storage/posix, libglusterfs: library function to sync filesystem

Convert an ad-hoc hack to a regular library function gf_syncfs().

Signed-off-by: Dmitry Antipov <dmantipov@yandex.ru>
Change-Id: I3ed93e9f28f22c273df1466ba4a458eacb8df395
Fixes: #1329

5 files changed, 39 insertions, 17 deletions

diff --git a/configure.ac b/configure.ac
index d24a7b5cee6..c2dc20260bd 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1037,6 +1037,19 @@ else
    CFLAGS=${OLD_CFLAGS}
 fi
 
+AC_CHECK_FUNC([syncfs], [have_syncfs=yes])
+if test "x${have_syncfs}" = "xyes"; then
+   AC_DEFINE(HAVE_SYNCFS, 1, [define if syncfs exists])
+else
+   OLD_CFLAGS=${CFLAGS}
+   CFLAGS="-D_GNU_SOURCE"
+   AC_CHECK_DECL([SYS_syncfs], , , [#include <sys/syscall.h>])
+   if test "x${ac_cv_have_decl_SYS_syncfs}" = "xyes"; then
+      AC_DEFINE(HAVE_SYNCFS_SYS, 1, [define if SYS_syncfs is available])
+   fi
+   CFLAGS=${OLD_CFLAGS}
+fi
+
 BUILD_NANOSECOND_TIMESTAMPS=no
 AC_CHECK_FUNC([utimensat], [have_utimensat=yes])
 if test "x${have_utimensat}" = "xyes"; then
diff --git a/libglusterfs/src/common-utils.c b/libglusterfs/src/common-utils.c
index 899d579e837..81c39959406 100644
--- a/libglusterfs/src/common-utils.c
+++ b/libglusterfs/src/common-utils.c
@@ -37,6 +37,9 @@
 #ifndef GF_LINUX_HOST_OS
 #include <sys/resource.h>
 #endif
+#ifdef HAVE_SYNCFS_SYS
+#include <sys/syscall.h>
+#endif
 
 #include "glusterfs/compat-errno.h"
 #include "glusterfs/common-utils.h"
@@ -5412,3 +5415,20 @@ gf_nanosleep(uint64_t nsec)
 
     return ret;
 }
+
+int
+gf_syncfs(int fd)
+{
+    int ret = 0;
+#if defined(HAVE_SYNCFS)
+    /* Linux with glibc recent enough. */
+    ret = syncfs(fd);
+#elif defined(HAVE_SYNCFS_SYS)
+    /* Linux with no library function. */
+    ret = syscall(SYS_syncfs, fd);
+#else
+    /* Fallback to generic UNIX stuff. */
+    sync();
+#endif
+    return ret;
+}
diff --git a/libglusterfs/src/glusterfs/common-utils.h b/libglusterfs/src/glusterfs/common-utils.h
index 1954cca639f..8948fada7c3 100644
--- a/libglusterfs/src/glusterfs/common-utils.h
+++ b/libglusterfs/src/glusterfs/common-utils.h
@@ -1205,6 +1205,9 @@ int
 gf_d_type_from_ia_type(ia_type_t type);
 
 int
+gf_syncfs(int fd);
+
+int
 gf_nanosleep(uint64_t nsec);
 
 #endif /* _COMMON_UTILS_H */
diff --git a/libglusterfs/src/libglusterfs.sym b/libglusterfs/src/libglusterfs.sym
index c80b892df25..70408711c57 100644
--- a/libglusterfs/src/libglusterfs.sym
+++ b/libglusterfs/src/libglusterfs.sym
@@ -1180,4 +1180,5 @@ glusterfs_process_svc_detach
 mgmt_is_multiplexed_daemon
 xlator_is_cleanup_starting
 gf_nanosleep
+gf_syncfs
 graph_total_client_xlator
diff --git a/xlators/storage/posix/src/posix-helpers.c b/xlators/storage/posix/src/posix-helpers.c
index 73443a6a2e5..7f69afedf1f 100644
--- a/xlators/storage/posix/src/posix-helpers.c
+++ b/xlators/storage/posix/src/posix-helpers.c
@@ -2395,23 +2395,8 @@ posix_fsyncer_syncfs(xlator_t *this, struct list_head *head)
 
     stub = list_entry(head->prev, call_stub_t, list);
     ret = posix_fd_ctx_get(stub->args.fd, this, &pfd, NULL);
-    if (ret)
-        return;
-
-#ifdef GF_LINUX_HOST_OS
-        /* syncfs() is not "declared" in RHEL's glibc even though
-           the kernel has support.
-        */
-#include <sys/syscall.h>
-#include <unistd.h>
-#ifdef SYS_syncfs
-    syscall(SYS_syncfs, pfd->fd);
-#else
-    sync();
-#endif
-#else
-    sync();
-#endif
+    if (!ret)
+        (void)gf_syncfs(pfd->fd);
 }
 
 void *