Re: [PATCH 04/11] xfs: refactor dquot iteration

[Brian Foster <bfoster@redhat.com>]

On Tue, Apr 17, 2018 at 07:40:01PM -0700, Darrick J. Wong wrote:
> From: Darrick J. Wong <darrick.wong@oracle.com>
> 
> Create a helper function to iterate all the dquots of a given type in
> the system, and refactor the dquot scrub to use it.  This will get more
> use in the quota repair code.  Note that the new function differs from
> xfs_qm_dqiterate in that _dqiterate iterates dquot buffers, not the
> in-core structures themselves.
> 
> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
> ---
>  fs/xfs/scrub/quota.c |   46 +++++++++++++++++++++-------------------------
>  fs/xfs/xfs_dquot.c   |   41 +++++++++++++++++++++++++++++++++++++++++
>  fs/xfs/xfs_dquot.h   |    5 +++++
>  3 files changed, 67 insertions(+), 25 deletions(-)
> 
> 
...
> diff --git a/fs/xfs/xfs_dquot.c b/fs/xfs/xfs_dquot.c
> index ed2e37c..ec00402 100644
> --- a/fs/xfs/xfs_dquot.c
> +++ b/fs/xfs/xfs_dquot.c
> @@ -1127,3 +1127,44 @@ xfs_qm_exit(void)
>  	kmem_zone_destroy(xfs_qm_dqtrxzone);
>  	kmem_zone_destroy(xfs_qm_dqzone);
>  }
> +
> +/*
> + * Iterate every dquot of a particular type.  The caller must ensure that the
> + * particular quota type is active.  iter_fn can return negative error codes,
> + * or XFS_BTREE_QUERY_RANGE_ABORT to indicate that it wants to stop iterating.
> + *
> + * Note that xfs_qm_dqiterate iterates all the dquot bufs, not the dquots
> + * themselves.
> + */
> +int
> +xfs_dquot_iterate(
> +	struct xfs_mount	*mp,
> +	uint			dqtype,
> +	uint			iter_flags,
> +	xfs_dquot_iterate_fn	iter_fn,
> +	void			*priv)
> +{
> +	struct xfs_dquot	*dq;
> +	xfs_dqid_t		id = 0;
> +	int			error;
> +
> +	while (id < ((xfs_dqid_t)-1ULL)) {
> +		error = xfs_qm_dqget(mp, NULL, id, dqtype,
> +				XFS_QMOPT_DQNEXT | iter_flags, &dq);
> +		if (error == -ENOENT) {
> +			error = 0;
> +			break;
> +		}
> +		if (error)
> +			break;
> +

It looks like this logic could be simplified a bit. E.g.:

	while ((error = xfs_qm_dqget(mp, NULL, id, dqtype,
				XFS_QMOPT_DQNEXT | iter_flags, &dq)) == 0) {
		id = be32_to_cpu(dq->q_core.d_id);
		...

	}
	return error == -ENOENT ? 0 : error;

Otherwise looks good.

Brian

> +		id = be32_to_cpu(dq->q_core.d_id);
> +		error = iter_fn(dq, dqtype, id, priv);
> +		xfs_qm_dqput(dq);
> +		id++;
> +		if (error || id == 0)
> +			break;
> +	}
> +
> +	return error;
> +}
> diff --git a/fs/xfs/xfs_dquot.h b/fs/xfs/xfs_dquot.h
> index 2f536f3..db0511e 100644
> --- a/fs/xfs/xfs_dquot.h
> +++ b/fs/xfs/xfs_dquot.h
> @@ -185,4 +185,9 @@ static inline struct xfs_dquot *xfs_qm_dqhold(struct xfs_dquot *dqp)
>  	return dqp;
>  }
>  
> +typedef int (*xfs_dquot_iterate_fn)(struct xfs_dquot *dq, uint dqtype,
> +		xfs_dqid_t id, void *priv);
> +int xfs_dquot_iterate(struct xfs_mount *mp, uint dqtype, uint iter_flags,
> +		xfs_dquot_iterate_fn iter_fn, void *priv);
> +
>  #endif /* __XFS_DQUOT_H__ */
> 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-xfs" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html