Re: [Qemu-devel] migration: qemu-coroutine-lock.c:141: qemu_co_mutex_unlock: Assertion `mutex->locked == 1' failed

[Paolo Bonzini]

Il 16/09/2014 14:34, Kevin Wolf ha scritto:
> I think bdrv_invalidate_cache() really needs to call bdrv_drain_all()
> before starting to reopen stuff. There could be requests in flight
> without holding the lock and if you can indeed reopen their BDS under
> their feet without breaking things (I doubt it), that would be pure
> luck.

But even that's not enough without a lock if .bdrv_invalidate_cache (the
callback) is called from a coroutine.  As soon as it yields, another
request can come in, for example from the NBD server.

Paolo