[PATCH 5.10 666/717] mtd: core: Fix refcounting for unpartitioned MTDs

Greg Kroah-Hartman
2020-12-28T14:32:06Z

From: Richard Weinberger <richard@nod.at>

commit 1ca71415f075353974524e96ed175306d8a937a8 upstream.

Apply changes to usecount also to the master partition.
Otherwise we have no refcounting at all if an MTD has no partitions.

Cc: stable@vger.kernel.org
Fixes: 46b5889cc2c5 ("mtd: implement proper partition handling")
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20201206202220.27290-1-richard@nod.at
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/mtd/mtdcore.c | 4 ++++
1 file changed, 4 insertions(+)

--- a/drivers/mtd/mtdcore.c
+++ b/drivers/mtd/mtdcore.c
@@ -993,6 +993,8 @@ int __get_mtd_device(struct mtd_info *mt
}
}

+ master->usecount++;
+
while (mtd->parent) {
mtd->usecount++;
mtd = mtd->parent;
@@ -1059,6 +1061,8 @@ void __put_mtd_device(struct mtd_info *m
mtd = mtd->parent;
}

+ master->usecount--;
+
if (master->_put_device)
master->_put_device(master);