MDEV-36482: Make liburing work WITH_MSAN=ON (fix)

The uring_ member of the aio_uring class needed to be
defined to make MSAN happy.

To make aio_uring consistent with aio_libaio in the 10.11 branch,
added the "using namespace tpool" and removed tpool scoped quantifiers.

10.6 aio_uring is defined in the tpool namespace however changing
that would just cause merge conflicts.

Author: grooverdan

tpool/aio_liburing.cc

@@ -29,11 +29,12 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02111 - 1301 USA*/
 
 namespace
 {
+using namespace tpool;
 
-class aio_uring final : public tpool::aio
+class aio_uring final : public aio
 {
 public:
-  aio_uring(tpool::thread_pool *tpool, int max_aio) : tpool_(tpool)
+  aio_uring(thread_pool *tpool, int max_aio) : tpool_(tpool)
   {
     if (const auto e= io_uring_queue_init(max_aio, &uring_, 0))
     {
@@ -71,6 +72,9 @@ class aio_uring final : public tpool::aio
       }
       throw std::runtime_error("aio_uring()");
     }
+#if __has_feature(memory_sanitizer)
+    MEM_MAKE_DEFINED(&uring_, sizeof(uring_));
+#endif
     if (io_uring_ring_dontfork(&uring_) != 0)
     {
       my_printf_error(ER_UNKNOWN_ERROR,
@@ -102,7 +106,7 @@ class aio_uring final : public tpool::aio
     io_uring_queue_exit(&uring_);
   }
 
-  int submit_io(tpool::aiocb *cb) final
+  int submit_io(aiocb *cb) final
   {
     cb->iov_base= cb->m_buffer;
     cb->iov_len= cb->m_len;
@@ -112,7 +116,7 @@ class aio_uring final : public tpool::aio
     std::lock_guard<std::mutex> _(mutex_);
 
     io_uring_sqe *sqe= io_uring_get_sqe(&uring_);
-    if (cb->m_opcode == tpool::aio_opcode::AIO_PREAD)
+    if (cb->m_opcode == aio_opcode::AIO_PREAD)
       io_uring_prep_readv(sqe, cb->m_fh, static_cast<struct iovec *>(cb), 1,
                           cb->m_offset);
     else
@@ -159,7 +163,7 @@ class aio_uring final : public tpool::aio
         abort();
       }
 
-      auto *iocb= static_cast<tpool::aiocb*>(io_uring_cqe_get_data(cqe));
+      auto *iocb= static_cast<aiocb*>(io_uring_cqe_get_data(cqe));
       if (!iocb)
         break; // ~aio_uring() told us to terminate
 
@@ -196,7 +200,7 @@ class aio_uring final : public tpool::aio
 
   io_uring uring_;
   std::mutex mutex_;
-  tpool::thread_pool *tpool_;
+  thread_pool *tpool_;
   std::thread thread_;
 
   std::vector<native_file_handle> files_;