UBI: Add ubi_open_volume_path

Add an 'ubi_open_volume_path(path, mode)' function which works like
'open_bdev_exclusive(path, mode, ...)' where path is the special file
representing the UBI volume, typically /dev/ubi0_0.

This is needed to teach UBIFS being able to mount UBI character devices.

[Comments and the patch were amended a bit by Artem]

Signed-off-by: Corentin Chary <corentincj@iksaif.net>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/include/linux/mtd/ubi.h b/include/linux/mtd/ubi.h
index 6913b71d9ab2..b31bd9e9bca3 100644
--- a/include/linux/mtd/ubi.h
+++ b/include/linux/mtd/ubi.h
@@ -174,6 +174,8 @@ void ubi_get_volume_info(struct ubi_volume_desc *desc,
 struct ubi_volume_desc *ubi_open_volume(int ubi_num, int vol_id, int mode);
 struct ubi_volume_desc *ubi_open_volume_nm(int ubi_num, const char *name,
                                            int mode);
+struct ubi_volume_desc *ubi_open_volume_path(const char *pathname, int mode);
+
 int ubi_register_volume_notifier(struct notifier_block *nb,
                                  int ignore_existing);
 int ubi_unregister_volume_notifier(struct notifier_block *nb);