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Message-ID: <5436a58dc63d7e7cc2cb2fbda722f0c0406e88bf.camel@redhat.com>
Subject: Re: [PATCH] Fix termination state for idr_for_each_entry_ul()
From:   Paolo Abeni <pabeni@redhat.com>
To:     NeilBrown <neilb@suse.de>, netdev@vger.kernel.org,
        "David S. Miller" <davem@davemloft.net>
Cc:     LKML <linux-kernel@vger.kernel.org>,
        Matthew Wilcox <willy@infradead.org>,
        Chris Mi <chrism@mellanox.com>,
        Cong Wang <xiyou.wangcong@gmail.com>
Date:   Thu, 26 Oct 2023 09:22:07 +0200
In-Reply-To: <169810161336.20306.1410058490199370047@noble.neil.brown.name>
References: <169810161336.20306.1410058490199370047@noble.neil.brown.name>
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On Tue, 2023-10-24 at 09:53 +1100, NeilBrown wrote:
> The comment for idr_for_each_entry_ul() states
>=20
>   after normal termination @entry is left with the value NULL
>=20
> This is not correct in the case where UINT_MAX has an entry in the idr.
> In that case @entry will be non-NULL after termination.
> No current code depends on the documentation being correct, but to
> save future code we should fix it.
>=20
> Also fix idr_for_each_entry_continue_ul().  While this is not documented
> as leaving @entry as NULL, the mellanox driver appears to depend on
> it doing so.  So make that explicit in the documentation as well as in
> the code.
>=20
> Fixes: e33d2b74d805 ("idr: fix overflow case for idr_for_each_entry_ul()"=
)
> Cc: Matthew Wilcox <willy@infradead.org>
> Cc: Chris Mi <chrism@mellanox.com>
> Cc: Cong Wang <xiyou.wangcong@gmail.com>
> Signed-off-by: NeilBrown <neilb@suse.de>

Since the affected user is in the netdev tree, I think we can take this
patch. But this is also a sort of gray area of the tree... @Matthew are
you ok with that?

Thanks,

Paolo