On Thu, Jun 20, 2019 at 08:45:05PM -0500, Eric Blake wrote:
If any callback fails, and if no prior error was set, then the
callback's failure becomes the failure reason for the overall
read. (Note that this is different from the block status callback,
which for now quits using the callback on subsequent chunks if an
earlier chunk failed - we may decide to change one or the other for
consistency before the API is stable.)
Nothing actually passes a callback function yet, so for now this is no
functional change; but this will make it possible for the next patch
to add an 'nbd_aio_pread_structred' API.
I don't think non-C callbacks will be able to reliably set errno, but
that's something we can solve in future. Therefore ACK.
Rich.
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