From 5a03cd009ae8d9c819c3f24f16695f8a334b8ad9 Mon Sep 17 00:00:00 2001
From: Aleksandar Markovic <aleksandar.markovic@imgtec.com>
Date: Mon, 10 Oct 2016 13:23:30 +0200
Subject: [PATCH] linux-user: Add support for syncfs() syscall

This patch implements Qemu user mode syncfs() syscall support. Syscall
syncfs() syncs the filesystem containing file determined by the open
file descriptor passed as the argument to syncfs().

The implementation consists of a straightforward invocation of host's
syncfs(). Configure and strace support is included as well.

Signed-off-by: Aleksandar Markovic <aleksandar.markovic@imgtec.com>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
---
 configure              | 18 ++++++++++++++++++
 linux-user/strace.list |  2 +-
 linux-user/syscall.c   |  5 +++++
 3 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/configure b/configure
index 1ce3d002ed..d3dafcbb37 100755
--- a/configure
+++ b/configure
@@ -3926,6 +3926,21 @@ if compile_prog "" "" ; then
   clock_adjtime=yes
 fi
 
+# syncfs probe
+syncfs=no
+cat > $TMPC <<EOF
+#include <unistd.h>
+
+int main(void)
+{
+    return syncfs(0);
+}
+EOF
+syncfs=no
+if compile_prog "" "" ; then
+  syncfs=yes
+fi
+
 # Check if tools are available to build documentation.
 if test "$docs" != "no" ; then
   if has makeinfo && has pod2man; then
@@ -5214,6 +5229,9 @@ fi
 if test "$clock_adjtime" = "yes" ; then
   echo "CONFIG_CLOCK_ADJTIME=y" >> $config_host_mak
 fi
+if test "$syncfs" = "yes" ; then
+  echo "CONFIG_SYNCFS=y" >> $config_host_mak
+fi
 if test "$inotify" = "yes" ; then
   echo "CONFIG_INOTIFY=y" >> $config_host_mak
 fi
diff --git a/linux-user/strace.list b/linux-user/strace.list
index dcd3812cad..3b1282ec1a 100644
--- a/linux-user/strace.list
+++ b/linux-user/strace.list
@@ -1459,7 +1459,7 @@
 { TARGET_NR_sync, "sync" , NULL, NULL, NULL },
 #endif
 #ifdef TARGET_NR_syncfs
-{ TARGET_NR_syncfs, "syncfs" , NULL, NULL, NULL },
+{ TARGET_NR_syncfs, "syncfs" , "%s(%d)", NULL, NULL },
 #endif
 #ifdef TARGET_NR_syscall
 { TARGET_NR_syscall, "syscall" , NULL, NULL, NULL },
diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index 14929965ff..14c52072f9 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -8090,6 +8090,11 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1,
         sync();
         ret = 0;
         break;
+#if defined(TARGET_NR_syncfs) && defined(CONFIG_SYNCFS)
+    case TARGET_NR_syncfs:
+        ret = get_errno(syncfs(arg1));
+        break;
+#endif
     case TARGET_NR_kill:
         ret = get_errno(safe_kill(arg1, target_to_host_signal(arg2)));
         break;