MDEV-11520 after-merge fix for 10.1: Use sparse files.

If page_compression (introduced in MariaDB Server 10.1) is enabled,
the logical action is to not preallocate space to the data files,
but to only logically extend the files with zeroes.

fil_create_new_single_table_tablespace(): Create smaller files for
ROW_FORMAT=COMPRESSED tables, but adhere to the minimum file size of
4*innodb_page_size.

fil_space_extend_must_retry(), os_file_set_size(): On Windows,
use SetFileInformationByHandle() and FILE_END_OF_FILE_INFO,
which depends on bumping _WIN32_WINNT to 0x0600.
FIXME: The files are not yet set up as sparse, so
this will currently end up physically extending (preallocating)
the files, wasting storage for unused pages.

os_file_set_size(): Add the parameter "bool sparse=false" to declare
that the file is to be extended logically, instead of being preallocated.
The only caller with sparse=true is
fil_create_new_single_table_tablespace().
(The system tablespace cannot be created with page_compression.)

fil_space_extend_must_retry(), os_file_set_size(): Outside Windows,
use ftruncate() to extend files that are supposed to be sparse.
On systems where ftruncate() is limited to files less than 4GiB
(if there are any), fil_space_extend_must_retry() retains the
old logic of physically extending the file.

1 files changed, 11 insertions, 9 deletions

diff --git a/storage/innobase/include/os0file.h b/storage/innobase/include/os0file.h
index 23276c5b471..af3961d9f82 100644
--- a/storage/innobase/include/os0file.h
+++ b/storage/innobase/include/os0file.h
@@ -881,17 +881,19 @@ os_file_get_size(
 /*=============*/
 	os_file_t	file)	/*!< in: handle to a file */
 	MY_ATTRIBUTE((warn_unused_result));
-/***********************************************************************//**
-Write the specified number of zeros to a newly created file.
-@return	TRUE if success */
+/** Set the size of a newly created file.
+@param[in]	name	file name
+@param[in]	file	file handle
+@param[in]	size	desired file size
+@param[in]	sparse	whether to create a sparse file (no preallocating)
+@return	whether the operation succeeded */
 UNIV_INTERN
-ibool
+bool
 os_file_set_size(
-/*=============*/
-	const char*	name,	/*!< in: name of the file or path as a
-				null-terminated string */
-	os_file_t	file,	/*!< in: handle to a file */
-	os_offset_t	size)	/*!< in: file size */
+	const char*	name,
+	os_file_t	file,
+	os_offset_t	size,
+	bool		is_sparse = false)
 	MY_ATTRIBUTE((nonnull, warn_unused_result));
 /***********************************************************************//**
 Truncates a file at its current position.