[PATCH] Correctly release and allocate a new request on TUR retries

From: Alan D. Brunelle
Date: Fri Dec 05 2008 - 09:37:20 EST




Commands needing to be retried (TUR in this case) would result in a block
I/O request being re-used, without being re-initialized properly. This
patch ensures that the requests are correctly re-initialized via
standard allocation means.

Prior to this patch, boots were failing consistently as in:
http://lkml.org/lkml/2008/12/5/161

With this patch in place, the system is booting reliably.

Signed-off-by: Alan D. Brunelle <alan.brunelle@xxxxxx>
Cc: Jens Axboe <jens.axboe@xxxxxxxxxx>
---
drivers/scsi/device_handler/scsi_dh_hp_sw.c | 6 ++++--
1 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/scsi/device_handler/scsi_dh_hp_sw.c b/drivers/scsi/device_handler/scsi_dh_hp_sw.c
index 9aec4ca..1f6b6a8 100644
--- a/drivers/scsi/device_handler/scsi_dh_hp_sw.c
+++ b/drivers/scsi/device_handler/scsi_dh_hp_sw.c
@@ -107,6 +107,7 @@ static int hp_sw_tur(struct scsi_device *sdev, struct hp_sw_dh_data *h)
struct request *req;
int ret;

+retry:
req = blk_get_request(sdev->request_queue, WRITE, GFP_NOIO);
if (!req)
return SCSI_DH_RES_TEMP_UNAVAIL;
@@ -121,7 +122,6 @@ static int hp_sw_tur(struct scsi_device *sdev, struct hp_sw_dh_data *h)
memset(req->sense, 0, SCSI_SENSE_BUFFERSIZE);
req->sense_len = 0;

-retry:
ret = blk_execute_rq(req->q, NULL, req, 1);
if (ret == -EIO) {
if (req->sense_len > 0) {
@@ -136,8 +136,10 @@ retry:
h->path_state = HP_SW_PATH_ACTIVE;
ret = SCSI_DH_OK;
}
- if (ret == SCSI_DH_IMM_RETRY)
+ if (ret == SCSI_DH_IMM_RETRY) {
+ blk_put_request(req);
goto retry;
+ }
if (ret == SCSI_DH_DEV_OFFLINED) {
h->path_state = HP_SW_PATH_PASSIVE;
ret = SCSI_DH_OK;
--
1.5.6.3