target_core_ua.c revision 4e857c58efeb99393cba5a5d0d8ec7117183137c
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(&deve->ua_count); 165 smp_mb__after_atomic(); 166 return 0; 167 } 168 list_add_tail(&ua->ua_nacl_list, &deve->ua_list); 169 spin_unlock(&deve->ua_lock); 170 spin_unlock_irq(&nacl->device_list_lock); 171 172 pr_debug("[%s]: Allocated UNIT ATTENTION, mapped LUN: %u, ASC:" 173 " 0x%02x, ASCQ: 0x%02x\n", 174 nacl->se_tpg->se_tpg_tfo->get_fabric_name(), unpacked_lun, 175 asc, ascq); 176 177 atomic_inc(&deve->ua_count); 178 smp_mb__after_atomic(); 179 return 0; 180} 181 182void core_scsi3_ua_release_all( 183 struct se_dev_entry *deve) 184{ 185 struct se_ua *ua, *ua_p; 186 187 spin_lock(&deve->ua_lock); 188 list_for_each_entry_safe(ua, ua_p, &deve->ua_list, ua_nacl_list) { 189 list_del(&ua->ua_nacl_list); 190 kmem_cache_free(se_ua_cache, ua); 191 192 atomic_dec(&deve->ua_count); 193 smp_mb__after_atomic(); 194 } 195 spin_unlock(&deve->ua_lock); 196} 197 198void core_scsi3_ua_for_check_condition( 199 struct se_cmd *cmd, 200 u8 *asc, 201 u8 *ascq) 202{ 203 struct se_device *dev = cmd->se_dev; 204 struct se_dev_entry *deve; 205 struct se_session *sess = cmd->se_sess; 206 struct se_node_acl *nacl; 207 struct se_ua *ua = NULL, *ua_p; 208 int head = 1; 209 210 if (!sess) 211 return; 212 213 nacl = sess->se_node_acl; 214 if (!nacl) 215 return; 216 217 spin_lock_irq(&nacl->device_list_lock); 218 deve = nacl->device_list[cmd->orig_fe_lun]; 219 if (!atomic_read(&deve->ua_count)) { 220 spin_unlock_irq(&nacl->device_list_lock); 221 return; 222 } 223 /* 224 * The highest priority Unit Attentions are placed at the head of the 225 * struct se_dev_entry->ua_list, and will be returned in CHECK_CONDITION + 226 * sense data for the received CDB. 227 */ 228 spin_lock(&deve->ua_lock); 229 list_for_each_entry_safe(ua, ua_p, &deve->ua_list, ua_nacl_list) { 230 /* 231 * For ua_intlck_ctrl code not equal to 00b, only report the 232 * highest priority UNIT_ATTENTION and ASC/ASCQ without 233 * clearing it. 234 */ 235 if (dev->dev_attrib.emulate_ua_intlck_ctrl != 0) { 236 *asc = ua->ua_asc; 237 *ascq = ua->ua_ascq; 238 break; 239 } 240 /* 241 * Otherwise for the default 00b, release the UNIT ATTENTION 242 * condition. Return the ASC/ASCQ of the highest priority UA 243 * (head of the list) in the outgoing CHECK_CONDITION + sense. 244 */ 245 if (head) { 246 *asc = ua->ua_asc; 247 *ascq = ua->ua_ascq; 248 head = 0; 249 } 250 list_del(&ua->ua_nacl_list); 251 kmem_cache_free(se_ua_cache, ua); 252 253 atomic_dec(&deve->ua_count); 254 smp_mb__after_atomic(); 255 } 256 spin_unlock(&deve->ua_lock); 257 spin_unlock_irq(&nacl->device_list_lock); 258 259 pr_debug("[%s]: %s UNIT ATTENTION condition with" 260 " INTLCK_CTRL: %d, mapped LUN: %u, got CDB: 0x%02x" 261 " reported ASC: 0x%02x, ASCQ: 0x%02x\n", 262 nacl->se_tpg->se_tpg_tfo->get_fabric_name(), 263 (dev->dev_attrib.emulate_ua_intlck_ctrl != 0) ? "Reporting" : 264 "Releasing", dev->dev_attrib.emulate_ua_intlck_ctrl, 265 cmd->orig_fe_lun, cmd->t_task_cdb[0], *asc, *ascq); 266} 267 268int core_scsi3_ua_clear_for_request_sense( 269 struct se_cmd *cmd, 270 u8 *asc, 271 u8 *ascq) 272{ 273 struct se_dev_entry *deve; 274 struct se_session *sess = cmd->se_sess; 275 struct se_node_acl *nacl; 276 struct se_ua *ua = NULL, *ua_p; 277 int head = 1; 278 279 if (!sess) 280 return -EINVAL; 281 282 nacl = sess->se_node_acl; 283 if (!nacl) 284 return -EINVAL; 285 286 spin_lock_irq(&nacl->device_list_lock); 287 deve = nacl->device_list[cmd->orig_fe_lun]; 288 if (!atomic_read(&deve->ua_count)) { 289 spin_unlock_irq(&nacl->device_list_lock); 290 return -EPERM; 291 } 292 /* 293 * The highest priority Unit Attentions are placed at the head of the 294 * struct se_dev_entry->ua_list. The First (and hence highest priority) 295 * ASC/ASCQ will be returned in REQUEST_SENSE payload data for the 296 * matching struct se_lun. 297 * 298 * Once the returning ASC/ASCQ values are set, we go ahead and 299 * release all of the Unit Attention conditions for the associated 300 * struct se_lun. 301 */ 302 spin_lock(&deve->ua_lock); 303 list_for_each_entry_safe(ua, ua_p, &deve->ua_list, ua_nacl_list) { 304 if (head) { 305 *asc = ua->ua_asc; 306 *ascq = ua->ua_ascq; 307 head = 0; 308 } 309 list_del(&ua->ua_nacl_list); 310 kmem_cache_free(se_ua_cache, ua); 311 312 atomic_dec(&deve->ua_count); 313 smp_mb__after_atomic(); 314 } 315 spin_unlock(&deve->ua_lock); 316 spin_unlock_irq(&nacl->device_list_lock); 317 318 pr_debug("[%s]: Released UNIT ATTENTION condition, mapped" 319 " LUN: %u, got REQUEST_SENSE reported ASC: 0x%02x," 320 " ASCQ: 0x%02x\n", nacl->se_tpg->se_tpg_tfo->get_fabric_name(), 321 cmd->orig_fe_lun, *asc, *ascq); 322 323 return (head) ? -EPERM : 0; 324} 325