Re: [PATCH] xfs: always init bma in xfs_bmapi_write

[Brian Foster <bfoster@redhat.com>]

On Mon, Mar 18, 2019 at 09:44:01AM -0700, Darrick J. Wong wrote:
> From: Darrick J. Wong <darrick.wong@oracle.com>
> 
> Always init the tp/ip fields of bma in xfs_bmapi_write so that the
> bmapi_finish at the bottom never trips over null transaction or inode
> pointers.
> 
> Coverity-id: 1443964
> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
> ---
>  fs/xfs/libxfs/xfs_bmap.c |   10 +++++-----
>  1 file changed, 5 insertions(+), 5 deletions(-)
> 
> diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c
> index 625ddfb9653e..17c7168966c6 100644
> --- a/fs/xfs/libxfs/xfs_bmap.c
> +++ b/fs/xfs/libxfs/xfs_bmap.c
> @@ -4254,9 +4254,13 @@ xfs_bmapi_write(
>  	struct xfs_bmbt_irec	*mval,		/* output: map values */
>  	int			*nmap)		/* i/o: mval size/count */
>  {
> +	struct xfs_bmalloca	bma = {
> +		.tp		= tp,
> +		.ip		= ip,
> +		.total		= total,
> +	};

This should continue to zero-init the rest of the structure, right? If
so, looks fine:

Reviewed-by: Brian Foster <bfoster@redhat.com>

>  	struct xfs_mount	*mp = ip->i_mount;
>  	struct xfs_ifork	*ifp;
> -	struct xfs_bmalloca	bma = { NULL };	/* args for xfs_bmap_alloc */
>  	xfs_fileoff_t		end;		/* end of mapped file region */
>  	bool			eof = false;	/* after the end of extents */
>  	int			error;		/* error return */
> @@ -4324,10 +4328,6 @@ xfs_bmapi_write(
>  		eof = true;
>  	if (!xfs_iext_peek_prev_extent(ifp, &bma.icur, &bma.prev))
>  		bma.prev.br_startoff = NULLFILEOFF;
> -	bma.tp = tp;
> -	bma.ip = ip;
> -	bma.total = total;
> -	bma.datatype = 0;
>  	bma.minleft = xfs_bmapi_minleft(tp, ip, whichfork);
>  
>  	n = 0;