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From:   Florian Weimer <fweimer@redhat.com>
To:     David Howells <dhowells@redhat.com>
Cc:     Christian Brauner <christian.brauner@ubuntu.com>,
        linux-api@vger.kernel.org, viro@zeniv.linux.org.uk,
        metze@samba.org, torvalds@linux-foundation.org, cyphar@cyphar.com,
        sfrench@samba.org, linux-fsdevel@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: Have RESOLVE_* flags superseded AT_* flags for new syscalls?
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Date:   Thu, 05 Mar 2020 15:38:31 +0100
In-Reply-To: <3606975.1583418833@warthog.procyon.org.uk> (David Howells's
        message of "Thu, 05 Mar 2020 14:33:53 +0000")
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* David Howells:

> Florian Weimer <fweimer@redhat.com> wrote:
>
>> Will there be any new flags for openat in the future?  If not, we can
>> just use a constant mask in an openat2-based implementation of openat.
>
> One thing we might want to look at is implementing support for
> lock-on-open/create and sharing modes in openat2().  Various network
> filesystems support this.  Wine, CIFS and Samba particularly might be
> interested in this.

But will those be O_ flags that need to be passed to openat?

Ignoring locking requests on older kernels because of the openat flag
handling seems problematic.

Thanks,
Florian