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Date:   Mon, 9 May 2022 09:23:10 -0400
From:   "Theodore Ts'o" <tytso@mit.edu>
To:     "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc:     linux-fsdevel@vger.kernel.org
Subject: Re: [PATCH 24/26] jbd2: Convert release_buffer_page() to use a folio
Message-ID: <YnkVvr6UR2NQLbWi@mit.edu>
References: <YngbFluT9ftR5dqf@casper.infradead.org>
 <20220508203247.668791-1-willy@infradead.org>
 <20220508203247.668791-25-willy@infradead.org>
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On Sun, May 08, 2022 at 09:32:45PM +0100, Matthew Wilcox (Oracle) wrote:
> Saves a few calls to compound_head().
>
> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>

Acked-by: Theodore Ts'o <tytso@mit.edu>

... although I have one question:

> -	get_page(page);
> +	folio_get(folio);
>  	__brelse(bh);
> -	try_to_free_buffers(page);
> -	unlock_page(page);
> -	put_page(page);
> +	try_to_free_buffers(&folio->page);

The patches in this series seem to assume that the folio contains only
a single page.  Or at least, a *lot* more detailed auditing to make
sure the right thing would happen if a page happens to be a member of
a folio with more than a single page.

Should we be adding some kind of WARN_ON to check this particular
assumption?

					- Ted