linux-kernel - Re: Copy on write hard links?

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: <1380117572.1974.81@driftwood>
Date:	Wed, 25 Sep 2013 08:59:32 -0500
From:	Rob Landley <rob@...dley.net>
To:	Thomas Meyer <thomas@...3r.de>
Cc:	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: Copy on write hard links?

On 09/24/2013 01:36:56 PM, Thomas Meyer wrote:
> Hi,
> 
> Is there such a thing?

In the kernel's vfs layer? No, although some filesystems (ala btrfs) do  
things like that with snapshots.

In userspace? Breaking hardlinks when updating a file is fairly normal,  
that's why they distinguish between "truncate and rewrite" (preserve  
hardlinks) and "write new file and rename over old file" (break  
hardlinks, avoiding the more obvious race conditions).

Rob--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/