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1// SPDX-License-Identifier: GPL-2.0-or-later2/*******************************************************************************3 * Filename: target_core_ua.c4 *5 * This file contains logic for SPC-3 Unit Attention emulation6 *7 * (c) Copyright 2009-2013 Datera, Inc.8 *9 * Nicholas A. Bellinger <nab@kernel.org>10 *11 ******************************************************************************/12 13#include <linux/slab.h>14#include <linux/spinlock.h>15#include <scsi/scsi_proto.h>16 17#include <target/target_core_base.h>18#include <target/target_core_fabric.h>19 20#include "target_core_internal.h"21#include "target_core_alua.h"22#include "target_core_pr.h"23#include "target_core_ua.h"24 25sense_reason_t26target_scsi3_ua_check(struct se_cmd *cmd)27{28 struct se_dev_entry *deve;29 struct se_session *sess = cmd->se_sess;30 struct se_node_acl *nacl;31 32 if (!sess)33 return 0;34 35 nacl = sess->se_node_acl;36 if (!nacl)37 return 0;38 39 rcu_read_lock();40 deve = target_nacl_find_deve(nacl, cmd->orig_fe_lun);41 if (!deve) {42 rcu_read_unlock();43 return 0;44 }45 if (list_empty_careful(&deve->ua_list)) {46 rcu_read_unlock();47 return 0;48 }49 rcu_read_unlock();50 /*51 * From sam4r14, section 5.14 Unit attention condition:52 *53 * a) if an INQUIRY command enters the enabled command state, the54 * device server shall process the INQUIRY command and shall neither55 * report nor clear any unit attention condition;56 * b) if a REPORT LUNS command enters the enabled command state, the57 * device server shall process the REPORT LUNS command and shall not58 * report any unit attention condition;59 * e) if a REQUEST SENSE command enters the enabled command state while60 * a unit attention condition exists for the SCSI initiator port61 * associated with the I_T nexus on which the REQUEST SENSE command62 * was received, then the device server shall process the command63 * and either:64 */65 switch (cmd->t_task_cdb[0]) {66 case INQUIRY:67 case REPORT_LUNS:68 case REQUEST_SENSE:69 return 0;70 default:71 return TCM_CHECK_CONDITION_UNIT_ATTENTION;72 }73}74 75int core_scsi3_ua_allocate(76 struct se_dev_entry *deve,77 u8 asc,78 u8 ascq)79{80 struct se_ua *ua, *ua_p, *ua_tmp;81 82 ua = kmem_cache_zalloc(se_ua_cache, GFP_ATOMIC);83 if (!ua) {84 pr_err("Unable to allocate struct se_ua\n");85 return -ENOMEM;86 }87 INIT_LIST_HEAD(&ua->ua_nacl_list);88 89 ua->ua_asc = asc;90 ua->ua_ascq = ascq;91 92 spin_lock(&deve->ua_lock);93 list_for_each_entry_safe(ua_p, ua_tmp, &deve->ua_list, ua_nacl_list) {94 /*95 * Do not report the same UNIT ATTENTION twice..96 */97 if ((ua_p->ua_asc == asc) && (ua_p->ua_ascq == ascq)) {98 spin_unlock(&deve->ua_lock);99 kmem_cache_free(se_ua_cache, ua);100 return 0;101 }102 /*103 * Attach the highest priority Unit Attention to104 * the head of the list following sam4r14,105 * Section 5.14 Unit Attention Condition:106 *107 * POWER ON, RESET, OR BUS DEVICE RESET OCCURRED highest108 * POWER ON OCCURRED or109 * DEVICE INTERNAL RESET110 * SCSI BUS RESET OCCURRED or111 * MICROCODE HAS BEEN CHANGED or112 * protocol specific113 * BUS DEVICE RESET FUNCTION OCCURRED114 * I_T NEXUS LOSS OCCURRED115 * COMMANDS CLEARED BY POWER LOSS NOTIFICATION116 * all others Lowest117 *118 * Each of the ASCQ codes listed above are defined in119 * the 29h ASC family, see spc4r17 Table D.1120 */121 if (ua_p->ua_asc == 0x29) {122 if ((asc == 0x29) && (ascq > ua_p->ua_ascq))123 list_add(&ua->ua_nacl_list,124 &deve->ua_list);125 else126 list_add_tail(&ua->ua_nacl_list,127 &deve->ua_list);128 } else if (ua_p->ua_asc == 0x2a) {129 /*130 * Incoming Family 29h ASCQ codes will override131 * Family 2AHh ASCQ codes for Unit Attention condition.132 */133 if ((asc == 0x29) || (ascq > ua_p->ua_asc))134 list_add(&ua->ua_nacl_list,135 &deve->ua_list);136 else137 list_add_tail(&ua->ua_nacl_list,138 &deve->ua_list);139 } else140 list_add_tail(&ua->ua_nacl_list,141 &deve->ua_list);142 spin_unlock(&deve->ua_lock);143 144 return 0;145 }146 list_add_tail(&ua->ua_nacl_list, &deve->ua_list);147 spin_unlock(&deve->ua_lock);148 149 pr_debug("Allocated UNIT ATTENTION, mapped LUN: %llu, ASC:"150 " 0x%02x, ASCQ: 0x%02x\n", deve->mapped_lun,151 asc, ascq);152 153 return 0;154}155 156void target_ua_allocate_lun(struct se_node_acl *nacl,157 u32 unpacked_lun, u8 asc, u8 ascq)158{159 struct se_dev_entry *deve;160 161 if (!nacl)162 return;163 164 rcu_read_lock();165 deve = target_nacl_find_deve(nacl, unpacked_lun);166 if (!deve) {167 rcu_read_unlock();168 return;169 }170 171 core_scsi3_ua_allocate(deve, asc, ascq);172 rcu_read_unlock();173}174 175void core_scsi3_ua_release_all(176 struct se_dev_entry *deve)177{178 struct se_ua *ua, *ua_p;179 180 spin_lock(&deve->ua_lock);181 list_for_each_entry_safe(ua, ua_p, &deve->ua_list, ua_nacl_list) {182 list_del(&ua->ua_nacl_list);183 kmem_cache_free(se_ua_cache, ua);184 }185 spin_unlock(&deve->ua_lock);186}187 188/*189 * Dequeue a unit attention from the unit attention list. This function190 * returns true if the dequeuing succeeded and if *@key, *@asc and *@ascq have191 * been set.192 */193bool core_scsi3_ua_for_check_condition(struct se_cmd *cmd, u8 *key, u8 *asc,194 u8 *ascq)195{196 struct se_device *dev = cmd->se_dev;197 struct se_dev_entry *deve;198 struct se_session *sess = cmd->se_sess;199 struct se_node_acl *nacl;200 struct se_ua *ua = NULL, *ua_p;201 int head = 1;202 bool dev_ua_intlck_clear = (dev->dev_attrib.emulate_ua_intlck_ctrl203 == TARGET_UA_INTLCK_CTRL_CLEAR);204 205 if (WARN_ON_ONCE(!sess))206 return false;207 208 nacl = sess->se_node_acl;209 if (WARN_ON_ONCE(!nacl))210 return false;211 212 rcu_read_lock();213 deve = target_nacl_find_deve(nacl, cmd->orig_fe_lun);214 if (!deve) {215 rcu_read_unlock();216 *key = ILLEGAL_REQUEST;217 *asc = 0x25; /* LOGICAL UNIT NOT SUPPORTED */218 *ascq = 0;219 return true;220 }221 *key = UNIT_ATTENTION;222 /*223 * The highest priority Unit Attentions are placed at the head of the224 * struct se_dev_entry->ua_list, and will be returned in CHECK_CONDITION +225 * sense data for the received CDB.226 */227 spin_lock(&deve->ua_lock);228 list_for_each_entry_safe(ua, ua_p, &deve->ua_list, ua_nacl_list) {229 /*230 * For ua_intlck_ctrl code not equal to 00b, only report the231 * highest priority UNIT_ATTENTION and ASC/ASCQ without232 * clearing it.233 */234 if (!dev_ua_intlck_clear) {235 *asc = ua->ua_asc;236 *ascq = ua->ua_ascq;237 break;238 }239 /*240 * Otherwise for the default 00b, release the UNIT ATTENTION241 * condition. Return the ASC/ASCQ of the highest priority UA242 * (head of the list) in the outgoing CHECK_CONDITION + sense.243 */244 if (head) {245 *asc = ua->ua_asc;246 *ascq = ua->ua_ascq;247 head = 0;248 }249 list_del(&ua->ua_nacl_list);250 kmem_cache_free(se_ua_cache, ua);251 }252 spin_unlock(&deve->ua_lock);253 rcu_read_unlock();254 255 pr_debug("[%s]: %s UNIT ATTENTION condition with"256 " INTLCK_CTRL: %d, mapped LUN: %llu, got CDB: 0x%02x"257 " reported ASC: 0x%02x, ASCQ: 0x%02x\n",258 nacl->se_tpg->se_tpg_tfo->fabric_name,259 dev_ua_intlck_clear ? "Releasing" : "Reporting",260 dev->dev_attrib.emulate_ua_intlck_ctrl,261 cmd->orig_fe_lun, cmd->t_task_cdb[0], *asc, *ascq);262 263 return head == 0;264}265 266int core_scsi3_ua_clear_for_request_sense(267 struct se_cmd *cmd,268 u8 *asc,269 u8 *ascq)270{271 struct se_dev_entry *deve;272 struct se_session *sess = cmd->se_sess;273 struct se_node_acl *nacl;274 struct se_ua *ua = NULL, *ua_p;275 int head = 1;276 277 if (!sess)278 return -EINVAL;279 280 nacl = sess->se_node_acl;281 if (!nacl)282 return -EINVAL;283 284 rcu_read_lock();285 deve = target_nacl_find_deve(nacl, cmd->orig_fe_lun);286 if (!deve) {287 rcu_read_unlock();288 return -EINVAL;289 }290 if (list_empty_careful(&deve->ua_list)) {291 rcu_read_unlock();292 return -EPERM;293 }294 /*295 * The highest priority Unit Attentions are placed at the head of the296 * struct se_dev_entry->ua_list. The First (and hence highest priority)297 * ASC/ASCQ will be returned in REQUEST_SENSE payload data for the298 * matching struct se_lun.299 *300 * Once the returning ASC/ASCQ values are set, we go ahead and301 * release all of the Unit Attention conditions for the associated302 * 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 spin_unlock(&deve->ua_lock);315 rcu_read_unlock();316 317 pr_debug("[%s]: Released UNIT ATTENTION condition, mapped"318 " LUN: %llu, got REQUEST_SENSE reported ASC: 0x%02x,"319 " ASCQ: 0x%02x\n", nacl->se_tpg->se_tpg_tfo->fabric_name,320 cmd->orig_fe_lun, *asc, *ascq);321 322 return (head) ? -EPERM : 0;323}324