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 <linux/export.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_backend.h>
  36 #include <target/target_core_fabric.h>
  37 #include <target/target_core_configfs.h>
  38
  39 #include "target_core_internal.h"
  40 #include "target_core_alua.h"
  41 #include "target_core_pr.h"
  42
  43 int core_tmr_alloc_req(
  44         struct se_cmd *se_cmd,
  45         void *fabric_tmr_ptr,
  46         u8 function,
  47         gfp_t gfp_flags)
  48 {
  49         struct se_tmr_req *tmr;
  50
  51         tmr = kzalloc(sizeof(struct se_tmr_req), gfp_flags);
  52         if (!tmr) {
  53                 pr_err("Unable to allocate struct se_tmr_req\n");
  54                 return -ENOMEM;
  55         }
  56
  57         se_cmd->se_cmd_flags |= SCF_SCSI_TMR_CDB;
  58         se_cmd->se_tmr_req = tmr;
  59         tmr->task_cmd = se_cmd;
  60         tmr->fabric_tmr_ptr = fabric_tmr_ptr;
  61         tmr->function = function;
  62         INIT_LIST_HEAD(&tmr->tmr_list);
  63
  64         return 0;
  65 }
  66 EXPORT_SYMBOL(core_tmr_alloc_req);
  67
  68 void core_tmr_release_req(
  69         struct se_tmr_req *tmr)
  70 {
  71         struct se_device *dev = tmr->tmr_dev;
  72         unsigned long flags;
  73
  74         if (!dev) {
  75                 kfree(tmr);
  76                 return;
  77         }
  78
  79         spin_lock_irqsave(&dev->se_tmr_lock, flags);
  80         list_del(&tmr->tmr_list);
  81         spin_unlock_irqrestore(&dev->se_tmr_lock, flags);
  82
  83         kfree(tmr);
  84 }
  85
  86 static void core_tmr_handle_tas_abort(
  87         struct se_node_acl *tmr_nacl,
  88         struct se_cmd *cmd,
  89         int tas,
  90         int fe_count)
  91 {
  92         if (!fe_count) {
  93                 transport_cmd_finish_abort(cmd, 1);
  94                 return;
  95         }
  96         /*
  97          * TASK ABORTED status (TAS) bit support
  98         */
  99         if ((tmr_nacl &&
 100              (tmr_nacl == cmd->se_sess->se_node_acl)) || tas)
 101                 transport_send_task_abort(cmd);
 102
 103         transport_cmd_finish_abort(cmd, 0);
 104 }
 105
 106 static int target_check_cdb_and_preempt(struct list_head *list,
 107                 struct se_cmd *cmd)
 108 {
 109         struct t10_pr_registration *reg;
 110
 111         if (!list)
 112                 return 0;
 113         list_for_each_entry(reg, list, pr_reg_abort_list) {
 114                 if (reg->pr_res_key == cmd->pr_res_key)
 115                         return 0;
 116         }
 117
 118         return 1;
 119 }
 120
 121 void core_tmr_abort_task(
 122         struct se_device *dev,
 123         struct se_tmr_req *tmr,
 124         struct se_session *se_sess)
 125 {
 126         struct se_cmd *se_cmd, *tmp_cmd;
 127         unsigned long flags;
 128         int ref_tag;
 129
 130         spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
 131         list_for_each_entry_safe(se_cmd, tmp_cmd,
 132                         &se_sess->sess_cmd_list, se_cmd_list) {
 133
 134                 if (dev != se_cmd->se_dev)
 135                         continue;
 136                 ref_tag = se_cmd->se_tfo->get_task_tag(se_cmd);
 137                 if (tmr->ref_task_tag != ref_tag)
 138                         continue;
 139
 140                 printk("ABORT_TASK: Found referenced %s task_tag: %u\n",
 141                         se_cmd->se_tfo->get_fabric_name(), ref_tag);
 142
 143                 spin_lock_irq(&se_cmd->t_state_lock);
 144                 if (se_cmd->transport_state & CMD_T_COMPLETE) {
 145                         printk("ABORT_TASK: ref_tag: %u already complete, skipping\n", ref_tag);
 146                         spin_unlock_irq(&se_cmd->t_state_lock);
 147                         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
 148                         goto out;
 149                 }
 150                 se_cmd->transport_state |= CMD_T_ABORTED;
 151                 spin_unlock_irq(&se_cmd->t_state_lock);
 152
 153                 list_del_init(&se_cmd->se_cmd_list);
 154                 kref_get(&se_cmd->cmd_kref);
 155                 spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
 156
 157                 cancel_work_sync(&se_cmd->work);
 158                 transport_wait_for_tasks(se_cmd);
 159                 /*
 160                  * Now send SAM_STAT_TASK_ABORTED status for the referenced
 161                  * se_cmd descriptor..
 162                  */
 163                 transport_send_task_abort(se_cmd);
 164                 /*
 165                  * Also deal with possible extra acknowledge reference..
 166                  */
 167                 if (se_cmd->se_cmd_flags & SCF_ACK_KREF)
 168                         target_put_sess_cmd(se_sess, se_cmd);
 169
 170                 target_put_sess_cmd(se_sess, se_cmd);
 171
 172                 printk("ABORT_TASK: Sending TMR_FUNCTION_COMPLETE for"
 173                                 " ref_tag: %d\n", ref_tag);
 174                 tmr->response = TMR_FUNCTION_COMPLETE;
 175                 return;
 176         }
 177         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
 178
 179 out:
 180         printk("ABORT_TASK: Sending TMR_TASK_DOES_NOT_EXIST for ref_tag: %d\n",
 181                         tmr->ref_task_tag);
 182         tmr->response = TMR_TASK_DOES_NOT_EXIST;
 183 }
 184
 185 static void core_tmr_drain_tmr_list(
 186         struct se_device *dev,
 187         struct se_tmr_req *tmr,
 188         struct list_head *preempt_and_abort_list)
 189 {
 190         LIST_HEAD(drain_tmr_list);
 191         struct se_tmr_req *tmr_p, *tmr_pp;
 192         struct se_cmd *cmd;
 193         unsigned long flags;
 194         /*
 195          * Release all pending and outgoing TMRs aside from the received
 196          * LUN_RESET tmr..
 197          */
 198         spin_lock_irqsave(&dev->se_tmr_lock, flags);
 199         list_for_each_entry_safe(tmr_p, tmr_pp, &dev->dev_tmr_list, tmr_list) {
 200                 /*
 201                  * Allow the received TMR to return with FUNCTION_COMPLETE.
 202                  */
 203                 if (tmr_p == tmr)
 204                         continue;
 205
 206                 cmd = tmr_p->task_cmd;
 207                 if (!cmd) {
 208                         pr_err("Unable to locate struct se_cmd for TMR\n");
 209                         continue;
 210                 }
 211                 /*
 212                  * If this function was called with a valid pr_res_key
 213                  * parameter (eg: for PROUT PREEMPT_AND_ABORT service action
 214                  * skip non regisration key matching TMRs.
 215                  */
 216                 if (target_check_cdb_and_preempt(preempt_and_abort_list, cmd))
 217                         continue;
 218
 219                 spin_lock(&cmd->t_state_lock);
 220                 if (!(cmd->transport_state & CMD_T_ACTIVE)) {
 221                         spin_unlock(&cmd->t_state_lock);
 222                         continue;
 223                 }
 224                 if (cmd->t_state == TRANSPORT_ISTATE_PROCESSING) {
 225                         spin_unlock(&cmd->t_state_lock);
 226                         continue;
 227                 }
 228                 spin_unlock(&cmd->t_state_lock);
 229
 230                 list_move_tail(&tmr_p->tmr_list, &drain_tmr_list);
 231         }
 232         spin_unlock_irqrestore(&dev->se_tmr_lock, flags);
 233
 234         list_for_each_entry_safe(tmr_p, tmr_pp, &drain_tmr_list, tmr_list) {
 235                 list_del_init(&tmr_p->tmr_list);
 236                 cmd = tmr_p->task_cmd;
 237
 238                 pr_debug("LUN_RESET: %s releasing TMR %p Function: 0x%02x,"
 239                         " Response: 0x%02x, t_state: %d\n",
 240                         (preempt_and_abort_list) ? "Preempt" : "", tmr_p,
 241                         tmr_p->function, tmr_p->response, cmd->t_state);
 242
 243                 transport_cmd_finish_abort(cmd, 1);
 244         }
 245 }
 246
 247 static void core_tmr_drain_state_list(
 248         struct se_device *dev,
 249         struct se_cmd *prout_cmd,
 250         struct se_node_acl *tmr_nacl,
 251         int tas,
 252         struct list_head *preempt_and_abort_list)
 253 {
 254         LIST_HEAD(drain_task_list);
 255         struct se_cmd *cmd, *next;
 256         unsigned long flags;
 257         int fe_count;
 258
 259         /*
 260          * Complete outstanding commands with TASK_ABORTED SAM status.
 261          *
 262          * This is following sam4r17, section 5.6 Aborting commands, Table 38
 263          * for TMR LUN_RESET:
 264          *
 265          * a) "Yes" indicates that each command that is aborted on an I_T nexus
 266          * other than the one that caused the SCSI device condition is
 267          * completed with TASK ABORTED status, if the TAS bit is set to one in
 268          * the Control mode page (see SPC-4). "No" indicates that no status is
 269          * returned for aborted commands.
 270          *
 271          * d) If the logical unit reset is caused by a particular I_T nexus
 272          * (e.g., by a LOGICAL UNIT RESET task management function), then "yes"
 273          * (TASK_ABORTED status) applies.
 274          *
 275          * Otherwise (e.g., if triggered by a hard reset), "no"
 276          * (no TASK_ABORTED SAM status) applies.
 277          *
 278          * Note that this seems to be independent of TAS (Task Aborted Status)
 279          * in the Control Mode Page.
 280          */
 281         spin_lock_irqsave(&dev->execute_task_lock, flags);
 282         list_for_each_entry_safe(cmd, next, &dev->state_list, state_list) {
 283                 /*
 284                  * For PREEMPT_AND_ABORT usage, only process commands
 285                  * with a matching reservation key.
 286                  */
 287                 if (target_check_cdb_and_preempt(preempt_and_abort_list, cmd))
 288                         continue;
 289
 290                 /*
 291                  * Not aborting PROUT PREEMPT_AND_ABORT CDB..
 292                  */
 293                 if (prout_cmd == cmd)
 294                         continue;
 295
 296                 list_move_tail(&cmd->state_list, &drain_task_list);
 297                 cmd->state_active = false;
 298         }
 299         spin_unlock_irqrestore(&dev->execute_task_lock, flags);
 300
 301         while (!list_empty(&drain_task_list)) {
 302                 cmd = list_entry(drain_task_list.next, struct se_cmd, state_list);
 303                 list_del(&cmd->state_list);
 304
 305                 pr_debug("LUN_RESET: %s cmd: %p"
 306                         " ITT/CmdSN: 0x%08x/0x%08x, i_state: %d, t_state: %d"
 307                         "cdb: 0x%02x\n",
 308                         (preempt_and_abort_list) ? "Preempt" : "", cmd,
 309                         cmd->se_tfo->get_task_tag(cmd), 0,
 310                         cmd->se_tfo->get_cmd_state(cmd), cmd->t_state,
 311                         cmd->t_task_cdb[0]);
 312                 pr_debug("LUN_RESET: ITT[0x%08x] - pr_res_key: 0x%016Lx"
 313                         " -- CMD_T_ACTIVE: %d"
 314                         " CMD_T_STOP: %d CMD_T_SENT: %d\n",
 315                         cmd->se_tfo->get_task_tag(cmd), cmd->pr_res_key,
 316                         (cmd->transport_state & CMD_T_ACTIVE) != 0,
 317                         (cmd->transport_state & CMD_T_STOP) != 0,
 318                         (cmd->transport_state & CMD_T_SENT) != 0);
 319
 320                 /*
 321                  * If the command may be queued onto a workqueue cancel it now.
 322                  *
 323                  * This is equivalent to removal from the execute queue in the
 324                  * loop above, but we do it down here given that
 325                  * cancel_work_sync may block.
 326                  */
 327                 if (cmd->t_state == TRANSPORT_COMPLETE)
 328                         cancel_work_sync(&cmd->work);
 329
 330                 spin_lock_irqsave(&cmd->t_state_lock, flags);
 331                 target_stop_cmd(cmd, &flags);
 332
 333                 fe_count = atomic_read(&cmd->t_fe_count);
 334
 335                 if (!(cmd->transport_state & CMD_T_ACTIVE)) {
 336                         pr_debug("LUN_RESET: got CMD_T_ACTIVE for"
 337                                 " cdb: %p, t_fe_count: %d dev: %p\n", cmd,
 338                                 fe_count, dev);
 339                         cmd->transport_state |= CMD_T_ABORTED;
 340                         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 341
 342                         core_tmr_handle_tas_abort(tmr_nacl, cmd, tas, fe_count);
 343                         continue;
 344                 }
 345                 pr_debug("LUN_RESET: Got !CMD_T_ACTIVE for cdb: %p,"
 346                         " t_fe_count: %d dev: %p\n", cmd, fe_count, dev);
 347                 cmd->transport_state |= CMD_T_ABORTED;
 348                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 349
 350                 core_tmr_handle_tas_abort(tmr_nacl, cmd, tas, fe_count);
 351         }
 352 }
 353
 354 int core_tmr_lun_reset(
 355         struct se_device *dev,
 356         struct se_tmr_req *tmr,
 357         struct list_head *preempt_and_abort_list,
 358         struct se_cmd *prout_cmd)
 359 {
 360         struct se_node_acl *tmr_nacl = NULL;
 361         struct se_portal_group *tmr_tpg = NULL;
 362         int tas;
 363         /*
 364          * TASK_ABORTED status bit, this is configurable via ConfigFS
 365          * struct se_device attributes.  spc4r17 section 7.4.6 Control mode page
 366          *
 367          * A task aborted status (TAS) bit set to zero specifies that aborted
 368          * tasks shall be terminated by the device server without any response
 369          * to the application client. A TAS bit set to one specifies that tasks
 370          * aborted by the actions of an I_T nexus other than the I_T nexus on
 371          * which the command was received shall be completed with TASK ABORTED
 372          * status (see SAM-4).
 373          */
 374         tas = dev->se_sub_dev->se_dev_attrib.emulate_tas;
 375         /*
 376          * Determine if this se_tmr is coming from a $FABRIC_MOD
 377          * or struct se_device passthrough..
 378          */
 379         if (tmr && tmr->task_cmd && tmr->task_cmd->se_sess) {
 380                 tmr_nacl = tmr->task_cmd->se_sess->se_node_acl;
 381                 tmr_tpg = tmr->task_cmd->se_sess->se_tpg;
 382                 if (tmr_nacl && tmr_tpg) {
 383                         pr_debug("LUN_RESET: TMR caller fabric: %s"
 384                                 " initiator port %s\n",
 385                                 tmr_tpg->se_tpg_tfo->get_fabric_name(),
 386                                 tmr_nacl->initiatorname);
 387                 }
 388         }
 389         pr_debug("LUN_RESET: %s starting for [%s], tas: %d\n",
 390                 (preempt_and_abort_list) ? "Preempt" : "TMR",
 391                 dev->transport->name, tas);
 392
 393         core_tmr_drain_tmr_list(dev, tmr, preempt_and_abort_list);
 394         core_tmr_drain_state_list(dev, prout_cmd, tmr_nacl, tas,
 395                                 preempt_and_abort_list);
 396
 397         /*
 398          * Clear any legacy SPC-2 reservation when called during
 399          * LOGICAL UNIT RESET
 400          */
 401         if (!preempt_and_abort_list &&
 402              (dev->dev_flags & DF_SPC2_RESERVATIONS)) {
 403                 spin_lock(&dev->dev_reservation_lock);
 404                 dev->dev_reserved_node_acl = NULL;
 405                 dev->dev_flags &= ~DF_SPC2_RESERVATIONS;
 406                 spin_unlock(&dev->dev_reservation_lock);
 407                 pr_debug("LUN_RESET: SCSI-2 Released reservation\n");
 408         }
 409
 410         spin_lock_irq(&dev->stats_lock);
 411         dev->num_resets++;
 412         spin_unlock_irq(&dev->stats_lock);
 413
 414         pr_debug("LUN_RESET: %s for [%s] Complete\n",
 415                         (preempt_and_abort_list) ? "Preempt" : "TMR",
 416                         dev->transport->name);
 417         return 0;
 418 }
 419