On Wed, Mar 30, 2016 at 2:48 PM, J. Bruce Fields <bfields@xxxxxxxxxxxx> wrote: > On Wed, Mar 30, 2016 at 02:20:40PM -0400, Trond Myklebust wrote: >> On Wed, Mar 30, 2016 at 1:40 PM, J. Bruce Fields <bfields@xxxxxxxxxxxx> wrote: >> > If we assume no other writers until we close, couldn't you on close wait >> > for all writes, send a final getattr for change attribute, and trust >> > that? If the extra getattr's too much, then you'd need some algorithm >> > like the above to determine which change attribute is the last. Or >> > implement >> > https://tools.ietf.org/html/draft-ietf-nfsv4-minorversion2-41#section-12.2.3 >> > on client and server and just track the maximum returned value when the >> > server returns something other than NFS4_CHANGE_TYPE_IS_UNDEFINED. >> > >> >> The correct tool to use for resolving these caching issues is >> ultimately a write delegation. >> >> You can also eliminate a lot of invalidations if you know that the >> server implements change_attr_type == >> NFS4_CHANGE_TYPE_IS_VERSION_COUNTER or >> NFS4_CHANGE_TYPE_IS_VERSION_COUNTER_NOPNFS, since that allows you to >> predict what the attribute should be after a change. > > Do we know of any implementations? Yes. The AFS client does this. > It looks difficult (and possibly not yet sufficiently well-defined) to > me, but I haven't thought it through. > > --b. -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
