Re: Block layer - meaning of REQ_FUA on not write requests

[Jeff Moyer]

Alex Bligh <alex@xxxxxxxxxxx> writes:

> I am trying to clean up the documentation of the NBD protocol. NBD's
> support for Force Unit Access (FUA) was modelled on the linux kernel
> block layer. When I added support a few years ago, I omitted to find
> out exactly what types of request it applies to. Obviously it applies
> to write requests, but how about others (e.g. read)?

Any request with REQ_FUA set will be treated as a flush by the block
layer.  As such, we do not expect reads to have this bit set.

Cheers,
Jeff