cmd/upspinfs: limit the size of the cache

upspinfs will cache all currently open files. However, it is
useful to also cache closed ones in the hopes that they will
be used again. Upspinfs was not cleaning these up until a
restart resulting in a lot of disk usage.

This CL keeps an LRU of closed files, removing them either
when the LRU overflows or the storage exceeds the value specified
by the cachesize option.

So that cachesize approximates the total storage used by both
upspinfs and cacheserver, when a cacheserver is specified
by the config, we actually reduce the maximum storage used
by upspinfs to cachesize/10.

Change-Id: I91b23537ee990cc7286039c11c886372297be121
Reviewed-by: Rob Pike <>
8 files changed
tree: 33cdb86cd134a805bd32bf47c3f98bb9a602addd
  1. .travis.yml
  6. Gopkg.lock
  7. Gopkg.toml
  10. README.binary
  12. access/
  13. bind/
  14. cache/
  15. client/
  16. cloud/
  17. cmd/
  18. config/
  19. dir/
  20. doc/
  21. errors/
  22. factotum/
  23. flags/
  24. key/
  25. log/
  26. metric/
  27. pack/
  28. path/
  29. rpc/
  30. serverutil/
  31. shutdown/
  32. store/
  33. subcmd/
  34. test/
  35. transports/
  36. upbox/
  37. upspin/
  38. user/
  39. valid/
  40. vendor/
  41. version/




About the project

Upspin is an experimental project to build a framework for naming and sharing files and other data securely, uniformly, and globally: a global name system of sorts.

It is not a file system, but a set of protocols and reference implementations that can be used to join things like file systems and other storage services to the name space.

Performance is not a primary goal. Uniformity and security are.

Upspin is not an official Google product.


Upspin has rough edges, and is not yet suitable for non-technical users.

Build Status


The code repository lives at and is mirrored to GitHub.

Note that the Upspin project does not use GitHub pull requests, and that we use the issue tracker for bug reports and proposals only.

See the Contribution Guidelines for more information on contributing to the project.

Reporting issues

Please report issues through our issue tracker.


All Upspin users should subscribe to the Upspin Announcements mailing list to receive critical information about the project.

Use the Upspin mailing list for discussion about Upspin use and development.

Code of Conduct

Please note that this project is released with a Contributor Code of Conduct. By participating in this project you agree to abide by its terms.

The Upspin mascot is Copyright 2017 Renee French. All Rights Reserved.