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 } 319