UBI: add UBI devices reference counting
This is one more step on the way to "removable" UBI devices. It
adds reference counting for UBI devices. Every time a volume on
this device is opened - the device's refcount is increased. It
is also increased if someone is reading any sysfs file of this
UBI device or of one of its volumes.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
diff --git a/drivers/mtd/ubi/ubi.h b/drivers/mtd/ubi/ubi.h
index 21c0283..91fde0e 100644
--- a/drivers/mtd/ubi/ubi.h
+++ b/drivers/mtd/ubi/ubi.h
@@ -245,6 +245,7 @@
* @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.
+ * @ref_count: count of references on the UBI device
*
* @rsvd_pebs: count of reserved physical eraseblocks
* @avail_pebs: count of available physical eraseblocks
@@ -325,6 +326,7 @@
int vol_count;
struct ubi_volume *volumes[UBI_MAX_VOLUMES+UBI_INT_VOL_COUNT];
spinlock_t volumes_lock;
+ int ref_count;
int rsvd_pebs;
int avail_pebs;
@@ -401,7 +403,6 @@
extern struct file_operations ubi_ctrl_cdev_operations;
extern struct file_operations ubi_cdev_operations;
extern struct file_operations ubi_vol_cdev_operations;
-extern struct ubi_device *ubi_devices[];
extern struct class *ubi_class;
/* vtbl.c */
@@ -479,6 +480,12 @@
int ubi_io_write_vid_hdr(struct ubi_device *ubi, int pnum,
struct ubi_vid_hdr *vid_hdr);
+/* build.c */
+struct ubi_device *ubi_get_device(int ubi_num);
+void ubi_put_device(struct ubi_device *ubi);
+struct ubi_device *ubi_get_by_major(int major);
+int ubi_major2num(int major);
+
/*
* ubi_rb_for_each_entry - walk an RB-tree.
* @rb: a pointer to type 'struct rb_node' to to use as a loop counter