Btrfs: early reference counting

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

1 files changed, 42 insertions, 3 deletions

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index fb2144496215..25d9cd169209 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -15,6 +15,39 @@
  */
 #define CTREE_EXTENT_PENDING 0
 
+static int inc_block_ref(struct ctree_root *root, u64 blocknr)
+{
+        struct ctree_path path;
+        int ret;
+        struct key key;
+        struct leaf *l;
+        struct extent_item *item;
+        init_path(&path);
+        key.objectid = blocknr;
+        key.flags = 0;
+        key.offset = 1;
+        ret = search_slot(root->extent_root, &key, &path, 0, 1);
+        BUG_ON(ret != 0);
+        l = &path.nodes[0]->leaf;
+        item = (struct extent_item *)(l->data +
+                                      l->items[path.slots[0]].offset);
+        item->refs++;
+        BUG_ON(list_empty(&path.nodes[0]->dirty));
+        release_path(root->extent_root, &path);
+        return 0;
+}
+
+int btrfs_inc_ref(struct ctree_root *root, struct tree_buffer *buf)
+{
+        u64 blocknr;
+        int i;
+        for (i = 0; i < buf->node.header.nritems; i++) {
+                blocknr = buf->node.blockptrs[i];
+                inc_block_ref(root, blocknr);
+        }
+        return 0;
+}
+
 /*
  * find all the blocks marked as pending in the radix tree and remove
  * them from the extent map
@@ -39,7 +72,7 @@ static int del_pending_extents(struct ctree_root *extent_root)
                         key.flags = 0;
                         key.offset = 1;
                         init_path(&path);
-                        ret = search_slot(extent_root, &key, &path, -1);
+                        ret = search_slot(extent_root, &key, &path, -1, 1);
                         if (ret) {
                                 print_tree(extent_root, extent_root->node);
                                 printf("unable to find %Lu\n", key.objectid);
@@ -83,7 +116,7 @@ int free_extent(struct ctree_root *root, u64 blocknr, u64 num_blocks)
                 return 0;
         }
         init_path(&path);
-        ret = search_slot(extent_root, &key, &path, -1);
+        ret = search_slot(extent_root, &key, &path, -1, 1);
         if (ret) {
                 print_tree(extent_root, extent_root->node);
                 printf("failed to find %Lu\n", key.objectid);
@@ -124,7 +157,7 @@ check_failed:
         ins->offset = 0;
         ins->flags = 0;
         start_found = 0;
-        ret = search_slot(root, ins, &path, 0);
+        ret = search_slot(root, ins, &path, 0, 0);
         if (ret < 0)
                 goto error;
 
@@ -221,6 +254,8 @@ static int insert_pending_extents(struct ctree_root *extent_root)
                         ret = insert_item(extent_root, &key, &item,
                                           sizeof(item));
                         if (ret) {
+                                printf("%Lu already in tree\n", key.objectid);
+                                print_tree(extent_root, extent_root->node);
                                 BUG();
                                 // FIXME undo it and return sane
                                 return ret;
@@ -228,6 +263,7 @@ static int insert_pending_extents(struct ctree_root *extent_root)
                         radix_tree_tag_clear(&extent_root->cache_radix,
                                              gang[i]->blocknr,
                                              CTREE_EXTENT_PENDING);
+                        printf("%Lu is not pending\n", gang[i]->blocknr);
                         tree_block_release(extent_root, gang[i]);
                 }
         }
@@ -266,15 +302,18 @@ int alloc_extent(struct ctree_root *root, u64 num_blocks, u64 search_start,
                 if (pending_ret)
                         return pending_ret;
                 *buf = find_tree_block(root, ins->objectid);
+                dirty_tree_block(root, *buf);
                 return 0;
         }
         /* we're allocating an extent for the extent tree, don't recurse */
         BUG_ON(ins->offset != 1);
         *buf = find_tree_block(root, ins->objectid);
         BUG_ON(!*buf);
+        printf("%Lu is pending\n", ins->objectid);
         radix_tree_tag_set(&root->cache_radix, ins->objectid,
                            CTREE_EXTENT_PENDING);
         (*buf)->count++;
+        dirty_tree_block(root, *buf);
         return 0;
 
 }