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