[PATCH] knfsd: Allow lockd to drop replies as appropriate

It is possible for the ->fopen callback from lockd into nfsd to find that an
answer cannot be given straight away (an upcall is needed) and so the request
has to be 'dropped', to be retried later.  That error status is not currently
propagated back.

So:
  Change nlm_fopen to return nlm error codes (rather than a private
  protocol) and define a new nlm_drop_reply code.
  Cause nlm_drop_reply to cause the rpc request to get rpc_drop_reply
  when this error comes back.
  Cause svc_process to drop a request which returns a status of
  rpc_drop_reply.

[akpm@osdl.org: fix warning storm]
Cc: Marc Eshel <eshel@almaden.ibm.com>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 8 insertions, 6 deletions

diff --git a/fs/nfsd/lockd.c b/fs/nfsd/lockd.c
index 7b889ff15ae..9b9e7e127c0 100644
--- a/fs/nfsd/lockd.c
+++ b/fs/nfsd/lockd.c
@@ -39,18 +39,20 @@ nlm_fopen(struct svc_rqst *rqstp, struct nfs_fh *f, struct file **filp)
 	fh_put(&fh);
 	rqstp->rq_client = NULL;
 	exp_readunlock();
- 	/* nlm and nfsd don't share error codes.
-	 * we invent: 0 = no error
-	 *            1 = stale file handle
-	 *	      2 = other error
+ 	/* We return nlm error codes as nlm doesn't know
+	 * about nfsd, but nfsd does know about nlm..
 	 */
 	switch (nfserr) {
 	case nfs_ok:
 		return 0;
+	case nfserr_dropit:
+		return nlm_drop_reply;
+#ifdef CONFIG_LOCKD_V4
 	case nfserr_stale:
-		return 1;
+		return nlm4_stale_fh;
+#endif
 	default:
-		return 2;
+		return nlm_lck_denied;
 	}
 }