Question to Attribute "ceph.dir.rctime" in Extended Attribute for Directory Inodes of CephFS

[juergenc]

Hello,

nine year old thread puzzles me a bit and I think (hope so) this is no longer the case. What Wido den Hollander says is more in my words:

The ceph.dir.rctime attribute with a high resolution Unix Epoch timestamp is updated as far as something has changed in the file system below a directory:

/dirA/
      dirB/
           dirC/    —-->    # ceph.dir.rctime updated
                …
                some.file   # added/updated/deleted
                …

But this doesn't make sense in my eyes. If you want to avoid to traverse over the entire directory tree starting with top level directory /A o the ceph.dir.rctime" attribute with the newer value of the timestamp must be propagated in the extended attributes of the upper in all (ideally) directory levels /A and /A/B avoiding more traversals in sub-directories where nothing has changed, e.g:

  /dirA/            —-->    # ceph.dir.rctime updated
      dirB/         —-->    # ceph.dir.rctime updated
           dirC/    —-->    # ceph.dir.rctime updated
                …
                  some.file   # added/updated/deleted
                …
      dirD/         —-->    # ceph.dir.rctime unchanged; don't go here

      dirE/    —-->    # ceph.dir.rctime updated
            dir_e1/     —-->  # ceph.dir.rctime unchanged; don't go here
            dir_e2/     —-->  # ceph.dir.rctime updated
                      a/         —-->  # ceph.dir.rctime unchanged; don't go here
                      b/         —-->  # ceph.dir.rctime changed
                            ...
                            some.file        added/updated/deleted

Is it like this?

Thank you!
J