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

[Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>]

> 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
>