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, 4 insertions, 4 deletions

diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 163c01a24498..b4a1bc62a784 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -70,7 +70,7 @@ static int join_transaction(struct btrfs_root *root)
                 INIT_LIST_HEAD(&cur_trans->pending_snapshots);
                 list_add_tail(&cur_trans->list, &root->fs_info->trans_list);
                 btrfs_ordered_inode_tree_init(&cur_trans->ordered_inode_tree);
-                extent_map_tree_init(&cur_trans->dirty_pages,
+                extent_io_tree_init(&cur_trans->dirty_pages,
                                      root->fs_info->btree_inode->i_mapping,
                                      GFP_NOFS);
         } else {
@@ -153,7 +153,7 @@ int btrfs_write_and_wait_transaction(struct btrfs_trans_handle *trans,
         int ret;
         int err;
         int werr = 0;
-        struct extent_map_tree *dirty_pages;
+        struct extent_io_tree *dirty_pages;
         struct page *page;
         struct inode *btree_inode = root->fs_info->btree_inode;
         u64 start;
@@ -610,7 +610,7 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
         struct btrfs_transaction *cur_trans;
         struct btrfs_transaction *prev_trans = NULL;
         struct list_head dirty_fs_roots;
-        struct extent_map_tree *pinned_copy;
+        struct extent_io_tree *pinned_copy;
         DEFINE_WAIT(wait);
         int ret;
 
@@ -639,7 +639,7 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
         if (!pinned_copy)
                 return -ENOMEM;
 
-        extent_map_tree_init(pinned_copy,
+        extent_io_tree_init(pinned_copy,
                              root->fs_info->btree_inode->i_mapping, GFP_NOFS);
 
         trans->transaction->in_commit = 1;