[PATCH 10/30] nfsd41: set the session maximum response size cached

[andros@netapp.com]

From: Andy Adamson <andros@netapp.com>

We don't cache the SEQUENCE operation because we can encode it from the session
slot values, so it is not included in NFSD_SLOT_CACHE_SIZE.

Fix the nfsd4_check_drc_limit() comment - the cache is no longer page based.

Signed-off-by: Andy Adamson <andros@netapp.com>
---
 fs/nfsd/nfs4state.c |   10 +++++++---
 fs/nfsd/nfs4xdr.c   |    2 --
 2 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index db56a8a..cdc2a5e 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -448,6 +448,12 @@ static int set_forechannel_maxreqs(struct nfsd4_channel_attrs *fchan)
 	}
 }
 
+/* rpc header + encoded OP_SEQUENCE reply + NFSD_SLOT_CACHE_SIZE in bytes */
+#define NFSD_MAX_RESPONSE_CACHED  ((RPC_MAX_HEADER_WITH_AUTH + \
+				  2 + /* OP_SEQUENCE header */ \
+				  XDR_QUADLEN(NFS4_MAX_SESSIONID_LEN) + 5 + \
+				  XDR_QUADLEN(NFSD_SLOT_CACHE_SIZE)) << 2)
+
 /*
  * fchan holds the client values on input, and the server values on output
  */
@@ -469,9 +475,7 @@ static int init_forechannel_attrs(struct svc_rqst *rqstp,
 		fchan->maxresp_sz = maxcount;
 	session->se_fmaxresp_sz = fchan->maxresp_sz;
 
-	/* Set the max response cached size our default which is
-	 * a multiple of PAGE_SIZE and small */
-	session->se_fmaxresp_cached = NFSD_PAGES_PER_SLOT * PAGE_SIZE;
+	session->se_fmaxresp_cached = NFSD_MAX_RESPONSE_CACHED;
 	fchan->maxresp_cached = session->se_fmaxresp_cached;
 
 	/* Use the client's maxops if possible */
diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index b73549d..7e6b139 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -3176,8 +3176,6 @@ static nfsd4_enc nfsd4_enc_ops[] = {
  *
  * Compare this length to the session se_fmaxresp_cached.
  *
- * Our se_fmaxresp_cached will always be a multiple of PAGE_SIZE, and so
- * will be at least a page and will therefore hold the xdr_buf head.
  */
 static int nfsd4_check_drc_limit(struct nfsd4_compoundres *resp)
 {
-- 
1.5.4.3