From sacadmin Wed Aug 8 14:51:23 2007 Received: from zion.eng.sun.com (zion [129.146.17.75]) by sac.sfbay.sun.com (8.13.8+Sun/8.13.8) with ESMTP id l78LpN7u029628 for ; Wed, 8 Aug 2007 14:51:23 -0700 (PDT) Received: from zion.eng.sun.com (localhost [127.0.0.1]) by zion.eng.sun.com (8.14.1+Sun/8.14.1) with ESMTP id l78Ln3WB002933; Wed, 8 Aug 2007 14:49:03 -0700 (PDT) Received: (from ahl@localhost) by zion.eng.sun.com (8.14.1+Sun/8.14.1/Submit) id l78Ln3fP002932; Wed, 8 Aug 2007 14:49:03 -0700 (PDT) Date: Wed, 8 Aug 2007 14:49:02 -0700 From: Adam Leventhal To: Adam Leventhal Cc: PSARC-record@sac.sfbay.sun.com, Eric.Schrock@Sun.COM, Adam Leventhal Subject: Re: /etc/{init,utmp}pipe to /var/run [PSARC/2007/455 FastTrack timeout 08/15/2007] Message-ID: <20070808214902.GB4529@eng.sun.com> References: <200708082109.l78L9AVZ007682@zion.eng.sun.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200708082109.l78L9AVZ007682@zion.eng.sun.com> User-Agent: Mutt/1.5.10i Status: RO Content-Length: 3522 This case would normally qualify for self review, however since the interfaces being changed predate any ARC classification, it is being filed as closed approved automatic to document the interfaces. The release binding is Minor. Adam ---8<--- A. DESCRIPTION Solaris currently delivers two files into /etc that are runtime FIFOs for daemons, /etc/initpipe and /etc/utmppipe. These files should be installed into /var/run in accordance with current practice. This case does not seek to change the location of any other runtime files in /etc. B. DETAILS The /etc/utmppipe file is managed by svc:/system/utmp:default, which has the dependency chain: milestone/sysconfig | V milestone/single-user | V filesystem/minimal This dependency is necessary because the daemon is responsible for managing files in /var/adm. As filesystem/minimal is responsible for mounting /var, it is permissible to use files in that directory -- there is no reason for this file to be in /etc. The /etc/initpipe file is managed by init, and therefore could theoretically be usable before filesystem/minimal is online, as early as filesystem/usr. However, svc.startd is responsible for poking init to indicate that the pipe is now writable, and it does not do this until after filesystem/minimal has come online, as part of special_fsminimal_post_online(). The pipe is used only when updating /var/adm/utmpx (so init can keep track of "godchildren"), so there is no reason for this functionality to be available before /var is mounted writable. These files will be renamed: /etc/initpipe -> /var/run/initpipe /etc/utmppipe -> /var/run/utmppipe As these are runtime files only, there is no need to migrate old files on upgrade. C. EXTERNAL USE Since these interfaces predate any formal ARC classification, a search was done to find any external consumers of these files. Within Sun, the following references were found: - WBEM includes a module for provisioning a diskless client's root filesystem configuration. Among other various broken assumptions (the module hasn't been updated since 2001), the smossclntmod() function does a mknod() of /etc/initpipe. This is entirely unnecessary, as the file will be created automatically if it isn't there. Creating this file is benign, since it simply won't be used. At a future point the WBEM code can be removed, but its removal is not a requirement for this case. Outside of Sun, a search through koders.com and Google code search found only the following non-Solaris references: - /etc/initpipe is used by a single script in the ISG Toolchest (http://isg.ee.ethz.ch/tools/isgtc/) as a "key file" for (as far as I can tell) identifying a Solaris host in a diskless client setting. - Tripwire identifies both /etc/initpipe and /etc/utmppipe as system FIFOs and therefore exceptions from monitoring. Various other home brewed tripwire-like programs also encode /etc/utmppipe as an exception. These applications are unaffected by the path change, as the file simply will be missing, and they already understand that files under /var/run are subject to modification while the system is running. Given these limited use cases, it is safe to qualify these as consolidation private interfaces. D. INTERFACES This case updates the following files: /var/run/initpipe Consolidation Private /var/run/utmppipe Consolidation Private -- Adam Leventhal, Solaris Kernel Development http://blogs.sun.com/ahl