qemu-kvm/kvm-virtiofsd-Add-ID-to-the-log-with-FUSE_LOG_DEBUG-leve.patch

From 4d9106acfd7ed9e4d197ddf9f22b79ba6c8afdd8 Mon Sep 17 00:00:00 2001
From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Date: Mon, 27 Jan 2020 19:01:38 +0100
Subject: [PATCH 067/116] virtiofsd: Add ID to the log with FUSE_LOG_DEBUG
 level
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RH-Author: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-id: <20200127190227.40942-64-dgilbert@redhat.com>
Patchwork-id: 93514
O-Subject: [RHEL-AV-8.2 qemu-kvm PATCH 063/112] virtiofsd: Add ID to the log with FUSE_LOG_DEBUG level
Bugzilla: 1694164
RH-Acked-by: Philippe Mathieu-Daudé <philmd@redhat.com>
RH-Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
RH-Acked-by: Sergio Lopez Pascual <slp@redhat.com>

From: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com>

virtiofsd has some threads, so we see a lot of logs with debug option.
It would be useful for debugging if we can identify the specific thread
from the log.

Add ID, which is got by gettid(), to the log with FUSE_LOG_DEBUG level
so that we can grep the specific thread.

The log is like as:

  ]# ./virtiofsd -d -o vhost_user_socket=/tmp/vhostqemu0 -o source=/tmp/share0 -o cache=auto
  ...
  [ID: 00000097]    unique: 12696, success, outsize: 120
  [ID: 00000097] virtio_send_msg: elem 18: with 2 in desc of length 120
  [ID: 00000003] fv_queue_thread: Got queue event on Queue 1
  [ID: 00000003] fv_queue_thread: Queue 1 gave evalue: 1 available: in: 65552 out: 80
  [ID: 00000003] fv_queue_thread: Waiting for Queue 1 event
  [ID: 00000071] fv_queue_worker: elem 33: with 2 out desc of length 80 bad_in_num=0 bad_out_num=0
  [ID: 00000071] unique: 12694, opcode: READ (15), nodeid: 2, insize: 80, pid: 2014
  [ID: 00000071] lo_read(ino=2, size=65536, off=131072)

Signed-off-by: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com>

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
  added rework as suggested by Daniel P. Berrangé during review
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
(cherry picked from commit 36f3846902bd41413f6c0bf797dee509028c29f4)

Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
---
 tools/virtiofsd/passthrough_ll.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/tools/virtiofsd/passthrough_ll.c b/tools/virtiofsd/passthrough_ll.c
index ff6910f..f08324f 100644
--- a/tools/virtiofsd/passthrough_ll.c
+++ b/tools/virtiofsd/passthrough_ll.c
@@ -43,6 +43,7 @@
 #include <cap-ng.h>
 #include <dirent.h>
 #include <errno.h>
+#include <glib.h>
 #include <inttypes.h>
 #include <limits.h>
 #include <pthread.h>
@@ -2268,10 +2269,17 @@ static void setup_nofile_rlimit(void)
 
 static void log_func(enum fuse_log_level level, const char *fmt, va_list ap)
 {
+    g_autofree char *localfmt = NULL;
+
     if (current_log_level < level) {
         return;
     }
 
+    if (current_log_level == FUSE_LOG_DEBUG) {
+        localfmt = g_strdup_printf("[ID: %08ld] %s", syscall(__NR_gettid), fmt);
+        fmt = localfmt;
+    }
+
     if (use_syslog) {
         int priority = LOG_ERR;
         switch (level) {
-- 
1.8.3.1