linux-kernel - Re: [PATCH 00/20] filelock: split struct file_lock into file_lock and file

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] [day] [month] [year] [list]

Message-id: <170551794427.23031.1969485804246583443@noble.neil.brown.name>
Date: Thu, 18 Jan 2024 05:59:04 +1100
From: "NeilBrown" <neilb@...e.de>
To: "Chuck Lever" <chuck.lever@...cle.com>
Cc: "Jeff Layton" <jlayton@...nel.org>,
 "Christian Brauner" <brauner@...nel.org>,
 "Alexander Viro" <viro@...iv.linux.org.uk>,
 "Eric Van Hensbergen" <ericvh@...nel.org>,
 "Latchesar Ionkov" <lucho@...kov.net>,
 "Dominique Martinet" <asmadeus@...ewreck.org>,
 "Christian Schoenebeck" <linux_oss@...debyte.com>,
 "David Howells" <dhowells@...hat.com>,
 "Marc Dionne" <marc.dionne@...istor.com>, "Xiubo Li" <xiubli@...hat.com>,
 "Ilya Dryomov" <idryomov@...il.com>, "Alexander Aring" <aahringo@...hat.com>,
 "David Teigland" <teigland@...hat.com>, "Miklos Szeredi" <miklos@...redi.hu>,
 "Andreas Gruenbacher" <agruenba@...hat.com>,
 "Trond Myklebust" <trond.myklebust@...merspace.com>,
 "Anna Schumaker" <anna@...nel.org>, "Olga Kornievskaia" <kolga@...app.com>,
 "Dai Ngo" <Dai.Ngo@...cle.com>, "Tom Talpey" <tom@...pey.com>,
 "Jan Kara" <jack@...e.cz>, "Mark Fasheh" <mark@...heh.com>,
 "Joel Becker" <jlbec@...lplan.org>, "Joseph Qi" <joseph.qi@...ux.alibaba.com>,
 "Steve French" <sfrench@...ba.org>, "Paulo Alcantara" <pc@...guebit.com>,
 "Ronnie Sahlberg" <lsahlber@...hat.com>,
 "Shyam Prasad N" <sprasad@...rosoft.com>,
 "Namjae Jeon" <linkinjeon@...nel.org>,
 "Sergey Senozhatsky" <senozhatsky@...omium.org>,
 "Steven Rostedt" <rostedt@...dmis.org>,
 "Masami Hiramatsu" <mhiramat@...nel.org>,
 "Mathieu Desnoyers" <mathieu.desnoyers@...icios.com>,
 linux-kernel@...r.kernel.org, v9fs@...ts.linux.dev,
 linux-afs@...ts.infradead.org, ceph-devel@...r.kernel.org,
 gfs2@...ts.linux.dev, linux-fsdevel@...r.kernel.org,
 linux-nfs@...r.kernel.org, ocfs2-devel@...ts.linux.dev,
 linux-cifs@...r.kernel.org, samba-technical@...ts.samba.org,
 linux-trace-kernel@...r.kernel.org
Subject: Re: [PATCH 00/20] filelock: split struct file_lock into file_lock and
 file_lease structs

On Thu, 18 Jan 2024, Chuck Lever wrote:
> On Tue, Jan 16, 2024 at 02:45:56PM -0500, Jeff Layton wrote:
> > Long ago, file locks used to hang off of a singly-linked list in struct
> > inode. Because of this, when leases were added, they were added to the
> > same list and so they had to be tracked using the same sort of
> > structure.
> > 
> > Several years ago, we added struct file_lock_context, which allowed us
> > to use separate lists to track different types of file locks. Given
> > that, leases no longer need to be tracked using struct file_lock.
> > 
> > That said, a lot of the underlying infrastructure _is_ the same between
> > file leases and locks, so we can't completely separate everything.
> 
> Naive question: locks and leases are similar. Why do they need to be
> split apart? The cover letter doesn't address that, and I'm new
> enough at this that I don't have that context.

For me, the big win was in the last patch where we got separate
lock_manager_operations and lease_manager_operations.  There is zero
overlap between the two.  This highlights that one one level these are
different things with different behaviours.

NeilBrown