@@ -1412,6 +1412,7 @@ static int create_image_file_range(struct btrfs_trans_handle *trans,
fail:
return ret;
}
+
/*
* Create the fs image file.
*/
@@ -1605,6 +1606,189 @@ fail:
return ret;
}
+static int create_image_file_range_v2(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct cache_tree *used,
+ struct btrfs_inode_item *inode,
+ u64 ino, u64 bytenr, u64 *ret_len,
+ int datacsum)
+{
+ struct cache_extent *cache;
+ struct btrfs_block_group_cache *bg_cache;
+ u64 len = *ret_len;
+ u64 disk_bytenr;
+ int ret;
+
+ BUG_ON(bytenr != round_down(bytenr, root->sectorsize));
+ BUG_ON(len != round_down(len, root->sectorsize));
+ len = min_t(u64, len, BTRFS_MAX_EXTENT_SIZE);
+
+ cache = search_cache_extent(used, bytenr);
+ if (cache) {
+ if (cache->start <= bytenr) {
+ /*
+ * |///////Used///////|
+ * |<--insert--->|
+ * bytenr
+ */
+ len = min_t(u64, len, cache->start + cache->size -
+ bytenr);
+ disk_bytenr = bytenr;
+ } else {
+ /*
+ * |//Used//|
+ * |<-insert-->|
+ * bytenr
+ */
+ len = min(len, cache->start - bytenr);
+ disk_bytenr = 0;
+ datacsum = 0;
+ }
+ } else {
+ /*
+ * |//Used//| |EOF
+ * |<-insert-->|
+ * bytenr
+ */
+ disk_bytenr = 0;
+ datacsum = 0;
+ }
+
+ if (disk_bytenr) {
+ /* Check if the range is in a data block group */
+ bg_cache = btrfs_lookup_block_group(root->fs_info, bytenr);
+ if (!bg_cache)
+ return -ENOENT;
+ if (!(bg_cache->flags & BTRFS_BLOCK_GROUP_DATA))
+ return -EINVAL;
+
+ /* The extent should never cross block group boundary */
+ len = min_t(u64, len, bg_cache->key.objectid +
+ bg_cache->key.offset - bytenr);
+ }
+
+ BUG_ON(len != round_down(len, root->sectorsize));
+ ret = btrfs_record_file_extent(trans, root, ino, inode, bytenr,
+ disk_bytenr, len);
+ if (ret < 0)
+ return ret;
+
+ if (datacsum)
+ ret = csum_disk_extent(trans, root, bytenr, len);
+ *ret_len = len;
+ return ret;
+}
+
+static int wipe_reserved_ranges(struct cache_tree *tree, u64 min_stripe_size,
+ int ensure_size);
+
+/*
+ * Create the fs image file of old filesystem.
+ *
+ * This is completely fs independent as we have cctx->used, only
+ * need to create file extents point to all the posistions.
+ * TODO: Add handler for reserved ranges in next patch
+ */
+static int create_image_v2(struct btrfs_root *root,
+ struct btrfs_mkfs_config *cfg,
+ struct btrfs_convert_context *cctx,
+ u64 size, char *name, int datacsum)
+{
+ struct btrfs_inode_item buf;
+ struct btrfs_trans_handle *trans;
+ struct btrfs_path *path = NULL;
+ struct btrfs_key key;
+ struct cache_extent *cache;
+ struct cache_tree used_tmp;
+ u64 cur;
+ u64 ino;
+ int ret;
+
+ trans = btrfs_start_transaction(root, 1);
+ if (!trans)
+ return -ENOMEM;
+
+ cache_tree_init(&used_tmp);
+
+ ret = btrfs_find_free_objectid(trans, root, BTRFS_FIRST_FREE_OBJECTID,
+ &ino);
+ if (ret < 0)
+ goto out;
+ ret = btrfs_new_inode(trans, root, ino, 0600 | S_IFREG);
+ if (ret < 0)
+ goto out;
+ ret = btrfs_add_link(trans, root, ino, BTRFS_FIRST_FREE_OBJECTID, name,
+ strlen(name), BTRFS_FT_REG_FILE, NULL, 1);
+ if (ret < 0)
+ goto out;
+
+ path = btrfs_alloc_path();
+ if (!path) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ key.objectid = ino;
+ key.type = BTRFS_INODE_ITEM_KEY;
+ key.offset = 0;
+
+ ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
+ if (ret) {
+ ret = (ret > 0 ? -ENOENT : ret);
+ goto out;
+ }
+ read_extent_buffer(path->nodes[0], &buf,
+ btrfs_item_ptr_offset(path->nodes[0], path->slots[0]),
+ sizeof(buf));
+ btrfs_release_path(path);
+
+ /*
+ * Create a new used space cache, which doesn't contain the reserved
+ * range
+ */
+ for (cache = first_cache_extent(&cctx->used); cache;
+ cache = next_cache_extent(cache)) {
+ ret = add_cache_extent(&used_tmp, cache->start, cache->size);
+ if (ret < 0)
+ goto out;
+ }
+ ret = wipe_reserved_ranges(&used_tmp, 0, 0);
+ if (ret < 0)
+ goto out;
+
+ /*
+ * Start from 1M, as 0~1M is reserved, and create_image_file_range_v2()
+ * can't handle bytenr 0(will consider it as a hole)
+ */
+ cur = 1024 * 1024;
+ while (cur < size) {
+ u64 len = size - cur;
+
+ ret = create_image_file_range_v2(trans, root, &used_tmp,
+ &buf, ino, cur, &len, datacsum);
+ if (ret < 0)
+ goto out;
+ cur += len;
+ }
+
+ key.objectid = ino;
+ key.type = BTRFS_INODE_ITEM_KEY;
+ key.offset = 0;
+ ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
+ if (ret) {
+ ret = (ret > 0 ? -ENOENT : ret);
+ goto out;
+ }
+ btrfs_set_stack_inode_size(&buf, cfg->num_bytes);
+ write_extent_buffer(path->nodes[0], &buf,
+ btrfs_item_ptr_offset(path->nodes[0], path->slots[0]),
+ sizeof(buf));
+out:
+ free_extent_cache_tree(&used_tmp);
+ btrfs_free_path(path);
+ btrfs_commit_transaction(trans, root);
+ return ret;
+}
+
static struct btrfs_root * link_subvol(struct btrfs_root *root,
const char *base, u64 root_objectid)
{
Use new function, create_convert_image_v2() to create snapshot of old filesystem. Unlike old function which is called after copying all inodes, this function need to be called before copying inodes. Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> --- btrfs-convert.c | 184 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 184 insertions(+)