From: Ian Kent <raven@themaw.net>
To: David Howells <dhowells@redhat.com>, Miklos Szeredi <miklos@szeredi.hu>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
Al Viro <viro@zeniv.linux.org.uk>,
Casey Schaufler <casey@schaufler-ca.com>,
Stephen Smalley <sds@tycho.nsa.gov>,
nicolas.dichtel@6wind.com,
Christian Brauner <christian@brauner.io>,
andres@anarazel.de, Jeff Layton <jlayton@redhat.com>,
dray@redhat.com, Karel Zak <kzak@redhat.com>,
keyrings@vger.kernel.org, Linux API <linux-api@vger.kernel.org>,
linux-fsdevel@vger.kernel.org,
LSM <linux-security-module@vger.kernel.org>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 13/17] watch_queue: Implement mount topology and attribute change notifications [ver #5]
Date: Fri, 24 Jul 2020 10:44:01 +0000 [thread overview]
Message-ID: <865566fb800a014868a9a7e36a00a14430efb11e.camel@themaw.net> (raw)
In-Reply-To: <2003787.1595585999@warthog.procyon.org.uk>
On Fri, 2020-07-24 at 11:19 +0100, David Howells wrote:
> David Howells <dhowells@redhat.com> wrote:
>
> > > What guarantees that mount_id is going to remain a 32bit entity?
> >
> > You think it likely we'd have >4 billion concurrent mounts on a
> > system? That
> > would require >1.2TiB of RAM just for the struct mount allocations.
> >
> > But I can expand it to __u64.
>
> That said, sys_name_to_handle_at() assumes it's a 32-bit signed
> integer, so
> we're currently limited to ~2 billion concurrent mounts:-/
I was wondering about id re-use.
Assuming that ids that are returned to the idr db are re-used
what would the chance that a recently used id would end up
being used?
Would that chance increase as ids are consumed and freed over
time?
Yeah, it's one of those questions ... ;)
Ian
WARNING: multiple messages have this Message-ID (diff)
From: Ian Kent <raven@themaw.net>
To: David Howells <dhowells@redhat.com>, Miklos Szeredi <miklos@szeredi.hu>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
Al Viro <viro@zeniv.linux.org.uk>,
Casey Schaufler <casey@schaufler-ca.com>,
Stephen Smalley <sds@tycho.nsa.gov>,
nicolas.dichtel@6wind.com,
Christian Brauner <christian@brauner.io>,
andres@anarazel.de, Jeff Layton <jlayton@redhat.com>,
dray@redhat.com, Karel Zak <kzak@redhat.com>,
keyrings@vger.kernel.org, Linux API <linux-api@vger.kernel.org>,
linux-fsdevel@vger.kernel.org,
LSM <linux-security-module@vger.kernel.org>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 13/17] watch_queue: Implement mount topology and attribute change notifications [ver #5]
Date: Fri, 24 Jul 2020 18:44:01 +0800 [thread overview]
Message-ID: <865566fb800a014868a9a7e36a00a14430efb11e.camel@themaw.net> (raw)
In-Reply-To: <2003787.1595585999@warthog.procyon.org.uk>
On Fri, 2020-07-24 at 11:19 +0100, David Howells wrote:
> David Howells <dhowells@redhat.com> wrote:
>
> > > What guarantees that mount_id is going to remain a 32bit entity?
> >
> > You think it likely we'd have >4 billion concurrent mounts on a
> > system? That
> > would require >1.2TiB of RAM just for the struct mount allocations.
> >
> > But I can expand it to __u64.
>
> That said, sys_name_to_handle_at() assumes it's a 32-bit signed
> integer, so
> we're currently limited to ~2 billion concurrent mounts:-/
I was wondering about id re-use.
Assuming that ids that are returned to the idr db are re-used
what would the chance that a recently used id would end up
being used?
Would that chance increase as ids are consumed and freed over
time?
Yeah, it's one of those questions ... ;)
Ian
next prev parent reply other threads:[~2020-07-24 10:44 UTC|newest]
Thread overview: 87+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-18 15:03 [PATCH 00/17] pipe: Keyrings, mount and superblock notifications [ver #5] David Howells
2020-03-18 15:03 ` David Howells
2020-03-18 15:03 ` [PATCH 01/17] uapi: General notification queue definitions " David Howells
2020-03-18 15:03 ` [PATCH 02/17] security: Add hooks to rule on setting a watch " David Howells
2020-03-18 15:03 ` David Howells
2020-03-18 18:56 ` James Morris
2020-03-18 18:56 ` James Morris
2020-03-18 15:03 ` [PATCH 03/17] security: Add a hook for the point of notification insertion " David Howells
2020-03-18 15:03 ` David Howells
2020-03-18 18:57 ` James Morris
2020-03-18 18:57 ` James Morris
2020-03-18 15:03 ` [PATCH 04/17] pipe: Add O_NOTIFICATION_PIPE " David Howells
2020-03-18 15:03 ` [PATCH 05/17] pipe: Add general notification queue support " David Howells
2020-03-18 15:03 ` David Howells
2020-03-18 15:04 ` [PATCH 06/17] watch_queue: Add a key/keyring notification facility " David Howells
2020-03-18 15:04 ` David Howells
2020-03-18 19:04 ` James Morris
2020-03-18 19:04 ` James Morris
2020-03-18 15:04 ` [PATCH 07/17] Add sample notification program " David Howells
2020-03-18 15:04 ` David Howells
2020-03-18 15:04 ` [PATCH 08/17] pipe: Allow buffers to be marked read-whole-or-error for notifications " David Howells
2020-03-18 15:04 ` David Howells
2020-03-18 15:04 ` [PATCH 09/17] pipe: Add notification lossage handling " David Howells
2020-03-18 15:04 ` David Howells
2020-03-18 15:04 ` [PATCH 10/17] selinux: Implement the watch_key security hook " David Howells
2020-03-18 15:04 ` David Howells
2020-03-18 19:06 ` James Morris
2020-03-18 19:06 ` James Morris
2020-03-18 15:04 ` [PATCH 11/17] smack: Implement the watch_key and post_notification hooks " David Howells
2020-03-18 15:04 ` David Howells
2020-03-18 15:05 ` [PATCH 12/17] watch_queue: Add security hooks to rule on setting mount and sb watches " David Howells
2020-03-18 15:05 ` David Howells
2020-03-18 19:07 ` James Morris
2020-03-18 19:07 ` James Morris
2020-03-18 15:05 ` [PATCH 13/17] watch_queue: Implement mount topology and attribute change notifications " David Howells
2020-03-18 15:05 ` David Howells
2020-04-02 15:19 ` Miklos Szeredi
2020-04-02 15:19 ` Miklos Szeredi
2020-06-14 3:07 ` Ian Kent
2020-06-14 3:07 ` Ian Kent
2020-06-15 8:44 ` Miklos Szeredi
2020-06-15 8:44 ` Miklos Szeredi
2020-07-23 10:48 ` David Howells
2020-07-23 10:48 ` David Howells
2020-08-03 9:29 ` Miklos Szeredi
2020-08-03 9:29 ` Miklos Szeredi
2020-08-04 11:38 ` Ian Kent
2020-08-04 11:38 ` Ian Kent
2020-08-04 13:19 ` Miklos Szeredi
2020-08-04 13:19 ` Miklos Szeredi
2020-08-05 1:53 ` Ian Kent
2020-08-05 1:53 ` Ian Kent
2020-08-05 7:43 ` Miklos Szeredi
2020-08-05 7:43 ` Miklos Szeredi
2020-08-05 11:36 ` Ian Kent
2020-08-05 11:36 ` Ian Kent
2020-08-05 11:56 ` Miklos Szeredi
2020-08-05 11:56 ` Miklos Szeredi
2020-07-24 10:19 ` David Howells
2020-07-24 10:19 ` David Howells
2020-07-24 10:44 ` Ian Kent [this message]
2020-07-24 10:44 ` Ian Kent
2020-07-24 11:36 ` David Howells
2020-07-24 11:36 ` David Howells
2020-08-03 10:02 ` Miklos Szeredi
2020-08-03 10:02 ` Miklos Szeredi
2020-08-03 10:08 ` David Howells
2020-08-03 10:08 ` David Howells
2020-08-03 10:18 ` David Howells
2020-08-03 10:18 ` David Howells
2020-08-03 11:17 ` Miklos Szeredi
2020-08-03 11:17 ` Miklos Szeredi
2020-08-03 11:49 ` David Howells
2020-08-03 11:49 ` David Howells
2020-08-03 12:01 ` Ian Kent
2020-08-03 12:01 ` Ian Kent
2020-08-03 12:31 ` David Howells
2020-08-03 12:31 ` David Howells
2020-08-03 14:30 ` Ian Kent
2020-08-03 14:30 ` Ian Kent
2020-03-18 15:05 ` [PATCH 14/17] watch_queue: sample: Display mount tree " David Howells
2020-03-18 15:05 ` David Howells
2020-03-18 15:05 ` [PATCH 15/17] watch_queue: Introduce a non-repeating system-unique superblock ID " David Howells
2020-03-18 15:05 ` [PATCH 16/17] watch_queue: Add superblock notifications " David Howells
2020-03-18 15:05 ` David Howells
2020-03-18 15:05 ` [PATCH 17/17] watch_queue: sample: Display " David Howells
2020-03-18 15:05 ` David Howells
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