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target_core_alua.c
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/*******************************************************************************
* Filename: target_core_alua.c
*
* This file contains SPC-3 compliant asymmetric logical unit assigntment (ALUA)
*
* Copyright (c) 2009-2010 Rising Tide Systems
* Copyright (c) 2009-2010 Linux-iSCSI.org
*
* 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/version.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/configfs.h>
#include <scsi/scsi.h>
#include <scsi/scsi_cmnd.h>
#include <target/target_core_base.h>
#include <target/target_core_device.h>
#include <target/target_core_transport.h>
#include <target/target_core_fabric_ops.h>
#include <target/target_core_configfs.h>
#include "target_core_alua.h"
#include "target_core_hba.h"
#include "target_core_ua.h"
static int core_alua_check_transition(int state, int *primary);
static int core_alua_set_tg_pt_secondary_state(
struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem,
struct se_port *port, int explict, int offline);
/*
* REPORT_TARGET_PORT_GROUPS
*
* See spc4r17 section 6.27
*/
int core_emulate_report_target_port_groups(struct se_cmd *cmd)
{
struct se_subsystem_dev *su_dev = SE_DEV(cmd)->se_sub_dev;
struct se_port *port;
struct t10_alua_tg_pt_gp *tg_pt_gp;
struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
unsigned char *buf = (unsigned char *)T_TASK(cmd)->t_task_buf;
u32 rd_len = 0, off = 4; /* Skip over RESERVED area to first
Target port group descriptor */
spin_lock(&T10_ALUA(su_dev)->tg_pt_gps_lock);
list_for_each_entry(tg_pt_gp, &T10_ALUA(su_dev)->tg_pt_gps_list,
tg_pt_gp_list) {
/*
* PREF: Preferred target port bit, determine if this
* bit should be set for port group.
*/
if (tg_pt_gp->tg_pt_gp_pref)
buf[off] = 0x80;
/*
* Set the ASYMMETRIC ACCESS State
*/
buf[off++] |= (atomic_read(
&tg_pt_gp->tg_pt_gp_alua_access_state) & 0xff);
/*
* Set supported ASYMMETRIC ACCESS State bits
*/
buf[off] = 0x80; /* T_SUP */
buf[off] |= 0x40; /* O_SUP */
buf[off] |= 0x8; /* U_SUP */
buf[off] |= 0x4; /* S_SUP */
buf[off] |= 0x2; /* AN_SUP */
buf[off++] |= 0x1; /* AO_SUP */
/*
* TARGET PORT GROUP
*/
buf[off++] = ((tg_pt_gp->tg_pt_gp_id >> 8) & 0xff);
buf[off++] = (tg_pt_gp->tg_pt_gp_id & 0xff);
off++; /* Skip over Reserved */
/*
* STATUS CODE
*/
buf[off++] = (tg_pt_gp->tg_pt_gp_alua_access_status & 0xff);
/*
* Vendor Specific field
*/
buf[off++] = 0x00;
/*
* TARGET PORT COUNT
*/
buf[off++] = (tg_pt_gp->tg_pt_gp_members & 0xff);
rd_len += 8;
spin_lock(&tg_pt_gp->tg_pt_gp_lock);
list_for_each_entry(tg_pt_gp_mem, &tg_pt_gp->tg_pt_gp_mem_list,
tg_pt_gp_mem_list) {
port = tg_pt_gp_mem->tg_pt;
/*
* Start Target Port descriptor format
*
* See spc4r17 section 6.2.7 Table 247
*/
off += 2; /* Skip over Obsolete */
/*
* Set RELATIVE TARGET PORT IDENTIFIER
*/
buf[off++] = ((port->sep_rtpi >> 8) & 0xff);
buf[off++] = (port->sep_rtpi & 0xff);
rd_len += 4;
}
spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
}
spin_unlock(&T10_ALUA(su_dev)->tg_pt_gps_lock);
/*
* Set the RETURN DATA LENGTH set in the header of the DataIN Payload
*/
buf[0] = ((rd_len >> 24) & 0xff);
buf[1] = ((rd_len >> 16) & 0xff);
buf[2] = ((rd_len >> 8) & 0xff);
buf[3] = (rd_len & 0xff);
return 0;
}
/*
* SET_TARGET_PORT_GROUPS for explict ALUA operation.
*
* See spc4r17 section 6.35
*/
int core_emulate_set_target_port_groups(struct se_cmd *cmd)
{
struct se_device *dev = SE_DEV(cmd);
struct se_subsystem_dev *su_dev = SE_DEV(cmd)->se_sub_dev;
struct se_port *port, *l_port = SE_LUN(cmd)->lun_sep;
struct se_node_acl *nacl = SE_SESS(cmd)->se_node_acl;
struct t10_alua_tg_pt_gp *tg_pt_gp = NULL, *l_tg_pt_gp;
struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem, *l_tg_pt_gp_mem;
unsigned char *buf = (unsigned char *)T_TASK(cmd)->t_task_buf;
unsigned char *ptr = &buf[4]; /* Skip over RESERVED area in header */
u32 len = 4; /* Skip over RESERVED area in header */
int alua_access_state, primary = 0, rc;
u16 tg_pt_id, rtpi;
if (!(l_port))
return PYX_TRANSPORT_LU_COMM_FAILURE;
/*
* Determine if explict ALUA via SET_TARGET_PORT_GROUPS is allowed
* for the local tg_pt_gp.
*/
l_tg_pt_gp_mem = l_port->sep_alua_tg_pt_gp_mem;
if (!(l_tg_pt_gp_mem)) {
printk(KERN_ERR "Unable to access l_port->sep_alua_tg_pt_gp_mem\n");
return PYX_TRANSPORT_UNKNOWN_SAM_OPCODE;
}
spin_lock(&l_tg_pt_gp_mem->tg_pt_gp_mem_lock);
l_tg_pt_gp = l_tg_pt_gp_mem->tg_pt_gp;
if (!(l_tg_pt_gp)) {
spin_unlock(&l_tg_pt_gp_mem->tg_pt_gp_mem_lock);
printk(KERN_ERR "Unable to access *l_tg_pt_gp_mem->tg_pt_gp\n");
return PYX_TRANSPORT_UNKNOWN_SAM_OPCODE;
}
rc = (l_tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_EXPLICT_ALUA);
spin_unlock(&l_tg_pt_gp_mem->tg_pt_gp_mem_lock);
if (!(rc)) {
printk(KERN_INFO "Unable to process SET_TARGET_PORT_GROUPS"
" while TPGS_EXPLICT_ALUA is disabled\n");
return PYX_TRANSPORT_UNKNOWN_SAM_OPCODE;
}
while (len < cmd->data_length) {
alua_access_state = (ptr[0] & 0x0f);
/*
* Check the received ALUA access state, and determine if
* the state is a primary or secondary target port asymmetric
* access state.
*/
rc = core_alua_check_transition(alua_access_state, &primary);
if (rc != 0) {
/*
* If the SET TARGET PORT GROUPS attempts to establish
* an invalid combination of target port asymmetric
* access states or attempts to establish an
* unsupported target port asymmetric access state,
* then the command shall be terminated with CHECK
* CONDITION status, with the sense key set to ILLEGAL
* REQUEST, and the additional sense code set to INVALID
* FIELD IN PARAMETER LIST.
*/
return PYX_TRANSPORT_INVALID_PARAMETER_LIST;
}
rc = -1;
/*
* If the ASYMMETRIC ACCESS STATE field (see table 267)
* specifies a primary target port asymmetric access state,
* then the TARGET PORT GROUP OR TARGET PORT field specifies
* a primary target port group for which the primary target
* port asymmetric access state shall be changed. If the
* ASYMMETRIC ACCESS STATE field specifies a secondary target
* port asymmetric access state, then the TARGET PORT GROUP OR
* TARGET PORT field specifies the relative target port
* identifier (see 3.1.120) of the target port for which the
* secondary target port asymmetric access state shall be
* changed.
*/
if (primary) {
tg_pt_id = ((ptr[2] << 8) & 0xff);
tg_pt_id |= (ptr[3] & 0xff);
/*
* Locate the matching target port group ID from
* the global tg_pt_gp list
*/
spin_lock(&T10_ALUA(su_dev)->tg_pt_gps_lock);
list_for_each_entry(tg_pt_gp,
&T10_ALUA(su_dev)->tg_pt_gps_list,
tg_pt_gp_list) {
if (!(tg_pt_gp->tg_pt_gp_valid_id))
continue;
if (tg_pt_id != tg_pt_gp->tg_pt_gp_id)
continue;
atomic_inc(&tg_pt_gp->tg_pt_gp_ref_cnt);
smp_mb__after_atomic_inc();
spin_unlock(&T10_ALUA(su_dev)->tg_pt_gps_lock);
rc = core_alua_do_port_transition(tg_pt_gp,
dev, l_port, nacl,
alua_access_state, 1);
spin_lock(&T10_ALUA(su_dev)->tg_pt_gps_lock);
atomic_dec(&tg_pt_gp->tg_pt_gp_ref_cnt);
smp_mb__after_atomic_dec();
break;
}
spin_unlock(&T10_ALUA(su_dev)->tg_pt_gps_lock);
/*
* If not matching target port group ID can be located
* throw an exception with ASCQ: INVALID_PARAMETER_LIST
*/
if (rc != 0)
return PYX_TRANSPORT_INVALID_PARAMETER_LIST;
} else {
/*
* Extact the RELATIVE TARGET PORT IDENTIFIER to identify
* the Target Port in question for the the incoming
* SET_TARGET_PORT_GROUPS op.
*/
rtpi = ((ptr[2] << 8) & 0xff);
rtpi |= (ptr[3] & 0xff);
/*
* Locate the matching relative target port identifer
* for the struct se_device storage object.
*/
spin_lock(&dev->se_port_lock);
list_for_each_entry(port, &dev->dev_sep_list,
sep_list) {
if (port->sep_rtpi != rtpi)
continue;
tg_pt_gp_mem = port->sep_alua_tg_pt_gp_mem;
spin_unlock(&dev->se_port_lock);
rc = core_alua_set_tg_pt_secondary_state(
tg_pt_gp_mem, port, 1, 1);
spin_lock(&dev->se_port_lock);
break;
}
spin_unlock(&dev->se_port_lock);
/*
* If not matching relative target port identifier can
* be located, throw an exception with ASCQ:
* INVALID_PARAMETER_LIST
*/
if (rc != 0)
return PYX_TRANSPORT_INVALID_PARAMETER_LIST;
}
ptr += 4;
len += 4;
}
return 0;
}
static inline int core_alua_state_nonoptimized(
struct se_cmd *cmd,
unsigned char *cdb,
int nonop_delay_msecs,
u8 *alua_ascq)
{
/*
* Set SCF_ALUA_NON_OPTIMIZED here, this value will be checked
* later to determine if processing of this cmd needs to be
* temporarily delayed for the Active/NonOptimized primary access state.
*/
cmd->se_cmd_flags |= SCF_ALUA_NON_OPTIMIZED;
cmd->alua_nonop_delay = nonop_delay_msecs;
return 0;
}
static inline int core_alua_state_standby(
struct se_cmd *cmd,
unsigned char *cdb,
u8 *alua_ascq)
{
/*
* Allowed CDBs for ALUA_ACCESS_STATE_STANDBY as defined by
* spc4r17 section 5.9.2.4.4
*/
switch (cdb[0]) {
case INQUIRY:
case LOG_SELECT:
case LOG_SENSE:
case MODE_SELECT:
case MODE_SENSE:
case REPORT_LUNS:
case RECEIVE_DIAGNOSTIC:
case SEND_DIAGNOSTIC:
case MAINTENANCE_IN:
switch (cdb[1]) {
case MI_REPORT_TARGET_PGS:
return 0;
default:
*alua_ascq = ASCQ_04H_ALUA_TG_PT_STANDBY;
return 1;
}
case MAINTENANCE_OUT:
switch (cdb[1]) {
case MO_SET_TARGET_PGS:
return 0;
default:
*alua_ascq = ASCQ_04H_ALUA_TG_PT_STANDBY;
return 1;
}
case REQUEST_SENSE:
case PERSISTENT_RESERVE_IN:
case PERSISTENT_RESERVE_OUT:
case READ_BUFFER:
case WRITE_BUFFER:
return 0;
default:
*alua_ascq = ASCQ_04H_ALUA_TG_PT_STANDBY;
return 1;
}
return 0;
}
static inline int core_alua_state_unavailable(
struct se_cmd *cmd,
unsigned char *cdb,
u8 *alua_ascq)
{
/*
* Allowed CDBs for ALUA_ACCESS_STATE_UNAVAILABLE as defined by
* spc4r17 section 5.9.2.4.5
*/
switch (cdb[0]) {
case INQUIRY:
case REPORT_LUNS:
case MAINTENANCE_IN:
switch (cdb[1]) {
case MI_REPORT_TARGET_PGS:
return 0;
default:
*alua_ascq = ASCQ_04H_ALUA_TG_PT_UNAVAILABLE;
return 1;
}
case MAINTENANCE_OUT:
switch (cdb[1]) {
case MO_SET_TARGET_PGS:
return 0;
default:
*alua_ascq = ASCQ_04H_ALUA_TG_PT_UNAVAILABLE;
return 1;
}
case REQUEST_SENSE:
case READ_BUFFER:
case WRITE_BUFFER:
return 0;
default:
*alua_ascq = ASCQ_04H_ALUA_TG_PT_UNAVAILABLE;
return 1;
}
return 0;
}
static inline int core_alua_state_transition(
struct se_cmd *cmd,
unsigned char *cdb,
u8 *alua_ascq)
{
/*
* Allowed CDBs for ALUA_ACCESS_STATE_TRANSITIO as defined by
* spc4r17 section 5.9.2.5
*/
switch (cdb[0]) {
case INQUIRY:
case REPORT_LUNS:
case MAINTENANCE_IN:
switch (cdb[1]) {
case MI_REPORT_TARGET_PGS:
return 0;
default:
*alua_ascq = ASCQ_04H_ALUA_STATE_TRANSITION;
return 1;
}
case REQUEST_SENSE:
case READ_BUFFER:
case WRITE_BUFFER:
return 0;
default:
*alua_ascq = ASCQ_04H_ALUA_STATE_TRANSITION;
return 1;
}
return 0;
}
/*
* Used for alua_type SPC_ALUA_PASSTHROUGH and SPC2_ALUA_DISABLED
* in transport_cmd_sequencer(). This function is assigned to
* struct t10_alua *->state_check() in core_setup_alua()
*/
static int core_alua_state_check_nop(
struct se_cmd *cmd,
unsigned char *cdb,
u8 *alua_ascq)
{
return 0;
}
/*
* Used for alua_type SPC3_ALUA_EMULATED in transport_cmd_sequencer().
* This function is assigned to struct t10_alua *->state_check() in
* core_setup_alua()
*
* Also, this function can return three different return codes to
* signal transport_generic_cmd_sequencer()
*
* return 1: Is used to signal LUN not accecsable, and check condition/not ready
* return 0: Used to signal success
* reutrn -1: Used to signal failure, and invalid cdb field
*/
static int core_alua_state_check(
struct se_cmd *cmd,
unsigned char *cdb,
u8 *alua_ascq)
{
struct se_lun *lun = SE_LUN(cmd);
struct se_port *port = lun->lun_sep;
struct t10_alua_tg_pt_gp *tg_pt_gp;
struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
int out_alua_state, nonop_delay_msecs;
if (!(port))
return 0;
/*
* First, check for a struct se_port specific secondary ALUA target port
* access state: OFFLINE
*/
if (atomic_read(&port->sep_tg_pt_secondary_offline)) {
*alua_ascq = ASCQ_04H_ALUA_OFFLINE;
printk(KERN_INFO "ALUA: Got secondary offline status for local"
" target port\n");
*alua_ascq = ASCQ_04H_ALUA_OFFLINE;
return 1;
}
/*
* Second, obtain the struct t10_alua_tg_pt_gp_member pointer to the
* ALUA target port group, to obtain current ALUA access state.
* Otherwise look for the underlying struct se_device association with
* a ALUA logical unit group.
*/
tg_pt_gp_mem = port->sep_alua_tg_pt_gp_mem;
spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
tg_pt_gp = tg_pt_gp_mem->tg_pt_gp;
out_alua_state = atomic_read(&tg_pt_gp->tg_pt_gp_alua_access_state);
nonop_delay_msecs = tg_pt_gp->tg_pt_gp_nonop_delay_msecs;
spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
/*
* Process ALUA_ACCESS_STATE_ACTIVE_OPTMIZED in a seperate conditional
* statement so the complier knows explictly to check this case first.
* For the Optimized ALUA access state case, we want to process the
* incoming fabric cmd ASAP..
*/
if (out_alua_state == ALUA_ACCESS_STATE_ACTIVE_OPTMIZED)
return 0;
switch (out_alua_state) {
case ALUA_ACCESS_STATE_ACTIVE_NON_OPTIMIZED:
return core_alua_state_nonoptimized(cmd, cdb,
nonop_delay_msecs, alua_ascq);
case ALUA_ACCESS_STATE_STANDBY:
return core_alua_state_standby(cmd, cdb, alua_ascq);
case ALUA_ACCESS_STATE_UNAVAILABLE:
return core_alua_state_unavailable(cmd, cdb, alua_ascq);
case ALUA_ACCESS_STATE_TRANSITION:
return core_alua_state_transition(cmd, cdb, alua_ascq);
/*
* OFFLINE is a secondary ALUA target port group access state, that is
* handled above with struct se_port->sep_tg_pt_secondary_offline=1
*/
case ALUA_ACCESS_STATE_OFFLINE:
default:
printk(KERN_ERR "Unknown ALUA access state: 0x%02x\n",
out_alua_state);
return -1;
}
return 0;
}
/*
* Check implict and explict ALUA state change request.
*/
static int core_alua_check_transition(int state, int *primary)
{
switch (state) {
case ALUA_ACCESS_STATE_ACTIVE_OPTMIZED:
case ALUA_ACCESS_STATE_ACTIVE_NON_OPTIMIZED:
case ALUA_ACCESS_STATE_STANDBY:
case ALUA_ACCESS_STATE_UNAVAILABLE:
/*
* OPTIMIZED, NON-OPTIMIZED, STANDBY and UNAVAILABLE are
* defined as primary target port asymmetric access states.
*/
*primary = 1;
break;
case ALUA_ACCESS_STATE_OFFLINE:
/*
* OFFLINE state is defined as a secondary target port
* asymmetric access state.
*/
*primary = 0;
break;
default:
printk(KERN_ERR "Unknown ALUA access state: 0x%02x\n", state);
return -1;
}
return 0;
}
static char *core_alua_dump_state(int state)
{
switch (state) {
case ALUA_ACCESS_STATE_ACTIVE_OPTMIZED:
return "Active/Optimized";
case ALUA_ACCESS_STATE_ACTIVE_NON_OPTIMIZED:
return "Active/NonOptimized";
case ALUA_ACCESS_STATE_STANDBY:
return "Standby";
case ALUA_ACCESS_STATE_UNAVAILABLE:
return "Unavailable";
case ALUA_ACCESS_STATE_OFFLINE:
return "Offline";
default:
return "Unknown";
}
return NULL;
}
char *core_alua_dump_status(int status)
{
switch (status) {
case ALUA_STATUS_NONE:
return "None";
case ALUA_STATUS_ALTERED_BY_EXPLICT_STPG:
return "Altered by Explict STPG";
case ALUA_STATUS_ALTERED_BY_IMPLICT_ALUA:
return "Altered by Implict ALUA";
default:
return "Unknown";
}
return NULL;
}
/*
* Used by fabric modules to determine when we need to delay processing
* for the Active/NonOptimized paths..
*/
int core_alua_check_nonop_delay(
struct se_cmd *cmd)
{
if (!(cmd->se_cmd_flags & SCF_ALUA_NON_OPTIMIZED))
return 0;
if (in_interrupt())
return 0;
/*
* The ALUA Active/NonOptimized access state delay can be disabled
* in via configfs with a value of zero
*/
if (!(cmd->alua_nonop_delay))
return 0;
/*
* struct se_cmd->alua_nonop_delay gets set by a target port group
* defined interval in core_alua_state_nonoptimized()
*/
msleep_interruptible(cmd->alua_nonop_delay);
return 0;
}
EXPORT_SYMBOL(core_alua_check_nonop_delay);
/*
* Called with tg_pt_gp->tg_pt_gp_md_mutex or tg_pt_gp_mem->sep_tg_pt_md_mutex
*
*/
static int core_alua_write_tpg_metadata(
const char *path,
unsigned char *md_buf,
u32 md_buf_len)
{
mm_segment_t old_fs;
struct file *file;
struct iovec iov[1];
int flags = O_RDWR | O_CREAT | O_TRUNC, ret;
memset(iov, 0, sizeof(struct iovec));
file = filp_open(path, flags, 0600);
if (IS_ERR(file) || !file || !file->f_dentry) {
printk(KERN_ERR "filp_open(%s) for ALUA metadata failed\n",
path);
return -ENODEV;
}
iov[0].iov_base = &md_buf[0];
iov[0].iov_len = md_buf_len;
old_fs = get_fs();
set_fs(get_ds());
ret = vfs_writev(file, &iov[0], 1, &file->f_pos);
set_fs(old_fs);
if (ret < 0) {
printk(KERN_ERR "Error writing ALUA metadata file: %s\n", path);
filp_close(file, NULL);
return -EIO;
}
filp_close(file, NULL);
return 0;
}
/*
* Called with tg_pt_gp->tg_pt_gp_md_mutex held
*/
static int core_alua_update_tpg_primary_metadata(
struct t10_alua_tg_pt_gp *tg_pt_gp,
int primary_state,
unsigned char *md_buf)
{
struct se_subsystem_dev *su_dev = tg_pt_gp->tg_pt_gp_su_dev;
struct t10_wwn *wwn = &su_dev->t10_wwn;
char path[ALUA_METADATA_PATH_LEN];
int len;
memset(path, 0, ALUA_METADATA_PATH_LEN);
len = snprintf(md_buf, tg_pt_gp->tg_pt_gp_md_buf_len,
"tg_pt_gp_id=%hu\n"
"alua_access_state=0x%02x\n"
"alua_access_status=0x%02x\n",
tg_pt_gp->tg_pt_gp_id, primary_state,
tg_pt_gp->tg_pt_gp_alua_access_status);
snprintf(path, ALUA_METADATA_PATH_LEN,
"/var/target/alua/tpgs_%s/%s", &wwn->unit_serial[0],
config_item_name(&tg_pt_gp->tg_pt_gp_group.cg_item));
return core_alua_write_tpg_metadata(path, md_buf, len);
}
static int core_alua_do_transition_tg_pt(
struct t10_alua_tg_pt_gp *tg_pt_gp,
struct se_port *l_port,
struct se_node_acl *nacl,
unsigned char *md_buf,
int new_state,
int explict)
{
struct se_dev_entry *se_deve;
struct se_lun_acl *lacl;
struct se_port *port;
struct t10_alua_tg_pt_gp_member *mem;
int old_state = 0;
/*
* Save the old primary ALUA access state, and set the current state
* to ALUA_ACCESS_STATE_TRANSITION.
*/
old_state = atomic_read(&tg_pt_gp->tg_pt_gp_alua_access_state);
atomic_set(&tg_pt_gp->tg_pt_gp_alua_access_state,
ALUA_ACCESS_STATE_TRANSITION);
tg_pt_gp->tg_pt_gp_alua_access_status = (explict) ?
ALUA_STATUS_ALTERED_BY_EXPLICT_STPG :
ALUA_STATUS_ALTERED_BY_IMPLICT_ALUA;
/*
* Check for the optional ALUA primary state transition delay
*/
if (tg_pt_gp->tg_pt_gp_trans_delay_msecs != 0)
msleep_interruptible(tg_pt_gp->tg_pt_gp_trans_delay_msecs);
spin_lock(&tg_pt_gp->tg_pt_gp_lock);
list_for_each_entry(mem, &tg_pt_gp->tg_pt_gp_mem_list,
tg_pt_gp_mem_list) {
port = mem->tg_pt;
/*
* After an implicit target port asymmetric access state
* change, a device server shall establish a unit attention
* condition for the initiator port associated with every I_T
* nexus with the additional sense code set to ASYMMETRIC
* ACCESS STATE CHAGED.
*
* After an explicit target port asymmetric access state
* change, a device server shall establish a unit attention
* condition with the additional sense code set to ASYMMETRIC
* ACCESS STATE CHANGED for the initiator port associated with
* every I_T nexus other than the I_T nexus on which the SET
* TARGET PORT GROUPS command
*/
atomic_inc(&mem->tg_pt_gp_mem_ref_cnt);
smp_mb__after_atomic_inc();
spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
spin_lock_bh(&port->sep_alua_lock);
list_for_each_entry(se_deve, &port->sep_alua_list,
alua_port_list) {
lacl = se_deve->se_lun_acl;
/*
* se_deve->se_lun_acl pointer may be NULL for a
* entry created without explict Node+MappedLUN ACLs
*/
if (!(lacl))
continue;
if (explict &&
(nacl != NULL) && (nacl == lacl->se_lun_nacl) &&
(l_port != NULL) && (l_port == port))
continue;
core_scsi3_ua_allocate(lacl->se_lun_nacl,
se_deve->mapped_lun, 0x2A,
ASCQ_2AH_ASYMMETRIC_ACCESS_STATE_CHANGED);
}
spin_unlock_bh(&port->sep_alua_lock);
spin_lock(&tg_pt_gp->tg_pt_gp_lock);
atomic_dec(&mem->tg_pt_gp_mem_ref_cnt);
smp_mb__after_atomic_dec();
}
spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
/*
* Update the ALUA metadata buf that has been allocated in
* core_alua_do_port_transition(), this metadata will be written
* to struct file.
*
* Note that there is the case where we do not want to update the
* metadata when the saved metadata is being parsed in userspace
* when setting the existing port access state and access status.
*
* Also note that the failure to write out the ALUA metadata to
* struct file does NOT affect the actual ALUA transition.
*/
if (tg_pt_gp->tg_pt_gp_write_metadata) {
mutex_lock(&tg_pt_gp->tg_pt_gp_md_mutex);
core_alua_update_tpg_primary_metadata(tg_pt_gp,
new_state, md_buf);
mutex_unlock(&tg_pt_gp->tg_pt_gp_md_mutex);
}
/*
* Set the current primary ALUA access state to the requested new state
*/
atomic_set(&tg_pt_gp->tg_pt_gp_alua_access_state, new_state);
printk(KERN_INFO "Successful %s ALUA transition TG PT Group: %s ID: %hu"
" from primary access state %s to %s\n", (explict) ? "explict" :
"implict", config_item_name(&tg_pt_gp->tg_pt_gp_group.cg_item),
tg_pt_gp->tg_pt_gp_id, core_alua_dump_state(old_state),
core_alua_dump_state(new_state));
return 0;
}
int core_alua_do_port_transition(
struct t10_alua_tg_pt_gp *l_tg_pt_gp,
struct se_device *l_dev,
struct se_port *l_port,
struct se_node_acl *l_nacl,
int new_state,
int explict)
{
struct se_device *dev;
struct se_port *port;
struct se_subsystem_dev *su_dev;
struct se_node_acl *nacl;
struct t10_alua_lu_gp *lu_gp;
struct t10_alua_lu_gp_member *lu_gp_mem, *local_lu_gp_mem;
struct t10_alua_tg_pt_gp *tg_pt_gp;
unsigned char *md_buf;
int primary;
if (core_alua_check_transition(new_state, &primary) != 0)
return -EINVAL;
md_buf = kzalloc(l_tg_pt_gp->tg_pt_gp_md_buf_len, GFP_KERNEL);
if (!(md_buf)) {
printk("Unable to allocate buf for ALUA metadata\n");
return -ENOMEM;
}
local_lu_gp_mem = l_dev->dev_alua_lu_gp_mem;
spin_lock(&local_lu_gp_mem->lu_gp_mem_lock);
lu_gp = local_lu_gp_mem->lu_gp;
atomic_inc(&lu_gp->lu_gp_ref_cnt);
smp_mb__after_atomic_inc();
spin_unlock(&local_lu_gp_mem->lu_gp_mem_lock);
/*
* For storage objects that are members of the 'default_lu_gp',
* we only do transition on the passed *l_tp_pt_gp, and not
* on all of the matching target port groups IDs in default_lu_gp.
*/
if (!(lu_gp->lu_gp_id)) {
/*
* core_alua_do_transition_tg_pt() will always return
* success.
*/
core_alua_do_transition_tg_pt(l_tg_pt_gp, l_port, l_nacl,
md_buf, new_state, explict);
atomic_dec(&lu_gp->lu_gp_ref_cnt);
smp_mb__after_atomic_dec();
kfree(md_buf);
return 0;
}
/*
* For all other LU groups aside from 'default_lu_gp', walk all of
* the associated storage objects looking for a matching target port
* group ID from the local target port group.
*/
spin_lock(&lu_gp->lu_gp_lock);
list_for_each_entry(lu_gp_mem, &lu_gp->lu_gp_mem_list,
lu_gp_mem_list) {
dev = lu_gp_mem->lu_gp_mem_dev;
su_dev = dev->se_sub_dev;
atomic_inc(&lu_gp_mem->lu_gp_mem_ref_cnt);
smp_mb__after_atomic_inc();
spin_unlock(&lu_gp->lu_gp_lock);
spin_lock(&T10_ALUA(su_dev)->tg_pt_gps_lock);
list_for_each_entry(tg_pt_gp,
&T10_ALUA(su_dev)->tg_pt_gps_list,
tg_pt_gp_list) {
if (!(tg_pt_gp->tg_pt_gp_valid_id))
continue;
/*
* If the target behavior port asymmetric access state
* is changed for any target port group accessiable via
* a logical unit within a LU group, the target port
* behavior group asymmetric access states for the same
* target port group accessible via other logical units
* in that LU group will also change.
*/
if (l_tg_pt_gp->tg_pt_gp_id != tg_pt_gp->tg_pt_gp_id)
continue;
if (l_tg_pt_gp == tg_pt_gp) {
port = l_port;
nacl = l_nacl;
} else {
port = NULL;
nacl = NULL;
}
atomic_inc(&tg_pt_gp->tg_pt_gp_ref_cnt);
smp_mb__after_atomic_inc();
spin_unlock(&T10_ALUA(su_dev)->tg_pt_gps_lock);
/*
* core_alua_do_transition_tg_pt() will always return
* success.
*/
core_alua_do_transition_tg_pt(tg_pt_gp, port,
nacl, md_buf, new_state, explict);
spin_lock(&T10_ALUA(su_dev)->tg_pt_gps_lock);
atomic_dec(&tg_pt_gp->tg_pt_gp_ref_cnt);
smp_mb__after_atomic_dec();
}
spin_unlock(&T10_ALUA(su_dev)->tg_pt_gps_lock);
spin_lock(&lu_gp->lu_gp_lock);
atomic_dec(&lu_gp_mem->lu_gp_mem_ref_cnt);
smp_mb__after_atomic_dec();
}
spin_unlock(&lu_gp->lu_gp_lock);
printk(KERN_INFO "Successfully processed LU Group: %s all ALUA TG PT"
" Group IDs: %hu %s transition to primary state: %s\n",
config_item_name(&lu_gp->lu_gp_group.cg_item),
l_tg_pt_gp->tg_pt_gp_id, (explict) ? "explict" : "implict",
core_alua_dump_state(new_state));
atomic_dec(&lu_gp->lu_gp_ref_cnt);
smp_mb__after_atomic_dec();
kfree(md_buf);
return 0;
}
/*
* Called with tg_pt_gp_mem->sep_tg_pt_md_mutex held
*/
static int core_alua_update_tpg_secondary_metadata(
struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem,
struct se_port *port,
unsigned char *md_buf,
u32 md_buf_len)
{
struct se_portal_group *se_tpg = port->sep_tpg;
char path[ALUA_METADATA_PATH_LEN], wwn[ALUA_SECONDARY_METADATA_WWN_LEN];
int len;
memset(path, 0, ALUA_METADATA_PATH_LEN);
memset(wwn, 0, ALUA_SECONDARY_METADATA_WWN_LEN);
len = snprintf(wwn, ALUA_SECONDARY_METADATA_WWN_LEN, "%s",
TPG_TFO(se_tpg)->tpg_get_wwn(se_tpg));
if (TPG_TFO(se_tpg)->tpg_get_tag != NULL)
snprintf(wwn+len, ALUA_SECONDARY_METADATA_WWN_LEN-len, "+%hu",
TPG_TFO(se_tpg)->tpg_get_tag(se_tpg));
len = snprintf(md_buf, md_buf_len, "alua_tg_pt_offline=%d\n"
"alua_tg_pt_status=0x%02x\n",
atomic_read(&port->sep_tg_pt_secondary_offline),
port->sep_tg_pt_secondary_stat);
snprintf(path, ALUA_METADATA_PATH_LEN, "/var/target/alua/%s/%s/lun_%u",
TPG_TFO(se_tpg)->get_fabric_name(), wwn,
port->sep_lun->unpacked_lun);
return core_alua_write_tpg_metadata(path, md_buf, len);
}
static int core_alua_set_tg_pt_secondary_state(
struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem,
struct se_port *port,
int explict,
int offline)
{
struct t10_alua_tg_pt_gp *tg_pt_gp;
unsigned char *md_buf;
u32 md_buf_len;
int trans_delay_msecs;
spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
tg_pt_gp = tg_pt_gp_mem->tg_pt_gp;
if (!(tg_pt_gp)) {
spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
printk(KERN_ERR "Unable to complete secondary state"
" transition\n");
return -1;
}
trans_delay_msecs = tg_pt_gp->tg_pt_gp_trans_delay_msecs;
/*
* Set the secondary ALUA target port access state to OFFLINE
* or release the previously secondary state for struct se_port
*/
if (offline)
atomic_set(&port->sep_tg_pt_secondary_offline, 1);
else
atomic_set(&port->sep_tg_pt_secondary_offline, 0);
md_buf_len = tg_pt_gp->tg_pt_gp_md_buf_len;
port->sep_tg_pt_secondary_stat = (explict) ?
ALUA_STATUS_ALTERED_BY_EXPLICT_STPG :
ALUA_STATUS_ALTERED_BY_IMPLICT_ALUA;
printk(KERN_INFO "Successful %s ALUA transition TG PT Group: %s ID: %hu"
" to secondary access state: %s\n", (explict) ? "explict" :
"implict", config_item_name(&tg_pt_gp->tg_pt_gp_group.cg_item),
tg_pt_gp->tg_pt_gp_id, (offline) ? "OFFLINE" : "ONLINE");