From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from zeniv.linux.org.uk (zeniv.linux.org.uk [62.89.141.173]) (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 0D0053B27DE for ; Fri, 10 Apr 2026 21:20:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=62.89.141.173 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775856021; cv=none; b=fi9T6PnqXjpSzJZr7EH4WSqFpev7jtuzn9+mWRsK5/n0Ir0//CaiIMG7HbyZxEcOGkGawlKhvmTQjYZ6fHyktUQdyccivpxhoJqHueldHTYVp8w/EtRFvTac1xUksPYFoHn78SN3EhnIz+ZuSILYOg2Ajb3bc1gSN/QSbzlEz+c= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775856021; c=relaxed/simple; bh=2+CepZtOh18fxVZHlepH9B+wHSV6mnU0B3Y5f8xPB5Y=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=ZFYym8TU8gxqqCF72qHzQHJhq2+DCWc46viRp+oKuLg/BJt0KOuNgQ6PyP/2UFMCiAJ9Xc1e2t55EfwvSJ3o+XAwcOK3ilecY+d+7itVJlbwCZGs6a1zJ6/oCSLStvSijm2Lna2rQDFO7icJhFKo4YqepxImJ7w3BtvL+tA7c2A= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=zeniv.linux.org.uk; spf=none smtp.mailfrom=ftp.linux.org.uk; dkim=pass (2048-bit key) header.d=linux.org.uk header.i=@linux.org.uk header.b=sb/MrHBz; arc=none smtp.client-ip=62.89.141.173 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=zeniv.linux.org.uk Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=ftp.linux.org.uk Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linux.org.uk header.i=@linux.org.uk header.b="sb/MrHBz" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=linux.org.uk; s=zeniv-20220401; h=Sender:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=vEo5/tRB06ZLFTtadNPD7Jq0xaU0j1A5jGAMg+L/ElA=; b=sb/MrHBz1xtfVDQpTTDvV6WP0J LI3AQpJmVmXwa5jFoMf34M1FDNe+oLuhZdAbeLmxdXQYVLNn1ubTbzc4hrCKf+toCQQJF6kV6EZt0 LPElIU86rRlaNj+Ak4/ggLkKqL33b5gVINulyHbP9FmF4E6pM7mWd7pOGNCmRnPNYyJxbGwpFVmZC P/la88TqTOVGCtdSfdDpgy2ZHmNyhvHSSIheaPLCF0kDdGRXhQ9uN8OdhigbYGI+nAtpRzhHOWXzq S2QgUiA8nzEXd8n4fGIBuBgkSdd38EW1xdOyFnj+ejRfO2wMzMVFBk0VGFxgKOL7bdpr7oxhhgHO3 Y+iuzZXA==; Received: from viro by zeniv.linux.org.uk with local (Exim 4.99.1 #2 (Red Hat Linux)) id 1wBJKd-00000007gCB-2jPV; Fri, 10 Apr 2026 21:24:03 +0000 Date: Fri, 10 Apr 2026 22:24:03 +0100 From: Al Viro To: Calvin Owens Cc: Jeff Layton , Linus Torvalds , Boqun Feng , "Paul E. McKenney" , Frederic Weisbecker , Neeraj Upadhyay , Joel Fernandes , Josh Triplett , Uladzislau Rezki , linux-fsdevel@vger.kernel.org, Christian Brauner , Jan Kara , Nikolay Borisov , Max Kellermann , Eric Sandeen , Paulo Alcantara Subject: Re: [RFC][PATCH] make sure that lock_for_kill() callers drop the locks in safe order Message-ID: <20260410212403.GY3836593@ZenIV> References: <41cfd0f95b7fde411c0d59463dce979be89cb8ef.camel@kernel.org> <20260409215733.GS3836593@ZenIV> <20260410084839.GA1310153@ZenIV> <4305138de599923591df7403aefc4d663f50324a.camel@kernel.org> <20260410191907.GV3836593@ZenIV> <30ac5108ada614560326636d4da353d6304c3f91.camel@kernel.org> Precedence: bulk X-Mailing-List: linux-fsdevel@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: Sender: Al Viro On Fri, Apr 10, 2026 at 02:13:10PM -0700, Calvin Owens wrote: > On Friday 04/10 at 15:32 -0400, Jeff Layton wrote: > > Yep, not even with that. One thing that claude pointed out: doing an > > mdelay() might prevent it from making any progress freeing dentries. > > I'm experimenting now with one that only randomly does a delay, but so > > far that hasn't turned up anything. I'll let you know if that changes. > > Hi Jeff, > > I've been poking at this one too. With the attached reproducer, the > waiter will get stuck in an infinite loop apparently in d_walk() with a > stock 7.0-rc7 (in my case with PREEMPT_LAZY): Interesting... I'll try it in a bit, but just in case - could you check if git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs.git #work.dcache-busy-wait steps into the same thing on your setup?