From 1e793f6fc0db920400574211c48f9157a37e3945 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 02b01e010afe ("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: 02b01e010afeeb49328d35650d70721d2ca3fd59 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 9ff57dee72d7..d8b1fbd4c8aa 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); -- 2.20.1