From: Logan Gunthorpe
> Sent: 13 April 2017 23:05
> Straightforward conversion to the new helper, except due to
> the lack of error path, we have to warn if unmapable memory
> is ever present in the sgl.
> 
> Signed-off-by: Logan Gunthorpe <log...@deltatee.com>
> ---
>  drivers/block/xen-blkfront.c | 33 +++++++++++++++++++++++++++------
>  1 file changed, 27 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
> index 5067a0a..7dcf41d 100644
> --- a/drivers/block/xen-blkfront.c
> +++ b/drivers/block/xen-blkfront.c
> @@ -807,8 +807,19 @@ static int blkif_queue_rw_req(struct request *req, 
> struct blkfront_ring_info *ri
>               BUG_ON(sg->offset + sg->length > PAGE_SIZE);
> 
>               if (setup.need_copy) {
> -                     setup.bvec_off = sg->offset;
> -                     setup.bvec_data = kmap_atomic(sg_page(sg));
> +                     setup.bvec_off = 0;
> +                     setup.bvec_data = sg_map(sg, SG_KMAP_ATOMIC);
> +                     if (IS_ERR(setup.bvec_data)) {
> +                             /*
> +                              * This should really never happen unless
> +                              * the code is changed to use memory that is
> +                              * not mappable in the sg. Seeing there is a
> +                              * questionable error path out of here,
> +                              * we WARN.
> +                              */
> +                             WARN(1, "Non-mappable memory used in sg!");
> +                             return 1;
> +                     }
...

Perhaps add a flag to mark failure as 'unexpected' and trace (and panic?)
inside sg_map().

        David


-- 
You received this message because you are subscribed to the Google Groups 
"open-iscsi" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to open-iscsi+unsubscr...@googlegroups.com.
To post to this group, send email to open-iscsi@googlegroups.com.
Visit this group at https://groups.google.com/group/open-iscsi.
For more options, visit https://groups.google.com/d/optout.

Reply via email to