On Wed, Sep 11, 2024 at 11:23 AM Max Kellermann <max.kellermann@xxxxxxxxx> wrote: > > On Wed, Sep 11, 2024 at 5:03 PM Patrick Donnelly <pdonnell@xxxxxxxxxx> wrote: > > Just because the client cooperatively maintains the quota limits with > > the MDS does not mean it can override the quota in a distributed > > system. > > I thought Ceph's quotas were implemented only on the client, just like > file permissions. Is that not correct? Is there an additional > server-side quota check? In my tests, I never saw one; it looked like > I could write arbitrary amounts of data with my patch. 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. Having root on a client does not extend to arbitrary superuser permissions on the distributed file system. Down that path lies chaos and inconsistency. -- Patrick Donnelly, Ph.D. He / Him / His Red Hat Partner Engineer IBM, Inc. GPG: 19F28A586F808C2402351B93C3301A3E258DD79D
