[PATCH 3.16 101/366] ubi: Fix error for write access

Ben Hutchings
2018-10-14T23:25:20Z

From: Romain Izard <romain.izard.pro@gmail.com>

commit 78a8dfbabbece22bee58ac4cb26cab10e7a19c5d upstream.

When opening a device with write access, ubiblock_open returns an error
code. Currently, this error code is -EPERM, but this is not the right
value.

The open function for other block devices returns -EROFS when opening
read-only devices with FMODE_WRITE set. When used with dm-verity, the
veritysetup userspace tool is expecting EROFS, and refuses to use the
ubiblock device.

Use -EROFS for ubiblock as well. As a result, veritysetup accepts the
ubiblock device as valid.

Fixes: 9d54c8a33eec (UBI: R/O block driver on top of UBI volumes)
Signed-off-by: Romain Izard <romain.izard.pro@gmail.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
drivers/mtd/ubi/block.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/mtd/ubi/block.c
+++ b/drivers/mtd/ubi/block.c
@@ -322,7 +322,7 @@ static int ubiblock_open(struct block_de
* in any case.
*/
if (mode & FMODE_WRITE) {
- ret = -EPERM;
+ ret = -EROFS;
goto out_unlock;
}