diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c
index 6c2ddfed2cfc..39aed901514b 100644
--- a/fs/nfsd/nfsctl.c
+++ b/fs/nfsd/nfsctl.c
@@ -57,6 +57,7 @@ enum {
 	NFSD_Pool_Threads,
 	NFSD_Versions,
 	NFSD_Ports,
+	NFSD_MaxBlkSize,
 	/*
 	 * The below MUST come last.  Otherwise we leave a hole in nfsd_files[]
 	 * with !CONFIG_NFSD_V4 and simple_fill_super() goes oops
@@ -82,6 +83,7 @@ static ssize_t write_threads(struct file *file, char *buf, size_t size);
 static ssize_t write_pool_threads(struct file *file, char *buf, size_t size);
 static ssize_t write_versions(struct file *file, char *buf, size_t size);
 static ssize_t write_ports(struct file *file, char *buf, size_t size);
+static ssize_t write_maxblksize(struct file *file, char *buf, size_t size);
 #ifdef CONFIG_NFSD_V4
 static ssize_t write_leasetime(struct file *file, char *buf, size_t size);
 static ssize_t write_recoverydir(struct file *file, char *buf, size_t size);
@@ -100,6 +102,7 @@ static ssize_t (*write_op[])(struct file *, char *, size_t) = {
 	[NFSD_Pool_Threads] = write_pool_threads,
 	[NFSD_Versions] = write_versions,
 	[NFSD_Ports] = write_ports,
+	[NFSD_MaxBlkSize] = write_maxblksize,
 #ifdef CONFIG_NFSD_V4
 	[NFSD_Leasetime] = write_leasetime,
 	[NFSD_RecoveryDir] = write_recoverydir,
@@ -555,6 +558,35 @@ static ssize_t write_ports(struct file *file, char *buf, size_t size)
 	return -EINVAL;
 }
 
+int nfsd_max_blksize;
+
+static ssize_t write_maxblksize(struct file *file, char *buf, size_t size)
+{
+	char *mesg = buf;
+	if (size > 0) {
+		int bsize;
+		int rv = get_int(&mesg, &bsize);
+		if (rv)
+			return rv;
+		/* force bsize into allowed range and
+		 * required alignment.
+		 */
+		if (bsize < 1024)
+			bsize = 1024;
+		if (bsize > NFSSVC_MAXBLKSIZE)
+			bsize = NFSSVC_MAXBLKSIZE;
+		bsize &= ~(1024-1);
+		lock_kernel();
+		if (nfsd_serv && nfsd_serv->sv_nrthreads) {
+			unlock_kernel();
+			return -EBUSY;
+		}
+		nfsd_max_blksize = bsize;
+		unlock_kernel();
+	}
+	return sprintf(buf, "%d\n", nfsd_max_blksize);
+}
+
 #ifdef CONFIG_NFSD_V4
 extern time_t nfs4_leasetime(void);
 
@@ -620,6 +652,7 @@ static int nfsd_fill_super(struct super_block * sb, void * data, int silent)
 		[NFSD_Pool_Threads] = {"pool_threads", &transaction_ops, S_IWUSR|S_IRUSR},
 		[NFSD_Versions] = {"versions", &transaction_ops, S_IWUSR|S_IRUSR},
 		[NFSD_Ports] = {"portlist", &transaction_ops, S_IWUSR|S_IRUGO},
+		[NFSD_MaxBlkSize] = {"max_block_size", &transaction_ops, S_IWUSR|S_IRUGO},
 #ifdef CONFIG_NFSD_V4
 		[NFSD_Leasetime] = {"nfsv4leasetime", &transaction_ops, S_IWUSR|S_IRUSR},
 		[NFSD_RecoveryDir] = {"nfsv4recoverydir", &transaction_ops, S_IWUSR|S_IRUSR},
diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c
index 19443056ec30..0603baad5426 100644
--- a/fs/nfsd/nfssvc.c
+++ b/fs/nfsd/nfssvc.c
@@ -198,9 +198,26 @@ int nfsd_create_serv(void)
 		unlock_kernel();
 		return 0;
 	}
+	if (nfsd_max_blksize == 0) {
+		/* choose a suitable default */
+		struct sysinfo i;
+		si_meminfo(&i);
+		/* Aim for 1/4096 of memory per thread
+		 * This gives 1MB on 4Gig machines
+		 * But only uses 32K on 128M machines.
+		 * Bottom out at 8K on 32M and smaller.
+		 * Of course, this is only a default.
+		 */
+		nfsd_max_blksize = NFSSVC_MAXBLKSIZE;
+		i.totalram >>= 12;
+		while (nfsd_max_blksize > i.totalram &&
+		       nfsd_max_blksize >= 8*1024*2)
+			nfsd_max_blksize /= 2;
+	}
 
 	atomic_set(&nfsd_busy, 0);
-	nfsd_serv = svc_create_pooled(&nfsd_program, NFSD_BUFSIZE,
+	nfsd_serv = svc_create_pooled(&nfsd_program,
+				      NFSD_BUFSIZE - NFSSVC_MAXBLKSIZE + nfsd_max_blksize,
 				      nfsd_last_thread,
 				      nfsd, SIG_NOCLEAN, THIS_MODULE);
 	if (nfsd_serv == NULL)
diff --git a/include/linux/nfsd/const.h b/include/linux/nfsd/const.h
index adbddf007898..f478066f9cd5 100644
--- a/include/linux/nfsd/const.h
+++ b/include/linux/nfsd/const.h
@@ -21,9 +21,9 @@
 #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)
 
diff --git a/include/linux/nfsd/nfsd.h b/include/linux/nfsd/nfsd.h
index e1dbc86c270b..259841bb2f6c 100644
--- a/include/linux/nfsd/nfsd.h
+++ b/include/linux/nfsd/nfsd.h
@@ -145,6 +145,7 @@ int nfsd_vers(int vers, enum vers_op change);
 void nfsd_reset_versions(void);
 int nfsd_create_serv(void);
 
+extern int nfsd_max_blksize;
 
 /* 
  * NFSv4 State