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

[Eric Sandeen]

On 2/25/14, 8:11 PM, Christoph Hellwig wrote:
> 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..

Your'e bot, aren't you.  ;)

yeah you're right.  I went down this path by starting a testcase
for 3-patches-ago, and got here.  That one can be sent soon, and
sure, it'd be worth doing this too.

>> -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.

Sure does!

-Eric