From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 89B183749FA; Mon, 24 Aug 2026 17:49:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787593766; cv=none; b=JW/+fJshRAxE3VrOG4qJmFw0uMStoiz5d3Rc78friyjeyxxJsXzEWXnHhRi+sK7u118kFtrE6kgBfJcoqHbFsmxvZwtjrhdP3dQklYNmYEM+pQKc2GsE9RhBq0b23W6K2yMesOOLk8BaTTeH7F7MIX8ykmLxmH7W4zU2XVWAcQQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787593766; c=relaxed/simple; bh=90suKUiXI7PlSRgK1Ox8F7w+EyQdnbS1Le8ieXJSXio=; h=MIME-Version:Date:From:To:Cc:Message-Id:In-Reply-To:References: Subject:Content-Type; b=hyMne8zjTd1JXuguZkHeeeXxLXZ1+VLZSFDlWYtRoAOJxetWoqBhdCA+Z4PjBprPBfwCvvY0IOPPJ5y/ZktxOy7EjQ7+liXf4Q3ZtIKTNd0lbD/u27UJa0RkNta0GPznT/s7bMywuooeMpc8PcvFFgByH62I8iat8yHkuW65/f4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=U0v/SvDj; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="U0v/SvDj" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A74871F00A3D; Mon, 24 Aug 2026 17:49:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1787593765; bh=PXcM5X3uBKvKFdABV+dXq4fIKyqlgx4ANk3fPDAXJGY=; h=Date:From:To:Cc:In-Reply-To:References:Subject; b=U0v/SvDjWTxpVVRAXEaFwXgetWu8mbgLqIy9RlYwGxFSFBnMciUU3Pa3W9drfPF25 2P5Y+TNzAJrFk3Lcjj+1e+4+1C7V0su9p3ITVPi6VaoexaDJeFgFpb0hqgptJVx928 wyjUsLid2AhCmc0A5qZa9Oomn+CZjcIIJb4B+uFskJxtCJibzDaHTu/S7HU/8fzfaB 82uVG3XkMoWoKPQIzBBHyf7cQtjt1nU8Q56k/cwTXDmK1qxkuoODPUKbKFxsW0TyLv bcFExql9IaoqLlH5bU9FlvivvQyWSx2WYvm0mXsVPA10FErjBWOt6DQTC4DnMLLx46 fHHPfXOl4niDg== Received: from phl-compute-10.internal (phl-compute-10.internal [10.202.2.50]) by mailfauth.phl.internal (Postfix) with ESMTP id 7B2DCF4006A; Mon, 24 Aug 2026 13:49:23 -0400 (EDT) Received: from phl-imap-15 ([10.202.2.104]) by phl-compute-10.internal (MEProxy); Mon, 24 Aug 2026 13:49:23 -0400 X-ME-Sender: X-ME-Proxy-Cause: dmFkZTEhxdDtUpllTHrqstN18oDAkCQb3QAt856ufTOaFLeUg8o+LMg/a4UZ3D4hP9DtZY F3Ryksg3VzUj9CzcUm3C9lk5xqxp3VHAxJbuzKYrfJEOXQF7166wHgRGQ1ssx7cte54Rum 3GktrAmFv6hlvG0EXZITf7bjBrr4JSjILoDLyWjxoscMWd3UzlJ3qmofuiQtCYrbtqNw3T a1vuRV5j2VaIj70DuMAK/H8m715VK8tEx1GB6+yQuWqz0BuXCLTmQYehSiDUmYJ0xeqiUz 9W3CmMCNA1G+smMDtcw3ONbTEkeE5j6MY8pylI82lOUvM1b+9W+MtHfzk/ApujlQeFzZm8 zn7eWrmzTmHm+r5U9JxBxUTFQQXuR7mtMTZCjQ88R648L1fL5K2uRVRWX2D2DrDYhH/6KM 2YR+TFvy0iYYhD4MxdIZytboaGV4+1JRaYOfeNdVR9wJVUItZZviUlme9jeCIdd8dO9fXR Q9cn/p0oEgcnU5fAED7LmcS3QUPGoRQWYmV0fQq0ndWlsd2L6yqMa7kuyA2ayNMNUyDzLK 3xS3VpjeHubqFxEmJDQiItVsEsWrPr1zJ8tgHWWUnN/4RE81JpOMGeJRWKLfR3pxJWB1mm fnSuyX38J6J8NdyUYbaX3tA6HdioZmYAQQcs6YlCA5gy1Ep3Dkdy2zi8t7Vg X-ME-Proxy: Feedback-ID: ifa6e4810:Fastmail Received: by mailuser.phl.internal (Postfix, from userid 501) id 54BA57811F0; Mon, 24 Aug 2026 13:49:23 -0400 (EDT) X-Mailer: MessagingEngine.com Webmail Interface Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-ThreadId: A-zzBGauvJA- Date: Mon, 24 Aug 2026 13:49:05 -0400 From: "Chuck Lever" To: NeilBrown , "Ian Kent" , "Jake Edge" , "Ilya Dryomov" , "Alex Markuze" , "Viacheslav Dubeyko" , "Jan Harkes" , coda@cs.cmu.edu, "Alexander Viro" , "Christian Brauner" , "Jan Kara" , "Trond Myklebust" , "Anna Schumaker" , "Amir Goldstein" , "Andrew Morton" , "Miklos Szeredi" Cc: autofs@vger.kernel.org, linux-kernel@vger.kernel.org, ceph-devel@vger.kernel.org, codalist@coda.cs.cmu.edu, linux-fsdevel@vger.kernel.org, linux-nfs@vger.kernel.org Message-Id: In-Reply-To: <20260815042707.2535717-5-neilb@ownmail.net> References: <20260815042707.2535717-1-neilb@ownmail.net> <20260815042707.2535717-5-neilb@ownmail.net> Subject: Re: [PATCH v2 04/18] nfs: separate locked regions in nfs_clear_verifier_directory() Content-Type: text/plain Content-Transfer-Encoding: 7bit On Sat, Aug 15, 2026, at 2:21 PM, NeilBrown wrote: > nfs_clear_verifier_directory() locks the dir to call > nfs_unset_verifier_delegated() > and also to walk the d_children list. > These are two separate needs and they don't need to both > be in the same locked region. > > Subsequent patches will use a helper for walking the d_children list and > that helper may drop the lock temporarily. To simplify this transition, > split the locked range by dropping and retaking the lock between to make > two separate locked regions. I hit this running xfstests against tmpfs with the series applied. The trigger was incidental (an unrelated process chmod'ed a file on an NFSv4 mount while xfstests was running) so it is not deterministic, but the path looks reachable by any SETATTR that returns a delegation on a directory: BUG: sleeping function called from invalid context at fs/nfs/dir.c:1497 in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 2385380 preempt_count: 1, expected: 0 Call Trace: __might_resched+0x165/0x180 nfs_clear_verifier_delegated+0x112/0x250 [nfs] nfs_start_delegation_return+0xa1/0x130 [nfsv4] nfs4_inode_return_delegation+0x1b/0xf0 [nfsv4] nfs4_inode_make_writeable+0xa9/0x130 [nfsv4] nfs4_proc_setattr+0xa2/0xf0 [nfsv4] nfs_setattr+0x1f2/0x480 [nfs] notify_change+0x321/0x380 chmod_common+0x10d/0x1c0 do_fchmodat+0x8a/0x110 __x64_sys_chmod+0x1d/0x30 Line 1497 is the d_for_each_positive_child() call. -- Chuck Lever