From crosby@nag.cs.colorado.edu Sat Nov 14 10:20:58 PST 1998 Article: 96515 of alt.sysadmin.recovery From: crosby@nag.cs.colorado.edu (Matthew Crosby) Newsgroups: alt.sysadmin.recovery Subject: Bug of the month Date: 13 Nov 1998 19:49:12 GMT Organization: University of Colorado, Boulder Lines: 58 Approved: me Message-ID: <72i2fo$jq2$1@csnews.cs.colorado.edu> NNTP-Posting-Host: nag.cs.colorado.edu Path: news1.meer.net!news3.best.com!news2.best.com!news.voicenet.com!newshub.northeast.verio.net!cpk-news-hub1.bbnplanet.com!denver-news-feed1.bbnplanet.com!news.gtei.net!coop.net!csnews!nag.cs.colorado.edu!crosby Xref: news1.meer.net alt.sysadmin.recovery:96515 Ladies and gentlemen! Welcome to Bug of the Month! And here's your host, Matthew Crosby! Thank you, thank you. Todays bug goes once again to one of our best players, Transarc. Yep, AFS again! And on top of that, it also involves one of our longer running solid competitors, Sun! Well folks, as some of you may or may not know, AFS uses an internal structure called vnodes. It uses these to provide emulated inodes which are, I believe, the low bits of the vnode. And it allways returns the same device. So, it's theoretically possible that two files in AFS have the same inode and device, which violates Unix semantics. But the chances of that are 1 in 2 billion. Hardly worth worrying about. And nothing uses inodes directly ANYWAY, right? RIGHT? Well, folks heres where Sun comes in! Guess what uses the same inode as an indication that files are the same! Yep, you got it: ld.so But after all, how many files out there are really shared libraries! Not bloody many, eh? I'd say 1 in 1000 at most. Hey, the chance of ld.so ignoring a shared library because it has the same inode as another must be 1 in a trillion! But in fact, looks like it was more like a million to one. Cause it happened. Guess how long it took to find! One day? Two days? Yes, almost a whole week! And if we didn't[1] have solaris source, we'd still probably be pulling hair out. And that's tonights winner! Tune in next month for another exciting episode of....BUG OF THE MONTH [1] I can't really say "we" here, as it wasn't me who found this. I did look through the source, but missed that aspect of it. The person who DID find it gets a lot of free beers over THIS one. -- Matthew Crosby crosby@cs.colorado.edu Disclaimer: It was in another country, and besides, the wench is dead.