Re: [PATCH 02/11] xfs: refactor quota expiration timer modification

[Christoph Hellwig <hch@infradead.org>]

On Thu, Aug 20, 2020 at 07:11:40PM -0700, Darrick J. Wong wrote:
> From: Darrick J. Wong <darrick.wong@oracle.com>
> 
> Define explicit limits on the range of quota grace period expiration
> timeouts and refactor the code that modifies the timeouts into helpers
> that clamp the values appropriately.  Note that we'll deal with the
> grace period timer separately.
> 
> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
> Reviewed-by: Amir Goldstein <amir73il@gmail.com>
> ---
>  fs/xfs/libxfs/xfs_format.h |   22 ++++++++++++++++++++++
>  fs/xfs/xfs_dquot.c         |   13 ++++++++++++-
>  fs/xfs/xfs_dquot.h         |    2 ++
>  fs/xfs/xfs_ondisk.h        |    2 ++
>  fs/xfs/xfs_qm_syscalls.c   |    9 +++++++--
>  5 files changed, 45 insertions(+), 3 deletions(-)
> 
> 
> diff --git a/fs/xfs/libxfs/xfs_format.h b/fs/xfs/libxfs/xfs_format.h
> index b1b8a5c05cea..ef36978239ac 100644
> --- a/fs/xfs/libxfs/xfs_format.h
> +++ b/fs/xfs/libxfs/xfs_format.h
> @@ -1197,6 +1197,28 @@ static inline void xfs_dinode_put_rdev(struct xfs_dinode *dip, xfs_dev_t rdev)
>  
>  #define XFS_DQTYPE_ANY		(XFS_DQTYPE_REC_MASK)
>  
> +/*
> + * XFS Quota Timers
> + * ================
> + *
> + * Quota grace period expiration timers are an unsigned 32-bit seconds counter;
> + * time zero is the Unix epoch, Jan  1 00:00:01 UTC 1970.  An expiration value
> + * of zero means that the quota limit has not been reached, and therefore no
> + * expiration has been set.
> + */
> +
> +/*
> + * Smallest possible quota expiration with traditional timestamps, which is
> + * Jan  1 00:00:01 UTC 1970.
> + */
> +#define XFS_DQ_TIMEOUT_MIN	((int64_t)1)
> +
> +/*
> + * Largest possible quota expiration with traditional timestamps, which is
> + * Feb  7 06:28:15 UTC 2106.
> + */
> +#define XFS_DQ_TIMEOUT_MAX	((int64_t)U32_MAX)
> +
>  /*
>   * This is the main portion of the on-disk representation of quota information
>   * for a user.  We pad this with some more expansion room to construct the on
> diff --git a/fs/xfs/xfs_dquot.c b/fs/xfs/xfs_dquot.c
> index bcd73b9c2994..2425b1c30d11 100644
> --- a/fs/xfs/xfs_dquot.c
> +++ b/fs/xfs/xfs_dquot.c
> @@ -98,6 +98,16 @@ xfs_qm_adjust_dqlimits(
>  		xfs_dquot_set_prealloc_limits(dq);
>  }
>  
> +/* Set the expiration time of a quota's grace period. */
> +void
> +xfs_dquot_set_timeout(
> +	time64_t		*timer,
> +	time64_t		value)
> +{
> +	*timer = clamp_t(time64_t, value, XFS_DQ_TIMEOUT_MIN,
> +					  XFS_DQ_TIMEOUT_MAX);
> +}

Why doesn't this just return the value?  That would seem like
a much more natural calling convention to me.