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(&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( 79 struct se_node_acl *tmr_nacl, 80 struct se_cmd *cmd, 81 int tas) 82 { 83 bool remove = true; 84 /* 85 * TASK ABORTED status (TAS) bit support 86 */ 87 if ((tmr_nacl && (tmr_nacl != cmd->se_sess->se_node_acl)) && tas) { 88 remove = false; 89 transport_send_task_abort(cmd); 90 } 91 92 transport_cmd_finish_abort(cmd, remove); 93 } 94 95 static int target_check_cdb_and_preempt(struct list_head *list, 96 struct se_cmd *cmd) 97 { 98 struct t10_pr_registration *reg; 99 100 if (!list) 101 return 0; 102 list_for_each_entry(reg, list, pr_reg_abort_list) { 103 if (reg->pr_res_key == cmd->pr_res_key) 104 return 0; 105 } 106 107 return 1; 108 } 109 110 void core_tmr_abort_task( 111 struct se_device *dev, 112 struct se_tmr_req *tmr, 113 struct se_session *se_sess) 114 { 115 struct se_cmd *se_cmd; 116 unsigned long flags; 117 u64 ref_tag; 118 119 spin_lock_irqsave(&se_sess->sess_cmd_lock, flags); 120 list_for_each_entry(se_cmd, &se_sess->sess_cmd_list, se_cmd_list) { 121 122 if (dev != se_cmd->se_dev) 123 continue; 124 125 /* skip task management functions, including tmr->task_cmd */ 126 if (se_cmd->se_cmd_flags & SCF_SCSI_TMR_CDB) 127 continue; 128 129 ref_tag = se_cmd->tag; 130 if (tmr->ref_task_tag != ref_tag) 131 continue; 132 133 printk("ABORT_TASK: Found referenced %s task_tag: %llu\n", 134 se_cmd->se_tfo->get_fabric_name(), ref_tag); 135 136 spin_lock(&se_cmd->t_state_lock); 137 if (se_cmd->transport_state & CMD_T_COMPLETE) { 138 printk("ABORT_TASK: ref_tag: %llu already complete," 139 " skipping\n", ref_tag); 140 spin_unlock(&se_cmd->t_state_lock); 141 spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags); 142 goto out; 143 } 144 se_cmd->transport_state |= CMD_T_ABORTED; 145 spin_unlock(&se_cmd->t_state_lock); 146 147 list_del_init(&se_cmd->se_cmd_list); 148 kref_get(&se_cmd->cmd_kref); 149 spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags); 150 151 cancel_work_sync(&se_cmd->work); 152 transport_wait_for_tasks(se_cmd); 153 154 target_put_sess_cmd(se_cmd); 155 transport_cmd_finish_abort(se_cmd, true); 156 157 printk("ABORT_TASK: Sending TMR_FUNCTION_COMPLETE for" 158 " ref_tag: %llu\n", ref_tag); 159 tmr->response = TMR_FUNCTION_COMPLETE; 160 return; 161 } 162 spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags); 163 164 out: 165 printk("ABORT_TASK: Sending TMR_TASK_DOES_NOT_EXIST for ref_tag: %lld\n", 166 tmr->ref_task_tag); 167 tmr->response = TMR_TASK_DOES_NOT_EXIST; 168 } 169 170 static void core_tmr_drain_tmr_list( 171 struct se_device *dev, 172 struct se_tmr_req *tmr, 173 struct list_head *preempt_and_abort_list) 174 { 175 LIST_HEAD(drain_tmr_list); 176 struct se_tmr_req *tmr_p, *tmr_pp; 177 struct se_cmd *cmd; 178 unsigned long flags; 179 /* 180 * Release all pending and outgoing TMRs aside from the received 181 * LUN_RESET tmr.. 182 */ 183 spin_lock_irqsave(&dev->se_tmr_lock, flags); 184 list_for_each_entry_safe(tmr_p, tmr_pp, &dev->dev_tmr_list, tmr_list) { 185 /* 186 * Allow the received TMR to return with FUNCTION_COMPLETE. 187 */ 188 if (tmr_p == tmr) 189 continue; 190 191 cmd = tmr_p->task_cmd; 192 if (!cmd) { 193 pr_err("Unable to locate struct se_cmd for TMR\n"); 194 continue; 195 } 196 /* 197 * If this function was called with a valid pr_res_key 198 * parameter (eg: for PROUT PREEMPT_AND_ABORT service action 199 * skip non regisration key matching TMRs. 200 */ 201 if (target_check_cdb_and_preempt(preempt_and_abort_list, cmd)) 202 continue; 203 204 spin_lock(&cmd->t_state_lock); 205 if (!(cmd->transport_state & CMD_T_ACTIVE)) { 206 spin_unlock(&cmd->t_state_lock); 207 continue; 208 } 209 if (cmd->t_state == TRANSPORT_ISTATE_PROCESSING) { 210 spin_unlock(&cmd->t_state_lock); 211 continue; 212 } 213 spin_unlock(&cmd->t_state_lock); 214 215 list_move_tail(&tmr_p->tmr_list, &drain_tmr_list); 216 } 217 spin_unlock_irqrestore(&dev->se_tmr_lock, flags); 218 219 list_for_each_entry_safe(tmr_p, tmr_pp, &drain_tmr_list, tmr_list) { 220 list_del_init(&tmr_p->tmr_list); 221 cmd = tmr_p->task_cmd; 222 223 pr_debug("LUN_RESET: %s releasing TMR %p Function: 0x%02x," 224 " Response: 0x%02x, t_state: %d\n", 225 (preempt_and_abort_list) ? "Preempt" : "", tmr_p, 226 tmr_p->function, tmr_p->response, cmd->t_state); 227 228 transport_cmd_finish_abort(cmd, 1); 229 } 230 } 231 232 static void core_tmr_drain_state_list( 233 struct se_device *dev, 234 struct se_cmd *prout_cmd, 235 struct se_node_acl *tmr_nacl, 236 int tas, 237 struct list_head *preempt_and_abort_list) 238 { 239 LIST_HEAD(drain_task_list); 240 struct se_cmd *cmd, *next; 241 unsigned long flags; 242 243 /* 244 * Complete outstanding commands with TASK_ABORTED SAM status. 245 * 246 * This is following sam4r17, section 5.6 Aborting commands, Table 38 247 * for TMR LUN_RESET: 248 * 249 * a) "Yes" indicates that each command that is aborted on an I_T nexus 250 * other than the one that caused the SCSI device condition is 251 * completed with TASK ABORTED status, if the TAS bit is set to one in 252 * the Control mode page (see SPC-4). "No" indicates that no status is 253 * returned for aborted commands. 254 * 255 * d) If the logical unit reset is caused by a particular I_T nexus 256 * (e.g., by a LOGICAL UNIT RESET task management function), then "yes" 257 * (TASK_ABORTED status) applies. 258 * 259 * Otherwise (e.g., if triggered by a hard reset), "no" 260 * (no TASK_ABORTED SAM status) applies. 261 * 262 * Note that this seems to be independent of TAS (Task Aborted Status) 263 * in the Control Mode Page. 264 */ 265 spin_lock_irqsave(&dev->execute_task_lock, flags); 266 list_for_each_entry_safe(cmd, next, &dev->state_list, state_list) { 267 /* 268 * For PREEMPT_AND_ABORT usage, only process commands 269 * with a matching reservation key. 270 */ 271 if (target_check_cdb_and_preempt(preempt_and_abort_list, cmd)) 272 continue; 273 274 /* 275 * Not aborting PROUT PREEMPT_AND_ABORT CDB.. 276 */ 277 if (prout_cmd == cmd) 278 continue; 279 280 list_move_tail(&cmd->state_list, &drain_task_list); 281 cmd->state_active = false; 282 } 283 spin_unlock_irqrestore(&dev->execute_task_lock, flags); 284 285 while (!list_empty(&drain_task_list)) { 286 cmd = list_entry(drain_task_list.next, struct se_cmd, state_list); 287 list_del(&cmd->state_list); 288 289 pr_debug("LUN_RESET: %s cmd: %p" 290 " ITT/CmdSN: 0x%08llx/0x%08x, i_state: %d, t_state: %d" 291 "cdb: 0x%02x\n", 292 (preempt_and_abort_list) ? "Preempt" : "", cmd, 293 cmd->tag, 0, 294 cmd->se_tfo->get_cmd_state(cmd), cmd->t_state, 295 cmd->t_task_cdb[0]); 296 pr_debug("LUN_RESET: ITT[0x%08llx] - pr_res_key: 0x%016Lx" 297 " -- CMD_T_ACTIVE: %d" 298 " CMD_T_STOP: %d CMD_T_SENT: %d\n", 299 cmd->tag, cmd->pr_res_key, 300 (cmd->transport_state & CMD_T_ACTIVE) != 0, 301 (cmd->transport_state & CMD_T_STOP) != 0, 302 (cmd->transport_state & CMD_T_SENT) != 0); 303 304 /* 305 * If the command may be queued onto a workqueue cancel it now. 306 * 307 * This is equivalent to removal from the execute queue in the 308 * loop above, but we do it down here given that 309 * cancel_work_sync may block. 310 */ 311 if (cmd->t_state == TRANSPORT_COMPLETE) 312 cancel_work_sync(&cmd->work); 313 314 spin_lock_irqsave(&cmd->t_state_lock, flags); 315 target_stop_cmd(cmd, &flags); 316 317 cmd->transport_state |= CMD_T_ABORTED; 318 spin_unlock_irqrestore(&cmd->t_state_lock, flags); 319 320 core_tmr_handle_tas_abort(tmr_nacl, cmd, tas); 321 } 322 } 323 324 int core_tmr_lun_reset( 325 struct se_device *dev, 326 struct se_tmr_req *tmr, 327 struct list_head *preempt_and_abort_list, 328 struct se_cmd *prout_cmd) 329 { 330 struct se_node_acl *tmr_nacl = NULL; 331 struct se_portal_group *tmr_tpg = NULL; 332 int tas; 333 /* 334 * TASK_ABORTED status bit, this is configurable via ConfigFS 335 * struct se_device attributes. spc4r17 section 7.4.6 Control mode page 336 * 337 * A task aborted status (TAS) bit set to zero specifies that aborted 338 * tasks shall be terminated by the device server without any response 339 * to the application client. A TAS bit set to one specifies that tasks 340 * aborted by the actions of an I_T nexus other than the I_T nexus on 341 * which the command was received shall be completed with TASK ABORTED 342 * status (see SAM-4). 343 */ 344 tas = dev->dev_attrib.emulate_tas; 345 /* 346 * Determine if this se_tmr is coming from a $FABRIC_MOD 347 * or struct se_device passthrough.. 348 */ 349 if (tmr && tmr->task_cmd && tmr->task_cmd->se_sess) { 350 tmr_nacl = tmr->task_cmd->se_sess->se_node_acl; 351 tmr_tpg = tmr->task_cmd->se_sess->se_tpg; 352 if (tmr_nacl && tmr_tpg) { 353 pr_debug("LUN_RESET: TMR caller fabric: %s" 354 " initiator port %s\n", 355 tmr_tpg->se_tpg_tfo->get_fabric_name(), 356 tmr_nacl->initiatorname); 357 } 358 } 359 pr_debug("LUN_RESET: %s starting for [%s], tas: %d\n", 360 (preempt_and_abort_list) ? "Preempt" : "TMR", 361 dev->transport->name, tas); 362 363 core_tmr_drain_tmr_list(dev, tmr, preempt_and_abort_list); 364 core_tmr_drain_state_list(dev, prout_cmd, tmr_nacl, tas, 365 preempt_and_abort_list); 366 367 /* 368 * Clear any legacy SPC-2 reservation when called during 369 * LOGICAL UNIT RESET 370 */ 371 if (!preempt_and_abort_list && 372 (dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS)) { 373 spin_lock(&dev->dev_reservation_lock); 374 dev->dev_reserved_node_acl = NULL; 375 dev->dev_reservation_flags &= ~DRF_SPC2_RESERVATIONS; 376 spin_unlock(&dev->dev_reservation_lock); 377 pr_debug("LUN_RESET: SCSI-2 Released reservation\n"); 378 } 379 380 atomic_long_inc(&dev->num_resets); 381 382 pr_debug("LUN_RESET: %s for [%s] Complete\n", 383 (preempt_and_abort_list) ? "Preempt" : "TMR", 384 dev->transport->name); 385 return 0; 386 } 387 388