From nobody Sun Sep 14 02:03:54 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 A4C67C61DA4 for ; Fri, 27 Jan 2023 19:42:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231881AbjA0Tm6 (ORCPT ); Fri, 27 Jan 2023 14:42:58 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50624 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231681AbjA0Tmx (ORCPT ); Fri, 27 Jan 2023 14:42:53 -0500 Received: from mail-pj1-x104a.google.com (mail-pj1-x104a.google.com [IPv6:2607:f8b0:4864:20::104a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A602B7AE44 for ; Fri, 27 Jan 2023 11:42:21 -0800 (PST) Received: by mail-pj1-x104a.google.com with SMTP id om10-20020a17090b3a8a00b002299e350deaso4781924pjb.1 for ; Fri, 27 Jan 2023 11:42:21 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=6D7AVbhEFxAo5EKdbJ2HQfTq9cKDp9C6gMDUsIDn2rU=; b=ij3G6594G9QMVIcaC7y7IotZlrRGSd461+VUEA/BMKS/DqdJRnleVk5IzJ5gil69bZ nXwMrZpHBfopZhY+dBOM8TntT+xgyMzx0lhn0c4XjFlDdq8hUc51rQLAJayIjAlxU0Vs tSDUCQts0+fWuoHVHrLcPeZOnjtBdS6uOzMiFPrkU4AVT++YMj0+eDXitszbX73gjVet Uj7on6Z68KT42I30IFAHZ8MnQyKVo+KH97KXkIJWbVMmYdISzeeP/HtVHdR/3Pzjnpiz r0YfwFvkG3mRoMMu6hvaQ0O0QqVpO+Mcl7G8itnKrK/kLoHBd5Ey6CcVhBTBp6nBJTd/ 24fw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=6D7AVbhEFxAo5EKdbJ2HQfTq9cKDp9C6gMDUsIDn2rU=; b=5nPrbRm9BDFfVpwkFKr5cFjhiDQgUq9n3D4YOhCJTh3mLLYu5Q8UFU4n9C/hQa0Fcv R99XWI96OyBysoEVRtRug/NvqAtSS2YT17qcKIu6Zax+mgQkNIzRXnufNyA7SZ6+EkKj 6CUb0Rfnnsr8mLX1yuw0vJ2evI5Bs/W/uP7qy2WPKIUS2HnQ1DbVkg8dFh+tB+vSOAkA E6b5/o162LD/ITIgYxTjp3UUKUh9hhSM0keF1mx265aRQk21g+O3x8FXTUKE/mfylNHL a8b25BLSXC2cWULM3x6Ztdr+m0KjG+9arJ4HUnoLCuTNbSWL4TC6pdNywR9jp6y9a9Az AX4A== X-Gm-Message-State: AO0yUKXgDJyHl8MsqKy2+pJFUILsmFRX0zIjGI6aGZkx7OvXYcokLyWz siwMAHxBRtY0wzm/ZkPAyJLSU5wopFI= X-Google-Smtp-Source: AK7set+8nPPCBQ/ToCHxQhHQnspD+CZKcqljSV2Aj5HMLvXZA8Wu8rpp2+AujJr6dncfulY9izqabQa2p3o= X-Received: from surenb-desktop.mtv.corp.google.com ([2620:15c:211:200:4e19:be9:c5d0:8483]) (user=surenb job=sendgmr) by 2002:a05:6a00:1990:b0:593:909f:ed45 with SMTP id d16-20020a056a00199000b00593909fed45mr72889pfl.0.1674848478930; Fri, 27 Jan 2023 11:41:18 -0800 (PST) Date: Fri, 27 Jan 2023 11:40:39 -0800 In-Reply-To: <20230127194110.533103-1-surenb@google.com> Mime-Version: 1.0 References: <20230127194110.533103-1-surenb@google.com> X-Mailer: git-send-email 2.39.1.456.gfc5497dd1b-goog Message-ID: <20230127194110.533103-3-surenb@google.com> Subject: [PATCH v2 02/33] maple_tree: Detect dead nodes in mas_start() From: Suren Baghdasaryan To: akpm@linux-foundation.org Cc: michel@lespinasse.org, jglisse@google.com, mhocko@suse.com, vbabka@suse.cz, hannes@cmpxchg.org, mgorman@techsingularity.net, dave@stgolabs.net, willy@infradead.org, liam.howlett@oracle.com, peterz@infradead.org, ldufour@linux.ibm.com, paulmck@kernel.org, mingo@redhat.com, will@kernel.org, luto@kernel.org, songliubraving@fb.com, peterx@redhat.com, david@redhat.com, dhowells@redhat.com, hughd@google.com, bigeasy@linutronix.de, kent.overstreet@linux.dev, punit.agrawal@bytedance.com, lstoakes@gmail.com, peterjung1337@gmail.com, rientjes@google.com, axelrasmussen@google.com, joelaf@google.com, minchan@google.com, rppt@kernel.org, jannh@google.com, shakeelb@google.com, tatashin@google.com, edumazet@google.com, gthelen@google.com, gurua@google.com, arjunroy@google.com, soheil@google.com, leewalsh@google.com, posk@google.com, linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, x86@kernel.org, linux-kernel@vger.kernel.org, kernel-team@android.com, surenb@google.com, Liam Howlett Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Liam Howlett When initially starting a search, the root node may already be in the process of being replaced in RCU mode. Detect and restart the walk if this is the case. This is necessary for RCU mode of the maple tree. Fixes: 54a611b60590 ("Maple Tree: add new data structure") Signed-off-by: Liam Howlett Signed-off-by: Suren Baghdasaryan --- lib/maple_tree.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/lib/maple_tree.c b/lib/maple_tree.c index e5eeecd14eee..482e17a460cb 100644 --- a/lib/maple_tree.c +++ b/lib/maple_tree.c @@ -1353,12 +1353,16 @@ static inline struct maple_enode *mas_start(struct = ma_state *mas) mas->max =3D ULONG_MAX; mas->depth =3D 0; =20 +retry: root =3D mas_root(mas); /* Tree with nodes */ if (likely(xa_is_node(root))) { mas->depth =3D 1; mas->node =3D mte_safe_root(root); mas->offset =3D 0; + if (mte_dead_node(mas->node)) + goto retry; + return NULL; } =20 --=20 2.39.1