Commit cf610bf4 authored May 31, 2011 by Artem Bityutskiy

UBIFS: fix shrinker object count reports

Sometimes VM asks the shrinker to return amount of objects it can shrink,
and we return the ubifs_clean_zn_cnt in that case. However, it is possible
that this counter is negative for a short period of time, due to the way
UBIFS TNC code updates it. And I can observe the following warnings sometimes:

shrink_slab: ubifs_shrinker+0x0/0x2b7 [ubifs] negative objects to delete nr=-8541616642706119788

This patch makes sure UBIFS never returns negative count of objects.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Cc: stable@kernel.org

parent da8b94ea

fs/ubifs/shrinker.c

+5 −1

Original line number	Diff line number	Diff line
		@@ -284,7 +284,11 @@ int ubifs_shrinker(struct shrinker shrink, struct shrink_control sc)
		long clean_zn_cnt = atomic_long_read(&ubifs_clean_zn_cnt);

		if (nr == 0)
		return clean_zn_cnt;
		/*
		* Due to the way UBIFS updates the clean znode counter it may
		* temporarily be negative.
		*/
		return clean_zn_cnt >= 0 ? clean_zn_cnt : 1;

		if (!clean_zn_cnt) {
		/*