Turn flush into a controlpath message

resolves: RHEL-85510

0018-server-Turn-flush-into-a-controlpath-message.patch

@@ -0,0 +1,33 @@
+From 23a2ec7a574dda51a5b4bd2ddef3dcc2b2c8b8f2 Mon Sep 17 00:00:00 2001
+From: "Richard W.M. Jones" <rjones@redhat.com>
+Date: Sat, 5 Apr 2025 09:02:03 +0100
+Subject: [PATCH] server: Turn flush into a controlpath message
+
+The server debug flags -D nbdkit.backend.controlpath=<bool> and
+-D nbdkit.backend.datapath=<bool> control the verbosity of messages.
+
+'flush' was categorized as a datapath message, but it's more arguably
+a controlpath message, and anyway it is rare and useful to see in
+virt-v2v output even when datapath messages are suppressed.
+
+(cherry picked from commit 079c8a91bf5161614916470dcb1f52bee8bfb397)
+---
+ server/backend.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/server/backend.c b/server/backend.c
+index 6232b69d..1f1bcfce 100644
+--- a/server/backend.c
++++ b/server/backend.c
+@@ -693,7 +693,7 @@ backend_flush (struct context *c,
+   assert (c->handle && (c->state & HANDLE_CONNECTED));
+   assert (c->can_flush == 1);
+   assert (flags == 0);
+-  datapath_debug ("%s: flush", b->name);
++  controlpath_debug ("%s: flush", b->name);
+ 
+   r = b->flush (c, flags, err);
+   if (r == -1)
+-- 
+2.47.1
+

nbdkit.spec

@@ -56,7 +56,7 @@
 
 Name:           nbdkit
 Version:        1.38.5
-Release:        4%{?dist}
+Release:        5%{?dist}
 Summary:        NBD server
 
 License:        BSD-3-Clause
@@ -98,6 +98,7 @@ Patch0014:     0014-tests-Add-more-generic-tests-of-file-cache-none.patch
 Patch0015:     0015-file-Hard-error-if-sync_file_range-fails.patch
 Patch0016:     0016-file-Reduce-the-size-of-the-lock-around-write-evicti.patch
 Patch0017:     0017-file-Document-implicit-assumption-about-eviction-win.patch
+Patch0018:     0018-server-Turn-flush-into-a-controlpath-message.patch
 
 # For automatic RPM Provides generation.
 # See: https://rpm-software-management.github.io/rpm/manual/dependency_generators.html
@@ -1516,7 +1517,7 @@ fi
 
 
 %changelog
-* Tue Apr 01 2025 Richard W.M. Jones <rjones@redhat.com> - 1.38.5-4
+* Mon Apr 07 2025 Richard W.M. Jones <rjones@redhat.com> - 1.38.5-5
 - Add extra system call checking and debugging to nbdkit-file-plugin
   resolves: RHEL-85510