buffer: make invalidate_bdev() drain all percpu LRU add caches
invalidate_bdev() should release all page cache pages which are clean
and not being used; however, if some pages are still in the percpu LRU
add caches on other cpus, those pages are considered in used and don't
get released. Fix it by calling lru_add_drain_all() before trying to
invalidate pages.
This problem was discovered while testing block automatic native
capacity unlocking. Null pages which were read before automatic
unlocking didn't get released by invalidate_bdev() and ended up
interfering with partition scan after unlocking.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/fs/buffer.c b/fs/buffer.c
index c9c266d..08e422d 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -275,6 +275,7 @@
return;
invalidate_bh_lrus();
+ lru_add_drain_all(); /* make sure all lru add caches are flushed */
invalidate_mapping_pages(mapping, 0, -1);
}
EXPORT_SYMBOL(invalidate_bdev);
