Re: [PATCH 6/8] xfs: fix uninitialized field in rtbitmap fsmap backend

["Darrick J. Wong" <darrick.wong@oracle.com>]

On Thu, Jun 21, 2018 at 11:41:18PM -0700, Christoph Hellwig wrote:
> On Thu, Jun 21, 2018 at 11:31:41AM -0700, Darrick J. Wong wrote:
> > From: Darrick J. Wong <darrick.wong@oracle.com>
> > 
> > Initialize the extent count field of the high key so that when we use
> > the high key to synthesize an 'unknown owner' record (i.e. used space
> > record) at the end of the queried range we have a field with which to
> > compute rm_blockcount.  This is not strictly necessary because the
> > synthesizer never uses the rm_blockcount field, but we can shut up the
> > static code analysis anyway.
> > 
> > Coverity-id: 1437358
> > Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
> 
> I'd rather ensure the structs are entirely zeroed to start with, e.g.:
> 
> diff --git a/fs/xfs/xfs_fsmap.c b/fs/xfs/xfs_fsmap.c
> index 0299febece9c..21bbdee451a6 100644
> --- a/fs/xfs/xfs_fsmap.c
> +++ b/fs/xfs/xfs_fsmap.c
> @@ -527,8 +527,8 @@ xfs_getfsmap_rtdev_rtbitmap_query(
>  	struct xfs_trans		*tp,
>  	struct xfs_getfsmap_info	*info)
>  {
> -	struct xfs_rtalloc_rec		alow;
> -	struct xfs_rtalloc_rec		ahigh;
> +	struct xfs_rtalloc_rec		alow = { 0, };
> +	struct xfs_rtalloc_rec		ahigh = { 0, };

Looks reasonable, I'll give it a spin overnight.

--D

>  	int				error;
>  
>  	xfs_ilock(tp->t_mountp->m_rbmip, XFS_ILOCK_SHARED);
> --
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