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