XFS shut down with -ENOSPC and 862 GiB free. The reservation was never initialised.
XFS (nvme0n1p2): Internal error at line 721 of file fs/xfs/libxfs/xfs_defer.c 862 GiB free. A 2 TB NVMe drive at 53% capacity. The filesystem shut itself down because it could not allocate one block. TL;DR xfs_parent_da_args_init() never sets args->total. The field stays zero, xfs_da_grow_inode_int() subtracts from it, and it underflows to 0xFFFFFFFF. Every downstream guard that should catch an impossible allocation is defeated by a single (int) cast, so maxlen gets clamped to zero and the allocator rejects its own arguments with a bare -ENOSPC. xfs_defer_finish_noroll() treats that as fatal and takes the filesystem down. ...