From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 7DD05D64087 for ; Wed, 17 Dec 2025 07:33:06 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id E64856B009D; Wed, 17 Dec 2025 02:33:05 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id E3EE26B00AF; Wed, 17 Dec 2025 02:33:05 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id D6B7B6B00B1; Wed, 17 Dec 2025 02:33:05 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id C5B076B009D for ; Wed, 17 Dec 2025 02:33:05 -0500 (EST) Received: from smtpin10.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay05.hostedemail.com (Postfix) with ESMTP id 849A15B85B for ; Wed, 17 Dec 2025 07:33:05 +0000 (UTC) X-FDA: 84228146730.10.96B3082 Received: from out-178.mta0.migadu.com (out-178.mta0.migadu.com [91.218.175.178]) by imf06.hostedemail.com (Postfix) with ESMTP id D44A918000E for ; Wed, 17 Dec 2025 07:33:03 +0000 (UTC) Authentication-Results: imf06.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=qss7+xs4; spf=pass (imf06.hostedemail.com: domain of qi.zheng@linux.dev designates 91.218.175.178 as permitted sender) smtp.mailfrom=qi.zheng@linux.dev; dmarc=pass (policy=none) header.from=linux.dev ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1765956784; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=3hCVtkwWInjeWp1lZK86oR9Lr8eWsGStrPfk/NkSL0k=; b=ZKUpPzDG3JydsfQQh8K0pq/nAz7fXSj1u9q3rsTC4LdydBdjQUTGdCHzNCk+oz3cov5QkJ HlKgkKrqYRPWxeI4b9vIGQiXOg+A9nyk7so94hyZzkYea2CHAIcmLWTIoM86r8RMuS+t47 UcCIfs+6btFCo8Seef48jRx05owqQlU= ARC-Authentication-Results: i=1; imf06.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=qss7+xs4; spf=pass (imf06.hostedemail.com: domain of qi.zheng@linux.dev designates 91.218.175.178 as permitted sender) smtp.mailfrom=qi.zheng@linux.dev; dmarc=pass (policy=none) header.from=linux.dev ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1765956784; a=rsa-sha256; cv=none; b=E47MhH3p56aVwRDuVi3RJjR4RUMyJWz3x1m+VZLiXAJRSfBoxid624Vq0hhYMmdWuj11OP 1MAnxPMaoMxiC4yoP35yoHmPep5ZoZ61C/G11MsxON0OelGzhLrvy+LIJyAYamMefyHae3 V6xATnfBTAPuJw58a3r6xQBml9e5qBU= X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1765956778; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=3hCVtkwWInjeWp1lZK86oR9Lr8eWsGStrPfk/NkSL0k=; b=qss7+xs4+fcC/k4TRH856pLkCsZ3zf6NmhCCKBEDP94wPzgJX5Se5bzxYs1nQvCcPAFf1H IUyFBywc0v7UZh6JX+MCryCQnvJm9NcBRnkhxr55rLWMPZBrpBYI7A4pbR3nSLhuCbDRTI 7cQwLAFU/zWeAVJrioGetOwSuqdGWIE= From: Qi Zheng To: hannes@cmpxchg.org, hughd@google.com, mhocko@suse.com, roman.gushchin@linux.dev, shakeel.butt@linux.dev, muchun.song@linux.dev, david@kernel.org, lorenzo.stoakes@oracle.com, ziy@nvidia.com, harry.yoo@oracle.com, imran.f.khan@oracle.com, kamalesh.babulal@oracle.com, axelrasmussen@google.com, yuanchu@google.com, weixugc@google.com, chenridong@huaweicloud.com, mkoutny@suse.com, akpm@linux-foundation.org, hamzamahfooz@linux.microsoft.com, apais@linux.microsoft.com, lance.yang@linux.dev Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, Muchun Song , Nhat Pham , Chengming Zhou , Qi Zheng Subject: [PATCH v2 20/28] mm: zswap: prevent lruvec release in zswap_folio_swapin() Date: Wed, 17 Dec 2025 15:27:44 +0800 Message-ID: In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT X-Stat-Signature: drhuw7x5qocc8ixdopmi6zn3xo3aitbn X-Rspam-User: X-Rspamd-Server: rspam07 X-Rspamd-Queue-Id: D44A918000E X-HE-Tag: 1765956783-731161 X-HE-Meta: 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 H5tneFxy R8Kyta/Xrdm4oGqH0Dq2im8Psd1mIcRbw6dh/kgGeKknrn5/ryd0/pyl2hn1S+oYDzRKiaNU6amWPj8P1BWC0BHUFQ4PN8twgQR+hcMnyya+fAJycdJRsQnaOXRIqEp3ARFIQfVzCJd+2bNY7+9sRyKoS7K3uwY4Q4SRcbb9V3xwI5y7qQJ1GC2cd8VIT3vWhHeZFAS1OIbJqEGaC72+12S6OcQUSRu68F1PeVuW5voqOioOKOCCWK6PerCxxv6sQcvzROugU3D3YfCE5D1eCsbnlig== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: From: Muchun Song In the near future, a folio will no longer pin its corresponding memory cgroup. So an lruvec returned by folio_lruvec() could be released without the rcu read lock or a reference to its memory cgroup. In the current patch, the rcu read lock is employed to safeguard against the release of the lruvec in zswap_folio_swapin(). This serves as a preparatory measure for the reparenting of the LRU pages. Signed-off-by: Muchun Song Acked-by: Nhat Pham Reviewed-by: Chengming Zhou Signed-off-by: Qi Zheng Reviewed-by: Harry Yoo --- mm/zswap.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/mm/zswap.c b/mm/zswap.c index b468046a90754..738d914e53549 100644 --- a/mm/zswap.c +++ b/mm/zswap.c @@ -664,8 +664,10 @@ void zswap_folio_swapin(struct folio *folio) struct lruvec *lruvec; if (folio) { + rcu_read_lock(); lruvec = folio_lruvec(folio); atomic_long_inc(&lruvec->zswap_lruvec_state.nr_disk_swapins); + rcu_read_unlock(); } } -- 2.20.1