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