Transfering inode numbers from PX entries to IsoNode during image import

and using these numbers in PX entries during next image generation.
This also answers the concerns about PX without ino in RRIP 1.12
and PX with ino in RRIP 1.10 images produced by mkisofs.

libisofs/image.h

@@ -13,6 +13,14 @@
 #include "fsource.h"
 #include "builder.h"
 
+/* Size of a inode recycling window. Each new window causes a tree traversal.
+   Window memory consumption is ISO_USED_INODE_RANGE / 8.
+   This must be a power of 2 smaller than 30 bit and larger than 8 bit.
+   Here: 32 kB memory for 256k inodes.
+*/
+#define ISO_USED_INODE_RANGE (1 << 18)
+
+
 /*
  * Image is a context for image manipulation.
  * Global objects such as the message_queues must belogn to that
@@ -121,6 +129,59 @@ struct Iso_Image
      */
     void *user_data;
     void (*user_data_free)(void *ptr);
+
+    /* ts A90427 */
+    /**
+     * Inode number management. inode_counter is taken over from
+     * IsoImageFilesystem._ImageFsData after image import.
+     * It is to be used with img_give_ino_number()
+     */
+    ino_t inode_counter;
+    /*
+     * A bitmap of used inode numbers in an interval beginning at
+     * used_inodes_start and holding ISO_USED_INODE_RANGE bits.
+     * If a bit is set, then the corresponding inode number is occupied.
+     * This interval is kept around inode_counter and eventually gets
+     * advanced by ISO_USED_INODE_RANGE numbers in a tree traversal
+     * done by img_collect_inos().
+     */
+    uint8_t *used_inodes;
+    ino_t used_inodes_start;
+
 };
 
+
+    
+/* ts A90428 */
+/* Collect the bitmap of used inode numbers in the range of
+   _ImageFsData.used_inodes_start + ISO_USED_INODE_RANGE
+   @param flag bit0= recursion is active
+*/
+int img_collect_inos(IsoImage *image, IsoDir *dir, int flag);
+
+/* ts A90428 */
+/**
+ * A global counter for inode numbers for the ISO image filesystem.
+ * On image import it gets maxed by the eventual inode numbers from PX
+ * entries. Up to the first 32 bit rollover it simply increments the counter.
+ * After the first rollover it uses a look ahead bitmap which gets filled
+ * by a full tree traversal. It covers the next inode numbers to come
+ * (somewhere between 1 and ISO_USED_INODE_RANGE which is quite many)
+ * and advances when being exhausted.
+ * @param image The image where the number shall be used
+ * @param flag  bit0= reset count (Caution: image must get new inos then)
+ * @return
+ *     Since ino_t 0 is used as default and considered self-unique, 
+ *     the value 0 should only be returned in case of error.
+ */ 
+ino_t img_give_ino_number(IsoImage *image, int flag);
+
+/* ts A90428 */
+/* @param flag bit0= overwrite any ino, else only ino == 0
+               bit1= install inode with non-data, non-directory files
+               bit2= install inode with directories
+               bit3= with bit2: install inode on parameter dir
+*/
+int img_make_inos(IsoImage *image, IsoDir *dir, int flag);
+
 #endif /*LIBISO_IMAGE_H_*/