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Date:   Tue, 19 Jan 2021 09:23:16 +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>,
        James Morris <jmorris@namei.org>,
        Mimi Zohar <zohar@linux.ibm.com>,
        Dmitry Kasatkin <dmitry.kasatkin@gmail.com>,
        Stephen Smalley <stephen.smalley.work@gmail.com>,
        Casey Schaufler <casey@schaufler-ca.com>,
        Arnd Bergmann <arnd@arndb.de>,
        Andreas Dilger <adilger.kernel@dilger.ca>,
        OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>,
        Geoffrey Thomas <geofft@ldpreload.com>,
        Mrunal Patel <mpatel@redhat.com>,
        Josh Triplett <josh@joshtriplett.org>,
        Andy Lutomirski <luto@kernel.org>,
        Theodore Tso <tytso@mit.edu>, Alban Crequy <alban@kinvolk.io>,
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        containers@lists.linux-foundation.org,
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        Christoph Hellwig <hch@lst.de>
Subject: Re: [PATCH v5 11/42] namei: make permission helpers idmapped mount
 aware
Message-ID: <20210119092316.GC3361757@infradead.org>
References: <20210112220124.837960-1-christian.brauner@ubuntu.com>
 <20210112220124.837960-12-christian.brauner@ubuntu.com>
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On Tue, Jan 12, 2021 at 11:00:53PM +0100, Christian Brauner wrote:
> The two helpers inode_permission() and generic_permission() are used by
> the vfs to perform basic permission checking by verifying that the
> caller is privileged over an inode. In order to handle idmapped mounts
> we extend the two helpers with an additional user namespace argument.
> On idmapped mounts the two helpers will make sure to map the inode
> according to the mount's user namespace and then peform identical
> permission checks to inode_permission() and generic_permission(). If the
> initial user namespace is passed nothing changes so non-idmapped mounts
> will see identical behavior as before.

More long lines in here.

Otherwise looks good:

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