linux-kernel - Re: [PATCH] ext4: Fix deadlock on page reclaim

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 for Android: free password hash cracker in your pocket

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

Message-ID: <20190730234716.GY7689@dread.disaster.area>
Date:   Wed, 31 Jul 2019 09:47:16 +1000
From:   Dave Chinner <david@...morbit.com>
To:     Damien Le Moal <Damien.LeMoal@....com>
Cc:     Andreas Dilger <adilger@...ger.ca>,
        "Theodore Y. Ts'o" <tytso@....edu>,
        Christoph Hellwig <hch@...radead.org>,
        "linux-ext4@...r.kernel.org" <linux-ext4@...r.kernel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "linux-fsdevel@...r.kernel.org" <linux-fsdevel@...r.kernel.org>,
        Christoph Hellwig <hch@....de>,
        Johannes Thumshirn <jthumshirn@...e.de>,
        Naohiro Aota <Naohiro.Aota@....com>,
        Masato Suzuki <masato.suzuki@....com>
Subject: Re: [PATCH] ext4: Fix deadlock on page reclaim

On Tue, Jul 30, 2019 at 02:06:33AM +0000, Damien Le Moal wrote:
> If we had a pread_nofs()/pwrite_nofs(), that would work. Or we could define a
> RWF_NORECLAIM flag for pwritev2()/preadv2(). This last one could actually be the
> cleanest approach.

Clean, yes, but I'm not sure we want to expose kernel memory reclaim
capabilities to userspace... It would be misleading, too, because we
still want to allow reclaim to occur, just not have reclaim recurse
into other filesystems....

Cheers,

Dave.
-- 
Dave Chinner
david@...morbit.com