bool allow_write_beyond_eof;
NotifierList remove_bs_notifiers, insert_bs_notifiers;
+
+ int quiesce_counter;
};
typedef struct BlockBackendAIOCB {
void *opaque)
{
/* All drivers that use blk_set_dev_ops() are qdevified and we want to keep
- * it that way, so we can assume blk->dev is a DeviceState if blk->dev_ops
- * is set. */
+ * it that way, so we can assume blk->dev, if present, is a DeviceState if
+ * blk->dev_ops is set. Non-device users may use dev_ops without device. */
assert(!blk->legacy_dev);
blk->dev_ops = ops;
blk->dev_opaque = opaque;
+
+ /* Are we currently quiesced? Should we enforce this right now? */
+ if (blk->quiesce_counter && ops->drained_begin) {
+ ops->drained_begin(opaque);
+ }
}
/*
{
BlockBackend *blk = child->opaque;
+ if (++blk->quiesce_counter == 1) {
+ if (blk->dev_ops && blk->dev_ops->drained_begin) {
+ blk->dev_ops->drained_begin(blk->dev_opaque);
+ }
+ }
+
/* Note that blk->root may not be accessible here yet if we are just
* attaching to a BlockDriverState that is drained. Use child instead. */
static void blk_root_drained_end(BdrvChild *child)
{
BlockBackend *blk = child->opaque;
+ assert(blk->quiesce_counter);
assert(blk->public.io_limits_disabled);
--blk->public.io_limits_disabled;
+
+ if (--blk->quiesce_counter == 0) {
+ if (blk->dev_ops && blk->dev_ops->drained_end) {
+ blk->dev_ops->drained_end(blk->dev_opaque);
+ }
+ }
}
* Runs when the size changed (e.g. monitor command block_resize)
*/
void (*resize_cb)(void *opaque);
+ /*
+ * Runs when the backend receives a drain request.
+ */
+ void (*drained_begin)(void *opaque);
+ /*
+ * Runs when the backend's last drain request ends.
+ */
+ void (*drained_end)(void *opaque);
} BlockDevOps;
/* This struct is embedded in (the private) BlockBackend struct and contains