From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pg1-f172.google.com (mail-pg1-f172.google.com [209.85.215.172]) (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 4B10913F43A for ; Thu, 12 Dec 2024 03:58:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.215.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733975913; cv=none; b=L1q2ASMnr7zRRIwvmjIpE2vLV03OAaYBFr+AuTwhKb+U6vSoSlMfMPn1+ZjjSna1ItH/ltd1/klu6qznLVJhMyNk/jMxyFd1sqdRVLmp3SnRXnGgh0HBa2ArvMdKtEUplBjJGSyn9UBDdZgtNTIjrmkbEOzUiEAl5kvnRNzvjwM= 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=209.85.215.172 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-f172.google.com with SMTP id 41be03b00d2f7-7feffe7cdb7so144452a12.1 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=ltpT3mh6UCD2yWygtCwmjLeneauwXH3kFU37nCqONAty37Bik5gM+3+1F3Joi5s7OQ PGKLNkRGPaI6eiMmpuyNpjpWMpZ/nCB2CgLO8uMcuF1A6FDLXuyB/8sy+lycti0eHkbE FX20fk4BzyHL8l50TIj7pZvjlHreR5VwEknF026mNWCuifx5lR9ndCTOzC0rImPCY6po s2vjKrLY3GeeS17w63i7CquRR9Gnu1PlK/VCqlx1O3qTmwBMzhRW2IPLrA+b7whUu4r2 581V5xURhr6S/XNFymv7na99JKuG+UJQUZuN8hYugewjfSWeDhS4GxrVmGzzM0MXMuC/ M6mA== X-Forwarded-Encrypted: i=1; AJvYcCUuee/x9YlNPjgYbMnrtbiF7WnTeWXCpKnpeZrHjgFZkj24niUb/BvcYbtnNB+jGkpsQh+wB1ugwWHMwg==@vger.kernel.org X-Gm-Message-State: AOJu0YyQSuKlBSui7+V7bfncDfk6b0914P1GHHmIQokLacBqqWMHGOX0 jSR1QAlsSy13jp3FczX+9lPKrniL1pYBNhzmJ00LywWYK+YC7q5RfVNlfyVIPA== X-Gm-Gg: ASbGncuav/SftKVwWszXGxFVNKnTY8jfrWEkiyNIqY1f8ce0h8Gnfa9rOtQ1N7m0Z5B MYzBv3kOlgU92hlUz1m+b25X8Edo4b7quwX17anBYa5ccX6xK7txBozBV6ajIg4rQ2z2VpZtiCP SeHqjZrnWPjaMEhsnIaHe8vZUoP97h+/0hVDHM5MC+H6RLEydKRnBaKS7qQArc+lKQ+5f4pf0Jp uonhzNf73Y2X6VWG5i3lC4uPC9CKLbUO8Hz+YpcK9VbyWK9hJGfPrF0556P 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-block@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