[GFS2] Add writepages for "data=writeback" mounts

#include <linux/pagevec.h>

#include <linux/mpage.h>

#include <linux/fs.h>

#include <linux/writeback.h>

#include <linux/gfs2_ondisk.h>

#include <linux/lm_interface.h>

	return 0;

}

/**

 * gfs2_writepages - Write a bunch of dirty pages back to disk

 * @mapping: The mapping to write

 * @wbc: Write-back control

 *

 * For journaled files and/or ordered writes this just falls back to the

 * kernel's default writepages path for now. We will probably want to change

 * that eventually (i.e. when we look at allocate on flush).

 *

 * For the data=writeback case though we can already ignore buffer heads

 * and write whole extents at once. This is a big reduction in the

 * number of I/O requests we send and the bmap calls we make in this case.

 */

int gfs2_writepages(struct address_space *mapping, struct writeback_control *wbc)

{

	struct inode *inode = mapping->host;

	struct gfs2_inode *ip = GFS2_I(inode);

	struct gfs2_sbd *sdp = GFS2_SB(inode);

	if (sdp->sd_args.ar_data == GFS2_DATA_WRITEBACK && !gfs2_is_jdata(ip))

		return mpage_writepages(mapping, wbc, gfs2_get_block_noalloc);

	return generic_writepages(mapping, wbc);

}

/**

 * stuffed_readpage - Fill in a Linux page with stuffed file data

 * @ip: the inode

const struct address_space_operations gfs2_file_aops = {

	.writepage = gfs2_writepage,

	.writepages = gfs2_writepages,

	.readpage = gfs2_readpage,

	.readpages = gfs2_readpages,

	.sync_page = block_sync_page,