Post Syndicated from jake original https://lwn.net/Articles/1079407/

A number of problems related to negative directory entries (dentries) were
the topic of a filesystem-track session at
the 2026 Linux Storage,
Filesystem, Memory Management, and BPF Summit. Negative dentries are
used to indicate that a file of a given name does not exist in a directory;
it is an optimization that short-circuits the lookup of the file name when
the answer is already known.

Miklos Szeredi led a
session that discussed
some problems that come from having too many negative dentries for a
directory.