Re: [PATCH 00/12] More cleanups and fixes for drain

[Kevin Wolf]

Am 12.12.2022 um 13:59 hat Paolo Bonzini geschrieben:
> There are a few more lines of code that can be removed around draining
> code, but especially the logic can be simplified by removing unnecessary
> parameters.
> 
> Due to the failure of the block-next branch, the first three patches
> drop patches 14+15 of Kevin's drain cleanup series, and then redo
> patch 15 in a slightly less satisfactory way that still enables the
> remaining cleanups.  These reverts are not supposed to be applied;
> either the offending patches are dropped from the branch, or if the
> issue is fixed then my first three patches can go away.

Can you remind me which problem this was? The patches are in master now,
but I'm not sure if the latest version fixed whatever you had in mind.

> The next three are taken from Emanuele's old subtree drain attempt
> at removing the AioContext.  The main one is the second, which is needed
> to avoid testcase failures, but I included all of them for simplicity.
> 
> Patch 7 fixes another latent bug exposed by the later cleanups, and while
> looking for a fix I noticed a general lack of thread-safety in BlockBackend's
> drain code.  There are some global properties that only need to be documented
> and enforced to be set only at creation time (patches 8/9), but also
> queued_requests is not protected by any mutex, which is fixed in patch 10.
> 
> Finally, patches 11-15 are the actual simplification.
> 
> Applies on top of block-next.

Not any more. :-)

I found out that it applies on top of 6355f90eef, which may work for
some basic review, but the conflicts when rebasing seem non-trivial, so
we'll need a v2.

Kevin