| Message ID | 20140915220813.GC31157@fieldses.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Mon, 15 Sep 2014 18:08:13 -0400 "J. Bruce Fields" <bfields@fieldses.org> wrote: > On Thu, Aug 28, 2014 at 04:24:43PM -0400, J. Bruce Fields wrote: > > On Thu, Aug 28, 2014 at 04:01:00PM -0400, J. Bruce Fields wrote: > > > On Tue, Aug 19, 2014 at 02:38:25PM -0400, Jeff Layton wrote: > > > > Currently, all of the grace period handling is part of lockd. Eventually > > > > though we'd like to be able to build v4-only servers, at which point > > > > we'll need to put all of this elsewhere. > > > > > > > > Move the code itself into fs/nfs_common and have it build a grace.ko > > > > module. Then, rejigger the Kconfig options so that both nfsd and lockd > > > > enable it automatically. > > > > > > Thanks, applying this one for 3.18 indepedently of the others. > > > > This code should also be fixed, though. > > > > Currently nfsd is recording the grace period as done when its own timer > > runs out, but then it continuing to accept reclaims until lockd is also > > done. > > I sat down to fix this today then decided there's not a real bug: > > All the grace_done upcall really does is throw away any previous clients > that haven't reclaimed yet. > > It's legal to do that as soon as the correct amount of time has passed. > It's actually OK to continue to allow the grace period to run past that > point, the only requirement is that all reclaims precede all new opens, > which the code still does enforce. > > So I think it might just be worth a little extra explanation. > > --b. > > diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c > index a298c3d..ca6f6ee 100644 > --- a/fs/nfsd/nfs4state.c > +++ b/fs/nfsd/nfs4state.c > @@ -4122,8 +4122,23 @@ nfsd4_end_grace(struct nfsd_net *nn) > > dprintk("NFSD: end of grace period\n"); > nn->grace_ended = true; > + /* > + * If the server goes down again right now, an NFSv4 > + * client will still be allowed to reclaim after it comes back up, > + * even if it hasn't yet had a chance to reclaim state this time. > + */ Might even be reasonable to lay out the v4.0/v4.1+ difference here? For a v4.0 client any lock reclaim will do, but for v4.1+ the client must have _completed_ reclaim at this point (a'la RECLAIM_COMPLETE) ...or at least that'll be the situation once the patches I sent go in... > nfsd4_record_grace_done(nn); > + /* > + * At this point, NFSv4 clients can still reclaim. But if > the > + * server crashes, any that have not yet reclaimed will be > out > + * of luck on the next boot. > + */ > locks_end_grace(&nn->nfsd4_manager); > + /* > + * At this point, and once lockd and/or any other containers > + * exit their grace period, further reclaims aren't permitted > + * and regular locking can resume. > + */ > } > > static time_t > -- > To unsubscribe from this list: send the line "unsubscribe linux-nfs" > in the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html ACK, overall. The comments make sense to me and it does clarify things a bit.
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index a298c3d..ca6f6ee 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -4122,8 +4122,23 @@ nfsd4_end_grace(struct nfsd_net *nn) dprintk("NFSD: end of grace period\n"); nn->grace_ended = true; + /* + * If the server goes down again right now, an NFSv4 + * client will still be allowed to reclaim after it comes back up, + * even if it hasn't yet had a chance to reclaim state this time. + */ nfsd4_record_grace_done(nn); + /* + * At this point, NFSv4 clients can still reclaim. But if the + * server crashes, any that have not yet reclaimed will be out + * of luck on the next boot. + */ locks_end_grace(&nn->nfsd4_manager); + /* + * At this point, and once lockd and/or any other containers + * exit their grace period, further reclaims aren't permitted + * and regular locking can resume. + */ } static time_t