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Date:   Tue, 19 Jan 2021 09:27:25 +0000
From:   Christoph Hellwig <hch@infradead.org>
To:     Christian Brauner <christian.brauner@ubuntu.com>
Cc:     Alexander Viro <viro@zeniv.linux.org.uk>,
        Christoph Hellwig <hch@infradead.org>,
        linux-fsdevel@vger.kernel.org,
        John Johansen <john.johansen@canonical.com>,
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        OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>,
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        Christoph Hellwig <hch@lst.de>
Subject: Re: [PATCH v5 15/42] fs: add file_user_ns() helper
Message-ID: <20210119092725.GG3361757@infradead.org>
References: <20210112220124.837960-1-christian.brauner@ubuntu.com>
 <20210112220124.837960-16-christian.brauner@ubuntu.com>
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On Tue, Jan 12, 2021 at 11:00:57PM +0100, Christian Brauner wrote:
> Add a simple helper to retrieve the user namespace associated with the
> vfsmount of a file. Christoph correctly points out that this makes
> codepaths (e.g. ioctls) way easier to follow that would otherwise
> dereference via mnt_user_ns(file->f_path.mnt).
> 
> In order to make file_user_ns() static inline we'd need to include
> mount.h in either file.h or fs.h which seems undesirable so let's simply
> not force file_user_ns() to be inline.

I'd be tempted to just make this an inline.

Otherwise this looks ok:

Reviewed-by: Christoph Hellwig <hch@lst.de>