Date: Tue, 29 Nov 2005 04:59:09 -0800 From: Doug Barton <dougb@FreeBSD.org> To: freebsd-arch@freebsd.org, freebsd-ports@FreeBSD.org Subject: [Fwd: Adding /usr/local/etc/rc.d to the base rcorder] Message-ID: <438C509D.9070905@FreeBSD.org>
next in thread | raw e-mail | index | archive | help
I sent the following message to the -rc list this morning. I'm interested in any input that you might have as well. I'd prefer followups to the -rc list, but if you feel more comfortable responding to _one_ of the lists above, I'll follow that discussion as well. Thanks, Doug -------- Original Message -------- Subject: Adding /usr/local/etc/rc.d to the base rcorder Date: Tue, 29 Nov 2005 03:13:37 -0800 From: Doug Barton <dougb@FreeBSD.org> Organization: http://www.FreeBSD.org/ To: freebsd-rc@FreeBSD.org Howdy, The idea to incorporate the scripts in the local startup directories (currently defined as /usr/local/etc/rc.d /usr/X11R6/etc/rc.d, or substitute whatever your PREFIX/LOCALBASE/X11BASE is), into the overall rcorder that the scripts in /etc/rc.d follow has been around basically since the new rc.d framework was introduced, but has been very difficult to implement. A thread on the freebsd-rc list back in June discussed the ramifications of this change, and how it might possibly be implemented safely. Since then, I've put together a set of patches that implement one approach to this change. Now that 6.0-RELEASE is done, I'd like to move fairly quickly in implementing this in HEAD, and once the bogons are shaken out, I'd like to MFC it to RELENG_6 prior to 6.1-RELEASE. I want to point out several things at the outset. This is _one_ possible approach to this problem. One that I believe will work well, and minimizes the pain of the transition. However, I am not necessarily tied into every detail of my patch, or even the approach generally. However, we need to move forward on this, and without compelling reasons to do things differently, I am confident that this approach will work. 1. In order for this to work, we need to first get the disks mounted. (Thanks to Brooks for this, and other important insights). Therefore I'm proposing that we split the rcorder function into two parts, one "early" stage that takes care of everything up to mountcritremote; then redo rcorder, skipping the scripts that were done in the early stage, and incorporating the scripts in /usr/local/etc/rc.d, etc. This is not a "perfect" approach, as theoretically some cases where a local package might want to insert itself into rcorder before mountcritremote, however given the various tradeoffs we have to make (for example, diskless booting), this is at least a reasonable place to start. Compare http://people.freebsd.org/~dougb/rcorder.all and http://people.freebsd.org/~dougb/rcorder.early to see how the ordering as it exists in HEAD at the moment would be affected. Of 127 scripts, 52 would be in the early stage. (/etc/rc.d/tmp is being forced into the early stage by my patch in order to avoid non-deterministic behavior when local scripts are added to rcorder. This could just as easily be forced into the late stage.) My method for implementing the distinction between the early boot stage and the later is derived from an idea suggested by J.R. Oldroyd. It stops processing in the early stage once mountcritremote is done. The "late" stage first finds scripts in the local directories, then runs rcorder again over both lists. It starts processing after mountcritremote is reached. 2. The next aspect of this plan is how to manage the transition for the ports. There are two phases to this. First, adding code to /etc/rc (and rc.subr) to pick up those scripts in local_startup that are ready to be added to rcorder. This is done by grep'ing for '^# PROVIDE:' in the script. This method is not entirely foolproof, as for example the cups.sh startup script is (from our perspective) an "old style" script, however it contains the PROVIDE line for NetBSD's purposes. Thus, some care will have to be taken during the transition period to avoid problems. By my count, there are roughly 640 ports that install some sort of startup script. Of these, roughly 345 have transitioned to the new style of rc.d scripts (based on the presence of USE_RCORDER/USE_RC_SUBR in the Makefile). Thus, there are roughly 300 ports with scripts that would _potentially_ have problems. Of these, I'm confident that the vast majority would work without modification, as the number of possibly fatal error conditions are very small. The situation with cups.sh above is the only one I've encountered, but there may be others. There are two more potential problems with the new style scripts that are already in the ports tree. First, there are probably some scripts that have errors in them that will not be exposed until they are run within the rcorder context. The other problems that are almost sure to arise are scripts whose ordering needs to be adjusted (via REQUIRE/BEFORE, etc.). These things will need to happen in order for the transition to be successful in any case, so although it is sure to be a non-zero amount of work, it's work that will have to be done regardless of what method is chosen to incorporate the local_startup scripts into rcorder. The other part of this transition is to modify the localpkg script. This is done using some ideas and code from J.R. Oldroyd. Brooks, and myself. First we sort out the scripts that start with a number (like 000.foo.sh) and run them in numerical order, as a lot of work has gone into this style of ordering already. Then we run the scripts that start with a letter. The original idea here was to use rcorder in localpkg, however in my testing I found that it's simpler to just run the new style scripts in the base rcorder, and run everything else in localpkg. Therefore, the function that searches for these scripts eliminates any that use the new rc.d style first. These changes dramatically simplify the localpkg script. 3. The last part of this proposal is to apply the same changes to how we pick up local scripts in rc to the shutdown process, both in rc.shutdown and in localpkg. My patch to implement all this is at http://people.freebsd.org/~dougb/local-rcorder.diff. Comments are welcome. Regards, Doug -- This .signature sanitized for your protection -- This .signature sanitized for your protection
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?438C509D.9070905>