Messages in this thread Patch in this message | | | From | Rusty Russell <> | Subject | Re: [PATCH] virtio-blk: allow toggling host cache between writeback and writethrough | Date | Wed, 25 Jul 2012 10:32:27 +0930 |
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On Thu, 05 Jul 2012 09:02:23 +0200, Sasha Levin <levinsasha928@gmail.com> wrote: > On Thu, 2012-07-05 at 08:47 +0200, Paolo Bonzini wrote: > > Il 04/07/2012 23:11, Sasha Levin ha scritto: > > > There are two things going on here: > > > 1. Rename VIRTIO_BLK_F_FLUSH to VIRTIO_BLK_F_WCE > > > 2. Add a new VIRTIO_BLK_F_CONFIG_WCE > > > > > > I'm concerned that the first change is going to break compilation for > > > any code that included linux/virtio-blk.h and used VIRTIO_BLK_F_FLUSH. > > > > That would be nlkt, right? :) > > nlkt, lguest, and probably others. > > linux/virtio_blk.h is a public kernel header, which is supposed to be > used from userspace - so I assume many others who implemented virtio-blk > for any reason took advantage of that header.
BTW, I have patched this myself now:
From: Rusty Russell <rusty@rustcorp.com.au> Subject: virtio-blk: return VIRTIO_BLK_F_FLUSH to header.
This got renamed and clarified, but let's not break any userspace out there.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> --- include/linux/virtio_blk.h | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/include/linux/virtio_blk.h b/include/linux/virtio_blk.h --- a/include/linux/virtio_blk.h +++ b/include/linux/virtio_blk.h @@ -41,6 +41,11 @@ #define VIRTIO_BLK_F_TOPOLOGY 10 /* Topology information is available */ #define VIRTIO_BLK_F_CONFIG_WCE 11 /* Writeback mode available in config */ +#ifndef __KERNEL__ +/* Old (deprecated) name for VIRTIO_BLK_F_WCE. */ +#define VIRTIO_BLK_F_FLUSH VIRTIO_BLK_F_WCE +#endif + #define VIRTIO_BLK_ID_BYTES 20 /* ID string length */ struct virtio_blk_config {
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