linux-kernel - Re: [PATCH RFC v2] fhandle: expose u64 mount id to name_to_handle

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: <20240527-montag-beruhen-523b74214339@brauner>
Date: Mon, 27 May 2024 14:22:26 +0200
From: Christian Brauner <brauner@...nel.org>
To: Christoph Hellwig <hch@...radead.org>
Cc: Aleksa Sarai <cyphar@...har.com>, 
	Alexander Viro <viro@...iv.linux.org.uk>, Jan Kara <jack@...e.cz>, Chuck Lever <chuck.lever@...cle.com>, 
	Jeff Layton <jlayton@...nel.org>, Amir Goldstein <amir73il@...il.com>, 
	Alexander Aring <alex.aring@...il.com>, linux-fsdevel@...r.kernel.org, linux-nfs@...r.kernel.org, 
	linux-kernel@...r.kernel.org, linux-api@...r.kernel.org
Subject: Re: [PATCH RFC v2] fhandle: expose u64 mount id to
 name_to_handle_at(2)

On Sun, May 26, 2024 at 02:25:34AM -0700, Christoph Hellwig wrote:
> On Thu, May 23, 2024 at 01:57:32PM -0700, Aleksa Sarai wrote:
> > Now that we provide a unique 64-bit mount ID interface in statx, we can
> > now provide a race-free way for name_to_handle_at(2) to provide a file
> > handle and corresponding mount without needing to worry about racing
> > with /proc/mountinfo parsing.
> 
> file handles are not tied to mounts, they are tied to super_blocks,
> and they can survive reboots or (less relevant) remounts.  This thus
> seems like a very confusing if not wrong interfaces.

I'm not fond of the interface as I've said on an earlier version, but
name_to_handle_at() has always exposed the mount id. IOW, this isn't
adding a new concept to the system call.