From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Fri, 29 Jun 2001 11:10:14 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Fri, 29 Jun 2001 11:10:04 -0400 Received: from s1.relay.oleane.net ([195.25.12.48]:5790 "HELO s1.relay.oleane.net") by vger.kernel.org with SMTP id ; Fri, 29 Jun 2001 11:09:55 -0400 From: Benjamin Herrenschmidt To: Subject: VFS locking & HFS problems (2.4.6pre6) Date: Fri, 29 Jun 2001 17:09:42 +0200 Message-Id: <20010629150942.1359@smtp.adsl.oleane.com> X-Mailer: CTM PowerMail 3.0.8 MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org I've had a deadlock twice with 2.4.6pre6 today. It's an SMP kernel running on an UP box (a PowerBook Pismo). The deadlock happen in the HFS filesystem in hfs_cat_put(), apparently (quickly looking at addresses) in spin_lock(). I don't have the complete backtrace at hand right now, but it basically went up to kswapd without anything evidently getting that spinlock, I'll try to gather more details. So my question: Is there any document explaining the various locking requirements & re-entrency possibilities in a filesystem. What I think might happen after a quick look is that HFS may be causing schedule() to be called while holding the spinlock, and gets then re-entered from another process context. I have to look at it in more detail (is there an HFS maintainer ?) but some background informations on VFS locking & reentrancy issues would be helpful. Ben.