Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.37 as permitted sender) client-ip=23.128.96.37;
Message-ID: <ebd87e1e-f941-498a-870e-15743ca3fb1f@linux.dev>
Date:   Mon, 6 Nov 2023 23:42:31 +0300
MIME-Version: 1.0
From:   Vasily Averin <vasily.averin@linux.dev>
Subject: zram: zram_free_page calls in zram_meta_free
To:     Sergey Senozhatsky <senozhatsky@chromium.org>,
        Minchan Kim <minchan@kernel.org>
Cc:     "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        linux-block@vger.kernel.org
Content-Language: en-US
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 7bit
Precedence: bulk

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?

Is it performance optimization? But zram reset is quite rare operation, I doubt it is called
on some performance-critical fast path. Am I missed something perhaps?

I would like to add proper zram_lock/unlock calls around zram_free_page here,
and would like to clarify,perhaps you have any objections?

Thank you,
	Vasily Averin