[{"id":3673116,"web_url":"http://patchwork.ozlabs.org/comment/3673116/","msgid":"<20260403130311.GD12260@macsyma-wired.lan>","list_archive_url":null,"date":"2026-04-03T13:03:11","subject":"Re: [PATCH 0/3] show orphan file inode detail info","submitter":{"id":350,"url":"http://patchwork.ozlabs.org/api/people/350/","name":"Theodore Ts'o","email":"tytso@mit.edu"},"content":"On Fri, Apr 03, 2026 at 04:25:04PM +0800, Ye Bin wrote:\n> From: Ye Bin \n> \n> In actual production environments, the issue of inconsistency between\n> df and du is frequently encountered. In many cases, the cause of the\n> problem can be identified through the use of lsof. However, when\n> overlayfs is combined with project quota configuration, the issue becomes\n> more complex and troublesome to diagnose. First, to determine the project\n> ID, one needs to obtain orphaned nodes using `fsck.ext4 -fn /dev/xx`, and\n> then retrieve file information through `debugfs`. However, the file names\n> cannot always be obtained, and it is often unclear which files they are.\n> To identify which files these are, one would need to use crash for online\n> debugging or use kprobe to gather information incrementally. However, some\n> customers in production environments do not agree to upload any tools, and\n> online debugging might impact the business. There are also scenarios where\n> files are opened in kernel mode, which do not generate file descriptors(fds),\n> making it impossible to identify which files were deleted but still have\n> references through lsof. This patchset adds a procfs interface to query\n> information about orphaned nodes, which can assist in the analysis and\n> localization of such issues.\n\nThere are some concens which were noted by Sashiko review, including\nraces with unmountings, a potential deadlock, and some issues relating\nto long pathnames, and a TOCTOU race that might lead to a file system\nerroneously being declared corrupted. PTAL:\n\nhttps://sashiko.dev/#/patchset/20260403082507.1882703-1-yebin%40huaweicloud.com\n\nThanks!\n\n\t\t\t\t\t\t- Ted","headers":{"Return-Path":"\n ","X-Original-To":["incoming@patchwork.ozlabs.org","linux-ext4@vger.kernel.org"],"Delivered-To":["patchwork-incoming@legolas.ozlabs.org","patchwork-incoming@ozlabs.org"],"Authentication-Results":["legolas.ozlabs.org;\n\tdkim=pass (2048-bit key;\n unprotected) header.d=mit.edu header.i=@mit.edu header.a=rsa-sha256\n header.s=outgoing header.b=IshiJhFV;\n\tdkim-atps=neutral","legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=ozlabs.org\n (client-ip=150.107.74.76; helo=mail.ozlabs.org;\n envelope-from=srs0=2vzp=cc=vger.kernel.org=linux-ext4+bounces-15627-patchwork-incoming=ozlabs.org@ozlabs.org;\n receiver=patchwork.ozlabs.org)","gandalf.ozlabs.org;\n arc=pass smtp.remote-ip=172.232.135.74 arc.chain=subspace.kernel.org","gandalf.ozlabs.org;\n dmarc=pass (p=none dis=none) header.from=mit.edu","gandalf.ozlabs.org;\n\tdkim=pass (2048-bit key;\n unprotected) header.d=mit.edu header.i=@mit.edu header.a=rsa-sha256\n header.s=outgoing header.b=IshiJhFV;\n\tdkim-atps=neutral","gandalf.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org\n (client-ip=172.232.135.74; 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arc=none smtp.client-ip=18.9.28.11"],"DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/relaxed; d=mit.edu; s=outgoing;\n\tt=1775221455; bh=LYZkTnoi1aTofONBpe4AonKQwhA2vCmJ1n5ctiy2dqY=;\n\th=Date:From:Subject:Message-ID:MIME-Version:Content-Type;\n\tb=IshiJhFVKmj2fG8q7mTrYX+2azkR3ubFbKAx3sgh+yziaZqCkkdQkFFj9cFbc5cg7\n\t R0N/iYy2vVJkTF03YkrpMNbyupVpsKVCjqimNoXiYTZuKMLBcRvXslLJo8KbIUVYSK\n\t LWdm1KzGXYj6cm+L3Qz72R0QMmqels+FvEHJWt1prGVbVrWYt4h6we28DEblCfZb1M\n\t pbY6fCU9xNY5/jxHHv9lMm0pngqC4Rkia+PTr8Hg5B7agG4l0FTHfQD/JJ3HbdDy+Z\n\t Akedv+k/suFsjsbPxtLcIM016rB/j+POv05C3wwqE0wDQUt8fsxRnACCFZzX30lj12\n\t 3N1aR0MNdO5Tg==","Date":"Fri, 3 Apr 2026 09:03:11 -0400","From":"\"Theodore Tso\" ","To":"Ye Bin ","Cc":"adilger.kernel@dilger.ca, linux-ext4@vger.kernel.org, jack@suse.cz","Subject":"Re: [PATCH 0/3] show orphan file inode detail info","Message-ID":"<20260403130311.GD12260@macsyma-wired.lan>","References":"<20260403082507.1882703-1-yebin@huaweicloud.com>","Precedence":"bulk","X-Mailing-List":"linux-ext4@vger.kernel.org","List-Id":"","List-Subscribe":"","List-Unsubscribe":"","MIME-Version":"1.0","Content-Type":"text/plain; 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