btrfs: Handle btrfs_set_extent_delalloc failure in relocate_file_extent_cluster

Essentially duplicate the error handling from the above block which
handles the !PageUptodate(page) case and additionally clear
EXTENT_BOUNDARY.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/relocation.c

@@ -3268,8 +3268,22 @@ static int relocate_file_extent_cluster(struct inode *inode,
 			nr++;
 		}
 
-		btrfs_set_extent_delalloc(inode, page_start, page_end, 0, NULL,
-					  0);
+		ret = btrfs_set_extent_delalloc(inode, page_start, page_end, 0,
+						NULL, 0);
+		if (ret) {
+			unlock_page(page);
+			put_page(page);
+			btrfs_delalloc_release_metadata(BTRFS_I(inode),
+							 PAGE_SIZE);
+			btrfs_delalloc_release_extents(BTRFS_I(inode),
+			                               PAGE_SIZE);
+
+			clear_extent_bits(&BTRFS_I(inode)->io_tree,
+					  page_start, page_end,
+					  EXTENT_LOCKED | EXTENT_BOUNDARY);
+			goto out;
+
+		}
 		set_page_dirty(page);
 
 		unlock_extent(&BTRFS_I(inode)->io_tree,