From b49d6f7885306ee636d5c1af52170f3069ccf5f7 Mon Sep 17 00:00:00 2001 From: David Disseldorp Date: Wed, 7 Nov 2018 14:11:07 +0100 Subject: 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_spc.c | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'drivers/target/target_core_spc.c') 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]; -- cgit v1.2.3