[Qemu-devel] Re: [PATCH] Disk image shared and exclusive locks.

[Paolo Bonzini]

On 12/07/2009 02:39 PM, Anthony Liguori wrote:
> That's a use-case that needs to be thought through.  Maybe commit should
> attempt to force the lower level to acquire a write lock first?

Yes.  This is an argument in favor of a "DWIM" lock option instead of 
giving shared/exclusive choice to the user: do not say what kind of 
operation you want to do, and let commit upgrade the lock in the future.

If the management tools wants to force shared/exclusive, they can do the 
locking themselves and tell QEMU to not lock.

Paolo