Re: [PATCH 2/6] xfs: pass xfs_dqblk to xfs_dquot_verify/xfs_dquot_repair

[Christoph Hellwig <hch@infradead.org>]

On Wed, Apr 04, 2018 at 01:54:26PM -0500, Eric Sandeen wrote:
> In order to validate the UUID in xfs_dquot_verify, we need
> the full xfs_qblk, not just the xfs_disk_dquot_t (which is
> a subset).
> 
> Do the same for xfs_dquot_repair, for the same reasons.
> Casting a xfs_disk_dquot to a xfs_qblk is risky if the source
> pointer wasn't a full xfs_dqblk, so enforce that by changing
> the arguments to these functions.
> 
> In xfs_qm_dqflush we move the memcpy up so that we have
> a full (and updated) xfs_dqblk to test.
> 
> Signed-off-by: Eric Sandeen <sandeen@redhat.com>
> ---
>  fs/xfs/libxfs/xfs_dquot_buf.c  | 23 +++++++++--------------
>  fs/xfs/libxfs/xfs_quota_defs.h |  4 ++--
>  fs/xfs/xfs_dquot.c             | 12 +++++++-----
>  fs/xfs/xfs_log_recover.c       |  6 ++++--
>  fs/xfs/xfs_qm.c                |  6 +++---
>  5 files changed, 25 insertions(+), 26 deletions(-)
> 
> diff --git a/fs/xfs/libxfs/xfs_dquot_buf.c b/fs/xfs/libxfs/xfs_dquot_buf.c
> index a926058..f94e8c2 100644
> --- a/fs/xfs/libxfs/xfs_dquot_buf.c
> +++ b/fs/xfs/libxfs/xfs_dquot_buf.c
> @@ -44,11 +44,13 @@
>   */
>  xfs_failaddr_t
>  xfs_dquot_verify(
> -	struct xfs_mount *mp,
> -	xfs_disk_dquot_t *ddq,
> -	xfs_dqid_t	 id,
> -	uint		 type)	  /* used only when IO_dorepair is true */
> +	struct xfs_mount	*mp,
> +	struct xfs_dqblk	*dqb,
> +	xfs_dqid_t		id,
> +	uint			type)	  /* used only during quota rebuild */
>  {
> +	struct xfs_disk_dquot	*ddq = &dqb->dd_diskdq;
> +
>  	/*
>  	 * We can encounter an uninitialized dquot buffer for 2 reasons:
>  	 * 1. If we crash while deleting the quotainode(s), and those blks got
> @@ -104,13 +106,10 @@
>  int
>  xfs_dquot_repair(
>  	struct xfs_mount	*mp,
> -	struct xfs_disk_dquot	*ddq,
> +	struct xfs_dqblk	*d,

Rename this to dqblks to make it clear that it is an array?

>  		if (i == 0)
> -			id = be32_to_cpu(ddq->d_id);
> +			id = be32_to_cpu(d[i].dd_diskdq.d_id);
>  
> -		fa = xfs_dquot_verify(mp, ddq, id + i, 0);
> +		fa = xfs_dquot_verify(mp, &d[i], id + i, 0);

Can we either use only array indices or only pointer arithmetics and
not mix the two?  (personall I prefer the pointer arithmetics).

Functionally the patch looks fine to me.