linux-kernel - Re: [PATCH 2/2] PM/hibernate: remove the bogus call to get_gendisk in software

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Message-ID: <20200925183828.GC7253@duo.ucw.cz>
Date:   Fri, 25 Sep 2020 20:38:28 +0200
From:   Pavel Machek <pavel@....cz>
To:     Christoph Hellwig <hch@....de>
Cc:     Tejun Heo <tj@...nel.org>, Jens Axboe <axboe@...nel.dk>,
        "Rafael J. Wysocki" <rjw@...ysocki.net>,
        Len Brown <len.brown@...el.com>, Minho Ban <mhban@...sung.com>,
        cgroups@...r.kernel.org, linux-block@...r.kernel.org,
        linux-kernel@...r.kernel.org, linux-pm@...r.kernel.org
Subject: Re: [PATCH 2/2] PM/hibernate: remove the bogus call to get_gendisk
 in software_resume

Hi!

> get_gendisk grabs a reference on the disk and file operation, so this
> code will leak both of them while having absolutely no use for the
> gendisk itself.
> 
> This effectively reverts commit 2df83fa4bce421f
> ("PM / Hibernate: Use get_gendisk to verify partition if resume_file is integer format")
> 
> Signed-off-by: Christoph Hellwig <hch@....de>
> ---
>  kernel/power/hibernate.c | 11 -----------
>  1 file changed, 11 deletions(-)
> 
> diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
> index e7aa57fb2fdc33..7d0b99d2e69631 100644
> --- a/kernel/power/hibernate.c
> +++ b/kernel/power/hibernate.c
> @@ -948,17 +948,6 @@ static int software_resume(void)
>  
>  	/* Check if the device is there */
>  	swsusp_resume_device = name_to_dev_t(resume_file);
> -
> -	/*
> -	 * name_to_dev_t is ineffective to verify parition if resume_file is in
> -	 * integer format. (e.g. major:minor)
> -	 */
> -	if (isdigit(resume_file[0]) && resume_wait) {
> -		int partno;
> -		while (!get_gendisk(swsusp_resume_device, &partno))
> -			msleep(10);
> -	}

I believe point of this code was to wait for resume device to appear
-- see the resume_wait condition. It should not be simply removed.

Best regards,
								Pavel
-- 
DENX Software Engineering GmbH,      Managing Director: Wolfgang Denk
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany

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