1 /******************************************************************************* 2 * Filename: target_core_tmr.c 3 * 4 * This file contains SPC-3 task management infrastructure 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 <linux/list.h> 29 #include <linux/export.h> 30 31 #include <target/target_core_base.h> 32 #include <target/target_core_backend.h> 33 #include <target/target_core_fabric.h> 34 35 #include "target_core_internal.h" 36 #include "target_core_alua.h" 37 #include "target_core_pr.h" 38 39 int core_tmr_alloc_req( 40 struct se_cmd *se_cmd, 41 void *fabric_tmr_ptr, 42 u8 function, 43 gfp_t gfp_flags) 44 { 45 struct se_tmr_req *tmr; 46 47 tmr = kzalloc(sizeof(struct se_tmr_req), gfp_flags); 48 if (!tmr) { 49 pr_err("Unable to allocate struct se_tmr_req\n"); 50 return -ENOMEM; 51 } 52 53 se_cmd->se_cmd_flags |= SCF_SCSI_TMR_CDB; 54 se_cmd->se_tmr_req = tmr; 55 tmr->task_cmd = se_cmd; 56 tmr->fabric_tmr_ptr = fabric_tmr_ptr; 57 tmr->function = function; 58 INIT_LIST_HEAD(&tmr->tmr_list); 59 60 return 0; 61 } 62 EXPORT_SYMBOL(core_tmr_alloc_req); 63 64 void core_tmr_release_req(struct se_tmr_req *tmr) 65 { 66 struct se_device *dev = tmr->tmr_dev; 67 unsigned long flags; 68 69 if (dev) { 70 spin_lock_irqsave(&dev->se_tmr_lock, flags); 71 list_del_init(&tmr->tmr_list); 72 spin_unlock_irqrestore(&dev->se_tmr_lock, flags); 73 } 74 75 kfree(tmr); 76 } 77 78 static int target_check_cdb_and_preempt(struct list_head *list, 79 struct se_cmd *cmd) 80 { 81 struct t10_pr_registration *reg; 82 83 if (!list) 84 return 0; 85 list_for_each_entry(reg, list, pr_reg_abort_list) { 86 if (reg->pr_res_key == cmd->pr_res_key) 87 return 0; 88 } 89 90 return 1; 91 } 92 93 static bool __target_check_io_state(struct se_cmd *se_cmd, 94 struct se_session *tmr_sess, int tas) 95 { 96 struct se_session *sess = se_cmd->se_sess; 97 98 assert_spin_locked(&sess->sess_cmd_lock); 99 WARN_ON_ONCE(!irqs_disabled()); 100 /* 101 * If command already reached CMD_T_COMPLETE state within 102 * target_complete_cmd() or CMD_T_FABRIC_STOP due to shutdown, 103 * this se_cmd has been passed to fabric driver and will 104 * not be aborted. 105 * 106 * Otherwise, obtain a local se_cmd->cmd_kref now for TMR 107 * ABORT_TASK + LUN_RESET for CMD_T_ABORTED processing as 108 * long as se_cmd->cmd_kref is still active unless zero. 109 */ 110 spin_lock(&se_cmd->t_state_lock); 111 if (se_cmd->transport_state & (CMD_T_COMPLETE | CMD_T_FABRIC_STOP)) { 112 pr_debug("Attempted to abort io tag: %llu already complete or" 113 " fabric stop, skipping\n", se_cmd->tag); 114 spin_unlock(&se_cmd->t_state_lock); 115 return false; 116 } 117 se_cmd->transport_state |= CMD_T_ABORTED; 118 119 if ((tmr_sess != se_cmd->se_sess) && tas) 120 se_cmd->transport_state |= CMD_T_TAS; 121 122 spin_unlock(&se_cmd->t_state_lock); 123 124 return kref_get_unless_zero(&se_cmd->cmd_kref); 125 } 126 127 void core_tmr_abort_task( 128 struct se_device *dev, 129 struct se_tmr_req *tmr, 130 struct se_session *se_sess) 131 { 132 struct se_cmd *se_cmd; 133 unsigned long flags; 134 u64 ref_tag; 135 136 spin_lock_irqsave(&se_sess->sess_cmd_lock, flags); 137 list_for_each_entry(se_cmd, &se_sess->sess_cmd_list, se_cmd_list) { 138 139 if (dev != se_cmd->se_dev) 140 continue; 141 142 /* skip task management functions, including tmr->task_cmd */ 143 if (se_cmd->se_cmd_flags & SCF_SCSI_TMR_CDB) 144 continue; 145 146 ref_tag = se_cmd->tag; 147 if (tmr->ref_task_tag != ref_tag) 148 continue; 149 150 printk("ABORT_TASK: Found referenced %s task_tag: %llu\n", 151 se_cmd->se_tfo->fabric_name, ref_tag); 152 153 if (!__target_check_io_state(se_cmd, se_sess, 154 dev->dev_attrib.emulate_tas)) 155 continue; 156 157 spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags); 158 159 /* 160 * Ensure that this ABORT request is visible to the LU RESET 161 * code. 162 */ 163 if (!tmr->tmr_dev) 164 WARN_ON_ONCE(transport_lookup_tmr_lun(tmr->task_cmd, 165 se_cmd->orig_fe_lun) < 0); 166 167 target_put_cmd_and_wait(se_cmd); 168 169 printk("ABORT_TASK: Sending TMR_FUNCTION_COMPLETE for" 170 " ref_tag: %llu\n", ref_tag); 171 tmr->response = TMR_FUNCTION_COMPLETE; 172 atomic_long_inc(&dev->aborts_complete); 173 return; 174 } 175 spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags); 176 177 printk("ABORT_TASK: Sending TMR_TASK_DOES_NOT_EXIST for ref_tag: %lld\n", 178 tmr->ref_task_tag); 179 tmr->response = TMR_TASK_DOES_NOT_EXIST; 180 atomic_long_inc(&dev->aborts_no_task); 181 } 182 183 static void core_tmr_drain_tmr_list( 184 struct se_device *dev, 185 struct se_tmr_req *tmr, 186 struct list_head *preempt_and_abort_list) 187 { 188 LIST_HEAD(drain_tmr_list); 189 struct se_session *sess; 190 struct se_tmr_req *tmr_p, *tmr_pp; 191 struct se_cmd *cmd; 192 unsigned long flags; 193 bool rc; 194 /* 195 * Release all pending and outgoing TMRs aside from the received 196 * LUN_RESET tmr.. 197 */ 198 spin_lock_irqsave(&dev->se_tmr_lock, flags); 199 if (tmr) 200 list_del_init(&tmr->tmr_list); 201 list_for_each_entry_safe(tmr_p, tmr_pp, &dev->dev_tmr_list, tmr_list) { 202 cmd = tmr_p->task_cmd; 203 if (!cmd) { 204 pr_err("Unable to locate struct se_cmd for TMR\n"); 205 continue; 206 } 207 /* 208 * If this function was called with a valid pr_res_key 209 * parameter (eg: for PROUT PREEMPT_AND_ABORT service action 210 * skip non registration key matching TMRs. 211 */ 212 if (target_check_cdb_and_preempt(preempt_and_abort_list, cmd)) 213 continue; 214 215 sess = cmd->se_sess; 216 if (WARN_ON_ONCE(!sess)) 217 continue; 218 219 spin_lock(&sess->sess_cmd_lock); 220 rc = __target_check_io_state(cmd, sess, 0); 221 spin_unlock(&sess->sess_cmd_lock); 222 223 if (!rc) { 224 printk("LUN_RESET TMR: non-zero kref_get_unless_zero\n"); 225 continue; 226 } 227 228 list_move_tail(&tmr_p->tmr_list, &drain_tmr_list); 229 } 230 spin_unlock_irqrestore(&dev->se_tmr_lock, flags); 231 232 list_for_each_entry_safe(tmr_p, tmr_pp, &drain_tmr_list, tmr_list) { 233 list_del_init(&tmr_p->tmr_list); 234 cmd = tmr_p->task_cmd; 235 236 pr_debug("LUN_RESET: %s releasing TMR %p Function: 0x%02x," 237 " Response: 0x%02x, t_state: %d\n", 238 (preempt_and_abort_list) ? "Preempt" : "", tmr_p, 239 tmr_p->function, tmr_p->response, cmd->t_state); 240 241 target_put_cmd_and_wait(cmd); 242 } 243 } 244 245 /** 246 * core_tmr_drain_state_list() - abort SCSI commands associated with a device 247 * 248 * @dev: Device for which to abort outstanding SCSI commands. 249 * @prout_cmd: Pointer to the SCSI PREEMPT AND ABORT if this function is called 250 * to realize the PREEMPT AND ABORT functionality. 251 * @tmr_sess: Session through which the LUN RESET has been received. 252 * @tas: Task Aborted Status (TAS) bit from the SCSI control mode page. 253 * A quote from SPC-4, paragraph "7.5.10 Control mode page": 254 * "A task aborted status (TAS) bit set to zero specifies that 255 * aborted commands shall be terminated by the device server 256 * without any response to the application client. A TAS bit set 257 * to one specifies that commands aborted by the actions of an I_T 258 * nexus other than the I_T nexus on which the command was 259 * received shall be completed with TASK ABORTED status." 260 * @preempt_and_abort_list: For the PREEMPT AND ABORT functionality, a list 261 * with registrations that will be preempted. 262 */ 263 static void core_tmr_drain_state_list( 264 struct se_device *dev, 265 struct se_cmd *prout_cmd, 266 struct se_session *tmr_sess, 267 int tas, 268 struct list_head *preempt_and_abort_list) 269 { 270 LIST_HEAD(drain_task_list); 271 struct se_session *sess; 272 struct se_cmd *cmd, *next; 273 unsigned long flags; 274 int rc; 275 276 /* 277 * Complete outstanding commands with TASK_ABORTED SAM status. 278 * 279 * This is following sam4r17, section 5.6 Aborting commands, Table 38 280 * for TMR LUN_RESET: 281 * 282 * a) "Yes" indicates that each command that is aborted on an I_T nexus 283 * other than the one that caused the SCSI device condition is 284 * completed with TASK ABORTED status, if the TAS bit is set to one in 285 * the Control mode page (see SPC-4). "No" indicates that no status is 286 * returned for aborted commands. 287 * 288 * d) If the logical unit reset is caused by a particular I_T nexus 289 * (e.g., by a LOGICAL UNIT RESET task management function), then "yes" 290 * (TASK_ABORTED status) applies. 291 * 292 * Otherwise (e.g., if triggered by a hard reset), "no" 293 * (no TASK_ABORTED SAM status) applies. 294 * 295 * Note that this seems to be independent of TAS (Task Aborted Status) 296 * in the Control Mode Page. 297 */ 298 spin_lock_irqsave(&dev->execute_task_lock, flags); 299 list_for_each_entry_safe(cmd, next, &dev->state_list, state_list) { 300 /* 301 * For PREEMPT_AND_ABORT usage, only process commands 302 * with a matching reservation key. 303 */ 304 if (target_check_cdb_and_preempt(preempt_and_abort_list, cmd)) 305 continue; 306 307 /* 308 * Not aborting PROUT PREEMPT_AND_ABORT CDB.. 309 */ 310 if (prout_cmd == cmd) 311 continue; 312 313 sess = cmd->se_sess; 314 if (WARN_ON_ONCE(!sess)) 315 continue; 316 317 spin_lock(&sess->sess_cmd_lock); 318 rc = __target_check_io_state(cmd, tmr_sess, tas); 319 spin_unlock(&sess->sess_cmd_lock); 320 if (!rc) 321 continue; 322 323 list_move_tail(&cmd->state_list, &drain_task_list); 324 cmd->state_active = false; 325 } 326 spin_unlock_irqrestore(&dev->execute_task_lock, flags); 327 328 while (!list_empty(&drain_task_list)) { 329 cmd = list_entry(drain_task_list.next, struct se_cmd, state_list); 330 list_del_init(&cmd->state_list); 331 332 target_show_cmd("LUN_RESET: ", cmd); 333 pr_debug("LUN_RESET: ITT[0x%08llx] - %s pr_res_key: 0x%016Lx\n", 334 cmd->tag, (preempt_and_abort_list) ? "preempt" : "", 335 cmd->pr_res_key); 336 337 target_put_cmd_and_wait(cmd); 338 } 339 } 340 341 int core_tmr_lun_reset( 342 struct se_device *dev, 343 struct se_tmr_req *tmr, 344 struct list_head *preempt_and_abort_list, 345 struct se_cmd *prout_cmd) 346 { 347 struct se_node_acl *tmr_nacl = NULL; 348 struct se_portal_group *tmr_tpg = NULL; 349 struct se_session *tmr_sess = NULL; 350 int tas; 351 /* 352 * TASK_ABORTED status bit, this is configurable via ConfigFS 353 * struct se_device attributes. spc4r17 section 7.4.6 Control mode page 354 * 355 * A task aborted status (TAS) bit set to zero specifies that aborted 356 * tasks shall be terminated by the device server without any response 357 * to the application client. A TAS bit set to one specifies that tasks 358 * aborted by the actions of an I_T nexus other than the I_T nexus on 359 * which the command was received shall be completed with TASK ABORTED 360 * status (see SAM-4). 361 */ 362 tas = dev->dev_attrib.emulate_tas; 363 /* 364 * Determine if this se_tmr is coming from a $FABRIC_MOD 365 * or struct se_device passthrough.. 366 */ 367 if (tmr && tmr->task_cmd && tmr->task_cmd->se_sess) { 368 tmr_sess = tmr->task_cmd->se_sess; 369 tmr_nacl = tmr_sess->se_node_acl; 370 tmr_tpg = tmr_sess->se_tpg; 371 if (tmr_nacl && tmr_tpg) { 372 pr_debug("LUN_RESET: TMR caller fabric: %s" 373 " initiator port %s\n", 374 tmr_tpg->se_tpg_tfo->fabric_name, 375 tmr_nacl->initiatorname); 376 } 377 } 378 pr_debug("LUN_RESET: %s starting for [%s], tas: %d\n", 379 (preempt_and_abort_list) ? "Preempt" : "TMR", 380 dev->transport->name, tas); 381 382 core_tmr_drain_tmr_list(dev, tmr, preempt_and_abort_list); 383 core_tmr_drain_state_list(dev, prout_cmd, tmr_sess, tas, 384 preempt_and_abort_list); 385 386 /* 387 * Clear any legacy SPC-2 reservation when called during 388 * LOGICAL UNIT RESET 389 */ 390 if (!preempt_and_abort_list && 391 (dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS)) { 392 spin_lock(&dev->dev_reservation_lock); 393 dev->dev_reserved_node_acl = NULL; 394 dev->dev_reservation_flags &= ~DRF_SPC2_RESERVATIONS; 395 spin_unlock(&dev->dev_reservation_lock); 396 pr_debug("LUN_RESET: SCSI-2 Released reservation\n"); 397 } 398 399 atomic_long_inc(&dev->num_resets); 400 401 pr_debug("LUN_RESET: %s for [%s] Complete\n", 402 (preempt_and_abort_list) ? "Preempt" : "TMR", 403 dev->transport->name); 404 return 0; 405 } 406 407