Merge tag 'xfs-for-linus-4.5-2' of git://git.kernel.org/pub/scm/linux/kernel/git...

[linux-drm-fsl-dcu.git] / fs / xfs / xfs_buf.c

diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c
index daed4bfb85b2f2d56a3e82fa5ba4156f9f41011d..435c7de42e5f322a82845382ad7e1fa54dfe3d0b 100644 (file)
--- a/fs/xfs/xfs_buf.c
+++ b/fs/xfs/xfs_buf.c
@@ -1527,6 +1527,16 @@ xfs_wait_buftarg(
        LIST_HEAD(dispose);
        int loop = 0;
 
+       /*
+        * We need to flush the buffer workqueue to ensure that all IO
+        * completion processing is 100% done. Just waiting on buffer locks is
+        * not sufficient for async IO as the reference count held over IO is
+        * not released until after the buffer lock is dropped. Hence we need to
+        * ensure here that all reference counts have been dropped before we
+        * start walking the LRU list.
+        */
+       drain_workqueue(btp->bt_mount->m_buf_workqueue);
+
        /* loop until there is nothing left on the lru list. */
        while (list_lru_count(&btp->bt_lru)) {
                list_lru_walk(&btp->bt_lru, xfs_buftarg_wait_rele,