Hello David!
On 2020-01-07 19:01, David Sterba wrote:
It's not a runtime overhead but typecasts should not be needed in
general and when there's one it should be there for a reason. Sometimes
it's apparent and does not need a comment to explain why but otherwise
I
see it as "overhead" when reading the code. Lots of calculations done
in
btrfs fit perfectly to 32bit, eg. the b-tree node or page-related ones.
Where it matters is eg. conversion from/to bio::bi_sector to/from btrfs
logical addresses that are u64, where the interface type is unsigned
long and not a fixed width.
Thanks for sharing that. As I said, I'm relatively new to btrfs
internals.
The size constraints of the variables used in the reported expression
are known to developers so I tend to think the typecast is not
necessary.
Agreed.
Maybe the static checker tool could be improved to know the
invariants, that are eg. verified in fs/btrfs/disk-io.c:validate_super.
That's something that I will do some research on.
We can ignore this patch.
Thank you!
--
Cengiz Can
@cengiz_io
