biodone vs geom_up

[Alexander Motin]

Hi, Max.

> Removing the BIO_DONE setting at [1] resolves the issue I'm seeing,
but I wonder if there is a better way to resolve this?  Should
g_disk_start() clone a bio for its callback instead?  Are there other
places that set a bio_done callback on the way down?

Originally requests were always cloned in g_disk_start(). Skipping BIO
cloning there was my change to reduce I/O processing overhead. It is
indeed kind of hack, but supposed to be a small one.

I think I see the problem there too now. Removing BIO_DONE setting at
[1] indeed should help. Grepping through the tree I don't see much other
checks for BIO_DONE, so I would guess it should not be a problem. Any
way, unlocked BIO_DONE setting there should be pointless or at least
unreliable, except may be for some debugging.

-- 
Alexander Motin