With misc-next and your debug patch I first ran into another assert: [ 250.848976][T35903] assertion failed: 0, in fs/btrfs/relocation.c:2042 [ 250.849963][T35903] ------------[ cut here ]------------ [ 250.850472][T35903] kernel BUG at fs/btrfs/relocation.c:2042! and here is the output from your assert: [ 1378.272143][T189001] BTRFS error (device loop1): reloc tree mismatch, root 8 has no reloc root, expect reloc root key (-8, 132, 8) gen 17 [ 1378.274019][T189001] ------------[ cut here ]------------ [ 1378.274540][T189001] BTRFS: Transaction aborted (error -117) [ 1378.277110][T189001] WARNING: CPU: 3 PID: 189001 at fs/btrfs/relocation.c:1946 prepare_to_merge+0x10e0/0x1460
