Re: [PATCH 1/1] xfs: Skip repetitive warnings about mount options

["Darrick J. Wong" <djwong@kernel.org>]

On Sat, Feb 20, 2021 at 11:15:49PM +0100, Pavel Reichl wrote:
> Skip the warnings about mount option being deprecated if we are
> remounting and deprecated option state is not changing.
> 
> Bug: https://bugzilla.kernel.org/show_bug.cgi?id=211605
> Fix-suggested-by: Eric Sandeen <sandeen@redhat.com>
> Signed-off-by: Pavel Reichl <preichl@redhat.com>
> ---
>  fs/xfs/xfs_super.c | 23 +++++++++++++++++++----
>  1 file changed, 19 insertions(+), 4 deletions(-)
> 
> diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
> index 813be879a5e5..6724a7018d1f 100644
> --- a/fs/xfs/xfs_super.c
> +++ b/fs/xfs/xfs_super.c
> @@ -1169,6 +1169,13 @@ xfs_fs_parse_param(
>  	struct fs_parse_result	result;
>  	int			size = 0;
>  	int			opt;
> +	uint64_t                prev_m_flags = 0; /* Mount flags of prev. mount */

Nit: spaces here^^^^^^^^^^^^^^^^ should be tabs.

> +	bool			remounting = fc->purpose & FS_CONTEXT_FOR_RECONFIGURE;
> +
> +	/* if reconfiguring then get mount flags of previous flags */
> +	if (remounting) {
> +		prev_m_flags  = XFS_M(fc->root->d_sb)->m_flags;
> +	}
>  
>  	opt = fs_parse(fc, xfs_fs_parameters, param, &result);
>  	if (opt < 0)
> @@ -1294,19 +1301,27 @@ xfs_fs_parse_param(
>  #endif
>  	/* Following mount options will be removed in September 2025 */
>  	case Opt_ikeep:
> -		xfs_warn(mp, "%s mount option is deprecated.", param->key);
> +		if (!remounting ||  !(prev_m_flags & XFS_MOUNT_IKEEP)) {
> +			xfs_warn(mp, "%s mount option is deprecated.", param->key);
> +		}

/me wonders if these could be refactored into a common helper, though I
can't really think of anything less clunky than:

static inline void
xfs_fs_warn_deprecated(
	struct fs_context	*fc,
	struct fs_parameter	*param)
	uint64_t		flag,
	bool			value);
{
	uint64_t		prev_m_flags;

	if (!(fc->purpose & FS_CONTEXT_FOR_RECONFIGURE))
		goto warn;
	prev_m_flags  = XFS_M(fc->root->d_sb)->m_flags;
	if (!!(prev_m_flags & flag) == value)
		goto warn;
	return;
warn:
	xfs_warn(mp, "%s mount option is deprecated.", param->key);
}
...
	case Opt_ikeep:
		xfs_fs_warn_deprecated(fc, param, XFS_MOUNT_IKEEP, true);
		mp->m_flags |= XFS_MOUNT_IKEEP;
		break;
	case Opt_noikeep:
		xfs_fs_warn_deprecated(fc, param, XFS_MOUNT_IKEEP, false);
		mp->m_flags &= ~XFS_MOUNT_IKEEP;
		break;

Thoughts?

--D

>  		mp->m_flags |= XFS_MOUNT_IKEEP;
>  		return 0;
>  	case Opt_noikeep:
> -		xfs_warn(mp, "%s mount option is deprecated.", param->key);
> +		if (!remounting || prev_m_flags & XFS_MOUNT_IKEEP) {
> +			xfs_warn(mp, "%s mount option is deprecated.", param->key);
> +		}
>  		mp->m_flags &= ~XFS_MOUNT_IKEEP;
>  		return 0;
>  	case Opt_attr2:
> -		xfs_warn(mp, "%s mount option is deprecated.", param->key);
> +		if (!remounting || !(prev_m_flags & XFS_MOUNT_ATTR2)) {
> +			xfs_warn(mp, "%s mount option is deprecated.", param->key);
> +		}
>  		mp->m_flags |= XFS_MOUNT_ATTR2;
>  		return 0;
>  	case Opt_noattr2:
> -		xfs_warn(mp, "%s mount option is deprecated.", param->key);
> +		if (!remounting || !(prev_m_flags & XFS_MOUNT_NOATTR2)) {
> +			xfs_warn(mp, "%s mount option is deprecated.", param->key);
> +		}
>  		mp->m_flags &= ~XFS_MOUNT_ATTR2;
>  		mp->m_flags |= XFS_MOUNT_NOATTR2;
>  		return 0;
> -- 
> 2.29.2
>