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Commit 33c3de32 authored by Steven Whitehouse's avatar Steven Whitehouse
Browse files

[GFS2] Don't flush everything on fdatasync 



The gfs2_fsync() function was doing a journal flush on each
and every call. While this is correct, its also a lot of
overhead. This patch means that on fdatasync flushes we
rely on the VFS to flush the data for us and we don't do
a journal flush unless we really need to.

We have to do a journal flush for stuffed files though because
they have the data and the inode metadata in the same block.
Journaled files also need a journal flush too of course.

Signed-off-by: default avatarSteven Whitehouse <swhiteho@redhat.com>
parent aac1a3c7

fs/gfs2/ops_file.c

+27 −3
Original line number Diff line number Diff line
@@ -22,6 +22,7 @@ 
#include <linux/ext2_fs.h>

#include <linux/crc32.h>

#include <linux/lm_interface.h>

#include <linux/writeback.h>

#include <asm/uaccess.h>



#include "gfs2.h"
@@ -503,18 +504,41 @@ static int gfs2_close(struct inode *inode, struct file *file) 
 * @file: the file that points to the dentry (we ignore this)

 * @dentry: the dentry that points to the inode to sync

 *

 * The VFS will flush "normal" data for us. We only need to worry

 * about metadata here. For journaled data, we just do a log flush

 * as we can't avoid it. Otherwise we can just bale out if datasync

 * is set. For stuffed inodes we must flush the log in order to

 * ensure that all data is on disk.

 *

 * Returns: errno

 */



static int gfs2_fsync(struct file *file, struct dentry *dentry, int datasync)

{

	struct gfs2_inode *ip = GFS2_I(dentry->d_inode);



	gfs2_log_flush(ip->i_gl->gl_sbd, ip->i_gl);

	struct inode *inode = dentry->d_inode;

	int sync_state = inode->i_state & (I_DIRTY_SYNC|I_DIRTY_DATASYNC);

	int ret = 0;

	struct writeback_control wbc = {

		.sync_mode = WB_SYNC_ALL,

		.nr_to_write = 0,

	};



	if (gfs2_is_jdata(GFS2_I(inode))) {

		gfs2_log_flush(GFS2_SB(inode), GFS2_I(inode)->i_gl);

		return 0;

	}



	if (sync_state != 0) {

		if (!datasync)

			ret = sync_inode(inode, &wbc);



		if (gfs2_is_stuffed(GFS2_I(inode)))

			gfs2_log_flush(GFS2_SB(inode), GFS2_I(inode)->i_gl);

	}



	return ret;

}



/**

 * gfs2_lock - acquire/release a posix lock on a file

 * @file: the file pointer