Btrfs: Fix compressed checksum fsync log copies

The fsync logging code makes sure to onl copy the relevant checksum for each
extent based on the file extent pointers it finds.

But for compressed extents, it needs to copy the checksum for the
entire extent.

Signed-off-by: Chris Mason <chris.mason@oracle.com>

fs/btrfs/file.c

@@ -1228,7 +1228,8 @@ int btrfs_sync_file(struct file *file, struct dentry *dentry, int datasync)
 	mutex_unlock(&root->fs_info->trans_mutex);
 
 	root->fs_info->tree_log_batch++;
-	filemap_fdatawait(inode->i_mapping);
+	filemap_fdatawrite(inode->i_mapping);
+	btrfs_wait_ordered_range(inode, 0, (u64)-1);
 	root->fs_info->tree_log_batch++;
 
 	/*

fs/btrfs/tree-log.c

@@ -2610,6 +2610,11 @@ static noinline int copy_items(struct btrfs_trans_handle *trans,
 				u64 cs = btrfs_file_extent_offset(src, extent);
 				u64 cl = btrfs_file_extent_num_bytes(src,
 								     extent);;
+				if (btrfs_file_extent_compression(src,
+								  extent)) {
+					cs = 0;
+					cl = dl;
+				}
 				/* ds == 0 is a hole */
 				if (ds != 0) {
 					ret = btrfs_inc_extent_ref(trans, log,