[PATCH 3/3] backup: initialize bcs bitmap on job create, not start

[Stefan Reiter]

After backup_init_bcs_bitmap the copy-before-write behaviour is active.
This way, multiple backup jobs created at once but running in a
sequential transaction will still represent the same point in time.

Signed-off-by: Stefan Reiter <s.reiter@proxmox.com>
---

I'd imagine this was done on job start for a purpose, so this is potentially
wrong. In testing it works fine.

Sent along for feedback, since it would be necessary to really make use of the
sequential backup feature (without it, the individual backup jobs would not have
a consistent view of the guest).


 block/backup.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/block/backup.c b/block/backup.c
index 4f13bb20a5..14660eef45 100644
--- a/block/backup.c
+++ b/block/backup.c
@@ -237,8 +237,6 @@ static int coroutine_fn backup_run(Job *job, Error **errp)
     BackupBlockJob *s = container_of(job, BackupBlockJob, common.job);
     int ret = 0;
 
-    backup_init_bcs_bitmap(s);
-
     if (s->sync_mode == MIRROR_SYNC_MODE_TOP) {
         int64_t offset = 0;
         int64_t count;
@@ -471,6 +469,8 @@ BlockJob *backup_job_create(const char *job_id, 
BlockDriverState *bs,
     block_job_add_bdrv(&job->common, "target", target, 0, BLK_PERM_ALL,
                        &error_abort);
 
+    backup_init_bcs_bitmap(job);
+
     return &job->common;
 
  error:
-- 
2.20.1