Re: [PATCH 2/2] block,scsi: convert and handle ERR_PTR from blk_get_request

[Joe Lawrence]

On Tue, 3 Jun 2014 16:07:01 -0400
Jeff Moyer <jmoyer@xxxxxxxxxx> wrote:

> Joe Lawrence <joe.lawrence@xxxxxxxxxxx> writes:
> 
> > diff --git a/block/bsg.c b/block/bsg.c
> > index 420a5a9..2b1c322 100644
> > --- a/block/bsg.c
> > +++ b/block/bsg.c
> > @@ -271,8 +271,8 @@ bsg_map_hdr(struct bsg_device *bd, struct sg_io_v4 *hdr, fmode_t has_write_perm,
> >  	 * map scatter-gather elements separately and string them to request
> >  	 */
> >  	rq = blk_get_request(q, rw, GFP_KERNEL);
> > -	if (!rq)
> > -		return ERR_PTR(-ENOMEM);
> > +	if (IS_ERR(rq))
> > +		return rq;
> >  	ret = blk_fill_sgv4_hdr_rq(q, rq, hdr, bd, has_write_perm);
> >  	if (ret)
> >  		goto out;
> > @@ -284,8 +284,8 @@ bsg_map_hdr(struct bsg_device *bd, struct sg_io_v4 *hdr, fmode_t has_write_perm,
> >  		}
> >  
> >  		next_rq = blk_get_request(q, READ, GFP_KERNEL);
> > -		if (!next_rq) {
> > -			ret = -ENOMEM;
> > +		if (IS_ERR(next_rq)) {
> > +			ret = PTR_ERR(rq);
> 
> ITYM ret = PTR_ERR(next_rq), right?

Oops, you are right of course.  I can include this change if there should be another version (Jens?)

> > diff --git a/drivers/scsi/device_handler/scsi_dh_hp_sw.c b/drivers/scsi/device_handler/scsi_dh_hp_sw.c
> > index 084062b..1cf4019 100644
> > --- a/drivers/scsi/device_handler/scsi_dh_hp_sw.c
> > +++ b/drivers/scsi/device_handler/scsi_dh_hp_sw.c
> > @@ -117,7 +117,7 @@ static int hp_sw_tur(struct scsi_device *sdev, struct hp_sw_dh_data *h)
> >  
> >  retry:
> >  	req = blk_get_request(sdev->request_queue, WRITE, GFP_NOIO);
> > -	if (!req)
> > +	if (IS_ERR(req))
> >  		return SCSI_DH_RES_TEMP_UNAVAIL;
> >  
> 
> Don't we have an opportunity here to differentiate between enomem and
> eio?  I have no idea what the right SCSI_DH error would be, I'm just
> asking the question.
> 
> >  	req->cmd_type = REQ_TYPE_BLOCK_PC;
> > @@ -247,7 +247,7 @@ static int hp_sw_start_stop(struct hp_sw_dh_data *h)
> >  	struct request *req;
> >  
> >  	req = blk_get_request(h->sdev->request_queue, WRITE, GFP_ATOMIC);
> > -	if (!req)
> > +	if (IS_ERR(req))
> >  		return SCSI_DH_RES_TEMP_UNAVAIL;
> 
> Same goes here.

This sounded familiar, so I dug through my mailbox and found the
following patch.  When the blk_get_request patches stalled, I stopped
working on the scsi_dh patch.  But I think you would be talking about
the introduction of something like "errno_to_SCSI_DH" below...

Thanks,

-- Joe

-- >8 --