mtd: core: Fix refcounting for unpartitioned MTDs

richardweinberger · miquelraynal · commit 1ca71415f075 · 2020-12-07T12:29:11.000+01:00
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: 46b5889 ("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
@@ -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);
 

Original file line number	Diff line number	Diff line change
`@@ -993,6 +993,8 @@ int __get_mtd_device(struct mtd_info *mtd)`
`993`	`993`	`}`
`994`	`994`	`}`
`995`	`995`
	`996`	`+ master->usecount++;`
	`997`	`+`
`996`	`998`	`while (mtd->parent) {`
`997`	`999`	`mtd->usecount++;`
`998`	`1000`	`mtd = mtd->parent;`
`@@ -1059,6 +1061,8 @@ void __put_mtd_device(struct mtd_info *mtd)`
`1059`	`1061`	`mtd = mtd->parent;`
`1060`	`1062`	`}`
`1061`	`1063`
	`1064`	`+ master->usecount--;`
	`1065`	`+`
`1062`	`1066`	`if (master->_put_device)`
`1063`	`1067`	`master->_put_device(master);`
`1064`	`1068`