On 19/06/19 12:31, Paolo Bonzini wrote: >> I'm a bit unsure if 'bd->last' is always set; it's quite obvious that >> it's present if set, but what about requests with 'bd->last == false' ? >> Is there a guarantee that they will _always_ be followed with a request >> with bd->last == true? >> And if so, is there a guarantee that this request is part of the same batch? > It's complicated. A request with bd->last == false _will_ always be > followed by a request with bd->last == true in the same batch. However, > due to e.g. errors it may be possible that the last request is not sent. > In that case, the block layer sends commit_rqs, as documented in the > comment above, to flush the requests that have been sent already. > > So, a driver that obeys bd->last (or SCMD_LAST) but does not implement > commit_rqs is bound to have bugs, which is why this patch was not split > further. > > Makes sense? Hannes, can you provide your Reviewed-by? Thanks, Paolo
