os/bluestore/bluefs: only bytes_written_slow > 0, we update perfcounter.

In fact, wrote data into slow devcie is unexpected(see
option: bluestore_warn_on_bluefs_spillover).

Signed-off-by: Jianpeng Ma <jianpeng.ma@intel.com>

diff --git a/src/os/bluestore/BlueFS.cc b/src/os/bluestore/BlueFS.cc
index bc40b66e5fa5e9d2073d4a2be8046bf6bb63283f..2f61997696094babde1bd3258cb19a56c26d5ccb 100644 (file)
--- a/src/os/bluestore/BlueFS.cc
+++ b/src/os/bluestore/BlueFS.cc
@@ -2886,7 +2886,9 @@ int BlueFS::_flush_range(FileWriter *h, uint64_t offset, uint64_t length)
     ++p;
     x_off = 0;
   }
-  logger->inc(l_bluefs_bytes_written_slow, bytes_written_slow);
+  if (bytes_written_slow) {
+    logger->inc(l_bluefs_bytes_written_slow, bytes_written_slow);
+  }
   for (unsigned i = 0; i < MAX_BDEV; ++i) {
     if (bdev[i]) {
       if (h->iocv[i] && h->iocv[i]->has_pending_aios()) {