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 <[email protected]>
Reviewed-by: Stefan Hajnoczi <[email protected]>
Reviewed-by: Fam Zheng <[email protected]>
Reviewed-by: Juan Quintela <[email protected]>
CC: Kevin Wolf <[email protected]>
Tested-by: Greg Kurz <[email protected]>
Signed-off-by: Juan Quintela <[email protected]>

diff --git a/block/snapshot.c b/block/snapshot.c
index eae4730fc6d91f2fed723bea63ef943b05daf83a..75d0b968f66df50d739c5b09b26f9cd6297ca146 100644 (file)
--- 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;
+}

diff --git a/include/block/snapshot.h b/include/block/snapshot.h
index 10ee582f2cfd2870c21763196d3e5850da3128a2..55e995a3fecfa1912630899479cfd26f5d122159 100644 (file)
--- a/include/block/snapshot.h
+++ b/include/block/snapshot.h
@@ -86,5 +86,9 @@ int bdrv_all_delete_snapshot(const char *name, BlockDriverState **first_bsd_bs,
                              Error **err);
 int bdrv_all_goto_snapshot(const char *name, BlockDriverState **first_bsd_bs);
 int bdrv_all_find_snapshot(const char *name, BlockDriverState **first_bad_bs);
+int bdrv_all_create_snapshot(QEMUSnapshotInfo *sn,
+                             BlockDriverState *vm_state_bs,
+                             uint64_t vm_state_size,
+                             BlockDriverState **first_bad_bs);
 
 #endif

diff --git a/migration/savevm.c b/migration/savevm.c
index 63c07e1b9afdeb51d5501e81f4842b55fdf1043d..80107e32b1b36f31637e571c00e4e52e560e8bd3 100644 (file)
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -1996,19 +1996,10 @@ void hmp_savevm(Monitor *mon, const QDict *qdict)
         goto the_end;
     }
 
-    /* create the snapshots */
-
-    bs1 = NULL;
-    while ((bs1 = bdrv_next(bs1))) {
-        if (bdrv_can_snapshot(bs1)) {
-            /* Write VM state size only to the image that contains the state */
-            sn->vm_state_size = (bs == bs1 ? vm_state_size : 0);
-            ret = bdrv_snapshot_create(bs1, sn);
-            if (ret < 0) {
-                monitor_printf(mon, "Error while creating snapshot on '%s'\n",
-                               bdrv_get_device_name(bs1));
-            }
-        }
+    ret = bdrv_all_create_snapshot(sn, bs, vm_state_size, &bs);
+    if (ret < 0) {
+        monitor_printf(mon, "Error while creating snapshot on '%s'\n",
+                       bdrv_get_device_name(bs));
     }
 
  the_end: