Re: [PATCH RESEND v6 1/3] xfs: Show realtime device stats on statfs calls if inherit flag set

["Darrick J. Wong" <darrick.wong@oracle.com>]

On Wed, Nov 22, 2017 at 02:40:07PM -0800, 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.
> 
> Reviewed-by: Christoph Hellwig <hch@lst.de>
> Reviewed-by: Dave Chinner <dchinner@redhat.com>
> Signed-off-by: Richard Wareing <rwareing@fb.com>
> ---
> Changes since v5:
> * None
> 
> Changes since v4:
> * None
> 
> 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 dcd1292..944b02d 100644
> --- a/fs/xfs/xfs_linux.h
> +++ b/fs/xfs/xfs_linux.h
> @@ -278,8 +278,10 @@ static inline uint64_t howmany_64(uint64_t x, uint32_t y)
>  #define XFS_IS_REALTIME_INODE(ip)			\
>  	(((ip)->i_d.di_flags & XFS_DIFLAG_REALTIME) &&	\
>  	 (ip)->i_mount->m_rtdev_targp)
> +#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
>  
>  #endif /* __XFS_LINUX__ */
> diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
> index f663022..3c9a989 100644
> --- a/fs/xfs/xfs_super.c
> +++ b/fs/xfs/xfs_super.c
> @@ -1153,6 +1153,14 @@ xfs_fs_statfs(
>  	    ((mp->m_qflags & (XFS_PQUOTA_ACCT|XFS_PQUOTA_ENFD))) ==
>  			      (XFS_PQUOTA_ACCT|XFS_PQUOTA_ENFD))
>  		xfs_qm_statvfs(ip, statp);
> +
> +	if (XFS_IS_REALTIME_MOUNT(mp) &&
> +	    (ip->i_d.di_flags & XFS_DIFLAG_RTINHERIT)) {

For everyone else following at home: I asked on IRC, shouldn't we report
rtdev stats for any file that has REALTIME, but not RTINHERIT, set?

--D

> +		statp->f_blocks = sbp->sb_rblocks;
> +		statp->f_bavail = statp->f_bfree =
> +			sbp->sb_frextents * sbp->sb_rextsize;
> +	}
> +
>  	return 0;
>  }
>  
> -- 
> 2.9.5
> 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-xfs" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html