On Fri, 29 Aug 2025 at 17:39, Darrick J. Wong <djwong@xxxxxxxxxx> wrote: > IMMUTABLE | APPEND seem to be captured in KSTAT_ATTR_VFS_FLAGS, so maybe > that just needs to include the last three, and then we can use it to > clear those bits from the fuse server's reply. Hmm. Fuse kernel module passes IMMUTABLE, APPEND and DAX through the fileattr interfaces. I.e. it doesn't query the respective VFS flags not does it try to set them. For IMMUTABLE and APPEND I can imagine the server being able to handle these mostly (i.e. reject ops should be rejected). It would be nice if the VFS was also aware. I wonder if we can fix this at this point. As for DAX, I don't see how the current behavior makes any sense, but again not seeing clearly what the best solution is. Currently fuse doesn't support DAX in the traditional sense, but does have DAX functionality in virtiofs and in will in famfs. Is this flag useful in that case? I also fell that all unknown flags should also be masked off, but maybe that's too paranoid. Thanks, Miklos
