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(
79 struct se_node_acl
*tmr_nacl
,
85 * TASK ABORTED status (TAS) bit support
87 if ((tmr_nacl
&& (tmr_nacl
!= cmd
->se_sess
->se_node_acl
)) && tas
) {
89 transport_send_task_abort(cmd
);
92 transport_cmd_finish_abort(cmd
, remove
);
95 static int target_check_cdb_and_preempt(struct list_head
*list
,
98 struct t10_pr_registration
*reg
;
102 list_for_each_entry(reg
, list
, pr_reg_abort_list
) {
103 if (reg
->pr_res_key
== cmd
->pr_res_key
)
110 static bool __target_check_io_state(struct se_cmd
*se_cmd
)
112 struct se_session
*sess
= se_cmd
->se_sess
;
114 assert_spin_locked(&sess
->sess_cmd_lock
);
115 WARN_ON_ONCE(!irqs_disabled());
117 * If command already reached CMD_T_COMPLETE state within
118 * target_complete_cmd(), this se_cmd has been passed to
119 * fabric driver and will not be aborted.
121 * Otherwise, obtain a local se_cmd->cmd_kref now for TMR
122 * ABORT_TASK + LUN_RESET for CMD_T_ABORTED processing as
123 * long as se_cmd->cmd_kref is still active unless zero.
125 spin_lock(&se_cmd
->t_state_lock
);
126 if (se_cmd
->transport_state
& CMD_T_COMPLETE
) {
127 pr_debug("Attempted to abort io tag: %llu already complete,"
128 " skipping\n", se_cmd
->tag
);
129 spin_unlock(&se_cmd
->t_state_lock
);
132 se_cmd
->transport_state
|= CMD_T_ABORTED
;
133 spin_unlock(&se_cmd
->t_state_lock
);
135 return kref_get_unless_zero(&se_cmd
->cmd_kref
);
138 void core_tmr_abort_task(
139 struct se_device
*dev
,
140 struct se_tmr_req
*tmr
,
141 struct se_session
*se_sess
)
143 struct se_cmd
*se_cmd
;
147 spin_lock_irqsave(&se_sess
->sess_cmd_lock
, flags
);
148 list_for_each_entry(se_cmd
, &se_sess
->sess_cmd_list
, se_cmd_list
) {
150 if (dev
!= se_cmd
->se_dev
)
153 /* skip task management functions, including tmr->task_cmd */
154 if (se_cmd
->se_cmd_flags
& SCF_SCSI_TMR_CDB
)
157 ref_tag
= se_cmd
->tag
;
158 if (tmr
->ref_task_tag
!= ref_tag
)
161 printk("ABORT_TASK: Found referenced %s task_tag: %llu\n",
162 se_cmd
->se_tfo
->get_fabric_name(), ref_tag
);
164 if (!__target_check_io_state(se_cmd
)) {
165 spin_unlock_irqrestore(&se_sess
->sess_cmd_lock
, flags
);
166 target_put_sess_cmd(se_cmd
);
169 list_del_init(&se_cmd
->se_cmd_list
);
170 spin_unlock_irqrestore(&se_sess
->sess_cmd_lock
, flags
);
172 cancel_work_sync(&se_cmd
->work
);
173 transport_wait_for_tasks(se_cmd
);
175 transport_cmd_finish_abort(se_cmd
, true);
176 target_put_sess_cmd(se_cmd
);
178 printk("ABORT_TASK: Sending TMR_FUNCTION_COMPLETE for"
179 " ref_tag: %llu\n", ref_tag
);
180 tmr
->response
= TMR_FUNCTION_COMPLETE
;
183 spin_unlock_irqrestore(&se_sess
->sess_cmd_lock
, flags
);
186 printk("ABORT_TASK: Sending TMR_TASK_DOES_NOT_EXIST for ref_tag: %lld\n",
188 tmr
->response
= TMR_TASK_DOES_NOT_EXIST
;
191 static 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
)
196 LIST_HEAD(drain_tmr_list
);
197 struct se_session
*sess
;
198 struct se_tmr_req
*tmr_p
, *tmr_pp
;
203 * Release all pending and outgoing TMRs aside from the received
206 spin_lock_irqsave(&dev
->se_tmr_lock
, flags
);
207 list_for_each_entry_safe(tmr_p
, tmr_pp
, &dev
->dev_tmr_list
, tmr_list
) {
209 * Allow the received TMR to return with FUNCTION_COMPLETE.
214 cmd
= tmr_p
->task_cmd
;
216 pr_err("Unable to locate struct se_cmd for TMR\n");
220 * If this function was called with a valid pr_res_key
221 * parameter (eg: for PROUT PREEMPT_AND_ABORT service action
222 * skip non registration key matching TMRs.
224 if (target_check_cdb_and_preempt(preempt_and_abort_list
, cmd
))
228 if (WARN_ON_ONCE(!sess
))
231 spin_lock(&sess
->sess_cmd_lock
);
232 spin_lock(&cmd
->t_state_lock
);
233 if (!(cmd
->transport_state
& CMD_T_ACTIVE
)) {
234 spin_unlock(&cmd
->t_state_lock
);
235 spin_unlock(&sess
->sess_cmd_lock
);
238 if (cmd
->t_state
== TRANSPORT_ISTATE_PROCESSING
) {
239 spin_unlock(&cmd
->t_state_lock
);
240 spin_unlock(&sess
->sess_cmd_lock
);
243 cmd
->transport_state
|= CMD_T_ABORTED
;
244 spin_unlock(&cmd
->t_state_lock
);
246 rc
= kref_get_unless_zero(&cmd
->cmd_kref
);
247 spin_unlock(&sess
->sess_cmd_lock
);
249 printk("LUN_RESET TMR: non-zero kref_get_unless_zero\n");
252 list_move_tail(&tmr_p
->tmr_list
, &drain_tmr_list
);
254 spin_unlock_irqrestore(&dev
->se_tmr_lock
, flags
);
256 list_for_each_entry_safe(tmr_p
, tmr_pp
, &drain_tmr_list
, tmr_list
) {
257 list_del_init(&tmr_p
->tmr_list
);
258 cmd
= tmr_p
->task_cmd
;
260 pr_debug("LUN_RESET: %s releasing TMR %p Function: 0x%02x,"
261 " Response: 0x%02x, t_state: %d\n",
262 (preempt_and_abort_list
) ? "Preempt" : "", tmr_p
,
263 tmr_p
->function
, tmr_p
->response
, cmd
->t_state
);
265 cancel_work_sync(&cmd
->work
);
266 transport_wait_for_tasks(cmd
);
268 transport_cmd_finish_abort(cmd
, 1);
269 target_put_sess_cmd(cmd
);
273 static void core_tmr_drain_state_list(
274 struct se_device
*dev
,
275 struct se_cmd
*prout_cmd
,
276 struct se_node_acl
*tmr_nacl
,
278 struct list_head
*preempt_and_abort_list
)
280 LIST_HEAD(drain_task_list
);
281 struct se_session
*sess
;
282 struct se_cmd
*cmd
, *next
;
287 * Complete outstanding commands with TASK_ABORTED SAM status.
289 * This is following sam4r17, section 5.6 Aborting commands, Table 38
292 * a) "Yes" indicates that each command that is aborted on an I_T nexus
293 * other than the one that caused the SCSI device condition is
294 * completed with TASK ABORTED status, if the TAS bit is set to one in
295 * the Control mode page (see SPC-4). "No" indicates that no status is
296 * returned for aborted commands.
298 * d) If the logical unit reset is caused by a particular I_T nexus
299 * (e.g., by a LOGICAL UNIT RESET task management function), then "yes"
300 * (TASK_ABORTED status) applies.
302 * Otherwise (e.g., if triggered by a hard reset), "no"
303 * (no TASK_ABORTED SAM status) applies.
305 * Note that this seems to be independent of TAS (Task Aborted Status)
306 * in the Control Mode Page.
308 spin_lock_irqsave(&dev
->execute_task_lock
, flags
);
309 list_for_each_entry_safe(cmd
, next
, &dev
->state_list
, state_list
) {
311 * For PREEMPT_AND_ABORT usage, only process commands
312 * with a matching reservation key.
314 if (target_check_cdb_and_preempt(preempt_and_abort_list
, cmd
))
318 * Not aborting PROUT PREEMPT_AND_ABORT CDB..
320 if (prout_cmd
== cmd
)
324 if (WARN_ON_ONCE(!sess
))
327 spin_lock(&sess
->sess_cmd_lock
);
328 rc
= __target_check_io_state(cmd
);
329 spin_unlock(&sess
->sess_cmd_lock
);
333 list_move_tail(&cmd
->state_list
, &drain_task_list
);
334 cmd
->state_active
= false;
336 spin_unlock_irqrestore(&dev
->execute_task_lock
, flags
);
338 while (!list_empty(&drain_task_list
)) {
339 cmd
= list_entry(drain_task_list
.next
, struct se_cmd
, state_list
);
340 list_del_init(&cmd
->state_list
);
342 pr_debug("LUN_RESET: %s cmd: %p"
343 " ITT/CmdSN: 0x%08llx/0x%08x, i_state: %d, t_state: %d"
345 (preempt_and_abort_list
) ? "Preempt" : "", cmd
,
347 cmd
->se_tfo
->get_cmd_state(cmd
), cmd
->t_state
,
349 pr_debug("LUN_RESET: ITT[0x%08llx] - pr_res_key: 0x%016Lx"
350 " -- CMD_T_ACTIVE: %d"
351 " CMD_T_STOP: %d CMD_T_SENT: %d\n",
352 cmd
->tag
, cmd
->pr_res_key
,
353 (cmd
->transport_state
& CMD_T_ACTIVE
) != 0,
354 (cmd
->transport_state
& CMD_T_STOP
) != 0,
355 (cmd
->transport_state
& CMD_T_SENT
) != 0);
358 * If the command may be queued onto a workqueue cancel it now.
360 * This is equivalent to removal from the execute queue in the
361 * loop above, but we do it down here given that
362 * cancel_work_sync may block.
364 cancel_work_sync(&cmd
->work
);
365 transport_wait_for_tasks(cmd
);
367 core_tmr_handle_tas_abort(tmr_nacl
, cmd
, tas
);
368 target_put_sess_cmd(cmd
);
372 int core_tmr_lun_reset(
373 struct se_device
*dev
,
374 struct se_tmr_req
*tmr
,
375 struct list_head
*preempt_and_abort_list
,
376 struct se_cmd
*prout_cmd
)
378 struct se_node_acl
*tmr_nacl
= NULL
;
379 struct se_portal_group
*tmr_tpg
= NULL
;
382 * TASK_ABORTED status bit, this is configurable via ConfigFS
383 * struct se_device attributes. spc4r17 section 7.4.6 Control mode page
385 * A task aborted status (TAS) bit set to zero specifies that aborted
386 * tasks shall be terminated by the device server without any response
387 * to the application client. A TAS bit set to one specifies that tasks
388 * aborted by the actions of an I_T nexus other than the I_T nexus on
389 * which the command was received shall be completed with TASK ABORTED
390 * status (see SAM-4).
392 tas
= dev
->dev_attrib
.emulate_tas
;
394 * Determine if this se_tmr is coming from a $FABRIC_MOD
395 * or struct se_device passthrough..
397 if (tmr
&& tmr
->task_cmd
&& tmr
->task_cmd
->se_sess
) {
398 tmr_nacl
= tmr
->task_cmd
->se_sess
->se_node_acl
;
399 tmr_tpg
= tmr
->task_cmd
->se_sess
->se_tpg
;
400 if (tmr_nacl
&& tmr_tpg
) {
401 pr_debug("LUN_RESET: TMR caller fabric: %s"
402 " initiator port %s\n",
403 tmr_tpg
->se_tpg_tfo
->get_fabric_name(),
404 tmr_nacl
->initiatorname
);
407 pr_debug("LUN_RESET: %s starting for [%s], tas: %d\n",
408 (preempt_and_abort_list
) ? "Preempt" : "TMR",
409 dev
->transport
->name
, tas
);
411 core_tmr_drain_tmr_list(dev
, tmr
, preempt_and_abort_list
);
412 core_tmr_drain_state_list(dev
, prout_cmd
, tmr_nacl
, tas
,
413 preempt_and_abort_list
);
416 * Clear any legacy SPC-2 reservation when called during
419 if (!preempt_and_abort_list
&&
420 (dev
->dev_reservation_flags
& DRF_SPC2_RESERVATIONS
)) {
421 spin_lock(&dev
->dev_reservation_lock
);
422 dev
->dev_reserved_node_acl
= NULL
;
423 dev
->dev_reservation_flags
&= ~DRF_SPC2_RESERVATIONS
;
424 spin_unlock(&dev
->dev_reservation_lock
);
425 pr_debug("LUN_RESET: SCSI-2 Released reservation\n");
428 atomic_long_inc(&dev
->num_resets
);
430 pr_debug("LUN_RESET: %s for [%s] Complete\n",
431 (preempt_and_abort_list
) ? "Preempt" : "TMR",
432 dev
->transport
->name
);