target_core_ua.c revision 0fd97ccf45be26fb01b3a412f1f6c6b5044b2f16
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_fabric.h> 34#include <target/target_core_configfs.h> 35 36#include "target_core_internal.h" 37#include "target_core_alua.h" 38#include "target_core_pr.h" 39#include "target_core_ua.h" 40 41int core_scsi3_ua_check( 42 struct se_cmd *cmd, 43 unsigned char *cdb) 44{ 45 struct se_dev_entry *deve; 46 struct se_session *sess = cmd->se_sess; 47 struct se_node_acl *nacl; 48 49 if (!sess) 50 return 0; 51 52 nacl = sess->se_node_acl; 53 if (!nacl) 54 return 0; 55 56 deve = nacl->device_list[cmd->orig_fe_lun]; 57 if (!atomic_read(&deve->ua_count)) 58 return 0; 59 /* 60 * From sam4r14, section 5.14 Unit attention condition: 61 * 62 * a) if an INQUIRY command enters the enabled command state, the 63 * device server shall process the INQUIRY command and shall neither 64 * report nor clear any unit attention condition; 65 * b) if a REPORT LUNS command enters the enabled command state, the 66 * device server shall process the REPORT LUNS command and shall not 67 * report any unit attention condition; 68 * e) if a REQUEST SENSE command enters the enabled command state while 69 * a unit attention condition exists for the SCSI initiator port 70 * associated with the I_T nexus on which the REQUEST SENSE command 71 * was received, then the device server shall process the command 72 * and either: 73 */ 74 switch (cdb[0]) { 75 case INQUIRY: 76 case REPORT_LUNS: 77 case REQUEST_SENSE: 78 return 0; 79 default: 80 return -EINVAL; 81 } 82 83 return -EINVAL; 84} 85 86int core_scsi3_ua_allocate( 87 struct se_node_acl *nacl, 88 u32 unpacked_lun, 89 u8 asc, 90 u8 ascq) 91{ 92 struct se_dev_entry *deve; 93 struct se_ua *ua, *ua_p, *ua_tmp; 94 /* 95 * PASSTHROUGH OPS 96 */ 97 if (!nacl) 98 return -EINVAL; 99 100 ua = kmem_cache_zalloc(se_ua_cache, GFP_ATOMIC); 101 if (!ua) { 102 pr_err("Unable to allocate struct se_ua\n"); 103 return -ENOMEM; 104 } 105 INIT_LIST_HEAD(&ua->ua_dev_list); 106 INIT_LIST_HEAD(&ua->ua_nacl_list); 107 108 ua->ua_nacl = nacl; 109 ua->ua_asc = asc; 110 ua->ua_ascq = ascq; 111 112 spin_lock_irq(&nacl->device_list_lock); 113 deve = nacl->device_list[unpacked_lun]; 114 115 spin_lock(&deve->ua_lock); 116 list_for_each_entry_safe(ua_p, ua_tmp, &deve->ua_list, ua_nacl_list) { 117 /* 118 * Do not report the same UNIT ATTENTION twice.. 119 */ 120 if ((ua_p->ua_asc == asc) && (ua_p->ua_ascq == ascq)) { 121 spin_unlock(&deve->ua_lock); 122 spin_unlock_irq(&nacl->device_list_lock); 123 kmem_cache_free(se_ua_cache, ua); 124 return 0; 125 } 126 /* 127 * Attach the highest priority Unit Attention to 128 * the head of the list following sam4r14, 129 * Section 5.14 Unit Attention Condition: 130 * 131 * POWER ON, RESET, OR BUS DEVICE RESET OCCURRED highest 132 * POWER ON OCCURRED or 133 * DEVICE INTERNAL RESET 134 * SCSI BUS RESET OCCURRED or 135 * MICROCODE HAS BEEN CHANGED or 136 * protocol specific 137 * BUS DEVICE RESET FUNCTION OCCURRED 138 * I_T NEXUS LOSS OCCURRED 139 * COMMANDS CLEARED BY POWER LOSS NOTIFICATION 140 * all others Lowest 141 * 142 * Each of the ASCQ codes listed above are defined in 143 * the 29h ASC family, see spc4r17 Table D.1 144 */ 145 if (ua_p->ua_asc == 0x29) { 146 if ((asc == 0x29) && (ascq > ua_p->ua_ascq)) 147 list_add(&ua->ua_nacl_list, 148 &deve->ua_list); 149 else 150 list_add_tail(&ua->ua_nacl_list, 151 &deve->ua_list); 152 } else if (ua_p->ua_asc == 0x2a) { 153 /* 154 * Incoming Family 29h ASCQ codes will override 155 * Family 2AHh ASCQ codes for Unit Attention condition. 156 */ 157 if ((asc == 0x29) || (ascq > ua_p->ua_asc)) 158 list_add(&ua->ua_nacl_list, 159 &deve->ua_list); 160 else 161 list_add_tail(&ua->ua_nacl_list, 162 &deve->ua_list); 163 } else 164 list_add_tail(&ua->ua_nacl_list, 165 &deve->ua_list); 166 spin_unlock(&deve->ua_lock); 167 spin_unlock_irq(&nacl->device_list_lock); 168 169 atomic_inc(&deve->ua_count); 170 smp_mb__after_atomic_inc(); 171 return 0; 172 } 173 list_add_tail(&ua->ua_nacl_list, &deve->ua_list); 174 spin_unlock(&deve->ua_lock); 175 spin_unlock_irq(&nacl->device_list_lock); 176 177 pr_debug("[%s]: Allocated UNIT ATTENTION, mapped LUN: %u, ASC:" 178 " 0x%02x, ASCQ: 0x%02x\n", 179 nacl->se_tpg->se_tpg_tfo->get_fabric_name(), unpacked_lun, 180 asc, ascq); 181 182 atomic_inc(&deve->ua_count); 183 smp_mb__after_atomic_inc(); 184 return 0; 185} 186 187void core_scsi3_ua_release_all( 188 struct se_dev_entry *deve) 189{ 190 struct se_ua *ua, *ua_p; 191 192 spin_lock(&deve->ua_lock); 193 list_for_each_entry_safe(ua, ua_p, &deve->ua_list, ua_nacl_list) { 194 list_del(&ua->ua_nacl_list); 195 kmem_cache_free(se_ua_cache, ua); 196 197 atomic_dec(&deve->ua_count); 198 smp_mb__after_atomic_dec(); 199 } 200 spin_unlock(&deve->ua_lock); 201} 202 203void core_scsi3_ua_for_check_condition( 204 struct se_cmd *cmd, 205 u8 *asc, 206 u8 *ascq) 207{ 208 struct se_device *dev = cmd->se_dev; 209 struct se_dev_entry *deve; 210 struct se_session *sess = cmd->se_sess; 211 struct se_node_acl *nacl; 212 struct se_ua *ua = NULL, *ua_p; 213 int head = 1; 214 215 if (!sess) 216 return; 217 218 nacl = sess->se_node_acl; 219 if (!nacl) 220 return; 221 222 spin_lock_irq(&nacl->device_list_lock); 223 deve = nacl->device_list[cmd->orig_fe_lun]; 224 if (!atomic_read(&deve->ua_count)) { 225 spin_unlock_irq(&nacl->device_list_lock); 226 return; 227 } 228 /* 229 * The highest priority Unit Attentions are placed at the head of the 230 * struct se_dev_entry->ua_list, and will be returned in CHECK_CONDITION + 231 * sense data for the received CDB. 232 */ 233 spin_lock(&deve->ua_lock); 234 list_for_each_entry_safe(ua, ua_p, &deve->ua_list, ua_nacl_list) { 235 /* 236 * For ua_intlck_ctrl code not equal to 00b, only report the 237 * highest priority UNIT_ATTENTION and ASC/ASCQ without 238 * clearing it. 239 */ 240 if (dev->dev_attrib.emulate_ua_intlck_ctrl != 0) { 241 *asc = ua->ua_asc; 242 *ascq = ua->ua_ascq; 243 break; 244 } 245 /* 246 * Otherwise for the default 00b, release the UNIT ATTENTION 247 * condition. Return the ASC/ASCQ of the highest priority UA 248 * (head of the list) in the outgoing CHECK_CONDITION + sense. 249 */ 250 if (head) { 251 *asc = ua->ua_asc; 252 *ascq = ua->ua_ascq; 253 head = 0; 254 } 255 list_del(&ua->ua_nacl_list); 256 kmem_cache_free(se_ua_cache, ua); 257 258 atomic_dec(&deve->ua_count); 259 smp_mb__after_atomic_dec(); 260 } 261 spin_unlock(&deve->ua_lock); 262 spin_unlock_irq(&nacl->device_list_lock); 263 264 pr_debug("[%s]: %s UNIT ATTENTION condition with" 265 " INTLCK_CTRL: %d, mapped LUN: %u, got CDB: 0x%02x" 266 " reported ASC: 0x%02x, ASCQ: 0x%02x\n", 267 nacl->se_tpg->se_tpg_tfo->get_fabric_name(), 268 (dev->dev_attrib.emulate_ua_intlck_ctrl != 0) ? "Reporting" : 269 "Releasing", dev->dev_attrib.emulate_ua_intlck_ctrl, 270 cmd->orig_fe_lun, cmd->t_task_cdb[0], *asc, *ascq); 271} 272 273int core_scsi3_ua_clear_for_request_sense( 274 struct se_cmd *cmd, 275 u8 *asc, 276 u8 *ascq) 277{ 278 struct se_dev_entry *deve; 279 struct se_session *sess = cmd->se_sess; 280 struct se_node_acl *nacl; 281 struct se_ua *ua = NULL, *ua_p; 282 int head = 1; 283 284 if (!sess) 285 return -EINVAL; 286 287 nacl = sess->se_node_acl; 288 if (!nacl) 289 return -EINVAL; 290 291 spin_lock_irq(&nacl->device_list_lock); 292 deve = nacl->device_list[cmd->orig_fe_lun]; 293 if (!atomic_read(&deve->ua_count)) { 294 spin_unlock_irq(&nacl->device_list_lock); 295 return -EPERM; 296 } 297 /* 298 * The highest priority Unit Attentions are placed at the head of the 299 * struct se_dev_entry->ua_list. The First (and hence highest priority) 300 * ASC/ASCQ will be returned in REQUEST_SENSE payload data for the 301 * matching struct se_lun. 302 * 303 * Once the returning ASC/ASCQ values are set, we go ahead and 304 * release all of the Unit Attention conditions for the associated 305 * struct se_lun. 306 */ 307 spin_lock(&deve->ua_lock); 308 list_for_each_entry_safe(ua, ua_p, &deve->ua_list, ua_nacl_list) { 309 if (head) { 310 *asc = ua->ua_asc; 311 *ascq = ua->ua_ascq; 312 head = 0; 313 } 314 list_del(&ua->ua_nacl_list); 315 kmem_cache_free(se_ua_cache, ua); 316 317 atomic_dec(&deve->ua_count); 318 smp_mb__after_atomic_dec(); 319 } 320 spin_unlock(&deve->ua_lock); 321 spin_unlock_irq(&nacl->device_list_lock); 322 323 pr_debug("[%s]: Released UNIT ATTENTION condition, mapped" 324 " LUN: %u, got REQUEST_SENSE reported ASC: 0x%02x," 325 " ASCQ: 0x%02x\n", nacl->se_tpg->se_tpg_tfo->get_fabric_name(), 326 cmd->orig_fe_lun, *asc, *ascq); 327 328 return (head) ? -EPERM : 0; 329} 330