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Date:   Fri, 22 Jan 2021 14:02:51 +1100 (AEDT)
From:   James Morris <jmorris@namei.org>
To:     Christian Brauner <christian.brauner@ubuntu.com>
cc:     Alexander Viro <viro@zeniv.linux.org.uk>,
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Subject: Re: [PATCH v6 05/39] namei: make permission helpers idmapped mount
 aware
In-Reply-To: <20210121131959.646623-6-christian.brauner@ubuntu.com>
Message-ID: <f4b5102b-529-7e43-c35b-bf956359461a@namei.org>
References: <20210121131959.646623-1-christian.brauner@ubuntu.com> <20210121131959.646623-6-christian.brauner@ubuntu.com>
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On Thu, 21 Jan 2021, 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.
> 
> Link: https://lore.kernel.org/r/20210112220124.837960-12-christian.brauner@ubuntu.com
> Cc: Christoph Hellwig <hch@lst.de>
> Cc: David Howells <dhowells@redhat.com>
> Cc: Al Viro <viro@zeniv.linux.org.uk>
> Cc: linux-fsdevel@vger.kernel.org
> Reviewed-by: Christoph Hellwig <hch@lst.de>
> Acked-by: Serge Hallyn <serge@hallyn.com>
> Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>


Reviewed-by: James Morris <jamorris@linux.microsoft.com>


-- 
James Morris
<jmorris@namei.org>