On Mon, 10/24 12:11, Kevin Wolf wrote: > Am 22.10.2016 um 03:00 hat Max Reitz geschrieben: > > <parenthesis> > > > > I personally still don't like making locking a qdev property very much > > because it doesn't make sense to me*. But I remember Kevin had his > > reasons (even though I can no longer remember them) for asking for it, > > and I don't have any besides "It doesn't make sense to me". After having > > though a bit about it (= having written three paragraphs and deleted > > them again), I guess I can make some sense of it, though it seems to be > > a rather esoteric use case still; it appears to me that a guest could > > use it to signal that it's fine with some block device being shared; > > then we could use a shared lock or none at all or I don't know. > > Otherwise, we should get an exclusive lock for write access and a shared > > lock for read access. > > The reason is pretty simple if you think about this question: Why do we > need user input in the first place?
I think the reason why we have an option at all is rather because of the special case of libguestfs [1], otherwise locks should just be acquired sensibly as the "auto" mode does. Other than that, I don't think we have a concrete use case of non-auto lock mode. Do we? [1]: https://lists.nongnu.org/archive/html/qemu-block/2016-04/msg00414.html Fam