UBI: Implement UBI_METAONLY
UBI_METAONLY is a new open mode for UBI volumes, it indicates
that only meta data is being changed.
Meta data in terms of UBI volumes means data which is stored in the
UBI volume table but not on the volume itself.
While it does not interfere with UBI_READONLY and UBI_READWRITE
it is not allowed to use UBI_METAONLY together with UBI_EXCLUSIVE.
Cc: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Cc: Andrew Murray <amurray@embedded-bits.co.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>
Tested-by: Guido MartÃnez <guido@vanguardiasur.com.ar>
Reviewed-by: Guido MartÃnez <guido@vanguardiasur.com.ar>
Tested-by: Christoph Fritz <chf.fritz@googlemail.com>
Tested-by: Andrew Murray <amurray@embedded-bits.co.uk>
diff --git a/drivers/mtd/ubi/cdev.c b/drivers/mtd/ubi/cdev.c
index 3410ea81..f5c715c 100644
--- a/drivers/mtd/ubi/cdev.c
+++ b/drivers/mtd/ubi/cdev.c
@@ -61,13 +61,13 @@
struct ubi_volume *vol = desc->vol;
spin_lock(&vol->ubi->volumes_lock);
- users = vol->readers + vol->writers + vol->exclusive;
+ users = vol->readers + vol->writers + vol->exclusive + vol->metaonly;
ubi_assert(users > 0);
if (users > 1) {
ubi_err(ubi, "%d users for volume %d", users, vol->vol_id);
err = -EBUSY;
} else {
- vol->readers = vol->writers = 0;
+ vol->readers = vol->writers = vol->metaonly = 0;
vol->exclusive = 1;
err = desc->mode;
desc->mode = UBI_EXCLUSIVE;
@@ -87,13 +87,15 @@
struct ubi_volume *vol = desc->vol;
spin_lock(&vol->ubi->volumes_lock);
- ubi_assert(vol->readers == 0 && vol->writers == 0);
+ ubi_assert(vol->readers == 0 && vol->writers == 0 && vol->metaonly == 0);
ubi_assert(vol->exclusive == 1 && desc->mode == UBI_EXCLUSIVE);
vol->exclusive = 0;
if (mode == UBI_READONLY)
vol->readers = 1;
else if (mode == UBI_READWRITE)
vol->writers = 1;
+ else if (mode == UBI_METAONLY)
+ vol->metaonly = 1;
else
vol->exclusive = 1;
spin_unlock(&vol->ubi->volumes_lock);
diff --git a/drivers/mtd/ubi/kapi.c b/drivers/mtd/ubi/kapi.c
index f3bab66..589c423 100644
--- a/drivers/mtd/ubi/kapi.c
+++ b/drivers/mtd/ubi/kapi.c
@@ -137,7 +137,7 @@
return ERR_PTR(-EINVAL);
if (mode != UBI_READONLY && mode != UBI_READWRITE &&
- mode != UBI_EXCLUSIVE)
+ mode != UBI_EXCLUSIVE && mode != UBI_METAONLY)
return ERR_PTR(-EINVAL);
/*
@@ -182,10 +182,17 @@
break;
case UBI_EXCLUSIVE:
- if (vol->exclusive || vol->writers || vol->readers)
+ if (vol->exclusive || vol->writers || vol->readers ||
+ vol->metaonly)
goto out_unlock;
vol->exclusive = 1;
break;
+
+ case UBI_METAONLY:
+ if (vol->metaonly || vol->exclusive)
+ goto out_unlock;
+ vol->metaonly = 1;
+ break;
}
get_device(&vol->dev);
vol->ref_count += 1;
@@ -343,6 +350,10 @@
break;
case UBI_EXCLUSIVE:
vol->exclusive = 0;
+ break;
+ case UBI_METAONLY:
+ vol->metaonly = 0;
+ break;
}
vol->ref_count -= 1;
spin_unlock(&ubi->volumes_lock);
diff --git a/drivers/mtd/ubi/ubi.h b/drivers/mtd/ubi/ubi.h
index f80ffab..20cabc0 100644
--- a/drivers/mtd/ubi/ubi.h
+++ b/drivers/mtd/ubi/ubi.h
@@ -261,6 +261,7 @@
* @readers: number of users holding this volume in read-only mode
* @writers: number of users holding this volume in read-write mode
* @exclusive: whether somebody holds this volume in exclusive mode
+ * @metaonly: whether somebody is altering only meta data of this volume
*
* @reserved_pebs: how many physical eraseblocks are reserved for this volume
* @vol_type: volume type (%UBI_DYNAMIC_VOLUME or %UBI_STATIC_VOLUME)
@@ -309,6 +310,7 @@
int readers;
int writers;
int exclusive;
+ int metaonly;
int reserved_pebs;
int vol_type;
@@ -339,7 +341,8 @@
/**
* struct ubi_volume_desc - UBI volume descriptor returned when it is opened.
* @vol: reference to the corresponding volume description object
- * @mode: open mode (%UBI_READONLY, %UBI_READWRITE, or %UBI_EXCLUSIVE)
+ * @mode: open mode (%UBI_READONLY, %UBI_READWRITE, %UBI_EXCLUSIVE
+ * or %UBI_METAONLY)
*/
struct ubi_volume_desc {
struct ubi_volume *vol;
@@ -390,7 +393,8 @@
* @volumes_lock: protects @volumes, @rsvd_pebs, @avail_pebs, beb_rsvd_pebs,
* @beb_rsvd_level, @bad_peb_count, @good_peb_count, @vol_count,
* @vol->readers, @vol->writers, @vol->exclusive,
- * @vol->ref_count, @vol->mapping and @vol->eba_tbl.
+ * @vol->metaonly, @vol->ref_count, @vol->mapping and
+ * @vol->eba_tbl.
* @ref_count: count of references on the UBI device
* @image_seq: image sequence number recorded on EC headers
*
diff --git a/include/linux/mtd/ubi.h b/include/linux/mtd/ubi.h
index c3918a0..8fa2753 100644
--- a/include/linux/mtd/ubi.h
+++ b/include/linux/mtd/ubi.h
@@ -34,11 +34,14 @@
* UBI_READONLY: read-only mode
* UBI_READWRITE: read-write mode
* UBI_EXCLUSIVE: exclusive mode
+ * UBI_METAONLY: modify only the volume meta-data,
+ * i.e. the data stored in the volume table, but not in any of volume LEBs.
*/
enum {
UBI_READONLY = 1,
UBI_READWRITE,
- UBI_EXCLUSIVE
+ UBI_EXCLUSIVE,
+ UBI_METAONLY
};
/**