From a7a8631bc3b8d5a6de58d501c9779ee0c620594f Mon Sep 17 00:00:00 2001
From: Leonid Yuriev <leo@yuriev.ru>
Date: Mon, 21 Sep 2020 03:27:40 +0300
Subject: [PATCH] mdbx: allow sync_file_range() to fail for Valgrind/QEMU
 cases.

Change-Id: I9aa77d1debfbd0cb18e940946533e4ed758d08e8
---
 src/core.c    | 18 ++++++++++++++----
 src/options.h |  6 +++---
 2 files changed, 17 insertions(+), 7 deletions(-)

diff --git a/src/core.c b/src/core.c
index 0a89b724..d5e2f7ac 100644
--- a/src/core.c
+++ b/src/core.c
@@ -4950,14 +4950,24 @@ __cold static int mdbx_wipe_steady(MDBX_env *env, const txnid_t last_steady) {
       return err;
   } else {
 #if MDBX_USE_SYNCFILERANGE
-    if (sync_file_range(env->me_lazy_fd, 0, pgno2bytes(env, NUM_METAS),
-                        SYNC_FILE_RANGE_WRITE | SYNC_FILE_RANGE_WAIT_AFTER))
+    static bool syncfilerange_unavailable;
+    if (likely(!syncfilerange_unavailable)) {
+      if (likely(!sync_file_range(
+              env->me_lazy_fd, 0, pgno2bytes(env, NUM_METAS),
+              SYNC_FILE_RANGE_WRITE | SYNC_FILE_RANGE_WAIT_AFTER)))
+        goto done_filesync;
       err = errno;
-#else
+      if (ignore_enosys(err) != MDBX_RESULT_TRUE)
+        return err;
+      syncfilerange_unavailable = true;
+    }
+#endif /* MDBX_USE_SYNCFILERANGE */
     err = mdbx_fsync(env->me_lazy_fd, MDBX_SYNC_DATA);
-#endif
     if (unlikely(err != MDBX_SUCCESS))
       return err;
+#if MDBX_USE_SYNCFILERANGE
+  done_filesync:
+#endif /* MDBX_USE_SYNCFILERANGE */
     mdbx_flush_incoherent_mmap(env->me_map, pgno2bytes(env, NUM_METAS),
                                env->me_os_psize);
   }
diff --git a/src/options.h b/src/options.h
index 75634013..8f0f213a 100644
--- a/src/options.h
+++ b/src/options.h
@@ -184,9 +184,9 @@
 
 /** Advanced: Using sync_file_range() syscall (autodetection by default). */
 #ifndef MDBX_USE_SYNCFILERANGE
-#if (defined(__linux__) || defined(__gnu_linux__)) &&                          \
-    (!defined(__ANDROID_API__) || __ANDROID_API__ >= 26) &&                    \
-    defined(_GNU_SOURCE) && !defined(MDBX_SAFE4QEMU)
+#if ((defined(__linux__) || defined(__gnu_linux__)) && __GLIBC_PREREQ(2, 6) && \
+     defined(_GNU_SOURCE)) ||                                                  \
+    (defined(__ANDROID_API__) && __ANDROID_API__ >= 26)
 #define MDBX_USE_SYNCFILERANGE 1
 #else
 #define MDBX_USE_SYNCFILERANGE 0