nfsd41: Use separate DRC for setclientid

Instead of trying to share the generic 4.1 reply cache code for the
CREATE_SESSION reply cache, it's simpler to handle CREATE_SESSION
separately.

The nfs41 single slot clientid DRC holds the results of create session
processing.  CREATE_SESSION can be preceeded by a SEQUENCE operation
(an embedded CREATE_SESSION) and the create session single slot cache must be
maintained.  nfsd4_replay_cache_entry() and nfsd4_store_cache_entry() do not
implement the replay of an embedded CREATE_SESSION.

The clientid DRC slot does not need the inuse, cachethis or other fields that
the multiple slot session cache uses.  Replace the clientid DRC cache struct
nfs4_slot cache with a new nfsd4_clid_slot cache.  Save the xdr struct
nfsd4_create_session into the cache at the end of processing, and on a replay,
replace the struct for the replay request with the cached version all while
under the state lock.

nfsd4_proc_compound will handle both the solo and embedded CREATE_SESSION case
via the normal use of encode_operation.

Errors that do not change the create session cache:
A create session NFS4ERR_STALE_CLIENTID error means that a client record
(and associated create session slot) could not be found and therefore can't
be changed.  NFSERR_SEQ_MISORDERED errors do not change the slot cache.

All other errors get cached.

Remove the clientid DRC specific check in nfs4svc_encode_compoundres to
put the session only if cstate.session is set which will now always be true.

Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

2 files changed, 20 insertions, 13 deletions

diff --git a/include/linux/nfsd/state.h b/include/linux/nfsd/state.h
index a6c87d62389..58bb19784e1 100644
--- a/include/linux/nfsd/state.h
+++ b/include/linux/nfsd/state.h
@@ -127,6 +127,25 @@ struct nfsd4_channel_attrs {
 	u32		rdma_attrs;
 };
 
+struct nfsd4_create_session {
+	clientid_t			clientid;
+	struct nfs4_sessionid		sessionid;
+	u32				seqid;
+	u32				flags;
+	struct nfsd4_channel_attrs	fore_channel;
+	struct nfsd4_channel_attrs	back_channel;
+	u32				callback_prog;
+	u32				uid;
+	u32				gid;
+};
+
+/* The single slot clientid cache structure */
+struct nfsd4_clid_slot {
+	u32				sl_seqid;
+	__be32				sl_status;
+	struct nfsd4_create_session	sl_cr_ses;
+};
+
 struct nfsd4_session {
 	struct kref		se_ref;
 	struct list_head	se_hash;	/* hash by sessionid */
@@ -193,7 +212,7 @@ struct nfs4_client {
 
 	/* for nfs41 */
 	struct list_head	cl_sessions;
-	struct nfsd4_slot	cl_slot;	/* create_session slot */
+	struct nfsd4_clid_slot	cl_cs_slot;	/* create_session slot */
 	u32			cl_exchange_flags;
 	struct nfs4_sessionid	cl_sessionid;
 };
diff --git a/include/linux/nfsd/xdr4.h b/include/linux/nfsd/xdr4.h
index 2bacf753506..5e4beb0deb8 100644
--- a/include/linux/nfsd/xdr4.h
+++ b/include/linux/nfsd/xdr4.h
@@ -366,18 +366,6 @@ struct nfsd4_exchange_id {
 	int		spa_how;
 };
 
-struct nfsd4_create_session {
-	clientid_t		clientid;
-	struct nfs4_sessionid	sessionid;
-	u32			seqid;
-	u32			flags;
-	struct nfsd4_channel_attrs fore_channel;
-	struct nfsd4_channel_attrs back_channel;
-	u32			callback_prog;
-	u32			uid;
-	u32			gid;
-};
-
 struct nfsd4_sequence {
 	struct nfs4_sessionid	sessionid;		/* request/response */
 	u32			seqid;			/* request/response */