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 <berra...@redhat.com>
---
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 +-
5 files changed, 160 insertions(+), 64 deletions(-)
diff --git a/block/monitor/block-hmp-cmds.c b/block/monitor/block-hmp-cmds.c
index bec794253d..30279bd15a 100644
--- a/block/monitor/block-hmp-cmds.c
+++ b/block/monitor/block-hmp-cmds.c
@@ -900,7 +900,7 @@ void hmp_info_snapshots(Monitor *mon, const QDict *qdict)
SnapshotEntry *snapshot_entry;
Error *err = NULL;
- bs = bdrv_all_find_vmstate_bs(&err);
+ bs = bdrv_all_find_vmstate_bs(false, NULL, &err);
if (!bs) {
error_report_err(err);
return;
@@ -952,7 +952,7 @@ 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, &image_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(&it); bs; bs = bdrv_next(&it)) {
+ bdrvs = g_list_append(bdrvs, bs);
+ }
+ }
+
+ *all_bdrvs = g_steal_pointer(&bdrvs);
+ 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(&it); bs; bs = bdrv_next(&it)) {
+ if (bdrv_all_get_snapshot_devices(has_devices, devices, &bdrvs, 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(&it);
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 = &sn1;
+ g_autoptr(GList) bdrvs = NULL;
+ GList *iterbdrvs;
+
+ if (bdrv_all_get_snapshot_devices(has_devices, devices, &bdrvs, errp) < 0)
{
+ return -1;
+ }
- for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) {
+ iterbdrvs = bdrvs;
+ while (iterbdrvs) {
+ BlockDriverState *bs = iterbdrvs->data;
AioContext *ctx = bdrv_get_aio_context(bs);
- int ret;
+ QEMUSnapshotInfo sn1, *snapshot = &sn1;
+ int ret = 0;
aio_context_acquire(ctx);
- if (bdrv_all_snapshots_includes_bs(bs) &&
+ if ((devices || bdrv_all_snapshots_includes_bs(bs)) &&
bdrv_snapshot_find(bs, snapshot, name) >= 0)
{
ret = bdrv_snapshot_delete(bs, snapshot->id_str,
@@ -508,61 +559,80 @@ int bdrv_all_delete_snapshot(const char *name, Error
**errp)
if (ret < 0) {
error_prepend(errp, "Could not delete snapshot '%s' on '%s': ",
name, bdrv_get_device_or_node_name(bs));
- bdrv_next_cleanup(&it);
return -1;
}
+
+ iterbdrvs = iterbdrvs->next;
}
return 0;
}
-int bdrv_all_goto_snapshot(const char *name, Error **errp)
+int bdrv_all_goto_snapshot(const char *name,
+ bool has_devices, strList *devices,
+ Error **errp)
{
- BlockDriverState *bs;
- BdrvNextIterator it;
+ g_autoptr(GList) bdrvs = NULL;
+ GList *iterbdrvs;
- for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) {
+ if (bdrv_all_get_snapshot_devices(has_devices, devices, &bdrvs, errp) < 0)
{
+ return -1;
+ }
+
+ iterbdrvs = bdrvs;
+ while (iterbdrvs) {
+ BlockDriverState *bs = iterbdrvs->data;
AioContext *ctx = bdrv_get_aio_context(bs);
- int ret;
+ int ret = 0;
aio_context_acquire(ctx);
- if (bdrv_all_snapshots_includes_bs(bs)) {
+ if (devices || bdrv_all_snapshots_includes_bs(bs)) {
ret = bdrv_snapshot_goto(bs, name, errp);
}
aio_context_release(ctx);
if (ret < 0) {
error_prepend(errp, "Could not load snapshot '%s' on '%s': ",
name, bdrv_get_device_or_node_name(bs));
- bdrv_next_cleanup(&it);
return -1;
}
+
+ iterbdrvs = iterbdrvs->next;
}
return 0;
}
-int bdrv_all_find_snapshot(const char *name, Error **errp)
+int bdrv_all_find_snapshot(const char *name,
+ bool has_devices, strList *devices,
+ Error **errp)
{
- QEMUSnapshotInfo sn;
- BlockDriverState *bs;
- BdrvNextIterator it;
+ g_autoptr(GList) bdrvs = NULL;
+ GList *iterbdrvs;
+
+ if (bdrv_all_get_snapshot_devices(has_devices, devices, &bdrvs, errp) < 0)
{
+ return -1;
+ }
- for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) {
+ iterbdrvs = bdrvs;
+ while (iterbdrvs) {
+ BlockDriverState *bs = iterbdrvs->data;
AioContext *ctx = bdrv_get_aio_context(bs);
- int ret;
+ QEMUSnapshotInfo sn;
+ int ret = 0;
aio_context_acquire(ctx);
- if (bdrv_all_snapshots_includes_bs(bs)) {
+ if (devices || bdrv_all_snapshots_includes_bs(bs)) {
ret = bdrv_snapshot_find(bs, &sn, name);
}
aio_context_release(ctx);
if (ret < 0) {
error_setg(errp, "Could not find snapshot '%s' on '%s'",
name, bdrv_get_device_or_node_name(bs));
- bdrv_next_cleanup(&it);
return -1;
}
+
+ iterbdrvs = iterbdrvs->next;
}
return 0;
@@ -571,20 +641,27 @@ int bdrv_all_find_snapshot(const char *name, Error **errp)
int bdrv_all_create_snapshot(QEMUSnapshotInfo *sn,
BlockDriverState *vm_state_bs,
uint64_t vm_state_size,
+ bool has_devices, strList *devices,
Error **errp)
{
- BlockDriverState *bs;
- BdrvNextIterator it;
+ g_autoptr(GList) bdrvs = NULL;
+ GList *iterbdrvs;
+
+ if (bdrv_all_get_snapshot_devices(has_devices, devices, &bdrvs, errp) < 0)
{
+ return -1;
+ }
- for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) {
+ iterbdrvs = bdrvs;
+ while (iterbdrvs) {
+ BlockDriverState *bs = iterbdrvs->data;
AioContext *ctx = bdrv_get_aio_context(bs);
- int ret;
+ int ret = 0;
aio_context_acquire(ctx);
if (bs == vm_state_bs) {
sn->vm_state_size = vm_state_size;
ret = bdrv_snapshot_create(bs, sn);
- } else if (bdrv_all_snapshots_includes_bs(bs)) {
+ } else if (devices || bdrv_all_snapshots_includes_bs(bs)) {
sn->vm_state_size = 0;
ret = bdrv_snapshot_create(bs, sn);
}
@@ -592,34 +669,43 @@ int bdrv_all_create_snapshot(QEMUSnapshotInfo *sn,
if (ret < 0) {
error_setg(errp, "Could not create snapshot '%s' on '%s'",
sn->name, bdrv_get_device_or_node_name(bs));
- bdrv_next_cleanup(&it);
return -1;
}
+
+ iterbdrvs = iterbdrvs->next;
}
return 0;
}
-BlockDriverState *bdrv_all_find_vmstate_bs(Error **errp)
+BlockDriverState *bdrv_all_find_vmstate_bs(bool has_devices, strList *devices,
+ Error **errp)
{
- BlockDriverState *bs;
- BdrvNextIterator it;
+ g_autoptr(GList) bdrvs = NULL;
+ GList *iterbdrvs;
- for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) {
+ if (bdrv_all_get_snapshot_devices(has_devices, devices, &bdrvs, errp) < 0)
{
+ return NULL;
+ }
+
+ iterbdrvs = bdrvs;
+ while (iterbdrvs) {
+ BlockDriverState *bs = iterbdrvs->data;
AioContext *ctx = bdrv_get_aio_context(bs);
- bool found;
+ bool found = false;
aio_context_acquire(ctx);
- found = bdrv_all_snapshots_includes_bs(bs) && bdrv_can_snapshot(bs);
+ found = (devices || bdrv_all_snapshots_includes_bs(bs)) &&
+ bdrv_can_snapshot(bs);
aio_context_release(ctx);
if (found) {
- bdrv_next_cleanup(&it);
- break;
+ return bs;
}
+
+ iterbdrvs = iterbdrvs->next;
}
- if (!bs) {
- error_setg(errp, "No block device supports snapshots");
- }
- return bs;
+
+ error_setg(errp, "No block device supports snapshots");
+ return NULL;
}
diff --git a/include/block/snapshot.h b/include/block/snapshot.h
index ba1528eee0..bac3409669 100644
--- a/include/block/snapshot.h
+++ b/include/block/snapshot.h
@@ -25,7 +25,7 @@
#ifndef SNAPSHOT_H
#define SNAPSHOT_H
-
+#include "qapi/qapi-builtin-types.h"
#define SNAPSHOT_OPT_BASE "snapshot."
#define SNAPSHOT_OPT_ID "snapshot.id"
@@ -76,15 +76,25 @@ int bdrv_snapshot_load_tmp_by_id_or_name(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);
-int bdrv_all_delete_snapshot(const char *name, Error **errp);
-int bdrv_all_goto_snapshot(const char *name, Error **errp);
-int bdrv_all_find_snapshot(const char *name, Error **errp);
+bool bdrv_all_can_snapshot(bool has_devices, strList *devices,
+ Error **errp);
+int bdrv_all_delete_snapshot(const char *name,
+ bool has_devices, strList *devices,
+ Error **errp);
+int bdrv_all_goto_snapshot(const char *name,
+ bool has_devices, strList *devices,
+ Error **errp);
+int bdrv_all_find_snapshot(const char *name,
+ bool has_devices, strList *devices,
+ Error **errp);
int bdrv_all_create_snapshot(QEMUSnapshotInfo *sn,
BlockDriverState *vm_state_bs,
uint64_t vm_state_size,
+ bool has_devices,
+ strList *devices,
Error **errp);
-BlockDriverState *bdrv_all_find_vmstate_bs(Error **errp);
+BlockDriverState *bdrv_all_find_vmstate_bs(bool has_devices, strList *devices,
+ Error **errp);
#endif
diff --git a/migration/savevm.c b/migration/savevm.c
index 3d77277f0b..5084c2da00 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -2680,18 +2680,18 @@ int save_snapshot(const char *name, Error **errp)
return ret;
}
- if (!bdrv_all_can_snapshot(errp)) {
+ if (!bdrv_all_can_snapshot(false, NULL, errp)) {
return ret;
}
/* Delete old snapshots of the same name */
if (name) {
- if (bdrv_all_delete_snapshot(name, errp) < 0) {
+ if (bdrv_all_delete_snapshot(name, false, NULL, errp) < 0) {
return ret;
}
}
- bs = bdrv_all_find_vmstate_bs(errp);
+ bs = bdrv_all_find_vmstate_bs(false, NULL, errp);
if (bs == NULL) {
return ret;
}
@@ -2757,7 +2757,7 @@ int save_snapshot(const char *name, Error **errp)
aio_context_release(aio_context);
aio_context = NULL;
- ret = bdrv_all_create_snapshot(sn, bs, vm_state_size, errp);
+ ret = bdrv_all_create_snapshot(sn, bs, vm_state_size, false, NULL, errp);
if (ret < 0) {
goto the_end;
}
@@ -2874,15 +2874,15 @@ int load_snapshot(const char *name, Error **errp)
return -1;
}
- if (!bdrv_all_can_snapshot(errp)) {
+ if (!bdrv_all_can_snapshot(false, NULL, errp)) {
return -1;
}
- ret = bdrv_all_find_snapshot(name, errp);
+ ret = bdrv_all_find_snapshot(name, false, NULL, errp);
if (ret < 0) {
return -1;
}
- bs_vm_state = bdrv_all_find_vmstate_bs(errp);
+ bs_vm_state = bdrv_all_find_vmstate_bs(false, NULL, errp);
if (!bs_vm_state) {
return -1;
}
@@ -2903,7 +2903,7 @@ int load_snapshot(const char *name, Error **errp)
/* Flush all IO requests so they don't interfere with the new state. */
bdrv_drain_all_begin();
- ret = bdrv_all_goto_snapshot(name, errp);
+ ret = bdrv_all_goto_snapshot(name, false, NULL, errp);
if (ret < 0) {
goto err_drain;
}
diff --git a/monitor/hmp-cmds.c b/monitor/hmp-cmds.c
index 14848a3381..f1b9df7250 100644
--- a/monitor/hmp-cmds.c
+++ b/monitor/hmp-cmds.c
@@ -1142,7 +1142,7 @@ void hmp_delvm(Monitor *mon, const QDict *qdict)
Error *err = NULL;
const char *name = qdict_get_str(qdict, "name");
- bdrv_all_delete_snapshot(name, &err);
+ bdrv_all_delete_snapshot(name, false, NULL, &err);
hmp_handle_error(mon, err);
}
--
2.26.2
