Re: [PATCH 08/11] mm: convert vma_interval_tree to half closed intervals

Michel Lespinasse
2019-10-04T12:30:49Z

On Thu, Oct 03, 2019 at 01:18:55PM -0700, Davidlohr Bueso wrote:
> The vma and anon vma interval tree really wants [a, b) intervals,
> not fully closed. As such convert it to use the new
> interval_tree_gen.h. Because of vma_last_pgoff(), the conversion
> is quite straightforward.

I am not certain if we need to worry about integer overflow here.
The problem case would be accessing the last block of a file that is
exactly 16TB long, on an arch where long (and thus pgoff_t) is 32-bit.
Maybe FS folks can tell us whether that case is currently supported,
or if we can just not worry about it ?

I would also want to rename the fields in struct zap_details into
start_index and end_index so we can verify we don't leave any
off-by-one uses.

--
Michel "Walken" Lespinasse
A program is never fully debugged until the last user dies.