From b49d6f7885306ee636d5c1af52170f3069ccf5f7 Mon Sep 17 00:00:00 2001 From: David Disseldorp Date: Wed, 7 Nov 2018 14:11:07 +0100 Subject: [PATCH] scsi: target: add emulate_pr backstore attr to toggle PR support The new emulate_pr backstore attribute allows for Persistent Reservation and SCSI2 RESERVE/RELEASE support to be completely disabled. This can be useful for scenarios such as: - Ensuring ATS (Compare & Write) usage on recent VMware ESXi initiators. - Allowing clustered (e.g. tcm-user) backends to block such requests, avoiding the multi-node reservation state propagation. When explicitly disabled, PR and RESERVE/RELEASE requests receive Invalid Command Operation Code response sense data. Signed-off-by: David Disseldorp Reviewed-by: Mike Christie Reviewed-by: Christoph Hellwig Signed-off-by: Martin K. Petersen --- drivers/target/target_core_configfs.c | 24 ++++++++++++++++++------ drivers/target/target_core_device.c | 13 +++++++++++++ drivers/target/target_core_pr.c | 2 ++ drivers/target/target_core_spc.c | 8 ++++++++ include/target/target_core_base.h | 3 +++ 5 files changed, 44 insertions(+), 6 deletions(-) diff --git a/drivers/target/target_core_configfs.c b/drivers/target/target_core_configfs.c index f6b1549f4142..70b9f6755c36 100644 --- a/drivers/target/target_core_configfs.c +++ b/drivers/target/target_core_configfs.c @@ -532,6 +532,7 @@ DEF_CONFIGFS_ATTRIB_SHOW(emulate_tpu); DEF_CONFIGFS_ATTRIB_SHOW(emulate_tpws); DEF_CONFIGFS_ATTRIB_SHOW(emulate_caw); DEF_CONFIGFS_ATTRIB_SHOW(emulate_3pc); +DEF_CONFIGFS_ATTRIB_SHOW(emulate_pr); DEF_CONFIGFS_ATTRIB_SHOW(pi_prot_type); DEF_CONFIGFS_ATTRIB_SHOW(hw_pi_prot_type); DEF_CONFIGFS_ATTRIB_SHOW(pi_prot_format); @@ -592,6 +593,7 @@ static ssize_t _name##_store(struct config_item *item, const char *page, \ DEF_CONFIGFS_ATTRIB_STORE_BOOL(emulate_fua_write); DEF_CONFIGFS_ATTRIB_STORE_BOOL(emulate_caw); DEF_CONFIGFS_ATTRIB_STORE_BOOL(emulate_3pc); +DEF_CONFIGFS_ATTRIB_STORE_BOOL(emulate_pr); DEF_CONFIGFS_ATTRIB_STORE_BOOL(enforce_pr_isids); DEF_CONFIGFS_ATTRIB_STORE_BOOL(is_nonrot); @@ -1116,6 +1118,7 @@ CONFIGFS_ATTR(, emulate_tpu); CONFIGFS_ATTR(, emulate_tpws); CONFIGFS_ATTR(, emulate_caw); CONFIGFS_ATTR(, emulate_3pc); +CONFIGFS_ATTR(, emulate_pr); CONFIGFS_ATTR(, pi_prot_type); CONFIGFS_ATTR_RO(, hw_pi_prot_type); CONFIGFS_ATTR(, pi_prot_format); @@ -1156,6 +1159,7 @@ struct configfs_attribute *sbc_attrib_attrs[] = { &attr_emulate_tpws, &attr_emulate_caw, &attr_emulate_3pc, + &attr_emulate_pr, &attr_pi_prot_type, &attr_hw_pi_prot_type, &attr_pi_prot_format, @@ -1427,6 +1431,9 @@ static ssize_t target_pr_res_holder_show(struct config_item *item, char *page) struct se_device *dev = pr_to_dev(item); int ret; + if (!dev->dev_attrib.emulate_pr) + return sprintf(page, "SPC_RESERVATIONS_DISABLED\n"); + if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_PGR) return sprintf(page, "Passthrough\n"); @@ -1567,12 +1574,14 @@ static ssize_t target_pr_res_type_show(struct config_item *item, char *page) { struct se_device *dev = pr_to_dev(item); + if (!dev->dev_attrib.emulate_pr) + return sprintf(page, "SPC_RESERVATIONS_DISABLED\n"); if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_PGR) return sprintf(page, "SPC_PASSTHROUGH\n"); - else if (dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS) + if (dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS) return sprintf(page, "SPC2_RESERVATIONS\n"); - else - return sprintf(page, "SPC3_PERSISTENT_RESERVATIONS\n"); + + return sprintf(page, "SPC3_PERSISTENT_RESERVATIONS\n"); } static ssize_t target_pr_res_aptpl_active_show(struct config_item *item, @@ -1580,7 +1589,8 @@ static ssize_t target_pr_res_aptpl_active_show(struct config_item *item, { struct se_device *dev = pr_to_dev(item); - if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_PGR) + if (!dev->dev_attrib.emulate_pr || + (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_PGR)) return 0; return sprintf(page, "APTPL Bit Status: %s\n", @@ -1592,7 +1602,8 @@ static ssize_t target_pr_res_aptpl_metadata_show(struct config_item *item, { struct se_device *dev = pr_to_dev(item); - if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_PGR) + if (!dev->dev_attrib.emulate_pr || + (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_PGR)) return 0; return sprintf(page, "Ready to process PR APTPL metadata..\n"); @@ -1638,7 +1649,8 @@ static ssize_t target_pr_res_aptpl_metadata_store(struct config_item *item, u16 tpgt = 0; u8 type = 0; - if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_PGR) + if (!dev->dev_attrib.emulate_pr || + (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_PGR)) return count; if (dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS) return count; diff --git a/drivers/target/target_core_device.c b/drivers/target/target_core_device.c index 47b5ef153135..3274a5fa825c 100644 --- a/drivers/target/target_core_device.c +++ b/drivers/target/target_core_device.c @@ -805,6 +805,7 @@ struct se_device *target_alloc_device(struct se_hba *hba, const char *name) dev->dev_attrib.emulate_tpws = DA_EMULATE_TPWS; dev->dev_attrib.emulate_caw = DA_EMULATE_CAW; dev->dev_attrib.emulate_3pc = DA_EMULATE_3PC; + dev->dev_attrib.emulate_pr = DA_EMULATE_PR; dev->dev_attrib.pi_prot_type = TARGET_DIF_TYPE0_PROT; dev->dev_attrib.enforce_pr_isids = DA_ENFORCE_PR_ISIDS; dev->dev_attrib.force_pr_aptpl = DA_FORCE_PR_APTPL; @@ -1158,6 +1159,18 @@ passthrough_parse_cdb(struct se_cmd *cmd, return TCM_NO_SENSE; } + /* + * With emulate_pr disabled, all reservation requests should fail, + * regardless of whether or not TRANSPORT_FLAG_PASSTHROUGH_PGR is set. + */ + if (!dev->dev_attrib.emulate_pr && + ((cdb[0] == PERSISTENT_RESERVE_IN) || + (cdb[0] == PERSISTENT_RESERVE_OUT) || + (cdb[0] == RELEASE || cdb[0] == RELEASE_10) || + (cdb[0] == RESERVE || cdb[0] == RESERVE_10))) { + return TCM_UNSUPPORTED_SCSI_OPCODE; + } + /* * For PERSISTENT RESERVE IN/OUT, RELEASE, and RESERVE we need to * emulate the response, since tcmu does not have the information diff --git a/drivers/target/target_core_pr.c b/drivers/target/target_core_pr.c index 10db5656fd5d..91a2927acd36 100644 --- a/drivers/target/target_core_pr.c +++ b/drivers/target/target_core_pr.c @@ -4095,6 +4095,8 @@ target_check_reservation(struct se_cmd *cmd) return 0; if (dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE) return 0; + if (!dev->dev_attrib.emulate_pr) + return 0; if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_PGR) return 0; diff --git a/drivers/target/target_core_spc.c b/drivers/target/target_core_spc.c index f459118bc11b..5c49eb6f4929 100644 --- a/drivers/target/target_core_spc.c +++ b/drivers/target/target_core_spc.c @@ -1281,6 +1281,14 @@ spc_parse_cdb(struct se_cmd *cmd, unsigned int *size) struct se_device *dev = cmd->se_dev; unsigned char *cdb = cmd->t_task_cdb; + if (!dev->dev_attrib.emulate_pr && + ((cdb[0] == PERSISTENT_RESERVE_IN) || + (cdb[0] == PERSISTENT_RESERVE_OUT) || + (cdb[0] == RELEASE || cdb[0] == RELEASE_10) || + (cdb[0] == RESERVE || cdb[0] == RESERVE_10))) { + return TCM_UNSUPPORTED_SCSI_OPCODE; + } + switch (cdb[0]) { case MODE_SELECT: *size = cdb[4]; diff --git a/include/target/target_core_base.h b/include/target/target_core_base.h index e3bdb0550a59..c15054116b86 100644 --- a/include/target/target_core_base.h +++ b/include/target/target_core_base.h @@ -87,6 +87,8 @@ #define DA_EMULATE_3PC 1 /* No Emulation for PSCSI by default */ #define DA_EMULATE_ALUA 0 +/* Emulate SCSI2 RESERVE/RELEASE and Persistent Reservations by default */ +#define DA_EMULATE_PR 1 /* Enforce SCSI Initiator Port TransportID with 'ISID' for PR */ #define DA_ENFORCE_PR_ISIDS 1 /* Force SPC-3 PR Activate Persistence across Target Power Loss */ @@ -664,6 +666,7 @@ struct se_dev_attrib { int emulate_tpws; int emulate_caw; int emulate_3pc; + int emulate_pr; int pi_prot_format; enum target_prot_type pi_prot_type; enum target_prot_type hw_pi_prot_type;