From c66094bf325ee406b92298d73089ee25484a0263 Mon Sep 17 00:00:00 2001 From: Hannes Reinecke Date: Tue, 17 Dec 2013 09:18:49 +0100 Subject: 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 Signed-off-by: Nicholas Bellinger --- drivers/target/target_core_alua.c | 154 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 154 insertions(+) (limited to 'drivers/target/target_core_alua.c') diff --git a/drivers/target/target_core_alua.c b/drivers/target/target_core_alua.c index 01f0c71891d6..0843c8f4b94e 100644 --- a/drivers/target/target_core_alua.c +++ b/drivers/target/target_core_alua.c @@ -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: -- cgit v1.2.1