writeback: check for registered bdi in flusher add and inode dirty

Also a debugging aid. We want to catch dirty inodes being added to
backing devices that don't do writeback.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h
index 2f218b7cb063..f169bcb90b58 100644
--- a/include/linux/backing-dev.h
+++ b/include/linux/backing-dev.h
@@ -29,6 +29,7 @@ enum bdi_state {
         BDI_wb_alloc,           /* Default embedded wb allocated */
         BDI_async_congested,    /* The async (write) queue is getting full */
         BDI_sync_congested,     /* The sync queue is getting full */
+        BDI_registered,         /* bdi_register() was done */
         BDI_unused,             /* Available bits start here */
 };