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From:   David Howells <dhowells@redhat.com>
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To:     Christian Brauner <christian@brauner.io>
Cc:     dhowells@redhat.com, Miklos Szeredi <mszeredi@redhat.com>,
        Al Viro <viro@ZenIV.linux.org.uk>,
        linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 5/6] fsmount: do not use legacy MS_ flags
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Date:   Mon, 24 Sep 2018 07:50:38 +0100
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Christian Brauner <christian@brauner.io> wrote:

> Ok, understood. What about passing the different attrs as a struct?
> 
> struct mount_attr {
>         unsigned int attr_cmd,
>         unsigned int attr_values,
>         unsigned int attr_mask,
> 
> };
> 
> mount_setattr(int dfd, const char *path, unsigned int atflags,
>               struct mount_attr *attr);
> 
> I find that to be a little cleaner in all honesty.
> One could also add a version argument similar to what we currently do
> for vfs fcaps so that kernel and userspace can easily navigate
> compabitility when a new member gets added or removed in later releases.

Yeah, we could do that - it's not like I expect mount_setattr() to have to be
particularly performant in the user interface.  I would put the attr_cmd in
the argument list, probably, so that you can use that to vary the struct in
future (say we run out of attribute bits).

David