1 /*******************************************************************************
2 * Filename: target_core_tmr.c
4 * This file contains SPC-3 task management infrastructure
6 * (c) Copyright 2009-2013 Datera, Inc.
8 * Nicholas A. Bellinger <nab@kernel.org>
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.
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.
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.
24 ******************************************************************************/
26 #include <linux/slab.h>
27 #include <linux/spinlock.h>
28 #include <linux/list.h>
29 #include <linux/export.h>
31 #include <target/target_core_base.h>
32 #include <target/target_core_backend.h>
33 #include <target/target_core_fabric.h>
35 #include "target_core_internal.h"
36 #include "target_core_alua.h"
37 #include "target_core_pr.h"
39 int core_tmr_alloc_req(
40 struct se_cmd *se_cmd,
45 struct se_tmr_req *tmr;
47 tmr = kzalloc(sizeof(struct se_tmr_req), gfp_flags);
49 pr_err("Unable to allocate struct se_tmr_req\n");
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);
62 EXPORT_SYMBOL(core_tmr_alloc_req);
64 void core_tmr_release_req(struct se_tmr_req *tmr)
66 struct se_device *dev = tmr->tmr_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);
78 static void core_tmr_handle_tas_abort(struct se_cmd *cmd, int tas)
81 bool remove = true, send_tas;
83 * TASK ABORTED status (TAS) bit support
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);
91 transport_send_task_abort(cmd);
94 transport_cmd_finish_abort(cmd, remove);
97 static int target_check_cdb_and_preempt(struct list_head *list,
100 struct t10_pr_registration *reg;
104 list_for_each_entry(reg, list, pr_reg_abort_list) {
105 if (reg->pr_res_key == cmd->pr_res_key)
112 static bool __target_check_io_state(struct se_cmd *se_cmd,
113 struct se_session *tmr_sess, int tas)
115 struct se_session *sess = se_cmd->se_sess;
117 assert_spin_locked(&sess->sess_cmd_lock);
118 WARN_ON_ONCE(!irqs_disabled());
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
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.
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);
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);
142 se_cmd->transport_state |= CMD_T_ABORTED;
144 if ((tmr_sess != se_cmd->se_sess) && tas)
145 se_cmd->transport_state |= CMD_T_TAS;
147 spin_unlock(&se_cmd->t_state_lock);
149 return kref_get_unless_zero(&se_cmd->cmd_kref);
152 void core_tmr_abort_task(
153 struct se_device *dev,
154 struct se_tmr_req *tmr,
155 struct se_session *se_sess)
157 struct se_cmd *se_cmd;
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) {
164 if (dev != se_cmd->se_dev)
167 /* skip task management functions, including tmr->task_cmd */
168 if (se_cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
171 ref_tag = se_cmd->tag;
172 if (tmr->ref_task_tag != ref_tag)
175 printk("ABORT_TASK: Found referenced %s task_tag: %llu\n",
176 se_cmd->se_tfo->get_fabric_name(), ref_tag);
178 if (!__target_check_io_state(se_cmd, se_sess, 0)) {
179 spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
180 target_put_sess_cmd(se_cmd);
183 list_del_init(&se_cmd->se_cmd_list);
184 spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
186 cancel_work_sync(&se_cmd->work);
187 transport_wait_for_tasks(se_cmd);
189 transport_cmd_finish_abort(se_cmd, true);
190 target_put_sess_cmd(se_cmd);
192 printk("ABORT_TASK: Sending TMR_FUNCTION_COMPLETE for"
193 " ref_tag: %llu\n", ref_tag);
194 tmr->response = TMR_FUNCTION_COMPLETE;
197 spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
200 printk("ABORT_TASK: Sending TMR_TASK_DOES_NOT_EXIST for ref_tag: %lld\n",
202 tmr->response = TMR_TASK_DOES_NOT_EXIST;
205 static void core_tmr_drain_tmr_list(
206 struct se_device *dev,
207 struct se_tmr_req *tmr,
208 struct list_head *preempt_and_abort_list)
210 LIST_HEAD(drain_tmr_list);
211 struct se_session *sess;
212 struct se_tmr_req *tmr_p, *tmr_pp;
217 * Release all pending and outgoing TMRs aside from the received
220 spin_lock_irqsave(&dev->se_tmr_lock, flags);
221 list_for_each_entry_safe(tmr_p, tmr_pp, &dev->dev_tmr_list, tmr_list) {
223 * Allow the received TMR to return with FUNCTION_COMPLETE.
228 cmd = tmr_p->task_cmd;
230 pr_err("Unable to locate struct se_cmd for TMR\n");
234 * If this function was called with a valid pr_res_key
235 * parameter (eg: for PROUT PREEMPT_AND_ABORT service action
236 * skip non registration key matching TMRs.
238 if (target_check_cdb_and_preempt(preempt_and_abort_list, cmd))
242 if (WARN_ON_ONCE(!sess))
245 spin_lock(&sess->sess_cmd_lock);
246 spin_lock(&cmd->t_state_lock);
247 if (!(cmd->transport_state & CMD_T_ACTIVE) ||
248 (cmd->transport_state & CMD_T_FABRIC_STOP)) {
249 spin_unlock(&cmd->t_state_lock);
250 spin_unlock(&sess->sess_cmd_lock);
253 if (cmd->t_state == TRANSPORT_ISTATE_PROCESSING) {
254 spin_unlock(&cmd->t_state_lock);
255 spin_unlock(&sess->sess_cmd_lock);
258 if (sess->sess_tearing_down || cmd->cmd_wait_set) {
259 spin_unlock(&cmd->t_state_lock);
260 spin_unlock(&sess->sess_cmd_lock);
263 cmd->transport_state |= CMD_T_ABORTED;
264 spin_unlock(&cmd->t_state_lock);
266 rc = kref_get_unless_zero(&cmd->cmd_kref);
268 printk("LUN_RESET TMR: non-zero kref_get_unless_zero\n");
269 spin_unlock(&sess->sess_cmd_lock);
272 spin_unlock(&sess->sess_cmd_lock);
274 list_move_tail(&tmr_p->tmr_list, &drain_tmr_list);
276 spin_unlock_irqrestore(&dev->se_tmr_lock, flags);
278 list_for_each_entry_safe(tmr_p, tmr_pp, &drain_tmr_list, tmr_list) {
279 list_del_init(&tmr_p->tmr_list);
280 cmd = tmr_p->task_cmd;
282 pr_debug("LUN_RESET: %s releasing TMR %p Function: 0x%02x,"
283 " Response: 0x%02x, t_state: %d\n",
284 (preempt_and_abort_list) ? "Preempt" : "", tmr_p,
285 tmr_p->function, tmr_p->response, cmd->t_state);
287 cancel_work_sync(&cmd->work);
288 transport_wait_for_tasks(cmd);
290 transport_cmd_finish_abort(cmd, 1);
291 target_put_sess_cmd(cmd);
295 static void core_tmr_drain_state_list(
296 struct se_device *dev,
297 struct se_cmd *prout_cmd,
298 struct se_session *tmr_sess,
300 struct list_head *preempt_and_abort_list)
302 LIST_HEAD(drain_task_list);
303 struct se_session *sess;
304 struct se_cmd *cmd, *next;
309 * Complete outstanding commands with TASK_ABORTED SAM status.
311 * This is following sam4r17, section 5.6 Aborting commands, Table 38
314 * a) "Yes" indicates that each command that is aborted on an I_T nexus
315 * other than the one that caused the SCSI device condition is
316 * completed with TASK ABORTED status, if the TAS bit is set to one in
317 * the Control mode page (see SPC-4). "No" indicates that no status is
318 * returned for aborted commands.
320 * d) If the logical unit reset is caused by a particular I_T nexus
321 * (e.g., by a LOGICAL UNIT RESET task management function), then "yes"
322 * (TASK_ABORTED status) applies.
324 * Otherwise (e.g., if triggered by a hard reset), "no"
325 * (no TASK_ABORTED SAM status) applies.
327 * Note that this seems to be independent of TAS (Task Aborted Status)
328 * in the Control Mode Page.
330 spin_lock_irqsave(&dev->execute_task_lock, flags);
331 list_for_each_entry_safe(cmd, next, &dev->state_list, state_list) {
333 * For PREEMPT_AND_ABORT usage, only process commands
334 * with a matching reservation key.
336 if (target_check_cdb_and_preempt(preempt_and_abort_list, cmd))
340 * Not aborting PROUT PREEMPT_AND_ABORT CDB..
342 if (prout_cmd == cmd)
346 if (WARN_ON_ONCE(!sess))
349 spin_lock(&sess->sess_cmd_lock);
350 rc = __target_check_io_state(cmd, tmr_sess, tas);
351 spin_unlock(&sess->sess_cmd_lock);
355 list_move_tail(&cmd->state_list, &drain_task_list);
356 cmd->state_active = false;
358 spin_unlock_irqrestore(&dev->execute_task_lock, flags);
360 while (!list_empty(&drain_task_list)) {
361 cmd = list_entry(drain_task_list.next, struct se_cmd, state_list);
362 list_del_init(&cmd->state_list);
364 pr_debug("LUN_RESET: %s cmd: %p"
365 " ITT/CmdSN: 0x%08llx/0x%08x, i_state: %d, t_state: %d"
367 (preempt_and_abort_list) ? "Preempt" : "", cmd,
369 cmd->se_tfo->get_cmd_state(cmd), cmd->t_state,
371 pr_debug("LUN_RESET: ITT[0x%08llx] - pr_res_key: 0x%016Lx"
372 " -- CMD_T_ACTIVE: %d"
373 " CMD_T_STOP: %d CMD_T_SENT: %d\n",
374 cmd->tag, cmd->pr_res_key,
375 (cmd->transport_state & CMD_T_ACTIVE) != 0,
376 (cmd->transport_state & CMD_T_STOP) != 0,
377 (cmd->transport_state & CMD_T_SENT) != 0);
380 * If the command may be queued onto a workqueue cancel it now.
382 * This is equivalent to removal from the execute queue in the
383 * loop above, but we do it down here given that
384 * cancel_work_sync may block.
386 cancel_work_sync(&cmd->work);
387 transport_wait_for_tasks(cmd);
389 core_tmr_handle_tas_abort(cmd, tas);
390 target_put_sess_cmd(cmd);
394 int core_tmr_lun_reset(
395 struct se_device *dev,
396 struct se_tmr_req *tmr,
397 struct list_head *preempt_and_abort_list,
398 struct se_cmd *prout_cmd)
400 struct se_node_acl *tmr_nacl = NULL;
401 struct se_portal_group *tmr_tpg = NULL;
402 struct se_session *tmr_sess = NULL;
405 * TASK_ABORTED status bit, this is configurable via ConfigFS
406 * struct se_device attributes. spc4r17 section 7.4.6 Control mode page
408 * A task aborted status (TAS) bit set to zero specifies that aborted
409 * tasks shall be terminated by the device server without any response
410 * to the application client. A TAS bit set to one specifies that tasks
411 * aborted by the actions of an I_T nexus other than the I_T nexus on
412 * which the command was received shall be completed with TASK ABORTED
413 * status (see SAM-4).
415 tas = dev->dev_attrib.emulate_tas;
417 * Determine if this se_tmr is coming from a $FABRIC_MOD
418 * or struct se_device passthrough..
420 if (tmr && tmr->task_cmd && tmr->task_cmd->se_sess) {
421 tmr_sess = tmr->task_cmd->se_sess;
422 tmr_nacl = tmr_sess->se_node_acl;
423 tmr_tpg = tmr_sess->se_tpg;
424 if (tmr_nacl && tmr_tpg) {
425 pr_debug("LUN_RESET: TMR caller fabric: %s"
426 " initiator port %s\n",
427 tmr_tpg->se_tpg_tfo->get_fabric_name(),
428 tmr_nacl->initiatorname);
431 pr_debug("LUN_RESET: %s starting for [%s], tas: %d\n",
432 (preempt_and_abort_list) ? "Preempt" : "TMR",
433 dev->transport->name, tas);
435 core_tmr_drain_tmr_list(dev, tmr, preempt_and_abort_list);
436 core_tmr_drain_state_list(dev, prout_cmd, tmr_sess, tas,
437 preempt_and_abort_list);
440 * Clear any legacy SPC-2 reservation when called during
443 if (!preempt_and_abort_list &&
444 (dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS)) {
445 spin_lock(&dev->dev_reservation_lock);
446 dev->dev_reserved_node_acl = NULL;
447 dev->dev_reservation_flags &= ~DRF_SPC2_RESERVATIONS;
448 spin_unlock(&dev->dev_reservation_lock);
449 pr_debug("LUN_RESET: SCSI-2 Released reservation\n");
452 atomic_long_inc(&dev->num_resets);
454 pr_debug("LUN_RESET: %s for [%s] Complete\n",
455 (preempt_and_abort_list) ? "Preempt" : "TMR",
456 dev->transport->name);