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-rw-r--r--arch/alpha/include/asm/fcntl.h19
1 files changed, 16 insertions, 3 deletions
diff --git a/arch/alpha/include/asm/fcntl.h b/arch/alpha/include/asm/fcntl.h
index 25da0017ec87..21b1117a0c61 100644
--- a/arch/alpha/include/asm/fcntl.h
+++ b/arch/alpha/include/asm/fcntl.h
@@ -1,8 +1,6 @@
#ifndef _ALPHA_FCNTL_H
#define _ALPHA_FCNTL_H
-/* open/fcntl - O_SYNC is only implemented on blocks devices and on files
- located on an ext2 file system */
#define O_CREAT 01000 /* not fcntl */
#define O_TRUNC 02000 /* not fcntl */
#define O_EXCL 04000 /* not fcntl */
@@ -10,13 +8,28 @@
#define O_NONBLOCK 00004
#define O_APPEND 00010
-#define O_SYNC 040000
+#define O_DSYNC 040000 /* used to be O_SYNC, see below */
#define O_DIRECTORY 0100000 /* must be a directory */
#define O_NOFOLLOW 0200000 /* don't follow links */
#define O_LARGEFILE 0400000 /* will be set by the kernel on every open */
#define O_DIRECT 02000000 /* direct disk access - should check with OSF/1 */
#define O_NOATIME 04000000
#define O_CLOEXEC 010000000 /* set close_on_exec */
+/*
+ * Before Linux 2.6.32 only O_DSYNC semantics were implemented, but using
+ * the O_SYNC flag. We continue to use the existing numerical value
+ * for O_DSYNC semantics now, but using the correct symbolic name for it.
+ * This new value is used to request true Posix O_SYNC semantics. It is
+ * defined in this strange way to make sure applications compiled against
+ * new headers get at least O_DSYNC semantics on older kernels.
+ *
+ * This has the nice side-effect that we can simply test for O_DSYNC
+ * wherever we do not care if O_DSYNC or O_SYNC is used.
+ *
+ * Note: __O_SYNC must never be used directly.
+ */
+#define __O_SYNC 020000000
+#define O_SYNC (__O_SYNC|O_DSYNC)
#define F_GETLK 7
#define F_SETLK 8