This is the function which iterates all metadata extent and change their
fsid.
This function also does it without transaction.
Signed-off-by: Qu Wenruo <quwenruo@xxxxxxxxxxxxxx>
---
v2:
Move to props.c
---
props.c | 68 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 68 insertions(+)
diff --git a/props.c b/props.c
index abc3ae0..33fc39b 100644
--- a/props.c
+++ b/props.c
@@ -219,6 +219,74 @@ static int change_header_uuid(struct btrfs_root *root, struct extent_buffer *eb)
return ret;
}
+static int change_extents_uuid(struct btrfs_fs_info *fs_info)
+{
+ struct btrfs_root *root = fs_info->extent_root;
+ struct btrfs_path *path;
+ struct btrfs_key key = {0, 0, 0};
+ int ret = 0;
+
+ if (!fs_info->new_fsid && !fs_info->new_chunk_tree_uuid)
+ return 0;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ /*
+ * Here we don't use transaction as it will takes a lot of reserve
+ * space, and that will make a near-full btrfs unable to change uuid
+ */
+ ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+ if (ret < 0)
+ goto out;
+
+ while (1) {
+ struct btrfs_extent_item *ei;
+ struct extent_buffer *eb;
+ u64 flags;
+ u64 bytenr;
+
+ btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
+ if (key.type != BTRFS_EXTENT_ITEM_KEY &&
+ key.type != BTRFS_METADATA_ITEM_KEY)
+ goto next;
+ ei = btrfs_item_ptr(path->nodes[0], path->slots[0],
+ struct btrfs_extent_item);
+ flags = btrfs_extent_flags(path->nodes[0], ei);
+ if (!(flags & BTRFS_EXTENT_FLAG_TREE_BLOCK))
+ goto next;
+
+ bytenr = key.objectid;
+ eb = read_tree_block(root, bytenr, root->nodesize, 0);
+ if (IS_ERR(eb)) {
+ fprintf(stderr, "Failed to read tree block: %llu\n",
+ bytenr);
+ ret = PTR_ERR(eb);
+ goto out;
+ }
+ ret = change_header_uuid(root, eb);
+ free_extent_buffer(eb);
+ if (ret < 0) {
+ fprintf(stderr, "Failed to change uuid of tree block: %llu\n",
+ bytenr);
+ goto out;
+ }
+next:
+ ret = btrfs_next_item(root, path);
+ if (ret < 0)
+ goto out;
+ if (ret > 0) {
+ ret = 0;
+ goto out;
+ }
+ }
+
+out:
+ btrfs_free_path(path);
+ return ret;
+}
+
const struct prop_handler prop_handlers[] = {
{"ro", "Set/get read-only flag of subvolume.", 0, prop_object_subvol,
prop_read_only},
--
2.4.0
--
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