diff options
Diffstat (limited to 'drivers/target/target_core_ua.c')
| -rw-r--r-- | drivers/target/target_core_ua.c | 334 |
1 files changed, 334 insertions, 0 deletions
diff --git a/drivers/target/target_core_ua.c b/drivers/target/target_core_ua.c new file mode 100644 index 000000000..c8ac242ce --- /dev/null +++ b/drivers/target/target_core_ua.c @@ -0,0 +1,334 @@ +/******************************************************************************* + * 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 (list_empty_careful(&deve->ua_list)) { + 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); + + 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); + + 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); + } + spin_unlock(&deve->ua_lock); +} + +/* + * Dequeue a unit attention from the unit attention list. This function + * returns true if the dequeuing succeeded and if *@key, *@asc and *@ascq have + * been set. + */ +bool core_scsi3_ua_for_check_condition(struct se_cmd *cmd, u8 *key, 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 (WARN_ON_ONCE(!sess)) + return false; + + nacl = sess->se_node_acl; + if (WARN_ON_ONCE(!nacl)) + return false; + + rcu_read_lock(); + deve = target_nacl_find_deve(nacl, cmd->orig_fe_lun); + if (!deve) { + rcu_read_unlock(); + *key = ILLEGAL_REQUEST; + *asc = 0x25; /* LOGICAL UNIT NOT SUPPORTED */ + *ascq = 0; + return true; + } + *key = UNIT_ATTENTION; + /* + * 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); + } + 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); + + return head == 0; +} + +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 (list_empty_careful(&deve->ua_list)) { + 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); + } + 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; +} |