On Tue, Feb 18 2025, Miklos Szeredi wrote: > On Tue, 18 Feb 2025 at 11:04, Luis Henriques <luis@xxxxxxxxxx> wrote: > >> The problem I'm trying to solve is that, if a filesystem wants to ask the >> kernel to get rid of all inodes, it has to request the kernel to forget >> each one, individually. The specific filesystem I'm looking at is CVMFS, >> which is a read-only filesystem that needs to be able to update the full >> set of filesystem objects when a new generation snapshot becomes >> available. > > Yeah, we talked about this use case. As I remember there was a > proposal to set an epoch, marking all objects for "revalidate needed", > which I think is a better solution to the CVMFS problem, than just > getting rid of unused objects. OK, so I think I'm missing some context here. And, obviously, I also miss some more knowledge on the filesystem itself. But, if I understand it correctly, the concept of 'inode' in CVMFS is very loose: when a new snapshot generation is available (you mentioned 'epoch', which is, I guess, the same thing) the inodes are all renewed -- the inode numbers aren't kept between generations/epochs. Do you have any links for such discussions, or any details on how this proposal is being implemented? This would probably be done mostly in user-space I guess, but it would still need a way to get rid of the unused inodes from old snapshots, right? (inodes from old snapshots still in use would obvious be kept aroud). Cheers, -- Luís
