4.16-stable review patch. If anyone has any objections, please let me know.
------------------
From: Romain Izard <romain.izard.pro@xxxxxxxxx>
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.
Cc: stable@xxxxxxxxxxxxxxx
Fixes: 9d54c8a33eec (UBI: R/O block driver on top of UBI volumes)
Signed-off-by: Romain Izard <romain.izard.pro@xxxxxxxxx>
Signed-off-by: Richard Weinberger <richard@xxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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
@@ -244,7 +244,7 @@ static int ubiblock_open(struct block_de
* in any case.
*/
if (mode & FMODE_WRITE) {
- ret = -EPERM;
+ ret = -EROFS;
goto out_unlock;
}