reproducing steps: mkfs.btrfs /dev/dm-2 -f mount /dev/dm-2 /btrfs umount /btrfs btrfs check /dev/dm-2 --repair mount /dev/dm-2 /btrfs
---- btrfs: mismatching generation and generation_v2 found in root item. This root was probably mounted with an older kernel. Resetting all new fields. ---- btrfs-debug-tree shows change in uuid < root data bytenr 29425664 level 0 dirid 0 refs 1 gen 43 < uuid 293596e8-7888-eb4c-9134-6df9db996fe5 --- > root data bytenr 29417472 level 0 dirid 0 refs 1 gen 46 > uuid 38d16308-fc48-0645-ac49-748f96634148 Signed-off-by: Anand Jain <anand.j...@oracle.com> --- root-tree.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/root-tree.c b/root-tree.c index c10d068..4454147 100644 --- a/root-tree.c +++ b/root-tree.c @@ -69,6 +69,7 @@ int btrfs_update_root(struct btrfs_trans_handle *trans, struct btrfs_root int ret; int slot; unsigned long ptr; + u32 old_size; path = btrfs_alloc_path(); BUG_ON(!path); @@ -79,6 +80,18 @@ int btrfs_update_root(struct btrfs_trans_handle *trans, struct btrfs_root l = path->nodes[0]; slot = path->slots[0]; ptr = btrfs_item_ptr_offset(l, slot); + /* + * If the btrfs-progs is newer and kernel is at + * generation_v1 then we don't touch v2 items + * otherwise when kernel is at same or greater + * version compared with btrfs-progs then update + * the needed + */ + old_size = btrfs_item_size_nr(l, slot); + if (old_size >= sizeof(*item)) { + btrfs_set_root_generation_v2(item, + btrfs_root_generation(item)); + } write_extent_buffer(l, item, ptr, sizeof(*item)); btrfs_mark_buffer_dirty(path->nodes[0]); out: -- 1.8.1.227.g44fe835 -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html