From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 B2F9A749D; Thu, 18 Jan 2024 05:49:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1705556981; cv=none; b=KW0w4d3DxA0zgRNElXvkrYybHslYCPA8vzWfhF6z2GuPc5lNrDbyF54kqy4tr8I9e8fBJxBcDLT8mMI5W20c3NtQDgbzlP9HPbQGuHHh6ct8LvdLh4HJQpJt2hNzxvGaG+iWVsa+HWWWVVJ76r1TSmj3BaUt40yGc8WS7PYMV2s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1705556981; c=relaxed/simple; bh=smVTYrpz7w+5HQWdbWbOy8VUmzkn+94GUCqw+7Dga5Y=; h=Received:DKIM-Signature:References:User-agent:From:To:Cc:Subject: Date:In-reply-to:Message-ID:MIME-Version:Content-Type; b=IbYnEuVQpe1ESD4PZIk26tyF4AjPCAXYAi6rKyEHxH01HgukbbWN7uUpF9VBI8B26KsFPLutz9LYbVfua8HOvCqLRKanXjJQSLG4xpixVN1V9YXnOsH3ypOEXsdtQdR/XQ0buxZW8rYQpS7G332RViM8bKyvicxQ4L8bKtN1Rjs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=NIJRhpwV; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="NIJRhpwV" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B8A92C433F1; Thu, 18 Jan 2024 05:49:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1705556981; bh=smVTYrpz7w+5HQWdbWbOy8VUmzkn+94GUCqw+7Dga5Y=; h=References:From:To:Cc:Subject:Date:In-reply-to:From; b=NIJRhpwVlSMzyIQv7cZAOp19MFxIxAdvwDkyMnVeDFcq1hMbF/8FJ5YDgAqsiqlxw bHGNqSSZ7bXp2R5ft2ZXBp0BuawNPhw/IhnkP4UThy9lzAoysszNVghNdPi6UUXfZR VZWpv+3o/rh625krmXjWcHS0GnDz6ImTYTAkYOTi0LmznODRwilN8jS3tjEneec/nc CLr0CTk7hkgn73zK0ucYLBjIKNn0QsNBFNfZuwQ0AGAWUXOzz5WUy9xh4eEwsnsG0i lXA4bUAIZdmBFUam24xb+AaE1TGIOQOwS1lo8mN95WHEzV2LapL0+OgNwTdF8zlV93 MFZuHeia+CGTg== References: <87le96lorq.fsf@debian-BULLSEYE-live-builder-AMD64> <20240104043420.GT361584@frogsfrogsfrogs> <87sf3d8c0u.fsf@debian-BULLSEYE-live-builder-AMD64> User-agent: mu4e 1.10.8; emacs 27.1 From: Chandan Babu R To: Chandan Babu R Cc: "Darrick J. Wong" , linux-fsdevel , linux-xfs@vger.kernel.org, viro@zeniv.linux.org.uk, brauner@kernel.org, jack@suse.cz Subject: Re: [BUG REPORT] shrink_dcache_parent() loops indefinitely on a next-20240102 kernel Date: Thu, 18 Jan 2024 10:59:06 +0530 In-reply-to: <87sf3d8c0u.fsf@debian-BULLSEYE-live-builder-AMD64> Message-ID: <874jfbjimn.fsf@debian-BULLSEYE-live-builder-AMD64> Precedence: bulk X-Mailing-List: linux-xfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain On Thu, Jan 04, 2024 at 06:40:43 PM +0530, Chandan Babu R wrote: > On Wed, Jan 03, 2024 at 08:34:20 PM -0800, Darrick J. Wong wrote: >> On Wed, Jan 03, 2024 at 12:12:12PM +0530, Chandan Babu R wrote: >>> Hi, >>> >>> Executing fstests' recoveryloop test group on XFS on a next-20240102 kernel >>> sometimes causes the following hung task report to be printed on the console, >>> Meanwhile, I have executed some more experiments. The bug can be recreated on a next-20240102 kernel by executing either generic/388 or generic/475 for a maximum of 10 iterations. I tried to do a git bisect based on this observation i.e. I would mark a commit as 'good' if the bug does not get recreated within 10 iterations. This led to the following git bisect log, # git bisect log # bad: [ab0b3e6ef50d305278b1971891cf1d82ab050b35] Add linux-next specific files for 20240102 # good: [33cc938e65a98f1d29d0a18403dbbee050dcad9a] Linux 6.7-rc4 git bisect start 'HEAD' 'v6.7-rc4' 'fs/' # bad: [ca20194665a58bb541cc9e4dc7abcf96a7c96bd9] Merge branch 'main' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next.git git bisect bad ca20194665a58bb541cc9e4dc7abcf96a7c96bd9 # good: [bb986dac9a56f88552418288c87e2223f8f448e3] Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git git bisect good bb986dac9a56f88552418288c87e2223f8f448e3 # bad: [964c80149d24b33bbddd222edbcc782be6eab841] Merge branch 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git git bisect bad 964c80149d24b33bbddd222edbcc782be6eab841 # good: [da9e5cca7e753dd96e07ae9212f4aeec1b9c68a6] Merge branch 'vfs.all' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs.git git bisect good da9e5cca7e753dd96e07ae9212f4aeec1b9c68a6 # bad: [9e02829aa9d2e5f2e080ba0191c36a50a384acf1] Merge branch 'hwmon-next' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging.git git bisect bad 9e02829aa9d2e5f2e080ba0191c36a50a384acf1 # bad: [3ac3331ea2c1826e3d30276e0a7e7e62fff519a8] Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci.git git bisect bad 3ac3331ea2c1826e3d30276e0a7e7e62fff519a8 # bad: [e01e3fb272cf7380dd5d70f52e955ac1122e2184] Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux.git git bisect bad e01e3fb272cf7380dd5d70f52e955ac1122e2184 # bad: [6d06b73bcd6eee6ca43f429a28e812ef2ad7a4ea] Merge branch 'work.simple_recursive_removal' into for-next git bisect bad 6d06b73bcd6eee6ca43f429a28e812ef2ad7a4ea # bad: [119dcc73a9c2df0da002054cdb2296cb32b7cb93] Merge branches 'work.dcache-misc' and 'work.dcache2' into work.dcache git bisect bad 119dcc73a9c2df0da002054cdb2296cb32b7cb93 # good: [6367b491c17a34b28aece294bddfda1a36ec0377] retain_dentry(): introduce a trimmed-down lockless variant git bisect good 6367b491c17a34b28aece294bddfda1a36ec0377 # good: [b33c14c8618edfc00bf8963e3b0c8a2b19c9eaa4] Merge branch 'no-rebase-overlayfs' into work.dcache-misc git bisect good b33c14c8618edfc00bf8963e3b0c8a2b19c9eaa4 # good: [f9453a1ad1fadae29fd7db5ad8ea16f35e737276] Merge branch 'merged-selinux' into work.dcache-misc git bisect good f9453a1ad1fadae29fd7db5ad8ea16f35e737276 # good: [57851607326a2beef21e67f83f4f53a90df8445a] get rid of DCACHE_GENOCIDE git bisect good 57851607326a2beef21e67f83f4f53a90df8445a # good: [ef69f0506d8f3a250ac5baa96746e17ae22c67b5] __d_unalias() doesn't use inode argument git bisect good ef69f0506d8f3a250ac5baa96746e17ae22c67b5 # first bad commit: [119dcc73a9c2df0da002054cdb2296cb32b7cb93] Merge branches 'work.dcache-misc' and 'work.dcache2' into work.dcache Looks like the bug is caused by changes that were made in two separate branches. I have also confirmed that the bug was not present in the v6.7-rc4 kernel by executing generic/388 in a loop for 44 times. I can also confirm that the issue can be recreated on a next-20240118 kernel. -- Chandan