Re: [PATCH] xfs_repair: coordinate parallel updates to the rt bitmap

[Christoph Hellwig <hch@infradead.org>]

On Wed, Sep 23, 2020 at 11:24:37AM -0700, Darrick J. Wong wrote:
> From: Darrick J. Wong <darrick.wong@oracle.com>
> 
> Actually take the rt lock before updating the bitmap from multiple
> threads.  This fixes an infrequent corruption problem when running
> generic/013 and rtinherit=1 is set on the root dir.
> 
> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
> ---
>  repair/dinode.c |    4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/repair/dinode.c b/repair/dinode.c
> index 57013bf149b2..07f3f83aef8c 100644
> --- a/repair/dinode.c
> +++ b/repair/dinode.c
> @@ -184,6 +184,7 @@ process_rt_rec(
>  	xfs_rfsblock_t		*tot,
>  	int			check_dups)
>  {
> +	struct aglock		*lock = &ag_locks[(signed)NULLAGNUMBER];

Err, what is this weird cast doing here?

The rest looks sane.