Re: [PATCH 2/8] xfs: don't use xfs_trans_reserve in xfs_trans_reserve_more

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

On Tue, Jul 15, 2025 at 02:25:35PM +0200, Christoph Hellwig wrote:
> xfs_trans_reserve_more just tries to allocate additional blocks and/or
> rtextents and is otherwise unrelated to the transaction reservation
> logic.  Open code the block and rtextent reservation in
> xfs_trans_reserve_more to prepare for simplifying xfs_trans_reserve.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>  fs/xfs/xfs_trans.c | 15 ++++++++++++---
>  1 file changed, 12 insertions(+), 3 deletions(-)
> 
> diff --git a/fs/xfs/xfs_trans.c b/fs/xfs/xfs_trans.c
> index 8b15bfe68774..1fddea8d761a 100644
> --- a/fs/xfs/xfs_trans.c
> +++ b/fs/xfs/xfs_trans.c
> @@ -1146,9 +1146,18 @@ xfs_trans_reserve_more(
>  	unsigned int		blocks,
>  	unsigned int		rtextents)
>  {
> -	struct xfs_trans_res	resv = { };
> -
> -	return xfs_trans_reserve(tp, &resv, blocks, rtextents);
> +	bool			rsvd = tp->t_flags & XFS_TRANS_RESERVE;
> +
> +	if (blocks && xfs_dec_fdblocks(tp->t_mountp, blocks, rsvd))
> +		return -ENOSPC;
> +	if (rtextents && xfs_dec_frextents(tp->t_mountp, rtextents) < 0) {

xfs_dec_frextents is checked for a negative return value, then why isn't
xfs_dec_fdblocks given the same treatment?  Or, since IIRC both return 0
or -ENOSPC you could omit the "< 0" ?

I like how this eliminates the pointless empty resv object though.

--D

> +		if (blocks)
> +			xfs_add_fdblocks(tp->t_mountp, blocks);
> +		return -ENOSPC;
> +	}
> +	tp->t_blk_res += blocks;
> +	tp->t_rtx_res += rtextents;
> +	return 0;
>  }
>  
>  /*
> -- 
> 2.47.2
> 
>