On Tue, Aug 28, 2018 at 08:07:52AM +0800, Qu Wenruo wrote: > > > On 2018/8/28 上午6:33, Tucker Boniface wrote: > > Hello, I am trying to convert an ext4 partition to btrfs using > > btrfs-convert. I am running Arch Linux with kernel 4.18.5 and > > btrfs-progs 4.17.1. The full error is inline below. > > > > -> # btrfs-convert /dev/sda1 > > create btrfs filesystem: > > blocksize: 4096 > > nodesize: 16384 > > features: extref, skinny-metadata (default) > > creating ext2 image file > > Unable to find block group for 0 > > Unable to find block group for 0 > > Unable to find block group for 0 > > extent-tree.c:2743: alloc_tree_block: BUG_ON `ret` triggered, value -28 > > This means ENOSPC. > Your ext* doesn't have enough free space to contain btrfs' metadata.
Can we do something better than a crash? The BUG_ON is in alloc_tree_block, there's only one caller btrfs_alloc_free_block that handles errors, so it should be straightforward to fix.
