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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)
*
* (c) Copyright 2009-2013 Datera, Inc.
*
* Nicholas A. Bellinger <[email protected]>
*
* 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 <linux/configfs.h>
#include <linux/export.h>
#include <linux/file.h>
#include <scsi/scsi.h>
#include <scsi/scsi_cmnd.h>
#include <asm/unaligned.h>
#include <target/target_core_base.h>
#include <target/target_core_backend.h>
#include <target/target_core_fabric.h>
#include <target/target_core_configfs.h>
#include "target_core_internal.h"
#include "target_core_alua.h"
#include "target_core_ua.h"
static sense_reason_t core_alua_check_transition(int state, int valid,
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 explicit, int offline);
static char *core_alua_dump_state(int state);
static u16 alua_lu_gps_counter;
static u32 alua_lu_gps_count;
static DEFINE_SPINLOCK(lu_gps_lock);
static LIST_HEAD(lu_gps_list);
struct t10_alua_lu_gp *default_lu_gp;
/*
* REPORT REFERRALS
*
* See sbc3r35 section 5.23
*/
sense_reason_t
target_emulate_report_referrals(struct se_cmd *cmd)
{
struct se_device *dev = cmd->se_dev;
struct t10_alua_lba_map *map;
struct t10_alua_lba_map_member *map_mem;
unsigned char *buf;
u32 rd_len = 0, off;
if (cmd->data_length < 4) {
pr_warn("REPORT REFERRALS allocation length %u too"
" small\n", cmd->data_length);
return TCM_INVALID_CDB_FIELD;
}
buf = transport_kmap_data_sg(cmd);
if (!buf)
return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
off = 4;
spin_lock(&dev->t10_alua.lba_map_lock);
if (list_empty(&dev->t10_alua.lba_map_list)) {
spin_unlock(&dev->t10_alua.lba_map_lock);
transport_kunmap_data_sg(cmd);
return TCM_UNSUPPORTED_SCSI_OPCODE;
}
list_for_each_entry(map, &dev->t10_alua.lba_map_list,
lba_map_list) {
int desc_num = off + 3;
int pg_num;
off += 4;
if (cmd->data_length > off)
put_unaligned_be64(map->lba_map_first_lba, &buf[off]);
off += 8;
if (cmd->data_length > off)
put_unaligned_be64(map->lba_map_last_lba, &buf[off]);
off += 8;
rd_len += 20;
pg_num = 0;
list_for_each_entry(map_mem, &map->lba_map_mem_list,
lba_map_mem_list) {
int alua_state = map_mem->lba_map_mem_alua_state;
int alua_pg_id = map_mem->lba_map_mem_alua_pg_id;
if (cmd->data_length > off)
buf[off] = alua_state & 0x0f;
off += 2;
if (cmd->data_length > off)
buf[off] = (alua_pg_id >> 8) & 0xff;
off++;
if (cmd->data_length > off)
buf[off] = (alua_pg_id & 0xff);
off++;
rd_len += 4;
pg_num++;
}
if (cmd->data_length > desc_num)
buf[desc_num] = pg_num;
}
spin_unlock(&dev->t10_alua.lba_map_lock);
/*
* Set the RETURN DATA LENGTH set in the header of the DataIN Payload
*/
put_unaligned_be16(rd_len, &buf[2]);
transport_kunmap_data_sg(cmd);
target_complete_cmd(cmd, GOOD);
return 0;
}
/*
* REPORT_TARGET_PORT_GROUPS
*
* See spc4r17 section 6.27
*/
sense_reason_t
target_emulate_report_target_port_groups(struct se_cmd *cmd)
{
struct se_device *dev = cmd->se_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;
u32 rd_len = 0, off;
int ext_hdr = (cmd->t_task_cdb[1] & 0x20);
/*
* Skip over RESERVED area to first Target port group descriptor
* depending on the PARAMETER DATA FORMAT type..
*/
if (ext_hdr != 0)
off = 8;
else
off = 4;
if (cmd->data_length < off) {
pr_warn("REPORT TARGET PORT GROUPS allocation length %u too"
" small for %s header\n", cmd->data_length,
(ext_hdr) ? "extended" : "normal");
return TCM_INVALID_CDB_FIELD;
}
buf = transport_kmap_data_sg(cmd);
if (!buf)
return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
spin_lock(&dev->t10_alua.tg_pt_gps_lock);
list_for_each_entry(tg_pt_gp, &dev->t10_alua.tg_pt_gps_list,
tg_pt_gp_list) {
/*
* Check if the Target port group and Target port descriptor list
* based on tg_pt_gp_members count will fit into the response payload.
* Otherwise, bump rd_len to let the initiator know we have exceeded
* the allocation length and the response is truncated.
*/
if ((off + 8 + (tg_pt_gp->tg_pt_gp_members * 4)) >
cmd->data_length) {
rd_len += 8 + (tg_pt_gp->tg_pt_gp_members * 4);
continue;
}
/*
* 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++] |= tg_pt_gp->tg_pt_gp_alua_supported_states;
/*
* 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(&dev->t10_alua.tg_pt_gps_lock);
/*
* Set the RETURN DATA LENGTH set in the header of the DataIN Payload
*/
put_unaligned_be32(rd_len, &buf[0]);
/*
* Fill in the Extended header parameter data format if requested
*/
if (ext_hdr != 0) {
buf[4] = 0x10;
/*
* Set the implicit transition time (in seconds) for the application
* client to use as a base for it's transition timeout value.
*
* Use the current tg_pt_gp_mem -> tg_pt_gp membership from the LUN
* this CDB was received upon to determine this value individually
* for ALUA target port group.
*/
port = cmd->se_lun->lun_sep;
tg_pt_gp_mem = port->sep_alua_tg_pt_gp_mem;
if (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;
if (tg_pt_gp)
buf[5] = tg_pt_gp->tg_pt_gp_implicit_trans_secs;
spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
}
}
transport_kunmap_data_sg(cmd);
target_complete_cmd(cmd, GOOD);
return 0;
}
/*
* SET_TARGET_PORT_GROUPS for explicit ALUA operation.
*
* See spc4r17 section 6.35
*/
sense_reason_t
target_emulate_set_target_port_groups(struct se_cmd *cmd)
{
struct se_device *dev = cmd->se_dev;
struct se_port *port, *l_port = cmd->se_lun->lun_sep;
struct se_node_acl *nacl = cmd->se_sess->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 *ptr;
sense_reason_t rc = TCM_NO_SENSE;
u32 len = 4; /* Skip over RESERVED area in header */
int alua_access_state, primary = 0, valid_states;
u16 tg_pt_id, rtpi;
if (!l_port)
return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
if (cmd->data_length < 4) {
pr_warn("SET TARGET PORT GROUPS parameter list length %u too"
" small\n", cmd->data_length);
return TCM_INVALID_PARAMETER_LIST;
}
buf = transport_kmap_data_sg(cmd);
if (!buf)
return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
/*
* Determine if explicit 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) {
pr_err("Unable to access l_port->sep_alua_tg_pt_gp_mem\n");
rc = TCM_UNSUPPORTED_SCSI_OPCODE;
goto out;
}
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);
pr_err("Unable to access *l_tg_pt_gp_mem->tg_pt_gp\n");
rc = TCM_UNSUPPORTED_SCSI_OPCODE;
goto out;
}
spin_unlock(&l_tg_pt_gp_mem->tg_pt_gp_mem_lock);
if (!(l_tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_EXPLICIT_ALUA)) {
pr_debug("Unable to process SET_TARGET_PORT_GROUPS"
" while TPGS_EXPLICIT_ALUA is disabled\n");
rc = TCM_UNSUPPORTED_SCSI_OPCODE;
goto out;
}
valid_states = l_tg_pt_gp->tg_pt_gp_alua_supported_states;
ptr = &buf[4]; /* Skip over RESERVED area in header */
while (len < cmd->data_length) {
bool found = false;
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,
valid_states, &primary);
if (rc) {
/*
* 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.
*/
goto out;
}
/*
* 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 = get_unaligned_be16(ptr + 2);
/*
* Locate the matching target port group ID from
* the global tg_pt_gp list
*/
spin_lock(&dev->t10_alua.tg_pt_gps_lock);
list_for_each_entry(tg_pt_gp,
&dev->t10_alua.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(&dev->t10_alua.tg_pt_gps_lock);
if (!core_alua_do_port_transition(tg_pt_gp,
dev, l_port, nacl,
alua_access_state, 1))
found = true;
spin_lock(&dev->t10_alua.tg_pt_gps_lock);
atomic_dec(&tg_pt_gp->tg_pt_gp_ref_cnt);
smp_mb__after_atomic_dec();
break;
}
spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
} else {
/*
* Extract the RELATIVE TARGET PORT IDENTIFIER to identify
* the Target Port in question for the the incoming
* SET_TARGET_PORT_GROUPS op.
*/
rtpi = get_unaligned_be16(ptr + 2);
/*
* Locate the matching relative target port identifier
* 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);
if (!core_alua_set_tg_pt_secondary_state(
tg_pt_gp_mem, port, 1, 1))
found = true;
spin_lock(&dev->se_port_lock);
break;
}
spin_unlock(&dev->se_port_lock);
}
if (!found) {
rc = TCM_INVALID_PARAMETER_LIST;
goto out;
}
ptr += 4;
len += 4;
}
out:
transport_kunmap_data_sg(cmd);
if (!rc)
target_complete_cmd(cmd, GOOD);
return rc;
}
static inline void set_ascq(struct se_cmd *cmd, u8 alua_ascq)
{
/*
* Set SCSI additional sense code (ASC) to 'LUN Not Accessible';
* The ALUA additional sense code qualifier (ASCQ) is determined
* by the ALUA primary or secondary access state..
*/
pr_debug("[%s]: ALUA TG Port not available, "
"SenseKey: NOT_READY, ASC/ASCQ: "
"0x04/0x%02x\n",
cmd->se_tfo->get_fabric_name(), alua_ascq);
cmd->scsi_asc = 0x04;
cmd->scsi_ascq = alua_ascq;
}
static inline void core_alua_state_nonoptimized(
struct se_cmd *cmd,
unsigned char *cdb,
int nonop_delay_msecs)
{
/*
* 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;
}
static inline int core_alua_state_lba_dependent(
struct se_cmd *cmd,
struct t10_alua_tg_pt_gp *tg_pt_gp)
{
struct se_device *dev = cmd->se_dev;
u64 segment_size, segment_mult, sectors, lba;
/* Only need to check for cdb actually containing LBAs */
if (!(cmd->se_cmd_flags & SCF_SCSI_DATA_CDB))
return 0;
spin_lock(&dev->t10_alua.lba_map_lock);
segment_size = dev->t10_alua.lba_map_segment_size;
segment_mult = dev->t10_alua.lba_map_segment_multiplier;
sectors = cmd->data_length / dev->dev_attrib.block_size;
lba = cmd->t_task_lba;
while (lba < cmd->t_task_lba + sectors) {
struct t10_alua_lba_map *cur_map = NULL, *map;
struct t10_alua_lba_map_member *map_mem;
list_for_each_entry(map, &dev->t10_alua.lba_map_list,
lba_map_list) {
u64 start_lba, last_lba;
u64 first_lba = map->lba_map_first_lba;
if (segment_mult) {
u64 tmp = lba;
start_lba = do_div(tmp, segment_size * segment_mult);
last_lba = first_lba + segment_size - 1;
if (start_lba >= first_lba &&
start_lba <= last_lba) {
lba += segment_size;
cur_map = map;
break;
}
} else {
last_lba = map->lba_map_last_lba;
if (lba >= first_lba && lba <= last_lba) {
lba = last_lba + 1;
cur_map = map;
break;
}
}
}
if (!cur_map) {
spin_unlock(&dev->t10_alua.lba_map_lock);
set_ascq(cmd, ASCQ_04H_ALUA_TG_PT_UNAVAILABLE);
return 1;
}
list_for_each_entry(map_mem, &cur_map->lba_map_mem_list,
lba_map_mem_list) {
if (map_mem->lba_map_mem_alua_pg_id !=
tg_pt_gp->tg_pt_gp_id)
continue;
switch(map_mem->lba_map_mem_alua_state) {
case ALUA_ACCESS_STATE_STANDBY:
spin_unlock(&dev->t10_alua.lba_map_lock);
set_ascq(cmd, ASCQ_04H_ALUA_TG_PT_STANDBY);
return 1;
case ALUA_ACCESS_STATE_UNAVAILABLE:
spin_unlock(&dev->t10_alua.lba_map_lock);
set_ascq(cmd, ASCQ_04H_ALUA_TG_PT_UNAVAILABLE);
return 1;
default:
break;
}
}
}
spin_unlock(&dev->t10_alua.lba_map_lock);
return 0;
}
static inline int core_alua_state_standby(
struct se_cmd *cmd,
unsigned char *cdb)
{
/*
* 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:
return 0;
case MAINTENANCE_IN:
switch (cdb[1] & 0x1f) {
case MI_REPORT_TARGET_PGS:
return 0;
default:
set_ascq(cmd, ASCQ_04H_ALUA_TG_PT_STANDBY);
return 1;
}
case MAINTENANCE_OUT:
switch (cdb[1]) {
case MO_SET_TARGET_PGS:
return 0;
default:
set_ascq(cmd, 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:
set_ascq(cmd, ASCQ_04H_ALUA_TG_PT_STANDBY);
return 1;
}
return 0;
}
static inline int core_alua_state_unavailable(
struct se_cmd *cmd,
unsigned char *cdb)
{
/*
* 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:
return 0;
case MAINTENANCE_IN:
switch (cdb[1] & 0x1f) {
case MI_REPORT_TARGET_PGS:
return 0;
default:
set_ascq(cmd, ASCQ_04H_ALUA_TG_PT_UNAVAILABLE);
return 1;
}
case MAINTENANCE_OUT:
switch (cdb[1]) {
case MO_SET_TARGET_PGS:
return 0;
default:
set_ascq(cmd, ASCQ_04H_ALUA_TG_PT_UNAVAILABLE);
return 1;
}
case REQUEST_SENSE:
case READ_BUFFER:
case WRITE_BUFFER:
return 0;
default:
set_ascq(cmd, ASCQ_04H_ALUA_TG_PT_UNAVAILABLE);
return 1;
}
return 0;
}
static inline int core_alua_state_transition(
struct se_cmd *cmd,
unsigned char *cdb)
{
/*
* Allowed CDBs for ALUA_ACCESS_STATE_TRANSITION as defined by
* spc4r17 section 5.9.2.5
*/
switch (cdb[0]) {
case INQUIRY:
case REPORT_LUNS:
return 0;
case MAINTENANCE_IN:
switch (cdb[1] & 0x1f) {
case MI_REPORT_TARGET_PGS:
return 0;
default:
set_ascq(cmd, ASCQ_04H_ALUA_STATE_TRANSITION);
return 1;
}
case REQUEST_SENSE:
case READ_BUFFER:
case WRITE_BUFFER:
return 0;
default:
set_ascq(cmd, ASCQ_04H_ALUA_STATE_TRANSITION);
return 1;
}
return 0;
}
/*
* return 1: Is used to signal LUN not accessible, and check condition/not ready
* return 0: Used to signal success
* return -1: Used to signal failure, and invalid cdb field
*/
sense_reason_t
target_alua_state_check(struct se_cmd *cmd)
{
struct se_device *dev = cmd->se_dev;
unsigned char *cdb = cmd->t_task_cdb;
struct se_lun *lun = cmd->se_lun;
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 (dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE)
return 0;
if (dev->transport->transport_type == TRANSPORT_PLUGIN_PHBA_PDEV)
return 0;
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)) {
pr_debug("ALUA: Got secondary offline status for local"
" target port\n");
set_ascq(cmd, ASCQ_04H_ALUA_OFFLINE);
return TCM_CHECK_CONDITION_NOT_READY;
}
/*
* 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;
if (!tg_pt_gp_mem)
return 0;
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_OPTIMIZED in a separate conditional
* statement so the compiler knows explicitly 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_OPTIMIZED)
return 0;
switch (out_alua_state) {
case ALUA_ACCESS_STATE_ACTIVE_NON_OPTIMIZED:
core_alua_state_nonoptimized(cmd, cdb, nonop_delay_msecs);
break;
case ALUA_ACCESS_STATE_STANDBY:
if (core_alua_state_standby(cmd, cdb))
return TCM_CHECK_CONDITION_NOT_READY;
break;
case ALUA_ACCESS_STATE_UNAVAILABLE:
if (core_alua_state_unavailable(cmd, cdb))
return TCM_CHECK_CONDITION_NOT_READY;
break;
case ALUA_ACCESS_STATE_TRANSITION:
if (core_alua_state_transition(cmd, cdb))
return TCM_CHECK_CONDITION_NOT_READY;
break;
case ALUA_ACCESS_STATE_LBA_DEPENDENT:
if (core_alua_state_lba_dependent(cmd, tg_pt_gp))
return TCM_CHECK_CONDITION_NOT_READY;
break;
/*
* 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:
pr_err("Unknown ALUA access state: 0x%02x\n",
out_alua_state);
return TCM_INVALID_CDB_FIELD;
}
return 0;
}
/*
* Check implicit and explicit ALUA state change request.
*/
static sense_reason_t
core_alua_check_transition(int state, int valid, int *primary)
{
/*
* OPTIMIZED, NON-OPTIMIZED, STANDBY and UNAVAILABLE are
* defined as primary target port asymmetric access states.
*/
switch (state) {
case ALUA_ACCESS_STATE_ACTIVE_OPTIMIZED:
if (!(valid & ALUA_AO_SUP))
goto not_supported;
*primary = 1;
break;
case ALUA_ACCESS_STATE_ACTIVE_NON_OPTIMIZED:
if (!(valid & ALUA_AN_SUP))
goto not_supported;
*primary = 1;
break;
case ALUA_ACCESS_STATE_STANDBY:
if (!(valid & ALUA_S_SUP))
goto not_supported;
*primary = 1;
break;
case ALUA_ACCESS_STATE_UNAVAILABLE:
if (!(valid & ALUA_U_SUP))
goto not_supported;
*primary = 1;
break;
case ALUA_ACCESS_STATE_LBA_DEPENDENT:
if (!(valid & ALUA_LBD_SUP))
goto not_supported;
*primary = 1;
break;
case ALUA_ACCESS_STATE_OFFLINE:
/*
* OFFLINE state is defined as a secondary target port
* asymmetric access state.
*/
if (!(valid & ALUA_O_SUP))
goto not_supported;
*primary = 0;
break;
case ALUA_ACCESS_STATE_TRANSITION:
/*
* Transitioning is set internally, and
* cannot be selected manually.
*/
goto not_supported;
default:
pr_err("Unknown ALUA access state: 0x%02x\n", state);
return TCM_INVALID_PARAMETER_LIST;
}
return 0;
not_supported:
pr_err("ALUA access state %s not supported",
core_alua_dump_state(state));
return TCM_INVALID_PARAMETER_LIST;
}
static char *core_alua_dump_state(int state)
{
switch (state) {
case ALUA_ACCESS_STATE_ACTIVE_OPTIMIZED:
return "Active/Optimized";
case ALUA_ACCESS_STATE_ACTIVE_NON_OPTIMIZED:
return "Active/NonOptimized";
case ALUA_ACCESS_STATE_LBA_DEPENDENT:
return "LBA Dependent";
case ALUA_ACCESS_STATE_STANDBY:
return "Standby";
case ALUA_ACCESS_STATE_UNAVAILABLE:
return "Unavailable";
case ALUA_ACCESS_STATE_OFFLINE:
return "Offline";
case ALUA_ACCESS_STATE_TRANSITION:
return "Transitioning";
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_EXPLICIT_STPG:
return "Altered by Explicit STPG";
case ALUA_STATUS_ALTERED_BY_IMPLICIT_ALUA:
return "Altered by Implicit 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)
{
struct file *file = filp_open(path, O_RDWR | O_CREAT | O_TRUNC, 0600);
int ret;
if (IS_ERR(file)) {
pr_err("filp_open(%s) for ALUA metadata failed\n", path);
return -ENODEV;
}
ret = kernel_write(file, md_buf, md_buf_len, 0);
if (ret < 0)
pr_err("Error writing ALUA metadata file: %s\n", path);
fput(file);
return (ret < 0) ? -EIO : 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)
{
unsigned char *md_buf;
struct t10_wwn *wwn = &tg_pt_gp->tg_pt_gp_dev->t10_wwn;
char path[ALUA_METADATA_PATH_LEN];
int len, rc;
md_buf = kzalloc(ALUA_MD_BUF_LEN, GFP_KERNEL);
if (!md_buf) {
pr_err("Unable to allocate buf for ALUA metadata\n");
return -ENOMEM;
}
memset(path, 0, ALUA_METADATA_PATH_LEN);
len = snprintf(md_buf, ALUA_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,
tg_pt_gp->tg_pt_gp_alua_pending_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));
rc = core_alua_write_tpg_metadata(path, md_buf, len);
kfree(md_buf);
return rc;
}
static void core_alua_do_transition_tg_pt_work(struct work_struct *work)
{
struct t10_alua_tg_pt_gp *tg_pt_gp = container_of(work,
struct t10_alua_tg_pt_gp, tg_pt_gp_transition_work.work);
struct se_device *dev = tg_pt_gp->tg_pt_gp_dev;
struct se_dev_entry *se_deve;
struct se_lun_acl *lacl;
struct se_port *port;
struct t10_alua_tg_pt_gp_member *mem;
bool explicit = (tg_pt_gp->tg_pt_gp_alua_access_status ==
ALUA_STATUS_ALTERED_BY_EXPLICIT_STPG);
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 CHANGED.
*
* 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;
/*