UBI: allow direct user-space I/O
Introduce a new ioctl UBI_IOCSETPROP to set properties
on a volume. Also add the first property:
UBI_PROP_DIRECT_WRITE, this property is used to set the
ability to use direct writes in userspace
Signed-off-by: Sidney Amani <seed@uffs.org>
Signed-off-by: Corentin Chary <corentincj@iksaif.net>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
diff --git a/drivers/mtd/ubi/cdev.c b/drivers/mtd/ubi/cdev.c
index f9631eb..e63c8fc 100644
--- a/drivers/mtd/ubi/cdev.c
+++ b/drivers/mtd/ubi/cdev.c
@@ -259,12 +259,9 @@
return err ? err : count_save - count;
}
-#ifdef CONFIG_MTD_UBI_DEBUG_USERSPACE_IO
-
/*
* This function allows to directly write to dynamic UBI volumes, without
- * issuing the volume update operation. Available only as a debugging feature.
- * Very useful for testing UBI.
+ * issuing the volume update operation.
*/
static ssize_t vol_cdev_direct_write(struct file *file, const char __user *buf,
size_t count, loff_t *offp)
@@ -276,6 +273,9 @@
size_t count_save = count;
char *tbuf;
+ if (!vol->direct_writes)
+ return -EPERM;
+
dbg_gen("requested: write %zd bytes to offset %lld of volume %u",
count, *offp, vol->vol_id);
@@ -339,10 +339,6 @@
return err ? err : count_save - count;
}
-#else
-#define vol_cdev_direct_write(file, buf, count, offp) (-EPERM)
-#endif /* CONFIG_MTD_UBI_DEBUG_USERSPACE_IO */
-
static ssize_t vol_cdev_write(struct file *file, const char __user *buf,
size_t count, loff_t *offp)
{
@@ -552,6 +548,30 @@
break;
}
+ /* Set volume property command*/
+ case UBI_IOCSETPROP:
+ {
+ struct ubi_set_prop_req req;
+
+ err = copy_from_user(&req, argp,
+ sizeof(struct ubi_set_prop_req));
+ if (err) {
+ err = -EFAULT;
+ break;
+ }
+ switch (req.property) {
+ case UBI_PROP_DIRECT_WRITE:
+ mutex_lock(&ubi->volumes_mutex);
+ desc->vol->direct_writes = !!req.value;
+ mutex_unlock(&ubi->volumes_mutex);
+ break;
+ default:
+ err = -EINVAL;
+ break;
+ }
+ break;
+ }
+
default:
err = -ENOTTY;
break;