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Date:   Mon, 14 Aug 2023 17:40:30 +0200
From:   Christian Brauner <brauner@kernel.org>
To:     Loic Poulain <loic.poulain@linaro.org>
Cc:     viro@zeniv.linux.org.uk, corbet@lwn.net,
        linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org,
        linux-fsdevel@vger.kernel.org, hch@infradead.org,
        rdunlap@infradead.org
Subject: Re: [PATCH v4] init: Add support for rootwait timeout parameter
Message-ID: <20230814-flaute-achsen-05169559ea75@brauner>
References: <20230813082349.513386-1-loic.poulain@linaro.org>
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In-Reply-To: <20230813082349.513386-1-loic.poulain@linaro.org>
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On Sun, Aug 13, 2023 at 10:23:49AM +0200, Loic Poulain wrote:
> Add an optional timeout arg to 'rootwait' as the maximum time in
> seconds to wait for the root device to show up before attempting
> forced mount of the root filesystem.
> 
> Use case:
> In case of device mapper usage for the rootfs (e.g. root=/dev/dm-0),
> if the mapper is not able to create the virtual block for any reason
> (wrong arguments, bad dm-verity signature, etc), the `rootwait` param
> causes the kernel to wait forever. It may however be desirable to only
> wait for a given time and then panic (force mount) to cause device reset.
> This gives the bootloader a chance to detect the problem and to take some
> measures, such as marking the booted partition as bad (for A/B case) or
> entering a recovery mode.
> 
> In success case, mounting happens as soon as the root device is ready,
> unlike the existing 'rootdelay' parameter which performs an unconditional
> pause.
> 
> Signed-off-by: Loic Poulain <loic.poulain@linaro.org>
> ---

Looks mostly fine to me now but that's v6.7 fodder as it's rather late
in the cycle. I'll earmark this but feel free to resend post merge
window closure.