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 int 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 return 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))
181 list_del_init(&se_cmd
->se_cmd_list
);
182 spin_unlock_irqrestore(&se_sess
->sess_cmd_lock
, flags
);
184 cancel_work_sync(&se_cmd
->work
);
185 transport_wait_for_tasks(se_cmd
);
187 if (!transport_cmd_finish_abort(se_cmd
, true))
188 target_put_sess_cmd(se_cmd
);
190 printk("ABORT_TASK: Sending TMR_FUNCTION_COMPLETE for"
191 " ref_tag: %llu\n", ref_tag
);
192 tmr
->response
= TMR_FUNCTION_COMPLETE
;
193 atomic_long_inc(&dev
->aborts_complete
);
196 spin_unlock_irqrestore(&se_sess
->sess_cmd_lock
, flags
);
198 printk("ABORT_TASK: Sending TMR_TASK_DOES_NOT_EXIST for ref_tag: %lld\n",
200 tmr
->response
= TMR_TASK_DOES_NOT_EXIST
;
201 atomic_long_inc(&dev
->aborts_no_task
);
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
)
209 LIST_HEAD(drain_tmr_list
);
210 struct se_session
*sess
;
211 struct se_tmr_req
*tmr_p
, *tmr_pp
;
216 * Release all pending and outgoing TMRs aside from the received
219 spin_lock_irqsave(&dev
->se_tmr_lock
, flags
);
220 list_del_init(&tmr
->tmr_list
);
221 list_for_each_entry_safe(tmr_p
, tmr_pp
, &dev
->dev_tmr_list
, tmr_list
) {
222 cmd
= tmr_p
->task_cmd
;
224 pr_err("Unable to locate struct se_cmd for TMR\n");
228 * If this function was called with a valid pr_res_key
229 * parameter (eg: for PROUT PREEMPT_AND_ABORT service action
230 * skip non registration key matching TMRs.
232 if (target_check_cdb_and_preempt(preempt_and_abort_list
, cmd
))
236 if (WARN_ON_ONCE(!sess
))
239 spin_lock(&sess
->sess_cmd_lock
);
240 spin_lock(&cmd
->t_state_lock
);
241 if (!(cmd
->transport_state
& CMD_T_ACTIVE
) ||
242 (cmd
->transport_state
& CMD_T_FABRIC_STOP
)) {
243 spin_unlock(&cmd
->t_state_lock
);
244 spin_unlock(&sess
->sess_cmd_lock
);
247 if (cmd
->t_state
== TRANSPORT_ISTATE_PROCESSING
) {
248 spin_unlock(&cmd
->t_state_lock
);
249 spin_unlock(&sess
->sess_cmd_lock
);
252 if (sess
->sess_tearing_down
|| cmd
->cmd_wait_set
) {
253 spin_unlock(&cmd
->t_state_lock
);
254 spin_unlock(&sess
->sess_cmd_lock
);
257 cmd
->transport_state
|= CMD_T_ABORTED
;
258 spin_unlock(&cmd
->t_state_lock
);
260 rc
= kref_get_unless_zero(&cmd
->cmd_kref
);
262 printk("LUN_RESET TMR: non-zero kref_get_unless_zero\n");
263 spin_unlock(&sess
->sess_cmd_lock
);
266 spin_unlock(&sess
->sess_cmd_lock
);
268 list_move_tail(&tmr_p
->tmr_list
, &drain_tmr_list
);
270 spin_unlock_irqrestore(&dev
->se_tmr_lock
, flags
);
272 list_for_each_entry_safe(tmr_p
, tmr_pp
, &drain_tmr_list
, tmr_list
) {
273 list_del_init(&tmr_p
->tmr_list
);
274 cmd
= tmr_p
->task_cmd
;
276 pr_debug("LUN_RESET: %s releasing TMR %p Function: 0x%02x,"
277 " Response: 0x%02x, t_state: %d\n",
278 (preempt_and_abort_list
) ? "Preempt" : "", tmr_p
,
279 tmr_p
->function
, tmr_p
->response
, cmd
->t_state
);
281 cancel_work_sync(&cmd
->work
);
282 transport_wait_for_tasks(cmd
);
284 if (!transport_cmd_finish_abort(cmd
, 1))
285 target_put_sess_cmd(cmd
);
289 static void core_tmr_drain_state_list(
290 struct se_device
*dev
,
291 struct se_cmd
*prout_cmd
,
292 struct se_session
*tmr_sess
,
294 struct list_head
*preempt_and_abort_list
)
296 LIST_HEAD(drain_task_list
);
297 struct se_session
*sess
;
298 struct se_cmd
*cmd
, *next
;
303 * Complete outstanding commands with TASK_ABORTED SAM status.
305 * This is following sam4r17, section 5.6 Aborting commands, Table 38
308 * a) "Yes" indicates that each command that is aborted on an I_T nexus
309 * other than the one that caused the SCSI device condition is
310 * completed with TASK ABORTED status, if the TAS bit is set to one in
311 * the Control mode page (see SPC-4). "No" indicates that no status is
312 * returned for aborted commands.
314 * d) If the logical unit reset is caused by a particular I_T nexus
315 * (e.g., by a LOGICAL UNIT RESET task management function), then "yes"
316 * (TASK_ABORTED status) applies.
318 * Otherwise (e.g., if triggered by a hard reset), "no"
319 * (no TASK_ABORTED SAM status) applies.
321 * Note that this seems to be independent of TAS (Task Aborted Status)
322 * in the Control Mode Page.
324 spin_lock_irqsave(&dev
->execute_task_lock
, flags
);
325 list_for_each_entry_safe(cmd
, next
, &dev
->state_list
, state_list
) {
327 * For PREEMPT_AND_ABORT usage, only process commands
328 * with a matching reservation key.
330 if (target_check_cdb_and_preempt(preempt_and_abort_list
, cmd
))
334 * Not aborting PROUT PREEMPT_AND_ABORT CDB..
336 if (prout_cmd
== cmd
)
340 if (WARN_ON_ONCE(!sess
))
343 spin_lock(&sess
->sess_cmd_lock
);
344 rc
= __target_check_io_state(cmd
, tmr_sess
, tas
);
345 spin_unlock(&sess
->sess_cmd_lock
);
349 list_move_tail(&cmd
->state_list
, &drain_task_list
);
350 cmd
->state_active
= false;
352 spin_unlock_irqrestore(&dev
->execute_task_lock
, flags
);
354 while (!list_empty(&drain_task_list
)) {
355 cmd
= list_entry(drain_task_list
.next
, struct se_cmd
, state_list
);
356 list_del_init(&cmd
->state_list
);
358 target_show_cmd("LUN_RESET: ", cmd
);
359 pr_debug("LUN_RESET: ITT[0x%08llx] - %s pr_res_key: 0x%016Lx\n",
360 cmd
->tag
, (preempt_and_abort_list
) ? "preempt" : "",
364 * If the command may be queued onto a workqueue cancel it now.
366 * This is equivalent to removal from the execute queue in the
367 * loop above, but we do it down here given that
368 * cancel_work_sync may block.
370 cancel_work_sync(&cmd
->work
);
371 transport_wait_for_tasks(cmd
);
373 if (!core_tmr_handle_tas_abort(cmd
, tas
))
374 target_put_sess_cmd(cmd
);
378 int core_tmr_lun_reset(
379 struct se_device
*dev
,
380 struct se_tmr_req
*tmr
,
381 struct list_head
*preempt_and_abort_list
,
382 struct se_cmd
*prout_cmd
)
384 struct se_node_acl
*tmr_nacl
= NULL
;
385 struct se_portal_group
*tmr_tpg
= NULL
;
386 struct se_session
*tmr_sess
= NULL
;
389 * TASK_ABORTED status bit, this is configurable via ConfigFS
390 * struct se_device attributes. spc4r17 section 7.4.6 Control mode page
392 * A task aborted status (TAS) bit set to zero specifies that aborted
393 * tasks shall be terminated by the device server without any response
394 * to the application client. A TAS bit set to one specifies that tasks
395 * aborted by the actions of an I_T nexus other than the I_T nexus on
396 * which the command was received shall be completed with TASK ABORTED
397 * status (see SAM-4).
399 tas
= dev
->dev_attrib
.emulate_tas
;
401 * Determine if this se_tmr is coming from a $FABRIC_MOD
402 * or struct se_device passthrough..
404 if (tmr
&& tmr
->task_cmd
&& tmr
->task_cmd
->se_sess
) {
405 tmr_sess
= tmr
->task_cmd
->se_sess
;
406 tmr_nacl
= tmr_sess
->se_node_acl
;
407 tmr_tpg
= tmr_sess
->se_tpg
;
408 if (tmr_nacl
&& tmr_tpg
) {
409 pr_debug("LUN_RESET: TMR caller fabric: %s"
410 " initiator port %s\n",
411 tmr_tpg
->se_tpg_tfo
->get_fabric_name(),
412 tmr_nacl
->initiatorname
);
415 pr_debug("LUN_RESET: %s starting for [%s], tas: %d\n",
416 (preempt_and_abort_list
) ? "Preempt" : "TMR",
417 dev
->transport
->name
, tas
);
419 core_tmr_drain_tmr_list(dev
, tmr
, preempt_and_abort_list
);
420 core_tmr_drain_state_list(dev
, prout_cmd
, tmr_sess
, tas
,
421 preempt_and_abort_list
);
424 * Clear any legacy SPC-2 reservation when called during
427 if (!preempt_and_abort_list
&&
428 (dev
->dev_reservation_flags
& DRF_SPC2_RESERVATIONS
)) {
429 spin_lock(&dev
->dev_reservation_lock
);
430 dev
->dev_reserved_node_acl
= NULL
;
431 dev
->dev_reservation_flags
&= ~DRF_SPC2_RESERVATIONS
;
432 spin_unlock(&dev
->dev_reservation_lock
);
433 pr_debug("LUN_RESET: SCSI-2 Released reservation\n");
436 atomic_long_inc(&dev
->num_resets
);
438 pr_debug("LUN_RESET: %s for [%s] Complete\n",
439 (preempt_and_abort_list
) ? "Preempt" : "TMR",
440 dev
->transport
->name
);