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 if (se_cmd->transport_state & CMD_T_PRE_EXECUTE) { 118 if (se_cmd->scsi_status) { 119 pr_debug("Attempted to abort io tag: %llu early failure" 120 " status: 0x%02x\n", se_cmd->tag, 121 se_cmd->scsi_status); 122 spin_unlock(&se_cmd->t_state_lock); 123 return false; 124 } 125 } 126 if (sess->sess_tearing_down) { 127 pr_debug("Attempted to abort io tag: %llu already shutdown," 128 " skipping\n", se_cmd->tag); 129 spin_unlock(&se_cmd->t_state_lock); 130 return false; 131 } 132 se_cmd->transport_state |= CMD_T_ABORTED; 133 134 if ((tmr_sess != se_cmd->se_sess) && tas) 135 se_cmd->transport_state |= CMD_T_TAS; 136 137 spin_unlock(&se_cmd->t_state_lock); 138 139 return kref_get_unless_zero(&se_cmd->cmd_kref); 140 } 141 142 void core_tmr_abort_task( 143 struct se_device *dev, 144 struct se_tmr_req *tmr, 145 struct se_session *se_sess) 146 { 147 struct se_cmd *se_cmd; 148 unsigned long flags; 149 u64 ref_tag; 150 151 spin_lock_irqsave(&se_sess->sess_cmd_lock, flags); 152 list_for_each_entry(se_cmd, &se_sess->sess_cmd_list, se_cmd_list) { 153 154 if (dev != se_cmd->se_dev) 155 continue; 156 157 /* skip task management functions, including tmr->task_cmd */ 158 if (se_cmd->se_cmd_flags & SCF_SCSI_TMR_CDB) 159 continue; 160 161 ref_tag = se_cmd->tag; 162 if (tmr->ref_task_tag != ref_tag) 163 continue; 164 165 printk("ABORT_TASK: Found referenced %s task_tag: %llu\n", 166 se_cmd->se_tfo->fabric_name, ref_tag); 167 168 if (!__target_check_io_state(se_cmd, se_sess, 169 dev->dev_attrib.emulate_tas)) 170 continue; 171 172 spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags); 173 174 /* 175 * Ensure that this ABORT request is visible to the LU RESET 176 * code. 177 */ 178 if (!tmr->tmr_dev) 179 WARN_ON_ONCE(transport_lookup_tmr_lun(tmr->task_cmd, 180 se_cmd->orig_fe_lun) < 0); 181 182 target_put_cmd_and_wait(se_cmd); 183 184 printk("ABORT_TASK: Sending TMR_FUNCTION_COMPLETE for" 185 " ref_tag: %llu\n", ref_tag); 186 tmr->response = TMR_FUNCTION_COMPLETE; 187 atomic_long_inc(&dev->aborts_complete); 188 return; 189 } 190 spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags); 191 192 printk("ABORT_TASK: Sending TMR_TASK_DOES_NOT_EXIST for ref_tag: %lld\n", 193 tmr->ref_task_tag); 194 tmr->response = TMR_TASK_DOES_NOT_EXIST; 195 atomic_long_inc(&dev->aborts_no_task); 196 } 197 198 static void core_tmr_drain_tmr_list( 199 struct se_device *dev, 200 struct se_tmr_req *tmr, 201 struct list_head *preempt_and_abort_list) 202 { 203 LIST_HEAD(drain_tmr_list); 204 struct se_session *sess; 205 struct se_tmr_req *tmr_p, *tmr_pp; 206 struct se_cmd *cmd; 207 unsigned long flags; 208 bool rc; 209 /* 210 * Release all pending and outgoing TMRs aside from the received 211 * LUN_RESET tmr.. 212 */ 213 spin_lock_irqsave(&dev->se_tmr_lock, flags); 214 if (tmr) 215 list_del_init(&tmr->tmr_list); 216 list_for_each_entry_safe(tmr_p, tmr_pp, &dev->dev_tmr_list, tmr_list) { 217 cmd = tmr_p->task_cmd; 218 if (!cmd) { 219 pr_err("Unable to locate struct se_cmd for TMR\n"); 220 continue; 221 } 222 /* 223 * If this function was called with a valid pr_res_key 224 * parameter (eg: for PROUT PREEMPT_AND_ABORT service action 225 * skip non registration key matching TMRs. 226 */ 227 if (target_check_cdb_and_preempt(preempt_and_abort_list, cmd)) 228 continue; 229 230 sess = cmd->se_sess; 231 if (WARN_ON_ONCE(!sess)) 232 continue; 233 234 spin_lock(&sess->sess_cmd_lock); 235 spin_lock(&cmd->t_state_lock); 236 if (!(cmd->transport_state & CMD_T_ACTIVE) || 237 (cmd->transport_state & CMD_T_FABRIC_STOP)) { 238 spin_unlock(&cmd->t_state_lock); 239 spin_unlock(&sess->sess_cmd_lock); 240 continue; 241 } 242 if (cmd->t_state == TRANSPORT_ISTATE_PROCESSING) { 243 spin_unlock(&cmd->t_state_lock); 244 spin_unlock(&sess->sess_cmd_lock); 245 continue; 246 } 247 if (sess->sess_tearing_down) { 248 spin_unlock(&cmd->t_state_lock); 249 spin_unlock(&sess->sess_cmd_lock); 250 continue; 251 } 252 cmd->transport_state |= CMD_T_ABORTED; 253 spin_unlock(&cmd->t_state_lock); 254 255 rc = kref_get_unless_zero(&cmd->cmd_kref); 256 if (!rc) { 257 printk("LUN_RESET TMR: non-zero kref_get_unless_zero\n"); 258 spin_unlock(&sess->sess_cmd_lock); 259 continue; 260 } 261 spin_unlock(&sess->sess_cmd_lock); 262 263 list_move_tail(&tmr_p->tmr_list, &drain_tmr_list); 264 } 265 spin_unlock_irqrestore(&dev->se_tmr_lock, flags); 266 267 list_for_each_entry_safe(tmr_p, tmr_pp, &drain_tmr_list, tmr_list) { 268 list_del_init(&tmr_p->tmr_list); 269 cmd = tmr_p->task_cmd; 270 271 pr_debug("LUN_RESET: %s releasing TMR %p Function: 0x%02x," 272 " Response: 0x%02x, t_state: %d\n", 273 (preempt_and_abort_list) ? "Preempt" : "", tmr_p, 274 tmr_p->function, tmr_p->response, cmd->t_state); 275 276 target_put_cmd_and_wait(cmd); 277 } 278 } 279 280 /** 281 * core_tmr_drain_state_list() - abort SCSI commands associated with a device 282 * 283 * @dev: Device for which to abort outstanding SCSI commands. 284 * @prout_cmd: Pointer to the SCSI PREEMPT AND ABORT if this function is called 285 * to realize the PREEMPT AND ABORT functionality. 286 * @tmr_sess: Session through which the LUN RESET has been received. 287 * @tas: Task Aborted Status (TAS) bit from the SCSI control mode page. 288 * A quote from SPC-4, paragraph "7.5.10 Control mode page": 289 * "A task aborted status (TAS) bit set to zero specifies that 290 * aborted commands shall be terminated by the device server 291 * without any response to the application client. A TAS bit set 292 * to one specifies that commands aborted by the actions of an I_T 293 * nexus other than the I_T nexus on which the command was 294 * received shall be completed with TASK ABORTED status." 295 * @preempt_and_abort_list: For the PREEMPT AND ABORT functionality, a list 296 * with registrations that will be preempted. 297 */ 298 static void core_tmr_drain_state_list( 299 struct se_device *dev, 300 struct se_cmd *prout_cmd, 301 struct se_session *tmr_sess, 302 int tas, 303 struct list_head *preempt_and_abort_list) 304 { 305 LIST_HEAD(drain_task_list); 306 struct se_session *sess; 307 struct se_cmd *cmd, *next; 308 unsigned long flags; 309 int rc; 310 311 /* 312 * Complete outstanding commands with TASK_ABORTED SAM status. 313 * 314 * This is following sam4r17, section 5.6 Aborting commands, Table 38 315 * for TMR LUN_RESET: 316 * 317 * a) "Yes" indicates that each command that is aborted on an I_T nexus 318 * other than the one that caused the SCSI device condition is 319 * completed with TASK ABORTED status, if the TAS bit is set to one in 320 * the Control mode page (see SPC-4). "No" indicates that no status is 321 * returned for aborted commands. 322 * 323 * d) If the logical unit reset is caused by a particular I_T nexus 324 * (e.g., by a LOGICAL UNIT RESET task management function), then "yes" 325 * (TASK_ABORTED status) applies. 326 * 327 * Otherwise (e.g., if triggered by a hard reset), "no" 328 * (no TASK_ABORTED SAM status) applies. 329 * 330 * Note that this seems to be independent of TAS (Task Aborted Status) 331 * in the Control Mode Page. 332 */ 333 spin_lock_irqsave(&dev->execute_task_lock, flags); 334 list_for_each_entry_safe(cmd, next, &dev->state_list, state_list) { 335 /* 336 * For PREEMPT_AND_ABORT usage, only process commands 337 * with a matching reservation key. 338 */ 339 if (target_check_cdb_and_preempt(preempt_and_abort_list, cmd)) 340 continue; 341 342 /* 343 * Not aborting PROUT PREEMPT_AND_ABORT CDB.. 344 */ 345 if (prout_cmd == cmd) 346 continue; 347 348 sess = cmd->se_sess; 349 if (WARN_ON_ONCE(!sess)) 350 continue; 351 352 spin_lock(&sess->sess_cmd_lock); 353 rc = __target_check_io_state(cmd, tmr_sess, tas); 354 spin_unlock(&sess->sess_cmd_lock); 355 if (!rc) 356 continue; 357 358 list_move_tail(&cmd->state_list, &drain_task_list); 359 cmd->state_active = false; 360 } 361 spin_unlock_irqrestore(&dev->execute_task_lock, flags); 362 363 while (!list_empty(&drain_task_list)) { 364 cmd = list_entry(drain_task_list.next, struct se_cmd, state_list); 365 list_del_init(&cmd->state_list); 366 367 target_show_cmd("LUN_RESET: ", cmd); 368 pr_debug("LUN_RESET: ITT[0x%08llx] - %s pr_res_key: 0x%016Lx\n", 369 cmd->tag, (preempt_and_abort_list) ? "preempt" : "", 370 cmd->pr_res_key); 371 372 target_put_cmd_and_wait(cmd); 373 } 374 } 375 376 int core_tmr_lun_reset( 377 struct se_device *dev, 378 struct se_tmr_req *tmr, 379 struct list_head *preempt_and_abort_list, 380 struct se_cmd *prout_cmd) 381 { 382 struct se_node_acl *tmr_nacl = NULL; 383 struct se_portal_group *tmr_tpg = NULL; 384 struct se_session *tmr_sess = NULL; 385 int tas; 386 /* 387 * TASK_ABORTED status bit, this is configurable via ConfigFS 388 * struct se_device attributes. spc4r17 section 7.4.6 Control mode page 389 * 390 * A task aborted status (TAS) bit set to zero specifies that aborted 391 * tasks shall be terminated by the device server without any response 392 * to the application client. A TAS bit set to one specifies that tasks 393 * aborted by the actions of an I_T nexus other than the I_T nexus on 394 * which the command was received shall be completed with TASK ABORTED 395 * status (see SAM-4). 396 */ 397 tas = dev->dev_attrib.emulate_tas; 398 /* 399 * Determine if this se_tmr is coming from a $FABRIC_MOD 400 * or struct se_device passthrough.. 401 */ 402 if (tmr && tmr->task_cmd && tmr->task_cmd->se_sess) { 403 tmr_sess = tmr->task_cmd->se_sess; 404 tmr_nacl = tmr_sess->se_node_acl; 405 tmr_tpg = tmr_sess->se_tpg; 406 if (tmr_nacl && tmr_tpg) { 407 pr_debug("LUN_RESET: TMR caller fabric: %s" 408 " initiator port %s\n", 409 tmr_tpg->se_tpg_tfo->fabric_name, 410 tmr_nacl->initiatorname); 411 } 412 } 413 pr_debug("LUN_RESET: %s starting for [%s], tas: %d\n", 414 (preempt_and_abort_list) ? "Preempt" : "TMR", 415 dev->transport->name, tas); 416 417 core_tmr_drain_tmr_list(dev, tmr, preempt_and_abort_list); 418 core_tmr_drain_state_list(dev, prout_cmd, tmr_sess, tas, 419 preempt_and_abort_list); 420 421 /* 422 * Clear any legacy SPC-2 reservation when called during 423 * LOGICAL UNIT RESET 424 */ 425 if (!preempt_and_abort_list && 426 (dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS)) { 427 spin_lock(&dev->dev_reservation_lock); 428 dev->dev_reserved_node_acl = NULL; 429 dev->dev_reservation_flags &= ~DRF_SPC2_RESERVATIONS; 430 spin_unlock(&dev->dev_reservation_lock); 431 pr_debug("LUN_RESET: SCSI-2 Released reservation\n"); 432 } 433 434 atomic_long_inc(&dev->num_resets); 435 436 pr_debug("LUN_RESET: %s for [%s] Complete\n", 437 (preempt_and_abort_list) ? "Preempt" : "TMR", 438 dev->transport->name); 439 return 0; 440 } 441 442