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; 124 125 spin_lock_irqsave(&dev->execute_task_lock, flags); 126 list_for_each_entry_safe(se_cmd, next, &dev->state_list, state_list) { 127 128 if (se_sess != se_cmd->se_sess) 129 continue; 130 131 /* skip task management functions, including tmr->task_cmd */ 132 if (se_cmd->se_cmd_flags & SCF_SCSI_TMR_CDB) 133 continue; 134 135 ref_tag = se_cmd->tag; 136 if (tmr->ref_task_tag != ref_tag) 137 continue; 138 139 printk("ABORT_TASK: Found referenced %s task_tag: %llu\n", 140 se_cmd->se_tfo->fabric_name, ref_tag); 141 142 spin_lock(&se_sess->sess_cmd_lock); 143 rc = __target_check_io_state(se_cmd, se_sess, 0); 144 spin_unlock(&se_sess->sess_cmd_lock); 145 if (!rc) 146 continue; 147 148 list_move_tail(&se_cmd->state_list, &aborted_list); 149 se_cmd->state_active = false; 150 151 spin_unlock_irqrestore(&dev->execute_task_lock, flags); 152 153 /* 154 * Ensure that this ABORT request is visible to the LU RESET 155 * code. 156 */ 157 if (!tmr->tmr_dev) 158 WARN_ON_ONCE(transport_lookup_tmr_lun(tmr->task_cmd) < 159 0); 160 161 if (dev->transport->tmr_notify) 162 dev->transport->tmr_notify(dev, TMR_ABORT_TASK, 163 &aborted_list); 164 165 list_del_init(&se_cmd->state_list); 166 target_put_cmd_and_wait(se_cmd); 167 168 printk("ABORT_TASK: Sending TMR_FUNCTION_COMPLETE for" 169 " ref_tag: %llu\n", ref_tag); 170 tmr->response = TMR_FUNCTION_COMPLETE; 171 atomic_long_inc(&dev->aborts_complete); 172 return; 173 } 174 spin_unlock_irqrestore(&dev->execute_task_lock, flags); 175 176 if (dev->transport->tmr_notify) 177 dev->transport->tmr_notify(dev, TMR_ABORT_TASK, &aborted_list); 178 179 printk("ABORT_TASK: Sending TMR_TASK_DOES_NOT_EXIST for ref_tag: %lld\n", 180 tmr->ref_task_tag); 181 tmr->response = TMR_TASK_DOES_NOT_EXIST; 182 atomic_long_inc(&dev->aborts_no_task); 183 } 184 185 static void core_tmr_drain_tmr_list( 186 struct se_device *dev, 187 struct se_tmr_req *tmr, 188 struct list_head *preempt_and_abort_list) 189 { 190 LIST_HEAD(drain_tmr_list); 191 struct se_session *sess; 192 struct se_tmr_req *tmr_p, *tmr_pp; 193 struct se_cmd *cmd; 194 unsigned long flags; 195 bool rc; 196 /* 197 * Release all pending and outgoing TMRs aside from the received 198 * LUN_RESET tmr.. 199 */ 200 spin_lock_irqsave(&dev->se_tmr_lock, flags); 201 if (tmr) 202 list_del_init(&tmr->tmr_list); 203 list_for_each_entry_safe(tmr_p, tmr_pp, &dev->dev_tmr_list, tmr_list) { 204 cmd = tmr_p->task_cmd; 205 if (!cmd) { 206 pr_err("Unable to locate struct se_cmd for TMR\n"); 207 continue; 208 } 209 /* 210 * If this function was called with a valid pr_res_key 211 * parameter (eg: for PROUT PREEMPT_AND_ABORT service action 212 * skip non registration key matching TMRs. 213 */ 214 if (target_check_cdb_and_preempt(preempt_and_abort_list, cmd)) 215 continue; 216 217 sess = cmd->se_sess; 218 if (WARN_ON_ONCE(!sess)) 219 continue; 220 221 spin_lock(&sess->sess_cmd_lock); 222 rc = __target_check_io_state(cmd, sess, 0); 223 spin_unlock(&sess->sess_cmd_lock); 224 225 if (!rc) { 226 printk("LUN_RESET TMR: non-zero kref_get_unless_zero\n"); 227 continue; 228 } 229 230 list_move_tail(&tmr_p->tmr_list, &drain_tmr_list); 231 } 232 spin_unlock_irqrestore(&dev->se_tmr_lock, flags); 233 234 list_for_each_entry_safe(tmr_p, tmr_pp, &drain_tmr_list, tmr_list) { 235 list_del_init(&tmr_p->tmr_list); 236 cmd = tmr_p->task_cmd; 237 238 pr_debug("LUN_RESET: %s releasing TMR %p Function: 0x%02x," 239 " Response: 0x%02x, t_state: %d\n", 240 (preempt_and_abort_list) ? "Preempt" : "", tmr_p, 241 tmr_p->function, tmr_p->response, cmd->t_state); 242 243 target_put_cmd_and_wait(cmd); 244 } 245 } 246 247 /** 248 * core_tmr_drain_state_list() - abort SCSI commands associated with a device 249 * 250 * @dev: Device for which to abort outstanding SCSI commands. 251 * @prout_cmd: Pointer to the SCSI PREEMPT AND ABORT if this function is called 252 * to realize the PREEMPT AND ABORT functionality. 253 * @tmr_sess: Session through which the LUN RESET has been received. 254 * @tas: Task Aborted Status (TAS) bit from the SCSI control mode page. 255 * A quote from SPC-4, paragraph "7.5.10 Control mode page": 256 * "A task aborted status (TAS) bit set to zero specifies that 257 * aborted commands shall be terminated by the device server 258 * without any response to the application client. A TAS bit set 259 * to one specifies that commands aborted by the actions of an I_T 260 * nexus other than the I_T nexus on which the command was 261 * received shall be completed with TASK ABORTED status." 262 * @preempt_and_abort_list: For the PREEMPT AND ABORT functionality, a list 263 * with registrations that will be preempted. 264 */ 265 static void core_tmr_drain_state_list( 266 struct se_device *dev, 267 struct se_cmd *prout_cmd, 268 struct se_session *tmr_sess, 269 bool tas, 270 struct list_head *preempt_and_abort_list) 271 { 272 LIST_HEAD(drain_task_list); 273 struct se_session *sess; 274 struct se_cmd *cmd, *next; 275 unsigned long flags; 276 int rc; 277 278 /* 279 * Complete outstanding commands with TASK_ABORTED SAM status. 280 * 281 * This is following sam4r17, section 5.6 Aborting commands, Table 38 282 * for TMR LUN_RESET: 283 * 284 * a) "Yes" indicates that each command that is aborted on an I_T nexus 285 * other than the one that caused the SCSI device condition is 286 * completed with TASK ABORTED status, if the TAS bit is set to one in 287 * the Control mode page (see SPC-4). "No" indicates that no status is 288 * returned for aborted commands. 289 * 290 * d) If the logical unit reset is caused by a particular I_T nexus 291 * (e.g., by a LOGICAL UNIT RESET task management function), then "yes" 292 * (TASK_ABORTED status) applies. 293 * 294 * Otherwise (e.g., if triggered by a hard reset), "no" 295 * (no TASK_ABORTED SAM status) applies. 296 * 297 * Note that this seems to be independent of TAS (Task Aborted Status) 298 * in the Control Mode Page. 299 */ 300 spin_lock_irqsave(&dev->execute_task_lock, flags); 301 list_for_each_entry_safe(cmd, next, &dev->state_list, state_list) { 302 /* 303 * For PREEMPT_AND_ABORT usage, only process commands 304 * with a matching reservation key. 305 */ 306 if (target_check_cdb_and_preempt(preempt_and_abort_list, cmd)) 307 continue; 308 309 /* 310 * Not aborting PROUT PREEMPT_AND_ABORT CDB.. 311 */ 312 if (prout_cmd == cmd) 313 continue; 314 315 sess = cmd->se_sess; 316 if (WARN_ON_ONCE(!sess)) 317 continue; 318 319 spin_lock(&sess->sess_cmd_lock); 320 rc = __target_check_io_state(cmd, tmr_sess, tas); 321 spin_unlock(&sess->sess_cmd_lock); 322 if (!rc) 323 continue; 324 325 list_move_tail(&cmd->state_list, &drain_task_list); 326 cmd->state_active = false; 327 } 328 spin_unlock_irqrestore(&dev->execute_task_lock, flags); 329 330 if (dev->transport->tmr_notify) 331 dev->transport->tmr_notify(dev, preempt_and_abort_list ? 332 TMR_LUN_RESET_PRO : TMR_LUN_RESET, 333 &drain_task_list); 334 335 while (!list_empty(&drain_task_list)) { 336 cmd = list_entry(drain_task_list.next, struct se_cmd, state_list); 337 list_del_init(&cmd->state_list); 338 339 target_show_cmd("LUN_RESET: ", cmd); 340 pr_debug("LUN_RESET: ITT[0x%08llx] - %s pr_res_key: 0x%016Lx\n", 341 cmd->tag, (preempt_and_abort_list) ? "preempt" : "", 342 cmd->pr_res_key); 343 344 target_put_cmd_and_wait(cmd); 345 } 346 } 347 348 int core_tmr_lun_reset( 349 struct se_device *dev, 350 struct se_tmr_req *tmr, 351 struct list_head *preempt_and_abort_list, 352 struct se_cmd *prout_cmd) 353 { 354 struct se_node_acl *tmr_nacl = NULL; 355 struct se_portal_group *tmr_tpg = NULL; 356 struct se_session *tmr_sess = NULL; 357 bool tas; 358 /* 359 * TASK_ABORTED status bit, this is configurable via ConfigFS 360 * struct se_device attributes. spc4r17 section 7.4.6 Control mode page 361 * 362 * A task aborted status (TAS) bit set to zero specifies that aborted 363 * tasks shall be terminated by the device server without any response 364 * to the application client. A TAS bit set to one specifies that tasks 365 * aborted by the actions of an I_T nexus other than the I_T nexus on 366 * which the command was received shall be completed with TASK ABORTED 367 * status (see SAM-4). 368 */ 369 tas = dev->dev_attrib.emulate_tas; 370 /* 371 * Determine if this se_tmr is coming from a $FABRIC_MOD 372 * or struct se_device passthrough.. 373 */ 374 if (tmr && tmr->task_cmd && tmr->task_cmd->se_sess) { 375 tmr_sess = tmr->task_cmd->se_sess; 376 tmr_nacl = tmr_sess->se_node_acl; 377 tmr_tpg = tmr_sess->se_tpg; 378 if (tmr_nacl && tmr_tpg) { 379 pr_debug("LUN_RESET: TMR caller fabric: %s" 380 " initiator port %s\n", 381 tmr_tpg->se_tpg_tfo->fabric_name, 382 tmr_nacl->initiatorname); 383 } 384 } 385 pr_debug("LUN_RESET: %s starting for [%s], tas: %d\n", 386 (preempt_and_abort_list) ? "Preempt" : "TMR", 387 dev->transport->name, tas); 388 389 core_tmr_drain_tmr_list(dev, tmr, preempt_and_abort_list); 390 core_tmr_drain_state_list(dev, prout_cmd, tmr_sess, tas, 391 preempt_and_abort_list); 392 393 /* 394 * Clear any legacy SPC-2 reservation when called during 395 * LOGICAL UNIT RESET 396 */ 397 if (!preempt_and_abort_list && 398 (dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS)) { 399 spin_lock(&dev->dev_reservation_lock); 400 dev->reservation_holder = NULL; 401 dev->dev_reservation_flags &= ~DRF_SPC2_RESERVATIONS; 402 spin_unlock(&dev->dev_reservation_lock); 403 pr_debug("LUN_RESET: SCSI-2 Released reservation\n"); 404 } 405 406 atomic_long_inc(&dev->num_resets); 407 408 pr_debug("LUN_RESET: %s for [%s] Complete\n", 409 (preempt_and_abort_list) ? "Preempt" : "TMR", 410 dev->transport->name); 411 return 0; 412 } 413 414