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 40 sense_reason_t 41 target_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 82 int 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 } 179 180 void 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 } 194 195 void 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 } 263 264 int 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