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Date: Fri, 2 Jun 2006 23:06:03 +0200
From: Olaf Hering <olh@suse.de>
To: Andrew Morton <akpm@osdl.org>
Cc: linux-kernel@vger.kernel.org, viro@ftp.linux.org.uk
Subject: Re: [PATCH] cramfs corruption after BLKFLSBUF on loop device
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 On Fri, Jun 02, Andrew Morton wrote:

> Oh, OK, we cannot use read_cache_page().  Because the above is still racy
> (and still needs the retry loop).  We need to set PG_checked before
> launching the read.  Something like:
> 
> /*
>  * Return a locked, uptodate, !PagePrivate, !PageChecked page which needs a
>  * single put_page by the caller.
>  */
> cramfs_read_getpage()
> {
> 	page = find_lock_page()
> 	if (PageUptodate(page))
> 		return page;
> 	SetPagePrivate()
> 	SetPageChecked()
> 	err = m->a_ops->readpage(page);

I guess we have to put a find_or_create_page in there, and fill it.
Will try that tomorrow.