[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, 4 insertions, 0 deletions

diff --git a/include/linux/lockd/xdr.h b/include/linux/lockd/xdr.h
index bb0a0f1caa91..66fdae3b490c 100644
--- a/include/linux/lockd/xdr.h
+++ b/include/linux/lockd/xdr.h
@@ -13,6 +13,8 @@
 #include <linux/nfs.h>
 #include <linux/sunrpc/xdr.h>
 
+struct svc_rqst;
+
 #define NLM_MAXCOOKIELEN    	32
 #define NLM_MAXSTRLEN		1024
 
@@ -22,6 +24,8 @@
 #define	nlm_lck_blocked		__constant_htonl(NLM_LCK_BLOCKED)
 #define	nlm_lck_denied_grace_period	__constant_htonl(NLM_LCK_DENIED_GRACE_PERIOD)
 
+#define nlm_drop_reply		__constant_htonl(30000)
+
 /* Lock info passed via NLM */
 struct nlm_lock {
 	char *			caller;