[Parted-maintainers] Bug#762236: parted: [kfreebsd] use of kern.geom.debugflags is unsafe

[Phillip Susi]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

On 9/19/2014 4:21 PM, Steven Chamberlain wrote:
<snip>
> * opening O_RDWR and closing a disk device on FreeBSD, causes its 
> partition tables to be rescanned (so, a 'commit' is implied - this
> also seems to be the cause of major slowness of partman in kfreebsd
> d-i, because it does this 'about' a hundred times in total)
> 
> * the CAM layer handles this as a MEDIACHANGE event, it will
> DESTROY /dev devices for the disk partitions, and when scanning is
> complete, CREATE them again (perhaps similar to udev?)

Umm... it seems to me that if you open your disk O_RDWR, for instance,
to update your boot loader, while you have a partition on the disk
mounted, and the kernel destroys an actively mounted partition device,
then the kernel is very, very broken...

As for the performance implications, yes, parted should not be using
O_RDWR when it do doesn't need it and does take care not to on linux.


-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2.0.17 (MingW32)

iQEcBAEBAgAGBQJUIB/6AAoJEI5FoCIzSKrwjE0H/3JiVspNyP2xm8qR5NFX0DYx
Uhzufj4TkxtfwVRQkRmW8XAYJVqil/mUuP8/J2gbseujaB1qpafWGgek0XaSWEAj
Rx4LsrjATwIqhudk4CxF0pV2idWQcoFYGYitRN8cowya13X7TcZBbLb6C77PL+ax
B4Cy7eZrUWHpVXWEfRb1JeuRf29TpB88wzaB0nAg1UOYlyxbr2J4J8qtIF4O6hMi
PlzbhQKJTwoIRIOWhGYXKet97khHM0KxIKMKNqdjVHhpXWVcKmFI/QoCZpsn3vX6
0OuIAjczMWgcn4sl2D8zc0dlQH4gWmnIC6Wk4aWzL5Q9Rg6yJhMmMxfTLn2EmRM=
=8mDs
-----END PGP SIGNATURE-----