Oops, I was confused when I wrote the initial Bug Description. The stat() function *does* follow symbolic links; it's lstat() that doesn't. So eglibc should, as it stands, also notice changes to /run/resolvconf/resolv.conf. I will revise the Description now.
** Description changed: Browsing the eglibc mailing list archives I notice[0] that the eglibc resolver has been enhanced[1] such that if /etc/resolv.conf's mtime changes then the client is asked to re-initialize the resolver state. I haven't tested the code, but if I understand the feature correctly it gives us an opportunity to eliminate from /etc/resolvconf/update.d/libc the code that restarts nscd. That would be a desirable simplification. Ditto for some other resolvconf update scripts. - We can't go ahead and eliminate the nscd-restart code yet for a simple - reason. The eglibc resolver monitors /etc/resolv.conf and thus watches - the mtime of the symlink, not the target, whereas of course resolvconf - modifies the target.[2] - - ret = stat (_PATH_RESCONF, &statbuf); - [...] - if ((ret == 0) && (last_mtime != statbuf.st_mtime)) { - last_mtime = statbuf.st_mtime; - atomicinc (__res_initstamp); - } - - The first question is, can we take advantage of this eglibc enhancement - in order to simplify resolvconf update scripts? Second question: do we - want to? - - If so, then the third question is, what's the best way to enhance the - new eglibc feature so that we can take advantage of it? Should the - eglibc code be changed so that, in addition to noticing a change in the - mtime of /etc/resolv.conf, it also notices a change in the mtime of the - target of /etc/resolv.conf if the latter is a symbolic link? + Can we take advantage of this eglibc enhancement in order to simplify + resolvconf update scripts? Do we want to? [0]http://www.eglibc.org/archives/patches/msg00977.html [1]http://patch-tracker.debian.org/patch/series/view/eglibc/2.11.3-4/any/submitted-resolv.conf-thread.diff - [2]Quoted code is at line 102 of resolv/res_libc.c ** Summary changed: - Enhance glibc to monitor mtime of resolv.conf + Eliminate nscd restart from update script? -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1110331 Title: Eliminate nscd restart from update script? To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/resolvconf/+bug/1110331/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs