From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753485AbbLVNFY (ORCPT ); Tue, 22 Dec 2015 08:05:24 -0500 Received: from mail-lb0-f195.google.com ([209.85.217.195]:36362 "EHLO mail-lb0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752711AbbLVNFW (ORCPT ); Tue, 22 Dec 2015 08:05:22 -0500 MIME-Version: 1.0 In-Reply-To: <20151221234443.GA11245@kroah.com> References: <20151209170813.GA12216@codebox> <20151221234443.GA11245@kroah.com> Date: Tue, 22 Dec 2015 18:35:21 +0530 Message-ID: Subject: Re: [PATCH] staging: lustre/lustre/libcfs: Fix type mismatch reported by sparse From: Niranjan Dighe To: Greg Kroah-Hartman Cc: Oleg Drokin , Andreas Dilger , Dmitry Eremin , James Simmons , Mike Rapoport , Patrick Boettcher , Matthew Tyler , devel@driverdev.osuosl.org, linux-kernel@vger.kernel.org, lustre-devel@lists.lustre.org Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Dec 22, 2015 at 5:14 AM, Greg Kroah-Hartman wrote: > On Wed, Dec 09, 2015 at 10:38:13PM +0530, Niranjan Dighe wrote: >> The third argument to function kportal_memhog_alloc is expected to >> be gfp_t whereas the actual argument was unsigned int. Fix this by >> explicitly typecasting to gfp_t >> >> Signed-off-by: Niranjan Dighe >> --- >> drivers/staging/lustre/lustre/libcfs/module.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/drivers/staging/lustre/lustre/libcfs/module.c b/drivers/staging/lustre/lustre/libcfs/module.c >> index 96d9d46..9c79f6e 100644 >> --- a/drivers/staging/lustre/lustre/libcfs/module.c >> +++ b/drivers/staging/lustre/lustre/libcfs/module.c >> @@ -268,7 +268,7 @@ static int libcfs_ioctl_int(struct cfs_psdev_file *pfile, unsigned long cmd, >> /* XXX The ioc_flags is not GFP flags now, need to be fixed */ >> err = kportal_memhog_alloc(pfile->private_data, >> data->ioc_count, >> - data->ioc_flags); >> + (__force gfp_t)data->ioc_flags); > > No, please fix the type to be correct properly, like the comment says > needs to be done. > > thanks, > > greg k-h Hello Greg, I could see that the ioc_flags member of the struct libcfs_ioctl_data is used as gfp_t only in the case of the ioctl IOC_LIBCFS_MEMHOG. I can think of following ways to correct it - 1. Create a union that has 2 different types encapsulated, something like this - union { __u32 ioc_flags; gfp_t alloc_flags; }flags; Because, the ioc_flags seems to be used in different contexts at different places throughout the drivers/staging/lustre directory. 2. Is it OK to hardcode the appropriate gfp_t flags for the IOC_LIBCFS_MEMHOG, as the userspace seems to be taking the decision about the page allocation zone/strategy, is this what is intended? Regards, Niranjan Dighe