Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762688AbXEPDxx (ORCPT ); Tue, 15 May 2007 23:53:53 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754665AbXEPDxr (ORCPT ); Tue, 15 May 2007 23:53:47 -0400 Received: from e35.co.us.ibm.com ([32.97.110.153]:47730 "EHLO e35.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758968AbXEPDxq (ORCPT ); Tue, 15 May 2007 23:53:46 -0400 Subject: [PATCH -stable] JFS: Fix race waking up jfsIO kernel thread From: Dave Kleikamp To: stable@kernel.org Cc: linux-kernel Content-Type: text/plain Date: Tue, 15 May 2007 22:53:36 -0500 Message-Id: <1179287616.8339.8.camel@kleikamp.austin.ibm.com> Mime-Version: 1.0 X-Mailer: Evolution 2.8.3 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1509 Lines: 43 This patch fixes a deadlock that has been reported by three different users on recent kernels. The problem exists on mainline kernels since 2.6.18. It is included in linux-2.6.22-rc1. JFS: Fix race waking up jfsIO kernel thread It's possible for a journal I/O request to be added to the log_redrive queue and the jfsIO thread to be awakened after the thread releases log_redrive_lock but before it sets its state to TASK_INTERRUPTIBLE. The jfsIO thread should set the state before giving up the spinlock, so the waking thread will really wake it. Signed-off-by: Dave Kleikamp diff -Nurp linux-2.6.21.1/fs/jfs/jfs_logmgr.c linux/fs/jfs/jfs_logmgr.c --- linux-2.6.21.1/fs/jfs/jfs_logmgr.c 2007-04-27 16:49:26.000000000 -0500 +++ linux/fs/jfs/jfs_logmgr.c 2007-05-15 22:39:31.000000000 -0500 @@ -2354,12 +2354,13 @@ int jfsIOWait(void *arg) lbmStartIO(bp); spin_lock_irq(&log_redrive_lock); } - spin_unlock_irq(&log_redrive_lock); if (freezing(current)) { + spin_unlock_irq(&log_redrive_lock); refrigerator(); } else { set_current_state(TASK_INTERRUPTIBLE); + spin_unlock_irq(&log_redrive_lock); schedule(); current->state = TASK_RUNNING; } -- David Kleikamp IBM Linux Technology Center - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/