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See http://www.infradead.org/rpr.html On Wed, Oct 28, 2026 at 01:20:24PM -0400, Jeff Layton wrote: > On Wed, 2026-10-28 at 08:54 -0700, Christoph Hellwig wrote: > > On Tue, Oct 27, 2026 at 09:58:50AM -0400, Jeff Layton wrote: > > > Ensure that the mtime and ctime apparently change, even when there are > > > multiple writes in quick succession. Since this is opt-in for in-kernel > > > filesystems and there is no way to test for this feature in userland, > > > limit it to just ext4, f2fs, btrfs, tmpfs and xfs for now. > > > > > > Signed-off-by: Jeff Layton > > > --- > > > I'd like to start testing this to make sure it doesn't break, but it's > > > not universally supported on all filesystems. Is an explicit allowlist > > > like this the right approach? > > > > Can we please expose the fact that multi-grain timestamp are supported > > from the kernel? This seems like it would be just one bit we'd need > > in sttx or something similar. > > I'd been resisting that, but maybe it's a good idea. I'll see what I > can come up with. We can probably just add a flag to stx_attributes? Yes, ever since STATX_ATTR_DAX/STATX_ATTR_WRITE_ATOMIC these don't seem to be tied to actual inode flags any more.