From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?windows-1252?Q?Roger_Pau_Monn=E9?= Subject: Re: [PATCH RFC 2/5] blkif: document new blkback path xenstore node Date: Tue, 2 Jun 2015 17:22:04 +0200 Message-ID: <556DCA1C.4040606@citrix.com> References: <1432286338-56077-1-git-send-email-roger.pau@citrix.com> <1432286338-56077-3-git-send-email-roger.pau@citrix.com> <20150601132405.GG19403@zion.uk.xensource.com> Mime-Version: 1.0 Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: quoted-printable Return-path: Received: from mail6.bemta5.messagelabs.com ([195.245.231.135]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1Yzo2B-00025d-3A for xen-devel@lists.xenproject.org; Tue, 02 Jun 2015 15:23:19 +0000 In-Reply-To: <20150601132405.GG19403@zion.uk.xensource.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Wei Liu Cc: xen-devel@lists.xenproject.org, Tim Deegan , Ian Jackson , Jan Beulich , Ian Campbell List-Id: xen-devel@lists.xenproject.org El 01/06/15 a les 15.24, Wei Liu ha escrit: > On Fri, May 22, 2015 at 11:18:55AM +0200, Roger Pau Monne wrote: >> FreeBSD blkback uses the path xenstore node in order to fetch the path to >> the underlying backing storage (either a block device or raw image). This >> node is set by the hotplug scripts. >> >> Signed-off-by: Roger Pau Monn=E9 >> Cc: Ian Campbell >> Cc: Ian Jackson >> Cc: Jan Beulich >> Cc: Tim Deegan >> --- >> xen/include/public/io/blkif.h | 12 ++++++++++-- >> 1 file changed, 10 insertions(+), 2 deletions(-) >> >> diff --git a/xen/include/public/io/blkif.h b/xen/include/public/io/blkif= .h >> index 6baf7fb..b1e2245 100644 >> --- a/xen/include/public/io/blkif.h >> +++ b/xen/include/public/io/blkif.h >> @@ -89,8 +89,15 @@ >> * Values: string >> * >> * A free formatted string providing sufficient information for the >> - * backend driver to open the backing device. (e.g. the path to t= he >> - * file or block device representing the backing store.) >> + * hotplug script to attach the device and provide a suitable >> + * handler (ie: a block device) for blkback to use. >> + * >> + * path >> + * Values: string >> + * Notes: 11 >> + * >> + * A free formatted string that contains the path to the backing d= evice >> + * for this blkback instance. > = > Why can't FreeBSD use the same "physical-device" node as Linux and > NetBSD do? AIUI from reading this doc "physical-device" node already > covers both "file" and "block device", i.e. it's a superset of the > proposed "path" node here. Not sure why, but "physical-device" is not documented at all in blkif.h. I don't mind using the "physical-device" node, it's just that both Linux and NetBSD use it to store the block device major and minor numbers, and FreeBSD instead needs to store an absolute path (to either a block or regular file). If people think it's fine to have different formats for "physical-device" depending on the underlying OS I don't mind using it on FreeBSD also. Roger.