From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pg1-f181.google.com (mail-pg1-f181.google.com [209.85.215.181]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6073214389F for ; Thu, 12 Dec 2024 03:58:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.215.181 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733975913; cv=none; b=pj3TATvbqvKP17rJP+hw76DKkjyfUBqFDkGB6BUSGcaiKSdXK6QjpaCjJ/0b6smVU4OWlf4lWkQnxvTIY8pbsVoZpxdMocvjuZyzBF8kfdtKUt4wro+qvK3e+UQ9VmqFaC1tDhoLkGyFx2ZJxlrmIbFC8c4wEw7k2695NcbBhsk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733975913; c=relaxed/simple; bh=F36O0Dgg1mhlcRno/fBPjRyjEsASJc7EpOfe35xMwec=; h=Date:From:To:Cc:Subject:Message-ID:MIME-Version:Content-Type: Content-Disposition; b=Ygw+NXnx9nNvyl7IoJsexdM4aXEPE3Ws6sFMh2ki2MFywBlqmOqLv4HLQe15hx+e9AAW801quK2LZoaop/aOcNInO8RFhy1xawXWBeOsKuL0UlpEhgXcqVQzWkZIp1nDvmbS1TUHShgnMiYJp29KVRPIgwF3t5cb0d05k3JZ0cQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=chromium.org; spf=pass smtp.mailfrom=chromium.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b=GIHOvg4U; arc=none smtp.client-ip=209.85.215.181 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=chromium.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=chromium.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="GIHOvg4U" Received: by mail-pg1-f181.google.com with SMTP id 41be03b00d2f7-7fc88476a02so162583a12.2 for ; Wed, 11 Dec 2024 19:58:32 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; t=1733975911; x=1734580711; darn=vger.kernel.org; h=content-disposition:mime-version:message-id:subject:cc:to:from:date :from:to:cc:subject:date:message-id:reply-to; bh=WgpWYN8QlsUV56/RVatR17L4XIXA6XIYGaqKFNGgJR8=; b=GIHOvg4UbiVaM9uJK6lQZFuZiHZSvykDeyOlu3rgwhXtP6D+dr37wy+QXu/W5zv+vB o4+ODtk4V/0FJZFwHC2d9UtjHmDpDyoXn4mCwJkMYXw9dw0A4MDCzhFdnEtE7qhoeCcd FkrAjSio9mns5VLH1IHWv8giyxJN5OIfO3NXg= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1733975911; x=1734580711; h=content-disposition:mime-version:message-id:subject:cc:to:from:date :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=WgpWYN8QlsUV56/RVatR17L4XIXA6XIYGaqKFNGgJR8=; b=Zbk+m4v6gOM1DJakz4grG9t12TAssDI9Q6S87Zm0aHpftYKiNCCrOB4/e88Fn+WcLs DXQs/9M/t61aRBfgXD1MrXVUWhZ1mfudniWfP/Z3uzynD6LIMzvx8+obC4AJKhnUrUVH Nvy5i1i8dZCcXJ/GFrIrwzAwxPLqJgMOE8RY+CCxKdlolZjsxvAdIEvjLZhV57k2su3S +yjkrK7oQTq6vs+enbwOPTuNEvff9PExSbVduNQRWKVebohCEA5mHXIH94shK2y1y4I9 PB/vAw7RFZjjY4ZkgqGvKlSNnWD+1ifdAFSgitspY13Ew0w9XjBm36MFqI0B+v59UxP6 763Q== X-Forwarded-Encrypted: i=1; AJvYcCWFsSyyoH8t6zMKLPaqvnUnrUwKCLlHJkegf0WM9o7M80a3YfO1D5Ki0vYs9rEMRccFN1/p7C5FpbR97PjU@vger.kernel.org X-Gm-Message-State: AOJu0Yycs6ulK0M9mUVH0Lhhke+eWnDksC71+TfkXbUDdrEUvIwMqX9t OJMriSbky/KFmJTBy/oEy8H1p2L8FAH7ZfRWgp2s/FPPSBzNUpz/s2mjfgJwYA== X-Gm-Gg: ASbGncsQQ6b+HNIsi1Nct2wYvMilnE+dFfmYpbJMxnWjR6SKQHeMPRxwKdWPfVO8u9K hQOSVjnZTfa7J6abJVzgQEOYWAnOuuLFoX7kKFJoU8IamjmKRgiad2TU5Qcp8iEC4uXzgfplINq 9tqI7mHhgk9so2aGKTeKDGWpIwsBsOkIroiewwhwq281U3oefCu26LoXScdj0rD/gHBHOCGL/ZS eu51ifcMX/y1PD6z2t1oTmhSc6OIqtUujtuY/p5jPNgl1h5XdPTsOwpRZdP X-Google-Smtp-Source: AGHT+IHKkfFoUJmuviCWJxeHOxw/i7OyuK3tNEwkKuGLCgFdomsJz63utqGvLX0dQV2QgpKkzX7kug== X-Received: by 2002:a17:90b:3ec6:b0:2ee:8031:cdbc with SMTP id 98e67ed59e1d1-2f13930b92amr3181455a91.23.1733975911667; Wed, 11 Dec 2024 19:58:31 -0800 (PST) Received: from google.com ([2401:fa00:8f:203:d087:4c7f:6de6:41eb]) by smtp.gmail.com with ESMTPSA id 98e67ed59e1d1-2f142d90d3asm218413a91.7.2024.12.11.19.58.29 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 11 Dec 2024 19:58:31 -0800 (PST) Date: Thu, 12 Dec 2024 12:58:26 +0900 From: Sergey Senozhatsky To: Theodore Ts'o , Christoph Hellwig , Jens Axboe , caiqingfu Cc: Andrew Morton , Sergey Senozhatsky , linux-ext4@vger.kernel.org, linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: [bugzilla:219548] the kernel crashes when storing an EXT4 file system in a ZRAM device Message-ID: <20241212035826.GH2091455@google.com> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Hi, We've got two reports [1] [2] (could be the same person) which suggest that ext4 may change page content while the page is under write(). The particular problem here the case when ext4 is on the zram device. zram compresses every page written to it, so if the page content can be modified concurrently with zram's compression then we can't really use zram with ext4. Can you take a look please? [1] https://bugzilla.kernel.org/show_bug.cgi?id=219548 [2] https://lore.kernel.org/linux-kernel/20241129115735.136033-1-baicaiaichibaicai@gmail.com