Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756574AbbKRR53 (ORCPT ); Wed, 18 Nov 2015 12:57:29 -0500 Received: from smtp113.iad3a.emailsrvr.com ([173.203.187.113]:56450 "EHLO smtp113.iad3a.emailsrvr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933331AbbKRRz3 (ORCPT ); Wed, 18 Nov 2015 12:55:29 -0500 X-Auth-ID: abbotti@mev.co.uk X-Sender-Id: abbotti@mev.co.uk From: Ian Abbott To: driverdev-devel@linuxdriverproject.org Cc: Greg Kroah-Hartman , Ian Abbott , H Hartley Sweeten , linux-kernel@vger.kernel.org Subject: [PATCH 6/8] staging: comedi: return error on "write" if no command set up Date: Wed, 18 Nov 2015 17:55:09 +0000 Message-Id: <1447869311-21955-7-git-send-email-abbotti@mev.co.uk> X-Mailer: git-send-email 2.6.2 In-Reply-To: <1447869311-21955-1-git-send-email-abbotti@mev.co.uk> References: <1447869311-21955-1-git-send-email-abbotti@mev.co.uk> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1649 Lines: 52 The "write" file operation handler, `comedi_write()` returns an error for pretty much any condition that prevents a "write" going ahead. One of the conditions that prevents a "write" going ahead is that no asynchronous command has been set up, but that currently results in a return value of 0 (unless COMEDI instructions are being processed or an asynchronous command has been set up by a different file object). Change it to return `-EINVAL` in this case. Signed-off-by: Ian Abbott --- drivers/staging/comedi/comedi_fops.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/drivers/staging/comedi/comedi_fops.c b/drivers/staging/comedi/comedi_fops.c index 4dd4289..2a2b5a0 100644 --- a/drivers/staging/comedi/comedi_fops.c +++ b/drivers/staging/comedi/comedi_fops.c @@ -2331,9 +2331,12 @@ static ssize_t comedi_write(struct file *file, const char __user *buf, } async = s->async; - - if (!s->busy || !nbytes) + if (!nbytes) + goto out; + if (!s->busy) { + retval = -EINVAL; goto out; + } if (s->busy != file) { retval = -EACCES; goto out; @@ -2373,8 +2376,10 @@ static ssize_t comedi_write(struct file *file, const char __user *buf, retval = -ERESTARTSYS; break; } - if (!s->busy) + if (!s->busy) { + retval = -EINVAL; break; + } if (s->busy != file) { retval = -EACCES; break; -- 2.6.2 -- 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/