From mboxrd@z Thu Jan 1 00:00:00 1970 Subject: Re: [PATCH 1/2] Massive code cleanup of sys_msync() From: Peter Zijlstra In-Reply-To: <4df4ef0c0801151126p5dfdbc13ga9862c995890c33c@mail.gmail.com> References: <12004129652397-git-send-email-salikhmetov@gmail.com> <12004129734126-git-send-email-salikhmetov@gmail.com> <20080115175705.GA21557@infradead.org> <4df4ef0c0801151102l4d72b6b5j702e21beb1ebe459@mail.gmail.com> <20080115111018.1e27a229.randy.dunlap@oracle.com> <4df4ef0c0801151126p5dfdbc13ga9862c995890c33c@mail.gmail.com> Content-Type: text/plain Date: Tue, 15 Jan 2008 20:28:48 +0100 Message-Id: <1200425328.26045.39.camel@twins> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Anton Salikhmetov Cc: Randy Dunlap , Christoph Hellwig , linux-mm@kvack.org, jakob@unthought.net, linux-kernel@vger.kernel.org, valdis.kletnieks@vt.edu, riel@redhat.com, ksm@42.dk, staubach@redhat.com, jesper.juhl@gmail.com, torvalds@linux-foundation.org, akpm@linux-foundation.org, protasnb@gmail.com, miklos@szeredi.hu List-ID: On Tue, 2008-01-15 at 22:26 +0300, Anton Salikhmetov wrote: > 2008/1/15, Randy Dunlap : > > On Tue, 15 Jan 2008 22:02:54 +0300 Anton Salikhmetov wrote: > > > > > 2008/1/15, Christoph Hellwig : > > > > On Tue, Jan 15, 2008 at 07:02:44PM +0300, Anton Salikhmetov wrote: > > > > > > > @@ -33,71 +34,65 @@ asmlinkage long sys_msync(unsigned long start, size_t len, int flags) > > > > > unsigned long end; > > > > > struct mm_struct *mm = current->mm; > > > > > struct vm_area_struct *vma; > > > > > - int unmapped_error = 0; > > > > > - int error = -EINVAL; > > > > > + int error = 0, unmapped_error = 0; > > > > > > > > > > if (flags & ~(MS_ASYNC | MS_INVALIDATE | MS_SYNC)) > > > > > - goto out; > > > > > + return -EINVAL; > > > > > if (start & ~PAGE_MASK) > > > > > - goto out; > > > > > + return -EINVAL; > > > > > > > > The goto out for a simple return style is used quite commonly in kernel > > > > code to have a single return statement which makes code maintaince, e.g. > > > > adding locks or allocations simpler. Not sure that getting rid of it > > > > makes a lot of sense. > > > > > > Sorry, I can't agree. That's what is written in the CodingStyle document: > > > > > > The goto statement comes in handy when a function exits from multiple > > > locations and some common work such as cleanup has to be done. > > > > CodingStyle does not try to cover Everything. Nor do we want it to. > > > > At any rate, there is a desire for functions to have a single point > > of return, regardless of the amount of cleanup to be done, so I agree > > with Christoph's comments. > > Should I replace "return -EINVAL;" statement with the following? > > { > error = -EINVAL; > goto out; > } Notice that error is already -EINVAL, so a simple goto should suffice. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org