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

[Jens Axboe <jens.axboe@oracle.com>]

On Fri, Dec 05 2008, Alan D. Brunelle wrote:
> 

> 
> 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@hp.com>
> Cc: Jens Axboe <jens.axboe@oracle.com>

Looks good.

Acked-by: Jens Axboe <jens.axboe@oracle.com>

Perhaps James can push it in, I'm about to shutdown for the day...


> ---
>  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
> 


-- 
Jens Axboe