Re: [PATCH 1/3] xfs: move more logic into xfs_extent_busy_clear_one

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

On Fri, Apr 05, 2024 at 08:07:08AM +0200, Christoph Hellwig wrote:
> Move the handling of discarded entries into xfs_extent_busy_clear_one
> to reuse the length check and tidy up the logic in the caller.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>

AFAICT, the return value of xfs_extent_busy_clear_one is whether
or not it actually changed the pagb_tree, right?  And if that return
value is true, then we want to wake up anyone who might be waiting on
busy extents to clear the pagb_tree, which is what the @wakeup logic
does, right?

If the answers are yes and yes, then:
Reviewed-by: Darrick J. Wong <djwong@kernel.org>

--D


> ---
>  fs/xfs/xfs_extent_busy.c | 23 ++++++++++++-----------
>  1 file changed, 12 insertions(+), 11 deletions(-)
> 
> diff --git a/fs/xfs/xfs_extent_busy.c b/fs/xfs/xfs_extent_busy.c
> index 56cfa1498571e3..6fbffa46e5e94b 100644
> --- a/fs/xfs/xfs_extent_busy.c
> +++ b/fs/xfs/xfs_extent_busy.c
> @@ -518,20 +518,26 @@ xfs_extent_busy_trim(
>  	goto out;
>  }
>  
> -STATIC void
> +static bool
>  xfs_extent_busy_clear_one(
> -	struct xfs_mount	*mp,
>  	struct xfs_perag	*pag,
> -	struct xfs_extent_busy	*busyp)
> +	struct xfs_extent_busy	*busyp,
> +	bool			do_discard)
>  {
>  	if (busyp->length) {
> -		trace_xfs_extent_busy_clear(mp, busyp->agno, busyp->bno,
> -						busyp->length);
> +		if (do_discard &&
> +		    !(busyp->flags & XFS_EXTENT_BUSY_SKIP_DISCARD)) {
> +			busyp->flags = XFS_EXTENT_BUSY_DISCARDED;
> +			return false;
> +		}
> +		trace_xfs_extent_busy_clear(pag->pag_mount, busyp->agno,
> +				busyp->bno, busyp->length);
>  		rb_erase(&busyp->rb_node, &pag->pagb_tree);
>  	}
>  
>  	list_del_init(&busyp->list);
>  	kfree(busyp);
> +	return true;
>  }
>  
>  static void
> @@ -575,13 +581,8 @@ xfs_extent_busy_clear(
>  			wakeup = false;
>  		}
>  
> -		if (do_discard && busyp->length &&
> -		    !(busyp->flags & XFS_EXTENT_BUSY_SKIP_DISCARD)) {
> -			busyp->flags = XFS_EXTENT_BUSY_DISCARDED;
> -		} else {
> -			xfs_extent_busy_clear_one(mp, pag, busyp);
> +		if (xfs_extent_busy_clear_one(pag, busyp, do_discard))
>  			wakeup = true;
> -		}
>  	}
>  
>  	if (pag)
> -- 
> 2.39.2
> 
>