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Date:   Wed, 21 Jun 2023 15:42:14 +0500
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Subject: Re: [PATCH 2/3] fd/locks: allow get the lock owner by F_OFD_GETLK
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To:     Jeff Layton <jlayton@kernel.org>, linux-kernel@vger.kernel.org
Cc:     Chuck Lever <chuck.lever@oracle.com>,
        Alexander Viro <viro@zeniv.linux.org.uk>,
        Christian Brauner <brauner@kernel.org>,
        linux-fsdevel@vger.kernel.org, Matthew Wilcox <willy@infradead.org>
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21.06.2023 15:35, Jeff Layton пишет:
> I don't think we can change this at this point.
>
> The bottom line (again) is that OFD locks are owned by the file
> descriptor (much like with flock()), and since file descriptors can be
> shared across multiple process it's impossible to say that some single
> process owns it.
What's the problem with 2 owners?
Can't you get one of them, rather than
meaningless -1?
Compare this situation with read locks.
They can overlap, so when you get an
info about a read lock (except for the
new F_UNLCK case), you get the info
about *some* of the locks in that range.
In the case of multiple owners, you
likewise get the info about about some
owner. If you iteratively send them a
"please release this lock" message
(eg in a form of SIGKILL), then you
traverse all, and end up with the
lock-free area.
Is there really any problem here?