[qemu-xen staging] migration/savevm: respect qemu_fclose() error code in save_snapshot()

[patchbot@xxxxxxx]

commit 66270a475cb81f24b53c8cc9ccaf152baf6bb10f
Author:     Denis V. Lunev <den@xxxxxxxxxx>
AuthorDate: Fri Jul 3 19:11:24 2020 +0300
Commit:     Juan Quintela <quintela@xxxxxxxxxx>
CommitDate: Mon Jul 13 18:15:35 2020 +0200

    migration/savevm: respect qemu_fclose() error code in save_snapshot()
    
    qemu_fclose() could return error, f.e. if bdrv_co_flush() will return
    the error.
    
    This validation will become more important once we will start waiting of
    asynchronous IO operations, started from bdrv_write_vmstate(), which are
    coming soon.
    
    Signed-off-by: Denis V. Lunev <den@xxxxxxxxxx>
    Reviewed-by: "Dr. David Alan Gilbert" <dgilbert@xxxxxxxxxx>
    Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@xxxxxxxxxxxxx>
    Reviewed-by: Juan Quintela <quintela@xxxxxxxxxx>
    CC: Kevin Wolf <kwolf@xxxxxxxxxx>
    CC: Max Reitz <mreitz@xxxxxxxxxx>
    CC: Stefan Hajnoczi <stefanha@xxxxxxxxxx>
    CC: Fam Zheng <fam@xxxxxxxxxx>
    CC: Juan Quintela <quintela@xxxxxxxxxx>
    CC: Denis Plotnikov <dplotnikov@xxxxxxxxxxxxx>
    Signed-off-by: Juan Quintela <quintela@xxxxxxxxxx>
---
 migration/savevm.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/migration/savevm.c b/migration/savevm.c
index 6e01724605..45c9dd9d8a 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -2635,7 +2635,7 @@ int save_snapshot(const char *name, Error **errp)
 {
     BlockDriverState *bs, *bs1;
     QEMUSnapshotInfo sn1, *sn = &sn1, old_sn1, *old_sn = &old_sn1;
-    int ret = -1;
+    int ret = -1, ret2;
     QEMUFile *f;
     int saved_vm_running;
     uint64_t vm_state_size;
@@ -2719,10 +2719,14 @@ int save_snapshot(const char *name, Error **errp)
     }
     ret = qemu_savevm_state(f, errp);
     vm_state_size = qemu_ftell(f);
-    qemu_fclose(f);
+    ret2 = qemu_fclose(f);
     if (ret < 0) {
         goto the_end;
     }
+    if (ret2 < 0) {
+        ret = ret2;
+        goto the_end;
+    }
 
     /* The bdrv_all_create_snapshot() call that follows acquires the AioContext
      * for itself.  BDRV_POLL_WHILE() does not support nested locking because
--
generated by git-patchbot for /home/xen/git/qemu-xen.git#staging