From nobody Fri Dec 19 02:50:43 2025 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id EA396C54FB9 for ; Sun, 19 Nov 2023 19:49:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231860AbjKSTty (ORCPT ); Sun, 19 Nov 2023 14:49:54 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34496 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231794AbjKSTt2 (ORCPT ); Sun, 19 Nov 2023 14:49:28 -0500 Received: from mail-pf1-x42c.google.com (mail-pf1-x42c.google.com [IPv6:2607:f8b0:4864:20::42c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8600D19A2 for ; Sun, 19 Nov 2023 11:48:57 -0800 (PST) Received: by mail-pf1-x42c.google.com with SMTP id d2e1a72fcca58-6c115026985so3870297b3a.1 for ; Sun, 19 Nov 2023 11:48:57 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1700423337; x=1701028137; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:reply-to:references :in-reply-to:message-id:date:subject:cc:to:from:from:to:cc:subject :date:message-id:reply-to; bh=FCPW0dI33gWre1bmPp4wG3A/kpp2Dtpn+fZQd/yP8/o=; b=kb+kvJTuqgPIZdsg4KJJjy4Vh03F0rOOeZzSaU+peAxitPCQ0MWo9ABfEVs7rZwyfS z31d/fxAwEsdIqbjZigitUmP9kWKcjX+K7kvGXrk+fb5YgU8iRigF+GxYXaKWB9SfiOQ o1TE0qSQmYaTMuuPz62JyWBVG5Lt7KoaU0BiaG0w3fXdqFmbMohiTWl3FQD7v91bOdev F3ujCKuGqWI5jqzdWoXJY6fHyQJlfyOqEP4nTHU21LO6fAwJZxQuzqMnsXdpd3HNCroY W7dC4sMoYYvi+BDePxgluzFC8G5PJ8JxxGPsDNhg14Snar4a8rukXcTwGxz9wwFLh9aM USlg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1700423337; x=1701028137; h=content-transfer-encoding:mime-version:reply-to:references :in-reply-to:message-id:date:subject:cc:to:from:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=FCPW0dI33gWre1bmPp4wG3A/kpp2Dtpn+fZQd/yP8/o=; b=ghxlr0cmFUU6IM9BG3A5q1d1ZbEsQ8uQuAWia1HdXcXoZc5CO4csurkVoQc0KuMNJV +I7ok0PGWjwDJCxQilEj2atfxeOrowANrzkvGS7rEnkcfKOnA8aN4zDTcdlB4kG3xTlj o1Qd44hoRUtsnjwAIDxnecYTAWTt8+fYajUXG7u48TM/LOEs7QvghKwPD4JF0f4yBt/L VS4V5hvvkZWBsj0S/6lw0szRhnqJZBDtds5paY2CcJDyA5TL5p26NMq6Bb7AO6zxnXEG oE2UBF0MfSyTtiHK4K+4MhGE4sX1/m2wfEVyjU2EUOnk7Oz1QdHeLYxYBX1gAYWDORLN SPbg== X-Gm-Message-State: AOJu0YyCwTVLjsMQOax9N3n0KiqcN4EagWRPhLyxNv+I3WTA4bWHK8Pf SL76K+Zj9t6UHxzVfsO9T7s= X-Google-Smtp-Source: AGHT+IF9QoAWouGwWEXuyCQ9NU0AgZDxQWALIyGpxr9BM9RgNBGPUMqyqjGgp7YBTc1CUFiZCcylkA== X-Received: by 2002:a05:6a20:244e:b0:187:f23d:f9f2 with SMTP id t14-20020a056a20244e00b00187f23df9f2mr6715469pzc.58.1700423336700; Sun, 19 Nov 2023 11:48:56 -0800 (PST) Received: from KASONG-MB2.tencent.com ([115.171.40.79]) by smtp.gmail.com with ESMTPSA id a6-20020aa78646000000b006cb7feae74fsm1237140pfo.164.2023.11.19.11.48.53 (version=TLS1_3 cipher=TLS_CHACHA20_POLY1305_SHA256 bits=256/256); Sun, 19 Nov 2023 11:48:56 -0800 (PST) From: Kairui Song To: linux-mm@kvack.org Cc: Andrew Morton , "Huang, Ying" , David Hildenbrand , Hugh Dickins , Johannes Weiner , Matthew Wilcox , Michal Hocko , linux-kernel@vger.kernel.org, Kairui Song Subject: [PATCH 17/24] mm/swap: fix false error when swapoff race with swapin Date: Mon, 20 Nov 2023 03:47:33 +0800 Message-ID: <20231119194740.94101-18-ryncsn@gmail.com> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20231119194740.94101-1-ryncsn@gmail.com> References: <20231119194740.94101-1-ryncsn@gmail.com> Reply-To: Kairui Song MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: Kairui Song When swapoff race with swapin, get_swap_device may fail and cause swapin_readahead to return -EBUSY. In such case check if the page is already swapped in by swapoff path. Signed-off-by: Kairui Song --- mm/memory.c | 29 +++++++++++++++-------------- 1 file changed, 15 insertions(+), 14 deletions(-) diff --git a/mm/memory.c b/mm/memory.c index e399b37ef395..620fa87557fd 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -3846,9 +3846,21 @@ vm_fault_t do_swap_page(struct vm_fault *vmf) =20 page =3D swapin_readahead(entry, GFP_HIGHUSER_MOVABLE, vmf, &cache_result); - if (PTR_ERR(page) =3D=3D -EBUSY) { - goto out; - } else if (page) { + if (IS_ERR_OR_NULL(page)) { + /* + * Back out if somebody else faulted in this pte + * while we released the pte lock. + */ + vmf->pte =3D pte_offset_map_lock(vma->vm_mm, vmf->pmd, + vmf->address, &vmf->ptl); + if (likely(vmf->pte && pte_same(ptep_get(vmf->pte), vmf->orig_pte))) { + if (!page) + ret =3D VM_FAULT_OOM; + else + ret =3D VM_FAULT_RETRY; + } + goto unlock; + } else { folio =3D page_folio(page); if (cache_result !=3D SWAP_CACHE_HIT) { /* Had to read the page from swap area: Major fault */ @@ -3866,17 +3878,6 @@ vm_fault_t do_swap_page(struct vm_fault *vmf) ret =3D VM_FAULT_HWPOISON; goto out_release; } - } else { - /* - * Back out if somebody else faulted in this pte - * while we released the pte lock. - */ - vmf->pte =3D pte_offset_map_lock(vma->vm_mm, vmf->pmd, - vmf->address, &vmf->ptl); - if (likely(vmf->pte && - pte_same(ptep_get(vmf->pte), vmf->orig_pte))) - ret =3D VM_FAULT_OOM; - goto unlock; } =20 ret |=3D folio_lock_or_retry(folio, vmf); --=20 2.42.0