snapshot: create bdrv_all_create_snapshot helper

to create snapshot for all loaded block drivers.

The patch also ensures proper locking.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
CC: Kevin Wolf <kwolf@redhat.com>
Tested-by: Greg Kurz <gkurz@linux.vnet.ibm.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>

1 files changed, 26 insertions, 0 deletions

diff --git a/block/snapshot.c b/block/snapshot.c
index eae4730..75d0b96 100644
--- a/block/snapshot.c
+++ b/block/snapshot.c
@@ -443,3 +443,29 @@ int bdrv_all_find_snapshot(const char *name, BlockDriverState **first_bad_bs)
     *first_bad_bs = bs;
     return err;
 }
+
+int bdrv_all_create_snapshot(QEMUSnapshotInfo *sn,
+                             BlockDriverState *vm_state_bs,
+                             uint64_t vm_state_size,
+                             BlockDriverState **first_bad_bs)
+{
+    int err = 0;
+    BlockDriverState *bs = NULL;
+
+    while (err == 0 && (bs = bdrv_next(bs))) {
+        AioContext *ctx = bdrv_get_aio_context(bs);
+
+        aio_context_acquire(ctx);
+        if (bs == vm_state_bs) {
+            sn->vm_state_size = vm_state_size;
+            err = bdrv_snapshot_create(bs, sn);
+        } else if (bdrv_can_snapshot(bs)) {
+            sn->vm_state_size = 0;
+            err = bdrv_snapshot_create(bs, sn);
+        }
+        aio_context_release(ctx);
+    }
+
+    *first_bad_bs = bs;
+    return err;
+}