From owner-svn-src-head@freebsd.org Wed Aug 2 12:29:00 2017 Return-Path: Delivered-To: svn-src-head@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 65BB1DCFA76; Wed, 2 Aug 2017 12:29:00 +0000 (UTC) (envelope-from hps@selasky.org) Received: from mail.turbocat.net (turbocat.net [88.99.82.50]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 2AA8E365A; Wed, 2 Aug 2017 12:28:59 +0000 (UTC) (envelope-from hps@selasky.org) Received: from hps2016.home.selasky.org (unknown [62.141.129.119]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.turbocat.net (Postfix) with ESMTPSA id 43164260179; Wed, 2 Aug 2017 14:28:57 +0200 (CEST) Subject: Re: svn commit: r321920 - head/sys/sys To: Konstantin Belousov Cc: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org References: <201708021014.v72AEHEk061037@repo.freebsd.org> <7b1d274f-a531-f788-742a-a8375fe76763@selasky.org> <20170802110607.GC1700@kib.kiev.ua> <760e0077-499e-fffb-a86b-979e410b35e1@selasky.org> <20170802111752.GD1700@kib.kiev.ua> <912d42d0-ea07-82ec-e754-f6b6d2b4cc94@selasky.org> <20170802114303.GE1700@kib.kiev.ua> From: Hans Petter Selasky Message-ID: Date: Wed, 2 Aug 2017 14:26:46 +0200 User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:52.0) Gecko/20100101 Thunderbird/52.2.0 MIME-Version: 1.0 In-Reply-To: <20170802114303.GE1700@kib.kiev.ua> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 02 Aug 2017 12:29:00 -0000 On 08/02/17 13:43, Konstantin Belousov wrote: > On Wed, Aug 02, 2017 at 01:27:50PM +0200, Hans Petter Selasky wrote: >> On 08/02/17 13:17, Konstantin Belousov wrote: >>> But y must be dev_t. >> >> Sure, but "struct cdev" 's si_drv0 is only "int" . How can it contain >> dev_t ? > > Why should it contain dev_t ? > Linux KPI abused that field it seems. > Hi, The LinuxKPI uses si_drv0 to contain the output from mkdev(). Before the mkdev() function would fit into 32-bits. Now it is 64-bits. I can fix the LinuxKPI bits this time. We can store this information in si_drv1->xxx instead of using si_drv0 and dev2unit(). > Lets change the focus of the discussion. > You cited the > struct linux_cdev * > linux_find_cdev(const char *name, unsigned major, unsigned minor) > function which finds cdev (or some mockup of the native cdev) by major/minor. > Where does these major/minor numbers come from ? The major number is in the range 0..255 and decides the type of device. The minor number is in the range 0..255 aswell typically and defines a unique number for each LinuxKPI created character device. > I mean that if they are contructed as major(struct stat.st_rdev) and > minor(struct stat.st_rdev), then even the original code looks wrong > without the ino64 addition. Since devfs reports the internal inode > number into st_rdev, which formally is not accessible outside the devfs > filesystem. So should the code for linux_find_cdev() changed to match > cdevs against inode number ? These numbers do not come from any user-visible files. They are just used internally in the kernel to pass around information. > cdp_inode is serially generated so on real machine it is really a small > number for any /dev node. You can watch that by ls -l /dev. Sure. > While at it, I found that contrib/mknod/pack_dev.c, still has hardcoded references to the old makedev(): > contrib/mknod/pack_dev.c:#define makedev_freebsd(x,y) ((portdev_t)((((x) << 8) & 0x0000ff00) | \ > contrib/mknod/pack_dev.c: dev = makedev_freebsd(numbers[0], numbers[1]); Same goes for: contrib/libarchive/libarchive/archive_pack_dev.c And if you "grep -r makedev /usr/src" you'll find more. --HPS