1 files changed, 17 insertions, 3 deletions

diff --git a/include/linux/nfsd/const.h b/include/linux/nfsd/const.h
index b75bb1b38d09..f0cc77790527 100644
--- a/include/linux/nfsd/const.h
+++ b/include/linux/nfsd/const.h
@@ -20,17 +20,31 @@
 #define NFSSVC_MAXVERS          3
 
 /*
- * Maximum blocksize supported by daemon currently at 32K
+ * Maximum blocksizes supported by daemon under various circumstances.
  */
-#define NFSSVC_MAXBLKSIZE       (32*1024)
+#define NFSSVC_MAXBLKSIZE       RPCSVC_MAXPAYLOAD
+/* NFSv2 is limited by the protocol specification, see RFC 1094 */
+#define NFSSVC_MAXBLKSIZE_V2    (8*1024)
 
 #ifdef __KERNEL__
 
+#include <linux/sunrpc/msg_prot.h>
+
 #ifndef NFS_SUPER_MAGIC
 # define NFS_SUPER_MAGIC        0x6969
 #endif
 
-#define NFSD_BUFSIZE            (1024 + NFSSVC_MAXBLKSIZE)
+/*
+ * Largest number of bytes we need to allocate for an NFS
+ * call or reply.  Used to control buffer sizes.  We use
+ * the length of v3 WRITE, READDIR and READDIR replies
+ * which are an RPC header, up to 26 XDR units of reply
+ * data, and some page data.
+ *
+ * Note that accuracy here doesn't matter too much as the
+ * size is rounded up to a page size when allocating space.
+ */
+#define NFSD_BUFSIZE            ((RPC_MAX_HEADER_WITH_AUTH+26)*XDR_UNIT + NFSSVC_MAXBLKSIZE)
 
 #ifdef CONFIG_NFSD_V4
 # define NFSSVC_XDRSIZE         NFS4_SVC_XDRSIZE