Bug in bsdinstall (fs found where not present)

[Nathan Whitehorn]

On 08/29/13 17:02, Warren Block wrote:
> On Thu, 29 Aug 2013, Nathan Whitehorn wrote:
>
>> On 08/29/13 14:04, Warren Block wrote:
>>>> From a 9.2-PRERELEASE snapshot, go into the shell, create a GPT disk
>>> layout with a bunch of partitions for filesystems and swap.  Exit the
>>> shell and run the installer.
>>>
>>> Go through each partition setting a mount point.  Tell bsdinstall to
>>> continue.  It reports that the / partition has a preexisting
>>> filesystem (it does not, in fact; this disk had a mishmash of MBR and
>>> NTFS on it).
>>>
>>> Tell bsdinstall to continue anyway.  It does, and then reports that it
>>> can't mount /dev/ada0p2 on /mnt, presumably because, contrary to the
>>> misleading and incorrect error message, there is no filesystem on
>>> there.
>>>
>>> The install fails, try again, entering all the mount points, and it
>>> will fail the same.
>>>
>>> Short term solution: newfs the / partition, so there really is a
>>> filesystem there for bsdinstall to detect and warn about.  Then it
>>> works.
>>
>> bsdinstall has no way to detect whether or not you already have UFS in a
>> freebsd-ufs file system. It assumes, when not given contrary
>> information, that a partition that exists is initialized. There does not
>> seem to be a way around this. If you have any ideas, those would of
>> course be helpful.
>
> file(1) works well for detecting filesystems.
>
> For that matter, what is bsdinstall doing now that makes it say there
> is a filesystem on a partition?  Maybe the message is misleading.

What that actually means is that the partition exists. (file doesn't
work on block devices, by the way) I'm happy to change the error
message. The default behavior is that, like partitioners on all other
operating systems, it treats creating partitions and running newfs as
intimately linked activities -- similarly, that the type marked in the
partition table is the actual filesystem type. Intermediate cases are
very hard to detect reliably.
-Nathan