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  * (c) Copyright 2009-2013 Datera, Inc.
   7  *
   8  * Nicholas A. Bellinger <nab@kernel.org>
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  23  *
  24  ******************************************************************************/
  25
  26 #include <linux/slab.h>
  27 #include <linux/spinlock.h>
  28 #include <scsi/scsi_proto.h>
  29
  30 #include <target/target_core_base.h>
  31 #include <target/target_core_fabric.h>
  32 #include <target/target_core_configfs.h>
  33
  34 #include "target_core_internal.h"
  35 #include "target_core_alua.h"
  36 #include "target_core_pr.h"
  37 #include "target_core_ua.h"
  38
  39 sense_reason_t
  40 target_scsi3_ua_check(struct se_cmd *cmd)
  41 {
  42         struct se_dev_entry *deve;
  43         struct se_session *sess = cmd->se_sess;
  44         struct se_node_acl *nacl;
  45
  46         if (!sess)
  47                 return 0;
  48
  49         nacl = sess->se_node_acl;
  50         if (!nacl)
  51                 return 0;
  52
  53         deve = nacl->device_list[cmd->orig_fe_lun];
  54         if (!atomic_read(&deve->ua_count))
  55                 return 0;
  56         /*
  57          * From sam4r14, section 5.14 Unit attention condition:
  58          *
  59          * a) if an INQUIRY command enters the enabled command state, the
  60          *    device server shall process the INQUIRY command and shall neither
  61          *    report nor clear any unit attention condition;
  62          * b) if a REPORT LUNS command enters the enabled command state, the
  63          *    device server shall process the REPORT LUNS command and shall not
  64          *    report any unit attention condition;
  65          * e) if a REQUEST SENSE command enters the enabled command state while
  66          *    a unit attention condition exists for the SCSI initiator port
  67          *    associated with the I_T nexus on which the REQUEST SENSE command
  68          *    was received, then the device server shall process the command
  69          *    and either:
  70          */
  71         switch (cmd->t_task_cdb[0]) {
  72         case INQUIRY:
  73         case REPORT_LUNS:
  74         case REQUEST_SENSE:
  75                 return 0;
  76         default:
  77                 return TCM_CHECK_CONDITION_UNIT_ATTENTION;
  78         }
  79 }
  80
  81 int core_scsi3_ua_allocate(
  82         struct se_node_acl *nacl,
  83         u32 unpacked_lun,
  84         u8 asc,
  85         u8 ascq)
  86 {
  87         struct se_dev_entry *deve;
  88         struct se_ua *ua, *ua_p, *ua_tmp;
  89         /*
  90          * PASSTHROUGH OPS
  91          */
  92         if (!nacl)
  93                 return -EINVAL;
  94
  95         ua = kmem_cache_zalloc(se_ua_cache, GFP_ATOMIC);
  96         if (!ua) {
  97                 pr_err("Unable to allocate struct se_ua\n");
  98                 return -ENOMEM;
  99         }
 100         INIT_LIST_HEAD(&ua->ua_nacl_list);
 101
 102         ua->ua_nacl = nacl;
 103         ua->ua_asc = asc;
 104         ua->ua_ascq = ascq;
 105
 106         spin_lock_irq(&nacl->device_list_lock);
 107         deve = nacl->device_list[unpacked_lun];
 108
 109         spin_lock(&deve->ua_lock);
 110         list_for_each_entry_safe(ua_p, ua_tmp, &deve->ua_list, ua_nacl_list) {
 111                 /*
 112                  * Do not report the same UNIT ATTENTION twice..
 113                  */
 114                 if ((ua_p->ua_asc == asc) && (ua_p->ua_ascq == ascq)) {
 115                         spin_unlock(&deve->ua_lock);
 116                         spin_unlock_irq(&nacl->device_list_lock);
 117                         kmem_cache_free(se_ua_cache, ua);
 118                         return 0;
 119                 }
 120                 /*
 121                  * Attach the highest priority Unit Attention to
 122                  * the head of the list following sam4r14,
 123                  * Section 5.14 Unit Attention Condition:
 124                  *
 125                  * POWER ON, RESET, OR BUS DEVICE RESET OCCURRED highest
 126                  * POWER ON OCCURRED or
 127                  * DEVICE INTERNAL RESET
 128                  * SCSI BUS RESET OCCURRED or
 129                  * MICROCODE HAS BEEN CHANGED or
 130                  * protocol specific
 131                  * BUS DEVICE RESET FUNCTION OCCURRED
 132                  * I_T NEXUS LOSS OCCURRED
 133                  * COMMANDS CLEARED BY POWER LOSS NOTIFICATION
 134                  * all others                                    Lowest
 135                  *
 136                  * Each of the ASCQ codes listed above are defined in
 137                  * the 29h ASC family, see spc4r17 Table D.1
 138                  */
 139                 if (ua_p->ua_asc == 0x29) {
 140                         if ((asc == 0x29) && (ascq > ua_p->ua_ascq))
 141                                 list_add(&ua->ua_nacl_list,
 142                                                 &deve->ua_list);
 143                         else
 144                                 list_add_tail(&ua->ua_nacl_list,
 145                                                 &deve->ua_list);
 146                 } else if (ua_p->ua_asc == 0x2a) {
 147                         /*
 148                          * Incoming Family 29h ASCQ codes will override
 149                          * Family 2AHh ASCQ codes for Unit Attention condition.
 150                          */
 151                         if ((asc == 0x29) || (ascq > ua_p->ua_asc))
 152                                 list_add(&ua->ua_nacl_list,
 153                                         &deve->ua_list);
 154                         else
 155                                 list_add_tail(&ua->ua_nacl_list,
 156                                                 &deve->ua_list);
 157                 } else
 158                         list_add_tail(&ua->ua_nacl_list,
 159                                 &deve->ua_list);
 160                 spin_unlock(&deve->ua_lock);
 161                 spin_unlock_irq(&nacl->device_list_lock);
 162
 163                 atomic_inc_mb(&deve->ua_count);
 164                 return 0;
 165         }
 166         list_add_tail(&ua->ua_nacl_list, &deve->ua_list);
 167         spin_unlock(&deve->ua_lock);
 168         spin_unlock_irq(&nacl->device_list_lock);
 169
 170         pr_debug("[%s]: Allocated UNIT ATTENTION, mapped LUN: %u, ASC:"
 171                 " 0x%02x, ASCQ: 0x%02x\n",
 172                 nacl->se_tpg->se_tpg_tfo->get_fabric_name(), unpacked_lun,
 173                 asc, ascq);
 174
 175         atomic_inc_mb(&deve->ua_count);
 176         return 0;
 177 }
 178
 179 void core_scsi3_ua_release_all(
 180         struct se_dev_entry *deve)
 181 {
 182         struct se_ua *ua, *ua_p;
 183
 184         spin_lock(&deve->ua_lock);
 185         list_for_each_entry_safe(ua, ua_p, &deve->ua_list, ua_nacl_list) {
 186                 list_del(&ua->ua_nacl_list);
 187                 kmem_cache_free(se_ua_cache, ua);
 188
 189                 atomic_dec_mb(&deve->ua_count);
 190         }
 191         spin_unlock(&deve->ua_lock);
 192 }
 193
 194 void core_scsi3_ua_for_check_condition(
 195         struct se_cmd *cmd,
 196         u8 *asc,
 197         u8 *ascq)
 198 {
 199         struct se_device *dev = cmd->se_dev;
 200         struct se_dev_entry *deve;
 201         struct se_session *sess = cmd->se_sess;
 202         struct se_node_acl *nacl;
 203         struct se_ua *ua = NULL, *ua_p;
 204         int head = 1;
 205
 206         if (!sess)
 207                 return;
 208
 209         nacl = sess->se_node_acl;
 210         if (!nacl)
 211                 return;
 212
 213         spin_lock_irq(&nacl->device_list_lock);
 214         deve = nacl->device_list[cmd->orig_fe_lun];
 215         if (!atomic_read(&deve->ua_count)) {
 216                 spin_unlock_irq(&nacl->device_list_lock);
 217                 return;
 218         }
 219         /*
 220          * The highest priority Unit Attentions are placed at the head of the
 221          * struct se_dev_entry->ua_list, and will be returned in CHECK_CONDITION +
 222          * sense data for the received CDB.
 223          */
 224         spin_lock(&deve->ua_lock);
 225         list_for_each_entry_safe(ua, ua_p, &deve->ua_list, ua_nacl_list) {
 226                 /*
 227                  * For ua_intlck_ctrl code not equal to 00b, only report the
 228                  * highest priority UNIT_ATTENTION and ASC/ASCQ without
 229                  * clearing it.
 230                  */
 231                 if (dev->dev_attrib.emulate_ua_intlck_ctrl != 0) {
 232                         *asc = ua->ua_asc;
 233                         *ascq = ua->ua_ascq;
 234                         break;
 235                 }
 236                 /*
 237                  * Otherwise for the default 00b, release the UNIT ATTENTION
 238                  * condition.  Return the ASC/ASCQ of the highest priority UA
 239                  * (head of the list) in the outgoing CHECK_CONDITION + sense.
 240                  */
 241                 if (head) {
 242                         *asc = ua->ua_asc;
 243                         *ascq = ua->ua_ascq;
 244                         head = 0;
 245                 }
 246                 list_del(&ua->ua_nacl_list);
 247                 kmem_cache_free(se_ua_cache, ua);
 248
 249                 atomic_dec_mb(&deve->ua_count);
 250         }
 251         spin_unlock(&deve->ua_lock);
 252         spin_unlock_irq(&nacl->device_list_lock);
 253
 254         pr_debug("[%s]: %s UNIT ATTENTION condition with"
 255                 " INTLCK_CTRL: %d, mapped LUN: %u, got CDB: 0x%02x"
 256                 " reported ASC: 0x%02x, ASCQ: 0x%02x\n",
 257                 nacl->se_tpg->se_tpg_tfo->get_fabric_name(),
 258                 (dev->dev_attrib.emulate_ua_intlck_ctrl != 0) ? "Reporting" :
 259                 "Releasing", dev->dev_attrib.emulate_ua_intlck_ctrl,
 260                 cmd->orig_fe_lun, cmd->t_task_cdb[0], *asc, *ascq);
 261 }
 262
 263 int core_scsi3_ua_clear_for_request_sense(
 264         struct se_cmd *cmd,
 265         u8 *asc,
 266         u8 *ascq)
 267 {
 268         struct se_dev_entry *deve;
 269         struct se_session *sess = cmd->se_sess;
 270         struct se_node_acl *nacl;
 271         struct se_ua *ua = NULL, *ua_p;
 272         int head = 1;
 273
 274         if (!sess)
 275                 return -EINVAL;
 276
 277         nacl = sess->se_node_acl;
 278         if (!nacl)
 279                 return -EINVAL;
 280
 281         spin_lock_irq(&nacl->device_list_lock);
 282         deve = nacl->device_list[cmd->orig_fe_lun];
 283         if (!atomic_read(&deve->ua_count)) {
 284                 spin_unlock_irq(&nacl->device_list_lock);
 285                 return -EPERM;
 286         }
 287         /*
 288          * The highest priority Unit Attentions are placed at the head of the
 289          * struct se_dev_entry->ua_list.  The First (and hence highest priority)
 290          * ASC/ASCQ will be returned in REQUEST_SENSE payload data for the
 291          * matching struct se_lun.
 292          *
 293          * Once the returning ASC/ASCQ values are set, we go ahead and
 294          * release all of the Unit Attention conditions for the associated
 295          * struct se_lun.
 296          */
 297         spin_lock(&deve->ua_lock);
 298         list_for_each_entry_safe(ua, ua_p, &deve->ua_list, ua_nacl_list) {
 299                 if (head) {
 300                         *asc = ua->ua_asc;
 301                         *ascq = ua->ua_ascq;
 302                         head = 0;
 303                 }
 304                 list_del(&ua->ua_nacl_list);
 305                 kmem_cache_free(se_ua_cache, ua);
 306
 307                 atomic_dec_mb(&deve->ua_count);
 308         }
 309         spin_unlock(&deve->ua_lock);
 310         spin_unlock_irq(&nacl->device_list_lock);
 311
 312         pr_debug("[%s]: Released UNIT ATTENTION condition, mapped"
 313                 " LUN: %u, got REQUEST_SENSE reported ASC: 0x%02x,"
 314                 " ASCQ: 0x%02x\n", nacl->se_tpg->se_tpg_tfo->get_fabric_name(),
 315                 cmd->orig_fe_lun, *asc, *ascq);
 316
 317         return (head) ? -EPERM : 0;
 318 }