[PATCH] xfs: clean up xfs_set_maxicount & use in growfs

[Christoph Hellwig]

On Mon, Feb 24, 2014 at 11:27:35PM -0600, Eric Sandeen wrote:
> xfs_set_maxicount() overflowed fairly easily for large filesystems
> and large maxicount; we started out by multiplying dblocks by
> the percentage, *then* dividing by 100, and never checked for
> an overflow.  The calculations were also, IMHO, a little hard
> to follow.

Would be useful to get this test case into xfstests..

> -STATIC void
> +void
>  xfs_set_maxicount(xfs_mount_t *mp)
>  {
>  	xfs_sb_t	*sbp = &(mp->m_sb);
> -	__uint64_t	icount;
> +	__uint64_t	iblocks;

Seems like this could move into the if clause below.

> @@ -388,6 +388,7 @@ extern int	xfs_mod_incore_sb_batch(xfs_mount_t *, xfs_mod_sb_t *,
>  extern int	xfs_mount_log_sb(xfs_mount_t *, __int64_t);
>  extern struct xfs_buf *xfs_getsb(xfs_mount_t *, int);
>  extern int	xfs_readsb(xfs_mount_t *, int);
> +void		xfs_set_maxicount(xfs_mount_t *mp);
>  extern void	xfs_freesb(xfs_mount_t *);
>  extern int	xfs_fs_writable(xfs_mount_t *);
>  extern int	xfs_sb_validate_fsb_count(struct xfs_sb *, __uint64_t);

A missing extern while all other prototypes around it have one seems
rather odd.