On Wed, Sep 11, 2024 at 8:04 PM Patrick Donnelly <pdonnell@xxxxxxxxxx> wrote: > CephFS has many components that are cooperatively maintained by the > MDS **and** the clients; i.e. the clients are trusted to follow the > protocols and restrictions in the file system. For example, > capabilities grant a client read/write permissions on an inode but a > client could easily just open any file and write to it at will. There > is no barrier preventing that misbehavior. To me, that sounds like you confirm my assumption on how Ceph works - both file permissions and quotas. As a superuser (CAP_DAC_OVERRIDE), I can write arbitrary files, and just as well CAP_SYS_RESOURCE should allow me to exceed quotas - that's how both capabilities are documented. > Having root on a client does not extend to arbitrary superuser > permissions on the distributed file system. Down that path lies chaos > and inconsistency. Fine for me - I'll keep my patch in our kernel fork (because we need the feature), together with the other Ceph patches that were rejected. Max
