drivers/target/target_core_ua.c

   1 /*******************************************************************************
   2  * Filename: target_core_ua.c
   3  *
   4  * This file contains logic for SPC-3 Unit Attention emulation
   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 <scsi/scsi.h>
  30 #include <scsi/scsi_cmnd.h>
  31
  32 #include <target/target_core_base.h>
  33 #include <target/target_core_fabric.h>
  34 #include <target/target_core_configfs.h>
  35
  36 #include "target_core_internal.h"
  37 #include "target_core_alua.h"
  38 #include "target_core_pr.h"
  39 #include "target_core_ua.h"
  40
  41 sense_reason_t
  42 target_scsi3_ua_check(struct se_cmd *cmd)
  43 {
  44         struct se_dev_entry *deve;
  45         struct se_session *sess = cmd->se_sess;
  46         struct se_node_acl *nacl;
  47
  48         if (!sess)
  49                 return 0;
  50
  51         nacl = sess->se_node_acl;
  52         if (!nacl)
  53                 return 0;
  54
  55         deve = nacl->device_list[cmd->orig_fe_lun];
  56         if (!atomic_read(&deve->ua_count))
  57                 return 0;
  58         /*
  59          * From sam4r14, section 5.14 Unit attention condition:
  60          *
  61          * a) if an INQUIRY command enters the enabled command state, the
  62          *    device server shall process the INQUIRY command and shall neither
  63          *    report nor clear any unit attention condition;
  64          * b) if a REPORT LUNS command enters the enabled command state, the
  65          *    device server shall process the REPORT LUNS command and shall not
  66          *    report any unit attention condition;
  67          * e) if a REQUEST SENSE command enters the enabled command state while
  68          *    a unit attention condition exists for the SCSI initiator port
  69          *    associated with the I_T nexus on which the REQUEST SENSE command
  70          *    was received, then the device server shall process the command
  71          *    and either:
  72          */
  73         switch (cmd->t_task_cdb[0]) {
  74         case INQUIRY:
  75         case REPORT_LUNS:
  76         case REQUEST_SENSE:
  77                 return 0;
  78         default:
  79                 return TCM_CHECK_CONDITION_UNIT_ATTENTION;
  80         }
  81 }
  82
  83 int core_scsi3_ua_allocate(
  84         struct se_node_acl *nacl,
  85         u32 unpacked_lun,
  86         u8 asc,
  87         u8 ascq)
  88 {
  89         struct se_dev_entry *deve;
  90         struct se_ua *ua, *ua_p, *ua_tmp;
  91         /*
  92          * PASSTHROUGH OPS
  93          */
  94         if (!nacl)
  95                 return -EINVAL;
  96
  97         ua = kmem_cache_zalloc(se_ua_cache, GFP_ATOMIC);
  98         if (!ua) {
  99                 pr_err("Unable to allocate struct se_ua\n");
 100                 return -ENOMEM;
 101         }
 102         INIT_LIST_HEAD(&ua->ua_dev_list);
 103         INIT_LIST_HEAD(&ua->ua_nacl_list);
 104
 105         ua->ua_nacl = nacl;
 106         ua->ua_asc = asc;
 107         ua->ua_ascq = ascq;
 108
 109         spin_lock_irq(&nacl->device_list_lock);
 110         deve = nacl->device_list[unpacked_lun];
 111
 112         spin_lock(&deve->ua_lock);
 113         list_for_each_entry_safe(ua_p, ua_tmp, &deve->ua_list, ua_nacl_list) {
 114                 /*
 115                  * Do not report the same UNIT ATTENTION twice..
 116                  */
 117                 if ((ua_p->ua_asc == asc) && (ua_p->ua_ascq == ascq)) {
 118                         spin_unlock(&deve->ua_lock);
 119                         spin_unlock_irq(&nacl->device_list_lock);
 120                         kmem_cache_free(se_ua_cache, ua);
 121                         return 0;
 122                 }
 123                 /*
 124                  * Attach the highest priority Unit Attention to
 125                  * the head of the list following sam4r14,
 126                  * Section 5.14 Unit Attention Condition:
 127                  *
 128                  * POWER ON, RESET, OR BUS DEVICE RESET OCCURRED highest
 129                  * POWER ON OCCURRED or
 130                  * DEVICE INTERNAL RESET
 131                  * SCSI BUS RESET OCCURRED or
 132                  * MICROCODE HAS BEEN CHANGED or
 133                  * protocol specific
 134                  * BUS DEVICE RESET FUNCTION OCCURRED
 135                  * I_T NEXUS LOSS OCCURRED
 136                  * COMMANDS CLEARED BY POWER LOSS NOTIFICATION
 137                  * all others                                    Lowest
 138                  *
 139                  * Each of the ASCQ codes listed above are defined in
 140                  * the 29h ASC family, see spc4r17 Table D.1
 141                  */
 142                 if (ua_p->ua_asc == 0x29) {
 143                         if ((asc == 0x29) && (ascq > ua_p->ua_ascq))
 144                                 list_add(&ua->ua_nacl_list,
 145                                                 &deve->ua_list);
 146                         else
 147                                 list_add_tail(&ua->ua_nacl_list,
 148                                                 &deve->ua_list);
 149                 } else if (ua_p->ua_asc == 0x2a) {
 150                         /*
 151                          * Incoming Family 29h ASCQ codes will override
 152                          * Family 2AHh ASCQ codes for Unit Attention condition.
 153                          */
 154                         if ((asc == 0x29) || (ascq > ua_p->ua_asc))
 155                                 list_add(&ua->ua_nacl_list,
 156                                         &deve->ua_list);
 157                         else
 158                                 list_add_tail(&ua->ua_nacl_list,
 159                                                 &deve->ua_list);
 160                 } else
 161                         list_add_tail(&ua->ua_nacl_list,
 162                                 &deve->ua_list);
 163                 spin_unlock(&deve->ua_lock);
 164                 spin_unlock_irq(&nacl->device_list_lock);
 165
 166                 atomic_inc(&deve->ua_count);
 167                 smp_mb__after_atomic_inc();
 168                 return 0;
 169         }
 170         list_add_tail(&ua->ua_nacl_list, &deve->ua_list);
 171         spin_unlock(&deve->ua_lock);
 172         spin_unlock_irq(&nacl->device_list_lock);
 173
 174         pr_debug("[%s]: Allocated UNIT ATTENTION, mapped LUN: %u, ASC:"
 175                 " 0x%02x, ASCQ: 0x%02x\n",
 176                 nacl->se_tpg->se_tpg_tfo->get_fabric_name(), unpacked_lun,
 177                 asc, ascq);
 178
 179         atomic_inc(&deve->ua_count);
 180         smp_mb__after_atomic_inc();
 181         return 0;
 182 }
 183
 184 void core_scsi3_ua_release_all(
 185         struct se_dev_entry *deve)
 186 {
 187         struct se_ua *ua, *ua_p;
 188
 189         spin_lock(&deve->ua_lock);
 190         list_for_each_entry_safe(ua, ua_p, &deve->ua_list, ua_nacl_list) {
 191                 list_del(&ua->ua_nacl_list);
 192                 kmem_cache_free(se_ua_cache, ua);
 193
 194                 atomic_dec(&deve->ua_count);
 195                 smp_mb__after_atomic_dec();
 196         }
 197         spin_unlock(&deve->ua_lock);
 198 }
 199
 200 void core_scsi3_ua_for_check_condition(
 201         struct se_cmd *cmd,
 202         u8 *asc,
 203         u8 *ascq)
 204 {
 205         struct se_device *dev = cmd->se_dev;
 206         struct se_dev_entry *deve;
 207         struct se_session *sess = cmd->se_sess;
 208         struct se_node_acl *nacl;
 209         struct se_ua *ua = NULL, *ua_p;
 210         int head = 1;
 211
 212         if (!sess)
 213                 return;
 214
 215         nacl = sess->se_node_acl;
 216         if (!nacl)
 217                 return;
 218
 219         spin_lock_irq(&nacl->device_list_lock);
 220         deve = nacl->device_list[cmd->orig_fe_lun];
 221         if (!atomic_read(&deve->ua_count)) {
 222                 spin_unlock_irq(&nacl->device_list_lock);
 223                 return;
 224         }
 225         /*
 226          * The highest priority Unit Attentions are placed at the head of the
 227          * struct se_dev_entry->ua_list, and will be returned in CHECK_CONDITION +
 228          * sense data for the received CDB.
 229          */
 230         spin_lock(&deve->ua_lock);
 231         list_for_each_entry_safe(ua, ua_p, &deve->ua_list, ua_nacl_list) {
 232                 /*
 233                  * For ua_intlck_ctrl code not equal to 00b, only report the
 234                  * highest priority UNIT_ATTENTION and ASC/ASCQ without
 235                  * clearing it.
 236                  */
 237                 if (dev->dev_attrib.emulate_ua_intlck_ctrl != 0) {
 238                         *asc = ua->ua_asc;
 239                         *ascq = ua->ua_ascq;
 240                         break;
 241                 }
 242                 /*
 243                  * Otherwise for the default 00b, release the UNIT ATTENTION
 244                  * condition.  Return the ASC/ASCQ of the highest priority UA
 245                  * (head of the list) in the outgoing CHECK_CONDITION + sense.
 246                  */
 247                 if (head) {
 248                         *asc = ua->ua_asc;
 249                         *ascq = ua->ua_ascq;
 250                         head = 0;
 251                 }
 252                 list_del(&ua->ua_nacl_list);
 253                 kmem_cache_free(se_ua_cache, ua);
 254
 255                 atomic_dec(&deve->ua_count);
 256                 smp_mb__after_atomic_dec();
 257         }
 258         spin_unlock(&deve->ua_lock);
 259         spin_unlock_irq(&nacl->device_list_lock);
 260
 261         pr_debug("[%s]: %s UNIT ATTENTION condition with"
 262                 " INTLCK_CTRL: %d, mapped LUN: %u, got CDB: 0x%02x"
 263                 " reported ASC: 0x%02x, ASCQ: 0x%02x\n",
 264                 nacl->se_tpg->se_tpg_tfo->get_fabric_name(),
 265                 (dev->dev_attrib.emulate_ua_intlck_ctrl != 0) ? "Reporting" :
 266                 "Releasing", dev->dev_attrib.emulate_ua_intlck_ctrl,
 267                 cmd->orig_fe_lun, cmd->t_task_cdb[0], *asc, *ascq);
 268 }
 269
 270 int core_scsi3_ua_clear_for_request_sense(
 271         struct se_cmd *cmd,
 272         u8 *asc,
 273         u8 *ascq)
 274 {
 275         struct se_dev_entry *deve;
 276         struct se_session *sess = cmd->se_sess;
 277         struct se_node_acl *nacl;
 278         struct se_ua *ua = NULL, *ua_p;
 279         int head = 1;
 280
 281         if (!sess)
 282                 return -EINVAL;
 283
 284         nacl = sess->se_node_acl;
 285         if (!nacl)
 286                 return -EINVAL;
 287
 288         spin_lock_irq(&nacl->device_list_lock);
 289         deve = nacl->device_list[cmd->orig_fe_lun];
 290         if (!atomic_read(&deve->ua_count)) {
 291                 spin_unlock_irq(&nacl->device_list_lock);
 292                 return -EPERM;
 293         }
 294         /*
 295          * The highest priority Unit Attentions are placed at the head of the
 296          * struct se_dev_entry->ua_list.  The First (and hence highest priority)
 297          * ASC/ASCQ will be returned in REQUEST_SENSE payload data for the
 298          * matching struct se_lun.
 299          *
 300          * Once the returning ASC/ASCQ values are set, we go ahead and
 301          * release all of the Unit Attention conditions for the associated
 302          * struct se_lun.
 303          */
 304         spin_lock(&deve->ua_lock);
 305         list_for_each_entry_safe(ua, ua_p, &deve->ua_list, ua_nacl_list) {
 306                 if (head) {
 307                         *asc = ua->ua_asc;
 308                         *ascq = ua->ua_ascq;
 309                         head = 0;
 310                 }
 311                 list_del(&ua->ua_nacl_list);
 312                 kmem_cache_free(se_ua_cache, ua);
 313
 314                 atomic_dec(&deve->ua_count);
 315                 smp_mb__after_atomic_dec();
 316         }
 317         spin_unlock(&deve->ua_lock);
 318         spin_unlock_irq(&nacl->device_list_lock);
 319
 320         pr_debug("[%s]: Released UNIT ATTENTION condition, mapped"
 321                 " LUN: %u, got REQUEST_SENSE reported ASC: 0x%02x,"
 322                 " ASCQ: 0x%02x\n", nacl->se_tpg->se_tpg_tfo->get_fabric_name(),
 323                 cmd->orig_fe_lun, *asc, *ascq);
 324
 325         return (head) ? -EPERM : 0;
 326 }