fs/9p: Mark file system with MS_SYNCHRONOUS only if it is not cached mode

We should not mark file system synchronous if mounted cache=* option
Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: NVenkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>

fs/9p/vfs_super.c

@@ -87,8 +87,9 @@ v9fs_fill_super(struct super_block *sb, struct v9fs_session_info *v9ses,
 		sb->s_op = &v9fs_super_ops;
 	sb->s_bdi = &v9ses->bdi;
 
-	sb->s_flags = flags | MS_ACTIVE | MS_SYNCHRONOUS | MS_DIRSYNC |
-	    MS_NOATIME;
+	sb->s_flags = flags | MS_ACTIVE | MS_DIRSYNC | MS_NOATIME;
+	if (!v9ses->cache)
+		sb->s_flags |= MS_SYNCHRONOUS;
 
 #ifdef CONFIG_9P_FS_POSIX_ACL
 	if ((v9ses->flags & V9FS_ACL_MASK) == V9FS_POSIX_ACL)