On Sat, May 22, 2021 at 12:41:32AM +0000, Daniel Rosenberg wrote:

commit 471fbbea7ff7 ("ext4: handle casefolding with encryption") is
missing a few checks for the encryption key which are needed to
support deleting enrypted casefolded files when the key is not
present.

Note from ebiggers:
(These checks for the encryption key are still racy since they happen
too late, but apparently they worked well enough...)

This bug made it impossible to delete encrypted+casefolded directories
without the encryption key, due to errors like:

    W         : EXT4-fs warning (device vdc): __ext4fs_dirhash:270: inode #49202: comm Binder:378_4: Siphash requires key

Repro steps in kvm-xfstests test appliance:
      mkfs.ext4 -F -E encoding=utf8 -O encrypt /dev/vdc
      mount /vdc
      mkdir /vdc/dir
      chattr +F /vdc/dir
      keyid=$(head -c 64 /dev/zero | xfs_io -c add_enckey /vdc | awk '{print $NF}')
      xfs_io -c "set_encpolicy $keyid" /vdc/dir
      for i in `seq 1 100`; do
          mkdir /vdc/dir/$i
      done
      xfs_io -c "rm_enckey $keyid" /vdc
      rm -rf /vdc/dir # fails with the bug

Fixes: 471fbbea7ff7 ("ext4: handle casefolding with encryption")
Signed-off-by: Daniel Rosenberg <redacted>

Applied, thanks.

					- Ted