From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jens Axboe Subject: Re: For the condition "file->f_mode", when it failed, it should return EACCES rather than EBADF. Date: Tue, 5 Feb 2013 14:21:17 +0100 Message-ID: <20130205132117.GU15092@kernel.dk> References: <2013020410070150879010@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-kernel , linux-fsdevel To: majianpeng Return-path: Content-Disposition: inline In-Reply-To: <2013020410070150879010@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org On Sun, Feb 03 2013, majianpeng wrote: > Hi all, > When I wanted to do discard operations,but i set the openflag was O_RDONLY,it returned a EBADF rather than EACCES or EPERM. > I searched the code and found: > >case BLKDISCARD: > >case BLKSECDISCARD: { > > uint64_t range[2]; > > > if (!(mode & FMODE_WRITE)) > > return -EBADF; > Initial i thought there was error.But i searched all code of kernel and found some places like this. > > The description of EBADF is "Bad file numbe". There are some places where returned EBADF like, > >if (!f.file) > > return -EBADF; > > So i think for checking file->f_mode when failed, it should return EACCESS. But that would break the ABI at this point. I agree with you, though, EBADF is not the right error for this case. -- Jens Axboe