From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from sc8-sf-mx1-b.sourceforge.net ([10.3.1.91] helo=mail.sourceforge.net) by sc8-sf-list1-new.sourceforge.net with esmtp (Exim 4.43) id 1H1TCv-0005oz-Hz for user-mode-linux-devel@lists.sourceforge.net; Mon, 01 Jan 2007 11:52:29 -0800 Received: from saraswathi.solana.com ([198.99.130.12]) by mail.sourceforge.net with esmtps (TLSv1:AES256-SHA:256) (Exim 4.44) id 1H1TCp-0004xk-VJ for user-mode-linux-devel@lists.sourceforge.net; Mon, 01 Jan 2007 11:52:26 -0800 Message-Id: <200701011947.l01Jl7vp020746@ccure.user-mode-linux.org> Mime-Version: 1.0 Date: Mon, 01 Jan 2007 14:47:07 -0500 From: Jeff Dike Subject: [uml-devel] [PATCH 1/8] UML - watchdog driver locking List-Id: The user-mode Linux development list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: user-mode-linux-devel-bounces@lists.sourceforge.net Errors-To: user-mode-linux-devel-bounces@lists.sourceforge.net To: akpm@osdl.org Cc: linux-kernel@vger.kernel.org, user-mode-linux-devel@lists.sourceforge.net Replace BKL use with a spinlock. Also fix the control so that open doesn't return holding a lock. Signed-off-by: Jeff Dike -- arch/um/drivers/harddog_kern.c | 23 +++++++++++++++-------- 1 file changed, 15 insertions(+), 8 deletions(-) Index: linux-2.6.18-mm/arch/um/drivers/harddog_kern.c =================================================================== --- linux-2.6.18-mm.orig/arch/um/drivers/harddog_kern.c 2006-12-29 18:25:36.000000000 -0500 +++ linux-2.6.18-mm/arch/um/drivers/harddog_kern.c 2006-12-29 21:02:50.000000000 -0500 @@ -44,12 +44,13 @@ #include #include #include +#include #include #include "mconsole.h" MODULE_LICENSE("GPL"); -/* Locked by the BKL in harddog_open and harddog_release */ +static DEFINE_SPINLOCK(lock); static int timer_alive; static int harddog_in_fd = -1; static int harddog_out_fd = -1; @@ -62,12 +63,12 @@ extern int start_watchdog(int *in_fd_ret static int harddog_open(struct inode *inode, struct file *file) { - int err; + int err = -EBUSY; char *sock = NULL; - lock_kernel(); + spin_lock(&lock); if(timer_alive) - return -EBUSY; + goto err; #ifdef CONFIG_HARDDOG_NOWAYOUT __module_get(THIS_MODULE); #endif @@ -76,11 +77,15 @@ static int harddog_open(struct inode *in sock = mconsole_notify_socket(); #endif err = start_watchdog(&harddog_in_fd, &harddog_out_fd, sock); - if(err) return(err); + if(err) + goto err; timer_alive = 1; - unlock_kernel(); + spin_unlock(&lock); return nonseekable_open(inode, file); +err: + spin_unlock(&lock); + return err; } extern void stop_watchdog(int in_fd, int out_fd); @@ -90,14 +95,16 @@ static int harddog_release(struct inode /* * Shut off the timer. */ - lock_kernel(); + + spin_lock(&lock); stop_watchdog(harddog_in_fd, harddog_out_fd); harddog_in_fd = -1; harddog_out_fd = -1; timer_alive=0; - unlock_kernel(); + spin_unlock(&lock); + return 0; } ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys - and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ User-mode-linux-devel mailing list User-mode-linux-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel