[sheepdog] [PATCH v2 2/6] write inode at one time in vdi_create() and vdi_clone()

[Liu Yuan]

On Wed, Oct 16, 2013 at 03:21:47AM +0900, MORITA Kazutaka wrote:
> At Tue, 15 Oct 2013 14:45:36 +0800,
> Robin Dong wrote:
> > 
> > It will improve performance for writing whole inode once after changing all vids
> > instead of writing each vid every time.
> > 
> > Signed-off-by: Robin Dong <sanbai at taobao.com>
> > ---
> >  dog/vdi.c |   50 ++++++++++++++++++++++++++++++++------------------
> >  1 files changed, 32 insertions(+), 18 deletions(-)
> > 
> > diff --git a/dog/vdi.c b/dog/vdi.c
> > index 28509e2..02267ab 100644
> > --- a/dog/vdi.c
> > +++ b/dog/vdi.c
> > @@ -536,15 +536,18 @@ static int vdi_create(int argc, char **argv)
> >  		}
> >  
> >  		sd_inode_set_vdi(inode, idx, vid);
> > -		ret = sd_write_object(vid_to_vdi_oid(vid), 0, &vid, sizeof(vid),
> > -				      SD_INODE_HEADER_SIZE + sizeof(vid) * idx,
> > -				      0, inode->nr_copies, inode->copy_policy,
> > -				      false, true);
> > -		if (ret) {
> > -			ret = EXIT_FAILURE;
> > -			goto out;
> > -		}
> >  	}
> > +
> > +	ret = sd_write_object(vid_to_vdi_oid(vid), 0, inode,
> > +			      sizeof(uint32_t) * MAX_DATA_OBJS,
> > +			      SD_INODE_HEADER_SIZE, 0,
> > +			      inode->nr_copies, inode->copy_policy,
> > +			      false, true);
> > +	if (ret) {
> > +		ret = EXIT_FAILURE;
> > +		goto out;
> > +	}
> > +
> 
> This improves performance, but generates lots of orphan data objects
> if we interrupt vdi creation.  Do you have any performance number?
> 

I guess we can firstly update inode and then write data objects. if operation is
interrupted, we can delete the vdi and no orphan.

Thanks
Yuan