Re: [Xen-devel] [PATCH] [RFC] Xen PV backend: Move call to bdrv_new from blk_init to blk_connect

[Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>]

On Mon, 1 Apr 2013, Alex Bligh wrote:
> Stefano,
> 
> --On 1 April 2013 16:44:05 +0100 Stefano Stabellini 
> <stefano.stabellini@xxxxxxxxxxxxx> wrote:
> 
> >> Note this patch is compile-tested only.
> >
> > I think the patch looks good, just a minor comment.
> 
> Thanks. I guess I ought to actually test it works then :-)
> 
> >> +    /* fill info
> >> +     * Temporarily write zero sectors as we won't know file size until
> >> +     * bdrv_new has been called. blk_connect corrects this.
> >> +     */
> >> +    xenstore_write_be_int(&blkdev->xendev, "feature-flush-cache", 1);
> >> +    xenstore_write_be_int(&blkdev->xendev, "feature-persistent", 1);
> >> +    xenstore_write_be_int(&blkdev->xendev, "info", info);
> >> +    xenstore_write_be_int(&blkdev->xendev, "sector-size", BLOCK_SIZE);
> >> +    xenstore_write_be_int(&blkdev->xendev, "sectors", 0);
> >> +    return 0;
> >
> > There is no need to fill the sector-size and sectors info here, you can
> > do it later in blk_connect.
> 
> My concern (not knowing how xenstore works) was the possibility of leaving
> them as uninitialized values. I'm taking it that if I don't initialise
> them, the key is just absent - correct?

Right


> I'll redo and move setting sector-size and sectors into blk_connect, and
> then add a second commit which removes BDRV_O_NOCACHE. Oh, and test it ...

Good :)

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel