Submitted as: https://github.com/ceph/ceph/pull/45185

--- a/src/os/bluestore/BlueStore.cc
+++ b/src/os/bluestore/BlueStore.cc
@@ -18548,7 +18548,7 @@
   uint64_t        extent_count       = 0;
   uint64_t        extents_bytes_left = file_size - (header_size + trailer_size + sizeof(crc));
   while (extents_bytes_left) {
-    int req_bytes  = std::min(extents_bytes_left, sizeof(buffer));
+    int req_bytes  = std::min(extents_bytes_left, static_cast<uint64_t>(sizeof(buffer)));
     int read_bytes = bluefs->read(p_handle.get(), offset, req_bytes, nullptr, (char*)buffer);
     if (read_bytes != req_bytes) {
       derr << "Failed bluefs->read()::read_bytes=" << read_bytes << ", req_bytes=" << req_bytes << dendl;