target_core_alua: Referrals infrastructure

Add infrastructure for referrals.

v2 changes:

 - Fix unsigned long long division in core_alua_state_lba_dependent on
   32-bit  (Fengguang + Chen + Hannes)
 - Fix compile warning in core_alua_state_lba_dependent (nab)
 - Convert segment_* + sectors variables in core_alua_state_lba_dependent
   to u64 (Hannes)

Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
This commit is contained in:
Hannes Reinecke 2013-12-17 09:18:49 +01:00 committed by Nicholas Bellinger
parent fbfe858fea
commit c66094bf32
8 changed files with 210 additions and 3 deletions

View File

@ -57,6 +57,75 @@ 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;
put_unaligned_be64(map->lba_map_first_lba, &buf[off]);
off += 8;
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) {
buf[off++] = map_mem->lba_map_mem_alua_state & 0x0f;
off++;
buf[off++] = (map_mem->lba_map_mem_alua_pg_id >> 8) & 0xff;
buf[off++] = (map_mem->lba_map_mem_alua_pg_id & 0xff);
rd_len += 4;
pg_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
*
@ -391,6 +460,81 @@ static inline int core_alua_state_nonoptimized(
return 0;
}
static inline int core_alua_state_lba_dependent(
struct se_cmd *cmd,
struct t10_alua_tg_pt_gp *tg_pt_gp,
u8 *alua_ascq)
{
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 = sector_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);
*alua_ascq = 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);
*alua_ascq = ASCQ_04H_ALUA_TG_PT_STANDBY;
return 1;
case ALUA_ACCESS_STATE_UNAVAILABLE:
spin_unlock(&dev->t10_alua.lba_map_lock);
*alua_ascq = 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,
@ -588,6 +732,9 @@ target_alua_state_check(struct se_cmd *cmd)
case ALUA_ACCESS_STATE_TRANSITION:
ret = core_alua_state_transition(cmd, cdb, &alua_ascq);
break;
case ALUA_ACCESS_STATE_LBA_DEPENDENT:
ret = core_alua_state_lba_dependent(cmd, tg_pt_gp, &alua_ascq);
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
@ -650,6 +797,11 @@ core_alua_check_transition(int state, int valid, int *primary)
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
@ -685,6 +837,8 @@ static char *core_alua_dump_state(int state)
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:

View File

@ -13,12 +13,13 @@
/*
* ASYMMETRIC ACCESS STATE field
*
* from spc4r17 section 6.27 Table 245
* from spc4r36j section 6.37 Table 307
*/
#define ALUA_ACCESS_STATE_ACTIVE_OPTIMIZED 0x0
#define ALUA_ACCESS_STATE_ACTIVE_NON_OPTIMIZED 0x1
#define ALUA_ACCESS_STATE_STANDBY 0x2
#define ALUA_ACCESS_STATE_UNAVAILABLE 0x3
#define ALUA_ACCESS_STATE_LBA_DEPENDENT 0x4
#define ALUA_ACCESS_STATE_OFFLINE 0xe
#define ALUA_ACCESS_STATE_TRANSITION 0xf
@ -88,6 +89,7 @@ extern struct kmem_cache *t10_alua_tg_pt_gp_mem_cache;
extern sense_reason_t target_emulate_report_target_port_groups(struct se_cmd *);
extern sense_reason_t target_emulate_set_target_port_groups(struct se_cmd *);
extern sense_reason_t target_emulate_report_referrals(struct se_cmd *);
extern int core_alua_check_nonop_delay(struct se_cmd *);
extern int core_alua_do_port_transition(struct t10_alua_tg_pt_gp *,
struct se_device *, struct se_port *,

View File

@ -2054,6 +2054,13 @@ static ssize_t target_core_alua_tg_pt_gp_store_attr_alua_access_state(
" transition while TPGS_IMPLICIT_ALUA is disabled\n");
return -EINVAL;
}
if (tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_EXPLICIT_ALUA &&
new_state == ALUA_ACCESS_STATE_LBA_DEPENDENT) {
/* LBA DEPENDENT is only allowed with implicit ALUA */
pr_err("Unable to process implicit configfs ALUA transition"
" while explicit ALUA management is enabled\n");
return -EINVAL;
}
ret = core_alua_do_port_transition(tg_pt_gp, dev,
NULL, NULL, new_state, 0);
@ -2188,7 +2195,7 @@ SE_DEV_ALUA_SUPPORT_STATE_SHOW(lba_dependent,
tg_pt_gp_alua_supported_states, ALUA_LBD_SUP);
SE_DEV_ALUA_SUPPORT_STATE_STORE(lba_dependent,
tg_pt_gp_alua_supported_states, ALUA_LBD_SUP);
SE_DEV_ALUA_TG_PT_ATTR(alua_support_lba_dependent, S_IRUGO | S_IWUSR);
SE_DEV_ALUA_TG_PT_ATTR(alua_support_lba_dependent, S_IRUGO);
SE_DEV_ALUA_SUPPORT_STATE_SHOW(unavailable,
tg_pt_gp_alua_supported_states, ALUA_U_SUP);

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@ -1439,6 +1439,8 @@ struct se_device *target_alloc_device(struct se_hba *hba, const char *name)
spin_lock_init(&dev->t10_pr.aptpl_reg_lock);
INIT_LIST_HEAD(&dev->t10_alua.tg_pt_gps_list);
spin_lock_init(&dev->t10_alua.tg_pt_gps_lock);
INIT_LIST_HEAD(&dev->t10_alua.lba_map_list);
spin_lock_init(&dev->t10_alua.lba_map_lock);
dev->t10_wwn.t10_dev = dev;
dev->t10_alua.t10_dev = dev;

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@ -33,7 +33,7 @@
#include "target_core_internal.h"
#include "target_core_ua.h"
#include "target_core_alua.h"
static sense_reason_t
sbc_emulate_readcapacity(struct se_cmd *cmd)
@ -731,6 +731,9 @@ sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops)
case SAI_READ_CAPACITY_16:
cmd->execute_cmd = sbc_emulate_readcapacity_16;
break;
case SAI_REPORT_REFERRALS:
cmd->execute_cmd = target_emulate_report_referrals;
break;
default:
pr_err("Unsupported SA: 0x%02x\n",
cmd->t_task_cdb[1] & 0x1f);

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@ -476,6 +476,11 @@ spc_emulate_evpd_86(struct se_cmd *cmd, unsigned char *buf)
/* If WriteCache emulation is enabled, set V_SUP */
if (spc_check_dev_wce(dev))
buf[6] = 0x01;
/* If an LBA map is present set R_SUP */
spin_lock(&cmd->se_dev->t10_alua.lba_map_lock);
if (!list_empty(&dev->t10_alua.lba_map_list))
buf[8] = 0x10;
spin_unlock(&cmd->se_dev->t10_alua.lba_map_lock);
return 0;
}
@ -634,6 +639,20 @@ spc_emulate_evpd_b2(struct se_cmd *cmd, unsigned char *buf)
return 0;
}
/* Referrals VPD page */
static sense_reason_t
spc_emulate_evpd_b3(struct se_cmd *cmd, unsigned char *buf)
{
struct se_device *dev = cmd->se_dev;
buf[0] = dev->transport->get_device_type(dev);
buf[3] = 0x0c;
put_unaligned_be32(dev->t10_alua.lba_map_segment_size, &buf[8]);
put_unaligned_be32(dev->t10_alua.lba_map_segment_size, &buf[12]);
return 0;
}
static sense_reason_t
spc_emulate_evpd_00(struct se_cmd *cmd, unsigned char *buf);
@ -648,6 +667,7 @@ static struct {
{ .page = 0xb0, .emulate = spc_emulate_evpd_b0 },
{ .page = 0xb1, .emulate = spc_emulate_evpd_b1 },
{ .page = 0xb2, .emulate = spc_emulate_evpd_b2 },
{ .page = 0xb3, .emulate = spc_emulate_evpd_b3 },
};
/* supported vital product data pages */

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@ -155,6 +155,7 @@ enum scsi_timeouts {
/* values for service action in */
#define SAI_READ_CAPACITY_16 0x10
#define SAI_GET_LBA_STATUS 0x12
#define SAI_REPORT_REFERRALS 0x13
/* values for VARIABLE_LENGTH_CMD service action codes
* see spc4r17 Section D.3.5, table D.7 and D.8 */
#define VLC_SA_RECEIVE_CREDENTIAL 0x1800

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@ -247,10 +247,28 @@ typedef enum {
struct se_cmd;
struct t10_alua_lba_map_member {
struct list_head lba_map_mem_list;
int lba_map_mem_alua_state;
int lba_map_mem_alua_pg_id;
};
struct t10_alua_lba_map {
u64 lba_map_first_lba;
u64 lba_map_last_lba;
struct list_head lba_map_list;
struct list_head lba_map_mem_list;
};
struct t10_alua {
/* ALUA Target Port Group ID */
u16 alua_tg_pt_gps_counter;
u32 alua_tg_pt_gps_count;
/* Referrals support */
spinlock_t lba_map_lock;
u32 lba_map_segment_size;
u32 lba_map_segment_multiplier;
struct list_head lba_map_list;
spinlock_t tg_pt_gps_lock;
struct se_device *t10_dev;
/* Used for default ALUA Target Port Group */