Commit c66094bf authored by Hannes Reinecke's avatar Hannes Reinecke Committed by Nicholas Bellinger
Browse files

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: default avatarHannes Reinecke <hare@suse.de>
Signed-off-by: default avatarNicholas Bellinger <nab@linux-iscsi.org>
parent fbfe858f

drivers/target/target_core_alua.c

+154 −0
Original line number Diff line number Diff line
@@ -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:

drivers/target/target_core_alua.h

+3 −1
Original line number Diff line number Diff line
@@ -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 *,

drivers/target/target_core_configfs.c

+8 −1
Original line number Diff line number Diff line
@@ -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);

drivers/target/target_core_device.c

+2 −0
Original line number Diff line number Diff line
@@ -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;

drivers/target/target_core_sbc.c

+4 −1
Original line number Diff line number Diff line
@@ -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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