9p: Add datasync to client side TFSYNC/RFSYNC for dotl

SYNOPSIS
    size[4] Tfsync tag[2] fid[4] datasync[4]

    size[4] Rfsync tag[2]

DESCRIPTION

    The Tfsync transaction transfers ("flushes") all modified in-core data of
    file identified by fid to the disk device (or other  permanent  storage
    device)  where that  file  resides.

    If datasync flag is specified data will be fleshed but does not flush
    modified metadata unless  that  metadata  is  needed  in order to allow a
    subsequent data retrieval to be correctly handled.

Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
diff --git a/fs/9p/v9fs_vfs.h b/fs/9p/v9fs_vfs.h
index d26db19..bab0eac 100644
--- a/fs/9p/v9fs_vfs.h
+++ b/fs/9p/v9fs_vfs.h
@@ -65,5 +65,6 @@
 ssize_t v9fs_file_readn(struct file *, char *, char __user *, u32, u64);
 void v9fs_blank_wstat(struct p9_wstat *wstat);
 int v9fs_vfs_setattr_dotl(struct dentry *, struct iattr *);
+int v9fs_file_fsync_dotl(struct file *filp, int datasync);
 
 #define P9_LOCK_TIMEOUT (30*HZ)
diff --git a/fs/9p/vfs_dir.c b/fs/9p/vfs_dir.c
index 170f5bb..b84ebe8 100644
--- a/fs/9p/vfs_dir.c
+++ b/fs/9p/vfs_dir.c
@@ -315,4 +315,5 @@
 	.readdir = v9fs_dir_readdir_dotl,
 	.open = v9fs_file_open,
 	.release = v9fs_dir_release,
+        .fsync = v9fs_file_fsync_dotl,
 };
diff --git a/fs/9p/vfs_file.c b/fs/9p/vfs_file.c
index 3a4352f..240c306 100644
--- a/fs/9p/vfs_file.c
+++ b/fs/9p/vfs_file.c
@@ -491,7 +491,7 @@
 	return retval;
 }
 
-static int v9fs_file_fsync_dotl(struct file *filp, int datasync)
+int v9fs_file_fsync_dotl(struct file *filp, int datasync)
 {
 	struct p9_fid *fid;
 	int retval;
@@ -501,7 +501,7 @@
 
 	fid = filp->private_data;
 
-	retval = p9_client_fsync(fid);
+	retval = p9_client_fsync(fid, datasync);
 	return retval;
 }