[Ocfs2-devel] [PATCH 1/2 v2] ocfs2: Flush drive's caches on fdatasync

[Jan Kara]

  Hi,

On Mon 02-08-10 21:55:39, Wengang Wang wrote:
> I think it will be better if you mention the BARRIER mount option in the patch
> description. That will accurately match your patch.
  OK. So the description could be:
When 'barrier' mount option is specified, we have to issue a cache flush
during fdatasync. We have to do this even if inode doesn't have
I_DIRTY_DATASYNC set because we still have to get written *data* to disk so
that they are not lost in case of crash.

  Better?

								Honza
> On 10-08-02 15:04, Jan Kara wrote:
> > We have to issue a cache flush during fdatasync even if inode doesn't have
> > I_DIRTY_DATASYNC set because we still have to get written *data* to disk to
> > observe fdatasync() guarantees.
> > 
> > Acked-by: Tao Ma <tao.ma at oracle.com>
> > Signed-off-by: Jan Kara <jack at suse.cz>
> > ---
> >  fs/ocfs2/file.c |   11 ++++++++++-
> >  1 files changed, 10 insertions(+), 1 deletions(-)
> > 
> >   Joel, would you merge this and the following patch please? Thanks.
> > 
> > 								Honza
> > 
> > diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c
> > index 2b10b36..3ed8efd 100644
> > --- a/fs/ocfs2/file.c
> > +++ b/fs/ocfs2/file.c
> > @@ -36,6 +36,7 @@
> >  #include <linux/writeback.h>
> >  #include <linux/falloc.h>
> >  #include <linux/quotaops.h>
> > +#include <linux/blkdev.h>
> >  
> >  #define MLOG_MASK_PREFIX ML_INODE
> >  #include <cluster/masklog.h>
> > @@ -190,8 +191,16 @@ static int ocfs2_sync_file(struct file *file, int datasync)
> >  	if (err)
> >  		goto bail;
> >  
> > -	if (datasync && !(inode->i_state & I_DIRTY_DATASYNC))
> > +	if (datasync && !(inode->i_state & I_DIRTY_DATASYNC)) {
> > +		/*
> > +		 * We still have to flush drive's caches to get data to the
> > +		 * platter
> > +		 */
> > +		if (osb->s_mount_opt & OCFS2_MOUNT_BARRIER)
> > +			blkdev_issue_flush(inode->i_sb->s_bdev, GFP_KERNEL,
> > +					   NULL, BLKDEV_IFL_WAIT);
> >  		goto bail;
> > +	}
> >  
> >  	journal = osb->journal->j_journal;
> >  	err = jbd2_journal_force_commit(journal);
> > -- 
> > 1.6.4.2
> > 
> > 
> > _______________________________________________
> > Ocfs2-devel mailing list
> > Ocfs2-devel at oss.oracle.com
> > http://oss.oracle.com/mailman/listinfo/ocfs2-devel
-- 
Jan Kara <jack at suse.cz>
SUSE Labs, CR