From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Disseldorp Date: Fri, 01 Jun 2018 00:05:32 +0000 Subject: [RFC PATCH] target: add emulate_pr backstore attr to toggle PR support Message-Id: <20180601000532.11058-1-ddiss@suse.de> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: target-devel@vger.kernel.org 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: - Enforcing 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 --- drivers/target/target_core_configfs.c | 21 ++++++++++++++++----- drivers/target/target_core_device.c | 1 + drivers/target/target_core_pr.c | 22 ++++++++++++++++++++++ include/target/target_core_base.h | 3 +++ 4 files changed, 42 insertions(+), 5 deletions(-) diff --git a/drivers/target/target_core_configfs.c b/drivers/target/target_core_configfs.c index 3f4bf126eed0..17b830e35a08 100644 --- a/drivers/target/target_core_configfs.c +++ b/drivers/target/target_core_configfs.c @@ -530,6 +530,7 @@ 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); @@ -590,6 +591,7 @@ 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); @@ -1114,6 +1116,7 @@ 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); @@ -1154,6 +1157,7 @@ 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, @@ -1428,6 +1432,9 @@ static ssize_t target_pr_res_holder_show(struct config_item *item, char *page) if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_PGR) return sprintf(page, "Passthrough\n"); + if (!dev->dev_attrib.emulate_pr) + return sprintf(page, "Reservations Disabled\n"); + spin_lock(&dev->dev_reservation_lock); if (dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS) ret = target_core_dev_pr_show_spc2_res(dev, page); @@ -1567,10 +1574,12 @@ static ssize_t target_pr_res_type_show(struct config_item *item, char *page) 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_attrib.emulate_pr) + return sprintf(page, "Reservations Disabled\n"); + 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, @@ -1578,7 +1587,8 @@ 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->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH) + || !dev->dev_attrib.emulate_pr) return 0; return sprintf(page, "APTPL Bit Status: %s\n", @@ -1590,7 +1600,8 @@ 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->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH) + || !dev->dev_attrib.emulate_pr) return 0; return sprintf(page, "Ready to process PR APTPL metadata..\n"); diff --git a/drivers/target/target_core_device.c b/drivers/target/target_core_device.c index e27db4d45a9d..96a60072e446 100644 --- a/drivers/target/target_core_device.c +++ b/drivers/target/target_core_device.c @@ -806,6 +806,7 @@ 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; diff --git a/drivers/target/target_core_pr.c b/drivers/target/target_core_pr.c index 2e865fdaa362..9960a44c3a59 100644 --- a/drivers/target/target_core_pr.c +++ b/drivers/target/target_core_pr.c @@ -208,6 +208,11 @@ target_scsi2_reservation_release(struct se_cmd *cmd) struct se_portal_group *tpg; int rc; + if (!dev->dev_attrib.emulate_pr) { + pr_err("failing SCSI2 RELEASE with emulate_pr disabled\n"); + return TCM_UNSUPPORTED_SCSI_OPCODE; + } + if (!sess || !sess->se_tpg) goto out; rc = target_check_scsi2_reservation_conflict(cmd); @@ -255,6 +260,11 @@ target_scsi2_reservation_reserve(struct se_cmd *cmd) sense_reason_t ret = 0; int rc; + if (!dev->dev_attrib.emulate_pr) { + pr_err("failing SCSI2 RESERVE with emulate_pr disabled\n"); + return TCM_UNSUPPORTED_SCSI_OPCODE; + } + if ((cmd->t_task_cdb[1] & 0x01) && (cmd->t_task_cdb[1] & 0x02)) { pr_err("LongIO and Obsolete Bits set, returning ILLEGAL_REQUEST\n"); @@ -3560,6 +3570,11 @@ target_scsi3_emulate_pr_out(struct se_cmd *cmd) int spec_i_pt = 0, all_tg_pt = 0, unreg = 0; sense_reason_t ret; + if (!dev->dev_attrib.emulate_pr) { + pr_err("failing PROUT with emulate_pr disabled\n"); + return TCM_UNSUPPORTED_SCSI_OPCODE; + } + /* * Following spc2r20 5.5.1 Reservations overview: * @@ -4045,6 +4060,11 @@ target_scsi3_emulate_pr_in(struct se_cmd *cmd) { sense_reason_t ret; + if (!cmd->se_dev->dev_attrib.emulate_pr) { + pr_err("failing PRIN with emulate_pr disabled\n"); + return TCM_UNSUPPORTED_SCSI_OPCODE; + } + /* * Following spc2r20 5.5.1 Reservations overview: * @@ -4097,6 +4117,8 @@ target_check_reservation(struct se_cmd *cmd) return 0; if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_PGR) return 0; + if (!dev->dev_attrib.emulate_pr) + return 0; spin_lock(&dev->dev_reservation_lock); if (dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS) diff --git a/include/target/target_core_base.h b/include/target/target_core_base.h index 9f9f5902af38..06d88645938b 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 */ @@ -665,6 +667,7 @@ 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; -- 2.13.6