From 1d8f69f453c2e8a2d99b158e58e02ed65031fa6d Mon Sep 17 00:00:00 2001 From: Mark Harmstone Date: Tue, 13 Jan 2026 18:37:56 +0000 Subject: [PATCH] btrfs: fix missing fields in superblock backup with BLOCK_GROUP_TREE When the BLOCK_GROUP_TREE compat_ro flag is set, the extent root and csum root fields are getting missed. This is because EXTENT_TREE_V2 treated these differently, and when they were split off this special-casing was mistakenly assigned to BGT rather than the rump EXTENT_TREE_V2. There's no reason why the existence of the block group tree should mean that we don't record the details of the last commit's extent root and csum root. Fix the code in backup_super_roots() so that the correct check gets made. Fixes: 1c56ab991903 ("btrfs: separate BLOCK_GROUP_TREE compat RO flag from EXTENT_TREE_V2") Reviewed-by: Qu Wenruo Signed-off-by: Mark Harmstone Reviewed-by: David Sterba Signed-off-by: David Sterba --- fs/btrfs/disk-io.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index fbd498aa9b99..22d706e4f341 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -1661,7 +1661,7 @@ static void backup_super_roots(struct btrfs_fs_info *info) btrfs_set_backup_chunk_root_level(root_backup, btrfs_header_level(info->chunk_root->node)); - if (!btrfs_fs_compat_ro(info, BLOCK_GROUP_TREE)) { + if (!btrfs_fs_incompat(info, EXTENT_TREE_V2)) { struct btrfs_root *extent_root = btrfs_extent_root(info, 0); struct btrfs_root *csum_root = btrfs_csum_root(info, 0); -- 2.47.3