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 #include <scsi/scsi.h> 31 #include <scsi/scsi_cmnd.h> 32 33 #include <target/target_core_base.h> 34 #include <target/target_core_backend.h> 35 #include <target/target_core_fabric.h> 36 #include <target/target_core_configfs.h> 37 38 #include "target_core_internal.h" 39 #include "target_core_alua.h" 40 #include "target_core_pr.h" 41 42 int core_tmr_alloc_req( 43 struct se_cmd *se_cmd, 44 void *fabric_tmr_ptr, 45 u8 function, 46 gfp_t gfp_flags) 47 { 48 struct se_tmr_req *tmr; 49 50 tmr = kzalloc(sizeof(struct se_tmr_req), gfp_flags); 51 if (!tmr) { 52 pr_err("Unable to allocate struct se_tmr_req\n"); 53 return -ENOMEM; 54 } 55 56 se_cmd->se_cmd_flags |= SCF_SCSI_TMR_CDB; 57 se_cmd->se_tmr_req = tmr; 58 tmr->task_cmd = se_cmd; 59 tmr->fabric_tmr_ptr = fabric_tmr_ptr; 60 tmr->function = function; 61 INIT_LIST_HEAD(&tmr->tmr_list); 62 63 return 0; 64 } 65 EXPORT_SYMBOL(core_tmr_alloc_req); 66 67 void core_tmr_release_req( 68 struct se_tmr_req *tmr) 69 { 70 struct se_device *dev = tmr->tmr_dev; 71 unsigned long flags; 72 73 if (!dev) { 74 kfree(tmr); 75 return; 76 } 77 78 spin_lock_irqsave(&dev->se_tmr_lock, flags); 79 list_del(&tmr->tmr_list); 80 spin_unlock_irqrestore(&dev->se_tmr_lock, flags); 81 82 kfree(tmr); 83 } 84 85 static void core_tmr_handle_tas_abort( 86 struct se_node_acl *tmr_nacl, 87 struct se_cmd *cmd, 88 int tas) 89 { 90 bool remove = true; 91 /* 92 * TASK ABORTED status (TAS) bit support 93 */ 94 if ((tmr_nacl && 95 (tmr_nacl != cmd->se_sess->se_node_acl)) && tas) { 96 remove = false; 97 transport_send_task_abort(cmd); 98 } 99 100 transport_cmd_finish_abort(cmd, remove); 101 } 102 103 static int target_check_cdb_and_preempt(struct list_head *list, 104 struct se_cmd *cmd) 105 { 106 struct t10_pr_registration *reg; 107 108 if (!list) 109 return 0; 110 list_for_each_entry(reg, list, pr_reg_abort_list) { 111 if (reg->pr_res_key == cmd->pr_res_key) 112 return 0; 113 } 114 115 return 1; 116 } 117 118 void core_tmr_abort_task( 119 struct se_device *dev, 120 struct se_tmr_req *tmr, 121 struct se_session *se_sess) 122 { 123 struct se_cmd *se_cmd, *tmp_cmd; 124 unsigned long flags; 125 int ref_tag; 126 127 spin_lock_irqsave(&se_sess->sess_cmd_lock, flags); 128 list_for_each_entry_safe(se_cmd, tmp_cmd, 129 &se_sess->sess_cmd_list, se_cmd_list) { 130 131 if (dev != se_cmd->se_dev) 132 continue; 133 134 /* skip se_cmd associated with tmr */ 135 if (tmr->task_cmd == se_cmd) 136 continue; 137 138 ref_tag = se_cmd->se_tfo->get_task_tag(se_cmd); 139 if (tmr->ref_task_tag != ref_tag) 140 continue; 141 142 printk("ABORT_TASK: Found referenced %s task_tag: %u\n", 143 se_cmd->se_tfo->get_fabric_name(), ref_tag); 144 145 spin_lock(&se_cmd->t_state_lock); 146 if (se_cmd->transport_state & CMD_T_COMPLETE) { 147 printk("ABORT_TASK: ref_tag: %u already complete, skipping\n", ref_tag); 148 spin_unlock(&se_cmd->t_state_lock); 149 spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags); 150 goto out; 151 } 152 se_cmd->transport_state |= CMD_T_ABORTED; 153 spin_unlock(&se_cmd->t_state_lock); 154 155 list_del_init(&se_cmd->se_cmd_list); 156 kref_get(&se_cmd->cmd_kref); 157 spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags); 158 159 cancel_work_sync(&se_cmd->work); 160 transport_wait_for_tasks(se_cmd); 161 162 target_put_sess_cmd(se_sess, se_cmd); 163 transport_cmd_finish_abort(se_cmd, true); 164 165 printk("ABORT_TASK: Sending TMR_FUNCTION_COMPLETE for" 166 " ref_tag: %d\n", ref_tag); 167 tmr->response = TMR_FUNCTION_COMPLETE; 168 return; 169 } 170 spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags); 171 172 out: 173 printk("ABORT_TASK: Sending TMR_TASK_DOES_NOT_EXIST for ref_tag: %d\n", 174 tmr->ref_task_tag); 175 tmr->response = TMR_TASK_DOES_NOT_EXIST; 176 } 177 178 static void core_tmr_drain_tmr_list( 179 struct se_device *dev, 180 struct se_tmr_req *tmr, 181 struct list_head *preempt_and_abort_list) 182 { 183 LIST_HEAD(drain_tmr_list); 184 struct se_tmr_req *tmr_p, *tmr_pp; 185 struct se_cmd *cmd; 186 unsigned long flags; 187 /* 188 * Release all pending and outgoing TMRs aside from the received 189 * LUN_RESET tmr.. 190 */ 191 spin_lock_irqsave(&dev->se_tmr_lock, flags); 192 list_for_each_entry_safe(tmr_p, tmr_pp, &dev->dev_tmr_list, tmr_list) { 193 /* 194 * Allow the received TMR to return with FUNCTION_COMPLETE. 195 */ 196 if (tmr_p == tmr) 197 continue; 198 199 cmd = tmr_p->task_cmd; 200 if (!cmd) { 201 pr_err("Unable to locate struct se_cmd for TMR\n"); 202 continue; 203 } 204 /* 205 * If this function was called with a valid pr_res_key 206 * parameter (eg: for PROUT PREEMPT_AND_ABORT service action 207 * skip non regisration key matching TMRs. 208 */ 209 if (target_check_cdb_and_preempt(preempt_and_abort_list, cmd)) 210 continue; 211 212 spin_lock(&cmd->t_state_lock); 213 if (!(cmd->transport_state & CMD_T_ACTIVE)) { 214 spin_unlock(&cmd->t_state_lock); 215 continue; 216 } 217 if (cmd->t_state == TRANSPORT_ISTATE_PROCESSING) { 218 spin_unlock(&cmd->t_state_lock); 219 continue; 220 } 221 spin_unlock(&cmd->t_state_lock); 222 223 list_move_tail(&tmr_p->tmr_list, &drain_tmr_list); 224 } 225 spin_unlock_irqrestore(&dev->se_tmr_lock, flags); 226 227 list_for_each_entry_safe(tmr_p, tmr_pp, &drain_tmr_list, tmr_list) { 228 list_del_init(&tmr_p->tmr_list); 229 cmd = tmr_p->task_cmd; 230 231 pr_debug("LUN_RESET: %s releasing TMR %p Function: 0x%02x," 232 " Response: 0x%02x, t_state: %d\n", 233 (preempt_and_abort_list) ? "Preempt" : "", tmr_p, 234 tmr_p->function, tmr_p->response, cmd->t_state); 235 236 transport_cmd_finish_abort(cmd, 1); 237 } 238 } 239 240 static void core_tmr_drain_state_list( 241 struct se_device *dev, 242 struct se_cmd *prout_cmd, 243 struct se_node_acl *tmr_nacl, 244 int tas, 245 struct list_head *preempt_and_abort_list) 246 { 247 LIST_HEAD(drain_task_list); 248 struct se_cmd *cmd, *next; 249 unsigned long flags; 250 251 /* 252 * Complete outstanding commands with TASK_ABORTED SAM status. 253 * 254 * This is following sam4r17, section 5.6 Aborting commands, Table 38 255 * for TMR LUN_RESET: 256 * 257 * a) "Yes" indicates that each command that is aborted on an I_T nexus 258 * other than the one that caused the SCSI device condition is 259 * completed with TASK ABORTED status, if the TAS bit is set to one in 260 * the Control mode page (see SPC-4). "No" indicates that no status is 261 * returned for aborted commands. 262 * 263 * d) If the logical unit reset is caused by a particular I_T nexus 264 * (e.g., by a LOGICAL UNIT RESET task management function), then "yes" 265 * (TASK_ABORTED status) applies. 266 * 267 * Otherwise (e.g., if triggered by a hard reset), "no" 268 * (no TASK_ABORTED SAM status) applies. 269 * 270 * Note that this seems to be independent of TAS (Task Aborted Status) 271 * in the Control Mode Page. 272 */ 273 spin_lock_irqsave(&dev->execute_task_lock, flags); 274 list_for_each_entry_safe(cmd, next, &dev->state_list, state_list) { 275 /* 276 * For PREEMPT_AND_ABORT usage, only process commands 277 * with a matching reservation key. 278 */ 279 if (target_check_cdb_and_preempt(preempt_and_abort_list, cmd)) 280 continue; 281 282 /* 283 * Not aborting PROUT PREEMPT_AND_ABORT CDB.. 284 */ 285 if (prout_cmd == cmd) 286 continue; 287 288 list_move_tail(&cmd->state_list, &drain_task_list); 289 cmd->state_active = false; 290 } 291 spin_unlock_irqrestore(&dev->execute_task_lock, flags); 292 293 while (!list_empty(&drain_task_list)) { 294 cmd = list_entry(drain_task_list.next, struct se_cmd, state_list); 295 list_del(&cmd->state_list); 296 297 pr_debug("LUN_RESET: %s cmd: %p" 298 " ITT/CmdSN: 0x%08x/0x%08x, i_state: %d, t_state: %d" 299 "cdb: 0x%02x\n", 300 (preempt_and_abort_list) ? "Preempt" : "", cmd, 301 cmd->se_tfo->get_task_tag(cmd), 0, 302 cmd->se_tfo->get_cmd_state(cmd), cmd->t_state, 303 cmd->t_task_cdb[0]); 304 pr_debug("LUN_RESET: ITT[0x%08x] - pr_res_key: 0x%016Lx" 305 " -- CMD_T_ACTIVE: %d" 306 " CMD_T_STOP: %d CMD_T_SENT: %d\n", 307 cmd->se_tfo->get_task_tag(cmd), cmd->pr_res_key, 308 (cmd->transport_state & CMD_T_ACTIVE) != 0, 309 (cmd->transport_state & CMD_T_STOP) != 0, 310 (cmd->transport_state & CMD_T_SENT) != 0); 311 312 /* 313 * If the command may be queued onto a workqueue cancel it now. 314 * 315 * This is equivalent to removal from the execute queue in the 316 * loop above, but we do it down here given that 317 * cancel_work_sync may block. 318 */ 319 if (cmd->t_state == TRANSPORT_COMPLETE) 320 cancel_work_sync(&cmd->work); 321 322 spin_lock_irqsave(&cmd->t_state_lock, flags); 323 target_stop_cmd(cmd, &flags); 324 325 cmd->transport_state |= CMD_T_ABORTED; 326 spin_unlock_irqrestore(&cmd->t_state_lock, flags); 327 328 core_tmr_handle_tas_abort(tmr_nacl, cmd, tas); 329 } 330 } 331 332 int core_tmr_lun_reset( 333 struct se_device *dev, 334 struct se_tmr_req *tmr, 335 struct list_head *preempt_and_abort_list, 336 struct se_cmd *prout_cmd) 337 { 338 struct se_node_acl *tmr_nacl = NULL; 339 struct se_portal_group *tmr_tpg = NULL; 340 int tas; 341 /* 342 * TASK_ABORTED status bit, this is configurable via ConfigFS 343 * struct se_device attributes. spc4r17 section 7.4.6 Control mode page 344 * 345 * A task aborted status (TAS) bit set to zero specifies that aborted 346 * tasks shall be terminated by the device server without any response 347 * to the application client. A TAS bit set to one specifies that tasks 348 * aborted by the actions of an I_T nexus other than the I_T nexus on 349 * which the command was received shall be completed with TASK ABORTED 350 * status (see SAM-4). 351 */ 352 tas = dev->dev_attrib.emulate_tas; 353 /* 354 * Determine if this se_tmr is coming from a $FABRIC_MOD 355 * or struct se_device passthrough.. 356 */ 357 if (tmr && tmr->task_cmd && tmr->task_cmd->se_sess) { 358 tmr_nacl = tmr->task_cmd->se_sess->se_node_acl; 359 tmr_tpg = tmr->task_cmd->se_sess->se_tpg; 360 if (tmr_nacl && tmr_tpg) { 361 pr_debug("LUN_RESET: TMR caller fabric: %s" 362 " initiator port %s\n", 363 tmr_tpg->se_tpg_tfo->get_fabric_name(), 364 tmr_nacl->initiatorname); 365 } 366 } 367 pr_debug("LUN_RESET: %s starting for [%s], tas: %d\n", 368 (preempt_and_abort_list) ? "Preempt" : "TMR", 369 dev->transport->name, tas); 370 371 core_tmr_drain_tmr_list(dev, tmr, preempt_and_abort_list); 372 core_tmr_drain_state_list(dev, prout_cmd, tmr_nacl, tas, 373 preempt_and_abort_list); 374 375 /* 376 * Clear any legacy SPC-2 reservation when called during 377 * LOGICAL UNIT RESET 378 */ 379 if (!preempt_and_abort_list && 380 (dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS)) { 381 spin_lock(&dev->dev_reservation_lock); 382 dev->dev_reserved_node_acl = NULL; 383 dev->dev_reservation_flags &= ~DRF_SPC2_RESERVATIONS; 384 spin_unlock(&dev->dev_reservation_lock); 385 pr_debug("LUN_RESET: SCSI-2 Released reservation\n"); 386 } 387 388 atomic_long_inc(&dev->num_resets); 389 390 pr_debug("LUN_RESET: %s for [%s] Complete\n", 391 (preempt_and_abort_list) ? "Preempt" : "TMR", 392 dev->transport->name); 393 return 0; 394 } 395 396