Hi!
A question about s->cow_bitmap, introduced in far b812f6719c
"mirror: perform COW if the cluster size is bigger than the granularity"
cow_bitmap is just a bitmap which tracks, what clusters of target are
allocated, to
prevent COW in target, if target backing is not ready yet. And it is done by
just
aligning request to be larget and cover unaligned border clusters.
so, questions:
1. Is it correct that we align only on COPY operation in mirror_co_read?
Misaligned
write_zero can also lead to COW, I think? Discard seems safe in this way, is it?
2. I don't see, how is it handled, if we align operation so that offset is
decreases,
then it may intersect with previous mirror operation request, which may be not
yet finished?
--
Best regards,
Vladimir
