Btrfs: Add a write ahead tree log to optimize synchronous operations

File syncs and directory syncs are optimized by copying their
items into a special (copy-on-write) log tree.  There is one log tree per
subvolume and the btrfs super block points to a tree of log tree roots.

After a crash, items are copied out of the log tree and back into the
subvolume.  See tree-log.c for all the details.

Signed-off-by: Chris Mason <chris.mason@oracle.com>

1 files changed, 1 insertions, 2 deletions

diff --git a/fs/btrfs/Makefile b/fs/btrfs/Makefile
index 3a01065d4ef1..b7addbfd8c22 100644
--- a/fs/btrfs/Makefile
+++ b/fs/btrfs/Makefile
@@ -7,8 +7,7 @@ btrfs-y := super.o ctree.o extent-tree.o print-tree.o root-tree.o dir-item.o \
            transaction.o bit-radix.o inode.o file.o tree-defrag.o \
            extent_map.o sysfs.o struct-funcs.o xattr.o ordered-data.o \
            extent_io.o volumes.o async-thread.o ioctl.o locking.o orphan.o \
-           ref-cache.o acl.o export.o
-
+           ref-cache.o export.o tree-log.o acl.o
 else
 
 # Normal Makefile