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Subject: Re: [patch] fix the ext3 data=journal unmount bug
From: "Stephen C. Tweedie" <sct@redhat.com>
To: Chris Mason <mason@suse.com>
Cc: Andrew Morton <akpm@digeo.com>, lkml <linux-kernel@vger.kernel.org>,
       ext3 users list <ext3-users@redhat.com>
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Hi,

On Fri, 2002-12-06 at 20:34, Chris Mason wrote:

> The bulk of the sync(2) will be async though, since most of the io is
> actually writing dirty data buffers out.  We already do that in two
> stages.

Not with data journaling.  That's the whole point: the VFS assumes too
much about where the data is being written, when.

> For 2.5, if an FS really wanted a two stage sync for it's non-data
> pages

But it's data that is the problem.  For sync() semantics,
data-journaling only requires that the pages have hit the journal.  For
umount, it is critical that we complete the final writeback before
destroying the inode lists.

Cheers,
 Stephen
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