btrfs-progs: convert: Introduce init_btrfs_v2 function.

Introduce new init_btrfs_v2() function for later newer do_convert().

Since we have good enough chunk allocation, a lot of wired chunk hack
won't ever be used.
We only need to insert data chunks and create needed subvolume.

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

diff --git a/btrfs-convert.c b/btrfs-convert.c
index 4489c58..47028d9 100644 (file)
--- a/btrfs-convert.c
+++ b/btrfs-convert.c
@@ -2329,6 +2329,67 @@ static int make_convert_data_block_groups(struct btrfs_trans_handle *trans,
        return ret;
 }
 
+/*
+ * Init the temp btrfs to a operational status.
+ *
+ * It will fix the extent usage accounting(XXX: Do we really need?) and
+ * insert needed data chunks, to ensure all old fs data extents are covered
+ * by DATA chunks, preventing wrong chunks are allocated.
+ *
+ * And also create convert image subvolume and relocation tree.
+ * (XXX: Not need again?)
+ * But the convert image subvolume is *NOT* linked to fs tree yet.
+ */
+static int init_btrfs_v2(struct btrfs_mkfs_config *cfg, struct btrfs_root *root,
+                        struct btrfs_convert_context *cctx, int datacsum,
+                        int packing, int noxattr)
+{
+       struct btrfs_key location;
+       struct btrfs_trans_handle *trans;
+       struct btrfs_fs_info *fs_info = root->fs_info;
+       int ret;
+
+       trans = btrfs_start_transaction(root, 1);
+       BUG_ON(!trans);
+       ret = btrfs_fix_block_accounting(trans, root);
+       if (ret)
+               goto err;
+       ret = make_convert_data_block_groups(trans, fs_info, cfg, cctx);
+       if (ret)
+               goto err;
+       ret = btrfs_make_root_dir(trans, fs_info->tree_root,
+                                 BTRFS_ROOT_TREE_DIR_OBJECTID);
+       if (ret)
+               goto err;
+       memcpy(&location, &root->root_key, sizeof(location));
+       location.offset = (u64)-1;
+       ret = btrfs_insert_dir_item(trans, fs_info->tree_root, "default", 7,
+                               btrfs_super_root_dir(fs_info->super_copy),
+                               &location, BTRFS_FT_DIR, 0);
+       if (ret)
+               goto err;
+       ret = btrfs_insert_inode_ref(trans, fs_info->tree_root, "default", 7,
+                               location.objectid,
+                               btrfs_super_root_dir(fs_info->super_copy), 0);
+       if (ret)
+               goto err;
+       btrfs_set_root_dirid(&fs_info->fs_root->root_item,
+                            BTRFS_FIRST_FREE_OBJECTID);
+
+       /* subvol for fs image file */
+       ret = create_subvol(trans, root, CONV_IMAGE_SUBVOL_OBJECTID);
+       if (ret < 0)
+               goto err;
+       /* subvol for data relocation tree */
+       ret = create_subvol(trans, root, BTRFS_DATA_RELOC_TREE_OBJECTID);
+       if (ret < 0)
+               goto err;
+
+       ret = btrfs_commit_transaction(trans, root);
+err:
+       return ret;
+}
+
 static int init_btrfs(struct btrfs_root *root)
 {
        int ret;