Btrfs: Reorder extent back refs to differentiate btree blocks from file data

Signed-off-by: Chris Mason <chris.mason@oracle.com>

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 035fa1550343ff8ed05ceeebf3a3a8e2bae4acd5..052555ced44d91425b6657359a88cacc368b4aae 100644 (file)
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -37,11 +37,12 @@ extern struct kmem_cache *btrfs_path_cachep;
 
 #define BTRFS_MAGIC "_B2RfS_M"
 
+#define BTRFS_MAX_LEVEL 8
 #define BTRFS_ROOT_TREE_OBJECTID 1ULL
 #define BTRFS_EXTENT_TREE_OBJECTID 2ULL
 #define BTRFS_FS_TREE_OBJECTID 3ULL
 #define BTRFS_ROOT_TREE_DIR_OBJECTID 4ULL
-#define BTRFS_FIRST_FREE_OBJECTID 5ULL
+#define BTRFS_FIRST_FREE_OBJECTID 256ULL
 
 /*
  * we can actually store much bigger names, but lets not confuse the rest
@@ -107,7 +108,6 @@ struct btrfs_header {
        u8 level;
 } __attribute__ ((__packed__));
 
-#define BTRFS_MAX_LEVEL 8
 #define BTRFS_NODEPTRS_PER_BLOCK(r) (((r)->nodesize - \
                                sizeof(struct btrfs_header)) / \
                                sizeof(struct btrfs_key_ptr))

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 057cdd49c09b5413a9e62481dd320e931a7c0578..00414836e963272c43157b606d9d5e2902aedc86 100644 (file)
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -520,13 +520,13 @@ out:
  *
  * When a tree block is created, back references are inserted:
  *
- * (root->root_key.objectid, trans->transid or zero, lowest_key_objectid, level)
+ * (root->root_key.objectid, trans->transid or zero, level, lowest_key_objectid)
  *
  * When a tree block is cow'd in a reference counted root,
  * new back references are added for all the blocks it points to.
  * These are of the form (trans->transid will have increased since creation):
  *
- * (root->root_key.objectid, trans->transid, lowest_key_objectid, level)
+ * (root->root_key.objectid, trans->transid, level, lowest_key_objectid)
  *
  * Because the lowest_key_objectid and the level are just hints
  * they are not used when backrefs are deleted.  When a backref is deleted:
@@ -702,7 +702,7 @@ int btrfs_inc_root_ref(struct btrfs_trans_handle *trans,
        }
        return btrfs_inc_extent_ref(trans, root, root->node->start,
                                    root->node->len, owner_objectid,
-                                   generation, key_objectid, level);
+                                   generation, level, key_objectid);
 }
 
 int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
@@ -750,8 +750,8 @@ int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
                        ret = btrfs_inc_extent_ref(trans, root, bytenr,
                                           btrfs_level_size(root, level - 1),
                                           root->root_key.objectid,
-                                          trans->transid, key.objectid,
-                                          level - 1);
+                                          trans->transid,
+                                          level - 1, key.objectid);
                        if (ret) {
                                faili = i;
                                goto fail;
@@ -1063,8 +1063,8 @@ static int finish_current_insert(struct btrfs_trans_handle *trans, struct
                }
                err = btrfs_insert_extent_backref(trans, extent_root, path,
                                          start, extent_root->root_key.objectid,
-                                         0, btrfs_disk_key_objectid(&first),
-                                         level);
+                                         0, level,
+                                         btrfs_disk_key_objectid(&first));
                BUG_ON(err);
                free_extent_buffer(eb);
        }
@@ -1640,7 +1640,7 @@ struct extent_buffer *__btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
 
        ret = btrfs_alloc_extent(trans, root, blocksize,
                                 root_objectid, ref_generation,
-                                first_objectid, level, empty_size, hint,
+                                level, first_objectid, empty_size, hint,
                                 (u64)-1, &ins, 0);
        if (ret) {
                BUG_ON(ret > 0);