On Mon, 12 Apr 2021 17:08:26 +0200 Miklos Szeredi <miklos@xxxxxxxxxx> wrote: > On Mon, Apr 12, 2021 at 4:59 PM Vivek Goyal <vgoyal@xxxxxxxxxx> wrote: > > > > Hi Miklos, > > > > Robert Krawitz drew attention to the fact that fuse does not seem to > > have a ->sync_fs implementation. That probably means that in case of > > virtiofs, upon sync()/syncfs(), host cache will not be written back > > to disk. And that's not something people expect. > > > > I read somewhere that fuse did not implement ->sync_fs because file > > server might not be trusted and it could block sync(). > > > > In case of virtiofs, file server is trusted entity (w.r.t guest kernel), > > so it probably should be ok to implement ->sync_fs atleast for virtiofs? > > Yes, that looks like a good idea. > I've started looking into this. First observation is that implementing ->sync_fs() is file server agnostic, so if we want this to only be used by a trusted file server, we need to introduce such a notion in FUSE. Not sure where though... in struct fuse_fs_context maybe ? > Thanks, > Miklos
