netdev - Re: [PATCH 03/10] mm: Add support for a filesystem to control swap files

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20110909130007.GA11810@infradead.org>
Date:	Fri, 9 Sep 2011 09:00:08 -0400
From:	Christoph Hellwig <hch@...radead.org>
To:	Mel Gorman <mgorman@...e.de>
Cc:	Linux-MM <linux-mm@...ck.org>,
	Linux-Netdev <netdev@...r.kernel.org>,
	Linux-NFS <linux-nfs@...r.kernel.org>,
	LKML <linux-kernel@...r.kernel.org>,
	Andrew Morton <akpm@...ux-foundation.org>,
	David Miller <davem@...emloft.net>,
	Trond Myklebust <Trond.Myklebust@...app.com>,
	Neil Brown <neilb@...e.de>,
	Peter Zijlstra <a.p.zijlstra@...llo.nl>
Subject: Re: [PATCH 03/10] mm: Add support for a filesystem to control swap
 files

On Fri, Sep 09, 2011 at 12:00:47PM +0100, Mel Gorman wrote:
> Currently swapfiles are managed entirely by the core VM by using
> ->bmap to allocate space and write to the blocks directly. This
> patch adds address_space_operations methods that allow a filesystem
> to optionally control the swapfile.
> 
>   int swap_activate(struct file *);
>   int swap_deactivate(struct file *);
>   int swap_writepage(struct file *, struct page *, struct writeback_control *);
>   int swap_readpage(struct file *, struct page *);

Just as the last two dozen times this came up:

NAK

The right fix is to add a filesystem method to support direct-I/O on
arbitrary kernel pages, instead of letting the wap abstraction leak into
the filesystem.
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html