On Mon, Feb 11, 2019 at 10:35:04AM +0200, Nikolay Borisov wrote: > Rather than hijacking the existing defines let's just define new bits, > with more descriptive names. Instead of using yet more (currently at 18) > bits for the new flags, use the fact those flags will be specific to > the device allocation tree so define them using existing EXTENT_* flags. > > Signed-off-by: Nikolay Borisov <nbori...@suse.com> > --- > fs/btrfs/extent_io.h | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h > index d7beb2b3bc7d..af7e00a3678c 100644 > --- a/fs/btrfs/extent_io.h > +++ b/fs/btrfs/extent_io.h > @@ -29,6 +29,10 @@ > EXTENT_CLEAR_DATA_RESV) > #define EXTENT_CTLBITS (EXTENT_DO_ACCOUNTING) > > + > +/* Redefined bits above which are used only in the device allocation tree */ > +#define CHUNK_ALLOCATED EXTENT_DIRTY
I see that 18 and more flags can be a lot, though for clarity could we use unique values? The bitmask is u32 or unsigned, so still some left to use. And I ve seen only 2 new more so it's not like you need 10, there it would make more sense to reuse. As the extent_io tree is used in different contexts, we can add some sanity checks based on the disjoint sets of flags, but that's just an idea and I don't have concrete examples.
