On Tue, Dec 01, 2020 at 03:16:41AM +0000, Trond Myklebust wrote: > On Mon, 2020-11-30 at 22:11 -0500, bfields@xxxxxxxxxxxx wrote: > > On Tue, Dec 01, 2020 at 03:06:46AM +0000, Trond Myklebust wrote: > > > A local filesystem might choose to set the 'non-atomic' flag > > > without > > > wanting to turn off NFSv3 WCC attributes. Yes, the latter are > > > assumed > > > to be atomic, but a number of commercial servers do abuse that > > > assumption in practice. > > > > What do you mean by abusing that assumption? > > > > I thought that leaving off the post-op attrs was the v3 protocol's > > way > > of saying that it couldn't give you atomic wcc information. > > > > I mean that a number of commercial servers will happily return NFSv3 > pre/post-operation WCC information that is not atomic with the > operation that is supposed to be 'protected'. Oh, OK. But why do *we* want to do that? If there's some reason a filesystem really needs NFSv3 post-operation WCC information without providing an atomic guarantee, they can make that argument when the filesystem's merged. Separating these two flags on the off chance a future filesystem may want to violate the protocol in this way seems unnecessary. --b.
