[Midnightbsd-cvs] src [8693] trunk/sys/fs/nfsserver/nfs_nfsdserv.c: make it possible to force async server side on NFS server.

[laffer1 at midnightbsd.org]

Revision: 8693
          http://svnweb.midnightbsd.org/src/?rev=8693
Author:   laffer1
Date:     2016-09-25 18:09:30 -0400 (Sun, 25 Sep 2016)
Log Message:
-----------
make it possible to force async server side on NFS server.

Modified Paths:
--------------
    trunk/sys/fs/nfsserver/nfs_nfsdserv.c

Modified: trunk/sys/fs/nfsserver/nfs_nfsdserv.c
===================================================================
--- trunk/sys/fs/nfsserver/nfs_nfsdserv.c	2016-09-25 22:09:05 UTC (rev 8692)
+++ trunk/sys/fs/nfsserver/nfs_nfsdserv.c	2016-09-25 22:09:30 UTC (rev 8693)
@@ -55,6 +55,11 @@
 extern int nfsrv_enable_crossmntpt;
 #endif	/* !APPLEKEXT */
 
+static int	nfs_async = 0;
+SYSCTL_DECL(_vfs_nfsd);
+SYSCTL_INT(_vfs_nfsd, OID_AUTO, async, CTLFLAG_RW, &nfs_async, 0,
+    "Tell client that writes were synced even though they were not");
+
 /*
  * This list defines the GSS mechanisms supported.
  * (Don't ask me how you get these strings from the RFC stuff like
@@ -912,7 +917,13 @@
 			goto out;
 		NFSM_BUILD(tl, u_int32_t *, 4 * NFSX_UNSIGNED);
 		*tl++ = txdr_unsigned(retlen);
-		if (stable == NFSWRITE_UNSTABLE)
+		/*
+		 * If nfs_async is set, then pretend the write was FILESYNC.
+		 * Warning: Doing this violates RFC1813 and runs a risk
+		 * of data written by a client being lost when the server
+		 * crashes/reboots.
+		 */
+		if (stable == NFSWRITE_UNSTABLE && nfs_async == 0)
 			*tl++ = txdr_unsigned(stable);
 		else
 			*tl++ = txdr_unsigned(NFSWRITE_FILESYNC);