Messages in this thread | | | Date | Wed, 19 Aug 2009 12:33:15 -0400 | From | Christoph Hellwig <> | Subject | Re: [PATCH 14/17] xfs: Use new syncing helper |
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On Wed, Aug 19, 2009 at 06:04:41PM +0200, Jan Kara wrote: > diff --git a/fs/xfs/linux-2.6/xfs_lrw.c b/fs/xfs/linux-2.6/xfs_lrw.c > index 7078974..aeb5a39 100644 > --- a/fs/xfs/linux-2.6/xfs_lrw.c > +++ b/fs/xfs/linux-2.6/xfs_lrw.c > @@ -817,7 +817,7 @@ write_retry: > xfs_iunlock(xip, iolock); > if (need_i_mutex) > mutex_unlock(&inode->i_mutex); > - error2 = sync_page_range(inode, mapping, pos, ret); > + error2 = generic_write_sync(file, pos, ret);
I don't think this is very optimal for XFS. This first starts an asynchronous writeout of the range in generic_write_sync, then calls into ->fsync which waits for all I/O on the file to finish, then forces the log inside xfs_fsync, then waits for the range again in generic_write_sync, and after this code calls into xfs_write_sync_logforce which forces to log _again_.
We should be fine just doing your new filemap_fdatawrite_range helper here and let xfs_write_sync_logforce do the work. Long term we should just get rid of this stupid submit writes before syncing the iode, then wait crap which is a pain for all modern filesystems.
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