1 /******************************************************************************* 2 * Filename: target_core_tmr.c 3 * 4 * This file contains SPC-3 task management infrastructure 5 * 6 * (c) Copyright 2009-2012 RisingTide Systems LLC. 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 int fe_count) 90 { 91 if (!fe_count) { 92 transport_cmd_finish_abort(cmd, 1); 93 return; 94 } 95 /* 96 * TASK ABORTED status (TAS) bit support 97 */ 98 if ((tmr_nacl && 99 (tmr_nacl == cmd->se_sess->se_node_acl)) || tas) 100 transport_send_task_abort(cmd); 101 102 transport_cmd_finish_abort(cmd, 0); 103 } 104 105 static int target_check_cdb_and_preempt(struct list_head *list, 106 struct se_cmd *cmd) 107 { 108 struct t10_pr_registration *reg; 109 110 if (!list) 111 return 0; 112 list_for_each_entry(reg, list, pr_reg_abort_list) { 113 if (reg->pr_res_key == cmd->pr_res_key) 114 return 0; 115 } 116 117 return 1; 118 } 119 120 void core_tmr_abort_task( 121 struct se_device *dev, 122 struct se_tmr_req *tmr, 123 struct se_session *se_sess) 124 { 125 struct se_cmd *se_cmd, *tmp_cmd; 126 unsigned long flags; 127 int ref_tag; 128 129 spin_lock_irqsave(&se_sess->sess_cmd_lock, flags); 130 list_for_each_entry_safe(se_cmd, tmp_cmd, 131 &se_sess->sess_cmd_list, se_cmd_list) { 132 133 if (dev != se_cmd->se_dev) 134 continue; 135 ref_tag = se_cmd->se_tfo->get_task_tag(se_cmd); 136 if (tmr->ref_task_tag != ref_tag) 137 continue; 138 139 printk("ABORT_TASK: Found referenced %s task_tag: %u\n", 140 se_cmd->se_tfo->get_fabric_name(), ref_tag); 141 142 spin_lock(&se_cmd->t_state_lock); 143 if (se_cmd->transport_state & CMD_T_COMPLETE) { 144 printk("ABORT_TASK: ref_tag: %u already complete, skipping\n", ref_tag); 145 spin_unlock(&se_cmd->t_state_lock); 146 spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags); 147 goto out; 148 } 149 se_cmd->transport_state |= CMD_T_ABORTED; 150 spin_unlock(&se_cmd->t_state_lock); 151 152 list_del_init(&se_cmd->se_cmd_list); 153 kref_get(&se_cmd->cmd_kref); 154 spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags); 155 156 cancel_work_sync(&se_cmd->work); 157 transport_wait_for_tasks(se_cmd); 158 /* 159 * Now send SAM_STAT_TASK_ABORTED status for the referenced 160 * se_cmd descriptor.. 161 */ 162 transport_send_task_abort(se_cmd); 163 /* 164 * Also deal with possible extra acknowledge reference.. 165 */ 166 if (se_cmd->se_cmd_flags & SCF_ACK_KREF) 167 target_put_sess_cmd(se_sess, se_cmd); 168 169 target_put_sess_cmd(se_sess, se_cmd); 170 171 printk("ABORT_TASK: Sending TMR_FUNCTION_COMPLETE for" 172 " ref_tag: %d\n", ref_tag); 173 tmr->response = TMR_FUNCTION_COMPLETE; 174 return; 175 } 176 spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags); 177 178 out: 179 printk("ABORT_TASK: Sending TMR_TASK_DOES_NOT_EXIST for ref_tag: %d\n", 180 tmr->ref_task_tag); 181 tmr->response = TMR_TASK_DOES_NOT_EXIST; 182 } 183 184 static void core_tmr_drain_tmr_list( 185 struct se_device *dev, 186 struct se_tmr_req *tmr, 187 struct list_head *preempt_and_abort_list) 188 { 189 LIST_HEAD(drain_tmr_list); 190 struct se_tmr_req *tmr_p, *tmr_pp; 191 struct se_cmd *cmd; 192 unsigned long flags; 193 /* 194 * Release all pending and outgoing TMRs aside from the received 195 * LUN_RESET tmr.. 196 */ 197 spin_lock_irqsave(&dev->se_tmr_lock, flags); 198 list_for_each_entry_safe(tmr_p, tmr_pp, &dev->dev_tmr_list, tmr_list) { 199 /* 200 * Allow the received TMR to return with FUNCTION_COMPLETE. 201 */ 202 if (tmr_p == tmr) 203 continue; 204 205 cmd = tmr_p->task_cmd; 206 if (!cmd) { 207 pr_err("Unable to locate struct se_cmd for TMR\n"); 208 continue; 209 } 210 /* 211 * If this function was called with a valid pr_res_key 212 * parameter (eg: for PROUT PREEMPT_AND_ABORT service action 213 * skip non regisration key matching TMRs. 214 */ 215 if (target_check_cdb_and_preempt(preempt_and_abort_list, cmd)) 216 continue; 217 218 spin_lock(&cmd->t_state_lock); 219 if (!(cmd->transport_state & CMD_T_ACTIVE)) { 220 spin_unlock(&cmd->t_state_lock); 221 continue; 222 } 223 if (cmd->t_state == TRANSPORT_ISTATE_PROCESSING) { 224 spin_unlock(&cmd->t_state_lock); 225 continue; 226 } 227 spin_unlock(&cmd->t_state_lock); 228 229 list_move_tail(&tmr_p->tmr_list, &drain_tmr_list); 230 } 231 spin_unlock_irqrestore(&dev->se_tmr_lock, flags); 232 233 list_for_each_entry_safe(tmr_p, tmr_pp, &drain_tmr_list, tmr_list) { 234 list_del_init(&tmr_p->tmr_list); 235 cmd = tmr_p->task_cmd; 236 237 pr_debug("LUN_RESET: %s releasing TMR %p Function: 0x%02x," 238 " Response: 0x%02x, t_state: %d\n", 239 (preempt_and_abort_list) ? "Preempt" : "", tmr_p, 240 tmr_p->function, tmr_p->response, cmd->t_state); 241 242 transport_cmd_finish_abort(cmd, 1); 243 } 244 } 245 246 static void core_tmr_drain_state_list( 247 struct se_device *dev, 248 struct se_cmd *prout_cmd, 249 struct se_node_acl *tmr_nacl, 250 int tas, 251 struct list_head *preempt_and_abort_list) 252 { 253 LIST_HEAD(drain_task_list); 254 struct se_cmd *cmd, *next; 255 unsigned long flags; 256 int fe_count; 257 258 /* 259 * Complete outstanding commands with TASK_ABORTED SAM status. 260 * 261 * This is following sam4r17, section 5.6 Aborting commands, Table 38 262 * for TMR LUN_RESET: 263 * 264 * a) "Yes" indicates that each command that is aborted on an I_T nexus 265 * other than the one that caused the SCSI device condition is 266 * completed with TASK ABORTED status, if the TAS bit is set to one in 267 * the Control mode page (see SPC-4). "No" indicates that no status is 268 * returned for aborted commands. 269 * 270 * d) If the logical unit reset is caused by a particular I_T nexus 271 * (e.g., by a LOGICAL UNIT RESET task management function), then "yes" 272 * (TASK_ABORTED status) applies. 273 * 274 * Otherwise (e.g., if triggered by a hard reset), "no" 275 * (no TASK_ABORTED SAM status) applies. 276 * 277 * Note that this seems to be independent of TAS (Task Aborted Status) 278 * in the Control Mode Page. 279 */ 280 spin_lock_irqsave(&dev->execute_task_lock, flags); 281 list_for_each_entry_safe(cmd, next, &dev->state_list, state_list) { 282 /* 283 * For PREEMPT_AND_ABORT usage, only process commands 284 * with a matching reservation key. 285 */ 286 if (target_check_cdb_and_preempt(preempt_and_abort_list, cmd)) 287 continue; 288 289 /* 290 * Not aborting PROUT PREEMPT_AND_ABORT CDB.. 291 */ 292 if (prout_cmd == cmd) 293 continue; 294 295 list_move_tail(&cmd->state_list, &drain_task_list); 296 cmd->state_active = false; 297 } 298 spin_unlock_irqrestore(&dev->execute_task_lock, flags); 299 300 while (!list_empty(&drain_task_list)) { 301 cmd = list_entry(drain_task_list.next, struct se_cmd, state_list); 302 list_del(&cmd->state_list); 303 304 pr_debug("LUN_RESET: %s cmd: %p" 305 " ITT/CmdSN: 0x%08x/0x%08x, i_state: %d, t_state: %d" 306 "cdb: 0x%02x\n", 307 (preempt_and_abort_list) ? "Preempt" : "", cmd, 308 cmd->se_tfo->get_task_tag(cmd), 0, 309 cmd->se_tfo->get_cmd_state(cmd), cmd->t_state, 310 cmd->t_task_cdb[0]); 311 pr_debug("LUN_RESET: ITT[0x%08x] - pr_res_key: 0x%016Lx" 312 " -- CMD_T_ACTIVE: %d" 313 " CMD_T_STOP: %d CMD_T_SENT: %d\n", 314 cmd->se_tfo->get_task_tag(cmd), cmd->pr_res_key, 315 (cmd->transport_state & CMD_T_ACTIVE) != 0, 316 (cmd->transport_state & CMD_T_STOP) != 0, 317 (cmd->transport_state & CMD_T_SENT) != 0); 318 319 /* 320 * If the command may be queued onto a workqueue cancel it now. 321 * 322 * This is equivalent to removal from the execute queue in the 323 * loop above, but we do it down here given that 324 * cancel_work_sync may block. 325 */ 326 if (cmd->t_state == TRANSPORT_COMPLETE) 327 cancel_work_sync(&cmd->work); 328 329 spin_lock_irqsave(&cmd->t_state_lock, flags); 330 target_stop_cmd(cmd, &flags); 331 332 fe_count = atomic_read(&cmd->t_fe_count); 333 334 if (!(cmd->transport_state & CMD_T_ACTIVE)) { 335 pr_debug("LUN_RESET: got CMD_T_ACTIVE for" 336 " cdb: %p, t_fe_count: %d dev: %p\n", cmd, 337 fe_count, dev); 338 cmd->transport_state |= CMD_T_ABORTED; 339 spin_unlock_irqrestore(&cmd->t_state_lock, flags); 340 341 core_tmr_handle_tas_abort(tmr_nacl, cmd, tas, fe_count); 342 continue; 343 } 344 pr_debug("LUN_RESET: Got !CMD_T_ACTIVE for cdb: %p," 345 " t_fe_count: %d dev: %p\n", cmd, fe_count, dev); 346 cmd->transport_state |= CMD_T_ABORTED; 347 spin_unlock_irqrestore(&cmd->t_state_lock, flags); 348 349 core_tmr_handle_tas_abort(tmr_nacl, cmd, tas, fe_count); 350 } 351 } 352 353 int core_tmr_lun_reset( 354 struct se_device *dev, 355 struct se_tmr_req *tmr, 356 struct list_head *preempt_and_abort_list, 357 struct se_cmd *prout_cmd) 358 { 359 struct se_node_acl *tmr_nacl = NULL; 360 struct se_portal_group *tmr_tpg = NULL; 361 int tas; 362 /* 363 * TASK_ABORTED status bit, this is configurable via ConfigFS 364 * struct se_device attributes. spc4r17 section 7.4.6 Control mode page 365 * 366 * A task aborted status (TAS) bit set to zero specifies that aborted 367 * tasks shall be terminated by the device server without any response 368 * to the application client. A TAS bit set to one specifies that tasks 369 * aborted by the actions of an I_T nexus other than the I_T nexus on 370 * which the command was received shall be completed with TASK ABORTED 371 * status (see SAM-4). 372 */ 373 tas = dev->dev_attrib.emulate_tas; 374 /* 375 * Determine if this se_tmr is coming from a $FABRIC_MOD 376 * or struct se_device passthrough.. 377 */ 378 if (tmr && tmr->task_cmd && tmr->task_cmd->se_sess) { 379 tmr_nacl = tmr->task_cmd->se_sess->se_node_acl; 380 tmr_tpg = tmr->task_cmd->se_sess->se_tpg; 381 if (tmr_nacl && tmr_tpg) { 382 pr_debug("LUN_RESET: TMR caller fabric: %s" 383 " initiator port %s\n", 384 tmr_tpg->se_tpg_tfo->get_fabric_name(), 385 tmr_nacl->initiatorname); 386 } 387 } 388 pr_debug("LUN_RESET: %s starting for [%s], tas: %d\n", 389 (preempt_and_abort_list) ? "Preempt" : "TMR", 390 dev->transport->name, tas); 391 392 core_tmr_drain_tmr_list(dev, tmr, preempt_and_abort_list); 393 core_tmr_drain_state_list(dev, prout_cmd, tmr_nacl, tas, 394 preempt_and_abort_list); 395 396 /* 397 * Clear any legacy SPC-2 reservation when called during 398 * LOGICAL UNIT RESET 399 */ 400 if (!preempt_and_abort_list && 401 (dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS)) { 402 spin_lock(&dev->dev_reservation_lock); 403 dev->dev_reserved_node_acl = NULL; 404 dev->dev_reservation_flags &= ~DRF_SPC2_RESERVATIONS; 405 spin_unlock(&dev->dev_reservation_lock); 406 pr_debug("LUN_RESET: SCSI-2 Released reservation\n"); 407 } 408 409 spin_lock_irq(&dev->stats_lock); 410 dev->num_resets++; 411 spin_unlock_irq(&dev->stats_lock); 412 413 pr_debug("LUN_RESET: %s for [%s] Complete\n", 414 (preempt_and_abort_list) ? "Preempt" : "TMR", 415 dev->transport->name); 416 return 0; 417 } 418 419