Btrfs: Split the extent_map code into two parts
There is now extent_map for mapping offsets in the file to disk and
extent_io for state tracking, IO submission and extent_bufers.
The new extent_map code shifts from [start,end] pairs to [start,len], and
pushes the locking out into the caller. This allows a few performance
optimizations and is easier to use.
A number of extent_map usage bugs were fixed, mostly with failing
to remove extent_map entries when changing the file.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/transaction.h b/fs/btrfs/transaction.h
index fd52e9b..c3172dd 100644
--- a/fs/btrfs/transaction.h
+++ b/fs/btrfs/transaction.h
@@ -29,7 +29,7 @@
int use_count;
int commit_done;
struct list_head list;
- struct extent_map_tree dirty_pages;
+ struct extent_io_tree dirty_pages;
unsigned long start_time;
struct btrfs_ordered_inode_tree ordered_inode_tree;
wait_queue_head_t writer_wait;