[linux-2.6-block.git] / drivers / target / target_core_ua.c

/*******************************************************************************
 * Filename: target_core_ua.c
 *
 * This file contains logic for SPC-3 Unit Attention emulation
 *
 * (c) Copyright 2009-2013 Datera, Inc.
 *
 * Nicholas A. Bellinger <nab@kernel.org>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 *
 ******************************************************************************/

#include <linux/slab.h>
#include <linux/spinlock.h>
#include <scsi/scsi.h>
#include <scsi/scsi_cmnd.h>

#include <target/target_core_base.h>
#include <target/target_core_fabric.h>
#include <target/target_core_configfs.h>

#include "target_core_internal.h"
#include "target_core_alua.h"
#include "target_core_pr.h"
#include "target_core_ua.h"

sense_reason_t
target_scsi3_ua_check(struct se_cmd *cmd)
{
	struct se_dev_entry *deve;
	struct se_session *sess = cmd->se_sess;
	struct se_node_acl *nacl;

	if (!sess)
		return 0;

	nacl = sess->se_node_acl;
	if (!nacl)
		return 0;

	deve = nacl->device_list[cmd->orig_fe_lun];
	if (!atomic_read(&deve->ua_count))
		return 0;
	/*
	 * From sam4r14, section 5.14 Unit attention condition:
	 *
	 * a) if an INQUIRY command enters the enabled command state, the
	 *    device server shall process the INQUIRY command and shall neither
	 *    report nor clear any unit attention condition;
	 * b) if a REPORT LUNS command enters the enabled command state, the
	 *    device server shall process the REPORT LUNS command and shall not
	 *    report any unit attention condition;
	 * e) if a REQUEST SENSE command enters the enabled command state while
	 *    a unit attention condition exists for the SCSI initiator port
	 *    associated with the I_T nexus on which the REQUEST SENSE command
	 *    was received, then the device server shall process the command
	 *    and either:
	 */
	switch (cmd->t_task_cdb[0]) {
	case INQUIRY:
	case REPORT_LUNS:
	case REQUEST_SENSE:
		return 0;
	default:
		return TCM_CHECK_CONDITION_UNIT_ATTENTION;
	}
}

int core_scsi3_ua_allocate(
	struct se_node_acl *nacl,
	u32 unpacked_lun,
	u8 asc,
	u8 ascq)
{
	struct se_dev_entry *deve;
	struct se_ua *ua, *ua_p, *ua_tmp;
	/*
	 * PASSTHROUGH OPS
	 */
	if (!nacl)
		return -EINVAL;

	ua = kmem_cache_zalloc(se_ua_cache, GFP_ATOMIC);
	if (!ua) {
		pr_err("Unable to allocate struct se_ua\n");
		return -ENOMEM;
	}
	INIT_LIST_HEAD(&ua->ua_nacl_list);

	ua->ua_nacl = nacl;
	ua->ua_asc = asc;
	ua->ua_ascq = ascq;

	spin_lock_irq(&nacl->device_list_lock);
	deve = nacl->device_list[unpacked_lun];

	spin_lock(&deve->ua_lock);
	list_for_each_entry_safe(ua_p, ua_tmp, &deve->ua_list, ua_nacl_list) {
		/*
		 * Do not report the same UNIT ATTENTION twice..
		 */
		if ((ua_p->ua_asc == asc) && (ua_p->ua_ascq == ascq)) {
			spin_unlock(&deve->ua_lock);
			spin_unlock_irq(&nacl->device_list_lock);
			kmem_cache_free(se_ua_cache, ua);
			return 0;
		}
		/*
		 * Attach the highest priority Unit Attention to
		 * the head of the list following sam4r14,
		 * Section 5.14 Unit Attention Condition:
		 *
		 * POWER ON, RESET, OR BUS DEVICE RESET OCCURRED highest
		 * POWER ON OCCURRED or
		 * DEVICE INTERNAL RESET
		 * SCSI BUS RESET OCCURRED or
		 * MICROCODE HAS BEEN CHANGED or
		 * protocol specific
		 * BUS DEVICE RESET FUNCTION OCCURRED
		 * I_T NEXUS LOSS OCCURRED
		 * COMMANDS CLEARED BY POWER LOSS NOTIFICATION
		 * all others                                    Lowest
		 *
		 * Each of the ASCQ codes listed above are defined in
		 * the 29h ASC family, see spc4r17 Table D.1
		 */
		if (ua_p->ua_asc == 0x29) {
			if ((asc == 0x29) && (ascq > ua_p->ua_ascq))
				list_add(&ua->ua_nacl_list,
						&deve->ua_list);
			else
				list_add_tail(&ua->ua_nacl_list,
						&deve->ua_list);
		} else if (ua_p->ua_asc == 0x2a) {
			/*
			 * Incoming Family 29h ASCQ codes will override
			 * Family 2AHh ASCQ codes for Unit Attention condition.
			 */
			if ((asc == 0x29) || (ascq > ua_p->ua_asc))
				list_add(&ua->ua_nacl_list,
					&deve->ua_list);
			else
				list_add_tail(&ua->ua_nacl_list,
						&deve->ua_list);
		} else
			list_add_tail(&ua->ua_nacl_list,
				&deve->ua_list);
		spin_unlock(&deve->ua_lock);
		spin_unlock_irq(&nacl->device_list_lock);

		atomic_inc(&deve->ua_count);
		smp_mb__after_atomic();
		return 0;
	}
	list_add_tail(&ua->ua_nacl_list, &deve->ua_list);
	spin_unlock(&deve->ua_lock);
	spin_unlock_irq(&nacl->device_list_lock);

	pr_debug("[%s]: Allocated UNIT ATTENTION, mapped LUN: %u, ASC:"
		" 0x%02x, ASCQ: 0x%02x\n",
		nacl->se_tpg->se_tpg_tfo->get_fabric_name(), unpacked_lun,
		asc, ascq);

	atomic_inc(&deve->ua_count);
	smp_mb__after_atomic();
	return 0;
}

void core_scsi3_ua_release_all(
	struct se_dev_entry *deve)
{
	struct se_ua *ua, *ua_p;

	spin_lock(&deve->ua_lock);
	list_for_each_entry_safe(ua, ua_p, &deve->ua_list, ua_nacl_list) {
		list_del(&ua->ua_nacl_list);
		kmem_cache_free(se_ua_cache, ua);

		atomic_dec(&deve->ua_count);
		smp_mb__after_atomic();
	}
	spin_unlock(&deve->ua_lock);
}

void core_scsi3_ua_for_check_condition(
	struct se_cmd *cmd,
	u8 *asc,
	u8 *ascq)
{
	struct se_device *dev = cmd->se_dev;
	struct se_dev_entry *deve;
	struct se_session *sess = cmd->se_sess;
	struct se_node_acl *nacl;
	struct se_ua *ua = NULL, *ua_p;
	int head = 1;

	if (!sess)
		return;

	nacl = sess->se_node_acl;
	if (!nacl)
		return;

	spin_lock_irq(&nacl->device_list_lock);
	deve = nacl->device_list[cmd->orig_fe_lun];
	if (!atomic_read(&deve->ua_count)) {
		spin_unlock_irq(&nacl->device_list_lock);
		return;
	}
	/*
	 * The highest priority Unit Attentions are placed at the head of the
	 * struct se_dev_entry->ua_list, and will be returned in CHECK_CONDITION +
	 * sense data for the received CDB.
	 */
	spin_lock(&deve->ua_lock);
	list_for_each_entry_safe(ua, ua_p, &deve->ua_list, ua_nacl_list) {
		/*
		 * For ua_intlck_ctrl code not equal to 00b, only report the
		 * highest priority UNIT_ATTENTION and ASC/ASCQ without
		 * clearing it.
		 */
		if (dev->dev_attrib.emulate_ua_intlck_ctrl != 0) {
			*asc = ua->ua_asc;
			*ascq = ua->ua_ascq;
			break;
		}
		/*
		 * Otherwise for the default 00b, release the UNIT ATTENTION
		 * condition.  Return the ASC/ASCQ of the highest priority UA
		 * (head of the list) in the outgoing CHECK_CONDITION + sense.
		 */
		if (head) {
			*asc = ua->ua_asc;
			*ascq = ua->ua_ascq;
			head = 0;
		}
		list_del(&ua->ua_nacl_list);
		kmem_cache_free(se_ua_cache, ua);

		atomic_dec(&deve->ua_count);
		smp_mb__after_atomic();
	}
	spin_unlock(&deve->ua_lock);
	spin_unlock_irq(&nacl->device_list_lock);

	pr_debug("[%s]: %s UNIT ATTENTION condition with"
		" INTLCK_CTRL: %d, mapped LUN: %u, got CDB: 0x%02x"
		" reported ASC: 0x%02x, ASCQ: 0x%02x\n",
		nacl->se_tpg->se_tpg_tfo->get_fabric_name(),
		(dev->dev_attrib.emulate_ua_intlck_ctrl != 0) ? "Reporting" :
		"Releasing", dev->dev_attrib.emulate_ua_intlck_ctrl,
		cmd->orig_fe_lun, cmd->t_task_cdb[0], *asc, *ascq);
}

int core_scsi3_ua_clear_for_request_sense(
	struct se_cmd *cmd,
	u8 *asc,
	u8 *ascq)
{
	struct se_dev_entry *deve;
	struct se_session *sess = cmd->se_sess;
	struct se_node_acl *nacl;
	struct se_ua *ua = NULL, *ua_p;
	int head = 1;

	if (!sess)
		return -EINVAL;

	nacl = sess->se_node_acl;
	if (!nacl)
		return -EINVAL;

	spin_lock_irq(&nacl->device_list_lock);
	deve = nacl->device_list[cmd->orig_fe_lun];
	if (!atomic_read(&deve->ua_count)) {
		spin_unlock_irq(&nacl->device_list_lock);
		return -EPERM;
	}
	/*
	 * The highest priority Unit Attentions are placed at the head of the
	 * struct se_dev_entry->ua_list.  The First (and hence highest priority)
	 * ASC/ASCQ will be returned in REQUEST_SENSE payload data for the
	 * matching struct se_lun.
	 *
	 * Once the returning ASC/ASCQ values are set, we go ahead and
	 * release all of the Unit Attention conditions for the associated
	 * struct se_lun.
	 */
	spin_lock(&deve->ua_lock);
	list_for_each_entry_safe(ua, ua_p, &deve->ua_list, ua_nacl_list) {
		if (head) {
			*asc = ua->ua_asc;
			*ascq = ua->ua_ascq;
			head = 0;
		}
		list_del(&ua->ua_nacl_list);
		kmem_cache_free(se_ua_cache, ua);

		atomic_dec(&deve->ua_count);
		smp_mb__after_atomic();
	}
	spin_unlock(&deve->ua_lock);
	spin_unlock_irq(&nacl->device_list_lock);

	pr_debug("[%s]: Released UNIT ATTENTION condition, mapped"
		" LUN: %u, got REQUEST_SENSE reported ASC: 0x%02x,"
		" ASCQ: 0x%02x\n", nacl->se_tpg->se_tpg_tfo->get_fabric_name(),
		cmd->orig_fe_lun, *asc, *ascq);

	return (head) ? -EPERM : 0;
}
Commit	Line	Data
c66ac9db NB	1	/*******************************************************************************
	2	* Filename: target_core_ua.c
	3	*
	4	* This file contains logic for SPC-3 Unit Attention emulation
	5	*
4c76251e	6	* (c) Copyright 2009-2013 Datera, Inc.
c66ac9db NB	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
c66ac9db NB	26	#include <linux/slab.h>
	27	#include <linux/spinlock.h>
	28	#include <scsi/scsi.h>
	29	#include <scsi/scsi_cmnd.h>
	30
	31	#include <target/target_core_base.h>
c4795fb2	32	#include <target/target_core_fabric.h>
c66ac9db NB	33	#include <target/target_core_configfs.h>
c66ac9db NB	34
e26d99ae	35	#include "target_core_internal.h"
c66ac9db	36	#include "target_core_alua.h"
c66ac9db NB	37	#include "target_core_pr.h"
	38	#include "target_core_ua.h"
	39
de103c93 CH	40	sense_reason_t
de103c93 CH	41	target_scsi3_ua_check(struct se_cmd *cmd)
c66ac9db NB	42	{
	43	struct se_dev_entry *deve;
	44	struct se_session *sess = cmd->se_sess;
	45	struct se_node_acl *nacl;
	46
6708bb27	47	if (!sess)
c66ac9db NB	48	return 0;
	49
	50	nacl = sess->se_node_acl;
6708bb27	51	if (!nacl)
c66ac9db NB	52	return 0;
c66ac9db NB	53
f2083241	54	deve = nacl->device_list[cmd->orig_fe_lun];
6708bb27	55	if (!atomic_read(&deve->ua_count))
c66ac9db NB	56	return 0;
	57	/*
	58	* From sam4r14, section 5.14 Unit attention condition:
	59	*
	60	* a) if an INQUIRY command enters the enabled command state, the
	61	* device server shall process the INQUIRY command and shall neither
	62	* report nor clear any unit attention condition;
	63	* b) if a REPORT LUNS command enters the enabled command state, the
	64	* device server shall process the REPORT LUNS command and shall not
	65	* report any unit attention condition;
	66	* e) if a REQUEST SENSE command enters the enabled command state while
	67	* a unit attention condition exists for the SCSI initiator port
	68	* associated with the I_T nexus on which the REQUEST SENSE command
	69	* was received, then the device server shall process the command
	70	* and either:
	71	*/
de103c93	72	switch (cmd->t_task_cdb[0]) {
c66ac9db NB	73	case INQUIRY:
	74	case REPORT_LUNS:
	75	case REQUEST_SENSE:
	76	return 0;
	77	default:
de103c93	78	return TCM_CHECK_CONDITION_UNIT_ATTENTION;
c66ac9db	79	}
c66ac9db NB	80	}
	81
	82	int core_scsi3_ua_allocate(
	83	struct se_node_acl *nacl,
	84	u32 unpacked_lun,
	85	u8 asc,
	86	u8 ascq)
	87	{
	88	struct se_dev_entry *deve;
	89	struct se_ua ua, ua_p, *ua_tmp;
	90	/*
	91	* PASSTHROUGH OPS
	92	*/
6708bb27	93	if (!nacl)
e3d6f909	94	return -EINVAL;
c66ac9db NB	95
c66ac9db NB	96	ua = kmem_cache_zalloc(se_ua_cache, GFP_ATOMIC);
6708bb27 AG	97	if (!ua) {
6708bb27 AG	98	pr_err("Unable to allocate struct se_ua\n");
e3d6f909	99	return -ENOMEM;
c66ac9db	100	}
c66ac9db NB	101	INIT_LIST_HEAD(&ua->ua_nacl_list);
	102
	103	ua->ua_nacl = nacl;
	104	ua->ua_asc = asc;
	105	ua->ua_ascq = ascq;
	106
	107	spin_lock_irq(&nacl->device_list_lock);
f2083241	108	deve = nacl->device_list[unpacked_lun];
c66ac9db NB	109
	110	spin_lock(&deve->ua_lock);
	111	list_for_each_entry_safe(ua_p, ua_tmp, &deve->ua_list, ua_nacl_list) {
	112	/*
	113	* Do not report the same UNIT ATTENTION twice..
	114	*/
	115	if ((ua_p->ua_asc == asc) && (ua_p->ua_ascq == ascq)) {
	116	spin_unlock(&deve->ua_lock);
	117	spin_unlock_irq(&nacl->device_list_lock);
	118	kmem_cache_free(se_ua_cache, ua);
	119	return 0;
	120	}
	121	/*
	122	* Attach the highest priority Unit Attention to
	123	* the head of the list following sam4r14,
	124	* Section 5.14 Unit Attention Condition:
	125	*
	126	* POWER ON, RESET, OR BUS DEVICE RESET OCCURRED highest
	127	* POWER ON OCCURRED or
	128	* DEVICE INTERNAL RESET
	129	* SCSI BUS RESET OCCURRED or
	130	* MICROCODE HAS BEEN CHANGED or
	131	* protocol specific
	132	* BUS DEVICE RESET FUNCTION OCCURRED
	133	* I_T NEXUS LOSS OCCURRED
	134	* COMMANDS CLEARED BY POWER LOSS NOTIFICATION
	135	* all others Lowest
	136	*
	137	* Each of the ASCQ codes listed above are defined in
	138	* the 29h ASC family, see spc4r17 Table D.1
	139	*/
	140	if (ua_p->ua_asc == 0x29) {
	141	if ((asc == 0x29) && (ascq > ua_p->ua_ascq))
	142	list_add(&ua->ua_nacl_list,
	143	&deve->ua_list);
	144	else
	145	list_add_tail(&ua->ua_nacl_list,
	146	&deve->ua_list);
	147	} else if (ua_p->ua_asc == 0x2a) {
	148	/*
	149	* Incoming Family 29h ASCQ codes will override
	150	* Family 2AHh ASCQ codes for Unit Attention condition.
	151	*/
	152	if ((asc == 0x29) \|\| (ascq > ua_p->ua_asc))
	153	list_add(&ua->ua_nacl_list,
	154	&deve->ua_list);
	155	else
	156	list_add_tail(&ua->ua_nacl_list,
	157	&deve->ua_list);
	158	} else
	159	list_add_tail(&ua->ua_nacl_list,
	160	&deve->ua_list);
	161	spin_unlock(&deve->ua_lock);
	162	spin_unlock_irq(&nacl->device_list_lock);
	163
	164	atomic_inc(&deve->ua_count);
4e857c58	165	smp_mb__after_atomic();
c66ac9db NB	166	return 0;
	167	}
	168	list_add_tail(&ua->ua_nacl_list, &deve->ua_list);
	169	spin_unlock(&deve->ua_lock);
	170	spin_unlock_irq(&nacl->device_list_lock);
	171
6708bb27	172	pr_debug("[%s]: Allocated UNIT ATTENTION, mapped LUN: %u, ASC:"
c66ac9db	173	" 0x%02x, ASCQ: 0x%02x\n",
e3d6f909	174	nacl->se_tpg->se_tpg_tfo->get_fabric_name(), unpacked_lun,
c66ac9db NB	175	asc, ascq);
	176
	177	atomic_inc(&deve->ua_count);
4e857c58	178	smp_mb__after_atomic();
c66ac9db NB	179	return 0;
	180	}
	181
	182	void core_scsi3_ua_release_all(
	183	struct se_dev_entry *deve)
	184	{
	185	struct se_ua ua, ua_p;
	186
	187	spin_lock(&deve->ua_lock);
	188	list_for_each_entry_safe(ua, ua_p, &deve->ua_list, ua_nacl_list) {
	189	list_del(&ua->ua_nacl_list);
	190	kmem_cache_free(se_ua_cache, ua);
	191
	192	atomic_dec(&deve->ua_count);
4e857c58	193	smp_mb__after_atomic();
c66ac9db NB	194	}
	195	spin_unlock(&deve->ua_lock);
	196	}
	197
	198	void core_scsi3_ua_for_check_condition(
	199	struct se_cmd *cmd,
	200	u8 *asc,
	201	u8 *ascq)
	202	{
5951146d	203	struct se_device *dev = cmd->se_dev;
c66ac9db NB	204	struct se_dev_entry *deve;
	205	struct se_session *sess = cmd->se_sess;
	206	struct se_node_acl *nacl;
	207	struct se_ua ua = NULL, ua_p;
	208	int head = 1;
	209
6708bb27	210	if (!sess)
c66ac9db NB	211	return;
	212
	213	nacl = sess->se_node_acl;
6708bb27	214	if (!nacl)
c66ac9db NB	215	return;
	216
	217	spin_lock_irq(&nacl->device_list_lock);
f2083241	218	deve = nacl->device_list[cmd->orig_fe_lun];
6708bb27	219	if (!atomic_read(&deve->ua_count)) {
c66ac9db NB	220	spin_unlock_irq(&nacl->device_list_lock);
	221	return;
	222	}
	223	/*
	224	* The highest priority Unit Attentions are placed at the head of the
	225	* struct se_dev_entry->ua_list, and will be returned in CHECK_CONDITION +
	226	* sense data for the received CDB.
	227	*/
	228	spin_lock(&deve->ua_lock);
	229	list_for_each_entry_safe(ua, ua_p, &deve->ua_list, ua_nacl_list) {
	230	/*
	231	* For ua_intlck_ctrl code not equal to 00b, only report the
	232	* highest priority UNIT_ATTENTION and ASC/ASCQ without
	233	* clearing it.
	234	*/
0fd97ccf	235	if (dev->dev_attrib.emulate_ua_intlck_ctrl != 0) {
c66ac9db NB	236	*asc = ua->ua_asc;
	237	*ascq = ua->ua_ascq;
	238	break;
	239	}
	240	/*
	241	* Otherwise for the default 00b, release the UNIT ATTENTION
25985edc	242	* condition. Return the ASC/ASCQ of the highest priority UA
c66ac9db NB	243	* (head of the list) in the outgoing CHECK_CONDITION + sense.
	244	*/
	245	if (head) {
	246	*asc = ua->ua_asc;
	247	*ascq = ua->ua_ascq;
	248	head = 0;
	249	}
	250	list_del(&ua->ua_nacl_list);
	251	kmem_cache_free(se_ua_cache, ua);
	252
	253	atomic_dec(&deve->ua_count);
4e857c58	254	smp_mb__after_atomic();
c66ac9db NB	255	}
	256	spin_unlock(&deve->ua_lock);
	257	spin_unlock_irq(&nacl->device_list_lock);
	258
6708bb27	259	pr_debug("[%s]: %s UNIT ATTENTION condition with"
c66ac9db NB	260	" INTLCK_CTRL: %d, mapped LUN: %u, got CDB: 0x%02x"
c66ac9db NB	261	" reported ASC: 0x%02x, ASCQ: 0x%02x\n",
e3d6f909	262	nacl->se_tpg->se_tpg_tfo->get_fabric_name(),
0fd97ccf CH	263	(dev->dev_attrib.emulate_ua_intlck_ctrl != 0) ? "Reporting" :
0fd97ccf CH	264	"Releasing", dev->dev_attrib.emulate_ua_intlck_ctrl,
a1d8b49a	265	cmd->orig_fe_lun, cmd->t_task_cdb[0], asc, ascq);
c66ac9db NB	266	}
	267
	268	int core_scsi3_ua_clear_for_request_sense(
	269	struct se_cmd *cmd,
	270	u8 *asc,
	271	u8 *ascq)
	272	{
	273	struct se_dev_entry *deve;
	274	struct se_session *sess = cmd->se_sess;
	275	struct se_node_acl *nacl;
	276	struct se_ua ua = NULL, ua_p;
	277	int head = 1;
	278
6708bb27	279	if (!sess)
e3d6f909	280	return -EINVAL;
c66ac9db NB	281
c66ac9db NB	282	nacl = sess->se_node_acl;
6708bb27	283	if (!nacl)
e3d6f909	284	return -EINVAL;
c66ac9db NB	285
c66ac9db NB	286	spin_lock_irq(&nacl->device_list_lock);
f2083241	287	deve = nacl->device_list[cmd->orig_fe_lun];
6708bb27	288	if (!atomic_read(&deve->ua_count)) {
c66ac9db	289	spin_unlock_irq(&nacl->device_list_lock);
e3d6f909	290	return -EPERM;
c66ac9db NB	291	}
	292	/*
	293	* The highest priority Unit Attentions are placed at the head of the
	294	* struct se_dev_entry->ua_list. The First (and hence highest priority)
	295	* ASC/ASCQ will be returned in REQUEST_SENSE payload data for the
	296	* matching struct se_lun.
	297	*
	298	* Once the returning ASC/ASCQ values are set, we go ahead and
25985edc	299	* release all of the Unit Attention conditions for the associated
c66ac9db NB	300	* struct se_lun.
	301	*/
	302	spin_lock(&deve->ua_lock);
	303	list_for_each_entry_safe(ua, ua_p, &deve->ua_list, ua_nacl_list) {
	304	if (head) {
	305	*asc = ua->ua_asc;
	306	*ascq = ua->ua_ascq;
	307	head = 0;
	308	}
	309	list_del(&ua->ua_nacl_list);
	310	kmem_cache_free(se_ua_cache, ua);
	311
	312	atomic_dec(&deve->ua_count);
4e857c58	313	smp_mb__after_atomic();
c66ac9db NB	314	}
	315	spin_unlock(&deve->ua_lock);
	316	spin_unlock_irq(&nacl->device_list_lock);
	317
6708bb27	318	pr_debug("[%s]: Released UNIT ATTENTION condition, mapped"
c66ac9db	319	" LUN: %u, got REQUEST_SENSE reported ASC: 0x%02x,"
e3d6f909	320	" ASCQ: 0x%02x\n", nacl->se_tpg->se_tpg_tfo->get_fabric_name(),
c66ac9db NB	321	cmd->orig_fe_lun, asc, ascq);
c66ac9db NB	322
e3d6f909	323	return (head) ? -EPERM : 0;
c66ac9db	324	}