qdev/qbus: add hidden device support

[mirror_qemu.git] / block / snapshot.c

diff --git a/block/snapshot.c b/block/snapshot.c
index f2f48f926a8f1db96860a29b8c1d4f710ce07cae..8081616ae91b98f18f58c231be3eaa2b995548d2 100644 (file)
--- a/block/snapshot.c
+++ b/block/snapshot.c
@@ -31,6 +31,7 @@
 #include "qapi/qmp/qerror.h"
 #include "qapi/qmp/qstring.h"
 #include "qemu/option.h"
+#include "sysemu/block-backend.h"
 
 QemuOptsList internal_snapshot_opts = {
     .name = "snapshot",
@@ -384,6 +385,16 @@ int bdrv_snapshot_load_tmp_by_id_or_name(BlockDriverState *bs,
     return ret;
 }
 
+static bool bdrv_all_snapshots_includes_bs(BlockDriverState *bs)
+{
+    if (!bdrv_is_inserted(bs) || bdrv_is_read_only(bs)) {
+        return false;
+    }
+
+    /* Include all nodes that are either in use by a BlockBackend, or that
+     * aren't attached to any node, but owned by the monitor. */
+    return bdrv_has_blk(bs) || QLIST_EMPTY(&bs->parents);
+}
 
 /* Group operations. All block drivers are involved.
  * These functions will properly handle dataplane (take aio_context_acquire
@@ -399,7 +410,7 @@ bool bdrv_all_can_snapshot(BlockDriverState **first_bad_bs)
         AioContext *ctx = bdrv_get_aio_context(bs);
 
         aio_context_acquire(ctx);
-        if (bdrv_is_inserted(bs) && !bdrv_is_read_only(bs)) {
+        if (bdrv_all_snapshots_includes_bs(bs)) {
             ok = bdrv_can_snapshot(bs);
         }
         aio_context_release(ctx);
@@ -426,8 +437,9 @@ int bdrv_all_delete_snapshot(const char *name, BlockDriverState **first_bad_bs,
         AioContext *ctx = bdrv_get_aio_context(bs);
 
         aio_context_acquire(ctx);
-        if (bdrv_can_snapshot(bs) &&
-                bdrv_snapshot_find(bs, snapshot, name) >= 0) {
+        if (bdrv_all_snapshots_includes_bs(bs) &&
+            bdrv_snapshot_find(bs, snapshot, name) >= 0)
+        {
             ret = bdrv_snapshot_delete(bs, snapshot->id_str,
                                        snapshot->name, err);
         }
@@ -455,7 +467,7 @@ int bdrv_all_goto_snapshot(const char *name, BlockDriverState **first_bad_bs,
         AioContext *ctx = bdrv_get_aio_context(bs);
 
         aio_context_acquire(ctx);
-        if (bdrv_can_snapshot(bs)) {
+        if (bdrv_all_snapshots_includes_bs(bs)) {
             ret = bdrv_snapshot_goto(bs, name, errp);
         }
         aio_context_release(ctx);
@@ -481,7 +493,7 @@ int bdrv_all_find_snapshot(const char *name, BlockDriverState **first_bad_bs)
         AioContext *ctx = bdrv_get_aio_context(bs);
 
         aio_context_acquire(ctx);
-        if (bdrv_can_snapshot(bs)) {
+        if (bdrv_all_snapshots_includes_bs(bs)) {
             err = bdrv_snapshot_find(bs, &sn, name);
         }
         aio_context_release(ctx);
@@ -512,7 +524,7 @@ int bdrv_all_create_snapshot(QEMUSnapshotInfo *sn,
         if (bs == vm_state_bs) {
             sn->vm_state_size = vm_state_size;
             err = bdrv_snapshot_create(bs, sn);
-        } else if (bdrv_can_snapshot(bs)) {
+        } else if (bdrv_all_snapshots_includes_bs(bs)) {
             sn->vm_state_size = 0;
             err = bdrv_snapshot_create(bs, sn);
         }
@@ -538,7 +550,7 @@ BlockDriverState *bdrv_all_find_vmstate_bs(void)
         bool found;
 
         aio_context_acquire(ctx);
-        found = bdrv_can_snapshot(bs);
+        found = bdrv_all_snapshots_includes_bs(bs) && bdrv_can_snapshot(bs);
         aio_context_release(ctx);
 
         if (found) {