linux-kernel - Re: zram: zram_free_page calls in zram_meta

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Message-ID: <20231107072335.GA11577@google.com>
Date:   Tue, 7 Nov 2023 16:23:35 +0900
From:   Sergey Senozhatsky <senozhatsky@...omium.org>
To:     Vasily Averin <vasily.averin@...ux.dev>
Cc:     Sergey Senozhatsky <senozhatsky@...omium.org>,
        Minchan Kim <minchan@...nel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        linux-block@...r.kernel.org
Subject: Re: zram: zram_free_page calls in zram_meta_free

On (23/11/06 23:42), Vasily Averin wrote:
> The only place where content of zram entry is accessed and even changed without taken zran lock is
> zram_free_page() calls from zram_meta_free().
> 
> It does not look like problem because zram should not have any users at this point,
> however I still do not understand why this is required?

It's simply pointless. Reset is performed under write init_lock,
which is an upper level per-device lock.