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 a6c87d623891..58bb19784e12 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 2bacf7535069..5e4beb0deb80 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 */