@@ -187,6 +187,42 @@ typedef enum BlockOpType {
BLOCK_OP_TYPE_MAX,
} BlockOpType;
+/* Block node permission constants */
+enum {
+ /**
+ * A user that has the "permission" of consistent reads is guaranteed that
+ * their view of the contents of the block device is complete and
+ * self-consistent, representing the contents of a disk at a specific
+ * point.
+ *
+ * For most block devices (including their backing files) this is true, but
+ * the property cannot be maintained in a few situations like for
+ * intermediate nodes of a commit block job.
+ */
+ BLK_PERM_CONSISTENT_READ = 0x01,
+
+ /** This permission is required to change the visible disk contents. */
+ BLK_PERM_WRITE = 0x02,
+
+ /**
+ * This permission (which is weaker than BLK_PERM_WRITE) is both enough and
+ * required for writes to the block node when the caller promises that
+ * the visible disk content doesn't change.
+ */
+ BLK_PERM_WRITE_UNCHANGED = 0x04,
+
+ /** This permission is required to change the size of a block node. */
+ BLK_PERM_RESIZE = 0x08,
+
+ /**
+ * This permission is required to change the node that this BdrvChild
+ * points to.
+ */
+ BLK_PERM_GRAPH_MOD = 0x10,
+
+ BLK_PERM_ALL = 0x1f,
+};
+
/* disk I/O throttling */
void bdrv_init(void);
void bdrv_init_with_whitelist(void);