Am Mittwoch, 13. März 2019, 13:36:02 CET schrieb Miklos Szeredi: > I don't get it. Does fscrypt try to check permissions via > ->d_revalidate? Why is it not doing that via ->permission()? Please let me explain. Suppose we have a fscrypto directory /mnt and I *don't* have the key. When reading the directory contents of /mnt will return an encrypted filename. e.g. # ls /mnt +mcQ46ne5Y8U6JMV9Wdq2C As soon I load my key the real name is shown and I can read the file contents too. That's why fscrypt has ->d_revalidate(). It checks for the key, if the key is still not here -> stay with the old encrypted name. If the key is present -> reveal the real name. Same happens on the other direction if I unlink my key from the keyring. > > > > 2. Teach overlayfs to deal with a upper that has ->d_revalidate(). > > Given the complexity of overlayfs I'm not sure how feasible this is. > > But I'm no overlayfs expert, maybe I miss something. > > I don't think it would be too complex. But first I'd like to > understand exactly why fscrypt is (ab) using d_revalidate(). I hope my answer makes things more clear. Thanks, //richard
