Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932649AbdCIPmX convert rfc822-to-8bit (ORCPT ); Thu, 9 Mar 2017 10:42:23 -0500 Received: from userp1050.oracle.com ([156.151.31.82]:26563 "EHLO userp1050.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932275AbdCIPmV (ORCPT ); Thu, 9 Mar 2017 10:42:21 -0500 Subject: Re: [PATCH v2 4/7] xen/9pfs: connect to the backend To: Stefano Stabellini , xen-devel@lists.xenproject.org References: <1489017502-18617-1-git-send-email-sstabellini@kernel.org> <1489017502-18617-4-git-send-email-sstabellini@kernel.org> Cc: linux-kernel@vger.kernel.org, Stefano Stabellini , jgross@suse.com, Eric Van Hensbergen , Ron Minnich , Latchesar Ionkov , v9fs-developer@lists.sourceforge.net From: Boris Ostrovsky Message-ID: <087e9f1a-824a-02af-6822-f74f906d3356@oracle.com> Date: Thu, 9 Mar 2017 10:40:38 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.6.0 MIME-Version: 1.0 In-Reply-To: <1489017502-18617-4-git-send-email-sstabellini@kernel.org> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 8BIT X-Source-IP: userp1040.oracle.com [156.151.31.81] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1247 Lines: 37 > + > +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