filestore: Don't keep checking for syncfs if found

Valgrind outputs a warning for unrecognized system calls,
and does so for the syscall(__SYS_syncfs,...) and
syscall(__NR_syncfs, ...) calls.  This patch avoids making
those calls (and the warning, when run in valgrind) if the
syncfs libc call is available.

INFO:teuthology.task.ceph.osd.1.err:--10568-- WARNING: unhandled syscall: 306
INFO:teuthology.task.ceph.osd.1.err:--10568-- You may be able to write your own handler.
INFO:teuthology.task.ceph.osd.1.err:--10568-- Read the file README_MISSING_SYSCALL_OR_IOCTL.
INFO:teuthology.task.ceph.osd.1.err:--10568-- Nevertheless we consider this a bug.  Please report
INFO:teuthology.task.ceph.osd.1.err:--10568-- it at http://valgrind.org/support/bug_reports.html.

Signed-off-by: Sam Lang <sam.lang@inktank.com>

1 files changed, 2 insertions, 4 deletions

diff --git a/src/os/FileStore.cc b/src/os/FileStore.cc
index 8cb8720738e..99cea7f22da 100644
--- a/src/os/FileStore.cc
+++ b/src/os/FileStore.cc
@@ -1227,16 +1227,14 @@ int FileStore::_detect_fs()
   } else {
     dout(0) << "mount syncfs(2) syscall supported by glibc BUT NOT the kernel" << dendl;
   }
-#endif
-#ifdef SYS_syncfs
+#elif defined(SYS_syncfs)
   if (syscall(SYS_syncfs, fd) == 0) {
     dout(0) << "mount syscall(SYS_syncfs, fd) fully supported" << dendl;
     have_syncfs = true;
   } else {
     dout(0) << "mount syscall(SYS_syncfs, fd) supported by libc BUT NOT the kernel" << dendl;
   }
-#endif
-#ifdef __NR_syncfs
+#elif defined(__NR_syncfs)
   if (syscall(__NR_syncfs, fd) == 0) {
     dout(0) << "mount syscall(__NR_syncfs, fd) fully supported" << dendl;
     have_syncfs = true;