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 void 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 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 (sess->sess_tearing_down || se_cmd->cmd_wait_set) { 137 pr_debug("Attempted to abort io tag: %llu already shutdown," 138 " skipping\n", se_cmd->tag); 139 spin_unlock(&se_cmd->t_state_lock); 140 return false; 141 } 142 se_cmd->transport_state |= CMD_T_ABORTED; 143 144 if ((tmr_sess != se_cmd->se_sess) && tas) 145 se_cmd->transport_state |= CMD_T_TAS; 146 147 spin_unlock(&se_cmd->t_state_lock); 148 149 return kref_get_unless_zero(&se_cmd->cmd_kref); 150 } 151 152 void core_tmr_abort_task( 153 struct se_device *dev, 154 struct se_tmr_req *tmr, 155 struct se_session *se_sess) 156 { 157 struct se_cmd *se_cmd; 158 unsigned long flags; 159 u64 ref_tag; 160 161 spin_lock_irqsave(&se_sess->sess_cmd_lock, flags); 162 list_for_each_entry(se_cmd, &se_sess->sess_cmd_list, se_cmd_list) { 163 164 if (dev != se_cmd->se_dev) 165 continue; 166 167 /* skip task management functions, including tmr->task_cmd */ 168 if (se_cmd->se_cmd_flags & SCF_SCSI_TMR_CDB) 169 continue; 170 171 ref_tag = se_cmd->tag; 172 if (tmr->ref_task_tag != ref_tag) 173 continue; 174 175 printk("ABORT_TASK: Found referenced %s task_tag: %llu\n", 176 se_cmd->se_tfo->get_fabric_name(), ref_tag); 177 178 if (!__target_check_io_state(se_cmd, se_sess, 0)) { 179 spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags); 180 target_put_sess_cmd(se_cmd); 181 goto out; 182 } 183 list_del_init(&se_cmd->se_cmd_list); 184 spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags); 185 186 cancel_work_sync(&se_cmd->work); 187 transport_wait_for_tasks(se_cmd); 188 189 transport_cmd_finish_abort(se_cmd, true); 190 target_put_sess_cmd(se_cmd); 191 192 printk("ABORT_TASK: Sending TMR_FUNCTION_COMPLETE for" 193 " ref_tag: %llu\n", ref_tag); 194 tmr->response = TMR_FUNCTION_COMPLETE; 195 return; 196 } 197 spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags); 198 199 out: 200 printk("ABORT_TASK: Sending TMR_TASK_DOES_NOT_EXIST for ref_tag: %lld\n", 201 tmr->ref_task_tag); 202 tmr->response = TMR_TASK_DOES_NOT_EXIST; 203 } 204 205 static void core_tmr_drain_tmr_list( 206 struct se_device *dev, 207 struct se_tmr_req *tmr, 208 struct list_head *preempt_and_abort_list) 209 { 210 LIST_HEAD(drain_tmr_list); 211 struct se_session *sess; 212 struct se_tmr_req *tmr_p, *tmr_pp; 213 struct se_cmd *cmd; 214 unsigned long flags; 215 bool rc; 216 /* 217 * Release all pending and outgoing TMRs aside from the received 218 * LUN_RESET tmr.. 219 */ 220 spin_lock_irqsave(&dev->se_tmr_lock, flags); 221 list_for_each_entry_safe(tmr_p, tmr_pp, &dev->dev_tmr_list, tmr_list) { 222 /* 223 * Allow the received TMR to return with FUNCTION_COMPLETE. 224 */ 225 if (tmr_p == tmr) 226 continue; 227 228 cmd = tmr_p->task_cmd; 229 if (!cmd) { 230 pr_err("Unable to locate struct se_cmd for TMR\n"); 231 continue; 232 } 233 /* 234 * If this function was called with a valid pr_res_key 235 * parameter (eg: for PROUT PREEMPT_AND_ABORT service action 236 * skip non registration key matching TMRs. 237 */ 238 if (target_check_cdb_and_preempt(preempt_and_abort_list, cmd)) 239 continue; 240 241 sess = cmd->se_sess; 242 if (WARN_ON_ONCE(!sess)) 243 continue; 244 245 spin_lock(&sess->sess_cmd_lock); 246 spin_lock(&cmd->t_state_lock); 247 if (!(cmd->transport_state & CMD_T_ACTIVE) || 248 (cmd->transport_state & CMD_T_FABRIC_STOP)) { 249 spin_unlock(&cmd->t_state_lock); 250 spin_unlock(&sess->sess_cmd_lock); 251 continue; 252 } 253 if (cmd->t_state == TRANSPORT_ISTATE_PROCESSING) { 254 spin_unlock(&cmd->t_state_lock); 255 spin_unlock(&sess->sess_cmd_lock); 256 continue; 257 } 258 if (sess->sess_tearing_down || cmd->cmd_wait_set) { 259 spin_unlock(&cmd->t_state_lock); 260 spin_unlock(&sess->sess_cmd_lock); 261 continue; 262 } 263 cmd->transport_state |= CMD_T_ABORTED; 264 spin_unlock(&cmd->t_state_lock); 265 266 rc = kref_get_unless_zero(&cmd->cmd_kref); 267 if (!rc) { 268 printk("LUN_RESET TMR: non-zero kref_get_unless_zero\n"); 269 spin_unlock(&sess->sess_cmd_lock); 270 continue; 271 } 272 spin_unlock(&sess->sess_cmd_lock); 273 274 list_move_tail(&tmr_p->tmr_list, &drain_tmr_list); 275 } 276 spin_unlock_irqrestore(&dev->se_tmr_lock, flags); 277 278 list_for_each_entry_safe(tmr_p, tmr_pp, &drain_tmr_list, tmr_list) { 279 list_del_init(&tmr_p->tmr_list); 280 cmd = tmr_p->task_cmd; 281 282 pr_debug("LUN_RESET: %s releasing TMR %p Function: 0x%02x," 283 " Response: 0x%02x, t_state: %d\n", 284 (preempt_and_abort_list) ? "Preempt" : "", tmr_p, 285 tmr_p->function, tmr_p->response, cmd->t_state); 286 287 cancel_work_sync(&cmd->work); 288 transport_wait_for_tasks(cmd); 289 290 transport_cmd_finish_abort(cmd, 1); 291 target_put_sess_cmd(cmd); 292 } 293 } 294 295 static void core_tmr_drain_state_list( 296 struct se_device *dev, 297 struct se_cmd *prout_cmd, 298 struct se_session *tmr_sess, 299 int tas, 300 struct list_head *preempt_and_abort_list) 301 { 302 LIST_HEAD(drain_task_list); 303 struct se_session *sess; 304 struct se_cmd *cmd, *next; 305 unsigned long flags; 306 int rc; 307 308 /* 309 * Complete outstanding commands with TASK_ABORTED SAM status. 310 * 311 * This is following sam4r17, section 5.6 Aborting commands, Table 38 312 * for TMR LUN_RESET: 313 * 314 * a) "Yes" indicates that each command that is aborted on an I_T nexus 315 * other than the one that caused the SCSI device condition is 316 * completed with TASK ABORTED status, if the TAS bit is set to one in 317 * the Control mode page (see SPC-4). "No" indicates that no status is 318 * returned for aborted commands. 319 * 320 * d) If the logical unit reset is caused by a particular I_T nexus 321 * (e.g., by a LOGICAL UNIT RESET task management function), then "yes" 322 * (TASK_ABORTED status) applies. 323 * 324 * Otherwise (e.g., if triggered by a hard reset), "no" 325 * (no TASK_ABORTED SAM status) applies. 326 * 327 * Note that this seems to be independent of TAS (Task Aborted Status) 328 * in the Control Mode Page. 329 */ 330 spin_lock_irqsave(&dev->execute_task_lock, flags); 331 list_for_each_entry_safe(cmd, next, &dev->state_list, state_list) { 332 /* 333 * For PREEMPT_AND_ABORT usage, only process commands 334 * with a matching reservation key. 335 */ 336 if (target_check_cdb_and_preempt(preempt_and_abort_list, cmd)) 337 continue; 338 339 /* 340 * Not aborting PROUT PREEMPT_AND_ABORT CDB.. 341 */ 342 if (prout_cmd == cmd) 343 continue; 344 345 sess = cmd->se_sess; 346 if (WARN_ON_ONCE(!sess)) 347 continue; 348 349 spin_lock(&sess->sess_cmd_lock); 350 rc = __target_check_io_state(cmd, tmr_sess, tas); 351 spin_unlock(&sess->sess_cmd_lock); 352 if (!rc) 353 continue; 354 355 list_move_tail(&cmd->state_list, &drain_task_list); 356 cmd->state_active = false; 357 } 358 spin_unlock_irqrestore(&dev->execute_task_lock, flags); 359 360 while (!list_empty(&drain_task_list)) { 361 cmd = list_entry(drain_task_list.next, struct se_cmd, state_list); 362 list_del_init(&cmd->state_list); 363 364 pr_debug("LUN_RESET: %s cmd: %p" 365 " ITT/CmdSN: 0x%08llx/0x%08x, i_state: %d, t_state: %d" 366 "cdb: 0x%02x\n", 367 (preempt_and_abort_list) ? "Preempt" : "", cmd, 368 cmd->tag, 0, 369 cmd->se_tfo->get_cmd_state(cmd), cmd->t_state, 370 cmd->t_task_cdb[0]); 371 pr_debug("LUN_RESET: ITT[0x%08llx] - pr_res_key: 0x%016Lx" 372 " -- CMD_T_ACTIVE: %d" 373 " CMD_T_STOP: %d CMD_T_SENT: %d\n", 374 cmd->tag, cmd->pr_res_key, 375 (cmd->transport_state & CMD_T_ACTIVE) != 0, 376 (cmd->transport_state & CMD_T_STOP) != 0, 377 (cmd->transport_state & CMD_T_SENT) != 0); 378 379 /* 380 * If the command may be queued onto a workqueue cancel it now. 381 * 382 * This is equivalent to removal from the execute queue in the 383 * loop above, but we do it down here given that 384 * cancel_work_sync may block. 385 */ 386 cancel_work_sync(&cmd->work); 387 transport_wait_for_tasks(cmd); 388 389 core_tmr_handle_tas_abort(cmd, tas); 390 target_put_sess_cmd(cmd); 391 } 392 } 393 394 int core_tmr_lun_reset( 395 struct se_device *dev, 396 struct se_tmr_req *tmr, 397 struct list_head *preempt_and_abort_list, 398 struct se_cmd *prout_cmd) 399 { 400 struct se_node_acl *tmr_nacl = NULL; 401 struct se_portal_group *tmr_tpg = NULL; 402 struct se_session *tmr_sess = NULL; 403 int tas; 404 /* 405 * TASK_ABORTED status bit, this is configurable via ConfigFS 406 * struct se_device attributes. spc4r17 section 7.4.6 Control mode page 407 * 408 * A task aborted status (TAS) bit set to zero specifies that aborted 409 * tasks shall be terminated by the device server without any response 410 * to the application client. A TAS bit set to one specifies that tasks 411 * aborted by the actions of an I_T nexus other than the I_T nexus on 412 * which the command was received shall be completed with TASK ABORTED 413 * status (see SAM-4). 414 */ 415 tas = dev->dev_attrib.emulate_tas; 416 /* 417 * Determine if this se_tmr is coming from a $FABRIC_MOD 418 * or struct se_device passthrough.. 419 */ 420 if (tmr && tmr->task_cmd && tmr->task_cmd->se_sess) { 421 tmr_sess = tmr->task_cmd->se_sess; 422 tmr_nacl = tmr_sess->se_node_acl; 423 tmr_tpg = tmr_sess->se_tpg; 424 if (tmr_nacl && tmr_tpg) { 425 pr_debug("LUN_RESET: TMR caller fabric: %s" 426 " initiator port %s\n", 427 tmr_tpg->se_tpg_tfo->get_fabric_name(), 428 tmr_nacl->initiatorname); 429 } 430 } 431 pr_debug("LUN_RESET: %s starting for [%s], tas: %d\n", 432 (preempt_and_abort_list) ? "Preempt" : "TMR", 433 dev->transport->name, tas); 434 435 core_tmr_drain_tmr_list(dev, tmr, preempt_and_abort_list); 436 core_tmr_drain_state_list(dev, prout_cmd, tmr_sess, tas, 437 preempt_and_abort_list); 438 439 /* 440 * Clear any legacy SPC-2 reservation when called during 441 * LOGICAL UNIT RESET 442 */ 443 if (!preempt_and_abort_list && 444 (dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS)) { 445 spin_lock(&dev->dev_reservation_lock); 446 dev->dev_reserved_node_acl = NULL; 447 dev->dev_reservation_flags &= ~DRF_SPC2_RESERVATIONS; 448 spin_unlock(&dev->dev_reservation_lock); 449 pr_debug("LUN_RESET: SCSI-2 Released reservation\n"); 450 } 451 452 atomic_long_inc(&dev->num_resets); 453 454 pr_debug("LUN_RESET: %s for [%s] Complete\n", 455 (preempt_and_abort_list) ? "Preempt" : "TMR", 456 dev->transport->name); 457 return 0; 458 } 459 460