> The NBD spec states that since trim requests can affect disk contents, > then they should allow for FUA semantics just like writes for ensuring > the disk has settled before returning. As bdrv_[co_]pdiscard() does > not (yet?) support a flags argument, we can't pass FUA down the block > layer stack, and must therefore emulate it with a flush at the NBD > layer.
TRIM requests should not need FUA since they're just advisory. On the other hand, WRITE ZEROES requests need to support FUA. Paolo
