[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.h>
#include <scsi/scsi_cmnd.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_node_acl *nacl,
	u64 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_asc = asc;
	ua->ua_ascq = ascq;

	rcu_read_lock();
	deve = target_nacl_find_deve(nacl, unpacked_lun);
	if (!deve) {
		rcu_read_unlock();
		return -EINVAL;
	}
	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);
			rcu_read_unlock();
			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);
		rcu_read_unlock();
		return 0;
	}
	list_add_tail(&ua->ua_nacl_list, &deve->ua_list);
	spin_unlock(&deve->ua_lock);

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

	atomic_inc_mb(&deve->ua_count);
	rcu_read_unlock();
	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_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>
	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	33
e26d99ae	34	#include "target_core_internal.h"
c66ac9db	35	#include "target_core_alua.h"
c66ac9db NB	36	#include "target_core_pr.h"
	37	#include "target_core_ua.h"
	38
de103c93 CH	39	sense_reason_t
de103c93 CH	40	target_scsi3_ua_check(struct se_cmd *cmd)
c66ac9db NB	41	{
	42	struct se_dev_entry *deve;
	43	struct se_session *sess = cmd->se_sess;
	44	struct se_node_acl *nacl;
	45
6708bb27	46	if (!sess)
c66ac9db NB	47	return 0;
	48
	49	nacl = sess->se_node_acl;
6708bb27	50	if (!nacl)
c66ac9db NB	51	return 0;
c66ac9db NB	52
29a05dee NB	53	rcu_read_lock();
	54	deve = target_nacl_find_deve(nacl, cmd->orig_fe_lun);
	55	if (!deve) {
	56	rcu_read_unlock();
c66ac9db	57	return 0;
29a05dee NB	58	}
	59	if (!atomic_read(&deve->ua_count)) {
	60	rcu_read_unlock();
	61	return 0;
	62	}
	63	rcu_read_unlock();
c66ac9db NB	64	/*
	65	* From sam4r14, section 5.14 Unit attention condition:
	66	*
	67	* a) if an INQUIRY command enters the enabled command state, the
	68	* device server shall process the INQUIRY command and shall neither
	69	* report nor clear any unit attention condition;
	70	* b) if a REPORT LUNS command enters the enabled command state, the
	71	* device server shall process the REPORT LUNS command and shall not
	72	* report any unit attention condition;
	73	* e) if a REQUEST SENSE command enters the enabled command state while
	74	* a unit attention condition exists for the SCSI initiator port
	75	* associated with the I_T nexus on which the REQUEST SENSE command
	76	* was received, then the device server shall process the command
	77	* and either:
	78	*/
de103c93	79	switch (cmd->t_task_cdb[0]) {
c66ac9db NB	80	case INQUIRY:
	81	case REPORT_LUNS:
	82	case REQUEST_SENSE:
	83	return 0;
	84	default:
de103c93	85	return TCM_CHECK_CONDITION_UNIT_ATTENTION;
c66ac9db	86	}
c66ac9db NB	87	}
	88
	89	int core_scsi3_ua_allocate(
	90	struct se_node_acl *nacl,
f2d30680	91	u64 unpacked_lun,
c66ac9db NB	92	u8 asc,
	93	u8 ascq)
	94	{
	95	struct se_dev_entry *deve;
	96	struct se_ua ua, ua_p, *ua_tmp;
	97	/*
	98	* PASSTHROUGH OPS
	99	*/
6708bb27	100	if (!nacl)
e3d6f909	101	return -EINVAL;
c66ac9db NB	102
c66ac9db NB	103	ua = kmem_cache_zalloc(se_ua_cache, GFP_ATOMIC);
6708bb27 AG	104	if (!ua) {
6708bb27 AG	105	pr_err("Unable to allocate struct se_ua\n");
e3d6f909	106	return -ENOMEM;
c66ac9db	107	}
c66ac9db NB	108	INIT_LIST_HEAD(&ua->ua_nacl_list);
c66ac9db NB	109
c66ac9db NB	110	ua->ua_asc = asc;
	111	ua->ua_ascq = ascq;
	112
29a05dee NB	113	rcu_read_lock();
	114	deve = target_nacl_find_deve(nacl, unpacked_lun);
	115	if (!deve) {
	116	rcu_read_unlock();
	117	return -EINVAL;
	118	}
c66ac9db NB	119	spin_lock(&deve->ua_lock);
	120	list_for_each_entry_safe(ua_p, ua_tmp, &deve->ua_list, ua_nacl_list) {
	121	/*
	122	* Do not report the same UNIT ATTENTION twice..
	123	*/
	124	if ((ua_p->ua_asc == asc) && (ua_p->ua_ascq == ascq)) {
	125	spin_unlock(&deve->ua_lock);
29a05dee	126	rcu_read_unlock();
c66ac9db NB	127	kmem_cache_free(se_ua_cache, ua);
	128	return 0;
	129	}
	130	/*
	131	* Attach the highest priority Unit Attention to
	132	* the head of the list following sam4r14,
	133	* Section 5.14 Unit Attention Condition:
	134	*
	135	* POWER ON, RESET, OR BUS DEVICE RESET OCCURRED highest
	136	* POWER ON OCCURRED or
	137	* DEVICE INTERNAL RESET
	138	* SCSI BUS RESET OCCURRED or
	139	* MICROCODE HAS BEEN CHANGED or
	140	* protocol specific
	141	* BUS DEVICE RESET FUNCTION OCCURRED
	142	* I_T NEXUS LOSS OCCURRED
	143	* COMMANDS CLEARED BY POWER LOSS NOTIFICATION
	144	* all others Lowest
	145	*
	146	* Each of the ASCQ codes listed above are defined in
	147	* the 29h ASC family, see spc4r17 Table D.1
	148	*/
	149	if (ua_p->ua_asc == 0x29) {
	150	if ((asc == 0x29) && (ascq > ua_p->ua_ascq))
	151	list_add(&ua->ua_nacl_list,
	152	&deve->ua_list);
	153	else
	154	list_add_tail(&ua->ua_nacl_list,
	155	&deve->ua_list);
	156	} else if (ua_p->ua_asc == 0x2a) {
	157	/*
	158	* Incoming Family 29h ASCQ codes will override
	159	* Family 2AHh ASCQ codes for Unit Attention condition.
	160	*/
	161	if ((asc == 0x29) \|\| (ascq > ua_p->ua_asc))
	162	list_add(&ua->ua_nacl_list,
	163	&deve->ua_list);
	164	else
	165	list_add_tail(&ua->ua_nacl_list,
	166	&deve->ua_list);
	167	} else
	168	list_add_tail(&ua->ua_nacl_list,
	169	&deve->ua_list);
	170	spin_unlock(&deve->ua_lock);
c66ac9db	171
33940d09	172	atomic_inc_mb(&deve->ua_count);
29a05dee	173	rcu_read_unlock();
c66ac9db NB	174	return 0;
	175	}
	176	list_add_tail(&ua->ua_nacl_list, &deve->ua_list);
	177	spin_unlock(&deve->ua_lock);
c66ac9db	178
f2d30680	179	pr_debug("[%s]: Allocated UNIT ATTENTION, mapped LUN: %llu, ASC:"
c66ac9db	180	" 0x%02x, ASCQ: 0x%02x\n",
e3d6f909	181	nacl->se_tpg->se_tpg_tfo->get_fabric_name(), unpacked_lun,
c66ac9db NB	182	asc, ascq);
c66ac9db NB	183
33940d09	184	atomic_inc_mb(&deve->ua_count);
29a05dee	185	rcu_read_unlock();
c66ac9db NB	186	return 0;
	187	}
	188
	189	void core_scsi3_ua_release_all(
	190	struct se_dev_entry *deve)
	191	{
	192	struct se_ua ua, ua_p;
	193
	194	spin_lock(&deve->ua_lock);
	195	list_for_each_entry_safe(ua, ua_p, &deve->ua_list, ua_nacl_list) {
	196	list_del(&ua->ua_nacl_list);
	197	kmem_cache_free(se_ua_cache, ua);
	198
33940d09	199	atomic_dec_mb(&deve->ua_count);
c66ac9db NB	200	}
	201	spin_unlock(&deve->ua_lock);
	202	}
	203
	204	void core_scsi3_ua_for_check_condition(
	205	struct se_cmd *cmd,
	206	u8 *asc,
	207	u8 *ascq)
	208	{
5951146d	209	struct se_device *dev = cmd->se_dev;
c66ac9db NB	210	struct se_dev_entry *deve;
	211	struct se_session *sess = cmd->se_sess;
	212	struct se_node_acl *nacl;
	213	struct se_ua ua = NULL, ua_p;
	214	int head = 1;
	215
6708bb27	216	if (!sess)
c66ac9db NB	217	return;
	218
	219	nacl = sess->se_node_acl;
6708bb27	220	if (!nacl)
c66ac9db NB	221	return;
c66ac9db NB	222
29a05dee NB	223	rcu_read_lock();
	224	deve = target_nacl_find_deve(nacl, cmd->orig_fe_lun);
	225	if (!deve) {
	226	rcu_read_unlock();
	227	return;
	228	}
6708bb27	229	if (!atomic_read(&deve->ua_count)) {
29a05dee	230	rcu_read_unlock();
c66ac9db NB	231	return;
	232	}
	233	/*
	234	* The highest priority Unit Attentions are placed at the head of the
	235	* struct se_dev_entry->ua_list, and will be returned in CHECK_CONDITION +
	236	* sense data for the received CDB.
	237	*/
	238	spin_lock(&deve->ua_lock);
	239	list_for_each_entry_safe(ua, ua_p, &deve->ua_list, ua_nacl_list) {
	240	/*
	241	* For ua_intlck_ctrl code not equal to 00b, only report the
	242	* highest priority UNIT_ATTENTION and ASC/ASCQ without
	243	* clearing it.
	244	*/
0fd97ccf	245	if (dev->dev_attrib.emulate_ua_intlck_ctrl != 0) {
c66ac9db NB	246	*asc = ua->ua_asc;
	247	*ascq = ua->ua_ascq;
	248	break;
	249	}
	250	/*
	251	* Otherwise for the default 00b, release the UNIT ATTENTION
25985edc	252	* condition. Return the ASC/ASCQ of the highest priority UA
c66ac9db NB	253	* (head of the list) in the outgoing CHECK_CONDITION + sense.
	254	*/
	255	if (head) {
	256	*asc = ua->ua_asc;
	257	*ascq = ua->ua_ascq;
	258	head = 0;
	259	}
	260	list_del(&ua->ua_nacl_list);
	261	kmem_cache_free(se_ua_cache, ua);
	262
33940d09	263	atomic_dec_mb(&deve->ua_count);
c66ac9db NB	264	}
c66ac9db NB	265	spin_unlock(&deve->ua_lock);
29a05dee	266	rcu_read_unlock();
c66ac9db	267
6708bb27	268	pr_debug("[%s]: %s UNIT ATTENTION condition with"
f2d30680	269	" INTLCK_CTRL: %d, mapped LUN: %llu, got CDB: 0x%02x"
c66ac9db	270	" reported ASC: 0x%02x, ASCQ: 0x%02x\n",
e3d6f909	271	nacl->se_tpg->se_tpg_tfo->get_fabric_name(),
0fd97ccf CH	272	(dev->dev_attrib.emulate_ua_intlck_ctrl != 0) ? "Reporting" :
0fd97ccf CH	273	"Releasing", dev->dev_attrib.emulate_ua_intlck_ctrl,
a1d8b49a	274	cmd->orig_fe_lun, cmd->t_task_cdb[0], asc, ascq);
c66ac9db NB	275	}
	276
	277	int core_scsi3_ua_clear_for_request_sense(
	278	struct se_cmd *cmd,
	279	u8 *asc,
	280	u8 *ascq)
	281	{
	282	struct se_dev_entry *deve;
	283	struct se_session *sess = cmd->se_sess;
	284	struct se_node_acl *nacl;
	285	struct se_ua ua = NULL, ua_p;
	286	int head = 1;
	287
6708bb27	288	if (!sess)
e3d6f909	289	return -EINVAL;
c66ac9db NB	290
c66ac9db NB	291	nacl = sess->se_node_acl;
6708bb27	292	if (!nacl)
e3d6f909	293	return -EINVAL;
c66ac9db	294
29a05dee NB	295	rcu_read_lock();
	296	deve = target_nacl_find_deve(nacl, cmd->orig_fe_lun);
	297	if (!deve) {
	298	rcu_read_unlock();
	299	return -EINVAL;
	300	}
6708bb27	301	if (!atomic_read(&deve->ua_count)) {
29a05dee	302	rcu_read_unlock();
e3d6f909	303	return -EPERM;
c66ac9db NB	304	}
	305	/*
	306	* The highest priority Unit Attentions are placed at the head of the
	307	* struct se_dev_entry->ua_list. The First (and hence highest priority)
	308	* ASC/ASCQ will be returned in REQUEST_SENSE payload data for the
	309	* matching struct se_lun.
	310	*
	311	* Once the returning ASC/ASCQ values are set, we go ahead and
25985edc	312	* release all of the Unit Attention conditions for the associated
c66ac9db NB	313	* struct se_lun.
	314	*/
	315	spin_lock(&deve->ua_lock);
	316	list_for_each_entry_safe(ua, ua_p, &deve->ua_list, ua_nacl_list) {
	317	if (head) {
	318	*asc = ua->ua_asc;
	319	*ascq = ua->ua_ascq;
	320	head = 0;
	321	}
	322	list_del(&ua->ua_nacl_list);
	323	kmem_cache_free(se_ua_cache, ua);
	324
33940d09	325	atomic_dec_mb(&deve->ua_count);
c66ac9db NB	326	}
c66ac9db NB	327	spin_unlock(&deve->ua_lock);
29a05dee	328	rcu_read_unlock();
c66ac9db	329
6708bb27	330	pr_debug("[%s]: Released UNIT ATTENTION condition, mapped"
f2d30680	331	" LUN: %llu, got REQUEST_SENSE reported ASC: 0x%02x,"
e3d6f909	332	" ASCQ: 0x%02x\n", nacl->se_tpg->se_tpg_tfo->get_fabric_name(),
c66ac9db NB	333	cmd->orig_fe_lun, asc, ascq);
c66ac9db NB	334
e3d6f909	335	return (head) ? -EPERM : 0;
c66ac9db	336	}