On Tue, Feb 04, 2020 at 03:25:09PM +0100, Jan Kara wrote:
> __xa_cmpxchg() relies on xas_store() to set XA_FREE_MARK when storing
> NULL into xarray that has free tracking enabled. Make the setting of
> XA_FREE_MARK explicit similarly as its clearing currently it.
>
> Signed-off-by: Jan Kara <jack@xxxxxxx>
> lib/xarray.c | 8 ++++++--
> 1 file changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/lib/xarray.c b/lib/xarray.c
> index ae8b7070e82c..4e32497c51bd 100644
> +++ b/lib/xarray.c
> @@ -1477,8 +1477,12 @@ void *__xa_cmpxchg(struct xarray *xa, unsigned long index,
> curr = xas_load(&xas);
> if (curr == old) {
> xas_store(&xas, entry);
> - if (xa_track_free(xa) && entry && !curr)
> - xas_clear_mark(&xas, XA_FREE_MARK);
> + if (xa_track_free(xa)) {
> + if (entry && !curr)
> + xas_clear_mark(&xas, XA_FREE_MARK);
> + else if (!entry && curr)
> + xas_set_mark(&xas, XA_FREE_MARK);
> + }
This feels like an optimization that should also happen for
__xa_store, which has very similar code:
curr = xas_store(&xas, entry);
if (xa_track_free(xa))
xas_clear_mark(&xas, XA_FREE_MARK);
Something like
if (xa_track_free(xa) && entry && !curr)
xas_clear_mark(&xas, XA_FREE_MARK);
?
Regards,
Jason
