From: Karel Zak <kzak@redhat.com>
To: Ian Kent <raven@themaw.net>
Cc: Miklos Szeredi <mszeredi@redhat.com>,
linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-api@vger.kernel.org, linux-man@vger.kernel.org,
linux-security-module@vger.kernel.org,
David Howells <dhowells@redhat.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
Al Viro <viro@zeniv.linux.org.uk>,
Christian Brauner <christian@brauner.io>,
Amir Goldstein <amir73il@gmail.com>,
Matthew House <mattlloydhouse@gmail.com>,
Florian Weimer <fweimer@redhat.com>,
Arnd Bergmann <arnd@arndb.de>
Subject: Re: [PATCH v4 0/6] querying mount attributes
Date: Mon, 6 Nov 2023 13:10:53 +0100 [thread overview]
Message-ID: <20231106121053.egamth3hr7zcfzji@ws.net.home> (raw)
In-Reply-To: <374433e3-ab72-64a3-0fa0-ab455268e5e0@themaw.net>
On Wed, Nov 01, 2023 at 07:52:45PM +0800, Ian Kent wrote:
> On 25/10/23 22:01, Miklos Szeredi wrote:
> Looks ok to me,covers the primary cases I needed when I worked
> on using fsinfo() in systemd.
Our work on systemd was about two areas: get mount info (stat/listmount()
now) from the kernel, and get the mount ID from notification.
There was watch_queue.h with WATCH_TYPE_MOUNT_NOTIFY and struct
mount_notification->auxiliary_mount (aka mount ID) and event subtype
to get the change status (new mount, umount, etc.)
For example David's:
https://patchwork.kernel.org/project/linux-security-module/patch/155991711016.15579.4449417925184028666.stgit@warthog.procyon.org.uk/
Do we have any replacement for this?
> Karel, is there anything missing you would need for adding
> libmount support?
Miklos's statmount() and listmount() API is excellent from my point of
view. It looks pretty straightforward to use, and with the unique
mount ID, it's safe too. It will be ideal for things like umount(8)
(and recursive umount, etc.).
For complex scenarios (systemd), we need to get from the kernel the
unique ID's after any change in the mount table to save resources and
call statmount() only for the affected mount node. Parse mountinfo
sucks, call for(listmount(-1)) { statmount() } sucks too :-)
Karel
--
Karel Zak <kzak@redhat.com>
http://karelzak.blogspot.com
next prev parent reply other threads:[~2023-11-06 12:11 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-10-25 14:01 [PATCH v4 0/6] querying mount attributes Miklos Szeredi
2023-10-25 14:01 ` [PATCH v4 1/6] add unique mount ID Miklos Szeredi
2023-10-25 14:02 ` [PATCH v4 2/6] mounts: keep list of mounts in an rbtree Miklos Szeredi
2023-10-27 3:11 ` Ian Kent
2023-10-27 8:17 ` Miklos Szeredi
2023-10-28 1:36 ` Ian Kent
2023-10-30 5:37 ` Ian Kent
2023-10-30 5:45 ` Ian Kent
2023-10-30 9:06 ` Miklos Szeredi
2023-10-31 1:23 ` Ian Kent
2023-10-25 14:02 ` [PATCH v4 3/6] namespace: extract show_path() helper Miklos Szeredi
2023-10-25 14:02 ` [PATCH v4 4/6] add statmount(2) syscall Miklos Szeredi
2023-11-08 2:58 ` Paul Moore
2023-11-08 7:58 ` Christian Brauner
2023-11-08 20:10 ` Paul Moore
2023-11-10 17:00 ` Paul Moore
2023-11-12 13:05 ` Christian Brauner
2023-11-12 20:29 ` Paul Moore
2023-10-25 14:02 ` [PATCH v4 5/6] add listmount(2) syscall Miklos Szeredi
2023-11-07 21:23 ` Jonathan Corbet
2023-11-08 7:53 ` Christian Brauner
2023-11-08 16:20 ` Jonathan Corbet
2023-11-08 16:23 ` Christian Brauner
2023-11-08 2:58 ` Paul Moore
2024-01-10 22:23 ` Guenter Roeck
2024-01-11 0:32 ` Linus Torvalds
2024-01-11 5:12 ` Guenter Roeck
2024-01-11 18:57 ` Guenter Roeck
2024-01-11 20:14 ` Linus Torvalds
2024-01-11 23:01 ` Arnd Bergmann
2024-01-11 23:57 ` Guenter Roeck
2024-01-12 3:40 ` Linus Torvalds
2024-01-12 5:24 ` Guenter Roeck
2024-01-12 9:00 ` Christian Brauner
2024-01-23 14:14 ` John Paul Adrian Glaubitz
2024-01-23 15:31 ` Guenter Roeck
2024-01-23 14:14 ` John Paul Adrian Glaubitz
2023-10-25 14:02 ` [PATCH v4 6/6] wire up syscalls for statmount/listmount Miklos Szeredi
2024-01-09 1:11 ` Florian Fainelli
2023-11-01 11:13 ` [PATCH v4 0/6] querying mount attributes Christian Brauner
2023-11-01 13:18 ` Miklos Szeredi
2023-11-01 15:54 ` Christian Brauner
2023-11-01 11:52 ` Ian Kent
2023-11-06 12:10 ` Karel Zak [this message]
2023-11-06 13:33 ` Amir Goldstein
2023-11-07 0:47 ` Ian Kent
2023-11-06 23:54 ` Ian Kent
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