btrfs-progs: Introduce function to initialize device tree

Introduce new function, setup_temp_device_tree(), to setup temporary
device tree for make_btrfs_v2().

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

diff --git a/utils.c b/utils.c
index fcabcb5..c782a7a 100644 (file)
--- a/utils.c
+++ b/utils.c
@@ -603,6 +603,59 @@ out:
        return ret;
 }
 
+static void insert_temp_dev_extent(struct extent_buffer *buf,
+                                  int *slot, u32 *itemoff, u64 start, u64 len)
+{
+       struct btrfs_dev_extent *dev_extent;
+       struct btrfs_disk_key disk_key;
+
+       btrfs_set_header_nritems(buf, *slot + 1);
+       (*itemoff) -= sizeof(*dev_extent);
+       btrfs_set_disk_key_type(&disk_key, BTRFS_DEV_EXTENT_KEY);
+       btrfs_set_disk_key_objectid(&disk_key, 1);
+       btrfs_set_disk_key_offset(&disk_key, start);
+       btrfs_set_item_key(buf, &disk_key, *slot);
+       btrfs_set_item_offset(buf, btrfs_item_nr(*slot), *itemoff);
+       btrfs_set_item_size(buf, btrfs_item_nr(*slot), sizeof(*dev_extent));
+
+       dev_extent = btrfs_item_ptr(buf, *slot, struct btrfs_dev_extent);
+       btrfs_set_dev_extent_chunk_objectid(buf, dev_extent,
+                                           BTRFS_FIRST_CHUNK_TREE_OBJECTID);
+       btrfs_set_dev_extent_length(buf, dev_extent, len);
+       btrfs_set_dev_extent_chunk_offset(buf, dev_extent, start);
+       btrfs_set_dev_extent_chunk_tree(buf, dev_extent,
+                                       BTRFS_CHUNK_TREE_OBJECTID);
+       (*slot)++;
+}
+
+static int setup_temp_dev_tree(int fd, struct btrfs_mkfs_config *cfg,
+                              u64 sys_chunk_start, u64 meta_chunk_start,
+                              u64 dev_bytenr)
+{
+       struct extent_buffer *buf = NULL;
+       u32 itemoff = __BTRFS_LEAF_DATA_SIZE(cfg->nodesize);
+       int slot = 0;
+       int ret;
+
+       /* Must ensure SYS chunk starts before META chunk */
+       BUG_ON(meta_chunk_start < sys_chunk_start);
+       buf = malloc(sizeof(*buf) + cfg->nodesize);
+       if (!buf)
+               return -ENOMEM;
+       ret = setup_temp_extent_buffer(buf, cfg, dev_bytenr,
+                                      BTRFS_DEV_TREE_OBJECTID);
+       if (ret < 0)
+               goto out;
+       insert_temp_dev_extent(buf, &slot, &itemoff, sys_chunk_start,
+                              BTRFS_MKFS_SYSTEM_GROUP_SIZE);
+       insert_temp_dev_extent(buf, &slot, &itemoff, meta_chunk_start,
+                              BTRFS_CONVERT_META_GROUP_SIZE);
+       ret = write_temp_extent_buffer(fd, buf, dev_bytenr);
+out:
+       free(buf);
+       return ret;
+}
+
 /*
  * Improved version of make_btrfs().
  *
@@ -696,7 +749,8 @@ static int make_convert_btrfs(int fd, struct btrfs_mkfs_config *cfg,
                                    chunk_bytenr);
        if (ret < 0)
                goto out;
-
+       ret = setup_temp_dev_tree(fd, cfg, sys_chunk_start, meta_chunk_start,
+                                 dev_bytenr);
 out:
        return ret;
 }