SUJ and "mount" reporting

[Scott Long]

On May 31, 2010, at 3:08 AM, Ivan Voras wrote:
> On 05/31/10 02:25, Bjoern A. Zeeb wrote:
>> On Mon, 31 May 2010, Ivan Voras wrote:
>> 
>>> Shouldn't SU+J be visible in the output of "mount" somehow? I've just
>>> enabled it on a root file system of a machine and while tunefs and
>>> dumpfs report both soft-updates and SUJ are enabled (after reboot),
>>> the "mount" command only shows "soft-updates". Alternative question:
>>> how to verify is it active on a live file system?
>>> 
>>> (running CURRENT from a few hours ago, kernel&world synced)
>> 
>> As previously stated - this is a hack to do what I think you are
>> asking for:
>> http://people.freebsd.org/~bz/20100309-03-mount.diff
> 
> Yes, this looks like it...
> 
>> Using tunefs, etc. for now would be better.
> 
> I did use tunefs, as I've said, but I'm concerned what would happen (if
> it can - stale kernel?) if the superblock that tunefs reads from the
> disk and the kernel state are different.
> 

MNT_* flags need to be deprecated, and the attributes passed in both directions as key-value pairs.  I don't know if anyone else has thought about this and what it means for backwards compatibility.

Scott