[pve-devel] [PATCH v2 qemu 2/2] savevm-async: set SAVE_STATE_DONE when closing state file was successful

[Fiona Ebner]

Without this change, it's necessary to send a second savevm-end QMP
command after aborting a snaphsot, before a new savevm-start QMP
command can succeed.

In process_savevm_finalize(), no longer set an error in the abort
scenario. If there already is another error, there's no need to
override it. If canceling was done intentionally, qmp_savevm_end()
is responsible for setting the state now.

Reported-by: Mira Limbeck <m.limbeck at proxmox.com>
Signed-off-by: Fiona Ebner <f.ebner at proxmox.com>
---

New in v2.

 ...async-for-background-state-snapshots.patch | 20 +++++++++++++------
 ...add-optional-buffer-size-to-QEMUFile.patch |  6 +++---
 ...-register-yank-before-migration_inco.patch |  4 ++--
 3 files changed, 19 insertions(+), 11 deletions(-)

diff --git a/debian/patches/pve/0016-PVE-add-savevm-async-for-background-state-snapshots.patch b/debian/patches/pve/0016-PVE-add-savevm-async-for-background-state-snapshots.patch
index 62a8e98..6bb06ec 100644
--- a/debian/patches/pve/0016-PVE-add-savevm-async-for-background-state-snapshots.patch
+++ b/debian/patches/pve/0016-PVE-add-savevm-async-for-background-state-snapshots.patch
@@ -31,13 +31,13 @@ Signed-off-by: Fiona Ebner <f.ebner at proxmox.com>
  include/migration/snapshot.h |   2 +
  include/monitor/hmp.h        |   5 +
  migration/meson.build        |   1 +
- migration/savevm-async.c     | 596 +++++++++++++++++++++++++++++++++++
+ migration/savevm-async.c     | 604 +++++++++++++++++++++++++++++++++++
  monitor/hmp-cmds.c           |  57 ++++
  qapi/migration.json          |  34 ++
  qapi/misc.json               |  32 ++
  qemu-options.hx              |  12 +
  softmmu/vl.c                 |  10 +
- 11 files changed, 795 insertions(+)
+ 11 files changed, 803 insertions(+)
  create mode 100644 migration/savevm-async.c
 
 diff --git a/hmp-commands-info.hx b/hmp-commands-info.hx
@@ -153,10 +153,10 @@ index 8b5ca5c047..1e2aec8486 100644
  ), gnutls)
 diff --git a/migration/savevm-async.c b/migration/savevm-async.c
 new file mode 100644
-index 0000000000..88215cdb70
+index 0000000000..b9a43c56bc
 --- /dev/null
 +++ b/migration/savevm-async.c
-@@ -0,0 +1,596 @@
+@@ -0,0 +1,604 @@
 +#include "qemu/osdep.h"
 +#include "migration/migration.h"
 +#include "migration/savevm.h"
@@ -422,8 +422,11 @@ index 0000000000..88215cdb70
 +    } else if (snap_state.state == SAVE_STATE_ACTIVE) {
 +        snap_state.state = SAVE_STATE_COMPLETED;
 +    } else if (aborted) {
-+        save_snapshot_error("process_savevm_cleanup: found aborted state: %d",
-+                            snap_state.state);
++        /*
++         * If there was an error, there's no need to set a new one here.
++         * If the snapshot was canceled, leave setting the state to
++         * qmp_savevm_end(), which is waked by save_snapshot_cleanup().
++         */
 +    } else {
 +        save_snapshot_error("process_savevm_cleanup: invalid state: %d",
 +                            snap_state.state);
@@ -664,6 +667,11 @@ index 0000000000..88215cdb70
 +        return;
 +    }
 +
++    // File closed and no other error, so ensure next snapshot can be started.
++    if (snap_state.state != SAVE_STATE_ERROR) {
++        snap_state.state = SAVE_STATE_DONE;
++    }
++
 +    DPRINTF("savevm-end: cleanup done\n");
 +}
 +
diff --git a/debian/patches/pve/0017-PVE-add-optional-buffer-size-to-QEMUFile.patch b/debian/patches/pve/0017-PVE-add-optional-buffer-size-to-QEMUFile.patch
index 788312a..c5cca9d 100644
--- a/debian/patches/pve/0017-PVE-add-optional-buffer-size-to-QEMUFile.patch
+++ b/debian/patches/pve/0017-PVE-add-optional-buffer-size-to-QEMUFile.patch
@@ -165,10 +165,10 @@ index 3f36d4dc8c..67501fd9cf 100644
  int qemu_get_fd(QEMUFile *f);
  int qemu_fclose(QEMUFile *f);
 diff --git a/migration/savevm-async.c b/migration/savevm-async.c
-index 88215cdb70..615a4484c8 100644
+index b9a43c56bc..0bc5799cf8 100644
 --- a/migration/savevm-async.c
 +++ b/migration/savevm-async.c
-@@ -417,7 +417,7 @@ void qmp_savevm_start(bool has_statefile, const char *statefile, Error **errp)
+@@ -420,7 +420,7 @@ void qmp_savevm_start(bool has_statefile, const char *statefile, Error **errp)
          goto restart;
      }
  
@@ -177,7 +177,7 @@ index 88215cdb70..615a4484c8 100644
  
      if (!snap_state.file) {
          error_set(errp, ERROR_CLASS_GENERIC_ERROR, "failed to open '%s'", statefile);
-@@ -565,7 +565,7 @@ int load_snapshot_from_blockdev(const char *filename, Error **errp)
+@@ -573,7 +573,7 @@ int load_snapshot_from_blockdev(const char *filename, Error **errp)
      blk_op_block_all(be, blocker);
  
      /* restore the VM state */
diff --git a/debian/patches/pve/0049-PVE-savevm-async-register-yank-before-migration_inco.patch b/debian/patches/pve/0049-PVE-savevm-async-register-yank-before-migration_inco.patch
index de6e2c2..a9413ab 100644
--- a/debian/patches/pve/0049-PVE-savevm-async-register-yank-before-migration_inco.patch
+++ b/debian/patches/pve/0049-PVE-savevm-async-register-yank-before-migration_inco.patch
@@ -11,7 +11,7 @@ Signed-off-by: Thomas Lamprecht <t.lamprecht at proxmox.com>
  1 file changed, 5 insertions(+)
 
 diff --git a/migration/savevm-async.c b/migration/savevm-async.c
-index 615a4484c8..161b4b9985 100644
+index 0bc5799cf8..10ebefef06 100644
 --- a/migration/savevm-async.c
 +++ b/migration/savevm-async.c
 @@ -19,6 +19,7 @@
@@ -22,7 +22,7 @@ index 615a4484c8..161b4b9985 100644
  
  /* #define DEBUG_SAVEVM_STATE */
  
-@@ -578,6 +579,10 @@ int load_snapshot_from_blockdev(const char *filename, Error **errp)
+@@ -586,6 +587,10 @@ int load_snapshot_from_blockdev(const char *filename, Error **errp)
      dirty_bitmap_mig_before_vm_start();
  
      qemu_fclose(f);
-- 
2.30.2