diff mbox series

[v6,06/10] migration: control whether snapshots are ovewritten

Message ID 20201008155001.3357288-7-berrange@redhat.com
State New
Headers show
Series migration: bring improved savevm/loadvm/delvm to QMP | expand

Commit Message

Daniel P. Berrangé Oct. 8, 2020, 3:49 p.m. UTC 
The traditional HMP "savevm" command will overwrite an existing snapshot
if it already exists with the requested name. This new flag allows this
to be controlled allowing for safer behaviour with a future QMP command.

Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
---
 include/migration/snapshot.h |  2 +-
 migration/savevm.c           | 19 ++++++++++++++++---
 monitor/hmp-cmds.c           |  2 +-
 replay/replay-debugging.c    |  2 +-
 replay/replay-snapshot.c     |  2 +-
 5 files changed, 20 insertions(+), 7 deletions(-)

Comments

Eric Blake Oct. 19, 2020, 9:37 p.m. UTC | #1 
On 10/8/20 10:49 AM, Daniel P. Berrangé wrote:
> The traditional HMP "savevm" command will overwrite an existing snapshot
> if it already exists with the requested name. This new flag allows this
> to be controlled allowing for safer behaviour with a future QMP command.
> 
> Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
> ---

Reviewed-by: Eric Blake <eblake@redhat.com>
diff mbox series

Patch

diff --git a/include/migration/snapshot.h b/include/migration/snapshot.h
index c85b6ec75b..d7db1174ef 100644
--- a/include/migration/snapshot.h
+++ b/include/migration/snapshot.h
@@ -15,7 +15,7 @@ 
 #ifndef QEMU_MIGRATION_SNAPSHOT_H
 #define QEMU_MIGRATION_SNAPSHOT_H
 
-int save_snapshot(const char *name, Error **errp);
+int save_snapshot(const char *name, bool overwrite, Error **errp);
 int load_snapshot(const char *name, Error **errp);
 
 #endif
diff --git a/migration/savevm.c b/migration/savevm.c
index dd714dba53..8dcb52a428 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -2658,7 +2658,7 @@  int qemu_load_device_state(QEMUFile *f)
     return 0;
 }
 
-int save_snapshot(const char *name, Error **errp)
+int save_snapshot(const char *name, bool overwrite, Error **errp)
 {
     BlockDriverState *bs;
     QEMUSnapshotInfo sn1, *sn = &sn1, old_sn1, *old_sn = &old_sn1;
@@ -2686,8 +2686,21 @@  int save_snapshot(const char *name, Error **errp)
 
     /* Delete old snapshots of the same name */
     if (name) {
-        if (bdrv_all_delete_snapshot(name, false, NULL, errp) < 0) {
-            return ret;
+        if (overwrite) {
+            if (bdrv_all_delete_snapshot(name, false, NULL, errp) < 0) {
+                return ret;
+            }
+        } else {
+            ret2 = bdrv_all_has_snapshot(name, false, NULL, errp);
+            if (ret2 < 0) {
+                return -1;
+            }
+            if (ret2 == 1) {
+                error_setg(errp,
+                           "Snapshot '%s' already exists in one or more devices",
+                           name);
+                return -1;
+            }
         }
     }
 
diff --git a/monitor/hmp-cmds.c b/monitor/hmp-cmds.c
index f1b9df7250..685014b544 100644
--- a/monitor/hmp-cmds.c
+++ b/monitor/hmp-cmds.c
@@ -1133,7 +1133,7 @@  void hmp_savevm(Monitor *mon, const QDict *qdict)
 {
     Error *err = NULL;
 
-    save_snapshot(qdict_get_try_str(qdict, "name"), &err);
+    save_snapshot(qdict_get_try_str(qdict, "name"), true, &err);
     hmp_handle_error(mon, err);
 }
 
diff --git a/replay/replay-debugging.c b/replay/replay-debugging.c
index 3ab5a15082..305bc97dbc 100644
--- a/replay/replay-debugging.c
+++ b/replay/replay-debugging.c
@@ -331,7 +331,7 @@  void replay_gdb_attached(void)
      */
     if (replay_mode == REPLAY_MODE_PLAY
         && !replay_snapshot) {
-        if (save_snapshot("start_debugging", NULL) != 0) {
+        if (save_snapshot("start_debugging", true, NULL) != 0) {
             /* Can't create the snapshot. Continue conventional debugging. */
         }
     }
diff --git a/replay/replay-snapshot.c b/replay/replay-snapshot.c
index e26fa4c892..8e7ff97d11 100644
--- a/replay/replay-snapshot.c
+++ b/replay/replay-snapshot.c
@@ -77,7 +77,7 @@  void replay_vmstate_init(void)
 
     if (replay_snapshot) {
         if (replay_mode == REPLAY_MODE_RECORD) {
-            if (save_snapshot(replay_snapshot, &err) != 0) {
+            if (save_snapshot(replay_snapshot, true, &err) != 0) {
                 error_report_err(err);
                 error_report("Could not create snapshot for icount record");
                 exit(1);