btrfs-progs: extent-tree: Introduce functions to free dev extents in a chunk

Introduce two functions, free_dev_extent_item and
free_chunk_dev_extent_items, to free dev extent items in a chunk.

Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/extent-tree.c b/extent-tree.c
index d002a4f..a9bef4b 100644 (file)
--- a/extent-tree.c
+++ b/extent-tree.c
@@ -3483,6 +3483,79 @@ out:
        return ret;
 }
 
+static int free_dev_extent_item(struct btrfs_trans_handle *trans,
+                               struct btrfs_fs_info *fs_info,
+                               u64 devid, u64 dev_offset)
+{
+       struct btrfs_root *root = fs_info->dev_root;
+       struct btrfs_path *path;
+       struct btrfs_key key;
+       int ret;
+
+       path = btrfs_alloc_path();
+       if (!path)
+               return -ENOMEM;
+
+       key.objectid = devid;
+       key.type = BTRFS_DEV_EXTENT_KEY;
+       key.offset = dev_offset;
+
+       ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
+       if (ret < 0)
+               goto out;
+       if (ret > 0) {
+               ret = -ENOENT;
+               goto out;
+       }
+
+       ret = btrfs_del_item(trans, root, path);
+out:
+       btrfs_free_path(path);
+       return ret;
+}
+
+static int free_chunk_dev_extent_items(struct btrfs_trans_handle *trans,
+                                      struct btrfs_fs_info *fs_info,
+                                      u64 chunk_offset)
+{
+       struct btrfs_chunk *chunk = NULL;
+       struct btrfs_root *root= fs_info->chunk_root;
+       struct btrfs_path *path;
+       struct btrfs_key key;
+       u16 num_stripes;
+       int i;
+       int ret;
+
+       path = btrfs_alloc_path();
+       if (!path)
+               return -ENOMEM;
+
+       key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
+       key.type = BTRFS_CHUNK_ITEM_KEY;
+       key.offset = chunk_offset;
+
+       ret = btrfs_search_slot(trans, root, &key, path, 0, 0);
+       if (ret < 0)
+               goto out;
+       if (ret > 0) {
+               ret = -ENOENT;
+               goto out;
+       }
+       chunk = btrfs_item_ptr(path->nodes[0], path->slots[0],
+                              struct btrfs_chunk);
+       num_stripes = btrfs_chunk_num_stripes(path->nodes[0], chunk);
+       for (i = 0; i < num_stripes; i++) {
+               ret = free_dev_extent_item(trans, fs_info,
+                       btrfs_stripe_devid_nr(path->nodes[0], chunk, i),
+                       btrfs_stripe_offset_nr(path->nodes[0], chunk, i));
+               if (ret < 0)
+                       goto out;
+       }
+out:
+       btrfs_free_path(path);
+       return ret;
+}
+
 /*
  * Fixup block accounting. The initial block accounting created by
  * make_block_groups isn't accuracy in this case.