orangefs: re-add flush_racache from out-of-tree

Signed-off-by: Martin Brandenburg <martin@omnibond.com>

fs/orangefs/file.c

@@ -14,6 +14,32 @@
 #include <linux/fs.h>
 #include <linux/pagemap.h>
 
+static int flush_racache(struct inode *inode)
+{
+	struct orangefs_inode_s *orangefs_inode = ORANGEFS_I(inode);
+	struct orangefs_kernel_op_s *new_op;
+	int ret;
+
+	gossip_debug(GOSSIP_UTILS_DEBUG,
+	    "%s: %pU: Handle is %pU | fs_id %d\n", __func__,
+	    get_khandle_from_ino(inode), &orangefs_inode->refn.khandle,
+	    orangefs_inode->refn.fs_id);
+
+	new_op = op_alloc(ORANGEFS_VFS_OP_RA_FLUSH);
+	if (!new_op)
+		return -ENOMEM;
+	new_op->upcall.req.ra_cache_flush.refn = orangefs_inode->refn;
+
+	ret = service_operation(new_op, "orangefs_flush_racache",
+	    get_interruptible_flag(inode));
+
+	gossip_debug(GOSSIP_UTILS_DEBUG, "%s: got return value of %d\n",
+	    __func__, ret);
+
+	op_release(new_op);
+	return ret;
+}
+
 /*
  * Copy to client-core's address space from the buffers specified
  * by the iovec upto total_size bytes.
@@ -597,9 +623,15 @@ static int orangefs_file_release(struct inode *inode, struct file *file)
 	 */
 	if (file->f_path.dentry->d_inode &&
 	    file->f_path.dentry->d_inode->i_mapping &&
-	    mapping_nrpages(&file->f_path.dentry->d_inode->i_data))
+	    mapping_nrpages(&file->f_path.dentry->d_inode->i_data)) {
+		gossip_debug(GOSSIP_INODE_DEBUG,
+		    "calling flush_racache on %pU\n",
+		    get_khandle_from_ino(inode));
+		flush_racache(inode);
+		gossip_debug(GOSSIP_INODE_DEBUG, "flush_racache finished\n");
 		truncate_inode_pages(file->f_path.dentry->d_inode->i_mapping,
 				     0);
+	}
 	return 0;
 }