Re: [PATCH 3/3] xfs: don't leak quotacheck dquots when cow recovery fails

[Christoph Hellwig <hch@infradead.org>]

On Wed, Aug 09, 2017 at 10:23:58PM -0700, Darrick J. Wong wrote:
> From: Darrick J. Wong <darrick.wong@oracle.com>
> 
> If we fail a mount on account of cow recovery errors, it's possible that
> a previous quotacheck left some dquots in memory.  The bailout clause of
> xfs_mountfs forgets to purge these, and so we leak them.  Fix that.
> 
> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
> ---
> v2: unmount quotas, then free all the quota information
> ---
>  fs/xfs/xfs_mount.c |    2 ++
>  1 file changed, 2 insertions(+)
> 
> 
> diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c
> index 8da5155..d50f4a7 100644
> --- a/fs/xfs/xfs_mount.c
> +++ b/fs/xfs/xfs_mount.c
> @@ -1057,6 +1057,8 @@ xfs_mountfs(
>  	xfs_fs_unreserve_ag_blocks(mp);
>   out_quota:
>  	xfs_qm_unmount_quotas(mp);
> +	/* Clean out dquots that might be in memory after quotacheck. */
> +	xfs_qm_unmount(mp);
>   out_rtunmount:
>  	xfs_rtunmount_inodes(mp);
>   out_rele_rip:

The unmount path calls this much later, e.g. the xfs_rtunmount_inodes
call follows ifirst, then we release the root inode, etc.

I'd suggest we try to follow that order as much as possible.