Messages in this thread | | | Date | Tue, 21 Feb 2017 17:04:08 +0100 | From | Peter Zijlstra <> | Subject | Re: [PATCH 2/7] fs, xfs: convert xfs_buf.b_hold and xfs_buf.b_lru_ref from atomic_t to refcount_t |
| |
On Tue, Feb 21, 2017 at 05:49:02PM +0200, Elena Reshetova wrote: > @@ -1684,10 +1684,11 @@ xfs_buftarg_isolate( > * zero. If the value is already zero, we need to reclaim the > * buffer, otherwise it gets another trip through the LRU. > */ > - if (!atomic_add_unless(&bp->b_lru_ref, -1, 0)) { > + if (!refcount_read(&bp->b_lru_ref)) { > spin_unlock(&bp->b_lock); > return LRU_ROTATE; > } > + refcount_dec_and_test(&bp->b_lru_ref); > > bp->b_state |= XFS_BSTATE_DISPOSE; > list_lru_isolate_move(lru, item, dispose);
This should never have passed testing.. refcount_dec_and_test() has a __must_check.
Furthermore the above seems to suggest thingies can live with a 0 refcount, so a straight conversion cannot work.
| |