On 3/17/22 6:14 PM, Luís Henriques wrote:
Xiubo Li <xiubli@xxxxxxxxxx> writes:
Hi Luis,
There has another issue you need to handle at the same time.
Currently only the empty directory could be enabled the file encryption, such as
for the following command:
$ fscrypt encrypt mydir/
But should we also make sure that the mydir/.snap/ is empty ?
Here the 'empty' is not totally empty, which allows it should allow long snap
names exist.
Make sense ?
Right, actually I had came across that question in the past but completely
forgot about it.
Right now we simply check the dir stats to ensure a directory is empty.
We could add an extra check in ceph_crypt_empty_dir() to ensure that there
are no snapshots _above_ that directory (i.e. that there are no
"mydir/.snap/_name_xxxxx").
Check this only in ceph_crypt_empty_dir() seems not enough, at least not
graceful.
Please see
https://github.com/google/fscrypt/blob/master/cmd/fscrypt/commands.go#L305.
The google/fscrypt will read that directory to check where it's empty or
not. So eventually we may need to fix it there. But for a workaround you
may could fix it in ceph_crypt_empty_dir() and ceph_ioctl() when setting
the key or policy ?
-- Xiubo
Unfortunately, I don't know enough of snapshots implementation details to
understand if it's a problem to consider a directory as being empty (in
the fscrypt context) when there are these '_name_xxx' directories. My
feeling is that this is not a problem but I really don't know.
Do you (or anyone) have any ideas/suggestions?
Cheers,
