mtd: core: Fix refcounting for unpartitioned MTDs

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

diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
index 31d1be4b22617d4cd7390202fe1ba66600138607..2d6423d89a1759f182f083156fc87b38c8388ff6 100644 (file)
--- a/drivers/mtd/mtdcore.c
+++ b/drivers/mtd/mtdcore.c
@@ -993,6 +993,8 @@ int __get_mtd_device(struct mtd_info *mtd)
                }
        }
 
+       master->usecount++;
+
        while (mtd->parent) {
                mtd->usecount++;
                mtd = mtd->parent;
@@ -1059,6 +1061,8 @@ void __put_mtd_device(struct mtd_info *mtd)
                mtd = mtd->parent;
        }
 
+       master->usecount--;
+
        if (master->_put_device)
                master->_put_device(master);