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Date:   Mon, 1 Nov 2021 16:03:05 +0100
From:   Jiri Pirko <jiri@resnulli.us>
To:     Leon Romanovsky <leon@kernel.org>
Cc:     "David S . Miller" <davem@davemloft.net>,
        Jakub Kicinski <kuba@kernel.org>,
        Leon Romanovsky <leonro@nvidia.com>,
        Jiri Pirko <jiri@nvidia.com>, linux-kernel@vger.kernel.org,
        netdev@vger.kernel.org, idosch@idosch.org, edwin.peer@broadcom.com
Subject: Re: [PATCH net-next] devlink: Require devlink lock during device
 reload
Message-ID: <YYABqfFy//g5Gdis@nanopsycho>
References: <9716f9a13e217a0a163b745b6e92e02d40973d2c.1635701665.git.leonro@nvidia.com>
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Sun, Oct 31, 2021 at 06:35:56PM CET, leon@kernel.org wrote:
>From: Leon Romanovsky <leonro@nvidia.com>
>
>Devlink reload was implemented as a special command which does _SET_
>operation, but doesn't take devlink->lock, while recursive devlink
>calls that were part of .reload_up()/.reload_down() sequence took it.
>
>This fragile flow was possible due to holding a big devlink lock
>(devlink_mutex), which effectively stopped all devlink activities,
>even unrelated to reloaded devlink.
>
>So let's make sure that devlink reload behaves as other commands and
>use special nested locking primitives with a depth of 1. Such change
>opens us to a venue of removing devlink_mutex completely, while keeping
>devlink locking complexity in devlink.c.
>
>Signed-off-by: Leon Romanovsky <leonro@nvidia.com>

Looks fine to me.

Reviewed-by: Jiri Pirko <jiri@nvidia.com>