[Bug 585027] Re: Race condition with dmsetup causes 'map already present' messages

[Alasdair G. Kergon]

On Mon, Jul 09, 2012 at 03:29:11PM -0000, Peter Petrakis wrote:
> In examining the ioctl interface to device mapper (kernel), I have not found any architecture that
> assures that when a device mapper device has been marked for deletion, that this information is
> relayed back to userspace so it can block on this deletion. An example will clarify things.
 
If this is the same process that issued the deletion that needs to wait
till the device has gone, then the udevcookie mechanism is meant to
provide that already.  (Multipathd is supposed to be using that
mechanism, upstream at least.)

If it's a different process, then I consider it's userspace's job to
co-ordinate the sequencing of ioctls that conflict with each other.

-- 
You received this bug notification because you are a member of Ubuntu
Server Team, which is subscribed to multipath-tools in Ubuntu.
https://bugs.launchpad.net/bugs/585027

Title:
  Race condition with dmsetup causes 'map already present' messages

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/multipath-tools/+bug/585027/+subscriptions