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Diffstat (limited to 'block.c')
-rw-r--r--block.c23
1 files changed, 16 insertions, 7 deletions
diff --git a/block.c b/block.c
index 8b46ba21b1..a8da4f2b25 100644
--- a/block.c
+++ b/block.c
@@ -2766,6 +2766,7 @@ BlockDriverState *bdrv_open(const char *filename, const char *reference,
* returns a pointer to bs_queue, which is either the newly allocated
* bs_queue, or the existing bs_queue being used.
*
+ * bs must be drained between bdrv_reopen_queue() and bdrv_reopen_multiple().
*/
static BlockReopenQueue *bdrv_reopen_queue_child(BlockReopenQueue *bs_queue,
BlockDriverState *bs,
@@ -2781,6 +2782,11 @@ static BlockReopenQueue *bdrv_reopen_queue_child(BlockReopenQueue *bs_queue,
BdrvChild *child;
QDict *old_options, *explicit_options;
+ /* Make sure that the caller remembered to use a drained section. This is
+ * important to avoid graph changes between the recursive queuing here and
+ * bdrv_reopen_multiple(). */
+ assert(bs->quiesce_counter > 0);
+
if (bs_queue == NULL) {
bs_queue = g_new0(BlockReopenQueue, 1);
QSIMPLEQ_INIT(bs_queue);
@@ -2905,6 +2911,8 @@ BlockReopenQueue *bdrv_reopen_queue(BlockReopenQueue *bs_queue,
* If all devices prepare successfully, then the changes are committed
* to all devices.
*
+ * All affected nodes must be drained between bdrv_reopen_queue() and
+ * bdrv_reopen_multiple().
*/
int bdrv_reopen_multiple(AioContext *ctx, BlockReopenQueue *bs_queue, Error **errp)
{
@@ -2914,11 +2922,8 @@ int bdrv_reopen_multiple(AioContext *ctx, BlockReopenQueue *bs_queue, Error **er
assert(bs_queue != NULL);
- aio_context_release(ctx);
- bdrv_drain_all_begin();
- aio_context_acquire(ctx);
-
QSIMPLEQ_FOREACH(bs_entry, bs_queue, entry) {
+ assert(bs_entry->state.bs->quiesce_counter > 0);
if (bdrv_reopen_prepare(&bs_entry->state, bs_queue, &local_err)) {
error_propagate(errp, local_err);
goto cleanup;
@@ -2947,8 +2952,6 @@ cleanup:
}
g_free(bs_queue);
- bdrv_drain_all_end();
-
return ret;
}
@@ -2958,12 +2961,18 @@ int bdrv_reopen(BlockDriverState *bs, int bdrv_flags, Error **errp)
{
int ret = -1;
Error *local_err = NULL;
- BlockReopenQueue *queue = bdrv_reopen_queue(NULL, bs, NULL, bdrv_flags);
+ BlockReopenQueue *queue;
+ bdrv_subtree_drained_begin(bs);
+
+ queue = bdrv_reopen_queue(NULL, bs, NULL, bdrv_flags);
ret = bdrv_reopen_multiple(bdrv_get_aio_context(bs), queue, &local_err);
if (local_err != NULL) {
error_propagate(errp, local_err);
}
+
+ bdrv_subtree_drained_end(bs);
+
return ret;
}