> +
> +static int xen_9pfs_front_alloc_dataring(struct xenbus_device *dev,
> + struct xen_9pfs_dataring *ring)
> +{
> + int i;
> + int ret = -ENOMEM;
> +
> + init_waitqueue_head(&ring->wq);
> + spin_lock_init(&ring->lock);
> + INIT_WORK(&ring->work, p9_xen_response);
> +
> + ring->intf = (struct xen_9pfs_data_intf *) get_zeroed_page(GFP_KERNEL |
> __GFP_ZERO);
> + if (!ring->intf)
> + return ret;
> + ring->ref = gnttab_grant_foreign_access(dev->otherend_id,
> virt_to_gfn(ring->intf), 0);
> + ring->bytes = (void*)__get_free_pages(GFP_KERNEL | __GFP_ZERO,
> + XEN_9PFS_RING_ORDER - (PAGE_SHIFT - XEN_PAGE_SHIFT));
> + if (ring->bytes == NULL)
> + goto out;
> + for (i = 0; i < (1 << XEN_9PFS_RING_ORDER); i++)
> + ring->intf->ref[i] =
> gnttab_grant_foreign_access(dev->otherend_id, virt_to_gfn(ring->bytes) + i,
> 0);
You need to handle gnttab_grant_foreign_access() returning an error. For
ring->ref too.
(and maybe wrap the line above)
> + ring->ring.in = ring->bytes;
ring->ring? Maybe 'dataring' for the top-level structure?
BTW, do we really need 'bytes' member? It's always 'ring.in' AFAICT. You
could make it a union with 'ring' (the second 'ring' ;-)) if you want to
keep a pointer to the whole thing as a dedicated name.
-boris
