diff --git a/fs/nfsd/export.c b/fs/nfsd/export.c
index 8a6f7c9..5bb2bd5 100644
--- a/fs/nfsd/export.c
+++ b/fs/nfsd/export.c
@@ -1439,6 +1439,7 @@ static struct flags {
 	{ NFSEXP_CROSSMOUNT, {"crossmnt", ""}},
 	{ NFSEXP_NOSUBTREECHECK, {"no_subtree_check", ""}},
 	{ NFSEXP_NOAUTHNLM, {"insecure_locks", ""}},
+	{ NFSEXP_PREALLOC, {"prealloc", "no_prealloc"}},
 #ifdef MSNFS
 	{ NFSEXP_MSNFS, {"msnfs", ""}},
 #endif
diff --git a/include/linux/nfsd/export.h b/include/linux/nfsd/export.h
index 5431512..0310659 100644
--- a/include/linux/nfsd/export.h
+++ b/include/linux/nfsd/export.h
@@ -32,7 +32,8 @@
 #define NFSEXP_ALLSQUASH	0x0008
 #define NFSEXP_ASYNC		0x0010
 #define NFSEXP_GATHERED_WRITES	0x0020
-/* 40 80 100 currently unused */
+#define NFSEXP_PREALLOC		0x0040
+/* 80 100 currently unused */
 #define NFSEXP_NOHIDE		0x0200
 #define NFSEXP_NOSUBTREECHECK	0x0400
 #define	NFSEXP_NOAUTHNLM	0x0800		/* Don't authenticate NLM requests - just trust */
@@ -40,7 +41,7 @@
 #define NFSEXP_FSID		0x2000
 #define	NFSEXP_CROSSMOUNT	0x4000
 #define	NFSEXP_NOACL		0x8000	/* reserved for possible ACL related use */
-#define NFSEXP_ALLFLAGS		0xFE3F
+#define NFSEXP_ALLFLAGS		0xFE7F
 
 /* The flags that may vary depending on security flavor: */
 #define NFSEXP_SECINFO_FLAGS	(NFSEXP_READONLY | NFSEXP_ROOTSQUASH \
@@ -113,6 +114,7 @@ struct svc_expkey {
 #define EX_ISSYNC(exp)		(!((exp)->ex_flags & NFSEXP_ASYNC))
 #define EX_NOHIDE(exp)		((exp)->ex_flags & NFSEXP_NOHIDE)
 #define EX_WGATHER(exp)		((exp)->ex_flags & NFSEXP_GATHERED_WRITES)
+#define EX_PREALLOC(exp)	((exp)->ex_flags & NFSEXP_PREALLOC)
 
 int nfsexp_flags(struct svc_rqst *rqstp, struct svc_export *exp);
 __be32 check_nfsd_access(struct svc_export *exp, struct svc_rqst *rqstp);