[PATCH 06/17] scsi_dh_alua: use flag for RTPG extended header

Hannes Reinecke
2015-05-04T12:42:28Z

We should be using a flag when RTPG extended header is not
supported, that saves us sending RTPG twice for older arrays.

Signed-off-by: Hannes Reinecke <hare@suse.de>
---
drivers/scsi/device_handler/scsi_dh_alua.c | 13 ++++++-------
1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/drivers/scsi/device_handler/scsi_dh_alua.c b/drivers/scsi/device_handler/scsi_dh_alua.c
index f5d5859..69cad2a 100644
--- a/drivers/scsi/device_handler/scsi_dh_alua.c
+++ b/drivers/scsi/device_handler/scsi_dh_alua.c
@@ -61,6 +61,7 @@

/* flags passed from user level */
#define ALUA_OPTIMIZE_STPG 1
+#define ALUA_RTPG_EXT_HDR_UNSUPP 2

struct alua_dh_data {
int group_id;
@@ -135,8 +136,7 @@ static struct request *get_alua_req(struct scsi_device *sdev,
* submit_rtpg - Issue a REPORT TARGET GROUP STATES command
* @sdev: sdev the command should be sent to
*/
-static unsigned submit_rtpg(struct scsi_device *sdev, struct alua_dh_data *h,
- bool rtpg_ext_hdr_req)
+static unsigned submit_rtpg(struct scsi_device *sdev, struct alua_dh_data *h)
{
struct request *rq;
int err;
@@ -149,7 +149,7 @@ static unsigned submit_rtpg(struct scsi_device *sdev, struct alua_dh_data *h,

/* Prepare the command. */
rq->cmd[0] = MAINTENANCE_IN;
- if (rtpg_ext_hdr_req)
+ if (!(h->flags & ALUA_RTPG_EXT_HDR_UNSUPP))
rq->cmd[1] = MI_REPORT_TARGET_PGS | MI_EXT_HDR_PARAM_FMT;
else
rq->cmd[1] = MI_REPORT_TARGET_PGS;
@@ -499,7 +499,6 @@ static int alua_rtpg(struct scsi_device *sdev, struct alua_dh_data *h, int wait_
int len, k, off, valid_states = 0;
unsigned char *ucp;
unsigned err, retval;
- bool rtpg_ext_hdr_req = 1;
unsigned long expiry, interval = 0;
unsigned int tpg_desc_tbl_off;
unsigned char orig_transition_tmo;
@@ -510,7 +509,7 @@ static int alua_rtpg(struct scsi_device *sdev, struct alua_dh_data *h, int wait_
expiry = round_jiffies_up(jiffies + h->transition_tmo * HZ);

retry:
- retval = submit_rtpg(sdev, h, rtpg_ext_hdr_req);
+ retval = submit_rtpg(sdev, h);

if (retval) {
if (h->senselen == 0 ||
@@ -534,10 +533,10 @@ static int alua_rtpg(struct scsi_device *sdev, struct alua_dh_data *h, int wait_
* The retry without rtpg_ext_hdr_req set
* handles this.
*/
- if (rtpg_ext_hdr_req == 1 &&
+ if (!(h->flags & ALUA_RTPG_EXT_HDR_UNSUPP) &&
sense_hdr.sense_key == ILLEGAL_REQUEST &&
sense_hdr.asc == 0x24 && sense_hdr.ascq == 0) {
- rtpg_ext_hdr_req = 0;
+ h->flags |= ALUA_RTPG_EXT_HDR_UNSUPP;
goto retry;
}

--
1.8.5.2