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References: <20230523074535.249802-1-hch@lst.de> <20230523074535.249802-3-hch@lst.de>
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From:   "Rafael J. Wysocki" <rafael@kernel.org>
Date:   Tue, 23 May 2023 20:25:06 +0200
Message-ID: <CAJZ5v0j2N7Cdih0B66-w3ig=2E=MHNt=71mdT5O3OUmq_jsULQ@mail.gmail.com>
Subject: Re: [PATCH 02/24] PM: hibernate: factor out a helper to find the
 resume device
To:     Christoph Hellwig <hch@lst.de>
Cc:     Jens Axboe <axboe@kernel.dk>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        "Rafael J. Wysocki" <rafael@kernel.org>,
        Mike Snitzer <snitzer@kernel.org>,
        Joern Engel <joern@lazybastard.org>,
        Miquel Raynal <miquel.raynal@bootlin.com>,
        Richard Weinberger <richard@nod.at>,
        Vignesh Raghavendra <vigneshr@ti.com>,
        Pavel Machek <pavel@ucw.cz>, dm-devel@redhat.com,
        linux-kernel@vger.kernel.org, linux-block@vger.kernel.org,
        linux-mtd@lists.infradead.org, linux-pm@vger.kernel.org
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On Tue, May 23, 2023 at 9:45 AM Christoph Hellwig <hch@lst.de> wrote:
>
> Split the logic to find the resume device out software_resume and into
> a separate helper to start unwindig the convoluted goto logic.
>
> Signed-off-by: Christoph Hellwig <hch@lst.de>

Acked-by: Rafael J. Wysocki <rafael@kernel.org>

> ---
>  kernel/power/hibernate.c | 72 +++++++++++++++++++++-------------------
>  1 file changed, 37 insertions(+), 35 deletions(-)
>
> diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
> index 30d1274f03f625..07279506366255 100644
> --- a/kernel/power/hibernate.c
> +++ b/kernel/power/hibernate.c
> @@ -910,6 +910,41 @@ int hibernate_quiet_exec(int (*func)(void *data), void *data)
>  }
>  EXPORT_SYMBOL_GPL(hibernate_quiet_exec);
>
> +static int find_resume_device(void)
> +{
> +       if (!strlen(resume_file))
> +               return -ENOENT;
> +
> +       pm_pr_dbg("Checking hibernation image partition %s\n", resume_file);
> +
> +       if (resume_delay) {
> +               pr_info("Waiting %dsec before reading resume device ...\n",
> +                       resume_delay);
> +               ssleep(resume_delay);
> +       }
> +
> +       /* Check if the device is there */
> +       swsusp_resume_device = name_to_dev_t(resume_file);
> +       if (swsusp_resume_device)
> +               return 0;
> +
> +       /*
> +        * Some device discovery might still be in progress; we need to wait for
> +        * this to finish.
> +        */
> +       wait_for_device_probe();
> +       if (resume_wait) {
> +               while (!(swsusp_resume_device = name_to_dev_t(resume_file)))
> +                       msleep(10);
> +               async_synchronize_full();
> +       }
> +
> +       swsusp_resume_device = name_to_dev_t(resume_file);
> +       if (!swsusp_resume_device)
> +               return -ENODEV;
> +       return 0;
> +}
> +
>  /**
>   * software_resume - Resume from a saved hibernation image.
>   *
> @@ -949,45 +984,12 @@ static int software_resume(void)
>
>         snapshot_test = false;
>
> -       if (swsusp_resume_device)
> -               goto Check_image;
> -
> -       if (!strlen(resume_file)) {
> -               error = -ENOENT;
> -               goto Unlock;
> -       }
> -
> -       pm_pr_dbg("Checking hibernation image partition %s\n", resume_file);
> -
> -       if (resume_delay) {
> -               pr_info("Waiting %dsec before reading resume device ...\n",
> -                       resume_delay);
> -               ssleep(resume_delay);
> -       }
> -
> -       /* Check if the device is there */
> -       swsusp_resume_device = name_to_dev_t(resume_file);
>         if (!swsusp_resume_device) {
> -               /*
> -                * Some device discovery might still be in progress; we need
> -                * to wait for this to finish.
> -                */
> -               wait_for_device_probe();
> -
> -               if (resume_wait) {
> -                       while ((swsusp_resume_device = name_to_dev_t(resume_file)) == 0)
> -                               msleep(10);
> -                       async_synchronize_full();
> -               }
> -
> -               swsusp_resume_device = name_to_dev_t(resume_file);
> -               if (!swsusp_resume_device) {
> -                       error = -ENODEV;
> +               error = find_resume_device();
> +               if (error)
>                         goto Unlock;
> -               }
>         }
>
> - Check_image:
>         pm_pr_dbg("Hibernation image partition %d:%d present\n",
>                 MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device));
>
> --
> 2.39.2
>