No idea if this is representative, but apparently 15K lines of test code were added just for id mapped mounts (before id mapped mounts was merged to mainline).

No idea if this is representative, but apparently 15K lines of test code were added just for id mapped mounts (before id mapped mounts was merged to mainline). > Brauner added that there are 15K lines of code in tests, already upstream in fstests, for ID-mapped mounts that aim to test the feature in all possible combinations. That includes things like access-control lists (ACLs), Linux capabilities, setuid and setgid execution, and so on. Every time a bug or regression is found, a new test is added to the suite. https://lwn.net/Articles/896255/ https://lwn.net/Articles/896255/ (just happened to read this LWN article immediately before reading your comment)