[PATCH 3/6] ubi: Add truncate callback

[Teresa Remmet]

The size of static ubi volumes changes depending on the content.
Add truncate callback to handle resizes.

Signed-off-by: Teresa Remmet <t.remmet at phytec.de>
---
 drivers/mtd/ubi/barebox.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/drivers/mtd/ubi/barebox.c b/drivers/mtd/ubi/barebox.c
index 329cf45..2ad731a 100644
--- a/drivers/mtd/ubi/barebox.c
+++ b/drivers/mtd/ubi/barebox.c
@@ -162,6 +162,21 @@ static loff_t ubi_volume_cdev_lseek(struct cdev *cdev, loff_t ofs)
 	return ofs;
 }
 
+static int ubi_volume_cdev_truncate(struct cdev *cdev, size_t size)
+{
+	struct ubi_volume_cdev_priv *priv = cdev->priv;
+	struct ubi_device *ubi = priv->ubi;
+	struct ubi_volume *vol = priv->vol;
+	uint64_t rsvd_bytes;
+
+	rsvd_bytes = (long long)vol->reserved_pebs *
+			ubi->leb_size - vol->data_pad;
+	if (size > rsvd_bytes)
+		return -ENOSPC;
+
+	return 0;
+}
+
 static int ubi_volume_cdev_ioctl(struct cdev *cdev, int cmd, void *buf)
 {
 	struct ubi_volume_cdev_priv *priv = cdev->priv;
@@ -210,6 +225,7 @@ static struct file_operations ubi_volume_fops = {
 	.write  = ubi_volume_cdev_write,
 	.lseek	= ubi_volume_cdev_lseek,
 	.ioctl  = ubi_volume_cdev_ioctl,
+	.truncate = ubi_volume_cdev_truncate,
 };
 
 int ubi_volume_cdev_add(struct ubi_device *ubi, struct ubi_volume *vol)
-- 
1.9.1