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#include <scsi/scsi.h> 31#include <scsi/scsi_cmnd.h> 32 33#include <target/target_core_base.h> 34#include <target/target_core_backend.h> 35#include <target/target_core_fabric.h> 36#include <target/target_core_configfs.h> 37 38#include "target_core_internal.h" 39#include "target_core_alua.h" 40#include "target_core_pr.h" 41 42int core_tmr_alloc_req( 43 struct se_cmd *se_cmd, 44 void *fabric_tmr_ptr, 45 u8 function, 46 gfp_t gfp_flags) 47{ 48 struct se_tmr_req *tmr; 49 50 tmr = kzalloc(sizeof(struct se_tmr_req), gfp_flags); 51 if (!tmr) { 52 pr_err("Unable to allocate struct se_tmr_req\n"); 53 return -ENOMEM; 54 } 55 56 se_cmd->se_cmd_flags |= SCF_SCSI_TMR_CDB; 57 se_cmd->se_tmr_req = tmr; 58 tmr->task_cmd = se_cmd; 59 tmr->fabric_tmr_ptr = fabric_tmr_ptr; 60 tmr->function = function; 61 INIT_LIST_HEAD(&tmr->tmr_list); 62 63 return 0; 64} 65EXPORT_SYMBOL(core_tmr_alloc_req); 66 67void core_tmr_release_req(struct se_tmr_req *tmr) 68{ 69 struct se_device *dev = tmr->tmr_dev; 70 unsigned long flags; 71 72 if (dev) { 73 spin_lock_irqsave(&dev->se_tmr_lock, flags); 74 list_del_init(&tmr->tmr_list); 75 spin_unlock_irqrestore(&dev->se_tmr_lock, flags); 76 } 77 78 kfree(tmr); 79} 80 81static void core_tmr_handle_tas_abort(struct se_cmd *cmd, int tas) 82{ 83 unsigned long flags; 84 bool remove = true, send_tas; 85 /* 86 * TASK ABORTED status (TAS) bit support 87 */ 88 spin_lock_irqsave(&cmd->t_state_lock, flags); 89 send_tas = (cmd->transport_state & CMD_T_TAS); 90 spin_unlock_irqrestore(&cmd->t_state_lock, flags); 91 92 if (send_tas) { 93 remove = false; 94 transport_send_task_abort(cmd); 95 } 96 97 transport_cmd_finish_abort(cmd, remove); 98} 99 100static int target_check_cdb_and_preempt(struct list_head *list, 101 struct se_cmd *cmd) 102{ 103 struct t10_pr_registration *reg; 104 105 if (!list) 106 return 0; 107 list_for_each_entry(reg, list, pr_reg_abort_list) { 108 if (reg->pr_res_key == cmd->pr_res_key) 109 return 0; 110 } 111 112 return 1; 113} 114 115static bool __target_check_io_state(struct se_cmd *se_cmd, 116 struct se_session *tmr_sess, int tas) 117{ 118 struct se_session *sess = se_cmd->se_sess; 119 120 assert_spin_locked(&sess->sess_cmd_lock); 121 WARN_ON_ONCE(!irqs_disabled()); 122 /* 123 * If command already reached CMD_T_COMPLETE state within 124 * target_complete_cmd() or CMD_T_FABRIC_STOP due to shutdown, 125 * this se_cmd has been passed to fabric driver and will 126 * not be aborted. 127 * 128 * Otherwise, obtain a local se_cmd->cmd_kref now for TMR 129 * ABORT_TASK + LUN_RESET for CMD_T_ABORTED processing as 130 * long as se_cmd->cmd_kref is still active unless zero. 131 */ 132 spin_lock(&se_cmd->t_state_lock); 133 if (se_cmd->transport_state & (CMD_T_COMPLETE | CMD_T_FABRIC_STOP)) { 134 pr_debug("Attempted to abort io tag: %u already complete or" 135 " fabric stop, skipping\n", 136 se_cmd->se_tfo->get_task_tag(se_cmd)); 137 spin_unlock(&se_cmd->t_state_lock); 138 return false; 139 } 140 if (sess->sess_tearing_down || se_cmd->cmd_wait_set) { 141 pr_debug("Attempted to abort io tag: %u already shutdown," 142 " skipping\n", se_cmd->se_tfo->get_task_tag(se_cmd)); 143 spin_unlock(&se_cmd->t_state_lock); 144 return false; 145 } 146 se_cmd->transport_state |= CMD_T_ABORTED; 147 148 if ((tmr_sess != se_cmd->se_sess) && tas) 149 se_cmd->transport_state |= CMD_T_TAS; 150 151 spin_unlock(&se_cmd->t_state_lock); 152 153 return kref_get_unless_zero(&se_cmd->cmd_kref); 154} 155 156void core_tmr_abort_task( 157 struct se_device *dev, 158 struct se_tmr_req *tmr, 159 struct se_session *se_sess) 160{ 161 struct se_cmd *se_cmd; 162 unsigned long flags; 163 int ref_tag; 164 165 spin_lock_irqsave(&se_sess->sess_cmd_lock, flags); 166 list_for_each_entry(se_cmd, &se_sess->sess_cmd_list, se_cmd_list) { 167 168 if (dev != se_cmd->se_dev) 169 continue; 170 171 /* skip task management functions, including tmr->task_cmd */ 172 if (se_cmd->se_cmd_flags & SCF_SCSI_TMR_CDB) 173 continue; 174 175 ref_tag = se_cmd->se_tfo->get_task_tag(se_cmd); 176 if (tmr->ref_task_tag != ref_tag) 177 continue; 178 179 printk("ABORT_TASK: Found referenced %s task_tag: %u\n", 180 se_cmd->se_tfo->get_fabric_name(), ref_tag); 181 182 if (!__target_check_io_state(se_cmd, se_sess, 0)) { 183 spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags); 184 goto out; 185 } 186 187 list_del_init(&se_cmd->se_cmd_list); 188 spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags); 189 190 cancel_work_sync(&se_cmd->work); 191 transport_wait_for_tasks(se_cmd); 192 193 transport_cmd_finish_abort(se_cmd, true); 194 target_put_sess_cmd(se_cmd); 195 196 printk("ABORT_TASK: Sending TMR_FUNCTION_COMPLETE for" 197 " ref_tag: %d\n", ref_tag); 198 tmr->response = TMR_FUNCTION_COMPLETE; 199 return; 200 } 201 spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags); 202 203out: 204 printk("ABORT_TASK: Sending TMR_TASK_DOES_NOT_EXIST for ref_tag: %d\n", 205 tmr->ref_task_tag); 206 tmr->response = TMR_TASK_DOES_NOT_EXIST; 207} 208 209static void core_tmr_drain_tmr_list( 210 struct se_device *dev, 211 struct se_tmr_req *tmr, 212 struct list_head *preempt_and_abort_list) 213{ 214 LIST_HEAD(drain_tmr_list); 215 struct se_session *sess; 216 struct se_tmr_req *tmr_p, *tmr_pp; 217 struct se_cmd *cmd; 218 unsigned long flags; 219 bool rc; 220 /* 221 * Release all pending and outgoing TMRs aside from the received 222 * LUN_RESET tmr.. 223 */ 224 spin_lock_irqsave(&dev->se_tmr_lock, flags); 225 list_for_each_entry_safe(tmr_p, tmr_pp, &dev->dev_tmr_list, tmr_list) { 226 /* 227 * Allow the received TMR to return with FUNCTION_COMPLETE. 228 */ 229 if (tmr_p == tmr) 230 continue; 231 232 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 regisration 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 transport_cmd_finish_abort(cmd, 1); 295 target_put_sess_cmd(cmd); 296 } 297} 298 299static 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 pr_debug("LUN_RESET: %s cmd: %p" 369 " ITT/CmdSN: 0x%08x/0x%08x, i_state: %d, t_state: %d" 370 "cdb: 0x%02x\n", 371 (preempt_and_abort_list) ? "Preempt" : "", cmd, 372 cmd->se_tfo->get_task_tag(cmd), 0, 373 cmd->se_tfo->get_cmd_state(cmd), cmd->t_state, 374 cmd->t_task_cdb[0]); 375 pr_debug("LUN_RESET: ITT[0x%08x] - pr_res_key: 0x%016Lx" 376 " -- CMD_T_ACTIVE: %d" 377 " CMD_T_STOP: %d CMD_T_SENT: %d\n", 378 cmd->se_tfo->get_task_tag(cmd), cmd->pr_res_key, 379 (cmd->transport_state & CMD_T_ACTIVE) != 0, 380 (cmd->transport_state & CMD_T_STOP) != 0, 381 (cmd->transport_state & CMD_T_SENT) != 0); 382 383 /* 384 * If the command may be queued onto a workqueue cancel it now. 385 * 386 * This is equivalent to removal from the execute queue in the 387 * loop above, but we do it down here given that 388 * cancel_work_sync may block. 389 */ 390 cancel_work_sync(&cmd->work); 391 transport_wait_for_tasks(cmd); 392 393 core_tmr_handle_tas_abort(cmd, tas); 394 target_put_sess_cmd(cmd); 395 } 396} 397 398int core_tmr_lun_reset( 399 struct se_device *dev, 400 struct se_tmr_req *tmr, 401 struct list_head *preempt_and_abort_list, 402 struct se_cmd *prout_cmd) 403{ 404 struct se_node_acl *tmr_nacl = NULL; 405 struct se_portal_group *tmr_tpg = NULL; 406 struct se_session *tmr_sess = NULL; 407 int tas; 408 /* 409 * TASK_ABORTED status bit, this is configurable via ConfigFS 410 * struct se_device attributes. spc4r17 section 7.4.6 Control mode page 411 * 412 * A task aborted status (TAS) bit set to zero specifies that aborted 413 * tasks shall be terminated by the device server without any response 414 * to the application client. A TAS bit set to one specifies that tasks 415 * aborted by the actions of an I_T nexus other than the I_T nexus on 416 * which the command was received shall be completed with TASK ABORTED 417 * status (see SAM-4). 418 */ 419 tas = dev->dev_attrib.emulate_tas; 420 /* 421 * Determine if this se_tmr is coming from a $FABRIC_MOD 422 * or struct se_device passthrough.. 423 */ 424 if (tmr && tmr->task_cmd && tmr->task_cmd->se_sess) { 425 tmr_sess = tmr->task_cmd->se_sess; 426 tmr_nacl = tmr_sess->se_node_acl; 427 tmr_tpg = tmr_sess->se_tpg; 428 if (tmr_nacl && tmr_tpg) { 429 pr_debug("LUN_RESET: TMR caller fabric: %s" 430 " initiator port %s\n", 431 tmr_tpg->se_tpg_tfo->get_fabric_name(), 432 tmr_nacl->initiatorname); 433 } 434 } 435 pr_debug("LUN_RESET: %s starting for [%s], tas: %d\n", 436 (preempt_and_abort_list) ? "Preempt" : "TMR", 437 dev->transport->name, tas); 438 439 core_tmr_drain_tmr_list(dev, tmr, preempt_and_abort_list); 440 core_tmr_drain_state_list(dev, prout_cmd, tmr_sess, tas, 441 preempt_and_abort_list); 442 443 /* 444 * Clear any legacy SPC-2 reservation when called during 445 * LOGICAL UNIT RESET 446 */ 447 if (!preempt_and_abort_list && 448 (dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS)) { 449 spin_lock(&dev->dev_reservation_lock); 450 dev->dev_reserved_node_acl = NULL; 451 dev->dev_reservation_flags &= ~DRF_SPC2_RESERVATIONS; 452 spin_unlock(&dev->dev_reservation_lock); 453 pr_debug("LUN_RESET: SCSI-2 Released reservation\n"); 454 } 455 456 atomic_long_inc(&dev->num_resets); 457 458 pr_debug("LUN_RESET: %s for [%s] Complete\n", 459 (preempt_and_abort_list) ? "Preempt" : "TMR", 460 dev->transport->name); 461 return 0; 462} 463 464