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>

1 files changed, 1 insertions, 1 deletions

diff --git a/fs/btrfs/transaction.h b/fs/btrfs/transaction.h
index fd52e9b23922..c3172ddb3321 100644
--- a/fs/btrfs/transaction.h
+++ b/fs/btrfs/transaction.h
@@ -29,7 +29,7 @@ struct btrfs_transaction {
         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;