Re: [PATCH 3/3] xfs: don't wake zone space waiters without m_zone_info

[Hans Holmberg <Hans.Holmberg@wdc.com>]

On 17/03/2025 06:45, Christoph Hellwig wrote:
> From: "Darrick J. Wong" <djwong@kernel.org>
> 
> xfs_zoned_wake_all checks SB_ACTIVE to make sure it does the right thing
> when a shutdown happens during unmount, but it fails to account for the
> log recovery special case that sets SB_ACTIVE temporarily.  Add a NULL
> check to cover both cases.
> 
> Signed-off-by: Darrick J. Wong <djwong@kernel.org>
> [hch: added a commit log and comment]
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>  fs/xfs/xfs_zone_alloc.c | 15 ++++++++++++---
>  1 file changed, 12 insertions(+), 3 deletions(-)
> 
> diff --git a/fs/xfs/xfs_zone_alloc.c b/fs/xfs/xfs_zone_alloc.c
> index fd4c60a050e6..52af234936a2 100644
> --- a/fs/xfs/xfs_zone_alloc.c
> +++ b/fs/xfs/xfs_zone_alloc.c
> @@ -853,13 +853,22 @@ xfs_zone_alloc_and_submit(
>  	bio_io_error(&ioend->io_bio);
>  }
>  
> +/*
> + * Wake up all threads waiting for a zoned space allocation when the file system
> + * is shut down.
> + */
>  void
>  xfs_zoned_wake_all(
>  	struct xfs_mount	*mp)
>  {
> -	if (!(mp->m_super->s_flags & SB_ACTIVE))
> -		return; /* can happen during log recovery */
> -	wake_up_all(&mp->m_zone_info->zi_zone_wait);
> +	/*
> +	 * Don't wake up if there is no m_zone_info.  This is complicated by the
> +	 * fact that unmount can't atomically clear m_zone_info and thus we need
> +	 * to check SB_ACTIVE for that, but mount temporarily enables SB_ACTIVE
> +	 * during log recovery so we can't entirely rely on that either.
> +	 */
> +	if ((mp->m_super->s_flags & SB_ACTIVE) && mp->m_zone_info)
> +		wake_up_all(&mp->m_zone_info->zi_zone_wait);
>  }
>  
>  /*

Looks good,

Reviewed-by: Hans Holmberg <hans.holmberg@wdc.com>