From owner-cvs-src@FreeBSD.ORG Thu Nov 10 15:55:19 2005 Return-Path: X-Original-To: cvs-src@FreeBSD.org Delivered-To: cvs-src@FreeBSD.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 8C80216A41F; Thu, 10 Nov 2005 15:55:19 +0000 (GMT) (envelope-from scottl@samsco.org) Received: from pooker.samsco.org (pooker.samsco.org [168.103.85.57]) by mx1.FreeBSD.org (Postfix) with ESMTP id A1EF543D49; Thu, 10 Nov 2005 15:55:05 +0000 (GMT) (envelope-from scottl@samsco.org) Received: from [192.168.254.11] (junior.samsco.home [192.168.254.11]) (authenticated bits=0) by pooker.samsco.org (8.13.4/8.13.4) with ESMTP id jAAFt2Jb032200; Thu, 10 Nov 2005 08:55:02 -0700 (MST) (envelope-from scottl@samsco.org) Message-ID: <43736D60.5060703@samsco.org> Date: Thu, 10 Nov 2005 08:55:12 -0700 From: Scott Long User-Agent: Mozilla/5.0 (X11; U; FreeBSD i386; en-US; rv:1.7.8) Gecko/20050615 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Poul-Henning Kamp References: <6146.1131637127@critter.freebsd.dk> In-Reply-To: <6146.1131637127@critter.freebsd.dk> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit X-Spam-Status: No, score=-1.4 required=3.8 tests=ALL_TRUSTED autolearn=failed version=3.1.0 X-Spam-Checker-Version: SpamAssassin 3.1.0 (2005-09-13) on pooker.samsco.org Cc: Doug White , cvs-src@FreeBSD.org, src-committers@FreeBSD.org, Doug White , cvs-all@FreeBSD.org Subject: Re: cvs commit: src/sys/kern vfs_subr.c src/sys/fs/devfs devfs_vnops.c X-BeenThere: cvs-src@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: CVS commit messages for the src tree List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 10 Nov 2005 15:55:19 -0000 Poul-Henning Kamp wrote: > In message <43735F4C.7070307@samsco.org>, Scott Long writes: > >>Poul-Henning Kamp wrote: >> >>>In message <437351BB.6000103@samsco.org>, Scott Long writes: >>> >>> >>> >>>>Putting the cookie into the dirent means either changing the size of the >>>>dirent struct and breaking the userland ABI (almost as bad as changing >>>>the size of stat, but not quite), or making a 'kdirent' struct and then >>>>manually shifting and copying it to a dirent struct. >>> >>> >>>Not really that bad. >>> >>>My idea was to make a >>> struct kdirent { >>> struct dirent foo; >>> cookie stuff bar; >>> } >>> >>>Filesystems would call vfs_read_dirent() with a struct kdirent and >>>depending on the userland/kernel flag in the uio vfs_read_dirent() >>>would copy either the entire kdirent or only the userspace dirent. >>> >>> >>>>What I really think this is is a ploy by PHK to get someone motivated to >>>>fix it for him ;-) >>> >>>I'm generally in favour of people doing work so I don't have to but >>>in this particular case that was not the motivation :-) >>> >>>(At least you can't prove anything!) >>> >>>Poul-Henning >>> >> >>I still don't see how this is supposed to work. VOP_READDIR() doesn't >>return the dirent array to the caller, it's directly copied to the user >>buffer. > > > vfs_read_dirent() is called from the filesystem, and determines > what to copy where. > > If the copy is to kernel space, the kdirent will be used and NFS > gets its cookies. > > If the copy is to user space, the dirent will be used and the > ABI and API is unchanged. > Ok, so now you need to teach the consumers like NFS to de-interleave the cookies from the dirents, which isn't all that straight forward because the dirents are all various sizes. Not a hard problem to solve, but I don't see what the net gain is here. Scott