1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /******************************************************************************* 3 * Filename: target_core_tmr.c 4 * 5 * This file contains SPC-3 task management infrastructure 6 * 7 * (c) Copyright 2009-2013 Datera, Inc. 8 * 9 * Nicholas A. Bellinger <nab@kernel.org> 10 * 11 ******************************************************************************/ 12 13 #include <linux/slab.h> 14 #include <linux/spinlock.h> 15 #include <linux/list.h> 16 #include <linux/export.h> 17 18 #include <target/target_core_base.h> 19 #include <target/target_core_backend.h> 20 #include <target/target_core_fabric.h> 21 22 #include "target_core_internal.h" 23 #include "target_core_alua.h" 24 #include "target_core_pr.h" 25 26 int core_tmr_alloc_req( 27 struct se_cmd *se_cmd, 28 void *fabric_tmr_ptr, 29 u8 function, 30 gfp_t gfp_flags) 31 { 32 struct se_tmr_req *tmr; 33 34 tmr = kzalloc(sizeof(struct se_tmr_req), gfp_flags); 35 if (!tmr) { 36 pr_err("Unable to allocate struct se_tmr_req\n"); 37 return -ENOMEM; 38 } 39 40 se_cmd->se_cmd_flags |= SCF_SCSI_TMR_CDB; 41 se_cmd->se_tmr_req = tmr; 42 tmr->task_cmd = se_cmd; 43 tmr->fabric_tmr_ptr = fabric_tmr_ptr; 44 tmr->function = function; 45 INIT_LIST_HEAD(&tmr->tmr_list); 46 47 return 0; 48 } 49 EXPORT_SYMBOL(core_tmr_alloc_req); 50 51 void core_tmr_release_req(struct se_tmr_req *tmr) 52 { 53 struct se_device *dev = tmr->tmr_dev; 54 unsigned long flags; 55 56 if (dev) { 57 spin_lock_irqsave(&dev->se_tmr_lock, flags); 58 list_del_init(&tmr->tmr_list); 59 spin_unlock_irqrestore(&dev->se_tmr_lock, flags); 60 } 61 62 kfree(tmr); 63 } 64 65 static int target_check_cdb_and_preempt(struct list_head *list, 66 struct se_cmd *cmd) 67 { 68 struct t10_pr_registration *reg; 69 70 if (!list) 71 return 0; 72 list_for_each_entry(reg, list, pr_reg_abort_list) { 73 if (reg->pr_res_key == cmd->pr_res_key) 74 return 0; 75 } 76 77 return 1; 78 } 79 80 static bool __target_check_io_state(struct se_cmd *se_cmd, 81 struct se_session *tmr_sess, bool tas) 82 { 83 struct se_session *sess = se_cmd->se_sess; 84 85 assert_spin_locked(&sess->sess_cmd_lock); 86 WARN_ON_ONCE(!irqs_disabled()); 87 /* 88 * If command already reached CMD_T_COMPLETE state within 89 * target_complete_cmd() or CMD_T_FABRIC_STOP due to shutdown, 90 * this se_cmd has been passed to fabric driver and will 91 * not be aborted. 92 * 93 * Otherwise, obtain a local se_cmd->cmd_kref now for TMR 94 * ABORT_TASK + LUN_RESET for CMD_T_ABORTED processing as 95 * long as se_cmd->cmd_kref is still active unless zero. 96 */ 97 spin_lock(&se_cmd->t_state_lock); 98 if (se_cmd->transport_state & (CMD_T_COMPLETE | CMD_T_FABRIC_STOP)) { 99 pr_debug("Attempted to abort io tag: %llu already complete or" 100 " fabric stop, skipping\n", se_cmd->tag); 101 spin_unlock(&se_cmd->t_state_lock); 102 return false; 103 } 104 se_cmd->transport_state |= CMD_T_ABORTED; 105 106 if ((tmr_sess != se_cmd->se_sess) && tas) 107 se_cmd->transport_state |= CMD_T_TAS; 108 109 spin_unlock(&se_cmd->t_state_lock); 110 111 return kref_get_unless_zero(&se_cmd->cmd_kref); 112 } 113 114 void core_tmr_abort_task( 115 struct se_device *dev, 116 struct se_tmr_req *tmr, 117 struct se_session *se_sess) 118 { 119 LIST_HEAD(aborted_list); 120 struct se_cmd *se_cmd, *next; 121 unsigned long flags; 122 bool rc; 123 u64 ref_tag; 124 int i; 125 126 for (i = 0; i < dev->queue_cnt; i++) { 127 spin_lock_irqsave(&dev->queues[i].lock, flags); 128 list_for_each_entry_safe(se_cmd, next, &dev->queues[i].state_list, 129 state_list) { 130 if (se_sess != se_cmd->se_sess) 131 continue; 132 133 /* 134 * skip task management functions, including 135 * tmr->task_cmd 136 */ 137 if (se_cmd->se_cmd_flags & SCF_SCSI_TMR_CDB) 138 continue; 139 140 ref_tag = se_cmd->tag; 141 if (tmr->ref_task_tag != ref_tag) 142 continue; 143 144 pr_err("ABORT_TASK: Found referenced %s task_tag: %llu\n", 145 se_cmd->se_tfo->fabric_name, ref_tag); 146 147 spin_lock(&se_sess->sess_cmd_lock); 148 rc = __target_check_io_state(se_cmd, se_sess, 0); 149 spin_unlock(&se_sess->sess_cmd_lock); 150 if (!rc) 151 continue; 152 153 list_move_tail(&se_cmd->state_list, &aborted_list); 154 se_cmd->state_active = false; 155 spin_unlock_irqrestore(&dev->queues[i].lock, flags); 156 157 /* 158 * Ensure that this ABORT request is visible to the LU 159 * RESET code. 160 */ 161 if (!tmr->tmr_dev) 162 WARN_ON_ONCE(transport_lookup_tmr_lun(tmr->task_cmd) < 0); 163 164 if (dev->transport->tmr_notify) 165 dev->transport->tmr_notify(dev, TMR_ABORT_TASK, 166 &aborted_list); 167 168 list_del_init(&se_cmd->state_list); 169 target_put_cmd_and_wait(se_cmd); 170 171 pr_err("ABORT_TASK: Sending TMR_FUNCTION_COMPLETE for ref_tag: %llu\n", 172 ref_tag); 173 tmr->response = TMR_FUNCTION_COMPLETE; 174 atomic_long_inc(&dev->aborts_complete); 175 return; 176 } 177 spin_unlock_irqrestore(&dev->queues[i].lock, flags); 178 } 179 180 if (dev->transport->tmr_notify) 181 dev->transport->tmr_notify(dev, TMR_ABORT_TASK, &aborted_list); 182 183 printk("ABORT_TASK: Sending TMR_TASK_DOES_NOT_EXIST for ref_tag: %lld\n", 184 tmr->ref_task_tag); 185 tmr->response = TMR_TASK_DOES_NOT_EXIST; 186 atomic_long_inc(&dev->aborts_no_task); 187 } 188 189 static void core_tmr_drain_tmr_list( 190 struct se_device *dev, 191 struct se_tmr_req *tmr, 192 struct list_head *preempt_and_abort_list) 193 { 194 LIST_HEAD(drain_tmr_list); 195 struct se_session *sess; 196 struct se_tmr_req *tmr_p, *tmr_pp; 197 struct se_cmd *cmd; 198 unsigned long flags; 199 bool rc; 200 /* 201 * Release all pending and outgoing TMRs aside from the received 202 * LUN_RESET tmr.. 203 */ 204 spin_lock_irqsave(&dev->se_tmr_lock, flags); 205 if (tmr) 206 list_del_init(&tmr->tmr_list); 207 list_for_each_entry_safe(tmr_p, tmr_pp, &dev->dev_tmr_list, tmr_list) { 208 cmd = tmr_p->task_cmd; 209 if (!cmd) { 210 pr_err("Unable to locate struct se_cmd for TMR\n"); 211 continue; 212 } 213 /* 214 * If this function was called with a valid pr_res_key 215 * parameter (eg: for PROUT PREEMPT_AND_ABORT service action 216 * skip non registration key matching TMRs. 217 */ 218 if (target_check_cdb_and_preempt(preempt_and_abort_list, cmd)) 219 continue; 220 221 sess = cmd->se_sess; 222 if (WARN_ON_ONCE(!sess)) 223 continue; 224 225 spin_lock(&sess->sess_cmd_lock); 226 rc = __target_check_io_state(cmd, sess, 0); 227 spin_unlock(&sess->sess_cmd_lock); 228 229 if (!rc) { 230 printk("LUN_RESET TMR: non-zero kref_get_unless_zero\n"); 231 continue; 232 } 233 234 list_move_tail(&tmr_p->tmr_list, &drain_tmr_list); 235 } 236 spin_unlock_irqrestore(&dev->se_tmr_lock, flags); 237 238 list_for_each_entry_safe(tmr_p, tmr_pp, &drain_tmr_list, tmr_list) { 239 list_del_init(&tmr_p->tmr_list); 240 cmd = tmr_p->task_cmd; 241 242 pr_debug("LUN_RESET: %s releasing TMR %p Function: 0x%02x," 243 " Response: 0x%02x, t_state: %d\n", 244 (preempt_and_abort_list) ? "Preempt" : "", tmr_p, 245 tmr_p->function, tmr_p->response, cmd->t_state); 246 247 target_put_cmd_and_wait(cmd); 248 } 249 } 250 251 /** 252 * core_tmr_drain_state_list() - abort SCSI commands associated with a device 253 * 254 * @dev: Device for which to abort outstanding SCSI commands. 255 * @prout_cmd: Pointer to the SCSI PREEMPT AND ABORT if this function is called 256 * to realize the PREEMPT AND ABORT functionality. 257 * @tmr_sess: Session through which the LUN RESET has been received. 258 * @tas: Task Aborted Status (TAS) bit from the SCSI control mode page. 259 * A quote from SPC-4, paragraph "7.5.10 Control mode page": 260 * "A task aborted status (TAS) bit set to zero specifies that 261 * aborted commands shall be terminated by the device server 262 * without any response to the application client. A TAS bit set 263 * to one specifies that commands aborted by the actions of an I_T 264 * nexus other than the I_T nexus on which the command was 265 * received shall be completed with TASK ABORTED status." 266 * @preempt_and_abort_list: For the PREEMPT AND ABORT functionality, a list 267 * with registrations that will be preempted. 268 */ 269 static void core_tmr_drain_state_list( 270 struct se_device *dev, 271 struct se_cmd *prout_cmd, 272 struct se_session *tmr_sess, 273 bool tas, 274 struct list_head *preempt_and_abort_list) 275 { 276 LIST_HEAD(drain_task_list); 277 struct se_session *sess; 278 struct se_cmd *cmd, *next; 279 unsigned long flags; 280 int rc, i; 281 282 /* 283 * Complete outstanding commands with TASK_ABORTED SAM status. 284 * 285 * This is following sam4r17, section 5.6 Aborting commands, Table 38 286 * for TMR LUN_RESET: 287 * 288 * a) "Yes" indicates that each command that is aborted on an I_T nexus 289 * other than the one that caused the SCSI device condition is 290 * completed with TASK ABORTED status, if the TAS bit is set to one in 291 * the Control mode page (see SPC-4). "No" indicates that no status is 292 * returned for aborted commands. 293 * 294 * d) If the logical unit reset is caused by a particular I_T nexus 295 * (e.g., by a LOGICAL UNIT RESET task management function), then "yes" 296 * (TASK_ABORTED status) applies. 297 * 298 * Otherwise (e.g., if triggered by a hard reset), "no" 299 * (no TASK_ABORTED SAM status) applies. 300 * 301 * Note that this seems to be independent of TAS (Task Aborted Status) 302 * in the Control Mode Page. 303 */ 304 for (i = 0; i < dev->queue_cnt; i++) { 305 spin_lock_irqsave(&dev->queues[i].lock, flags); 306 list_for_each_entry_safe(cmd, next, &dev->queues[i].state_list, 307 state_list) { 308 /* 309 * For PREEMPT_AND_ABORT usage, only process commands 310 * with a matching reservation key. 311 */ 312 if (target_check_cdb_and_preempt(preempt_and_abort_list, 313 cmd)) 314 continue; 315 316 /* 317 * Not aborting PROUT PREEMPT_AND_ABORT CDB.. 318 */ 319 if (prout_cmd == cmd) 320 continue; 321 322 sess = cmd->se_sess; 323 if (WARN_ON_ONCE(!sess)) 324 continue; 325 326 spin_lock(&sess->sess_cmd_lock); 327 rc = __target_check_io_state(cmd, tmr_sess, tas); 328 spin_unlock(&sess->sess_cmd_lock); 329 if (!rc) 330 continue; 331 332 list_move_tail(&cmd->state_list, &drain_task_list); 333 cmd->state_active = false; 334 } 335 spin_unlock_irqrestore(&dev->queues[i].lock, flags); 336 } 337 338 if (dev->transport->tmr_notify) 339 dev->transport->tmr_notify(dev, preempt_and_abort_list ? 340 TMR_LUN_RESET_PRO : TMR_LUN_RESET, 341 &drain_task_list); 342 343 while (!list_empty(&drain_task_list)) { 344 cmd = list_entry(drain_task_list.next, struct se_cmd, state_list); 345 list_del_init(&cmd->state_list); 346 347 target_show_cmd("LUN_RESET: ", cmd); 348 pr_debug("LUN_RESET: ITT[0x%08llx] - %s pr_res_key: 0x%016Lx\n", 349 cmd->tag, (preempt_and_abort_list) ? "preempt" : "", 350 cmd->pr_res_key); 351 352 target_put_cmd_and_wait(cmd); 353 } 354 } 355 356 int core_tmr_lun_reset( 357 struct se_device *dev, 358 struct se_tmr_req *tmr, 359 struct list_head *preempt_and_abort_list, 360 struct se_cmd *prout_cmd) 361 { 362 struct se_node_acl *tmr_nacl = NULL; 363 struct se_portal_group *tmr_tpg = NULL; 364 struct se_session *tmr_sess = NULL; 365 bool tas; 366 /* 367 * TASK_ABORTED status bit, this is configurable via ConfigFS 368 * struct se_device attributes. spc4r17 section 7.4.6 Control mode page 369 * 370 * A task aborted status (TAS) bit set to zero specifies that aborted 371 * tasks shall be terminated by the device server without any response 372 * to the application client. A TAS bit set to one specifies that tasks 373 * aborted by the actions of an I_T nexus other than the I_T nexus on 374 * which the command was received shall be completed with TASK ABORTED 375 * status (see SAM-4). 376 */ 377 tas = dev->dev_attrib.emulate_tas; 378 /* 379 * Determine if this se_tmr is coming from a $FABRIC_MOD 380 * or struct se_device passthrough.. 381 */ 382 if (tmr && tmr->task_cmd && tmr->task_cmd->se_sess) { 383 tmr_sess = tmr->task_cmd->se_sess; 384 tmr_nacl = tmr_sess->se_node_acl; 385 tmr_tpg = tmr_sess->se_tpg; 386 if (tmr_nacl && tmr_tpg) { 387 pr_debug("LUN_RESET: TMR caller fabric: %s" 388 " initiator port %s\n", 389 tmr_tpg->se_tpg_tfo->fabric_name, 390 tmr_nacl->initiatorname); 391 } 392 } 393 pr_debug("LUN_RESET: %s starting for [%s], tas: %d\n", 394 (preempt_and_abort_list) ? "Preempt" : "TMR", 395 dev->transport->name, tas); 396 397 core_tmr_drain_tmr_list(dev, tmr, preempt_and_abort_list); 398 core_tmr_drain_state_list(dev, prout_cmd, tmr_sess, tas, 399 preempt_and_abort_list); 400 401 /* 402 * Clear any legacy SPC-2 reservation when called during 403 * LOGICAL UNIT RESET 404 */ 405 if (!preempt_and_abort_list && 406 (dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS)) { 407 spin_lock(&dev->dev_reservation_lock); 408 dev->reservation_holder = NULL; 409 dev->dev_reservation_flags &= ~DRF_SPC2_RESERVATIONS; 410 spin_unlock(&dev->dev_reservation_lock); 411 pr_debug("LUN_RESET: SCSI-2 Released reservation\n"); 412 } 413 414 atomic_long_inc(&dev->num_resets); 415 416 pr_debug("LUN_RESET: %s for [%s] Complete\n", 417 (preempt_and_abort_list) ? "Preempt" : "TMR", 418 dev->transport->name); 419 return 0; 420 } 421 422