Re: [PATCH v3 2/9] xfs: make the seq argument to xfs_bmapi_convert_delalloc() optional

["Darrick J. Wong" <djwong@kernel.org>]

On Tue, Mar 19, 2024 at 09:10:55AM +0800, Zhang Yi wrote:
> From: Zhang Yi <yi.zhang@huawei.com>
> 
> Allow callers to pass a NULLL seq argument if they don't care about
> the fork sequence number.
> 
> Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
> Reviewed-by: Christoph Hellwig <hch@lst.de>

Aha, you want this because xfs_bmbt_to_iomap will set the iomap validity
cookie for us, whereas writeback wants to track the per-fork cookie in
the xfs writeback structure.  Ok.

Reviewed-by: Darrick J. Wong <djwong@kernel.org>

--D

> ---
>  fs/xfs/libxfs/xfs_bmap.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c
> index f362345467fa..07dc35de8ce5 100644
> --- a/fs/xfs/libxfs/xfs_bmap.c
> +++ b/fs/xfs/libxfs/xfs_bmap.c
> @@ -4574,7 +4574,8 @@ xfs_bmapi_convert_delalloc(
>  	if (!isnullstartblock(bma.got.br_startblock)) {
>  		xfs_bmbt_to_iomap(ip, iomap, &bma.got, 0, flags,
>  				xfs_iomap_inode_sequence(ip, flags));
> -		*seq = READ_ONCE(ifp->if_seq);
> +		if (seq)
> +			*seq = READ_ONCE(ifp->if_seq);
>  		goto out_trans_cancel;
>  	}
>  
> @@ -4623,7 +4624,8 @@ xfs_bmapi_convert_delalloc(
>  	ASSERT(!isnullstartblock(bma.got.br_startblock));
>  	xfs_bmbt_to_iomap(ip, iomap, &bma.got, 0, flags,
>  				xfs_iomap_inode_sequence(ip, flags));
> -	*seq = READ_ONCE(ifp->if_seq);
> +	if (seq)
> +		*seq = READ_ONCE(ifp->if_seq);
>  
>  	if (whichfork == XFS_COW_FORK)
>  		xfs_refcount_alloc_cow_extent(tp, bma.blkno, bma.length);
> -- 
> 2.39.2
> 
>