1 /******************************************************************************* 2 * Filename: target_core_tmr.c 3 * 4 * This file contains SPC-3 task management infrastructure 5 * 6 * Copyright (c) 2009,2010 Rising Tide Systems 7 * Copyright (c) 2009,2010 Linux-iSCSI.org 8 * 9 * Nicholas A. Bellinger <nab@kernel.org> 10 * 11 * This program is free software; you can redistribute it and/or modify 12 * it under the terms of the GNU General Public License as published by 13 * the Free Software Foundation; either version 2 of the License, or 14 * (at your option) any later version. 15 * 16 * This program is distributed in the hope that it will be useful, 17 * but WITHOUT ANY WARRANTY; without even the implied warranty of 18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 19 * GNU General Public License for more details. 20 * 21 * You should have received a copy of the GNU General Public License 22 * along with this program; if not, write to the Free Software 23 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. 24 * 25 ******************************************************************************/ 26 27 #include <linux/slab.h> 28 #include <linux/spinlock.h> 29 #include <linux/list.h> 30 #include <linux/export.h> 31 #include <scsi/scsi.h> 32 #include <scsi/scsi_cmnd.h> 33 34 #include <target/target_core_base.h> 35 #include <target/target_core_backend.h> 36 #include <target/target_core_fabric.h> 37 #include <target/target_core_configfs.h> 38 39 #include "target_core_internal.h" 40 #include "target_core_alua.h" 41 #include "target_core_pr.h" 42 43 int core_tmr_alloc_req( 44 struct se_cmd *se_cmd, 45 void *fabric_tmr_ptr, 46 u8 function, 47 gfp_t gfp_flags) 48 { 49 struct se_tmr_req *tmr; 50 51 tmr = kzalloc(sizeof(struct se_tmr_req), gfp_flags); 52 if (!tmr) { 53 pr_err("Unable to allocate struct se_tmr_req\n"); 54 return -ENOMEM; 55 } 56 57 se_cmd->se_cmd_flags |= SCF_SCSI_TMR_CDB; 58 se_cmd->se_tmr_req = tmr; 59 tmr->task_cmd = se_cmd; 60 tmr->fabric_tmr_ptr = fabric_tmr_ptr; 61 tmr->function = function; 62 INIT_LIST_HEAD(&tmr->tmr_list); 63 64 return 0; 65 } 66 EXPORT_SYMBOL(core_tmr_alloc_req); 67 68 void core_tmr_release_req( 69 struct se_tmr_req *tmr) 70 { 71 struct se_device *dev = tmr->tmr_dev; 72 unsigned long flags; 73 74 if (!dev) { 75 kfree(tmr); 76 return; 77 } 78 79 spin_lock_irqsave(&dev->se_tmr_lock, flags); 80 list_del(&tmr->tmr_list); 81 spin_unlock_irqrestore(&dev->se_tmr_lock, flags); 82 83 kfree(tmr); 84 } 85 86 static void core_tmr_handle_tas_abort( 87 struct se_node_acl *tmr_nacl, 88 struct se_cmd *cmd, 89 int tas, 90 int fe_count) 91 { 92 if (!fe_count) { 93 transport_cmd_finish_abort(cmd, 1); 94 return; 95 } 96 /* 97 * TASK ABORTED status (TAS) bit support 98 */ 99 if ((tmr_nacl && 100 (tmr_nacl == cmd->se_sess->se_node_acl)) || tas) 101 transport_send_task_abort(cmd); 102 103 transport_cmd_finish_abort(cmd, 0); 104 } 105 106 static int target_check_cdb_and_preempt(struct list_head *list, 107 struct se_cmd *cmd) 108 { 109 struct t10_pr_registration *reg; 110 111 if (!list) 112 return 0; 113 list_for_each_entry(reg, list, pr_reg_abort_list) { 114 if (reg->pr_res_key == cmd->pr_res_key) 115 return 0; 116 } 117 118 return 1; 119 } 120 121 void core_tmr_abort_task( 122 struct se_device *dev, 123 struct se_tmr_req *tmr, 124 struct se_session *se_sess) 125 { 126 struct se_cmd *se_cmd, *tmp_cmd; 127 unsigned long flags; 128 int ref_tag; 129 130 spin_lock_irqsave(&se_sess->sess_cmd_lock, flags); 131 list_for_each_entry_safe(se_cmd, tmp_cmd, 132 &se_sess->sess_cmd_list, se_cmd_list) { 133 134 if (dev != se_cmd->se_dev) 135 continue; 136 ref_tag = se_cmd->se_tfo->get_task_tag(se_cmd); 137 if (tmr->ref_task_tag != ref_tag) 138 continue; 139 140 printk("ABORT_TASK: Found referenced %s task_tag: %u\n", 141 se_cmd->se_tfo->get_fabric_name(), ref_tag); 142 143 spin_lock_irq(&se_cmd->t_state_lock); 144 if (se_cmd->transport_state & CMD_T_COMPLETE) { 145 printk("ABORT_TASK: ref_tag: %u already complete, skipping\n", ref_tag); 146 spin_unlock_irq(&se_cmd->t_state_lock); 147 spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags); 148 goto out; 149 } 150 se_cmd->transport_state |= CMD_T_ABORTED; 151 spin_unlock_irq(&se_cmd->t_state_lock); 152 153 list_del_init(&se_cmd->se_cmd_list); 154 kref_get(&se_cmd->cmd_kref); 155 spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags); 156 157 cancel_work_sync(&se_cmd->work); 158 transport_wait_for_tasks(se_cmd); 159 /* 160 * Now send SAM_STAT_TASK_ABORTED status for the referenced 161 * se_cmd descriptor.. 162 */ 163 transport_send_task_abort(se_cmd); 164 /* 165 * Also deal with possible extra acknowledge reference.. 166 */ 167 if (se_cmd->se_cmd_flags & SCF_ACK_KREF) 168 target_put_sess_cmd(se_sess, se_cmd); 169 170 target_put_sess_cmd(se_sess, se_cmd); 171 172 printk("ABORT_TASK: Sending TMR_FUNCTION_COMPLETE for" 173 " ref_tag: %d\n", ref_tag); 174 tmr->response = TMR_FUNCTION_COMPLETE; 175 return; 176 } 177 spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags); 178 179 out: 180 printk("ABORT_TASK: Sending TMR_TASK_DOES_NOT_EXIST for ref_tag: %d\n", 181 tmr->ref_task_tag); 182 tmr->response = TMR_TASK_DOES_NOT_EXIST; 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_tmr_req *tmr_p, *tmr_pp; 192 struct se_cmd *cmd; 193 unsigned long flags; 194 /* 195 * Release all pending and outgoing TMRs aside from the received 196 * LUN_RESET tmr.. 197 */ 198 spin_lock_irqsave(&dev->se_tmr_lock, flags); 199 list_for_each_entry_safe(tmr_p, tmr_pp, &dev->dev_tmr_list, tmr_list) { 200 /* 201 * Allow the received TMR to return with FUNCTION_COMPLETE. 202 */ 203 if (tmr_p == tmr) 204 continue; 205 206 cmd = tmr_p->task_cmd; 207 if (!cmd) { 208 pr_err("Unable to locate struct se_cmd for TMR\n"); 209 continue; 210 } 211 /* 212 * If this function was called with a valid pr_res_key 213 * parameter (eg: for PROUT PREEMPT_AND_ABORT service action 214 * skip non regisration key matching TMRs. 215 */ 216 if (target_check_cdb_and_preempt(preempt_and_abort_list, cmd)) 217 continue; 218 219 spin_lock(&cmd->t_state_lock); 220 if (!(cmd->transport_state & CMD_T_ACTIVE)) { 221 spin_unlock(&cmd->t_state_lock); 222 continue; 223 } 224 if (cmd->t_state == TRANSPORT_ISTATE_PROCESSING) { 225 spin_unlock(&cmd->t_state_lock); 226 continue; 227 } 228 spin_unlock(&cmd->t_state_lock); 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 transport_cmd_finish_abort(cmd, 1); 244 } 245 } 246 247 static void core_tmr_drain_state_list( 248 struct se_device *dev, 249 struct se_cmd *prout_cmd, 250 struct se_node_acl *tmr_nacl, 251 int tas, 252 struct list_head *preempt_and_abort_list) 253 { 254 LIST_HEAD(drain_task_list); 255 struct se_cmd *cmd, *next; 256 unsigned long flags; 257 int fe_count; 258 259 /* 260 * Complete outstanding commands with TASK_ABORTED SAM status. 261 * 262 * This is following sam4r17, section 5.6 Aborting commands, Table 38 263 * for TMR LUN_RESET: 264 * 265 * a) "Yes" indicates that each command that is aborted on an I_T nexus 266 * other than the one that caused the SCSI device condition is 267 * completed with TASK ABORTED status, if the TAS bit is set to one in 268 * the Control mode page (see SPC-4). "No" indicates that no status is 269 * returned for aborted commands. 270 * 271 * d) If the logical unit reset is caused by a particular I_T nexus 272 * (e.g., by a LOGICAL UNIT RESET task management function), then "yes" 273 * (TASK_ABORTED status) applies. 274 * 275 * Otherwise (e.g., if triggered by a hard reset), "no" 276 * (no TASK_ABORTED SAM status) applies. 277 * 278 * Note that this seems to be independent of TAS (Task Aborted Status) 279 * in the Control Mode Page. 280 */ 281 spin_lock_irqsave(&dev->execute_task_lock, flags); 282 list_for_each_entry_safe(cmd, next, &dev->state_list, state_list) { 283 /* 284 * For PREEMPT_AND_ABORT usage, only process commands 285 * with a matching reservation key. 286 */ 287 if (target_check_cdb_and_preempt(preempt_and_abort_list, cmd)) 288 continue; 289 290 /* 291 * Not aborting PROUT PREEMPT_AND_ABORT CDB.. 292 */ 293 if (prout_cmd == cmd) 294 continue; 295 296 list_move_tail(&cmd->state_list, &drain_task_list); 297 cmd->state_active = false; 298 } 299 spin_unlock_irqrestore(&dev->execute_task_lock, flags); 300 301 while (!list_empty(&drain_task_list)) { 302 cmd = list_entry(drain_task_list.next, struct se_cmd, state_list); 303 list_del(&cmd->state_list); 304 305 pr_debug("LUN_RESET: %s cmd: %p" 306 " ITT/CmdSN: 0x%08x/0x%08x, i_state: %d, t_state: %d" 307 "cdb: 0x%02x\n", 308 (preempt_and_abort_list) ? "Preempt" : "", cmd, 309 cmd->se_tfo->get_task_tag(cmd), 0, 310 cmd->se_tfo->get_cmd_state(cmd), cmd->t_state, 311 cmd->t_task_cdb[0]); 312 pr_debug("LUN_RESET: ITT[0x%08x] - pr_res_key: 0x%016Lx" 313 " -- CMD_T_ACTIVE: %d" 314 " CMD_T_STOP: %d CMD_T_SENT: %d\n", 315 cmd->se_tfo->get_task_tag(cmd), cmd->pr_res_key, 316 (cmd->transport_state & CMD_T_ACTIVE) != 0, 317 (cmd->transport_state & CMD_T_STOP) != 0, 318 (cmd->transport_state & CMD_T_SENT) != 0); 319 320 /* 321 * If the command may be queued onto a workqueue cancel it now. 322 * 323 * This is equivalent to removal from the execute queue in the 324 * loop above, but we do it down here given that 325 * cancel_work_sync may block. 326 */ 327 if (cmd->t_state == TRANSPORT_COMPLETE) 328 cancel_work_sync(&cmd->work); 329 330 spin_lock_irqsave(&cmd->t_state_lock, flags); 331 target_stop_cmd(cmd, &flags); 332 333 fe_count = atomic_read(&cmd->t_fe_count); 334 335 if (!(cmd->transport_state & CMD_T_ACTIVE)) { 336 pr_debug("LUN_RESET: got CMD_T_ACTIVE for" 337 " cdb: %p, t_fe_count: %d dev: %p\n", cmd, 338 fe_count, dev); 339 cmd->transport_state |= CMD_T_ABORTED; 340 spin_unlock_irqrestore(&cmd->t_state_lock, flags); 341 342 core_tmr_handle_tas_abort(tmr_nacl, cmd, tas, fe_count); 343 continue; 344 } 345 pr_debug("LUN_RESET: Got !CMD_T_ACTIVE for cdb: %p," 346 " t_fe_count: %d dev: %p\n", cmd, fe_count, dev); 347 cmd->transport_state |= CMD_T_ABORTED; 348 spin_unlock_irqrestore(&cmd->t_state_lock, flags); 349 350 core_tmr_handle_tas_abort(tmr_nacl, cmd, tas, fe_count); 351 } 352 } 353 354 int core_tmr_lun_reset( 355 struct se_device *dev, 356 struct se_tmr_req *tmr, 357 struct list_head *preempt_and_abort_list, 358 struct se_cmd *prout_cmd) 359 { 360 struct se_node_acl *tmr_nacl = NULL; 361 struct se_portal_group *tmr_tpg = NULL; 362 int tas; 363 /* 364 * TASK_ABORTED status bit, this is configurable via ConfigFS 365 * struct se_device attributes. spc4r17 section 7.4.6 Control mode page 366 * 367 * A task aborted status (TAS) bit set to zero specifies that aborted 368 * tasks shall be terminated by the device server without any response 369 * to the application client. A TAS bit set to one specifies that tasks 370 * aborted by the actions of an I_T nexus other than the I_T nexus on 371 * which the command was received shall be completed with TASK ABORTED 372 * status (see SAM-4). 373 */ 374 tas = dev->se_sub_dev->se_dev_attrib.emulate_tas; 375 /* 376 * Determine if this se_tmr is coming from a $FABRIC_MOD 377 * or struct se_device passthrough.. 378 */ 379 if (tmr && tmr->task_cmd && tmr->task_cmd->se_sess) { 380 tmr_nacl = tmr->task_cmd->se_sess->se_node_acl; 381 tmr_tpg = tmr->task_cmd->se_sess->se_tpg; 382 if (tmr_nacl && tmr_tpg) { 383 pr_debug("LUN_RESET: TMR caller fabric: %s" 384 " initiator port %s\n", 385 tmr_tpg->se_tpg_tfo->get_fabric_name(), 386 tmr_nacl->initiatorname); 387 } 388 } 389 pr_debug("LUN_RESET: %s starting for [%s], tas: %d\n", 390 (preempt_and_abort_list) ? "Preempt" : "TMR", 391 dev->transport->name, tas); 392 393 core_tmr_drain_tmr_list(dev, tmr, preempt_and_abort_list); 394 core_tmr_drain_state_list(dev, prout_cmd, tmr_nacl, tas, 395 preempt_and_abort_list); 396 397 /* 398 * Clear any legacy SPC-2 reservation when called during 399 * LOGICAL UNIT RESET 400 */ 401 if (!preempt_and_abort_list && 402 (dev->dev_flags & DF_SPC2_RESERVATIONS)) { 403 spin_lock(&dev->dev_reservation_lock); 404 dev->dev_reserved_node_acl = NULL; 405 dev->dev_flags &= ~DF_SPC2_RESERVATIONS; 406 spin_unlock(&dev->dev_reservation_lock); 407 pr_debug("LUN_RESET: SCSI-2 Released reservation\n"); 408 } 409 410 spin_lock_irq(&dev->stats_lock); 411 dev->num_resets++; 412 spin_unlock_irq(&dev->stats_lock); 413 414 pr_debug("LUN_RESET: %s for [%s] Complete\n", 415 (preempt_and_abort_list) ? "Preempt" : "TMR", 416 dev->transport->name); 417 return 0; 418 } 419 420