When running snapshot operations, there are various rules for which
blockdevs are included/excluded. While this provides reasonable default
behaviour, there are scenarios that are not well handled by the default
logic. Some of the conditions do not have a single correct answer.
Thus there needs to be a way for the mgmt app to provide an explicit
list of blockdevs to perform snapshots across. This can be achieved
by passing a list of node names that should be used.
Signed-off-by: Daniel P. Berrangé
---
block/monitor/block-hmp-cmds.c | 4 +-
block/snapshot.c | 180 -
include/block/snapshot.h | 22 ++--
migration/savevm.c | 16 +--
monitor/hmp-cmds.c | 2 +-
replay/replay-debugging.c | 4 +-
6 files changed, 162 insertions(+), 66 deletions(-)
diff --git a/block/monitor/block-hmp-cmds.c b/block/monitor/block-hmp-cmds.c
index 548bb6b5e3..ebb6ae0333 100644
--- a/block/monitor/block-hmp-cmds.c
+++ b/block/monitor/block-hmp-cmds.c
@@ -901,7 +901,7 @@ void hmp_info_snapshots(Monitor *mon, const QDict *qdict)
SnapshotEntry *snapshot_entry;
Error *err = NULL;
-bs = bdrv_all_find_vmstate_bs();
+bs = bdrv_all_find_vmstate_bs(false, NULL, );
if (!bs) {
error_report_err(err);
return;
@@ -953,7 +953,7 @@ void hmp_info_snapshots(Monitor *mon, const QDict *qdict)
total = 0;
for (i = 0; i < nb_sns; i++) {
SnapshotEntry *next_sn;
-if (bdrv_all_find_snapshot(sn_tab[i].name, NULL) == 0) {
+if (bdrv_all_find_snapshot(sn_tab[i].name, false, NULL, NULL) == 0) {
global_snapshots[total] = i;
total++;
QTAILQ_FOREACH(image_entry, _list, next) {
diff --git a/block/snapshot.c b/block/snapshot.c
index 50e35bb9fa..155b8aad88 100644
--- a/block/snapshot.c
+++ b/block/snapshot.c
@@ -447,6 +447,41 @@ int bdrv_snapshot_load_tmp_by_id_or_name(BlockDriverState
*bs,
return ret;
}
+
+static int bdrv_all_get_snapshot_devices(bool has_devices, strList *devices,
+ GList **all_bdrvs,
+ Error **errp)
+{
+g_autoptr(GList) bdrvs = NULL;
+
+if (has_devices) {
+if (!devices) {
+error_setg(errp, "At least one device is required for snapshot");
+return -1;
+}
+
+while (devices) {
+BlockDriverState *bs = bdrv_find_node(devices->value);
+if (!bs) {
+error_setg(errp, "No block device node '%s'", devices->value);
+return -1;
+}
+bdrvs = g_list_append(bdrvs, bs);
+devices = devices->next;
+}
+} else {
+BlockDriverState *bs;
+BdrvNextIterator it;
+for (bs = bdrv_first(); bs; bs = bdrv_next()) {
+bdrvs = g_list_append(bdrvs, bs);
+}
+}
+
+*all_bdrvs = g_steal_pointer();
+return 0;
+}
+
+
static bool bdrv_all_snapshots_includes_bs(BlockDriverState *bs)
{
if (!bdrv_is_inserted(bs) || bdrv_is_read_only(bs)) {
@@ -462,43 +497,59 @@ static bool
bdrv_all_snapshots_includes_bs(BlockDriverState *bs)
* These functions will properly handle dataplane (take aio_context_acquire
* when appropriate for appropriate block drivers) */
-bool bdrv_all_can_snapshot(Error **errp)
+bool bdrv_all_can_snapshot(bool has_devices, strList *devices,
+ Error **errp)
{
-BlockDriverState *bs;
-BdrvNextIterator it;
+g_autoptr(GList) bdrvs = NULL;
+GList *iterbdrvs;
-for (bs = bdrv_first(); bs; bs = bdrv_next()) {
+if (bdrv_all_get_snapshot_devices(has_devices, devices, , errp) < 0)
{
+return false;
+}
+
+iterbdrvs = bdrvs;
+while (iterbdrvs) {
+BlockDriverState *bs = iterbdrvs->data;
AioContext *ctx = bdrv_get_aio_context(bs);
bool ok;
aio_context_acquire(ctx);
-if (bdrv_all_snapshots_includes_bs(bs)) {
+if (devices || bdrv_all_snapshots_includes_bs(bs)) {
ok = bdrv_can_snapshot(bs);
}
aio_context_release(ctx);
if (!ok) {
error_setg(errp, "Device '%s' is writable but does not support "
"snapshots", bdrv_get_device_or_node_name(bs));
-bdrv_next_cleanup();
return false;
}
+
+iterbdrvs = iterbdrvs->next;
}
return true;
}
-int bdrv_all_delete_snapshot(const char *name, Error **errp)
+int bdrv_all_delete_snapshot(const char *name,
+ bool has_devices, strList *devices,
+ Error **errp)
{
-BlockDriverState *bs;
-BdrvNextIterator it;
-QEMUSnapshotInfo sn1, *snapshot =
+g_autoptr(GList) bdrvs = NULL;
+GList *iterbdrvs;
+
+if (bdrv_all_get_snapshot_devices(has_devices, devices, , errp) < 0)
{
+return -1;
+}
-for (bs = bdrv_first();
