static sense_reason_t core_alua_check_transition()

in target_core_alua.c [32:128]

• 73 lines of code
• 10 McCabe index (conditional complexity)

static sense_reason_t core_alua_check_transition(int state, int valid,
						 int *primary, int explicit);
static int core_alua_set_tg_pt_secondary_state(
		struct se_lun *lun, int explicit, int offline);

static char *core_alua_dump_state(int state);

static void __target_attach_tg_pt_gp(struct se_lun *lun,
		struct t10_alua_tg_pt_gp *tg_pt_gp);

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, SAM_STAT_GOOD);
	return 0;
}