Pull btrfs fixes from Chris Mason:
"This fixes some lockups in btrfs reported with rc1. It probably has
some performance impact because it is backing off our spinning locks
more often and switching to a blocking lock. I'll be able to nail
that down next week, but for now I want to get the lockups taken care
of.
Otherwise some more stack reduction and assorted fixes"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
Btrfs: fix wrong error handle when the device is missing or is not writeable
Btrfs: fix deadlock when mounting a degraded fs
Btrfs: use bio_endio_nodec instead of open code
Btrfs: fix NULL pointer crash when running balance and scrub concurrently
btrfs: Skip scrubbing removed chunks to avoid -ENOENT.
Btrfs: fix broken free space cache after the system crashed
Btrfs: make free space cache write out functions more readable
Btrfs: remove unused wait queue in struct extent_buffer
Btrfs: fix deadlocks with trylock on tree nodes