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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*******************************************************************************
3 * Filename: target_core_tmr.c
4 *
5 * This file contains SPC-3 task management infrastructure
6 *
7 * (c) Copyright 2009-2013 Datera, Inc.
8 *
9 * Nicholas A. Bellinger <nab@kernel.org>
10 *
11 ******************************************************************************/
12
13#include <linux/slab.h>
14#include <linux/spinlock.h>
15#include <linux/list.h>
16#include <linux/export.h>
17
18#include <target/target_core_base.h>
19#include <target/target_core_backend.h>
20#include <target/target_core_fabric.h>
21
22#include "target_core_internal.h"
23#include "target_core_alua.h"
24#include "target_core_pr.h"
25
26int core_tmr_alloc_req(
27 struct se_cmd *se_cmd,
28 void *fabric_tmr_ptr,
29 u8 function,
30 gfp_t gfp_flags)
31{
32 struct se_tmr_req *tmr;
33
34 tmr = kzalloc(sizeof(struct se_tmr_req), gfp_flags);
35 if (!tmr) {
36 pr_err("Unable to allocate struct se_tmr_req\n");
37 return -ENOMEM;
38 }
39
40 se_cmd->se_cmd_flags |= SCF_SCSI_TMR_CDB;
41 se_cmd->se_tmr_req = tmr;
42 tmr->task_cmd = se_cmd;
43 tmr->fabric_tmr_ptr = fabric_tmr_ptr;
44 tmr->function = function;
45 INIT_LIST_HEAD(&tmr->tmr_list);
46
47 return 0;
48}
49EXPORT_SYMBOL(core_tmr_alloc_req);
50
51void core_tmr_release_req(struct se_tmr_req *tmr)
52{
53 kfree(tmr);
54}
55
56static int target_check_cdb_and_preempt(struct list_head *list,
57 struct se_cmd *cmd)
58{
59 struct t10_pr_registration *reg;
60
61 if (!list)
62 return 0;
63 list_for_each_entry(reg, list, pr_reg_abort_list) {
64 if (reg->pr_res_key == cmd->pr_res_key)
65 return 0;
66 }
67
68 return 1;
69}
70
71static bool __target_check_io_state(struct se_cmd *se_cmd,
72 struct se_session *tmr_sess, bool tas)
73{
74 struct se_session *sess = se_cmd->se_sess;
75
76 lockdep_assert_held(&sess->sess_cmd_lock);
77
78 /*
79 * If command already reached CMD_T_COMPLETE state within
80 * target_complete_cmd() or CMD_T_FABRIC_STOP due to shutdown,
81 * this se_cmd has been passed to fabric driver and will
82 * not be aborted.
83 *
84 * Otherwise, obtain a local se_cmd->cmd_kref now for TMR
85 * ABORT_TASK + LUN_RESET for CMD_T_ABORTED processing as
86 * long as se_cmd->cmd_kref is still active unless zero.
87 */
88 spin_lock(&se_cmd->t_state_lock);
89 if (se_cmd->transport_state & (CMD_T_COMPLETE | CMD_T_FABRIC_STOP)) {
90 pr_debug("Attempted to abort io tag: %llu already complete or"
91 " fabric stop, skipping\n", se_cmd->tag);
92 spin_unlock(&se_cmd->t_state_lock);
93 return false;
94 }
95 se_cmd->transport_state |= CMD_T_ABORTED;
96
97 if ((tmr_sess != se_cmd->se_sess) && tas)
98 se_cmd->transport_state |= CMD_T_TAS;
99
100 spin_unlock(&se_cmd->t_state_lock);
101
102 return kref_get_unless_zero(&se_cmd->cmd_kref);
103}
104
105void core_tmr_abort_task(
106 struct se_device *dev,
107 struct se_tmr_req *tmr,
108 struct se_session *se_sess)
109{
110 LIST_HEAD(aborted_list);
111 struct se_cmd *se_cmd, *next;
112 unsigned long flags;
113 bool rc;
114 u64 ref_tag;
115 int i;
116
117 for (i = 0; i < dev->queue_cnt; i++) {
118 flush_work(&dev->queues[i].sq.work);
119
120 spin_lock_irqsave(&dev->queues[i].lock, flags);
121 list_for_each_entry_safe(se_cmd, next, &dev->queues[i].state_list,
122 state_list) {
123 if (se_sess != se_cmd->se_sess)
124 continue;
125
126 /*
127 * skip task management functions, including
128 * tmr->task_cmd
129 */
130 if (se_cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
131 continue;
132
133 ref_tag = se_cmd->tag;
134 if (tmr->ref_task_tag != ref_tag)
135 continue;
136
137 pr_err("ABORT_TASK: Found referenced %s task_tag: %llu\n",
138 se_cmd->se_tfo->fabric_name, ref_tag);
139
140 spin_lock(&se_sess->sess_cmd_lock);
141 rc = __target_check_io_state(se_cmd, se_sess, 0);
142 spin_unlock(&se_sess->sess_cmd_lock);
143 if (!rc)
144 continue;
145
146 list_move_tail(&se_cmd->state_list, &aborted_list);
147 se_cmd->state_active = false;
148 spin_unlock_irqrestore(&dev->queues[i].lock, flags);
149
150 if (dev->transport->tmr_notify)
151 dev->transport->tmr_notify(dev, TMR_ABORT_TASK,
152 &aborted_list);
153
154 list_del_init(&se_cmd->state_list);
155 target_put_cmd_and_wait(se_cmd);
156
157 pr_err("ABORT_TASK: Sending TMR_FUNCTION_COMPLETE for ref_tag: %llu\n",
158 ref_tag);
159 tmr->response = TMR_FUNCTION_COMPLETE;
160 atomic_long_inc(&dev->aborts_complete);
161 return;
162 }
163 spin_unlock_irqrestore(&dev->queues[i].lock, flags);
164 }
165
166 if (dev->transport->tmr_notify)
167 dev->transport->tmr_notify(dev, TMR_ABORT_TASK, &aborted_list);
168
169 printk("ABORT_TASK: Sending TMR_TASK_DOES_NOT_EXIST for ref_tag: %lld\n",
170 tmr->ref_task_tag);
171 tmr->response = TMR_TASK_DOES_NOT_EXIST;
172 atomic_long_inc(&dev->aborts_no_task);
173}
174
175static void core_tmr_drain_tmr_list(
176 struct se_device *dev,
177 struct se_tmr_req *tmr,
178 struct list_head *preempt_and_abort_list)
179{
180 LIST_HEAD(drain_tmr_list);
181 struct se_session *sess;
182 struct se_tmr_req *tmr_p, *tmr_pp;
183 struct se_cmd *cmd;
184 unsigned long flags;
185 bool rc;
186 /*
187 * Release all pending and outgoing TMRs aside from the received
188 * LUN_RESET tmr..
189 */
190 spin_lock_irqsave(&dev->se_tmr_lock, flags);
191 if (tmr)
192 list_del_init(&tmr->tmr_list);
193 list_for_each_entry_safe(tmr_p, tmr_pp, &dev->dev_tmr_list, tmr_list) {
194 cmd = tmr_p->task_cmd;
195 if (!cmd) {
196 pr_err("Unable to locate struct se_cmd for TMR\n");
197 continue;
198 }
199 /*
200 * If this function was called with a valid pr_res_key
201 * parameter (eg: for PROUT PREEMPT_AND_ABORT service action
202 * skip non registration key matching TMRs.
203 */
204 if (target_check_cdb_and_preempt(preempt_and_abort_list, cmd))
205 continue;
206
207 sess = cmd->se_sess;
208 if (WARN_ON_ONCE(!sess))
209 continue;
210
211 spin_lock(&sess->sess_cmd_lock);
212 rc = __target_check_io_state(cmd, sess, 0);
213 spin_unlock(&sess->sess_cmd_lock);
214
215 if (!rc) {
216 printk("LUN_RESET TMR: non-zero kref_get_unless_zero\n");
217 continue;
218 }
219
220 list_move_tail(&tmr_p->tmr_list, &drain_tmr_list);
221 tmr_p->tmr_dev = NULL;
222 }
223 spin_unlock_irqrestore(&dev->se_tmr_lock, flags);
224
225 list_for_each_entry_safe(tmr_p, tmr_pp, &drain_tmr_list, tmr_list) {
226 list_del_init(&tmr_p->tmr_list);
227 cmd = tmr_p->task_cmd;
228
229 pr_debug("LUN_RESET: %s releasing TMR %p Function: 0x%02x,"
230 " Response: 0x%02x, t_state: %d\n",
231 (preempt_and_abort_list) ? "Preempt" : "", tmr_p,
232 tmr_p->function, tmr_p->response, cmd->t_state);
233
234 target_put_cmd_and_wait(cmd);
235 }
236}
237
238/**
239 * core_tmr_drain_state_list() - abort SCSI commands associated with a device
240 *
241 * @dev: Device for which to abort outstanding SCSI commands.
242 * @prout_cmd: Pointer to the SCSI PREEMPT AND ABORT if this function is called
243 * to realize the PREEMPT AND ABORT functionality.
244 * @tmr_sess: Session through which the LUN RESET has been received.
245 * @tas: Task Aborted Status (TAS) bit from the SCSI control mode page.
246 * A quote from SPC-4, paragraph "7.5.10 Control mode page":
247 * "A task aborted status (TAS) bit set to zero specifies that
248 * aborted commands shall be terminated by the device server
249 * without any response to the application client. A TAS bit set
250 * to one specifies that commands aborted by the actions of an I_T
251 * nexus other than the I_T nexus on which the command was
252 * received shall be completed with TASK ABORTED status."
253 * @preempt_and_abort_list: For the PREEMPT AND ABORT functionality, a list
254 * with registrations that will be preempted.
255 */
256static void core_tmr_drain_state_list(
257 struct se_device *dev,
258 struct se_cmd *prout_cmd,
259 struct se_session *tmr_sess,
260 bool tas,
261 struct list_head *preempt_and_abort_list)
262{
263 LIST_HEAD(drain_task_list);
264 struct se_session *sess;
265 struct se_cmd *cmd, *next;
266 unsigned long flags;
267 int rc, i;
268
269 /*
270 * Complete outstanding commands with TASK_ABORTED SAM status.
271 *
272 * This is following sam4r17, section 5.6 Aborting commands, Table 38
273 * for TMR LUN_RESET:
274 *
275 * a) "Yes" indicates that each command that is aborted on an I_T nexus
276 * other than the one that caused the SCSI device condition is
277 * completed with TASK ABORTED status, if the TAS bit is set to one in
278 * the Control mode page (see SPC-4). "No" indicates that no status is
279 * returned for aborted commands.
280 *
281 * d) If the logical unit reset is caused by a particular I_T nexus
282 * (e.g., by a LOGICAL UNIT RESET task management function), then "yes"
283 * (TASK_ABORTED status) applies.
284 *
285 * Otherwise (e.g., if triggered by a hard reset), "no"
286 * (no TASK_ABORTED SAM status) applies.
287 *
288 * Note that this seems to be independent of TAS (Task Aborted Status)
289 * in the Control Mode Page.
290 */
291 for (i = 0; i < dev->queue_cnt; i++) {
292 flush_work(&dev->queues[i].sq.work);
293
294 spin_lock_irqsave(&dev->queues[i].lock, flags);
295 list_for_each_entry_safe(cmd, next, &dev->queues[i].state_list,
296 state_list) {
297 /*
298 * For PREEMPT_AND_ABORT usage, only process commands
299 * with a matching reservation key.
300 */
301 if (target_check_cdb_and_preempt(preempt_and_abort_list,
302 cmd))
303 continue;
304
305 /*
306 * Not aborting PROUT PREEMPT_AND_ABORT CDB..
307 */
308 if (prout_cmd == cmd)
309 continue;
310
311 sess = cmd->se_sess;
312 if (WARN_ON_ONCE(!sess))
313 continue;
314
315 spin_lock(&sess->sess_cmd_lock);
316 rc = __target_check_io_state(cmd, tmr_sess, tas);
317 spin_unlock(&sess->sess_cmd_lock);
318 if (!rc)
319 continue;
320
321 list_move_tail(&cmd->state_list, &drain_task_list);
322 cmd->state_active = false;
323 }
324 spin_unlock_irqrestore(&dev->queues[i].lock, flags);
325 }
326
327 if (dev->transport->tmr_notify)
328 dev->transport->tmr_notify(dev, preempt_and_abort_list ?
329 TMR_LUN_RESET_PRO : TMR_LUN_RESET,
330 &drain_task_list);
331
332 while (!list_empty(&drain_task_list)) {
333 cmd = list_entry(drain_task_list.next, struct se_cmd, state_list);
334 list_del_init(&cmd->state_list);
335
336 target_show_cmd("LUN_RESET: ", cmd);
337 pr_debug("LUN_RESET: ITT[0x%08llx] - %s pr_res_key: 0x%016Lx\n",
338 cmd->tag, (preempt_and_abort_list) ? "preempt" : "",
339 cmd->pr_res_key);
340
341 target_put_cmd_and_wait(cmd);
342 }
343}
344
345int core_tmr_lun_reset(
346 struct se_device *dev,
347 struct se_tmr_req *tmr,
348 struct list_head *preempt_and_abort_list,
349 struct se_cmd *prout_cmd)
350{
351 struct se_node_acl *tmr_nacl = NULL;
352 struct se_portal_group *tmr_tpg = NULL;
353 struct se_session *tmr_sess = NULL;
354 bool tas;
355 /*
356 * TASK_ABORTED status bit, this is configurable via ConfigFS
357 * struct se_device attributes. spc4r17 section 7.4.6 Control mode page
358 *
359 * A task aborted status (TAS) bit set to zero specifies that aborted
360 * tasks shall be terminated by the device server without any response
361 * to the application client. A TAS bit set to one specifies that tasks
362 * aborted by the actions of an I_T nexus other than the I_T nexus on
363 * which the command was received shall be completed with TASK ABORTED
364 * status (see SAM-4).
365 */
366 tas = dev->dev_attrib.emulate_tas;
367 /*
368 * Determine if this se_tmr is coming from a $FABRIC_MOD
369 * or struct se_device passthrough..
370 */
371 if (tmr && tmr->task_cmd && tmr->task_cmd->se_sess) {
372 tmr_sess = tmr->task_cmd->se_sess;
373 tmr_nacl = tmr_sess->se_node_acl;
374 tmr_tpg = tmr_sess->se_tpg;
375 if (tmr_nacl && tmr_tpg) {
376 pr_debug("LUN_RESET: TMR caller fabric: %s"
377 " initiator port %s\n",
378 tmr_tpg->se_tpg_tfo->fabric_name,
379 tmr_nacl->initiatorname);
380 }
381 }
382 pr_debug("LUN_RESET: %s starting for [%s], tas: %d\n",
383 (preempt_and_abort_list) ? "Preempt" : "TMR",
384 dev->transport->name, tas);
385
386 core_tmr_drain_tmr_list(dev, tmr, preempt_and_abort_list);
387 core_tmr_drain_state_list(dev, prout_cmd, tmr_sess, tas,
388 preempt_and_abort_list);
389
390 /*
391 * Clear any legacy SPC-2 reservation when called during
392 * LOGICAL UNIT RESET
393 */
394 if (!preempt_and_abort_list &&
395 (dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS)) {
396 spin_lock(&dev->dev_reservation_lock);
397 dev->reservation_holder = NULL;
398 dev->dev_reservation_flags &= ~DRF_SPC2_RESERVATIONS;
399 spin_unlock(&dev->dev_reservation_lock);
400 pr_debug("LUN_RESET: SCSI-2 Released reservation\n");
401 }
402
403 atomic_long_inc(&dev->num_resets);
404
405 pr_debug("LUN_RESET: %s for [%s] Complete\n",
406 (preempt_and_abort_list) ? "Preempt" : "TMR",
407 dev->transport->name);
408 return 0;
409}
410
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
39int 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}
62EXPORT_SYMBOL(core_tmr_alloc_req);
63
64void 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
78static void 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 transport_cmd_finish_abort(cmd, remove);
95}
96
97static 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
112static 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
152void 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 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
198out:
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
204static 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 registration 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 transport_cmd_finish_abort(cmd, 1);
290 target_put_sess_cmd(cmd);
291 }
292}
293
294static 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 core_tmr_handle_tas_abort(cmd, tas);
389 target_put_sess_cmd(cmd);
390 }
391}
392
393int 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