rm: -r option fails to remove unreadable directory

[jfinkels]

Environment: Ubuntu 20.04, main branch (git commit 00d1866), GNU coreutils v8.30

Steps to reproduce:

mkdir -m a-r -p a/unreadable
rm -rf a

What happens now: uutils rm terminates with an error message, removing neither a nor a/unreadable:

rm: cannot remove 'a': Permission denied

What I expected to happen: GNU rm terminates successfully and removes both directories.

Notes: this is causing a failure in GNU test file tests/rm/empty-inacc.sh.

[r3yc0n1c]

hi, i'd like to work on this

[cakebaker]

@r3yc0n1c sure, go ahead :)

[jfinkels]

I made a first draft in pull request #7299 but it's not as straightforward as it seems. My implementation passed all of our Rust tests, but it caused lots of failures in the GNU test cases. So I think there are lots of holes in our tests.

Also our implementation has a different code path for the verbose and not verbose cases. You can get a sense of the differences here:

$ ./target/debug/rm -vrf a
./target/debug/rm: recursing in 'a': IO error for operation on a/unreadable: Permission denied (os error 13)
./target/debug/rm: cannot remove 'a/unreadable': Directory not empty
./target/debug/rm: cannot remove 'a': Directory not empty

$ ./target/debug/rm -rf a
./target/debug/rm: cannot remove 'a': Permission denied

For comparison, here are the --verbose messages from GNU rm:

$ ../gnu/src/rm -vrf a
removed directory 'a/unreadable'
removed directory 'a'

So I think some things to do here would be

1. Use the failures in rm: correctly remove inaccessible but empty directory #7299 to create new test cases in Rust to improve our test coverage.
2. Unify the two code paths for --verbose and not --verbose, if possible.
3. Then allow deleting the unreadable directory in the test case originally reported.