| 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_init(&tmr->tmr_list); |
| 72 | spin_unlock_irqrestore(&dev->se_tmr_lock, flags); |
| 73 | } |
| 74 | |
| 75 | kfree(tmr); |
| 76 | } |
| 77 | |
| 78 | static int core_tmr_handle_tas_abort(struct se_cmd *cmd, int tas) |
| 79 | { |
| 80 | unsigned long flags; |
| 81 | bool remove = true, send_tas; |
| 82 | /* |
| 83 | * TASK ABORTED status (TAS) bit support |
| 84 | */ |
| 85 | spin_lock_irqsave(&cmd->t_state_lock, flags); |
| 86 | send_tas = (cmd->transport_state & CMD_T_TAS); |
| 87 | spin_unlock_irqrestore(&cmd->t_state_lock, flags); |
| 88 | |
| 89 | if (send_tas) { |
| 90 | remove = false; |
| 91 | transport_send_task_abort(cmd); |
| 92 | } |
| 93 | |
| 94 | return transport_cmd_finish_abort(cmd, remove); |
| 95 | } |
| 96 | |
| 97 | static int target_check_cdb_and_preempt(struct list_head *list, |
| 98 | struct se_cmd *cmd) |
| 99 | { |
| 100 | struct t10_pr_registration *reg; |
| 101 | |
| 102 | if (!list) |
| 103 | return 0; |
| 104 | list_for_each_entry(reg, list, pr_reg_abort_list) { |
| 105 | if (reg->pr_res_key == cmd->pr_res_key) |
| 106 | return 0; |
| 107 | } |
| 108 | |
| 109 | return 1; |
| 110 | } |
| 111 | |
| 112 | static bool __target_check_io_state(struct se_cmd *se_cmd, |
| 113 | struct se_session *tmr_sess, int tas) |
| 114 | { |
| 115 | struct se_session *sess = se_cmd->se_sess; |
| 116 | |
| 117 | assert_spin_locked(&sess->sess_cmd_lock); |
| 118 | WARN_ON_ONCE(!irqs_disabled()); |
| 119 | /* |
| 120 | * If command already reached CMD_T_COMPLETE state within |
| 121 | * target_complete_cmd() or CMD_T_FABRIC_STOP due to shutdown, |
| 122 | * this se_cmd has been passed to fabric driver and will |
| 123 | * not be aborted. |
| 124 | * |
| 125 | * Otherwise, obtain a local se_cmd->cmd_kref now for TMR |
| 126 | * ABORT_TASK + LUN_RESET for CMD_T_ABORTED processing as |
| 127 | * long as se_cmd->cmd_kref is still active unless zero. |
| 128 | */ |
| 129 | spin_lock(&se_cmd->t_state_lock); |
| 130 | if (se_cmd->transport_state & (CMD_T_COMPLETE | CMD_T_FABRIC_STOP)) { |
| 131 | pr_debug("Attempted to abort io tag: %llu already complete or" |
| 132 | " fabric stop, skipping\n", se_cmd->tag); |
| 133 | spin_unlock(&se_cmd->t_state_lock); |
| 134 | return false; |
| 135 | } |
| 136 | if (sess->sess_tearing_down || se_cmd->cmd_wait_set) { |
| 137 | pr_debug("Attempted to abort io tag: %llu already shutdown," |
| 138 | " skipping\n", se_cmd->tag); |
| 139 | spin_unlock(&se_cmd->t_state_lock); |
| 140 | return false; |
| 141 | } |
| 142 | se_cmd->transport_state |= CMD_T_ABORTED; |
| 143 | |
| 144 | if ((tmr_sess != se_cmd->se_sess) && tas) |
| 145 | se_cmd->transport_state |= CMD_T_TAS; |
| 146 | |
| 147 | spin_unlock(&se_cmd->t_state_lock); |
| 148 | |
| 149 | return kref_get_unless_zero(&se_cmd->cmd_kref); |
| 150 | } |
| 151 | |
| 152 | void core_tmr_abort_task( |
| 153 | struct se_device *dev, |
| 154 | struct se_tmr_req *tmr, |
| 155 | struct se_session *se_sess) |
| 156 | { |
| 157 | struct se_cmd *se_cmd; |
| 158 | unsigned long flags; |
| 159 | u64 ref_tag; |
| 160 | |
| 161 | spin_lock_irqsave(&se_sess->sess_cmd_lock, flags); |
| 162 | list_for_each_entry(se_cmd, &se_sess->sess_cmd_list, se_cmd_list) { |
| 163 | |
| 164 | if (dev != se_cmd->se_dev) |
| 165 | continue; |
| 166 | |
| 167 | /* skip task management functions, including tmr->task_cmd */ |
| 168 | if (se_cmd->se_cmd_flags & SCF_SCSI_TMR_CDB) |
| 169 | continue; |
| 170 | |
| 171 | ref_tag = se_cmd->tag; |
| 172 | if (tmr->ref_task_tag != ref_tag) |
| 173 | continue; |
| 174 | |
| 175 | printk("ABORT_TASK: Found referenced %s task_tag: %llu\n", |
| 176 | se_cmd->se_tfo->get_fabric_name(), ref_tag); |
| 177 | |
| 178 | if (!__target_check_io_state(se_cmd, se_sess, 0)) { |
| 179 | spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags); |
| 180 | goto out; |
| 181 | } |
| 182 | list_del_init(&se_cmd->se_cmd_list); |
| 183 | spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags); |
| 184 | |
| 185 | cancel_work_sync(&se_cmd->work); |
| 186 | transport_wait_for_tasks(se_cmd); |
| 187 | |
| 188 | if (!transport_cmd_finish_abort(se_cmd, true)) |
| 189 | target_put_sess_cmd(se_cmd); |
| 190 | |
| 191 | printk("ABORT_TASK: Sending TMR_FUNCTION_COMPLETE for" |
| 192 | " ref_tag: %llu\n", ref_tag); |
| 193 | tmr->response = TMR_FUNCTION_COMPLETE; |
| 194 | return; |
| 195 | } |
| 196 | spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags); |
| 197 | |
| 198 | out: |
| 199 | printk("ABORT_TASK: Sending TMR_TASK_DOES_NOT_EXIST for ref_tag: %lld\n", |
| 200 | tmr->ref_task_tag); |
| 201 | tmr->response = TMR_TASK_DOES_NOT_EXIST; |
| 202 | } |
| 203 | |
| 204 | static void core_tmr_drain_tmr_list( |
| 205 | struct se_device *dev, |
| 206 | struct se_tmr_req *tmr, |
| 207 | struct list_head *preempt_and_abort_list) |
| 208 | { |
| 209 | LIST_HEAD(drain_tmr_list); |
| 210 | struct se_session *sess; |
| 211 | struct se_tmr_req *tmr_p, *tmr_pp; |
| 212 | struct se_cmd *cmd; |
| 213 | unsigned long flags; |
| 214 | bool rc; |
| 215 | /* |
| 216 | * Release all pending and outgoing TMRs aside from the received |
| 217 | * LUN_RESET tmr.. |
| 218 | */ |
| 219 | spin_lock_irqsave(&dev->se_tmr_lock, flags); |
| 220 | list_for_each_entry_safe(tmr_p, tmr_pp, &dev->dev_tmr_list, tmr_list) { |
| 221 | /* |
| 222 | * Allow the received TMR to return with FUNCTION_COMPLETE. |
| 223 | */ |
| 224 | if (tmr_p == tmr) |
| 225 | continue; |
| 226 | |
| 227 | cmd = tmr_p->task_cmd; |
| 228 | if (!cmd) { |
| 229 | pr_err("Unable to locate struct se_cmd for TMR\n"); |
| 230 | continue; |
| 231 | } |
| 232 | /* |
| 233 | * If this function was called with a valid pr_res_key |
| 234 | * parameter (eg: for PROUT PREEMPT_AND_ABORT service action |
| 235 | * skip non regisration key matching TMRs. |
| 236 | */ |
| 237 | if (target_check_cdb_and_preempt(preempt_and_abort_list, cmd)) |
| 238 | continue; |
| 239 | |
| 240 | sess = cmd->se_sess; |
| 241 | if (WARN_ON_ONCE(!sess)) |
| 242 | continue; |
| 243 | |
| 244 | spin_lock(&sess->sess_cmd_lock); |
| 245 | spin_lock(&cmd->t_state_lock); |
| 246 | if (!(cmd->transport_state & CMD_T_ACTIVE) || |
| 247 | (cmd->transport_state & CMD_T_FABRIC_STOP)) { |
| 248 | spin_unlock(&cmd->t_state_lock); |
| 249 | spin_unlock(&sess->sess_cmd_lock); |
| 250 | continue; |
| 251 | } |
| 252 | if (cmd->t_state == TRANSPORT_ISTATE_PROCESSING) { |
| 253 | spin_unlock(&cmd->t_state_lock); |
| 254 | spin_unlock(&sess->sess_cmd_lock); |
| 255 | continue; |
| 256 | } |
| 257 | if (sess->sess_tearing_down || cmd->cmd_wait_set) { |
| 258 | spin_unlock(&cmd->t_state_lock); |
| 259 | spin_unlock(&sess->sess_cmd_lock); |
| 260 | continue; |
| 261 | } |
| 262 | cmd->transport_state |= CMD_T_ABORTED; |
| 263 | spin_unlock(&cmd->t_state_lock); |
| 264 | |
| 265 | rc = kref_get_unless_zero(&cmd->cmd_kref); |
| 266 | if (!rc) { |
| 267 | printk("LUN_RESET TMR: non-zero kref_get_unless_zero\n"); |
| 268 | spin_unlock(&sess->sess_cmd_lock); |
| 269 | continue; |
| 270 | } |
| 271 | spin_unlock(&sess->sess_cmd_lock); |
| 272 | |
| 273 | list_move_tail(&tmr_p->tmr_list, &drain_tmr_list); |
| 274 | } |
| 275 | spin_unlock_irqrestore(&dev->se_tmr_lock, flags); |
| 276 | |
| 277 | list_for_each_entry_safe(tmr_p, tmr_pp, &drain_tmr_list, tmr_list) { |
| 278 | list_del_init(&tmr_p->tmr_list); |
| 279 | cmd = tmr_p->task_cmd; |
| 280 | |
| 281 | pr_debug("LUN_RESET: %s releasing TMR %p Function: 0x%02x," |
| 282 | " Response: 0x%02x, t_state: %d\n", |
| 283 | (preempt_and_abort_list) ? "Preempt" : "", tmr_p, |
| 284 | tmr_p->function, tmr_p->response, cmd->t_state); |
| 285 | |
| 286 | cancel_work_sync(&cmd->work); |
| 287 | transport_wait_for_tasks(cmd); |
| 288 | |
| 289 | if (!transport_cmd_finish_abort(cmd, 1)) |
| 290 | target_put_sess_cmd(cmd); |
| 291 | } |
| 292 | } |
| 293 | |
| 294 | static void core_tmr_drain_state_list( |
| 295 | struct se_device *dev, |
| 296 | struct se_cmd *prout_cmd, |
| 297 | struct se_session *tmr_sess, |
| 298 | int tas, |
| 299 | struct list_head *preempt_and_abort_list) |
| 300 | { |
| 301 | LIST_HEAD(drain_task_list); |
| 302 | struct se_session *sess; |
| 303 | struct se_cmd *cmd, *next; |
| 304 | unsigned long flags; |
| 305 | int rc; |
| 306 | |
| 307 | /* |
| 308 | * Complete outstanding commands with TASK_ABORTED SAM status. |
| 309 | * |
| 310 | * This is following sam4r17, section 5.6 Aborting commands, Table 38 |
| 311 | * for TMR LUN_RESET: |
| 312 | * |
| 313 | * a) "Yes" indicates that each command that is aborted on an I_T nexus |
| 314 | * other than the one that caused the SCSI device condition is |
| 315 | * completed with TASK ABORTED status, if the TAS bit is set to one in |
| 316 | * the Control mode page (see SPC-4). "No" indicates that no status is |
| 317 | * returned for aborted commands. |
| 318 | * |
| 319 | * d) If the logical unit reset is caused by a particular I_T nexus |
| 320 | * (e.g., by a LOGICAL UNIT RESET task management function), then "yes" |
| 321 | * (TASK_ABORTED status) applies. |
| 322 | * |
| 323 | * Otherwise (e.g., if triggered by a hard reset), "no" |
| 324 | * (no TASK_ABORTED SAM status) applies. |
| 325 | * |
| 326 | * Note that this seems to be independent of TAS (Task Aborted Status) |
| 327 | * in the Control Mode Page. |
| 328 | */ |
| 329 | spin_lock_irqsave(&dev->execute_task_lock, flags); |
| 330 | list_for_each_entry_safe(cmd, next, &dev->state_list, state_list) { |
| 331 | /* |
| 332 | * For PREEMPT_AND_ABORT usage, only process commands |
| 333 | * with a matching reservation key. |
| 334 | */ |
| 335 | if (target_check_cdb_and_preempt(preempt_and_abort_list, cmd)) |
| 336 | continue; |
| 337 | |
| 338 | /* |
| 339 | * Not aborting PROUT PREEMPT_AND_ABORT CDB.. |
| 340 | */ |
| 341 | if (prout_cmd == cmd) |
| 342 | continue; |
| 343 | |
| 344 | sess = cmd->se_sess; |
| 345 | if (WARN_ON_ONCE(!sess)) |
| 346 | continue; |
| 347 | |
| 348 | spin_lock(&sess->sess_cmd_lock); |
| 349 | rc = __target_check_io_state(cmd, tmr_sess, tas); |
| 350 | spin_unlock(&sess->sess_cmd_lock); |
| 351 | if (!rc) |
| 352 | continue; |
| 353 | |
| 354 | list_move_tail(&cmd->state_list, &drain_task_list); |
| 355 | cmd->state_active = false; |
| 356 | } |
| 357 | spin_unlock_irqrestore(&dev->execute_task_lock, flags); |
| 358 | |
| 359 | while (!list_empty(&drain_task_list)) { |
| 360 | cmd = list_entry(drain_task_list.next, struct se_cmd, state_list); |
| 361 | list_del_init(&cmd->state_list); |
| 362 | |
| 363 | pr_debug("LUN_RESET: %s cmd: %p" |
| 364 | " ITT/CmdSN: 0x%08llx/0x%08x, i_state: %d, t_state: %d" |
| 365 | "cdb: 0x%02x\n", |
| 366 | (preempt_and_abort_list) ? "Preempt" : "", cmd, |
| 367 | cmd->tag, 0, |
| 368 | cmd->se_tfo->get_cmd_state(cmd), cmd->t_state, |
| 369 | cmd->t_task_cdb[0]); |
| 370 | pr_debug("LUN_RESET: ITT[0x%08llx] - pr_res_key: 0x%016Lx" |
| 371 | " -- CMD_T_ACTIVE: %d" |
| 372 | " CMD_T_STOP: %d CMD_T_SENT: %d\n", |
| 373 | cmd->tag, cmd->pr_res_key, |
| 374 | (cmd->transport_state & CMD_T_ACTIVE) != 0, |
| 375 | (cmd->transport_state & CMD_T_STOP) != 0, |
| 376 | (cmd->transport_state & CMD_T_SENT) != 0); |
| 377 | |
| 378 | /* |
| 379 | * If the command may be queued onto a workqueue cancel it now. |
| 380 | * |
| 381 | * This is equivalent to removal from the execute queue in the |
| 382 | * loop above, but we do it down here given that |
| 383 | * cancel_work_sync may block. |
| 384 | */ |
| 385 | cancel_work_sync(&cmd->work); |
| 386 | transport_wait_for_tasks(cmd); |
| 387 | |
| 388 | if (!core_tmr_handle_tas_abort(cmd, tas)) |
| 389 | target_put_sess_cmd(cmd); |
| 390 | } |
| 391 | } |
| 392 | |
| 393 | int core_tmr_lun_reset( |
| 394 | struct se_device *dev, |
| 395 | struct se_tmr_req *tmr, |
| 396 | struct list_head *preempt_and_abort_list, |
| 397 | struct se_cmd *prout_cmd) |
| 398 | { |
| 399 | struct se_node_acl *tmr_nacl = NULL; |
| 400 | struct se_portal_group *tmr_tpg = NULL; |
| 401 | struct se_session *tmr_sess = NULL; |
| 402 | int tas; |
| 403 | /* |
| 404 | * TASK_ABORTED status bit, this is configurable via ConfigFS |
| 405 | * struct se_device attributes. spc4r17 section 7.4.6 Control mode page |
| 406 | * |
| 407 | * A task aborted status (TAS) bit set to zero specifies that aborted |
| 408 | * tasks shall be terminated by the device server without any response |
| 409 | * to the application client. A TAS bit set to one specifies that tasks |
| 410 | * aborted by the actions of an I_T nexus other than the I_T nexus on |
| 411 | * which the command was received shall be completed with TASK ABORTED |
| 412 | * status (see SAM-4). |
| 413 | */ |
| 414 | tas = dev->dev_attrib.emulate_tas; |
| 415 | /* |
| 416 | * Determine if this se_tmr is coming from a $FABRIC_MOD |
| 417 | * or struct se_device passthrough.. |
| 418 | */ |
| 419 | if (tmr && tmr->task_cmd && tmr->task_cmd->se_sess) { |
| 420 | tmr_sess = tmr->task_cmd->se_sess; |
| 421 | tmr_nacl = tmr_sess->se_node_acl; |
| 422 | tmr_tpg = tmr_sess->se_tpg; |
| 423 | if (tmr_nacl && tmr_tpg) { |
| 424 | pr_debug("LUN_RESET: TMR caller fabric: %s" |
| 425 | " initiator port %s\n", |
| 426 | tmr_tpg->se_tpg_tfo->get_fabric_name(), |
| 427 | tmr_nacl->initiatorname); |
| 428 | } |
| 429 | } |
| 430 | pr_debug("LUN_RESET: %s starting for [%s], tas: %d\n", |
| 431 | (preempt_and_abort_list) ? "Preempt" : "TMR", |
| 432 | dev->transport->name, tas); |
| 433 | |
| 434 | core_tmr_drain_tmr_list(dev, tmr, preempt_and_abort_list); |
| 435 | core_tmr_drain_state_list(dev, prout_cmd, tmr_sess, tas, |
| 436 | preempt_and_abort_list); |
| 437 | |
| 438 | /* |
| 439 | * Clear any legacy SPC-2 reservation when called during |
| 440 | * LOGICAL UNIT RESET |
| 441 | */ |
| 442 | if (!preempt_and_abort_list && |
| 443 | (dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS)) { |
| 444 | spin_lock(&dev->dev_reservation_lock); |
| 445 | dev->dev_reserved_node_acl = NULL; |
| 446 | dev->dev_reservation_flags &= ~DRF_SPC2_RESERVATIONS; |
| 447 | spin_unlock(&dev->dev_reservation_lock); |
| 448 | pr_debug("LUN_RESET: SCSI-2 Released reservation\n"); |
| 449 | } |
| 450 | |
| 451 | atomic_long_inc(&dev->num_resets); |
| 452 | |
| 453 | pr_debug("LUN_RESET: %s for [%s] Complete\n", |
| 454 | (preempt_and_abort_list) ? "Preempt" : "TMR", |
| 455 | dev->transport->name); |
| 456 | return 0; |
| 457 | } |
| 458 | |