From: Vratislav Bendel Date: Wed, 7 Mar 2018 01:07:44 +0000 (-0800) Subject: xfs: Correctly invert xfs_buftarg LRU isolation logic X-Git-Tag: v4.19~1210^2~48 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=19957a181608d25c8f4136652d0ea00b3738972d;p=platform%2Fkernel%2Flinux-rpi.git xfs: Correctly invert xfs_buftarg LRU isolation logic Due to an inverted logic mistake in xfs_buftarg_isolate() the xfs_buffers with zero b_lru_ref will take another trip around LRU, while isolating buffers with non-zero b_lru_ref. Additionally those isolated buffers end up right back on the LRU once they are released, because b_lru_ref remains elevated. Fix that circuitous route by leaving them on the LRU as originally intended. Signed-off-by: Vratislav Bendel Reviewed-by: Brian Foster Reviewed-by: Christoph Hellwig Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong --- diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c index d1da2ee..ac669a1 100644 --- a/fs/xfs/xfs_buf.c +++ b/fs/xfs/xfs_buf.c @@ -1708,7 +1708,7 @@ 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 (atomic_add_unless(&bp->b_lru_ref, -1, 0)) { spin_unlock(&bp->b_lock); return LRU_ROTATE; }