Re: [dm-crypt] The weird bug again: semid XXXXXX: semop failed for cookie 0xdeadbeef: incorrect semaphore state

[Milan Broz <mbroz@redhat.com>]

On 08/16/2011 10:45 PM, Thomas Bächler wrote:
> I am getting reports of this error again:
> 
> semid 491524: semop failed for cookie 0xd4dc159: incorrect semaphore state
> Failed to set a proper state for notification semaphore identified by
> cookie value 223199577 (0xd4dc159) to initialize waiting for incoming
> notifications.
> 
> This issue is so weird that I don't know where to start. Apparently,
> this problem appears whenever chromium is running, and disappears when
> you quit chromium. I'm confused about this. Very confused.

I know that this bug is still there. I think that the problem is:

- kernel, in response to devmapper library request, send uevent with cookie
- kernel reports failure (despite uevent was sent), I guess it is
some memory allocation error later
- libdevmapper takes error path, destroying semaphore, which was already
destroyed in udev rules

So my guess is that connection with chromium just it perhaps allocates most
of system memory and some allocation in kernel perhaps fail then.

The final state should be correct, so you can (I hope) ignore that error
for now.

It is not a cryptsetup bug but I would like to fix it anyway,
the problem is the bug appears and disappears quite randomly.

Does anyone see this bug in some other libdevmapper user?
(lvm, multipath, kpartx, ... ?)

(Another possibility is that you have broken udev rules and
"dmsetup udevcomplete" is called twice there, but I do not think it
the issue.)

Milan