btrfs and mainline and git

Hello,

1.
I normally copy btrfs into the mainline and run make, however with the recent btrfs release its failing with the following, any idea. ?

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# make
scripts/kconfig/conf --silentoldconfig Kconfig
fs/btrfs/Kconfig:6: syntax error
fs/Kconfig:9: missing end statement for this entry
fs/Kconfig:5: missing end statement for this entry
fs/btrfs/Kconfig:5: invalid statement
arch/x86/Kconfig:253: recursive inclusion detected. Inclusion path:
  current file : 'arch/x86/Kconfig'
  included from: 'fs/btrfs/Kconfig:11'
  included from: 'fs/Kconfig:36'
  included from: 'arch/x86/Kconfig:2145'
make[2]: *** [silentoldconfig] Error 1
make[1]: *** [silentoldconfig] Error 2
make: *** No rule to make target `include/config/auto.conf', needed by `include/config/kernel.release'.  Stop.
#
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2.
Looks like the official way is to use git merge. What are the recommended git (merge ?) steps, to integrate btrfs into the mainline ?

Thanks for your time,
-Anand