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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/version.h>
28#include <linux/slab.h>
29#include <linux/spinlock.h>
30#include <linux/list.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_device.h>
36#include <target/target_core_tmr.h>
37#include <target/target_core_transport.h>
38#include <target/target_core_fabric_ops.h>
39#include <target/target_core_configfs.h>
40
41#include "target_core_alua.h"
42#include "target_core_pr.h"
43
44struct se_tmr_req *core_tmr_alloc_req(
45 struct se_cmd *se_cmd,
46 void *fabric_tmr_ptr,
47 u8 function)
48{
49 struct se_tmr_req *tmr;
50
51 tmr = kmem_cache_zalloc(se_tmr_req_cache, (in_interrupt()) ?
52 GFP_ATOMIC : GFP_KERNEL);
53 if (!tmr) {
54 pr_err("Unable to allocate struct se_tmr_req\n");
55 return ERR_PTR(-ENOMEM);
56 }
57 tmr->task_cmd = se_cmd;
58 tmr->fabric_tmr_ptr = fabric_tmr_ptr;
59 tmr->function = function;
60 INIT_LIST_HEAD(&tmr->tmr_list);
61
62 return tmr;
63}
64EXPORT_SYMBOL(core_tmr_alloc_req);
65
66void core_tmr_release_req(
67 struct se_tmr_req *tmr)
68{
69 struct se_device *dev = tmr->tmr_dev;
70
71 if (!dev) {
72 kmem_cache_free(se_tmr_req_cache, tmr);
73 return;
74 }
75
76 spin_lock_irq(&dev->se_tmr_lock);
77 list_del(&tmr->tmr_list);
78 spin_unlock_irq(&dev->se_tmr_lock);
79
80 kmem_cache_free(se_tmr_req_cache, tmr);
81}
82
83static void core_tmr_handle_tas_abort(
84 struct se_node_acl *tmr_nacl,
85 struct se_cmd *cmd,
86 int tas,
87 int fe_count)
88{
89 if (!fe_count) {
90 transport_cmd_finish_abort(cmd, 1);
91 return;
92 }
93 /*
94 * TASK ABORTED status (TAS) bit support
95 */
96 if ((tmr_nacl &&
97 (tmr_nacl == cmd->se_sess->se_node_acl)) || tas)
98 transport_send_task_abort(cmd);
99
100 transport_cmd_finish_abort(cmd, 0);
101}
102
103int core_tmr_lun_reset(
104 struct se_device *dev,
105 struct se_tmr_req *tmr,
106 struct list_head *preempt_and_abort_list,
107 struct se_cmd *prout_cmd)
108{
109 struct se_cmd *cmd, *tcmd;
110 struct se_node_acl *tmr_nacl = NULL;
111 struct se_portal_group *tmr_tpg = NULL;
112 struct se_queue_obj *qobj = &dev->dev_queue_obj;
113 struct se_tmr_req *tmr_p, *tmr_pp;
114 struct se_task *task, *task_tmp;
115 unsigned long flags;
116 int fe_count, tas;
117 /*
118 * TASK_ABORTED status bit, this is configurable via ConfigFS
119 * struct se_device attributes. spc4r17 section 7.4.6 Control mode page
120 *
121 * A task aborted status (TAS) bit set to zero specifies that aborted
122 * tasks shall be terminated by the device server without any response
123 * to the application client. A TAS bit set to one specifies that tasks
124 * aborted by the actions of an I_T nexus other than the I_T nexus on
125 * which the command was received shall be completed with TASK ABORTED
126 * status (see SAM-4).
127 */
128 tas = dev->se_sub_dev->se_dev_attrib.emulate_tas;
129 /*
130 * Determine if this se_tmr is coming from a $FABRIC_MOD
131 * or struct se_device passthrough..
132 */
133 if (tmr && tmr->task_cmd && tmr->task_cmd->se_sess) {
134 tmr_nacl = tmr->task_cmd->se_sess->se_node_acl;
135 tmr_tpg = tmr->task_cmd->se_sess->se_tpg;
136 if (tmr_nacl && tmr_tpg) {
137 pr_debug("LUN_RESET: TMR caller fabric: %s"
138 " initiator port %s\n",
139 tmr_tpg->se_tpg_tfo->get_fabric_name(),
140 tmr_nacl->initiatorname);
141 }
142 }
143 pr_debug("LUN_RESET: %s starting for [%s], tas: %d\n",
144 (preempt_and_abort_list) ? "Preempt" : "TMR",
145 dev->transport->name, tas);
146 /*
147 * Release all pending and outgoing TMRs aside from the received
148 * LUN_RESET tmr..
149 */
150 spin_lock_irq(&dev->se_tmr_lock);
151 list_for_each_entry_safe(tmr_p, tmr_pp, &dev->dev_tmr_list, tmr_list) {
152 /*
153 * Allow the received TMR to return with FUNCTION_COMPLETE.
154 */
155 if (tmr && (tmr_p == tmr))
156 continue;
157
158 cmd = tmr_p->task_cmd;
159 if (!cmd) {
160 pr_err("Unable to locate struct se_cmd for TMR\n");
161 continue;
162 }
163 /*
164 * If this function was called with a valid pr_res_key
165 * parameter (eg: for PROUT PREEMPT_AND_ABORT service action
166 * skip non regisration key matching TMRs.
167 */
168 if (preempt_and_abort_list &&
169 (core_scsi3_check_cdb_abort_and_preempt(
170 preempt_and_abort_list, cmd) != 0))
171 continue;
172 spin_unlock_irq(&dev->se_tmr_lock);
173
174 spin_lock_irqsave(&cmd->t_state_lock, flags);
175 if (!atomic_read(&cmd->t_transport_active)) {
176 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
177 spin_lock_irq(&dev->se_tmr_lock);
178 continue;
179 }
180 if (cmd->t_state == TRANSPORT_ISTATE_PROCESSING) {
181 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
182 spin_lock_irq(&dev->se_tmr_lock);
183 continue;
184 }
185 pr_debug("LUN_RESET: %s releasing TMR %p Function: 0x%02x,"
186 " Response: 0x%02x, t_state: %d\n",
187 (preempt_and_abort_list) ? "Preempt" : "", tmr_p,
188 tmr_p->function, tmr_p->response, cmd->t_state);
189 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
190
191 transport_cmd_finish_abort_tmr(cmd);
192 spin_lock_irq(&dev->se_tmr_lock);
193 }
194 spin_unlock_irq(&dev->se_tmr_lock);
195 /*
196 * Complete outstanding struct se_task CDBs with TASK_ABORTED SAM status.
197 * This is following sam4r17, section 5.6 Aborting commands, Table 38
198 * for TMR LUN_RESET:
199 *
200 * a) "Yes" indicates that each command that is aborted on an I_T nexus
201 * other than the one that caused the SCSI device condition is
202 * completed with TASK ABORTED status, if the TAS bit is set to one in
203 * the Control mode page (see SPC-4). "No" indicates that no status is
204 * returned for aborted commands.
205 *
206 * d) If the logical unit reset is caused by a particular I_T nexus
207 * (e.g., by a LOGICAL UNIT RESET task management function), then "yes"
208 * (TASK_ABORTED status) applies.
209 *
210 * Otherwise (e.g., if triggered by a hard reset), "no"
211 * (no TASK_ABORTED SAM status) applies.
212 *
213 * Note that this seems to be independent of TAS (Task Aborted Status)
214 * in the Control Mode Page.
215 */
216 spin_lock_irqsave(&dev->execute_task_lock, flags);
217 list_for_each_entry_safe(task, task_tmp, &dev->state_task_list,
218 t_state_list) {
219 if (!task->task_se_cmd) {
220 pr_err("task->task_se_cmd is NULL!\n");
221 continue;
222 }
223 cmd = task->task_se_cmd;
224
225 /*
226 * For PREEMPT_AND_ABORT usage, only process commands
227 * with a matching reservation key.
228 */
229 if (preempt_and_abort_list &&
230 (core_scsi3_check_cdb_abort_and_preempt(
231 preempt_and_abort_list, cmd) != 0))
232 continue;
233 /*
234 * Not aborting PROUT PREEMPT_AND_ABORT CDB..
235 */
236 if (prout_cmd == cmd)
237 continue;
238
239 list_del(&task->t_state_list);
240 atomic_set(&task->task_state_active, 0);
241 spin_unlock_irqrestore(&dev->execute_task_lock, flags);
242
243 spin_lock_irqsave(&cmd->t_state_lock, flags);
244 pr_debug("LUN_RESET: %s cmd: %p task: %p"
245 " ITT/CmdSN: 0x%08x/0x%08x, i_state: %d, t_state/"
246 "def_t_state: %d/%d cdb: 0x%02x\n",
247 (preempt_and_abort_list) ? "Preempt" : "", cmd, task,
248 cmd->se_tfo->get_task_tag(cmd), 0,
249 cmd->se_tfo->get_cmd_state(cmd), cmd->t_state,
250 cmd->deferred_t_state, cmd->t_task_cdb[0]);
251 pr_debug("LUN_RESET: ITT[0x%08x] - pr_res_key: 0x%016Lx"
252 " t_task_cdbs: %d t_task_cdbs_left: %d"
253 " t_task_cdbs_sent: %d -- t_transport_active: %d"
254 " t_transport_stop: %d t_transport_sent: %d\n",
255 cmd->se_tfo->get_task_tag(cmd), cmd->pr_res_key,
256 cmd->t_task_list_num,
257 atomic_read(&cmd->t_task_cdbs_left),
258 atomic_read(&cmd->t_task_cdbs_sent),
259 atomic_read(&cmd->t_transport_active),
260 atomic_read(&cmd->t_transport_stop),
261 atomic_read(&cmd->t_transport_sent));
262
263 if (atomic_read(&task->task_active)) {
264 atomic_set(&task->task_stop, 1);
265 spin_unlock_irqrestore(
266 &cmd->t_state_lock, flags);
267
268 pr_debug("LUN_RESET: Waiting for task: %p to shutdown"
269 " for dev: %p\n", task, dev);
270 wait_for_completion(&task->task_stop_comp);
271 pr_debug("LUN_RESET Completed task: %p shutdown for"
272 " dev: %p\n", task, dev);
273 spin_lock_irqsave(&cmd->t_state_lock, flags);
274 atomic_dec(&cmd->t_task_cdbs_left);
275
276 atomic_set(&task->task_active, 0);
277 atomic_set(&task->task_stop, 0);
278 } else {
279 if (atomic_read(&task->task_execute_queue) != 0)
280 transport_remove_task_from_execute_queue(task, dev);
281 }
282 __transport_stop_task_timer(task, &flags);
283
284 if (!atomic_dec_and_test(&cmd->t_task_cdbs_ex_left)) {
285 spin_unlock_irqrestore(
286 &cmd->t_state_lock, flags);
287 pr_debug("LUN_RESET: Skipping task: %p, dev: %p for"
288 " t_task_cdbs_ex_left: %d\n", task, dev,
289 atomic_read(&cmd->t_task_cdbs_ex_left));
290
291 spin_lock_irqsave(&dev->execute_task_lock, flags);
292 continue;
293 }
294 fe_count = atomic_read(&cmd->t_fe_count);
295
296 if (atomic_read(&cmd->t_transport_active)) {
297 pr_debug("LUN_RESET: got t_transport_active = 1 for"
298 " task: %p, t_fe_count: %d dev: %p\n", task,
299 fe_count, dev);
300 atomic_set(&cmd->t_transport_aborted, 1);
301 spin_unlock_irqrestore(&cmd->t_state_lock,
302 flags);
303 core_tmr_handle_tas_abort(tmr_nacl, cmd, tas, fe_count);
304
305 spin_lock_irqsave(&dev->execute_task_lock, flags);
306 continue;
307 }
308 pr_debug("LUN_RESET: Got t_transport_active = 0 for task: %p,"
309 " t_fe_count: %d dev: %p\n", task, fe_count, dev);
310 atomic_set(&cmd->t_transport_aborted, 1);
311 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
312 core_tmr_handle_tas_abort(tmr_nacl, cmd, tas, fe_count);
313
314 spin_lock_irqsave(&dev->execute_task_lock, flags);
315 }
316 spin_unlock_irqrestore(&dev->execute_task_lock, flags);
317 /*
318 * Release all commands remaining in the struct se_device cmd queue.
319 *
320 * This follows the same logic as above for the struct se_device
321 * struct se_task state list, where commands are returned with
322 * TASK_ABORTED status, if there is an outstanding $FABRIC_MOD
323 * reference, otherwise the struct se_cmd is released.
324 */
325 spin_lock_irqsave(&qobj->cmd_queue_lock, flags);
326 list_for_each_entry_safe(cmd, tcmd, &qobj->qobj_list, se_queue_node) {
327 /*
328 * For PREEMPT_AND_ABORT usage, only process commands
329 * with a matching reservation key.
330 */
331 if (preempt_and_abort_list &&
332 (core_scsi3_check_cdb_abort_and_preempt(
333 preempt_and_abort_list, cmd) != 0))
334 continue;
335 /*
336 * Not aborting PROUT PREEMPT_AND_ABORT CDB..
337 */
338 if (prout_cmd == cmd)
339 continue;
340
341 atomic_dec(&cmd->t_transport_queue_active);
342 atomic_dec(&qobj->queue_cnt);
343 list_del(&cmd->se_queue_node);
344 spin_unlock_irqrestore(&qobj->cmd_queue_lock, flags);
345
346 pr_debug("LUN_RESET: %s from Device Queue: cmd: %p t_state:"
347 " %d t_fe_count: %d\n", (preempt_and_abort_list) ?
348 "Preempt" : "", cmd, cmd->t_state,
349 atomic_read(&cmd->t_fe_count));
350 /*
351 * Signal that the command has failed via cmd->se_cmd_flags,
352 */
353 transport_new_cmd_failure(cmd);
354
355 core_tmr_handle_tas_abort(tmr_nacl, cmd, tas,
356 atomic_read(&cmd->t_fe_count));
357 spin_lock_irqsave(&qobj->cmd_queue_lock, flags);
358 }
359 spin_unlock_irqrestore(&qobj->cmd_queue_lock, flags);
360 /*
361 * Clear any legacy SPC-2 reservation when called during
362 * LOGICAL UNIT RESET
363 */
364 if (!preempt_and_abort_list &&
365 (dev->dev_flags & DF_SPC2_RESERVATIONS)) {
366 spin_lock(&dev->dev_reservation_lock);
367 dev->dev_reserved_node_acl = NULL;
368 dev->dev_flags &= ~DF_SPC2_RESERVATIONS;
369 spin_unlock(&dev->dev_reservation_lock);
370 pr_debug("LUN_RESET: SCSI-2 Released reservation\n");
371 }
372
373 spin_lock_irq(&dev->stats_lock);
374 dev->num_resets++;
375 spin_unlock_irq(&dev->stats_lock);
376
377 pr_debug("LUN_RESET: %s for [%s] Complete\n",
378 (preempt_and_abort_list) ? "Preempt" : "TMR",
379 dev->transport->name);
380 return 0;
381}
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 struct se_device *dev = tmr->tmr_dev;
54 unsigned long flags;
55
56 if (dev) {
57 spin_lock_irqsave(&dev->se_tmr_lock, flags);
58 list_del_init(&tmr->tmr_list);
59 spin_unlock_irqrestore(&dev->se_tmr_lock, flags);
60 }
61
62 kfree(tmr);
63}
64
65static int target_check_cdb_and_preempt(struct list_head *list,
66 struct se_cmd *cmd)
67{
68 struct t10_pr_registration *reg;
69
70 if (!list)
71 return 0;
72 list_for_each_entry(reg, list, pr_reg_abort_list) {
73 if (reg->pr_res_key == cmd->pr_res_key)
74 return 0;
75 }
76
77 return 1;
78}
79
80static bool __target_check_io_state(struct se_cmd *se_cmd,
81 struct se_session *tmr_sess, bool tas)
82{
83 struct se_session *sess = se_cmd->se_sess;
84
85 assert_spin_locked(&sess->sess_cmd_lock);
86 WARN_ON_ONCE(!irqs_disabled());
87 /*
88 * If command already reached CMD_T_COMPLETE state within
89 * target_complete_cmd() or CMD_T_FABRIC_STOP due to shutdown,
90 * this se_cmd has been passed to fabric driver and will
91 * not be aborted.
92 *
93 * Otherwise, obtain a local se_cmd->cmd_kref now for TMR
94 * ABORT_TASK + LUN_RESET for CMD_T_ABORTED processing as
95 * long as se_cmd->cmd_kref is still active unless zero.
96 */
97 spin_lock(&se_cmd->t_state_lock);
98 if (se_cmd->transport_state & (CMD_T_COMPLETE | CMD_T_FABRIC_STOP)) {
99 pr_debug("Attempted to abort io tag: %llu already complete or"
100 " fabric stop, skipping\n", se_cmd->tag);
101 spin_unlock(&se_cmd->t_state_lock);
102 return false;
103 }
104 se_cmd->transport_state |= CMD_T_ABORTED;
105
106 if ((tmr_sess != se_cmd->se_sess) && tas)
107 se_cmd->transport_state |= CMD_T_TAS;
108
109 spin_unlock(&se_cmd->t_state_lock);
110
111 return kref_get_unless_zero(&se_cmd->cmd_kref);
112}
113
114void core_tmr_abort_task(
115 struct se_device *dev,
116 struct se_tmr_req *tmr,
117 struct se_session *se_sess)
118{
119 LIST_HEAD(aborted_list);
120 struct se_cmd *se_cmd, *next;
121 unsigned long flags;
122 bool rc;
123 u64 ref_tag;
124 int i;
125
126 for (i = 0; i < dev->queue_cnt; i++) {
127 flush_work(&dev->queues[i].sq.work);
128
129 spin_lock_irqsave(&dev->queues[i].lock, flags);
130 list_for_each_entry_safe(se_cmd, next, &dev->queues[i].state_list,
131 state_list) {
132 if (se_sess != se_cmd->se_sess)
133 continue;
134
135 /*
136 * skip task management functions, including
137 * tmr->task_cmd
138 */
139 if (se_cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
140 continue;
141
142 ref_tag = se_cmd->tag;
143 if (tmr->ref_task_tag != ref_tag)
144 continue;
145
146 pr_err("ABORT_TASK: Found referenced %s task_tag: %llu\n",
147 se_cmd->se_tfo->fabric_name, ref_tag);
148
149 spin_lock(&se_sess->sess_cmd_lock);
150 rc = __target_check_io_state(se_cmd, se_sess, 0);
151 spin_unlock(&se_sess->sess_cmd_lock);
152 if (!rc)
153 continue;
154
155 list_move_tail(&se_cmd->state_list, &aborted_list);
156 se_cmd->state_active = false;
157 spin_unlock_irqrestore(&dev->queues[i].lock, flags);
158
159 /*
160 * Ensure that this ABORT request is visible to the LU
161 * RESET code.
162 */
163 if (!tmr->tmr_dev)
164 WARN_ON_ONCE(transport_lookup_tmr_lun(tmr->task_cmd) < 0);
165
166 if (dev->transport->tmr_notify)
167 dev->transport->tmr_notify(dev, TMR_ABORT_TASK,
168 &aborted_list);
169
170 list_del_init(&se_cmd->state_list);
171 target_put_cmd_and_wait(se_cmd);
172
173 pr_err("ABORT_TASK: Sending TMR_FUNCTION_COMPLETE for ref_tag: %llu\n",
174 ref_tag);
175 tmr->response = TMR_FUNCTION_COMPLETE;
176 atomic_long_inc(&dev->aborts_complete);
177 return;
178 }
179 spin_unlock_irqrestore(&dev->queues[i].lock, flags);
180 }
181
182 if (dev->transport->tmr_notify)
183 dev->transport->tmr_notify(dev, TMR_ABORT_TASK, &aborted_list);
184
185 printk("ABORT_TASK: Sending TMR_TASK_DOES_NOT_EXIST for ref_tag: %lld\n",
186 tmr->ref_task_tag);
187 tmr->response = TMR_TASK_DOES_NOT_EXIST;
188 atomic_long_inc(&dev->aborts_no_task);
189}
190
191static void core_tmr_drain_tmr_list(
192 struct se_device *dev,
193 struct se_tmr_req *tmr,
194 struct list_head *preempt_and_abort_list)
195{
196 LIST_HEAD(drain_tmr_list);
197 struct se_session *sess;
198 struct se_tmr_req *tmr_p, *tmr_pp;
199 struct se_cmd *cmd;
200 unsigned long flags;
201 bool rc;
202 /*
203 * Release all pending and outgoing TMRs aside from the received
204 * LUN_RESET tmr..
205 */
206 spin_lock_irqsave(&dev->se_tmr_lock, flags);
207 if (tmr)
208 list_del_init(&tmr->tmr_list);
209 list_for_each_entry_safe(tmr_p, tmr_pp, &dev->dev_tmr_list, tmr_list) {
210 cmd = tmr_p->task_cmd;
211 if (!cmd) {
212 pr_err("Unable to locate struct se_cmd for TMR\n");
213 continue;
214 }
215 /*
216 * If this function was called with a valid pr_res_key
217 * parameter (eg: for PROUT PREEMPT_AND_ABORT service action
218 * skip non registration key matching TMRs.
219 */
220 if (target_check_cdb_and_preempt(preempt_and_abort_list, cmd))
221 continue;
222
223 sess = cmd->se_sess;
224 if (WARN_ON_ONCE(!sess))
225 continue;
226
227 spin_lock(&sess->sess_cmd_lock);
228 rc = __target_check_io_state(cmd, sess, 0);
229 spin_unlock(&sess->sess_cmd_lock);
230
231 if (!rc) {
232 printk("LUN_RESET TMR: non-zero kref_get_unless_zero\n");
233 continue;
234 }
235
236 list_move_tail(&tmr_p->tmr_list, &drain_tmr_list);
237 }
238 spin_unlock_irqrestore(&dev->se_tmr_lock, flags);
239
240 list_for_each_entry_safe(tmr_p, tmr_pp, &drain_tmr_list, tmr_list) {
241 list_del_init(&tmr_p->tmr_list);
242 cmd = tmr_p->task_cmd;
243
244 pr_debug("LUN_RESET: %s releasing TMR %p Function: 0x%02x,"
245 " Response: 0x%02x, t_state: %d\n",
246 (preempt_and_abort_list) ? "Preempt" : "", tmr_p,
247 tmr_p->function, tmr_p->response, cmd->t_state);
248
249 target_put_cmd_and_wait(cmd);
250 }
251}
252
253/**
254 * core_tmr_drain_state_list() - abort SCSI commands associated with a device
255 *
256 * @dev: Device for which to abort outstanding SCSI commands.
257 * @prout_cmd: Pointer to the SCSI PREEMPT AND ABORT if this function is called
258 * to realize the PREEMPT AND ABORT functionality.
259 * @tmr_sess: Session through which the LUN RESET has been received.
260 * @tas: Task Aborted Status (TAS) bit from the SCSI control mode page.
261 * A quote from SPC-4, paragraph "7.5.10 Control mode page":
262 * "A task aborted status (TAS) bit set to zero specifies that
263 * aborted commands shall be terminated by the device server
264 * without any response to the application client. A TAS bit set
265 * to one specifies that commands aborted by the actions of an I_T
266 * nexus other than the I_T nexus on which the command was
267 * received shall be completed with TASK ABORTED status."
268 * @preempt_and_abort_list: For the PREEMPT AND ABORT functionality, a list
269 * with registrations that will be preempted.
270 */
271static void core_tmr_drain_state_list(
272 struct se_device *dev,
273 struct se_cmd *prout_cmd,
274 struct se_session *tmr_sess,
275 bool tas,
276 struct list_head *preempt_and_abort_list)
277{
278 LIST_HEAD(drain_task_list);
279 struct se_session *sess;
280 struct se_cmd *cmd, *next;
281 unsigned long flags;
282 int rc, i;
283
284 /*
285 * Complete outstanding commands with TASK_ABORTED SAM status.
286 *
287 * This is following sam4r17, section 5.6 Aborting commands, Table 38
288 * for TMR LUN_RESET:
289 *
290 * a) "Yes" indicates that each command that is aborted on an I_T nexus
291 * other than the one that caused the SCSI device condition is
292 * completed with TASK ABORTED status, if the TAS bit is set to one in
293 * the Control mode page (see SPC-4). "No" indicates that no status is
294 * returned for aborted commands.
295 *
296 * d) If the logical unit reset is caused by a particular I_T nexus
297 * (e.g., by a LOGICAL UNIT RESET task management function), then "yes"
298 * (TASK_ABORTED status) applies.
299 *
300 * Otherwise (e.g., if triggered by a hard reset), "no"
301 * (no TASK_ABORTED SAM status) applies.
302 *
303 * Note that this seems to be independent of TAS (Task Aborted Status)
304 * in the Control Mode Page.
305 */
306 for (i = 0; i < dev->queue_cnt; i++) {
307 flush_work(&dev->queues[i].sq.work);
308
309 spin_lock_irqsave(&dev->queues[i].lock, flags);
310 list_for_each_entry_safe(cmd, next, &dev->queues[i].state_list,
311 state_list) {
312 /*
313 * For PREEMPT_AND_ABORT usage, only process commands
314 * with a matching reservation key.
315 */
316 if (target_check_cdb_and_preempt(preempt_and_abort_list,
317 cmd))
318 continue;
319
320 /*
321 * Not aborting PROUT PREEMPT_AND_ABORT CDB..
322 */
323 if (prout_cmd == cmd)
324 continue;
325
326 sess = cmd->se_sess;
327 if (WARN_ON_ONCE(!sess))
328 continue;
329
330 spin_lock(&sess->sess_cmd_lock);
331 rc = __target_check_io_state(cmd, tmr_sess, tas);
332 spin_unlock(&sess->sess_cmd_lock);
333 if (!rc)
334 continue;
335
336 list_move_tail(&cmd->state_list, &drain_task_list);
337 cmd->state_active = false;
338 }
339 spin_unlock_irqrestore(&dev->queues[i].lock, flags);
340 }
341
342 if (dev->transport->tmr_notify)
343 dev->transport->tmr_notify(dev, preempt_and_abort_list ?
344 TMR_LUN_RESET_PRO : TMR_LUN_RESET,
345 &drain_task_list);
346
347 while (!list_empty(&drain_task_list)) {
348 cmd = list_entry(drain_task_list.next, struct se_cmd, state_list);
349 list_del_init(&cmd->state_list);
350
351 target_show_cmd("LUN_RESET: ", cmd);
352 pr_debug("LUN_RESET: ITT[0x%08llx] - %s pr_res_key: 0x%016Lx\n",
353 cmd->tag, (preempt_and_abort_list) ? "preempt" : "",
354 cmd->pr_res_key);
355
356 target_put_cmd_and_wait(cmd);
357 }
358}
359
360int core_tmr_lun_reset(
361 struct se_device *dev,
362 struct se_tmr_req *tmr,
363 struct list_head *preempt_and_abort_list,
364 struct se_cmd *prout_cmd)
365{
366 struct se_node_acl *tmr_nacl = NULL;
367 struct se_portal_group *tmr_tpg = NULL;
368 struct se_session *tmr_sess = NULL;
369 bool tas;
370 /*
371 * TASK_ABORTED status bit, this is configurable via ConfigFS
372 * struct se_device attributes. spc4r17 section 7.4.6 Control mode page
373 *
374 * A task aborted status (TAS) bit set to zero specifies that aborted
375 * tasks shall be terminated by the device server without any response
376 * to the application client. A TAS bit set to one specifies that tasks
377 * aborted by the actions of an I_T nexus other than the I_T nexus on
378 * which the command was received shall be completed with TASK ABORTED
379 * status (see SAM-4).
380 */
381 tas = dev->dev_attrib.emulate_tas;
382 /*
383 * Determine if this se_tmr is coming from a $FABRIC_MOD
384 * or struct se_device passthrough..
385 */
386 if (tmr && tmr->task_cmd && tmr->task_cmd->se_sess) {
387 tmr_sess = tmr->task_cmd->se_sess;
388 tmr_nacl = tmr_sess->se_node_acl;
389 tmr_tpg = tmr_sess->se_tpg;
390 if (tmr_nacl && tmr_tpg) {
391 pr_debug("LUN_RESET: TMR caller fabric: %s"
392 " initiator port %s\n",
393 tmr_tpg->se_tpg_tfo->fabric_name,
394 tmr_nacl->initiatorname);
395 }
396 }
397 pr_debug("LUN_RESET: %s starting for [%s], tas: %d\n",
398 (preempt_and_abort_list) ? "Preempt" : "TMR",
399 dev->transport->name, tas);
400
401 core_tmr_drain_tmr_list(dev, tmr, preempt_and_abort_list);
402 core_tmr_drain_state_list(dev, prout_cmd, tmr_sess, tas,
403 preempt_and_abort_list);
404
405 /*
406 * Clear any legacy SPC-2 reservation when called during
407 * LOGICAL UNIT RESET
408 */
409 if (!preempt_and_abort_list &&
410 (dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS)) {
411 spin_lock(&dev->dev_reservation_lock);
412 dev->reservation_holder = NULL;
413 dev->dev_reservation_flags &= ~DRF_SPC2_RESERVATIONS;
414 spin_unlock(&dev->dev_reservation_lock);
415 pr_debug("LUN_RESET: SCSI-2 Released reservation\n");
416 }
417
418 atomic_long_inc(&dev->num_resets);
419
420 pr_debug("LUN_RESET: %s for [%s] Complete\n",
421 (preempt_and_abort_list) ? "Preempt" : "TMR",
422 dev->transport->name);
423 return 0;
424}
425