From 3425fbfe2293244abba72c80b215d09ead32d1ad Mon Sep 17 00:00:00 2001 From: "Moger, Babu" Date: Fri, 8 Apr 2011 11:39:30 -0600 Subject: [PATCH] [SCSI] scsi_dh_rdac : decide whether to send mode select based on operating mode Based on the operating modes, handler decides whether to send mode select or not. Purpose here is to reduce io-shipping as much as possible whenever there is an option. Signed-off-by: Babu Moger Reviewed-by: Yanling Qi Reviewed-by: Sudhir Dachepalli Reviewed-by: Somasundaram Krishnasamy Reviewed-by: Bob Stankey Reviewed-by: Vijay Chauhan Signed-off-by: James Bottomley --- drivers/scsi/device_handler/scsi_dh_rdac.c | 17 ++++++++++++++++- 1 file changed, 16 insertions(+), 1 deletion(-) diff --git a/drivers/scsi/device_handler/scsi_dh_rdac.c b/drivers/scsi/device_handler/scsi_dh_rdac.c index 4efe638..e7fc70d 100644 --- a/drivers/scsi/device_handler/scsi_dh_rdac.c +++ b/drivers/scsi/device_handler/scsi_dh_rdac.c @@ -670,12 +670,27 @@ static int rdac_activate(struct scsi_device *sdev, { struct rdac_dh_data *h = get_rdac_data(sdev); int err = SCSI_DH_OK; + int act = 0; err = check_ownership(sdev, h); if (err != SCSI_DH_OK) goto done; - if (h->lun_state == RDAC_LUN_UNOWNED) { + switch (h->mode) { + case RDAC_MODE: + if (h->lun_state == RDAC_LUN_UNOWNED) + act = 1; + break; + case RDAC_MODE_IOSHIP: + if ((h->lun_state == RDAC_LUN_UNOWNED) && + (h->preferred == RDAC_PREFERRED)) + act = 1; + break; + default: + break; + } + + if (act) { err = queue_mode_select(sdev, fn, data); if (err == SCSI_DH_OK) return 0; -- 2.7.4