branches/5.1: Remove the innodb_flush_method fdatasync option since it was

not being used and there was a potential it could mislead users.

include/srv0srv.h

@@ -249,11 +249,7 @@ extern srv_sys_t*	srv_sys;
 
 /* Alternatives for the file flush option in Unix; see the InnoDB manual
 about what these mean */
-#define SRV_UNIX_FDATASYNC	1	/* This is the default; it is
-					currently mapped to a call of
-					fsync() because fdatasync() seemed
-					to corrupt files in Linux and
-					Solaris */
+#define SRV_UNIX_FSYNC		1	/* This is the default */
 #define SRV_UNIX_O_DSYNC	2
 #define SRV_UNIX_LITTLESYNC	3
 #define SRV_UNIX_NOSYNC		4

os/os0file.c

@@ -22,8 +22,6 @@ Created 10/21/1995 Heikki Tuuri
 #include <errno.h>
 #endif /* UNIV_HOTBACKUP */
 
-#undef HAVE_FDATASYNC
-
 #ifdef POSIX_ASYNC_IO
 /* We assume in this case that the OS has standard Posix aio (at least SunOS
 2.6, HP-UX 11i and AIX 4.3 have) */
@@ -1879,8 +1877,6 @@ os_file_flush(
 			ret = fsync(file);
 		}
 	}
-#elif HAVE_FDATASYNC
-	ret = fdatasync(file);
 #else
 	/*	fprintf(stderr, "Flushing to file %p\n", file); */
 	ret = fsync(file);

srv/srv0srv.c

@@ -192,7 +192,7 @@ a heavier load on the I/O sub system. */
 ulong	srv_insert_buffer_batch_size = 20;
 
 char*	srv_file_flush_method_str = NULL;
-ulint	srv_unix_file_flush_method = SRV_UNIX_FDATASYNC;
+ulint	srv_unix_file_flush_method = SRV_UNIX_FSYNC;
 ulint	srv_win_file_flush_method = SRV_WIN_IO_UNBUFFERED;
 
 ulint	srv_max_n_open_files	  = 300;

srv/srv0start.c

@@ -1122,12 +1122,12 @@ innobase_start_or_create_for_mysql(void)
 	if (srv_file_flush_method_str == NULL) {
 		/* These are the default options */
 
-		srv_unix_file_flush_method = SRV_UNIX_FDATASYNC;
+		srv_unix_file_flush_method = SRV_UNIX_FSYNC;
 
 		srv_win_file_flush_method = SRV_WIN_IO_UNBUFFERED;
 #ifndef __WIN__
-	} else if (0 == ut_strcmp(srv_file_flush_method_str, "fdatasync")) {
-		srv_unix_file_flush_method = SRV_UNIX_FDATASYNC;
+	} else if (0 == ut_strcmp(srv_file_flush_method_str, "fsync")) {
+		srv_unix_file_flush_method = SRV_UNIX_FSYNC;
 
 	} else if (0 == ut_strcmp(srv_file_flush_method_str, "O_DSYNC")) {
 		srv_unix_file_flush_method = SRV_UNIX_O_DSYNC;