MDEV-27901 Windows : expensive system calls used to calculate file system block sizebb-10.2-wlad

The result is not used anywhere but in the output of Innodb information
schema, but this can take as much as 7%CPU (only) on a benchmark.

Fix to move fs blocksize calculate to where it is used.

2 files changed, 37 insertions, 64 deletions

diff --git a/storage/innobase/handler/i_s.cc b/storage/innobase/handler/i_s.cc
index 1111d974ad0..fb7f0e5ecbb 100644
--- a/storage/innobase/handler/i_s.cc
+++ b/storage/innobase/handler/i_s.cc
@@ -6745,6 +6745,9 @@ static ST_FIELD_INFO innodb_sys_tablespaces_fields_info[]=
   END_OF_ST_FIELD_INFO
 };
 
+
+extern size_t os_file_get_fs_block_size(const char *path);
+
 /**********************************************************************//**
 Function to fill INFORMATION_SCHEMA.INNODB_SYS_TABLESPACES with information
 collected by scanning SYS_TABLESPACESS table.
@@ -6814,11 +6817,10 @@ i_s_dict_fill_sys_tablespaces(
 	OK(fields[SYS_TABLESPACES_ZIP_PAGE_SIZE]->store(
 		   page_size.physical(), true));
 
-	os_file_stat_t	stat;
+	size_t fs_block_size = 0;
 	os_file_size_t	file;
 
 	memset(&file, 0xff, sizeof(file));
-	memset(&stat, 0x0, sizeof(stat));
 
 	if (fil_space_t* s = fil_space_acquire_silent(space)) {
 		const char *filepath = s->chain.start
@@ -6828,36 +6830,19 @@ i_s_dict_fill_sys_tablespaces(
 		}
 
 		file = os_file_get_size(filepath);
-
-		/* Get the file system (or Volume) block size. */
-		switch (dberr_t err = os_file_get_status(filepath, &stat,
-							 false, false)) {
-		case DB_FAIL:
-			ib::warn()
-				<< "File '" << filepath << "', failed to get "
-				<< "stats";
-			break;
-
-		case DB_SUCCESS:
-		case DB_NOT_FOUND:
-			break;
-
-		default:
-			ib::error() << "File '" << filepath << "' " << err;
-			break;
-		}
+		fs_block_size= os_file_get_fs_block_size(filepath);
 
 file_done:
 		fil_space_release(s);
 	}
 
 	if (file.m_total_size == static_cast<os_offset_t>(~0)) {
-		stat.block_size = 0;
+		fs_block_size = 0;
 		file.m_total_size = 0;
 		file.m_alloc_size = 0;
 	}
 
-	OK(fields[SYS_TABLESPACES_FS_BLOCK_SIZE]->store(stat.block_size, true));
+	OK(fields[SYS_TABLESPACES_FS_BLOCK_SIZE]->store(fs_block_size, true));
 
 	OK(fields[SYS_TABLESPACES_FILE_SIZE]->store(file.m_total_size, true));
 
diff --git a/storage/innobase/os/os0file.cc b/storage/innobase/os/os0file.cc
index 48be5256ab1..fbfbdb27c0c 100644
--- a/storage/innobase/os/os0file.cc
+++ b/storage/innobase/os/os0file.cc
@@ -4795,48 +4795,6 @@ os_file_get_status_win32(
 				CloseHandle(fh);
 			}
 		}
-		stat_info->block_size = 0;
-
-		/* What follows, is calculation of FS block size, which is not important
-		(it is just shown in I_S innodb tables). The error to calculate it will be ignored.*/
-		char	volname[MAX_PATH];
-		BOOL	result = GetVolumePathName(path, volname, MAX_PATH);
-		static	bool warned_once = false;
-		if (!result) {
-			if (!warned_once) {
-				ib::warn()
-					<< "os_file_get_status_win32: "
-					<< "Failed to get the volume path name for: "
-					<< path
-					<< "- OS error number " << GetLastError();
-				warned_once = true;
-			}
-			return(DB_SUCCESS);
-		}
-
-		DWORD	sectorsPerCluster;
-		DWORD	bytesPerSector;
-		DWORD	numberOfFreeClusters;
-		DWORD	totalNumberOfClusters;
-
-		result = GetDiskFreeSpace(
-			(LPCSTR) volname,
-			&sectorsPerCluster,
-			&bytesPerSector,
-			&numberOfFreeClusters,
-			&totalNumberOfClusters);
-
-		if (!result) {
-			if (!warned_once) {
-				ib::warn()
-					<< "GetDiskFreeSpace(" << volname << ",...) "
-					<< "failed "
-					<< "- OS error number " << GetLastError();
-				warned_once = true;
-			}
-			return(DB_SUCCESS);
-		}
-		stat_info->block_size = bytesPerSector * sectorsPerCluster;
 	} else {
 		stat_info->type = OS_FILE_TYPE_UNKNOWN;
 	}
@@ -5736,6 +5694,36 @@ os_is_sparse_file_supported(os_file_t fh)
 #endif /* _WIN32 */
 }
 
+/*
+  Get file system block size, by path.
+
+  This is expensive on Windows, and not very useful in general,
+  (only shown in some I_S table), so we keep that out of usual
+  stat.
+*/
+size_t os_file_get_fs_block_size(const char *path)
+{
+#ifdef _WIN32
+  char volname[MAX_PATH];
+  if (!GetVolumePathName(path, volname, MAX_PATH))
+    return 0;
+  DWORD sectorsPerCluster;
+  DWORD bytesPerSector;
+  DWORD numberOfFreeClusters;
+  DWORD totalNumberOfClusters;
+
+  if (GetDiskFreeSpace(volname, &sectorsPerCluster, &bytesPerSector,
+                       &numberOfFreeClusters, &totalNumberOfClusters))
+    return ((size_t) bytesPerSector) * sectorsPerCluster;
+#else
+  os_file_stat_t info;
+  if (os_file_get_status(path, &info, false, false) == DB_SUCCESS)
+    return info.block_size;
+#endif
+  return 0;
+}
+
+
 /** This function returns information about the specified file
 @param[in]	path		pathname of the file
 @param[out]	stat_info	information of a file in a directory