On Tue, Mar 22, 2022, at 3:19 PM, James Bottomley wrote: > > Well, firstly what is the exact problem? People maliciously looking up > nonexistent files Maybe most people have seen it, but for those who haven't: https://bugzilla.redhat.com/show_bug.cgi?id=1571183 was definitely one of those things that just makes one recoil in horror. TL;DR NSS used to have code that tried to detect "is this a network filesystem" by timing `stat()` calls to nonexistent paths, and this massively boated the negative dentry cache and caused all sorts of performance problems. It was particularly confusing because this would just happen as a side effect of e.g. executing `curl https://somewebsite`. That code wasn't *intentionally* malicious but...
