Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751658AbaABMIK (ORCPT ); Thu, 2 Jan 2014 07:08:10 -0500 Received: from moutng.kundenserver.de ([212.227.17.9]:60171 "EHLO moutng.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751061AbaABMIG (ORCPT ); Thu, 2 Jan 2014 07:08:06 -0500 From: Arnd Bergmann To: linux-kernel@vger.kernel.org Cc: Arnd Bergmann , Geert Uytterhoeven , "James E.J. Bottomley" , linux-scsi@vger.kernel.org Subject: [PATCH, RFC 02/30] scsi: atari_scsi: fix sleep_on race Date: Thu, 2 Jan 2014 13:07:26 +0100 Message-Id: <1388664474-1710039-3-git-send-email-arnd@arndb.de> X-Mailer: git-send-email 1.8.3.2 In-Reply-To: <1388664474-1710039-1-git-send-email-arnd@arndb.de> References: <1388664474-1710039-1-git-send-email-arnd@arndb.de> X-Provags-ID: V02:K0:YrGLOyTyTECINH32Ppmxw1ZGyczAygtn05HSgG42qqR DJH5+GdNQBVCW2EcwSJXOO9SwKWHSIJhegl3G7DPO/cLRwHsob YSkGhQCmZq61kljbsmuG2pz2+Jr3R3gqiBGptsbnbq/SH1BHvC zrkanHb3hj4N4H2KkY2T4LVk52oWhPE7wKbWNK5YtX3515Qedz m8EJxCiHE56GQuQDIWezW5EmZEEG/eIJ92g3pqavJNOghQQyd8 rf9Lo17pUADk5CAKPgTXxeWru9Qsmkpxfs8E/GHpLT8b0bMmrE 9XM97SIBzpOs0UPQs2ppC7fPpc7IC2cL9RdMbOFW3v0jxZEFA2 TpTtwGRlYzD7zWhsrt3t37hYFlLAWlrRzgt6gyQoB Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2007 Lines: 60 sleep_on is known broken and going away. The atari_scsi driver is one of two remaining users in the falcon_get_lock() function, which is a rather crazy piece of code. This does not attempt to fix the driver's locking scheme in general, but at least prevents falcon_get_lock from going to sleep when no other thread holds the same lock or tries to get it, and we no longer schedule with irqs disabled. Signed-off-by: Arnd Bergmann Cc: Geert Uytterhoeven Cc: James E.J. Bottomley Cc: linux-scsi@vger.kernel.org --- drivers/scsi/atari_scsi.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/drivers/scsi/atari_scsi.c b/drivers/scsi/atari_scsi.c index a3e6c8a..b55a58a 100644 --- a/drivers/scsi/atari_scsi.c +++ b/drivers/scsi/atari_scsi.c @@ -90,6 +90,7 @@ #include #include #include +#include #include #include @@ -549,8 +550,10 @@ static void falcon_get_lock(void) local_irq_save(flags); - while (!in_irq() && falcon_got_lock && stdma_others_waiting()) - sleep_on(&falcon_fairness_wait); + wait_event_cmd(falcon_fairness_wait, + !in_irq() && falcon_got_lock && stdma_others_waiting(), + local_irq_restore(flags), + local_irq_save(flags)); while (!falcon_got_lock) { if (in_irq()) @@ -562,7 +565,10 @@ static void falcon_get_lock(void) falcon_trying_lock = 0; wake_up(&falcon_try_wait); } else { - sleep_on(&falcon_try_wait); + wait_event_cmd(falcon_try_wait, + !falcon_got_lock && !falcon_trying_lock, + local_irq_restore(flags), + local_irq_save(flags)); } } -- 1.8.3.2 -- 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/