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>
diff --git a/mm/backing-dev.c b/mm/backing-dev.c
index 5cb32c5..d3ca0da 100644
--- a/mm/backing-dev.c
+++ b/mm/backing-dev.c
@@ -465,6 +465,12 @@
if (!bdi_cap_writeback_dirty(bdi))
return;
+ if (WARN_ON(!test_bit(BDI_registered, &bdi->state))) {
+ printk(KERN_ERR "bdi %p/%s is not registered!\n",
+ bdi, bdi->name);
+ return;
+ }
+
/*
* Check with the helper whether to proceed adding a task. Will only
* abort if we two or more simultanous calls to
@@ -528,6 +534,7 @@
}
bdi_debug_register(bdi, dev_name(dev));
+ set_bit(BDI_registered, &bdi->state);
exit:
return ret;
}