4e857c58ef
Mostly scripted conversion of the smp_mb__* barriers. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Link: http://lkml.kernel.org/n/tip-55dhyhocezdw1dg7u19hmh1u@git.kernel.org Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: linux-arch@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
324 lines
8.9 KiB
C
324 lines
8.9 KiB
C
/*******************************************************************************
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* Filename: target_core_ua.c
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*
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* This file contains logic for SPC-3 Unit Attention emulation
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*
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* (c) Copyright 2009-2013 Datera, Inc.
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*
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* Nicholas A. Bellinger <nab@kernel.org>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
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*
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******************************************************************************/
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#include <linux/slab.h>
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#include <linux/spinlock.h>
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#include <scsi/scsi.h>
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#include <scsi/scsi_cmnd.h>
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#include <target/target_core_base.h>
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#include <target/target_core_fabric.h>
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#include <target/target_core_configfs.h>
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#include "target_core_internal.h"
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#include "target_core_alua.h"
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#include "target_core_pr.h"
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#include "target_core_ua.h"
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sense_reason_t
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target_scsi3_ua_check(struct se_cmd *cmd)
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{
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struct se_dev_entry *deve;
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struct se_session *sess = cmd->se_sess;
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struct se_node_acl *nacl;
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if (!sess)
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return 0;
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nacl = sess->se_node_acl;
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if (!nacl)
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return 0;
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deve = nacl->device_list[cmd->orig_fe_lun];
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if (!atomic_read(&deve->ua_count))
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return 0;
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/*
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* From sam4r14, section 5.14 Unit attention condition:
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*
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* a) if an INQUIRY command enters the enabled command state, the
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* device server shall process the INQUIRY command and shall neither
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* report nor clear any unit attention condition;
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* b) if a REPORT LUNS command enters the enabled command state, the
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* device server shall process the REPORT LUNS command and shall not
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* report any unit attention condition;
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* e) if a REQUEST SENSE command enters the enabled command state while
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* a unit attention condition exists for the SCSI initiator port
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* associated with the I_T nexus on which the REQUEST SENSE command
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* was received, then the device server shall process the command
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* and either:
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*/
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switch (cmd->t_task_cdb[0]) {
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case INQUIRY:
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case REPORT_LUNS:
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case REQUEST_SENSE:
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return 0;
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default:
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return TCM_CHECK_CONDITION_UNIT_ATTENTION;
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}
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}
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int core_scsi3_ua_allocate(
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struct se_node_acl *nacl,
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u32 unpacked_lun,
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u8 asc,
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u8 ascq)
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{
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struct se_dev_entry *deve;
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struct se_ua *ua, *ua_p, *ua_tmp;
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/*
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* PASSTHROUGH OPS
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*/
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if (!nacl)
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return -EINVAL;
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ua = kmem_cache_zalloc(se_ua_cache, GFP_ATOMIC);
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if (!ua) {
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pr_err("Unable to allocate struct se_ua\n");
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return -ENOMEM;
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}
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INIT_LIST_HEAD(&ua->ua_nacl_list);
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ua->ua_nacl = nacl;
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ua->ua_asc = asc;
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ua->ua_ascq = ascq;
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spin_lock_irq(&nacl->device_list_lock);
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deve = nacl->device_list[unpacked_lun];
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spin_lock(&deve->ua_lock);
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list_for_each_entry_safe(ua_p, ua_tmp, &deve->ua_list, ua_nacl_list) {
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/*
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* Do not report the same UNIT ATTENTION twice..
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*/
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if ((ua_p->ua_asc == asc) && (ua_p->ua_ascq == ascq)) {
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spin_unlock(&deve->ua_lock);
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spin_unlock_irq(&nacl->device_list_lock);
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kmem_cache_free(se_ua_cache, ua);
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return 0;
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}
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/*
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* Attach the highest priority Unit Attention to
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* the head of the list following sam4r14,
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* Section 5.14 Unit Attention Condition:
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*
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* POWER ON, RESET, OR BUS DEVICE RESET OCCURRED highest
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* POWER ON OCCURRED or
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* DEVICE INTERNAL RESET
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* SCSI BUS RESET OCCURRED or
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* MICROCODE HAS BEEN CHANGED or
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* protocol specific
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* BUS DEVICE RESET FUNCTION OCCURRED
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* I_T NEXUS LOSS OCCURRED
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* COMMANDS CLEARED BY POWER LOSS NOTIFICATION
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* all others Lowest
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*
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* Each of the ASCQ codes listed above are defined in
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* the 29h ASC family, see spc4r17 Table D.1
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*/
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if (ua_p->ua_asc == 0x29) {
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if ((asc == 0x29) && (ascq > ua_p->ua_ascq))
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list_add(&ua->ua_nacl_list,
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&deve->ua_list);
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else
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list_add_tail(&ua->ua_nacl_list,
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&deve->ua_list);
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} else if (ua_p->ua_asc == 0x2a) {
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/*
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* Incoming Family 29h ASCQ codes will override
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* Family 2AHh ASCQ codes for Unit Attention condition.
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*/
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if ((asc == 0x29) || (ascq > ua_p->ua_asc))
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list_add(&ua->ua_nacl_list,
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&deve->ua_list);
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else
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list_add_tail(&ua->ua_nacl_list,
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&deve->ua_list);
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} else
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list_add_tail(&ua->ua_nacl_list,
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&deve->ua_list);
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spin_unlock(&deve->ua_lock);
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spin_unlock_irq(&nacl->device_list_lock);
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atomic_inc(&deve->ua_count);
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smp_mb__after_atomic();
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return 0;
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}
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list_add_tail(&ua->ua_nacl_list, &deve->ua_list);
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spin_unlock(&deve->ua_lock);
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spin_unlock_irq(&nacl->device_list_lock);
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pr_debug("[%s]: Allocated UNIT ATTENTION, mapped LUN: %u, ASC:"
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" 0x%02x, ASCQ: 0x%02x\n",
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nacl->se_tpg->se_tpg_tfo->get_fabric_name(), unpacked_lun,
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asc, ascq);
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atomic_inc(&deve->ua_count);
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smp_mb__after_atomic();
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return 0;
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}
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void core_scsi3_ua_release_all(
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struct se_dev_entry *deve)
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{
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struct se_ua *ua, *ua_p;
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spin_lock(&deve->ua_lock);
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list_for_each_entry_safe(ua, ua_p, &deve->ua_list, ua_nacl_list) {
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list_del(&ua->ua_nacl_list);
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kmem_cache_free(se_ua_cache, ua);
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atomic_dec(&deve->ua_count);
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smp_mb__after_atomic();
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}
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spin_unlock(&deve->ua_lock);
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}
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void core_scsi3_ua_for_check_condition(
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struct se_cmd *cmd,
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u8 *asc,
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u8 *ascq)
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{
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struct se_device *dev = cmd->se_dev;
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struct se_dev_entry *deve;
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struct se_session *sess = cmd->se_sess;
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struct se_node_acl *nacl;
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struct se_ua *ua = NULL, *ua_p;
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int head = 1;
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if (!sess)
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return;
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nacl = sess->se_node_acl;
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if (!nacl)
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return;
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spin_lock_irq(&nacl->device_list_lock);
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deve = nacl->device_list[cmd->orig_fe_lun];
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if (!atomic_read(&deve->ua_count)) {
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spin_unlock_irq(&nacl->device_list_lock);
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return;
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}
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/*
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* The highest priority Unit Attentions are placed at the head of the
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* struct se_dev_entry->ua_list, and will be returned in CHECK_CONDITION +
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* sense data for the received CDB.
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*/
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spin_lock(&deve->ua_lock);
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list_for_each_entry_safe(ua, ua_p, &deve->ua_list, ua_nacl_list) {
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/*
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* For ua_intlck_ctrl code not equal to 00b, only report the
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* highest priority UNIT_ATTENTION and ASC/ASCQ without
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* clearing it.
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*/
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if (dev->dev_attrib.emulate_ua_intlck_ctrl != 0) {
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*asc = ua->ua_asc;
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*ascq = ua->ua_ascq;
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break;
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}
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/*
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* Otherwise for the default 00b, release the UNIT ATTENTION
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* condition. Return the ASC/ASCQ of the highest priority UA
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* (head of the list) in the outgoing CHECK_CONDITION + sense.
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*/
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if (head) {
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*asc = ua->ua_asc;
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*ascq = ua->ua_ascq;
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head = 0;
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}
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list_del(&ua->ua_nacl_list);
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kmem_cache_free(se_ua_cache, ua);
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atomic_dec(&deve->ua_count);
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smp_mb__after_atomic();
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}
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spin_unlock(&deve->ua_lock);
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spin_unlock_irq(&nacl->device_list_lock);
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pr_debug("[%s]: %s UNIT ATTENTION condition with"
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" INTLCK_CTRL: %d, mapped LUN: %u, got CDB: 0x%02x"
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" reported ASC: 0x%02x, ASCQ: 0x%02x\n",
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nacl->se_tpg->se_tpg_tfo->get_fabric_name(),
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(dev->dev_attrib.emulate_ua_intlck_ctrl != 0) ? "Reporting" :
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"Releasing", dev->dev_attrib.emulate_ua_intlck_ctrl,
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cmd->orig_fe_lun, cmd->t_task_cdb[0], *asc, *ascq);
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}
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int core_scsi3_ua_clear_for_request_sense(
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struct se_cmd *cmd,
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u8 *asc,
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u8 *ascq)
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{
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struct se_dev_entry *deve;
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struct se_session *sess = cmd->se_sess;
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struct se_node_acl *nacl;
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struct se_ua *ua = NULL, *ua_p;
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int head = 1;
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if (!sess)
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return -EINVAL;
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nacl = sess->se_node_acl;
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if (!nacl)
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return -EINVAL;
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spin_lock_irq(&nacl->device_list_lock);
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deve = nacl->device_list[cmd->orig_fe_lun];
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if (!atomic_read(&deve->ua_count)) {
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spin_unlock_irq(&nacl->device_list_lock);
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return -EPERM;
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}
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/*
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* The highest priority Unit Attentions are placed at the head of the
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* struct se_dev_entry->ua_list. The First (and hence highest priority)
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* ASC/ASCQ will be returned in REQUEST_SENSE payload data for the
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* matching struct se_lun.
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*
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* Once the returning ASC/ASCQ values are set, we go ahead and
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* release all of the Unit Attention conditions for the associated
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* struct se_lun.
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*/
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spin_lock(&deve->ua_lock);
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list_for_each_entry_safe(ua, ua_p, &deve->ua_list, ua_nacl_list) {
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if (head) {
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*asc = ua->ua_asc;
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*ascq = ua->ua_ascq;
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head = 0;
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}
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list_del(&ua->ua_nacl_list);
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kmem_cache_free(se_ua_cache, ua);
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atomic_dec(&deve->ua_count);
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smp_mb__after_atomic();
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}
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spin_unlock(&deve->ua_lock);
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spin_unlock_irq(&nacl->device_list_lock);
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pr_debug("[%s]: Released UNIT ATTENTION condition, mapped"
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" LUN: %u, got REQUEST_SENSE reported ASC: 0x%02x,"
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" ASCQ: 0x%02x\n", nacl->se_tpg->se_tpg_tfo->get_fabric_name(),
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cmd->orig_fe_lun, *asc, *ascq);
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return (head) ? -EPERM : 0;
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}
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