Btrfs: Remove offset field from struct btrfs_extent_ref

The offset field in struct btrfs_extent_ref records the position
inside file that file extent is referenced by. In the new back
reference system, tree leaves holding references to file extent
are recorded explicitly. We can scan these tree leaves very quickly, so the
offset field is not required.

This patch also makes the back reference system check the objectid
when extents are in deleting.

Signed-off-by: Yan Zheng <zheng.yan@oracle.com>

1 files changed, 2 insertions, 4 deletions

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index f9df89c5fdfc..3ab147dc3c05 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -647,8 +647,7 @@ static int btrfs_finish_ordered_io(struct inode *inode, u64 start, u64 end)
         ins.type = BTRFS_EXTENT_ITEM_KEY;
         ret = btrfs_alloc_reserved_extent(trans, root, leaf->start,
                                           root->root_key.objectid,
-                                          trans->transid, inode->i_ino,
-                                          ordered_extent->file_offset, &ins);
+                                          trans->transid, inode->i_ino, &ins);
         BUG_ON(ret);
         btrfs_release_path(root, path);
 
@@ -1734,8 +1733,7 @@ delete:
                         ret = btrfs_free_extent(trans, root, extent_start,
                                                 extent_num_bytes,
                                                 leaf->start, root_owner,
-                                                root_gen, inode->i_ino,
-                                                found_key.offset, 0);
+                                                root_gen, inode->i_ino, 0);
                         BUG_ON(ret);
                 }
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