Re: [PATCH v1.1 3/3] xfs: make inode unlinked bucket recovery work with quotacheck

[Dave Chinner <david@fromorbit.com>]

On Tue, Sep 05, 2023 at 09:33:03AM -0700, Darrick J. Wong wrote:
> From: Darrick J. Wong <djwong@kernel.org>
> 
> Teach quotacheck to reload the unlinked inode lists when walking the
> inode table.  This requires extra state handling, since it's possible
> that a reloaded inode will get inactivated before quotacheck tries to
> scan it; in this case, we need to ensure that the reloaded inode does
> not have dquots attached when it is freed.
> 
> Signed-off-by: Darrick J. Wong <djwong@kernel.org>
> ---
> v1.1: s/CONFIG_QUOTA/CONFIG_XFS_QUOTA/ and fix tracepoint flags decoding
> ---
>  fs/xfs/xfs_inode.c |   12 +++++++++---
>  fs/xfs/xfs_inode.h |    5 ++++-
>  fs/xfs/xfs_mount.h |   10 +++++++++-
>  fs/xfs/xfs_qm.c    |    7 +++++++
>  4 files changed, 29 insertions(+), 5 deletions(-)
> 
> diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
> index 56f6bde6001b..22af7268169b 100644
> --- a/fs/xfs/xfs_inode.c
> +++ b/fs/xfs/xfs_inode.c
> @@ -1743,9 +1743,13 @@ xfs_inactive(
>  	     ip->i_df.if_nextents > 0 || ip->i_delayed_blks > 0))
>  		truncate = 1;
>  
> -	error = xfs_qm_dqattach(ip);
> -	if (error)
> -		goto out;
> +	if (xfs_iflags_test(ip, XFS_IQUOTAUNCHECKED)) {
> +		xfs_qm_dqdetach(ip);
> +	} else {
> +		error = xfs_qm_dqattach(ip);
> +		if (error)
> +			goto out;
> +	}

That needs a comment - I'm not going to remember why sometimes we
detatch dquots instead of attach them here....


....
> diff --git a/fs/xfs/xfs_qm.c b/fs/xfs/xfs_qm.c
> index 6abcc34fafd8..7256090c3895 100644
> --- a/fs/xfs/xfs_qm.c
> +++ b/fs/xfs/xfs_qm.c
> @@ -1160,6 +1160,10 @@ xfs_qm_dqusage_adjust(
>  	if (error)
>  		return error;
>  
> +	error = xfs_inode_reload_unlinked(ip);
> +	if (error)
> +		goto error0;

Same comment here about doing millions of transaction create/cancel
for inodes that have non-zero link counts....

Also, same comment here about shutting down on reload error because
the irele() call will inactivate the inode and try to remove it from
the unlinked list....

Cheers,

Dave.
-- 
Dave Chinner
david@fromorbit.com