On Tue, Nov 22, 2022 at 11:58:33PM -0800, Christoph Hellwig wrote: > On Tue, Nov 22, 2022 at 03:21:17PM +0100, Lukas Czerner wrote: > > > That seems like a good idea for memory usage, but I think this might > > > also make the code much simpler, as that just requires fairly trivial > > > quota_read and quota_write methods in the shmem code instead of new > > > support for an in-memory quota file. > > > > You mean like the implementation in the v1 ? > > Having now found it: yes. > Jan, do you have any argument for this, since it was your suggestion? I also think that the implementation is much simpler with in-memory dquots because we will avoid all the hassle with creating and maintaining quota file in a proper format. It's not just reads and writes it's the entire machinery befind it in quota_v2.c and quota_tree.c. But it is true that even with only user modified dquots being non-reclaimable until unmount it could theoreticaly represent a substantial memory consumption. Although I do wonder if this problem is even real. How many user/group ids would you expect extremely heavy quota user would have the limits set for? 1k, 10k, million, or even more? Do you know? -Lukas