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Date:   Tue, 30 May 2023 07:55:17 -0700
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Subject: Re: [PATCH -next 0/2] lsm: Change inode_setattr() to take struct
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To:     Christoph Hellwig <hch@lst.de>,
        Christian Brauner <brauner@kernel.org>
Cc:     =?UTF-8?Q?Micka=c3=abl_Sala=c3=bcn?= <mic@digikod.net>,
        Xiu Jianfeng <xiujianfeng@huawei.com>,
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        hirofumi@mail.parknet.co.jp, linkinjeon@kernel.org,
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        chuck.lever@oracle.com, jlayton@kernel.org, miklos@szeredi.hu,
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        linux-security-module@vger.kernel.org, selinux@vger.kernel.org,
        wangweiyang2@huawei.com, Casey Schaufler <casey@schaufler-ca.com>
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From:   Casey Schaufler <casey@schaufler-ca.com>
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On 5/30/2023 7:28 AM, Christoph Hellwig wrote:
> On Tue, May 30, 2023 at 03:58:35PM +0200, Christian Brauner wrote:
>> The main concern which was expressed on other patchsets before is that
>> modifying inode operations to take struct path is not the way to go.
>> Passing struct path into individual filesystems is a clear layering
>> violation for most inode operations, sometimes downright not feasible,
>> and in general exposing struct vfsmount to filesystems is a hard no. At
>> least as far as I'm concerned.
> Agreed.  Passing struct path into random places is not how the VFS works.
>
>> So the best way to achieve the landlock goal might be to add new hooks
> What is "the landlock goal", and why does it matter?
>
>> or not. And we keep adding new LSMs without deprecating older ones (A
>> problem we also face in the fs layer.) and then they sit around but
>> still need to be taken into account when doing changes.
> Yes, I'm really worried about th amount of LSMs we have, and the weird
> things they do.

Which LSM(s) do you think ought to be deprecated? I only see one that I
might consider a candidate. As for weird behavior, that's what LSMs are
for, and the really weird ones proposed (e.g. pathname character set limitations)
(and excepting for BPF, of course) haven't gotten far.