Re: [PATCH 1/2] nfsd: convert nfs4_client->cl_cb_flags to a generic flags field

["J. Bruce Fields" <bfields@fieldses.org>]

On Tue, Mar 06, 2012 at 03:11:19PM -0500, J. Bruce Fields wrote:
> On Mon, Mar 05, 2012 at 11:42:35AM -0500, Jeff Layton wrote:
> > We'll need a way to flag the nfs4_client as already being recorded on
> > stable storage so that we don't continually upcall. Currently, that's
> > recorded in the cl_firststate field of the client struct. Using an
> > entire u32 to store a flag is rather wasteful though.
> > 
> > The cl_cb_flags field is only using 2 bits right now, so repurpose that
> > to a generic flags field. Rename NFSD4_CLIENT_KILL to
> > NFSD4_CLIENT_CB_KILL to make it evident that it's part of the callback
> > flags. Add a mask that we can use for existing checks that look to see
> > whether any flags are set, so that the new flags don't interfere.
> > 
> > Convert all references to cl_firstate to the NFSD4_CLIENT_STABLE flag,
> > and add a new NFSD4_CLIENT_RECLAIM_COMPLETE flag. I believe there's an
> > existing bug here too that this should fix:
> > 
> > nfs4_set_claim_prev sets cl_firststate on the first CLAIM_PREV open.
> > nfsd4_reclaim_complete looks for that flag though, and returns
> > NFS4ERR_COMPLETE_ALREADY if it's set. The upshot here is that once a
> > client does a CLAIM_PREV open, the RECLAIM_COMPLETE call will fail.
> > Let's fix this by adding a new RECLAIM_COMPLETE flag on the client to
> > indicate that that's already been done.
> 
> I think this is right, and agree that flags make more sense.  But as a
> quick bugfix only, how about this?

Also I think there's another preexisting bug here.  Yuch.

commit e02c696c47958adb0a2f5499aa6032288c5b475b
Author: J. Bruce Fields <bfields@redhat.com>
Date:   Tue Mar 6 14:43:36 2012 -0500

    nfsd4: purge stable client records with insufficient state
    
    To escape having your stable storage record purged at the end of the
    grace period, it's not sufficient to simply have performed a
    setclientid_confirm; you also need to meet the same requirements as
    someone creating a new record: either you should have done an open or
    open reclaim (in the 4.0 case) or a reclaim_complete (in the 4.1 case).
    
    Signed-off-by: J. Bruce Fields <bfields@redhat.com>

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 207c3bd..c9c446d 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -4415,7 +4415,9 @@ nfs4_has_reclaimed_state(const char *name, bool use_exchange_id)
 	struct nfs4_client *clp;
 
 	clp = find_confirmed_client_by_str(name, strhashval);
-	return clp ? 1 : 0;
+	if (!clp)
+		return 0;
+	return clp->cl_firststate;
 }
 
 /*