LXR linux/drivers/target/target_core

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