target_core_ua.c revision fd9a11d7076e1d534a760032d2b8f3b59e10f9b5
1/******************************************************************************* 2 * Filename: target_core_ua.c 3 * 4 * This file contains logic for SPC-3 Unit Attention emulation 5 * 6 * (c) Copyright 2009-2012 RisingTide Systems LLC. 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 40sense_reason_t 41target_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 82int 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_dev_list); 102 INIT_LIST_HEAD(&ua->ua_nacl_list); 103 104 ua->ua_nacl = nacl; 105 ua->ua_asc = asc; 106 ua->ua_ascq = ascq; 107 108 spin_lock_irq(&nacl->device_list_lock); 109 deve = nacl->device_list[unpacked_lun]; 110 111 spin_lock(&deve->ua_lock); 112 list_for_each_entry_safe(ua_p, ua_tmp, &deve->ua_list, ua_nacl_list) { 113 /* 114 * Do not report the same UNIT ATTENTION twice.. 115 */ 116 if ((ua_p->ua_asc == asc) && (ua_p->ua_ascq == ascq)) { 117 spin_unlock(&deve->ua_lock); 118 spin_unlock_irq(&nacl->device_list_lock); 119 kmem_cache_free(se_ua_cache, ua); 120 return 0; 121 } 122 /* 123 * Attach the highest priority Unit Attention to 124 * the head of the list following sam4r14, 125 * Section 5.14 Unit Attention Condition: 126 * 127 * POWER ON, RESET, OR BUS DEVICE RESET OCCURRED highest 128 * POWER ON OCCURRED or 129 * DEVICE INTERNAL RESET 130 * SCSI BUS RESET OCCURRED or 131 * MICROCODE HAS BEEN CHANGED or 132 * protocol specific 133 * BUS DEVICE RESET FUNCTION OCCURRED 134 * I_T NEXUS LOSS OCCURRED 135 * COMMANDS CLEARED BY POWER LOSS NOTIFICATION 136 * all others Lowest 137 * 138 * Each of the ASCQ codes listed above are defined in 139 * the 29h ASC family, see spc4r17 Table D.1 140 */ 141 if (ua_p->ua_asc == 0x29) { 142 if ((asc == 0x29) && (ascq > ua_p->ua_ascq)) 143 list_add(&ua->ua_nacl_list, 144 &deve->ua_list); 145 else 146 list_add_tail(&ua->ua_nacl_list, 147 &deve->ua_list); 148 } else if (ua_p->ua_asc == 0x2a) { 149 /* 150 * Incoming Family 29h ASCQ codes will override 151 * Family 2AHh ASCQ codes for Unit Attention condition. 152 */ 153 if ((asc == 0x29) || (ascq > ua_p->ua_asc)) 154 list_add(&ua->ua_nacl_list, 155 &deve->ua_list); 156 else 157 list_add_tail(&ua->ua_nacl_list, 158 &deve->ua_list); 159 } else 160 list_add_tail(&ua->ua_nacl_list, 161 &deve->ua_list); 162 spin_unlock(&deve->ua_lock); 163 spin_unlock_irq(&nacl->device_list_lock); 164 165 atomic_inc(&deve->ua_count); 166 smp_mb__after_atomic_inc(); 167 return 0; 168 } 169 list_add_tail(&ua->ua_nacl_list, &deve->ua_list); 170 spin_unlock(&deve->ua_lock); 171 spin_unlock_irq(&nacl->device_list_lock); 172 173 pr_debug("[%s]: Allocated UNIT ATTENTION, mapped LUN: %u, ASC:" 174 " 0x%02x, ASCQ: 0x%02x\n", 175 nacl->se_tpg->se_tpg_tfo->get_fabric_name(), unpacked_lun, 176 asc, ascq); 177 178 atomic_inc(&deve->ua_count); 179 smp_mb__after_atomic_inc(); 180 return 0; 181} 182 183void core_scsi3_ua_release_all( 184 struct se_dev_entry *deve) 185{ 186 struct se_ua *ua, *ua_p; 187 188 spin_lock(&deve->ua_lock); 189 list_for_each_entry_safe(ua, ua_p, &deve->ua_list, ua_nacl_list) { 190 list_del(&ua->ua_nacl_list); 191 kmem_cache_free(se_ua_cache, ua); 192 193 atomic_dec(&deve->ua_count); 194 smp_mb__after_atomic_dec(); 195 } 196 spin_unlock(&deve->ua_lock); 197} 198 199void core_scsi3_ua_for_check_condition( 200 struct se_cmd *cmd, 201 u8 *asc, 202 u8 *ascq) 203{ 204 struct se_device *dev = cmd->se_dev; 205 struct se_dev_entry *deve; 206 struct se_session *sess = cmd->se_sess; 207 struct se_node_acl *nacl; 208 struct se_ua *ua = NULL, *ua_p; 209 int head = 1; 210 211 if (!sess) 212 return; 213 214 nacl = sess->se_node_acl; 215 if (!nacl) 216 return; 217 218 spin_lock_irq(&nacl->device_list_lock); 219 deve = nacl->device_list[cmd->orig_fe_lun]; 220 if (!atomic_read(&deve->ua_count)) { 221 spin_unlock_irq(&nacl->device_list_lock); 222 return; 223 } 224 /* 225 * The highest priority Unit Attentions are placed at the head of the 226 * struct se_dev_entry->ua_list, and will be returned in CHECK_CONDITION + 227 * sense data for the received CDB. 228 */ 229 spin_lock(&deve->ua_lock); 230 list_for_each_entry_safe(ua, ua_p, &deve->ua_list, ua_nacl_list) { 231 /* 232 * For ua_intlck_ctrl code not equal to 00b, only report the 233 * highest priority UNIT_ATTENTION and ASC/ASCQ without 234 * clearing it. 235 */ 236 if (dev->dev_attrib.emulate_ua_intlck_ctrl != 0) { 237 *asc = ua->ua_asc; 238 *ascq = ua->ua_ascq; 239 break; 240 } 241 /* 242 * Otherwise for the default 00b, release the UNIT ATTENTION 243 * condition. Return the ASC/ASCQ of the highest priority UA 244 * (head of the list) in the outgoing CHECK_CONDITION + sense. 245 */ 246 if (head) { 247 *asc = ua->ua_asc; 248 *ascq = ua->ua_ascq; 249 head = 0; 250 } 251 list_del(&ua->ua_nacl_list); 252 kmem_cache_free(se_ua_cache, ua); 253 254 atomic_dec(&deve->ua_count); 255 smp_mb__after_atomic_dec(); 256 } 257 spin_unlock(&deve->ua_lock); 258 spin_unlock_irq(&nacl->device_list_lock); 259 260 pr_debug("[%s]: %s UNIT ATTENTION condition with" 261 " INTLCK_CTRL: %d, mapped LUN: %u, got CDB: 0x%02x" 262 " reported ASC: 0x%02x, ASCQ: 0x%02x\n", 263 nacl->se_tpg->se_tpg_tfo->get_fabric_name(), 264 (dev->dev_attrib.emulate_ua_intlck_ctrl != 0) ? "Reporting" : 265 "Releasing", dev->dev_attrib.emulate_ua_intlck_ctrl, 266 cmd->orig_fe_lun, cmd->t_task_cdb[0], *asc, *ascq); 267} 268 269int core_scsi3_ua_clear_for_request_sense( 270 struct se_cmd *cmd, 271 u8 *asc, 272 u8 *ascq) 273{ 274 struct se_dev_entry *deve; 275 struct se_session *sess = cmd->se_sess; 276 struct se_node_acl *nacl; 277 struct se_ua *ua = NULL, *ua_p; 278 int head = 1; 279 280 if (!sess) 281 return -EINVAL; 282 283 nacl = sess->se_node_acl; 284 if (!nacl) 285 return -EINVAL; 286 287 spin_lock_irq(&nacl->device_list_lock); 288 deve = nacl->device_list[cmd->orig_fe_lun]; 289 if (!atomic_read(&deve->ua_count)) { 290 spin_unlock_irq(&nacl->device_list_lock); 291 return -EPERM; 292 } 293 /* 294 * The highest priority Unit Attentions are placed at the head of the 295 * struct se_dev_entry->ua_list. The First (and hence highest priority) 296 * ASC/ASCQ will be returned in REQUEST_SENSE payload data for the 297 * matching struct se_lun. 298 * 299 * Once the returning ASC/ASCQ values are set, we go ahead and 300 * release all of the Unit Attention conditions for the associated 301 * struct se_lun. 302 */ 303 spin_lock(&deve->ua_lock); 304 list_for_each_entry_safe(ua, ua_p, &deve->ua_list, ua_nacl_list) { 305 if (head) { 306 *asc = ua->ua_asc; 307 *ascq = ua->ua_ascq; 308 head = 0; 309 } 310 list_del(&ua->ua_nacl_list); 311 kmem_cache_free(se_ua_cache, ua); 312 313 atomic_dec(&deve->ua_count); 314 smp_mb__after_atomic_dec(); 315 } 316 spin_unlock(&deve->ua_lock); 317 spin_unlock_irq(&nacl->device_list_lock); 318 319 pr_debug("[%s]: Released UNIT ATTENTION condition, mapped" 320 " LUN: %u, got REQUEST_SENSE reported ASC: 0x%02x," 321 " ASCQ: 0x%02x\n", nacl->se_tpg->se_tpg_tfo->get_fabric_name(), 322 cmd->orig_fe_lun, *asc, *ascq); 323 324 return (head) ? -EPERM : 0; 325} 326