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 core_tmr_handle_tas_abort(struct se_cmd *cmd, int tas) 79 { 80 unsigned long flags; 81 bool remove = true, send_tas; 82 /* 83 * TASK ABORTED status (TAS) bit support 84 */ 85 spin_lock_irqsave(&cmd->t_state_lock, flags); 86 send_tas = (cmd->transport_state & CMD_T_TAS); 87 spin_unlock_irqrestore(&cmd->t_state_lock, flags); 88 89 if (send_tas) { 90 remove = false; 91 transport_send_task_abort(cmd); 92 } 93 94 return transport_cmd_finish_abort(cmd, remove); 95 } 96 97 static int target_check_cdb_and_preempt(struct list_head *list, 98 struct se_cmd *cmd) 99 { 100 struct t10_pr_registration *reg; 101 102 if (!list) 103 return 0; 104 list_for_each_entry(reg, list, pr_reg_abort_list) { 105 if (reg->pr_res_key == cmd->pr_res_key) 106 return 0; 107 } 108 109 return 1; 110 } 111 112 static bool __target_check_io_state(struct se_cmd *se_cmd, 113 struct se_session *tmr_sess, int tas) 114 { 115 struct se_session *sess = se_cmd->se_sess; 116 117 assert_spin_locked(&sess->sess_cmd_lock); 118 WARN_ON_ONCE(!irqs_disabled()); 119 /* 120 * If command already reached CMD_T_COMPLETE state within 121 * target_complete_cmd() or CMD_T_FABRIC_STOP due to shutdown, 122 * this se_cmd has been passed to fabric driver and will 123 * not be aborted. 124 * 125 * Otherwise, obtain a local se_cmd->cmd_kref now for TMR 126 * ABORT_TASK + LUN_RESET for CMD_T_ABORTED processing as 127 * long as se_cmd->cmd_kref is still active unless zero. 128 */ 129 spin_lock(&se_cmd->t_state_lock); 130 if (se_cmd->transport_state & (CMD_T_COMPLETE | CMD_T_FABRIC_STOP)) { 131 pr_debug("Attempted to abort io tag: %llu already complete or" 132 " fabric stop, skipping\n", se_cmd->tag); 133 spin_unlock(&se_cmd->t_state_lock); 134 return false; 135 } 136 if (se_cmd->transport_state & CMD_T_PRE_EXECUTE) { 137 if (se_cmd->scsi_status) { 138 pr_debug("Attempted to abort io tag: %llu early failure" 139 " status: 0x%02x\n", se_cmd->tag, 140 se_cmd->scsi_status); 141 spin_unlock(&se_cmd->t_state_lock); 142 return false; 143 } 144 } 145 if (sess->sess_tearing_down || se_cmd->cmd_wait_set) { 146 pr_debug("Attempted to abort io tag: %llu already shutdown," 147 " skipping\n", se_cmd->tag); 148 spin_unlock(&se_cmd->t_state_lock); 149 return false; 150 } 151 se_cmd->transport_state |= CMD_T_ABORTED; 152 153 if ((tmr_sess != se_cmd->se_sess) && tas) 154 se_cmd->transport_state |= CMD_T_TAS; 155 156 spin_unlock(&se_cmd->t_state_lock); 157 158 return kref_get_unless_zero(&se_cmd->cmd_kref); 159 } 160 161 void core_tmr_abort_task( 162 struct se_device *dev, 163 struct se_tmr_req *tmr, 164 struct se_session *se_sess) 165 { 166 struct se_cmd *se_cmd; 167 unsigned long flags; 168 u64 ref_tag; 169 170 spin_lock_irqsave(&se_sess->sess_cmd_lock, flags); 171 list_for_each_entry(se_cmd, &se_sess->sess_cmd_list, se_cmd_list) { 172 173 if (dev != se_cmd->se_dev) 174 continue; 175 176 /* skip task management functions, including tmr->task_cmd */ 177 if (se_cmd->se_cmd_flags & SCF_SCSI_TMR_CDB) 178 continue; 179 180 ref_tag = se_cmd->tag; 181 if (tmr->ref_task_tag != ref_tag) 182 continue; 183 184 printk("ABORT_TASK: Found referenced %s task_tag: %llu\n", 185 se_cmd->se_tfo->get_fabric_name(), ref_tag); 186 187 if (!__target_check_io_state(se_cmd, se_sess, 0)) 188 continue; 189 190 list_del_init(&se_cmd->se_cmd_list); 191 spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags); 192 193 cancel_work_sync(&se_cmd->work); 194 transport_wait_for_tasks(se_cmd); 195 196 if (!transport_cmd_finish_abort(se_cmd, true)) 197 target_put_sess_cmd(se_cmd); 198 199 printk("ABORT_TASK: Sending TMR_FUNCTION_COMPLETE for" 200 " ref_tag: %llu\n", ref_tag); 201 tmr->response = TMR_FUNCTION_COMPLETE; 202 atomic_long_inc(&dev->aborts_complete); 203 return; 204 } 205 spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags); 206 207 printk("ABORT_TASK: Sending TMR_TASK_DOES_NOT_EXIST for ref_tag: %lld\n", 208 tmr->ref_task_tag); 209 tmr->response = TMR_TASK_DOES_NOT_EXIST; 210 atomic_long_inc(&dev->aborts_no_task); 211 } 212 213 static void core_tmr_drain_tmr_list( 214 struct se_device *dev, 215 struct se_tmr_req *tmr, 216 struct list_head *preempt_and_abort_list) 217 { 218 LIST_HEAD(drain_tmr_list); 219 struct se_session *sess; 220 struct se_tmr_req *tmr_p, *tmr_pp; 221 struct se_cmd *cmd; 222 unsigned long flags; 223 bool rc; 224 /* 225 * Release all pending and outgoing TMRs aside from the received 226 * LUN_RESET tmr.. 227 */ 228 spin_lock_irqsave(&dev->se_tmr_lock, flags); 229 if (tmr) 230 list_del_init(&tmr->tmr_list); 231 list_for_each_entry_safe(tmr_p, tmr_pp, &dev->dev_tmr_list, tmr_list) { 232 cmd = tmr_p->task_cmd; 233 if (!cmd) { 234 pr_err("Unable to locate struct se_cmd for TMR\n"); 235 continue; 236 } 237 /* 238 * If this function was called with a valid pr_res_key 239 * parameter (eg: for PROUT PREEMPT_AND_ABORT service action 240 * skip non registration key matching TMRs. 241 */ 242 if (target_check_cdb_and_preempt(preempt_and_abort_list, cmd)) 243 continue; 244 245 sess = cmd->se_sess; 246 if (WARN_ON_ONCE(!sess)) 247 continue; 248 249 spin_lock(&sess->sess_cmd_lock); 250 spin_lock(&cmd->t_state_lock); 251 if (!(cmd->transport_state & CMD_T_ACTIVE) || 252 (cmd->transport_state & CMD_T_FABRIC_STOP)) { 253 spin_unlock(&cmd->t_state_lock); 254 spin_unlock(&sess->sess_cmd_lock); 255 continue; 256 } 257 if (cmd->t_state == TRANSPORT_ISTATE_PROCESSING) { 258 spin_unlock(&cmd->t_state_lock); 259 spin_unlock(&sess->sess_cmd_lock); 260 continue; 261 } 262 if (sess->sess_tearing_down || cmd->cmd_wait_set) { 263 spin_unlock(&cmd->t_state_lock); 264 spin_unlock(&sess->sess_cmd_lock); 265 continue; 266 } 267 cmd->transport_state |= CMD_T_ABORTED; 268 spin_unlock(&cmd->t_state_lock); 269 270 rc = kref_get_unless_zero(&cmd->cmd_kref); 271 if (!rc) { 272 printk("LUN_RESET TMR: non-zero kref_get_unless_zero\n"); 273 spin_unlock(&sess->sess_cmd_lock); 274 continue; 275 } 276 spin_unlock(&sess->sess_cmd_lock); 277 278 list_move_tail(&tmr_p->tmr_list, &drain_tmr_list); 279 } 280 spin_unlock_irqrestore(&dev->se_tmr_lock, flags); 281 282 list_for_each_entry_safe(tmr_p, tmr_pp, &drain_tmr_list, tmr_list) { 283 list_del_init(&tmr_p->tmr_list); 284 cmd = tmr_p->task_cmd; 285 286 pr_debug("LUN_RESET: %s releasing TMR %p Function: 0x%02x," 287 " Response: 0x%02x, t_state: %d\n", 288 (preempt_and_abort_list) ? "Preempt" : "", tmr_p, 289 tmr_p->function, tmr_p->response, cmd->t_state); 290 291 cancel_work_sync(&cmd->work); 292 transport_wait_for_tasks(cmd); 293 294 if (!transport_cmd_finish_abort(cmd, 1)) 295 target_put_sess_cmd(cmd); 296 } 297 } 298 299 static void core_tmr_drain_state_list( 300 struct se_device *dev, 301 struct se_cmd *prout_cmd, 302 struct se_session *tmr_sess, 303 int tas, 304 struct list_head *preempt_and_abort_list) 305 { 306 LIST_HEAD(drain_task_list); 307 struct se_session *sess; 308 struct se_cmd *cmd, *next; 309 unsigned long flags; 310 int rc; 311 312 /* 313 * Complete outstanding commands with TASK_ABORTED SAM status. 314 * 315 * This is following sam4r17, section 5.6 Aborting commands, Table 38 316 * for TMR LUN_RESET: 317 * 318 * a) "Yes" indicates that each command that is aborted on an I_T nexus 319 * other than the one that caused the SCSI device condition is 320 * completed with TASK ABORTED status, if the TAS bit is set to one in 321 * the Control mode page (see SPC-4). "No" indicates that no status is 322 * returned for aborted commands. 323 * 324 * d) If the logical unit reset is caused by a particular I_T nexus 325 * (e.g., by a LOGICAL UNIT RESET task management function), then "yes" 326 * (TASK_ABORTED status) applies. 327 * 328 * Otherwise (e.g., if triggered by a hard reset), "no" 329 * (no TASK_ABORTED SAM status) applies. 330 * 331 * Note that this seems to be independent of TAS (Task Aborted Status) 332 * in the Control Mode Page. 333 */ 334 spin_lock_irqsave(&dev->execute_task_lock, flags); 335 list_for_each_entry_safe(cmd, next, &dev->state_list, state_list) { 336 /* 337 * For PREEMPT_AND_ABORT usage, only process commands 338 * with a matching reservation key. 339 */ 340 if (target_check_cdb_and_preempt(preempt_and_abort_list, cmd)) 341 continue; 342 343 /* 344 * Not aborting PROUT PREEMPT_AND_ABORT CDB.. 345 */ 346 if (prout_cmd == cmd) 347 continue; 348 349 sess = cmd->se_sess; 350 if (WARN_ON_ONCE(!sess)) 351 continue; 352 353 spin_lock(&sess->sess_cmd_lock); 354 rc = __target_check_io_state(cmd, tmr_sess, tas); 355 spin_unlock(&sess->sess_cmd_lock); 356 if (!rc) 357 continue; 358 359 list_move_tail(&cmd->state_list, &drain_task_list); 360 cmd->state_active = false; 361 } 362 spin_unlock_irqrestore(&dev->execute_task_lock, flags); 363 364 while (!list_empty(&drain_task_list)) { 365 cmd = list_entry(drain_task_list.next, struct se_cmd, state_list); 366 list_del_init(&cmd->state_list); 367 368 target_show_cmd("LUN_RESET: ", cmd); 369 pr_debug("LUN_RESET: ITT[0x%08llx] - %s pr_res_key: 0x%016Lx\n", 370 cmd->tag, (preempt_and_abort_list) ? "preempt" : "", 371 cmd->pr_res_key); 372 373 /* 374 * If the command may be queued onto a workqueue cancel it now. 375 * 376 * This is equivalent to removal from the execute queue in the 377 * loop above, but we do it down here given that 378 * cancel_work_sync may block. 379 */ 380 cancel_work_sync(&cmd->work); 381 transport_wait_for_tasks(cmd); 382 383 if (!core_tmr_handle_tas_abort(cmd, tas)) 384 target_put_sess_cmd(cmd); 385 } 386 } 387 388 int core_tmr_lun_reset( 389 struct se_device *dev, 390 struct se_tmr_req *tmr, 391 struct list_head *preempt_and_abort_list, 392 struct se_cmd *prout_cmd) 393 { 394 struct se_node_acl *tmr_nacl = NULL; 395 struct se_portal_group *tmr_tpg = NULL; 396 struct se_session *tmr_sess = NULL; 397 int tas; 398 /* 399 * TASK_ABORTED status bit, this is configurable via ConfigFS 400 * struct se_device attributes. spc4r17 section 7.4.6 Control mode page 401 * 402 * A task aborted status (TAS) bit set to zero specifies that aborted 403 * tasks shall be terminated by the device server without any response 404 * to the application client. A TAS bit set to one specifies that tasks 405 * aborted by the actions of an I_T nexus other than the I_T nexus on 406 * which the command was received shall be completed with TASK ABORTED 407 * status (see SAM-4). 408 */ 409 tas = dev->dev_attrib.emulate_tas; 410 /* 411 * Determine if this se_tmr is coming from a $FABRIC_MOD 412 * or struct se_device passthrough.. 413 */ 414 if (tmr && tmr->task_cmd && tmr->task_cmd->se_sess) { 415 tmr_sess = tmr->task_cmd->se_sess; 416 tmr_nacl = tmr_sess->se_node_acl; 417 tmr_tpg = tmr_sess->se_tpg; 418 if (tmr_nacl && tmr_tpg) { 419 pr_debug("LUN_RESET: TMR caller fabric: %s" 420 " initiator port %s\n", 421 tmr_tpg->se_tpg_tfo->get_fabric_name(), 422 tmr_nacl->initiatorname); 423 } 424 } 425 pr_debug("LUN_RESET: %s starting for [%s], tas: %d\n", 426 (preempt_and_abort_list) ? "Preempt" : "TMR", 427 dev->transport->name, tas); 428 429 core_tmr_drain_tmr_list(dev, tmr, preempt_and_abort_list); 430 core_tmr_drain_state_list(dev, prout_cmd, tmr_sess, tas, 431 preempt_and_abort_list); 432 433 /* 434 * Clear any legacy SPC-2 reservation when called during 435 * LOGICAL UNIT RESET 436 */ 437 if (!preempt_and_abort_list && 438 (dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS)) { 439 spin_lock(&dev->dev_reservation_lock); 440 dev->dev_reserved_node_acl = NULL; 441 dev->dev_reservation_flags &= ~DRF_SPC2_RESERVATIONS; 442 spin_unlock(&dev->dev_reservation_lock); 443 pr_debug("LUN_RESET: SCSI-2 Released reservation\n"); 444 } 445 446 atomic_long_inc(&dev->num_resets); 447 448 pr_debug("LUN_RESET: %s for [%s] Complete\n", 449 (preempt_and_abort_list) ? "Preempt" : "TMR", 450 dev->transport->name); 451 return 0; 452 } 453 454