[PATCH] kNFSd: Allow request for nfsv4 pseudo root to perform an upcall.

Most cache-lookups to find export information will cause
an upcall, but currently the lookup to find the pseudo root
for nfsv4 wont asthe  cache-handle isn't made available.
This patch makes it available and makes sure that if the
upcall is made, the request is dropped (for now).

fs/nfsd/export.c

@@ -848,12 +848,18 @@ exp_rootfh(svc_client *clp, char *path, struct knfsd_fh *f, int maxsize)
  * export point with fsid==0
  */
 int
-exp_pseudoroot(struct auth_domain *clp, struct svc_fh *fhp)
+exp_pseudoroot(struct auth_domain *clp, struct svc_fh *fhp,
+	       struct cache_req *creq)
 {
 	struct svc_expkey *fsid_key;
 	int rv;
+	u32 fsidv[2];
+
+	mk_fsid_v1(fsidv, 0);
 
-	fsid_key = exp_get_fsid_key(clp, 0);
+	fsid_key = exp_find_key(clp, 1, fsidv, creq);
+	if (IS_ERR(fsid_key) && PTR_ERR(fsid_key) == -EAGAIN)
+		return nfserr_dropit;
 	if (!fsid_key || IS_ERR(fsid_key))
 		return nfserr_perm;
 

fs/nfsd/nfs4proc.c

@@ -179,7 +179,8 @@ static inline int
 nfsd4_putrootfh(struct svc_rqst *rqstp, struct svc_fh *current_fh)
 {
 	fh_put(current_fh);
-	return exp_pseudoroot(rqstp->rq_client, current_fh);
+	return exp_pseudoroot(rqstp->rq_client, current_fh,
+			      &rqstp->rq_chandle);
 }
 
 static inline int

include/linux/nfsd/export.h

@@ -100,7 +100,7 @@ struct svc_export *	exp_parent(struct auth_domain *clp,
 				   struct cache_req *reqp);
 int			exp_rootfh(struct auth_domain *, 
 					char *path, struct knfsd_fh *, int maxsize);
-int			exp_pseudoroot(struct auth_domain *, struct svc_fh *fhp);
+int			exp_pseudoroot(struct auth_domain *, struct svc_fh *fhp, struct cache_req *creq);
 int			nfserrno(int errno);
 
 extern void expkey_put(struct cache_head *item, struct cache_detail *cd);