For created snapshots, the full root_item is copied from the source root and afterwards selectively modified. The current code forgets to clear the field received_uuid. The only problem is that it is confusing when you look at it with 'btrfs subv list', since for writable snapshots, the contents of the snapshot can be completely unrelated to the previously received snapshot. The receiver ignores such snapshots anyway because he also checks the field stransid in the root_item and that value used to be reset to zero for all created snapshots.
This commit changes two things: - clear the received_uuid field for new writable snapshots. - don't clear the send/receive related information like the stransid for read-only snapshots (which makes them useable as a parent for the automatic selection of parents in the receive code). Signed-off-by: Stefan Behrens <sbehr...@giantdisaster.de> --- fs/btrfs/transaction.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c index ffac232..94cbd10 100644 --- a/fs/btrfs/transaction.c +++ b/fs/btrfs/transaction.c @@ -1170,13 +1170,17 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans, memcpy(new_root_item->uuid, new_uuid.b, BTRFS_UUID_SIZE); memcpy(new_root_item->parent_uuid, root->root_item.uuid, BTRFS_UUID_SIZE); + if (!(root_flags & BTRFS_ROOT_SUBVOL_RDONLY)) { + memset(new_root_item->received_uuid, 0, + sizeof(new_root_item->received_uuid)); + memset(&new_root_item->stime, 0, sizeof(new_root_item->stime)); + memset(&new_root_item->rtime, 0, sizeof(new_root_item->rtime)); + btrfs_set_root_stransid(new_root_item, 0); + btrfs_set_root_rtransid(new_root_item, 0); + } new_root_item->otime.sec = cpu_to_le64(cur_time.tv_sec); new_root_item->otime.nsec = cpu_to_le32(cur_time.tv_nsec); btrfs_set_root_otransid(new_root_item, trans->transid); - memset(&new_root_item->stime, 0, sizeof(new_root_item->stime)); - memset(&new_root_item->rtime, 0, sizeof(new_root_item->rtime)); - btrfs_set_root_stransid(new_root_item, 0); - btrfs_set_root_rtransid(new_root_item, 0); old = btrfs_lock_root_node(root); ret = btrfs_cow_block(trans, root, old, NULL, 0, &old); -- 1.8.2.1 -- 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