mm: export bdi_unregister

Patch series "simplify bdi unregistation".

This series simplifies the BDI code to get rid of the magic
auto-unregister feature that hid a recent block layer refcounting bug.

This patch (of 5):

To wind down the magic auto-unregister semantics we'll need to push this
into modular code.

Link: https://lkml.kernel.org/r/20211021124441.668816-1-hch@lst.de
Link: https://lkml.kernel.org/r/20211021124441.668816-2-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Miquel Raynal <miquel.raynal@bootlin.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Vignesh Raghavendra <vigneshr@ti.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/backing-dev.c b/mm/backing-dev.c
index 4a9d4e2..8a46a0a 100644 (file)
--- a/mm/backing-dev.c
+++ b/mm/backing-dev.c
@@ -958,6 +958,7 @@ void bdi_unregister(struct backing_dev_info *bdi)
                bdi->owner = NULL;
        }
 }
+EXPORT_SYMBOL(bdi_unregister);
 
 static void release_bdi(struct kref *ref)
 {