Re: [Xen-devel] [PATCH] xen-blkback: fix two memleaks

[Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>]

> diff --git a/drivers/block/xen-blkback/xenbus.c 
> b/drivers/block/xen-blkback/xenbus.c
> index 44396b8..dabdb18 100644
> --- a/drivers/block/xen-blkback/xenbus.c
> +++ b/drivers/block/xen-blkback/xenbus.c
> @@ -246,6 +246,9 @@ static int xen_blkif_disconnect(struct xen_blkif *blkif)
>       struct pending_req *req, *n;
>       unsigned int j, r;
>  
> +     if (!blkif->rings)
> +             goto out;
> +

I dropped this and instead added: blkif->nr_rings = 0.

Which will mean we can still run through this function many
times but that should not be a problem.

>       for (r = 0; r < blkif->nr_rings; r++) {
>               struct xen_blkif_ring *ring = &blkif->rings[r];
>               unsigned int i = 0;
> @@ -299,7 +302,14 @@ static int xen_blkif_disconnect(struct xen_blkif *blkif)
>               WARN_ON(i != (XEN_BLKIF_REQS_PER_PAGE * blkif->nr_ring_pages));
>       }
>       blkif->nr_ring_pages = 0;

> +     /*
> +      * blkif->rings was allocated in connect_ring, so we should free it in
> +      * disconnect.

s/disconnect/here/

> +      */
> +     kfree(blkif->rings);
> +     blkif->rings = NULL;

And perhaps also:
        blkif->nr_rings = 0?
>  
> +out:
>       return 0;
>  }
>  
> @@ -310,7 +320,6 @@ static void xen_blkif_free(struct xen_blkif *blkif)
>       xen_vbd_free(&blkif->vbd);
>  
>       /* Make sure everything is drained before shutting down */
> -     kfree(blkif->rings);
>       kmem_cache_free(xen_blkif_cachep, blkif);
>  }
>  
> @@ -505,6 +514,8 @@ static int xen_blkbk_remove(struct xenbus_device *dev)
>                       xen_blkif_put(be->blkif);
>       }
>  
> +     /* Put the reference got in xen_blkif_alloc(). */

s/got/we set/

Updated this and testing it as such.
> +     xen_blkif_put(be->blkif);
>       kfree(be->mode);
>       kfree(be);
>       return 0;
> -- 
> 1.7.10.4
> 

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