From: Kashyap Desai Date: Fri, 21 Oct 2016 13:33:32 +0000 (-0700) Subject: scsi: megaraid_sas: Fix data integrity failure for JBOD (passthrough) devices X-Git-Tag: v3.2.85~73 X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?p=pandora-kernel.git;a=commitdiff_plain;h=fd56263c04ae975c4d3ca367d09fa521836b8799 scsi: megaraid_sas: Fix data integrity failure for JBOD (passthrough) devices commit 1e793f6fc0db920400574211c48f9157a37e3945 upstream. 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 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 Signed-off-by: Ben Hutchings --- diff --git a/drivers/scsi/megaraid/megaraid_sas_base.c b/drivers/scsi/megaraid/megaraid_sas_base.c index 10550f3c7b45..6e1ae5951dea 100644 --- a/drivers/scsi/megaraid/megaraid_sas_base.c +++ b/drivers/scsi/megaraid/megaraid_sas_base.c @@ -1486,16 +1486,13 @@ megasas_queue_command_lck(struct scsi_cmnd *scmd, void (*done) (struct scsi_cmnd 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; } if (instance->instancet->build_and_issue_cmd(instance, scmd)) {