diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c
index 0d5a3846811a..43e8c331168e 100644
--- a/fs/btrfs/relocation.c
+++ b/fs/btrfs/relocation.c
@@ -2811,6 +2811,20 @@ static noinline_for_stack int prealloc_file_extent_cluster(struct reloc_control
 		 * will re-read the whole page anyway.
 		 */
 		if (!IS_ERR(folio)) {
+			/*
+			 * release_folio() could have cleared the folio private data
+			 * while we were not holding the lock. Reset the mapping if
+			 * needed so subpage operations can access a valid private
+			 * folio state.
+			 */
+			ret = set_folio_extent_mapped(folio);
+			if (ret) {
+				folio_unlock(folio);
+				folio_put(folio);
+
+				return ret;
+			}
+
 			btrfs_subpage_clear_uptodate(fs_info, folio, i_size,
 					round_up(i_size, PAGE_SIZE) - i_size);
 			folio_unlock(folio);