Upstream: add qemu_fdatasync()

Change-Id: I232b9c4df372e1fded97694fffcd72ef9ea113c4

4 files changed, 27 insertions, 0 deletions

diff --git a/android-configure.sh b/android-configure.sh
index 7a23954..0e95e04 100755
--- a/android-configure.sh
+++ b/android-configure.sh
@@ -419,6 +419,14 @@ echo "#define CONFIG_GDBSTUB  1" >> $config_h
 echo "#define CONFIG_SLIRP    1" >> $config_h
 echo "#define CONFIG_SKINS    1" >> $config_h
 echo "#define CONFIG_TRACE    1" >> $config_h
+
+# only Linux has fdatasync()
+case "$OS" in
+    linux-*)
+        echo "#define CONFIG_FDATASYNC    1" >> $config_h
+        ;;
+esac
+
 # the -nand-limits options can only work on non-windows systems
 if [ "$OS" != "windows" ] ; then
     echo "#define CONFIG_NAND_LIMITS  1" >> $config_h
diff --git a/android/config/linux-x86/config-host.h b/android/config/linux-x86/config-host.h
index a97d2c6..904dbfa 100644
--- a/android/config/linux-x86/config-host.h
+++ b/android/config/linux-x86/config-host.h
@@ -11,3 +11,4 @@
 #define CONFIG_UNAME_RELEASE ""
 #define CONFIG_IOTHREAD 1
 #define CONFIG_IOVEC 1
+#define CONFIG_FDATASYNC 1
diff --git a/cutils.c b/cutils.c
index ffe5c71..2365e68 100644
--- a/cutils.c
+++ b/cutils.c
@@ -115,6 +115,22 @@ int qemu_fls(int i)
     return 32 - clz32(i);
 }
 
+/*
+ * Make sure data goes on disk, but if possible do not bother to
+ * write out the inode just for timestamp updates.
+ *
+ * Unfortunately even in 2009 many operating systems do not support
+ * fdatasync and have to fall back to fsync.
+ */
+int qemu_fdatasync(int fd)
+{
+#ifdef CONFIG_FDATASYNC
+    return fdatasync(fd);
+#else
+    return fsync(fd);
+#endif
+}
+
 /* io vectors */
 
 void qemu_iovec_init(QEMUIOVector *qiov, int alloc_hint)
diff --git a/qemu-common.h b/qemu-common.h
index 1416dfd..664e83f 100644
--- a/qemu-common.h
+++ b/qemu-common.h
@@ -110,8 +110,10 @@ void pstrcpy(char *buf, int buf_size, const char *str);
 char *pstrcat(char *buf, int buf_size, const char *s);
 int strstart(const char *str, const char *val, const char **ptr);
 int stristart(const char *str, const char *val, const char **ptr);
+int qemu_strnlen(const char *s, int max_len);
 time_t mktimegm(struct tm *tm);
 int qemu_fls(int i);
+int qemu_fdatasync(int fd);
 
 #define qemu_isalnum(c)		isalnum((unsigned char)(c))
 #define qemu_isalpha(c)		isalpha((unsigned char)(c))