From 4f1adbc42c93d406d73e30243ddaa6cb11257a24 Mon Sep 17 00:00:00 2001
From: John Snow <jsnow@redhat.com>
Date: Tue, 4 Jun 2019 17:47:22 +0200
Subject: [PATCH 8/9] blockdev: fix missed target unref for drive-backup

RH-Author: John Snow <jsnow@redhat.com>
Message-id: <20190604174722.30906-2-jsnow@redhat.com>
Patchwork-id: 88526
O-Subject: [RHEL-7.7 qemu-kvm-rhev PATCH 1/1] blockdev: fix missed target unref for drive-backup
Bugzilla: 1703916
RH-Acked-by: Max Reitz <mreitz@redhat.com>
RH-Acked-by: Kevin Wolf <kwolf@redhat.com>
RH-Acked-by: Stefano Garzarella <sgarzare@redhat.com>

If the bitmap can't be used for whatever reason, we skip putting down
the reference. Fix that.

In practice, this means that if you attempt to gracefully exit QEMU
after a backup command being rejected, bdrv_close_all will fail and
tell you some unpleasant things via assert().

Reported-by: aihua liang <aliang@redhat.com>
Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1703916
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
(cherry picked from commit 4da26f138db06c9c6d7199d42bd3c2be552cb956)
Signed-off-by: John Snow <jsnow@redhat.com>
Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
---
 blockdev.c | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/blockdev.c b/blockdev.c
index 61218b4..739441d 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -3673,8 +3673,7 @@ static BlockJob *do_drive_backup(DriveBackup *backup, JobTxn *txn,
     if (set_backing_hd) {
         bdrv_set_backing_hd(target_bs, source, &local_err);
         if (local_err) {
-            bdrv_unref(target_bs);
-            goto out;
+            goto unref;
         }
     }
 
@@ -3682,11 +3681,10 @@ static BlockJob *do_drive_backup(DriveBackup *backup, JobTxn *txn,
         bmap = bdrv_find_dirty_bitmap(bs, backup->bitmap);
         if (!bmap) {
             error_setg(errp, "Bitmap '%s' could not be found", backup->bitmap);
-            bdrv_unref(target_bs);
-            goto out;
+            goto unref;
         }
         if (bdrv_dirty_bitmap_check(bmap, BDRV_BITMAP_DEFAULT, errp)) {
-            goto out;
+            goto unref;
         }
     }
     if (!backup->auto_finalize) {
@@ -3700,12 +3698,13 @@ static BlockJob *do_drive_backup(DriveBackup *backup, JobTxn *txn,
                             backup->sync, bmap, backup->compress,
                             backup->on_source_error, backup->on_target_error,
                             job_flags, NULL, NULL, txn, &local_err);
-    bdrv_unref(target_bs);
     if (local_err != NULL) {
         error_propagate(errp, local_err);
-        goto out;
+        goto unref;
     }
 
+unref:
+    bdrv_unref(target_bs);
 out:
     aio_context_release(aio_context);
     return job;
-- 
1.8.3.1