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_device.h>
  34 #include <target/target_core_transport.h>
  35 #include <target/target_core_fabric_ops.h>
  36 #include <target/target_core_configfs.h>
  37
  38 #include "target_core_internal.h"
  39 #include "target_core_alua.h"
  40 #include "target_core_pr.h"
  41 #include "target_core_ua.h"
  42
  43 int core_scsi3_ua_check(
  44         struct se_cmd *cmd,
  45         unsigned char *cdb)
  46 {
  47         struct se_dev_entry *deve;
  48         struct se_session *sess = cmd->se_sess;
  49         struct se_node_acl *nacl;
  50
  51         if (!sess)
  52                 return 0;
  53
  54         nacl = sess->se_node_acl;
  55         if (!nacl)
  56                 return 0;
  57
  58         deve = &nacl->device_list[cmd->orig_fe_lun];
  59         if (!atomic_read(&deve->ua_count))
  60                 return 0;
  61         /*
  62          * From sam4r14, section 5.14 Unit attention condition:
  63          *
  64          * a) if an INQUIRY command enters the enabled command state, the
  65          *    device server shall process the INQUIRY command and shall neither
  66          *    report nor clear any unit attention condition;
  67          * b) if a REPORT LUNS command enters the enabled command state, the
  68          *    device server shall process the REPORT LUNS command and shall not
  69          *    report any unit attention condition;
  70          * e) if a REQUEST SENSE command enters the enabled command state while
  71          *    a unit attention condition exists for the SCSI initiator port
  72          *    associated with the I_T nexus on which the REQUEST SENSE command
  73          *    was received, then the device server shall process the command
  74          *    and either:
  75          */
  76         switch (cdb[0]) {
  77         case INQUIRY:
  78         case REPORT_LUNS:
  79         case REQUEST_SENSE:
  80                 return 0;
  81         default:
  82                 return -EINVAL;
  83         }
  84
  85         return -EINVAL;
  86 }
  87
  88 int core_scsi3_ua_allocate(
  89         struct se_node_acl *nacl,
  90         u32 unpacked_lun,
  91         u8 asc,
  92         u8 ascq)
  93 {
  94         struct se_dev_entry *deve;
  95         struct se_ua *ua, *ua_p, *ua_tmp;
  96         /*
  97          * PASSTHROUGH OPS
  98          */
  99         if (!nacl)
 100                 return -EINVAL;
 101
 102         ua = kmem_cache_zalloc(se_ua_cache, GFP_ATOMIC);
 103         if (!ua) {
 104                 pr_err("Unable to allocate struct se_ua\n");
 105                 return -ENOMEM;
 106         }
 107         INIT_LIST_HEAD(&ua->ua_dev_list);
 108         INIT_LIST_HEAD(&ua->ua_nacl_list);
 109
 110         ua->ua_nacl = nacl;
 111         ua->ua_asc = asc;
 112         ua->ua_ascq = ascq;
 113
 114         spin_lock_irq(&nacl->device_list_lock);
 115         deve = &nacl->device_list[unpacked_lun];
 116
 117         spin_lock(&deve->ua_lock);
 118         list_for_each_entry_safe(ua_p, ua_tmp, &deve->ua_list, ua_nacl_list) {
 119                 /*
 120                  * Do not report the same UNIT ATTENTION twice..
 121                  */
 122                 if ((ua_p->ua_asc == asc) && (ua_p->ua_ascq == ascq)) {
 123                         spin_unlock(&deve->ua_lock);
 124                         spin_unlock_irq(&nacl->device_list_lock);
 125                         kmem_cache_free(se_ua_cache, ua);
 126                         return 0;
 127                 }
 128                 /*
 129                  * Attach the highest priority Unit Attention to
 130                  * the head of the list following sam4r14,
 131                  * Section 5.14 Unit Attention Condition:
 132                  *
 133                  * POWER ON, RESET, OR BUS DEVICE RESET OCCURRED highest
 134                  * POWER ON OCCURRED or
 135                  * DEVICE INTERNAL RESET
 136                  * SCSI BUS RESET OCCURRED or
 137                  * MICROCODE HAS BEEN CHANGED or
 138                  * protocol specific
 139                  * BUS DEVICE RESET FUNCTION OCCURRED
 140                  * I_T NEXUS LOSS OCCURRED
 141                  * COMMANDS CLEARED BY POWER LOSS NOTIFICATION
 142                  * all others                                    Lowest
 143                  *
 144                  * Each of the ASCQ codes listed above are defined in
 145                  * the 29h ASC family, see spc4r17 Table D.1
 146                  */
 147                 if (ua_p->ua_asc == 0x29) {
 148                         if ((asc == 0x29) && (ascq > ua_p->ua_ascq))
 149                                 list_add(&ua->ua_nacl_list,
 150                                                 &deve->ua_list);
 151                         else
 152                                 list_add_tail(&ua->ua_nacl_list,
 153                                                 &deve->ua_list);
 154                 } else if (ua_p->ua_asc == 0x2a) {
 155                         /*
 156                          * Incoming Family 29h ASCQ codes will override
 157                          * Family 2AHh ASCQ codes for Unit Attention condition.
 158                          */
 159                         if ((asc == 0x29) || (ascq > ua_p->ua_asc))
 160                                 list_add(&ua->ua_nacl_list,
 161                                         &deve->ua_list);
 162                         else
 163                                 list_add_tail(&ua->ua_nacl_list,
 164                                                 &deve->ua_list);
 165                 } else
 166                         list_add_tail(&ua->ua_nacl_list,
 167                                 &deve->ua_list);
 168                 spin_unlock(&deve->ua_lock);
 169                 spin_unlock_irq(&nacl->device_list_lock);
 170
 171                 atomic_inc(&deve->ua_count);
 172                 smp_mb__after_atomic_inc();
 173                 return 0;
 174         }
 175         list_add_tail(&ua->ua_nacl_list, &deve->ua_list);
 176         spin_unlock(&deve->ua_lock);
 177         spin_unlock_irq(&nacl->device_list_lock);
 178
 179         pr_debug("[%s]: Allocated UNIT ATTENTION, mapped LUN: %u, ASC:"
 180                 " 0x%02x, ASCQ: 0x%02x\n",
 181                 nacl->se_tpg->se_tpg_tfo->get_fabric_name(), unpacked_lun,
 182                 asc, ascq);
 183
 184         atomic_inc(&deve->ua_count);
 185         smp_mb__after_atomic_inc();
 186         return 0;
 187 }
 188
 189 void core_scsi3_ua_release_all(
 190         struct se_dev_entry *deve)
 191 {
 192         struct se_ua *ua, *ua_p;
 193
 194         spin_lock(&deve->ua_lock);
 195         list_for_each_entry_safe(ua, ua_p, &deve->ua_list, ua_nacl_list) {
 196                 list_del(&ua->ua_nacl_list);
 197                 kmem_cache_free(se_ua_cache, ua);
 198
 199                 atomic_dec(&deve->ua_count);
 200                 smp_mb__after_atomic_dec();
 201         }
 202         spin_unlock(&deve->ua_lock);
 203 }
 204
 205 void core_scsi3_ua_for_check_condition(
 206         struct se_cmd *cmd,
 207         u8 *asc,
 208         u8 *ascq)
 209 {
 210         struct se_device *dev = cmd->se_dev;
 211         struct se_dev_entry *deve;
 212         struct se_session *sess = cmd->se_sess;
 213         struct se_node_acl *nacl;
 214         struct se_ua *ua = NULL, *ua_p;
 215         int head = 1;
 216
 217         if (!sess)
 218                 return;
 219
 220         nacl = sess->se_node_acl;
 221         if (!nacl)
 222                 return;
 223
 224         spin_lock_irq(&nacl->device_list_lock);
 225         deve = &nacl->device_list[cmd->orig_fe_lun];
 226         if (!atomic_read(&deve->ua_count)) {
 227                 spin_unlock_irq(&nacl->device_list_lock);
 228                 return;
 229         }
 230         /*
 231          * The highest priority Unit Attentions are placed at the head of the
 232          * struct se_dev_entry->ua_list, and will be returned in CHECK_CONDITION +
 233          * sense data for the received CDB.
 234          */
 235         spin_lock(&deve->ua_lock);
 236         list_for_each_entry_safe(ua, ua_p, &deve->ua_list, ua_nacl_list) {
 237                 /*
 238                  * For ua_intlck_ctrl code not equal to 00b, only report the
 239                  * highest priority UNIT_ATTENTION and ASC/ASCQ without
 240                  * clearing it.
 241                  */
 242                 if (dev->se_sub_dev->se_dev_attrib.emulate_ua_intlck_ctrl != 0) {
 243                         *asc = ua->ua_asc;
 244                         *ascq = ua->ua_ascq;
 245                         break;
 246                 }
 247                 /*
 248                  * Otherwise for the default 00b, release the UNIT ATTENTION
 249                  * condition.  Return the ASC/ASCQ of the highest priority UA
 250                  * (head of the list) in the outgoing CHECK_CONDITION + sense.
 251                  */
 252                 if (head) {
 253                         *asc = ua->ua_asc;
 254                         *ascq = ua->ua_ascq;
 255                         head = 0;
 256                 }
 257                 list_del(&ua->ua_nacl_list);
 258                 kmem_cache_free(se_ua_cache, ua);
 259
 260                 atomic_dec(&deve->ua_count);
 261                 smp_mb__after_atomic_dec();
 262         }
 263         spin_unlock(&deve->ua_lock);
 264         spin_unlock_irq(&nacl->device_list_lock);
 265
 266         pr_debug("[%s]: %s UNIT ATTENTION condition with"
 267                 " INTLCK_CTRL: %d, mapped LUN: %u, got CDB: 0x%02x"
 268                 " reported ASC: 0x%02x, ASCQ: 0x%02x\n",
 269                 nacl->se_tpg->se_tpg_tfo->get_fabric_name(),
 270                 (dev->se_sub_dev->se_dev_attrib.emulate_ua_intlck_ctrl != 0) ? "Reporting" :
 271                 "Releasing", dev->se_sub_dev->se_dev_attrib.emulate_ua_intlck_ctrl,
 272                 cmd->orig_fe_lun, cmd->t_task_cdb[0], *asc, *ascq);
 273 }
 274
 275 int core_scsi3_ua_clear_for_request_sense(
 276         struct se_cmd *cmd,
 277         u8 *asc,
 278         u8 *ascq)
 279 {
 280         struct se_dev_entry *deve;
 281         struct se_session *sess = cmd->se_sess;
 282         struct se_node_acl *nacl;
 283         struct se_ua *ua = NULL, *ua_p;
 284         int head = 1;
 285
 286         if (!sess)
 287                 return -EINVAL;
 288
 289         nacl = sess->se_node_acl;
 290         if (!nacl)
 291                 return -EINVAL;
 292
 293         spin_lock_irq(&nacl->device_list_lock);
 294         deve = &nacl->device_list[cmd->orig_fe_lun];
 295         if (!atomic_read(&deve->ua_count)) {
 296                 spin_unlock_irq(&nacl->device_list_lock);
 297                 return -EPERM;
 298         }
 299         /*
 300          * The highest priority Unit Attentions are placed at the head of the
 301          * struct se_dev_entry->ua_list.  The First (and hence highest priority)
 302          * ASC/ASCQ will be returned in REQUEST_SENSE payload data for the
 303          * matching struct se_lun.
 304          *
 305          * Once the returning ASC/ASCQ values are set, we go ahead and
 306          * release all of the Unit Attention conditions for the associated
 307          * struct se_lun.
 308          */
 309         spin_lock(&deve->ua_lock);
 310         list_for_each_entry_safe(ua, ua_p, &deve->ua_list, ua_nacl_list) {
 311                 if (head) {
 312                         *asc = ua->ua_asc;
 313                         *ascq = ua->ua_ascq;
 314                         head = 0;
 315                 }
 316                 list_del(&ua->ua_nacl_list);
 317                 kmem_cache_free(se_ua_cache, ua);
 318
 319                 atomic_dec(&deve->ua_count);
 320                 smp_mb__after_atomic_dec();
 321         }
 322         spin_unlock(&deve->ua_lock);
 323         spin_unlock_irq(&nacl->device_list_lock);
 324
 325         pr_debug("[%s]: Released UNIT ATTENTION condition, mapped"
 326                 " LUN: %u, got REQUEST_SENSE reported ASC: 0x%02x,"
 327                 " ASCQ: 0x%02x\n", nacl->se_tpg->se_tpg_tfo->get_fabric_name(),
 328                 cmd->orig_fe_lun, *asc, *ascq);
 329
 330         return (head) ? -EPERM : 0;
 331 }