suse:~/btrfs-unstable # git am < ../btrfs-quasi-round-robin-for-chunk-allocation.patch
Applying: btrfs: quasi-round-robin for chunk allocation
error: patch failed: fs/btrfs/volumes.c:2255
error: fs/btrfs/volumes.c: patch does not apply
error: patch failed: fs/btrfs/volumes.h:144
error: fs/btrfs/volumes.h: patch does not apply
Patch failed at 0001 btrfs: quasi-round-robin for chunk allocation
When you have resolved this problem run "git am --resolved".
If you would prefer to skip this patch, instead run "git am --skip".
To restore the original branch and stop patching run "git am --abort".