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>
diff --git a/fs/btrfs/btrfs_inode.h b/fs/btrfs/btrfs_inode.h
index 111f905..fcc8cf2 100644
--- a/fs/btrfs/btrfs_inode.h
+++ b/fs/btrfs/btrfs_inode.h
@@ -33,6 +33,7 @@
struct extent_io_tree io_failure_tree;
struct mutex csum_mutex;
struct mutex extent_mutex;
+ struct mutex log_mutex;
struct inode vfs_inode;
struct btrfs_ordered_inode_tree ordered_tree;
@@ -44,10 +45,17 @@
struct list_head delalloc_inodes;
+ /* full 64 bit generation number */
+ u64 generation;
+
/*
* transid of the trans_handle that last modified this inode
*/
u64 last_trans;
+ /*
+ * transid that last logged this inode
+ */
+ u64 logged_trans;
u64 delalloc_bytes;
u64 disk_i_size;
u32 flags;