Re: [PATCH v4 1/3] xfs: Show realtime device stats on statfs calls if inherit flag set

[Dave Chinner <david@fromorbit.com>]

On Mon, Sep 18, 2017 at 08:52:36PM -0700, Richard Wareing wrote:
> - Reports realtime device free blocks in statfs calls if inheritance
>   bit is set on the inode of directory.  This is a bit more intuitive,
>   especially for use-cases which are using a much larger device for
>   the realtime device.
> - Add XFS_IS_REALTIME_MOUNT option to gate based on the existence of a
>   realtime device on the mount, similar to the XFS_IS_REALTIME_INODE
>   option.
> 
> Signed-off-by: Richard Wareing <rwareing@fb.com>

Didn't Christoph give a Reviewed-by for this one? Normally when we
repost a patch that already has a revewied-by we include it in the
commit message. That tells other reviewers and the maintainer that
it has already been reviewed :P

> Changes since v3:
> * Fixed accounting bug, we are not required to substract m_alloc_set_aside
>   as this is a data device only requirement.
> * Added XFS_IS_REALTIME_MOUNT macro based on learnings from CVE-2017-14340,
>   now provides similar gating on the mount as XFS_IS_REALTIME_INODE does
>   for the inode.
> 
> Changes since v2:
> * Style updated per Christoph Hellwig's comment
> * Fixed bug: statp->f_bavail = statp->f_bfree
> 
>  fs/xfs/xfs_linux.h | 2 ++
>  fs/xfs/xfs_super.c | 8 ++++++++
>  2 files changed, 10 insertions(+)
> 
> diff --git a/fs/xfs/xfs_linux.h b/fs/xfs/xfs_linux.h
> index 044fb0e..fe46e71 100644
> --- a/fs/xfs/xfs_linux.h
> +++ b/fs/xfs/xfs_linux.h
> @@ -280,8 +280,10 @@ static inline __uint64_t howmany_64(__uint64_t x, __uint32_t y)
>  
>  #ifdef CONFIG_XFS_RT
>  #define XFS_IS_REALTIME_INODE(ip) ((ip)->i_d.di_flags & XFS_DIFLAG_REALTIME)
> +#define XFS_IS_REALTIME_MOUNT(mp) ((mp)->m_rtdev_targp ? 1 : 0)
>  #else
>  #define XFS_IS_REALTIME_INODE(ip) (0)
> +#define XFS_IS_REALTIME_MOUNT(mp) (0)
>  #endif

Good idea. I think we should probably turn these into inline
functions. That can be done in a new patch, though.

Reviewed-by: Dave Chinner <dchinner@redhat.com>

Cheers,

Dave.
-- 
Dave Chinner
david@fromorbit.com