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 9B7ED56B79; Tue, 23 Jan 2024 08:41:12 +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=1705999272; cv=none; b=QC+H/3a0LGtvG7xH5fSQPBsrFmPrOM4WzhlvvfE7RT+yVJGM/7zgOLzNZu32xciBAq//9M4iW4rYc+v3/RHyVQep9LWQAbPzjNvVnYSoqmnKstWN/3G2dLf7PKDdHIdBvE6ru9r0g3iW8GHggyqpk+8qrZkiLiQTCS8xWWfb+20= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1705999272; c=relaxed/simple; bh=HhePdDiV1RoPyzweu+6A0rKcyr2VkNNep3AQr53Isxo=; h=References:From:To:Cc:Subject:Date:In-reply-to:Message-ID: MIME-Version:Content-Type; b=IW87s+ngSJ4sa6iKosmywMSPbHJkcDTCPNtMpc3Xbm8/M5YBMJvvGZqeIdoI3mfb7gej0yJiYdYmtDNGLzXJhsUN8zEkRi/BlYSOOQYtiMZC8kMBwzWuNW2cPeVjnJz0j/DpdP3f9ue1YQQSLl7Xu7qZfgm9//Mx/D9XVxEzycM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=c1RodUQZ; 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="c1RodUQZ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 82C2DC433F1; Tue, 23 Jan 2024 08:41:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1705999272; bh=HhePdDiV1RoPyzweu+6A0rKcyr2VkNNep3AQr53Isxo=; h=References:From:To:Cc:Subject:Date:In-reply-to:From; b=c1RodUQZMUmnQwcz7E/TARb86KVq+PnQhc4ODnUT4ZmHAqZdWDgwpOtL+cVKlzsm6 j4tJsds3RQmDafmrYgsQPoOYdAVRiukdPryTc6EVzrp3zkPJjYPDGTQ361Db6YooX9 DcHVqsrj38wCIPmVC33UqaOhbIkUWDUv9VE7u6uxfiIacbig6GS+zVQMRVgpcowSsd Za+xbMiTU02Qy9SJ8MEUqFAdGGnDX6A9/PDYM+AsC2THbghsI/x/uHu/MW+O9IuLL/ a73+UAuRbTdDPKfxiMYxFAm/sWe6on0g/jMkPontiHJMDSwckBNES7dYDnpjgz5VC3 msg+ZBq8BIMbQ== References: <87le96lorq.fsf@debian-BULLSEYE-live-builder-AMD64> <20240104043420.GT361584@frogsfrogsfrogs> <87sf3d8c0u.fsf@debian-BULLSEYE-live-builder-AMD64> <874jfbjimn.fsf@debian-BULLSEYE-live-builder-AMD64> <20240118063930.GP1674809@ZenIV> User-agent: mu4e 1.10.8; emacs 27.1 From: Chandan Babu R To: Al Viro Cc: "Darrick J. Wong" , linux-fsdevel , linux-xfs@vger.kernel.org, brauner@kernel.org, jack@suse.cz Subject: Re: [BUG REPORT] shrink_dcache_parent() loops indefinitely on a next-20240102 kernel Date: Tue, 23 Jan 2024 11:31:00 +0530 In-reply-to: <20240118063930.GP1674809@ZenIV> Message-ID: <87ede8787u.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 18, 2024 at 06:39:30 AM +0000, Al Viro wrote: > On Thu, Jan 18, 2024 at 10:59:06AM +0530, Chandan Babu R wrote: >> 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, > >> # 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 57851607326a2beef21e67f83f4f53a90df8445a >> # good: [ef69f0506d8f3a250ac5baa96746e17ae22c67b5] __d_unalias() doesn't use inode argument > > Lovely... Could you try to do the following: > > bisect from 6.7-rc1 to work.dcache-misc; for each of those revisions > git worktree add ../test HEAD > cd ../test > git merge work.dcache2 > build > test the result > cd - > git worktree remove -f ../test > git bisect {good,bad} accordingly The result of the above suggested bisect operation is, # git bisect log # bad: [0695819b3988e7e4d8099f8388244c1549d230cc] __d_unalias() doesn't use inode argument # good: [b85ea95d086471afb4ad062012a4d73cd328fa86] Linux 6.7-rc1 git bisect start 'HEAD' 'v6.7-rc1' 'fs/' # good: [b33c14c8618edfc00bf8963e3b0c8a2b19c9eaa4] Merge branch 'no-rebase-overlayfs' into work.dcache-misc git bisect good b33c14c8618edfc00bf8963e3b0c8a2b19c9eaa4 # good: [ef8a633ee84d8b57eba1f5b2908a3e0bf61837aa] Merge branch 'merged-selinux' into work.dcache-misc git bisect good ef8a633ee84d8b57eba1f5b2908a3e0bf61837aa # good: [53f99622a2b24704766469af23360836432eb88a] d_genocide(): move the extern into fs/internal.h git bisect good 53f99622a2b24704766469af23360836432eb88a # bad: [ce54c803d57ab6e872b670f0b46fc65840c8d7ca] d_alloc_parallel(): in-lookup hash insertion doesn't need an RCU variant git bisect bad ce54c803d57ab6e872b670f0b46fc65840c8d7ca # bad: [f7aff128d8c70493d614786ba7ec5f743feafe51] get rid of DCACHE_GENOCIDE git bisect bad f7aff128d8c70493d614786ba7ec5f743feafe51 # first bad commit: [f7aff128d8c70493d614786ba7ec5f743feafe51] get rid of DCACHE_GENOCIDE commit f7aff128d8c70493d614786ba7ec5f743feafe51 Author: Al Viro Date: Sun Nov 12 21:38:48 2023 -0500 get rid of DCACHE_GENOCIDE ... now that we never call d_genocide() other than from kill_litter_super() Signed-off-by: Al Viro fs/dcache.c | 5 +---- include/linux/dcache.h | 1 - 2 files changed, 1 insertion(+), 5 deletions(-) -- Chandan