Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable:
Btrfs: make sure fallocate properly starts a transaction
Btrfs: make metadata chunks smaller
Btrfs: Show discard option in /proc/mounts
Btrfs: deny sys_link across subvolumes.
Btrfs: fail mount on bad mount options
Btrfs: don't add extent 0 to the free space cache v2
Btrfs: Fix per root used space accounting
Btrfs: Fix btrfs_drop_extent_cache for skip pinned case
Btrfs: Add delayed iput
Btrfs: Pass transaction handle to security and ACL initialization functions
Btrfs: Make truncate(2) more ENOSPC friendly
Btrfs: Make fallocate(2) more ENOSPC friendly
Btrfs: Avoid orphan inodes cleanup during committing transaction
Btrfs: Avoid orphan inodes cleanup while replaying log
Btrfs: Fix disk_i_size update corner case
Btrfs: Rewrite btrfs_drop_extents
Btrfs: Add btrfs_duplicate_item
Btrfs: Avoid superfluous tree-log writeout