commit 5a03cd009ae8d9c819c3f24f16695f8a334b8ad9
author Aleksandar Markovic <aleksandar.markovic@imgtec.com> Mon Oct 10 13:23:30 2016 +0200
committer Riku Voipio <riku.voipio@linaro.org> Fri Oct 21 15:20:13 2016 +0300
tree d86a30aef0ffce1c052152b0106ac6f61e44280d
parent 38860a0343df894a1c3371597eb4d305078642fb

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

diff --git a/configure b/configure
index 1ce3d00..d3dafcb 100755
--- a/configure
+++ b/configure
@@ -3926,6 +3926,21 @@
   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 @@
 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

linux-user/strace.list

diff --git a/linux-user/strace.list b/linux-user/strace.list
index dcd3812..3b1282e 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 },

linux-user/syscall.c

diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index 1492996..14c5207 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -8090,6 +8090,11 @@
         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;