From 99a4f452c951c41f24b9bafd0910035e85c36854 Mon Sep 17 00:00:00 2001 From: Kashyap Desai Date: Fri, 21 Oct 2016 06:33:32 -0700 Subject: [PATCH] scsi: megaraid_sas: Fix data integrity failure for JBOD (passthrough) devices Commit 5c8fb9ee4e89 ("megaraid_sas: return sync cache call with success") modified the driver to successfully complete SYNCHRONIZE_CACHE commands without passing them to the controller. Disk drive caches are only explicitly managed by controller firmware when operating in RAID mode. So this commit effectively disabled writeback cache flushing for any drives used in JBOD mode, leading to data integrity failures. [mkp: clarified patch description] Fixes: 5c8fb9ee4e891eb3b83f2e32f81b864f050d24be CC: stable@vger.kernel.org Signed-off-by: Kashyap Desai Signed-off-by: Sumit Saxena Reviewed-by: Tomas Henzl Reviewed-by: Hannes Reinecke Reviewed-by: Ewan D. Milne Signed-off-by: Martin K. Petersen --- drivers/scsi/megaraid/megaraid_sas_base.c | 13 +++++-------- 1 file changed, 5 insertions(+), 8 deletions(-) diff --git a/drivers/scsi/megaraid/megaraid_sas_base.c b/drivers/scsi/megaraid/megaraid_sas_base.c index 9ff57dee72d7b..d8b1fbd4c8aaf 100644 --- a/drivers/scsi/megaraid/megaraid_sas_base.c +++ b/drivers/scsi/megaraid/megaraid_sas_base.c @@ -1700,16 +1700,13 @@ megasas_queue_command(struct Scsi_Host *shost, struct scsi_cmnd *scmd) goto out_done; } - switch (scmd->cmnd[0]) { - case SYNCHRONIZE_CACHE: - /* - * FW takes care of flush cache on its own - * No need to send it down - */ + /* + * FW takes care of flush cache on its own for Virtual Disk. + * No need to send it down for VD. For JBOD send SYNCHRONIZE_CACHE to FW. + */ + if ((scmd->cmnd[0] == SYNCHRONIZE_CACHE) && MEGASAS_IS_LOGICAL(scmd)) { scmd->result = DID_OK << 16; goto out_done; - default: - break; } return instance->instancet->build_and_issue_cmd(instance, scmd); -- 2.39.5