From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from outgoing.mit.edu (outgoing-auth-1.mit.edu [18.9.28.11]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B1A4D218827 for ; Tue, 15 Jul 2025 03:42:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=18.9.28.11 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752550961; cv=none; b=ST5vaeh8Q/ms0whXlXIiiYa0/eNbKohXBGUYf0/MKmN0RBoUzpjbEVYkaqhMDfFigLUWd6n9uQ6kUi/VZverGvXZYW3pQnW+o7NbT7uo03YIR0+6qH/0daSVnA6/yBurdyagjnWlVrYzh8ryhG2KDRhbYJUEUU1KzKkINce/oGM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752550961; c=relaxed/simple; bh=u+mlZQExcRMItsKnSkEqpccOS0uFJMtlkke0irurtkA=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Ym68IY1tBgqRaF+WvN/Z8JFdKy4U+a3p1ucOHmMtS8x2HKKAmnXIDE/vdrAn3XDbPiTbe+YTochNeXkM33MbiaJSnTrILMEUBMMPhtp7r/ZAB8qB90ry6wLekBGkjCutZfpE+qXRqFJha0dSxYVgDiE7/F20s2xcPgwWeUZApUM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=mit.edu; spf=pass smtp.mailfrom=mit.edu; dkim=pass (2048-bit key) header.d=mit.edu header.i=@mit.edu header.b=lonv20cY; arc=none smtp.client-ip=18.9.28.11 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=mit.edu Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=mit.edu Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=mit.edu header.i=@mit.edu header.b="lonv20cY" Received: from trampoline.thunk.org (pool-108-26-156-88.bstnma.fios.verizon.net [108.26.156.88]) (authenticated bits=0) (User authenticated as tytso@ATHENA.MIT.EDU) by outgoing.mit.edu (8.14.7/8.12.4) with ESMTP id 56F3g47e027598 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 14 Jul 2025 23:42:05 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mit.edu; s=outgoing; t=1752550927; bh=UbC5XqbUuDYvUapkndbSlyKNWPJ06LZ10S/ex1fui6g=; h=Date:From:Subject:Message-ID:MIME-Version:Content-Type; b=lonv20cYMsk5WCaP6unuCyKbeRbtvUJz7+ZLIdS/dzIAxIrmO8z/+mVaQmq0XVY9L OhCR++y4KsY3jLZSonLj0UvW5qzXLcxiUt6Ngr7e8gbDA2mNfd+CA7GD22GQ71gJp9 gt0V8z9sGfWQQhy3ukdUzVrkwo+zi5yQOm5ouhf/JbwCu9xo6gNqogcHorh17yOTLe +8CGShh89wb0PdgypQc6Cz7RpW7Aw+0HPI46clRooJ1ZqQtFuv7/dTQP4ScTQhaoBr eoqwAyLIuoLATf88yaP9e0gBbq4bf6ro8zlRJM1ieBXachOov/CS9YMeXOcNjsUhnz wWvrn0hlR4Oxw== Received: by trampoline.thunk.org (Postfix, from userid 15806) id CBB332E00D5; Mon, 14 Jul 2025 23:42:04 -0400 (EDT) Date: Mon, 14 Jul 2025 23:42:04 -0400 From: "Theodore Ts'o" To: Jiany Wu Cc: "Darrick J. Wong" , yi.zhang@huawei.com, jack@suse.cz, linux-ext4@vger.kernel.org Subject: Re: Issue with ext4 filesystem corruption when writing to a file after disk exhaustion Message-ID: <20250715034204.GD23343@mit.edu> References: <20250711052905.GC2026761@mit.edu> <20250711154012.GB4040@mit.edu> <20250712042714.GG2672022@frogsfrogsfrogs> <20250712143432.GE4040@mit.edu> <20250714130951.GB41071@mit.edu> Precedence: bulk X-Mailing-List: linux-ext4@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Tue, Jul 15, 2025 at 09:27:01AM +0800, Jiany Wu wrote: > > Thanks indeed for the clarification, it is clear now. > OK, if using a loopback mounted image on a disk, underlying file > system full then the block device will have I/O error. > This loopback mount belongs to a third party common config. I'll > fallocate lower disk space to not exhaust disk as a work around > firstly. The question I'd ask is *why* someone set up that loopback mount in the first place. As a guess, perhaps the goal was to restrict the mount of disk space could be used for log files in /var/log, so that if there is runaway logging, that all of the free space on the root partition won't be consumed. But if that's the case, there are much better ways of achieving the same goal. For example, in addition to using log rotation programs, you could back that up with using project quotas , which restricts how much space can get used in a subdirectory. Cheers, - Ted