TMR %p Function: 0x%02x,"
 194                         " Response: 0x%02x, t_state: %d\n",
 195                         (preempt_and_abort_list) ? "Preempt" : "", tmr_p,
 196                         tmr_p->function, tmr_p->response, cmd->t_state);
 197                 spin_unlock_irqrestore(&T_TASK(cmd)->t_state_lock, flags);
 198
 199                 transport_cmd_finish_abort_tmr(cmd);
 200                 spin_lock(&dev->se_tmr_lock);
 201         }
 202         spin_unlock(&dev->se_tmr_lock);
 203         /*
 204          * Complete outstanding struct se_task CDBs with TASK_ABORTED SAM status.
 205          * This is following sam4r17, section 5.6 Aborting commands, Table 38
 206          * for TMR LUN_RESET:
 207          *
 208          * a) "Yes" indicates that each command that is aborted on an I_T nexus
 209          * other than the one that caused the SCSI device condition is
 210          * completed with TASK ABORTED status, if the TAS bit is set to one in
 211          * the Control mode page (see SPC-4). "No" indicates that no status is
 212          * returned for aborted commands.
 213          *
 214          * d) If the logical unit reset is caused by a particular I_T nexus
 215          * (e.g., by a LOGICAL UNIT RESET task management function), then "yes"
 216          * (TASK_ABORTED status) applies.
 217          *
 218          * Otherwise (e.g., if triggered by a hard reset), "no"
 219          * (no TASK_ABORTED SAM status) applies.
 220          *
 221          * Note that this seems to be independent of TAS (Task Aborted Status)
 222          * in the Control Mode Page.
 223          */
 224         spin_lock_irqsave(&dev->execute_task_lock, flags);
 225         list_for_each_entry_safe(task, task_tmp, &dev->state_task_list,
 226                                 t_state_list) {
 227                 if (!(TASK_CMD(task))) {
 228                         printk(KERN_ERR "TASK_CMD(task) is NULL!\n");
 229                         continue;
 230                 }
 231                 cmd = TASK_CMD(task);
 232
 233                 if (!T_TASK(cmd)) {
 234                         printk(KERN_ERR "T_TASK(cmd) is NULL for task: %p cmd:"
 235                                 " %p ITT: 0x%08x\n", task, cmd,
 236                                 CMD_TFO(cmd)->get_task_tag(cmd));
 237                         continue;
 238                 }
 239                 /*
 240                  * For PREEMPT_AND_ABORT usage, only process commands
 241                  * with a matching reservation key.
 242                  */
 243                 if ((preempt_and_abort_list != NULL) &&
 244                     (core_scsi3_check_cdb_abort_and_preempt(
 245                                         preempt_and_abort_list, cmd) != 0))
 246                         continue;
 247                 /*
 248                  * Not aborting PROUT PREEMPT_AND_ABORT CDB..
 249                  */
 250                 if (prout_cmd == cmd)
 251                         continue;
 252
 253                 list_del(&task->t_state_list);
 254                 atomic_set(&task->task_state_active, 0);
 255                 spin_unlock_irqrestore(&dev->execute_task_lock, flags);
 256
 257                 spin_lock_irqsave(&T_TASK(cmd)->t_state_lock, flags);
 258                 DEBUG_LR("LUN_RESET: %s cmd: %p task: %p"
 259                         " ITT/CmdSN: 0x%08x/0x%08x, i_state: %d, t_state/"
 260                         "def_t_state: %d/%d cdb: 0x%02x\n",
 261                         (preempt_and_abort_list) ? "Preempt" : "", cmd, task,
 262                         CMD_TFO(cmd)->get_task_tag(cmd), 0,
 263                         CMD_TFO(cmd)->get_cmd_state(cmd), cmd->t_state,
 264                         cmd->deferred_t_state, T_TASK(cmd)->t_task_cdb[0]);
 265                 DEBUG_LR("LUN_RESET: ITT[0x%08x] - pr_res_key: 0x%016Lx"
 266                         " t_task_cdbs: %d t_task_cdbs_left: %d"
 267                         " t_task_cdbs_sent: %d -- t_transport_active: %d"
 268                         " t_transport_stop: %d t_transport_sent: %d\n",
 269                         CMD_TFO(cmd)->get_task_tag(cmd), cmd->pr_res_key,
 270                         T_TASK(cmd)->t_task_cdbs,
 271                         atomic_read(&T_TASK(cmd)->t_task_cdbs_left),
 272                         atomic_read(&T_TASK(cmd)->t_task_cdbs_sent),
 273                         atomic_read(&T_TASK(cmd)->t_transport_active),
 274                         atomic_read(&T_TASK(cmd)->t_transport_stop),
 275                         atomic_read(&T_TASK(cmd)->t_transport_sent));
 276
 277                 if (atomic_read(&task->task_active)) {
 278                         atomic_set(&task->task_stop, 1);
 279                         spin_unlock_irqrestore(
 280                                 &T_TASK(cmd)->t_state_lock, flags);
 281
 282                         DEBUG_LR("LUN_RESET: Waiting for task: %p to shutdown"
 283                                 " for dev: %p\n", task, dev);
 284                         wait_for_completion(&task->task_stop_comp);
 285                         DEBUG_LR("LUN_RESET Completed task: %p shutdown for"
 286                                 " dev: %p\n", task, dev);
 287                         spin_lock_irqsave(&T_TASK(cmd)->t_state_lock, flags);
 288                         atomic_dec(&T_TASK(cmd)->t_task_cdbs_left);
 289
 290                         atomic_set(&task->task_active, 0);
 291                         atomic_set(&task->task_stop, 0);
 292                 } else {
 293                         if (atomic_read(&task->task_execute_queue) != 0)
 294                                 transport_remove_task_from_execute_queue(task, dev);
 295                 }
 296                 __transport_stop_task_timer(task, &flags);
 297
 298                 if (!(atomic_dec_and_test(&T_TASK(cmd)->t_task_cdbs_ex_left))) {
 299                         spin_unlock_irqrestore(
 300                                         &T_TASK(cmd)->t_state_lock, flags);
 301                         DEBUG_LR("LUN_RESET: Skipping task: %p, dev: %p for"
 302                                 " t_task_cdbs_ex_left: %d\n", task, dev,
 303                                 atomic_read(&T_TASK(cmd)->t_task_cdbs_ex_left));
 304
 305                         spin_lock_irqsave(&dev->execute_task_lock, flags);
 306                         continue;
 307                 }
 308                 fe_count = atomic_read(&T_TASK(cmd)->t_fe_count);
 309
 310                 if (atomic_read(&T_TASK(cmd)->t_transport_active)) {
 311                         DEBUG_LR("LUN_RESET: got t_transport_active = 1 for"
 312                                 " task: %p, t_fe_count: %d dev: %p\n", task,
 313                                 fe_count, dev);
 314                         atomic_set(&T_TASK(cmd)->t_transport_aborted, 1);
 315                         spin_unlock_irqrestore(&T_TASK(cmd)->t_state_lock,
 316                                                 flags);
 317                         core_tmr_handle_tas_abort(tmr_nacl, cmd, tas, fe_count);
 318
 319                         spin_lock_irqsave(&dev->execute_task_lock, flags);
 320                         continue;
 321                 }
 322                 DEBUG_LR("LUN_RESET: Got t_transport_active = 0 for task: %p,"
 323                         " t_fe_count: %d dev: %p\n", task, fe_count, dev);
 324                 atomic_set(&T_TASK(cmd)->t_transport_aborted, 1);
 325                 spin_unlock_irqrestore(&T_TASK(cmd)->t_state_lock, flags);
 326                 core_tmr_handle_tas_abort(tmr_nacl, cmd, tas, fe_count);
 327
 328                 spin_lock_irqsave(&dev->execute_task_lock, flags);
 329         }
 330         spin_unlock_irqrestore(&dev->execute_task_lock, flags);
 331         /*
 332          * Release all commands remaining in the struct se_device cmd queue.
 333          *
 334          * This follows the same logic as above for the struct se_device
 335          * struct se_task state list, where commands are returned with
 336          * TASK_ABORTED status, if there is an outstanding $FABRIC_MOD
 337          * reference, otherwise the struct se_cmd is released.
 338          */
 339         spin_lock_irqsave(&qobj->cmd_queue_lock, flags);
 340         list_for_each_entry_safe(qr, qr_tmp, &qobj->qobj_list, qr_list) {
 341                 cmd = (struct se_cmd *)qr->cmd;
 342                 if (!(cmd)) {
 343                         /*
 344                          * Skip these for non PREEMPT_AND_ABORT usage..
 345                          */
 346                         if (preempt_and_abort_list != NULL)
 347                                 continue;
 348
 349                         atomic_dec(&qobj->queue_cnt);
 350                         list_del(&qr->qr_list);
 351                         kfree(qr);
 352                         continue;
 353                 }
 354                 /*
 355                  * For PREEMPT_AND_ABORT usage, only process commands
 356                  * with a matching reservation key.
 357                  */
 358                 if ((preempt_and_abort_list != NULL) &&
 359                     (core_scsi3_check_cdb_abort_and_preempt(
 360                                         preempt_and_abort_list, cmd) != 0))
 361                         continue;
 362                 /*
 363                  * Not aborting PROUT PREEMPT_AND_ABORT CDB..
 364                  */
 365                 if (prout_cmd == cmd)
 366                         continue;
 367
 368                 atomic_dec(&T_TASK(cmd)->t_transport_queue_active);
 369                 atomic_dec(&qobj->queue_cnt);
 370                 list_del(&qr->qr_list);
 371                 spin_unlock_irqrestore(&qobj->cmd_queue_lock, flags);
 372
 373                 state = qr->state;
 374                 kfree(qr);
 375
 376                 DEBUG_LR("LUN_RESET: %s from Device Queue: cmd: %p t_state:"
 377                         " %d t_fe_count: %d\n", (preempt_and_abort_list) ?
 378                         "Preempt" : "", cmd, state,
 379                         atomic_read(&T_TASK(cmd)->t_fe_count));
 380                 /*
 381                  * Signal that the command has failed via cmd->se_cmd_flags,
 382                  * and call TFO->new_cmd_failure() to wakeup any fabric
 383                  * dependent code used to wait for unsolicited data out
 384                  * allocation to complete.  The fabric module is expected
 385                  * to dump any remaining unsolicited data out for the aborted
 386                  * command at this point.
 387                  */
 388                 transport_new_cmd_failure(cmd);
 389
 390                 core_tmr_handle_tas_abort(tmr_nacl, cmd, tas,
 391                                 atomic_read(&T_TASK(cmd)->t_fe_count));
 392                 spin_lock_irqsave(&qobj->cmd_queue_lock, flags);
 393         }
 394         spin_unlock_irqrestore(&qobj->cmd_queue_lock, flags);
 395         /*
 396          * Clear any legacy SPC-2 reservation when called during
 397          * LOGICAL UNIT RESET
 398          */
 399         if (!(preempt_and_abort_list) &&
 400              (dev->dev_flags & DF_SPC2_RESERVATIONS)) {
 401                 spin_lock(&dev->dev_reservation_lock);
 402                 dev->dev_reserved_node_acl = NULL;
 403                 dev->dev_flags &= ~DF_SPC2_RESERVATIONS;
 404                 spin_unlock(&dev->dev_reservation_lock);
 405                 printk(KERN_INFO "LUN_RESET: SCSI-2 Released reservation\n");
 406         }
 407
 408         spin_lock_irq(&dev->stats_lock);
 409         dev->num_resets++;
 410         spin_unlock_irq(&dev->stats_lock);
 411
 412         DEBUG_LR("LUN_RESET: %s for [%s] Complete\n",
 413                         (preempt_and_abort_list) ? "Preempt" : "TMR",
 414                         TRANSPORT(dev)->name);
 415         return 0;
 416 }