[PATCH stable-5.4] backport enospc issues during balance

[Anand Jain]

Patch 1 is a preparatory patch to reduce conflicts. Patch 2 fixes
balance failure due to ENOSPC in btrfs/156 on arm64 systems with
pagesize=64k. Minor conflicts in fs/btrfs/block-group.c are resolved.
Thanks.

Josef Bacik (2):
  btrfs: don't pass system_chunk into can_overcommit
  btrfs: take overcommit into account in inc_block_group_ro

 fs/btrfs/block-group.c | 38 ++++++++++++++++++++++----------
 fs/btrfs/space-info.c  | 50 +++++++++++++++++-------------------------
 fs/btrfs/space-info.h  |  3 +++
 3 files changed, 49 insertions(+), 42 deletions(-)

-- 
2.18.4