From 47032d04b2de9a51ed371c73c129b3f74e1a5a5d Mon Sep 17 00:00:00 2001 From: Nicholas Bellinger Date: Mon, 30 Aug 2010 08:04:02 +0000 Subject: [RFC 13/22] tcm: Add UNIT_ATTENTION infrastructure support This patch adds support for SPC-3 compliant UNIT Attention emulation that is used by Persistent Reservations, ALUA, and TCM fabric module code. Signed-off-by: Nicholas A. Bellinger --- drivers/target/target_core_ua.c | 332 +++++++++++++++++++++++++++++++++++++++ drivers/target/target_core_ua.h | 36 +++++ 2 files changed, 368 insertions(+), 0 deletions(-) create mode 100644 drivers/target/target_core_ua.c create mode 100644 drivers/target/target_core_ua.h diff --git a/drivers/target/target_core_ua.c b/drivers/target/target_core_ua.c new file mode 100644 index 0000000..2de23bd --- /dev/null +++ b/drivers/target/target_core_ua.c @@ -0,0 +1,332 @@ +/******************************************************************************* + * Filename: target_core_ua.c + * + * This file contains logic for SPC-3 Unit Attention emulation + * + * Copyright (c) 2009,2010 Rising Tide Systems + * Copyright (c) 2009,2010 Linux-iSCSI.org + * + * Nicholas A. Bellinger + * + * 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 +#include +#include +#include +#include + +#include +#include +#include +#include +#include + +#include "target_core_alua.h" +#include "target_core_hba.h" +#include "target_core_pr.h" +#include "target_core_ua.h" + +int core_scsi3_ua_check( + struct se_cmd *cmd, + unsigned char *cdb) +{ + 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 (cdb[0]) { + case INQUIRY: + case REPORT_LUNS: + case REQUEST_SENSE: + return 0; + default: + return -1; + } + + return -1; +} + +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 -1; + + ua = kmem_cache_zalloc(se_ua_cache, GFP_ATOMIC); + if (!(ua)) { + printk(KERN_ERR "Unable to allocate struct se_ua\n"); + return -1; + } + INIT_LIST_HEAD(&ua->ua_dev_list); + INIT_LIST_HEAD(&ua->ua_nacl_list); + + ua->ua_nacl = nacl; + ua->ua_asc = asc; + ua->ua_ascq = ascq; + + spin_lock(&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(&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(&nacl->device_list_lock); + + atomic_inc(&deve->ua_count); + smp_mb__after_atomic_inc(); + return 0; + } + list_add_tail(&ua->ua_nacl_list, &deve->ua_list); + spin_unlock(&deve->ua_lock); + spin_unlock(&nacl->device_list_lock); + + printk(KERN_INFO "[%s]: Allocated UNIT ATTENTION, mapped LUN: %u, ASC:" + " 0x%02x, ASCQ: 0x%02x\n", + TPG_TFO(nacl->se_tpg)->get_fabric_name(), unpacked_lun, + asc, ascq); + + atomic_inc(&deve->ua_count); + smp_mb__after_atomic_inc(); + 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_dec(); + } + spin_unlock(&deve->ua_lock); +} + +void core_scsi3_ua_for_check_condition( + struct se_cmd *cmd, + u8 *asc, + u8 *ascq) +{ + struct se_device *dev = SE_DEV(cmd); + 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(&nacl->device_list_lock); + deve = &nacl->device_list[cmd->orig_fe_lun]; + if (!(atomic_read(&deve->ua_count))) { + spin_unlock(&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_ATTRIB(dev)->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 higest 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_dec(); + } + spin_unlock(&deve->ua_lock); + spin_unlock(&nacl->device_list_lock); + + printk(KERN_INFO "[%s]: %s UNIT ATTENTION condition with" + " INTLCK_CTRL: %d, mapped LUN: %u, got CDB: 0x%02x" + " reported ASC: 0x%02x, ASCQ: 0x%02x\n", + TPG_TFO(nacl->se_tpg)->get_fabric_name(), + (DEV_ATTRIB(dev)->emulate_ua_intlck_ctrl != 0) ? "Reporting" : + "Releasing", DEV_ATTRIB(dev)->emulate_ua_intlck_ctrl, + cmd->orig_fe_lun, T_TASK(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 -1; + + nacl = sess->se_node_acl; + if (!(nacl)) + return -1; + + spin_lock(&nacl->device_list_lock); + deve = &nacl->device_list[cmd->orig_fe_lun]; + if (!(atomic_read(&deve->ua_count))) { + spin_unlock(&nacl->device_list_lock); + return -1; + } + /* + * 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 assoicated + * 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_dec(); + } + spin_unlock(&deve->ua_lock); + spin_unlock(&nacl->device_list_lock); + + printk(KERN_INFO "[%s]: Released UNIT ATTENTION condition, mapped" + " LUN: %u, got REQUEST_SENSE reported ASC: 0x%02x," + " ASCQ: 0x%02x\n", TPG_TFO(nacl->se_tpg)->get_fabric_name(), + cmd->orig_fe_lun, *asc, *ascq); + + return (head) ? -1 : 0; +} diff --git a/drivers/target/target_core_ua.h b/drivers/target/target_core_ua.h new file mode 100644 index 0000000..6e6b034 --- /dev/null +++ b/drivers/target/target_core_ua.h @@ -0,0 +1,36 @@ +#ifndef TARGET_CORE_UA_H + +/* + * From spc4r17, Table D.1: ASC and ASCQ Assignement + */ +#define ASCQ_29H_POWER_ON_RESET_OR_BUS_DEVICE_RESET_OCCURED 0x00 +#define ASCQ_29H_POWER_ON_OCCURRED 0x01 +#define ASCQ_29H_SCSI_BUS_RESET_OCCURED 0x02 +#define ASCQ_29H_BUS_DEVICE_RESET_FUNCTION_OCCURRED 0x03 +#define ASCQ_29H_DEVICE_INTERNAL_RESET 0x04 +#define ASCQ_29H_TRANSCEIVER_MODE_CHANGED_TO_SINGLE_ENDED 0x05 +#define ASCQ_29H_TRANSCEIVER_MODE_CHANGED_TO_LVD 0x06 +#define ASCQ_29H_NEXUS_LOSS_OCCURRED 0x07 + +#define ASCQ_2AH_PARAMETERS_CHANGED 0x00 +#define ASCQ_2AH_MODE_PARAMETERS_CHANGED 0x01 +#define ASCQ_2AH_LOG_PARAMETERS_CHANGED 0x02 +#define ASCQ_2AH_RESERVATIONS_PREEMPTED 0x03 +#define ASCQ_2AH_RESERVATIONS_RELEASED 0x04 +#define ASCQ_2AH_REGISTRATIONS_PREEMPTED 0x05 +#define ASCQ_2AH_ASYMMETRIC_ACCESS_STATE_CHANGED 0x06 +#define ASCQ_2AH_IMPLICT_ASYMMETRIC_ACCESS_STATE_TRANSITION_FAILED 0x07 +#define ASCQ_2AH_PRIORITY_CHANGED 0x08 + +#define ASCQ_2CH_PREVIOUS_RESERVATION_CONFLICT_STATUS 0x09 + +extern struct kmem_cache *se_ua_cache; + +extern int core_scsi3_ua_check(struct se_cmd *, unsigned char *); +extern int core_scsi3_ua_allocate(struct se_node_acl *, u32, u8, u8); +extern void core_scsi3_ua_release_all(struct se_dev_entry *); +extern void core_scsi3_ua_for_check_condition(struct se_cmd *, u8 *, u8 *); +extern int core_scsi3_ua_clear_for_request_sense(struct se_cmd *, + u8 *, u8 *); + +#endif /* TARGET_CORE_UA_H */ -- 1.7.2.2