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