+ mm-simplify-bdi-refcounting-fix.patch added to -mm tree

[akpm@linux-foundation.org]

The patch titled
     Subject: mm-simplify-bdi-refcounting-fix
has been added to the -mm tree.  Its filename is
     mm-simplify-bdi-refcounting-fix.patch

This patch should soon appear at
    https://ozlabs.org/~akpm/mmots/broken-out/mm-simplify-bdi-refcounting-fix.patch
and later at
    https://ozlabs.org/~akpm/mmotm/broken-out/mm-simplify-bdi-refcounting-fix.patch

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------------------------------------------------------
From: Christoph Hellwig <hch@lst.de>
Subject: mm-simplify-bdi-refcounting-fix

add comment

Link: https://lkml.kernel.org/r/20211027074207.GA12793@lst.de
Cc: 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>
---

 include/linux/backing-dev-defs.h |    3 +++
 1 file changed, 3 insertions(+)

--- a/include/linux/backing-dev-defs.h~mm-simplify-bdi-refcounting-fix
+++ a/include/linux/backing-dev-defs.h
@@ -103,6 +103,9 @@ struct wb_completion {
  * change as blkcg is disabled and enabled higher up in the hierarchy, a wb
  * is tested for blkcg after lookup and removed from index on mismatch so
  * that a new wb for the combination can be created.
+ *
+ * Each bdi_writeback that is no embedded into the backing_dev_info must hold
+ * a reference to the parent backing_dev_info.  See cgwb_create() for details.
  */
 struct bdi_writeback {
 	struct backing_dev_info *bdi;	/* our parent bdi */
_

Patches currently in -mm which might be from hch@lst.de are

mm-dont-include-linux-daxh-in-linux-mempolicyh.patch
mm-export-bdi_unregister.patch
mtd-call-bdi_unregister-explicitly.patch
fs-explicitly-unregister-per-superblock-bdis.patch
mm-dont-automatically-unregister-bdis.patch
mm-simplify-bdi-refcounting.patch
mm-simplify-bdi-refcounting-fix.patch
mm-unexport-folio_memcg_unlock.patch
mm-unexport-unlock_page_memcg.patch