Messages in this thread Patch in this message | | | From | Vratislav Bendel <> | Subject | [PATCH] xfs: Correctly invert xfs_buftarg LRU isolation logic | Date | Tue, 6 Mar 2018 11:26:38 +0100 |
| |
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 <vbendel@redhat.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> --- fs/xfs/xfs_buf.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c index d1da2ee9e6db..ac669a10c62f 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; } -- 2.14.3
| |