[deliverable/linux.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_proto.h>

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

	rcu_read_lock();
	deve = target_nacl_find_deve(nacl, cmd->orig_fe_lun);
	if (!deve) {
		rcu_read_unlock();
		return 0;
	}
	if (!atomic_read(&deve->ua_count)) {
		rcu_read_unlock();
		return 0;
	}
	rcu_read_unlock();
	/*
	 * 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_dev_entry *deve,
	u8 asc,
	u8 ascq)
{
	struct se_ua *ua, *ua_p, *ua_tmp;

	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_asc = asc;
	ua->ua_ascq = ascq;

	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);
			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);

		atomic_inc_mb(&deve->ua_count);
		return 0;
	}
	list_add_tail(&ua->ua_nacl_list, &deve->ua_list);
	spin_unlock(&deve->ua_lock);

	pr_debug("Allocated UNIT ATTENTION, mapped LUN: %llu, ASC:"
		" 0x%02x, ASCQ: 0x%02x\n", deve->mapped_lun,
		asc, ascq);

	atomic_inc_mb(&deve->ua_count);
	return 0;
}

void target_ua_allocate_lun(struct se_node_acl *nacl,
			    u32 unpacked_lun, u8 asc, u8 ascq)
{
	struct se_dev_entry *deve;

	if (!nacl)
		return;

	rcu_read_lock();
	deve = target_nacl_find_deve(nacl, unpacked_lun);
	if (!deve) {
		rcu_read_unlock();
		return;
	}

	core_scsi3_ua_allocate(deve, asc, ascq);
	rcu_read_unlock();
}

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_mb(&deve->ua_count);
	}
	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;

	rcu_read_lock();
	deve = target_nacl_find_deve(nacl, cmd->orig_fe_lun);
	if (!deve) {
		rcu_read_unlock();
		return;
	}
	if (!atomic_read(&deve->ua_count)) {
		rcu_read_unlock();
		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_mb(&deve->ua_count);
	}
	spin_unlock(&deve->ua_lock);
	rcu_read_unlock();

	pr_debug("[%s]: %s UNIT ATTENTION condition with"
		" INTLCK_CTRL: %d, mapped LUN: %llu, 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;

	rcu_read_lock();
	deve = target_nacl_find_deve(nacl, cmd->orig_fe_lun);
	if (!deve) {
		rcu_read_unlock();
		return -EINVAL;
	}
	if (!atomic_read(&deve->ua_count)) {
		rcu_read_unlock();
		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_mb(&deve->ua_count);
	}
	spin_unlock(&deve->ua_lock);
	rcu_read_unlock();

	pr_debug("[%s]: Released UNIT ATTENTION condition, mapped"
		" LUN: %llu, 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>
c66ac9db NB	27	#include <linux/spinlock.h>
ba929992	28	#include <scsi/scsi_proto.h>
c66ac9db NB	29
c66ac9db NB	30	#include <target/target_core_base.h>
c4795fb2	31	#include <target/target_core_fabric.h>
c66ac9db	32
e26d99ae	33	#include "target_core_internal.h"
c66ac9db	34	#include "target_core_alua.h"
c66ac9db NB	35	#include "target_core_pr.h"
	36	#include "target_core_ua.h"
	37
de103c93 CH	38	sense_reason_t
de103c93 CH	39	target_scsi3_ua_check(struct se_cmd *cmd)
c66ac9db NB	40	{
	41	struct se_dev_entry *deve;
	42	struct se_session *sess = cmd->se_sess;
	43	struct se_node_acl *nacl;
	44
6708bb27	45	if (!sess)
c66ac9db NB	46	return 0;
	47
	48	nacl = sess->se_node_acl;
6708bb27	49	if (!nacl)
c66ac9db NB	50	return 0;
c66ac9db NB	51
29a05dee NB	52	rcu_read_lock();
	53	deve = target_nacl_find_deve(nacl, cmd->orig_fe_lun);
	54	if (!deve) {
	55	rcu_read_unlock();
c66ac9db	56	return 0;
29a05dee NB	57	}
	58	if (!atomic_read(&deve->ua_count)) {
	59	rcu_read_unlock();
	60	return 0;
	61	}
	62	rcu_read_unlock();
c66ac9db NB	63	/*
	64	* From sam4r14, section 5.14 Unit attention condition:
	65	*
	66	* a) if an INQUIRY command enters the enabled command state, the
	67	* device server shall process the INQUIRY command and shall neither
	68	* report nor clear any unit attention condition;
	69	* b) if a REPORT LUNS command enters the enabled command state, the
	70	* device server shall process the REPORT LUNS command and shall not
	71	* report any unit attention condition;
	72	* e) if a REQUEST SENSE command enters the enabled command state while
	73	* a unit attention condition exists for the SCSI initiator port
	74	* associated with the I_T nexus on which the REQUEST SENSE command
	75	* was received, then the device server shall process the command
	76	* and either:
	77	*/
de103c93	78	switch (cmd->t_task_cdb[0]) {
c66ac9db NB	79	case INQUIRY:
	80	case REPORT_LUNS:
	81	case REQUEST_SENSE:
	82	return 0;
	83	default:
de103c93	84	return TCM_CHECK_CONDITION_UNIT_ATTENTION;
c66ac9db	85	}
c66ac9db NB	86	}
	87
	88	int core_scsi3_ua_allocate(
c51c8e7b	89	struct se_dev_entry *deve,
c66ac9db NB	90	u8 asc,
	91	u8 ascq)
	92	{
c66ac9db	93	struct se_ua ua, ua_p, *ua_tmp;
c66ac9db NB	94
c66ac9db NB	95	ua = kmem_cache_zalloc(se_ua_cache, GFP_ATOMIC);
6708bb27 AG	96	if (!ua) {
6708bb27 AG	97	pr_err("Unable to allocate struct se_ua\n");
e3d6f909	98	return -ENOMEM;
c66ac9db	99	}
c66ac9db NB	100	INIT_LIST_HEAD(&ua->ua_nacl_list);
c66ac9db NB	101
c66ac9db NB	102	ua->ua_asc = asc;
	103	ua->ua_ascq = ascq;
	104
c66ac9db NB	105	spin_lock(&deve->ua_lock);
	106	list_for_each_entry_safe(ua_p, ua_tmp, &deve->ua_list, ua_nacl_list) {
	107	/*
	108	* Do not report the same UNIT ATTENTION twice..
	109	*/
	110	if ((ua_p->ua_asc == asc) && (ua_p->ua_ascq == ascq)) {
	111	spin_unlock(&deve->ua_lock);
c66ac9db NB	112	kmem_cache_free(se_ua_cache, ua);
	113	return 0;
	114	}
	115	/*
	116	* Attach the highest priority Unit Attention to
	117	* the head of the list following sam4r14,
	118	* Section 5.14 Unit Attention Condition:
	119	*
	120	* POWER ON, RESET, OR BUS DEVICE RESET OCCURRED highest
	121	* POWER ON OCCURRED or
	122	* DEVICE INTERNAL RESET
	123	* SCSI BUS RESET OCCURRED or
	124	* MICROCODE HAS BEEN CHANGED or
	125	* protocol specific
	126	* BUS DEVICE RESET FUNCTION OCCURRED
	127	* I_T NEXUS LOSS OCCURRED
	128	* COMMANDS CLEARED BY POWER LOSS NOTIFICATION
	129	* all others Lowest
	130	*
	131	* Each of the ASCQ codes listed above are defined in
	132	* the 29h ASC family, see spc4r17 Table D.1
	133	*/
	134	if (ua_p->ua_asc == 0x29) {
	135	if ((asc == 0x29) && (ascq > ua_p->ua_ascq))
	136	list_add(&ua->ua_nacl_list,
	137	&deve->ua_list);
	138	else
	139	list_add_tail(&ua->ua_nacl_list,
	140	&deve->ua_list);
	141	} else if (ua_p->ua_asc == 0x2a) {
	142	/*
	143	* Incoming Family 29h ASCQ codes will override
	144	* Family 2AHh ASCQ codes for Unit Attention condition.
	145	*/
	146	if ((asc == 0x29) \|\| (ascq > ua_p->ua_asc))
	147	list_add(&ua->ua_nacl_list,
	148	&deve->ua_list);
	149	else
	150	list_add_tail(&ua->ua_nacl_list,
	151	&deve->ua_list);
	152	} else
	153	list_add_tail(&ua->ua_nacl_list,
	154	&deve->ua_list);
	155	spin_unlock(&deve->ua_lock);
c66ac9db	156
33940d09	157	atomic_inc_mb(&deve->ua_count);
c66ac9db NB	158	return 0;
	159	}
	160	list_add_tail(&ua->ua_nacl_list, &deve->ua_list);
	161	spin_unlock(&deve->ua_lock);
c66ac9db	162
c51c8e7b HR	163	pr_debug("Allocated UNIT ATTENTION, mapped LUN: %llu, ASC:"
c51c8e7b HR	164	" 0x%02x, ASCQ: 0x%02x\n", deve->mapped_lun,
c66ac9db NB	165	asc, ascq);
c66ac9db NB	166
33940d09	167	atomic_inc_mb(&deve->ua_count);
c66ac9db NB	168	return 0;
	169	}
	170
c51c8e7b HR	171	void target_ua_allocate_lun(struct se_node_acl *nacl,
	172	u32 unpacked_lun, u8 asc, u8 ascq)
	173	{
	174	struct se_dev_entry *deve;
	175
	176	if (!nacl)
	177	return;
	178
	179	rcu_read_lock();
	180	deve = target_nacl_find_deve(nacl, unpacked_lun);
	181	if (!deve) {
	182	rcu_read_unlock();
	183	return;
	184	}
	185
	186	core_scsi3_ua_allocate(deve, asc, ascq);
	187	rcu_read_unlock();
	188	}
	189
c66ac9db NB	190	void core_scsi3_ua_release_all(
	191	struct se_dev_entry *deve)
	192	{
	193	struct se_ua ua, ua_p;
	194
	195	spin_lock(&deve->ua_lock);
	196	list_for_each_entry_safe(ua, ua_p, &deve->ua_list, ua_nacl_list) {
	197	list_del(&ua->ua_nacl_list);
	198	kmem_cache_free(se_ua_cache, ua);
	199
33940d09	200	atomic_dec_mb(&deve->ua_count);
c66ac9db NB	201	}
	202	spin_unlock(&deve->ua_lock);
	203	}
	204
	205	void core_scsi3_ua_for_check_condition(
	206	struct se_cmd *cmd,
	207	u8 *asc,
	208	u8 *ascq)
	209	{
5951146d	210	struct se_device *dev = cmd->se_dev;
c66ac9db NB	211	struct se_dev_entry *deve;
	212	struct se_session *sess = cmd->se_sess;
	213	struct se_node_acl *nacl;
	214	struct se_ua ua = NULL, ua_p;
	215	int head = 1;
	216
6708bb27	217	if (!sess)
c66ac9db NB	218	return;
	219
	220	nacl = sess->se_node_acl;
6708bb27	221	if (!nacl)
c66ac9db NB	222	return;
c66ac9db NB	223
29a05dee NB	224	rcu_read_lock();
	225	deve = target_nacl_find_deve(nacl, cmd->orig_fe_lun);
	226	if (!deve) {
	227	rcu_read_unlock();
	228	return;
	229	}
6708bb27	230	if (!atomic_read(&deve->ua_count)) {
29a05dee	231	rcu_read_unlock();
c66ac9db NB	232	return;
	233	}
	234	/*
	235	* The highest priority Unit Attentions are placed at the head of the
	236	* struct se_dev_entry->ua_list, and will be returned in CHECK_CONDITION +
	237	* sense data for the received CDB.
	238	*/
	239	spin_lock(&deve->ua_lock);
	240	list_for_each_entry_safe(ua, ua_p, &deve->ua_list, ua_nacl_list) {
	241	/*
	242	* For ua_intlck_ctrl code not equal to 00b, only report the
	243	* highest priority UNIT_ATTENTION and ASC/ASCQ without
	244	* clearing it.
	245	*/
0fd97ccf	246	if (dev->dev_attrib.emulate_ua_intlck_ctrl != 0) {
c66ac9db NB	247	*asc = ua->ua_asc;
	248	*ascq = ua->ua_ascq;
	249	break;
	250	}
	251	/*
	252	* Otherwise for the default 00b, release the UNIT ATTENTION
25985edc	253	* condition. Return the ASC/ASCQ of the highest priority UA
c66ac9db NB	254	* (head of the list) in the outgoing CHECK_CONDITION + sense.
	255	*/
	256	if (head) {
	257	*asc = ua->ua_asc;
	258	*ascq = ua->ua_ascq;
	259	head = 0;
	260	}
	261	list_del(&ua->ua_nacl_list);
	262	kmem_cache_free(se_ua_cache, ua);
	263
33940d09	264	atomic_dec_mb(&deve->ua_count);
c66ac9db NB	265	}
c66ac9db NB	266	spin_unlock(&deve->ua_lock);
29a05dee	267	rcu_read_unlock();
c66ac9db	268
6708bb27	269	pr_debug("[%s]: %s UNIT ATTENTION condition with"
f2d30680	270	" INTLCK_CTRL: %d, mapped LUN: %llu, got CDB: 0x%02x"
c66ac9db	271	" reported ASC: 0x%02x, ASCQ: 0x%02x\n",
e3d6f909	272	nacl->se_tpg->se_tpg_tfo->get_fabric_name(),
0fd97ccf CH	273	(dev->dev_attrib.emulate_ua_intlck_ctrl != 0) ? "Reporting" :
0fd97ccf CH	274	"Releasing", dev->dev_attrib.emulate_ua_intlck_ctrl,
a1d8b49a	275	cmd->orig_fe_lun, cmd->t_task_cdb[0], asc, ascq);
c66ac9db NB	276	}
	277
	278	int core_scsi3_ua_clear_for_request_sense(
	279	struct se_cmd *cmd,
	280	u8 *asc,
	281	u8 *ascq)
	282	{
	283	struct se_dev_entry *deve;
	284	struct se_session *sess = cmd->se_sess;
	285	struct se_node_acl *nacl;
	286	struct se_ua ua = NULL, ua_p;
	287	int head = 1;
	288
6708bb27	289	if (!sess)
e3d6f909	290	return -EINVAL;
c66ac9db NB	291
c66ac9db NB	292	nacl = sess->se_node_acl;
6708bb27	293	if (!nacl)
e3d6f909	294	return -EINVAL;
c66ac9db	295
29a05dee NB	296	rcu_read_lock();
	297	deve = target_nacl_find_deve(nacl, cmd->orig_fe_lun);
	298	if (!deve) {
	299	rcu_read_unlock();
	300	return -EINVAL;
	301	}
6708bb27	302	if (!atomic_read(&deve->ua_count)) {
29a05dee	303	rcu_read_unlock();
e3d6f909	304	return -EPERM;
c66ac9db NB	305	}
	306	/*
	307	* The highest priority Unit Attentions are placed at the head of the
	308	* struct se_dev_entry->ua_list. The First (and hence highest priority)
	309	* ASC/ASCQ will be returned in REQUEST_SENSE payload data for the
	310	* matching struct se_lun.
	311	*
	312	* Once the returning ASC/ASCQ values are set, we go ahead and
25985edc	313	* release all of the Unit Attention conditions for the associated
c66ac9db NB	314	* struct se_lun.
	315	*/
	316	spin_lock(&deve->ua_lock);
	317	list_for_each_entry_safe(ua, ua_p, &deve->ua_list, ua_nacl_list) {
	318	if (head) {
	319	*asc = ua->ua_asc;
	320	*ascq = ua->ua_ascq;
	321	head = 0;
	322	}
	323	list_del(&ua->ua_nacl_list);
	324	kmem_cache_free(se_ua_cache, ua);
	325
33940d09	326	atomic_dec_mb(&deve->ua_count);
c66ac9db NB	327	}
c66ac9db NB	328	spin_unlock(&deve->ua_lock);
29a05dee	329	rcu_read_unlock();
c66ac9db	330
6708bb27	331	pr_debug("[%s]: Released UNIT ATTENTION condition, mapped"
f2d30680	332	" LUN: %llu, got REQUEST_SENSE reported ASC: 0x%02x,"
e3d6f909	333	" ASCQ: 0x%02x\n", nacl->se_tpg->se_tpg_tfo->get_fabric_name(),
c66ac9db NB	334	cmd->orig_fe_lun, asc, ascq);
c66ac9db NB	335
e3d6f909	336	return (head) ? -EPERM : 0;
c66ac9db	337	}