Re: LVM/Device mapper breaks with -mm (was: Re: 2.5.66-mm1)

[Andries Brouwer <aebr@win.tue.nl>]

On Wed, Mar 26, 2003 at 10:47:23AM -0800, Joel Becker wrote:

> We need to start tracking down what userspace needs fixing.

My current series of patches is for the ioctls that use a
structure with dev_t field. If someone has time to burn,
or has automated tools that can identify these, that would
be good.

There is a double audit: find these ioctls, and then find
the userspace tools that use them.

For example, struct umsdos_ioctl has twice dev_t followed
by padding. Probably these should become unsigned longs.
I'll send a patch later tonight.

Is it used anywhere? That requires detective work.
It is used by the utilities udosctl (a useless demo utility),
umssync and umssetup. I do not know of any others.
No doubt people will tell me what I overlooked.
Less conservative people will tell me that umsdos has to
be killed entirely.

In old posts and other letters I have mentioned some more ioctls.
The list is not long but they have to be examined one by one,
and in some cases correspondence with authors/maintainers
is required.

> We also should iron out our representations.  eg, hpa's
> recommendation for 64bits, or the 12/20 split for 32bit, or etc.

There is no hurry. These changes are just editing a few lines
in kdev_t.h. I tend to prefer 64 bits, like hpa.
Maybe I should send another patch tonight, just for playing.

Andries