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 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 rcu_read_lock(); 54 deve = target_nacl_find_deve(nacl, cmd->orig_fe_lun); 55 if (!deve) { 56 rcu_read_unlock(); 57 return 0; 58 } 59 if (!atomic_read(&deve->ua_count)) { 60 rcu_read_unlock(); 61 return 0; 62 } 63 rcu_read_unlock(); 64 /* 65 * From sam4r14, section 5.14 Unit attention condition: 66 * 67 * a) if an INQUIRY command enters the enabled command state, the 68 * device server shall process the INQUIRY command and shall neither 69 * report nor clear any unit attention condition; 70 * b) if a REPORT LUNS command enters the enabled command state, the 71 * device server shall process the REPORT LUNS command and shall not 72 * report any unit attention condition; 73 * e) if a REQUEST SENSE command enters the enabled command state while 74 * a unit attention condition exists for the SCSI initiator port 75 * associated with the I_T nexus on which the REQUEST SENSE command 76 * was received, then the device server shall process the command 77 * and either: 78 */ 79 switch (cmd->t_task_cdb[0]) { 80 case INQUIRY: 81 case REPORT_LUNS: 82 case REQUEST_SENSE: 83 return 0; 84 default: 85 return TCM_CHECK_CONDITION_UNIT_ATTENTION; 86 } 87 } 88 89 int core_scsi3_ua_allocate( 90 struct se_node_acl *nacl, 91 u64 unpacked_lun, 92 u8 asc, 93 u8 ascq) 94 { 95 struct se_dev_entry *deve; 96 struct se_ua *ua, *ua_p, *ua_tmp; 97 /* 98 * PASSTHROUGH OPS 99 */ 100 if (!nacl) 101 return -EINVAL; 102 103 ua = kmem_cache_zalloc(se_ua_cache, GFP_ATOMIC); 104 if (!ua) { 105 pr_err("Unable to allocate struct se_ua\n"); 106 return -ENOMEM; 107 } 108 INIT_LIST_HEAD(&ua->ua_nacl_list); 109 110 ua->ua_asc = asc; 111 ua->ua_ascq = ascq; 112 113 rcu_read_lock(); 114 deve = target_nacl_find_deve(nacl, unpacked_lun); 115 if (!deve) { 116 rcu_read_unlock(); 117 return -EINVAL; 118 } 119 spin_lock(&deve->ua_lock); 120 list_for_each_entry_safe(ua_p, ua_tmp, &deve->ua_list, ua_nacl_list) { 121 /* 122 * Do not report the same UNIT ATTENTION twice.. 123 */ 124 if ((ua_p->ua_asc == asc) && (ua_p->ua_ascq == ascq)) { 125 spin_unlock(&deve->ua_lock); 126 rcu_read_unlock(); 127 kmem_cache_free(se_ua_cache, ua); 128 return 0; 129 } 130 /* 131 * Attach the highest priority Unit Attention to 132 * the head of the list following sam4r14, 133 * Section 5.14 Unit Attention Condition: 134 * 135 * POWER ON, RESET, OR BUS DEVICE RESET OCCURRED highest 136 * POWER ON OCCURRED or 137 * DEVICE INTERNAL RESET 138 * SCSI BUS RESET OCCURRED or 139 * MICROCODE HAS BEEN CHANGED or 140 * protocol specific 141 * BUS DEVICE RESET FUNCTION OCCURRED 142 * I_T NEXUS LOSS OCCURRED 143 * COMMANDS CLEARED BY POWER LOSS NOTIFICATION 144 * all others Lowest 145 * 146 * Each of the ASCQ codes listed above are defined in 147 * the 29h ASC family, see spc4r17 Table D.1 148 */ 149 if (ua_p->ua_asc == 0x29) { 150 if ((asc == 0x29) && (ascq > ua_p->ua_ascq)) 151 list_add(&ua->ua_nacl_list, 152 &deve->ua_list); 153 else 154 list_add_tail(&ua->ua_nacl_list, 155 &deve->ua_list); 156 } else if (ua_p->ua_asc == 0x2a) { 157 /* 158 * Incoming Family 29h ASCQ codes will override 159 * Family 2AHh ASCQ codes for Unit Attention condition. 160 */ 161 if ((asc == 0x29) || (ascq > ua_p->ua_asc)) 162 list_add(&ua->ua_nacl_list, 163 &deve->ua_list); 164 else 165 list_add_tail(&ua->ua_nacl_list, 166 &deve->ua_list); 167 } else 168 list_add_tail(&ua->ua_nacl_list, 169 &deve->ua_list); 170 spin_unlock(&deve->ua_lock); 171 172 atomic_inc_mb(&deve->ua_count); 173 rcu_read_unlock(); 174 return 0; 175 } 176 list_add_tail(&ua->ua_nacl_list, &deve->ua_list); 177 spin_unlock(&deve->ua_lock); 178 179 pr_debug("[%s]: Allocated UNIT ATTENTION, mapped LUN: %llu, ASC:" 180 " 0x%02x, ASCQ: 0x%02x\n", 181 nacl->se_tpg->se_tpg_tfo->get_fabric_name(), unpacked_lun, 182 asc, ascq); 183 184 atomic_inc_mb(&deve->ua_count); 185 rcu_read_unlock(); 186 return 0; 187 } 188 189 void core_scsi3_ua_release_all( 190 struct se_dev_entry *deve) 191 { 192 struct se_ua *ua, *ua_p; 193 194 spin_lock(&deve->ua_lock); 195 list_for_each_entry_safe(ua, ua_p, &deve->ua_list, ua_nacl_list) { 196 list_del(&ua->ua_nacl_list); 197 kmem_cache_free(se_ua_cache, ua); 198 199 atomic_dec_mb(&deve->ua_count); 200 } 201 spin_unlock(&deve->ua_lock); 202 } 203 204 void core_scsi3_ua_for_check_condition( 205 struct se_cmd *cmd, 206 u8 *asc, 207 u8 *ascq) 208 { 209 struct se_device *dev = cmd->se_dev; 210 struct se_dev_entry *deve; 211 struct se_session *sess = cmd->se_sess; 212 struct se_node_acl *nacl; 213 struct se_ua *ua = NULL, *ua_p; 214 int head = 1; 215 216 if (!sess) 217 return; 218 219 nacl = sess->se_node_acl; 220 if (!nacl) 221 return; 222 223 rcu_read_lock(); 224 deve = target_nacl_find_deve(nacl, cmd->orig_fe_lun); 225 if (!deve) { 226 rcu_read_unlock(); 227 return; 228 } 229 if (!atomic_read(&deve->ua_count)) { 230 rcu_read_unlock(); 231 return; 232 } 233 /* 234 * The highest priority Unit Attentions are placed at the head of the 235 * struct se_dev_entry->ua_list, and will be returned in CHECK_CONDITION + 236 * sense data for the received CDB. 237 */ 238 spin_lock(&deve->ua_lock); 239 list_for_each_entry_safe(ua, ua_p, &deve->ua_list, ua_nacl_list) { 240 /* 241 * For ua_intlck_ctrl code not equal to 00b, only report the 242 * highest priority UNIT_ATTENTION and ASC/ASCQ without 243 * clearing it. 244 */ 245 if (dev->dev_attrib.emulate_ua_intlck_ctrl != 0) { 246 *asc = ua->ua_asc; 247 *ascq = ua->ua_ascq; 248 break; 249 } 250 /* 251 * Otherwise for the default 00b, release the UNIT ATTENTION 252 * condition. Return the ASC/ASCQ of the highest priority UA 253 * (head of the list) in the outgoing CHECK_CONDITION + sense. 254 */ 255 if (head) { 256 *asc = ua->ua_asc; 257 *ascq = ua->ua_ascq; 258 head = 0; 259 } 260 list_del(&ua->ua_nacl_list); 261 kmem_cache_free(se_ua_cache, ua); 262 263 atomic_dec_mb(&deve->ua_count); 264 } 265 spin_unlock(&deve->ua_lock); 266 rcu_read_unlock(); 267 268 pr_debug("[%s]: %s UNIT ATTENTION condition with" 269 " INTLCK_CTRL: %d, mapped LUN: %llu, got CDB: 0x%02x" 270 " reported ASC: 0x%02x, ASCQ: 0x%02x\n", 271 nacl->se_tpg->se_tpg_tfo->get_fabric_name(), 272 (dev->dev_attrib.emulate_ua_intlck_ctrl != 0) ? "Reporting" : 273 "Releasing", dev->dev_attrib.emulate_ua_intlck_ctrl, 274 cmd->orig_fe_lun, cmd->t_task_cdb[0], *asc, *ascq); 275 } 276 277 int core_scsi3_ua_clear_for_request_sense( 278 struct se_cmd *cmd, 279 u8 *asc, 280 u8 *ascq) 281 { 282 struct se_dev_entry *deve; 283 struct se_session *sess = cmd->se_sess; 284 struct se_node_acl *nacl; 285 struct se_ua *ua = NULL, *ua_p; 286 int head = 1; 287 288 if (!sess) 289 return -EINVAL; 290 291 nacl = sess->se_node_acl; 292 if (!nacl) 293 return -EINVAL; 294 295 rcu_read_lock(); 296 deve = target_nacl_find_deve(nacl, cmd->orig_fe_lun); 297 if (!deve) { 298 rcu_read_unlock(); 299 return -EINVAL; 300 } 301 if (!atomic_read(&deve->ua_count)) { 302 rcu_read_unlock(); 303 return -EPERM; 304 } 305 /* 306 * The highest priority Unit Attentions are placed at the head of the 307 * struct se_dev_entry->ua_list. The First (and hence highest priority) 308 * ASC/ASCQ will be returned in REQUEST_SENSE payload data for the 309 * matching struct se_lun. 310 * 311 * Once the returning ASC/ASCQ values are set, we go ahead and 312 * release all of the Unit Attention conditions for the associated 313 * struct se_lun. 314 */ 315 spin_lock(&deve->ua_lock); 316 list_for_each_entry_safe(ua, ua_p, &deve->ua_list, ua_nacl_list) { 317 if (head) { 318 *asc = ua->ua_asc; 319 *ascq = ua->ua_ascq; 320 head = 0; 321 } 322 list_del(&ua->ua_nacl_list); 323 kmem_cache_free(se_ua_cache, ua); 324 325 atomic_dec_mb(&deve->ua_count); 326 } 327 spin_unlock(&deve->ua_lock); 328 rcu_read_unlock(); 329 330 pr_debug("[%s]: Released UNIT ATTENTION condition, mapped" 331 " LUN: %llu, got REQUEST_SENSE reported ASC: 0x%02x," 332 " ASCQ: 0x%02x\n", nacl->se_tpg->se_tpg_tfo->get_fabric_name(), 333 cmd->orig_fe_lun, *asc, *ascq); 334 335 return (head) ? -EPERM : 0; 336 } 337