MDEV-22177 more fsync() -> fdatasync() in InnoDB

Replace all fsync() with fdatasync() when possible (e.g. On Linux)

InnoDB doesn't care about file timestamps. So, to achieve a better
performance it makes sense to use fdatasync() everywhere.

file_io::flush(): renamed from flush_data_only()

os_file_flush_data(): removed

os_file_sync_posix(): renamed from os_file_fsync_posix(). Now it uses
fdatasync() when it's available.

Author: kevgs

storage/innobase/handler/ha_innodb.cc

@@ -18566,7 +18566,7 @@ checkpoint_now_set(THD*, st_mysql_sys_var*, void*, const void* save)
 		       + SIZE_OF_FILE_CHECKPOINT
 		       < log_sys.get_lsn()) {
 			log_make_checkpoint();
-			log_sys.log.flush_data_only();
+			log_sys.log.flush();
 		}
 
 		dberr_t err = fil_write_flushed_lsn(log_sys.get_lsn());

storage/innobase/include/log0log.h

@@ -442,9 +442,9 @@ class file_io
   virtual dberr_t read(os_offset_t offset, span<byte> buf) noexcept= 0;
   virtual dberr_t write(const char *path, os_offset_t offset,
                         span<const byte> buf) noexcept= 0;
-  virtual dberr_t flush_data_only() noexcept= 0;
+  virtual dberr_t flush() noexcept= 0;
 
-  /** Durable writes doesn't require calling flush_data_only() */
+  /** Durable writes doesn't require calling flush() */
   bool writes_are_durable() const noexcept { return m_durable_writes; }
 
 protected:
@@ -468,7 +468,7 @@ class file_os_io final: public file_io
   dberr_t read(os_offset_t offset, span<byte> buf) noexcept final;
   dberr_t write(const char *path, os_offset_t offset,
                 span<const byte> buf) noexcept final;
-  dberr_t flush_data_only() noexcept final;
+  dberr_t flush() noexcept final;
 
 private:
   pfs_os_file_t m_fd{OS_FILE_CLOSED};
@@ -490,7 +490,7 @@ class log_file_t
   dberr_t read(os_offset_t offset, span<byte> buf) noexcept;
   bool writes_are_durable() const noexcept;
   dberr_t write(os_offset_t offset, span<const byte> buf) noexcept;
-  dberr_t flush_data_only() noexcept;
+  dberr_t flush() noexcept;
 
 private:
   std::unique_ptr<file_io> m_file;
@@ -596,14 +596,14 @@ struct log_t{
     @param[in]	offset		offset in log file
     @param[in]	buf		buffer where to read */
     void read(os_offset_t offset, span<byte> buf);
-    /** Tells whether writes require calling flush_data_only() */
+    /** Tells whether writes require calling flush() */
     bool writes_are_durable() const noexcept;
     /** writes buffer to log file
     @param[in]	offset		offset in log file
     @param[in]	buf		buffer from which to write */
     void write(os_offset_t offset, span<byte> buf);
     /** flushes OS page cache (excluding metadata!) for log file */
-    void flush_data_only();
+    void flush();
     /** closes log file */
     void close_file();
 

storage/innobase/include/os0file.h

@@ -744,9 +744,6 @@ The wrapper functions have the prefix of "innodb_". */
 # define os_file_flush(file)					\
 	pfs_os_file_flush_func(file, __FILE__, __LINE__)
 
-#define os_file_flush_data(file)                                              \
-  pfs_os_file_flush_data_func(file, __FILE__, __LINE__)
-
 # define os_file_rename(key, oldpath, newpath)				\
 	pfs_os_file_rename_func(key, oldpath, newpath, __FILE__, __LINE__)
 
@@ -992,17 +989,6 @@ pfs_os_file_flush_func(
 	const char*	src_file,
 	uint		src_line);
 
-/** NOTE! Please use the corresponding macro os_file_flush_data(), not directly
-this function!
-This is the performance schema instrumented wrapper function for
-os_file_flush_data() which flushes only(!) data (excluding metadata) from OS
-page cache of a given file to the disk.
-@param[in]	file		Open file handle
-@param[in]	src_file	file name where func invoked
-@param[in]	src_line	line where the func invoked
-@return true if success */
-bool pfs_os_file_flush_data_func(pfs_os_file_t file, const char *src_file,
-                                 uint src_line);
 
 /** NOTE! Please use the corresponding macro os_file_rename(), not directly
 this function!
@@ -1098,8 +1084,6 @@ to original un-instrumented file I/O APIs */
 
 # define os_file_flush(file)	os_file_flush_func(file)
 
-#define os_file_flush_data(file) os_file_flush_data_func(file)
-
 # define os_file_rename(key, oldpath, newpath)				\
 	os_file_rename_func(oldpath, newpath)
 
@@ -1179,14 +1163,6 @@ bool
 os_file_flush_func(
 	os_file_t	file);
 
-/** NOTE! Use the corresponding macro os_file_flush_data(), not directly this
-function!
-Flushes only(!) data (excluding metadata) from OS page cache of a given file to
-the disk.
-@param[in]	file		handle to a file
-@return true if success */
-bool os_file_flush_data_func(os_file_t file);
-
 /** Retrieves the last error number if an error occurs in a file io function.
 The number should be retrieved before any other OS calls (because they may
 overwrite the error number). If the number is not known to this program,

storage/innobase/log/log0log.cc

@@ -633,9 +633,9 @@ dberr_t file_os_io::write(const char *path, os_offset_t offset,
                        buf.size());
 }
 
-dberr_t file_os_io::flush_data_only() noexcept
+dberr_t file_os_io::flush() noexcept
 {
-  return os_file_flush_data(m_fd) ? DB_SUCCESS : DB_ERROR;
+  return os_file_flush(m_fd) ? DB_SUCCESS : DB_ERROR;
 }
 
 #ifdef HAVE_PMEM
@@ -674,7 +674,7 @@ class file_pmem_io final : public file_io
     pmem_memcpy_persist(m_file.data() + offset, buf.data(), buf.size());
     return DB_SUCCESS;
   }
-  dberr_t flush_data_only() noexcept final
+  dberr_t flush() noexcept final
   {
     ut_ad(0);
     return DB_SUCCESS;
@@ -746,10 +746,10 @@ dberr_t log_file_t::write(os_offset_t offset, span<const byte> buf) noexcept
   return m_file->write(m_path.c_str(), offset, buf);
 }
 
-dberr_t log_file_t::flush_data_only() noexcept
+dberr_t log_file_t::flush() noexcept
 {
   ut_ad(is_opened());
-  return m_file->flush_data_only();
+  return m_file->flush();
 }
 
 void log_t::file::open_file(std::string path)
@@ -788,7 +788,7 @@ void log_t::file::write_header_durable(lsn_t lsn)
 
   log_sys.log.write(0, buf);
   if (!log_sys.log.writes_are_durable())
-    log_sys.log.flush_data_only();
+    log_sys.log.flush();
 }
 
 void log_t::file::read(os_offset_t offset, span<byte> buf)
@@ -813,11 +813,11 @@ void log_t::file::write(os_offset_t offset, span<byte> buf)
   log_sys.n_log_ios++;
 }
 
-void log_t::file::flush_data_only()
+void log_t::file::flush()
 {
   log_sys.pending_flushes.fetch_add(1, std::memory_order_acquire);
-  if (const dberr_t err= fd.flush_data_only())
-    ib::fatal() << "flush_data_only(" << fd.get_path() << ") returned " << err;
+  if (const dberr_t err= fd.flush())
+    ib::fatal() << "flush(" << fd.get_path() << ") returned " << err;
   log_sys.pending_flushes.fetch_sub(1, std::memory_order_release);
   log_sys.flushes.fetch_add(1, std::memory_order_release);
 }
@@ -936,7 +936,7 @@ log_write_buf(
 and invoke log_mutex_enter(). */
 static void log_write_flush_to_disk_low(lsn_t lsn)
 {
-  log_sys.log.flush_data_only();
+  log_sys.log.flush();
   ut_a(lsn >= log_sys.get_flushed_lsn());
   log_sys.set_flushed_lsn(lsn);
 }
@@ -1294,7 +1294,7 @@ void log_write_checkpoint_info(lsn_t end_lsn)
 							   : LOG_CHECKPOINT_1,
 			  {buf, OS_FILE_LOG_BLOCK_SIZE});
 
-	log_sys.log.flush_data_only();
+	log_sys.log.flush();
 
 	log_mutex_enter();
 
@@ -1742,7 +1742,7 @@ logs_empty_and_mark_files_at_shutdown(void)
 
 		/* Ensure that all buffered changes are written to the
 		redo log before fil_close_all_files(). */
-		log_sys.log.flush_data_only();
+		log_sys.log.flush();
 	} else {
 		lsn = recv_sys.recovered_lsn;
 	}

storage/innobase/os/os0file.cc

@@ -78,6 +78,9 @@ Created 10/21/1995 Heikki Tuuri
 #include <my_sys.h>
 #endif
 
+#include <thread>
+#include <chrono>
+
 /* Per-IO operation environment*/
 class io_slots
 {
@@ -879,55 +882,53 @@ os_file_get_last_error_low(
 	return(OS_FILE_ERROR_MAX + err);
 }
 
-/** Wrapper to fsync(2) that retries the call on some errors.
+/** Wrapper to fsync() or fdatasync() that retries the call on some errors.
 Returns the value 0 if successful; otherwise the value -1 is returned and
 the global variable errno is set to indicate the error.
 @param[in]	file		open file handle
 @return 0 if success, -1 otherwise */
-static
-int
-os_file_fsync_posix(
-	os_file_t	file)
+static int os_file_sync_posix(os_file_t file)
 {
-	ulint		failures = 0;
-
-	for (;;) {
-
-		++os_n_fsyncs;
-
-		int	ret = fsync(file);
+#if !defined(HAVE_FDATASYNC) || HAVE_DECL_FDATASYNC == 0
+  auto func= fsync;
+  auto func_name= "fsync()";
+#else
+  auto func= fdatasync;
+  auto func_name= "fdatasync()";
+#endif
 
-		if (ret == 0) {
-			return(ret);
-		}
+  ulint failures= 0;
 
-		switch(errno) {
-		case ENOLCK:
+  for (;;)
+  {
+    ++os_n_fsyncs;
 
-			++failures;
-			ut_a(failures < 1000);
+    int ret= func(file);
 
-			if (!(failures % 100)) {
+    if (ret == 0)
+      return ret;
 
-				ib::warn()
-					<< "fsync(): "
-					<< "No locks available; retrying";
-			}
+    switch (errno)
+    {
+    case ENOLCK:
+      ++failures;
+      ut_a(failures < 1000);
 
-			/* 0.2 sec */
-			os_thread_sleep(200000);
-			break;
+      if (!(failures % 100))
+        ib::warn() << func_name << ": No locks available; retrying";
 
-		case EINTR:
+      std::this_thread::sleep_for(std::chrono::milliseconds(200));
+      break;
 
-			++failures;
-			ut_a(failures < 2000);
-			break;
+    case EINTR:
+      ++failures;
+      ut_a(failures < 2000);
+      break;
 
-		default:
-			ib::fatal() << "fsync() returned " << errno;
-		}
-	}
+    default:
+      ib::fatal() << func_name << " returned " << errno;
+    }
+  }
 }
 
 /** Check the existence and type of the given file.
@@ -988,7 +989,7 @@ os_file_flush_func(
 	int	ret;
 
 	WAIT_ALLOW_WRITES();
-	ret = os_file_fsync_posix(file);
+	ret = os_file_sync_posix(file);
 
 	if (ret == 0) {
 		return(true);
@@ -4604,32 +4605,3 @@ os_normalize_path(
 		}
 	}
 }
-
-bool os_file_flush_data_func(os_file_t file) {
-#if defined(_WIN32) || !defined(HAVE_FDATASYNC) || HAVE_DECL_FDATASYNC == 0
-  return os_file_flush_func(file);
-#else
-  bool success= fdatasync(file) != -1;
-  if (!success) {
-    ib::error() << "fdatasync() errno: " << errno;
-  }
-  return success;
-#endif
-}
-
-#ifdef UNIV_PFS_IO
-bool pfs_os_file_flush_data_func(pfs_os_file_t file, const char *src_file,
-                                 uint src_line)
-{
-  PSI_file_locker_state state;
-  struct PSI_file_locker *locker= NULL;
-
-  register_pfs_file_io_begin(&state, locker, file, 0, PSI_FILE_SYNC, src_file,
-                             src_line);
-
-  bool success= os_file_flush_data_func(file);
-
-  register_pfs_file_io_end(locker, 0);
-  return success;
-}
-#endif

storage/innobase/srv/srv0start.cc

@@ -1033,7 +1033,7 @@ static lsn_t srv_prepare_to_delete_redo_log_file(bool old_exists)
 
 		if (flushed_lsn != log_sys.get_flushed_lsn()) {
 			log_write_up_to(flushed_lsn, false);
-			log_sys.log.flush_data_only();
+			log_sys.log.flush();
 		}
 
 		ut_ad(flushed_lsn == log_get_lsn());