From f268a97669b2871735fb0a2bb9cda275bf8c204f Mon Sep 17 00:00:00 2001
From: tangbinzy <tangbin_yewu@cmss.chinamobile.com>
Date: Thu, 24 Nov 2022 02:45:01 +0000
Subject: [PATCH 13/23] vircgroupv2devices: fix counting entries in BPF  map
 BPF syscall BPF_MAP_GET_NEXT_KEY returns -1 if something fails but it will
 also return -1 if trying to get next key using the last key in the map with
 errno set to ENOENT.

If there are VMs running and libvirtd is restarted and user tries to
call some cgroup devices operation on a VM we need to get the count of
entries in BPF map and it fails which will result in error when trying
to attach/detech devices.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1833321

Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Reviewed-by: Erik Skultety <eskultet@redhat.com>

Signed-off-by: tangbin <tangbin_yewu@cmss.chinamobile.com>
(cherry-pick from 7e574d1a079bd13aeeedb7024cc45f85b1843fcc)
---
 src/util/vircgroupv2devices.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/util/vircgroupv2devices.c b/src/util/vircgroupv2devices.c
index d62ee12a05..234e0f2278 100644
--- a/src/util/vircgroupv2devices.c
+++ b/src/util/vircgroupv2devices.c
@@ -342,7 +342,7 @@ virCgroupV2DevicesCountMapEntries(int mapfd)
         prevKey = key;
     }
 
-    if (rc < 0)
+    if (rc < 0 && errno != ENOENT)
         return -1;
 
     return ret;
-- 
2.27.0

