[PATCH] reiserfs 64 bit bug in get_virtual_node_size

This patch fixes a problem with reiserfs on 64 bit machines.  Our
struct virtual_item is a different size there, and some calculations
that assume otherwise lead to this panic create_virtual_node:

vs-8030: create_virtual_node: virtual node space consumed

fs/reiserfs/fix_node.c

@@ -2011,16 +2011,20 @@ void reiserfs_kfree (const void * vp, size_t size, struct super_block * s)
 
 static int get_virtual_node_size (struct super_block * sb, struct buffer_head * bh)
 {
-  //  int size = sizeof (struct virtual_item); /* for new item in case of insert */
-  //  int i, nr_items;
-  //  struct item_head * ih;
+    int max_num_of_items;
+    int max_num_of_entries;
+    unsigned long blocksize = sb->s_blocksize;
 
-  // this is enough for _ALL_ currently possible cases. In 4 k block
-  // one may put < 170 empty items. Each virtual item eats 12
-  // byte. The biggest direntry item may have < 256 entries. Each
-  // entry would eat 2 byte of virtual node space
-  return sb->s_blocksize;
+#define MIN_NAME_LEN 1
 
+    max_num_of_items = (blocksize - BLKH_SIZE) / (IH_SIZE + MIN_ITEM_LEN);
+    max_num_of_entries = (blocksize - BLKH_SIZE - IH_SIZE) / 
+                         (DEH_SIZE + MIN_NAME_LEN);
+
+    return sizeof(struct virtual_node) + 
+           max(max_num_of_items * sizeof (struct virtual_item),
+	       sizeof (struct virtual_item) + sizeof(struct direntry_uarea) + 
+               (max_num_of_entries - 1) * sizeof (__u16));
 }
 
 

fs/reiserfs/item_ops.c

@@ -466,13 +466,6 @@ static void direntry_check_item (struct item_head * ih, char * item)
 
 #define DIRENTRY_VI_FIRST_DIRENTRY_ITEM 1
 
-struct direntry_uarea {
-    int flags;
-    __u16 entry_count;
-    __u16 entry_sizes[1];
-} __attribute__ ((__packed__)) ;
-
-
 /*
  * function returns old entry number in directory item in real node
  * using new entry number in virtual item in virtual node */

include/linux/reiserfs_fs.h

@@ -1342,6 +1342,13 @@ struct virtual_node
   struct virtual_item * vn_vi;	/* array of items (including a new one, excluding item to be deleted) */
 };
 
+/* used by directory items when creating virtual nodes */
+struct direntry_uarea {
+    int flags;
+    __u16 entry_count;
+    __u16 entry_sizes[1];
+} __attribute__ ((__packed__)) ;
+
 
 /***************************************************************************/
 /*                  TREE BALANCE                                           */