[patch] patch to add fdatasync support

submitted-fdatasync.diff (text/plain), 3.77 KB, created by Matt Turner on 2009-10-19 00:55:52 UTC

2009-07-25  Aurelien Jarno  <[e-mail]>

	* sysdeps/unix/sysv/linux/kernel-features.h: define 
	__ASSUME_FDATASYNC. 
	* sysdeps/unix/sysv/linux/fdatasync.c: New file.
	* sysdeps/unix/sysv/linux/Makefile: compile fdatasync.c with
	-fexceptions.
	* sysdeps/unix/sysv/linux/syscalls.list: Remove fdatasync.

---
 sysdeps/unix/sysv/linux/Makefile          |    1 
 sysdeps/unix/sysv/linux/fdatasync.c       |   69 ++++++++++++++++++++++++++++++
 sysdeps/unix/sysv/linux/kernel-features.h |    6 ++
 sysdeps/unix/sysv/linux/syscalls.list     |    1 
 4 files changed, 76 insertions(+), 1 deletion(-)

--- a/sysdeps/unix/sysv/linux/kernel-features.h
+++ b/sysdeps/unix/sysv/linux/kernel-features.h
@@ -474,6 +474,12 @@
 # define __ASSUME_FUTEX_LOCK_PI	1
 #endif
 
+/* Support for fsyncdata syscall was added in 2.6.22 on alpha, but it
+   was already present in 2.0 kernels on other architectures.  */
+#if (!defined __alpha || __LINUX_KERNEL_VERSION >= 0x020616)
+# define __ASSUME_FDATASYNC	1
+#endif
+
 /* Support for utimensat syscall was added in 2.6.22, on alpha and s390
    only after 2.6.22-rc1.  */
 #if __LINUX_KERNEL_VERSION >= 0x020616 \
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/fdatasync.c
@@ -0,0 +1,69 @@
+/* fdatasync -- synchronize at least the data part of a file with 
+   the underlying media. Linux version. 
+
+   Copyright (C) 2007 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#include <errno.h>
+#include <unistd.h>
+
+#include <sysdep-cancel.h>
+#include <sys/syscall.h>
+#include <bp-checks.h>
+
+#include <kernel-features.h>
+
+#if defined __NR_fdatasync && !defined __ASSUME_FDATASYNC
+static int __have_no_fdatasync;
+#endif
+
+static int
+do_fdatasync (int fd)
+{
+#ifdef __ASSUME_FDATASYNC
+  return INLINE_SYSCALL (fdatasync, 1, fd);
+#elif defined __NR_fdatasync
+  if (!__builtin_expect (__have_no_fdatasync, 0))
+    {
+      int result = INLINE_SYSCALL (fdatasync, 1, fd);
+      if (__builtin_expect (result, 0) != -1 || errno != ENOSYS)
+	return result;
+
+      __have_no_fdatasync = 1;
+    }
+#endif
+  return INLINE_SYSCALL (fsync, 1, fd);
+}
+
+int
+__fdatasync (int fd)
+{
+  if (SINGLE_THREAD_P)
+    return do_fdatasync (fd);
+
+  int oldtype = LIBC_CANCEL_ASYNC ();
+
+  int result = do_fdatasync (fd);
+
+  LIBC_CANCEL_RESET (oldtype);
+
+  return result;
+}
+
+weak_alias (__fdatasync, fdatasync)
+
--- a/sysdeps/unix/sysv/linux/syscalls.list
+++ b/sysdeps/unix/sysv/linux/syscalls.list
@@ -11,7 +11,6 @@
 epoll_create1	EXTRA	epoll_create1	i:i	epoll_create1
 epoll_ctl	EXTRA	epoll_ctl	i:iiip	epoll_ctl
 epoll_wait	EXTRA	epoll_wait	Ci:ipii	epoll_wait
-fdatasync	-	fdatasync	Ci:i	fdatasync
 flock		-	flock		i:ii	__flock		flock
 fork		-	fork		i:	__libc_fork	__fork fork
 get_kernel_syms	EXTRA	get_kernel_syms	i:p	get_kernel_syms
--- a/sysdeps/unix/sysv/linux/Makefile
+++ b/sysdeps/unix/sysv/linux/Makefile
@@ -17,6 +17,7 @@
 		   eventfd eventfd_read eventfd_write
 
 
+CFLAGS-fdatasync.c = -fexceptions
 CFLAGS-gethostid.c = -fexceptions
 
 sysdep_headers += sys/mount.h sys/acct.h sys/sysctl.h \