target_core_ua.c revision 9f5c3125d433b3044b013471fa92f1b5738036fe
1/******************************************************************************* 2 * Filename: target_core_ua.c 3 * 4 * This file contains logic for SPC-3 Unit Attention emulation 5 * 6 * Copyright (c) 2009,2010 Rising Tide Systems 7 * Copyright (c) 2009,2010 Linux-iSCSI.org 8 * 9 * Nicholas A. Bellinger <nab@kernel.org> 10 * 11 * This program is free software; you can redistribute it and/or modify 12 * it under the terms of the GNU General Public License as published by 13 * the Free Software Foundation; either version 2 of the License, or 14 * (at your option) any later version. 15 * 16 * This program is distributed in the hope that it will be useful, 17 * but WITHOUT ANY WARRANTY; without even the implied warranty of 18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 19 * GNU General Public License for more details. 20 * 21 * You should have received a copy of the GNU General Public License 22 * along with this program; if not, write to the Free Software 23 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. 24 * 25 ******************************************************************************/ 26 27#include <linux/slab.h> 28#include <linux/spinlock.h> 29#include <scsi/scsi.h> 30#include <scsi/scsi_cmnd.h> 31 32#include <target/target_core_base.h> 33#include <target/target_core_device.h> 34#include <target/target_core_transport.h> 35#include <target/target_core_fabric_ops.h> 36#include <target/target_core_configfs.h> 37 38#include "target_core_alua.h" 39#include "target_core_hba.h" 40#include "target_core_pr.h" 41#include "target_core_ua.h" 42 43int core_scsi3_ua_check( 44 struct se_cmd *cmd, 45 unsigned char *cdb) 46{ 47 struct se_dev_entry *deve; 48 struct se_session *sess = cmd->se_sess; 49 struct se_node_acl *nacl; 50 51 if (!sess) 52 return 0; 53 54 nacl = sess->se_node_acl; 55 if (!nacl) 56 return 0; 57 58 deve = &nacl->device_list[cmd->orig_fe_lun]; 59 if (!atomic_read(&deve->ua_count)) 60 return 0; 61 /* 62 * From sam4r14, section 5.14 Unit attention condition: 63 * 64 * a) if an INQUIRY command enters the enabled command state, the 65 * device server shall process the INQUIRY command and shall neither 66 * report nor clear any unit attention condition; 67 * b) if a REPORT LUNS command enters the enabled command state, the 68 * device server shall process the REPORT LUNS command and shall not 69 * report any unit attention condition; 70 * e) if a REQUEST SENSE command enters the enabled command state while 71 * a unit attention condition exists for the SCSI initiator port 72 * associated with the I_T nexus on which the REQUEST SENSE command 73 * was received, then the device server shall process the command 74 * and either: 75 */ 76 switch (cdb[0]) { 77 case INQUIRY: 78 case REPORT_LUNS: 79 case REQUEST_SENSE: 80 return 0; 81 default: 82 return -EINVAL; 83 } 84 85 return -EINVAL; 86} 87 88int core_scsi3_ua_allocate( 89 struct se_node_acl *nacl, 90 u32 unpacked_lun, 91 u8 asc, 92 u8 ascq) 93{ 94 struct se_dev_entry *deve; 95 struct se_ua *ua, *ua_p, *ua_tmp; 96 /* 97 * PASSTHROUGH OPS 98 */ 99 if (!nacl) 100 return -EINVAL; 101 102 ua = kmem_cache_zalloc(se_ua_cache, GFP_ATOMIC); 103 if (!ua) { 104 pr_err("Unable to allocate struct se_ua\n"); 105 return -ENOMEM; 106 } 107 INIT_LIST_HEAD(&ua->ua_dev_list); 108 INIT_LIST_HEAD(&ua->ua_nacl_list); 109 110 ua->ua_nacl = nacl; 111 ua->ua_asc = asc; 112 ua->ua_ascq = ascq; 113 114 spin_lock_irq(&nacl->device_list_lock); 115 deve = &nacl->device_list[unpacked_lun]; 116 117 spin_lock(&deve->ua_lock); 118 list_for_each_entry_safe(ua_p, ua_tmp, &deve->ua_list, ua_nacl_list) { 119 /* 120 * Do not report the same UNIT ATTENTION twice.. 121 */ 122 if ((ua_p->ua_asc == asc) && (ua_p->ua_ascq == ascq)) { 123 spin_unlock(&deve->ua_lock); 124 spin_unlock_irq(&nacl->device_list_lock); 125 kmem_cache_free(se_ua_cache, ua); 126 return 0; 127 } 128 /* 129 * Attach the highest priority Unit Attention to 130 * the head of the list following sam4r14, 131 * Section 5.14 Unit Attention Condition: 132 * 133 * POWER ON, RESET, OR BUS DEVICE RESET OCCURRED highest 134 * POWER ON OCCURRED or 135 * DEVICE INTERNAL RESET 136 * SCSI BUS RESET OCCURRED or 137 * MICROCODE HAS BEEN CHANGED or 138 * protocol specific 139 * BUS DEVICE RESET FUNCTION OCCURRED 140 * I_T NEXUS LOSS OCCURRED 141 * COMMANDS CLEARED BY POWER LOSS NOTIFICATION 142 * all others Lowest 143 * 144 * Each of the ASCQ codes listed above are defined in 145 * the 29h ASC family, see spc4r17 Table D.1 146 */ 147 if (ua_p->ua_asc == 0x29) { 148 if ((asc == 0x29) && (ascq > ua_p->ua_ascq)) 149 list_add(&ua->ua_nacl_list, 150 &deve->ua_list); 151 else 152 list_add_tail(&ua->ua_nacl_list, 153 &deve->ua_list); 154 } else if (ua_p->ua_asc == 0x2a) { 155 /* 156 * Incoming Family 29h ASCQ codes will override 157 * Family 2AHh ASCQ codes for Unit Attention condition. 158 */ 159 if ((asc == 0x29) || (ascq > ua_p->ua_asc)) 160 list_add(&ua->ua_nacl_list, 161 &deve->ua_list); 162 else 163 list_add_tail(&ua->ua_nacl_list, 164 &deve->ua_list); 165 } else 166 list_add_tail(&ua->ua_nacl_list, 167 &deve->ua_list); 168 spin_unlock(&deve->ua_lock); 169 spin_unlock_irq(&nacl->device_list_lock); 170 171 atomic_inc(&deve->ua_count); 172 smp_mb__after_atomic_inc(); 173 return 0; 174 } 175 list_add_tail(&ua->ua_nacl_list, &deve->ua_list); 176 spin_unlock(&deve->ua_lock); 177 spin_unlock_irq(&nacl->device_list_lock); 178 179 pr_debug("[%s]: Allocated UNIT ATTENTION, mapped LUN: %u, 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(&deve->ua_count); 185 smp_mb__after_atomic_inc(); 186 return 0; 187} 188 189void 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(&deve->ua_count); 200 smp_mb__after_atomic_dec(); 201 } 202 spin_unlock(&deve->ua_lock); 203} 204 205void core_scsi3_ua_for_check_condition( 206 struct se_cmd *cmd, 207 u8 *asc, 208 u8 *ascq) 209{ 210 struct se_device *dev = cmd->se_dev; 211 struct se_dev_entry *deve; 212 struct se_session *sess = cmd->se_sess; 213 struct se_node_acl *nacl; 214 struct se_ua *ua = NULL, *ua_p; 215 int head = 1; 216 217 if (!sess) 218 return; 219 220 nacl = sess->se_node_acl; 221 if (!nacl) 222 return; 223 224 spin_lock_irq(&nacl->device_list_lock); 225 deve = &nacl->device_list[cmd->orig_fe_lun]; 226 if (!atomic_read(&deve->ua_count)) { 227 spin_unlock_irq(&nacl->device_list_lock); 228 return; 229 } 230 /* 231 * The highest priority Unit Attentions are placed at the head of the 232 * struct se_dev_entry->ua_list, and will be returned in CHECK_CONDITION + 233 * sense data for the received CDB. 234 */ 235 spin_lock(&deve->ua_lock); 236 list_for_each_entry_safe(ua, ua_p, &deve->ua_list, ua_nacl_list) { 237 /* 238 * For ua_intlck_ctrl code not equal to 00b, only report the 239 * highest priority UNIT_ATTENTION and ASC/ASCQ without 240 * clearing it. 241 */ 242 if (dev->se_sub_dev->se_dev_attrib.emulate_ua_intlck_ctrl != 0) { 243 *asc = ua->ua_asc; 244 *ascq = ua->ua_ascq; 245 break; 246 } 247 /* 248 * Otherwise for the default 00b, release the UNIT ATTENTION 249 * condition. Return the ASC/ASCQ of the highest priority UA 250 * (head of the list) in the outgoing CHECK_CONDITION + sense. 251 */ 252 if (head) { 253 *asc = ua->ua_asc; 254 *ascq = ua->ua_ascq; 255 head = 0; 256 } 257 list_del(&ua->ua_nacl_list); 258 kmem_cache_free(se_ua_cache, ua); 259 260 atomic_dec(&deve->ua_count); 261 smp_mb__after_atomic_dec(); 262 } 263 spin_unlock(&deve->ua_lock); 264 spin_unlock_irq(&nacl->device_list_lock); 265 266 pr_debug("[%s]: %s UNIT ATTENTION condition with" 267 " INTLCK_CTRL: %d, mapped LUN: %u, got CDB: 0x%02x" 268 " reported ASC: 0x%02x, ASCQ: 0x%02x\n", 269 nacl->se_tpg->se_tpg_tfo->get_fabric_name(), 270 (dev->se_sub_dev->se_dev_attrib.emulate_ua_intlck_ctrl != 0) ? "Reporting" : 271 "Releasing", dev->se_sub_dev->se_dev_attrib.emulate_ua_intlck_ctrl, 272 cmd->orig_fe_lun, cmd->t_task_cdb[0], *asc, *ascq); 273} 274 275int core_scsi3_ua_clear_for_request_sense( 276 struct se_cmd *cmd, 277 u8 *asc, 278 u8 *ascq) 279{ 280 struct se_dev_entry *deve; 281 struct se_session *sess = cmd->se_sess; 282 struct se_node_acl *nacl; 283 struct se_ua *ua = NULL, *ua_p; 284 int head = 1; 285 286 if (!sess) 287 return -EINVAL; 288 289 nacl = sess->se_node_acl; 290 if (!nacl) 291 return -EINVAL; 292 293 spin_lock_irq(&nacl->device_list_lock); 294 deve = &nacl->device_list[cmd->orig_fe_lun]; 295 if (!atomic_read(&deve->ua_count)) { 296 spin_unlock_irq(&nacl->device_list_lock); 297 return -EPERM; 298 } 299 /* 300 * The highest priority Unit Attentions are placed at the head of the 301 * struct se_dev_entry->ua_list. The First (and hence highest priority) 302 * ASC/ASCQ will be returned in REQUEST_SENSE payload data for the 303 * matching struct se_lun. 304 * 305 * Once the returning ASC/ASCQ values are set, we go ahead and 306 * release all of the Unit Attention conditions for the associated 307 * struct se_lun. 308 */ 309 spin_lock(&deve->ua_lock); 310 list_for_each_entry_safe(ua, ua_p, &deve->ua_list, ua_nacl_list) { 311 if (head) { 312 *asc = ua->ua_asc; 313 *ascq = ua->ua_ascq; 314 head = 0; 315 } 316 list_del(&ua->ua_nacl_list); 317 kmem_cache_free(se_ua_cache, ua); 318 319 atomic_dec(&deve->ua_count); 320 smp_mb__after_atomic_dec(); 321 } 322 spin_unlock(&deve->ua_lock); 323 spin_unlock_irq(&nacl->device_list_lock); 324 325 pr_debug("[%s]: Released UNIT ATTENTION condition, mapped" 326 " LUN: %u, got REQUEST_SENSE reported ASC: 0x%02x," 327 " ASCQ: 0x%02x\n", nacl->se_tpg->se_tpg_tfo->get_fabric_name(), 328 cmd->orig_fe_lun, *asc, *ascq); 329 330 return (head) ? -EPERM : 0; 331} 332