xfs: set WQ_SYSFS on all workqueues in debug mode

When CONFIG_XFS_DEBUG=y, set WQ_SYSFS on all workqueues that we create
so that we (developers) have a means to monitor cpu affinity and whatnot
for background workers.  In the next patchset we'll expose knobs for
more of the workqueues publicly and document it, but not now.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c
index d8b8142..9aa30e7 100644
--- a/fs/xfs/xfs_log.c
+++ b/fs/xfs/xfs_log.c
@@ -1492,8 +1492,9 @@ xlog_alloc_log(
 	log->l_iclog->ic_prev = prev_iclog;	/* re-write 1st prev ptr */
 
 	log->l_ioend_workqueue = alloc_workqueue("xfs-log/%s",
-			WQ_MEM_RECLAIM | WQ_FREEZABLE | WQ_HIGHPRI, 0,
-			mp->m_super->s_id);
+			XFS_WQFLAGS(WQ_FREEZABLE | WQ_MEM_RECLAIM |
+				    WQ_HIGHPRI),
+			0, mp->m_super->s_id);
 	if (!log->l_ioend_workqueue)
 		goto out_free_iclog;