[PATCH 3.13.y-ckt 60/86] Btrfs: fix race leading to BUG_ON when running delalloc for nodatacow

3.13.11-ckt31 -stable review patch. If anyone has any objections, please let me know. -- From: Filipe Manana commit 1d512cb77bdbda80f0dd0620a3b260d697fd581d upstream. If we are using the NO_HOLES feature, we have a tiny time window when running delalloc for a nodatacow inode

[PATCH 3.13.y-ckt 60/86] Btrfs: fix race leading to BUG_ON when running delalloc for nodatacow

3.13.11-ckt31 -stable review patch. If anyone has any objections, please let me know. -- From: Filipe Manana commit 1d512cb77bdbda80f0dd0620a3b260d697fd581d upstream. If we are using the NO_HOLES feature, we have a tiny time window when running delalloc